JP4120891B2 - Sheet material supply apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet material supply apparatus and an image forming apparatus, and more particularly to drive control of a stacking unit on which sheet materials are stacked.

  For example, in Patent Document 1 below, a pickup roller (feeding roller) that is provided so as to be vertically movable and abuts against a sheet material stacked on a stacking unit, and a paper feeding roller (separation) provided downstream of the pickup roller in the conveying direction. A sheet material supply device including a separation mechanism having a roller) and a separation pad (separation means) is disclosed. When the pickup roller rotates while being in contact with the sheet material on the stacking section, the sheet material is sent to the separation mechanism side, and the sheet material is separated one by one by the nip of the paper feed roller and the separation roller and further conveyed. Operates to be conveyed downstream in the direction.

Here, if the pickup roller is always brought into contact with the sheet material, there arises a problem that paper dust and conveyance sound are generated due to friction between the pickup roller and the sheet material, and a conveyance load increases. Therefore, in Patent Document 1, when the sheet material reaches the nip position between the sheet feeding roller and the separation roller, the solenoid switch is turned on to separate the pickup roller from the sheet material on the stacking unit.
JP 2001-80774 A

  By the way, in order to reduce the size of the apparatus and reduce the cost, the above-described pickup roller separation operation is performed by gear control while mechanically detecting the position of the pickup roller without using a dedicated detection sensor or the like. Is desired. In this configuration, the stacking unit is raised based on the position of the pickup roller. In other words, when the position of the pickup roller that contacts the sheet material on the stacking unit rises and reaches a predetermined height, the drive is turned off, and when the sheet material is reduced and the pickup roller is lowered by a predetermined amount again Drive up.

  However, in this configuration, for example, when the storage cassette having the stacking unit is reset for replenishment of the sheet material, the pickup roller is positioned at an initial position separated from the sheet material, and the stacking unit is at the lowest point. Located in. As described above, since the ascending drive of the stacking unit is switched based on the position of the pickup roller, the stacking unit ascending drive is not started until the gear mechanism is driven to some extent, and a sheet material supply error (pick miss) is not started. In addition, there is a problem that the start of the supply operation is delayed.

  The present invention has been completed based on the above circumstances, and an object of the present invention is to provide a sheet material supply device and an image forming apparatus that can perform a normal supply operation even when a storage cassette is reset. And

As a means for achieving the above object, a sheet material supply apparatus according to the invention of claim 1 includes an apparatus main body and a stacking portion on which the sheet material is stacked so as to be movable up and down. A storage cassette that is mounted so as to be capable of being pulled out, and a feed roller that is provided on the apparatus main body side so as to be movable up and down, and that rotates in contact with the upper surface of the sheet material on the stacking unit and feeds the sheet material And a rotating member provided rotatably, and a member to be pressed that rotates in conjunction with the rotating member and forcibly rotates the rotating member by receiving a pressing force, and with the rotation of the rotating member A delivery roller displacing means for displacing the delivery roller between an initial position spaced from the sheet material on the stacking section and a delivery position capable of contacting the sheet material on the stacking section; Is at the delivery position In addition, on the condition that the moving position of the delivery roller is equal to or less than a predetermined height, the stacking unit lifting mechanism that lifts the stacking unit and the storage cassette enters and moves toward the pressed member side. A feeding roller forced displacement means having a pressing member that is retracted from the pressed member side in the process of pulling out the storage cassette and that can be moved up and down in the forward and backward movement process, and the pressing member in the mounting process. The approach path for allowing the pressed member to enter a position where the pressed member can be pressed, and the pressing member located at the position moved in the pressing direction of the pressed member from the position where the pressure can be pressed An exit path for exiting via a different path, and the delivery roller forced displacement means pushes the pressed member by the pressing member that has entered the pressable position. And wherein the forcibly displaced to the delivery position the delivery roller from the initial position.
The “sheet material” in the present invention may be a sheet material other than a recording medium, such as paper money or an OHP sheet, for example, a bill.
"Sheet material supply device" is detachable even if it is detachably attached to the main body of an image forming apparatus (such as a printer, a facsimile machine, or a multifunction machine having a printer function and a scanner function). It may be anything. Further, the present invention is not limited to supplying a sheet material to the main body of the image forming apparatus, and may be provided in an apparatus for counting sheet materials such as banknotes.
As long as the “accommodating cassette” can be pulled out, the “accommodating cassette” may be detached from the apparatus main body or not.

  According to a second aspect of the present invention, in the sheet material supply apparatus according to the first aspect, the rotating member and the pressed member are integrally formed.

  A third aspect of the present invention is the sheet material supply apparatus according to the first or second aspect, further comprising a gear mechanism that controls the rotation of the feed roller in response to a sheet material supply start signal. The gear mechanism is configured to be driven to rotate with a play with respect to the rotation of the gear mechanism, and the sending roller forced displacement means forcibly moves the sending roller by rotating the rotating member through the play. It is made to displace to.

  According to a fourth aspect of the present invention, in the sheet material supply apparatus according to the third aspect, when the storage cassette is mounted on the apparatus main body, the gear mechanism is not in an initial state waiting for the supply start signal. It further comprises a regulating means for regulating the operation of the delivery roller forced displacement means until the mechanism is in an initial state.

  According to a fifth aspect of the present invention, there is provided the sheet material supply apparatus according to the fourth aspect, wherein the restricting means is interlocked with the gear mechanism, and the pressing force of the pressing member is in an initial state in which the gear mechanism waits for the supply start signal. It is a restricting member that allows entry into a possible position and restricts entry of the pressing member into the pressable position in a state other than the initial state.

  According to a sixth aspect of the present invention, in the sheet material supply device according to the fifth aspect, the restriction member is provided coaxially with the gear of the gear mechanism and rotates integrally with the rotation of the gear. And

  A seventh aspect of the present invention is the sheet material supply apparatus according to any one of the first to sixth aspects, wherein the feeding roller forced displacement means biases the pressing member in a pressing direction of the pressed member. An urging means is provided, and the pressing member enters the pressable position via the approach path against the urging force of the urging means.

  The invention according to claim 8 is the sheet material supply apparatus according to any one of claims 1 to 6, wherein the approach path and the exit path are joined at the end side in the drawer direction of the storage cassette. And the delivery roller forced displacement means includes a biasing means for biasing the tip member in the approach direction to the pressed member side so as to maintain a basic posture in the approach direction. The joining portion of the approach route and the exit route has a shape that guides the distal end portion of the pressing member in the basic posture toward the approach route side in the mounting process, and the approach route is subjected to the biasing force of the biasing means. Accordingly, the tip portion of the pressing member is moved upward or downward to enter the pressable position, and the exit path presses the pressed member at the pressable position. Push that has returned to the basic position Characterized in that the distal portion of the member is a shape that can exit.

  According to a ninth aspect of the present invention, in the sheet material supply apparatus according to the eighth aspect, the approach path has a tapered surface inclined upward or downward from the joining portion toward the pressable position. It is characterized by.

  According to a tenth aspect of the present invention, in the sheet material supply apparatus according to the eighth or ninth aspect, the pressing member is provided on the storage cassette side so that the tip end portion can be moved up and down via a rotation shaft. The urging means is a coil spring arranged along the approach direction, one end side of which is connected to the base end portion of the pressing member and the other end side is fixed to the storage cassette side.

  According to an eleventh aspect of the present invention, in the sheet material supply apparatus according to the tenth aspect, the storage cassette is formed with an arcuate guide groove centered on the rotation axis of the pressing member, and the distal end portion of the pressing member An engaging projection that engages with the guide groove is provided at a position near the guide groove.

An image forming apparatus according to a twelfth aspect of the present invention provides an image on the sheet material supply apparatus according to any one of the first to eleventh aspects and a recording medium as a sheet material supplied from the sheet material supply apparatus. And image forming means for forming the image.
The “image forming apparatus” is not limited to a printing apparatus such as a printer (for example, a laser printer), but may be a facsimile machine or a multifunction machine having a printer function and a reading function (scanner function).

<Invention of Claim 1>
In the present invention, when the storage cassette is reattached to the apparatus main body by replenishing the sheet material, the sending roller is forcibly moved from the initial position to the sending position where the sheet can be brought into contact with the sheet material stacked on the stacking unit. Displaced. As a result, the feeding roller becomes a predetermined height or less, the stacking unit is raised by the stacking unit raising mechanism, and when the next sheet material supply start signal is received, the sheet material can be sent out early by the feeding roller. Can be.

  Further, in a configuration in which the advance / retreat path of the pressing member is common when the storage cassette is mounted and pulled out, a means for returning the pressing member to the same path after pressing the pressed member is required. Moreover, for example, the storage cassette may not be properly attached to the apparatus main body, and the means for returning may not function. In this case, the pressing member is pressed by the pressed member that has moved around again, and the forced displacement operation of the delivery roller may not be performed thereafter. Therefore, in the present invention, the pressing member after pressing the pressed member is made to exit through a path different from the approach path at the time of mounting.

<Invention of Claim 2>
According to the present invention, the number of parts can be reduced.

<Invention of Claim 3>
According to this configuration, when the sheet material supply operation is completed and the storage cassette is pulled out from the apparatus main body, the feeding roller is arranged at the initial position by the rotating member. When the storage cassette is mounted, the rotating member is rotated through play (clearance) by the pressing force of the pressing member, and as a result, the delivery roller is moved to the delivery position. Therefore, the delivery roller forced displacement means can be realized with a relatively simple configuration.

