Image forming apparatus

Abstract

To improve user convenience in image forming apparatus equipped with media sensors. [Solution] When a sheet placed in the manual feed tray has a special shape that makes it difficult to correctly detect the sheet size, a "shape selection screen" prompting the user to input the special shape is displayed on the liquid crystal display. By the user inputting the special shape of the sheet placed in the manual feed tray from the "shape selection screen," the sheet with the special shape is transported from the manual feed tray based on the sheet size corresponding to the input special shape, and an image is formed. The user can easily set the sheet size of a sheet with a special shape simply by inputting the special shape from the "shape selection screen."

Description

Technical Field

[0001] The present invention relates to an image forming apparatus such as a printer, a copier, a facsimile machine, or a multifunction machine.

Background Art

[0002] An image forming apparatus develops an electrostatic latent image formed on a photoreceptor with toner, and transfers and fixes the developed toner image onto a sheet. The sheets are set in a manual feed tray or a paper cassette, and are conveyed one by one from them. The sheets may have different sheet characteristics such as thickness and surface property, and the image forming apparatus performs image formation by changing the operating conditions of the image forming operation according to the sheet characteristics. The sheet characteristics are set manually by the user from an operation unit or the like, or are set by detection of a media sensor disposed on a conveyance path along which the sheets are conveyed. In Patent Document 1, an image forming apparatus has been proposed that determines the operating conditions of an image forming operation including sheet feeding conveyance control based on the sheet characteristics detected by a media sensor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, conventionally, detecting the shape of a sheet by a detection unit that detects the characteristics of the sheet has not been considered, and there has been room for further improvement.

[0005] The present disclosure has been made in view of the above problems, and an object thereof is to improve the convenience of the user in an image forming apparatus having a detection unit that detects the characteristics of a sheet.

Means for Solving the Problems

[0006] An image forming apparatus according to one embodiment of the present invention is an image forming apparatus for forming an image on a recording material, comprising: a loading section capable of loading recording material; a transport section for transporting recording material from the loading section; a detection section for detecting the characteristics of the recording material; a display section capable of displaying information; and a control section for controlling the display section, wherein the control section, when in a mode for detecting the characteristics of the recording material by the detection section, causes a screen for inputting information regarding the shape of the recording material to be displayed on the display section. [Effects of the Invention]

[0007] According to this disclosure, it is possible to improve user convenience in an image forming apparatus having a media sensor. [Brief explanation of the drawing]

[0008] [Figure 1] A schematic diagram showing the image forming apparatus of this embodiment. [Figure 2] A block diagram showing the control system of an image forming apparatus. [Figure 3] A schematic diagram showing the configuration of a media sensor. [Figure 4] A diagram illustrating the sheet size detection configuration. [Figure 5] This diagram shows the initial media settings screen. [Figure 6] A flowchart illustrating the media setup process of the first embodiment. [Figure 7] (a) Diagram showing the settings selection screen, (b) Diagram showing the shape selection screen, (c) Diagram showing the sheet type input screen. [Figure 8] A flowchart illustrating the sheet feeding process. [Figure 9] A flowchart illustrating the control sheet size setting process in the first embodiment. [Figure 10] A flowchart illustrating the media setup process of the second embodiment. [Figure 11] A flowchart illustrating the display process for the sheet shape selection button. [Figure 12] A diagram showing an example of the shape selection screen in the second embodiment. [Figure 13] A flowchart illustrating the control sheet size setting process in the third embodiment. [Modes for carrying out the invention]

[0009] [First Embodiment] Embodiments of the present invention will now be described with reference to the drawings. Figure 1 is a schematic diagram showing the configuration of the image forming apparatus of this embodiment, and Figure 2 is a block diagram showing the control system for controlling the image forming apparatus. In the control system of the image forming apparatus, various other components may be connected to the control unit 300 in addition to those shown in Figure 2, but their illustration and description are omitted here as they are not relevant to the essence of the invention.

[0010] The control unit 300 shown in Figure 2 consists of a CPU (Central Processing Unit) 301, a ROM (Read Only Memory) 302, a RAM (Random Access Memory) 303, and an EEPROM (Electrically Erasable Programmable Read-Only Memory) 304. The CPU 301 controls the entire image forming apparatus 1 to form an image on a sheet by executing programs stored in the ROM 302 and EEPROM 304. At that time, the CPU 301 can use the RAM 303 as a work area.

[0011] The image forming apparatus 1 includes an operation unit 330 that can receive user input. The operation unit 330 has an input unit 331 that can receive user input for starting a printing operation (referred to as an image forming job) on a sheet and various information such as information about the sheet, and a liquid crystal display 332 as a display unit. The liquid crystal display 332 can display various programs, various data, or various screens described later. Note that the operation unit 330 may be a touch panel that receives information input according to the touch location in response to a touch operation on the screen displayed on the liquid crystal display 332 by the user. The CPU 301 can control the liquid crystal display 332 to display various screens.

[0012] The CPU 301 can execute an image forming job and starts a printing operation in response to an input for starting an image forming job from the operation unit 330. The CPU 301 can drive and control a pre-fixing conveyance motor 145, a fixing motor 173, a post-fixing conveyance motor 146, a sheet conveyance motor 147, a paper discharge conveyance 1 motor 148, and a paper discharge conveyance 2 motor 149 connected via an input / output interface (I / O) 307. Also, the CPU 301 can detect input signals input from a sheet conveyance sensor 171, a pre-registration conveyance sensor 160, and a paper feed pickup sensor 152 via the input / output interface (I / O) 307.

