JP2004299822A - Inversion mechanism of recording medium, and image recording apparatus with the inversion mechanism mounted thereon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact image recording apparatus capable of reducing the installation space and realizing double-sided recording with a simple configuration. <P>SOLUTION: An inversion mechanism of a recording medium has an inversion roller 12 and a spur 18 abutted thereon and rotated thereby, and the spur 18 is turnable around a center of rotation of the inversion roller 12. The spur 18 is located at the first position during the forward feed of a paper sheet P when performing recording on a first face of the paper sheet by a recording unit and during the reverse feed of the paper sheet P with the first face recorded, the spur 18 holding the paper sheet P to be fed in the reverse direction with a rear end part thereof left behind is turned to the second position around the center of the inversion roller 12 together with the inversion roller 12, and the rear end part of the paper sheet P is wound around an outer circumference of the inversion roller 12. Thereafter, the inversion roller 12 is rotated at the second position, the paper sheet P is held by the inversion roller 12 and the spur 18, and fed in the reverse direction, the inversion roller 12 is rotated in the reverse direction, and the paper sheet P is fed to the recording unit in the forward direction while the paper sheet is inverted. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a reversing mechanism of a recording medium and an image recording apparatus such as a laser beam printer or an ink jet printer capable of recording on both sides, which is equipped with the reversing mechanism.
[0002]
[Prior art]
In an image recording apparatus such as a laser printer or an ink jet printer capable of performing double-sided recording, a reversing mechanism for reversing the front and back of a sheet as a recording medium is provided. A conventional example of the reversing mechanism is shown in FIGS. Each is shown schematically.
[0003]
That is, the reversing mechanism shown in FIG. 14 is a mechanism generally employed in a laser printer or the like. , {Circle around (2)} and {circle around (3)}, the sheet P is turned upside down.
[0004]
The reversing mechanism shown in FIG. 15 is a mechanism generally employed in an ink-jet printer or the like, in which a reversing unit 202 is provided on the back of the paper feeding cassette 201, and is sent out from the paper feeding cassette 201 in the direction (1) in the figure. Then, the sheet P on which the image is formed is reversely fed, and as shown by the arrow (2), the reversing unit 202 reverses the front and back of the sheet P and supplies it in the direction of the arrow (3) to supply it to the back side. Also forms an image.
[0005]
Further, the reversing mechanism shown in FIG. 16 is a mechanism employed in, for example, a thermal transfer printer described in Patent Document 1, and is first sent out by a pair of rollers 301 in the (1) direction shown in the drawing to form an image on its surface. The fed sheet P is reversely fed, the sheet P is conveyed in the direction of arrow (2) by a pair of rollers 302 by a sheet guide (not shown), and then the sheet guide is switched to move the sheet P in the direction of arrow (3) by a pair of rollers 303. This method employs a method in which the sheet P is fed and turned upside down, and the sheet P turned upside down is transported by the roller pair 301 in the direction of the arrow (4) to form an image on the back side.
[0006]
[Patent Document 1]
JP-A-11-151840
[0007]
[Problems to be solved by the invention]
However, the reversing mechanism shown in FIG. 14 has a problem that a large space is required because an S-shaped path must be provided in the main body of the image recording apparatus, and it is impossible to make the apparatus compact. Was.
[0008]
In addition, the reversing mechanism shown in FIGS. 15 and 16 requires a transport path longer than the paper length, and thus has a problem that the size of the apparatus is increased.
[0009]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to reduce the installation space in a compact size because an S-shaped path and a reversing conveyance path longer than the paper length are not required in the main body. It is an object of the present invention to provide a recording medium reversing mechanism capable of realizing double-sided recording with a simple configuration and an image recording apparatus equipped with the reversing mechanism.
[0010]
Means for Solving the Problems and Effects of the Invention
In order to achieve the above object, the invention according to claim 1 includes a recording unit that records an image on a surface of a recording medium, and a transport unit that transports the recording medium in a predetermined transport direction toward the recording unit. In a recording medium reversing mechanism, which is mounted on an image recording apparatus and reverses the recording medium on which an image is recorded on one side by the recording means for recording on both sides of the recording medium, a first recording medium for reversing the recording medium. A reversing roller rotatable in a second rotation direction opposite to the first rotation direction and a rotation direction of the reversing roller, the recording medium being rotatable in contact with the reversing roller, and being capable of sandwiching a recording medium between the reversing roller. A spur roller rotatable around the rotation axis of the reversing roller from a first spur position to a second spur position around the reversing roller; and an image recorded on one side of the spur roller by the recording unit. Recording medium And a second reversing conveyance path on which a recording medium is conveyed from the first reversing conveyance path, wherein the spur roller is at the first spur position. When the reversing roller rotates in the first rotation direction, the recording medium on which an image is recorded on one side by the recording means is transported to the first reversing transport path, and the reversing roller is rotated by the second reversing roller. , The spur roller rotates from the first spur position to the second spur position, and the recording medium is transferred from the first reverse conveying path to the second reverse conveying path. When the spur roller is at the second spur position, the reversing roller rotates again in the first rotation direction, thereby reversing and conveying the recording medium toward the recording unit. And
[0011]
Therefore, according to the first aspect of the present invention, the reversing mechanism includes the reversing roller and the spur roller, and the spur roller is rotated around the reversing roller so that the recording medium is reversed. A reversing path or the like longer than the medium length is not required, so that the reversing mechanism and the image recording apparatus equipped with the reversing mechanism can be made compact to reduce the installation space for the reversing mechanism and to perform duplex recording with a simple configuration. Can be realized.
[0012]
According to a second aspect of the present invention, in the first aspect of the present invention, the spur roller can be positioned at a third spur position between a first spur position and a second spur position, and the spur roller Further comprising fixing means for fixing at three spur positions,
When the spur roller is fixed at the first spur position by the fixing means, the reversing roller rotates in a first rotation direction, whereby a recording medium having an image recorded on one side thereof by the recording means. After the first end of the first spur has passed through the spur roller, the first end of the first end until the second end near the other end is sandwiched between the reversing roller and the spur roller. The spur roller is conveyed to a reversing conveyance path, and the spur roller is rotated in the second rotation direction, so that the spur roller is in a state where the vicinity of the second end of the recording medium is sandwiched between the spur roller and the first spur roller. After rotating from the spur position to the third spur position, the fixing means fixes the spur roller at the third spur position, and the vicinity of the first end is held between the reversing roller and the spur roller. Until the reversing roller rotates in the second rotational direction. By rotating, the recording medium is conveyed from the first reversing conveyance path to the second reversing conveyance path, and the vicinity of the first end of the recording medium is fixed while being held between the spur rollers. After the means releases the fixation of the third spur position of the spur roller, the reversing roller further rotates in the second rotational direction, so that the spur roller moves from the third spur position to the second spur position. After the rotation, the fixing means fixes the spur roller at the second spur position, and then the reversing roller rotates again in the first rotation direction, thereby reversing the recording medium toward the recording means. It is transported.
[0013]
Therefore, according to the second aspect of the present invention, the spur roller is fixed at the first, second and third spur positions by the fixing means, and the spur roller performs a predetermined action together with the reversing roller at each spur position. Thus, the reversing operation of the recording medium is reliably performed.
