Image forming apparatus and transport control method

Abstract

The objective is to provide an image forming apparatus and a transport control method that can reduce damage to the original document in an image forming apparatus where the transport path of a reading means for reading the original document and the transport path of a recording medium for forming the image intersect. [Solution] The image forming apparatus of the present invention comprises: an image forming means for forming an image on a recording medium; a reading means for reading a document; a first transport path which is a transport path for the recording medium; a second transport path which is a transport path for the document; an intersection point in the first transport path where the passage through which the recording medium passes before image formation intersects with the second transport path; a transport means for moving the recording medium at the intersection point backward in the first transport path in the direction opposite to the direction of travel from the intersection point toward the image forming means; and a control means for controlling the transport of the recording medium and the document. The control means is characterized in that, when transporting a document before reading, if the image forming operation of the recording medium has not been started, the transport means moves the recording medium at the intersection point backward beyond the intersection point, allowing the document to enter the intersection point.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus and a conveyance control method.

Background Art

[0002] There is a composite apparatus having a reading mechanism for reading a document and a recording mechanism for recording an image on a recording medium, and a document discharge port is disposed vertically above a medium discharge port (Patent Document 1).

[0003] In Patent Document 1, the document discharged from the document discharge port and the recording medium discharged from the medium discharge port are discharged in intersecting paths. When the recording medium is discharged while the document is being discharged, the leading end of the recording medium abuts on the document at the intersection position, and the recording medium receives a force in the downward direction in which it is discharged from the contact surface with the document and is discharged together with the document. In addition, since the document discharge port is arranged such that the document would fall as it is when the document is discharged, the trailing end of the document is nipped by a discharge roller and the conveyance is stopped. According to the disclosed configuration, when the recording medium is discharged while the document is in a stopped state, the stopped state is canceled and the document is dropped, or a notification for removing the document by an operator is given. There is also a disclosure of conveying the document in a direction opposite to the discharge direction to a position where the leading end path of the recording medium is not blocked before the leading end of the medium discharged from the medium discharge port reaches the intersection position.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The configuration disclosed in Patent Document 1 has the potential to damage the original document because, after the image is formed, the recording medium and the original document come into contact at an intersection when both are ejected. Furthermore, if the original document is nipped by the ejection roller and dropped to avoid contact when the recording medium is ejected, there is still a possibility of damage to the original document due to the impact from the fall. Additionally, if the operator is required to remove the original document, the frequency of handling increases, raising the probability of damage. Moreover, in the configuration disclosed in Patent Document 1, the description of transporting the original document in the reverse direction interrupts the original document reading process if it is already in progress, requiring the original document reading operation to be restarted after the recording medium is ejected. In this case, the distance the original document is transported increases, either by transporting it in the reverse direction or by transporting it again in the forward direction to perform the original document reading again, thus increasing the probability of damage to the original document during transport. Additionally, the time required for original document reading increases compared to normal. Thus, conventional configurations have the problem of a high probability of original document damage.

[0005] The present invention has been made in view of the above, and aims to provide an image forming apparatus and a transport control method that can reduce damage to an original document in an image forming apparatus in which a transport path for a reading means that reads an original document and a transport path for a recording medium that forms an image intersect. [Means for solving the problem]

[0006] To solve the above-mentioned problems and achieve the objective, the present invention provides an image forming apparatus comprising: an image forming means for forming an image on a recording medium; a reading means for reading a document; a first transport path which is a transport path for the recording medium; a second transport path which is a transport path for the document; an intersection point in the first transport path where the passage through which the recording medium passes before image formation intersects with the second transport path; a transport means for moving the recording medium at the intersection point backward in the first transport path in the direction opposite to the direction of travel from the intersection point toward the image forming means; and a control means for controlling the transport of the recording medium and the document, wherein, when transporting the document before reading, if the image forming operation of the recording medium has not been started, the transport means moves the recording medium at the intersection point backward beyond the intersection point, thereby allowing the document to enter the intersection point. [Effects of the Invention]

[0007] According to the present invention, the effect is to reduce damage to the original document during scanning. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram showing an example of the configuration of an image forming apparatus according to an embodiment. [Figure 2] Figure 2 is a plan view showing an example of the configuration of an inkjet printer in an image forming apparatus according to an embodiment. [Figure 3] Figure 3 shows an example of the configuration of the control block of an image forming apparatus according to an embodiment. [Figure 4] Figure 4 shows an example of the operation of a pair of recording paper retraction rollers in an image forming apparatus. [Figure 5] Figure 5 shows an example of the operation of a pair of recording paper retraction rollers in an image forming apparatus (continued). [Figure 6] Figure 6 shows an example of the control flow by the main control unit of the image forming apparatus. [Figure 7]Figure 7 shows an example of the operation during printing. [Figure 8] Figure 8 shows an example of the control flow during printing. [Modes for carrying out the invention]

[0009] The embodiments of the image forming apparatus and transport control method according to the present invention will be described in detail below with reference to the attached drawings. In the following, "recording paper" is an example of a "recording medium." Specific examples of "recording medium" include paper, recording paper, recording paper, film, cloth, etc., and unless otherwise specified, all materials to which liquids such as ink adhere are included. Furthermore, "original document" refers to the paper, recording paper, recording paper, film, cloth, etc. to be read, and includes materials that do not bend. In the following, "printing" is used in the sense of image formation. Image formation is a term that includes printing and other similar processes.