<Invention of Claims 4 and 5>
For example, the storage cassette may be pulled out and reattached when the sheet material is clogged in the conveyance path during the supply operation of the sheet material or when the supply abnormality occurs and stops. In this case, the gear mechanism stops in the middle of the supply operation for one sheet material. At this time, the gear mechanism as in the present invention cannot grasp in which state the gear mechanism is stopped. Therefore, in the present invention, when the gear mechanism is re-driven and enters the initial state waiting for the next sheet material supply start signal, the restriction by the restricting means (the restricting member in claim 3) is released, and the sending roller forced displacement means Thus, the delivery roller is moved from the initial position to the delivery position. Thereby, a smooth supply operation can be resumed even when the storage cassette is remounted after supply abnormality.

<Invention of Claim 6>
According to this configuration, the regulating means is configured to perform timing control by a mechanical configuration. Thereby, malfunctions such as soft control can be prevented. In addition, since this control is performed by the driving force from the gear mechanism that controls the rotation of the delivery roller, the regulation timing by the regulation means can be easily set based on the rotational position of the delivery roller.

<Invention of Claim 7>
As a configuration for pressing the member to be pressed by the pressing member, a guide portion that guides the pressing member pressed by the mounting operation of the storage cassette in the direction in which the pressing member is pressed is provided. There may be. However, with the configuration of the present invention using the biasing means, the pressed member can be reliably pressed with a relatively simple configuration.

<Invention of Claim 8>
According to the present invention, the forcible displacement operation of the delivery roller can be executed only by attaching the storage cassette to the apparatus main body, and the storage cassette can be easily pulled out.

<Invention of Claim 9>
According to the present invention, the tip end portion of the pressing member can be smoothly guided from the joining portion to a position where it can be pressed by the tapered surface of the approach path.

<Invention of Claim 10>
According to the present invention, the pressing member can be maintained in the basic posture with a very simple configuration.

<Invention of Claim 11>
According to the present invention, the engaging protrusion is guided along the guide groove, so that the tip end portion of the pressing member can be stably moved without being displaced.

<Invention of Claim 12>
According to this configuration, the effects of the above-described configurations can be obtained in the image forming apparatus.

  Next, an embodiment of the present invention will be described with reference to FIGS.

1. FIG. 1 is a side sectional view of an essential part showing a laser printer as an image forming apparatus of the present invention. The laser printer 1 includes a main body casing 2 and a feeder unit 4 (corresponding to the “sheet material supply device” of the present invention) housed in the main body casing 2 for feeding a sheet 3 as a sheet material. And an image forming section 5 (corresponding to the “image forming means” of the present invention) for forming an image on the fed paper 3.

(1) Main Body Casing An attachment / detachment opening 6 for attaching / detaching a process cartridge 20 described later is formed on one side wall of the main body casing 2, and a front cover 7 for opening / closing the attachment / detachment opening 6 is provided. ing. The front cover 7 is rotatably supported by a cover shaft (not shown) inserted through the lower end portion thereof. As a result, when the front cover 7 is closed around the cover shaft, as shown in FIG. 1, the attachment / detachment opening 6 is closed by the front cover 7 and when the front cover 7 is opened with the cover shaft as a fulcrum (when tilted), The attachment / detachment opening 6 is opened, and the process cartridge 20 can be attached to / detached from the main casing 2 through the attachment / detachment opening 6.

  In the following description, the side of the laser printer 1 on which the front cover 7 is provided (the right side in FIG. 1) is referred to as “front side, front side”, and the opposite side is referred to as “rear side, rear side”.

(2) Feeder unit The feeder unit 4 includes a sheet feeding cassette 9 (corresponding to the “storage cassette” of the present invention) mounted on the bottom of the main body casing 2 so as to be able to be pulled out forward, Separation roller 10 and separation pad 11 as separation means provided above the front end portion, and paper supply roller 12 (book) provided on the rear side of separation roller 10 (upstream in the conveyance direction of paper 3 with respect to separation pad 11) Equivalent to the “sending roller” of the invention. In addition, the feeder unit 4 is provided with a paper dust removing roller 8 and a counter roller 13 that are disposed to face each other on the upper front side of the separation roller 10 (downstream in the transport direction of the paper 3 with respect to the separation roller 10).

  Then, the conveyance path 56 of the paper 3 is folded back in the U-shape from the vicinity of the arrangement of the paper dust removing roller 8 and further below the process cartridge 20 on the downstream side in the conveyance direction from a pair of rollers. The registration rollers 14 and 14 are provided.

  Inside the paper feed cassette 9, a paper pressing plate 15 (corresponding to the “stacking portion” of the present invention) on which the paper 3 can be stacked is provided. The sheet pressing plate 15 is rotatably supported at the rear end portion, so that the front end portion is positioned below and is placed along the bottom plate 16 of the sheet feeding cassette 9 (the state shown in FIG. 1). The front end portion is located above and can swing to an inclined supply position (the state shown in FIGS. 11 to 14).

  A lever 17 for lifting the front end portion of the paper pressing plate 15 upward is provided at the front end portion of the paper feed cassette 9. The lever 17 is supported at a position below the front end portion of the paper pressing plate 15 so that the rear end portion is rotatably supported by the lever shaft 18, and the front end portion is in a prone posture (see FIG. 1). (Shown state) and the front end portion can swing between the inclined posture in which the paper pressing plate 15 is lifted (the state shown in FIGS. 11 to 14). When the counterclockwise rotational driving force in FIG. 1 is input to the lever shaft 18, the lever 17 rotates counterclockwise in FIG. 1 with the lever shaft 18 as a fulcrum, and the front end of the lever 17 is the paper pressing plate. The front end of 15 is lifted, and the paper pressing plate 15 is moved to the supply position.

  When the sheet pressing plate 15 is located at the supply position, the uppermost sheet 3 on the sheet pressing plate 15 is pressed by a sheet feeding roller 12 at a contact position described later, and the separation roller 10 is rotated by the rotation of the sheet feeding roller 12. Is started toward the separation position X between the separation pad 11 and the separation pad 11.

  On the other hand, when the paper feed cassette 9 is pulled out from the feeder unit 4, the paper pressing plate 15 is positioned at the loading position by moving its front end downward due to its own weight, and the paper 3 is placed on the paper pressing plate 15. It can be mounted in a laminated form. The separation pad 11, the paper dust removing roller 8, the paper pressing plate 15 and the lever 17 are provided in the paper feed cassette 9, and the paper feed roller 12, the separation roller 10, the opposing roller 13 and the registration roller 14 are provided in the main body casing 2. Is provided. Further, the portion of the feeder unit 4 excluding the paper feed cassette 9 corresponds to the “apparatus main body” of the present invention (hereinafter referred to as “apparatus main body 4a”). Further, as shown in FIG. 1, the state in which the paper feed cassette 9 is inserted into the apparatus main body 4a and placed in the proper storage position and the installation is completed is referred to as “when installed in the apparatus main body / state” in the present invention. Is equivalent to.

  The sheets 3 fed toward the separation position X by the paper feed roller 12 are separated one by one when they are sandwiched at the separation position X between the separation roller 10 and the separation pad 11 by the rotation of the separation roller 10. Paper is fed. The fed paper 3 is folded along the U-shaped transport path 56. More specifically, the fed paper 3 is first transported upward through the separation position X between the separation roller 10 and the separation pad 11, and further, between the paper dust removing roller 8 and the opposing roller 13. After the paper dust is removed here through the gap, it is conveyed to the registration roller 14. The sheet feeding direction of the sheet 3 corresponds to the “sheet material conveyance direction” in the present invention.

  The registration roller 14 conveys the sheet 3 to a transfer position between the photosensitive drum 29 and the transfer roller 32 (to be described later) and to transfer the toner image on the photosensitive drum 29 to the sheet 3 after registration.

(3) Image Forming Unit The image forming unit 5 includes a scanner unit 19, a process cartridge 20, a fixing unit 21, and the like.
(A) Scanner unit The scanner unit 19 is provided in the upper part of the main casing 2 and includes a laser light source (not shown), a polygon mirror 22 that is driven to rotate, an fθ lens 23, a reflecting mirror 24, a lens 25, a reflecting mirror 26, and the like. ing. The laser beam based on the image data emitted from the laser light source is deflected by the polygon mirror 22 as shown by a chain line, passes through the fθ lens 23, then the optical path is turned back by the reflecting mirror 24, and further passes through the lens 25. After that, the optical path is further bent downward by the reflecting mirror 26, so that the surface of a photosensitive drum 29 (to be described later) of the process cartridge 20 is irradiated.

(B) Process Cartridge The process cartridge 20 is detachably attached to the main body casing 2 below the scanner unit 19. The process cartridge 20 includes an upper frame 27 and a lower frame 28 formed separately from the upper frame 27 and combined with the upper frame 27 as a casing. The process cartridge 20 includes a photosensitive drum 29, a scorotron charger 30, a developing cartridge 31, a transfer roller 32, and a cleaning brush 33 in a housing.