[0014]
The invention according to claim 3 is the invention according to claim 2, further comprising a guide member that rotates integrally with the spur roller around the reversing roller, wherein the spur roller is fixed to a first spur position. The guide member guides the recording medium such that the recording medium having an image recorded on one side thereof by the recording means is conveyed to the first reversing conveyance path, and the spur roller is driven by the third spur roller. When fixed at the spur position, the guide member guides the recording medium so that the recording medium is conveyed from the first reversing conveyance path to the second reversing conveyance path, and the spur roller is driven by the spur roller. When the recording medium is fixed at the second spur position, the guide member guides the recording medium such that the recording medium is conveyed from the second reverse conveyance path toward the recording means.
[0015]
Therefore, according to the third aspect of the present invention, when the spur roller is fixed at the first, second, and third spur positions, the guide member guides the recording medium to a predetermined path. Is performed reliably and stably.
[0016]
The invention according to claim 4 is the invention according to claim 3, wherein the spur roller is rotatably held, and the spur roller is moved from the first spur position to a second spur position via a third spur position. A spur roller holder rotatable around the reversing roller so that the spur roller can rotate up to the rotation axis of the reversing roller. Means for guiding a recording medium having an image recorded on one side thereof to the first reversing conveyance path, and when the recording medium is conveyed from the first reversing conveyance path to the second reversing conveyance path. A first guide member rotatably held between a retreat position for retreating and retreating from the recording medium when conveyed from the second reversing conveyance path toward the recording means; With rotation A retreat position at which the recording medium is separated and retracted from the recording medium when at least the recording medium is conveyed from the first reverse conveyance path to the second reverse conveyance path; And a second guide member rotatably held between a guide position for guiding the recording medium toward the recording means when the recording medium is conveyed toward the recording means. When fixed at the spur position, the first guide member is arranged at the guide position, and when the spur roller is fixed at the third spur position, the first guide member and the second guide are arranged. The members are disposed at respective retracted positions, and when the spur roller is fixed at the second spur position, the first guide member is disposed at the retracted position, and the second guide member is positioned at the guide position. Characterized in that it is disposed.
[0017]
Therefore, according to the fourth aspect of the present invention, since the guide member is disposed at the predetermined guide position and the retracted position in conjunction with the rotation of the spur roller holder holding the spur roller, the reversing operation of the recording medium is reliably performed. It is performed stably.
[0018]
According to a fifth aspect of the present invention, in the invention of the fourth aspect, the spur roller holder has a cam portion that contacts the first guide member, and a first gear portion that can mesh with the second guide member. And the first guide member is rotatable about a first rotation axis fixedly arranged in the reversing mechanism, and a first guide for guiding a recording medium on one surface thereof. A main body, first urging means for urging the first guide main body so as to always be located at the guide position, and a cam of the spur roller holder fixedly disposed on the first guide main body. The second guide member is rotatable about a second rotation shaft fixedly arranged in the reversing mechanism, and guides the recording medium on one surface thereof. The second guide body to be A second urging means for urging the second guide body so as to be always located at the retracted position; and a first urging means which rotates integrally with the second guide body and rotates the first spur roller holder. And a second gear portion that can mesh with the second gear portion.
[0019]
Therefore, according to the fifth aspect of the present invention, the guide member is constituted by the first guide member and the second guide member, and the first guide member which is always urged to be located at the guide position, The rotation of the spur roller holder causes the cam member to come into contact with the cam follower portion to retreat to prevent interference with the spur roller, and the second guide member is provided with a spur roller holder on a second gear portion provided thereon. The first gear portion is rotated by engagement with the first gear portion to be positioned at a predetermined guide position and a retreat position, so that the reversing operation of the recording medium is performed reliably and stably.
[0020]
According to a sixth aspect of the present invention, in the third aspect of the invention, the spur roller is rotatably held, and the spur roller is moved from the first spur position to a second spur position via a third spur position. Further comprising a spur roller holder rotatable around the reversing roller about the rotation axis of the reversing roller so that the guide member has an image recorded on one surface thereof by the recording means. When the recording medium is transported to the first reverse transport path, when the recording medium is transported from the first reverse transport path to the second reverse transport path, and when the recording medium is transported to the second reverse transport path. A third guide member that guides the recording medium when conveyed from the reverse conveyance path toward the recording unit and that is held on the recording unit side of the spur roller holder; The image is written And a second guide for guiding the recording medium when the recording medium is conveyed to the first reverse conveyance path and when the recording medium is conveyed from the first reverse conveyance path to the second reverse conveyance path. 1 and a second guide position for guiding the recording medium when the recording medium is conveyed from the second reverse conveying path toward the recording means. A fourth guide member held on the side of the first reversing conveyance path of the roller holder, wherein the fourth spur roller is fixed at the first spur position or the second spur position. The guide member is arranged at a first guide position, and the fourth guide member is arranged at a second guide position when the spur roller is fixed at a third spur position.
[0021]
Therefore, according to the sixth aspect of the present invention, when the spur roller is fixed at the first, second, and third spur positions, the guide member guides the recording medium to a predetermined path. Is performed reliably and stably.
[0022]
The invention according to claim 7 is the invention according to claim 6, wherein the third guide member has a first guide surface and a second guide surface,
The first guide surface guides the recording medium on which an image has been recorded on one side thereof by the recording means when the recording medium is conveyed to the first reversing conveyance path, and guides the recording medium. When the recording medium is transported from the first reverse transport path to the second reverse transport path and when the recording medium is transported from the second reverse transport path toward the recording unit, Guide the recording medium,
The fourth guide member includes a third guide surface and a fourth guide surface,
When the fourth guide member is located at the first guide position, the third guide surface moves the recording medium on which one side of the image is recorded by the recording means to the first reverse conveyance path. And when the recording medium is conveyed from the first reverse conveyance path to the second reverse conveyance path, the recording medium is guided, and the fourth guide member is connected to the second guide. When the recording medium is located at the position, the fourth guide surface guides the recording medium when the recording medium is conveyed from the second reverse conveyance path toward the recording means.
[0023]
Therefore, according to the seventh aspect of the present invention, the third guide member and the fourth guide member constituting the guide member are respectively positioned at the predetermined guide positions according to the spur position of the spur roller to guide the recording medium. Therefore, the reversing operation of the recording medium is performed reliably and stably.
[0024]
According to another aspect of the present invention, there is provided recording means for recording an image on a surface of a recording medium, conveying means for conveying the recording medium in a predetermined conveying direction toward the recording means, and recording on both surfaces of the recording medium. An image recording apparatus comprising: the recording medium reversing mechanism according to any one of claims 1 to 7 for reversing the recording medium.
[0025]
Therefore, according to the eighth aspect of the present invention, the image recording apparatus includes the recording medium reversing mechanism according to any one of the first to seventh aspects. can get.
[0026]
According to a ninth aspect of the present invention, in the invention according to the eighth aspect, the second end detecting means for detecting the second end of the recording medium is transported from the recording means to the reversing roller. It is characterized by being provided in the route.
[0027]
Therefore, according to the ninth aspect of the present invention, the second end of the recording medium is detected by the second end detecting means, so that the second end of the recording medium is connected to the spur roller and the reversing roller. Thus, the timing for pinching can be accurately set, so that the reversing operation of the recording medium is performed reliably and stably.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0029]
<Embodiment 1>
1 is a schematic cross-sectional view of an image recording apparatus according to the present invention, FIGS. 2, 4 to 7 are cross-sectional views illustrating the operation of a reversing mechanism according to the present invention mounted on the image recording apparatus, and FIG. FIG. 2 is a plan view showing only a part of the configuration of the mechanism.
