Image forming apparatus

Abstract

To appropriate consider a factor affecting whether a medium falls from a device regardless of a length of the medium.SOLUTION: Discharge trays 7 and 8 selectively take storage states and drawn states. Discharge lengths that are lengths between a discharge paper roller pair 24 and downstream ends of the trays are different depending on the storage states and the drawn states. A first discharge mode is a mode of discharging paper P to the discharge tray 7 or 8 while allowing the discharge paper roller pair 24 to maintain the paper P. A second discharge mode is a mode of discharging the paper P to the discharge tray 7 or 8 without allowing the discharge paper roller pair 24 to maintain the paper P. A control part 9 selects the first discharge mode or the second discharge mode according to a situation indicating the discharge length.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus having a discharge section through which a medium on which an image has been formed is discharged. [Background Art]

[0002] The image forming apparatus disclosed in Patent Document 1 includes means for discharging the discharged medium while holding the medium by keeping the discharged medium in a nipped state, in order to prevent the medium on which an image has been formed and discharged from falling from the apparatus. In the apparatus of Patent Document 1, when the length of a sheet, which is the medium, exceeds a threshold value, the discharged sheet is maintained in a state of being nipped by discharge rollers. [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2016-74513 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] In Patent Document 1, as described above, whether to maintain the discharged medium in a nipped state is determined according to the length of the medium. However, whether the medium falls from the apparatus is not affected only by the length of the medium.

[0005] An object of the present invention is to provide an image forming apparatus that appropriately considers factors affecting whether a medium falls from the apparatus, not limited to the length of the medium. [Means for Solving the Problem]

[0006] The image forming apparatus of the present invention comprises a media storage section capable of accommodating a medium, an image forming section that forms an image on the medium accommodated in the media storage section, a discharge section from which the medium on which the image has been formed by the image forming section is discharged, a media transport section that transports the medium accommodated in the media storage section to the image forming section and transports the medium on which the image has been formed by the image forming section to the discharge section along a predetermined transport direction, a media maintenance section capable of maintaining the medium discharged to the discharge section in a state hanging down from the discharge section, and a control unit, wherein the discharge section controls the media in relation to the predetermined transport direction. The discharge length, which is the length from the body holding unit to the downstream end of the discharge unit, is changeable, and the system further includes an acquisition unit that acquires a status indicating the discharge length. The control unit selects one of two modes based at least on the status indicating the discharge length acquired by the acquisition unit: a first discharge mode in which the medium is discharged to the discharge unit while the medium is held in the medium holding unit, and a second discharge mode in which the medium is discharged to the discharge unit without the medium being held in the medium holding unit. The control unit then controls the operation of the image forming unit, the medium transport unit, and the medium holding unit based on the selected first discharge mode or second discharge mode. [Effects of the Invention]

[0007] The likelihood of the medium falling from the device is influenced by the discharge length, which is the distance from the medium holding section to the downstream end of the discharge section. This is because the range in which the discharged medium can be supported is from the medium holding section to the downstream end of the discharge section. Therefore, if the discharge length is small, the range in which the discharged medium can be supported is small. For this reason, if the medium is not held in the medium holding section, the likelihood of the medium falling increases. According to the image forming apparatus of the present invention, the decision of whether or not to hold the medium in the medium holding section (first discharge mode or second discharge mode) is made based at least on the situation indicating the discharge length, making it easier to appropriately avoid the medium falling. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic side view showing the internal structure of a printer according to one embodiment of the present invention. [Figure 2]Figure 1 is a magnified view of the area around the paper output tray. [Figure 3] This block diagram shows the electrical configuration of the printer shown in Figure 1. [Figure 4] Figure 1 is a flowchart showing the process by which the control unit selects one of the first discharge mode and the second discharge mode. [Modes for carrying out the invention]

[0009] A printer 100 (corresponding to the "image forming apparatus" of the present invention) according to a preferred embodiment of the present invention will be described below with reference to Figures 1 to 4. The vertical, horizontal, and front-to-back directions shown in Figure 1 refer to the vertical, front-to-back, and left-to-right directions of the printer 100.

[0010] As shown in Figure 1, the printer 100 mainly comprises a housing 100a, feed trays 1x and 1y, transport mechanism 2, cutter 3, carriage 4, head 5, moving mechanism 6, output trays 7 and 8, and control unit 9.

