JP2007204182A - Paper feeding device and image recording device provided with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify a constitution for shutting off transmission of motive power to a feed roller 7 when paper P runs out regardless of the constitution capable of certainly feeding the paper P while separating every sheet of the paper P piled up and stored in a paper feed cassette 5. <P>SOLUTION: An insertion hole of an operation body 48 is turnably freely fitted to a spindle 47 laterally projected on one outer side surface of an arm body 6a, and a detection part 49 of the operation body 48 and the feed roller 7 are also abutted on the uppermost surface of the paper P when the paper P exists. Then, when one sheet of the last paper P is fed by the feed roller 7 and a release part 50 of a bottom plate 5a appears, the detection part 49 of the operation body 48 is fitted to the release part 50 and an operation part 51 of the operation body 48 upwardly pushes up a planetary gear 15 provided on the arm body 6a. Thereby, engagement with a gear transmission mechanism 45 provided on the arm body 6a is released to shut off transmission of motive power to the feed roller 7. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a paper feeding device that feeds paper (recording medium) one by one to an image recording unit and a configuration of an image recording device including the paper feeding device.

  Conventionally, in order to feed a sheet (recording medium) so as to face a recording unit of an ink jet type image recording apparatus or the like, the base end is fed to the tip of an arm pivotally supported on the apparatus main body. A sheet feeding device including a roller is known. According to this paper feeding device, the paper feeding roller (feeding roller) is pressed against the uppermost surface of the paper accumulated and accommodated in the paper feeding unit such as a paper feeding cassette whose upper surface is opened by the urging force of the spring for pressing the arm. Has been. In this state, the paper feed roller is rotationally driven, so that the end of the paper abuts against the inclined separation wall formed at the end of the paper feed unit on the downstream side in the feeding direction, and the uppermost layer Only the sheet is separated and fed in the direction of the image recording unit (see Patent Documents 1 and 2).

  In such a paper feeding device, when there is no more paper from the paper feeding unit, the circumferential surface of the paper feeding roller rotates while being pressed against the bottom surface of the paper feeding unit, so that the circumferential surface of the paper feeding roller is more than necessary. There are problems such as wear, frictional force becoming excessively large, the paper feed roller being locked, the drive system of the paper feed roller being damaged, and the drive motor being burned out. Therefore, as disclosed in Patent Document 2, it has been proposed to form a relief hole that prevents the peripheral surface of the paper feed roller from coming into contact with the bottom surface of the paper feed unit.

  However, in the configuration of Patent Document 2, since the state where the paper feeding roller is rotating (idling) in the escape hole continues, there is a problem that it becomes a generation source of noise and waste of electric power.

  In order to solve this problem, the case of the paper feed roller unit in Patent Document 3 is rotatably supported with respect to the drive shaft, and in this case, there are a drive gear and an arm member (which rotate integrally with the drive shaft). A planetary arm), a clutch gear (planetary gear), an indirect gear, a gear portion on the side of the paper feed roller that meshes with the indirect gear, and an actuator portion for shutting off the drive to the paper feed roller when there is no sheet on the mounting plate. I have. Further, the case is configured to be urged by a torsion spring so that the sheet feeding roller presses the uppermost surface of the sheet. The base end portion of the arm member is rotatably fitted to the drive shaft on the side of the drive gear. The clutch gear mounted on the tip of the substantially T-shaped arm member in side view always meshes with the drive gear. When the drive gear rotates in one direction, the clutch gear approaches the indirect gear so that it can be fed. The paper roller is rotated in the paper feeding direction (paper feeding operation). On the other hand, when the drive gear rotates in the other direction, the arm member rotates so that the clutch gear is separated from the indirect gear, and the power transmission to the paper feed roller is interrupted (non-paper feed operation).

  The actuator unit includes a sheet detection actuator that is rotatably fitted to the drive shaft, and a drive actuator that is rotatably supported coaxially with the indirect gear. The top surface is pressed by its own weight, and when the sheet runs out, it fits into a hole formed in the mounting plate. A convex portion protruding at one end of the drive actuator fits into a long groove provided at a predetermined position of the sheet detection actuator, and is configured to be movable.

