JP5075613B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  An image forming apparatus employing an inkjet head mainly includes an image forming unit and a paper transport unit that transports paper to the image forming unit. The image forming unit has a plurality of ink jet heads, and each ink jet head has an ink discharge port.

  In such an image forming apparatus, the sheet is conveyed by the sheet conveying unit below the image forming unit. Then, based on the image information, ink is ejected from the ink discharge port of the inkjet head onto the paper, and an image is formed on the paper surface. Then, the paper on which the image is formed is transported to the discharge unit by the paper transport unit.

  On the other hand, in the image forming apparatus, when the image forming operation is completed and the standby state continues for a long time, the ink in the ink discharge port is dried and the vicinity of the ink discharge port is clogged, or dust adheres around the ink discharge port. There is a risk of falling. For this reason, when the image forming apparatus is in a standby state, for example, the ink discharge port may be protected by a cap (see Patent Document 1).

Specifically, in the apparatus of Patent Document 1, when the image forming operation is completed and the image forming apparatus is in a standby state, the image forming unit moves in a direction (upward) away from the paper transport unit. Then, the cap unit that protects the ink ejection surface is inserted between the image forming unit and the sheet conveyance unit from a direction orthogonal to the sheet conveyance direction. Then, the image forming unit moves in a direction (downward) close to the paper transport unit. Then, the ink discharge port of the image forming unit is covered with the cap of the cap unit. That is, the ink discharge port of the image forming unit is protected by the cap of the cap unit.
JP 2002-120386 A

  In the conventional image forming apparatus, when the image forming operation ends and enters a standby state, the image forming unit retreats upward from the paper transport unit. When the cap unit is inserted between the image forming unit and the sheet conveying unit, the image forming unit moves downward. Then, the ink discharge port of the image forming unit is covered and protected by the cap of the cap unit.

  In such an image forming apparatus, it is necessary to move the image forming unit up and down in order to protect the ink discharge port of the image forming unit with the cap of the cap unit. As described above, a plurality of inkjet heads are incorporated in this image forming unit. For this reason, when the standby state is repeated, the movement of the inkjet head is also repeated. Then, depending on the situation, there is a risk that the positional accuracy of the inkjet head cannot be sufficiently secured.

  An object of the present invention is to provide an image forming apparatus capable of ensuring the positional accuracy of an ink discharge portion and protecting the ink discharge portion.

An image forming apparatus according to the present invention includes an image forming unit, a recording medium transport unit, a transport unit moving mechanism, an ejection recovery unit, and a recovery unit moving mechanism. The image forming unit includes an ink discharge unit that discharges ink, and forms an image on a recording medium by discharging ink from the ink discharge unit. The recording medium transport unit is disposed below the ink ejection unit so as to face the ink ejection unit, and transports the recording medium to a position facing the ink ejection unit. The transport unit moving mechanism moves the recording medium transport unit in a direction close to the ink discharge unit and a direction away from the ink discharge unit. The ejection recovery unit includes a protection member for protecting the ink ejection unit and a support member that supports the protection member.

  The recovery unit moving mechanism includes a frame body, a first recovery unit moving mechanism, and a second recovery unit moving mechanism. The first recovery unit moving mechanism is provided on the frame body. The first recovery unit moving mechanism moves the ejection recovery unit in a direction orthogonal to the recording medium conveyance direction when the recording medium conveyance unit moves in a direction away from the ink ejection unit. The second recovery unit moving mechanism is provided on the frame body. The second recovery portion moving mechanism moves the discharge recovery portion in a direction close to the ink discharge portion and a direction away from the ink discharge portion when the discharge recovery portion is located at a position facing the ink discharge portion.

  In this image forming apparatus, the ink discharge portion is protected as follows. First, the recording medium transport unit moves in a direction away from the ink discharge unit. Next, the ejection recovery unit moves in a direction perpendicular to the conveyance direction of the recording medium. Subsequently, when the ejection recovery unit is located at a position facing the ink ejection unit, the ejection recovery unit moves in a direction close to the ink ejection unit of the image forming unit. Then, the protection member of the ejection recovery unit covers the ink ejection unit and protects the ink ejection unit.

  On the other hand, when the image forming operation is performed, the ejection recovery unit moves to the standby position as follows. First, the ejection recovery unit moves in a direction away from the ink ejection unit of the image forming unit. Next, the ejection recovery unit moves in a direction orthogonal to the conveyance direction of the recording medium and stops at the standby position. Subsequently, the recording medium transport unit moves in the direction approaching the ink ejection unit. Then, the recording medium transport unit is disposed at a predetermined position facing the ink discharge unit of the image forming unit, and the image forming operation is executed.

  As described above, in the present image forming apparatus, the ink ejection unit can be protected by the protection member of the ejection recovery unit without moving the image forming unit, that is, the ink ejection unit. In the image forming apparatus, the image forming operation can be executed without moving the image forming unit, that is, the ink discharge unit. As described above, in the present image forming apparatus, the ink discharge unit can be protected by the protective member and the image forming operation can be performed while maintaining the positional accuracy of the ink discharge unit that plays an important role during image formation. Can do.

