The present application claims priority under 35 U.S.C. ยง 119 to Japanese Patent Application No. 2018-221333, filed on Nov. 27, 2018. The contents of this application are incorporated herein by reference in their entirety.
The present disclosure relates to an image forming apparatus.
An inkjet printer includes a line head, a head cap, and a head frame. The line head forms an image with ink on paper. The head cap moves from a second position to a first position and closes the line head. The head frame guides the head cap between the second position and the first position. In the inkjet printer, the head cap moves in a right-left direction of the inkjet printer between the second position and the first position.
An image forming apparatus according to an aspect of the present disclosure includes a housing, a movable body, a rack, a gear, a stepping motor, and a first action body. The movable body moves between a first position and a second position with respect to the housing. The rack is provided on the movable body. The gear engages with the rack. The stepping motor is provided in the housing. The first action body acts on the movable body. The stepping motor includes a motor body and an output shaft that rotates the gear. When the output shaft rotates in a first rotation direction, the gear rotates to move the movable body in a first direction from the second position toward the first position. The first action body applies a pressing force in a second direction opposite to the first direction to the movable body moving in the first direction beyond the first position. The pressing force is smaller than a force enough to rotate the output shaft of the stepping motor by one step in a second rotation direction opposite to the first rotation direction.
The following describes an inkjet recording apparatus 1 according to an embodiment of the present disclosure with reference to drawings. The inkjet recording apparatus 1 is an example of an image forming apparatus. Note that elements that are the same or equivalent are indicated by the same reference signs in the drawings and description thereof is not repeated. The drawings mainly illustrate respective elements in a schematic manner for easy understanding.
With reference to
As illustrated in
The sheet feed section 3 includes sheet feed cassettes 31, sheet feed rollers 32a, a sheet feed roller 32b, and a manual feed tray 33. The sheet feed cassettes 31 are disposed in a lower part of the housing 2. The sheet feed cassettes 31 are detachably attached to the housing 2. In each of the sheet feed cassettes 31, a plurality of sheets S can be stored in a stacked state. A portion of the manual feed tray 33 is exposed from the housing 2 to the outside. On the manual feed tray 33, a plurality of sheets S can be loaded in a stacked state.
Each sheet S is, for example, plain paper, copy paper, recycled paper, thin paper, thick paper, glossy paper, or an overhead projector (OHP) sheet.
The sheet feed rollers 32a and the sheet feed roller 32b are pickup rollers. Each sheet feed roller 32a takes out the sheets S stored in the sheet feed cassette 31 one by one from the top. The sheet feed roller 32b takes out the sheets S loaded on the manual feed tray 33 one by one from the top. The sheet feed rollers 32a and the sheet feed roller 32b each send out the taken sheet S to the conveyance section 5.
The conveyance section 5 conveys the sheet S along a conveyance path of the sheet S. The conveyance path of the sheet S extends from the sheet feed section 3 to the ejection section 8 via the recording head section 4. The conveyance section 5 includes a conveyance unit 51 and a plurality of roller pairs disposed along the conveyance path.
The conveyance unit 51 conveys the sheet S in the conveyance direction D. The conveyance unit 51 includes a conveyor belt 51a, a driving roller 51b, and a driven roller 51c. The conveyor belt 51a is an endless belt. The conveyor belt 51a is stretched around the driving roller 51b and the driven roller 51c. The conveyance unit 51 conveys the sheet S with it loaded on a loading surface to the ejection section 8. The loading surface means a part of an outer surface of the conveyor belt 51a on which the sheet S is loaded.
The recording head section 4 is disposed to face the loading surface of the conveyance unit 51. The recording head section 4 forms an image with ink on the sheet S being conveyed by the conveyance unit 51. Subsequently, the sheet S with the image formed thereon is sent to the ejection section 8.