When the arm member is rotating upward and the sheet is not fed, the sheet detection actuator swings so that the leading end of the sheet detection actuator fits into the hole. Since the drive blocking boss protruding on the opposite side of the convex portion of the drive actuator interlocking with this swinging comes into contact with one stopper portion of the arm member, the meshing between the clutch gear and the indirect gear is hindered. Even if the drive gear rotates in one direction (paper feeding direction), the power to the paper feeding roller is not transmitted.
JP 2002-249248 A JP 2004-338905 A (see FIGS. 7 and 9) JP 2004-51285 A (see FIGS. 6 to 11)

  However, in the configuration as described in Patent Document 3, when the sheet feeding operation is continuously performed, that is, when the drive gear continues to rotate in one direction (the sheet feeding direction), the sheet on the mounting plate. Even if the sheet detection actuator swings due to the amount of accumulated material, the rotation trajectory of the drive cutoff boss intersects the tip of the arm member. There is no action that prevents the meshing. That is, in the case of continuous paper feed, the problem that the paper feed roller continues to rotate cannot be solved.

  Furthermore, the configuration of Patent Document 3 has a problem that the number of components of the actuator portion increases, and the cost including assembly work and the like increases.

  The present invention has been made to solve the above-described conventional problems, and reliably feeds sheets (recording medium) stacked and stored in a sheet feeding unit such as a sheet feeding cassette while separating them one by one. It is an object of the present invention to provide a paper feeding device that can cut off power transmission to the feeding roller when paper runs out with a simple configuration, and an image recording apparatus including the paper feeding device. is there.

  In order to achieve the above object, a paper feeding device according to a first aspect of the present invention has a feeding roller at a tip portion of an arm body that can be rotated according to the amount of accumulated sheet-like recording medium that is accumulated and accommodated. The recording medium can be stored in a stacked state in a paper feeding device that is arranged and rotated while the feeding roller presses the uppermost surface of the recording medium to separate and feed the recording media one by one. An open portion that is opened when the recording medium does not exist is provided on the bottom surface of the paper feeding portion, and the arm body is provided with a planetary gear that is provided on a planetary arm and meshes with a drive gear, and the planetary gear is And a gear transmission mechanism that meshes with each other when it rotates forward and transmits power to the feeding roller, and further, the arm body includes the planetary gear in relation to the opening when the recording medium is not present. Separate from the gear transmission Those having a spaced actuation means for moving the direction.

  According to a second aspect of the present invention, in the paper feeding device according to the first aspect, the separation operation unit includes a second engagement portion that can be engaged with a first engagement portion provided in the arm body. An actuating body that is vertically rotatable around the second engaging portion as a center of rotation, and extends in the feeding direction at a side of the feeding roller; and downstream of the operating body in the feeding direction A detecting portion that is provided on the lower surface of the recording medium and contacts the uppermost surface of the recording medium and fits into the opening when the recording medium does not exist, and the second engaging portion of the operating body than the second engaging portion. Provided on the upstream side in the feeding direction, and provided with an operating portion for separating the planetary gear from the gear transmission mechanism when the detecting portion is fitted into the opening portion.

  According to a third aspect of the present invention, in the paper feeding device according to the second aspect, the operating body is constantly urged to abut on the uppermost surface of the recording medium by the weight of the detection unit. It is.

  According to a fourth aspect of the present invention, there is provided an image recording apparatus according to any one of the first to third aspects, and a recording unit for recording an image on a recording medium fed from the paper feeding apparatus. It is equipped with.

