Image forming device

Abstract

To allow a user to easily grasp a degree of a possibility of image formation until a color material runs out in a case where an image is formed on a long recording medium such as a roll sheet.SOLUTION: Length derivation processing is executed for deriving the length of a recording medium on which an image can be formed until ink in an ink storage part runs out from an ink residual amount. Length display processing is executed for displaying on a display part the length derived in the length deriving processing of the recording medium on which the image can be formed.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus. [Background technology]

[0002] Patent document 1 describes an inkjet recording device that forms images using ink, which displays printable page count information regarding the number of pages that can be printed with the remaining amount of ink, based on statistical data on the amount of ink used and the number of pages printed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-335043 A Summary of the Invention [Problem to be solved by the invention]

[0004] Some image forming devices can print on long recording media such as rolled paper instead of cut paper. In such image forming devices, the length of one printed recording medium is often different from a standard size such as A4 size or B5 size, and the length of one printed recording medium can change each time printing is performed. Therefore, even if the number of printable sheets is displayed using the technology of Patent Document 1, it is difficult for a user to easily understand how much printing can be performed before the ink runs out.

[0005] An object of the present invention is to provide an image forming apparatus that allows a user to easily grasp, when forming an image on a long recording medium, how much image formation is possible before color material runs out. [Means for solving the problem]

[0006] The image forming apparatus of the present invention comprises: In the first perspective,The recording medium supplying device includes a first supplying unit that supplies a long recording medium, an image forming unit that forms an image on the recording medium supplied from the first supplying unit using coloring material supplied from a coloring material storage unit capable of storing coloring material, a remaining amount signal output unit that outputs a signal indicating the remaining amount of coloring material stored in the coloring material storage unit, and a control unit. The control unit is capable of executing a length derivation process that derives the length of the recording medium on which an image can be formed before the coloring material in the coloring material storage unit runs out based on the signal output from the remaining amount signal output unit, and a length display process that causes a display unit to display the length of the recording medium on which an image can be formed derived by the length derivation process. In a second aspect, an image forming apparatus of the present invention includes a first supply unit that supplies a long recording medium, an image forming unit that forms an image on the recording medium supplied from the first supply unit using colorant supplied from a colorant storage unit capable of storing colorant, a remaining amount signal output unit that outputs a signal indicating the remaining amount of colorant stored in the colorant storage unit, and a control unit, wherein the control unit is capable of executing a length derivation process that derives a length of the recording medium on which an image can be formed before the colorant in the colorant storage unit runs out based on the signal output from the remaining amount signal output unit, and a length display process that causes a display unit to display the length of the recording medium on which an image can be formed derived by the length derivation process, wherein the first supply unit is capable of storing a long recording medium and a plurality of short recording media having a predetermined length stacked together or exclusively, and further includes a medium information output unit that outputs information on whether or not a long recording medium is stored in the first supply unit, and the control unit executes the length display process when the medium information output unit outputs information that a long recording medium is stored in the first supply unit. In a third aspect, an image forming apparatus of the present invention includes a first supply unit which supplies a long recording medium, an image forming unit which forms an image on the recording medium supplied from the first supply unit using colorant supplied from a colorant storage unit capable of storing colorant, a remaining amount signal output unit which outputs a signal indicating a remaining amount of colorant stored in the colorant storage unit, and a control unit, the control unit being capable of executing a length derivation process which derives a length of the recording medium on which an image can be formed before the colorant in the colorant storage unit runs out based on the signal output from the remaining amount signal output unit, and a length display process which causes a display unit to display the length of the recording medium on which an image can be formed derived by the length derivation process, and the first supply unit is capable of storing a long recording medium and a plurality of short recording media having a predetermined length which are stacked together or exclusively. The control unit is capable of executing a number derivation process for deriving the number of short recording media on which images can be formed before the colorant in the colorant storage unit runs out based on the signal output from the remaining amount signal output unit, and a number display process for displaying on the display unit the number of recording media on which images can be formed derived by the number derivation process, and executes the length display process when the medium information output unit outputs information that the recording media contained in the first supply unit are only long recording media, and executes the number display process when the medium information output unit outputs information that the recording media contained in the first supply unit are only short recording media. In a fourth aspect, an image forming apparatus of the present invention includes a first supply unit which supplies a long recording medium, an image forming unit which forms an image on the recording medium supplied from the first supply unit by using colorant supplied from a colorant storage unit capable of storing colorant, a remaining amount signal output unit which outputs a signal indicative of a remaining amount of colorant stored in the colorant storage unit, a second supply unit which supplies a plurality of short recording media having a predetermined length which are stacked, a medium information output unit which outputs information as to whether a recording medium is stored in each of the first supply unit and the second supply unit, and a control unit, wherein the control unit performs a length derivation process which derives a length of the recording medium on which an image can be formed before the colorant in the colorant storage unit runs out based on the signal output from the remaining amount signal output unit, and a length derivation process which determines a length of the recording medium on which an image can be formed before the colorant in the colorant storage unit runs out. The control unit is capable of executing a length display process for displaying on a display unit the length of the recording medium on which an image can be formed that has been determined, a number derivation process for deriving the number of short recording media on which an image can be formed before the color material in the color material storage unit runs out based on a signal output from the remaining amount signal output unit, and a number display process for displaying on the display unit the number of recording media on which an image can be formed that has been derived by the number derivation process.The control unit is capable of executing the length display process when the medium information output unit outputs information that a recording medium is contained in the first supply unit and a recording medium is not contained in the second supply unit, and executing the number display process when the medium information output unit outputs information that a recording medium is not contained in the first supply unit and a recording medium is contained in the second supply unit. Effect of the Invention

[0007] According to the present invention, when forming an image on a long recording medium, the user can easily grasp how much image formation is possible before the color material runs out. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating the overall configuration of a printer according to an embodiment of the present invention. [Diagram 2] 2 is an overall configuration diagram showing a state in which cut paper is stored in the printer of FIG. 1. [Diagram 3] FIG. 2 is a block diagram of the printer shown in FIG. [Figure 4] 2 is a diagram showing a remaining ink level display screen on a touch panel included in the printer shown in FIG. 1. [Diagram 5] 4 is a flowchart showing the remaining ink level display of the printer shown in FIG. [Figure 6] 13 is a diagram showing an ink remaining amount display screen in a printer according to another embodiment. [Figure 7] FIG. 13 is a diagram showing a remaining ink level display screen in a printer according to yet another embodiment. [Figure 8]FIG. 13 is a diagram showing a remaining ink level display screen in a printer according to yet another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] <Overall printer configuration> First, the overall configuration of a printer 100 (image forming apparatus) according to one embodiment of the present invention will be described with reference to Figures 1 and 2. The up-down direction and front-rear direction shown in Figures 1 and 2 are the up-down direction and front-rear direction of the printer 100. In this embodiment, the printer 100 is an inkjet printer that forms an image by ejecting ink toward a recording medium.