In the image forming apparatus according to the present invention, in the image forming apparatus, a first recovery unit moving mechanism has an engaging portion that engages with the discharge recovery unit is mounted on the frame body. In the first recovery portion moving mechanism, the ejection recovery portion moves in a direction orthogonal to the recording medium conveyance direction via the engaging portion operated by the driving means.

  In this case, the engaging unit is operated by the driving unit, and the ejection recovery unit moves in a direction orthogonal to the conveyance direction of the recording medium in conjunction with the operation of the engaging unit. For this reason, even if the discharge recovery part and the drive means are separated, the driving force of the drive means can be transmitted to the discharge recovery part via the engagement part. That is, it is not necessary to secure a special space for disposing the driving means in the vicinity of the discharge recovery portion, and the driving means can be disposed in a dead space or the like. Thereby, the image forming apparatus can be made compact.

In the image forming apparatus according to the present invention, the image forming apparatus, a second recovery unit moving mechanism has a can abut the eccentric cam to the support member is rotatably mounted to the frame body. In the second recovery portion moving mechanism, when the discharge recovery portion is located at a position facing the ink discharge portion, the eccentric cam rotates and contacts the support member, so that the discharge recovery portion moves in the direction closer to the ink discharge portion. Move.

  In this case, the eccentric cam of the second recovery portion moving mechanism rotates when the discharge recovery portion is positioned at a position facing the ink discharge portion. Then, the eccentric cam comes into contact with the support member of the discharge recovery portion. Then, the ejection recovery unit moves in the direction close to the ink ejection unit. Then, the protection member supported by the support member of the ejection recovery unit covers the ink ejection unit and protects the ink ejection unit. As described above, in this image forming apparatus, by using the eccentric cam, the ejection recovery unit can be reliably moved in the direction close to the ink ejection unit, and the ink ejection unit is protected by the protection member of the ejection recovery unit. Can do. That is, in the present image forming apparatus, the ink ejection unit can be protected by the protection member while maintaining the positional accuracy of the ink ejection unit that plays an important role during image formation.

In the image forming apparatus according to the present invention, in the image forming apparatus, ejection recovery portion further has a biasing member. The urging member is disposed between the protection member and the support member, and urges the protection member in a direction away from the support member.

  In this case, the discharge recovery unit includes a protection member, a support member, and an urging member that urges the protection member in a direction away from the support member. As a result, when the ejection recovery unit moves in a direction closer to the ink ejection unit and the protection member of the ejection recovery unit comes into contact with the ink ejection unit, the urging member ensures that the protection member is in close contact with the ink ejection unit. be able to. That is, the ink discharge portion can be reliably protected by the protective member.

  In the image forming apparatus according to the present invention, the ink discharge portion can be protected by the protection member without moving the image forming portion, that is, the ink discharge portion. In the image forming apparatus, the image forming operation can be executed without moving the image forming unit, that is, the ink discharge unit. As described above, in the present image forming apparatus, the ink discharge unit can be protected by the protective member and the image forming operation can be performed while maintaining the positional accuracy of the ink discharge unit that plays an important role during image formation. Can do.

<Overall configuration>
FIG. 1 shows a schematic configuration of an image forming apparatus 1 in which an embodiment of the present invention is adopted. The image forming apparatus 1 shown here is an inkjet printer capable of forming an image on a sheet (recording medium) based on image information transmitted from an external computer. Such an image forming apparatus 1 includes an image forming unit 2, a paper storage unit 3, a paper transport unit 4, a transport unit moving mechanism 5, a discharge recovery unit 6, a recovery unit moving mechanism 7, and a paper holding mechanism. 8 and a discharge unit 9 (see FIG. 2 for the discharge recovery unit 6 and the recovery unit moving mechanism 7).

  The image forming unit 2 is a part that forms an image based on image information. The image forming unit 2 includes a plurality of ink discharge units, that is, a plurality of inkjet heads 21. The plurality of inkjet heads 21 are arranged side by side above a conveyance belt 41d of a sheet conveyance unit 4 described later, and are portions that eject ink onto a sheet based on image information. Each inkjet head 21 is a line-type head capable of forming an image by ejecting ink in a direction perpendicular to the paper transport direction.

  Here, for example, four sets of inkjet heads (12 inkjet heads) 21 are arranged above the conveyance belt 41 d of the sheet conveyance unit 4. The four sets of inkjet heads 21 store inks of different colors for each set. Each of the four sets of inkjet heads 21 has an ink ejection surface 22. The ink discharge surface 22 is provided with a plurality of holes for discharging ink. In FIG. 1, only one of the ink ejection surfaces 22 is given a reference numeral and the others are omitted. The ink discharge surface 22 is provided on the lower surface of the inkjet head 21. The ink discharge surface 22 is formed in a rectangular shape that is long in a direction orthogonal to the paper transport direction. By ejecting ink from the ink ejection surface 22, an image is formed on the paper.

