Paper feed cassette and image formation apparatus

Abstract

To prevent breakage of components with a simple configuration.SOLUTION: A paper feed cassette 51 attached to an image forming apparatus includes a push-up plate 55 arranged on an inner bottom surface 53 and on which a recording medium is placed, a lift-up mechanism M1 that is driven by a driving unit 71 provided in the image forming apparatus and pushes up the push-up plate 55, and a fixing member 81 that fixes the push-up plate 55 to the inner bottom surface 53. The fixing member 81 includes a shut-off portion 83 disposed between the lift-up mechanism M1 and the driving unit 71 and configured to maintain a state in which the lift-up mechanism M1 and the driving unit 71 are not connected.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to a paper feed cassette and an image forming apparatus, and more particularly to a paper feed cassette that accommodates recording media and an image forming apparatus that includes the paper feed cassette. [Background technology]

[0002] In recent years, image forming apparatuses, such as multifunction peripherals, have been equipped with a paper feed cassette capable of storing multiple recording media for forming images on sheet-like recording media such as paper. This paper feed cassette is equipped with a push-up mechanism for transporting recording media in order, starting with the top recording medium, regardless of the number of recording media stored. When no recording media are stored in the push-up mechanism, a portion of the push-up mechanism is free to move upward. For this reason, for example, during transportation of the image forming apparatus prior to installation, external vibrations can cause a portion of the push-up mechanism to move up and down, resulting in a malfunction.

[0003] JP 2008-265981 A describes a paper feed cassette that includes a cassette frame that is detachably attached to a paper feed device and that holds and stores paper sheets; and a lift plate whose upstream end in the paper feed direction is supported on the inner bottom surface of the cassette frame, that is swingable around this fulcrum, and on whose upper surface paper sheets are placed. The paper feed cassette further includes a lift plate push-up plate that lifts and swings the lift plate from below, and a lift plate swinging shaft that has one end attached to the lift plate push-up plate and the other end attached to a coupling means that connects to a drive transmission means arranged in the paper feed device. The lift plate swinging shaft is selectively positioned at a first position where the lift plate push-up plate engages with an engagement portion provided on the back surface of the lift plate and releases the coupling means from the drive transmission means, and a second position where the lift plate push-up plate releases the engagement with the engagement portion and connects the coupling means to the drive transmission means.

[0004] However, the paper feed cassette described in JP 2008-265981 A requires a mechanism for selectively positioning the lift plate swing shaft between the first and second positions, which makes the mechanism complicated. Furthermore, space is required to accommodate the mechanism, which results in an increase in the size of the paper feed tray or a reduction in the space available for storing recording media. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-265981 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made to solve the above-mentioned problems, and one of the objects of the present invention is to provide a paper feed cassette with a simple structure that prevents damage to parts.

[0007] Another object of the present invention is to provide an image forming apparatus with a simple structure that prevents damage to parts. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, according to one aspect of the present invention, a paper feed cassette is a paper feed cassette that is attached to an image forming device and includes: a boost plate that is arranged on the inner bottom surface and on which a recording medium is placed; a lift-up mechanism that is driven by a drive unit provided in the image forming device and pushes up the boost plate; and a fixing member that fixes the boost plate to the inner bottom surface, wherein the fixing member is arranged between the lift-up mechanism and the drive unit and has a blocking portion that maintains a state in which the lift-up mechanism and the drive unit are not connected.

[0009] According to another aspect of the present invention, an image forming apparatus includes the above-described paper feed cassette. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view of an MFP according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an example of the internal configuration of an MFP. [Figure 3] FIG. 2 is a perspective view illustrating an example of a paper feed cassette. [Figure 4] FIG. 2 is a plan view illustrating an example of a paper feed cassette. [Figure 5] FIG. 2 is a perspective view showing an example of a drive unit. [Figure 6] FIG. 10 is a perspective view showing an example of a connection between a lift-up mechanism and a drive unit. [Figure 7] FIG. 2 is a first side view of the paper feed cassette. [Figure 8] FIG. 10 is a second side view of the paper feed cassette. [Figure 9] FIG. 10 is a first view illustrating the engagement between the transmission part and the connection receiving part. [Figure 10] 10 is a second view illustrating the engagement between the transmission part and the connection receiving part. FIG. [Figure 11] 10 is a cross-sectional view showing an example of a paper feed cassette in a state in which a push-up plate is fixed by a fixing member. FIG. [Figure 12] FIG. 12 is an enlarged view of a part of FIG. [Figure 13] FIG. 2 is a cross-sectional view illustrating an example of a paper feed cassette with a fixing member removed. [Figure 14] FIG. 10 is a side view showing an example of a fixing member 81 in a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same components are designated by the same reference numerals. The names and functions of these components are also the same. Therefore, detailed description thereof will not be repeated.

