JP2010150033A - Image recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To set the total driving quantity of a driving shaft required for carrying paper to a recording part constant, regardless of the size of a deposit quantity of the paper P, by changing the paper feeding starting (paper feeding roller driving starting) timing, by arranging a rotation regulating body 40 changeable as a separation quantity θ1-θ2 in response to the deposit quantity of the paper P stored in a paper feeding tray 3, with a simple constitution. <P>SOLUTION: A longitudinally long guide groove 43 is formed in the rotation regulating body 40 rotatably journaled by a pivot shaft 42, and a connecting body 45 projecting to an installation part 44 of an arm body 30c is slidably fitted to the guide groove 43, and the arm body 30c and the rotation regulating body 40 are connected. An attitude of the rotation regulating body 40 abutting on a planetary gear means 34 is constituted so as to vary in response to an inclined attitude of the arm body 30c. When a driving shaft 39 reversely rotates, a separation quantity θ to a transmission gear group 35 of the planetary gear means 34 in the arm body 30c can be changed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image recording apparatus such as a printer, a copying machine, and a facsimile machine having a paper feed tray, and more specifically, according to the amount of recording medium (paper) stored in the paper feed tray. Image recording with a mechanism that makes it possible to make the drive amount of the paper feed roller that conveys paper to the recording unit constant, regardless of the amount of paper accumulation, by changing the timing of paper start (drive roller drive start) It relates to the device.

  2. Description of the Related Art Conventionally, in an image recording apparatus such as a printer, a copier, or a facsimile machine, as in Patent Document 1 and Patent Document 2, a paper feed cassette whose upper surface is opened at the bottom of a housing (apparatus housing) is arranged in a substantially horizontal direction. An inclined separation plate is provided on the downstream side in the insertion direction of the paper feed cassette, and a paper feed roller is provided at the tip of the arm body that is pivotally supported about a drive shaft provided in the housing. A configuration with the is known. The arm body includes a planetary gear that rotates up and down around the drive shaft, and a transmission gear group that transmits power to the paper feed roller when meshed with the planetary gear. The gear rotates in a direction to mesh with the transmission gear group. There is disclosed a configuration that is configured to rotate in a separating direction in which the meshing between the planetary gear and the transmission gear group is released by the reverse rotation of the drive shaft.

  According to this configuration, when the drive shaft rotates in the reverse direction, the paper feed roller is brought into contact with the uppermost paper accumulated and stored in the feed tray with a light force, and the paper is fed when the paper is conveyed by the registration roller pair. It is constructed so that the roller can move around. Then, the paper feed roller is rotationally driven in a predetermined direction (the drive shaft is rotated forward), so that the leading edge of the paper is placed on the inclined separation wall formed at the downstream end of the paper feed tray in the feed direction. The sheet of only the uppermost layer is separated by being abutted, and the sheet is conveyed to the image recording unit via a U-shaped conveyance path formed upward adjacent to the upper end of the inclined separation plate.

As described above, when a paper feed roller is provided on a so-called pendulum type arm body, as the number of fed papers increases, the amount of paper accumulated on the paper feed tray decreases, The height position of the paper feed roller in contact with the paper also decreases. Then, from the contact position between the uppermost sheet and the sheet feeding roller to the position of the registration roller pair in front of the image recording unit or the detection position by the sheet detection sensor positioned upstream of the position (these are referred to as predetermined positions) The length of the transport path becomes longer. In other words, when the amount of accumulated paper on the paper feed tray is large, the conveyance path length is short, and therefore, assuming that the rotation speed of the paper feed roller is constant, from the start of rotation of the paper feed roller to the predetermined position. The rotational driving amount of the paper feed roller for transporting the paper is small. On the contrary, when the amount of paper accumulated on the paper feed tray is small, the transport path length becomes long. Therefore, the rotation of the paper feed roller for transporting the paper from the start of rotation of the paper feed roller to the predetermined position is driven. The amount increases.
JP 2007-062965 A (see FIGS. 3 to 12) Japanese Unexamined Patent Publication No. 2007-204182 (see FIG. 7 etc.)

  Incidentally, in Patent Documents 1 and 2, when the drive shaft is rotated in the reverse direction, the amount (separation amount) by which the planetary gear rotates in the separation direction in which the meshing between the planetary gear and the transmission gear group is released is defined as the supply amount. Regardless of the amount of paper accumulated on the paper tray, it was set constant.

  Then, in response to the image recording command, the drive shaft rotates positively at a predetermined constant rotation speed, so that the time required for the spaced planetary gears to mesh with the transmission gear group is equal to the amount of paper on the paper feed tray. It becomes constant regardless of the amount of deposition.