  Here, the definition of the wording indicating the direction used in the present embodiment is shown. In the following, the term “front-rear direction” may be used. This wording is a wording indicating a direction perpendicular to the paper surface in FIG. 1 (corresponding to a direction orthogonal to the paper conveyance direction). In the following, the term “front (front side)” and the term “rear (rear side)” may be used. The term “front (front side)” is a term indicating the front side in a direction perpendicular to the paper surface of FIG. 1. The term “rear (rear side)” is a term indicating the back side in a direction perpendicular to the paper surface of FIG. 1. Furthermore, in the following, the term “left-right direction” and the term “up-down direction” may be used. The term “left / right direction” is a term indicating the left / right direction (corresponding to the paper transport direction) in FIG. 1. The term “vertical direction” means the vertical direction in FIG.

  The sheet storage unit 3 is a portion that can store a sheet on which an image is formed, and is disposed at the lower part of the image forming apparatus 1. The paper storage unit 3 includes a paper feed cassette 31 that stores paper and a paper supply roller 32 for supplying paper to the paper transport unit 4.

  The paper transport unit 4 is a part that transports the paper from the paper storage unit 3 to the discharge unit 9, and includes a transport unit 4A, a plurality of rollers 33 that transports the paper, and temporarily stops the paper to perform oblique correction and the like. And a registration roller pair 34 for feeding paper again to the transport unit 4A. The transport unit 4 </ b> A is disposed below the image forming unit 2 so as to face the image forming unit 2. The transport unit 4 </ b> A transports the paper on which the image is formed on the surface by the image forming unit 2 to the discharge unit 9. Specifically, the transport unit 4 </ b> A is disposed below the ink ejection surface 22 so as to face the ink ejection surface 22 of the image forming unit 2. The transport unit 4 </ b> A transports the paper to a position facing the ink ejection surface 22, and transports the paper to the discharge unit 9 when an image is formed on the paper.

  When the sheet is conveyed by the registration roller, the leading end of the sheet is detected by an optical sheet leading end detection sensor 35 disposed on the right side of the inkjet head 21. Then, ink is ejected from the inkjet head 21 to form an image on the basis of the time when the leading edge of the sheet is detected by the sheet leading edge detection sensor 35.

  The transport unit 4A includes a frame body 41a, rollers 41b and 41c, and a transport belt 41d. The frame main body 41 a is disposed below the inkjet head 21. The rollers 41b and 41c are rotatably mounted on the frame body 41a with a predetermined interval in the paper transport direction. The conveyor belt 41d is an endless belt, and is stretched over the rollers 41b and 41c. The transport belt 41d is provided with a plurality of holes through which air can pass. These holes have a diameter of about 4 mm, for example, and are uniformly provided on the conveyor belt 41d with an interval of about 20 mm.

  Here, the upper surface of the transport belt 41 d is defined as the transport surface 47. The transport surface 47 faces the ink discharge surface 22 below the ink discharge surfaces 22 of the plurality of inkjet heads 21. The paper stored in the paper feed cassette 31 of the paper storage unit 3 is transported to the paper transport unit 4 by a paper supply roller 32 and a plurality of rollers 33 for transporting the paper from the paper storage unit 3 to the paper transport unit 4. The

  The paper transport unit 4 is disposed below the image forming unit 2 so as to face the image forming unit 2. The paper transport unit 4 transports the paper on which the image is formed by the image forming unit 2 to the discharge unit 9. Specifically, the paper transport unit 4 is disposed below the ink ejection surface 22 so as to face the ink ejection surface 22 of the image forming unit 2. The paper transport unit 4 transports the paper to a position facing the ink ejection surface 22, and transports the paper to the discharge unit 9 when an image is formed on the paper.

  The paper transport unit 4 includes a frame main body 41a, rollers 41b and 41c, and a transport belt 41d. The frame main body 41 a is disposed below the inkjet head 21. The rollers 41b and 41c are rotatably mounted on the frame body 41a with a predetermined interval in the paper transport direction. The conveyor belt 41d is an endless belt, and is stretched over the rollers 41b and 41c. The transport belt 41d is provided with a plurality of holes through which air can pass. These holes have a diameter of about 4 mm, for example, and are uniformly provided on the conveyor belt 41d with an interval of about 20 mm.

  Here, the upper surface of the transport belt 41 d is defined as the transport surface 47. The transport surface 47 faces the ink discharge surface 22 below the ink discharge surfaces 22 of the plurality of inkjet heads 21.

  The transport unit moving mechanism 5 is a device for moving the transport unit 4 </ b> A in the vertical direction to bring the transport surface 47 close to the ink discharge surface 22 or to separate the transport surface 47 from the ink discharge surface 22. . The transport unit moving mechanism 5 is disposed below the transport unit 4A, and is a device for moving the transport unit 4A in a direction close to the ink discharge surface 22 and a direction away from the ink discharge surface 22.

  The transport unit moving mechanism 5 has a pair of eccentric cams 5a and 5b for the transport unit. Of the pair of eccentric cams 5a and 5b for the conveyance unit, the eccentric cam 5a for the conveyance unit located on the left side in FIG. 1 (hereinafter referred to as "first eccentric cam") is provided rotatably about the shaft portion. And is rotationally driven by a drive motor (not shown). The first eccentric cam 5a is provided with a plurality of bearings 51a, and the first eccentric cam 5a supports the frame main body 41a of the transport unit 4A via the bearings 51a.