[0010] (Embodiment) Figure 1 is a schematic diagram showing an example of the configuration of an image forming apparatus according to an embodiment. The image forming apparatus 1 shown in Figure 1 is a side view of its internal configuration. The side of the original document 20 shown in Figure 1 is the front of the image forming apparatus 1, and the side of the recording paper 10 shown in Figure 1 is the back of the image forming apparatus 1.

[0011] The image forming apparatus 1 shown in Figure 1 is configured to supply the recording paper 10 in a direction (+B) that intersects the insertion direction (+A) of the document 20, taking into consideration the possibility of misinsertion of the document 20 and the recording paper 10. As an example, a configuration in which the supply port for the recording paper 10 is located on the back side of the image forming apparatus 1 is shown.

[0012] As shown in Figure 1, the image forming apparatus 1 has a first transport path 100 and a second transport path 200, with an image forming means on the path of the first transport path 100 and a reading means on the path of the second transport path 200. In Figure 1, the image forming means is an inkjet printer 17, and the reading means is an image reading sensor 23 such as a CIS (Contact Image Sensor).

[0013] The recording paper 10 is transported from the supply port on the rear side of the image forming apparatus 1 along the first transport path 100 to the inkjet printer 17, where printing is performed on the recording paper 10 and then it is discharged to the outside from the front of the image forming apparatus 1. The original document 20 is transported from the front of the image forming apparatus 1 along the second transport path 200 to the image reading sensor 23, where the original image of the original document 20 is read and then it is discharged to the outside.

[0014] As shown in Figure 1, the recording paper 10 is supplied in a direction (+B) that intersects the insertion direction (+A) of the original document 20. Therefore, the passage through which the recording paper 10 passes before image formation, corresponding to the first transport path 100, intersects with the second transport path 200. Consequently, at the intersection point 101 shown in Figure 1, there is a possibility that the recording paper 10 and the original document 20 may come into contact. If one is present at the intersection point 101 and the other is attempted to enter, the recording paper 10 and the original document 20 will come into contact. Note that the intersection point 101 is the entire range in which the recording paper 10 and the original document 20 may come into contact. In this embodiment, the entire range in which the recording paper 10 and the original document 20 may come into contact may also be referred to as the intersection section.

[0015] (Detailed explanation of the transport route 1) The first transport path 100, along the direction of travel of the recording paper 10 (+B direction), includes a recording paper stacking tray 11, a pair of recording paper retraction rollers 12 (first roller 12-1, second roller 12-2), a recording paper set detection sensor 13, a paper feed separation roller 14, a paper feed transport roller 15, a registration sensor 16, an inkjet printer 17, and a paper discharge roller 18, among others.

[0016] The recording paper stacking tray 11 is a tray that stacks the recording paper 10 at a set position where the end of the recording paper 10 on the direction of travel (+B direction) side is closer to the inkjet printer 17 (image forming means side) than the intersection position 101.

[0017] The recording paper retraction roller pair 12 (a roller pair consisting of the first roller 12-1 and the second roller 12-2) is an example of a "conveying means". The recording paper retraction roller pair 12 is provided as a means to move the recording paper 10 at the intersection position 101 backward in the first transport path 100 in the direction opposite to the direction of travel toward the inkjet printer 17 (image forming means side) (+B direction). In other words, by controlling the recording paper retraction roller pair 12, it is possible to move the recording paper 10 backward in the first transport path 100 beyond the intersection position 101. Hereafter, when we refer to the rear side, we mean the rear side in the direction opposite to the direction of travel (+B direction) in the first transport path 100.

[0018] In the case of the recording paper retraction roller pair 12, when in the drive-off state, the first roller 12-1 retracts to a state where it is stored outside the passage of the first conveyance path 100, and the progress of the recording paper 10 to the intersection position 101 is not hindered by the first roller 12-1 and the second roller 12-2 (initial state) (FIG. 4(a) described later). Here, the second roller 12-2 facing the first roller 12-1 is provided with a roller contact / separation mechanism that enables a pressure contact operation and a pressure contact release operation. The roller pair of the first roller 12-1 and the second roller 12-2 of the recording paper retraction roller pair 12 and the roller contact / separation mechanism are located on the rear side of the intersection position 101 in the first conveyance path 100. The roller contact / separation mechanism, when in the drive-on state, presses the first roller 12-1 against the opposing second roller 12-2, and when the drive is turned off, the roller contact / separation mechanism releases the state where the second roller 12-2 facing the first roller 12-1 is in pressure contact and retracts the first roller 12-1 to a state where it is stored outside the passage. Here, as an example, a configuration in which the first roller 12-1 side performs the pressure contact and release operations is shown, but it may be modified to a configuration in which the second roller 12-2 side performs the pressure contact and release operations, or it may be modified to a configuration in which both the first roller 12-1 and the second roller 12-2 perform the pressure contact and release operations. By being in the retracted state, the recording paper 10 advances from the end through the intersection position 101, and one end of the recording paper 10 is laminated at a set position on the inkjet printer 17 side (image forming means side) from the intersection position 101. Thereafter, when the operation of conveying the recording paper 10 to the inkjet printer 17 side (image forming means side) is started, the recording paper 10 is conveyed to the inkjet printer 17 and image formation is performed. In the configuration of the example in FIG. 1, the laminated recording paper is set so that one end is located at a position in front of the paper feed separation roller 14 (FIG. 4(a) described later).