[0010] The printer 100 includes a housing 100a, a lower paper feed tray 1, an upper paper feed tray 2, a transport mechanism 3, a cutter mechanism 4, a head 5, a paper discharge tray 6, an ink storage unit 31, and a control unit 10. The lower paper feed tray 1 and the upper paper feed tray 2 have a box shape that opens upward. The upper paper feed tray 2 is detachable from the lower part of the housing 100a, and the lower paper feed tray 1 is detachable from the lower part of the upper paper feed tray 2. The printer 100 is equipped with a tray sensor 34 (see FIG. 3) that detects whether the lower paper feed tray 1 and the upper paper feed tray 2 are attached to a predetermined position. The paper discharge tray 6 is formed of a side wall at the front of the upper part of the housing 100a, and can be opened and closed relative to the housing 100a.

[0011] The lower paper feed tray 1 is provided with a roll paper storage section 11 capable of storing a roll R (see FIG. 1) on which long paper (recording medium) is wound, and a cut paper storage section 12 capable of storing cut paper Pc (see FIG. 2). The lower paper feed tray 1 corresponds to the "first supply section" of the present invention.

[0012] The roll R (see FIG. 1) is a long sheet of paper wound in a roll shape around the outer circumferential surface of a cylindrical core member Rc. The roll R is stored in the roll paper storage unit 11 with its rotation axis Rx (the central axis of the core member Rc) aligned in a direction perpendicular to the up-down direction and the front-rear direction (the "scanning direction" described below, which is the width direction of the paper P).

[0013] The roll paper storage section 11 has a recess 11x that stores the roll R. Two rollers 14, 15 are provided at the bottom of the recess 11x. The two rollers 14, 15 are rotatable about shafts 14a, 15a that extend in the scanning direction, respectively. When the roll R is stored in the recess 11x, the outer circumferential surface of its lower portion is supported by the two rollers 14, 15.

[0014] The roll paper storage section 11 further has a hole 11y that communicates with the recess 11x and extends in the vertical direction, and a groove 11z that communicates with the hole 11y and extends in the front-rear direction. Both the hole 11y and the groove 11z open to the bottom surface of the roll paper storage section 11. The roll paper P unwound from the roll R passes through the hole 11y and the groove 11z and is transported toward the head 5.

[0015] The cut paper Pc (see FIG. 2) is paper P (recording medium) that is shorter than the paper that constitutes the roll body R. The cut paper storage section 12 is the space behind the roll paper storage section 11 in the lower paper feed tray 1, and can store multiple cut papers Pc stacked vertically.

[0016] In printer 100, when using roll R, cut paper Pc is removed from cut paper storage section 12 (see FIG. 1), and when using cut paper Pc, roll R is removed from roll paper storage section 11 or roll paper P unwound from roll R is rewound to a position where it does not interfere with the transport path of cut paper Pc (see FIG. 2). In this way, lower paper feed tray 1 can store roll R and cut paper Pc together, but there are limitations to its use because they share lower feed roller 3a as described below.

[0017] The upper paper feed tray 2 is provided with a cut paper storage section 22 capable of storing cut paper Pc. The upper paper feed tray 2 corresponds to the "second supply section" of the present invention. The cut paper Pc in the upper paper feed tray 2 may be the same length as that stored in the lower paper feed tray 1, or may be a different length. The cut paper storage section 22 is capable of storing multiple cut paper sheets Pc stacked vertically.

[0018] The transport mechanism 3 is configured to transport paper P selectively from three storage sections (roll paper storage section 11 and cut paper storage sections 12, 22), and includes a lower feed roller 3a, a pair of intermediate rollers 3b, a pair of transport rollers 3c, a pair of paper discharge rollers 3d, an upper feed roller 3e, and guides 7, 8, 9. The transport mechanism 3 configures two transport paths C1, C2. Transport path C1 is a path that runs from either the roll paper storage section 11 or the cut paper storage section 12, from the storage section 11, 12, passing below the head 5 toward the paper discharge tray 6, and transports paper P in the transport direction A. Transport path C2 is a path that runs from the cut paper storage section 22, from the storage section 22, passing below the head 5 toward the paper discharge tray 6, and transports paper P in the transport direction A.

[0019] The lower feed roller 3a is located above the cut paper storage section 12, and is disposed on the transport path C1 between the roll paper storage section 11 and the head 5. The intermediate roller pair 3b is disposed on the transport path C1 between the lower feed roller 3a and the head 5. The transport roller pair 3c is disposed on the transport path C1 between the intermediate roller pair 3b and the head 5. The paper discharge roller pair 3d is disposed on the transport path C1 between the head 5 and the paper discharge tray 6.

[0020] The upper feed roller 3e is located above the cut paper storage section 22 and is disposed upstream of the conveying roller pair 3c on the conveying path C2. The conveying roller pair 3c is disposed between the upper feed roller 3e and the head 5 on the conveying path C2. The paper discharge roller pair 3d is disposed between the head 5 and the paper discharge tray 6 on the conveying path C2.

[0021] The lower feed roller 3a is supported at the tip of an arm 3y1. The arm 3y1 is supported rotatably on a support shaft 3x1, and the lower feed roller 3a is biased so as to approach the bottom surface of the lower feed tray 1. As shown in FIG. 1, when the roll R is stored in the roll paper storage section 11 and the cut paper Pc is not stored in the cut paper storage section 12, the lower feed motor (not shown) is driven under the control of the control unit 10, and the lower feed roller 3a rotates, causing the roll R to rotate in the direction of the arrow B, and the roll paper P unwound from the roll R is fed toward the intermediate roller pair 3b. Alternatively, as shown in FIG. 2, when the cut paper Pc is stored in the cut paper storage section 12, the lower feed motor is driven under the control of the control unit 10, and the lower feed roller 3a rotates, causing the uppermost cut paper Pc among the multiple cut papers Pc stored in the cut paper storage section 12 to be fed toward the intermediate roller pair 3b.

[0022] The upper feed roller 3e is journaled at the tip of an arm 3y2. The arm 3y2 is rotatably supported on a support shaft 3x2, and is biased so that the upper feed roller 3e approaches the bottom surface of the upper paper feed tray 2. As shown in Fig. 2, when cut sheets Pc are stored in the cut sheet storage section 22, an upper feed motor (not shown) is driven under the control of the control section 10 to rotate the upper feed roller 3e, and the uppermost cut sheet Pc among the multiple cut sheets Pc stored in the cut sheet storage section 22 is fed toward the transport roller pair 3c.

[0023] The intermediate roller pair 3b, the conveying roller pair 3c, and the paper discharge roller pair 3d each include a drive roller that rotates by being driven by a conveying motor (not shown), and a driven roller that rotates along with the drive roller. The conveying motor is driven under the control of the control unit 10, and the intermediate roller pair 3b, the conveying roller pair 3c, and the paper discharge roller pair 3d rotate while holding the paper P, whereby the paper P is conveyed in the conveying direction A along the conveying path C1 or C2.

