JP4761153B2 - Recording medium supply device and image forming apparatus using the same - Google Patents

Description

  The present invention relates to a recording medium supply device and an image forming apparatus using the same.

  In general, in an image forming apparatus such as a copying machine or a printer, for example, a structure in which an image (toner image, ink image, etc.) formed in an image forming unit is transferred to a sheet (recording medium) such as paper, or an image (ink Image or the like) is directly attached to a sheet (recording medium) such as paper, so that a large number of sheets are stored in advance and a sheet supply device ( Recording medium supply device).

  As a conventional sheet supply apparatus, there is a sheet supply unit including a sheet tray in which sheets are stored, and a sheet supply unit is installed above the sheet tray, and the sheet output unit sequentially supplies the sheet from the topmost sheet. is there.

  As the sheet feeding unit, for example, a pickup roller which is a feeding means for feeding out a sheet, and a sheet feeding mechanism for separating the fed sheets one by one (for example, a mechanism configured by a feed roller and a sheet rolling roller pressed against each other). There is something with.

  In such a sheet supply apparatus, for example, a bottom plate lift system is employed to send out the sheets in the sheet tray.

  In this bottom plate lift system, a bottom plate (stacking member) on which sheets are stacked is provided on the bottom of the sheet tray so as to be movable up and down. After the sheet is pressed and the sheet is fed by the pickup roller, the fed sheet is guided to the rolling mechanism so as to roll one by one.

As a technique describing the sheet feeding apparatus, there is, for example, Japanese Patent Laid-Open No. 2003-182861.
JP 2003-182861 A

  The present invention has been made from the above-described technical background, and is a compact device that suppresses fluctuations in the pressing force between the sending means and the recording medium regardless of the number of stacked recording media stacked on the stacking member. It is an object of the present invention to provide a recording medium supply device and an image forming apparatus using the same.

  In order to solve the above-described problems, a recording medium supply device according to the first aspect of the present invention includes a stacking member that is loaded on a recording medium and movably provided on the side on which the recording medium is stacked, and the stacking member is elastic. An elastic member that is pressed by force, and a reciprocating motion between a first position and a second position that is further away from the recording medium loaded than the first position. The upper recording medium is brought into contact with the upper recording medium and moved from the first position side to the second position side and rotated in the first rotation direction so that the uppermost recording medium is loaded in cooperation with the winding means. A sending means for sending the paper from a position, a pressing force applying means for urging the sending means toward the first position, and pressing the sending means against the recording medium loaded on the stacking member; and the sending means Moved to the second position side And having a position regulating means for regulating the position to stop the movement of the loading member.

  According to a second aspect of the present invention, in the first aspect of the present invention, the position restricting means is attached to the stacking member, and moves together with the stacking member. When the delivery means moves to the second position side, the engagement means engages with the engagement member to prevent the loading member from moving, and the delivery means is moved to the first position. And a restraining member that separates from the engaging member when moved.

  The invention according to claim 3 is the invention according to claim 2, wherein the engagement member is a tooth-like member fixed to the stacking member, and the restraining member is a tooth meshing with the tooth-like member. Is a rack formed.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects of the present invention, the elastic member is provided so as to be able to rotate in conjunction with the rotation of the delivery means, and the elastic member is elastic at a first rotation angle. The loading member is moved to the side where the recording medium is loaded by force, and the loading member is moved to the side opposite to the side where the recording medium is loaded against the elastic force of the elastic member at the second rotation angle. And a cam that is further provided.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the spreading means is disposed opposite to the sending means, and a predetermined recording medium is sent by the sending means. The delivery means is provided so as to be capable of reciprocating between the first position and the second position while maintaining a facing relationship with the rolling means. To do.

  According to a sixth aspect of the present invention, in the first aspect of the present invention, the rotational force of the rotational driving means is transmitted, and the first gear arranged coaxially with the rotational axis of the rolling means that is a rotating body. And a rotation shaft is provided so as to be reciprocally rotatable around a rotation axis of the first gear over a predetermined rotation angle, and the rotational force of the first gear is increased. A second gear to be transmitted to the delivery means, and a support member that rotatably supports the rotation shaft of the delivery means and is swingable with respect to a swing fulcrum coaxial with the rotation shaft of the rolling means. The delivery means reciprocates between the first position and the second position about the rotation axis of the rolling means.

  The invention according to claim 7 is the invention according to claim 6, and is attached to the rotation shaft of the delivery means and meshes with the second gear, and the rotational force of the second gear is applied to the delivery means. One-way power transmission means for transmitting and rotating the delivery means in the first rotational direction is further provided.

  The invention according to claim 8 is the invention according to claim 6 or 7, wherein the support member is provided with a feed gear in which teeth are formed at least partially around the swing fulcrum. The rack is provided with an advancing / retreating gear that meshes with the feed gear and is formed along an approaching / separating direction with respect to the tooth-like member, and accompanying the movement of the delivery means to the second position side. When the support member is swung, the rack is advanced by the advance / retreat gear meshed with the feed gear and meshed with the tooth-like member, and as the delivery means moves to the first position side. When the support member is swung, the rack is retracted by the advance / retreat gear engaged with the feed gear, and the engagement with the toothed member is released.

  The invention according to claim 9 is the invention according to any one of claims 1 to 8, wherein the pressing force applying means is configured to elastically force the delivery means via the rotation shaft of the delivery means. It is a coil spring which is urged toward the position of 1.

  A tenth aspect of the present invention is the invention according to any one of the sixth to ninth aspects, wherein the rolling means has a through hole formed in the rotation axis direction at a central portion of the inner wall of the through hole. An annular protrusion is provided, and is rotatably attached to a rod-like member that penetrates the through hole.

  The invention described in claim 11 is characterized in that, in the invention described in claim 10, there is provided pressure contact means for pressing the whirling means against the delivery means.

  An image forming apparatus according to a twelfth aspect of the present invention includes the recording medium supply device according to any one of the first to eleventh aspects, and forms a predetermined image on the recording medium sent from the recording medium supply device. It is characterized by that.