[0012] In the following description, an MFP (Multi Function Peripheral) will be used as an example of an image forming apparatus. The MFP forms an image on a recording medium. Recording media include paper and OHP (Over Head Projector) film. Here, the case where paper is used as the sheet-like medium will be described as an example.

[0013] FIG. 1 is a perspective view of an MFP according to one embodiment of the present invention. Here, the X, Y, and Z directions are defined, each perpendicular to the other. The X and Y directions are parallel to a horizontal plane. The direction parallel to the Y direction is called the front-to-rear direction, the direction from the back of the MFP1 toward the front (the direction from the positive side to the negative side in the Y direction) is called the front direction, and the horizontal direction from the front to the back (the direction from the negative side to the positive side in the Y direction) is called the rear direction. The direction parallel to the X direction is called the left-to-right direction, the direction from the right side toward the left side of the MFP1 (the direction from the positive side to the negative side in the X direction) is called the left direction, and the horizontal direction from the left side toward the right side (the direction from the negative side to the positive side in the X direction) is called the right direction.

[0014] Referring to FIG. 1, MFP 1 includes automatic document feeder 11, document reading unit 13, image forming unit 15, and paper feeding unit 17.

[0015] The automatic document feeder 11 automatically transports multiple documents set on a document tray one by one to a document reading position of the document reading unit 13, and ejects the documents onto a document output tray after the images formed on them have been read by the document reading unit 13. The document reading unit 13 includes a light source that irradiates light onto the documents transported to the document reading position and a photoelectric conversion element that receives light reflected from the documents, and scans the document image according to the size of the documents. The photoelectric conversion element converts the received light into image data, which is an electrical signal. The document reading unit 13 reads the documents and outputs the image data it acquires. The document reading unit 13 stores the image data in a storage device such as a hard disk drive (HD), for example.

[0016] The paper feed unit 17 includes a paper feed cassette 51 that stores paper sheets, which are recording media. The paper feed cassette 51 can store multiple sheets of paper. The paper feed cassette 51 can be pulled out forward (from the positive side to the negative side in the Y direction) from the housing 1A of the MFP 1 so that the user can supply paper sheets. The state in which the paper feed cassette 51 is pulled out is the open state, and the state in which the paper feed cassette 51 is not pulled out from the housing 1A is the closed state. FIG. 1 shows the paper feed cassette 51 pulled out in the open state. The paper feed cassette 51 is a cube with an open top, and in the open state, the user can supply a stack of paper sheets consisting of multiple sheets of paper from the top. The paper feed unit 17 transports the multiple sheets of paper stored in the paper feed cassette 51 one by one to the image forming unit 15.

[0017] The image forming unit 15 forms images using a well-known electrophotographic method, and forms an image on paper transported by the paper feed unit 17 based on image data, and discharges the paper with the image formed on it to a paper output tray.

[0018] FIG. 2 is a schematic cross-sectional view showing an example of the internal configuration of an MFP. Referring to FIG. 2, image forming section 15 has developing units 20Y, 20M, 20C, and 20K, and toner bottles 21Y, 21M, 21C, and 21K. Here, "Y," "M," "C," and "K" represent yellow, magenta, cyan, and black, respectively. Developing units 20Y, 20M, 20C, and 20K correspond to yellow, magenta, cyan, and black, respectively. Toner bottles 21Y, 21M, 21C, and 21K correspond to yellow, magenta, cyan, and black, respectively.

[0019] The developing units 20Y, 20M, 20C, and 20K and the toner bottles 21Y, 21M, 21C, and 21K differ only in the color of the toner they handle, so here, the developing unit 20Y and the toner bottle 21Y for forming a yellow image will be described.

[0020] The toner bottle 21Y contains yellow toner. The toner bottle 21Y rotates using a toner bottle motor as a drive source and discharges toner to the outside. The toner discharged from the toner bottle 21Y is supplied to the developing unit 20Y. The toner bottle 21Y supplies developer to the developing unit 20Y when the remaining amount of toner contained in the developing unit 20Y falls below a predetermined lower limit.

[0021] The transfer belt 30 is suspended without slack by a drive roller 31 and a driven roller 32. When the drive roller 31 rotates counterclockwise in FIG. 2, the transfer belt 30 rotates counterclockwise in the drawing at a predetermined speed. As the transfer belt 30 rotates, the driven roller 32 rotates counterclockwise.

[0022] The developing unit 20Y contains developer. The developer contains non-magnetic toner and magnetic carrier. The developing unit 20Y receives toner from a toner bottle 21Y and agitates the toner and carrier. The developing unit 20Y forms a toner image using the toner contained in the developer and transfers the toner image to the transfer belt 30. The timing at which the developing unit 20Y transfers the toner image onto the transfer belt 30 is adjusted by detecting a reference mark on the transfer belt 30.