[0011] The feeding tray 1x (corresponding to the "media storage section" of the present invention) is a component for storing paper P used for image formation. In this embodiment, the paper P includes a long roll of paper Rp and cut paper Kp that is shorter than the roll of paper Rp. The cut paper Kp is, for example, a standard-sized sheet of paper such as A4 or B5. The feeding tray 1x can accommodate both the roll of paper R and the cut paper Kp. The feeding tray 1x may be able to accommodate both the roll of paper R and the cut paper Kp simultaneously, or it may be able to selectively accommodate either the roll of paper R or the cut paper Kp.

[0012] The feeding tray 1x has a roll support section 11 that supports the roll body R and a mounting surface 12 on which the cut paper Kp is placed. The feeding tray 1x is located below the head 5 inside the housing 100a. The roll body R is formed by winding roll paper Rp in a roll shape around the outer circumference of a cylindrical core member Rc. Multiple cut paper Kp are placed on the mounting surface 12 in a stacked state. The feeding tray 1x can be inserted into and removed from the housing 100a in the front-rear direction through an opening 100p formed in the front wall of the housing 100a.

[0013] The feeding tray 1y (corresponding to the "media storage section" of the present invention) is a flat plate-shaped member that accommodates cut paper Kp used for image formation, and is installed separately from the feeding tray 1x. The feeding tray 1y is inclined so that the rear portion is located higher. On each of the feeding trays 1y, the cut paper Kp is placed on the surface facing diagonally upward.

[0014] The transport mechanism 2 (corresponding to the "media transport unit" of the present invention) is capable of selectively transporting paper P contained in the feed trays 1x and 1y to the head 5. Paper P is transported from the feed tray 1x to the head 5 via the main transport path ρ0 (the path along the thick solid line representing the roll paper Rp in Figure 1). The main transport path ρ0 extends from the feed tray 1x through the head 5 to the output tray 7. Hereinafter, the terms "upstream" and "downstream" refer to upstream and downstream, respectively, with respect to the transport direction D0 of paper P along the main transport path ρ0.

[0015] The transport mechanism 2 is configured to transport paper P along the main transport path ρ0 and includes a feed roller 21, an intermediate roller pair 22, a transport roller pair 23, and a paper discharge roller pair 24. These rollers and roller pairs are arranged along the main transport path ρ0 from upstream to downstream in the order of feed roller 21, intermediate roller pair 22, transport roller pair 23, and paper discharge roller pair 24.

[0016] The feeding roller 21 feeds the roll paper Rp unwound from the roll body R supported by the roll body support section 11, or the cut paper Kp placed on the mounting surface 12, from the feeding tray 1x.

[0017] The feed roller 21 rotates when driven by the feed motor 21a (see Figure 3). When the feed motor 21a is driven by the control unit 9, the feed roller 21 rotates, and a transport force is applied to the paper P in contact with the feed roller 21 in a direction from front to back. As a result, the paper P is fed out from the feed tray 1x. The rear wall 15, which is provided at the rear end of the feed tray 1x, is inclined so that its upper end is located behind its lower end. Therefore, the paper P fed out from the feed tray 1x moves diagonally upward.

[0018] The intermediate roller pair 22 consists of a drive roller that rotates by the drive of the intermediate motor 22a (see Figure 3) and a driven roller that moves along with the drive roller. When the intermediate motor 22a is driven by the control unit 9, the intermediate roller pair 22 rotates while gripping the paper P and transports the paper P. The intermediate roller pair 22 is located above the rear end of the feed tray 1x. The intermediate roller pair 22 transports the paper P upwards while gripping it as it is fed out of the feed tray 1x by the feed roller 21 and moves diagonally upward.

[0019] The transport roller pair 23 consists of a drive roller that rotates by the drive of the transport motor 23a (see Figure 3) and a driven roller that moves along with the drive roller. The paper discharge roller pair 24 (corresponding to the "media maintenance unit" of the present invention) consists of a drive roller that rotates by the drive of the paper discharge motor 24a (see Figure 3) and a driven roller that moves along with the drive roller. The transport roller pair 23 and the paper discharge roller pair 24 are arranged on either side of the head 5 in the front-rear direction, with the transport roller pair 23 positioned behind the head 5 (upstream in the transport direction D0) and the paper discharge roller pair 24 positioned in front of the head 5 (downstream in the transport direction D0).

[0020] When the conveying motor 23a and the paper discharge motor 24a are driven under the control of the control unit 9, the conveying roller pair 23 and the paper discharge roller pair 24 rotate while nipping the sheet P to convey the sheet P. The conveying roller pair 23 feeds the sheet P from the intermediate roller pair 22 to a position facing the lower surface of the head 5. At the position facing the lower surface of the head 5, an image is formed on the image forming surface, which is the upper surface of the sheet P, by an image forming operation of the head 5 described later. The paper discharge roller pair 24 receives the sheet P fed by the conveying roller pair 23 and further feeds the sheet P forward.