[0019] One example of the recording paper retraction roller pair 12 (the first roller 12-1 and the second roller 12-2) shown in FIG. 1, in the drive-on state, pushes the first roller 12-1 stored outside the passage of the first conveyance path 100 to the passage side of the first conveyance path 100, and the first roller 12-1 presses against the second roller 12-2 facing the first roller 12-1 to sandwich the recording paper 10 at that position. Further, the recording paper retraction roller pair 12 rotates the first roller 12-1 and the second roller 12-2 in a direction in which the recording paper 10 retreats backward in the direction opposite to the traveling direction (+B direction) while the recording paper 10 is in a pressed state, and performs an operation of retreating the leading end of the recording paper 10 from the intersection position 101 (FIG. 4(b) described later). The rotation of the first roller 12-1 and the second roller 12-2 is controlled by a drive motor. Although the first roller 12-1 and the second roller 12-2 are rotationally driven, either one of the first roller 12-1 and the second roller 12-2 may be rotationally driven. However, as described above, it is desirable to make the first roller 12-1 and the second roller 12-2 rotatable, because even when a plurality of recording papers 10 overlap, the overlapping recording papers 10 can be retracted in a bundle, so that the driving time for retracting the plurality of recording papers 10 is shortened.

[0020] The recording paper set detection sensor 13 is an example of "medium detection means" for detecting the recording paper 10 at the set position. One example of the recording paper set detection sensor 13 detects that the recording paper 10 has been set in front of the paper feed separation roller 14. When the recording paper retraction roller pair 12 (the first roller 12- and the second roller 12-2) is in the initial state, along the recording paper stacking tray 11, the recording paper 10 passes between the first roller 12-1 and the second roller 12- from the leading end of the recording paper 10 by its own weight and is set in front of the paper feed separation roller 14. The intersection position 101 is blocked by the recording paper 10 when the recording paper 10 is set.

[0021] The paper feed separation roller 14 feeds the recording paper 10 from the leading end. When a bundle of a plurality of recording papers 10 is set, the recording papers 10 are separated one by one from the bundle and fed.

[0022] The paper feed roller 15 transports the recording paper 10 fed by the paper feed separation roller 14 one sheet at a time.

[0023] The resist sensor 16 detects the recording paper 10 on the resist roller.

[0024] The inkjet printer 17 prints an image on the recording paper 10 using an inkjet method.

[0025] The paper discharge roller 18 discharges the printed recording paper 10 from the front of the image forming apparatus 1 to the outside.

[0026] (Detailed explanation of the transport route 2) The second transport path 200 is located along the insertion direction (+A direction) of the document 20 and includes a document insertion detection sensor 21, a first document transport roller 22, an image reading sensor 23, a document rear sensor 24, and a second document transport roller 25. The image forming apparatus 1 has an insertion slot for the document 20 on its front, and in this system, as an example, the document 20 is read using a straight switchback document transport method.

[0027] The document insertion detection sensor 21 detects the leading edge of the document 20 when it is inserted in the insertion direction (+A direction).

[0028] The first document transport roller 22 and the second document transport roller 25 transport the document 20 by rotating the rollers. In this example, a straight switchback document transport method is used, so the document 20 is transported in a straight line in the insertion direction (+A direction) (Figure 5(a) described later), and after the trailing edge of the document 20 passes the image reading sensor 23, it switches back and transports the document 20 in the reverse direction (-A direction) (Figure 5(b) described later) while image reading is performed. Then, the document 20 for which image reading has been performed is ejected to the outside from the insertion slot.

[0029] As an example, the image reading sensor 23 has CIS positioned above and below the second transport path 200, and performs double-sided reading of the document 20 in one pass where the document 20 is transported in the reverse direction (-A direction) by a switchback.

[0030] The document rear sensor 24 is a sensor that detects the rear end of the document 20. If the leading edge of the document 20 is considered the first end and the rear end of the document 20 is considered the second end when the document 20 is being transported in the +A direction, the document rear sensor 24 detects the second end when the document 20 is being transported in the +A direction. When the second end of the document 20 is detected, the second end is gripped by the second document transport roller 25, so the transport direction is switched back to the -A direction, which is the opposite direction to the +A direction, by reversing the roller of the second document transport roller 25.