  The photosensitive drum 29 has a cylindrical shape, the outermost layer is formed of a positively chargeable photosensitive layer made of polycarbonate or the like, and an axial center of the drum main body 34 along the longitudinal direction of the drum main body 34. A metal drum shaft 35 is provided as an extending shaft. The drum shaft 35 is supported by the upper frame 27, and the drum main body 34 is rotatably supported by the drum shaft 35, so that the photosensitive drum 29 is rotatable about the drum shaft 35 in the upper frame 27. Is provided.

  The scorotron charger 30 is supported by the upper frame 27, and is disposed opposite to the photosensitive drum 29 at a predetermined interval so as not to contact the photosensitive drum 29 at an obliquely upper rear side of the photosensitive drum 29. The scorotron charger 30 is provided between the discharge wire 37 and the photosensitive drum 29, and is disposed between the discharge wire 37 and the photosensitive drum 29 so as to face the photosensitive drum 29 at a predetermined interval. And a grid 38 for controlling the amount. In the scorotron charger 30, a bias voltage is applied to the grid 38 and at the same time, a high voltage is applied to the discharge wire 37 to cause corona discharge of the discharge wire 37, so that the surface of the photosensitive drum 29 is uniformly positive. Can be charged.

  The developing cartridge 31 includes a box-shaped storage case 60 whose rear side is opened, and is detachably attached to the lower frame 28. In the developing cartridge 31, a toner storage chamber 39, a toner supply roller 40, a developing roller 41, and a layer thickness regulating blade 42 are provided.

  The toner storage chamber 39 is formed as an internal space on the front side of the storage case 60 partitioned by the partition plate 43. The toner storage chamber 39 is filled with a positively chargeable nonmagnetic one-component toner T as a developer.

  In the toner storage chamber 39, an agitator 44 supported by a rotation shaft 55 provided in the center is provided. The agitator 44 is rotationally driven by the input of power from a motor (not shown). When the agitator 44 is driven to rotate, the toner T in the toner storage chamber 39 is agitated and discharged toward the toner supply roller 40 from the opening 45 communicating in the front-rear direction below the partition plate 43.

  The toner supply roller 40 is disposed below the rear side of the opening 45 and is rotatably supported by the developing cartridge 31. The toner supply roller 40 is configured by covering a metal roller shaft with a roller made of a conductive foam material. The toner supply roller 40 is rotationally driven by power input from a motor (not shown).

  The developing roller 41 is rotatably supported by the developing cartridge 31 in a state in which the developing roller 41 is in contact with the toner supplying roller 40 so as to be compressed on the rear side of the toner supplying roller 40. The developing roller 41 is opposed to and contacts the photosensitive drum 29 in a state where the developing cartridge 31 is mounted on the lower frame 28. The developing roller 41 is configured by covering a metal roller shaft 41a with a roller made of a conductive rubber material. The roller shaft 41a projects from the side surface of the developing cartridge 31 outward in the width direction perpendicular to the front-rear direction at the front end portion of the developing cartridge 31. A developing bias is applied to the developing roller 41 during development. The developing roller 41 is rotationally driven in the same direction as the toner supply roller 40 by the input of power from a motor (not shown).

  The layer thickness regulating blade 42 includes a pressing portion 47 having a semicircular cross section made of insulating silicone rubber at the tip of a blade body 46 made of a metal leaf spring material. The layer thickness regulating blade 42 is supported by the developing cartridge 31 above the developing roller 41, and the pressing portion 47 is pressed onto the developing roller 41 by the elastic force of the blade body 46.

  The toner T discharged from the opening 45 is supplied to the developing roller 41 by the rotation of the toner supply roller 40. At this time, the toner T is positively frictionally charged between the toner supply roller 40 and the developing roller 41. The toner T supplied onto the developing roller 41 enters between the pressing portion 47 of the layer thickness regulating blade 42 and the developing roller 41 as the developing roller 41 rotates, and forms the developing roller as a thin layer with a constant thickness. 41 is carried.

  The transfer roller 32 is rotatably supported by the lower frame 28. When the upper frame 27 and the lower frame 28 are combined, the transfer roller 32 is opposed to and contacts the photosensitive drum 29 in the vertical direction. They are arranged to form a nip therebetween. The transfer roller 32 is configured by covering a metal roller shaft 32a with a roller made of a conductive rubber material. A transfer bias is applied to the transfer roller 32 during transfer. The transfer roller 32 is rotationally driven in the opposite direction to the photosensitive drum 29 by the input of power from a motor (not shown).

  The cleaning brush 33 is attached to the lower frame 28, and is arranged to face and contact the photosensitive drum 29 on the rear side of the photosensitive drum 29 in a state where the upper frame 27 and the lower frame 28 are combined. ing.

  The surface of the photosensitive drum 29 is first uniformly charged positively by the scorotron charger 30 as the photosensitive drum 29 rotates, and then exposed by high-speed scanning of the laser beam from the scanner unit 19. An electrostatic latent image corresponding to the image to be formed is formed.

  Next, the electrostatic charge formed on the surface of the photosensitive drum 29 when the positively charged toner carried on the developing roller 41 comes into contact with the photosensitive drum 29 by the rotation of the developing roller 41. The latent image is supplied to an exposed portion of the surface of the photosensitive drum 29 that is uniformly positively charged and exposed to a laser beam and having a lowered potential. As a result, the electrostatic latent image on the photosensitive drum 29 is visualized, and a toner image by reversal development is carried on the surface of the photosensitive drum 29.

  Thereafter, as shown in FIG. 1, the toner image carried on the surface of the photosensitive drum 29 is passed through the transfer position between the photosensitive drum 29 and the transfer roller 32 by the sheet 3 conveyed by the registration roller 14. In the meantime, the image is transferred to the paper 3 by a transfer bias applied to the transfer roller 32. The sheet 3 on which the toner image is transferred is conveyed to the fixing unit 21.

(C) Fixing Unit The fixing unit 21 is provided on the rear side of the process cartridge 20, and includes a fixing frame 48, and a heating roller 49 and a pressure roller 50 in the fixing frame 48.
In the fixing unit 21, the toner transferred onto the paper 3 at the transfer position is thermally fixed while the paper 3 passes between the heating roller 49 and the pressure roller 50. The sheet 3 on which the toner is fixed is conveyed to a sheet discharge path 51 that extends in the vertical direction toward the upper surface of the main casing 2. The sheet 3 conveyed to the sheet discharge path 51 is discharged onto a sheet discharge tray 53 formed on the upper surface of the main body casing 2 by a sheet discharge roller 52 provided on the upper side.

2. Configuration of Paper Feed Roller and Separation Roller FIG. 2 is a perspective view of the gear mechanism portion viewed from the front side. In the drawing, the lower right direction on the paper is the front side of the laser printer 1, and the upper left direction on the paper is the rear side of the laser printer 1.

  As shown in FIG. 2, the paper feed roller 12 and the separation roller 10 rotate with respect to the bearing member 70 in a state where the respective rotary shaft bodies 71 and 72 are arranged in the front-rear direction along the direction orthogonal to the transport direction. Bearing is possible. Among them, one end side of the rotating shaft 72 of the separation roller 10 penetrates one side wall (left direction in FIG. 2) of the bearing member 70, and a separation roller gear 73 is integrally provided at the tip. It has been. Then, when the separation roller gear 73 receives a driving force from a gear mechanism 80 to be described later, the rotating shaft body 72 rotates, and the separation roller 10 rotates integrally with this. In addition, the rotating shaft body 72 is shape | molded with resin, and the several recessed part for preventing sink is formed in the outer peripheral surface.

  Further, the bearing member 70 is configured such that the paper feed roller 12 side swings around the rotation shaft 72 of the separation roller 10 (in the direction of the white arrow in FIG. 1). When the paper pressing plate 15 is driven up by the rotation of the lever shaft 18, the paper feed roller 12 in the contact position is positioned on the surface of the uppermost paper 3 in the paper group loaded on the paper pressing plate 15. It contacts from below and swings upward.

  Further, gears 74 and 75 that rotate integrally with the respective rotary shaft bodies 71 and 72 are provided on the same axis of the paper feed roller 12 and the separation roller 10, and a connecting gear 76 that meshes with these gears 74 and 75 is provided. Both rollers 10 and 12 are rotated in conjunction with each other. That is, as the separation roller 10 rotates, the paper feed roller 12 rotates in a dependent manner.

3. As shown in FIG. 2, at the rear of the rotary shaft 72 (in the upper left direction in the figure), the roller is substantially parallel to the rotary shaft 72, and a substantially central position 77a is rotatable. A supported arm member 77 is provided. One end 77 b of the arm member 77 is engaged with the swing end of the bearing member 70 where the paper feed roller 12 is provided, and the other end 77 c is engaged with the gear mechanism 80. ing.

  3 and 4 are front views of the feeder unit 4 as seen from the rear side, and FIG. 3 shows a state in which the paper feed roller 12 is in the separated position (corresponding to the “initial position” in the present invention). FIG. 4 shows a state in which the paper feed roller 12 is in a contact position (corresponding to “feeding position” in the present invention, hereinafter referred to as “paper feeding position”). In these drawings, the front side of the page is the rear side of the laser printer 1, and the back side of the page is the front side of the laser printer 1.

  With the above configuration, as shown in FIG. 3, the other end 77 c of the arm member 77 is pushed downward by the gear mechanism 80, so that the paper feed roller 12 is separated from the paper group stacked on the paper pressing plate 15. Move to the initial position. On the other hand, as shown in FIG. 4, when the pressing force by the gear mechanism 80 is released, the paper feeding roller 12 hangs downward due to its own weight and comes into contact with the paper group loaded on the paper pressing plate 15. Move to the paper feed position.

