JP5148461B2 - Image recording device - Google Patents

Description

  The present invention relates to an image recording apparatus, and more particularly, to a paper guide roller cleaning mechanism of an image recording apparatus that can set a plurality of intervals between a head and a transport mechanism.

  2. Description of the Related Art In recent years, an ink jet printer using an ink jet recording head is generally known as an image recording apparatus that records an image simply and inexpensively. In this ink jet printer, a nozzle array formed by a plurality of nozzles is arranged over a length longer than the width of the recording medium in order to improve the recording speed, and ink is sequentially ejected onto the conveyed recording medium. However, some perform image recording.

  Here, the use environment of the ink jet printer is not limited to the office but is exposed to various use environments. When the recording medium is left in a high temperature and high humidity environment for a long time without packaging, the recording medium absorbs moisture, and the end of the cut sheet-shaped recording medium is warped in a half-curl shape. When the recording medium having the curled end portion is passed through the ink jet printer, the curled portion at the leading end portion of the recording medium is rubbed against the nozzle surface of the recording head, and the end portion of the recording medium. Or the problem of soiling the printing surface occurs.

  Further, when the leading end of the curled recording medium comes into contact with the side surface of the recording head or the like, the recording medium often becomes jammed and paper feeding is often unstable. Further, when a recording medium having a stiff stiffness such as cardboard collides with the recording head in a curled state, the recording head may be damaged.

In order to solve such a problem, there is a technique of installing a paper pressing roller for preventing the recording medium from floating on the upstream side in the transport direction from the head as disclosed in Patent Document 1 below.
Japanese Patent Laid-Open No. 7-53082

  By the way, in an ink jet printer, image recording is performed by ejecting ink from a fine ejection port onto a recording medium. However, not all of the ejected ink reaches the recording medium, and some of the ink droplets May separate and become ink mist floating in the apparatus without reaching the recording medium. The ink mist floating in these apparatuses adheres to some part in the apparatus with time. In particular, there is a high probability of adhering to a roller for preventing a recording medium arranged near the head from floating, and dirt accumulates over time. When the recording medium comes into contact in such a state, the ink is retransferred to the recording medium, and the quality of the recorded image is deteriorated.

  Therefore, the present invention has been made in view of the above problems, and its purpose is to clean the surface of a roller arranged to prevent the recording medium from floating by using a simple configuration and an existing mechanism. It is an object of the present invention to provide an image recording apparatus that can carry out and maintain stable print quality.

  An image recording apparatus of the present invention includes a conveyance mechanism having a conveyance belt that conveys a recording medium, and an image recording unit having a line head that is disposed to face the conveyance mechanism and includes one or a plurality of recording heads. A paper guide that is provided in the image recording unit, is disposed upstream of the line head in the conveyance direction of the recording medium, and includes a paper guide roller that rotates in contact with the conveyance belt, and a cleaning member that cleans the paper guide roller. The transport mechanism and the image recording unit are arranged such that the distance between the mechanism, the transport mechanism, and the image recording unit is a first position where an image is recorded on the recording medium and a second position different from the first position. A moving mechanism that moves at least one of the first and second portions, and in the first position, the paper guide roller and the conveying belt are in contact with each other, and the paper guide roller and the cleaning member are not in contact with each other, The second position, the paper guide roller and the conveyor belt comes into contact, and a paper guide roller and the cleaning member, characterized in that the contact.

  According to the present invention, by using a simple configuration and an existing mechanism, it is possible to provide an image recording apparatus capable of cleaning the roller surface and maintaining stable print quality.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
First, a first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 shows a schematic configuration of an image recording apparatus according to a first embodiment of the present invention. (A) is a schematic side view showing a state of a cleaning position of a sheet guide roller of the image recording apparatus. b) is a schematic side view showing the state of the image recording position of the image recording apparatus, and (c) is a schematic side view showing the state of the non-recording position of the image recording apparatus. FIG. 2 is a diagram showing the shape of the platen. FIG. 3 is a view of the image recording unit as viewed from below. 4A and 4B show details of the paper guide mechanism. FIG. 4A is a view seen from the transport direction, and FIG. 4B is a side view of the paper guide mechanism. 5A and 5B show the positional relationship between the paper guide mechanism and the transport mechanism as seen from the transport direction. FIG. 5A shows the positional relationship in the cleaning state of the paper guide roller, and FIG. 5B shows the image recording. The figure which showed the positional relationship in a state, (c) is the figure which showed the positional relationship in a non-image recording state.

  FIG. 6 is a perspective view of the gap adjusting mechanism in the first embodiment of the present invention. FIG. 7 is a cross-sectional view showing a state in which the gap adjusting mechanism is attached to the head unit. FIG. 8 is an external perspective view of the guide piece. FIG. 9 is a perspective view of the adjustment piece, and (a) and (b) are views shown from different angles. FIG. 10 is an enlarged perspective view showing a state in which the protrusion is engaged with the groove of the guide piece. FIG. 11 is an enlarged perspective view showing only the bottom surface of the adjustment piece. FIGS. 12A and 12B illustrate the bottom surface of the adjustment frame. FIG. 12A is a plan view seen from the bottom surface side of the adjustment frame, and FIG. 12B is a view of the guide frame along the line FF ′ in FIG. Sectional drawing of a contact part, (c) is sectional drawing of the contact part with the guide piece along the GG 'line of (a). FIGS. 13A and 13B illustrate the bottom surface of the guide frame. FIG. 13A is a plan view seen from the bottom surface of the guide frame, and FIG. 13B corresponds to the adjustment frame along the line H-H 'in FIG. Sectional drawing of a contact part, (c) is sectional drawing of the contact part with the adjustment piece along the II 'line of (a). FIG. 14 is a plan view showing an engaged state between the guide piece and the adjustment piece. FIG. 15 is a cross-sectional view showing an engaged state between the guide piece and the adjustment piece. FIG. 16 is a diagram for explaining the operation of the gap adjusting mechanism in the first embodiment of the present invention, and is a view in which a guide piece is developed along the outer peripheral surface. FIG. 17 is a diagram showing the positional relationship between the adjustment piece and the guide piece during the operation of the gap adjustment mechanism.