[0013] Furthermore, the CPU 301 can detect input signals input from a media sensor 280, a sheet presence / absence detection sensor 214, a sheet width volume sensor 217, a sheet sub-scanning length detection 1 sensor 218, and a sheet sub-scanning length detection 2 sensor 219 via the input / output interface (I / O) 307. Additionally, the CPU 301 can also receive an input for starting an image forming job input from a network interface (I / F) 314 or a fax interface (I / F) 315.

[0014] The CPU 301 has an image processing unit 316 that processes an image corresponding to an image formation job input from an operation unit 330 or the like, and performs image processing such as image expansion and rotation. Also, the CPU 301 is configured to be able to control an image forming unit 320. The image forming unit 320 includes a process unit 120, a transfer belt 130, a secondary transfer unit 140, and a laser scanner unit 110 shown in FIG. 1. Further, the CPU 301 can control the temperature of a heater (not shown) of the fixing unit 170 shown in FIG. 1. The scanner unit 101 can read a document when performing copying.

[0015] Next, a basic image forming operation will be described using FIGS. 1 and 2. When the start of an image formation job is input from the operation unit 330 to the CPU 301, the CPU 301 analyzes the image formation job and starts the printing operation. By driving a pre-fixing conveyance motor 145 that is a driving source of a paper feed pickup roller 151 via an input / output interface (I / O) 307, the CPU 301 causes the paper feed pickup roller 151 to rotate and drive, and sheets in a paper feed cassette 150 are conveyed one by one. At this time, the CPU 301 monitors whether the paper feeding operation of the sheet is normally performed using a paper feed pickup sensor 152.

[0016] Sheet conveyance from a manual feed tray 210 capable of stacking a plurality of sheets will be described. Note that sheet conveyance from the paper feed cassette 150 may be the same, so the description thereof will be omitted. When there is an instruction to convey a sheet on the manual feed tray 210 from the operation unit 330 with a plurality of sheets stacked on the manual feed tray 210 as a stacking unit, the CPU 301 drives a sheet conveyance motor 147 via an input / output interface (I / O) 307. Then, since a sheet pickup roller 211 rotates, sheets are conveyed one by one from the manual feed tray 210. The sheet conveyance motor 147 and the sheet pickup roller 211 constitute a part of the conveyance unit. The CPU 301 monitors a pre-registration conveyance sensor 160 and determines whether the paper feeding operation from the manual feed tray 210 is normally performed.

[0017] In this embodiment, the sheets include rectangular or square sheets such as A-size, B-size, and postcards, which have no limitations on the image-forming area (referred to as sheets of a normal shape), sheets with some limitations on the image-forming area such as envelopes with the flaps open, index sheets with an index section, and punched sheets with holes formed in them (referred to as sheets of a special shape), plastic films such as sheets for overhead projectors, and recording materials such as cloth.

[0018] The CPU 301 determines the sheet length before the paper feeding operation starts, based on the detection results from the sheet presence detection sensor 214, sheet width volume sensor 217, sheet sub-scan length detection sensor 1 218, and sheet sub-scan length detection sensor 219, all located on the manual feed tray 210. Here, sheet length refers to the length of the sheet in the transport direction. The sheet transported from the manual feed tray 210 has its sheet characteristics, such as thickness and surface properties, automatically detected by the media sensor 280 located on the transport path. Based on the detected sheet characteristics, the CPU 301 changes the operating conditions for the image formation operation, such as the fixing temperature and transfer voltage. The configuration of the manual feed tray 210 and the media sensor 280 will be described in detail later.

[0019] The CPU 301 starts the image formation operation in the process unit 120 in accordance with the timing of the sheet's arrival at the secondary transfer unit 140. The process unit 120 consists of a photosensitive drum, a developer, a charging roller, a photosensitive drum cleaner, and the like. In the process unit 120, after the surface of the photosensitive drum is charged, an electrostatic latent image is formed on the photosensitive drum by a laser irradiated from the laser scanner unit 110. The electrostatic latent image formed on the photosensitive drum is then developed on the photosensitive drum by toner in the developer. Subsequently, the toner image developed on the photosensitive drum is subjected to a primary transfer voltage in the primary transfer unit 121 and transferred to the transfer belt 130. The toner image transferred to the transfer belt 130 is then moved to the secondary transfer unit 140 by the rotation of the transfer belt 130.

[0020] Furthermore, the CPU 301 detects the position of the sheet transported by the transport rollers A153, B154, and C155 by monitoring the pre-cash register transport sensor 160. Considering the timing when the leading edge of the sheet reaches the pre-cash register transport sensor 160, the CPU 301 controls the transport of the sheet so that the leading edge of the sheet and the leading edge of the toner image on the transfer belt 130 coincide at the secondary transfer unit 140. For example, if the sheet arrives at the toner image earlier than the CPU 301, the CPU 301 stops the sheet at the pre-cash register transport roller 161 for a predetermined time before resuming transport. In this way, the CPU 301 applies a secondary transfer voltage to the secondary transfer unit 140 to the sheet and toner image that have reached the secondary transfer unit 140, thereby transferring the toner image to the sheet.