[0030]
The image recording apparatus shown in FIG. 1 is an ink jet printer 50 capable of performing double-sided recording. When an image recording is instructed to the inkjet printer 50, first, the paper P, which is a recording medium stacked and accommodated in the paper feed cassette 51, is separated one by one by a paper feed roller 52, and is separated through a paper feed path 53. The sheet is conveyed to one conveying roller pair 54.
[0031]
Then, the sheet P is conveyed onto the platen 55 by the first conveying roller pair 54, and an image is formed on the surface (first surface) by the recording head 56 as recording means. Since the recording head 56 is disposed above the platen 55, the first surface is the upper surface of the sheet P in a state where the sheet P is transported onto the platen 55. Here, in the case of single-sided printing, the sheet P on which an image is formed on the first side is discharged out of the apparatus by a second pair of conveying rollers (a pair of discharging rollers) 57 and stacked on a discharging tray 58. Is done. Here, in the first transport roller pair 54 and the second transport roller pair 57, the roller (that is, the upper roller in FIG. 1) on the side that comes into contact with the first surface of the sheet P on which an image is formed by the recording head 56 is Each of them is constituted by a spur roller, and even if it comes into contact with the sheet P immediately after image formation, the roller pairs 54 and 57 are not stained. The first transport roller pair 54 has a configuration in which both upper and lower rollers are formed of rubber rollers, and when the paper P is fed backward in the direction of the reversing mechanism 11, the pressure contact is released, that is, the upper and lower rollers are separated. It may be configured.
[0032]
On the other hand, in the case of double-sided recording, the rotation direction of the second conveying roller pair 57 is rotated in the reverse direction before the sheet P on which the image is formed on the first side is completely discharged onto the discharge tray 58. As a result, the sheet P is fed backward toward the reversing mechanism 11 according to the present invention. Then, after the sheet is turned over by the reversing mechanism 11 as described later, the sheet is again conveyed to the recording head 56, and an image is formed on the back surface (second surface). The sheet P on which double-sided recording has been performed is discharged out of the apparatus by the second conveying roller pair 57, and is stacked on the sheet discharge tray 58.
[0033]
Next, the configuration of the reversing mechanism 11 according to the present invention will be described with reference to FIGS.
[0034]
In FIG. 2, reference numerals 1 and 2 denote a pair of upper and lower feed rollers which rotate while contacting each other, and these pinch a sheet P which is fed back after an image is formed on its first surface by the recording head 56. This is further fed back to the reversing mechanism 11.
[0035]
Here, the feed roller 1 is a spur roller, which is rotatably supported at a predetermined position on the inner casing 3 of the image recording apparatus 50. Spur rollers 4, 5 are rotatably supported at respective predetermined positions of the inner housing 3. A part of the inner casing 3 is formed in an arcuate curved shape, and a guide roller 6 composed of a spur roller is rotatably supported at the rear end thereof. As described above, since the image recording apparatus 50 according to the present embodiment is an ink jet printer, it is desirable that the rollers that come into contact with the image recording surface of the paper P be spur rollers. Further, a stopper 40 is formed at an end of the inner housing 3 (near the guide roller 6), which is fixing means for fixing a spur roller 18 described later at a first spur position. In the first embodiment, the stopper 40 is described only in FIG. 2, and the description is omitted in FIGS. 4 to 7. Even if the reversing roller 12 continues to rotate counterclockwise in FIG. 2, the arm 14 slides with respect to the rotation shaft 13 by the sector gear 20 fixed to the arm 14, which will be described later, coming into contact with the stopper 40. Since the spur roller 18 is fixed at the position shown in FIG. 2 to move, the spur roller 18 rotates while being fixed at the first spur position.
[0036]
By the way, the feeding rollers 1 and 2 transport the paper P along the horizontal transport path 7, and another transport path 8 is formed obliquely below the transport path 7. Another feeding roller 9 is pressed against the roller 2. The feed rollers 2 and 9 hold the sheet P, which is turned upside down as described later, and convey the sheet P along the conveyance path 8 to the recording head 56 (see FIG. 1). An image is formed by the recording head 56 on the back surface (second surface) of the paper P on which no is formed. In the present embodiment, the feed roller 9 is formed of a rubber roller or the like, but may be formed of a spur roller similarly to the feed roller 1.
[0037]
A sensor 10 for detecting the end of the sheet P is provided in the middle of the conveyance path 7 and near the feeding roller 2. When the sheet P on which an image is recorded on one surface (the first surface) by the recording head 56 is conveyed to the conveyance guide 26 which is a first reversing conveyance path described later, the sensor 10 It is a sensor that detects a second end that is the rear end.
[0038]
Thus, as shown in FIG. 1, the side (the left side in FIG. 2) facing the recording head 56 and the first transport roller pair 54 via the feed rollers 1 and 2 according to the first embodiment. A reversing mechanism 11 is provided.
[0039]
In the reversing mechanism 11 according to the first embodiment, as shown in FIG. 3, two reversing rollers 12 are fixedly arranged on one rotating shaft 13 at a predetermined interval. The two reversing rollers 12 are configured to be disposed in two gap portions 21b provided between three guide arms 21a of a transport guide 21 having a substantially “E” shape in plan view, which will be described later. The arm 14 having the rotation shaft 13 as the center of rotation is frictionally slidably mounted on the rotation shaft 13 so as to sandwich the two reversing rollers 12 and the conveyance guide 21 therebetween. The arm 14 is composed of two side portions 14d and an outer end portion 14e connecting the two side portions 14d, and has a substantially “U” shape (bridge shape) when viewed from the front. A side surface portion 14d of the arm 14 extends radially outward of the reversing roller 12 from the rotating shaft 13, and two spur rollers 18, 19 are rotatably provided at an outer end portion 14e at a position facing the reversing roller 12. The spur roller 18 is supported by the shaft, and one of the spur rollers 18 abuts on the outer periphery of the reversing roller 12 as shown in the drawing, and is driven to rotate. This spur roller 18 is the spur roller in the present invention. The other spur roller 19 guides the paper P conveyed from the recording head 56 along the conveyance path 7 toward the spur roller 18 when in the position shown in FIG. An arcuate sector gear 20 is fixed to the outer end 14e of the arm 14. An arcuate guide protrusion 14a serving as a cam member is formed inside the side surface 14d of the arm 14. In FIGS. 2, 4 to 7, the guide projection 14a is indicated by a solid line, but since it is formed inside the side surface portion 14d of the arm 14, from the viewpoint of FIGS. I can't. The arm 14 thus holds at least the spur roller 18 as the spur roller according to the present invention in a rotatable manner, and thus constitutes a spur roller holder according to the present invention.
[0040]
2 and 4 to 7, only the reversing roller 12 on the near side of the two reversing rollers 12 is illustrated, and only the side surface portion 14d on the near side of the arm 14 is illustrated. The side surface portion 14d on the opposite side of the arm 14 has the same configuration as the side surface portion 14d on the near side.
[0041]
Further, a gear 15 is connected to one end of the rotating shaft 13. However, illustration of the gear 15 is omitted in FIGS. 3, 4, and 6. As shown in FIG. 2, the gear 15 is meshed with a small-diameter drive gear 17 connected to an output shaft of a drive motor 16. Accordingly, as the drive motor 16 rotates forward and backward, the reversing roller 12 also rotates forward and backward. However, in this configuration, it goes without saying that the rotation direction of the drive motor 16 and the rotation direction of the reversing roller 12 are opposite to each other.