4). Pressure changing mechanism between separation pad and separation roller As shown in FIG. 1, the separation pad 11 is laid on a rectangular arrangement plate 11a, and the front end of the arrangement plate 11a can be rotated by a support shaft 11b. As a result, the rear end side can be swung. A spring member 78 (for example, a coil spring) is pressed below the placement plate 11a with the lower surface of the placement plate 11a facing upward from below, and the separation pad 11 is separated from the separation roller by the biasing force of the spring member 78. 10 is pressed.

  As shown in FIG. 2, an arm member 79 is provided below the rotary shaft 72 so as to be substantially parallel to the rotary shaft 72 and rotatably supported at a substantially central position 79a. The arm member 79 has one end 79b abutted against the lower end of the spring member 78 and the other end 79c engaged with a gear mechanism 80 described later.

  5 and 6 are front views of the feeder portion as viewed from the front side. FIG. 5 shows a low pressure state, and FIG. 6 shows a high pressure state. In these drawings, the front side of the paper surface is the front side of the laser printer 1, and the back side of the paper surface is the rear side of the laser printer 1.

  With this configuration, as shown in FIG. 5, when the other end 79c of the arm member 79 is positioned upward, the one end 79b is positioned downward, and the spring member 78 is It is compressed and deformed by an amount corresponding to the distance between the end 79b and the rear surface of the arrangement plate 11a (hereinafter, this state is referred to as “low pressure state”). On the other hand, as shown in FIG. 6, when the other end 79c of the arm member 79 moves downward, the one end 79b moves upward to push up the lower end of the spring member 78, and the spring member 78 is further compressed. Deformed. Thereby, the pressing force of the separation pad 11 on the separation roller 10 can be made stronger than the low pressure state (hereinafter, this state is referred to as “high pressure state”).

  As shown in FIGS. 5 and 6, one end 79 b of the arm member 79 is provided with a protruding portion 79 d erected upward, and this protruding portion 79 d extends from the lower end of the spring member 78 to the inside. Has been inserted. Thereby, the positional deviation between the end 79b and the spring member 78 is restricted.

5. Gear Mechanism Next, the gear mechanism 80 will be described. The gear mechanism 80 includes a plurality of gears that rotate by receiving a driving force from a driving motor (not shown) provided on the main casing 2 side, and mainly controls the following operation.
(A) Control of an operation (hereinafter referred to as “roller driving operation”) for rotating the rotating shaft 72 to rotate the separation roller 10 and the paper feed roller 12.
(B) Control of an operation (hereinafter referred to as “paper feed roller switching operation”) in which the end 77 c of the arm member 77 is moved up and down to raise and lower the paper feed roller 12.
(C) Control of the operation of changing the pressure between the separation roller 10 and the separation pad 11 by moving the end 79c of the arm member 79 up and down (hereinafter referred to as “pressure reduction operation”).
(D) With the paper supply roller 12 in the paper supply position, the lever 17 is rotated to raise the paper pressing plate 15 until the paper supply roller 12 reaches a predetermined height at which paper can be supplied. Control of the operation (hereinafter referred to as “paper pressing plate raising operation”) as a placement portion raising mechanism that stops the rotation of the lever 17 when the height of the lever 17 is reached.

  Specifically, as shown in FIG. 2, the gear mechanism 80 includes the separation roller gear 73, an input gear 81 (see FIG. 7), a solenoid switch 82, a solenoid lever 83, a sector gear 84, and a lift lever. 85, a separation lever 86, and the like.

(1) Solenoid Switch and Solenoid Lever FIGS. 7 to 9 are simplified diagrams showing the configuration of the gear mechanism. In these drawings, the right side of the page is the front side of the laser printer 1, and the left side of the page is the laser printer 1. It is the back side.

  As shown also in FIG. 7, the solenoid switch 82 functions as a switch unit that is turned on every time an image forming operation start signal (corresponding to a “sheet material supply start signal” in the present invention) is received. The solenoid lever 83 is rotatably supported at a substantially central position 83a, and the front end thereof is lifted upward by the ON operation of the solenoid switch 82. A locking claw 83 b that engages with a locking projection 84 a that protrudes from the outer peripheral surface of the sector gear 84 is integrally provided at the rear end of the solenoid lever 83.

(2) Sector gear The sector gear 84 includes a first cam 88, a first chipped gear 89, a second chipped gear 90, and a second cam 91 that rotate integrally with respect to the same rotating shaft 87. And a third cam 92 (corresponding to the “rotating member” of the present invention) that is rotatable with a play (clearance).

(A) First missing tooth gear More specifically, as shown in FIG. 7, a part of the first missing tooth gear 89 is continuously missing, and the driving force from the drive motor is reduced. By being engaged with the input input gear 81, it is driven to rotate. Here, when the latching claw 83b of the solenoid lever 83 and the latching protrusion 84a of the sector gear 84 are engaged, the missing tooth portion of the first missing gear 89 is adjusted so as to face the input gear 81. ing. That is, at this time, the driving force from the input gear 81 is not transmitted to the sector gear 84.

(B) First Cam Next, the first cam 88 is arranged on the right side of the first chipped gear 89 (the lower left direction in FIG. 2 and the front side in FIG. 7). In addition, the first cam 88 has a substantially D-shaped cross section orthogonal to the rotation shaft 87 as a whole, and has a large-diameter portion 88b in which one end portion of the flat portion 88a protrudes. In the vicinity of the first cam 88, a sector spring 95 that contacts the large diameter portion 88b of the first cam 88 in a pressed state in the state shown in FIG. 7 is provided. When the solenoid switch 82 is turned on and the locking by the solenoid lever 83 is released, the sector spring 95 forcibly presses the first cam 88 in the clockwise direction in FIG. It plays the role of rotating the sector gear 84 to a position where 86 and the input gear 81 mesh.

(C) Second missing tooth gear The second missing tooth gear 90 is arranged on the left side of the first missing tooth gear 89 (in the upper right direction on the paper surface in FIG. 2 and in the rear direction on the paper surface in FIG. 7). In addition, the second chipped gear 90 has a portion of substantially one third of the entire circumference continuously missing, and meshes with the separating roller gear 73 to rotate the separating roller 10. Fulfill. In the state of FIG. 7, the separation roller gear 73 is not yet engaged, and the separation roller 10 can idle. That is, the above-described roller driving operation cannot be executed.

(D) Second Cam The second cam 91 is arranged on the left side of the second chipped gear 90. In this second chipped gear 90, approximately one-fourth of the entire circumference continuously forms a small-diameter portion 91a. In the vicinity of the second cam 91, a separation lever 86 is provided in a state where its substantially central position 86a is rotatably supported. The front end portion of the separation lever 86 is in contact with the end portion 79c of the arm member 79 for changing the biasing force by the spring member 78 from above. On the other hand, the rear end portion of the separation lever 86 is in contact with the outer peripheral surface of the second cam 91. With such a configuration, the separation lever 86 is tilted so that the rear end portion is lowered when the rear end portion of the separation lever 86 rides from the small diameter portion 91a of the second cam 91 to the large diameter portion 91b. As a result, the spring member 78 is compressed and deformed to increase the pressure between the separation roller 10 and the separation pad 11. That is, the pressure reducing operation described above can be executed.

(E) Third Cam The third cam 92 is disposed on the left side of the second cam 91. The third cam 92 has a shape projecting to one side as a whole, and a lift lever 85 is provided in the vicinity of the third cam 92. The lift lever 85 has a substantially L-shape and a central position 85a rotatably supported. ing. The lift lever 85 has its base end in contact with the protruding end 92a of the third cam 92, and at its tip, the lift lever 85 raises the end 77c of the arm member 77 for raising and lowering the paper feed roller 12. It will be in the state pushed down from. That is, at this time, the paper feed roller 12 is located at the initial position. On the other hand, when the third cam 92 rotates and its protruding end 92a moves away from the inside of the lift lever 85, the lock by the lift lever 85 is released, and the paper feed roller 12 is moved by the dead weight. Move to position. That is, the above-described sheet feeding roller switching operation can be executed. As shown in FIG. 7, the input gear 81 is connected to a drive gear 93 for rotating the counter roller 13 via a transmission gear 94.

(F) Loading Unit Lifting Mechanism FIG. 10 is a right side view of the gear mechanism 80 and the paper feed cassette 9. In this drawing, the right side of the drawing is the front side of the laser printer 1, and the left side of the drawing is the rear side of the laser printer 1.

  As shown in FIGS. 2 and 10, a switching tilting member 100 is provided behind the end portion 77 c of the arm member 77 for turning on and off the driving of the paper pressing plate raising operation. The switching tilting member 100 can be tilted with its center portion pivotally supported by a rotation shaft parallel to the rotation shaft 87 of each gear 84 and the like, and the front end portion 100a is located above the end portion 77c of the arm member 77. The engaging claw is integrally provided at the tip of the rear end portion 100b.