[0021] The conveying mechanism 2 has a guide member that guides the sheet P fed out by the feeding roller 21, the intermediate roller pair 22, the conveying roller pair 23, and the paper discharge roller pair 24. The guide member contacts and guides the sheet P such that the sheet P travels along the main conveying path ρ0. For example, a guide member 25 is disposed above the intermediate roller pair 22. The guide member 25 forwardly guides the sheet P conveyed upward by the intermediate roller pair 22.

[0022] Further, in front of the paper discharge roller pair 24, a guide member 26 that sorts the sheet P conveyed forward by the paper discharge roller pair 24 to the paper discharge trays 7 and 8 is disposed. The guide member 26 is supported by the housing 100a so as to be movable between a position indicated by a solid line in FIGS. 1 and 2 and a position indicated by a two-dot chain line. The solid-line position is a position that guides the sheet P from the paper discharge roller pair 24 to the paper discharge tray 7. The two-dot chain line position is a position that guides the sheet P from the paper discharge roller pair 24 to the paper discharge tray 8. The guide member 26 is operated by driving of a guide motor 26a (see FIG. 3).

[0023] When the guide motor 26a is driven by the control unit 9, the guide member 26 moves between the position of the solid line and the position of the dashed line in accordance with the forward and reverse rotation of the guide motor 26a. When the guide member 26 is in the position of the solid line, the paper P fed from the paper discharge roller pair 24 along the transport direction D0 continues to move along the transport direction D0 toward the paper discharge tray 7 in front. When the guide member 26 is in the position of the dashed line, the paper P fed from the paper discharge roller pair 24 along the transport direction D0 hits the guide member 26, changes direction, and is transported along the branch path ρ2. The branch path ρ2 is a path that branches off from the main transport path ρ0 at the guide member 26, goes downwards once, and then goes toward the paper discharge tray 8 in front along the transport direction D1.

[0024] Furthermore, a guide member 29 is positioned slightly below the lower end of the feed tray 1y. The guide member 29 guides the paper P from the feed roller 27 (described later) to the main transport path ρ0.

[0025] Paper P is transported from the feed tray 1y to the head 5 via the feed path ρ1 and the main transport path ρ0. The feed path ρ1 is defined by the feed tray 1y and the guide member 29. The transport mechanism 2 has a feed roller 27 as a member that transports the paper P along the feed path ρ1. The feed roller 27 feeds the paper P from the feed tray 1y. The feed roller 27 comes into contact with the paper P placed on the feed tray 1y. The feed roller 27 rotates when driven by the feed motor 27a (see Figure 3). When the feed motor 27a is driven by the control unit 9, the feed roller 27 rotates, and a transport force is applied to the paper P in contact with the feed roller 27 in the direction of arrow D2 in Figure 1. As a result, the paper P is fed out from the feed tray 1y along the feed path ρ1. The fed-out paper P is then sent to a position slightly upstream of the transport roller pair 23 in the main transport path ρ0.

[0026] The cutter 3 is located upstream of the intermediate roller pair 22 in the main transport path ρ0, and is positioned between the rear end of the feed tray 1x and the intermediate roller pair 22. The cutter 3 consists of, for example, a disc-shaped rotating blade and a driven blade. The cutter 3 rotates and reciprocates along the left-right direction when driven by the cutting motor 3a (see Figure 3). The roll paper Rp, unwound from the roll body R and transported, is cut in the width direction by the cutter 3 when the cutting motor 3a is driven by the control unit 9, so that the length after cutting is the cut length shown in the image data described later. As a result, a rear end is formed on the roll paper Rp, and each sheet of paper is discharged into the output tray 7 or 8.

[0027] The print head 5 (corresponding to the "image forming unit" of the present invention) includes a plurality of nozzles formed on its lower surface and a driver IC 52 (see Figure 3). When the driver IC 52 is driven by the control unit 9, ink is ejected from the nozzles, and this ink adheres to the paper P to form dots. The print head 5 is mounted on the carriage 4.

[0028] The moving mechanism 6 includes two guide rails 61 and 62 and a carriage motor 63 (see Figure 3). The two guide rails 61 and 62 are spaced apart from each other in the front-rear direction and each extends in the left-right direction. The carriage 4 is positioned to straddle the two guide rails 61 and 62. The carriage 4 is connected to the carriage motor 63 via a belt (not shown) or the like. When the carriage motor 63 is driven by the control unit 9, the carriage 4 moves along the guide rails 61 and 62 in the scanning direction (left-right direction).