[0024] The conveying direction A is configured to be reversed between the intermediate roller pair 3b and the conveying roller pair 3c, or between the guide 8 and the conveying roller pair 3c. In this embodiment, the front-to-rear component of the conveying direction A is opposite in the portion of the conveying path C1 from the storage units 11, 12 to the intermediate roller pair 3b, and in the portion of the conveying path C1 from the conveying roller pair 3c to the paper output tray 6. Similarly, the front-to-rear component of the conveying direction A is opposite in the portion of the conveying path C2 from the storage unit 22 to the guide 8, and in the portion of the conveying path C2 from the conveying roller pair 3c to the paper output tray 6.

[0025] The guide 7 is disposed between the lower feed roller 3a and the pair of intermediate rollers 3b on the transport path C1, and guides the paper P fed by the lower feed roller 3a to the pair of intermediate rollers 3b. The guide 7 is formed from the rear side wall of the lower paper feed tray 1, and is inclined so that it is positioned higher from front to rear. The surface of the guide 7 (the surface that defines the transport path C1) is formed with fine irregularities 7x that repeat along the transport direction A. The irregularities 7x make it possible to prevent double feeding (a phenomenon in which multiple cut papers Pc are transported in an overlapping state).

[0026] The guide 8 is disposed between the upper feed roller 3e and the pair of transport rollers 3c on the transport path C2, and guides the paper P fed by the upper feed roller 3e to the pair of transport rollers 3c. The guide 8 is formed from the rear side wall of the upper paper feed tray 2, and is inclined so that it is positioned higher from front to rear. The surface of the guide 8 (the surface that defines the transport path C2) is formed with fine irregularities 8x that repeat along the transport direction A. The irregularities 8x make it possible to prevent double feeding.

[0027] The guide 9 is disposed between the intermediate roller pair 3b and the transport roller pair 3c on the transport path C1, and guides the paper transported by the intermediate roller pair 3b to the transport roller pair 3c. The guide 9 is composed of a pair of path members 9a, 9b disposed on either side of the transport path C1. The path member 9a of the guide 9 guides the paper P that has passed through the guide 8 to the transport roller pair 3c on the transport path C2.

[0028] The cutter mechanism 4 is configured to cut the paper P (roll paper P unwound from the roll body R) between the guide 7 and the pair of intermediate rollers 3b (a specified position Cx) on the conveying path C1, and includes a cutter 4a, a cutter unit 4b to which the cutter 4a is attached, and a holder 4c that holds the cutter unit 4b, and can be moved back and forth in a scanning direction (a direction perpendicular to the conveying direction A at the specified position Cx) by a scanning mechanism (not shown).

[0029] The conveying path C1 includes a straight portion Cs between the lower feed roller 3a and the pair of intermediate rollers 3b. A predetermined position Cx where the cutter mechanism 4 is disposed is provided in the straight portion Cs.

[0030] The cutter 4a is composed of a pair of rotary blades 4a1, 4a2 arranged to sandwich the conveying path C1. The pair of rotary blades 4a1, 4a2 are perpendicular to the conveying path C1 and have overlapping portions. Specifically, of the pair of rotary blades 4a1, 4a2, the rotary blade 4a1 is arranged downstream in the conveying direction A, and the rotary blade 4a2 is arranged upstream in the conveying direction A, and the pair of rotary blades 4a1, 4a2 have overlapping portions when viewed from the conveying direction A.

[0031] The cutter unit 4b rotatably supports a pair of rotary blades 4a1 and 4a2. The holder 4c is a case-like member that holds the cutter unit 4b from the outside.

[0032] When a cutting motor (not shown) included in the scanning mechanism is driven under the control of the control unit 10, the cutter mechanism 4 moves from a standby position D outside the conveying path C1 into the conveying path C1. At this time, the rotary blades 4a1 and 4a2 are rotated by the driving of the cutting motor. The roll paper P unwound from the roll body R is cut in the width direction of the paper P by the cutter 4a at a predetermined position Cx.

[0033] The head 5 is disposed between the pair of conveying rollers 3c and the pair of paper discharge rollers 3d on the conveying paths C1 and C2. The head 5 corresponds to the "image forming unit" of the present invention, and includes a plurality of nozzles (not shown) formed on the bottom surface and a driver IC 5a (see FIG. 3). When ejection data based on image data is supplied from the control unit 10 to the driver IC 5a, ink is ejected from the nozzles, and an image is formed on the paper P when the paper P conveyed by the conveying mechanism 3 passes a position facing the bottom surface of the head 5. In this embodiment, the head 5 ejects ink of four colors: magenta (M), cyan (C), yellow (Y), and black (BK). The head 5 may be either a line type that ejects ink from nozzles while being fixed in position, or a serial type that ejects ink from nozzles while moving in the scanning direction.

[0034] The paper P on which the image has been formed by the head 5 is received in a paper discharge tray 6 that is in an open state relative to the housing 100a.

[0035] The ink storage section 31 is connected to the head 5 by a tube (not shown) and supplies ink to the head 5. In this embodiment, the ink storage section 31 stores ink of four colors: magenta (M), cyan (C), yellow (Y), and black (BK). As described later, the remaining ink amount of each color in the ink storage section 31 is repeatedly calculated by the control section 10 at time intervals, and the latest data is stored in the EEPROM 10d (see FIG. 3). The ink storage section 31 may be a cartridge type that can be replaced with a new ink storage section 31 that is full of ink, or a tank type that can be refilled with ink in a fixed container. In this embodiment, the ink storage section 31 may have one container for each color, or may have two or more containers for each color (for example, a main tank and a sub tank). In that case, the remaining ink amount of each color in the ink storage section 31 is the sum of the remaining ink amounts in the two or more containers.

[0036] An empty sensor 32 is disposed for each ink near the ink storage section 31. Each empty sensor 32 is an optical sensor including a light emitting element and a light receiving element, and detects when the remaining amount of ink in the ink storage section 31 is a predetermined amount (near empty) or less.

[0037] The lower paper feed tray 1 is equipped with a roll paper sensor 18 and a cut paper sensor 19a. The roll paper sensor 18 is composed of a movable actuator and an optical sensor (a pair of a light receiving element and a light emitting element). The movable actuator is located below the groove 11z so as to interfere with the roll paper P that is unwound from the roll R and heading toward the guide 7. As shown in FIG. 1, when the movable actuator interferes with the roll paper P that is unwound from the roll R and heading toward the guide 7, the movable actuator is displaced and the roll paper sensor 18 outputs an ON signal to the control unit 10, and when the movable actuator does not interfere with the roll paper P that is unwound from the roll R and heading toward the guide 7, as shown in FIG. 2, the roll paper sensor 18 outputs an OFF signal to the control unit 10. Therefore, the roll paper sensor 18 outputs information to the control unit 10 as to whether or not the roll paper R is stored in the lower paper feed tray 1.