  Therefore, for example, on the basis of the case where the amount of paper accumulated on the paper feed tray is large, the time required until the separated planetary gear meshes with the transmission gear group is set, and the rotation of the paper feed roller is started. It is assumed that the rotation driving amount of the paper feed roller for conveying the paper to the predetermined position (paper sensor position) is set. When the paper feeding operation proceeds in this state, the amount of paper accumulated on the paper feeding tray gradually decreases. As a result, the necessary rotational drive amount of the paper feed roller for conveying the paper from the start of rotation of the paper feed roller to the predetermined position (paper sensor position) gradually increases. If the rotation driving amount of the paper feed roller is set, a paper conveyance unreachable jam that the front end of the paper does not reach the paper sensor position occurs.

  Conversely, when the rotation amount of the paper feed roller is set based on the case where the paper accumulation amount in the paper feed tray is small, the paper feed roller is rotated by a predetermined amount when the paper accumulation amount in the paper feed tray is large. When driven, a paper jam such as bending of the paper due to excessive feeding of the paper occurs.

  In order to eliminate such an inconvenience, a sensor for detecting the accumulated amount of paper on the paper feed tray or a detection sensor for detecting a rotation angle with respect to a reference angle of the paper feed roller, and a paper sensor are provided. Based on the detection value of the sensor, it is necessary to perform automatic control to execute a calculation for determining a necessary rotational driving amount of the paper feed roller. In such a configuration, it is necessary to provide the above-described sensor and calculation means (control means) that can continuously detect from full loading to empty loading of the paper, and there is a problem that the apparatus is increased in size and cost.

  The present invention has been made to solve the above-described conventional problems, and according to the amount of recording medium (paper) stored in the paper feed tray, the paper feeding means is rotated when the drive shaft rotates in the reverse direction. The rotation of the planetary gears provided on the arm body with respect to the transmission gear group is provided, and a rotation restricting body is provided to change the timing of paper feed start (feed roller drive start), thereby accumulating paper. An object of the present invention is to provide an image recording apparatus provided with a mechanical mechanism capable of making a paper feed driving amount (time required for paper feed) constant regardless of the amount of paper.

  In order to achieve the above object, an image recording apparatus according to a first aspect of the present invention includes a paper feed tray having a storage unit that can store recording media in a stacked state, and a recording medium stored in the paper feeding tray. A sheet feeding means for feeding one sheet at a time, a conveyance path for conveying a recording medium fed from the sheet feeding tray by the sheet feeding means, and conveyance from the sheet feeding tray via the conveyance path An image recording apparatus having an image recording unit capable of recording an image on the recording medium that has been recorded, wherein the paper feeding means is a recording medium deposited on the storage unit of the paper feeding tray. Among them, an arm body that can be rotated around a drive shaft disposed in the apparatus housing with respect to the uppermost recording medium, and provided at the tip of the arm body, is transmitted from the drive shaft. To contact the top recording medium by the driving force And the arm body is driven from the drive shaft to the paper feed roller when meshed with the planetary gear means. A transmission gear group for transmitting force, and the planetary gear means rotates in a direction to mesh with the transmission gear group by forward rotation of the drive shaft, and the planetary gear means by reverse rotation of the drive shaft. Is configured to rotate in a separating direction to release the meshing with the transmission gear group, and is rotatably provided in the apparatus housing, and is accommodated in the accommodating portion by being connected to the arm body. The planetary gear means includes a rotation restricting body that changes the amount of separation of the planetary gear unit from the transmission gear group when the drive shaft rotates in the reverse direction according to the height of the recording medium.

  According to a second aspect of the present invention, in the image recording apparatus according to the first aspect, the planetary gear means that is separated from the transmission gear group contacts the rotation restricting body when the drive shaft rotates in the reverse direction. Thus, the magnitude of the separation amount is determined.

  According to a third aspect of the present invention, in the image recording apparatus according to the second aspect, the separation amount when the drive shaft rotates reversely as the deposition height of the recording medium deposited in the housing portion increases. Is configured to be large.

  According to a fourth aspect of the present invention, in the image recording apparatus according to any one of the first to third aspects, the arm body is disposed on the downstream side in the insertion direction of the paper feed tray as it approaches the bottom surface of the paper feed tray. The rotation restricting body, which is configured to extend, is slidably connected to a guide groove formed in the rotation restricting body, and in contact with the planetary gear means. The posture is configured to vary corresponding to the inclined posture of the arm body.

  According to a fifth aspect of the present invention, in the image recording apparatus according to any one of the first to fourth aspects, a paper sensor for detecting a leading end portion and a trailing end portion of a recording medium to be conveyed is provided in the conveyance path. Regardless of the amount of separation, the amount of drive of the paper feed roller from the contact portion of the paper feed roller to the recording medium to the end of the recording medium reaching the paper sensor is approximately It is set to be equal.