  According to the first aspect of the present invention, the recording medium can be reduced in size so as to suppress fluctuations in the pressing force between the sending means and the recording medium regardless of the number of recording media stacked on the stacking member. A feeding device can be provided.

  According to the second aspect of the present invention, since the position of the stacking member can be regulated without providing a motor and a sensor, the pressing force between the feeding means and the recording medium is stabilized, and the apparatus It becomes possible to reduce the size.

  According to invention of Claim 3, the position of a stacking member can be controlled with a simple mechanism of a tooth-like member and a rack.

  According to the fourth aspect of the present invention, the stability of the pressing force between the feeding means and the recording medium is improved even if the stacking member moves each time the recording medium is sent out. Further, since the recording medium loaded on the stacking member is separated from the sending means when the sending means is not performing the feeding operation, it is not necessary to push down the stacking member when the recording medium is replenished, and replenishment work is facilitated. It becomes possible to do.

  According to the fifth aspect of the present invention, regardless of the position of the sending means, the winding means can reliably feed the recording medium one by one.

  According to the invention described in claim 6, since the delivery means reciprocates between the first position and the second position while drawing an arcuate locus coaxially with the rotation axis of the rolling means. It is possible to move smoothly between these positions without changing the pressure contact force with the rolling means.

  According to the seventh aspect of the present invention, since the rotational force when the delivery means rotates in the second rotational direction opposite to the first rotational direction is not transmitted to the rotational drive means, damage to the drive system is prevented. The

  According to invention of Claim 8, the rack which is a restraint member can be meshed | engaged with the tooth-like member which is an engagement member by simple linear movement.

  According to the ninth aspect of the present invention, a desired pressing force against the recording medium can be easily obtained by selecting a wound spring having a necessary elastic force.

  According to the invention described in claim 10, since the winding means swings in the axial direction with the projection as a fulcrum, there is no variation in the distribution of the pressure contact force with the sending means, and the recording medium can be sent in a stable posture. it can.

  According to the eleventh aspect of the present invention, since the rush angle of the recording medium with respect to the winding means is stabilized, the fluctuation of the recording medium sending prevention force due to the fluctuation of the position of the winding means is eliminated. Even if a large sending prevention force is not applied, the rolling means can reliably roll the recording medium.

  According to the twelfth aspect of the present invention, it is possible to stably feed out various types of recording media regardless of the thickness, stiffness, or surface roughness of the recording media.

  Hereinafter, an embodiment as an example of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

  In FIG. 1, for example, an electrophotographic image forming engine 21 is mounted in an apparatus main body 20 of the image forming apparatus, and a drawer type sheet supply device 40 housed below the image forming engine 21 is disposed. ing. Further, a manual sheet supply device (recording medium supply device) 70 is disposed on the side of the apparatus main body 20 so as to protrude outward. A discharge tray 27 is formed in the upper part of the apparatus main body 20, and sheets (recording media) such as sheets sent from the sheet supply apparatuses 40 and 70 are discharged through the image forming engine 21 in the apparatus main body 20. A sheet conveyance path 28 leading from the outlet 26 to the discharge tray 27 is formed in a substantially vertical direction.

  In the present embodiment, the sheet supply apparatus 40 has a two-stage configuration in the apparatus main body 20 (specifically, the sheet supply apparatus 40a located at the lower part and the sheet supply apparatus 40b located at the upper part). However, the present invention is not limited to this, and a one-stage configuration may be used, or a three-stage or more configuration may be used.

  In this embodiment, the image forming engine 21 uses a process cartridge 22 in which a plurality of electrophotographic devices are integrated. The process cartridge 22 includes a photosensitive drum 22a as an image holding member, A charging device 22b for charging the photosensitive drum 22a, a developing device 22c for visualizing the electrostatic latent image formed on the photosensitive drum 22a with toner, and residual toner on the photosensitive drum 22a are cleaned. And a cleaning device 22d. The process cartridge 22 can be attached and detached through a tray cover 27 a provided on the discharge tray 27 so as to be opened and closed.

  Further, the image forming engine 21 includes an exposure device 23 composed of, for example, a laser scanning device for writing an electrostatic latent image by light onto the photosensitive drum 22a uniformly charged to a predetermined potential by the charging device 22b, and a photosensitive drum. A transfer roller 24 for transferring the toner image formed on the sheet 22a onto the sheet, and a fixing device 25 for fixing the toner image transferred by the transfer roller 24 onto the sheet by thermocompression bonding.

  In the present embodiment, a registration roller 29 for positioning and transporting the sheet is disposed on the upstream side of the photosensitive drum 22 a in the sheet transport path 28, and in the vicinity of the discharge port 26 in the sheet transport path 28. A discharge roller 30 is provided.

  Note that the photosensitive drum 22a, the transfer roller 24, and the fixing device 25 that face the sheet conveying path 28 also function as a sheet conveying unit.

  Therefore, the sheets supplied from the sheet supply devices 40 and 70 are aligned by the registration rollers 29 in the sheet conveyance path 28, sent to the image transfer portion of the process cartridge 22 at a predetermined timing, and then transferred. The paper is discharged from the discharge port 26 to the discharge tray 27 by the discharge roller 30 through the device 25.

  In the image forming apparatus according to the present embodiment, the reversing path 31 is formed. In the double-sided recording mode, a sheet on which an image is formed on one side is returned to the reversing path 31. That is, in the sheet conveyance path 28, the front of the discharge roller 30 is bifurcated, and a switching gate 33 is provided at the branch portion, and a reverse path 31 is formed from the branch portion to the registration roller 29. .

  A conveying roller 32 is appropriately disposed in the reversing path 31. In the double-sided recording mode, the switching gate 33 is switched to the side where the reversing path 31 is opened, and the discharging roller 30 is positioned when the discharge roller 30 is in front of the trailing edge of the sheet. After the sheet 30 is reversed and the sheet is guided to the reversing path 31, the reversed sheet is guided to the discharge tray 27 between the registration roller 29, the photosensitive drum 22 a and the transfer roller 24, and the fixing device 25. It is like that.

  A sheet feeding unit 45 is provided above the sheet feeding apparatus 40 on the sheet feeding direction side.