  In the present embodiment, the recording medium conveyance direction is the X direction, the direction orthogonal to the X direction is the Y direction or the width direction, and the direction orthogonal to the X direction and the Y direction is the Z direction or the vertical direction. Shall be referred to as

  In this embodiment, the image recording apparatus 10 is roughly divided into a supply unit 11, an image recording unit 12, a transport mechanism 13, an elevating mechanism 14, and a discharge unit 15. .

  First, the supply unit 11 will be described.

  The supply unit 11 includes a paper feed table 22 that accommodates the recording medium 21, a paper feed roller 23, and a registration roller pair 24.

  The paper feed roller 23 is also referred to as a pickup roller, and comes into contact with the recording medium 21 accommodated in the paper feed table 22 and sequentially takes out the recording medium 21 to the image recording unit 12 one by one.

  The registration roller pair 24 includes a pair of upper and lower registration rollers 24 a and 24 b, and is arranged so that the upper surface of the lower registration roller 24 b is substantially flush with the conveyance path extension line of the recording medium 21. Yes. Further, a registration roller 24a biased by a spring (not shown) is provided above the registration roller 24b so as to press the registration roller 24b downward.

  The support shafts of the registration roller 24a and the registration roller 24b are substantially parallel. Further, the registration roller pair 24 is arranged so that the recording medium 21 is conveyed in the conveyance direction (X-axis direction) when the leading end of the recording medium 21 fed by the paper feeding roller 23 comes into contact with the nip portion of the registration roller pair 24. ) Is corrected (corrected), and then the recording medium 21 is conveyed to the conveying mechanism 13 in accordance with the image recording timing in the image recording unit 12 described later.

  Next, the image recording unit 12 will be described.

  In this embodiment, for example, the image recording unit 12 is a head unit 31 (31C, 31K, 31M) that ejects ink of four colors (cyan (C), black (B), magenta (M), yellow (Y)). , 31Y), a head holding member 32 for holding the head portion 31, and a paper guide mechanism 40.

  As shown in FIG. 3, the head holding member 32 is provided with a plurality of openings 35. A short recording head (not shown) is positioned and fixed in the opening 35. Accordingly, the head unit 31 constitutes a line head that is equal to or more than the recording area in which image recording is performed in the width direction of the recording medium 21.

  In the present embodiment, six recording heads for each color are arranged in a staggered manner in the direction (Y direction) orthogonal to the transport direction, and the head unit 31 that is equal to or larger than the width of the recording medium 21 is configured. . Of course, the number of recording heads is not limited to this, and the head unit 31 may be configured by one long recording head. Further, the arrangement of the recording heads is not limited to the staggered arrangement, and the head unit 31 may be configured by overlapping a part of the recording heads and arranging them in a direction orthogonal to the transport direction.

  The head unit 31 (31C to 31Y) records each image by ejecting each color ink supplied from an ink supply unit (not shown) to the recording medium 21. In addition, gap adjusting mechanisms 33 as adjusting mechanisms are provided at the four corners of the head holding member 32, and a paper guide mechanism 40 is provided on the upstream side in the transport direction with respect to the head portion 31 of each color. Details of the gap adjusting mechanism 33 and the sheet guide mechanism 40 will be described later.

  Next, the transport mechanism 13 will be described.

  The transport mechanism 13 is disposed on the downstream side in the transport direction of the supply unit 11 and is disposed to face the image recording unit 12. The transport mechanism 13 includes a suction fan 51, a transport belt 52, a platen 53, a driving roller 54, a driven roller 55, tension rollers 56 (56a and 56b), and a transport frame 57.

  The conveying belt 52 has a width equal to or larger than the width of the recording medium 21 to be conveyed, is formed in an endless belt shape, and a large number of holes are provided on the surface thereof. The conveyor belt 52 is held in a tensioned state by a driving roller 54, a driven roller 55, and a tension roller 56 that are rotatably held by the conveying frame 57, and rotates in a predetermined direction by driving the driving roller 54. To do.

  A platen 53 is provided below the conveyor belt 52. The platen 53 is also held by the transport frame 57. The platen 53 is processed so that at least a region facing the image recording unit 12 is a flat surface, and a large number of holes 53a are formed as shown in FIG.

  Further, the suction fan 51 is disposed below the platen 53 and is held by the transport frame 57. The suction fan 51 sucks air through a large number of holes formed in the conveyance belt 52 and holes 53 a of the platen 53. As a result, the recording medium 21 conveyed from the registration roller pair 24 is attracted onto the conveyance belt 52 and conveyed downstream at a predetermined conveyance speed.

  Next, the lifting mechanism 14 will be described.

  The elevating mechanism 14 is installed below the transport mechanism 13 and is a moving mechanism that holds the transport mechanism 13 movably. The elevating mechanism 14 includes a recording position (FIG. 1B) where the transport mechanism 13 can record an image on the recording medium 21, a cleaning position of the paper guide roller 41 (FIG. 1A), and a JAM (jam). ) Or at the retreat position (FIG. 1C) during head cleaning.