  As described above, according to the invention described in claim 1, the paper feeding unit is configured to perform recording on the top recording medium among the recording media accumulated in the storage portion of the paper feeding tray. An arm body that is rotatable around a drive shaft disposed in the apparatus housing, and provided at the tip of the arm body, the drive force transmitted from the drive shaft causes the uppermost recording medium to be recorded. A paper feed roller that rotates while abutting, and the arm body rotates with the drive shaft as a center, and planetary gear means that rotates around the drive shaft, and the paper feed roller from the drive shaft when meshed with the planetary gear means. A transmission gear group for transmitting a driving force to the planetary gear means, and the planetary gear means rotates in a direction to mesh with the transmission gear group by forward rotation of the drive shaft, and the planetary gear by reverse rotation of the drive shaft. The gear means releases the meshing with the transmission gear group. It is configured to rotate in the middle direction, is provided rotatably in the apparatus housing, and is connected to the arm body, thereby depending on the deposition height of the recording medium deposited in the accommodating portion. The planetary gear means includes a rotation restricting body that changes the amount of separation away from the transmission gear group when the drive shaft rotates in the reverse direction.

  Therefore, when the drive shaft rotates forward in order to convey the subsequent recording medium from the paper feed tray, the paper feed roller starts to be driven with a delay corresponding to the separation amount (release time). . In the present invention, a rotation restricting body that can change the separation amount according to the amount of recording medium stored in the paper feed tray is provided, and the timing of the paper feed start (feed roller start) is set. By changing this, the total drive amount of the drive shaft required to transport the sheet to the recording unit can be made constant regardless of the amount of the recording medium deposited. Therefore, there is no need to provide the above-mentioned sensor that can continuously detect from full loading to empty loading of the arm body, such as a sensor for detecting the tilt angle of the arm body, the paper sensor, and the calculation means (control means) as in the prior art. Is simplified, and there is an effect that an increase in size and cost of the apparatus can be avoided.

  According to the second aspect of the present invention, when the drive shaft rotates in the reverse direction, the planetary gear means that is separated from the transmission gear group comes into contact with the rotation restricting body, whereby the amount of separation is determined. is there. Therefore, the posture of the rotation restricting body with which the planetary gear means abuts is configured to vary according to the tilted posture of the arm body. Then, when the drive shaft rotates in the reverse direction, the planetary gear means comes into contact with the rotation restricting body connected to the arm body in an inclined posture corresponding to the height of the recording medium deposited in the accommodating portion. As a result, the distance by which the planetary gear means is separated from the transmission gear group is determined, and the configuration for that purpose is extremely simple.

  According to the third aspect of the present invention, as described above, the inclination posture of the rotation restricting body is set in advance according to the accumulated height of the recording medium accumulated in the storage portion of the paper feed tray. In addition, the separation amount is increased as the deposition height of the recording medium deposited in the accommodating portion increases. In other words, the rotation restricting body increases the recording medium deposition height, so that the timing of the paper feeding start (feeding roller driving start) is delayed, so that the recording medium can be recorded regardless of the amount of recording medium accumulated. The total drive amount of the drive shaft required for transporting the sheet to the section can be made constant.

  According to the invention described in claim 4, the arm body is configured to extend to the downstream side in the insertion direction of the paper feed tray as it approaches the bottom surface of the paper feed tray, and is formed in the rotation restricting body. On the other hand, the connecting body provided on the arm body is slidably connected, and the posture of the rotation restricting body with which the planetary gear means abuts is configured to vary corresponding to the tilting posture of the arm body. As a result, the structure is compact, and the configuration for determining the tilt posture of the rotation restricting body can be easily predicted by design, and the incorporation can be extremely easily achieved.

  According to the fifth aspect of the present invention, the conveyance path is provided with the paper sensor for detecting the leading edge and the trailing edge of the recording medium to be conveyed, and the paper feeding is performed regardless of the amount of separation. Since the driving amount of the paper feed roller from the contact portion of the roller to the recording medium until the leading end of the recording medium reaches the paper sensor is set to be approximately equal, When the slip of the roller with respect to the recording medium is generated, the slip correction value can be set simply and accurately, and the recording medium can be stably fed.

  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 schematic side sectional view of an image recording unit, a paper feeding device, and the like, and FIG. 3 is a paper feeding roller and a drive shaft. FIG. 4 is a side sectional view of the recording unit and the sheet feeding unit in a state where the amount of accumulated paper in the sheet feeding tray is small, and FIG. 5 is a recording in a state where the amount of accumulated paper in the sheet feeding tray is large. FIG. 6A and FIG. 6B are diagrams for explaining the operation of the rotation restricting body.

