Image forming device

Abstract

To provide an image forming apparatus capable of more accurately outputting a residual amount of paper sheets stored on a paper feed tray.SOLUTION: According to an embodiment, a gear body of an image forming apparatus turns between a first position and a second position with a direction of attaching / removing a paper storage part to / from a tray storage part as a rotation axis. Concerning a protrusion part, a protrusion amount of a protrusion edge part protruding toward a back face of a body from the gear body gradually increases toward a second end portion from a first end portion in a direction crossing a protrusion direction from the gear body. As the gear body moves toward a second position from a first position, the protrusion part interposes between a light-emission part and the plurality of light-receiving parts, and a sensor increases or decreases an output signal according to the number of light reception at the plurality of light-receiving parts, and the number of light-receiving parts for detection.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to an image forming apparatus. [Background technology]

[0002] When the paper feed tray is attached to the tray housing of the image forming device, the downstream end of the rotating plate on which the paper is placed rises, bringing the paper into contact with the paper feed roller. At this time, the image forming device detects the amount of paper remaining in the paper feed tray in accordance with the movement of the rotating plate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-214162 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present invention is to provide an image forming apparatus that can output the remaining amount of paper stored in a paper feed tray with higher accuracy. [Means for solving the problem]

[0005] According to an embodiment, an image forming apparatus includes a main body, a tray storage unit, a paper storage unit, a gear body, a protrusion, a sensor, and a processor. The tray storage unit is provided in the main body. The paper storage unit holds paper and is attached to and detached from the tray storage unit. The gear body is provided in the paper storage unit. When the paper storage unit is attached to the tray storage unit, the gear body rotates between a first position and a second position around a rotation axis that is along the direction in which the paper storage unit is attached to and detached from the tray storage unit. The protrusion moves in accordance with the rotation of the gear body between the first position and the second position. The protrusion protrudes from the gear body toward the back surface of the main body. The protrusion has a first end and a second end in a direction intersecting the protruding direction from the gear body. The protrusion has a protruding edge that protrudes from the gear body toward the back surface of the main body between the first end and the second end. The protruding amount of the protruding edge portion is set so that the protruding portion is curved. From the first end to the second end in a direction intersecting the direction of protrusion from the gear body Continuously Gradual increase Let The sensor is provided in the tray storage section or the paper storage section. The sensor has a light emitting section and a plurality of light receiving sections that face the light emitting section and are arranged in a direction along the axial direction of the rotation shaft. As the gear body moves from the first position to the second position, a protrusion is interposed between the light emitting section and the plurality of light receiving sections of the sensor. The protrusion determines the number of light receiving sections that detect light reception among the plurality of light receiving sections. Continuously The processor converts the output signal of the sensor into the amount of paper remaining and outputs the amount of paper remaining. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a schematic perspective view showing an image forming apparatus according to an embodiment. [Figure 2] 1 is a schematic diagram showing an overview of an image forming apparatus according to an embodiment; [Figure 3] 1 is a schematic block diagram of an image forming apparatus according to an embodiment; [Figure 4] 2 is a schematic perspective view showing the positional relationship between a tray drive unit and a paper amount detection sensor on the main body side of the image forming apparatus according to the embodiment, and a tray up mechanism on the paper feed tray side. FIG. [Figure 5] 3 is a schematic diagram of a paper amount detection sensor on the main body side of the image forming apparatus according to the embodiment, and a tray-up gear on the paper feed tray side, viewed from above; FIG. [Figure 6] 6 is a graph showing the relationship between the number of received lights at the light receiving unit of the paper amount detection sensor shown in FIG. 5 and the output based on the number of received lights. [Figure 7] FIG. 2 is a schematic top view showing a paper feed tray of the image forming apparatus according to the embodiment. [Figure 8] FIG. 2 is a schematic perspective view showing a paper storage section of a paper feed tray and a part of a tray-up mechanism of the image forming apparatus according to the embodiment. [Figure 9] 10 is a schematic diagram showing the positional relationship between a paper amount detection sensor on the main body side of the image forming apparatus according to the embodiment, and a second coupling and a tray-up gear on the paper feed tray side, as viewed from the rear side of the main body. FIG. [Figure 10] 10 is a schematic cross-sectional view showing the positional relationship between a protruding portion of the tray-up gear and a paper amount detection sensor on the main body side at a position along the line AA in FIG. 9. [Figure 11] 10 is a schematic diagram showing the positional relationship between a paper amount detection sensor on the main body side of the image forming apparatus according to the embodiment, and a second coupling and a tray-up gear on the paper feed tray side, as viewed from the rear side of the main body. FIG. [Figure 12] 12 is a schematic cross-sectional view showing the positional relationship between a protruding portion of the tray-up gear and a paper amount detection sensor on the main body side at a position along the line BB in FIG. 11. [Figure 13] 10 is a schematic diagram showing the positional relationship between a paper amount detection sensor on the main body side of the image forming apparatus according to the embodiment, and a second coupling and a tray-up gear on the paper feed tray side, as viewed from the rear side of the main body. FIG. [Figure 14] 14 is a schematic cross-sectional view showing the positional relationship between a protruding portion of the tray-up gear and a paper amount detection sensor on the main body side at a position along the line CC in FIG. 13. [Figure 15] 10 is a process flow relating to displaying the amount of paper remaining in a paper feed tray according to an embodiment; [Figure 16] 16 is a process flow relating to the tray-up operation in FIG. 15 . [Figure 17] 10 is a schematic diagram of a paper amount detection sensor on the main body side and a tray up gear on the paper feed tray side of an image forming apparatus according to a modified example, viewed from above. DETAILED DESCRIPTION OF THE INVENTION

[0007] An embodiment of the image forming apparatus 10 will be described below with reference to the drawings.