[0029] The print head 5 performs the following image formation operation on the paper P. As the print head 5 moves back and forth in the scanning direction with the movement of the carriage 4, ink is ejected, sequentially forming dots along the scanning direction. These rows of dots along the scanning direction are formed sequentially as the paper P is transported by the transport mechanism 2. In the image formation area on the paper P, dots are arranged in both the scanning direction and the transport direction D0, and an image consisting of this arrangement of dots appears. The image formation area is a rectangular area corresponding to the size of the image.

[0030] The output trays 7 and 8 (both corresponding to the "output section" of the present invention and each corresponding to the "support member" of the present invention) are located in front of the head 5 within the housing 100a and above the feed tray 1x. The output trays 7 and 8 extend along the front-to-back direction and are aligned vertically with each other. Output tray 7 is shorter in the front-to-back direction than output tray 8.

[0031] The output tray 7 (first output section) is movable in the front-rear direction along the transport direction D0. The output tray 8 (second output section) is movable in the front-rear direction along the transport direction D1. The fact that the output trays 7 and 8 are movable in this manner corresponds to the present invention's provision that "the support member is movable in both directions, in the direction away from the image forming section and in the opposite direction, with respect to the predetermined transport direction." Of these, the forward movement of the output trays 7 and 8 corresponds to movement in the "direction away from the image forming section," and the backward movement of the output trays 7 and 8 corresponds to movement in the "opposite direction."

[0032] The output trays 7 and 8 can be manually pulled out toward the front of the housing 100a through an opening 100q formed in the front wall of the housing 100a, or retracted into the housing 100a, respectively. The solid lines in Figures 1 and 2 show the position where the output trays 7 and 8 are pulled out to their maximum extent toward the front of the housing 100a (corresponding to the "second position" of the present invention). In this state, the front end of the output tray 8 is located in front of the front end of the output tray 7. The dashed lines in Figures 1 and 2 show the position where the output trays 7 and 8 are completely retracted into the housing 100a (corresponding to the "first position" of the present invention).

[0033] In the paper output tray 7, the position of the downstream end (front end) in the transport direction D0 when it is pulled out to its maximum extent forward (hereinafter referred to as the "pulled-out state") is T1, and the position of the downstream end (front end) in the transport direction D0 when it is stored inside the housing 100a (hereinafter referred to as the "stored state") is T2. In the paper output tray 8, the position of the downstream end (front end) in the transport direction D1 when it is in the pulled-out state is T3, and the position of the downstream end (front end) in the transport direction D1 when it is in the stored state is T4. At this time, each length from position T0 of the paper output roller pair 24 to positions T1 to T4 along the transport direction of the paper P (corresponding to the "discharge length" of the present invention) satisfies the following (1) to (3).

[0034] (1) The length from position T0 to position T1 along the main transport path ρ0 is greater than the length from position T0 to position T2 along the main transport path ρ0. (2) The length from position T0 to position T3 along the main transport path ρ0 and branch path ρ2 is greater than the length from position T0 to position T4 along the main transport path ρ0 and branch path ρ2. (3) The length from position T0 to position T1 along the main transport path ρ0 is less than the length from position T0 to position T3 along the main transport path ρ0 and branch path ρ2.

[0035] Furthermore, the fact that positions T1 and T2 satisfy condition (1) above corresponds to the "first position and a second position in which the discharge length is greater than that when the device is in the first position" of the present invention. Also, the fact that positions T3 and T4 satisfy condition (2) above corresponds to the "first position and a second position in which the discharge length is greater than that when the device is in the first position" of the present invention.

[0036] Furthermore, regarding the output tray 7, as described in (1) above, the fact that the length from position T0 to the downstream end differs between the stored state and the pulled-out state corresponds to the present invention's provision that "the output unit has a changeable output length, which is the length from the media holding unit to the downstream end of the output unit in the predetermined transport direction." Regarding the output tray 8, as described in (2) above, the fact that the length from position T0 to the downstream end differs between the stored state and the pulled-out state corresponds to the present invention's provision that "the output unit has a changeable output length, which is the length from the media holding unit to the downstream end of the output unit in the predetermined transport direction." Moreover, the fact that the length from position T0 to the downstream end differs between the output tray 7 and the output tray 8 when both are in the pulled-out state corresponds to the present invention's provision that "the output unit has a changeable output length, which is the length from the media holding unit to the downstream end of the output unit in the predetermined transport direction."

[0037] Tray sensors 96 and 97 are installed near the output trays 7 and 8, respectively. The tray sensors 96 and 97 detect whether the output trays 7 and 8 are in the positions indicated by the solid lines or the dashed lines in Figures 1 and 2, respectively; that is, whether they are housed within the housing 100a or extended to their maximum extent forward. The detection results from the tray sensors 96 and 97 are sent to the control unit 9.