[0021] After secondary transfer, the sheet is transported to the transport belt 190 and then to the fuser 170. In the fuser 170, the toner image on the sheet is heated and fixed to the sheet. When the leading edge of the fixed sheet, which has been transported downstream in the sheet transport direction, reaches the sheet transport sensor 171, the CPU 301 performs the following operation. Specifically, the CPU 301 determines which transport path—sheet transport path A230, sheet transport path B231, or sheet transport path C234—to transport the sheet using the transport roller 162, according to the contents of the image forming job specified in advance by the operation unit 330, and switches the destination of the sheet by switching the transport flapper A172 and transport flapper B182 according to the determination.

[0022] Specifically, when the image forming job input from the operation unit 330 is a double-sided print job, or when the printed side is to be ejected to the output tray A200 with the printed side facing downwards, the CPU 301 switches the transport flapper A172 to transport the sheet to the sheet transport path A230. Also, when the image forming job input from the operation unit 330 is a single-sided print job, or when the sheet is to be ejected to the output tray B196 or output tray C199 during double-sided printing, the CPU 301 switches the transport flapper B182 to transport the sheet to the sheet transport path B231. Then, when the sheet is to be ejected to the output tray A200, the CPU 301 switches between the transport flapper A172 and the transport flapper B182 to transport the sheet to the sheet transport path C234.

[0023] The sheets transported to sheet transport path B231 are further transported downstream in the transport direction by transport roller E232. Subsequently, the sheets are transported to sheet transport path D181 and then to output tray B196 and output tray C199. The sheets transported to sheet transport path D181 are transported by output rollers F241, G242, and H243, which are driven by output transport motor 148. When CPU 301 wants to output a sheet to output tray B196, it switches flapper 183 to transport the sheet to transport path 193 and outputs the sheet to output tray B196. When CPU 301 wants to output a sheet to output tray C199, it switches flapper 183 to transport path 184. Next, the CPU 301 uses the paper output rollers I244, J245, and K246, driven by the paper output transport motor 149, to transport the sheets to the transport path 184 and eject them into the paper output tray C199.

[0024] When printing on one side and ejecting the printed side downwards to the output tray A200, the sheet moves along the sheet transport path A230, and when the trailing edge of the sheet passes the reversal roller 163, the CPU 301 reverses its drive towards the output roller 180 and ejects the sheet to the output tray A200.

[0025] During double-sided printing, the sheet proceeds to the sheet transport path A230 and is then transported to the double-sided reversal transport path D233 by double-sided transport rollers A164, B165, C166, D179, and E168. Next, when the trailing edge of the sheet passes double-sided transport roller D179, the double-sided reversal flapper 178 is switched to the side of double-sided transport roller F169, and the drive is reversed. Subsequently, the sheet is transported by double-sided transport rollers F169, G175, H176, and I177 and handed over to transport roller C155. When all image forming jobs are completed, the CPU 301 displays completion to the operation unit 330.

[0026] <Media Sensor> Next, the media sensor 280, which acts as a detection unit for detecting sheet characteristics such as sheet thickness and surface properties, will be explained using Figure 3. As shown in Figure 3, the media sensor 280 has a media sensor main unit 54 and an external LED (light-emitting diode) 55b. The media sensor main unit 54 has an LED 55a as a light source, a phototransistor 56a, and a phototransistor 56b within the unit.

[0027] <Sheet surface texture detection> First, the method for detecting the surface properties of the sheet using the media sensor 280 will be explained. Light emitted from the LED (light-emitting element) 55a passes through the slit 57a and the upper window provided in the sheet transport guide 40, and irradiates the surface of the sheet P being transported while being guided by the sheet transport guide 40. The reflected light from the sheet P passes through the slits 57b and 57c and is received by the phototransistors 56a and 56b (light-receiving elements). Phototransistor 56a receives a portion of the diffusely reflected light emitted from the LED 55a and reflected from the surface of the sheet P, and outputs a diffuse reflection output value. Phototransistor 56b receives the specularly reflected light emitted from the LED 55a and reflected from the surface of the sheet P, and outputs a specular reflection output value. The surface property value x is calculated by Equation 1 shown below. Surface quality value x = Specular reflection output value / Diffuse reflection output value ... (Equation 1)

[0028] Equation 1 utilizes the characteristic that the smoother and finer the surface of sheet P, the easier it is to specularly reflect light. A calculation device (not shown) located on the media sensor 280 quantifies the surface properties of sheet P using Equation 1 and sends the calculated surface property value x to the CPU 301. The CPU 301 uses the received surface property value x and a threshold value for determining surface properties to determine the surface properties of sheet P. If the surface property value x is greater than the threshold value, the CPU 301 determines that the surface properties of sheet P are smooth and fine. If the surface property value x is less than or equal to the threshold value, the CPU 301 determines that the surface properties of sheet P are rough and coarse. Here, one threshold value is used to detect two types of sheet surface properties, but multiple threshold values ​​may be used to further subdivide and detect them.

[0029] <Sheet thickness detection> Next, the method for detecting the sheet thickness using the media sensor 280 will be described. The sheet transport guide 40 is provided with a lower window for irradiating light from the back side of the sheet P. Light emitted from the external LED (light-emitting element) 55b passes through the light-gathering guide 57d and the lower window to irradiate the back side of the sheet P. The transmitted light from the sheet P passes through the upper window and the slit 57b to be received by the phototransistor 56a. The phototransistor 56a receives the positively transmitted light emitted from the external LED 55b and transmitted through the sheet P and outputs a positively transmitted output value. The positively transmitted output value detected by the phototransistor 56a is sent to the CPU 301.