  The elevating mechanism 14 is provided with four elevating arms 61a, 61b, 61c, 61d (only two of 61a, 61b are shown in the figure). Rollers 62a, 62b, 62c, and 62d (only two of 62a and 62b are shown in the figure) are provided at the tips of the four lifting arms 61, 61b, 61c, and 61d. The rollers 62a, 62b, 62c, and 62d are in contact with the lower end edge of the transport frame 57, respectively.

  The elevating arms 61a and 61c are held by an arm shaft 63a that is rotatably held by a printer frame (not shown), and the elevating arms 61b and 61d are also held by an arm shaft 63b that is also rotatably held by a printer frame. Has been. The arm shaft 63a is connected to a drive source (not shown), and the arm shaft 63b is linked to the arm shaft 63a via a drive transmission system (not shown). The arm shaft 63b is configured to rotate in the direction opposite to the arm shaft 63a around the rotation axis.

  That is, when the arm shafts 63a and 63b rotate in synchronization with the arrow E1 direction and the arrow E2 direction in FIG. 1, each roller 62 (62a, 62b, 62c, 62d) of the lifting arm 61 (61a, 61b, 61c, 61d). ) Moves while abutting against the lower end edge of the transport frame 57. Accordingly, the transport mechanism 13 can be lowered while maintaining the posture of holding the transport mechanism 13 in parallel with the image recording unit 12.

  Further, when the arm shafts 63a and 63b are rotated in synchronization with the direction of the arrow E1 and the direction of the arrow E2, the rollers 62 (62a, 62b, 62c) of the lifting arm 61 (61a, 61b, 61c, 61d) are rotated. 62d) moves while abutting against the lower edge of the transport frame 57. Thereby, the conveyance mechanism 13 can be raised.

  As the lifting mechanism 14, for example, the transport mechanism 13 may be a wire lifting mechanism, or a link mechanism or the like may be applied.

  Next, the discharge unit 15 will be described.

  The discharge unit 15 is disposed downstream of the transport mechanism 13 in the transport direction. The discharge unit 15 includes a discharge roller pair 66 and a stocker 67. The paper discharge roller pair 66 serves to discharge the recording medium 21 on which an image has been recorded from the transport mechanism 13. The stocker 67 serves to stock the recording medium 21 on which an image has been recorded.

  Next, the paper guide mechanism 40 will be described.

  The paper guide mechanism 40 is provided on the opposite surface of the head holding member 32 that faces the transport mechanism 13, and as shown in FIG. ing. In the present embodiment, paper guide mechanisms 40 are provided at four locations.

  As shown in FIGS. 4A and 4B, the paper guide mechanism 40 mainly includes a paper guide roller 41, a roller bearing 43, a holder 45, a pressing spring 46, and a cleaning member 48. Has been.

  The paper guide roller 41 has a shape as shown in FIG. That is, both end portions 41a of the sheet guide roller 41 are places where the conveyance belt 52 abuts, and the central portion 41b is a place where the diameter is narrower than both end portions 41a and the recording medium 21 passes. The dimension indicated by A in FIG. 4A indicates a step between the both end portions 41a and the central portion 41b, and is set so that the recording medium 21 does not contact the head. If it is plain paper, about 0.5 mm is desirable. In addition, the dimension B indicated by B in the drawing needs to be longer than the width of the recording medium 21.

  Both ends of the sheet guide roller 41 are held by roller bearings 43 via a shaft 42. The roller bearing 43 is attached to the holder 45 so as to be slidable in the vertical direction. The roller bearing 43 is urged downward (conveying mechanism) by a pressing spring 46 as an urging member.

  The holder 45 is attached to the facing surface of the head holding member 32 that faces the transport mechanism 13. A cleaning member 48 is detachably attached to the holder 45 at a portion facing the central portion 41b where the diameter of the paper guide roller 41 is small. In this embodiment, the cleaning member 48 uses an ink absorber such as a sponge. Therefore, the ink adhering to the surface of the central portion 41b of the paper guide roller 41 is absorbed by the cleaning member 48 when the cleaning member 48 comes into contact with the roller, thereby cleaning the roller surface. . Further, the cleaning member 48 is held so that a certain gap is opened from the paper guide roller 41 when the transport mechanism 13 is in a printing state.

  Next, the gap adjusting mechanism 33 will be described in detail.

  As shown in FIG. 6, the gap adjusting mechanism 33 has a substantially cylindrical guide piece 75 as a first member, and a substantially cylindrical adjustment as a second member into which the guide piece 75 can be inserted and removed. A top 76 and a biasing spring 77 as a biasing member wound around the outer periphery of the guide top 75 are configured.

  As shown in FIG. 8, the guide piece 75 has a groove 75c formed on the outer peripheral surface thereof as an adjustment member for rotating the adjustment piece 76 (a developed view of the groove 75c is shown in FIG. 16). At the same time, a fan-shaped convex portion 75 b is provided on the bottom surface (the transport mechanism 13 side) 75 a of the guide piece 75.