[0008] 1 and 2 is, for example, a multifunction printer (MFP). The image forming apparatus 10 includes a main body 12, a conveying unit 14, a printer 16, a control panel 18 having a display 181, a scanner 20, and a paper feed tray housing 22.

[0009] 3, the image forming apparatus 10 further includes a control unit 26 and a paper amount calculation data table 28. The transport unit 14, printer 16, control panel 18, scanner 20, paper feed tray housing unit 22, and control unit 26 are provided in the main body 12. The control unit 26 controls the transport unit 14, printer 16, control panel 18, scanner 20, paper feed tray housing unit 22, and paper amount calculation data table 28.

[0010] 1 and 2, the paper feed tray housing section 22 has multiple paper feed trays 221 arranged, for example, vertically. Each paper feed tray 221 stores, for example, multiple stacked sheets of paper as paper sheets (image forming media). The paper sheets are, for example, paper or label paper. The paper sheets may be any type as long as an image can be formed on their surface.

[0011] The front side of the image forming apparatus 10 is the side where the user stores each paper feed tray 221 in the paper feed tray housing section 22 and where an opening for pulling out the paper feed trays 221 is provided. The rear side of the image forming apparatus 10 is the side opposite the front side. The image forming apparatus 10 is used with each paper feed tray 221 stored in the paper feed tray housing section 22. In this embodiment, the paper feed tray housing section 22 removes the paper sheets stored in the paper feed trays 221 one by one to the downstream side in the paper feed direction, for example, on the right side as viewed from the front side of the image forming apparatus 10.

[0012] The transport unit 14 transports paper to the printer 16. Paper removed from the paper feed tray 221 is transported to the printer 16 by the transport unit 14. The printer 16 forms an image on the paper using a developer such as toner. After the printer 16 forms the image on the paper, the transport unit 14 transports the paper to the paper discharge unit 121 of the main body 12.

[0013] The control panel 18 is an operation input unit through which the user of the image forming apparatus 10 inputs instructions to the control unit 26. The display 181 of the control panel 18 displays various information such as icons and error messages related to the image forming apparatus 10 based on signals output from the control unit 26. The display 181 displays the amount of paper remaining in each paper feed tray 221 based on signals output from the control unit 26.

[0014] The scanner 20 is provided, for example, above the paper discharge unit 121 of the main body 12. The scanner 20 has an automatic document feeder 201 and a document table glass 202. The automatic document feeder 201 is rotatably supported with respect to the main body 12. When the ADF 201 is closed, the ADF 201 covers the entire document reading area on the document table glass 202.

[0015] Figure 4 shows the positional relationship between the first coupling 442 and the paper amount detection sensor 52 arranged in the paper feed tray storage section 22, the positional relationship between the second coupling 82 of the paper feed tray 221 connected to the first coupling 442, and the tray up gear 84 meshing with the outer peripheral gear 821 of the second coupling 82.

[0016] As shown in Figures 2, 3, and 4, the paper feed tray storage section 22 has a tray detection sensor 42, a tray drive section 44, a paper feed roller drive section 46, a paper feed roller 48, a tray up sensor 50, and a paper amount detection sensor 52.

[0017] The tray detection sensor 42 detects the attachment and detachment of the paper feed tray 221 to and from a predetermined position in the paper feed tray housing portion 22 .

[0018] The tray driving unit 44 shown in Fig. 4 has a motor 441 (see Fig. 3) and a first coupling 442 that rotates when driven by the motor 441. The first coupling 442 rotates in a predetermined direction by the motor 441.

[0019] The paper feed roller driving unit 46 shown in FIG. 3 drives the paper feed roller 48 in accordance with a command from the control unit 26 when an image is printed using the image forming apparatus 10.

[0020] 2 is disposed above the side panel 742, for example. The paper feed roller 48 comes into contact with the paper sheets placed on the paper feed tray 221. The paper feed roller 48 is driven by the paper feed roller drive unit 46 and takes out the paper sheets one by one from the paper feed tray 221. That is, the paper feed roller 48 sends out the paper sheets to be placed on the paper storage unit 62 in a direction that intersects with the direction in which the paper storage unit 62 is attached to and removed from the paper feed tray storage unit 22.

[0021] The tray-up sensor 50 shown in Figure 3 detects that the paper has come into contact with the paper feed roller 48 and has been separated from the paper feed roller 48 due to the rise of the downstream end 902 of the second rotating plate 90 of the paper feed tray 221 described later in the paper feed direction.

[0022] The paper amount detection sensor 52 shown in FIG. 4 outputs a signal to the control unit 26 based on the operation of the gear 84 on the paper feed tray 221 side, which operates in conjunction with the rotation of the first coupling 442.

[0023] 5 is a schematic diagram showing the positional relationship between the paper amount detection sensor 52 and the tray-up gear 84, as viewed from above the main body 12 of the image forming apparatus 10. Note that the tray-up gear 84 in FIG. 5 shows an example in which it is positioned at a first position where the paper feed tray 221 is removed from the paper feed tray housing section 22.

[0024] 5 has a light-emitting unit 521 and a plurality of light-receiving units 522 that face the light-emitting unit 521 and are arranged, for example, in a direction along the attachment direction and removal direction of the paper feed tray 221 relative to the paper feed tray housing unit 22, i.e., a direction along the axial direction of the rotation shaft of the gear body 841. The plurality of light-receiving units 522 may be, for example, 20 light-receiving elements arranged in one direction. The number of light-receiving units 522 can be set as appropriate.

[0025] In this embodiment, the light-emitting unit 521 and the light-receiving unit 522 are arranged so that the direction of light from the light-emitting unit 521 to the light-receiving unit 522 is not horizontal but is inclined. Depending on the positional relationship with the tray-up gear 84, the light-emitting unit 521 and the light-receiving unit 522 may be arranged so that the direction of light from the light-emitting unit 521 to the light-receiving unit 522 is horizontal.