[0038] A cartridge mounting section is installed inside the housing 100a. Four ink cartridges, each containing black, yellow, cyan, and magenta ink, can be detachably installed in the cartridge mounting section. Ink is supplied to the print head 5 from the ink cartridges installed in the cartridge mounting section via tubes or similar means.

[0039] The control unit 9 controls the entire printer 100. As shown in Figure 3, the control unit 9 is electrically connected to the feed motors 21a and 27a, the intermediate motor 22a, the transport motor 23a, the paper ejection motor 24a, the cutting motor 3a, the driver IC 52, the carriage motor 63, and the tray sensors 96 and 97.

[0040] As shown in Figure 3, the control unit 9 includes a CPU (Central Processing Unit) 91, ROM (Read Only Memory) 92, RAM (Random Access Memory) 93, ASIC (Application Specific Integrated Circuit) 94, and the like.

[0041] ROM92 stores programs executed by CPU91 and ASIC94. ROM92 also stores various reference values. For example, these reference values ​​include the paper length related to the transport direction of cut paper Kp, and thresholds used when selecting the paper output mode (described later). There are thresholds related to output tray 7 and thresholds related to output tray 8. The former threshold is smaller than the latter.

[0042] RAM93 temporarily stores data necessary for program execution. This data includes image data transmitted from external devices such as PCs or read from recording media. The image data includes data indicating the image to be formed on the paper P, and data indicating user instructions regarding related information for image formation. The related information includes information indicating whether cut paper Kp or roll paper Rp is used, information indicating the cutting length in the transport direction D0 if roll paper Rp is used, and information indicating whether output trays 7 or 8 are used (hereinafter referred to as "used tray").

[0043] Furthermore, the control unit 9 may perform various processing using only the CPU 91, or only the ASIC 94, or the CPU 91 and ASIC 94 may cooperate in performing various processing. Also, the control unit 9 may be performed by a single CPU 91 alone, or by multiple CPUs 91 sharing the processing. Furthermore, the control unit 9 may be performed by a single ASIC 94 alone, or by multiple ASICs 94 sharing the processing.

[0044] The control unit 9 performs image formation processing based on image data stored in the RAM 93. In the image formation processing, the transport mechanism 2 transports the paper P along the transport path by a predetermined distance, and the movement mechanism 6 moves the carriage 4 back and forth in the scanning direction while ejecting ink from multiple nozzles of the head 5 onto the paper P. These processes are performed alternately and repeatedly.

[0045] If the paper P is roll paper Rp, the roll paper Rp is transported by the transport mechanism 2 and receives ink ejected from the head 5. The roll paper Rp is cut to the cutting length indicated by the image data by the operation of the cutter 3, which is controlled by the control unit 9. The roll paper Rp cut by the cutter 3 is discharged into the output tray 7 or 8 as individual sheets of paper with the image indicated by the image data formed on them. The control unit 9 operates the guide member 26 appropriately so that the roll paper Rp is discharged into the tray of use indicated by the image data among the output trays 7 and 8.

[0046] If the paper P is cut paper Kp, the cut paper Kp is transported by the transport mechanism 2 and receives ink ejected from the head 5. As a result, the cut paper Kp becomes a sheet of paper with the image indicated by the image data formed on it and is discharged to the output tray 7. The control unit 9 operates the guide member 26 appropriately so that the roll paper Kp is discharged to the tray used, among the output trays 7 and 8, as indicated by the image data.

[0047] Incidentally, in the image forming process described above, the control unit 9 selects one of the first and second discharge modes when the paper P is discharged to the paper output tray 7 or 8, and controls the transport mechanism 2 and the head 5 based on the selected mode. The first discharge mode is a mode in which the rear end of the paper P (the upstream end in the transport direction D0) is gripped by the paper output roller pair 24, thereby maintaining the paper P in a state hanging down from the front end of the paper output tray 7 or 8, as shown by the dashed line in Figures 1 and 2. Specifically, in the control of the transport mechanism 2, when discharging the paper P to the paper output tray 7 or 8, the drive of the paper output roller pair 24 is stopped while the paper output roller pair 24 is gripping the rear end of the paper P. This prevents the paper P from falling from the front end of the paper output tray 7 or 8. The second discharge mode is a mode in which the paper P is discharged to the paper output tray 7 or 8 without the paper output roller pair 24 maintaining the paper P in this way. Specifically, in the control of the transport mechanism 2, when discharging the paper P into the paper output tray 7 or 8, the drive of the paper output roller pair 24 is stopped after the rear end of the paper P has passed the paper output roller pair 24.