[0042]
Next, the transport guide 21 according to the first embodiment will be described in detail with reference to FIG. As described above, in the reversing mechanism 11 according to the first embodiment, the transport guide 21 having a substantially “E” shape in plan view is turned up and down around the shaft 22 fixed and arranged in the inner housing 3. It is movably provided. As described above, the two reversing rollers 12 are configured to be disposed in the two gaps 21b of the transport guide 21. On the lower surface of the distal end of the outer guide arm 21a, a columnar projection 23 serving as a cam follower is formed outward. The protrusion 23 is engaged with a guide protrusion 14 a formed inside the side surface portion 14 d of the arm 14. Therefore, as shown in FIGS. 5 to 7, as the arm 14 rotates clockwise around the reversing roller 12, the projection 23 of the transport guide 21 is gradually pushed down by the guide projection 14 a of the arm 14. As a result, the transport guide 21 gradually moves downward. Since the reversing roller 12 is disposed in the gap 21b, even if the transport guide 21 moves up and down, the transport guide 21 does not hinder the operation such as rotation of the reversing roller 12.
[0043]
The transport guide 21 is normally urged counterclockwise about the shaft 22 by a spring 24 as first urging means attached to the rear end. Therefore, when the arm 14 is at the position shown in FIG. 2, that is, when the spur roller 18 supported by the arm 14 is at the first spur position in FIG. 2 (substantially right above the rotating shaft 13 or the reversing roller 12), The transport guide 21 is kept horizontal by the distal end of the guide arm 21 a contacting the end of the fixed transport guide 25 and forms the transport path 7 together with the transport guide 25.
[0044]
Here, on the left side of the transport path 7 in FIG. 2, a transport guide 26 that is a first reverse transport path that is inclined further diagonally upward toward the left is provided, and the guide surface of the transport guide 26 is , And is connected to a reversing tray 27 which is a second reversing conveyance path which is set up obliquely behind the conveyance guide 26. In the present embodiment, the guide surface of the transport guide 26 is configured to be continuous with the reversing tray 27, but may be configured independently without being connected.
[0045]
Further, a plurality of spur rollers are arranged on the surface of the reversing tray 27 facing the reversing roller 12, and the spur roller and the reversing roller 27 sandwich the sheet, so that the ink adhering surface of the sheet and the reversing tray 27 are separated. It is good also as a structure which does not contact directly.
[0046]
On the other hand, a paper guide 28 serving as a second guide member is provided near the entrance of the transport path 8 so as to be rotatable around a shaft 29, and a gear 30 is integrally attached to the shaft 29. . A spring 28a serving as a second urging means is wound around the shaft 29, and always urges the paper guide 28 clockwise in FIG. Therefore, when the spur roller 18 supported by the arm 14 is at the first spur position (substantially right above the rotating shaft 13 or the reversing roller 12) as shown in FIG. 2, the paper guide 28 is moved clockwise by the spring 28a. Since it is biased, it is in the illustrated first retracted position, and blocks the entrance of the transport path 8. Note that only the spring 28a is shown in FIG. 2 and is not shown in FIGS.
[0047]
In the vicinity of the outer periphery of the reversing roller 12 and below the paper guide 28, the spur roller 18 supported by the arm 14 is moved to the third spur position shown in FIG. 5 and to the second spur position shown in FIGS. In the present embodiment, the fixing device 31 includes an electromagnetic solenoid 32 and an engaging lever 33 attached to a shaft end thereof. It is composed of
[0048]
Next, the operation of the sheet reversing mechanism 11 having the above configuration will be described.
[0049]
As shown in FIG. 2, when the spur roller 18 is at the first spur position (substantially right above the reversing roller 12 or the rotating shaft 13), the paper is conveyed from the paper cassette 51 shown in FIG. The sheet P supplied via the path 53 is nipped by a pair of upper and lower first conveying rollers (main rollers) 54 and conveyed (sequentially) on the conveying path between the platen 55 and the recording head 56. In the recording head 56, an image is formed on the surface (first surface).
[0050]
When it is instructed that an image is formed only on the first side of the sheet P, the image recording device 50 moves the sheet P on which the image is formed only on the front side, that is, one side (first side) into a pair of upper and lower sheets. The sheet P is nipped by the second conveying roller pair 57 and further conveyed (sequentially) outside the apparatus, and the sheet P is discharged onto the sheet discharge tray 58.
[0051]
However, when an image is formed on both sides of the sheet P, that is, when double-sided recording is instructed, the image recording apparatus 50 performs a reversing operation of the sheet P as follows.
[0052]
That is, when an image is formed on the front surface (first surface) of the sheet P as described above, the first transport roller pair 54 and the second transport roller pair 57 shown in FIG. , 2 also rotate so as to convey (reversely feed) the paper P toward the reversing mechanism 11. Further, as shown in FIG. 2, the reversing roller 12 of the reversing mechanism 11 is also driven in the direction shown by the arrow (counterclockwise), and the spur roller 18 that comes into contact therewith is driven to rotate in the direction shown by the arrow (clockwise). At this time, the arm 14 also attempts to rotate in the same direction as the rotation direction of the reversing roller 12 due to the frictional force with the rotating shaft 13, but the arm 14 is positioned by the sector gear 20 abutting against the stopper 40 of the internal housing 3. Is fixed, the spur roller 18 is driven to rotate at the first spur position.
[0053]
As a result, the sheet P is fed back on the transport path 7 in the direction indicated by the arrow. At this time, the leading end (the leading end in the reverse feeding direction) of the sheet P is first sandwiched between the reversing roller 12 and the spur roller 18, and the sheet P is further fed back in that state. Then, after the rear end (rear end in the reverse feeding direction) of the second end of the sheet P is detected by the sensor 10, the sheet P is further conveyed by a predetermined amount, so that the sheet P is as shown in FIG. The reverse feed is stopped in a state where a slight rear end is left, that is, in a state where the vicinity of the second end is sandwiched between the spur roller 18 and the reversing roller 12. Therefore, most of the other sheet P is placed on the transport guide 26 as shown.
[0054]
Next, in the above state, the reversing roller 12 is rotated in the direction of the arrow (clockwise) shown in FIG. That is, the drive motor 16 is driven, and its rotation is transmitted to the rotation shaft 13 via the drive gear 17 and the gear 15, thereby driving the reversing roller 12. Along with this, the arm 14 slidable with respect to the rotating shaft 13 and the spur rollers 18 and 19 supported by the same rotate together with the reversing roller 12 integrally in the direction of the arrow (clockwise) in the figure. Therefore, in a state where the vicinity of the rear end (second end) of the sheet P is sandwiched between the spur roller 18 and the reversing roller 12, the spur roller 18 is moved together with the reversing roller 12 to the third spur position shown in FIG. It is integrally rotated around the rotation shaft 13. The arm 14 is fixed by the fixing device 31 so that the spur roller 18 is fixed at the third spur position. Note that the rotation of the arm 14 at this time causes the guide projection 14 a formed on the side of the arm 14 to engage with the projection 23 of the transport guide 21, so that the transport guide 21 is pivoted against the spring 24. The arm 14 rotates around the arm 22 in the same direction as the arm 14. Therefore, with the rotation of the arm 14, the conveyance guide 21 is retracted from the guide position to the retracted position, and interference between the two is prevented. As a result, the rotation of the spur roller 18 to the third spur position is reliably performed. Done. Further, when the transport guide 21 is retracted to the retreat position, the transport guide 21 also retreats from the peripheral surface of the reversing roller 12 on which the sheet P is transported. It is also the evacuation position. The frictional resistance between the arm 14 and the rotating shaft 13 is set to be larger than the value obtained by adding the load by the spring 24 to the frictional resistance between the transport guide 26 and the sheet P.