[0023] When forming a full-color image, the MFP 1 drives all of the developing units 20Y, 20M, 20C, and 20K. As a result, yellow, magenta, cyan, and black toner images are superimposed on the transfer belt 30. When forming a monochrome image, the MFP 1 drives any one of the developing units 20Y, 20M, 20C, and 20K. It is also possible to form an image using a combination of two or more of the developing units 20Y, 20M, 20C, and 20K.

[0024] In the MFP 1 of this embodiment, multiple types of rollers are arranged on the paper transport path. Each of the multiple types of rollers is basically cylindrical and rotates around a central axis of rotation, bringing the side surface into contact with the paper.

[0025] The MFP 1 includes a pickup roller 41, a paper feed roller 42, a separation roller 43, a transport roller 33, a timing roller 34, a transfer roller 35, a fuser roller 36, and a discharge roller 37. The pickup roller 41, the paper feed roller 42, the transport roller 33, the timing roller 34, the fuser roller 36, and the discharge roller 37 are rotated by a torque transmitted from a drive source such as a motor, and transport paper using friction generated at the portions that come into contact with the paper. Furthermore, the separation roller 43 and the transfer roller 35 do not receive a torque transmitted from the drive source.

[0026] A plurality of sheets of paper are set in paper feed cassette 51. The plurality of sheets of paper stored in paper feed cassette 51 are picked up in order from the top by pickup roller 41 provided corresponding to paper feed cassette 51. The paper picked up by pickup roller 41 is transported by paper feed roller 42 and enters a transport path. The paper transported by paper feed roller 42 to transport roller 33 is further transported by transport roller 33 through the transport path to reach timing roller 34.

[0027] Timing rollers 34 transport the paper transported by transport rollers 33 at a predetermined timing. The paper transported along the transport path by timing rollers 34 enters a nip formed between transfer belt 30 and transfer roller 35. The timing at which timing rollers 34 start transporting the paper is determined based on the timing at which the toner image formed on transfer belt 30 reaches the nip. This allows the toner image to be transferred to a predetermined position on the paper.

[0028] Transfer roller 35 generates an electric field at the nip. As the paper enters the nip and passes through it, the toner image formed on transfer belt 30 is transferred to the paper by the action of the electric field force generated at the nip. The paper with the transferred toner image is transported along the transport path to fixing roller 36. Fixing roller 36 heats and presses the paper as it transports it. The paper and the toner image transferred to it are heated and pressurized by fixing roller 36 as it passes through fixing roller 36. This melts the toner and fixes the toner image to the paper. The paper transported by fixing roller 36 is transported along the transport path to discharge roller 37. Discharge roller 37 discharges the paper to paper output tray 39.

[0029] Here, an example will be described in which the MFP 1 employs a tandem system in which development units 20Y, 20M, 20C, and 20K form four color toners on the transfer belt 30. Alternatively, the MFP 1 may employ a four-cycle system in which one photosensitive drum transfers the four color toners onto the paper in sequence.

[0030] FIG. 3 is a perspective view showing an example of a paper feed cassette. FIG. 4 is a plan view showing an example of a paper feed cassette. Referring to FIGS. 3 and 4, paper feed cassette 51 has a storage space for stacking and storing paper such as unprinted cut paper. Paper feed cassette 51 is formed in the shape of a flat box with an open top, and has a bottom portion with a rectangular inner bottom surface 53 and four side walls 51A, 51B, 51C, and 51D extending upward from each of the four sides of inner bottom surface 53. Paper is stacked and stored in paper feed cassette 51 from the top surface direction. Note that paper is sent out toward the left of paper feed cassette 51 (from the positive side to the negative side in the X direction).

[0031] A push-up plate 55 is disposed on the inner bottom surface 53 of the paper feed cassette 51. Paper is placed on the push-up plate 55 and stacked up. The push-up plate 55 is supported on the inner bottom surface 53 by a push-up plate shaft 56 provided at the end on the downstream side in the paper feed direction. The paper feed direction is to the left of the left-right direction (direction from the positive side to the negative side in the X direction). The push-up plate shaft 56 extends in the front-rear direction that intersects with the paper feed direction. The push-up plate 55 can swing around the push-up plate shaft 56, with the downstream end as the free end. The tilt angle of the push-up plate 55 in the paper feed direction changes depending on the amount of paper loaded on its upper surface by the push-up section 65.