[0026] 6 shows an example of an output signal relative to the number of light received from the light-emitting element 521 by, for example, 20 light-receiving elements 522. As shown in FIG. 6, when 20 of the 20 light-receiving elements 522 receive light from the light-emitting element 521, the paper amount detection sensor 52 outputs 3.3 V. When, for example, 19 of the 20 light-receiving elements 522 receive light from the light-emitting element 521, the paper amount detection sensor 52 outputs 2.9 V. When, for example, 18 of the 20 light-receiving elements 522 receive light from the light-emitting element 521, the paper amount detection sensor 52 outputs 2.8 V. When, for example, one of the 20 light-receiving elements 522 receives light from the light-emitting element 521, the paper amount detection sensor 52 outputs 1.1 V. When zero of the 20 light receiving elements 522 receives light from the light emitting element 521, the paper amount detection sensor 52 outputs 0.7 V. In this way, the paper amount detection sensor 52 outputs in 20 steps according to the number of light receiving elements 522 among the plurality of light receiving elements 522. In the paper amount detection sensor 52 according to this embodiment, the output signal from the paper amount detection sensor 52 decreases in steps of 0.1 V as the number of light receiving elements 522 decreases from 1 to 19 among the 20 light receiving elements 522. In other words, the paper amount detection sensor 52 increases the output signal in steps of 0.1 V as the number of light receiving elements 522 increases from 1 to 19 among the 20 light receiving elements 522. The relationship between the number of light receiving elements 522 and the output signal (voltage) is shown in FIG. 6.

[0027] A paper amount calculation data table 28 is connected to the control unit 26. The paper amount calculation data table 28 stores, for example, the following correspondence relationship according to the positional relationship between the paper amount detection sensor 52 and a protrusion 843 of a tray-up gear 84 described later.

[0028] When the number of light receiving elements is 19 (output value is 2.9V), the paper remaining amount is 100%; when the number of light receiving elements is 18 (output value is 2.8V), the paper remaining amount is 93%; when the number of light receiving elements is 17 (output value is 2.7V), the paper remaining amount is 87%; when the number of light receiving elements is 16 (output value is 2.6V), the paper remaining amount is 80%; when the number of light receiving elements is 15 (output value is 2.5V), the paper remaining amount is 73%; when the number of light receiving elements is 14 (output value is 2.4V), the paper remaining amount is 67%; when the number of light receiving elements is 13 (output value is 2.3V), the paper remaining amount is 60%; when the number of light receiving elements is 12 (output value is 2.2V), the paper remaining amount is 53%. %, and the number of received light elements is 11 (output value is 2.1V), the remaining paper amount is 47%, when the number of received light elements is 10 (output value is 2.0V), the remaining paper amount is 40%, when the number of received light elements is 9 (output value is 1.9V), the remaining paper amount is 33%, when the number of received light elements is 8 (output value is 1.8V), the remaining paper amount is 27%, when the number of received light elements is 7 (output value is 1.7V), the remaining paper amount is 20%, when the number of received light elements is 6 (output value is 1.6V), the remaining paper amount is 13%, when the number of received light elements is 5 (output value is 1.5V), the remaining paper amount is 7%, and when the number of received light elements is 4 (output value is 1.4V), the remaining paper amount is 0%. Therefore, control unit 26 detects the output of paper amount detection sensor 52 and outputs the amount of paper present in paper tray 221 as an amount relative to the maximum amount.

[0029] FIG. 7 shows a top view of the paper feed tray 221. The upper side in FIG. 7 is located at the back of the paper feed tray housing unit 22, and the lower side in FIG. 7 is the handle side when a user removes or pushes back the paper feed tray 221. As shown in FIG. 7, the paper feed tray 221 has a paper housing unit 62, side fences 641, 642, and 643, and a tray-up mechanism 66. Note that the two-dot chain line in FIG. 7 indicates the side fences 641 and 642 and the second pivot plate 90 that is operated by the tray-up mechanism 66.

[0030] The paper storage section 62 is formed, for example, in a box shape with an open top. Paper is placed in the paper storage section 62, which is attached to and detached from the tray storage section 22. The paper storage section 62 has, for example, a substantially rectangular bottom plate 72 and side plates 741, 742, 743, and 744. The side plates 741 and 742 are used as rails when the paper storage section 62 of the paper feed tray 221 is pulled out from and pushed back into a predetermined position in the paper feed tray storage section 22. The side plate 743 is used as a handle when the user attaches the paper storage section 62 of the paper feed tray 221 to and removes the paper storage section 62 of the paper feed tray 221 from and to a predetermined position in the main body 12. The side plate 744 is located on the rear side (rear side) when the paper storage section 62 of the paper feed tray 221 is stored in a predetermined position in the main body 12.

[0031] The side fences 641, 642 face each other between the side plates 743, 744. The side fences 641, 642 are movable in a direction along the direction in which the paper storage section 62 of the paper feed tray 221 is pulled out and pushed in from a predetermined position in the paper feed tray housing section 22. Therefore, the side fences 641, 642 are slidable in a direction intersecting, or preferably perpendicular to, the paper feed direction from the paper feed tray 221 toward the paper feed roller 48 (the direction from left to right in FIG. 7), and the opposing side fences 641, 642 move in unison. The opposing side fences 641, 642 come into contact with both ends of the paper, thereby positioning the paper on the paper feed tray 221 in a direction along the direction in which the paper storage section 62 is pulled out and pushed in.

[0032] Of the side plate 742, a surface 7421 on the side plate 741 side abuts against the edge surface of the paper. The side fence 643 moves toward and away from the surface 7421 of the side plate 742. Therefore, the side fence 643 can move in the paper feed direction (from left to right in FIG. 7) from the paper feed tray 221 toward the paper feed roller 48. The side fence 643 and the surface 7421 of the side plate 742 come into contact with both ends of the paper, thereby positioning the paper on the paper feed tray 221 in the paper feed direction.