  As described above, according to the first aspect of the present invention, the planetary gear is alternately executed in the forward rotation and the reverse rotation, and the feed roller rotates intermittently. A sheet-like recording medium that is accumulated and accommodated in any of the continuous paper feeding modes in which the gear always meshes with a gear transmission mechanism provided on the arm body and the paper feeding roller always rotates in the feeding direction. A feeding roller is arranged at the tip of the arm body that can be rotated according to the amount of the recording medium, and the feeding roller rotates while pressing the uppermost surface of the recording medium. Can be separated and fed one by one.

  The bottom surface of the paper supply unit that can store the recording medium in a stacked state is provided with an opening portion that is opened when the recording medium does not exist, and the arm body is provided on a planetary arm, A planetary gear that meshes with the drive gear; and a gear transmission mechanism that meshes with the planetary gear when the planetary gear rotates forward and transmits power to the feeding roller. In relation to the opening portion, the planetary gear is provided with separation operation means for moving the planetary gear in a direction away from the gear transmission mechanism. Therefore, when the recording medium does not exist, a feeding roller is provided. It stops immediately, no frictional force with the bottom surface is generated, and no noise is generated here. Further, since the power transmission to the feeding roller is interrupted, there is an effect that no overload is applied to the upstream side of the transmission.

  According to a second aspect of the present invention, the separation operation means has a second engagement portion that can be engaged with a first engagement portion provided in the arm body, and the second engagement portion. And a working body extending in the feeding direction on the side of the feeding roller, and provided on a lower surface of the working body on the downstream side in the feeding direction. A detection unit that is in contact with the uppermost surface of the recording medium and that fits in the opening when the recording medium does not exist; and is provided on the upstream side in the feeding direction with respect to the second engagement unit of the operating body, And an actuating part for separating the planetary gear from the gear transmission mechanism when the detecting part is fitted into the open part. As described above, the separation operation means has a simple and simple structure in which only one operation body provided with the detection unit and the operation unit rotates around both engagement units, so that the manufacturing cost can be reduced. There is an effect.

  According to the third aspect of the present invention, since the operating body is always urged to abut against the uppermost surface of the recording medium by the weight of the detection unit, the operation body moves. Simple and reliable operation can be guaranteed.

  According to a fourth aspect of the present invention, there is provided an image recording apparatus according to any one of the first to third aspects, and a recording unit for recording an image on a recording medium fed from the paper feeding apparatus. Therefore, the configuration of the image recording apparatus is simplified, the manufacturing cost can be reduced, and the durability can be improved.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. 1 is an overall perspective view of a multifunctional image recording apparatus 1 according to an embodiment of the present invention, FIG. 2 is a plan view of a main body case from which an upper case is removed, and FIG. 4 is a perspective view of the recording unit, FIG. 5 is a perspective view of the feeding roller unit and the separating operation means, FIG. 6 is a partially cutaway plan view of the feeding roller unit and the separating operation means, and FIG. FIG. 7B is a side view showing the attitude of the separating operation means and the feeding roller unit when the number of sheets in the sheet feeding cassette is low, and FIG. 7B is the attitude of the separating operation means and the feeding roller unit when no sheets are left. FIG.

  A multifunction image recording apparatus 1 shown in FIG. 1 has a facsimile function, a printer function, a copying function, a scanner function, and the like. An image recording apparatus 1 serving as a multi-function device has a substantially box-shaped main body case 2 having an open top surface and a hinge with respect to one side of the main body case 2 (right rear side in the embodiment of FIG. 1). The upper case 3 is pivotally mounted so as to be pivotable up and down via a pivotal axis part (not shown) such as a hinge part. In the following description, the front side of the image recording apparatus 1 in FIG. 1 is the front side, and the horizontal direction (main scanning direction, Y-axis direction), the front-rear direction (sub-scanning direction, X-axis direction), and the vertical direction are also described. Description will be made with reference to the orientation of the image recording apparatus 1 in FIG. The main body case 2 and the upper case 3 are synthetic resin injection molded products.

  An operation panel 30 is disposed on the upper front portion of the upper case 3. Various buttons such as a numeric button, a start button, and a function operation button are provided on the operation panel 30, and various operations are performed by pressing these buttons. The operation panel 30 is provided with a display unit 31 such as a liquid crystal (LCD), and the setting state of the image recording apparatus 1 and various operation messages are displayed as necessary.