[0031] Furthermore, the document rear sensor 24 can also be used as a sensor to detect the first edge of the document 20. During printing on the recording paper 10, if the document 20 is transported in the +A direction, the document 20 may be damaged by contact with the remaining recording paper 10 at the intersection point 101, or a jam (failure to transport) may occur. For this reason, if the document 20 is inserted during printing, the first edge of the document 20 is detected, and the transport of the document 20 is stopped at that point.

[0032] (Regarding the control panel) The operation unit 80 shown in Figure 1 is an operation unit for performing operations such as setting and executing document reading and setting and executing printing. As an example, the operation unit 80 is provided on the front of the image forming apparatus 1. The series of operations described above, including paper feeding and transport in the first transport path 100 and printing by the inkjet printer 17, are triggered by an execution operation based on the settings of the operation unit 80. Similarly, the series of operations described above, including transport in the second transport path 200 and image reading by the image reading sensor 23, are triggered by an execution operation based on the settings of the operation unit 80.

[0033] (Inkjet printer configuration) Figure 2 is a plan view showing an example of the configuration of an inkjet printer in an image forming apparatus according to an embodiment.

[0034] The inkjet printer 17 is equipped with a mechanism for driving the ink ejection head 31 at the top of the first transport path 100.

[0035] The ink ejection head 31 is fitted with ink cartridges 32 that supply ink, and ink droplets are ejected from the ejection nozzles of the ink ejection head 31 according to color. In this example, black (K), cyan (C), magenta (M), and yellow (Y) ink cartridges 32 are fitted.

[0036] The ink ejection head 31 ejects ink of each color from its ejection surface onto the recording paper 10 to form an image within the image-forming area of ​​the recording paper 10. Multiple rows of ejection nozzles are provided on the ejection surface of the ink ejection head 31.

[0037] In the configuration shown in Figure 2, the ink ejection head 31 is mounted on a carriage 33. The carriage 33 is slidably held by guide rods 34, which are guide members horizontally mounted on the left and right side plates of the main body of the device, and is fixed to a timing belt 37 stretched between a drive pulley 35 and a driven pulley 38. The drive pulley 35 is driven by the control of the main scanning motor 36 to move the carriage 33 in the main scanning direction (X direction), thereby moving the ink ejection head 31 in the main scanning direction (X direction).

[0038] The carriage 33 detects the position of the ink ejection head 31 by reading the encoder sheet (linear scale) 39 along the direction of movement of the carriage 33 (X direction) using an encoder sensor.

[0039] The lower part of the first transport path 100 is equipped with means for intermittently driving the recording paper 10 in the sub-scanning direction (Y direction).

[0040] The recording paper 10 is held between the rotating rollers, which are the register roller and the pinch roller, and is intermittently fed along the platen 41 in the sub-scanning direction (Y direction).

[0041] The platen 41 is equipped with an adsorption means to prevent the recording paper 10 from lifting. The platen 41 is also equipped with heaters such as a cure heater and a post heater. These heaters harden the ink dropped onto the recording paper 10 and fix the image.

[0042] In the inkjet printer 17 with the configuration shown in Figure 2, the ink ejection head 31 creates an image on the recording paper 10 in the main scanning direction by reciprocating the carriage 33 in the X direction. After completing the image creation in the main scanning direction, the recording paper 10 is fed a predetermined amount in the Y direction, and the carriage 33 is again reciprocated in the X direction to create an image on the recording paper 10 in the main scanning direction. In this way, the inkjet printer 17 repeatedly creates an image in the main scanning direction by the ink ejection head 31 and transports the recording paper 10 in the sub-scanning direction to form an image on the recording paper 10.

[0043] Note that the X direction shown in Figure 2 is the direction orthogonal to the +A direction and the +B direction in the image forming apparatus 1 shown in Figure 1, and the Y direction shown in Figure 2 corresponds to the opposite direction of the +A direction (-A direction) in the image forming apparatus 1 shown in Figure 1.

[0044] (Configuration of the control block of the image forming apparatus) Figure 3 shows an example of the configuration of a control block in an image forming apparatus according to an embodiment. In the example configuration shown in Figure 3, the main control unit 50 of the image forming apparatus 1 communicates with the reading control block 60 of the first transport path 100, the image forming control block 70 of the second transport path 200, and the operation unit 80 to control each part.

[0045] The main control unit 50 may include, for example, a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), NVLAM, and ASIC (Application Specific Integrated Circuit).

[0046] The CPU controls the entire device by executing control programs. ROM stores control programs and data executed by the CPU. RAM is used as the CPU's work area. NVLAM retains data even when the device's power is cut off. ASICs perform image processing and other tasks.

[0047] The reading control block 60, including the reading control unit 61, motor control unit 62, and each of the sensors 21 and 24, communicates with the main control unit 50.

[0048] The reading control unit 61 controls the image reading sensor 23 to read image data.

[0049] The motor control unit 62 controls the transport motor 63 to rotate the rollers of the first document transport roller 22 and the second document transport roller 25 to transport the document 20.

[0050] The sensors 21 and 24 are a document insertion detection sensor 21 and a document post sensor 24.

[0051] The image formation control block 70, including the print control unit 71, motor control unit 72, and sensors 13 and 16, communicates with the main control unit 50.