[0033] FIG. 8 is a perspective view showing the side plate 744 of the paper storage section 62 of the paper feed tray 221, and the second coupling 82 and tray-up gear 84 of the tray-up mechanism 66. As shown in FIG.

[0034] As shown in FIGS. 4, 7, and 8, the tray-up mechanism 66 includes a second coupling 82, a tray-up gear 84, a tray-up shaft 86, a first rotating plate 88, and a second rotating plate 90.

[0035] The second coupling 82 is formed in a cylindrical shape. The second coupling 82 is connected to the first coupling 442 of the tray drive unit 44 when the paper feed tray 221 is attached to the paper feed tray housing unit 22. The first coupling 442 and the second coupling 82 are fitted together around the same central axis. Therefore, the second coupling 82 rotates together with the first coupling 442. When the paper feed tray 221 is removed from the paper feed tray housing unit 22, the second coupling 82 is released from its connection with the first coupling 442 of the tray drive unit 44.

[0036] The second coupling 82 has an outer circumferential gear 821 on its outer circumferential surface. The outer circumferential gear 821 meshes with the tray-up gear 84.

[0037] The tray-up gear 84 is formed, for example, in a fan shape. The tray-up gear 84 rotates within a predetermined range in accordance with the rotation of the second coupling 82. The rotation axis (center axis) of the tray-up gear 84 is parallel to the rotation axis of the second coupling 82, and is spaced a predetermined distance from it.

[0038] As shown in FIGS. 4, 5, and 8, the tray-up gear 84 has a gear body 841, an outer peripheral gear 842, and a protrusion 843.

[0039] The gear body 841 is formed, for example, in a fan shape, and has a rear surface 8411 and a first arc portion 8412. The gear body 841 is provided in the paper storage unit 62. When the paper storage unit 62 is attached to the tray storage unit 22, the gear body 841 rotates between a first position and a second position, with the rotation axis being in the direction along the attaching direction and detaching direction of the paper storage unit 62 to the tray storage unit 22.

[0040] The outer peripheral gear 842 is formed on an outer peripheral surface extending from the position of the first arc portion 8412 of the gear body 841 toward the front side. The outer peripheral gear 842 meshes with the outer peripheral gear 821 of the second coupling 82. Therefore, the gear 84 rotates in accordance with the rotation of the second coupling 82.

[0041] The protrusion 843 protrudes from a surface 8411 on the rear side of the gear body 841 toward the rear of the main body 12 of the image forming apparatus 10. The protrusion 843 moves as the gear body 841 of the tray-up gear 84 rotates between the first position and the second position. The protrusion 843 has a plate-shaped second arc portion 8431 whose central axis is the rotation axis of the gear 84, and a protruding edge portion 8432. The second arc portion 8431 has a first end portion 84311 and a second end portion 84312 in the direction around the rotation axis (central axis) of the gear 84. That is, the protrusion 843 has the first end portion 84311 and the second end portion 84312 in the direction intersecting the protruding direction from the gear body 841. The protrusion 843 has a protruding edge 8432 that protrudes from the gear body 841 between the first end 84311 and the second end 84312 toward the rear surface of the main body 12, and the protruding amount of the protruding edge 8432 gradually increases from the first end 84311 to the second end 84312. In this embodiment, the protruding edge 8432 of the protrusion 843 is formed, for example, in a straight line when the tray-up gear 84 is viewed from above. The protrusion 843 is positioned so as to cross the space between the light-emitting unit 521 and the light-receiving unit 522 of the paper amount detection sensor 52. The protrusion 843 is positioned so as not to come into contact with the paper amount detection sensor 52.

[0042] A protrusion amount Da of the first end 84311 of the second arc portion 8431 toward the rear surface of the main body 12 relative to a rear surface 8411 of the gear body 841 is smaller than a protrusion amount Db of the second end 84312 of the second arc portion 8431 relative to a rear surface 8411 of the gear body 841. The protrusion amount (protrusion amount in the direction along the rotation axis of the tray-up gear 84) from the surface 8411 of the gear body 841 of the tray-up gear 84 between the first end 84311 and the second end 84312 toward the rear surface of the main body 12 of the image forming apparatus 10 gradually increases from the first end 84311 toward the second end 84312. Therefore, the protrusion amount Dc between the second arc portion 8431 and the protruding edge portion 8432 at any position between the first end portion 84311 and the second end portion 84312 is greater than the protrusion amount Da and less than the protrusion amount Db.

[0043] 9 to 14 show the protrusion 843 of the tray-up gear 84, and the light-emitting element 521 and light-receiving element 522 of the paper amount detection sensor 52. The two-dot chain line in FIG. 9 indicates a state in which the gear body 841 is in the first position. The solid line in FIG. 9 and FIG. 10 indicate a state in which the vicinity of the first end 84311 of the protrusion 843 of the tray-up gear 84 is between the light-emitting element 521 and the light-receiving element 522 of the paper amount detection sensor 52, blocking part of the light-receiving element 522. FIG. 10 shows a cross section taken along line AA in FIG. 9. The two-dot chain line in FIG. 11 indicates a state in which the gear body 841 is in the first position. The solid line in FIG. 11 and FIG. 12 show a state in which the vicinity of the second end 84312 of the protrusion 843 of the tray-up gear 84 is between the light-emitting element 521 and the light-receiving element 522 of the paper amount detection sensor 52, blocking part of the light-receiving element 522. FIG. 12 shows a cross section taken along line BB in FIG. 11. The two-dot chain line in FIG. 13 shows a state in which the gear body 841 is in the first position. The solid line in FIG. 13 and FIG. 14 show a state in which the portion between the first end 84311 and the second end 84312 of the protrusion 843 of the tray-up gear 84 is between the light-emitting element 521 and the light-receiving element 522 of the paper amount detection sensor 52, blocking part of the light-receiving element 522. FIG. 14 shows a cross section taken along line CC in FIG. 13.