  The sheet feeding unit 45 is arranged in contact with the uppermost sheet of the sheets stacked on the sheet feeding device 40 and sends out the sheet, and the sheet fed by the pickup roller 46 is fed. A rolling mechanism 47 is provided for each sheet.

  The winding mechanism 47 includes a feed roller 48 that feeds a sheet in the direction of the sheet conveyance path 28, and a winding roller 49 that rotates in pressure contact with the feed roller 48 and is provided with a predetermined rotation blocking force.

  The pickup roller 46 is rotatably attached to the free end side of a swinging plate (not shown) that can swing about the rotation axis of the feed roller 48 as a swinging point. A biasing force directed downward by a spring is applied to the swing plate, and the pickup roller 46 is pressed against the uppermost sheet with a predetermined force.

  As shown in detail in FIGS. 1 and 2, the manual sheet supply apparatus 70 includes a sheet tray 101 that is attached to the apparatus main body 20 and protrudes outward. In the sheet tray 101, protrusions 101 a formed on both sides of the end of the apparatus main body 20 are fitted in attachment holes (not shown) formed in the apparatus main body 20 so that the sheet tray 101 can swing in the vertical direction. A stopper that prevents further downward swing when a predetermined inclination angle with respect to the apparatus main body 20 is reached (a predetermined inclination angle in a positional relationship in which the apparatus main body 20 side is lower than the opposite side). It has a structure.

  As shown in FIGS. 2 to 4, for example, a metal bottom plate (stacking member) 102 on which the sheets S are stacked can move up and down in front of the sheet tray 101 in the sheet feeding direction (that is, the sheets S are stacked). It can be moved to the other side). Further, a pair of sheet guide plates 103 for aligning the width of the sheet S to be sent out and regulating the sending position of the sheet S so as to sandwich the bottom plate 102 from both sides can be approached and separated in conjunction with each other. Is provided. As a result, the sheet S (sheet bundle) is set on the sheet tray 101 so that the front in the sheet feeding direction is stacked on the bottom plate 102, and the sheet guide plate 103 is adjusted to the sheet width, whereby the sheet on the sheet tray 101 is set. S is aligned to the proper delivery position.

  A unit cover 110 of the sheet supply apparatus 70 is attached to the apparatus main body 20. The unit cover 110 has a cover body portion 110a which is long in the lateral direction and has a mounting space in which one side is concave and can accommodate a feed roller (feeding means) 120 and the like which will be described later, and on both sides of the cover body portion 110a. The cover main body 110a and the side wall 110b integrally formed have a structure. Various members described below are attached to form a unit. The side wall portion 110b is formed on the concave side of the cover main body portion 110a.

  On the unit cover 110, a feed roller 120 that is rotationally driven in a first rotational direction that is a direction in which the sheet S is fed into the apparatus main body 20 by a rotational driving unit (not shown) is stacked on the bottom plate 102. The sheet S1 is positioned above the sheet S and attached to the uppermost sheet S1 stacked on the bottom plate 102 so as to come into contact therewith. The feed roller 120 is fixed to a feed shaft (rotating shaft) 121 and is located at the center of the unit cover 110 in the width direction. Both sides of the feed shaft 121 pass through a bearing 130 that is located in an arc-shaped long hole 111 formed in the side wall portion 110b and is movable along the long hole 111. A one-way clutch (one-way power transmission means) 135 is attached.

  Therefore, the feed roller 120 is moved from the first position P1 and the sheet S stacked from the first position P1 by the feed shaft 121 being held by the bearing 130 and guided along the long hole 111. It reciprocates between the second position P2 in the upper direction (more precisely, diagonally upward along the arcuate trajectory), which is the separated direction.

  The amount of elevation of the bottom plate 102, the shape of the long hole 111, and the feed roller so that the feed roller 120 moves from the first position P1 side to the second position P2 side so as to be pushed up by the raised bottom plate 102. A roller diameter of 120 is set. Therefore, regardless of the number of stacked sheets S (that is, even if there is only one sheet S), when the bottom plate 102 rises, the feed roller 120 contacts the uppermost sheet S1 of the bottom plate 102. The first position P1 side then moves to the second position P2 side. Then, when the feed roller 120 is rotationally driven in the first rotation direction, the uppermost sheet S1 stacked on the bottom plate 102 is sent into the apparatus main body 20.

  A belt 120a made of, for example, a rubber material is attached to the outer periphery of the feed roller 120 in order to eliminate slippage between the sheet S1 to be sent out.

  A sheet stopper 140 against which the leading edge of the sheet S abuts is attached at a position below the unit cover 110 and sandwiched between the side walls 110b so as to face the bottom plate 102. As described above, since the sheet tray 101 is lower on the apparatus main body 20 side than the opposite side, the sheet S (sheet bundle) loaded on the sheet tray 101 is stacked on the bottom plate 102 in the front of the sheet feeding direction. The front-rear direction is easily aligned by abutting the front end (the front end in the sheet feeding direction) against the sheet stopper 140.

  A notch 140 a is formed in the center of the sheet stopper 140 in the width direction. The notch 140a is attached with a facing roller 150 that is in pressure contact with the feed roller 120 and rotated by the feed roller 120 so as to face the feed roller 120. The whirling roller 150 is axially coupled to a torque limiter 151 provided on the side of the whirling roller 150, and the torque limiter 151 causes a rotation prevention force (less than the rotational force of the feed roller 120 in the first rotational direction) ( That is, a force for preventing the driven rotation) is applied.

  As described above, when the feed roller 120 is rotationally driven in the first rotation direction, the uppermost sheet S1 stacked on the bottom plate 102 is sent out and reaches between the feed roller 120 and the separating roller 150. .

  At this time, if a plurality of sheets S including the uppermost sheet S1 have been taken out from the bottom plate 102, the uppermost sheet S1 is sandwiched between the feed roller 120 and the separating roller 150 by the feed roller 120. The sheet S moves to the inside of the apparatus main body 20, but the other sheets S are blocked from being moved forward by the rolling roller 150 to which the rotation preventing force is applied, so that the sheets S are one by one. Twisted to prevent double feeding. If only the uppermost sheet S1 has been sent from the bottom plate 102, the rotational force of the feed roller 120 exceeding the rotation prevention force applied by the torque limiter 151 is transmitted to the rolling roller 150 via the sheet S1. Therefore, the rolling roller 150 is driven to rotate against the rotation blocking force from the torque limiter 151, and the sheet S1 moves into the apparatus main body 20.