[0052] The printing control unit 71 controls the ink ejection head 31.

[0053] The motor control unit 72 controls the transport motor 73 to rotate the paper feed separation roller 14, paper feed transport roller 15, and paper discharge roller 18, etc., to transport the recording paper 10 in the +B direction. The motor control unit 72 also controls the drive motor 74 to press the recording paper retraction roller pair 12 (first roller 12-1, second roller 12-2) into contact with or retract them using the roller contact / separation mechanism, and further controls the rotational drive of the rollers of the recording paper retraction roller pair 12 when pressing them into contact with each other. The drive motor that performs the pressing operation of the recording paper retraction roller pair 12 and the drive motor that rotates the rollers of the recording paper retraction roller pair 12 may be provided separately. The motor control unit 72 also controls the main scanning motor 36.

[0054] The sensors 13 and 16 are a recording paper set detection sensor 13 and a resist sensor 16.

[0055] (Operation and control flow 1) Figures 4 and 5 show an example of the operation of the recording paper retraction roller pair 12 (first roller 12-1, second roller 12-2) in the image forming apparatus 1. Figure 6 shows an example of the control flow by the main control unit 50 of the image forming apparatus 1. The operations shown in Figures 4 and 5 will be explained together with the control flow in Figure 6.

[0056] In Figure 6, the main control unit 50 first determines whether the image forming apparatus 1 is in the process of printing (step S1). For example, the main control unit 50 communicates with the image forming control block 70 of the image forming apparatus 1 and determines that the image forming apparatus 1 is in the process of printing if the feeding of recording paper 10 has started in the first transport path 100. Note that "in the process of printing" is used here to mean the same thing as "the printing process has started".

[0057] The state shown in Figure 4(a) is determined not to be in printing operation because, although two sheets of recording paper 10 are set in the set position of the recording paper stacking tray 11, the recording paper 10 separated from the paper feed separator roller 14 has not been fed. The state in printing operation corresponds to the case where the recording paper 10 separated from the paper feed separator roller 14 has been fed.

[0058] Next, if the main control unit 50 determines that the image forming apparatus 1 is in the process of printing (step S1: Yes), it proceeds to step S11 (see Figure 8). The process from step S11 onwards includes the operation shown in Figure 7, and will be explained in more detail later.

[0059] If the main control unit 50 determines that the image forming apparatus 1 is not in printing operation (step S1: No), it determines whether the document insertion detection sensor 21 of the image forming apparatus 1 is ON (step S2). For example, the document insertion detection sensor 21 of the image forming apparatus 1 turns ON when it detects the insertion of a document 20. The main control unit 50 communicates with the reading control block 60 of the image forming apparatus 1 to determine whether the document insertion detection sensor 21 is ON.

[0060] At the point shown in Figure 4(a), the document 20 has not yet been inserted, so the document insertion detection sensor 21 is OFF, but at the point shown in Figure 4(b), it is ON.

[0061] If the main control unit 50 determines that the document insertion detection sensor 21 of the image forming apparatus 1 is not ON (determination of non-detection) (step S2: No), it proceeds to the process in step S3.

[0062] If the main control unit 50 determines that the document insertion detection sensor 21 of the image forming apparatus 1 is ON (detection determination) (step S2: Yes), it communicates with the image forming control block 70 of the image forming apparatus 1 and moves the first roller 12-1 of the recording paper retraction roller pair 12 in the +c direction (step S4, Figure 4(b)).

[0063] Next, the main control unit 50 determines whether the recording paper set detection sensor 13 of the image forming apparatus 1 is ON (step S5). For example, the recording paper set detection sensor 13 turns ON when it detects recording paper 10. The main control unit 50 communicates with the image forming control block 70 of the image forming apparatus 1 to determine whether the recording paper set detection sensor 13 is ON.

[0064] If the main control unit 50 determines that the recording paper set detection sensor 13 is ON (detection determination) (step S5: Yes), it communicates with the image forming control block 70 of the image forming apparatus 1 and uses the recording paper retraction roller pair 12 to transport the recording paper 10 to the rear in the opposite direction to the direction of travel (+B direction) and move it backward from the intersection position 101 (step S6). For example, the main control unit 50 communicates with the image forming control block 70 of the image forming apparatus 1 and rotates the first roller 12-1 and the second roller 12-2 in the direction that moves the recording paper 10 backward while the recording paper 10 is pressed against it by the recording paper retraction roller pair 12, thereby moving the leading edge of the recording paper 10 backward from the intersection position 101.

[0065] At the point shown in Figure 4(a), the paper set detection sensor 13 is ON. Therefore, when the document 20 is inserted in this state and the document insertion detection sensor 21 is turned ON, the first roller 12-1 moves in the +c direction, pressing the stack of recording paper 10 against it and retracting the stack of recording paper 10, bringing the stack of recording paper 10 into the state shown in Figure 4(b). In the state shown in Figure 4(b), the leading edge of the stack of recording paper 10 has retracted from the intersection position 101. Also, because the first roller 12-1 of the recording paper retraction roller pair 12 presses against the second roller 12-2, the recording paper 10 does not advance to the intersection position 101 and stops.