[0044] 10, the protrusion 843 blocks a portion of the light from the light-emitting unit 521. Therefore, most (e.g., 19) of the plurality of light-receiving units 522 receive the light from the light-emitting unit 521, but, for example, one light-receiving unit 522 does not receive the light from the light-emitting unit 521.

[0045] 12, the protrusion 843 blocks most of the light from the light-emitting unit 521. Therefore, some of the multiple light-receiving units 522 (for example, four light-receiving units 522) receive the light from the light-emitting unit 521, but the remaining light-receiving units 522, for example, 16 light-receiving units 522 out of, for example, 20 light-receiving units 522, do not receive the light from the light-emitting unit 521.

[0046] 14, the protrusion 843 blocks approximately half of the light from the light-emitting unit 521. Therefore, some of the multiple light-receiving units 522 (for example, 12 light-receiving units 522) receive the light from the light-emitting unit 521, but the remaining light-receiving units 522, for example, 8 light-receiving units 522 out of, for example, 20 light-receiving units 522, do not receive the light from the light-emitting unit 521.

[0047] Therefore, as the gear body 841 moves from the first position to the second position, the protrusion 843 is interposed between the light-emitting unit 521 and the plurality of light-receiving units 522 of the paper amount detection sensor 52. The protrusion 843 increases or decreases the number of light-receiving units 522 that detect light reception among the plurality of light-receiving units 522, and the paper amount detection sensor 52 increases or decreases the output signal depending on the number of light-receiving units 522 that detect light reception. Therefore, the paper amount detection sensor 52 outputs an output signal depending on the positional relationship with the protrusion 843 of the tray-up gear 84.

[0048] The tray-up shaft 86 is fixed to the central axis of the tray-up gear 84 so as to be prevented from rotating. The tray-up shaft 86 passes through the side plate 744 and extends toward the side plate 743. The tray-up shaft 86 rotates in conjunction with the rotation of the tray-up gear 84. The tray-up shaft 86 is prevented from protruding upward from the bottom plate 72 by, for example, a recess in the bottom plate 72.

[0049] The first rotating plate 88 is formed in a plate shape and is fixed to the tray-up shaft 86. The first rotating plate 88 rotates in accordance with the rotation of the tray-up shaft 86. An end 881 on the downstream side in the paper feed direction of the first rotating plate 88 moves up and down relative to the bottom plate 72 in accordance with the rotation of the tray-up shaft 86.

[0050] The second rotating plate 90 is provided in the paper storage unit 62. The second rotating plate 90 has a rotation axis 901 that is parallel to the extension direction of the tray-up shaft 86 and that corresponds to the direction in which the paper feed tray 221 is attached to and removed from the paper feed tray storage unit 22. The rotation axis 901 is formed on the opposite side of the tray-up shaft 86 from the downstream side in the paper feed direction. The second rotating plate 90 is located above the first rotating plate 88. Paper is placed on the upper side of the second rotating plate 90. A downstream end 902 of the second rotating plate 90 in the paper feed direction rises and falls in accordance with the rise and fall of a downstream end 881 of the first rotating plate 88 in the paper feed direction. Therefore, when the downstream end 881 of the first rotating plate 88 in the paper feed direction rises, the downstream end 902 of the second rotating plate 90 rises, and the paper is tray-up. The paper feed roller 48 is located above the downstream side in the paper feed direction of the paper feed tray 221. When the downstream end 881 of the first rotating plate 88 in the paper feed direction descends, the downstream end 902 of the second rotating plate 90 descends.

[0051] When the gear body 841 is in the first position, the downstream end 902 of the second rotating plate 90 in the paper feed direction on the paper feed roller 48 side is positioned in a position that contacts or is closest to the bottom plate 72 of the paper storage unit 62. When the gear body 841 is in the second position, the downstream end 902 of the second rotating plate 90 in the paper feed direction is positioned in a position that is farthest from the bottom plate 72 of the paper storage unit 62. In this way, the downstream end 902 of the second rotating plate 90 in the paper feed direction relative to the bottom plate 72 rises in accordance with the amount of rotation of the gear body 841.

[0052] When the paper feed tray 221 is inserted into the paper feed tray housing section 22 and the second rotating plate 90 of the paper feed tray 221 is raised up to the tray-up mechanism 66, the paper feed roller 48 is pushed upward by the paper on the second rotating plate 90. In other words, when the paper storage section 62 is attached to the tray housing section 22, the second rotating plate 90 operates in accordance with the rotation of the gear body 841, and brings the paper placed in the paper storage section 62 into contact with the paper feed roller 48.

[0053] The control unit 26 converts the output signal of the paper amount detection sensor 52 into the remaining amount of paper and outputs the remaining amount of paper to the control panel 18.

[0054] The control unit 26, for example, uses one or more processors such as CPUs to load a control program stored in a memory such as ROM onto RAM, and executes appropriate processing for the transport unit 14, printer 16, control panel 18, scanner 20, and paper feed tray housing unit 22. Alternatively, the control unit 26, for example, uses one or more processors such as CPUs to read out a program via a network, and executes appropriate processing for the transport unit 14, printer 16, control panel 18, scanner 20, and paper feed tray housing unit 22. The control unit 26 can control the transport unit 14, printer 16, control panel 18, scanner 20, and paper feed tray housing unit 22 using a circuit (for example, an ASIC) that implements one or more functions.

[0055] The control unit 26 of the image forming apparatus 10 executes processing related to displaying the amount of remaining paper in the paper feed tray 221, for example, in accordance with the flowcharts shown in FIGS.