[0048] The process by which the control unit 9 selects either the first discharge mode or the second discharge mode will be explained below based on the flowchart in Figure 4.

[0049] First, the control unit 9 determines, based on the detection result of the tray sensor 96 or 97, whether the tray being used, as indicated by the image data, is in the pulled-out or retracted state (S1). If it determines that the tray being used is in the retracted state (S1, retracted state), the control unit 9 selects the first discharge mode (S4). Then, it terminates the series of processes. If it determines that the tray being used is in the pulled-out state (S1, pulled-out state), the control unit 9 obtains a threshold value for the tray being used from the ROM 92 (S2). Next, the control unit 9 determines whether the paper length indicated by the image data exceeds the threshold value obtained in S2 (S3). The paper length is obtained from the ROM 92 if cut paper Kp is being used, and corresponds to the cutting length indicated by the image data if roll paper Rp is being used. If it determines that the paper length exceeds the threshold value (S3, Yes), the control unit 9 selects the first discharge mode (S4). Then, it terminates the series of processes. Conversely, if it determines that the paper length is less than or equal to the threshold value (S3, No), the control unit 9 selects the second discharge mode (S5). Then, the series of processes is terminated.

[0050] The embodiment described above provides the following advantages. The possibility of the paper P falling from the tray is influenced by the length from the output roller pair 24 to the downstream end of the tray. This is because the area in which the paper P discharged into the tray is supported is from near the output roller pair 24 to the downstream end of the tray. Therefore, for example, if the length from the output roller pair 24 to the downstream end of the tray is small, the area in which the discharged paper P is supported is small. For this reason, if the paper P is not held in place by the output roller pair 24, the possibility of the paper P falling increases.

[0051] In contrast, according to this embodiment, as shown in the flowchart of Figure 4, the first or second discharge mode is selected based on the state of the tray in use and a comparison of the paper length and a threshold. As described in (1) and (2) above, the length from the paper output roller pair 24 to the downstream end of the tray in use differs depending on the state of the tray in use (stored or unfolded). Therefore, based on the state of the tray in use, the first or second discharge mode is selected based on the length from the paper output roller pair 24 to the downstream end of the tray in use.

[0052] Specifically, when the tray being used is in the retracted position, that is, when the length from the output roller pair 24 to the downstream end of the tray being used is relatively small, the first discharge mode, which suppresses the dropping of paper P, is selected. Furthermore, when the tray being used is in the extended position, that is, when the length from the output roller pair 24 to the downstream end of the tray being used is relatively large, the first or second discharge mode is selected based on a comparison of the paper length and a threshold. Here, the threshold when the tray being used is output tray 7 is smaller than the threshold when the tray being used is output tray 8. Therefore, when output tray 7 is used, the first discharge mode is more likely to be selected than when output tray 8 is used. This is because, as shown in (3) above, when the tray is in the extended position, the length from the output roller pair 24 to the downstream end of output tray 7 is smaller than the length from the output roller pair 24 to the downstream end of output tray 8, so paper P is relatively more likely to drop when discharged to output tray 7. In this way, the paper length is appropriately evaluated when selecting the first and second output modes, depending on whether output tray 7 or output tray 8 is being used.

[0053] As described above, the first or second ejection mode is appropriately selected based on the length from the paper output roller pair 24 to the downstream end of the tray in use. Furthermore, when the tray in use is in the retracted position, the first ejection mode is selected regardless of the paper length. This is because there is a high probability that the paper P will fall out of the tray when it is in the retracted position. On the other hand, when the tray in use is in the extended position, the mode is selected based on a comparison of the paper length and a threshold. Therefore, a selection is made that is appropriate to the possibility of the paper P falling out. In this way, appropriate control is performed according to the state of the tray in use.

[0054] Furthermore, the function of the control unit 9 to acquire the state of the discharge tray 7 or 8 based on the detection result of the tray sensor 96 or 97 corresponds to the function of the "acquisition unit for acquiring the status indicating the discharge length" in the present invention. As described above, determining whether it is the first discharge mode or the second discharge mode based on the state of the discharge tray 7 or 8 corresponds to determining whether it is based on the status indicating the length from the paper discharge roller pair 24 to the downstream end of the tray being used. In a similar view, the control unit 9 acquiring whether the discharge tray 7 or 8 is in the stored state or the pulled-out state corresponds to "acquiring the status indicating the discharge length based on whether the support member is in the first position or the second position" in the present invention.