  As shown in FIG. 5, the rolling roller 150 is a rotating body having a through hole 150 b formed in the rotation axis direction with an annular protrusion 150 a in the center of the inner wall. And it is rotatably attached to the shaft (bar-shaped member) 152 that has penetrated the through hole 150b. As a result, a gap is formed between the through-hole 150b and the shaft 152 at a place other than the protrusion 150a. Therefore, the rolling roller 150 swings in the axial direction around the protrusion 150a and follows the feed roller 120. , And press-contact with the feed roller 120 over the entire width. Accordingly, there is no variation in the distribution of the pressure contact force between the rolling roller 150 and the feed roller 120, and the sheet S is sent in a stable posture.

  A structure in which the entire circumference of the through-hole 150b is in close contact with the shaft 152 without forming the projection 150a may be used.

  2 to 4, a coil spring (pressing means) 145 is stretched between a bearing 130 through which the feed shaft 121 is rotatably passed and a sheet stopper 140 to which a winding roller 150 is attached. The sheet stopper 140 side of the spring 145 is attached coaxially with the winding roller 150. Therefore, the compressive force of the coil spring 145 acts on the feed roller 120 (rotary shaft thereof) via the bearing 130 and the feed shaft 121, so that the rotation center axis of the feed roller 120 is relative to the rotation center axis of the rolling roller 150. Pressed.

  Here, contrary to the above, when the roller 150 is configured to be in pressure contact with the feed roller 120, the roller is wound when a plurality of sheets are fed or when a thick sheet is fed. As the roller 150 moves backward, the pressure contact force against the feed roller 120, in other words, the sheet S feeding prevention force decreases. Therefore, in the case of this structure, in consideration of the position variation, the pressure preventing force obtained by the pressure contact force of the roller 150 against the feed roller 120 or the rotation blocking force of the torque limiter 151 against the roller 150 must be increased. In other words, the load on the drive system becomes large.

  On the other hand, in the present application, since the feed roller 120 is configured to be in pressure contact with the winding roller 150, the position of the winding roller 150 does not fluctuate. Stabilize. Therefore, the decrease in the feeding prevention force of the winding roller 150 as described above is eliminated, and the sheets S are reliably wound one by one by the rolling roller 150 without giving a large feeding prevention force in advance. .

  In addition, the separating roller 150 is disposed in pressure contact with the feed roller 120 in this way, and the feed roller 120 is in pressure contact with the separating roller 150 to maintain an opposing relationship between the first position P1 and the second position P2. By reciprocating the sheet S, the sheet roller S is reliably wound one sheet at a time regardless of the position of the feed roller 120.

  Note that the winding roller 150 does not necessarily have to be provided, and if it is acceptable for the sheet rolling function to be lowered by the rolling roller 150, a structure in which the rolling roller 150 is pressed against the feed roller 120 is adopted. Also good.

  Now, on both sides of the sheet stopper 140, shaft pivots 160 projecting outward through the bearings 161 located in the shaft holes 112 formed in the side wall portion 110 b of the unit cover 110 are coaxial with the rolling roller 150. Positioned and rotatably mounted. A sun gear (first gear) 162 is attached to the outer side of the bearing 161 of the shaft pivot 160, and further, on the outer side of one shaft pivot 160 (the shaft pivot 160 on the left side in the drawing). A tooth missing gear 163 having a gear missing portion 163b that is intermittently meshed with a rotation driving means (not shown) to transmit the rotational force is attached. Therefore, the sun gear 162 is arranged coaxially with the rotating shaft (virtual rotating shaft) of the whirling roller 150.

  The coil spring 145 described above is attached to the bearing 161 on the sheet stopper 140 side, so that the sheet stopper 140 side is coaxial with the winding roller 150.

  Instead of the shaft pivots 160 provided on both sides of the sheet stopper 140 as in the present embodiment, a single shaft may be used so as to penetrate the sheet stopper 140. In this case, the sun gear 162 and the rolling roller 150 are mounted on the same shaft.

  On the same axis as the tooth-missing gear 163, a lock ring portion 165 having a recess 165a formed at one location on the outer periphery is formed integrally with the tooth-missing gear 163. A lock claw 171 attached to the plunger of the solenoid 170 is disposed on the lock ring portion 165 so as to be able to contact and separate. In a state where the solenoid 170 is not energized, the plunger protrudes due to the spring force, and the lock claw 171 engages with the recess 165a of the lock ring portion 165, thereby preventing the toothless gear 163 from rotating. Further, when the solenoid 170 is energized, the plunger is retracted against the spring force, so that the lock claw 171 is separated from the lock ring portion 165 to be disengaged, and the tooth missing gear 163 can be rotated. .

  Here, at the position where the lock claw 171 is engaged with the recess 165a of the lock ring portion 165 without energization of the solenoid 170, the gear missing portion 163b of the tooth missing gear 163 is released from meshing with the rotation driving means. The rotation angle of the toothless gear 163 and the rotation driving means are positioned. Further, the tooth missing gear 163 is provided with an urging force in a direction of meshing with the rotation driving means by attaching one end of the coil spring 164 to a protruding portion 163a formed at an eccentric position.

  Therefore, when the solenoid 170 is energized and the engagement of the lock claw 171 with the recess 165a of the lock ring portion 165 is released, the tooth missing gear 163 is rotated by a predetermined rotation angle by the biasing force of the coil spring 164, and the tooth missing portion is removed. The position of the gear missing part 163b of the gear 163 moves. As a result, the tooth missing gear 163 meshes with the rotation driving means and starts rotating, and the sun gear 162 is rotated through the shaft pivot 160 to which the tooth missing gear 163 is attached.