[Basic structure of multi-function device 1]
As shown in FIG. 1, an opening 2 a is opened on the front side (front side in FIG. 1) of the housing 2 (corresponding to the device casing in the claims) in the multi-function device 1. The sheet feeding tray 3 having an open top surface for accommodating sheets as recording media in a stacked state is mounted so as to be insertable / removable along the X-axis direction. A paper discharge tray 33 is mounted on the upper surface of the paper feed tray 3. Hereinafter, the side having the opening 2a of the housing 2 made of synthetic resin is referred to as the front (front), and is referred to as the rear (back, back), left and right of the apparatus based on this. As described above, the front-rear direction of the multi-function device 1 is the X-axis direction, and the left-right direction is the Y-axis direction. The term “insertion / removal” is not limited to the case where the paper feed tray 3 is detachable from the housing 2, and even when the paper feed tray 3 is pulled out of the housing 2, This is intended to include those in which the tray 3 cannot be removed (cannot be attached or detached).

  An image reading device 5 for reading a document in a copy function or a facsimile function is disposed on the upper part of the housing 2 made of synthetic resin. The image reading device 5 is configured to be vertically openable and closable with respect to one side end of the housing 2 via a pivot portion (not shown). Further, the upper surface of the image reading device 5 is constituted by a glass plate for placing a document, and this glass plate is a document cover body 6 that can be turned up and down around the pivot with respect to the rear end of the image reading device 5. Covered with. After the document is placed on the glass plate by opening and closing the document cover body 6, an image of the document is read by moving a document reading scanner (for example, CIS: Contact Image Sensor) below the glass plate.

  On the upper surface of the housing 2 and in front of the document cover body 6, an operation panel unit 7 having various operation buttons and a liquid crystal display device 8 for displaying an operation procedure and a state of processing being executed are provided. ing. The various operation buttons include a start button, a stop button, and the like, and various operations are performed by pressing these operation buttons. In addition, the setting state of the multi-function device 1 and various operation messages are displayed as necessary.

  An external memory insertion portion 11 for inserting an external memory is provided on the front surface of the housing 2 and above the opening 2a. The external memory corresponds to, for example, CompactFlash (registered trademark), SmartMedia (registered trademark), Memory Stick (registered trademark), SD card (registered trademark), xD (registered trademark), and the like. The data stored in the external memory inserted into the external memory insertion unit 11 is read into the internal memory of the multi-function device 1 and recorded on the paper by the recording device.

  Next, the image recording unit 10 and the paper feeding device 12 as a paper feeding unit will be described with reference to FIGS. 3 and 4 are side cross-sectional views of the image recording unit 10 and the paper feeder 12.

[Image recording section]
The image recording unit 10 is supported by a box-shaped main frame 21 (shown in FIG. 2) having an open upper surface and a pair of left and right side plates, and as shown in FIG. 2, in the Y-axis direction (main scanning direction). It is formed between the horizontally long plate-like first and second guide members 22 and 23 that extend. In FIG. 3, the second guide member 23 is omitted. The carriage 13 in which the recording head 14 in the image recording unit 10 is mounted on the lower surface side is slidably supported across the first guide member 22 on the upstream side and the second guide member 23 on the downstream side in the paper transport direction. (Mounted) and can be reciprocated.

  In order to reciprocate the carriage 13, timing is arranged on the upper surface of the second guide member 23 arranged on the downstream side in the paper conveyance direction (arrow A direction) so as to extend in the main scanning direction (Y-axis direction). A belt (not shown) is wound around a pulley (not shown), and a CR (carriage) motor 51 (see FIG. 7) for driving the timing belt is fixed to the lower surface of the second guide member 23. .

  A flat platen 26 extending in the Y-axis direction so as to face the lower surface of the recording head 14 in the carriage 13 is fixed between the guide members 22 and 23 and above the bottom plate of the main frame 21. . A space between the platen 26 and the bottom plate (not shown) of the housing 2 is a tray storage portion that stores a paper feed tray 3 described later and that can be inserted and removed. At least a part of the bottom plate 3 a of the paper feed tray 3 is supported on the bottom plate of the housing 2.

  In addition, a registration roller (conveyance roller) pair 27 for sending the sheet to the lower surface of the recording head 14 is disposed on the upstream side of the conveyance with the platen 26 interposed therebetween. When passing over the platen 26, an image is recorded on the paper P. Disposed on the downstream side of the platen 26 is a pair of paper discharge rollers 28 for transporting the recorded paper P onto a paper discharge tray section 33 provided on the upper surface of the paper feed tray 3.