[0032] The paper feed cassette 51 has a first side restriction plate 52A and a second side restriction plate 52B, each having a surface perpendicular to the Y direction. The first side restriction plate 52A and the second side restriction plate 52B engage with a guide rail 52C formed on the inner bottom surface 53. The guide rail 52C extends in the front-rear direction. The first side restriction plate 52A and the second side restriction plate 52B are guided by the guide rail 52C and are movable in the front-rear direction. The positions of the first side restriction plate 52A and the second side restriction plate 52B on the guide rail 52C are adjusted by the user to match the front-rear length of the paper sheets placed on the lifting plate 55. The first side restriction plate 52A and the second side restriction plate 52B abut against the front and rear end faces of the stack of paper sheets, respectively. In this way, the first side restriction plate 52A and the second side restriction plate 52B restrict the front-rear position of the paper sheets.

[0033] Furthermore, a rear end restriction plate 52D is disposed upstream in the paper feed direction of the sheets loaded on the upper surface of the push-up plate 55. The rear end restriction plate 52D is movable in the paper feed direction. The position of the rear end restriction plate 52D in the paper feed direction is adjusted by the user to match the length in the paper feed direction of the sheets placed on the push-up plate 55. The rear end restriction plate 52D abuts against the rear end in the paper feed direction of the sheets placed on the upper surface of the push-up plate 55. In this way, the rear end restriction plate 52D restricts the position of the rear end in the paper feed direction of the sheets. The position of the rear end restriction plate 52D is adjusted by the user to match the left-right length of the sheets placed on the push-up plate 55.

[0034] The paper feed cassette 51 has a lift-up mechanism M1 that lifts up the boost plate 55. The lift-up mechanism M1 includes a rotating shaft 63, a boost portion 65, and a connection receiving portion 67. The rotating shaft 63 is rotatably supported on the rear side wall 51B of the paper feed cassette 51. The rotating shaft 63 has a shape that extends in the front-rear direction along the inner bottom surface 53 and is rotatable around the axis extending in the front-rear direction. The boost portion 65 is fixed to the front end of the rotating shaft 63. The boost portion 65 is located in the center of the boost plate 55 in the front-rear direction, with one end fixed to the rotating shaft 63 and the other end contacting the underside of the boost plate 55. The rear end of the rotating shaft 63 penetrates the rear side wall 51B of the paper feed cassette 51 and protrudes further rearward from the side wall 51B. The connection receiving portion 67 is fixed to the rear end of the rotating shaft 63.

[0035] A driving unit 71 is fixed to the housing 1A of the MFP 1. The driving unit 71 is fixed to the housing 1A at a position opposite to the rear end of the rotation shaft 63. The driving unit 71 has a built-in motor as a driving source.

[0036] Fig. 5 is a perspective view showing an example of a drive unit. Referring to Fig. 5, drive unit 71 has a transmission unit 73 that protrudes forward from the front surface. Drive unit 71 incorporates a motor as a drive source, a drive shaft 75 (see Fig. 9), and a gear that transmits the driving force of the motor to drive shaft 75. Transmission unit 73 is fixed to drive shaft 75 of drive unit 71. Transmission unit 73 has a cylindrical shape, and four axially extending grooves 74 are formed at positions spaced 90 degrees apart in the circumferential direction.

[0037] 6 is a perspective view showing an example of the connection between the lift-up mechanism and the drive unit. Referring to FIG. 6, in the lift-up mechanism M1, a connection receiving portion 67 fixed to the rotating shaft 63 engages with a transmission portion 73 provided on the drive unit 71. The connection receiving portion 67 has two engagement pins 69 provided at positions 180 degrees apart in the circumferential direction of the rotating shaft 63. The two engagement pins 69 protrude radially outward from the outer periphery of the rotating shaft 63. When the connection receiving portion 67 and the transmission portion 73 engage with each other, the two engagement pins 69 of the connection receiving portion 67 fit into two of four grooves 74 formed in the transmission portion 73.

[0038] FIG. 7 is a first side view of the paper feed cassette. FIG. 8 is a second side view of the paper feed cassette. In FIGS. 7 and 8, components other than the boost plate 55, the boost portion 65, and the rotating shaft 63 are omitted. FIG. 7 shows the boost plate 55 in its lowest position. The lowest position of the boost plate 55 occurs, for example, when the paper feed cassette 51 is open. When the paper feed cassette 51 is open, the connection receiving portion 67 of the rotating shaft 63 does not engage with the transmission portion 73 of the drive unit 71, so the rotating shaft 63 does not receive any external force. Therefore, the boost plate 55 is positioned downward by gravity, and the boost plate 55 contacts the inner bottom surface 53. When the paper feed cassette 51 is closed, the connection receiving portion 67 of the rotating shaft 63 engages with the transmission portion 73 of the drive unit 71. However, before the drive unit 71 operates, the boost plate 55 is in its lowest position. In this state, when the driving unit 71 operates, the rotation shaft 63 rotates in the direction of the arrow in the figure (counterclockwise) as shown in Figure 8. As the rotation shaft 63 rotates, the push-up unit 65 rotates around the rotation shaft 63, and the push-up plate 55 is pushed up.