The recording head section 4 includes a head housing 4a and recording heads 4y, 4m, 4c, and 4k. The recording heads 4y, 4m, 4c, and 4k are each an exemplary ink nozzle. The recording heads 4y, 4m, 4c, 4k are held by the head housing 4a. The recording head 4y ejects a yellow ink. The recording head 4m ejects a magenta ink. The recording head 4c ejects a cyan ink. The recording head 4k ejects a black ink.
The ejection section 8 includes an exit tray 81. A portion of the exit tray 81 is exposed from the housing 2 to the outside. The sheet S with the image formed thereon is ejected onto the exit tray 81. The sheets S with an image formed thereon are stacked one by one on the exit tray 81.
The wiper unit 7 includes wiper blades 7y, 7m, 7c, and 7k. The wiper blades 7y, 7m, 7c, and 7k clean the recording head section 4. The wiper blade 7y corresponds to the recording head 4y. The wiper blade 7m corresponds to the recording head 4m. The wiper blade 7c corresponds to the recording head 4c. The wiper blade 7k corresponds to the recording head 4k.
The cap unit 6 includes caps 6y, 6m, 6c, and 6k. The cap 6y corresponds to the recording head 4y. The cap 6m corresponds to the recording head 4m. The cap 6c corresponds to the recording head 4c. The cap 6k corresponds to the recording head 4k.
For example, the caps 6y. 6m, 6c, and 6k cover the recording heads 4y. 4m, 4c, and 4k when the recording head section 4 is not used for a specific time period or longer. As a result, drying of the inks of the recording heads 4y, 4m, 4c, and 4k is prevented.
The controller 9 controls operation of the inkjet recording apparatus 1. Specifically, the controller 9 includes a processor such as a central processing unit (CPU), and a storage device such as a hard disk drive and memory. The storage device stores therein various computer programs executed by the processor. The processor executes the various computer programs stored in the storage device to control the sheet feed section 3, the recording head section 4, the conveyance section 5, the cap unit 6, the wiper unit 7, and the moving mechanism 10.
Next, with reference to
The upper limit position P1 is a position at which the conveyance unit 51 is close to the recording head section 4. The lower limit position P2 is a position which is vertically below the upper limit position P1 and at which the conveyance unit 51 is separated from the recording head section 4. The retraction position P3 is a position to which the movable body 100 is moved in the conveyance direction D relative to the recording head section 4.
As illustrated in
The second casing 12 is fixed to the housing 2. The second casing 12 includes a wall 12a and a wall 12b, and a support plate 12c parallel to the XY plane. The wall 12a and the wall 12b face each other in the X-axis direction. The conveyance unit 51 is placed on the support plate 12c.
The conveyance unit moving mechanism moves the conveyance unit 51 placed on the support plate 12c up and down between the upper limit position P1 and the lower limit position P2 in the second casing 12. The loading surface of the conveyance unit 51 at the upper limit position P1 faces the recording head section 4 in a vertical direction. At the upper limit position P1, the loading surface of the conveyance unit 51 is close to the lower end of the recording head section 4 at a clearance sufficient for conveyance of the sheet S (for example, 3 mm). By contrast, at the lower limit position P2, the clearance between the loading surface of the conveyance unit 51 and the lower end of the recording head section 4 is, for example, 200 mm.
The first casing 11 includes a wall 11a and a wall 11b. The wall 11a and the wall 11b face each other in the X-axis direction. The first casing 11 supports at least one unit of the cap unit 6 and the wiper unit 7. In the present embodiment, the first casing 11 supports the cap unit 6 and the wiper unit 7.
The housing 2 of the inkjet recording apparatus 1 includes paired rails 2a and 2b, a first detector 221, and a second detector 220. The first detector 221 is an example of a detector. The paired rails 2a and 2b are fixed to the housing 2 and extend in a predetermined direction. The predetermined direction is, for example, the horizontal direction and is substantially parallel to the conveyance direction D of the sheet S.