[0055]
When the arm 14 rotates so that the spur roller 18 rotates from the first spur position to the third spur position as described above, the sector gear 20 fixed to the arm 14 rotates the shaft of the paper guide 28. The gear 29 meshes with the gear 30 connected to the gear 29, and rotates the paper guide 28 counterclockwise around the shaft 29 against the spring 28a. As a result, the paper guide 28 is separated from the paper P in order to guide the paper P from the transport guide 26 as the first reverse transport path to the reverse tray 27 as the second reverse transport path, as shown in FIG. To the retracted position). In the paper guide 28, the first retreat position shown in FIG. 2 or FIG. 4 and the second retreat position shown in FIG. That is, regardless of whether the paper guide 28 is located at the first retracted position or the second retracted position, the paper guide 28 is separated and retracted from the paper P.
[0056]
As described above, when the spur roller 18 supported by the arm 14 moves to the third spur position and the arm 14 is fixed by the fixing device 31, the spur roller 18 is positioned and fixed at the third spur position. The paper P whose rear end (second end) is sandwiched by the reversing roller 12 and the spur roller 18 is further rotated in the direction of the arrow (clockwise) shown in FIG. Along the outer circumference of the reversing roller 12, a state is sandwiched between the reversing roller 12 and the spur roller 18 that is driven to rotate, from the conveyance guide 26 as the first reversing conveyance path to the reversing tray 27 as the second reversing conveyance path. Conveyed.
[0057]
That is, the sheet P on the transport guide 26 is turned over until the vicinity of the front end (first end) of the sheet P is sandwiched between the spur roller 18 and the reversing roller 12 in the state where the sheet guide 28 is shown in FIG. The sheet is conveyed to the tray 27. At this time, the spur roller 19 guides the sheet P to be conveyed to the reversing tray 27. Further, a plurality of transport rollers (not shown) are arranged inside the transport path of the reversing tray 27 to easily transport the paper P.
[0058]
Here, the state in which the vicinity of the front end (first end) of the sheet P is sandwiched by the spur roller 18 and the reversing roller 12 means, as shown in FIG. The state in which the sheet P is nipped by the roller 18 and the reversing roller 12. The slight length of the end portion varies depending on the roller diameter and the transport amount, but may be appropriately set according to the specifications of the image recording apparatus 50.
[0059]
Then, in FIG. 5, when the vicinity of the front end (first end) of the sheet P is nipped by the spur roller 18 and the reversing roller 12, the fixing device 31 releases the fixing of the arm 14. Accordingly, the positioning and fixing of the spur roller 18 at the third spur position is also released.
[0060]
On the other hand, the reversing roller 12 is further rotated in the arrow direction (clockwise direction) shown in FIG. 5 so that the vicinity of the front end (first end) of the sheet P is pinched by the spur roller 18 and the reversing roller 12. In this state, the spur roller 18 rotates to the second spur position as shown in FIG. That is, until the vicinity of the front end (first end) of the sheet P is sandwiched between the spur roller 18 and the reversing roller 12 at the third spur position, the sheet guide 28 is in the state shown in FIG. After the sheet P is pinched near the front end (first end), the reversing roller 12 is further rotated clockwise to move the spur roller 18 to the second spur position. Move it up.
[0061]
If the spur roller 18 is rotated from the first spur position to the second spur position without stopping at the third spur position, the paper guide 28 rotates to the guide position shown in FIG. This is because P cannot be transported from the transport guide 26 to the reversing tray 27. Then, in order to position and fix the spur roller 18 at the second spur position, the fixing device 31 fixes the arm 14 again.
[0062]
Next, when the reversing roller 12 is rotated in the illustrated arrow direction (counterclockwise) as shown in FIG. 7 from the above state, the reversing roller 12 and the spur roller 18 cause the rear end (second end). The paper P whose neighborhood is nipped is guided by the paper guide 28 with its rear end (second end) first, and is introduced into the transport path 8, and the feeding roller provided in the middle of the transport path 8 The recording paper is conveyed toward the recording head 56 (see FIG. 1) by the recording heads 2 and 9. At this time, the sheet P is turned upside down, and the first conveyance (the front side) on which the recording is already performed is turned down, and the first conveyance is performed with the second side (the back side) on which the recording is not yet performed facing up. The sheet is conveyed to the recording head 56 via the roller pair 54, and the recording head 56 performs recording on the second surface.
[0063]
As described above, the paper P on which recording has been performed on both sides is discharged to the discharge tray 58 shown in FIG. When such double-sided recording is performed continuously, after the leading end (first end) of the sheet P is introduced into the transport path 8, the arm 14 by the fixing device 31 in the state shown in FIG. The arm 14 and the spur rollers 18 and 19 move along the outer circumference of the reversing roller 12 around the rotation shaft 13 with the counterclockwise rotation of the reversing roller 12 and the state shown in FIG. Then, the same operation as described above is repeated, and an image is formed on both sides of the sheet P.
[0064]
As described above, the reversing mechanism 11 according to the present embodiment includes the reversing roller 12 and the spur 18, and rotates the spur roller 18 around the reversing roller 12 to thereby rotate the rear end of the sheet P (the second end). The sheet P is first conveyed in a state where the vicinity of the end portion) is sandwiched, and the sheet P is reversed by being conveyed from the conveyance guide 26 to the reversing tray 27, so that the sheet P is placed inside the ink jet printer 50 as an image recording apparatus. There is no need to provide a reversing path longer than the length, so that the reversing mechanism 11 can be made more compact, reducing its installation space and realizing double-sided recording with a simple configuration.
[0065]
Further, by detecting the rear end (second end) of the sheet P by the sensor 10, the amount of the sheet P to be fed backward from the nip portion between the reversing roller 12 and the spur roller 18 (the remaining sheet P ) Can be set accurately, so that the subsequent reversal of the sheet P can be performed stably and reliably.
[0066]
Further, the paper guide 28 is rotated in conjunction with the rotation of the arm 14 and the spur rollers 18 and 19 around the rotation axis 13, and when the spur roller 18 is at the second spur position, the paper guide 28 removes the sheet P. Since the sheet P is guided to the transport path 8, the sheet P is always inverted.
[0067]
Further, in the present embodiment, since the fixing device 31 for fixing the spur roller 18 at the third spur position and the second spur position by contacting the arm 14 is provided, the spur roller 18 is fixed by the fixing device 31. Is reliably fixed at the third spur position and the second spur position, and as a result, the reversal of the sheet P is stably and reliably performed.
[0068]
Further, in the present embodiment, the two reversing rollers 12 and the conveyance guide 21 having a substantially “E” shape in plan view are employed, but the number of reversing rollers may be one or three or more. In that case, the transport guide 21 may also form the guide arm 21a and the gap 21b according to the number of the reversing rollers 12.
[0069]
4, 6, and 7, the illustration of the transport guide 21 is omitted.
[0070]
<Embodiment 2>
Next, a second embodiment of the present invention will be described.
[0071]
8 to 13 are cross-sectional views for explaining the operation of the reversing mechanism 110 according to the present embodiment. In these drawings, the same elements as those shown in FIGS. The reference numerals are used, and the description thereof will be omitted as appropriate.