[0039] A sensor is provided to detect the upper limit of the height of the topmost sheet of paper placed on push-up plate 55, and when the sensor detects the upper limit, driving unit 71 is stopped. In this way, driving unit 71 is controlled so that the height of the topmost sheet of paper is always at the upper limit.

[0040] 9 and 10 are diagrams illustrating engagement between the transmission part and the connection receiving part. FIG. 9 is an enlarged view of the transmission part 73 when the transmission part 73 is not engaged with the connection receiving part 67. FIG. 10 is an enlarged view of the transmission part 73 when the transmission part 73 is engaged with the connection receiving part 67. Referring to FIGS. 9 and 10, the transmission part 73 has a cylindrical support part 733 that protrudes forward from the front side surface of the main body of the drive part 71. The support part 733 has a claw-shaped part 734 that protrudes radially inward at its tip. A spring 735 is provided in the internal space of the support part 733. The spring 735 is a compression coil spring.

[0041] A movable part 731 is provided that is movable within the internal space of the support part 733. The movable part 731 is cylindrical. A flange part 732 that protrudes radially outward from the outer periphery is formed at the rear end of the movable part 731. The outer diameter of the flange part 732 is smaller than the inner diameter of the support part 733 and larger than the inner diameter of the claw-shaped part 734. The outer diameter of the portion of the movable part 731 other than the flange part 732 is smaller than the inner diameter of the claw-shaped part 734. The movable part 731 is attached to the internal space of the support part 733 against the biasing force of the spring 735. The flange part 732 of the movable part 731 engages with the claw-shaped part 734 of the support part 733. The movable part 731 is held by the support part 733 by the spring 735 and the claw-shaped part 734. The movable part 731 is connected to the drive shaft 75 of the drive part 71 and rotates by the driving force of the motor built into the drive part 71 .

[0042] 9, when the paper feed cassette 51 is in the open state, the connection receiving portion 67 of the paper feed cassette 51 is separated from the transmission portion 73 and does not engage with it. As shown in FIG. 10, the two engagement pins 69 of the connection receiving portion 67 fit into two of the four grooves 74 formed in the transmission portion 73.

[0043] In the paper feed cassette 51 provided in the MFP 1 of the present embodiment, the push-up plate 55 is connected to the inner bottom surface 53 so as to be rotatable around the axis of the push-up plate shaft 56. Therefore, the push-up plate 55 is stable in contact with the inner bottom surface 53. However, if a force in the vertical direction is applied to the MFP 1 when the MFP 1 is transported, for example, the push-up plate 55 rotates around the axis of the push-up plate shaft 56. Therefore, before the MFP 1 is installed, the push-up plate 55 is fixed to the inner bottom surface 53 by a fixing member 81.

[0044] Fig. 11 is a cross-sectional view showing an example of a paper feed cassette in a state where the booster plate 55 is fixed by a fixing member. Fig. 12 is an enlarged view of a portion of Fig. 11. Figs. 11 and 12 show a portion of paper feed cassette 51 and drive unit 71 in a state where booster plate 55 is fixed by a fixing member 81.

[0045] 11 , fixing member 81 is an adhesive tape. Fixing member 81 has two oppositely facing surfaces, one of which has an adhesive applied to an adhesive surface 85. Fixing member 81 includes a blocking portion 83, a fixing portion 87, and a connecting portion 89. Fixing portion 87 of fixing member 81 has its adhesive surface 85 adhered to a portion of push-up plate 55 and a portion of inner bottom surface 53. Push-up plate 55 is fixed to inner bottom surface 53 by fixing portion 87 of fixing member 81. Therefore, while MFP 1 is being transported, push-up plate 55 moves up and down together with inner bottom surface 53, thereby preventing push-up plate 55 from colliding with inner bottom surface 53.

[0046] The interrupter 83 is disposed between the transmission unit 73 and the connection receiver 67. Therefore, when the paper feed cassette 51 is in the closed state, the transmission unit 73 and the connection receiver 67 are separated from each other. Therefore, even if the drive unit 71 operates when the paper feed cassette 51 is in the closed state, the drive force of the drive unit 71 is not transmitted to the connection receiver 67. Therefore, when the boost plate 55 is fixed to the inner bottom surface 53 by the fixing portion 87, the drive force of the drive unit 71 is not applied to the rotation shaft 63. This prevents damage to the drive unit 71, the rotation shaft 63, the boost unit 65, and the boost plate 55.