[0030] The CPU 301 determines the thickness of sheet P using the transmitted positive transmission output value and a threshold value for determining the thickness. In this embodiment, thresholds A and B are used to make three types of distinctions: "thick," "normal," and "thin" (threshold A < threshold B). If the positive transmission output value is less than or equal to threshold A, the CPU 301 determines that the thickness of sheet P is "thin." If the positive transmission output value is greater than threshold A and less than or equal to threshold B, the CPU 301 determines that the thickness of sheet P is "normal." If the positive transmission output value is greater than threshold B, the CPU 301 determines that the thickness of sheet P is "thick."

[0031] In this embodiment, two thresholds are used, but one threshold may be used, or three or more thresholds may be used to determine a more finely subdivided thickness. Also, in this embodiment, an optical sensor is used for the media sensor 280, but it is not limited to this, and other types of sensors such as ultrasonic sensors may be used as long as they can detect surface properties or thickness.

[0032] <Automatic sheet size detection> Next, the automatic detection configuration for the sheet size of the sheet P set in the manual feed tray 210 will be explained using Figure 4. Note that the same automatic detection configuration may be used in the paper feed cassette 150, so the explanation will be omitted here. As shown in Figure 4, the manual feed tray 210 is equipped with a sheet pickup roller 211 and sheet side regulating guides 212 and 213. The sheet set in the manual feed tray 210 is held in place by the sheet side regulating guides 212 and 213, which prevent the sheet from being transported at an angle when the sheet is separated and transported by the sheet pickup roller 211. The sheet side regulating guides 212 and 213 are slidable in the direction of arrows 215 and 216 in the figure, so that even if sheets P of different widths are set, the sheets can be prevented from becoming skewed.

[0033] Furthermore, the manual feed tray 210 is equipped with a sheet presence detection sensor 214, a sheet width volume sensor 217, a sheet sub-scan length detection sensor 1 218, and a sheet sub-scan length detection sensor 219. The sheet presence detection sensor 214, acting as an acquisition unit (first detection unit), is provided to detect whether or not a sheet is loaded in the manual feed tray 210. When a sheet is set on the manual feed tray 210, the sheet presence detection sensor 214 turns ON, an ON signal is input to the CPU 301 from the sheet presence detection sensor 214, and the CPU 301 determines that there is a sheet in the manual feed tray 210. When no sheet is set on the manual feed tray 210, the sheet presence detection sensor 214 turns OFF, an OFF signal is input to the CPU 301 from the sheet presence detection sensor 214, and the CPU 301 determines that there is no sheet in the manual feed tray 210.

[0034] The sheet width volume sensor 217, acting as an acquisition unit (second detection unit), is connected to the sheet side regulating guides 212 and 213 via a link member (not shown). Therefore, the sheet width volume sensor 217 outputs a signal (AD value) to the CPU 301 corresponding to the position of the sheet side regulating guides 212 and 213, in conjunction with the operation of the sheet side regulating guides 212 and 213. The CPU 301 detects the sheet width based on the signal (AD value) output from the sheet width volume sensor 217. Here, the sheet width is the length in the width direction intersecting the sheet transport direction (main scan length). In contrast, the sheet sub-scan length detection 1 sensor 218 and the sheet sub-scan length detection 2 sensor 219, acting as acquisition units (third detection units), are configured, for example, with a flag type configuration and are provided to detect the presence or absence of a sheet according to the length in the transport direction of the sheet set on the manual feed tray 210. Based on the combination of signals output from each of the sensors described above, the CPU 301 can automatically detect the sheet size, including the main scan length and sub scan length, for the sheet P set in the manual feed tray 210.

[0035] <Initial media settings screen> In this embodiment, when a sheet is detected in the manual feed tray 210 as described above, the "Media Setup Initial Screen" is displayed on the liquid crystal display 332. Figure 5 shows the "Media Setup Initial Screen". In the following explanation, the case of the manual feed tray 210 is used as an example, but the case of the paper feed cassette 150 may also be used.

[0036] As shown in Figure 5, the "Media Settings Initial Screen" displays the automatically detected sheet size 503 for the sheet P set in the manual feed tray 210. The sheet detection size 503 is displayed based on the main scan length, which is determined by the detection result of the sheet width volume sensor 217, and the sub-scan length, which is determined by the detection results of the sheet sub-scan length detection sensor 1 218 and the sheet sub-scan length detection sensor 219. For example, if the main scan length is "210 mm" and the sub-scan length is "297 mm", "A4 Portrait" will be displayed in the sheet detection size 503, and if the main scan length is "257 mm" and the sub-scan length is "182 mm", "B5 Landscape" will be displayed in the sheet detection size 503. Although not explained here, the user can also manually input the size of the sheet P set in the manual feed tray 210.

[0037] Additionally, the "Media Settings Initial Screen" displays a "Change Sheet Type" button 501 and an "OK" button 550. When the "Change Sheet Type" button 501 is pressed, the "Settings Selection Screen" (Figure 7(a) described later) is displayed on the LCD display 332.

[0038] <Media setup process> Next, in order to prompt the user to perform "media settings" such as changing the sheet type and setting the sheet shape, the various screens displayed on the liquid crystal display 332 after transitioning from the "initial media settings screen" described above will be explained using Figures 5 to 7(c) with reference to Figure 2. Figure 6 is a flowchart of the "media settings process" in the first embodiment. As the control unit 300 executes the "media settings process," the various screens displayed on the liquid crystal display 332 transition. The "media settings process" is started by the control unit 300 (specifically the CPU 301) when the power of the image forming apparatus 1 is turned on. In the following explanation, the case in which a sheet is set in the manual feed tray 210 will be used as an example, but the case in which a sheet is set in the paper feed cassette 150 may be similar, so the explanation will be omitted.