[0038] The cut paper sensor 19a is an optical sensor (a pair of a light receiving element and a light emitting element) that emits light toward the cut paper storage section 12 and receives the reflected light, thereby outputting an ON signal to the control section 10 when there is cut paper in the cut paper storage section 12 and an OFF signal when there is not. Therefore, the roll paper sensor 18 and the cut paper sensor 19a work together to output information to the control section 10 as to whether a recording medium is stored in the lower paper feed tray 1 and information about the type of recording medium stored. In addition, a cut paper sensor 19b similar to the cut paper sensor 19a is attached to the upper paper feed tray 2. The cut paper sensor 19b outputs an ON signal to the control section 10 when there is cut paper in the cut paper storage section 22 and outputs an OFF signal to the control section 10 when there is not cut paper. Therefore, by working together, the roll paper sensor 18 and the cut paper sensors 19a, 19b output to the control unit 10 information regarding whether or not recording media is contained in each of the lower paper feed tray 1 and the upper paper feed tray 2, and the type of recording media contained therein.

[0039] <Configuration of control unit 30> Next, a description will be given of the control unit 10 that controls the operation of the printer 100. As shown in Fig. 3, the control unit 10 includes a CPU (Central Processing Unit) 10a, a ROM (Read Only Memory) 10b, a RAM (Random Access Memory) 10c, an EEPROM (Electrically Erasable Programmable Read Only Memory) 10d, and an ASIC (Application Specific Integrated Circuit) 10e.

[0040] The CPU 10a performs various calculations according to the programs. The ROM 10b stores programs for controlling the printer 100, various settings, initial values, etc. The RAM 10c is used as a work area from which the various programs are read out, or as a storage area for temporarily storing data. The EEPROM 10d is a rewritable non-volatile memory. The ASIC 10e performs specific calculations. These work together to allow the control unit 10 to perform calculations and control the operation of each part of the printer 100.

[0041] The motors M, the driver IC 5a, the four empty sensors 32 (only one is shown in FIG. 3), the roll paper sensor 18, the cut paper sensor 19a, the cut paper sensor 19b, the tray sensor 34, the touch panel 35, and the communication interface 37 are electrically connected to the control unit 10. The motors M include the upper feed motor, the lower feed motor, the transport motor, and the cutting motor described above. The tray sensor 34 outputs a signal to the control unit 10 indicating whether the lower feed tray 1 and the upper feed tray 2 are attached to the predetermined position. Although a tray sensor is provided for each of the lower feed tray 1 and the upper feed tray 2, the following description is based on the assumption that one tray sensor can detect the attachment of both trays. The touch panel 35 is a user interface with input and display functions, and includes a color display including a display module such as liquid crystal or organic EL (Electro Luminescence), and a transparent position input device that covers the color display. The communication interface 37 may be a wired interface such as a Universal Serial Bus (USB) port, or may be a wireless interface, which allows the printer 100 to transmit and receive data to and from an external device (such as a personal computer (PC) 41 or a smartphone 42) via the communication interface 37.

[0042] The control unit 10 acquires image data from the communication interface 37 or a USB port (not shown) provided on the printer 100. Furthermore, the control unit 10 creates ejection data from the image data that indicates the amount of ink ejected from each nozzle for each ejection cycle. Then, by controlling the motors M and the driver IC 5a based on the ejection data, the desired paper is transported from one of the three storage units (the roll paper storage unit 11 and the cut paper storage units 12, 22) and an image is formed on the paper P by ejecting ink from the head 5.

[0043] The EEPROM 10d stores the remaining ink amount of each color in the ink storage section 31. The control section 10 repeatedly calculates the amount of ink ejected from the head 5 (amount of ink used) based on the image data or ejection data at time intervals (for example, at predetermined time intervals, each time printing of one sheet is completed, or each time a job is completed). The amount of ink ejected from the head 5 includes ink discharged from the head 5 when performing maintenance work on the head 5 such as flushing or purging. The remaining amount is updated by subtracting the amount of ink used from the remaining amount stored in the EEPROM 10d, and the updated latest remaining amount is stored in the EEPROM 10d. The control section 10 initializes the stored remaining amount to return it to the maximum value when replacing the cartridge or refilling the tank with ink. In this embodiment, the EEPROM 10d functions as a remaining amount signal output section.

[0044] The EEPROM 10d also stores the ink consumption per sheet of the predetermined paper, as defined by standards such as ISO (International Organization for Standardization), and the length (length along the transport direction) of the predetermined paper, such as A4, as defined by the standard. The control unit 10 multiplies the remaining ink amount stored in the EEPROM 10d by a first coefficient to derive, for each ink, the length of the paper P on which an image can be formed before the ink in the ink storage unit 31 runs out (length derivation process). In this embodiment, the first coefficient is calculated as (length of the predetermined paper) / (ink consumption per sheet of the predetermined paper, as defined by the standard). As a modified example, the EEPROM 10d may store the first coefficient instead of the ink consumption per sheet of the predetermined paper and the length of the predetermined paper. As the first coefficient, a value set by the user through a user operation on the touch panel 35, the reciprocal of the ink consumption per unit length calculated from the history of image formation in the printer 100, or the like may be used.

[0045] In addition, the control unit 10 multiplies the remaining ink amount stored in the EEPROM 10d by the second coefficient to derive the number of sheets of cut paper Pc on which images can be formed before the ink in the ink storage unit 31 runs out for each ink (number deriving process). In this embodiment, the second coefficient is calculated as (length of the specified paper) / [(ink consumption per sheet of specified paper defined by the standard)·(length of the cut paper Pc)]. In this embodiment, the cut paper Pc used may be a type of specified paper defined by a standard such as ISO. As a modified example, the second coefficient may be stored in the EEPROM 10d. As the second coefficient, a value set by the user through a user operation on the touch panel 35, the reciprocal of the ink consumption per sheet of cut paper calculated from the history of image formation in the printer 100, or the like may be used.

[0046] When a predetermined condition described below is satisfied, the control unit 10 causes the touch panel 35 (or the display of the PC 41 or smartphone 42) to display the remaining ink amount of each color in a display form like a bar graph within a figure that represents the ink storage unit 31. Furthermore, when a predetermined condition described below is satisfied, the control unit 10 causes the touch panel 35 (or the display of the PC 41 or smartphone 42) to display the length of the paper P on which an image can be formed, derived in the length derivation process, for each ink (length display process). In the length display process, the control unit 10 can cause the display unit to display the length of the paper P on which an image can be formed for each ink, based on the unit of length (in this embodiment, millimeters (mm) are used as the unit).

[0047] FIG. 4(a) is an example of a screen displayed on the touch panel 35 by the length display process. In this example, it is displayed that the length of paper P on which an image can be formed, calculated based on ISO standards, is 2500 mm for magenta (M), 2200 mm for cyan (C), 3100 mm for yellow (Y), and 5900 mm for black (BK). Also, in FIG. 4(a), above the length of paper P on which an image can be formed, the remaining ink amount of each color is displayed in the form of a bar graph (remaining amount bar) within a figure that represents the ink storage section 31. In this example, the ink of each color is stored separately in two containers (main tank and sub tank).

[0048] Furthermore, when certain conditions described below are satisfied, the control unit 10 causes the touch panel 35 (or the display of the PC 41 or smartphone 42) to display the number of cut sheets Pc on which images can be formed, which was derived in the number derivation process, for each ink (number display process).