[0047] Connecting portion 89 is a portion that connects blocking portion 83 and fixed portion 87. After installing MFP 1, the user removes fixing member 81 before using MFP 1. At this time, the user pulls paper feed cassette 51 toward the user from housing 1A of MFP 1, and then removes fixing member 81. With paper feed cassette 51 pulled toward the user from housing 1A of MFP 1, fixing portion 87 of fixing member 81 is visible to the user. Therefore, fixing portion 87 of fixing member 81 is peeled off by the user from push-up plate 55 and inner bottom surface 53. Fixing portion 87 is connected to connecting portion 89, and connecting portion 89 is connected to blocking portion 83. Therefore, when the user peels fixing portion 87 off push-up plate 55 and inner bottom surface 53, connecting portion 89 and blocking portion 83 are removed together with fixing portion 87.

[0048] The blocking portion 83 of the fixing member 81 has a double structure with overlapping tape. The adhesive tape is folded back at the blocking portion 83 so that the adhesive surfaces 85 of the folded portion and the opposing portion face each other. The folded portion and the opposing portion are adhered together. This prevents the fixing member 81 from being adhered to the transmission portion 73 or the connection receiving portion 67. The connecting portion 89 of the fixing member 81 may also have a double structure with overlapping tape. In this case, the fixing member 81 can be easily removed.

[0049] 13 is a cross-sectional view showing an example of a paper feed cassette with fixing member 81 removed. After fixing member 81 is removed from paper feed cassette 51, if a user pushes paper feed cassette 51 into housing 1A of MFP 1, paper feed cassette 51 enters a closed state and connection receiving portion 67 engages with transmission portion 73.

[0050] <Modification> (1) In the above-described embodiment, an example of a double-layered structure of overlapping tape was shown as an example of the blocking portion 83. However, the present invention is not limited to this. The blocking portion 83 may be formed of resin or metal. In this case, if the fixing portion 87 and the connecting portion 89 are formed of adhesive tape, the blocking portion 83 is attached to the adhesive surface 85 of the tape extending from the connecting portion 89.

[0051] (2) The fixing member 81 may be made of resin. FIG. 14 is a side view showing an example of the fixing member 81 in a modified example. Referring to FIG. 14, the fixing member 81 includes a fixing portion 87, a blocking portion 83, and a connecting portion 89. The lower surface of the fixing portion 87 is an adhesive surface 85 to which an adhesive is applied. The blocking portion 83 is located behind the connection receiving portion 67 in a state in which the fixing portion 87 is adhered to a part of the push-up plate 55 and a part of the inner bottom surface 53 of the paper feed cassette 51. The connecting portion 89 connects the fixing portion 87 and the blocking portion 83 and has a shape that climbs over the side wall 51B of the paper feed cassette 51. Note that the inner bottom surface 53 may be provided with a portion that engages with the fixing portion 87. The fixing portion 87 engages with the inner bottom surface 53, thereby fixing the fixing member 81 to the inner bottom surface 53. In this case, the fixing member 81 does not need to have the adhesive surface 85.

[0052] (3) In the present embodiment, the MFP 1 has been described as an example of an image forming apparatus, but the present invention is not limited to this. The image forming apparatus may also be a printer or a facsimile machine. Furthermore, the image forming function is not limited to an electrophotographic method that forms images using toner, but may also be an inkjet method that forms images using ink.

[0053] As described above, the sheet feed cassette 51 in this embodiment includes the push-up plate 55 disposed on the inner bottom surface 53, the lift-up mechanism M1 that pushes up the push-up plate 55, and the fixing member 81 that fixes the push-up plate 55 to the inner bottom surface 53. The fixing member 81 fixes the push-up plate 55 to the inner bottom surface 53, preventing the push-up plate 55 from vibrating and thus from being damaged. The blocking member 83 maintains a disconnection between the lift-up mechanism M1 and the drive unit 71 fixed to the housing 1A of the MFP 1, preventing the lift-up mechanism M1 from operating. With the push-up plate 55 fixed to the inner bottom surface 53, the lift-up mechanism M1 does not operate, preventing damage to the push-up plate 55 and the lift-up mechanism M1. Furthermore, with the fixing member 81 removed, the lift-up mechanism M1 is connected to the drive unit 71, allowing the lift-up mechanism M1 to operate and push up the push-up plate 55.

[0054] Furthermore, the paper feed cassette 51 can slide back and forth relative to the housing 1A of the MFP 1, moving between an open state and a closed state. The lift-up mechanism M1 can be connected to the drive unit 71 when the paper feed cassette 51 is in the closed state. The blocking unit 83 maintains a state in which the lift-up mechanism M1 and the drive unit 71 are not connected when the paper feed cassette 51 is in the closed state. Therefore, with the fixing member 81 fixing the push-up plate 55 to the inner bottom surface 53, the lift-up mechanism M1 cannot operate when the paper feed cassette 51 is in the closed state. When the fixing member 81 is removed, the lift-up mechanism M1 and the drive unit 71 are connected, so the lift-up mechanism M1 can be operated.