  Further, as shown in FIGS. 9A and 9B, the cylindrical adjustment piece 76 is fitted to the guide piece 75 so as to be slidable in the vertical direction. Two protrusions 76 c are provided at predetermined positions on the inner peripheral surface of the adjustment piece 76. As shown in FIG. 10, these protrusions 76 c engage with the groove portions 75 c of the guide piece 75, so that the adjustment piece 76 moves around the guide piece 75 when the adjustment piece 76 is slid in the vertical direction. Rotate. Details of the movement in the rotational direction will be described later. Furthermore, as shown in FIGS. 11 and 12, a fan-shaped convex portion 76 b is formed in a portion that contacts the guide piece 75 inside the bottom surface 76 a of the adjustment piece 76. The urging spring 77 is a spring for urging the adjustment piece 76 downward, that is, in a direction away from the guide piece 75.

  Next, the positional relationship when the gap adjusting mechanism 33 configured as described above is attached to the head holding member 32 will be described with reference to FIG.

  A pin 80 is formed on the portion of the head holding member 32 where the gap adjusting mechanism 33 is provided. In this embodiment, the pins 80 are installed at the four corners of the head holding member 32. At this time, the tips 80a of the four pins are set at an accurate height with respect to the head nozzle surface.

The guide piece 75 is press-fitted so that there is no gap in the pin 80. After the biasing spring 77 is wound and attached to the guide piece 75 fixed in this manner, the adjustment piece 76 is fitted to the guide piece 75. At this time, as described above, the groove 75c of the guide piece 75 and the protrusion 76c on the inner peripheral surface of the adjustment piece 76 need to be fitted to each other. Since the groove portion 75c of the guide piece 75 is formed with a portion (75c _{1 in} FIG. 16) opened in the bottom surface 75a, the adjustment piece 76 has the projection 76c engaged with the groove portion 75c of the guide piece 75 from that portion. It is so fitted. As a result, the guide piece 75 and the adjustment piece 76 are integrated, and the adjustment piece 75 does not fall. The adjustment piece 76 is urged toward the platen 53 by the urging spring 77.

  In the present embodiment, the pin 80 is provided on the head holding member 32 and the guide piece 75 is press-fitted into the pin 80. However, the guide piece 75 may be formed directly on the head holding member 32.

  Next, a method for adjusting the height by rotating the adjustment piece 76 relative to the guide piece 75 will be described.

  As described above, the fan-shaped convex portion 76 b is formed on the bottom surface 76 a of the adjustment piece 76. The difference in the height direction between the convex portion 76b and the bottom surface 76a is a step a as shown in FIGS. 12 (b) and 12 (c). Further, as shown in FIG. 12A, the circumferential range of the portion where the convex portion 76b is formed on the bottom surface 76a is set to θ1, and the circle of the portion where the convex portion 76b is not formed. The circumferential range is set to θ2.

  On the other hand, the difference in the height direction between the bottom surface 75a of the guide piece 75 and the convex portion 75b is a step b as shown in FIGS. 13B and 13C. Further, as shown in FIG. 13A, the range of the portion where the convex portion 75b is formed on the bottom surface 75a and the portion where the convex portion 75b is not formed is θ1, θ2 as in the adjustment piece 76. Is set to The relationship between the step a and the step b is a> b, and the relationship between θ1 and θ2 is θ1 <θ2. This is to prevent the projection 75b of the guide piece 75 and the projection 76b of the adjustment piece 76 from interfering with each other when the gap amount is varied.

  Then, as the adjustment piece 76 moves relative to the guide piece 75, the position where the convex portion 76b of the adjustment piece 76 abuts against the guide piece 75 changes as shown in FIGS. The gap amount between 32 and the transport mechanism 13 is variable. The positions shown in FIGS. 14A and 15A are the recording positions, and the positions shown in FIGS. 14B and 15B are the cleaning positions of the paper guide rollers (the gap is step b from the standard). The position is set to be narrower by a minute).

  Next, a method of rotating by the abutting operation of the transport mechanism 13 while the groove 75c of the guide piece 75 and the protrusion 76c of the adjustment piece 76 are engaged will be described.

FIG. 16 is a diagram in which the groove 75c formed in the guide piece 75 is developed along the outer peripheral surface. In the figure, 76c _{1 to} 76c ₈ indicate the positions of the protrusions 76c formed on the inner peripheral surface of the adjustment piece 76, and 75c ₁ is a groove part through which the protrusions 76c are passed when the gap adjustment mechanism 70 is assembled. FIG. 17 is a diagram showing the positional relationship between the bottom surface 76a and the convex portion 76b of the adjustment piece 76 and the bottom surface 75a and the convex portion 75b of the guide piece 75. For convenience, the adjustment piece 76 is indicated by a broken line and the guide piece 75 is indicated by a solid line. ing.

  In the following description, the vertical movement of the adjustment piece 76 is realized by the abutment operation of the conveyance mechanism 13 against the adjustment piece 76 by the vertical movement.

Now, the state in which the conveying mechanism 13 is separated from the adjusting piece 76, i.e., as shown in FIG. 7, in the state in which adjustment piece 76 is pushed downward by the biasing spring 77, the protrusion 76c is of 76c ₁ Located in place (initial position). At this time, the guide frame 75 and the adjustment frame 76 are in the positional relationship shown in FIG.

When the transport mechanism 13 is lifted by the elevating mechanism 14 from this state, the contact portion formed on the platen 53 contacts the adjustment piece 76. When the transport mechanism 13 is further lifted, the adjustment piece 76 rises and the protrusion 76c. There pushed upward from the initial position, it reaches the position of 76c _2. Further increasing the adjustment piece 76 from this position, the projection 76c is moved to the position of 76c ₃ along the slope 75c ₂ and the groove 75c _3.