  In the upper case 3, a scanner device (image reading unit) 33 is disposed on the rear side of the operation panel 30. That is, a scanner device 33 for reading a facsimile document to be transmitted to the counterpart facsimile device during the facsimile function or an image of a document to be copied during the copying function includes a flat bed reading unit that reads an image of a document on a large glass plate. , And a rotatable cover body 34 covering the upper surface of the flat bed reading unit.

  Although not shown, a line-type contact image sensor (CIS: Contact Image) as an example of a photoelectric conversion element for reading an image surface of a document in contact with the glass plate is provided directly below the glass plate in the flat bed reading unit. Sensor) is provided so as to be capable of reciprocating along a guide shaft extending in a direction parallel to a carriage movement direction (main scanning direction, Y-axis direction) described later. Note that the cover body 34 is configured to be openable and closable via a hinge around the back side (the back side in FIG. 1) of the image recording apparatus 1.

  Next, the configuration of the printer device (recording unit) will be described. As shown in FIG. 1, at the central portion in the left-right direction in the main body case 2, a paper feeding unit serving as a plurality of recording media P in a substantially horizontal state is stacked on the bottom. A paper cassette 5 is disposed, and the paper feed cassette 5 is configured to be insertable / removable from the opening 2 a on the front surface of the main body case 2.

  Further, in the main body case 2, a feeding roller unit 6 as a feeding means provided with a feeding roller 7 above the paper feeding cassette 5, and an upward U-shape at the rear end of the main body case 2. Ink is ejected to the surface of the paper P on the platen 11 as a flat paper support portion disposed in the transport path, and a transport path for transporting the paper P in a substantially horizontal direction forward through the U-turn transport path 9. Then, a recording unit 10 having an inkjet recording head 12 for recording an image is arranged (see FIG. 3).

  An ink cartridge 26 for supplying ink to the recording head 12 for color recording is disposed in the main body case 2 on the inner surface of the side plate at a position farthest from the side plate having the rotation axis portion. It is comprised so that attachment or detachment is possible from the upper direction with respect to the accommodating part 27 (refer FIG. 2) of the approached position. The ink cartridge 26 stores ink for each of a plurality of colors. In the embodiment, the ink cartridge 26 has four colors of black, cyan, magenta, and yellow. However, inks of more colors may be stored. Ink is supplied from each ink cartridge 26 to the recording head 12 by connecting a flexible ink tube 28.

  2 to 4, the recording unit 10 includes a carriage 13 having a recording head 12, a plate-like platen 11 made of synthetic resin, a CR (carriage) motor 24 for reciprocating the carriage 13, and the CR. The timing belt 25 connected to the motor 24 and an engine frame 39 made of a metal plate for supporting them are mainly configured. The engine frame 39 is disposed on the rear side of the main body case 2 and above the supply cassette 5. The engine frame 39 as a support frame is made of metal and extends in the left-right direction (main scanning direction, Y-axis direction) of the main body case 2 on the upper side of the box-shaped main body as shown in FIGS. Thus, a pair of guide plates 40 and 41 for slidably supporting the carriage 13 are mounted. A linear encoder (encoder strip) 38 is arranged on the guide plate 41 on the downstream side in the transport direction so as to extend along the longitudinal direction (main scanning direction), and the position of the carriage 13 in the Y-axis direction (main scanning direction). Is detected. This strip-shaped linear encoder (encoder strip) is arranged such that the inspection surface (formation surface of slits arranged at regular intervals in the Y-axis direction) is along the vertical direction.