  When the energization of the solenoid 170 is released after the tooth missing gear 163 starts rotating, the plunger protrudes by the spring force, and the lock claw 171 contacts the outer peripheral surface of the lock ring portion 165. Thereafter, when the tooth missing gear 163 rotates once and the concave portion 165a of the lock ring portion 165 reaches the position of the lock claw 171, the lock claw 171 is fitted again into the concave portion 165a, and the rotation of the tooth missing gear 163 is stopped. The meshing with the rotation driving means is released by the gear missing part 163b.

  The planetary gear (second gear) 166 is engaged with the sun gear 162. The planetary gear 166 is rotatably supported by a bearing 167 that is swingably attached to the shaft pivot 160, and the rotation shaft can reciprocate around the rotation shaft of the sun gear 162 over a predetermined rotation angle. It has become.

  The above-described one-way clutch 135 meshes with the planetary gear 166, and the rotational force transmitted from the rotation driving means via the tooth-missing gear 163, the shaft pivot 160, the sun gear 162 and the planetary gear 166 is fed by the one-way clutch 135. The feed roller 120 is transmitted to the roller 120 to rotate in the first rotation direction.

  On the other hand, when the feed roller 120 is rotated in the second rotation direction opposite to the first rotation direction by the one-way clutch 135, the connection with the planetary gear 166 is disconnected.

  Here, when the feed roller 120 moves from the first position P <b> 1 to the second position P <b> 2, the planetary gear 166 moves while rotating on the outer periphery of the sun gear 162. Then, the rotational force at that time tries to rotate the one-way clutch 135 in the second rotation direction, but the one-way clutch 135 cuts off the driving in the rotation direction. Therefore, since the rotational force in the second rotational direction is not transmitted to the feed roller 120, the drive system is prevented from being damaged.

  Further, the drive system from the rotation driving means to the feed roller 120 is not limited to the one shown in the present embodiment, and may be various as long as the structure can rotate the feed roller 120 in the first rotation direction. The thing of a various form is employable.

  A bracket feed (supporting member) 180 that rotatably supports the feed shaft 121 of the feed roller 120 via the bearing 130 is provided on the shaft pivot 160 (that is, coaxially with the rotation axis of the rolling roller 150) via the bearing 161. And can be swung. Therefore, the feed roller 120 supported by the bracket feed 180 draws an arc-shaped locus centering on the rotation axis of the rolling roller 150, and the first position P <b> 1 does not change the pressure contact force with the rolling roller 150. And reciprocating smoothly between the second position P2.

  Between the stopper piece 110c formed to protrude outward in the width direction from the side wall part 110b of the unit cover 110 and the bracket feed 180, the feed roller 120 is elastically forced through the bracket feed 180 and the feed shaft 121 by the first force. A coil spring (winding spring / pressing force applying means) 181 for urging in the direction of the position P1 is provided. By the coil spring 181, the sheet S stacked on the raised bottom plate 102 is pressed against the bottom plate 102 by the feed roller 120 with a predetermined pressing force. At this time, a desired pressing force can be obtained by selecting a coil spring 181 having a necessary elastic force.

  In addition, as the pressing force applying means, a device other than the coil spring 181 can be used. Even when the coil spring 181 is used, as long as the urging force can be applied to the feed roller 120, the arrangement location is not limited to the present embodiment. Further, an urging force may be applied to the feed roller 120 by the compression force of the coil spring 181.

  A shaft 104 extending along the width direction of the unit cover 110 is fixed to both sides of the bottom lower end of the bottom plate 102. The shaft 104 is movable along a substantially straight long hole 113 formed in the vertical direction on the side wall portion 110b, and penetrates and protrudes outward. An engagement gear (engagement member) 105 as a tooth-like member, which is one component of the position restricting means, is attached to the outside of the side wall portion 110b of the shaft 104, and further, the bottom plate 102 is attached to the outside thereof. One side of a coil spring (elastic member) 106 that raises the spring by an elastic force is attached. Therefore, the engagement gear 105 is attached to the bottom plate 102 via the shaft 104 and moves up and down (moves) together with the bottom plate 102.

  The other side of the coil spring 106 is attached to an arm 108 that swings by a cam 187 that rotates in conjunction with the rotation of the feed roller 120, and the coil spring 106 is pulled by the upward swing of the arm 108 to be elastic. When the force is generated, the bottom plate 102 is raised, and the elastic force is lost from the coil spring 106 due to the downward swing, and the bottom plate 102 is lowered. Although details of the cam 187 will be described later, the following description will be made in a state where the elastic force of the coil spring 106 is generated.

  To engage / separate with the engagement gear 105, teeth that mesh with the engagement gear 105 are formed, and a rack (restraining member) 107, which is another component of the position restricting means, is provided.

  The bracket feed 180 described above is formed with a feed gear 180a having teeth formed at least partially around the pivot point. Further, the rack 107 is formed with an advancing / retreating gear 107a, which is a tooth meshing with the feed gear 180a, on a straight line along the approaching / separating direction with respect to the engaging gear 105.

  Thus, when the bracket feed 180 swings as the feed roller 120 moves to the second position P2 side, the rack 107 moves forward and meshes with the engagement gear 105 by the advance / retreat gear 107a meshing with the feed gear 180a. Further, when the bracket feed 180 swings as the feed roller 120 moves to the first position P1 side, the rack 107 is retracted by the advance / retreat gear 107a meshing with the feed gear 180a, and the meshing with the engagement gear 105 is released. Is done. That is, the rack 107 is engaged with the engagement gear 105 or released from engagement by a simple linear movement by the advance / retreat gear 107a.

  Note that a rectangular notch 107 b is formed in the lower portion of the rack 107. Further, a stopper 110d is formed on the side wall portion 110b so as to protrude from the notch portion 107b. Between the stopper 110d and the inner wall of the notch 107b, a coil spring 109 for urging the rack 107 in a direction in which the engagement with the engagement gear 105 is released is fitted. As a result, the backlash between the advance / retreat gear 107a of the rack 107 and the feed gear 180a of the bracket feed 180 is eliminated.