[0055] Furthermore, the control unit 9 acquiring the tray in use based on image data corresponds to "acquiring a situation indicating the discharge length based on whether the first discharge unit or the second discharge unit is being used" in the present invention. As described above, determining whether it is the first discharge mode or the second discharge mode based on whether the tray in use is the output tray 7 or the output tray 8 corresponds to determining based on a situation indicating the length from the output roller pair 24 to the downstream end of the tray in use.

[0056] <Variation> Although embodiments of the present invention have been described above with reference to the drawings, it should be understood that the specific configurations are not limited to these embodiments. The scope of the present invention is indicated by the claims rather than the above description of embodiments, and all modifications within the meaning and scope equivalent to the claims are included.

[0057] For example, according to the flowchart in Figure 4 of the above embodiment, when the tray in use is in the extended position (S1, extended position), a comparison of the paper length and a threshold is performed (S3), and based on the result, either the first or second ejection mode is selected. However, when the tray in use is in the extended position, the second ejection mode may be selected without regard to the paper length.

[0058] Furthermore, in the first discharge mode according to the above embodiment, it is assumed that the paper P is maintained in a state where it hangs down from the output tray 7 or 8 and the rear end of the paper P is held between the pair of output rollers 24. However, depending on the size of the output tray, the cutting length, and other conditions, in the first discharge mode, the paper P may be maintained in a state where it does not protrude from the output tray 7 or 8 and does not hang down, and the rear end of the paper P is held between the pair of output rollers 24.

[0059] Furthermore, in the above-described embodiment, the first discharge mode or the second discharge mode is selected at least based on whether the tray in use is in a stored state or an extended state. The stored state refers to a state in which the tray is completely stored within the housing 100a. The extended state refers to a state in which the tray is extended to its maximum extent from the housing 100a. In contrast, the selection of the first discharge mode or the second discharge mode may be made based on other states of the tray in use. For example, the selection may be made depending on whether the tray in use is in a stored state or partially extended from the stored state. Alternatively, the selection may be made depending on whether the length from position T0 to the downstream end of the tray in use is within a first range or a second range. The first and second ranges may, for example, be a range where one is L1 or greater and less than L2, and the other is L2 or greater. Here, L1 <L2とする。

[0060] Furthermore, the above-described embodiment is configured such that the paper P on which the image is formed is discharged into the tray indicated by the image data. In contrast, the output tray to be used may be predetermined depending on the type of paper P used (cut paper Kp or roll paper Rp, A4 paper or A3 paper, etc.) and whether the paper feed tray used is paper feed tray 1x or 1y. In this case, the control unit 9 selects the output tray according to the type of paper P indicated by the image data and the paper feed tray used.

[0061] Furthermore, in the above-described embodiment, two configurations are employed as the acquisition means of the present invention: (a) the control unit 9 acquires the state of the discharge tray 7 or 8 based on the detection result of the tray sensor 96 or 97, and (b) the control unit 9 acquires the tray in use based on image data. Alternatively, or in addition to these, a configuration may be adopted in which a sensor is installed to detect some reference part on the paper output tray 7 or 8, and the control unit 9 acquires the state of the paper output tray 7 or 8 based on the detection result of the sensor, as the acquisition means of the present invention. In this case, the reference part may be set to the front end of the paper output tray 7 or 8, or it may not be set that way. For example, the reference part may be set to a location slightly separated from the front end of the paper output tray 7 towards the pair of paper output rollers 24. Even in this case, by detecting the position of this reference part with respect to the transport direction D0 using a sensor, it is possible to acquire the status of the paper output tray 7, such as whether it is in the pulled-out state or the stored state, that is, the status indicating the discharge length of the present invention.

[0062] Furthermore, in the above-described embodiment, the paper P is maintained by the paper output roller pair 24 performing a maintenance operation on the paper being discharged into the paper output tray 7 or 8. In contrast, another means (corresponding to the "media maintenance unit" of the present invention) for maintaining the paper P being discharged into the paper output tray 7 or 8 may be installed in the printer 100 instead of, or in addition to, the paper output roller pair 24. For example, a means for maintaining the paper P by bringing a block-shaped member into contact with the paper P from above and sandwiching the paper P between the member and the paper output tray 7 or 8 may be installed in the printer 100. In this case, the block-shaped member may be placed either inside or outside the housing 100a. Alternatively, a suction means for maintaining the paper P by sucking the air between the paper P and the paper output tray 7 or 8 to attract the paper P to the paper output tray 7 or 8 may be installed in the printer 100.