[0055] The lift-up mechanism M1 includes a rotating shaft 63 arranged below the boost plate 55, a boost portion 65 attached to the rotating shaft 63, and a connection receiving portion 67 attached to the rotating shaft 63. Because the interrupting portion 83 is arranged between the transmission portion 73 and the connection receiving portion 67, the driving force of the driving portion 71 is not transmitted to the connection receiving portion 67. Therefore, with the boost plate 55 fixed to the inner bottom surface 53, the boost plate 55 cannot operate, and damage to the boost plate 55, the boost portion 65, the rotating shaft 63, and the connection receiving portion 67 can be prevented.

[0056] The fixing member 81 is made of an adhesive tape having an adhesive surface 85. Therefore, the cost of the fixing member 81 can be reduced.

[0057] Furthermore, fixing member 81 has blocking portion 83, fixing portion 87, and connecting portion 89. Connecting portion 89 has a portion of adhesive tape or another member adhered to its adhesive surface 85. Therefore, connecting portion 89 does not have adhesive properties, and fixing member 81 can be easily removed.

[0058] Furthermore, the interrupting portion 83 may be made of resin or metal. In this case, the strength of the interrupting portion 83 is increased, so that the disconnection state between the transmitting portion 73 and the connection receiving portion 67 can be reliably maintained.

[0059] Furthermore, the fixing member 81 in this modification is made of resin, which makes it easy to manufacture the fixing member 81.

[0060] <Summary of implementation form> (Item 1) A paper feed cassette to be installed in an image forming apparatus, a push-up plate disposed on the inner bottom surface and on which a recording medium is placed; a lift-up mechanism that is driven by a drive unit provided in the image forming apparatus to push up the push-up plate; a fixing member that fixes the push-up plate to the inner bottom surface, The fixing member is disposed between the lift-up mechanism and the drive unit, and has a disconnecting portion that maintains a disconnected state between the lift-up mechanism and the drive unit.

[0061] According to this aspect, the fixing portion fixes the boost plate to the inner bottom surface, preventing the boost plate from vibrating and suppressing damage. The blocking portion maintains a state in which the lift mechanism and the drive unit are not connected, preventing the lift mechanism from operating. With the boost plate fixed to the inner bottom surface, the lift mechanism does not operate, preventing damage to the boost plate and lift mechanism. Furthermore, with the fixing portion removed, the lift mechanism is connected to the drive unit, allowing the lift mechanism to operate and push up the boost plate, moving the recording medium upward. As a result, a paper feed cassette can be provided that has a simple configuration and prevents damage to components.

[0062] (Item 2) The door is slidable relative to the housing of the image forming apparatus between an open state and a closed state, the lift-up mechanism is connectable to the drive unit in the closed state, Item 2. The paper feed cassette according to item 1, wherein the disconnecting unit maintains a state in which the lift-up mechanism and the drive unit are not connected to each other when the paper feed cassette is in the closed state.

[0063] According to this aspect, when the paper feed cassette is in the closed state, the lift-up mechanism and the drive unit are kept disconnected. Therefore, when the fixing member fixes the push-up plate to the inner bottom surface, the lift-up mechanism cannot operate when the paper feed cassette is in the closed state. When the fixing member is removed, the lift-up mechanism and the drive unit are connected, so the lift-up mechanism can be operated.

[0064] (Item 3) The lift-up mechanism includes a rotary shaft disposed below the lift-up plate; a lifting portion attached to the rotary shaft and configured to lift up the lifting plate as the rotary shaft rotates; a connection receiving portion attached to the rotating shaft and connectable to a transmission portion attached to the driving portion, Item 3. The paper feed cassette according to item 1 or 2, wherein the blocking portion is disposed between the transmission portion and the connection receiving portion.

[0065] According to this aspect, the booster is attached to a rotating shaft disposed below the booster plate and pushes up the booster plate as the rotating shaft rotates. This pushes up the recording medium placed on the booster plate. A blocking portion of a fixing member that fixes the booster plate to the inner bottom surface is disposed between the connection receiving portion attached to the rotating shaft and the transmission portion attached to the drive unit. This prevents the driving force of the drive unit from being transmitted to the connection receiving portion. Therefore, with the booster plate fixed to the inner bottom surface, the booster does not operate, preventing damage to the booster plate, the booster, the rotating shaft, and the connection receiving portion. Furthermore, with the fixing portion removed, the transmission portion and the connection receiving portion are connected, so the booster operates to push up the booster plate and move the recording medium upward.

[0066] (Item 4) The paper feed cassette according to any one of items 1 to 3, wherein the fixing member is made of an adhesive tape having an adhesive surface.