Here, when the projection 76c is moved along the slope 75c _2, adjustment frame 76 is shown in FIG. 17 (b) along the outer circumferential surface of the guide piece 75 from the position shown in FIG. 17 (a) Move (rise) while rotating clockwise to position. When projection 76c is moved along the groove 75c _3, adjustment frame 76 is raised without rotation. The position of 76c ₃ and the projection 76c is along the groove 75c _3, that is, it reaches the cleaning position, as shown in FIG. 15 (b), the convex portion 76b of the bottom surface 75a of the guide frame 75 adjustment piece 76 is brought Touch. Thereby, the gap amount between the head holding member 32 and the transport mechanism 13 is determined.

Thus, the state in which the protrusion 62c is positioned at the position of at 76c ₃ the groove 75c _3, with respect to the first set position which is an image recording position to be described later, a second set position of the gap adjustment mechanism 70 ( Roller cleaning state). In addition, when the bottom surface 75a of the guide piece 75 and the convex portion 76b of the adjustment piece 76 come into contact with each other, the step a and the step a as described above are prevented so that the convex portion 76b of the guide piece 75 does not come into contact with the bottom surface 75a of the adjustment piece 75. b.

Next, when changing the gap amount between the image recording unit 12 and the transport mechanism 13, that is, when changing the gap adjusting mechanism 70 to the first setting position (image recording state) different from the second setting position, Once the transport mechanism 13 is lowered. Thereby, since the adjustment piece 76 is urged toward the transport mechanism 13 by the urging spring 77, the projection 76c at the position of 76c ₃ is lowered to the position of 76c ₄ .

When is further lowered, the projections 76c reaches the position of 76c ₅ slides down a slope 75c _4. When the projections 76c are moved along the inclined surface 75c _4, adjustment frame 76 clockwise to the position shown in FIG. 17 (c) along the outer circumferential surface of the guide piece 75 from the position shown in FIG. 17 (b) Move (lower) while rotating. Note that until the protrusion 76c reaches the position of 76c ₅ from the position of 76c _4, contact portion and the adjusting piece 76 formed in the platen 53, the contact state is maintained.

When the projection 76c reaches the position of 76c _5, stops the lowering of the transport mechanism 13, raising again. Thus, adjustment frame 76 is raised, the projections 76c is moved from the position of 76c ₅ to the position of 76c _6, moves to a position of 76c ₇ along the inclined surface 75c ₅ and the groove 75c _6. When the protrusion 76c is moving slope 75c _5, adjustment frame 76 is rotated while moved to the position shown in FIG. 17 (d) from the position shown in FIG. 17 (c). Further, when the projection 76c is moved along the groove portion 75c _6, adjustment frame 76 is raised without rotation. The position of 76c ₇ with projection 76c is along the groove 75c _6, that is, reaches the recording position, as shown in FIG. 15 (a), the convex portion 75b of the guide piece 75 projecting portion 76b of the adjusting piece 76 Abut. As a result, the gap amount between the image recording unit 12 and the transport mechanism 13 is spaced by a step b from the gap amount at the second setting position (roller cleaning state) described above. The state in which the protrusion 62c is positioned at the position of 76c _{6 in} the groove 75c ₆ in this way is the first set position (image recording state) of the gap adjusting mechanism 70.

Here, increasing the transport mechanism 13 in a state which is located 76c ₄ side from the position shown the projections 76c in dashed alpha, projection 76c moves along the slope 75c _8, adjustment frame 76 is 17 As shown in (e), it rises while rotating counterclockwise. And the state of the 2nd setting position shown in Drawing 17 (b) is maintained. Further, since lowers the conveyance mechanism 13 so that the position of the protrusion 76c becomes 76c ₅ side from the position indicated by the broken line alpha, if caused to increase the conveying mechanism 13 again, the protrusion 76c along the inclined surface 75c ₅ It moves to the first set position (image recording state) shown in FIG.

Further, to lower the transfer mechanism 13, when releasing the contact between the contact portion of the adjusting piece 76 and the platen 53, the projection 76c reaches the position of 76c _8. The position of 76c ₈ is the same positional relationship as the position of 76c ₁ described above. That is, the adjustment piece 76 at the position of 76c ₈ is in a state shown in FIG. 17 (a). Accordingly, when the transport mechanism 13 is lowered and the contact portion of the platen 53 is separated from the adjustment piece 76, the position of the protrusion 76c can always be returned to the initial position. Thereby, for example, when the contact between the contact portion of the platen 53 and the adjustment piece 76 is released by JAM processing or the like, and the transport mechanism 13 is moved (raised) again, the gap adjustment mechanism 33 is moved to the second installation position. It can be positioned in the (roller cleaning state), and control becomes easy.

Furthermore, when changing from a first set position (recording state) in the second set position (roller cleaning state), lowers the transport mechanism 13, indicated by a broken line β along the protrusion 76c on the slopes 75c ₄ is moved to 76c ₈ side from the position can be changed to the second set position if caused to increase the conveying mechanism 13 again. When the transport mechanism 13 is raised on the 76c ₅ side from the position indicated by the broken line β, the adjustment piece 76 rises while rotating counterclockwise as shown in FIG. The state of the first set position shown in 17 (d) is maintained.

  As described above, according to the first embodiment, the position (the bottom surface 75 a or the convex portion 75 b) where the convex portion 76 b of the adjustment piece 76 contacts the guide piece 75 can be varied only by the movement of the transport mechanism 13. Thereby, the gap amount between the transport mechanism 13 and the image recording unit 12 can be easily and accurately varied.

  Next, the operation of the image recording apparatus 10 configured as described above will be described.