[Paper Feeder]
The recording medium accommodated in the paper feed tray 3 is hereinafter referred to as paper for convenience. However, the recording medium is not only plain paper, but also special paper such as postcards and envelopes, special paper such as glossy paper, and resin. It is a concept that includes films and the like.

  Next, the configuration of the sheet feeding device 12 will be described in detail. The container 3b of the paper feed tray 3, which is an injection molded product of synthetic resin material, has an open top surface. For example, the A4 size paper P has a long side along the X-axis direction and a short side along the Y-axis direction. It is accommodated so as to be along. The accommodating portion 3b includes a bottom plate 3a, left and right side plates 3c, and an inclined separation plate 18 connected to a downstream end in the feeding direction. A handle 3f is provided at the rear end of the housing 3b. An elastic separation piece 18 a (see FIGS. 4 and 5, which is made of a leaf spring in the embodiment) is provided as a separation means at the center of the inclined separation plate 18 in the Y-axis direction.

  In the embodiment, the maximum accumulation amount of the paper P on the paper feed tray 3 is about 150 sheets of plain paper, and the accumulation height is about 15 mm. The sheets P in the sheet feed tray 3 are separated one by one by the cooperative action of a pendulum-type sheet feeding means 30 (to be described later) and an elastic separation piece 18a in the inclined separation plate 18, and then conveyed in a U-turn shape. The paper is fed to the image recording unit 10 one by one through the road bodies 32 and 33.

  Note that a paper sensor 31 that detects the leading edge and the trailing edge of the paper P to be transported is provided in the transport path formed by the transport path bodies 32 and 33. In the embodiment, the sheet sensor 31 is an optical sensor that is provided upstream of the registration roller pair 27 in the conveyance direction, and the light emitting unit and the light receiving unit are arranged with the conveyance path interposed therebetween.

[Paper Tray]
Next, the structure of the sheet feeding means (also referred to as a sheet feeding roller unit) 30 will be described in detail with reference to FIGS. 2 to 6A and 6B. In the embodiment, the arm 30c made of synthetic resin in the paper feeding means 30 can be turned up and down around the drive shaft 39, and the arm 30c approaches the bottom plate (bottom surface) 3a of the paper feed tray 3. The arm body 30c extends so as to approach the inclined separation plate 18, and a paper feed roller 30a is disposed at the tip of the arm body 30c. The pair of paper feed rollers 30a in the embodiment are provided at symmetrical positions with respect to the center line in the Y direction (see FIG. 3). The LF motor 52 (see FIG. 7) can rotate forward and backward, and the drive shaft 39 is rotationally driven by the LF motor 52. Further, a rotary encoder 53 (see FIG. 7) for detecting the forward / reverse rotation direction and the rotation amount is provided in the gear transmission portion to the LF motor 52 or the drive shaft 39. In the present embodiment, the rotational force of the LF motor 52 is configured to be selectively transmitted to the drive shaft 39 and the registration roller pair 27 via a power transmission switching mechanism (not shown). The registration roller pair 27 (including the paper discharge roller pair 28) may be driven by separate motors.

  The arm body 30c is provided with a planetary gear means 34 and a gear transmission mechanism 35 composed of a plurality of gears (not shown in FIG. 2). The planetary gear means 34 includes a planetary arm 37 that is rotatably supported with respect to the drive shaft 39 and a planetary gear 38 that is rotatably supported on the free end side thereof. The planetary gear 38 is always meshed with the drive gear 36 that rotates integrally with the drive shaft 39. Due to the forward rotation of the drive shaft 39 (clockwise rotation in FIGS. 4, 6 (A) and 6 (B)), the planetary arm 37 rotates clockwise in FIGS. 4, 6 (A) and 6 (B). To turn. As a result, the planetary gear 38 can mesh with the gear 35 a on the transmission upstream side of the gear transmission mechanism 35. On the contrary, as shown in FIG. 5, when the drive shaft 39 rotates in the reverse direction and the planetary arm 37 rotates counterclockwise, the planetary gear 38 is separated so that the meshing with the transmission upstream gear 35a is released. It is.

[Rotation regulator]
Next, the configuration of the rotation restricting body 40 will be described. The rotation restricting body 40 is rotatably provided on an apparatus housing, for example, the main frame 21, and is connected to the arm body 30 c, so that the stacking height of the paper P accumulated in the storage portion 3 b of the paper feed tray 3 is increased. Accordingly, when the drive shaft 39 rotates in the reverse direction, the planetary gear unit 34 has a function of changing the amount of separation away from the transmission gear group 35. As described above, it goes without saying that the planetary gear means 34 moves away from the rotation restricting body 40 and the planetary gear 38 meshes with the transmission upstream gear 35a by the forward rotation of the drive shaft 39. .