[0066] If the main control unit 50 determines that the recording paper set detection sensor 13 of the image forming apparatus 1 is not ON (determination of non-detection) (step S5: No), it skips the control in step S6, which is the control to rotate the first roller 12-1 and the second roller 12-2 to retract the recording paper 10.

[0067] Next, the main control unit 50 starts the document scanning operation (document reading operation) of the image forming apparatus 1 (step S7). For example, the main control unit 50 communicates with the reading control block 60 of the image forming apparatus 1 and moves the document 20 in the second transport path 200 past the document rear sensor 24 in the insertion direction (+A direction). When the document rear sensor 24 detects the second end, which is the rear end of the document 20, the transport of the document 20 is stopped.

[0068] As shown in Figure 5(a), the passage at intersection 101 is open, and the document 20 moves in the +A direction without coming into contact with the recording paper 10, entering intersection 101.

[0069] Next, as shown in Figure 5(b), after the second end of the document 20 is detected by the document rear sensor 24 and transport in the +A direction is stopped, the main control unit 50 communicates with the reading control block 60 of the image forming apparatus 1 and switches back the document 20 on the second transport path and transports it in the -A direction. Then, while transporting the document 20 in the reverse direction (-A direction) from the position of the document rear sensor 24, the image reading sensors 23, which have CIS positioned above and below the second transport path 200, perform double-sided reading of the document 20.

[0070] Next, the main control unit 50 determines whether the document scanning operation of the image forming apparatus 1 is complete (step S8). For example, the completion of the document scanning operation is determined when the ejection of the document 20 is detected by the document insertion detection sensor 21. Once the document scanning operation is complete, the passage at the intersection position 101 becomes free, allowing the recording paper 10 to advance to the intersection position 101.

[0071] If the document scanning operation of the image forming apparatus 1 is not completed (step S8: No), the main control unit 50 repeatedly determines when the document scanning operation is complete.

[0072] If the document scanning operation of the image forming apparatus 1 is completed (step S8: Yes), the main control unit 50 communicates with the image forming control block 70 of the image forming apparatus 1 and moves the first roller 12-1 of the recording paper retraction roller pair 12 in the -c direction, that is, returns it to its initial position (step S9).

[0073] By returning the first roller 12-1 of the paper retraction roller pair 12 to its initial position, the stack of paper 10 moves by its own weight through the space between the first roller 12-1 and the second roller 12-2 to the crossing position 101, and is set in front of the paper feed separation roller 14.

[0074] In step S2, if the main control unit 50 determines that the document insertion detection sensor 21 is not ON (step S2: No), it moves the first roller 12-1 of the recording paper retraction roller pair 12 in the -c direction (step S3) and terminates the process.

[0075] (Operation and control flow 2) Figure 7 shows an example of the operation during printing. Figure 8 shows an example of the control flow during printing. The operation shown in Figure 7 will be explained together with the control flow in Figure 8. In Figure 7(a), the recording paper 10 that has been separated from the paper feed separator roller 14 has been fed. Therefore, the following describes the processing to be performed when it is determined that printing is in progress.

[0076] In Figure 8, the main control unit 50 first determines whether the document insertion detection sensor 21 of the image forming apparatus 1 is ON (step S11).

[0077] If the main control unit 50 determines that the document insertion detection sensor 21 of the image forming apparatus 1 is not ON (step S11: No), it will terminate the transport process without performing the transport operation of the document 20.

[0078] If the main control unit 50 determines that the document insertion detection sensor 21 of the image forming apparatus 1 is ON (step S11: Yes), it transports the inserted document 20 in the insertion direction (+A direction) (step S12).

[0079] Furthermore, the main control unit 50 detects the first leading edge of the document 20 with the document rear sensor 24 and stops the document 20 in that position by gripping the first leading edge of the document 20 with the second document transport roller 25 (step S13).

[0080] The state shown in Figure 7(b) is when the first end of the document 20 is gripped and stopped by the second document transport roller 25. At this time, the recording paper retraction roller pair 12 is in its initial drive-off state.

[0081] Next, the main control unit 50 determines whether the printing operation is complete (step S14). If the main control unit 50 determines that the printing operation is not complete (step S14: No), it returns to the process in step S13.

[0082] If the main control unit 50 determines that the printing operation is complete (step S14: Yes), it determines whether the recording paper set detection sensor 13 of the image forming apparatus 1 is ON (step S15).

[0083] In the state shown in Figure 7(b), if the printing operation of the fed recording paper 10 proceeds and the remaining recording paper 10 set in the recording paper stack tray 11 is not fed thereafter, the remaining recording paper 10 remains in the set position, and therefore the recording paper set detection sensor 13 is ON.

[0084] If the main control unit 50 determines that the recording paper set detection sensor 13 is ON (step S15: Yes), it communicates with the image forming control block 70 of the image forming apparatus 1 and uses the recording paper retraction roller pair 12 to transport the recording paper 10 to the rear in the opposite direction to the direction of travel (+B direction), causing it to move backward from the intersection position 101 (step S16). In other words, the recording paper 10 is moved backward by the recording paper retraction roller pair 12 to the state shown in Figure 4(b).