  When an image formation instruction is input from an operation panel (not shown) of the image recording apparatus 10 or an image formation instruction signal is input from a host device (not shown) connected by a signal line, the transport mechanism 13 moves up and down. The mechanism 14 is lifted from the retracted position, the contact surface between the gap adjusting mechanism 33 of the head holding member 32 and the platen 53 is abutted, and stops at the second set position by the operation as described above.

  The state shown in FIG. 5A represents the second set position. Since both end portions 41a of the paper guide roller 41 are in contact with the conveyance belt 52, the conveyance belt 52 is used as a drive source. Can be carried around. Further, the cleaning member 48 is in contact with the central portion 41 b of the paper guide roller 41 at the second setting position. Therefore, when the transport belt 52 is run in this state, the paper guide roller 41 rotates and the ink attached to the roller surface is absorbed by the cleaning member 48 in contact with the roller. In this way, the paper guide roller 41 is cleaned by the cleaning member 48.

  The time for driving the conveyance belt 52 is set to a time required for cleaning the paper guide roller 41. However, the present invention is not limited to this, and the time setting may be changed depending on the usage time of the apparatus.

  Thereafter, the lifting mechanism 14 is operated by a control mechanism (not shown) to move the transport mechanism 13. Then, the gap adjusting mechanism 33 stops at the first set position (image recording state) as shown in FIG. At this time, both end portions 41 a of the paper guide roller 41 are kept in contact with the conveying belt 52 by the pressing spring 46. Further, the central portion 41 b of the paper guide roller 41 is in a state in which contact with the cleaning member 48 is released. Then, after the registration roller pair 24, the drive roller 55, and the paper discharge roller pair 66 are driven, the paper feed roller 23 is driven. As a result, the uppermost recording medium 21 is removed from the paper feed tray 22. Then, the recording medium 21 reaches the gripping portion formed by the facing portion between the registration roller 24a and the registration roller 24b of the registration roller pair 24.

  At this time, the rotation of the registration rollers 24a and 24b is temporarily stopped by a registration clutch (not shown). As a result, the recording medium 21 conveyed toward the registration roller pair 24 hits the gripping portion and is temporarily stopped from traveling, and the conveyed posture is corrected. That is, if there is a skew, the skew is corrected.

  Then, after a predetermined time, the rotation restriction by the registration clutch is released, and the rotation of the registration roller pair 24 is started, whereby the recording medium 21 is fed onto the conveyance belt 52 of the conveyance mechanism 13 at a predetermined speed. A suction force by the suction fan 51 acts on the transport belt 52 through an infinite number of holes provided in the platen 53 and an infinite number of holes provided in the transport belt 52.

  The recording medium 21 fed from the registration roller pair 24 onto the conveyor belt 52 is transported in a predetermined manner in a state where it is adsorbed by the suction force described above onto the conveyor belt 52 that circulates in the clockwise direction in FIG. It is conveyed in the X direction at a speed.

  The sheet guide roller 41 presses a part of the recording medium 21 floating from the upper surface of the conveying belt 52 against the conveying belt 52, so that the recording medium 21 is reliably attracted to the conveying belt 52 and recorded on the head unit 31. The contact of the medium 21 is avoided. As described above, since both end portions 41 a of the paper guide roller 41 are in contact with the transport belt 52, the paper guide roller 41 rotates following the movement of the transport belt 52. Thereby, JAM by the paper guide roller 41 can be prevented.

  Then, ink droplets are ejected from the head portions 31C, 31K, 31M, and 31Y onto the recording medium 21 conveyed by the conveyance belt 52 in accordance with the timing when the image formation position is reached, and an image is recorded.

  In this way, the recording medium 21 on which the images of the respective colors are recorded in an overlapping manner is discharged out of the apparatus by the discharge roller pair 66 and is placed and accommodated in the discharge tray 67.

  Further, at the time of JAM or head cleaning, as shown in FIG. 5C, the transport mechanism 13 is moved to the third set position as the retracted position. In this case, the transport mechanism 13 is at a position lower than the second set position (roller cleaning state) or the first set position (image recording state) described above. At this time, the cleaning member 48 is not in contact with the paper guide roller 41 (41b).

  As described above, according to the first embodiment, by utilizing the existing gap adjusting mechanism 33, the roller surface can be cleaned and stable printing quality can be maintained.

  In the first embodiment, the paper guide roller cleaning operation is performed at the beginning of the printing operation. However, the paper guide roller may be performed at an appropriate interval without being performed every printing operation. Further, it is effective to execute the cleaning after the JAM processing.

  Furthermore, in the first embodiment, an example in which a sponge is used as the cleaning member has been shown. However, the present invention is not limited to this, and other materials may be used as long as they can remove ink and ink mist. Also good.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.

  18A and 18B show the positional relationship between the paper guide mechanism and the transport mechanism according to the second embodiment of the present invention. FIG. 18A is a side view showing the positional relationship at the retracted position, and FIG. Is a side view showing the positional relationship in the cleaning state of the paper guide roller, (c) is a side view showing the positional relationship in the image recording state. FIG. 19 shows the positional relationship between the paper guide mechanism and the transport mechanism in the second embodiment of the present invention as viewed from the transport direction. FIG. 19A shows the positional relationship at the retracted position. FIG. 4B is a diagram showing the positional relationship in the cleaning state of the paper guide roller, and FIG. 5C is a diagram showing the positional relationship in the image recording state.