  The embodiment of the rotation restricting body 40 will be described in more detail. As shown in FIG. 3 to FIG. 6B, the base portion of the vertically long link-shaped rotation restricting body 40 can be rotated from a support member 41 erected on the main frame 21 to a pivot 42 projecting sideways. It is pivotally supported. A vertically long guide groove 43 is formed in the rotation restricting body 40 extending downward. The attachment portion 44 formed so as to extend upward at the base portion of the arm body 30c is provided with a connecting body 45 that also projects laterally. A round shaft-like connecting body 45 is slidably fitted into the guide groove 43, and the arm body 30c and the rotation restricting body 40 are connected.

  And the attitude | position of the rotation control body 40 which the planetary gear means 34 contact | abuts is comprised so that it may respond | correspond according to the inclination attitude | position of the arm body 30c. That is, as shown in FIG. 4 and FIG. 6A, when the accumulation height of the paper P accumulated in the storage portion 3b is the smallest, when the paper feed roller 30a contacts the uppermost paper P The depression angle α1 (also referred to as an inclination angle) between the plane of the uppermost sheet P and the arm body 30c increases. In this case, the posture of the arm body 30 c that is pivotally supported by the pivot 42 and extends downward is held in an inclined posture so as to approach a straight line connecting the pivot 42 and the center line of the drive shaft 39.

  On the other hand, as shown in FIG. 6B, when the accumulation height of the paper P accumulated in the accommodating portion 3b is the highest, the paper feed roller 30a is in contact with the uppermost paper P. The depression angle α2 (also referred to as an inclination angle) between the plane of the uppermost sheet P and the arm body 30c increases. In this case, the posture of the arm body 30c that is pivotally supported by the pivot shaft 42 and extends downward is set in a direction away from the position of the sheet feed roller 30a with respect to a straight line connecting the pivot shaft 42 and the center line of the drive shaft 39. It is held in an inclined posture. In other words, as the stacking height of the paper P decreases and the downward rotation amount of the arm body 30c increases (the inclination angle α of the arm body 30c increases), the rotation restricting body 40 is in the standing posture. Become.

  When the drive shaft 39 rotates in the reverse direction, the planetary gear means 34 that is separated from the transmission gear group 35 contacts the rotation restricting body 40, whereby the magnitude of the separation amount is determined. Further, the higher the accumulated height of the paper P accumulated in the storage portion 3b of the paper feed tray 3, the larger the separation amount when the drive shaft 39 rotates in the reverse direction. Here, as can be understood with reference to FIGS. 6 (A) and 6 (B), the separation amount is such that the planetary gear 38 in the planetary gear means 34 meshes with the transmission upstream gear 35a in the transmission gear group 35. The rotation angle θ about the drive shaft 39 from the position (angle) to the position (angle) at which the rotation restricting body 40 abuts on the planetary gear 38 or the planetary arm 37 in the planetary gear means 34. 4 and 6A, the minimum rotation angle θ1 is obtained when the accumulation height of the paper P accumulated in the accommodating portion 3b is the smallest. In FIG. 6B, the maximum rotation angle θ2 is obtained when the accumulated height of the paper P accumulated in the accommodating portion 3b is the largest. FIG. 5 is a cross-sectional view showing a state where the planetary gear unit 34 is separated by a predetermined amount when the accumulated height of the paper P is large.

  Accordingly, when the drive shaft 39 rotates in the reverse direction with respect to the rotation restricting body 40 connected to the arm body 30c having an inclined posture corresponding to the accumulated height of the paper P accumulated in the accommodating portion 3b, the planetary gear means. 34 comes into contact, and the separation amount (the rotation angle θ) by which the planetary gear unit 34 is separated from the transmission gear group 35 is determined. As described above, since the inclination angle α of the arm body 30c increases as the stacking height of the paper P decreases (inversely proportional), the inversely proportional relationship that the separation amount decreases as the inclination angle α of the arm body 30c increases. It becomes.

  In the above configuration, when the paper P is separated and fed from the paper feed tray 3 one by one, the LF motor 52 (see FIG. 7) rotates forward and the drive shaft 39 rotates forward. At this time, the planetary gear 38 of the planetary gear means 34 meshes with the drive gear 36 that rotates integrally with the drive shaft 39, and the planetary arm 37 is relatively rotatable about the drive shaft 39. 6 (A) and 6 (B), the planetary arm 37 rotates clockwise. Then, the planetary gear 38 at the tip of the planetary arm 37 meshes with the transmission upstream gear 35a of the transmission gear group 35 (see the solid line state in FIGS. 6A and 6B). As a result, the arm body 30c is urged downward, and the paper feed roller 30a at the front end of the arm body 30c is pressed against the uppermost surface of the paper P deposited on the paper feed tray 3, while the gear transmission mechanism 35 is pressed. The sheet feeding roller 30a is rotated in the feeding direction (counterclockwise direction in FIGS. 6A and 6B).