  When the end 77c of the arm member 77 is pushed downward by the lift lever 85 and the paper feed roller 12 is in the initial position, the switching tilting member 100 is lowered by the urging means (not shown) and the front end 100a is lowered. The part 100b rises (state shown in FIG. 2). On the other hand, when the push-down by the lift lever 85 is released, the end 77c of the arm member 77 moves upward, and the paper feed roller 12 reaches the paper feed position, the front end 100a of the switching tilting member 100 is raised accordingly. The rear end portion 100b is lowered. At this time, the engaging claw of the rear end portion 100 b can be engaged with the drive switching gear 94 a of the control gear group 94 that rotates the lever 17, whereby the driving force from the input gear 81 is transmitted to the control gear group 94. Thus, the paper pressing plate raising operation for raising the paper pressing plate 15 is enabled.

6). Basic Operation of the Present Embodiment FIGS. 11 to 14 are left sectional views of the feeder unit. In these drawings, the left direction on the paper surface is the front side of the laser printer 1 and the right direction on the paper surface is the rear side of the laser printer 1.

(1) Home position Here, the “home position” refers to a standby state in which the gear mechanism 80 normally feeds and waits for a start signal for the next image forming operation. Equivalent to. On the other hand, the state of the gear mechanism 80 during the paper feeding operation corresponds to the “state other than the initial state” of the present invention.

  When the laser printer 1 is powered on, the drive motor is driven and this driving force is transmitted to the input gear 81. Along with this, the opposing roller 13 is rotationally driven via the transmission gear 94 and the drive gear 93. At this time, the gear mechanism 80 is in the state shown in FIG. That is, the sector gear 84 is locked by the solenoid lever 83 and is in a state where the driving force from the input gear 81 is not transmitted. Further, the lift lever 85 is locked in a state in which the end portion 77c of the arm member 77 is pushed downward by contact with the protruding end 92a of the third cam 92. That is, as shown in FIG. 11, the paper feed roller 12 is in an initial position separated from the paper group stacked on the paper pressing plate 15 (see also FIG. 3).

  At this time, the switching tilting member 100 is restricted from engaging the engagement claw of the rear end portion 100b with the drive switching gear 94a of the control gear group 94, and the drive of the sheet pressing plate raising operation is cut off. It is in a state.

  Further, as shown in FIG. 7, the separation lever 86 is in contact with the small diameter portion 91 a of the second cam 91 and allows the upward movement of the end 79 c of the arm member 79. That is, the end 79b of the arm member 79 is inclined downward, and the spring member 78 is compressed and deformed to a length corresponding to the distance (the length L1 shown in FIG. 11) between the end 79b and the arrangement plate 11a. (See also FIG. 5).

(2) When feeding operation (sending operation) starts When the image forming operation is started and the start signal of the image forming operation for the first sheet 3 is given to the solenoid switch 82, the solenoid switch 82 is turned on. Then, as shown in FIG. 8, the locking by the solenoid lever 83 is released, and the urging force of the sector spring 95 causes the sector gear 84 to rotate to a position where the first chip gear 86 and the input gear 81 are engaged with each other. Thus, rotation driving of the sector gear 84 (that is, transmission of driving force from the input gear 81 to the sector gear 84) is started.

  At the same time, the locking state of the lift lever 85 is released by the rotation of the third cam 92, and the upward movement of the end 77c of the arm member 77 is allowed. As a result, as shown in FIG. 12, the paper feed roller 12 is lowered to the paper feed position where it abuts against the paper group stacked on the paper pressing plate 15 (see also FIG. 4).

  At this time, the switching tilting member 100 performs a sheet pressing plate raising operation in which the engagement claw of the rear end portion 100b can be engaged with the drive switching gear 94a of the control gear group 94. That is, when the paper feed roller 12 in the paper feed position is below a predetermined height at which the paper 3 can be fed, the engagement claw of the rear end portion 100b is engaged with the drive switching gear 94a of the control gear group 94. Then, the driving force from the input gear 81 is transmitted to the control gear group 94 and the paper pressing plate 15 is raised. When the predetermined height is reached, the engagement between the engagement claw of the rear end portion 100b and the drive switching gear 94a is released, and the driving force from the input gear 81 is not transmitted to the control gear group 94. The pressing plate 15 stops at that height.

  Further, by the rotation of the second cam 91, the rear end portion of the separation lever 86 rides on the large diameter portion 91b, and the end portion 79c of the arm member 79 is pushed downward. As a result, as shown in FIG. 13, the end 79 b of the arm member 79 tilts upward, and the spring member 78 is further compressed and deformed (length L <b> 2 (<L <b> 1) shown in FIG. 13). And the separation roller 10 are in a high pressure state (see also FIG. 6).

  Thereafter, as shown in FIG. 8, the second chipped gear 90 and the separation roller gear 73 are engaged with each other, and the separation roller 10 is rotationally driven (that is, transmission of driving force from the input gear 81 to the separation roller 10). Is started. Then, the paper feed roller 12 is also rotated in a dependent manner, whereby the paper feed operation of the paper 3 is started.

  As described above, the sheet group is sent to the downstream side in the conveying direction by the contact of the sheet feeding roller 12 and is separated from the separation pad 11 and the separation roller 10 which are pressed against each other with a relatively strong urging force according to the length L2. At the position X, the uppermost sheet 3 is reliably separated.

(3) Ascent of paper feed roller and pressure reduction of separation pad Subsequently, when the leading edge of the paper 3 separated by the separation pad 11 and the separation roller 10 reaches the nip position of the paper dust removing roller 8 and the opposing roller 13 Further, as shown in FIG. 9, the protruding end 92 a of the third cam 92 starts to come into contact with the tapered surface 85 b provided on the distal end side of the proximal end portion of the lift lever 85. Then, the lift lever 85 is gradually guided to a position where the end 77c of the arm member 77 is pushed downward again so as to be guided by the tapered surface 85b. As a result, as shown in FIG. 14, the paper feed roller 12 moves to an initial position separated from the paper group stacked on the paper pressing plate 15 (lifting operation of the paper feed roller). Thus, in this embodiment, the paper feed roller 12 is once moved to the paper feed position and then returned to the initial position.

  Next, the rear end portion of the separation lever 86 enters the small diameter portion 91 a from the large diameter portion 91 b of the second cam 91. Thereby, the upward movement of the end 79c of the arm member 79 is allowed, and as shown in FIG. 11, the spring member 78 returns to the length L1, and the biasing force weaker than that at the start of the paper feeding operation is separated. A low pressure state in which the pad 11 and the separation roller 10 are pressed is brought about (pressure reduction operation).

  Here, since the paper feed roller 12 is already in the initial position, there is no conveyance resistance due to contact with the paper feed roller 12. Therefore, even if the pressure between the separation pad 11 and the separation roller 10 is reduced, sufficient separation capability can be exhibited. At this time, there is no conveyance resistance due to the paper feed roller 12, and conveyance resistance due to the separation pad 11 and the separation roller 10 is reduced. Is smooth.

  After that, when the missing tooth portion of the first missing gear 89 faces the input gear 81, the sector gear 84 is again locked by the solenoid lever 83, and the home position is restored. As a result, the separation roller 10 becomes idle.

  In this way, the gear mechanism 80 repeatedly executes the above-described series of operations each time the start signal for the image forming operation for the second and subsequent sheets 3 is given to the solenoid switch 82.

7). Paper Feed Roller Forced Displacement Means As the paper feed roller forced displacement means, the applicant of the present application has already applied for a technique (prior application technique) described below. The present embodiment has been developed to solve the problems in the prior application technique. FIGS. 15 to 21 are drawings relating to the prior art, but the configuration on the gear mechanism (device main body) side is basically the same as that of the present embodiment except for a contact member 102 and a first spring member 103 described later. Common.

  Therefore, in the following, first, the common configuration between the prior application technique and the present embodiment will be described with reference to FIGS. 15 and 16, and then the prior application technique and its defects will be described, and finally, the present embodiment will be described. I will explain.

(1) Common Configuration FIG. 15 is a perspective view of a gear mechanism 80 and a paper feed cassette 9 partially showing a configuration corresponding to the paper feed roller forced displacement means of the prior application (the lower right side of the paper is the front side of the laser printer 1). It is. FIG. 16 is a partially enlarged view showing the gear mechanism 80 portion of the apparatus main body 4a (the left side of the drawing is the front side of the laser printer 1). FIG. 16 shows a state where the gear mechanism 80 is at the home position and the paper feed roller 12 is at the initial position.

  As shown in FIG. 16, the third cam 92 has a disk member 101 (corresponding to the “pressed member” of the present invention) in which approximately a half of the entire circumference is continuously reduced in diameter. Are integrated. The second cam 91 that rotates integrally with the sector gear 84 and the like is provided with a protrusion 91b. On the other hand, on the third cam 92 side, an arcuate opening 92b is formed, into which the protrusion 91b can be inserted, and has play (clearance) in the rotation direction of the third cam 92.

  When the gear mechanism 80 is in the home position, the disk member 101 has one end surface of the large diameter portion (hereinafter referred to as a pressed portion 101a) facing the front side of the laser printer 1 in the lower position, and the protrusion 91b is in contact with the end in the counterclockwise direction in the drawing in the arc-shaped opening 92b. That is, the third cam 92 is ahead of the second cam 91 and the like in the rotation direction (counterclockwise in the drawing in the drawing) of the second cam 91 and the like when driven by the driving force applied to the gear mechanism 80. It can be rotated.