The first detector 221 detects that the movable body 100 is located at the standby position P4. The first detector 221 is fixed to an end of the rail 2a on a side of the standby position P4. The first detector 221 includes a light emitting element and a light receiving element that are disposed with a predetermined distance therebetween.
The first blocking member 103 of the movable body 100 blocks an optical path between the light emitting element and the light receiving element of the first detector 221 when the movable body 100 is located at the standby position P4. The first blocking member 103 is, for example, a plate-like body. The first detector 221 outputs a signal indicating that the optical path is blocked to the controller 9. In this way, the controller 9 recognizes that the movable body 100 is located at the standby position P4.
The second detector 220 detects that the movable body 100 is located at the retraction position P3. The second detector 220 is fixed to the housing 2. The second detector 220 includes a light emitting element and a light receiving element that are disposed with a predetermined distance therebetween.
The second blocking member 101 of the movable body 100 blocks an optical path between the light emitting element and the light receiving element of the second detector 220 when the movable body 100 is located at the retraction position P3. The second blocking member 101 is, for example, a plate-like body. The second detector 220 outputs a signal indicating that the optical path is blocked to the controller 9. In this way, the controller 9 recognizes that the movable body 100 is located at the retraction position P3.
Here, the movable body moving mechanism 15 is described in detail. As illustrated in
The inkjet recording apparatus 1 further includes a first rack 102a and a second rack 102b. The first rack 102a is provided in an upper portion of the wall 11a. The second rack 102b is provided in an upper portion of the wall 11b.
The gear unit 211 includes a first gear 211a, a second gear 211b, and a connecting shaft 211c. The connecting shaft 211c connects a rotating shaft of the first gear 211a and a rotating shaft of the second gear 211b. The first gear 211a meshes with the first rack 102a. The second gear 211b meshes with the second rack 102b.
The stepping motor 210 is provided in the second casing 12. The stepping motor 210 includes a motor body 210a and an output shaft 210b that rotates the first gear 211a when energized. The output shaft 210b extends in a horizontal direction. The output shaft 210b includes a gear 210c on a side near a tip end thereof (see
When the output shaft 210b rotates in a first rotation direction, the first gear 211a and the second gear 211b rotate to move the movable body 100 in the first direction D1 from the retraction position P3 toward the standby position P4. Specifically, during movement of the movable body 100 from the retraction position P3 to the standby position P4, the controller 9 outputs a predetermined number of pulse waves to the stepping motor 210. When the output shaft 210b of the stepping motor 210 rotates by a predetermined number of steps in the first rotation direction, the movable body 100 moves from the retraction position P3 to the standby position P4.
With reference to
With reference to
As illustrated in
Even when the output shaft 210b stops the rotation in the first rotation direction R1, an inertial force acts on the movable body 100 having a heavy weight. As a result, due to the presence of the first gear 211a and the connecting gear 212 between the stepping motor 210 and the first rack 102, and also the presence of play RC in the rotational direction for the meshing of each gear, the movable body 100 continues to move in the first direction D1 beyond the standby position P4. The movable body 100 continues to moving in the first direction D1, and therefore, the first action body 310a contacts the housing 2 and the first action body 310b also contacts the housing 2 before the movable body 100 stops.
The first action body 310a applies a pressing force FA1 (restoring force) toward a second direction D2 opposite to the first direction D1 to the movable body 100 moving in the first direction D1 beyond the standby position P4. Specifically, the first action body 310a contracts as a result of contacting the housing 2. After the contraction, the first action body 310a having a force to expand again is pushed back by the housing 2. As with the first action body 310a, the first action body 310b also applies a pressing force FA2 in the second direction D2 to the movable body 100.
The pressing force FA1 is smaller than a force enough to rotate the output shaft 210b of the stepping motor 210 by one step in the second rotation direction R2 opposite to the first rotation direction R1 (retaining force). Accordingly, application of the pressing force FA1 moves the movable body 100 in the second direction D2. As a result of the movement of the movable body 100 in the second direction D2, the first gear 211a is rotated by the first rack 102a. The rotation of the first gear 211a rotates the connecting gear 212. Even when the connecting gear 212 rotates, the output shaft 210b only rotates less than one step in the second rotation direction R2.