  The eccentric cam 5b (hereinafter referred to as “second eccentric cam”) located on the right side in FIG. 1 has the same structure as the first eccentric cam 5a, and the first eccentric cam 5a in FIG. Are arranged in a mirror image relationship. The second eccentric cam 5b is provided with a plurality of bearings 51b, and the second eccentric cam 5b supports the frame body 41a of the transport unit 4A via the bearings 51b. FIG. 1 shows a state in which the transport unit 4A is raised. When the pair of eccentric cams 5a and 5b rotate inward from each other in this state, the transport unit 4A descends (see FIG. 3).

  When the image forming unit 2 forms an image on a sheet, the transport unit moving mechanism 5 raises the transport unit 4A and moves it to the position shown in FIG. 1 (image forming position, proximity position). In a state where the transport unit 4A is positioned at the image forming position, the gap between the ink ejection surface 22 of the inkjet head 21 and the paper is set to an optimum gap for printing, for example, about 1.0 mm. On the other hand, when the transport unit moving mechanism 5 protects the ink discharge surface 22 of the inkjet head 21 by the cap member 61 when the operation is stopped, or when processing a paper jam occurring on the transport belt 41d, the transport unit 4A is lowered and moved to the position (separation position) shown in FIG.

  As shown in FIGS. 2 to 3 and 5, the ejection recovery unit 6 includes a cap member 61 for protecting the ink ejection surface 22 of the image forming unit 2, a support member 62 that supports the cap member 61, and a cap. A spring member 63 that biases the member 61 away from the support member 62 and a locking member 67 for locking the cap member 61 to the support member 62 are provided.

  The cap member 61 is a member for protecting the ink discharge surface 22 by covering the ink discharge surface 22. The cap member 61 includes a plate portion 61a, a side wall portion 61b, and a shaft portion 61c. The plate portion 61 a is a portion facing the ink ejection surface 22 and is formed in a rectangular plate shape corresponding to the shape of the ink ejection surface 22. The side wall portion 61b is erected on the upper surface of the plate portion 61a, that is, the surface facing the ink ejection surface 22. Specifically, the side wall part 61b is erected along the outer periphery of the plate part 61a. The side wall portion 61b is provided over the entire circumference of the plate portion 61a so that the plate portion 61a does not contact the ink discharge hole of the ink discharge surface 22. The shaft portion 61c is provided so as to protrude outward from the surface of the plate portion 61a opposite to the surface on which the side wall portion 61b is formed. Specifically, it protrudes outward from the lower surface of the plate portion 61a.

  The support member 62 supports a plurality of cap members 61. 2 and 3, the support member 62 includes a support portion 62a that supports the twelve cap members 61, a pair of wall portions 62b that face each other on both sides of the support portion 62a, and a pair of walls. And a pair of flange portions 62c extending outward from the portion 62b.

  The support part 62a has a two-layer structure, and includes a first support part 162a (a support part positioned upward in FIG. 3) and a second support part 162b (a support part positioned downward in FIG. 3). Yes. The first support portion 162a is supported by the second support portion 162b above the second support portion 162b. Specifically, the first support part 162a and the second support part 162b are formed in a rectangular plate shape. The first support portion 162a is supported by the second support portion 162b via a spacing member 65 provided on the second support portion 162b above the second support portion 162b. Further, a through hole 262a for fitting the shaft portion 61c of the cap member 61 is formed in the first support portion 162a.

  The pair of wall portions 62b are formed integrally with the second support portion 162b at both ends of the second support portion 162b. In addition, a rotating member, for example, a roller member 64 is rotatably mounted on each of the pair of wall portions 62b (see FIGS. 2, 6, and 7). Here, the two roller members 64 are rotatably attached to the respective wall portions 62b with a predetermined interval. The pair of flange portions 62c are engaged with the recovery portion moving mechanism 7 (see FIGS. 2, 6, and 7).

  As shown in FIG. 5, the spring member 63 is disposed between the cap member 61 and the support member 62 (162a). Here, one end of the spring member 63 contacts the upper surface of the support member 62, and the other end of the spring member 63 contacts the lower surface of the cap member 61. Specifically, one end of the spring member 63 abuts on the first surface of the first support portion 162a (hereinafter referred to as “the upper surface of the first support portion”), and the other end of the spring member 63 is the plate portion 61a. In contact with the surface opposite to the surface on which the side wall portion 61b is formed (hereinafter referred to as “the lower surface of the plate portion”). In this way, the spring member 63 is sandwiched between the cap member 61 and the support member 62.

  As shown in FIG. 5, the locking member 67 is a retaining member for preventing the cap member 61 from coming out of the support member 62. The locking member 67 is attached to the distal end portion of the shaft portion 61 c of the cap member 61. Here, for example, an E-ring is used as the retaining member, that is, the locking member 67. The locking member 67 has a diameter larger than the diameter of the through hole 262 a of the support member 62. For this reason, when the locking member 67 is attached to the distal end portion of the shaft portion 61c of the cap member 61, the shaft portion 61c can be prevented from coming off from the through hole 262a of the support member 62.