  Further, for example, between the second cam 91 and the third cam 92, a stopper member 104 corresponding to the “regulating means, regulating member” of the present invention is provided. As shown in FIG. 16, the stopper member 104 has a disk shape in which approximately one fifth of the entire circumference is continuously reduced in diameter. The stopper member 104 has an engaged portion 104 a that engages with the protrusion 91 b of the second cam 91 in a state where there is no play, and rotates together with the second cam 91. In the home position, the stopper member 104 is in a state where the small diameter portion faces downward and does not interfere with the movement path of the contact member 102 from the retracted position to the contact position.

(2) Feature configuration of prior application technology a. Configuration on the Gear Mechanism (Device Main Body) Side As shown in FIG. 15, a substantially central portion 102a is pivotally supported on the device main body 4a side, and the pressed portion 101a at the lower position is applied from the front to the rear at the home position. A contact member 102 that can swing between a contact position that contacts and a retract position (refer to FIG. 16) that retracts in front of the gear mechanism 80 is provided. The contact member 102 has a lower end connected to the first spring member 103 and is always biased to the retracted position.

  As shown in FIG. 15, a contact portion 102 b that presses the pressed portion 101 a of the disk member 101 from the front is formed at the upper end portion of the contact member 102. In addition, an extending portion 102 c extending toward the sheet feeding cassette 9 is integrally provided at the upper end portion of the contact member 102. The extending portion 102c includes a first surface 102d along the longitudinal direction of the abutting member 102, a second surface 102e in which the first surface 102d and the tip are connected to each other, and inclined with respect to the first surface 102d. have.

b. FIG. 17 is a partial side view of the paper feed cassette 9 in a state pulled out from the apparatus main body 4a (the left side of the paper is the front side of the laser printer 1).

  As shown in FIG. 17, a substantially central portion 105 a is pivotally supported on the paper feed cassette 9 side, and a pressing position (the state of FIG. 17) in which the upper end portion is inclined toward the rear end side of the paper feed cassette 9, A pressing member 105 that can swing between a contact position in which an upper end portion is inclined toward the front end side of the sheet feeding cassette 9 is provided. The pressing member 105 has a lower end connected to the second spring member 106 and is always urged to the pressing position. The second spring member 106 has a stronger urging force than the first spring member 103.

  Further, as shown in FIG. 15, when the paper feed cassette 9 is accommodated in the apparatus main body 4a at the upper end portion of the pressing member 105, the extending portion 102c of the abutting member 102 is arranged from the front to the rear (the paper feed cassette 9 The pressing portion 105b that is pressed toward the back side in the insertion direction of the is extended.

c. Feed roller forced displacement operation (when replenishing paper)
18 and 19 are left-side cross-sectional views of the feeder section at the home position and during the paper feed roller forced displacement operation. In these drawings, the left side of the drawing is the front side of the laser printer 1, and the right side of the drawing is the rear side of the laser printer 1.

  When the gear mechanism 80 returns to the home position normally after receiving the image forming operation start signal and performing the paper feeding operation of the paper 3, the gear mechanism 80 and the paper feeding cassette 9 are in the state shown in FIG. In this state, for example, when the paper feed cassette 9 is pulled out from the apparatus main body 4a for paper replenishment, the gear mechanism 80 maintains the home position as shown in FIG. On the other hand, when the paper cassette 9 is disconnected from the gear mechanism 80, as shown in FIG. 17, the front end of the paper pressing plate 15 moves downward due to its own weight, and becomes the placement position.

  After the paper 3 is replenished, the paper feed cassette 9 is reattached to the apparatus main body 4a. In this process, the pressing portion 105b (see FIG. 15) of the pressing member 105 on the paper feed cassette 9 side comes into contact with the second surface 102e of the extending portion 102c of the contact member 102 on the apparatus main body 4a side from the front. Here, the biasing force of the second spring member 106 is stronger than that of the first spring member 103. Therefore, by further pushing the sheet feeding cassette 9 into the back side of the apparatus main body 4a, as shown in FIG. 19, the pressing member 105 is pressed to displace the contact member 102 from the retracted position to the contact position.

  At this time, the contact portion 102b (see FIG. 15) of the contact member 102 presses the pressed portion 101a of the disk member 101 to rotate the third cam 92 itself counterclockwise in the drawing. Thereby, the latching state of the lift lever 85 by the third cam 92 is released, and the upward movement of the end 77c of the arm member 77 is allowed. When the paper feeding cassette 9 is further pushed into the back side and disposed at the proper storage position, the pressing portion 105b (see FIG. 15) of the pressing member 105 is moved to the second surface 102e of the extending portion 102c of the contact member 102. In the same manner as in the state of FIG. 18, the pressing member 105 becomes the pressing position, and the contact member 102 returns to the retracted position.

  As a result, as shown in FIG. 12, the paper feed roller 12 is lowered to the paper feed position where it abuts against the paper group loaded on the paper pressing plate 15 (see also FIG. 4). As a result, it is possible to control the operation of raising the paper pressing plate, and the paper pressing plate 15 that has been placed is raised to a position where the paper feed roller 12 reaches a predetermined height. That is, before receiving the start signal of the next image forming operation, the paper pressing plate 15 can be arranged in advance at a supply position where paper can be fed. Therefore, after the paper cassette 9 is remounted, the paper 3 can be normally fed even during the first paper feeding operation.

(When an error occurs during paper feeding)
FIG. 20 is a left side cross-sectional view of the feeder unit when the paper feed roller forced displacement operation is restricted. In this drawing, the left side of the drawing is the front side of the laser printer 1, and the right side of the drawing is the rear side of the laser printer 1.

  For example, when an abnormality such as a paper jam occurs during the paper feeding operation, the gear mechanism 80 stops in the middle of the paper feeding operation. At this time, the paper feed roller 12 is at the paper feed position. In this state, when the paper feeding cassette 9 is pulled out from the apparatus main body 4a, the paper pressing plate 15 is also at the placement position. Then, after performing jam processing for removing the jammed paper 3, the paper feed cassette 9 is mounted again on the apparatus main body 4a. In this process, the pressing portion 105b of the pressing member 105 also comes into contact with the second surface 102e of the extending portion 102c of the contact member 102 from the front. However, as shown in FIG. 20, the contact member 102 has its contact portion 102b in contact with the large diameter portion of the stopper member 104, and movement to the contact position is restricted. Accordingly, the pressing member 105 is also displaced to the contact position against the urging force of the second spring member 106. In this state, the paper feed cassette 9 is placed at a regular storage position.

  Then, the gear mechanism 80 starts to be driven. At this time, as shown in FIG. 20, since the lift lever 85 is released from the locked state by the third cam 92, the paper feed roller 12 is in the paper feed position and the paper pressing plate ascending operation is executed and placed. The paper pressing plate 15 in the position starts to rise. Further, when the gear mechanism 80 further rotates and the lift lever 85 is about to be locked by the third cam 92, or when the lift lever 85 is locked, the contact member 102 is restricted by the stopper member 14. Is released. As a result, the pressing member 105 moves the contact member 102 to the contact position by the restoring force of the second spring member 106, and presses the pressed portion 101a of the disk member 101 so that the third cam 92 is shown in FIG. The paper is rotated counterclockwise (see FIG. 19). Thereby, the latching state of the lift lever 85 by the third cam 92 is released, and the sheet pressing plate raising operation is continued or resumed. Therefore, also in this case, before receiving the start signal of the next image forming operation, the paper pressing plate 15 can be arranged in advance in a supply position where paper can be fed. Even during the paper operation, the paper 3 can be normally fed.

d. Problems with Prior Application Technology FIG. 21 is an enlarged view of the gear mechanism portion of the prior application technology. For example, when the paper feed cassette 9 is remounted on the apparatus main body 4a after the above-mentioned paper replenishment, the contact member 102 must originally return to the retracted position after pressing the pressed portion 101a of the disk member 101 ( (See FIG. 18). However, for example, since the paper feed cassette 9 is mounted halfway, the contact member 102 may remain in the contact position as shown in FIG. In such a state, when the gear mechanism 80 is driven in response to an image forming operation start signal for the next sheet 3, the contact portion 102 b is locked by the disk member 101 that has rotated one turn. It is pushed into the contact position (see FIG. 5B). As a result, the contact member 102 cannot be returned to the retracted position.

(3) Characteristic configuration of the embodiment of the present invention a. 22 and 23 are partially enlarged views of the paper feed cassette 9 in a state of being pulled out from the apparatus main body 4a in the embodiment of the present invention. FIG. 23 shows a state in which the pressing member 110 is removed. Has been. In FIG. 22, the upper right side of the drawing is the front side of the laser printer 1 (the direction of pulling out from the apparatus main body 4a), and the left side of the page of FIG. 23 is the front side of the laser printer 1 (the drawing direction from the apparatus main body 4a).

  A pressing member 110 on which a substantially central portion 110a (corresponding to the “rotating shaft of the pressing member” of the present invention) is pivotally supported is rotatably provided on one side wall on the front side of the sheet feeding cassette 9. As shown in FIG. 23, the pressing member 110 has a rod-like shape as a whole, and is integrally provided with a hooking portion 110b on which a coil spring 111 is hooked at a base end portion directed toward the front side, and is directed toward the rear side. A columnar pressing portion 110c that protrudes toward the opposing wall of the apparatus main body 4a is integrally provided at the tip.