[0056] 15, for example, when the power of the main body 12 of the image forming apparatus 10 is switched ON, the control unit 26 puts the tray detection sensor 42 of the paper feed tray housing unit 22 into a standby state for tray detection (Act 1). Even after the image forming apparatus 10 has performed printing, the control unit 26 puts the tray detection sensor 42 into a standby state for tray detection.

[0057] The control unit 26 determines whether the paper feed tray 221 is in the attachment position or the removal position relative to the paper feed tray housing unit 22 using a signal from the tray detection sensor 42 (Act 2). If the tray detection sensor 42 cannot detect that the paper feed tray 221 is attached to the paper feed tray housing unit 22 (Act 2-No), the control unit 26 continues processing until the tray detection sensor 42 detects that the paper feed tray 221 is attached to the paper feed tray housing unit 22.

[0058] When the control unit 26 detects that the paper feed tray 221 has been attached to the paper feed tray housing unit 22 using the tray detection sensor 42 (Act 2-Yes), the control unit 26 operates the tray-up mechanism 66 (Act 3).

[0059] 16, the control unit 26 drives the motor 441 of the tray drive unit 44 to rotate the second coupling 82 connected to the first coupling 442 and located on the side of the sheet feed tray 221. The rotation of the second coupling 82 rotates the tray-up gear 84. At this time, the rotation of the tray-up gear 84 rotates the tray-up shaft 86, and the downstream end 881 of the first rotating plate 88 in the sheet feed direction rises relative to the bottom plate 72. As a result, the second rotating plate 90 rotates around the rotation shaft 901, and the downstream end 902 of the second rotating plate 90 in the sheet feed direction rises away from the bottom plate 72 (Act 31).

[0060] The control unit 26 uses the tray-up sensor 50 to determine whether the paper on the second rotating plate 90 has risen to a predetermined position where it contacts the paper feed roller 48 (Act 32).

[0061] If the paper on the second rotating plate 90 has not risen to a predetermined position where it contacts the paper feed roller 48 (Act 32-No), the control unit 26 drives the motor 441 to further rotate the second coupling 82 on the paper feed tray 221 side, which is connected to the first coupling 442. Therefore, the control unit 26 drives the motor 441 to further raise the end 902 of the second rotating plate 90 on the downstream side in the paper feed direction.

[0062] When the control unit 26 determines, using the tray-up sensor 50, that the paper on the second rotating plate 90 has risen to a predetermined position where it contacts the paper feed roller 48 (Act 32-Yes), the control unit 26 stops the operation of the motor 441. The control unit 26 continues to control the motor 441, and maintains the position of the end 902 of the second rotating plate 90 on the downstream side in the paper feed direction relative to the bottom plate 72 (Act 33).

[0063] As shown in FIG. 15, when the control unit 26 stops the operation of the motor 441, the control unit 26 detects the output of the paper amount detection sensor 52 (Act 4). The paper amount detection sensor 52 changes its output signal depending on the number of light receiving units 522, for example, out of 20 light receiving units 522. For example, when a predetermined maximum amount of paper is loaded in the paper feed tray 221, the amount of rotation until the paper contacts the paper feed roller 48 is from the first position indicated by the two-dot chain line in FIG. 9 to the position indicated by the solid line in FIG. 9. As shown in FIGS. 9 and 10, for example, one light receiving unit 522 is shielded from light, and the remaining 19 light receiving units 522 receive light from the light emitting unit 521. In this case, the paper amount detection sensor 52 outputs an output signal of 2.9 V.

[0064] The control unit 26 calculates the remaining amount of paper that can be placed in the paper feed tray 221 based on the output signal of the paper amount detection sensor 52 (Act 5). For example, the control unit 26 outputs the remaining amount of paper based on the output signal of the paper amount detection sensor 52 from the paper amount calculation data table 28 shown in FIG.

[0065] 9 and 10 , when the vicinity of the first end 84311 of the protrusion 843 is interposed between the light-emitting unit 521 and the light-receiving unit 522, for example, light reception by one light-receiving unit 522 is blocked, and light from the light emitter 521 is received by 19 light-receiving units 522. As shown in FIGS. 13 and 14 , when a portion approximately in the center between the first end 84311 and the second end 84312 of the protrusion 843 is interposed between the light-emitting unit 521 and the light-receiving unit 522, light reception by eight light-receiving units 522 is blocked, and light from the light emitter 521 is received by 12 light-receiving units 522. As shown in Figures 11 and 12, when the vicinity of the second end 84312 of the protrusion 843 is interposed between the light-emitting unit 521 and the light-receiving unit 522, for example, light reception at 16 light-receiving units 522 is blocked, and light from the light-emitting unit 521 is received by four light-receiving units 522.

[0066] For this reason, the output signal from paper amount detection sensor 52 decreases, for example, by 0.1 V from a full state where the remaining amount of paper is less than a predetermined amount until the paper runs out. If protrusion 843 blocks light reception by a maximum of N (N is a natural number) light receiving elements 522 in the positional relationship between light receiving elements 522 and light emitting elements 521 of paper amount detection sensor 52, the remaining paper amount is output in N stages.

[0067] The control unit 26 calculates the amount of paper, for example, as a relative amount, from the output of the paper amount detection sensor 52 (Act 5). That is, the control unit 26 converts the output of the paper amount detection sensor 52 into the amount of paper. In this embodiment, for example, a maximum of 16 light receiving units 522 are shielded, and therefore the remaining amount of paper is output in 16 stages.

[0068] The control unit 26 displays (updates) the remaining amount of paper on the display 181 (Act 6). The remaining amount of paper may be displayed, for example, as an icon with horizontal bars arranged vertically, with the upper bar disappearing as the paper decreases, or may be displayed as a relative value, such as a percentage display, where 100% is when the paper is full and 0% is when there is no paper.

[0069] Then, the control unit 26 puts the image forming apparatus 10 into a print standby state (Act 7).

[0070] Therefore, the control unit 26 ends the process related to the remaining paper amount display.