[0039] As shown in Figure 6, the control unit 300 determines whether or not a sheet is set in the manual feed tray 210 based on the detection result (ON signal or OFF signal) sent from the sheet presence detection sensor 214 (S1). If no sheet is set in the manual feed tray 210 (NO in S1), the control unit 300 repeatedly executes the process in step S1. If a sheet is set in the manual feed tray 210 (YES in S1), the control unit 300 displays the above "media setting initial screen" (see Figure 5) on the liquid crystal display 332 (S2). At this time, the control unit 300 displays the automatically detected sheet detection size 503.

[0040] Then, the control unit 300 determines whether the user has pressed the "Change Sheet Type" button 501 on the "Initial Media Settings Screen" (S3). If the "Change Sheet Type" button 501 has not been pressed (NO in S3), the control unit 300 determines whether the user has pressed the "OK" button 550 on the "Initial Media Settings Screen" (S4). If the "OK" button 550 has not been pressed (NO in S4), the control unit 300 returns to the process in step S3. If the "OK" button 550 has been pressed (YES in S4), the control unit 300 terminates the "Media Settings Process".

[0041] If the "Change Sheet Type" button 501 on the "Initial Media Settings Screen" is pressed (YES in S3), the control unit 300 displays the "Setting Selection Screen" on the liquid crystal display 332 (S5). Figure 7(a) shows the "Setting Selection Screen". As shown in Figure 7(a), the "Setting Selection Screen" displays the "Automatically Detect During Printing" button 511 and the "Select from List" button 512. The "Select from List" button 512 is for the user to manually input the sheet type. The "Automatically Detect During Printing" button 511 is for the user to set up automatic detection of sheet characteristics by the media sensor 280.

[0042] After the "Settings Selection Screen" is displayed, the control unit 300 determines whether the "Automatically detect during printing" button 511 on the "Settings Selection Screen" has been pressed by the user (S6). If the "Automatically detect during printing" button 511 has been pressed by the user (YES in S6), the control unit 300 displays the "Shape Selection Screen" on the liquid crystal display 332 (S7). At this time, the control unit 300 sets the system to automatically detect the sheet characteristics using the media sensor 280 when executing an image forming job.

[0043] Figure 7(b) shows the "Shape Selection Screen". As shown in Figure 7(b), the "Shape Selection Screen" displays a "Automatically Detect During Printing" button 511 and a "Select from List" button 512. However, the "Automatically Detect During Printing" button 511 is not selected on the "Shape Selection Screen" so that it cannot be operated by the user.

[0044] The "Shape Selection Screen" is a screen for inputting information about the shape of sheet P, and displays multiple candidate images for special-shaped sheets. As candidate images, sheet shape selection buttons such as the "Index Paper" button 521, the "Pre-punched" button 522, and the "Envelope Flap" button 523 are displayed. These sheet shape selection buttons prompt the user to input the shape of the sheet set in the manual feed tray 210. The user can input the special shape "Index Sheet" by operating the "Index Paper" button 521, the special shape "Punched Sheet" by operating the "Pre-punched" button 522, and the special shape "Envelope with Flap Open" by operating the "Envelope Flap" button 523. The control unit 300 stores the special shapes corresponding to the sheet shape selection buttons (521, 522, 523) operated by the user in the RAM 303.

[0045] If the "Automatically detect during printing" button 511 on the "Settings Selection Screen" is not pressed by the user (NO in S6), the control unit 300 determines whether the "Select from list" button 512 on the "Settings Selection Screen" has been pressed by the user (S8). If the "Select from list" button 512 has not been pressed by the user (NO in S8), that is, if the "OK" button 551 on the "Settings Selection Screen" has been pressed, the control unit 300 returns to the process in step S6. On the other hand, if the "Select from list" button 512 has been pressed by the user (YES in S8), the control unit 300 displays the "Sheet Type Input Screen" on the liquid crystal display 332 (S9).

[0046] Figure 7(c) shows the "Sheet Type Input Screen". The "Sheet Type Input Screen" is a screen for inputting information about multiple sheet types P, and as shown in Figure 7(c), the sheet types are displayed in a list to prompt the user to input the sheet type. Here, the sheet types (thin paper 1, plain paper 1, etc.) are displayed along with their basis weight. The control unit 300 stores the sheet type selected by the user from the list in the RAM 303.

[0047] The control unit 300 determines whether the user has pressed the "OK" button 552 on the "Shape Setting Screen" or the "OK" button 553 on the "Sheet Type Input Screen" (S10). If the user has pressed the "OK" button 552 on the "Shape Setting Screen" or the "OK" button 553 on the "Sheet Type Input Screen" (YES in S10), the control unit 300 returns to step S2 and displays the "Media Setting Initial Screen" (see Figure 5) on the liquid crystal display 332 (S2).

[0048] On the other hand, if the user has not pressed the "OK" button 552 on the "Shape Setting Screen" or the "OK" button 553 on the "Sheet Type Input Screen" (NO in S10), the control unit 300 returns to the process in step S6. In this case, even if the user has pressed any of the sheet shape selection buttons (521, 522, 523) on the "Shape Selection Screen," the control unit 300 does not store the special shape corresponding to the user-pressed sheet shape selection button (521, 522, 523) in the RAM 303. Also, even if the user has selected any of the sheet types from the list displayed on the "Sheet Type Input Screen," the user-selected sheet type is not stored in the RAM 303.