  Accordingly, the uppermost sheet and the leading ends of the plurality of sheets P below it are moved in the direction approaching the inclined separation plate 18 by the rotationally driven paper feed roller 30a, but the cooperative action of the inclined separation plate 18 with the separating means 18a. Thus, only the uppermost sheet P in the storage section 3b is separated and conveyed (paper fed) to the conveyance path between the conveyance path bodies 32 and 33.

  When the leading edge of the conveyed paper P crosses the location of the paper sensor 31, a predetermined signal (pre-registration signal) is output to the control device 50 (see FIG. 7). The controller 50 calculates the registration feed rotation amount of the LF motor 52 corresponding to the distance of the sheet conveyance path from the position of the sheet sensor 31 to the registration roller pair 27 using the pre-registration signal as a trigger, and if the registration rotation amount is reached. Then, the LF motor 52 is temporarily stopped and the sheet P is subjected to a resist action. After that, when an image print command is output, a normal rotation of the registration roller pair 27 that conveys the paper P in the direction of the carriage 13 and a rotation drive of the paper feed roller 30a in the feeding direction are performed according to the command of the control device 50. Execute.

  When the leading end portion of the paper P is nipped by the registration roller pair 27, it is left to the conveyance of the paper P by the registration roller pair 27 and the paper feed roller 30a is rotated together. In B), the drive shaft 39 is reversely rotated in the counterclockwise direction. Due to this reverse rotation, the planetary arm 37 is moved in the counterclockwise direction in FIGS. 6A and 6B through the rotation of the planetary gear 38, and the planetary gear means is provided on the side of the rotation restricting body 40. 34 (one or both of the planetary arm 37 and the planetary gear 38) is in contact with the planetary arm 37 (see the two-dot chain line states in FIGS. 6A and 6B). ). Thereafter, driving of the drive shaft 39 is stopped.

  When the image recording on the preceding one sheet P is completed and the sheet sensor 31 detects the trailing edge of the sheet P, a command to convey the subsequent sheet P from the sheet feed tray 3 is output. As a result, the LF motor 52 rotates forward so that the drive shaft 39 rotates forward. Then, the planetary arm 37 which is separated by a predetermined separation amount θ corresponding to the inclination angle α of the arm body 30c when the paper feeding roller 30a comes into contact with the topmost of the sheets P accumulated in the storage portion 3b. 6A and 6B, it moves in the clockwise direction, and the planetary gear 38 meshes with the transmission upstream gear 35a. From this state, the paper feed roller 30a starts to rotate and starts transporting the paper P (hereinafter referred to as “paper feed start”). Therefore, when the paper conveyance command is output, the rotation driving of the paper feed roller 30a is started with a delay corresponding to the separation amount θ (release time).

  As described above, the conveyance path length L from the position where the paper feeding roller 30a contacts the top of the sheets P accumulated in the storage unit 3b to the sheet sensor 31 along the conveyance path is equal to the accumulation of the sheets P. The larger the amount, the shorter. On the contrary, the conveyance path length L becomes longer as the accumulation amount is smaller.

  Assuming that the rotation amount (rotation speed or unit drive amount) per unit time of the drive shaft 39 and the paper feed roller 30a is constant, the longer the conveyance path length L, the longer the paper feed start to the paper sensor 31. Although the required transport time Th of the paper P becomes longer, the release time tr is shorter. On the other hand, the shorter the transport path length L, the shorter the transport time Th for transporting the paper P from the paper feed start to the paper sensor 31, but the release time tr becomes longer.

  In the present invention, the amount θ of separation of the planetary gear means 34 provided on the arm body 30c from the transmission gear group 35 when the drive shaft 39 rotates in reverse according to the accumulation amount of the paper P stored in the paper feed tray 3. The above-described rotation restricting body 40 is provided so as to change the sheet feeding time, and by changing the timing of the sheet feeding start (starting driving of the sheet feeding roller 30a), the recording unit 10 can be controlled regardless of the amount of accumulated sheets P. The total drive amount of the drive shaft 39 required for transporting the sheet can be made constant. The drive amount of the drive shaft 39 can be calculated by the rotary encoder 53.

  The required time may be measured by providing a timer 54 instead of the rotary encoder 53. In that case, the total time corresponding to the total driving amount (corresponding to the time required from the start of rotation of the drive shaft 39 in response to the paper transport command until the leading edge of the paper P reaches the paper sensor 31), that is, the time required for transport. The total time of Th and release time tr (paper feed drive time) is made constant regardless of the amount of paper P deposited.