[0049] Fig. 4(b) is an example of a screen displayed on the touch panel 35 by the sheet number display process. In this example, it is displayed that the number of sheets of paper P on which an image can be formed, calculated based on the ISO standard, is 300 sheets for magenta (M), 400 sheets for cyan (C), 300 sheets for yellow (Y), and 300 sheets for black (BK). Also, in Fig. 4(b), above the number of sheets of paper P on which an image can be formed, the remaining ink amount of each color is displayed in the form of a bar graph within a figure that resembles the ink reservoir 31.

[0050] Furthermore, the EEPROM 10d stores usage history information of the roll body R and the cut paper Pc in the printer 100. The usage history information includes, for example, information on whether the roll paper or the cut paper Pc was used to form an image in each job within a predetermined period (e.g., the most recent month) or in each job for a predetermined number of jobs (e.g., the most recent job or the most recent 100 jobs), and information on the usage rate of the roll paper and the cut paper Pc in a predetermined period. The EEPROM 10d also stores used tray / medium information on whether the image is formed on the roll paper and the cut paper Pc in the lower paper feed tray 1 or the cut paper Pc in the upper paper feed tray 2. The used tray / medium information can be rewritten by the user operating the touch panel 35. In this way, the EEPROM 10d also functions as a history storage unit, a used medium storage unit, and a used tray storage unit.

[0051] <Operation procedure for displaying remaining battery level> Next, the operation procedure of the length display process and the number of sheets display process in the printer 100 according to this embodiment will be described with further reference to Fig. 5. The operation described below is mainly performed by the control unit 10.

[0052] First, in step S1, it is determined whether either the lower paper feed tray 1 or the upper paper feed tray 2 has changed from a non-installed state to an installed state based on an output signal from the tray sensor 34. If it has changed to the installed state (S1: YES), the process proceeds to step S2. In step S2, a screen that asks the user whether or not they wish to display the remaining amount display screen is displayed on the touch panel 35. Then, if a request to display the remaining amount display screen (request to display remaining amount) is input from the touch panel 35 (S2: YES), the process proceeds to step S3. If a request to not display the remaining amount display screen is input from the touch panel 35 (S2: NO), the process returns to step S1.

[0053] In step S3, it is determined whether or not a roll R is stored in the lower paper feed tray 1 based on the output signal of the roll paper sensor 18. If it is determined that the roll R is stored in the lower paper feed tray 1 (S3: YES), the process proceeds to step S4, and if it is determined that the roll R is not stored in the lower paper feed tray 1 (S3: NO), the process proceeds to step S9.

[0054] In step S4, it is determined based on the output signal of cut paper sensor 19b whether cut paper Pc is stored in upper paper feed tray 2. If it is determined that cut paper Pc is not stored (S4: NO), the process proceeds to step S5, and if it is determined that cut paper Pc is stored (S4: YES), the process proceeds to step S6. If it proceeds to step S5, it means that printer 100 only stores roll paper, and if it proceeds to step S6, it means that printer 100 stores both roll paper and cut paper.

[0055] In step S5, the above-mentioned length display process is executed. As a result, as shown in Fig. 4(a), the length of the paper P on which an image can be formed, which is derived in the length derivation process, is displayed for each ink on the touch panel 35 (or the display of the PC 41 or smartphone 42). Note that the length derivation process may be performed in step S5, or may be performed before that (preferably after the end of the most recent print job).

[0056] In step S6, a display determination process is executed to determine whether the length display process or the number display process should be executed with priority. Here, "priority" may mean executing only one of the display processes that should be executed with priority, executing one display process before executing the other display process, making the display area based on one display process larger than the display area based on the other display process, or making the display time based on one display process longer than the display time based on the other display process. In this embodiment, only one of the display processes that should be executed with priority is executed.

[0057] In this embodiment, the display determination process has three modes that can be selectively adopted by the user by operating the touch panel 35.

[0058] The first is based on whether the most recent image formation was performed using roll paper or cut paper Pc. That is, if it is determined from the usage history information stored in EEPROM 10d that the most recent image formation in printer 100 was performed using roll paper, it is determined that the length display process is to be executed with priority, and if it is determined that the most recent image formation was performed using cut paper Pc, it is determined that the number of sheets display process is to be executed with priority. Note that whether the most recent image formation was performed using roll paper or cut paper Pc may be determined based on information obtained from elsewhere, such as image data related to the most recent image formation, without using the usage history information stored in EEPROM 10d.

[0059] The second is based on whether roll paper or cut paper Pc has been used more frequently in image formation during a specified period of time or a specified number of jobs in the past. In other words, if it is determined from the usage history information stored in EEPROM 10d that roll paper has been used more frequently than cut paper, it is determined that the length display process should be executed with priority, and if it is determined that cut paper has been used more frequently than roll paper, it is determined that the number of sheets display process should be executed with priority.

[0060] The third is based on information set by the user. As described above, the EEPROM 10d stores the tray / medium information to be used, which indicates whether the image is to be formed on the roll paper and cut paper Pc in the lower paper feed tray 1 or the cut paper Pc in the upper paper feed tray 2, in a manner that can be rewritten by the user. That is, if it is determined from the tray / medium information to be used stored in the EEPROM 10d that the image is to be formed on the roll paper, it is determined that the length display process is to be executed with priority, and if it is determined that the image is to be formed on the cut paper, it is determined that the number of sheets display process is to be executed with priority.

[0061] Next, in step S7, it is determined whether the process determined in the display determination process in step S6 is the length display process or the number display process. If it is determined that the process is the length display process, the process proceeds to step S5, where the length display process is executed, and if it is determined that the process is the number display process, the process proceeds to step S8. Note that the specific display contents of steps S5 and S8, which are moved from step S7, should be changed depending on the meaning of "priority" described above, but in this embodiment, since only one of the display processes that should be prioritized is executed, there is no difference in the specific display contents of steps S5 and S8 between the case where the process is moved from step S7 and the case where it is not.

[0062] In step S8, the number display process described above is executed. As a result, as shown in Fig. 4(b), the number of sheets P on which images can be formed, which is derived in the number derivation process, is displayed for each ink on the touch panel 35 (or the display of the PC 41 or smartphone 42). Note that the number derivation process may be performed in step S8, or may be performed before that (preferably after the end of the most recent print job).

[0063] In step S9, it is determined whether cut paper Pc is stored in the lower feed tray 1 or the upper feed tray 2 based on the output signals of the cut paper sensors 19a, 19b. If it is determined that cut paper Pc is not stored (S9: NO), the process proceeds to step S6. If it is determined that cut paper Pc is stored (S9: YES), the process proceeds to step S8. If it proceeds to step S6, it means that neither roll paper nor cut paper is stored in the printer 100, and if it proceeds to step S8, it means that only cut paper is stored in the printer 100. If it is determined that neither roll paper nor cut paper is stored (S9: NO), it is possible to display a message on the touch panel 35 to inform the user that no paper is stored without proceeding to step S6. Also, even if it proceeds to step S6, it is possible to display the remaining ink amount and a message on the touch panel 35 to inform the user that no paper is stored in the length display process (S5) or the number of sheets display process (S8) executed thereafter.