[0085] If the main control unit 50 determines that the recording paper set detection sensor 13 of the image forming apparatus 1 is not ON (step S15: No), it skips the control in step S16 because there is no recording paper 10 set in the set position.

[0086] Next, the main control unit 50 starts the document scanning operation of the image forming apparatus 1 (step S17). For example, the main control unit 50 communicates with the reading control block 60 of the image forming apparatus 1 and moves the first end of the document 20 ahead of the document rear sensor 24 in the second transport path 200. When the document rear sensor 24 detects the second end, which is the rear end of the document 20, it switches the document 20 back and performs image reading while transporting the document 20 in the reverse direction (-A direction).

[0087] The scanning operation of the document 20 can be started from the position of the document 20 shown in Figure 7(b), and from that position, the document 20 is scanned according to the procedures in Figures 5(a) and 5(b).

[0088] Next, the main control unit 50 determines whether the document scanning operation of the image forming apparatus 1 has been completed (step S18).

[0089] If the document scanning operation of the image forming apparatus 1 is not completed (step S18: No), the main control unit 50 repeatedly determines when the document scanning operation is complete.

[0090] If the document scanning operation of the image forming apparatus 1 is completed (step S18: Yes), the main control unit 50 communicates with the image forming control block 70 of the image forming apparatus 1 and moves the first roller 12-1 of the recording paper retraction roller pair 12 in the -c direction, that is, returns it to its initial position (see Figure 4(a)) (step S19).

[0091] (modified version) In this embodiment, the image forming apparatus 1 shows a serial image forming means configuration in which printing is performed by moving an ink ejection head as an example of the image forming means, but it is not limited to this. The image forming means does not have to be serial, nor is it limited to an inkjet recording method. For example, image forming means other than inkjet, such as an electrophotographic method or a thermal transfer method, may be used.

[0092] (Effects of the image forming apparatus according to the embodiment) As described above, in the image forming apparatus 1 of this embodiment, the document transport path and the recording paper transport path are configured to intersect, so that the recording paper before image formation and the document before scanning pass through the same path. However, in the image forming apparatus 1 of this embodiment, a pair of recording paper retraction rollers is provided to automatically control the transport of the recording paper so that the document does not come into contact with the recording paper at the intersection. Therefore, even if an operator inserts a document for scanning while the recording paper is already set, the control of the transport of the recording paper by the pair of recording paper retraction rollers reduces damage to the document. Since these controls are performed automatically, the operability when an operator scans a document can be improved. In addition, because the document and the recording paper are controlled to not come into contact, not only damage to the document but also jams can be reduced. Therefore, the amount of work that operators have to do to remove the recording paper is reduced, and the impact on image quality can be minimized.

[0093] Furthermore, in the image forming apparatus 1 of this embodiment, if an original document is inserted by an operator while the recording paper is printing, the inserted original document is kept in a predetermined position until the printing operation is completed. Therefore, the operator can insert an original document without having to worry about whether the recording paper is printing, and the original document reading operation will start automatically from the predetermined position after the printing operation is completed, thereby improving the operability of the original document reading operation by the operator.

[0094] Furthermore, in the image forming apparatus 1 of this embodiment, the operator can insert the document without worrying even while printing is in progress on the recording paper. In this case, since the document has advanced to just before the intersection point by the time printing on the recording paper is finished, the remaining transport distance of the document is short once printing is complete, so the document reading operation can be completed in a short time without any loss of time.

[0095] Furthermore, in the image forming apparatus 1 of this embodiment, once the document reading operation is complete, the pair of recording paper retraction rollers automatically return to their initial positions, so that the stack of recording paper 10 is set in front of the paper feed separation roller by its own weight. As a result, when the printing operation is started, paper feeding begins immediately, and the printing operation can be completed in a short time without any loss of time.

[0096] Furthermore, although the image forming apparatus 1 of this embodiment is equipped with a reading means, the overall size can be made smaller because the document transport path and the recording paper transport path are arranged to intersect. In particular, in the image forming apparatus 1 of this embodiment, the recording paper is set at the intersection point, and this configuration can be applied to small devices.

[0097] Furthermore, in the image forming apparatus 1 of this embodiment, the original document is read using a straight switchback document transport system. In this system, the original document is read by horizontal transport in the front-to-back direction, so the original document is transported without being bent and maintains its shape. This reduces damage to the original document and allows for the reading of thick original documents. In addition, because it uses a switchback document transport system, the overall size of the apparatus can be made smaller.

[0098] Furthermore, in the image forming apparatus 1 of this embodiment, the recording paper is supplied in a direction intersecting the direction in which the original document is read, making it less likely for errors to occur in the paper supply port.

[0099] Furthermore, in the image forming apparatus 1 of this embodiment, by configuring the document transport path and the recording paper transport path to intersect, the positions for inserting and ejecting documents and for ejecting recording paper can be placed in front of the image forming apparatus 1. This improves the operability for the operator.