  With the above configuration, when the feed roller 120 moves to the second position P2 side, the position restricting means including the engagement gear 105 and the rack 107 stops the rise by the coil spring 106 of the bottom plate 102, and the position is restricted. The

  Therefore, if the number of sheets S stacked on the bottom plate 102 is small (FIG. 7: reference numeral H1), the bottom plate 102 is greatly raised and the feed roller 120 moves to the second position P2 side, whereby the bottom plate 102 is moved to the bottom position. The plate 102 is regulated at its large raised position. Further, if the number of sheets S stacked on the bottom plate 102 is large (FIG. 7: reference numeral H2), the bottom plate 102 is slightly raised and the feed roller 120 moves to the second position P2 side. Thus, the position of the bottom plate 102 is restricted at its slightly raised position.

  Therefore, as shown in FIG. 7, the bottom plate 102 is regulated to the raised position according to the sheet stacking amount, and the feed roller 120 always moves to the second position P2 side regardless of the sheet stacking amount. The sheet S stacked on the bottom plate 102 is pressed by the pressing force applied by the coil spring 181 on the second position P2 side.

  Therefore, fluctuations in the pressing force applied to the uppermost sheet S1 of the bottom plate 102 by the feed roller 120 are suppressed regardless of the number of sheets S stacked.

  The rack 107 as a restraining member moves in conjunction with the movement of the feed roller 120, and engages with the engagement gear 105 as an engagement member when the feed roller 120 moves to the second position P2. The bottom plate 102 is prevented from rising, and is separated when the feed roller 120 moves to the first position P1 side. Therefore, there are no motors and sensors for regulating the amount of rise of the bottom plate 102, or dedicated rollers.

  Here, since the engaging gear 105 is fixed to the bottom plate 102 and attached to the shaft 104 that cannot be rotated, it is sufficient that teeth are formed on at least a part of the outer periphery that engages with the rack 107. It is not necessary to be formed over the entire circumference. Further, for example, instead of the engaging gear 105, various shapes of tooth-like members having protrusions that mesh with the rack 107 can be used, and the position restricting means is configured by a unit other than the engaging gear 105 and the rack 107. Can do. In addition, by using a tooth-like member such as the engagement gear 105 and the rack 107, the rising position of the bottom plate 102 can be regulated by a simple mechanism.

  Further, as the position restricting means, as long as the feed roller 120 moves to the second position P2 side, the rise of the bottom plate 102 can be stopped and the position thereof can be restricted. It can be configured by a member other than the combination member and the restraint member represented by the rack 107.

  The first position P1 is a range in which the sheet S can be loaded and a range in which the feed shaft 121 to which the feed roller 120 is attached can swing (for example, if the swing range is regulated by the long hole 111, the regulation position, regulation If not, it may vary depending on the bottom plate 102 in the lowered position), and may not be a fixed position. Similarly, the second position P2 may also vary depending on the position of the meshing tooth such as which tooth of the engagement gear 105 the rack 107 meshes with or the meshing play seen in the backlash, etc., and not the fixed position. May be.

  Now, a cam 187 is attached to the above-described shaft pivot 160 so that it can rotate in conjunction with the rotation of the feed roller 120. Further, an arm hole 114 is formed in the side wall portion 110b, and the first arm piece 108a that comes into contact with the cam 187 passes therethrough so as to be swingable. Further, the second arm piece 108b to which the other side of the coil spring 106 is attached is fitted to the first arm piece 108a, and the arm 108 having a substantially U-shape as a whole is configured. The arm 108 can swing up and down with the arm hole 114 as a fulcrum.

  Then, when the cam 187 is rotated by the shaft pivot 160, the arm 108 is swung upward and the coil spring 106 is pulled by the profile of the cam 187, and an elastic force is generated in the coil spring 106. The bottom plate 102 is raised (that is, moved to the side where the sheets S are stacked). Further, when it further rotates and reaches the second rotation angle, this time, the arm 108 is swung downward to eliminate the tension of the coil spring 106, the elastic force is lost from the coil spring 106, and the bottom plate 102 is lowered ( That is, the sheet S is moved to the side opposite to the side on which the sheets S are stacked.

  Since the rotation of the cam 187 is interlocked with the rotation of the feed roller 120, the series of swinging motions of the arm 108 by the cam 187 is performed corresponding to the feeding operation of one sheet S. Accordingly, the pressing force applied to the sheet S by the feed roller 120 is adjusted every time the sheet S is sent out, and the pressing force is stabilized against a slight change in the number of sheets S stacked.

  Further, when the feed roller 120 is not performing the feeding operation, the arm 108 swings downward and the elastic force of the coil spring 106 is lost, the bottom plate 102 is lowered, and the sheet S and the feed roller 120 are separated. This eliminates the need to push down the bottom plate 102 when the sheet S is replenished.

  Note that the cam 187 and the arm 108 do not have to be a structure that generates or loses the elastic force with respect to the coil spring 106. That is, without using a cam mechanism or the like, the bottom spring 102 may be urged upward by constantly generating a resilient force on the coil spring 106.

  Next, the operation of the sheet supply apparatus having the above configuration will be described.

  In a state where the solenoid 170 is not energized, the lock claw 171 of the solenoid 170 is fitted into the recess 165a of the lock ring portion 165, and the rotation of the tooth missing gear 163 is prevented. By positioning 163b on the rotational drive means side, the rotational drive means is idle.

  At this time, as shown in FIGS. 2 and 6, the cam 187 has a second rotation angle, the arm 108 swings downward, and the elastic force of the coil spring 106 is lost. Therefore, the bottom plate 102 on which the sheets S are stacked is in the lowered position due to its own weight, and the shaft 104 fixed to the bottom plate 102 is in contact with the lowermost portion of the long hole 113 formed in the vertical direction of the side wall portion 110b.

  Further, since the bottom plate 102 is in the lowered position, the feed roller 120 supported by the bracket feed 180 is moved to the first position with the rotating shaft of the shaft pivot 160 as a swing fulcrum by the spring force of the coil spring 181. It is on the P1 side. Further, the rack 107 is separated from the engagement gear 105 by such a swinging position of the bracket feed 180.