  In such a discharge recovery portion 6, first, one end of the spring member 63 contacts the upper surface of the first support portion 162 a so that the center of the spring member 63 and the center of the through hole 262 a of the first support portion 162 a coincide with each other. Touched. Next, the shaft portion 61 c of the cap member 61 is inserted into the spring member 63 from the other end side of the spring member 63. Subsequently, the lower surface of the plate portion 61 a is brought into contact with the other end of the spring member 63. Then, in a state where the spring member 63 is compressed between the upper surface of the first support portion 162a and the lower surface of the plate portion 61a of the cap member 61, the distal end portion of the shaft portion 61c of the cap member 61 is the first support portion 162a. Is fitted into the through hole 262a. Then, the tip end portion of the shaft portion 61c of the cap member 61 passes through the through hole 262a of the first support portion 162a, and the second surface (hereinafter referred to as “first” It protrudes outward from the lower surface of the support part. Then, the locking member 67 is attached to the distal end portion of the shaft portion 61 c of the cap member 61 on the lower surface side of the first support portion 162 a. Thereby, the cap member 61 is attached to the support member 62.

  The recovery unit moving mechanism 7 is a device for moving the discharge recovery unit 6 on the surface defined by the transport surface 47 in a direction orthogonal to the paper transport direction and in a direction orthogonal to the surface defined by the transport surface 47. It is. Specifically, the recovery unit moving mechanism 7 is a device for moving the discharge recovery unit 6 in the horizontal direction (front-rear direction) and the vertical direction. By this recovery portion moving mechanism 7, the discharge recovery portion 6 performs the image forming operation without protecting the ink discharge surface 22 by the cap member 61 and the position (protection position) where the ink discharge surface 22 can be protected by the cap member 61. It is moved to a standby position (standby position).

  As shown in FIGS. 2, 6, and 7, the recovery unit moving mechanism 7 includes a frame body 71, a first recovery unit moving mechanism 72, and a second recovery unit moving mechanism 73.

  The frame main body 71 supports the discharge recovery portion 6 so as to be movable in the horizontal direction and the vertical direction. The frame main body 71 has a pair of guide rails 71 a for guiding the movement of the discharge recovery portion 6. The pair of guide rails 71a are arranged in parallel to each other in a direction orthogonal to the paper transport direction. In addition, each of the pair of guide rails 71a is disposed between the support member 62 of the discharge recovery portion 6 and an eccentric cam for a protection portion described later.

  Here, each of the pair of guide rails 71a has a substantially Z-shaped cross section. The guide rail 71a having such a cross section is formed long in one direction. Further, as shown in FIGS. 6 and 7, each of the pair of guide rails 71 a is configured so that the eccentric cam for the protective portion can be brought into contact with the support member 62 without interfering with the guide rail 71 a. A slit 171a is provided. The slit 171a is provided in the guide rail 71a at a position where a surface perpendicular to the axis of the eccentric cam for the protection portion intersects the guide rail 71a. A roller member 64 rotatably mounted on the wall portion 62b of the support member 62 is placed on each of the pair of guide rails 71a.

  The first recovery portion moving mechanism 72 is a device for moving the discharge recovery portion 6 in the horizontal direction, and is provided on the frame main body 71. The first recovery portion moving mechanism 72 includes an engagement portion 72a that engages with the support member 62 of the discharge recovery portion 6 and a drive motor 72b that inputs a driving force to the engagement portion 72a. The engaging portion 72a moves the support member 62 of the ejection recovery portion 6 in a direction orthogonal to the paper transport direction in a state where the transport unit 4A is stopped at a position (separation position) away from the image forming position. In other words, the engaging portion 72a moves the support member 62 of the discharge recovery portion 6 in the horizontal direction (front-rear direction) in a state where the transport unit 4A moves in the direction away from the ink discharge surface 22 and stops.

  Here, an example is shown in which the ejection recovery unit 6 moves in a direction orthogonal to the paper transport direction while the transport unit 4A is stopped at the separation position. However, when a sufficient distance can be ensured between the separation position of the transport unit 4A and the ink ejection surface 22, the ejection recovery can be performed while the transport unit 4A is moving away from the ink ejection surface 22. The unit 6 can be moved in a direction orthogonal to the paper transport direction. That is, if the transport unit 4A and the ejection recovery unit 6 do not collide, the ejection recovery unit 6 is orthogonal to the paper transport direction while the transport unit 4A is moving away from the ink ejection surface 22. You may make it move to the direction to do.

  The drive motor 72b is attached to the frame body 71. In FIG. 2, the drive motor 72 b is fixed inside the corner portion of the frame body 71 (the corner portion at the right back in FIG. 2). A gear is attached to the tip of the motor shaft of the drive motor 72b.