  An arm body 6a of the feed roller unit 6 is mounted on the engine frame 39 so as to be rotatable about the drive shaft 14 and is a flat platen plate for supporting the paper P facing the lower surface of the recording head 12. 11 is arranged. The arm body 6a is constantly urged in the downward rotation direction by urging means such as a torsion spring (not shown). Further, the arm body 6a is provided with a planetary gear 15 attached to a planetary arm 15a with the drive shaft 14 as a rotation center, a gear transmission mechanism 45, and a feeding roller 7 on the tip side. The planetary gear 15 is always meshed with the drive gear 14 a that rotates integrally with the drive shaft 14. The gear transmission mechanism 45 includes a plurality (three in the embodiment) of transmission gears 45 a, 45 b, 45 c, and a side gear 7 a that rotates integrally therewith is provided on the side of the feeding roller 7.

  In FIG. 3, when the drive shaft 14 rotates clockwise, the planetary gear 15 rotates and the planetary arm 15 a rotates clockwise, and the planetary gear 15 meshes with the adjacent transmission gear 45 a in the gear transmission mechanism 45. Power is transmitted from the drive shaft 14 to the feed roller 7 via the gear transmission mechanism 45. In FIG. 3, when the drive shaft 14 rotates counterclockwise, the planetary gear 15 and the transmission gear 45a are disengaged, and the feeding roller 7 is in a free rotating state.

  Further, of the registration roller (conveyance roller) pair 20 that is disposed on the upstream side in the conveyance direction with the platen 11 interposed therebetween and sends the paper P to the lower surface of the recording head 12, both ends of the conveyance roller 20 a to be driven and the platen 11 Disposed to be driven among the pair of paper discharge rollers 21 that are arranged further downstream in the transport direction and transport the recorded paper P toward the paper discharge unit (see the arrow B direction in FIGS. 1 and 3). Both ends of the roller 21a are rotatably supported by shaft support portions provided on the pair of side plates 39b and 39c in the engine frame 39. The transported paper P is nipped (clamped) between a transport roller 20a that is driven at an upper position and a driven transport roller 20b that is driven at a lower position. Further, the driven paper discharge roller 21a in the paper discharge roller pair 21 is in contact with the lower surface of the paper P to be discharged, and the spur roller 21b is nipped so as to be in contact with the upper surface of the paper P.

  In the transport roller 20a, the discharge roller 21a, and the maintenance unit 36, one LF motor (paper transport motor) 42 (see FIG. 4) disposed in the vicinity of the side plate 39b opposite to the side where the maintenance unit 36 is disposed. Power is transmitted through a predetermined gear transmission mechanism 43 (see FIG. 4). In the embodiment, the rotational force from the LF motor 42 is transmitted from the other end of the transport roller 20a to the feed roller unit 6 via a power transmission switching portion (not shown) to the maintenance unit 36. The

  Further, a part of the gear transmission mechanism 43 is provided with a rotary encoder 44 for detecting the transport amount of the paper P by the transport roller pair 20a. Both the CR motor 24 and the LF motor 42 are configured to be able to rotate forward and reverse.

  When the sheets P are separated and fed from the sheet cassette 5 one by one, the LF motor 42 rotates in the reverse direction, and the drive shaft 14 rotates forward (clockwise in FIG. 3) via the maintenance unit 36. Since the arm body 6a is always urged downward by the urging force of the urging means, the feeding roller 7 at the tip of the arm body 6a presses against the uppermost surface of the paper P accumulated in the paper feeding cassette 5. The feeding roller 7 is rotated in the feeding direction (counterclockwise direction in FIG. 3) via a gear transmission mechanism 45 provided on the arm body 6a.

  When the paper P is not separated and fed from the paper feed cassette 5, the LF motor 42 rotates forward, the drive shaft 14 rotates reversely, the planetary gear 15 disengages from the gear transmission mechanism 45, and the feed roller 7 Power is not transmitted to the motor, and free rotation is possible.