[0100] The program executed by the image forming apparatus according to this embodiment is provided as a file in an installable or executable format, recorded on a computer-readable recording medium such as a CD-ROM, flexible disk (FD), CD-R, or DVD (Digital Versatile Disk).

[0101] Furthermore, the program executed by the image forming apparatus according to this embodiment may be stored on a computer connected to a network such as the Internet and provided by downloading it via the network. Alternatively, the program executed by the image forming apparatus according to this embodiment may be provided or distributed via a network such as the Internet.

[0102] Furthermore, the program for the image forming apparatus according to this embodiment may be provided pre-installed in a ROM or the like. [Explanation of symbols]

[0103] 1. Image forming apparatus 10 Recording paper 11. Paper stacking tray 12. Recording paper retraction roller pair 12-1 Laura 1 12-2 Laura's Second 13. Paper set detection sensor 14 Paper feed separator roller 15 Paper feed conveyor roller 16 Resist Sensor 17. Inkjet printers 18 Paper output roller 20 Manuscripts 21 Document insertion detection sensor 22 First manuscript transport roller 23 Image reading sensor 24. Document after sensor 25. Second manuscript transport roller 50 Main control unit 60 Read control block 61 Reading Control Unit 62 Motor Control Unit 70 Image Forming Control Block 71 Printing Control Unit 72 Motor Control Unit 80 Control section 100 First transport path 101 Intersection 200 Second transport path [Prior art documents] [Patent Documents]

[0104] [Patent Document 1] Japanese Patent Publication No. 2023-085693

Claims

1. Image forming means for forming an image on a recording medium, A reading device for reading the document, The first transport path is the transport path for the recording medium, The second transport path is the transport path for the aforementioned manuscript, The intersection point where the passage through which the recording medium passes before image formation in the first transport path intersects with the second transport path, A transport means that moves the recording medium at the intersection point backward in the first transport path in the direction opposite to the direction of travel from the intersection point toward the image forming means, Control means for controlling the transport of the recording medium and the original document, Equipped with, When transporting the document before reading, if the image forming operation of the recording medium has not started, the transport means moves the recording medium at the intersection point backward from the intersection point to allow the document to enter the intersection point. Image forming apparatus.

2. A tray for stacking the recording medium at a set position where the end on the direction of travel side is on the side of the image forming means side than the intersection position, A media detection means for detecting the recording medium at the set position, Equipped with, When transporting the original document before reading, if the image forming operation of the recording medium has not started, the control means, on the condition that the medium detection means detects the medium, moves the recording medium backward to the rear of the crossing position using the transport means. The image forming apparatus according to claim 1.

3. The conveying means comprises a pair of rollers located on the rear side of the intersection point in the first conveying path and a roller contact / separation mechanism. The control means is When transporting the document before reading, if the image forming operation of the recording medium has not started, and provided that the media detection means detects the recording medium, the roller contact / separation mechanism presses the roller pair together, rotating the rollers of the roller pair to move the recording medium backward beyond the intersection point. The image forming apparatus according to claim 2.

4. The control means is When transporting the document before reading, if the media detection means does not detect the recording medium, the roller contact / separation mechanism presses the roller pair together. The image forming apparatus according to claim 3.

5. The control means releases the pressure between the roller pair by the roller contact / separation mechanism after the completion of the document reading operation. The image forming apparatus according to claim 4.

6. The control means, when the insertion of the document is detected after the image forming operation of the recording medium has started, stops the document before the intersection point of the second transport path. The image forming apparatus according to claim 5.

7. The control means is After the image forming operation of the recording medium is completed, if the medium detection means detects the recording medium, the roller contact / separation mechanism presses the roller pair together, and rotates the rollers of the roller pair to move the recording medium backward beyond the intersection position. The reading operation of the document by the reading means is started from a position where the second transport path is stopped before the intersection point. The image forming apparatus according to claim 6.

8. The control means is If the media detection means does not detect the recording medium after the image forming operation of the recording medium is completed, the roller contact / separation mechanism presses the roller pair together. The reading operation of the document by the reading means is started from a position where the second transport path is stopped before the intersection point. The image forming apparatus according to claim 6.

9. The control means, after the document being transported on the second transport path has entered the intersection position, transports the document in the opposite direction to the insertion direction of the document. The reading means performs reading on the document being transported in the opposite direction to the insertion direction. The image forming apparatus according to any one of claims 1 to 8.

10. Image forming means for forming an image on a recording medium, A reading device for reading the document, The first transport path is the transport path for the recording medium, The second transport path is the transport path for the aforementioned manuscript, The intersection point where the passage through which the recording medium passes before image formation in the first transport path intersects with the second transport path, A transport control method performed by a control device of an image forming apparatus, comprising: When the control device is transporting the original document before reading, if the image forming operation of the recording medium has not been started, it performs transport control to move the recording medium at the intersection point backward in the first transport path, in the direction opposite to the direction of travel from the intersection point toward the image forming means, thereby bringing the original document into the intersection point. A method for controlling transport.

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