  The engaging portion 72 a is attached to the frame main body 71. The engaging portion 72a includes a first pulley 172a, a second pulley 172b, a third pulley 172c, a fourth pulley 172d, a fifth pulley 172e, a pair of moving belts 272 (272a, 272b), A transmission belt 372.

  The first pulley 172a meshes with a gear attached to the motor shaft of the drive motor 72b. In FIG. 2, the first pulley 172a is disposed at the right back corner, and the second pulley 172b is disposed at the left back corner. In FIG. 2, the third pulley 172c is disposed at the left front corner, and the fourth pulley 172d is disposed at the right front corner. Further, in FIG. 2, the fifth pulley 172e is disposed at the right back and is arranged side by side with the first pulley 172a.

  The pair of moving belts 272 are provided so as to be circulated along the respective guide rails 71a. One moving belt 272 (272a) is spanned between the first pulley 172a and the fourth pulley 172d. The other moving belt 272 (272b) is bridged between the second pulley 172b and the third pulley 172c. Further, each of the pair of moving belts 272 (272a, 272b) is engaged with the support member 62 of the discharge recovery portion 6. For example, the inner belt of each of the pair of moving belts 272 (272a, 272b) is fixed to the lower surface of the flange portion 62c of the support member 62 of the discharge recovery portion 6.

  The transmission belt 372 is for transmitting the driving force from the drive motor 72b to the one moving belt 272a. The transmission belt 372 is spanned between the fifth pulley 172e and the second pulley 172b. An idle gear 172f is disposed between a gear (not shown) attached to the drive motor and the fifth pulley 172e. The driving force from the driving motor 72b is transmitted to the fifth pulley 172e via the idle gear 172f. Specifically, the driving force from the drive motor 72b is transmitted from the gear attached to the drive motor to the fifth pulley 172e via the idle gear 172f.

  The second recovery portion moving mechanism 73 is a device for moving the discharge recovery portion 6 in the vertical direction, and is provided on the frame main body 71. When the discharge recovery unit 6 is located at a position facing the image forming unit 2, the second recovery unit moving mechanism 73 is configured to eject the discharge recovery unit 6 in a direction close to the image forming unit 2 and away from the image forming unit 2. Move. Specifically, the second recovery portion moving mechanism 73 is configured so that the direction close to the ink discharge surface 22 and the ink discharge surface 22 when the support member 62 of the discharge recovery portion 6 is located at a position facing the ink discharge surface 22. The support member 62 of the discharge recovery unit 6 is moved in a direction away from the discharge recovery unit 6.

  As shown in FIGS. 6 and 7, the second recovery unit moving mechanism 73 includes a plurality of eccentric cams 73a for the protection unit and a drive motor device (not shown) for rotationally driving the plurality of eccentric cams 73a for the protection unit. Not).

  The four eccentric cams 73a for the protection portion are provided on the front side of the frame body 71. Here, the eccentric cams 73a for the two protection parts are arranged at a predetermined interval in the longitudinal direction of one guide rail 71a (see FIG. 4), and the eccentric cams for the remaining two protection parts 73a are arranged at a predetermined interval in the longitudinal direction of the other guide rail 71a. FIG. 4 shows a view when the discharge recovery portion 6, the guide rail 71a, and the pair of moving belts 272 are removed.

  Four eccentric cams 73a for the protection unit are rotatably attached to the frame body 71. Here, the four eccentric cams 73a for the protective portion are rotatably mounted on the frame body 71 so that the rotation axis direction and the direction in which the guide rail 71a extends (longitudinal direction of the guide rail 71a) are parallel to each other. ing.

  The eccentric cam 73a for the protective part can come into contact with the support member 62 of the discharge recovery part 6. For example, the eccentric cam 73a for the protection portion can pass through a slit 171a formed in the guide rail 71a and can come into contact with the lower surface of the flange portion 62c of the support member 62 of the discharge recovery portion 6.

  The paper holding mechanism 8 is a mechanism for holding the paper on the transport surface 47. As shown in FIG. 1, the sheet holding mechanism 8 includes a suction device 81, for example, a plurality of blower fans, and a motor (not shown) that rotationally drives these blower fans 81. The paper holding mechanism 8 generates a flow of air that passes from above to below through holes provided in the transport belt 41 d by the blower fan 81. As a result, the sheet is sucked and held on the transport surface 47.

  The discharge unit 9 is a part for discharging the sheet on which the image is formed by the image forming unit 2, and is provided at the top of the image forming apparatus 1. The discharge unit 9 includes a plurality of rollers 91, and the sheet on which the image is formed by the image forming unit 2 is conveyed by the conveyance belt 41 d of the conveyance unit 4 </ b> A and the roller 91 of the discharge unit 9. It is discharged outside.

<Operation>
Here, an image forming operation will be described.

  First, when a command for forming an image is issued from a computer connected to the outside, a sheet is sent out from the sheet storage unit 3 to the transport unit 4A. Then, when the paper is being transported by the transport belt 41d of the transport unit 4A, ink is ejected from the inkjet head 21 and an image is formed on the paper. The sheet on which the image is formed is conveyed by the roller 91 of the discharge unit 9 and discharged from the discharge port 92 to the outside of the apparatus. In this way, the image forming operation is executed.