[0064] In step S1, if neither lower paper feed tray 1 nor upper paper feed tray 2 has changed from a non-attached state to an attached state (S1: NO), proceed to step S10. In step S10, it is determined whether a print job has been completed (or whether a print job is to be started) in printer 100. If it is determined that a print job has not been completed (S10: NO), return to step S1. If it is determined that a print job has been completed (S10: YES), proceed to step S11.

[0065] In step S11, it is determined whether the remaining ink amount in at least one of the ink storage sections 31 is a predetermined amount (near empty) or less based on the detection signals from the four empty sensors 32 arranged for each ink. If none of the remaining ink amounts is near empty or less (S11: NO), the process returns to step S1. If at least one of the remaining ink amounts is near empty or less (S11: YES), the process proceeds to step S12.

[0066] In step S12, it is determined whether or not roll paper was used in the most recent image formation in printer 100, based on the usage history information stored in EEPROM 10d. If it is determined that roll paper was used (S12: YES), the process proceeds to step S5. If it is determined that cut paper was used (S12: NO), the process proceeds to step S8. In other words, in this embodiment, if at least one ink level is near empty or below, the ink level display screen corresponding to the type of paper used in the most recent image formation is displayed, even if the user does not wish to display the ink level display screen.

[0067] In steps S5 and S8 following step S12, the remaining ink amount may be displayed, and at the same time, a message may be displayed on the touch panel 35 informing the user that the remaining amount of the relevant ink is nearly empty.

[0068] Also, in step S12, it is determined whether or not the most recent image formation was performed using roll paper, but instead, the processes in steps S3, S4, S6, S7, and S9 may be performed.

[0069] After the length display process (S5) or the number of sheets display process (S8) is performed, the process proceeds to step S13. In step S13, it is determined whether a condition for erasing the screen (FIGS. 4(a) and 4(b)) displayed on the touch panel 35 by the length display process or the number of sheets display process from the touch panel 35 is met. This condition may be, for example, that the user touches a display end button (not shown) on the touch panel 35, that a predetermined time has elapsed since the start of display, that the printer 100 has received a new print job, that the cartridge-type ink storage unit 31 has been replaced with a new ink storage unit 31, or the like.

[0070] In the embodiment described above, in printer 100 capable of printing on roll paper, a length derivation process is executed to derive the length of paper on which an image can be formed before the ink in ink storage section 31 runs out, based on the remaining amount of ink of each color in ink storage section 31, and a length display process is executed to display on touch panel 35 or the like the length of paper on which an image can be formed, derived by the length derivation process, so that a user who intends to print using roll paper can easily understand how much of an image can be formed before the ink in ink storage section 31 runs out.

[0071] Furthermore, in this embodiment, a length display process is executed when the roll paper sensor 18 outputs information indicating that the roll body R is stored in the lower paper feed tray 1 (S3 (YES) → S5), so that the user can easily grasp how much image formation is possible before the ink in the ink storage section 31 runs out before printing on the roll paper.

[0072] Furthermore, in this embodiment, when the roll paper sensor 18 and the cut paper sensor 19b output information that the roll R is stored in the lower paper feed tray 1 and the cut paper Pc is not stored in the upper paper feed tray 2 (S4: NO), a length display process is executed, and when the roll paper sensor 18, the cut paper sensor 19a, and the cut paper sensor 19b output information that the roll R is not stored in the lower paper feed tray 1 and the cut paper Pc is stored in the lower paper feed tray 1 or the upper paper feed tray 2 (S9: YES), a number display process is executed. Therefore, before printing on the cut paper, the user can be informed of how many sheets of cut paper can be imaged, and before printing on the roll paper, the user can be informed of how long of the roll paper can be imaged.

[0073] In addition, the roll paper sensor 18, the cut paper sensor 19a, and the cut paper sensor 19b can detect whether paper is stored in the lower paper feed tray 1 and the upper paper feed tray 2, so that a display according to the type of paper stored can be quickly made.

[0074] In this embodiment, when the roll R is stored in the lower paper feed tray 1 and the cut paper Pc is stored in the upper paper feed tray 2, the display determination process (S6) is executed, so that it is possible to appropriately determine whether the length display process or the number of sheets display process should be executed with priority. As a specific method of the display determination process, one of the above-mentioned three modes selected by the user can be adopted.

[0075] <Another embodiment> Next, a printer according to another embodiment different from the embodiment described above will be described. In the printer 100 according to the embodiment described above, when the roll R is stored in the lower paper feed tray 1 and the cut paper Pc is stored in the upper paper feed tray 2 (S4: YES), a display determination process (S6) is performed to determine whether the length display process or the number of sheets display process should be executed with priority, but in this embodiment, the display determination process is not performed and the length display process and the number of sheets display process are executed simultaneously. The printer according to this embodiment is otherwise the same as the printer 100 described above.

[0076] FIG. 6 is an example of a screen displayed on the touch panel 35 when the length display process and the number display process are executed simultaneously. In this example, the number of sheets of paper P on which an image can be formed in ISO conversion is 230 sheets for magenta (M), 200 sheets for cyan (C), 300 sheets for yellow (Y), and 500 sheets for black (BK), and the length of the paper P on which an image can be formed in ISO conversion is 2500 mm for magenta (M), 2200 mm for cyan (C), 3100 mm for yellow (Y), and 5900 mm for black (BK), are displayed in parallel above and below. In addition, in FIG. 6), the remaining ink amount of each color is displayed in a bar graph-like display form in a figure that represents the ink storage section 31 above the number of sheets of paper P on which an image can be formed. In this example, the ink of each color is stored separately in two containers (main tank and sub tank).

[0077] According to this embodiment, when a roll R is stored in the lower paper feed tray 1 and cut paper Pc is stored in the upper paper feed tray 2, the length display process and the number of sheets display process are executed simultaneously, so that the user can be informed simultaneously of the number and length of sheets of paper P on which images can be formed.

[0078] <Further Alternative Embodiment> Next, a printer according to yet another embodiment will be described. In the printer 100 according to the embodiment described above, in the length display process, the length of the paper P on which an image can be formed is displayed in units of millimeters (mm) as shown in FIG. 4(a), but in this embodiment, the length of the paper P on which an image can be formed is displayed in units of centimeters (cm) as shown in FIG. 7(a). In the example shown in FIG. 7(a), the length of the paper P on which an image can be formed according to ISO conversion is displayed as 250 cm for magenta (M), 220 cm for cyan (C), 310 cm for yellow (Y), and 590 cm for black (BK). The printer according to this embodiment is otherwise the same as the printer 100 described above.

[0079] In addition, in a printer according to yet another embodiment, in the length display process, the length of the paper P on which an image can be formed is displayed in meters (m) as shown in Fig. 7(b). In the example shown in Fig. 7(b), the length of the paper P on which an image can be formed, as converted into ISO format, is displayed as 2.5 m for magenta (M), 2.2 m for cyan (C), 3.1 m for yellow (Y), and 5.9 m for black (BK). The printer according to this embodiment is otherwise the same as the printer 100 described above.