[0072]
In the reversing mechanism 110 according to the present embodiment, another conveying path 8 is formed obliquely below the conveying path 7, and another feeding roller 9 made of a rubber roller is pressed against the feeding roller 2. I have. The feed rollers 2 and 9 hold the paper P, which is turned upside down, and convey it along the conveyance path 8 as described later.
[0073]
The reversing mechanism 110 according to the present embodiment is provided on the side (the left side in FIG. 8) facing the recording head 56 and the first transport roller pair 54 via the feed rollers 1 and 2.
[0074]
In the reversing mechanism 110 according to the present embodiment, a reversing roller 12 is rotatably provided in the same manner as the reversing mechanism 11 according to the first embodiment. As in the first embodiment, the arm 14 is slidably attached. Although not shown in FIG. 8 and subsequent figures, a mechanism (gear or drive motor) for driving the reversing roller 12 is also provided in the second embodiment similarly to the first embodiment. Needless to say. The arm 14 is also formed in a substantially “U” shape as viewed from the front, similarly to the first embodiment.
[0075]
Further, a guide arm 34 is pivotally supported on the arm 14 so as to be rotatable around a shaft 35 fixedly arranged on the arm 14. The guide arm 34 is also formed in a substantially “U” shape in a front view similarly to the arm 14, and is arranged so as to further sandwich the arm 14 arranged so as to sandwich the reversing roller 12. Further, stoppers 14b and 14c for positioning the guide arm 34 are formed on the side surface 14d of the arm 14. Therefore, the position of the guide arm 34 is fixed by contacting the stopper 14b or the stopper 14c, and the guide arm 34 is rotatable about the shaft 35 between the stoppers 14b and 14c. Note that the guide arm 34 is also slidable with respect to the arm 14 so that it is always stationary with respect to the arm 14.
[0076]
A guide portion 34a as a fourth guide member is formed at the tip of the guide arm 34. When the spur roller 18 supported by the arm 14 is at the first spur position as shown in FIG. The distal end of the arm 34 is engaged with a projection 3a formed at the rear end of the internal housing 3 of the image recording device 50 as shown in the figure. At this time, the guide arm 34 is also in contact with the stopper 14c of the arm 14. In the state shown in FIG. 8, since the lower surface 34b, which is the third guide surface of the guide portion 34a, is separated from the surface of the reversing roller 12, the paper P is transported from the transport path 7 via the feed rollers 1 and 2. When transported to the guide 26, the sheet P is guided by the lower surface 34b of the guide portion 34a and the spur roller 18. The position of the guide portion 34a in FIG. 8 is the first guide position. Note that the sheet P is transported from the transport path 7 to the transport guide 26 in a state where a plurality of portions are sandwiched between the reversing roller 12 and the spur roller 18. Therefore, when the guide portion 34 a is at the first guide position, The entire P is guided by the lower surface 34b and the spur roller 18.
[0077]
A side surface portion 14d of the arm 14 extends radially outward from the rotation shaft 13, and two spur rollers 18 and 19 are rotatably supported at the outer end thereof. As shown in the drawing, the roller rotates in accordance with the outer periphery of the reversing roller 12. This spur roller 18 is the spur roller in the present invention. In the vicinity of the arm 14, a paper guide 36 as a third guide member is rotatably supported about a shaft 37, and this paper guide 36 cooperates with the arm 14 to rotate the rotating shaft 13 of the reversing roller 12. It rotates along the outer periphery of the reversing roller 12 as a center. Although not shown, the shaft 37 is supported by the arm 14. The paper guide 36 includes a flat surface 36a serving as a first guide surface and a peripheral surface 36b serving as a second guide surface. Here, the flat surface 36a of the paper guide 36 is a surface that guides the paper P on which an image is recorded on one side thereof by the recording head 56 when the paper P is transported to the transport guide 26 which is a first reverse transport path. When the sheet P is conveyed from the conveyance guide 26 to the reversing tray 27, which is the second reversing conveyance path, and when the sheet P is conveyed from the reversing tray 27 toward the recording head 56. The surface for guiding the sheet P. The paper guide 36 is always disposed at a position shown in FIG. 9 (a state in which the peripheral surface 36b is in contact with the peripheral surface of the reversing roller 12) by a spring 37a wound around a shaft 37. As shown in FIGS. 10 to 13, when abutting against the abutting portion 27 a provided on the inner housing 3, the peripheral surface 36 b is arranged at a position separated from the peripheral surface of the reversing roller 12. The spring 37a is shown only in FIG. 8, and is not shown in FIGS.
[0078]
Arms for fixing the spur roller 18 at the third spur position shown in FIG. 11 and the second spur position shown in FIG. A fixing device 31 is provided as fixing means for abutting and fixing to the fixing member 14. In the present embodiment, the fixing device 31 includes an electromagnetic solenoid 32 and an engaging lever 33 attached to a shaft end thereof. Have been.
[0079]
Next, the operation of the reversing mechanism 110 having the above configuration will be described.
[0080]
The process until the sheet P having an image formed on its surface (first surface) by the recording head 56 is conveyed to the reversing mechanism 110 is the same as that of the first embodiment, and the description is omitted here.
[0081]
When the sheet P is conveyed to the reversing mechanism 110, as shown in FIG. 8, the reversing roller 12 of the reversing mechanism 110 is driven in the direction indicated by the arrow (counterclockwise), and the spur roller 18 which comes into contact therewith is moved by the arrow shown in the figure. It rotates in the direction (clockwise). At this time, the arm 14 also tries to rotate in the same direction as the reversing roller 12, but since the arm 14 is fixed by the protrusion 3a of the inner casing 3, the spur roller 18 is driven to rotate at the first spur position. become. As a result, the sheet P is fed back on the transport path 7 in the direction indicated by the arrow. At this time, the leading end (the leading end in the reverse feeding direction) of the sheet P, which is the first end, is first pinched by the reversing roller 12 and the spur roller 18, and the sheet P is further fed back in that state. Then, after the rear end (rear end in the reverse feed direction) of the sheet P, which is the second end, is detected by the sensor 10, the sheet P is further conveyed by a predetermined amount, so that the sheet P becomes as shown in FIG. Reverse feeding is stopped in a state where a slight rear end is left, that is, in a state where the vicinity of the second end is held between the spur roller 18 and the reversing roller 12. Accordingly, most of the other sheet P is placed on the transport guide 26 as shown.
[0082]
When the paper guide 36 is at the position shown in FIGS. 8 and 9, the paper guide 36 guides the paper P that is reversely fed on the transport path 7 by the above-described flat surface 36a serving as the first guide surface. .
[0083]
Next, in the above state, the reversing roller 12 is rotated in the direction of the arrow (clockwise) shown in FIG. Along with this, the arm 14 slidable with respect to the rotating shaft 13 and the spur rollers 18 and 19 supported by the same rotate together with the reversing roller 12 integrally in the direction of the arrow (clockwise) in the figure. Accordingly, in a state where the vicinity of the rear end (second end) of the sheet P is sandwiched between the spur roller 18 and the reversing roller 12, the spur roller 18 moves together with the reversing roller 12 to the third spur position shown in FIG. It is integrally rotated around the rotation shaft 13. The arm 14 is fixed by the fixing device 31 so that the spur roller 18 is fixed at the third spur position. At this time, since the paper guide 36 comes into contact with the contact portion 27a, the paper guide 36 rotates about the shaft 37 against the spring 37a. As a result, the peripheral surface 36b of the paper guide 36 is disposed at a position separated from the peripheral surface of the reversing roller 12, and the peripheral surface 36b moves the paper P from the transport guide 26 to the reversing tray 27 serving as a second reversing transport path. When the sheet P is conveyed, the sheet P is guided. The frictional resistance between the arm 14 and the rotating shaft 13 is set to be larger than the value obtained by adding the load by the spring 37a to the frictional resistance between the transport guide 26 and the paper P.