  In the second embodiment, since the basic configuration and operation of the image recording apparatus are the same as those of the first embodiment described above, these configuration and operation are the same. Are denoted by the same reference numerals, illustration and description thereof will be omitted, and only the configuration and operation of different parts will be described.

  18 and 19, the paper guide mechanism 90 includes a paper guide roller 41, a pressing spring 46, a cleaning member 48, a holder 91, a swing arm 92, and a biasing spring 94. Composed.

  The swing arm 92 is formed in, for example, a V shape, and is pivotally supported at both ends by a fulcrum 93 with respect to the holder 91, and swings about the fulcrum 93. Further, a cleaning member 48 is attached to one end portion (upstream side in the transport direction) 92 a of the swing arm 92 at a position where it contacts the paper guide roller 41. Further, an urging spring 94 is provided in the vicinity of the other end (downstream side in the transport direction) 92b of the swing arm 92 so that the cleaning member 48 comes into contact with the central portion 41b of the paper guide roller 41. Energized. The end 92 b of the swing arm 92 is in a position to engage with the platen 53 of the transport mechanism 13.

  As shown in FIGS. 18A and 19A, the sheet guide roller 41 and the contact portion of the platen 53 are separated from each other. This state is a retracted position during JAM or head cleaning, and represents that the transport mechanism 13 is in the third set position (retracted state). In this case, the transport mechanism 13 is at a position lower than a first set position (image recording state) and a second set position (roller cleaning state) which will be described later. At this time, the cleaning member 48 is in contact with the central portion 41 b of the paper guide roller 41.

  Next, as shown in FIGS. 18B and 19B, when the transport mechanism 13 is raised, both end portions 41 a of the paper guide roller 41 come into contact with the transport belt 52, and the end of the swing arm 92 is reached. The portion 92b is separated from the contact portion of the platen 53. This state is the second set position (roller cleaning state). At this time, the cleaning member 48 is in contact with the central portion 41 b of the paper guide roller 41.

  Further, as shown in FIGS. 18C and 19C, when the transport mechanism 13 is raised, the end portion 92 b of the swing arm 92 is also in contact with the contact portion of the platen 53. This state is the first set position (image recording state). In this case, the transport mechanism 13 is located at a position higher than the second set position (roller cleaning state) or the third set position (retracted state). At this time, since the transport mechanism 13 is raised and the platen 53 comes into contact with the end 92b of the swing arm 92, the swing arm 92 is swung, and the cleaning member 48 is moved to the central portion 41b of the paper guide roller 41. In a non-contact state.

  Next, the operation of the image recording apparatus according to the second embodiment of the present invention will be described.

  Since the conveyance and recording operation of the recording medium 21 are the same as those in the first embodiment described above, description thereof will be omitted, and operations different from those in the first embodiment will be described below.

  When the transport mechanism 13 is lifted from the third set position, which is the retracted position shown in FIGS. 18A and 19A, by the elevating mechanism 14, it is shown in FIGS. 18B and 19B. Thus, it stops once before reaching the image recording position. At this time, both end portions 41a of the sheet guide roller 41 are in contact with the conveyor belt 52 and are in a state where they can be rotated with the conveyor belt 52 as a drive source. Further, the end 92 b of the swing arm 92 has not yet contacted the platen 53, and the cleaning member 48 contacts the central portion 41 b of the guide roller 41 by the action of the biasing spring 94. When the conveyor belt 52 is run in this state, the paper guide roller 41 rotates and the surface of the roller is cleaned.

  When the cleaning operation is completed, the lifting mechanism 14 is driven to raise the transport mechanism 13 and stop at the image recording position as shown in FIGS. 18C and 19C. At this time, the end 92b of the swing arm 92 contacts the platen 53, and the swing arm 92 rotates clockwise around the fulcrum 93 in FIG. The contact with 41b is released.

  As described above, according to the second embodiment, the roller surface can be cleaned and a stable print quality can be maintained by using a simple configuration and an existing mechanism.

  Also, in the second embodiment, an example in which a sponge is used as the cleaning member has been shown. However, as in the first embodiment described above, any other ink and ink mist can be used. May be used.

  In the first and second embodiments described above, it has been described that the transport mechanism is movable and the interval between the transport mechanism and the image recording unit is adjusted. However, the present invention is not limited to this, and the transport mechanism is not limited thereto. May be fixed, and the image recording unit may be movable to adjust the distance between them. Further, both the transport mechanism and the image recording unit may be provided so as to be movable.

  The gap adjusting mechanism has been described as being attached to the image recording unit side, but it is needless to say that the gap adjusting mechanism may be attached to the transport mechanism side.

  Furthermore, in the above-described embodiment, it has been described that the gap adjustment mechanism adjusts the gap amount in two stages. However, the present invention is not limited to this, and it is needless to say that the gap adjustment mechanism can be set in two or more stages.

  Further, the paper guide roller is described as being provided in the vicinity of the recording head and on the upstream side in the recording paper conveyance direction. However, the present invention is not limited to this and may be on the downstream side, or on the upstream side and the downstream side. It may be provided on both sides.

  While the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

  Further, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be extracted as an invention.