  On the outer side of the width of the paper P to be conveyed (the short side of the paper P), one side thereof (in the embodiment, in the main body of the engine frame 39 in FIG. 4, the left side plate as viewed from the paper P feeding direction). An ink receiving portion 35 is disposed at a portion close to 39b), and a maintenance portion 36 including a maintenance unit is disposed at the other end (portion close to the right side plate 39c in FIG. 4). As a result, the recording head 12 periodically discharges ink to prevent nozzle clogging during the recording operation at the flushing position provided in the ink receiving portion 35, and receives ink at the ink receiving portion 35.

  In the maintenance unit 36, when the carriage 13 is in the main scanning direction (Y-axis direction) and is positioned at the rightmost end in FIG. 4, the carriage 13 is moved from the origin position to the left side along the Y-axis direction. This position is used as a maintenance position that also serves as a standby position. At the maintenance position also serving as a standby position, a cap portion (not shown) in the maintenance portion 36 covers the nozzle surface of the recording head 12 from below. The LF motor 42 is driven, and a suction pump (not shown) is operated to selectively suck ink from the nozzles, or a recovery process for removing bubbles in a buffer tank (not shown) on the recording head 12. To go. When the carriage 13 moves from the maintenance unit 36 to the image recording area in the lateral direction, cleaning is performed by wiping the nozzle surface with a cleaner (wiper blade) (not shown).

  Next, when there is no paper P to be stored in the paper feed cassette 5 (it does not exist), power is transmitted to the feed roller 7 in association with the opening 50 formed on the bottom plate 5a of the paper feed cassette 5. In order to shut off, the configuration of the separation operation means that operates the planetary gear 15 to separate from the gear transmission mechanism 45 will be described.

  The first embodiment of the separation actuating means is provided on the outer surface of one side of the arm body 6a as shown in FIGS. 3, 5, 6, 7A and 7B. Has an insertion hole (second engagement portion) 53 that can be loosely fitted (engaged) with the support shaft 47 (first engagement portion) protruding from the outer surface, and the insertion hole 53 inserted through the support shaft 47. An actuating body 48 that can be turned up and down with the (both engaging portions) as the center of rotation and extends in the feeding direction of the paper P on the side of the feeding roller 7, and the working body 48 downstream in the feeding direction. A detecting unit 49 that is provided on the lower surface of the sheet and contacts the uppermost surface of the sheet P and fits into an opening 50 that is opened in the shape of an opening in the bottom plate 5a when the sheet P is not present; The planetary gear 15 is provided on the upstream side of the insertion hole 53 in the feeding direction, and when the detection unit 49 is fitted into the opening 50, the planetary gear 15 is connected to the gear transmission mechanism 4. And a working portion 51 to separate from. The second engaging portion may be a concave bearing in which the support shaft 47 can be inserted instead of the insertion hole 53. Moreover, it is good also as a structure which provides an insertion hole and a bearing in the outer surface of one side of an arm body, provides a support shaft in an action body, and loosely fits both.

  The support shaft 47 and the operating portion 51 are formed in parallel with the drive shaft 14, and the operating portion 51 is connected to the planetary gear 15 through an arcuate guide hole 52 drilled on one side of the arm body 6 a. It is provided so as to face the lower surface side (see FIGS. 5 and 6). And the weight of the downstream part of the feeding body 48 in the feeding direction and / or the position of the detection part 49 is set to be considerably larger than that of the working part 51 side with respect to the support shaft 47. That is, as will be described later, when the paper P runs out of the bottom plate 5a, the detection unit 49 fits into the open unit 50, and at that time, the operating unit 51 can abut against the lower surface of the planetary gear 15 and push it up. To some extent, the weight of the downstream portion of the working body 48 in the feeding direction and / or the location of the detection portion 49 is increased. For this purpose, the detection unit 49 may be made of a metal member, or a biasing means such as a torsion spring for biasing the detection unit 49 side of the operating body 48 downward may be provided. Furthermore, it goes without saying that the weight and the biasing means may be used in appropriate combination.