Therefore, according to the present embodiment, even when the predetermined magnitude of force is applied to the output shaft 210b, the output shaft 210b does not rotate in the second rotation direction R2, and therefore, the movable body 100 stops. Thus, it is possible to stop the movable body 100 at a predetermined position. That is, it is possible to accurately stop the movable body 100 at the standby position P4 as a specified position.
In the present embodiment, the first action body 310 includes the first action body 310a and the first action body 310b. The total force of the pressing force FA1 and the pressing force FA2 is set smaller than the force enough to rotate the output shaft 210b of the stepping motor 210 by one step in the second rotation direction R2 opposite to the first rotation direction R1 (retaining force).
In a situation in which the stepping motor 210 is energized even after the predetermined number of pulse waves are output to the stepping motor 210, the total force of the pressing force FA1 and the pressing force FA2 is set smaller than the force enough to rotate the output shaft 210b of the energized stepping motor 210 by one step in the second rotation direction R2. In a situation in which the stepping motor 210 is not energized after the predetermined number of pulse waves are output to the stepping motor 210, the total force of the pressing force FA1 and the pressing force FA2 is set smaller than the force enough to rotate the output shaft 210b of the non-energized stepping motor 210 by one step in the second rotation direction R2.
The total force of the pressing force FA1 and the pressing force FA2 is a force enough to move the movable body 100 having a heavy weight.
Thus, the movable body 100 to which the total force of the pressing force FA1 and the pressing force FA2 is applied moves in the second direction D2. As a result of the movement of the movable body 100 in the second direction D2, the first gear 211a is rotated by the first rack 102a. The rotation of the first gear 211a rotates the connecting gear 212. Even when the connecting gear 212 rotates, the output shaft 210b only rotates less than one step in the second rotation direction R2.
Therefore, according to the present embodiment, it is possible to accurately stop the movable body 100 at the standby position P4 as a specified position.
According to the present embodiment, as a result of the inkjet recording apparatus 1 including the recording heads 4y. 4m, 4c, and 4k, and the movable body 100 including the caps 6y, 6m, 6c, and 6k, the caps 6y, 6m, 6c, and 6k are enabled to accurately cover the recording heads 4y, 4m, 4c, and 4k.
Furthermore, according to the present embodiment, when the first action body 310a and the first action body 310b are disposed as dampers at the respective ends of the movable body 100 in the first direction D1, the dampers act to absorb and repel impact, and thus are enabled to apply appropriate pressing force (restoring force) to the movable body 100. Further, when the two first action bodies 310 are provided at the respective ends of the movable body 100 in the first direction D1, the first action body 310a and the first action body 310b can be reduced in size.
According to the present embodiment, when the inkjet recording apparatus 1 includes the first detector 221 and the first blocking member 103, the first blocking member 103 is capable of blocking the optical path between the light emitting element and the light receiving element even in a case where the blocking member 103 is reduced in size.
With reference to
As illustrated in
Even when the output shaft 210b stops the rotation in the first rotation direction R1, due to the presence of the first gear 211a and the plurality of connecting gears 212 to 214 between the stepping motor 210 and the first rack 102a, and also the presence of the play RC in the rotational direction for the meshing of each gear, the movable body 100 continues to move in the first direction D1 beyond the standby position P4. As illustrated in
The first action body 310a applies the pressing force FA1 (restoring force) in the second direction D2 to the movable body 100 moving in the first direction D1 beyond the standby position P4. As with the first action body 310a, the first action body 310b also applies the pressing force FA2 in the second direction D2 to the movable body 100.