[0084]
As described above, the spur roller 18 supported by the arm 14 moves to the third spur position shown in FIG. 10, and the spur roller 18 is positioned at the third spur position by the arm 14 being fixed by the fixing device 31. When the paper P is fixed, the paper P, whose rear end (the second end) is sandwiched by the reversing roller 12 and the spur roller 18, is driven to rotate in the direction of the arrow (clockwise) shown in FIG. 11. As a result, while being sandwiched between the reversing roller 12 and the spur roller 18 that is driven to rotate, the paper is sequentially fed along the outer periphery of the reversing roller 12 toward the reversing tray 27 as a second reversing conveyance path. As shown in (2), the conveyance is stopped in a state where the vicinity of the rear end is nipped by the reversing roller 12 and the spur roller 18.
[0085]
Next, as shown in FIG. 12, the arm 14 and the spur rollers 18 and 19 and the guide arm 34 are rotated in the directions indicated by the arrows in the above state, and the arm 14 and the spur rollers 18 and 19 are fixed at the second spur position. While being positioned and fixed by the device 31, the guide arm 34 is brought into contact with the stopper 14b of the arm 14 to position it, and the lower surface 34b of the guide portion 34a is brought into close contact with the outer periphery of the reversing roller 12 as shown in the figure.
[0086]
When the reversing roller 12 is rotated in the direction shown by the arrow (counterclockwise) in the state shown in FIG. 12, the vicinity of the rear end (second end) of the reversing roller 12 and the spur roller 18 is adjusted. The nipped paper P is guided by the guide portion 34 a of the guide arm 34 with its rear end first, and is introduced into the transport path 8. As a result, the inverted sheet P is transported through the transport path 8 to the recording head 56 shown in FIG. At this time, the sheet P is also guided by the peripheral surface 36b as the second guide surface of the sheet guide 36.
[0087]
When the leading end (first end) of the sheet P is guided to the transport path 8, the fixing of the arm 14 by the fixing device 31 is released. Further, when the reversing roller 12 rotates in the direction indicated by the arrow (counterclockwise), the arm 14, the guide arm 34, and the paper guide 36 are integrally rotated counterclockwise to the position shown in FIG. 8 or FIG. Go to
[0088]
Therefore, also in the reversing mechanism 110 according to the present embodiment, the sheet P is turned upside down so that the first surface (front surface) on which recording has already been performed is turned down, and the second surface (recording has not yet been performed) is performed. The recording medium is conveyed to the recording head 56 via the first conveying roller pair 54 with the back surface facing upward, and the recording head 56 performs recording on the second surface.
[0089]
As described above, the paper P on which recording has been performed on both sides is discharged to the discharge tray 58 shown in FIG. When such double-sided printing is performed continuously, the operation described in the second embodiment described above is repeatedly executed, and images are formed on both sides of a plurality of sheets P.
[0090]
As described above, the reversing mechanism 110 according to the present embodiment also includes the reversing roller 12 and the spur roller 18 as in the first embodiment, and rotates the spur roller 18 around the reversing roller 12. Since the sheet P is first conveyed while holding the vicinity of the rear end (second end) of the sheet P, and the sheet P is further conveyed from the conveyance guide 26 to the reversing tray 27, the image is inverted. There is no need to provide a reversing path longer than the paper length inside the ink jet printer 50 as a recording device, so that the reversing mechanism 11 can be made compact and the installation space can be reduced. Recording can be realized.
[0091]
In the second embodiment, the lower surface 34b of the guide portion 34a is configured to be in contact with the peripheral surface of the reversing roller 12, but between the plurality of reversing rollers 12 fixed to the rotating shaft 13 at a predetermined interval. The lower surface 34b of the guide portion 34a may be configured to enter slightly inside the height of the peripheral surface of the reversing roller 12. That is, the guide portion 34a has a substantially "E" shape in plan view like the transport guide 21 shown in FIG. 3, and a portion such as the guide arm 21a is inserted between the reversing rollers 12. With this configuration, the sheet P is more stably conveyed by the guide portion 34a.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of an image recording apparatus according to the present invention.
FIG. 2 is an operation explanatory view of the reversing mechanism according to the first embodiment of the present invention.
FIG. 3 is a plan view showing a part of the reversing mechanism according to the first embodiment of the present invention.
FIG. 4 is an operation explanatory view of the reversing mechanism according to the first embodiment of the present invention.
FIG. 5 is an operation explanatory view of the reversing mechanism according to the first embodiment of the present invention.
FIG. 6 is an operation explanatory view of the reversing mechanism according to the first embodiment of the present invention.
FIG. 7 is an operation explanatory view of the reversing mechanism according to the first embodiment of the present invention.
FIG. 8 is an operation explanatory view of a reversing mechanism according to Embodiment 2 of the present invention.
FIG. 9 is an operation explanatory view of a reversing mechanism according to Embodiment 2 of the present invention.
FIG. 10 is an operation explanatory view of a reversing mechanism according to Embodiment 2 of the present invention.
FIG. 11 is an operation explanatory view of a reversing mechanism according to Embodiment 2 of the present invention.
FIG. 12 is an operation explanatory view of a reversing mechanism according to Embodiment 2 of the present invention.
FIG. 13 is an operation explanatory view of the reversing mechanism according to the second embodiment of the present invention.
FIG. 14 is a schematic view showing a conventional example 1 of a reversing mechanism.
FIG. 15 is a schematic diagram showing a second conventional example of the reversing mechanism.
FIG. 16 is a schematic diagram showing a third conventional example of the reversing mechanism.
[Explanation of symbols]
1, 2 feed roller
3 Internal housing
7, 8 transport path
9 Feed roller
10 sensors
11,110 Inversion mechanism
12 Reverse roller
13 Rotation axis
14 Arm (Spur roller holder)
14a Guide protrusion (cam member)
18,19 spur roller
21 transport guide (first guide member)
23 Projection (Cam Follower)
24 spring (first biasing means)
26 Transport guide (first reverse transport path)
27 Reverse tray (second reverse transport path)
27a contact part
28 Paper Guide (Second Guide Member)
28a spring (second biasing means)
31 Fixing device (fixing means)
34 Guide arm
34a Guide part (fourth guide member)
34b Lower surface (third guide surface)
36 Paper Guide (Third Guide Member)
36a plane (first guide surface)
36b Peripheral surface (second guide surface)
37 axes
37a spring
50 Image recording device
51 Paper cassette
52 Paper feed roller
54 First Transport Roller Pair
56 recording head (recording means)
57 Second transport roller pair
P paper (recording medium)

Claims (9)

The image forming apparatus is mounted on an image recording apparatus including a recording unit that records an image on a surface of a recording medium, and a transport unit that transports the recording medium in a predetermined transport direction toward the recording unit, and performs recording on both sides of the recording medium. In a recording medium reversing mechanism for reversing a recording medium on which an image is recorded on one side by the recording means,
A reversing roller rotatable in a first rotation direction and a second rotation direction opposite to the first rotation direction to reverse the recording medium;
While rotating in contact with the reversing roller, the recording medium can be sandwiched between the reversing roller and the periphery of the reversing roller about the rotation axis of the reversing roller as a center from a first spur position to a second spur position. A spur roller that can rotate to the spur position of
A first reverse conveyance path on which a recording medium on which an image is recorded on one side by the recording means is conveyed;
A second reversing conveyance path on which the recording medium is conveyed from the first reversing conveyance path,
When the spur roller is at the first spur position, the reversing roller rotates in a first rotation direction, whereby the recording medium on which one side of the recording medium has been recorded by the recording means is subjected to the first reversal. Transport to the transport path,
As the reversing roller rotates in the second rotation direction, the spur roller rotates from the first spur position to the second spur position, and the recording medium is moved from the first reversing conveyance path to the second spur position. Transported to a second reverse transport path,
When the spur roller is at the second spur position, the reversing roller rotates again in the first rotational direction, thereby reversing and conveying the recording medium toward the recording means. Inversion mechanism. The spur roller can be positioned at a third spur position between a first spur position and a second spur position, and further includes fixing means for fixing the spur roller at each of the three spur positions.