[0080] In addition, in a printer according to yet another embodiment, in the length display process, the length of paper P on which an image can be formed is displayed in units of inches as shown in Fig. 8(a). In the example shown in Fig. 8(a), the length of paper P on which an image can be formed, as calculated based on the ISO standard, is displayed as 900 inches for magenta (M), 880 inches for cyan (C), 930 inches for yellow (Y), and 940 inches for black (BK). The printer according to this embodiment is otherwise the same as the printer 100 described above.

[0081] In addition, in a printer according to yet another embodiment, in the length display process, the length of the paper P on which an image can be formed is displayed in feet as shown in Fig. 8(b). In the example shown in Fig. 8(b), the length of the paper P on which an image can be formed, as calculated based on the ISO standard, is displayed as 140 feet for magenta (M), 180 feet for cyan (C), 200 feet for yellow (Y), and 260 feet for black (BK). The printer according to this embodiment is otherwise the same as the printer 100 described above.

[0082] As a variant, in the length display process, the user may be able to select, by operating the touch panel 35, in which unit to display the length of the paper P on which an image can be formed: m, cm, mm, feet, or inches.

[0083] <Modification> Although a preferred embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various design modifications are possible within the scope of the claims, as described below.

[0084] The printer 100 according to the embodiment described above has a roll paper sensor 18 and cut paper sensors 19a, 19b that function as a medium information output unit, but the image forming apparatus according to the present invention may not have a medium information output unit. In the printer 100 according to the embodiment described above, the lower paper feed tray 1 can accommodate both a roll body and cut paper, but in the image forming apparatus according to the present invention, the lower paper feed tray may be capable of accommodating only a roll body, or may be capable of exclusively accommodating either a roll body or cut paper (when a roll body is accommodated, cut paper cannot be accommodated, and when cut paper is accommodated, a roll body cannot be accommodated). In addition, the printer 100 according to the embodiment described above has two paper feed trays 1 and 2, but the image forming apparatus according to the present invention may have only one paper feed tray that can accommodate only a roll body, or may have two or more paper feed trays that can accommodate a roll body. In these cases, the length display process may be performed at all times, or may be performed only when a predetermined condition (for example, a predetermined operation by the user) is satisfied. Also, instead of the paper feed tray, a feed unit (e.g., a multipurpose (MP) tray) that does not store recording media but can feed recording media to the transport path may be used. The paper feed tray may be fixed to the main body rather than being detachable.

[0085] The image forming apparatus according to the present invention may have one or more feed trays capable of accommodating cut sheets, and may not perform the number display process when cut sheets are accommodated therein. Specifically, the image forming apparatus according to the present invention has one or more feed trays capable of accommodating a roll body (which may be capable of accommodating only a roll body, or which may be capable of accommodating a roll body and a stacked plurality of cut sheets together or exclusively), and further has one or more feed trays capable of accommodating cut sheets (which may be capable of accommodating only cut sheets, or which may be capable of accommodating a roll body and a stacked plurality of cut sheets together or exclusively), and further includes a medium information output unit that outputs information on whether or not a roll body is accommodated in the feed tray, and includes a control unit that executes the length display process regardless of whether or not cut sheets are accommodated in any feed tray when the medium information output unit outputs information that a roll body is accommodated in any feed tray. As an example, in the above-mentioned embodiment, when it is determined that the roll body R is accommodated in the lower feed tray 1 (S3: YES), the process of step S4 may be omitted and the length display process (S5) may be executed.

[0086] In addition, the image forming device of the present invention includes a paper feed tray that can accommodate a roll body and multiple stacked cut papers together or exclusively, and when the medium information output unit outputs information that the paper feed tray contains only a roll body, it executes a length display process, and when the medium information output unit outputs information that the paper feed tray contains only cut papers, it executes a number display process.

[0087] In this case, a storage means such as EEPROM 10d can be used as the medium information output unit instead of the roll paper sensor 18 and the cut paper sensor 19a. Based on a user operation on the touch panel 35, the control unit 10 can rewritably store information in the EEPROM 10d that indicates whether the lower paper feed tray 1 contains only a roll, only cut paper, or both a roll and cut paper.

[0088] In addition, the image forming device of the present invention has one paper feed tray that can accommodate both a roll body and multiple stacked cut papers together, and when the medium information output unit outputs information that both the roll body and cut papers are stored in the paper feed tray, it includes a unit that executes a display decision process that determines whether to give priority to the length display process or the number of sheets display process, and a unit that executes both the length display process and the number of sheets display process simultaneously.

[0089] The remaining amount signal output unit may be a sensor that detects the remaining amount of color material in real time, instead of a storage device such as an EEPROM. The long recording medium may be a long medium that is not wound, instead of rolled paper. The recording medium is not limited to paper, and may be, for example, cloth, a resin member, or the like.

[0090] In the present invention, the image forming unit may be a laser engine that uses toner as a color material other than an inkjet head that ejects ink. The present invention is not limited to printers, and can also be applied to facsimiles, copy machines, multifunction machines, etc. [Explanation of symbols]

[0091] 1 Lower paper feed tray (first feed section) 2 Upper paper feed tray (second feed section) 3. Conveyor mechanism 3a Lower feed roller 3b Intermediate roller 3c Transport roller 3e Upper feed roller 4a Cutter 5 Head (image forming section) 10 Control section 11 Paper roll compartment 12, 22 Cut paper storage compartment 100 Printers (image forming devices) 100a housing

Claims

1. a first supply unit that supplies a long recording medium; an image forming unit that forms an image on a recording medium supplied from the first supply unit by using a coloring material supplied from a coloring material storage unit capable of accommodating the coloring material; a remaining amount signal output unit that outputs a signal indicating a remaining amount of the color material stored in the color material storage unit; A control unit, The control unit is a length deriving process for deriving a length of the recording medium on which an image can be formed until the color material in the color material storage unit runs out, based on the signal output from the remaining amount signal output unit; and a length display process for displaying on a display unit the length of the recording medium on which an image can be formed, the length derivation process being carried out.

2. The image forming apparatus comprises: The recording medium supplying unit further includes a second supplying unit that supplies a plurality of short recording media each having a predetermined length that are stacked together, The image forming apparatus further includes a medium information output unit that outputs information on whether a recording medium is accommodated in the first supply unit, The control unit is 2. The image forming apparatus according to claim 1, wherein the length display process is executed when the medium information output section outputs information that a recording medium is accommodated in the first supply section.

3. A first supply unit that supplies a long recording medium; an image forming unit that forms an image on a recording medium supplied from the first supply unit by using a coloring material supplied from a coloring material storage unit capable of accommodating the coloring material; a remaining amount signal output unit that outputs a signal indicating a remaining amount of the color material stored in the color material storage unit; A control unit, The control unit is a length deriving process for deriving a length of the recording medium on which an image can be formed until the color material in the color material storage unit runs out, based on the signal output from the remaining amount signal output unit; a length display process for displaying the length of the recording medium on which an image can be formed, the length derivation process being determined on a display unit; The first supply unit can accommodate a long recording medium and a plurality of stacked short recording media having a predetermined length, either together or exclusively; The apparatus further includes a medium information output unit that outputs information on whether a long recording medium is accommodated in the first supply unit, An image forming apparatus characterized in that the control unit executes the length display process when the medium information output unit outputs information that a long recording medium is stored in the first supply unit.