  In the present embodiment, the operating body 48 is formed in a flat plate shape, and may be made of metal or a synthetic resin member. In addition, it is preferable that the detection portion 49 that can come into contact with the surface of the paper P and the front end portion of the operating body 48 have a downward convex curve so that there is little friction with the surface of the paper P. Alternatively, a surface layer having a small friction coefficient may be formed by attaching a sheet or the like having a small friction coefficient to the lower surface of the detection part 49 and the tip of the operating body 48. Further, in order to rotate the detection unit 49 so that the friction is reduced, a rotation shaft of the detection unit 49 may be provided from the operating body 48 to rotate the detection unit 49.

  According to the configuration of the first embodiment, in the state where a plurality of sheets P are accumulated and accommodated in the sheet feeding cassette 5, as shown in FIG. 7A, the top surface of the accumulated sheets P is stored. The feed roller 7 is in contact with (pressed).

  Since the operating body 48 is rotatable around the support shaft 47 of the arm body 6a, the detecting portion 49 of the operating body 48 is also in contact with the uppermost surface of the paper P. At this time, the inclination angle θ1 of the operating body 48 is small, and the operating portion 51 does not contact the lower surface of the planetary gear 15 and an appropriate gap Δh1 is formed. When a paper feed command is issued in this state, the drive shaft 14 rotates in a predetermined direction (counterclockwise in FIG. 7A). In FIG. 7A, the planetary gear 15 meshed with the drive gear 14a revolves counterclockwise together with the planetary arm 15a while rotating clockwise (forward rotation), and meshes with the transmission gear 45a in the gear transmission mechanism 45. . As a result, the feed roller 7 rotates clockwise in FIG. 7A via the gear transmission mechanism 45 and the side gear 7a, and the paper P stored and stored is fed to the front end of the paper feed cassette 5 (FIG. 7A). ) Abuts against the separating inclined plate 5b for separating the paper disposed at the left end). Only the uppermost sheet P is separated by an elastic separation pad (made of a leaf spring in the embodiment) as a separating means provided in the central portion in the width direction of the sheet P in the separation inclined plate 5b, and the U-turn conveyance path 9 can be fed to the recording unit.

  The above state is maintained until the last sheet P remains on the bottom plate 5a. Then, when the last sheet P is fed by the feeding roller 7 and the opening 50 of the bottom plate 5a appears, the detection unit 49 fits into the opening 50 and the operating body is set so that the inclination angle θ2 is increased. 48 rotates (see FIG. 7B). As a result, the operating portion 51 side of the operating body 48 rotates upward, and the operating portion 51 pushes the lower surface side of the planetary gear 15 upward, so that the meshing between the planetary gear 15 and the transmission gear 45a is released. Accordingly, the non-power transmission state immediately enters the feed roller 7, and the feed roller 7 immediately stops rotating.

  Therefore, even if the feed roller 7 is in contact with the bottom plate 5a or the high friction coefficient member provided on the upper surface thereof, the LF motor 42 on the drive shaft 14 side (upstream side of power transmission) is not overloaded, Problems such as burning can be solved. Further, since the feed roller 7 is stopped, no noise is generated due to idling.

  Note that the power transmission between the planetary gear 15 and the gear transmission mechanism 45 may be cut off by the operating portion 51 of the operating body 48 pushing up the planetary arm 15a.

  Further, by setting the arc length of the guide hole 52 drilled in the arm body 6a to a predetermined length, the pivotable angle of the operating body 48 can be set. Therefore, as shown in FIG. 7B, it is sufficient that the operating body 48 can be rotated by a sufficiently large inclination angle θ2 in order to release the meshing between the planetary gear 15 and the transmission gear 45a by the operating portion 51, and beyond that. The operating body 48 can be restricted so as not to rotate.