  The coil spring 111 (corresponding to the “biasing means” of the present invention) is provided in a posture along the substantially horizontal direction as a whole, its rear end is hooked on the hooking portion 110b of the pressing member 110, and its front end is the paper feed cassette 9 It is fixed to. With such a configuration, in a state in which the paper feed cassette 9 is pulled out from the apparatus main body 4a, the pressing member 110 extends along the horizontal direction as a whole, and a basic posture in which the tip end portion is directed forward in the mounting direction to the apparatus main body 4a. And the tip portion can swing up and down against the biasing force of the coil spring 111.

  In addition, the pressing member 110 is integrally provided with an engaging protrusion 110 d that protrudes toward the opposite surface of the sheet feeding cassette 9 at a position near the tip. On the other hand, an arcuate guide groove 112 centering on the shaft support position of the pressing member 110 is formed through the opposing surface side of the paper feed cassette 9. When the pressing member 110 is attached to the paper feeding cassette 9, the engaging protrusion 110 d is engaged with the guide groove 112 while being prevented from coming off. Thus, when the pressing member 110 swings against the urging force of the coil spring 111, the engaging protrusion 110d on the tip end side is guided by the guide groove 112, so that stable pressing is possible. Become.

b. Configuration on Gear Mechanism (Device Main Body) Side FIGS. 24 to 28 are a side view and a perspective view showing the opening side of the housing portion in which the paper feed cassette 9 is housed in the device main body 4a. In each figure (a), the left side of the drawing is the front side of the laser printer 1, and only the pressing member 110 and the coil spring 111 are shown in the configuration of the paper feed cassette 9. In each figure (b), the lower left side of the drawing is the front side of the laser printer 1, and only the pressing member 110 and the coil spring 111 are shown for the configuration of the paper feed cassette 9.

  As shown in FIG. 24, on the inner side wall on the opening side of the sheet feeding cassette housing portion of the apparatus main body 4a, the pressing portion 110c of the pressing member 110 can be pressed at a position Y (where the pressed portion 101a of the disk member 101 can be pressed. There are provided an entry path 120 for entering into the rotation path of the pressed part 101a of the disk member 101, and an exit path 121 for retracting the pressing part 110c of the pressing member 110 after pressing the pressed part 101a. It has been.

  Specifically, the entrance path 120 and the exit path 121 share the open end side of the sheet cassette accommodating portion, and are formed to be separated vertically from each other via the separation wall 122. The separating wall 122 is gradually inclined upward from the opening end portion that becomes the junction P between the approach path 120 and the exit path 121, and is tilted downward at a position reaching the rotation path of the pressed part 101a. I am doing. Further, the separation wall 122 extends to a position where the junction P is lower than the pressing portion 110c of the pressing member 110 in the basic posture.

  Further, a triangular guide portion 123 is provided at a lower position before the junction P of the separation wall 122. This is because, for example, when the paper feeding cassette 9 is inserted in a posture in which the pressing portion 110c of the pressing member 110 faces obliquely downward for some reason, the pressing member 110c is guided upward to guide the pressing member 110. It functions as a guide means that guides the vehicle so as to be directed toward the approach path 120.

c. Feed roller forced displacement operation (when replenishing paper)
As described above, after the image forming operation start signal is received and the paper feeding operation of the paper 3 is performed, the paper is fed from the apparatus main body 4a, for example, for paper replenishment in a state where the gear mechanism 80 has normally returned to the home position. When the cassette 9 is pulled out, the gear mechanism 80 maintains the home position. On the other hand, when the paper cassette 9 is disconnected from the gear mechanism 80, the front end portion of the paper pressing plate 15 moves downward due to its own weight and becomes the placement position.

  After the paper 3 is replenished, the paper feed cassette 9 is reattached to the apparatus main body 4a. In this process, as shown in FIG. 24, the pressing member 110 in the basic posture by the biasing force of the coil spring 111 has its leading end directed rearward (forward in the insertion direction of the paper feed cassette 9), and the entry path 120 And toward the junction P with the exit path 121. Then, as shown in FIG. 25, the pressing member 110 has its pressing portion 110c sent to the entrance path 120 side at this junction P, and the front taper surface 122a of the separation wall 122 (the “taper surface” of the present invention). To the upper position against the urging force of the coil spring 111, the tip portion swings.

  The pressing portion 110 c of the pressing member 110 becomes a position Y at which the pressed portion 101 a of the disk member 101 can be pressed at the time when it exceeds the highest vertex of the separation wall 122. Then, the pressing portion 110c is gradually guided downward by the rear tapered surface 122b of the separation wall 122, and presses the pressed portion 101a of the disk member 101 counterclockwise by the restoring force of the coil spring 111 so as to be third. The cam 92 itself is rotated counterclockwise in the drawing (see FIG. 26). Thereby, the latching state of the lift lever 85 by the third cam 92 is released, and the upward movement of the end 77c of the arm member 77 is allowed.

  As a result, as shown in FIG. 12, the paper feed roller 12 is lowered to the paper feed position where it abuts against the paper group loaded on the paper pressing plate 15 (see also FIG. 4). As a result, it is possible to control the operation of raising the paper pressing plate, and the paper pressing plate 15 that has been placed is raised to a position where the paper feed roller 12 reaches a predetermined height. That is, before receiving the start signal of the next image forming operation, the paper pressing plate 15 can be arranged in advance at a supply position where paper can be fed. Therefore, after the paper cassette 9 is remounted, the paper 3 can be normally fed even during the first paper feeding operation.

  Now, the pressing member 110 after pressing the pressed portion 101a of the disk member 101 returns to the basic posture by the restoring force of the coil spring 111, as shown in FIG. At this time, the pressing part 110c of the pressing member 110 is at a position deviating from the rotation locus of the pressed part 101a. When the paper feeding cassette 9 is pulled out from the apparatus main body 4a, the pressing member 110 keeps the basic posture, and the pressing portion 110c passes below the rear taper surface 122b of the separation wall 122 and the back surface of the front taper surface 122a. Abuts on the bottom surface. Then, as shown in FIG. 27, the pressing member 110 assumes a posture in which the pressing portion 110 c is once lowered, and returns to the basic posture when the junction point P is exited.

  In short, in the present embodiment, the pressing portion 110c of the pressing member 110 is guided to the position Y that can pass through the entry path 120 and can press the pressed portion 101a in the mounting process of the paper feed cassette 9, and in the pulling process, It passes through the exit path 121 and is pulled out from the apparatus main body 4a.

(When an error occurs during paper feeding)
For example, when an abnormality such as a paper jam occurs during the paper feeding operation, the gear mechanism 80 stops in the middle of the paper feeding operation. At this time, the paper feed roller 12 is at the paper feed position. In this state, when the paper feeding cassette 9 is pulled out from the apparatus main body 4a, the paper pressing plate 15 is also at the placement position. Then, after performing jam processing for removing the jammed paper 3, the paper feed cassette 9 is mounted again on the apparatus main body 4a. In this process, the pressing member 110 is guided to the entry path 120 and moves toward the position Y where the pressed portion 101a can be pressed. However, as shown in FIG. 20, the pressing member 110 has its pressing portion 110c abutted against the large-diameter portion of the stopper member 104, and the movement to the pressable position Y is restricted. In this state, the paper feed cassette 9 is placed at a regular storage position.

  Then, the gear mechanism 80 starts to be driven. At this time, as shown in FIG. 25, since the lift lever 85 is unlocked by the third cam 92, the paper feed roller 12 is in the paper feed position and the paper pressing plate ascending operation is executed and placed. The paper pressing plate 15 in the position starts to rise. When the gear mechanism 80 is further rotated and the lift lever 85 is about to be locked by the third cam 92, or when the lift lever 85 is locked, the stopper member 14 restricts the pressing member 110. Canceled. Thereby, the pressing member 110 presses the pressed portion 101a of the disk member 101 by the restoring force of the coil spring 111, and the third cam 92 is rotated counterclockwise in the drawing (see FIG. 19). Thereby, the latching state of the lift lever 85 by the third cam 92 is released, and the sheet pressing plate raising operation is continued or resumed. Accordingly, in this case as well, before receiving the start signal of the next image forming operation, the paper pressing plate 15 can be arranged in advance at a supply position where paper can be fed. Even during the paper operation, the paper 3 can be normally fed.

8). Effects of this embodiment (1) According to this embodiment, the pressing portion 110c of the pressing member 110 presses the pressed portion 101a of the disk member 101 in the process of mounting the paper feed cassette 9 on the apparatus main body 4a. Then, the paper feed roller 12 is lowered to the paper feed position where it contacts the paper group loaded on the paper pressing plate 15 (see also FIG. 4), and the paper pressing plate ascending operation can be controlled. That is, before receiving the start signal of the next image forming operation, the paper pressing plate 15 can be arranged in advance at a supply position where paper can be fed. Therefore, after the paper cassette 9 is remounted, the paper 3 can be normally fed even during the first paper feeding operation.
(2) In addition, since the pressing member 110 is moved through separate paths in the entrance path 120 and the exit path 121 when the paper feed cassette 9 is mounted and pulled out, as in the prior art, It is possible to avoid a situation in which the return of the contact member 102 to the retracted position becomes impossible.

(3) Further, since the third cam 92 and the disk member 101 are integrally formed, the number of parts can be reduced and the rotational position timing of both can be set with high accuracy.
(4) When an abnormality occurs during the paper feeding operation, the forced displacement operation of the third cam 92 by the pressing member 110 is executed after waiting for the gear mechanism 80 to return to the home position. Smooth supply operation can be resumed.