  Next, an outline of the protective operation of the inkjet head 21 will be described.

  The image forming apparatus 1 can form an image when an image forming command is not issued for a predetermined time after the image forming operation is completed, or when a power switch (not shown) is turned off. Shifts from a normal state to a standby state

  At this time, the transport unit 4A is moved from the image forming position (proximity position) to the separation position by the transport unit moving mechanism 5. When the transport unit 4A is located at the separation position, the ejection recovery unit 6 is moved from the standby position to a predetermined position between the transport unit 4A and the image forming unit 2 by the first recovery unit moving mechanism 72. Hereinafter, the predetermined position is referred to as a via position. When the discharge recovery unit 6 is located at the via position, the discharge recovery unit 6 is moved from the via position to the protection position by the second recovery unit moving mechanism 73. Then, the inkjet head 21 is protected by the cap member 61 of the discharge recovery unit 6.

  Here, an example in which the discharge recovery unit 6 starts to move after the transport unit 4A is located at the separation position is shown, but before the transport unit 4A is located at the separation position, the discharge recovery unit 6 6 may start moving.

  On the other hand, in a state where the ink ejection surface 22 is capped by the cap member 61 of the ejection recovery unit 6, when the image formation command is issued or the power switch is turned on, the ejection recovery unit 6 The recovery unit moving mechanism 73 moves the protection position to the transit position. When the discharge recovery unit 6 is located at the via position, the discharge recovery unit 6 is moved from the via position to the standby position by the first recovery unit moving mechanism 72. In this way, the protection of the inkjet head 21 by the cap member 61 of the ejection recovery unit 6 is released. Subsequently, when the ejection recovery unit 6 is positioned at the standby position, the transport unit 4A is moved from the separation position to the image forming position by the transport unit moving mechanism 5. When the transport unit 4A is positioned at the image forming position, the image forming unit 2 can form an image on the paper.

  Here, an example is shown in which the transport unit 4A starts moving after the discharge recovery unit 6 is positioned at the standby position. However, before the discharge recovery unit 6 is positioned at the standby position, the transport unit 4A is started. 4A may start moving.

  Finally, details of the operation of the recovery unit moving mechanism 7 will be described.

  In the first recovery portion moving mechanism 72, when the driving force from the driving motor 72b is input to the first pulley 172a, the pair of moving belts 272 circulate in opposite directions. Then, the support member 62 is pulled by the pair of moving belts 272 in a direction (front side or rear side) orthogonal to the paper transport direction. As a result, the discharge recovery unit 6 can be moved in a direction orthogonal to the paper transport direction.

  Specifically, when the driving force from the drive motor 72b is input to the first pulley 172a and the first pulley 172a rotates clockwise in FIG. 2, one moving belt 272a circulates counterclockwise, The moving belt 272b circulates clockwise. Then, the support member 62 is pulled to the rear side. In this case, the discharge recovery unit 6 moves from the via position to the standby position. On the other hand, when the first pulley 172a rotates counterclockwise in FIG. 2, one moving belt 272a circulates clockwise and the other moving belt 272b circulates counterclockwise. Then, the support member 62 is pulled to the front side. In this case, the discharge recovery unit 6 moves from the standby position to the transit position. In this way, the first recovery portion moving mechanism 72 can move the discharge recovery portion 6 between the standby position and the transit position.

  In the second recovery portion moving mechanism 73, the drive motor is in a state where the support member 62 of the discharge recovery portion 6 is positioned below the ink discharge surface 22 and facing the ink discharge surface 22 (see FIG. 6: via position). Is rotated from the posture in which the long axis of the eccentric cam 73a for the protective portion is horizontal (first posture) to the posture in which the long axis of the eccentric cam 73a for the protective portion is vertical (second posture). The eccentric cam 73a for use rotates. Then, the portion farthest from the shaft center of the eccentric cam 73a for the protective portion passes through the slit 171a formed in the guide rail 71a and comes into contact with the lower surface of the flange portion 62c of the support member 62. Then, the support member 62 is pushed up by the four eccentric cams 73a for the protective part, and the discharge recovery part 6 moves upward. When the drive motor stops when the four protective cams 73a are in the second posture (see FIG. 7: protection position), the ink ejection surface 22 is capped by the cap member 61 of the ejection recovery unit 6. Is done.

  On the other hand, when the drive motor rotates reversely in a state where the ink ejection surface 22 is capped by the cap member 61 of the ejection recovery unit 6, the eccentric cam 73a for the protection unit rotates from the second posture to the first posture. . Then, the portion of the protective cam eccentric cam 73a that is farthest from the axis moves from the upper side of the axis toward the side of the axis (see FIGS. 7 and 6). Then, the discharge recovery unit 6 moves downward. Then, the roller member 64 comes into contact with the guide rail 71a and the downward movement of the discharge recovery portion 6 stops. At this time, the state where the cap member 61 of the ejection recovery unit 6 is detached from the ink ejection surface 22 and the cap member 61 of the ejection recovery unit 6 covers the ink ejection surface 22 is released. Then, the drive motor stops when the four eccentric cams 73a for the protection portion take the first posture (see FIG. 6).