[0071] 15 and 16 after, for example, one printing operation or after removing and attaching the paper feed tray 221 to the paper feed tray housing 22. That is, the control unit 26 drives the motor 441 to adjust the positional relationship between the paper feed roller 48 and the paper. Therefore, the positional relationship between the protruding edge 8432 of the protruding portion 843 of the tray-up gear 84 and the paper amount detection sensor 52 is adjusted in accordance with the rotation of the motor 441. Therefore, as described above, the control unit 26 updates the remaining paper amount displayed on the display 181.

[0072] The tray-up gear 84 according to this embodiment changes its rotation position depending on the amount of paper placed in the paper feed tray 221. When the paper amount is at or near 100%, the tray-up gear 84 rotates from the first position indicated by the two-dot chain line in FIG. 9 to the position indicated by the solid line. When the paper amount is at or near 0%, the tray-up gear 84 rotates from the first position indicated by the two-dot chain line in FIG. 11 to the second position indicated by the solid line. The remaining paper amount during this period can be displayed in stages depending on the number of light-receiving elements 522 of the paper amount detection sensor 52, i.e., the resolution. That is, the paper amount detection sensor 52 increases its output signal as the number of light-receiving elements 522 that detect light increases. The paper amount detection sensor 52 changes its output signal in stages corresponding to the resolution determined by the number of light-receiving elements 522.

[0073] When the paper feed tray 221 is 100% full of paper, as shown in FIGS. 9 and 10 , the first rotating plate 88 and the second rotating plate 90 rotate a predetermined minimum angle from the first position to bring the paper into contact with the paper feed roller 48. At this time, the first end 84311 of the protrusion 843 and its vicinity block light from, for example, one of the 20 light receiving sections 522. As a result, the remaining 19 light receiving sections 522 receive light from the light emitting section 521. At this time, the control section 26 detects, for example, an output of 2.9 V from the paper amount detection sensor 52.

[0074] When there is no paper in the paper feed tray 221, as shown in FIGS. 11 and 12 , the first rotating plate 88 and the second rotating plate 90 rotate to the maximum angle from the first position to bring the paper into contact with the paper feed roller 48. At this time, the curved protrusion 843 between the first end 84311 and the second end 84312 blocks light from, for example, 16 of the 20 light receiving units 522. As a result, the remaining four of the 20 light receiving units 522 receive light from the light emitting unit 521. At this time, the control unit 26 detects, for example, an output of 1.4 V from the paper amount detection sensor 52.

[0075] As described above, in the image forming apparatus 10 according to this embodiment, the number of light beams blocked by the protrusion 843 on the light receiving unit 522 changes depending on the position of the downstream end 902 of the second rotating plate 90 in the paper feed direction. The output of the paper amount detection sensor 52 changes depending on the number of light beams blocked by the light receiving unit 522. The control unit 26 calculates the amount of paper, for example, as a relative amount, from the output of the paper amount detection sensor 52. The output of the paper amount detection sensor 52 can be set in stages depending on the resolution of the paper amount detection sensor 52. This allows the control unit 26 to output the remaining amount of paper in stages depending on the resolution of the paper amount detection sensor 52. Therefore, if the paper amount detection sensor 52 has an appropriate resolution, the user can easily determine the amount of paper remaining in the image forming apparatus 10, for example, when printing a large amount of paper or refilling paper, by looking at the display 181 of the control panel 18.

[0076] According to this embodiment, it is possible to provide the image forming apparatus 10 that can output the remaining amount of paper stored in the paper feed tray 221 with higher accuracy.

[0077] Note that a part of the protrusion 843 of the tray-up gear 84 may be positioned so as to block light reception by one light-receiving portion 522 between the light-emitting portion 521 and the light-receiving portion 522 of the paper amount detection sensor 52 when the gear body 841 is in the first position. The control portion 26 can detect the amount of paper using a signal generated by light reception by one light-receiving portion 522 of the paper amount detection sensor 52 as a trigger.

[0078] In the above description, the protruding edge 8432 of the protruding portion 843 is formed to be straight when the tray-up gear 84 is viewed from above, as shown in Fig. 5. The protruding edge 8432 of the protruding portion 843 may be formed to be curved when the tray-up gear 84 is viewed from above, as shown in Fig. 17. The protruding edge 8432 of the protruding portion 843 may also be formed in a stepped shape.

[0079] In the protrusion 843 described in this embodiment, the protrusion amount Da at the first end 84311 toward the rear side of the main body 12 relative to the rear surface 8411 of the gear body 841 is smaller than the protrusion amount Db at the second end 84312 toward the rear side of the main body 12 relative to the rear surface 8411 of the gear body 841. It is also preferable that the protrusion amount Da at the first end 84311 is larger than the protrusion amount Db at the second end 84312. In this case, when the protrusion 843 blocks a portion of the light receiving unit 522 at the first end 84311, the output of the paper amount detection sensor 52 is minimized. Then, as the gear body 841 rotates from the first position to the second position, the output of the paper amount detection sensor 52 increases.

[0080] The paper amount detection sensor 52 described in this embodiment is configured to increase its output as the number of light beams received by the light-receiving unit 522 increases. However, the paper amount detection sensor 52 may be configured to decrease its output as the number of light beams received by the light-receiving unit 522 increases, for example.

[0081] The number of light receiving sections 522 and the number of levels of paper volume are merely examples and can be set appropriately depending on the relationship between the number of light receiving sections 522 and the number of light-blocking sections using the protrusions 843, for example, in increments of 5% or 10%.

[0082] According to the image forming apparatus 10 of at least one of the embodiments described above, the remaining amount of paper stored in the paper feed tray 221 can be output with higher accuracy.