When the spur roller is fixed at the first spur position by the fixing means, the reversing roller rotates in a first rotation direction, whereby a recording medium having an image recorded on one side thereof by the recording means. After the first end of the first spur has passed through the spur roller, the first end of the first end until the second end near the other end is sandwiched between the reversing roller and the spur roller. Transport to the reverse transport path,
By rotating the reversing roller in the second rotation direction, the spur roller is moved from the first spur position to the third spur while the vicinity of the second end of the recording medium is sandwiched between the spur roller and the recording medium. After rotating to the position, the fixing means fixes the spur roller to the third spur position, and furthermore, the reversing roller is rotated until the vicinity of the first end is sandwiched between the reversing roller and the spur roller. The recording medium is transported from the first reverse transport path to the second reverse transport path by rotating in the rotation direction of 2, and
After the fixing means releases the fixation of the third spur position of the spur roller in a state where the vicinity of the first end of the recording medium is held between the spur roller and the spur roller, the reversing roller further moves in the second rotational direction. By rotating the spur roller from the third spur position to the second spur position, the fixing means fixes the spur roller at the second spur position,
2. The recording medium reversing mechanism according to claim 1, wherein the recording medium is reversed and conveyed toward the recording unit by rotating the reversing roller again in the first rotation direction. A guide member that rotates integrally with the spur roller around the reversing roller,
When the spur roller is fixed at the first spur position, the guide member operates such that the recording medium having an image recorded on one side thereof by the recording means is transported to the first reverse transport path. Guide the recording medium,
When the spur roller is fixed at the third spur position, the guide member guides the recording medium such that the recording medium is conveyed from the first reverse conveying path to the second reverse conveying path. And
When the spur roller is fixed at the second spur position, the guide member guides the recording medium so that the recording medium is conveyed from the second reverse conveyance path toward the recording unit. 3. The reversing mechanism of a recording medium according to claim 2, wherein: The spur roller is rotatably held and the spur roller is rotatable from a first spur position to a second spur position via a third spur position, about a rotation axis of the reversing roller. Further comprising a spur roller holder rotatable around the reversing roller,
The guide member is
With the rotation of the spur roller holder, a guide position for guiding the recording medium having an image recorded on one side thereof by the recording means to the first reversing conveyance path, and the recording medium is moved to the first reversing conveyance path. Is held rotatably between a position where the recording medium is conveyed to the second reversing conveyance path and a position where the recording medium is conveyed from the second reversing conveyance path toward the recording unit. A first guide member,
With the rotation of the spur roller holder, at least when the recording medium is conveyed from the first reversing conveyance path to the second reversing conveyance path, a retreat position for retreating away from the recording medium; A second guide member rotatably held between a guide position for guiding the recording medium toward the recording means when the recording medium is conveyed toward the recording means from the second reverse conveyance path; Consisting of
When the spur roller is fixed at the first spur position, the first guide member is disposed at the guide position,
When the spur roller is fixed at a third spur position, the first guide member and the second guide member are arranged at respective retracted positions,
When the spur roller is fixed at a second spur position, the first guide member is disposed at a retracted position, and the second guide member is disposed at a guide position. Item 4. A reversing mechanism of a recording medium according to Item 3. The spur roller holder,
A cam portion abutting on the first guide member;
A first gear portion meshable with the second guide member;
The first guide member includes:
A first guide main body that is rotatable about a first rotation axis fixedly arranged in the reversing mechanism, and guides a recording medium on one surface thereof;
First urging means for urging the first guide main body to be always located at the guide position;
A cam follower portion fixedly disposed on the first guide body portion and abutting on a cam member of the spur roller holder;
The second guide member includes:
A second guide body that is rotatable about a second rotation shaft fixedly arranged in the reversing mechanism, and guides the recording medium on one surface thereof;
Second urging means for urging the second guide body to always be located at the retracted position;
A second gear portion that rotates integrally with the second guide body portion and can mesh with the first gear portion of the spur roller holder;
5. The reversing mechanism of a recording medium according to claim 4, comprising: The spur roller is rotatably held and the spur roller is rotatable from a first spur position to a second spur position via a third spur position, about a rotation axis of the reversing roller. Further comprising a spur roller holder rotatable around the reversing roller,
The guide member is
When the recording medium having an image recorded on one side thereof by the recording means is transported to the first reverse transport path, and when the recording medium is transported from the first reverse transport path to the second reverse transport path. And when the recording medium is conveyed from the second reverse conveyance path toward the recording means, the third medium held on the recording means side of the spur roller holder for guiding the recording medium. A guide member,
When the recording medium on which an image is recorded on one side of the recording medium is conveyed to the first reverse conveying path, and when the recording medium is conveyed from the first reverse conveying path to the second reverse conveying path. And a second guide position for guiding the recording medium when the recording medium is conveyed from the second reverse conveyance path toward the recording means. A fourth guide member rotatably held between the spur roller holder and the first reversing conveyance path.
When the spur roller is fixed at the first spur position or the second spur position, the fourth guide member is disposed at the first guide position,
4. The recording medium reversing mechanism according to claim 3, wherein the fourth guide member is arranged at a second guide position when the spur roller is fixed at a third spur position. The third guide member includes a first guide surface and a second guide surface,
The first guide surface guides the recording medium on which an image has been recorded on one side thereof by the recording means when the recording medium is conveyed to the first reversing conveyance path, and guides the recording medium. When the recording medium is transported from the first reverse transport path to the second reverse transport path and when the recording medium is transported from the second reverse transport path toward the recording unit, Guide the recording medium,
The fourth guide member includes a third guide surface and a fourth guide surface,
When the fourth guide member is located at the first guide position, the third guide surface moves the recording medium on which one side of the image is recorded by the recording means to the first reverse conveyance path. And when the recording medium is conveyed from the first reverse conveyance path to the second reverse conveyance path, the recording medium is guided, and the fourth guide member is connected to the second guide. When located at a position, the fourth guide surface guides the recording medium when the recording medium is conveyed from the second reverse conveyance path toward the recording means. 7. The reversing mechanism of the recording medium according to 6. Recording means for recording an image on a surface of a recording medium;
Conveying means for conveying the recording medium in a predetermined conveying direction toward the recording means,
A recording medium reversing mechanism according to any one of claims 1 to 7, wherein the recording medium is reversed for recording on both sides of the recording medium.
An image recording apparatus comprising: 9. The image according to claim 8, wherein a second end detecting means for detecting the second end of the recording medium is provided in a recording medium transport path from the recording means to the reversing roller. Recording device.

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