  In the present invention, in order to intermittently feed the paper P one by one, the drive shaft 14 is rotated forward and the drive shaft 14 is rotated backward after the leading end of the paper P reaches the position of the registration roller pair 20. In addition to the intermittent paper feeding mode in which the driving roller 20a of the registration roller pair 20 is normally rotated in a state in which the driving of the feeding roller 7 is stopped, the paper feeding is performed without performing the resist action at the resist roller pair 20. Even in the continuous paper feed mode in which the paper P on the cassette 5 is continuously fed to the recording unit to execute quick image recording, when the paper P on the paper feed cassette 5 runs out, Power transmission can be cut off. Since the separating operation means for achieving the above-described operation and effect is composed of only one operating body provided with the detecting section and the operating section, the structure is extremely simple and the manufacturing cost can be reduced.

  The present invention is not limited to the embodiments described with reference to the above description and drawings, and various modifications can be made without departing from the scope of the invention. For example, the outer peripheral surfaces of the pair of left and right feed rollers 7 as the feed rollers may be configured by a member having a large friction coefficient such as rubber, and each of the above-mentioned feeds among the bottom plate 5 a of the paper feed cassette 5. A base pad that is also composed of a high-friction coefficient member (for example, cork or the like) may be adhered (adhered) to a portion facing the outer peripheral surface of the roller 7.

  Furthermore, in addition to the paper feed cassette 5 that is arranged so as to be able to be inserted and removed in a substantially horizontal direction with respect to the main body case 2, a plate-shaped feeding portion that is inclined and provided at the rear of the main body case 2. It goes without saying that is also applicable.

1 is an overall perspective view of an image recording apparatus. It is a top view of the main body case which removed the upper case. It is a sectional side view of the left-right center part of a recording part. It is a perspective view of a recording part. It is a perspective view of a feeding roller unit and a separation operation means. FIG. 6 is a partially cutaway plan view of a feeding roller unit and a separation operation unit. (A) is a side view showing the posture of the separating operation means and the feeding roller unit in a state in which the number of sheets in the sheet feeding cassette is low, and (b) is the posture of the separating operation means and the feeding roller unit in a state where there is no paper. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image recording apparatus 2 Main body case 5 Paper feed cassette 6 Feed roller unit 6a Feed body 6a Arm body 7 Feed roller 10 Recording part unit 11 Platen 12 Recording head 13 Carriage 14 Drive shaft 15 Planetary gear 15a Planetary arm 39 Engine Frame 40, 41 Guide plate 42 LF motor 45 Gear transmission mechanism 47 Support shaft 48 Actuator 49 Detector 50 Opening part 51 Actuator 53 Insertion hole

Claims (4)

A feeding roller is disposed at the tip of the arm body that can be rotated according to the amount of accumulated sheet-like recording medium that is accumulated and accommodated, and the feeding roller rotates while pressing the top surface of the recording medium. In a paper feeding device that separates and feeds recording media one by one by driving,
On the bottom surface of the paper feed unit that can store the recording medium in a stacked state, an open portion that is opened when the recording medium does not exist is provided,
The arm body includes a planetary gear that is provided on the planetary arm and meshes with the drive gear, and a gear transmission mechanism that meshes when the planetary gear rotates forward and transmits power to the feeding roller.
Further, the arm body is provided with a separation operation means for moving the planetary gear in a direction away from the gear transmission mechanism in relation to the opening when the recording medium does not exist. A paper feeder. The separation operation means includes
The feeding roller has a second engaging portion that can be engaged with a first engaging portion provided on the arm body, and is rotatable up and down around the second engaging portion as a center of rotation. An actuating body extending laterally in the feeding direction;
A detecting portion provided on a lower surface of the operating body on the downstream side in the feeding direction, abutting on an uppermost surface of the recording medium, and fitted into the opening when the recording medium does not exist;
An operating portion provided upstream of the second engaging portion of the operating body in the feeding direction, and separating the planetary gear from the gear transmission mechanism when the detecting portion is fitted into the opening portion; The paper feeding device according to claim 1, further comprising:   The sheet feeding device according to claim 2, wherein the operating body is constantly urged to abut on the uppermost surface of the recording medium by the weight of the detection unit.   4. An image recording apparatus comprising: the paper feeding device according to claim 1; and a recording unit that records an image on a recording medium fed from the paper feeding device.

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