<Features>
In the image forming apparatus 1, the ink discharge surface 22 can be protected by the cap member 61 without moving the image forming unit 2. In the image forming apparatus 1, an image forming operation can be executed without moving the image forming unit 2. As described above, in the image forming apparatus 1, the ink ejection surface 22 can be protected by the cap member 61 while maintaining the positional accuracy of the inkjet head 21 that plays an important role in image formation, and the image forming operation can be performed. Can be executed.

[Other Embodiments]
(A) In the above-described embodiment, the discharge recovery unit 6 is moved in the horizontal direction by using a belt and a pulley in the first recovery unit moving mechanism 72. However, the ejection recovery unit 6 may be moved in the horizontal direction using a mechanism different from the above.

  (B) In the above-described embodiment, the sheet is held on the conveyance surface 47 by generating an air flow from the conveyance side 47 toward the opposite side and sucking the sheet. However, the sheet may be held on the transport surface 47 by using a mechanism different from the above, such as using an electric suction method.

  (C) In the above embodiment, an example of a color printer is shown as an embodiment of the image forming apparatus 1, but the present invention is not limited to this. For example, a multi-function device having a function as a copy machine or a facsimile machine or one having only a copy function may be used. Further, the image processing apparatus is not limited to the one that can form a color image, and may be an image processing apparatus that can form only a monochrome image.

1 is a diagram illustrating a schematic configuration of an image forming apparatus. The perspective view which shows the structure of a recovery part moving mechanism. The figure which looked at the image formation part, the discharge recovery part, the paper conveyance part, and the conveyance part moving mechanism from the side. The elements on larger scale which show the position of the eccentric cam for protection parts, and the position of a roller member. Sectional drawing of a discharge recovery part. The figure which looked at the 2nd recovery part movement mechanism from the side (the 1st posture, a way position). The figure which looked at the 2nd recovery part movement mechanism from the side (2nd posture, protection position).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Image forming part 21 Inkjet head 22 Ink discharge surface 4 Paper conveyance part 4A Conveyance unit 5 Conveyance part moving mechanism 5a, 5b Eccentric cam for conveyance parts 6 Discharge recovery part 61 Cap member 62 Support member 63 Spring member ( (Biasing member)
DESCRIPTION OF SYMBOLS 7 Recovery part moving mechanism 71 Frame main body 71a Guide rail 72 1st recovery part moving mechanism 72a Engagement part 73 2nd recovery part moving mechanism 73a Eccentric cam for protection parts

Claims (3)

An image forming unit that has an ink discharge unit that discharges ink and forms an image on a recording medium by discharging ink from the ink discharge unit;
A recording medium transport unit that is disposed below the ink ejection unit so as to face the ink ejection unit and transports a recording medium to a position facing the ink ejection unit;
A transport unit moving mechanism that moves the recording medium transport unit in a direction approaching the ink discharge unit and in a direction away from the ink discharge unit;
An ejection recovery unit having a protection member for protecting the ink ejection unit, and a support member for supporting the protection member;
A frame main body, and a discharge recovery unit that is provided on the frame main body and moves the ejection recovery unit in a direction orthogonal to the recording medium conveyance direction when the recording medium conveyance unit moves in a direction away from the ink ejection unit. 1 recovery unit moving mechanism and a direction provided in the frame body, the direction approaching the ink ejection unit and the direction separating from the ink ejection unit when the ejection recovery unit is located at a position facing the ink ejection unit A recovery part moving mechanism having a second recovery part moving mechanism for moving the discharge recovery part to
Equipped with a,
The frame main body has a guide rail for guiding movement of the discharge recovery portion in a direction perpendicular to the conveyance direction of the recording medium,
The second recovery portion moving mechanism has an eccentric cam that is rotatably attached to the frame body and can come into contact with the support member of the discharge recovery portion,
The recovery portion moving mechanism is a rotating member that is rotatably mounted on the support member of the discharge recovery portion, and the second recovery portion moving mechanism moves the discharge recovery portion away from the ink discharge portion. A rotating member that contacts the guide rail or moves away from the guide rail when the second recovery portion moving mechanism brings the discharge recovery portion close to the ink discharge portion;
The guide rail has a slit through which the eccentric cam can pass,
The second recovery portion moving mechanism is configured to rotate the eccentric cam and pass the eccentric cam through the slit when the discharge recovery portion is located at a position facing the ink discharge portion. By moving the discharge recovery portion in a direction closer to the ink discharge portion,
Image forming apparatus. The first recovery portion moving mechanism has an engaging portion that is attached to the frame body and engages with the discharge recovery portion,
In the first recovery unit moving mechanism, the ejection recovery unit is moved in a direction orthogonal to the recording medium conveyance direction via the engagement unit operated by a driving unit.
The image forming apparatus according to claim 1. The discharge recovery portion further includes a biasing member that is disposed between the protection member and the support member and biases the protection member in a direction away from the support member.
The image forming apparatus according to claim 1 or 2.

Images