  When the solenoid 170 is energized from the above state, the lock claw 171 is separated from the lock ring portion 165, so that the fitting between them is released and the toothless gear 163 can rotate. Then, the tooth missing gear 163 rotates by a predetermined rotation angle by the biasing force of the coil spring 164, so that the tooth missing gear 163 meshes with the rotation driving means and starts rotating.

  As a result, when the cam 187 attached to the shaft pivot 160 rotates to the first rotation angle, the arm 108 swings upward and the coil spring 106 is pulled to generate a resilient force, thereby generating a bottom plate. 102 rises. Then, the feed roller 120 is pushed up in contact with the uppermost sheet S1 stacked on the raised bottom plate 102 and starts to move toward the second position P2.

  If the tooth missing gear 163 starts to rotate, the solenoid 170 is de-energized, whereby the plunger protrudes by the spring force, and the lock claw 171 contacts the outer peripheral surface of the lock ring portion 165.

  When the feed roller 120 starts moving to the second position P2 side and the bracket feed 180 that rotatably supports the feed shaft 121 of the feed roller 120 swings along with this, the bracket feed 180 is formed. The rack 107 moves forward by meshing with the engagement gear 105 by the rotation of the feed gear 180a.

  As a result, as shown in FIGS. 8 and 9, the bottom plate 102 is stopped from being lifted by the coil spring 106, and as described above, the bottom plate 102 is regulated at the lifted position corresponding to the sheet stacking amount. Completes the movement toward the second position P2. FIG. 10 shows the movement of each component when the feed roller 120 moves from the first position P1 side to the second position P2 side.

  The feed roller 120 presses the sheet S stacked on the bottom plate 102 with the pressing force applied from the coil spring 181 on the second position P2 side. Accordingly, the pressing force applied to the uppermost sheet S1 of the bottom plate 102 by the feed roller 120 is substantially constant regardless of the number of sheets S stacked.

  On the other hand, the rotational force of the rotational drive means is transmitted from the sun gear attached to the shaft pivot 160 to the feed shaft 121 through the planetary gear 166 and the one-way clutch 135 by the rotation of the toothless gear 163, and the feed roller 120 is fed to the first roller 120. It is rotated in the direction of rotation.

  Then, the uppermost sheet S1 stacked on the bottom plate 102 and pressed by the feed roller 120 is taken out by the rotational force of the feed roller 120 rotating in the first rotational direction.

  At this time, as described above, the pressing force of the feed roller 120 against the uppermost sheet S1 of the bottom plate 102 is substantially constant regardless of the number of sheets S stacked (see FIG. 7). Variations in the pressing force due to variations in the number of sheets (particularly a phenomenon in which the number of stacked sheets increases and the pressing force becomes excessive (for example, about 6N)) are suppressed. Thereby, regardless of the thickness of the sheet S, the strength of the waist, the surface roughness, and the like, the multi-feeding of various types of sheets S is prevented and stable feeding is realized.

  In the case of the present embodiment, the pressing force against the uppermost sheet S1 of the bottom plate 102 is set to about 2 to 2.5N. However, since the optimum value of the pressing force varies depending on the surface roughness and type of the sheet, it is needless to say that the present invention is not limited to the above pressing force.

  The extracted uppermost sheet S1 is guided to the press contact portion between the feed roller 120 and the rolling roller 150. When a plurality of sheets S have been taken out by the feed roller 120, the apparatus main body 20 is wound one by one by the pressure contact force between the feed roller 120 and the separation roller 150 and the rotation prevention force of the separation roller 150. The sheet is fed into the inner sheet conveyance path 28 (FIG. 1), and the sheet feeding operation is completed.

  If the sheet S1 is sent out by the feed roller 120, the cam 187 again becomes the second rotation angle, the arm 108 swings downward, and the elasticity of the coil spring 106 that biases the bottom plate 102 upward. Power is lost. Along with this, the bottom plate 102 is slightly pressed toward the first position P1 by the biasing force of the coil spring 181 because the pressure contact force with the feed roller 120 decreases due to the force acting in the vertical direction. The bracket feed 180 starts to swing toward the first position P1.

  Then, the rack 107 moves backward by the rotation of the feed gear 180a formed on the bracket feed 180, and the meshing with the engagement gear 105 that regulates the bottom plate 102 at the raised position is released. As a result, the bottom plate 102 is lowered by its own weight, and the feed roller 120 having no pressure contact force from the bottom plate 102 is moved to the first position P1 side with the swing of the bracket feed 180 by the biasing force of the coil spring 181. Complete the move.

  Then, if the series of operations described above is executed by one rotation of the tooth missing gear 163, the concave portion 165a rotating around by the rotation of the lock ring portion 165 rotating together with the tooth missing gear 163 reaches the position of the lock claw 171. As a result, the lock claw 171 is fitted into the recess 165a by the spring force, the rotation of the tooth missing gear 163 is stopped, and the mesh with the rotation driving means is released by the gear missing portion 163b.

  Note that the sheet S sent to the sheet conveyance path 28 in the apparatus main body 20 is aligned by a registration roller 29 in FIG. 1, and sent to an image transfer portion of the process cartridge 22 at a predetermined timing for image transfer. Finally, the sheet is discharged from the discharge port 26 to the discharge tray 27 by the discharge roller 30 through the fixing device 25.

  In the above description, the case where the present invention is applied to a manual sheet feeding apparatus is shown, but the present invention is not limited to this, for example, a drawer-type sheet feeding apparatus, a document feeding apparatus, etc. The present invention can be applied to various recording medium supply devices.

  Further, in the above description, the case where the sheet supply device of the present invention is mounted on an image forming apparatus for recording toner is shown. However, various images such as an ink jet type image forming apparatus for recording with ejected ink are shown. Can be mounted on a forming device.

  Furthermore, various sheets capable of recording visual information, such as paper and film, can be applied as a sheet as a recording medium.