[0067] According to this aspect, the fixing member is made of an adhesive tape having an adhesive surface, so that the cost of the fixing member can be reduced.

[0068] (Item 5) The fixing member includes a fixing portion that is adhered to a portion of the lifting plate and a portion of the inner bottom surface, and a connecting portion between the fixing portion and the blocking portion, Item 5. The paper feed cassette according to item 4, wherein the connecting portion includes a portion to which a part of the adhesive tape or another member is adhered on the adhesive surface.

[0069] According to this aspect, the fixing member includes a fixing portion adhered to a portion of the push-up plate and a portion of the inner bottom surface, and a connecting portion between the fixing portion and the blocking portion, and the connecting portion has an adhesive surface to which a portion of adhesive tape or other member is adhered. Therefore, since the connecting portion does not have adhesive ability, the fixing member can be easily removed.

[0070] (Item 6) The paper feed cassette according to item 4, wherein the blocking portion is configured by overlapping the adhesive tape.

[0071] According to this aspect, since the blocking portion is formed by overlapping adhesive tapes, the cost of the fixing member can be reduced, and the adhesive ability of the blocking portion can be easily eliminated.

[0072] (Item 7) The paper feed cassette according to item 4, wherein the blocking portion has a member made of resin or metal adhered to the adhesive surface.

[0073] According to this aspect, a member made of resin or metal is bonded to the bonding surface of the interrupter, which increases the strength of the interrupter, thereby reliably maintaining the disconnected state between the connection receiving portion and the transmission portion.

[0074] (Item 8) The paper feed cassette according to any one of Items 1 to 3, wherein the fixing member is made of resin.

[0075] According to this aspect, the fixing member is made of resin, so that the fixing member can be easily formed.

[0076] (Item 9) An image forming apparatus equipped with the paper feed cassette according to any one of items 1 to 8.

[0077] According to this aspect, it is possible to provide an image forming apparatus with a simple configuration that prevents damage to components.

[0078] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0079] 1 MFP, 1A housing, 11 automatic document feeder, 13 document reading unit, 15 image forming unit, 17 paper feeding unit, 51 paper feeding cassette, 51A, 51B, 51C, 51D side wall, 52A first side regulating plate, 52B second side regulating plate, 52C guide rail, 52D rear end regulating plate, 53 inner bottom surface, 55 push-up plate, 56 push-up plate shaft, 63 rotating shaft, 65 push-up portion, 67 connection receiving portion, 69 engagement pin, 71 drive portion, 73 transmission portion, 74 groove, 75 drive shaft, 81 fixing member, 83 blocking portion, 85 adhesive surface, 87 fixing portion, 89 connecting portion, 731 movable portion, 732 flange portion, 733 support portion, 734 claw-shaped portion, 735 spring, M1 lift-up mechanism.

Claims

1. A paper feed cassette to be installed in an image forming apparatus, a push-up plate disposed on the inner bottom surface and on which a recording medium is placed; a lift-up mechanism that is driven by a drive unit provided in the image forming apparatus to push up the push-up plate; a fixing member that fixes the push-up plate to the inner bottom surface, The fixing member is disposed between the lift-up mechanism and the drive unit, and has a disconnecting portion that maintains a disconnected state between the lift-up mechanism and the drive unit.

2. The door is slidable relative to the housing of the image forming apparatus between an open state and a closed state, the lift-up mechanism is connectable to the drive unit in the closed state, The paper feed cassette according to claim 1 , wherein the cutoff section maintains a state in which the lift-up mechanism and the drive section are not connected to each other in the closed state.

3. The lift-up mechanism includes a rotation shaft disposed below the lift-up plate; a lifting portion attached to the rotary shaft and configured to lift up the lifting plate as the rotary shaft rotates; a connection receiving portion attached to the rotating shaft and connectable to a transmission portion attached to the driving portion, The paper feed cassette according to claim 1 , wherein the blocking portion is disposed between the transmission portion and the connection receiving portion.

4. 4. The paper feed cassette according to claim 1, wherein the fixing member is made of an adhesive tape having an adhesive surface.

5. the fixing member includes a fixing portion bonded to a portion of the lifting plate and a portion of the inner bottom surface, and a connecting portion between the fixing portion and the blocking portion, The paper feed cassette according to claim 4 , wherein the connecting portion includes a portion to which a part of the adhesive tape or another member is adhered on the adhesive surface.

6. The paper feed cassette according to claim 4 , wherein the blocking portion is formed by overlapping the adhesive tape.

7. The paper feed cassette according to claim 4 , wherein the blocking portion has a member made of resin or metal adhered to the adhesive surface.

8. 4. The paper feed cassette according to claim 1, wherein the fixing member is made of resin.

9. An image forming apparatus comprising the paper feed cassette according to any one of claims 1 to 3.

Images