[0083] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. The following is a summary of the claims of this application at the time of filing. [Appendix 1] The main body and a tray storage section provided in the main body; a paper storage section on which paper is placed and which is attached to and detached from the tray storage section; a gear body that is provided in the paper storage unit and that, when the paper storage unit is attached to the tray storage unit, rotates between a first position and a second position around a rotation axis that is aligned with a direction in which the paper storage unit is attached to and removed from the tray storage unit; a protrusion that moves in accordance with the rotation of the gear body between the first position and the second position, and has a protruding edge that protrudes from the gear body toward the rear surface of the main body, the protruding amount of the protruding edge gradually increasing from a first end toward a second end in a direction intersecting the protruding direction from the gear body; a sensor provided in the tray storage section or the paper storage section, the sensor having a light emitting section and a plurality of light receiving sections facing the light emitting section and arranged in a direction along the axial direction of the rotation shaft, wherein a protrusion is interposed between the light emitting section and the plurality of light receiving sections as the gear body moves from the first position to the second position, the number of light receiving sections that detect light reception increases or decreases among the plurality of light receiving sections, and the sensor increases or decreases an output signal according to the number of light receiving sections that detect light reception; a processor that converts an output signal from the sensor into the remaining amount of paper and outputs the remaining amount of paper; An image forming apparatus comprising: [Appendix 2] the sensor increases the output signal as the number of light receiving sections that detect light reception increases, 2. The image forming apparatus according to claim 1, wherein the sensor outputs an output signal at a level corresponding to a resolution that depends on the number of the light receiving units. [Appendix 3] a paper feed roller that feeds the paper to be placed in the paper storage unit in a direction that intersects with a direction in which the paper storage unit is attached to and detached from the tray storage unit; a rotating plate that is provided in the paper storage unit, on which the paper is placed, and that rotates in accordance with the rotation of the gear body when the paper storage unit is attached to the tray storage unit, thereby bringing the paper into contact with the paper feed roller; 3. The image forming apparatus according to claim 1, further comprising: [Appendix 4] When the gear body is in the first position, an end portion of the rotating plate on the downstream side in the paper feed direction on the paper feed roller side is disposed at a position in contact with or closest to a bottom plate of the paper storage unit, When the gear body is in the second position, a downstream end of the rotating plate in the paper feed direction is disposed at a position furthest from a bottom plate of the paper storage unit, 4. The image forming apparatus according to claim 3, wherein an end portion of the rotating plate on a downstream side in the paper feed direction relative to the bottom plate rises in accordance with an amount of rotation of the gear body. [Appendix 5] The image forming apparatus according to any one of claims 1 to 4, wherein the protrusion has an arc portion with the rotation axis as its central axis between the first end and the second end of the gear body. [Explanation of symbols]

[0084] 10...image forming apparatus, 12...main body, 18...control panel, 181...display, 22...paper feed tray housing, 221...paper feed tray, 26...controller, 44...tray drive unit, 441...motor, 442...first coupling, 52...paper amount detection sensor, 521...light emitting unit, 522...light receiving unit, 62...paper housing unit, 641, 642, 643...side fence, 66...tray up mechanism, 72...bottom plate, 741, 742, 743, 744...side plates, 82...second cup Ring, 821...peripheral gear, 84...tray up gear, 841...gear body, 8411...rear surface of gear body, 8412...first arc portion, 842...peripheral gear, 843...protruding portion, 8431...second arc portion, 8432...protruding edge portion, 84311...first end, 84312...second end, 86...tray up shaft, 88...first rotating plate, 881...end portion downstream in the paper feed direction, 90...second rotating plate, 901...rotating shaft, 902...end portion downstream in the paper feed direction.

Claims

1. The main body and a tray storage section provided in the main body; a paper storage section on which paper is placed and which is attached to and detached from the tray storage section; a gear body that is provided in the paper storage unit and that, when the paper storage unit is attached to the tray storage unit, rotates between a first position and a second position around a rotation axis that is aligned with a direction in which the paper storage unit is attached to and detached from the tray storage unit; a protruding portion that moves in accordance with the rotation of the gear body between the first position and the second position, and that gradually increases the protruding amount of the protruding edge portion from the gear body toward the rear surface of the main body from a first end toward a second end in a direction intersecting the protruding direction from the gear body so that the protruding edge portion protruding from the gear body toward the rear surface of the main body forms a curve; a sensor provided in the tray storage section or the paper storage section, the sensor having a light emitting section and a plurality of light receiving sections facing the light emitting section and aligned in a direction along the axial direction of the rotation shaft, wherein a protrusion is interposed between the light emitting section and the plurality of light receiving sections as the gear body moves from the first position to the second position, the number of light receiving sections that detect light reception being continuously increased or decreased among the plurality of light receiving sections, and the sensor increases or decreases an output signal according to the number of light receiving sections that detect light reception; a processor that converts an output signal from the sensor into the remaining amount of paper and outputs the remaining amount of paper; An image forming apparatus comprising:

2. An image forming device as described in Claim 1, wherein the curve of the protruding edge portion is farther away from the gear body than when the protruding edge portion is connected between the first end and the second end by a straight line.

3. the sensor increases the output signal as the number of light receiving sections that detect light reception increases, 3. The image forming apparatus according to claim 1, wherein the sensor outputs an output signal in stages corresponding to a resolution that depends on the number of the light receiving portions.

4. a paper feed roller that feeds the paper to be placed in the paper storage unit in a direction that intersects with a direction in which the paper storage unit is attached to and detached from the tray storage unit; a rotating plate that is provided in the paper storage unit, on which the paper is placed, and that rotates in accordance with the rotation of the gear body when the paper storage unit is attached to the tray storage unit, thereby bringing the paper into contact with the paper feed roller; The image forming apparatus according to claim 1 , further comprising:

5. 5. The image forming apparatus according to claim 1, wherein the protrusion has an arc portion with the rotation shaft as a central axis between the first end and the second end of the gear body.

Images