(5) Since the stopper member 104 is provided coaxially with the third cam 92 and the like, the restriction timing by the stopper member 104 can be easily set on the basis of the rotation position of the paper feed roller 12.
(6) The pressing portion 110 c of the pressing member 110 can be smoothly guided to the position Y that can be pressed by the front tapered surface 122 a of the approach path 120.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) The paper feed cassette 9 may be detached or may not be detached as long as it can be pulled out from the apparatus main body 4a.

  (2) In contrast to the above-described embodiment, the configuration may be such that only the problem at the time of mounting the paper feed cassette 9 at the time of paper replenishment is provided without providing the stopper member 104.

  (3) The configuration may be such that the pressing member 110 is swung manually without providing the coil spring 111.

  (4) In the above embodiment, the coil spring 111 is employed as the urging means, but other elastic members such as a rubber member may be used instead of such a spring member.

  (5) In the above embodiment, the disk member 101 is integrated with the third cam 92. However, if the disk member 101 is configured to rotate in conjunction with each other, the disk member 101 rotates integrally on the same axis or a different rotating shaft. It may be a gear connected above.

  (6) In the above-described embodiment, the entrance path 120 and the exit path 121 are configured to share the opening end side of the sheet cassette housing unit. However, the present invention is not limited to this, and the path is an individual path from the opening end side. It may be a configuration.

  (7) In the above-described embodiment, the pressing member 110 is configured to be biased in the vertical direction by the coil spring 111 with respect to the basic posture. However, the configuration is not limited thereto, and the pressing member 101a of the disk member 101 is pressed. It may be configured to be biased by the biasing means only in the direction (downward in the above embodiment) and to guide the pressing member 110 toward the approach path 120 against this biasing force.

  (8) In the above embodiment, the pressing member 110 is provided on the paper cassette 9 side. However, the pressing member 110 is not limited to this, and is provided on the apparatus body 4 a side so as to be horizontally movable. Accordingly, it may be configured to move in and out in the process of mounting the paper cassette 9 and to move out in the process of pulling out.

1 is a side sectional view showing a main part of a laser printer according to an embodiment of the present invention. The perspective view which looked at the gear mechanism part from the front side Front view of feeder section viewed from the rear (paper feed roller in initial position) Front view of feeder section viewed from the rear (paper feed roller in the paper feed position) Front view of the feeder section from the front (low pressure state) Front view of feeder section viewed from the front (high pressure state) Simplified diagram showing the structure of the gear mechanism (Part 1) Simplified diagram showing the configuration of the gear mechanism (Part 2) Simplified diagram showing the structure of the gear mechanism (Part 3) Right side view of gear mechanism and paper cassette Left section of the feeder section (home position) Left sectional view of the feeder section (with the paper feed roller moved downward) Left sectional view of the feeder (high pressure state) Left sectional view of the feeder section (with the paper feed roller moved upward) A perspective view of a gear mechanism and a paper feed cassette partially showing a configuration corresponding to the paper feed roller forced displacement means in the prior application technology Left side view showing the gear mechanism of the device body in the prior application technology Left side view of the paper feed cassette pulled out from the main unit Left sectional view of the feeder section at the home position in the prior application technology Left side cross-sectional view of feeder section during forced displacement operation of feed roller in prior application technology Left sectional view of the feeder section when regulating the forced displacement operation of the paper feed roller in the prior application technology Enlarged view of gear mechanism in prior application technology Partial enlarged view of the paper feed cassette in this embodiment (part 1) Partial enlarged view of the paper feed cassette in this embodiment (part 1) The side view and perspective view which expanded the paper feed cassette accommodating part of the apparatus main body in this embodiment (the 1) The side view and perspective view which expanded the paper feed cassette accommodating part of the main part of an apparatus in this embodiment (the 2) The side view and perspective view which expanded the paper-feed cassette accommodating part of the apparatus main body in this embodiment (the 3) The side view and perspective view which expanded the paper feed cassette accommodating part of the main part of a device in this embodiment (the 4) The side view and perspective view which expanded the paper feed cassette accommodating part of the apparatus main body in this embodiment (the 5)

Explanation of symbols

1. Laser printer (image forming device)
3. Paper (sheet material, recording medium)
4. Feeder unit (sheet material supply device)
4a: apparatus main body 5 ... image forming unit (image forming means)
9: Paper cassette (storage cassette)
12: Paper feed roller (sending roller)
15: Paper pressing plate (stacking section)
80 ... gear mechanism 92 ... third cam (rotating member)
92b ... Arc-shaped opening 101 ... Disk member (pressed member)
104: Stopper member (regulating means, regulating member)
110 ... Pressing member 110a ... Approximate center (rotating shaft of pressing member)
110d ... engaging protrusion 111 ... coil spring (biasing means)
DESCRIPTION OF SYMBOLS 112 ... Guide groove 120 ... Entrance route 121 ... Retraction route 122a ... Front side taper surface (taper surface)
P ... Junction point Y ... Pushable position

Claims (12)

The device body;
A storage cassette on which sheet material is stacked and provided so as to be movable up and down;
A feed roller that is provided on the apparatus main body side so as to be movable up and down, rotates in a state of being in contact with the upper surface of the sheet material on the stacking unit, and sends out the sheet material;
A rotating member provided to be rotatable, and a pressed member that rotates in conjunction with the rotating member and receives a pressing force to forcibly rotate the rotating member, and with the rotation of the rotating member, A delivery roller displacing means for displacing the delivery roller between an initial position spaced from the sheet material on the stacking unit and a delivery position capable of contacting the sheet material on the stacking unit;
A stacking unit raising mechanism for raising the stacking unit on the condition that the sending roller is at the sending position and the moving position of the sending roller is equal to or lower than a predetermined height;
It has a pressing member that enters and moves to the pressed member side in the mounting process of the storage cassette, moves out of the pressed member side in the drawing process of the storage cassette, and can move up and down in the forward and backward movement process. A delivery roller forced displacement means;
In the mounting process, an approach path for causing the pressing member to enter a position where the pressed member can be pressed; and
A retreat path for retreating the pressing member at a position moved in the pressing direction of the pressed member from the position capable of being pressed through a path different from the entry path in the pulling process,
The delivery roller forcible displacing means presses the pressed member by the pressing member that has entered the pressable position to forcibly displace the delivery roller from the initial position to the delivery position. Sheet material supply device. The sheet material supply apparatus according to claim 1, wherein the rotating member and the pressed member are integrally formed. A gear mechanism that controls the rotation of the feed roller in response to a sheet material supply start signal,
The rotating member is configured to be driven to rotate with play with respect to the rotation of the gear mechanism,
The sheet material supply device according to claim 1, wherein the delivery roller forcibly displacing unit forcibly displaces the delivery roller by rotating the rotating member through the play. When the storage cassette is mounted on the apparatus main body, if the gear mechanism is not in an initial state waiting for the supply start signal, a regulation for restricting the operation of the delivery roller forced displacement means until the gear mechanism is in the initial state. The sheet material supply apparatus according to claim 3, further comprising means. The restricting means is interlocked with the gear mechanism, allows the pressing member to enter the pressable position in an initial state where the gear mechanism waits for the supply start signal, and presses in the state other than the initial state. The sheet material supply device according to claim 4, wherein the sheet material supply device is a restriction member that restricts entry of the member into the pressable position. The sheet material supply device according to claim 5, wherein the restriction member is provided coaxially with the gear of the gear mechanism and rotates integrally with the rotation of the gear. The delivery roller forced displacing means includes urging means for urging the pressing member in a pressing direction of the pressed member,
The said pressing member enters into the said position which can be pressed via the said approach path | route against the urging | biasing force of the said urging | biasing means, The claim 1 characterized by the above-mentioned. Sheet material supply device. The approach path and the exit path are configured to merge on the end side in the drawer direction of the storage cassette,
The delivery roller forced displacement means includes an urging means for urging the tip member in the approach direction to the pressed member side of the pressing member so as to maintain a basic posture in the approach direction,
The joining portion of the approach path and the exit path has a shape that guides the tip portion of the pressing member in the basic posture to the approach path side in the mounting process,
The approach path has a shape for entering the pressable position while moving the tip of the pressing member upward or downward against the biasing force of the biasing means,
The said withdrawal path | route is a shape which can withdraw the front-end | tip part of the press member which returned to the said basic attitude, pressing the said to-be-pressed member in the said position which can be pressed. The sheet | seat material supply apparatus in any one. The sheet material supply device according to claim 8, wherein the approach path has a tapered surface inclined upward or downward from the joining portion toward the pressable position. The pressing member is provided on the storage cassette side so that the tip portion can be moved up and down via a rotation shaft,
The said urging means is a coil spring arranged along the said approach direction, one end side being connected with the base end part of the said press member, and the other end side being fixed to the said storage cassette side, The sheet material supply apparatus according to claim 9. The storage cassette is formed with an arcuate guide groove centered on the rotation axis of the pressing member,
The sheet material supply device according to claim 10, wherein an engagement protrusion that engages with the guide groove is provided at a position near the tip of the pressing member. The sheet material supply device according to any one of claims 1 to 11, and an image forming unit that forms an image on a recording medium as a sheet material supplied from the sheet material supply device. A featured image forming apparatus.

Images