1A and 1B show a schematic configuration of an image recording apparatus according to a first embodiment of the present invention, in which FIG. 1A is a schematic side view showing a cleaning position of a paper guide roller of the image recording apparatus, and FIG. FIG. 4C is a schematic side view showing a state of an image recording position of the image recording apparatus, and FIG. 5C is a schematic side view showing a state of a non-recording position of the image recording apparatus. It is the figure which showed the shape of the platen of the image recording apparatus of FIG. It is the figure which looked at the image recording part of Drawing 1 from the lower part. The details of the paper guide mechanism are shown, (a) is a view seen from the transport direction, (b) is a side view of the paper guide mechanism. The positional relationship between the paper guide mechanism and the transport mechanism is shown as viewed from the transport direction. (A) is a diagram showing the positional relationship in the cleaning state of the paper guide roller, and (b) is the image recording state. (C) is a diagram showing the positional relationship in the non-image recording state. It is a perspective view of the gap adjustment mechanism in the 1st Embodiment of this invention. It is sectional drawing which showed the state in which the gap adjustment mechanism was attached to the head unit. It is an external appearance perspective view of a guide top. It is a perspective view of an adjustment piece, (a) and (b) are the figures shown from a different angle. It is the perspective view which expanded and showed the state which the projection part has engaged with the groove part of the guide top. It is the perspective view which expanded and showed only the bottom face part of an adjustment top. The bottom of the adjustment piece will be described. (A) is a plan view seen from the bottom side of the adjustment piece, and (b) is a contact portion with the guide piece along the line FF ′ in (a). Sectional drawing (c) is a sectional view of the abutting portion with the guide piece along line GG ′ in (a). The bottom surface portion of the guide frame will be described. (A) is a plan view seen from the bottom surface side of the guide frame, (b) is a view of the contact portion with the adjustment frame along the line H-H 'in (a). Sectional drawing (c) is a sectional view of the abutting portion with the adjusting piece along the line II 'in (a). It is a top view which shows the engagement state of a guide top and an adjustment top. It is sectional drawing which shows the engagement state of a guide top and an adjustment top. FIG. 5 is a view in which a guide piece is developed along the outer peripheral surface for explaining the operation of the gap adjusting mechanism in the first embodiment. FIG. 6 is a diagram showing a positional relationship between an adjustment piece and a guide piece when a gap adjustment mechanism is operated. FIGS. 4A and 4B show a positional relationship between a paper guide mechanism and a transport mechanism in a second embodiment of the present invention, where FIG. 5A is a side view showing the positional relationship at a retracted position, and FIG. FIG. 4C is a side view showing the positional relationship in the cleaning state of the roller, and FIG. 5C is a side view showing the positional relationship in the image recording state. The positional relationship between the paper guide mechanism and the transport mechanism in the second embodiment of the present invention is shown as viewed from the transport direction, (a) is a diagram showing the positional relationship in the non-image recording state, (B) is a diagram showing the positional relationship in the cleaning state of the paper guide roller, (c) is a diagram showing the positional relationship in the image recording state.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Image recording apparatus, 11 ... Supply part, 12 ... Image recording part, 13 ... Conveyance mechanism, 14 ... Elevating mechanism, 15 ... Ejection part, 21 ... Recording medium, 22 ... Paper feed stand, 23 ... Paper feed roller, 24 ... Registration roller pair, 24a, 24b ... Registration roller, 31, 31K, 31C, 31M, 31Y ... Head portion, 32 ... Head holding member, 33 ... Gap adjustment mechanism, 35 ... Opening, 40, 90 ... Paper guide mechanism, 41 ... Paper guide roller 41a ... Both ends 41b ... Center part 42 ... Shaft 43 ... Roller bearing 45 ... Holder 46 ... Pressing spring 48 ... Cleaning member 51 ... Suction fan 52 ... Conveying belt 53 ... Platen 54 ... Driving roller 55 ... Driven roller 56 ... Tension roller 57 ... Conveying frame 75 ... Guide frame 75a ... Bottom surface 75b ... Convex part 75c ... Groove part 76 ... Sei piece, 76a ... bottom, 76 b ... protrusion, 76c ... projection, 77 ... biasing spring, 91 ... holder, 92 ... swinging arm, 94 ... biasing spring.

Claims (6)

A transport mechanism having a transport belt for transporting a recording medium;
An image recording unit having a line head arranged opposite to the transport mechanism and configured by one or a plurality of recording heads;
A paper guide roller that is provided in the image recording unit, is arranged upstream of the line head in the conveyance direction of the recording medium, rotates in contact with the conveyance belt, and a cleaning member that cleans the paper guide roller; A paper guide mechanism having
The transport mechanism and the image recording unit are arranged such that an interval between the transport mechanism and the image recording unit is a first position where an image is recorded on the recording medium and a second position different from the first position. A moving mechanism for moving at least one of the image recording unit,
Comprising
In the first position, the paper guide roller and the transport belt are in contact with each other, and the paper guide roller and the cleaning member are not in contact with each other. In the second position, the paper guide roller and the transport belt are in contact with each other. And the sheet guide roller and the cleaning member are in contact with each other.   The image recording apparatus according to claim 1, wherein the conveying belt is driven for a predetermined time at the second position.   The image recording apparatus according to claim 1, wherein the second position is a position where the transport mechanism is closer to the image recording unit side than the first position.   3. The image recording apparatus according to claim 1, wherein the second position is a position where the transport mechanism is separated from the image recording unit side from the first position. 4.   The image recording apparatus according to claim 1, wherein the moving mechanism moves the transport mechanism up and down. An adjustment mechanism provided to stand on one of the transport mechanism or the image recording unit;
The adjustment mechanism adjusts the interval to the first position or the second position by contacting the conveyance mechanism or the image recording unit, and the adjustment mechanism is in the contacted state. The distance is varied to the first position or the second position by reciprocally moving at least one of the transport mechanism or the image recording unit in the upright direction by the moving mechanism. The image recording apparatus according to any one of claims 1 to 5.

Images