[0049] <Sheet feeding process> Next, the "sheet feeding process" during image formation job execution will be explained using Figure 8 with reference to Figure 2. When the start of an image formation job is input from the operation unit 330, the job information is stored in the RAM 303. Here, the image formation job is assumed to be a job that performs image formation on a desired number of sheets fed from the manual feed tray 210. The "sheet feeding process" shown in Figure 9 is executed by the control unit 300 (specifically the CPU 301) based on the job information.

[0050] The control unit 300 determines whether the user-specified number of sheets have been fed from the manual feed tray 210 (S11). If the specified number of sheets have been fed from the manual feed tray 210 (YES in S11), the control unit 300 terminates the "sheet feeding process". If the specified number of sheets have not been fed from the manual feed tray 210 (NO in S11), the control unit 300 executes the "control sheet size setting process" to determine the "control sheet size" (S12). The "control sheet size setting process" will be described later (see Figure 9).

[0051] After the "control sheet size setting process," the control unit 300 determines the paper feeding timing for feeding sheets from the manual feed tray 210 according to the "control sheet size" (S13). The control unit 300 determines whether or not the determined paper feeding timing is correct (S14). If it is the correct paper feeding timing (NO in S14), it drives the sheet transport motor 147 to rotate the sheet pickup roller 211 and feeds sheets one by one from the manual feed tray 210 (S15). In this way, the transport interval of the sheets P is adjusted. When the control unit 300 feeds one sheet from the manual feed tray 210, it adds "1" to the "number of sheets fed" stored in the RAM 303 (S16), returns to the process in step S11, and repeats the processes in steps S11 to S16. The "number of sheets fed" stored in RAM 303 is used by the control unit 300 to compare with the specified number of sheets when determining whether the specified number of sheets have been fed from the manual feed tray 210 (S11). When the "number of sheets fed" reaches the specified number, the control unit 300 determines that the specified number of sheets have been fed from the manual feed tray 210.

[0052] <Control sheet size setting process> The "control sheet size setting process" (S12 in Figure 8) described above will be explained using Figure 9. As shown in Figure 9, the control unit 300 determines whether the "Automatic detection during printing" button 511 (see Figure 7(a)) on the "setting selection screen" has been operated by the user, that is, whether the system is set to automatically detect the sheet characteristics using the media sensor 280 (S21). If the "Automatic detection during printing" button 511 has not been operated by the user, that is, if automatic detection of the sheet characteristics using the media sensor 280 is not performed (NO in S21), the control unit 300 adds the "set sheet size" and the size of the sheet type selected by the user from the "sheet type input screen" (see Figure 7(c)) and sets it as the "control sheet size" (S25). For example, if "envelope" is selected as the sheet type and the "set sheet size" is long envelope No. 3 (235mm x 120mm), the "control sheet size" will be set to "265mm (235+30)". The "set sheet size" refers to the sheet size automatically detected by the manual feed tray 210, or the sheet size manually entered by the user. The "control sheet size" is used to determine the timing for feeding sheets from the manual feed tray 210 during the execution of an image forming job, as described above (see S13 in Figure 8).

[0053] If the "Automatic detection during printing" button 511 is pressed by the user, that is, if the media sensor 280 is performing automatic detection of the sheet characteristics (YES in S21), the control unit 300 determines whether or not the sheet shape has been set (S22). That is, it determines whether or not a special shape has been selected by the user using the sheet shape selection buttons (521, 522, 523) on the "shape selection screen" (see Figure 7(b)). If a special shape has not been selected (NO in S22), the control unit 300 sets the "set sheet size" to the "control sheet size" (S24). For example, if the automatically detected sheet size is "A4 portrait (297mm x 210mm)", it is set to "297mm".

[0054] If a special shape is selected (YES in S22), the control unit 300 adds the "set sheet size" and the special shape size value pre-assigned to the selected special shape and sets it as the "control sheet size" (S23). For example, if the special shape "index sheet" is selected, and the automatically detected sheet size is "A4 landscape", then the control sheet size is set to "222.6 mm (210 + 12.6)", which is the short side of the automatically detected A4 sheet size "210 mm x 297 mm" plus the special shape size value "12.6 mm".

[0055] As described above, the transport interval of the sheets P is adjusted by the control unit 300 feeding sheets one by one from the manual feed tray 210 according to the paper feeding timing. The "control sheet size" is used to determine this paper feeding timing. The transport interval of the sheets P is the distance in the sheet transport direction between the leading edge of the preceding sheet P and the leading edge of the following sheet P. As described above, for example, if the sheet P is a "long envelope No. 3", the "control sheet size" is set to "265 mm", and if the sheet P is "A4 portrait", the "control sheet size" is set to "297 mm". When the sheet P is a "long envelope No. 3", the paper feeding timing is determined so that the "control sheet size" is shorter than the transport interval of the comparatively longer "A4 portrait" sheet.

[0056] As described above, in this embodiment, when the media sensor 280 automatically detects the sheet characteristics, a "shape selection screen" prompting the user to input a special shape is displayed on the liquid crystal display 332. When the user inputs a special shape from the "shape selection screen," the "control sheet size" corresponding to the input special shape is set. Then, when the image forming job is executed, the special-shaped sheet P is transported from the manual feed tray 210 at a transport interval adjusted based on the "control sheet size." This prevents abnormalities such as the special-shaped sheet P getting stuck in the transport path when the media sensor 280 automatically detects the sheet characteristics. The user can easily set the "control sheet size" simply by inputting a special shape from the "shape selection screen," thus improving user convenience.