[0063] In addition, although the embodiments described above describe the application of the present invention to a printer 100, the invention is not limited thereto. The present invention may also be applied to other inkjet-type image forming apparatuses that eject ink from a head, such as multifunction printers and copiers. Furthermore, it may be applied to laser-type image forming apparatuses that perform image recording processing by attaching toner to the paper P instead of attaching ink to the paper P using an inkjet method. [Explanation of Symbols]

[0064] 2. Conveying mechanism 3 cutters 4 carriages 5 heads 6 Moving mechanism 7,8 Paper output tray 9. Control Unit 100 Printers P paper Rp roll paper Kp cut paper

Claims

1. A media storage section capable of accommodating media, The media storage unit includes an image forming unit that forms an image on the medium stored in the media storage unit, A discharge unit from which the medium on which the image has been formed by the image forming unit is discharged, A media transport unit transports the media contained in the media storage unit to the image forming unit along a predetermined transport direction, and transports the media on which an image has been formed by the image forming unit to the discharge unit. A media maintenance unit capable of maintaining the medium discharged to the discharge unit in a state where it hangs down from the discharge unit, It is equipped with a control unit, The discharge unit includes a first discharge unit and a second discharge unit that can be selectively used. Each of the first and second discharge sections has a support member for supporting the discharged medium. The support member can selectively assume a first position and a second position in which the discharge length, which is the length from the medium holding section to the downstream end of the support member with respect to the predetermined transport direction, is greater than when it is in the first position. The discharge length of the second discharge portion when it is in the second position on the support member is greater than the discharge length of the first discharge portion when it is in the second position on the support member. The system further comprises a first acquisition unit that acquires whether the first discharge unit or the second discharge unit is used, and a second acquisition unit that acquires whether the support member is in the first position or the second position. The control unit, A first discharge mode is selected according to a predetermined selection method, in which the medium is discharged to the discharge unit while the medium is held in the medium holding unit, and a second discharge mode is selected in which the medium is discharged to the discharge unit without the medium being held in the medium holding unit. Based on the selected first discharge mode and second discharge mode, the operation of the image forming unit, the medium transport unit, and the medium holding unit is controlled. The aforementioned predetermined selection method is: Based on the acquisition results by the first acquisition unit and the second acquisition unit, The first discharge mode is selected when the support member of the first and second discharge sections that is being used is in the first position. An image forming apparatus, wherein when the support member of the first and second discharge sections that is used is in the second position, the first discharge section is selected at least based on a comparison between the medium length, which is the length of the medium discharged to the discharge section in the predetermined transport direction, and a first threshold when the first discharge section is used, and the second discharge section is selected at least based on a comparison between the medium length and a second threshold that is greater than the first threshold when the second discharge section is used.

2. A media storage section capable of accommodating media, The media storage unit includes an image forming unit that forms an image on the medium stored in the media storage unit, A discharge unit from which the medium on which the image has been formed by the image forming unit is discharged, A media transport unit transports the media contained in the media storage unit to the image forming unit along a predetermined transport direction, and transports the media on which an image has been formed by the image forming unit to the discharge unit via a transport path from the image forming unit to the discharge unit, A media maintenance unit capable of maintaining the medium discharged to the discharge unit in a state where it hangs down from the discharge unit, It is equipped with a control unit, The discharge unit includes a first discharge unit and a second discharge unit that can be selectively used. The transport path includes a first path extending from the image forming unit to the first discharge unit, and a second path branching off from the first path and extending to the second discharge unit. With respect to the predetermined transport direction, the discharge length from the medium maintenance unit to the downstream end of the second discharge unit via the first and second paths is greater than the discharge length from the medium maintenance unit to the downstream end of the second discharge unit via the first and second paths with respect to the predetermined transport direction. The system further includes an acquisition unit that acquires whether the first discharge unit or the second discharge unit is used. The control unit, An image forming apparatus characterized in that, if the result acquired by the acquisition unit indicates the use of the first discharge unit, the first discharge mode is selected based at least on a comparison between the media length, which is the length of the media discharged to the discharge unit in the predetermined transport direction, and a first threshold; if the result acquired by the acquisition unit indicates the use of the second discharge unit, the second discharge mode is selected based at least on a comparison between the media length and a second threshold that is greater than the first threshold; and the operation of the image forming unit, the media transport unit, and the media maintenance unit is controlled based on the selected first discharge mode and the second discharge mode.

3. The support member is movable in both directions: in the direction away from the image forming unit and in the opposite direction with respect to the predetermined transport direction. The first position is the position closest to the image forming unit in the predetermined transport direction, The image forming apparatus according to claim 1, characterized in that the second position is a position separated from the first position with respect to the predetermined transport direction.

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