  With the above-described configuration, as in the prior art, the sensor capable of continuously detecting from full loading to empty loading of the paper, such as a sensor for detecting the inclination angle of the arm body 30c, the paper sensor 31, and the calculation means (control) Means), the configuration is simplified, and an increase in size and cost of the apparatus can be avoided.

  The total drive amount and the total time are theoretical values when no slip occurs between the rotating paper feed roller 30a and the paper P. Therefore, in a state where slip occurs, the slip amount is the difference between the total drive amount or total time actually calculated or measured and the theoretical value. In the present invention, by determining the slip correction value based on this slip amount, it is possible to set an optimum slip correction value regardless of the amount of accumulation of the paper P. Problems related to the performance of the image recording apparatus, such as failure of the sheet P to reach the sensor, can be easily solved.

  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, a pair of left and right paper feed rollers 30a as the paper feed rollers or only one of the paper feed rollers 30a may be used. Further, the outer peripheral surface of the paper feed roller 30a may be configured by a member having a large friction coefficient such as rubber.

1 is an overall perspective view of an image recording apparatus. It is a sectional side view of an image recording part and a paper feeding means. FIG. 4 is a perspective view of a main frame and a sheet feeding / feeding unit of an image recording unit. FIG. 6 is a cross-sectional view of a paper feed arm and the like in a state where the amount of paper P deposited is small. FIG. 6 is a cross-sectional view of a paper feed arm and the like in a state in which the amount of accumulated paper P is large. (A) is an operation explanatory diagram in a state where the accumulation amount of the paper P is small, and (B) is an operation explanatory diagram in a state where the accumulation amount of the paper P is large. It is a functional block diagram of a control device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Paper feed tray 3a Bottom plate 30 Paper feed roller unit 30a Paper feed roller 30c Arm body 31 Paper sensor 34 Planetary gear means 35 Transmission gear group 35a Transmission upstream side gear 37 Planetary arm 38 Planetary gear 39 Drive shaft 40 times Movement restricting body 41 Support member 42 Axis 43 Guide groove 45 Linked body

Claims (5)

A paper feed tray having a storage section capable of storing recording media in a stacked state; a paper feeding means for feeding one by one from the recording media contained in the paper feeding tray; and A transport path for transporting a recording medium fed from a paper feed tray, and an image recording unit capable of recording an image on the recording medium transported from the paper feed tray via the transport path. An image recording device,
The paper feeding means rotates around the drive shaft disposed in the apparatus housing with respect to the uppermost recording medium among the recording media accumulated in the accommodating portion of the paper feed tray. A movable arm body, and a paper feed roller that is provided at a distal end portion of the arm body and rotates while abutting against the uppermost recording medium by a driving force transmitted from the driving shaft,
The arm body includes planetary gear means that rotates about the drive shaft, and a transmission gear group that transmits a driving force from the drive shaft to the paper feed roller when meshing with the planetary gear means. ,
The planetary gear means is rotated in the direction of meshing with the transmission gear group by forward rotation of the drive shaft, and the planetary gear means is disengaged from the meshing with the transmission gear group by reverse rotation of the drive shaft. Configured to rotate in the direction,
When the drive shaft rotates reversely according to the deposition height of the recording medium accommodated in the accommodating portion by being rotatably connected to the apparatus housing and connected to the arm body, An image recording apparatus, comprising: a rotation restricting body that changes a separation amount of the planetary gear unit that is separated from the transmission gear group.   2. The magnitude of the separation amount is determined by the planetary gear means that is separated from the transmission gear group coming into contact with the rotation restricting body when the drive shaft rotates in the reverse direction. The image recording apparatus described in 1.   3. The configuration according to claim 2, wherein the separation amount when the drive shaft rotates reversely increases as the deposition height of the recording medium deposited in the storage portion increases. Image recording device. The arm body is configured to extend downstream in the insertion direction of the paper feed tray as it approaches the bottom surface of the paper feed tray.
A connection body provided on the arm body is slidably connected to a guide groove formed on the rotation restricting body,
The posture of the rotation restricting body with which the planetary gear means abuts is configured to vary corresponding to the inclined posture of the arm body. Image recording device. The transport path is provided with a paper sensor for detecting the leading end and the trailing end of the recording medium to be transported,
Regardless of the amount of separation, the drive amount of the paper feed roller until the leading end of the recording medium reaches the paper sensor from the contact portion of the paper feed roller with respect to the recording medium is made substantially equal. 5. The image recording apparatus according to claim 1, wherein the image recording apparatus is set to the following.

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