[0057] [Second Embodiment] Next, the second embodiment will be described using Figures 10 to 12 with reference to Figure 2. The second embodiment differs from the first embodiment in that, in the "shape selection screen" shown in Figure 7(b) of the first embodiment described above, at least one of the sheet shape selection buttons (521, 522, 523) is displayed in a non-selected state, meaning it cannot be selected by the user.

[0058] Figure 10 is a flowchart of the "media setup process" in the second embodiment. In the "media setup process" of the second embodiment shown in Figure 10, the process in step S31 is added compared to the "media setup process" of the first embodiment shown in Figure 6. Therefore, the same processes as in the "media setup process" of the first embodiment are given the same step numbers and their explanations are simplified or omitted, and the process mainly related to the process in step S31 will be described.

[0059] After the "settings selection screen" is displayed (S5), the control unit 300 determines whether the "automatic detection during printing" button 511 on the "settings selection screen" has been operated by the user (S6). If the "automatic detection during printing" button 511 has been operated by the user (YES in S6), the control unit 300 executes the "shape selection button display process" (S31). Then, the control unit 300 displays a "shape selection screen" (see Figure 12) on the liquid crystal display 332, in which at least one of the sheet shape selection buttons (521, 522, 523) determined by the "shape selection button display process" is set to a non-selectable button that cannot be selected by the user (S7).

[0060] <Display processing for the sheet shape selection button> The "display process of the sheet shape selection button" described above will be explained using Figure 11. In the second embodiment, the "set sheet size" is one of the predetermined sizes "A4, LTR, or envelope". As shown in Figure 11, the control unit 300 determines whether the "set sheet size" is "A4 or LTR" (S41). If the "set sheet size" is "A4" or "LTR" (YES in S41), the control unit 300 sets the "envelope flap" button 523 to a non-selection button (S42). In this case, the "index paper" button 521 and the "pre-punch" button 522 become user-selectable sheet shape selection buttons.

[0061] If the "set sheet size" is not "A4" or "LTR" (NO in S41), the control unit 300 determines whether the "set sheet size" is "envelope" (S43). If the "set sheet size" is "envelope" (YES in S43), the control unit 300 sets the "index paper" button 521 and the "pre-punch" button 522 to deselected buttons (S44). In this case, only the "envelope flap" button 523 becomes a user-selectable sheet shape selection button. If the "set sheet size" is not "envelope" (NO in S43), the control unit 300 sets the "index paper" button 521 and the "envelope flap" button 523 to deselected buttons (S45). In this case, only the "pre-punch" button 522 becomes a user-selectable sheet shape selection button. The setting of deselected buttons is based on the correspondence relationships pre-stored in the ROM 302 for each special shape (for example, the envelope flap open button is hidden when it is A4).

[0062] Figure 12 shows an example of the "shape selection screen" in the second embodiment, where the "index paper" button 521 and the "pre-punch" button 522 are set to non-selectable buttons. As shown in Figure 12, when the "set sheet size" is "envelope," the "index paper" button 521 and the "pre-punch" button 522 are unnecessary and are displayed as non-selectable buttons, and only the "envelope flap" button 523 is displayed as a user-selectable button. The non-selectable sheet shape selection buttons (521, 522, 523) are displayed faintly and cannot be operated by the user. Note that the non-selectable sheet shape selection buttons (521, 522, 523) may not be displayed on the "shape selection screen."

[0063] As described above, in the second embodiment, as in the first embodiment described above, when the media sensor 280 automatically detects the sheet characteristics, a "shape selection screen" prompting the user to input a special shape is displayed on the liquid crystal display 332. However, in the second embodiment, when the "shape selection screen" is displayed on the liquid crystal display 332, the user is prompted to input only the special shapes that correspond to the "set sheet size" from among the multiple special shapes. In this way, by limiting the special shapes that can be input from among the multiple special shapes on the "shape selection screen" and presenting them to the user, it is possible to prevent the user from mistakenly selecting a special shape that does not correspond to the "set sheet size," thereby improving user convenience.

[0064] [Third Embodiment] Next, the third embodiment will be described using Figure 13. In the first and second embodiments described above, the "control sheet size" is set according to the special shape input by the user, but in the third embodiment, the "control sheet size" can be set for a special-shaped sheet P without requiring the user to input the special shape. Figure 13 shows the "control sheet size setting process" of the third embodiment that realizes this. The "control sheet size setting process" of the third embodiment is executed during the "sheet feeding process" as described above (see S12 in Figure 8). In the third embodiment as well as in the second embodiment described above, the "set sheet size" is one of the predetermined sizes "A4, LTR, or envelope".

[0065] As shown in Figure 13, the control unit 300 determines whether the "Automatic detection during printing" button 511 (see Figure 7(a)) on the "Setting selection screen" has been pressed by the user, that is, whether the system is set to automatically detect the sheet characteristics using the media sensor 280 (S51). If the "Automatic detection during printing" button 511 has not been pressed by the user, that is, if automatic detection of the sheet characteristics using the media sensor 280 is not performed (NO in S51), the control unit 300 adds the "Set sheet size" and the size of the sheet type selected by the user from the "Sheet type input screen" (see Figure 7(c)) and sets this to the "Control sheet size" (S57). For example, if "Envelope" is selected as the sheet type and the set sheet size is No. 3 long envelope (235mm x 120mm), the "Control sheet size" is set to "265mm (235 + 30)".