1 is a schematic diagram illustrating an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view showing a sheet feeding apparatus according to an embodiment of the present invention mounted on the image forming apparatus in FIG. 1 with a feed roller in a first position. FIG. 3 is an exploded perspective view of a main part of the sheet supply apparatus of FIG. 2. FIG. 4 is an exploded perspective view of a main part showing the sheet feeding device of FIG. 2 from a direction different from FIG. 3. It is sectional drawing which shows the principal part of a winding roller. FIG. 3 is a side view showing an arrangement of components when a feed roller is in a first position in the sheet supply apparatus of FIG. 2. FIG. 6 is an explanatory diagram illustrating a relationship between a feed roller at a second position and a sheet stacking amount. FIG. 2 is a perspective view showing a sheet feeding apparatus according to an embodiment of the present invention mounted on the image forming apparatus of FIG. 1 with a feed roller in a second position. FIG. 3 is a side view showing the arrangement of components when a feed roller is in a second position in the sheet supply apparatus of FIG. 2. FIG. 6 is an explanatory diagram illustrating movements of main components when a feed roller moves from a first position side to a second position side in the sheet supply apparatus of the present invention.

Explanation of symbols

20 apparatus main body 70 sheet supply apparatus 101 sheet tray 101a protrusion 102 bottom plate (stacking member)
105 engaging gear (engaging member, tooth-like member, part of position regulating means)
106 Coil spring (elastic member)
107 rack (restraint member, part of position restricting means)
107a advance / retreat gear 108 arm 110 unit cover 110a cover body 110b side wall 120 feed roller (feeding means)
121 Feed shaft (Rotating shaft)
135 One-way clutch (one-way power transmission means)
145 Coil spring (pressure contact means)
150 Rolling roller (rolling means)
150a Protrusion 150b Through-hole 152 Shaft (bar-shaped member)
162 Sun gear (first gear)
166 Planetary gear (second gear)
180 Bracket feed (support member)
180a Feed gear 181 Coil spring (winding spring / pressing force applying means)
187 Cam P1 First position P2 Second position S Sheet (recording medium)
S1 Uppermost sheet (uppermost recording medium)

Claims (12)

A stacking member that is loaded with a recording medium and is movably provided on the side on which the recording medium is stacked;
An elastic member for pressing the stacking member with an elastic force;
A reciprocating motion is provided between a first position and a second position farther from the recording medium loaded than the first position, and is in contact with the uppermost recording medium loaded on the stacking member. The sending means is moved from the first position side to the second position side and rotated in the first rotation direction to send the uppermost recording medium from the stacked position in cooperation with the winding means. When,
A pressing force applying means that urges the sending means toward the first position and presses the sending means against a recording medium loaded on the stacking member;
Position restricting means for restricting the position by stopping the movement of the stacking member when the sending means is moved to the second position side;
A recording medium supply apparatus comprising: The position regulating means is
An engaging member attached to the stacking member and moving together with the stacking member;
It is provided so as to be movable in conjunction with the movement of the sending means, and when the sending means moves to the second position side, it engages with the engaging member to prevent the loading member from moving, and the sending means A restraining member that is spaced apart from the engaging member when moved to the first position;
The recording medium supply device according to claim 1, comprising: The engagement member is a tooth-like member fixed to the stacking member,
The restraining member is a rack in which teeth that mesh with the toothed member are formed.
3. The recording medium supply device according to claim 2, wherein It is provided rotatably in conjunction with the rotation of the delivery means, and the stacking member is moved to the side on which the recording medium is loaded by the elastic force of the elastic member at a first rotation angle, and the rotation member is moved at the second rotation angle. A cam for moving the stacking member to the side opposite to the side on which the recording medium is stacked against the elastic force of the elastic member;
The recording medium supply device according to claim 1, further comprising: The winding means is disposed opposite to the sending means, and gives a predetermined sending blocking force to the recording medium sent by the sending means,
The delivery means is provided to be capable of reciprocating between the first position and the second position while maintaining a facing relationship with the rolling means.
The recording medium supply apparatus according to claim 1, wherein the recording medium supply apparatus is a recording medium supply apparatus. A first gear disposed on the same axis as the rotating shaft of the rolling means, wherein the rotational force of the rotation driving means is transmitted;
The first gear is rotated while meshing with the first gear, and a rotation shaft is provided so as to be reciprocally rotatable around the rotation shaft of the first gear over a predetermined rotation angle, and the rotational force of the first gear is sent out. A second gear to be transmitted to the means;
A support member that rotatably supports the rotation shaft of the sending means and is swingable with respect to a swing fulcrum coaxial with the rotation shaft of the rolling means;
The delivery means reciprocates between the first position and the second position about a rotation axis of the rolling means;
6. The recording medium supply apparatus according to claim 5, wherein One-way power that is attached to the rotation shaft of the delivery means and meshes with the second gear, and transmits the rotational force of the second gear to the delivery means to rotate the delivery means in the first rotational direction. Transmission means,
The recording medium supply apparatus according to claim 6, further comprising: The support member is provided with a feed gear having teeth formed at least in part around the swing fulcrum,
The rack is provided with an advancing / retreating gear that is meshed with the feed gear and formed along the approaching / separating direction with respect to the toothed member,
When the support member is swung as the delivery means moves to the second position side, the rack is advanced by the advance / retreat gear engaged with the feed gear and is engaged with the tooth-like member. ,
When the support member is swung as the delivery means moves toward the first position, the rack is retracted by the advance / retreat gear meshed with the feed gear and meshed with the toothed member. Is released,
8. The recording medium supply apparatus according to claim 6, wherein the recording medium supply apparatus is a recording medium supply apparatus. The pressing force applying means is a winding spring that urges the delivery means to the first position side by a resilient force via a rotation shaft of the delivery means.
The recording medium supply apparatus according to claim 1, wherein the recording medium supply apparatus is a recording medium supply apparatus. The whirling means has a through hole formed in the direction of the rotation axis, is provided with an annular protrusion at the center of the inner wall of the through hole, and is rotatably attached to a rod-like member that penetrates the through hole.
The recording medium supply apparatus according to claim 6, wherein the recording medium supply apparatus is a recording medium supply apparatus. Pressure contact means for pressing the rolling means against the delivery means;
The recording medium supply device according to claim 10. A recording medium supply device according to any one of claims 1 to 11, comprising:
A predetermined image is formed on the recording medium sent from the recording medium supply apparatus;
An image forming apparatus.

Images