4. A first supply unit that supplies a long recording medium; an image forming unit that forms an image on a recording medium supplied from the first supply unit by using a coloring material supplied from a coloring material storage unit capable of accommodating the coloring material; a remaining amount signal output unit that outputs a signal indicating a remaining amount of the color material stored in the color material storage unit; A control unit, The control unit is a length deriving process for deriving a length of the recording medium on which an image can be formed until the color material in the color material storage unit runs out, based on the signal output from the remaining amount signal output unit; a length display process for displaying the length of the recording medium on which an image can be formed, the length derivation process being determined on a display unit; The first supply unit can accommodate a long recording medium and a plurality of stacked short recording media having a predetermined length, either together or exclusively; The recording medium supply unit further includes a medium information output unit that outputs information about the type of the recording medium contained in the first supply unit, The control unit is a number deriving process for deriving the number of short recording media on which images can be formed until the color material in the color material storage unit runs out, based on the signal output from the remaining amount signal output unit; a number display process for displaying on the display unit the number of recording media on which images can be formed, the number being derived in the number derivation process; When the medium information output unit outputs information that the recording media contained in the first supply unit are all long recording media, the length display process is executed; An image forming apparatus characterized in that the number display process is executed when the medium information output unit outputs information that the recording media contained in the first supply unit are only short recording media.

5. 5. The image forming apparatus according to claim 4, wherein the medium information output section includes one or more sensors that detect the type of the recording medium accommodated in the first supply section.

6. 5. The image forming apparatus according to claim 4, wherein the medium information output section includes a medium-used storage section that stores the type of recording medium accommodated in the first supply section in a manner that allows a user to rewrite the type.

7. The control unit is An image forming device as described in any one of claims 4 to 6, characterized in that when the medium information output unit outputs information that both long and short recording media are stored in the first supply unit, a display determination process is executed to determine whether the length display process or the number of sheets display process should be executed with priority.

8. The control unit is An image forming apparatus as described in any one of claims 4 to 6, characterized in that when the medium information output unit outputs information that both long and short recording media are stored in the first supply unit, both the length display process and the number of sheets display process are executed simultaneously.

9. A first supply unit that supplies a long recording medium; an image forming unit that forms an image on a recording medium supplied from the first supply unit by using a coloring material supplied from a coloring material storage unit capable of accommodating the coloring material; a remaining amount signal output unit that outputs a signal indicating a remaining amount of the color material stored in the color material storage unit; a second supply unit that supplies a plurality of short recording media each having a predetermined length that are stacked; a medium information output unit that outputs information on whether a recording medium is accommodated in each of the first supply unit and the second supply unit; A control unit, The control unit is a length deriving process for deriving a length of the recording medium on which an image can be formed until the color material in the color material storage unit runs out, based on the signal output from the remaining amount signal output unit; a length display process for displaying on a display unit the length of the recording medium on which an image can be formed, the length derivation process being determined; a number deriving process for deriving the number of short recording media on which images can be formed until the color material in the color material storage unit runs out, based on the signal output from the remaining amount signal output unit; a number display process for displaying the number of recording media on which images can be formed, which is derived in the number derivation process, on the display unit; executing the length display process when the medium information output unit outputs information that a recording medium is accommodated in the first supply unit and a recording medium is not accommodated in the second supply unit; An image forming apparatus characterized in that the number display process is executed when the medium information output unit outputs information that a recording medium is not contained in the first supply unit and a recording medium is contained in the second supply unit.

10. 10. The image forming apparatus according to claim 9, wherein the medium information output unit includes one or more sensors that detect whether or not a recording medium is stored in the first supply unit and the second supply unit.

11. The control unit is An image forming apparatus as described in any one of claims 9 or 10, characterized in that when the medium information output unit outputs information that recording media are stored in both the first supply unit and the second supply unit, a display determination process is executed to determine whether the length display process or the number of sheets display process should be executed with priority.

12. The control unit is An image forming apparatus as described in claim 9 or 10, characterized in that when the medium information output unit outputs information that recording media are stored in both the first supply unit and the second supply unit, both the length display process and the number of sheets display process are executed simultaneously.

13. The image forming apparatus according to claim 7 or 11, characterized in that, when the control unit determines in the display decision process that the most recent image formation was performed using a long recording medium, it decides to prioritize execution of the length display process, and when it determines that the most recent image formation was performed using a short recording medium, it decides to prioritize execution of the number of sheets display process.

14. the image forming apparatus further includes a history storage unit that stores usage history information of the long recording medium and the short recording medium in the image forming apparatus; The image forming apparatus according to claim 7 or 11, characterized in that, in the display decision process, when the control unit determines, based on the usage history information stored in the history memory unit, that long recording media are used more frequently than short recording media, it decides to prioritize execution of the length display process, and when it determines that short recording media are used more frequently than long recording media, it decides to prioritize execution of the number display process.

15. The image forming apparatus further includes a medium-usage storage unit that stores medium-usage information regarding whether an image is to be formed on a long recording medium or a short recording medium in a manner that allows a user to rewrite the medium-usage information, The image forming apparatus according to claim 8, characterized in that, in the display determination process, when the control unit determines, based on the medium information stored in the medium storage unit, that an image will be formed on a long recording medium, it decides to prioritize execution of the length display process, and when it determines that an image will be formed on a short recording medium, it decides to prioritize execution of the number display process.

16. the image forming apparatus further includes a used tray storage unit configured to store, in a user-rewritable manner, used tray information as to which of the first supply unit and the second supply unit a recording medium is to be used for forming an image on, The image forming apparatus according to claim 11, characterized in that, in the display determination process, when the control unit determines, based on the used tray information stored in the used tray memory unit, that an image will be formed on a long recording medium supplied from the first supply unit, it decides to prioritize execution of the length display process, and when it determines, based on the used tray information stored in the used tray memory unit, that an image will be formed on a short recording medium supplied from the second supply unit, it decides to prioritize execution of the number display process.

17. The image forming apparatus according to any one of claims 1 to 16, characterized in that, in the length display process, the control unit causes the display unit to display the length of the recording medium on which an image can be formed in units of m, cm, mm, feet, or inches.

18. 18. The image forming apparatus according to claim 1, wherein the color material is ink, and the image forming section is an inkjet head.

19. 19. The image forming apparatus according to claim 1, wherein the long recording medium is a roll of paper.

20. An image forming device as described in Claim 1 or 3, characterized in that the control unit causes the display unit to display the remaining amount of colorant above the length of the image-formable recording medium displayed on the display unit during the length display process.

21. An image forming device as described in Claim 4 or 9, characterized in that the control unit causes the display unit to display the remaining amount of colorant above the number of recording media on which images can be formed displayed on the display unit during the number display process.

Images