[0066] If the "Automatic detection during printing" button 511 is pressed by the user, that is, if the media sensor 280 is performing automatic detection of the sheet characteristics (YES in S51), the control unit 300 determines whether the "set sheet size" is "A4 or LTR" (S41). If the "set sheet size" is "A4 or LTR" (YES in S52), the control unit 300 adds the "A4 or LTR" sheet size and the "index length" that has been pre-stored in the ROM 302 corresponding to "A4 or LTR" and sets it as the "control sheet size" (S53). For example, if the "set sheet size" is "A4 landscape", the "control sheet size" is set to "222.6 mm (210 + 12.6)", which is the shorter side of the "A4 landscape" sheet size "210 mm x 297 mm" plus the index length "12.6 mm" corresponding to "A4 landscape".

[0067] If the "set sheet size" is not "A4 or LTR" (NO in S52), the control unit 300 determines whether the "set sheet size" is an "envelope" (S54). If the "set sheet size" is an "envelope" (YES in S54), the control unit 300 adds the sheet size of the "envelope" to the "flap length" which is pre-stored in the ROM 302 corresponding to the "envelope" and sets it as the "control sheet size" (S55). For example, if the "set sheet size" is a "No. 3 long envelope", the control unit 300 adds the flap length "30 mm" corresponding to the "No. 3 long envelope" to the longer side of the "No. 3 long envelope" sheet size "235 mm x 120 mm" to set "265 mm (235 + 30)" as the "control sheet size". If the "set sheet size" is not an envelope (NO in S54), the control unit 300 sets the "set sheet size" as the "control sheet size" (S56).

[0068] As described above, in this embodiment, when the media sensor 280 automatically detects the sheet characteristics, the "control sheet size" for special-shaped sheets P can be set without displaying the "shape selection screen" (see Figure 7(b)) on the liquid crystal display 332, that is, without the user inputting the special shape. If the user is required to input the special shape according to the "shape selection screen" when the media sensor 280 automatically detects the sheet characteristics, it may lead to a decrease in productivity. On the other hand, if the "control sheet size" is not set for special-shaped sheets P when the media sensor 280 automatically detects the sheet characteristics, abnormalities such as the special-shaped sheet P getting stuck in the transport path may occur. Therefore, if the "set sheet size" is a specific size (A4, LTR, envelope), it is treated as a special shape, and special shape size values ​​such as index values ​​and flap length corresponding to the specific size are added to the "set sheet size" to set the "control sheet size". This improves user convenience and does not reduce the productivity of the image forming apparatus 1, as the user does not need to input special shapes for specific sizes when the media sensor 280 automatically detects the sheet characteristics. [Explanation of Symbols]

[0069] 1…Image forming apparatus, 147…Transportation unit (sheet transport motor), 150…Loading unit (paper feed cassette), 210…Loading unit (manual feed tray), 211…Transportation unit (sheet pickup roller), 214…Acquisition unit (first detection unit, sheet presence / absence detection sensor), 217…Acquisition unit (second detection unit, sheet width volume sensor), 218, 219…Acquisition unit (third detection unit, sheet sub-scan length detection sensor 1, sheet sub-scan length detection sensor 2), 280…Detection unit (media sensor), 300…Control unit, 331…Input unit, 332…Display unit (liquid crystal display), P…Recording material (sheet)

Claims

1. An image forming apparatus for forming an image on a recording material, A loading section capable of loading recording materials, A transport unit for transporting recording materials from the aforementioned loading unit, A detection unit that detects the characteristics of the recording material, A display unit capable of displaying information, The system comprises a control unit for controlling the display unit, When the control unit is in a mode in which the characteristics of the recording material are detected by the detection unit, it causes the display unit to display a screen for inputting information regarding the shape of the recording material. An image forming apparatus characterized by the following features.

2. The information relating to the shape of the recording material includes at least information relating to an index sheet having an index portion, a punched sheet with holes formed in it, or an envelope with the flap open. The image forming apparatus according to feature 1.

3. When the control unit is not in a mode for detecting the characteristics of the recording material using the detection unit, it causes the display unit to display a screen for inputting information about multiple types of recording materials. The image forming apparatus according to feature 1.

4. The loading section is equipped with an acquisition unit that acquires the size of the recording material loaded on it. When the size of the acquired recording material is a predetermined size, the control unit displays on the display unit a predetermined set of information regarding the shape of the recording material, selected from a plurality of pieces of information regarding the shape of the recording material to be displayed on the screen, in a non-selected state that cannot be selected by the user. The image forming apparatus according to feature 1.

5. The loading unit comprises a first detection unit for detecting whether or not recording material is loaded, a second detection unit for detecting the length in the width direction intersecting the transport direction of the loaded recording material, and a third detection unit for detecting the presence or absence of recording material according to the length of the loaded recording material in the transport direction. The acquisition unit acquires the size of the recording material based on the detection results of the first to third detection units. The image forming apparatus according to feature 4.

6. The display unit includes an input unit that allows the user to input any of the information regarding the shape of the multiple recording materials displayed on the display unit, When performing an image forming job to form an image on recording material transported from the loading unit, the transport unit transports the recording material from the loading unit according to the transport interval between preceding and succeeding recording material, which is determined according to information regarding the shape of the recording material. The image forming apparatus according to feature 1.

7. The aforementioned loading section is a manual feed tray. The image forming apparatus according to feature 1.

8. The aforementioned loading section is a paper feed cassette. The image forming apparatus according to feature 1.

Images