The total force of the pressing force FA1 and the pressing force FA2 is smaller than the force enough to rotate the output shaft 210b of the stepping motor 210 by one step in the second rotation direction R2 (retaining force). Also, the total force of the pressing force FA1 and the pressing force FA2 is a force enough to move the movable body 100 having a heavy weight.
Thus, the movable body 100 to which the total force of the pressing force FA1 and the pressing force FA2 is applied moves in the second direction D2. As a result of the movement of the movable body 100 in the second direction D2, the first gear 211a is rotated by the first rack 102a. The rotation of the first gear 211a rotates the connecting gear 214. The rotation of the connecting gear 214 rotates the connecting gear 213. The rotation of the connecting gear 213 rotates the connecting gear 212. Even when the connecting gear 212 rotates, the output shaft 210b only rotates less than one step in the second rotation direction R2.
Therefore, according to the present embodiment, since the first gear 211a and the connecting gears 212 to 214 are disposed between the stepping motor 210 and the first rack 102a, it is possible to accurately stop the movable body 100 at the standby position P4 even when the movable body 100 continues to move in the direction D1 for a long distance beyond the standby position P4.
With reference to
As illustrated in
Even when the output shaft 210b stops the rotation in the second rotation direction R2, due to the presence of the first gear 211a and the connecting gear 212 between the stepping motor 210 and the first rack 102a, and also the presence of the play RC in the rotational direction for the meshing of each gear, the movable body 100 continues to move in the second direction D2 beyond the retraction position P3. The movable body 100 continues to moving in the second direction D2, and therefore, the movable body 100 contacts the second action body 320b and also the second action body 320a before the movable body 100 stops.
The second action body 320b applies a pressing force FA4 (restoring force) in the first direction D1 to the movable body 100 moving in the second direction D2 beyond the retraction position P3, and the second action body 320a also applies a pressing force FA3 in the first direction D1 as with the second action body 320b.
The total force of the pressing force FA3 and the pressing force FA4 is smaller than the force enough to rotate the output shaft 210b of the stepping motor 210 by one step in the first rotation direction R1 (retaining force). The total force of the pressing force FA3 and the pressing force FA4 is a force enough to move the movable body 100 having a heavy weight.
Thus, the movable body 100 to which the total force of the pressing force FA3 and the pressing force FA4 is applied moves in the first direction D1. As a result of the movement of the movable body 100 in the first direction D1, the first gear 211a is rotated by the first rack 102a. The rotation of the first gear 211a rotates the connecting gear 212. Even when the connecting gear 212 rotates, the output shaft 210b only rotates less than one step in the first rotation direction R1.
Therefore, according to the present embodiment, it is possible to accurately stop the movable body 100 at the retraction position P3 as a specified position.
Further, according to the present embodiment, when the second action bodies 320 are provided at the respective ends of the paired rails 2a and 2b, the second action body 320a and the second action body 320b can be reduced in size.
According to the present embodiment, when the inkjet recording apparatus 1 includes the second detector 220 and the second blocking member 101, the second blocking member 101 is enabled to block the optical path between the light emitting element and the light receiving element of the second detector 220 even in a case where the blocking member 101 is reduced in size.
Hereinbefore, an embodiment of the present disclosure has been described with reference to the drawings. However, the present disclosure is not limited to the above embodiment and may be implemented in various different forms that do not deviate from the essence of the present disclosure. The drawings schematically illustrate elements of configuration in order to facilitate understanding, and properties of elements of configuration illustrated in the drawings, such as thicknesses, lengths, and numbers thereof, may differ from actual properties thereof in order to facilitate preparation of the drawings. Shapes, dimensions, and the like of the elements of configuration given in the above embodiment are merely examples that do not impose any particular limitations and may be altered in various ways so long as such alterations do not substantially deviate from the configuration of the present disclosure.
(1) As described with reference to
(2) As described with reference to
(3) As described with reference to
Number | Date | Country | Kind |
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2018-221333 | Nov 2018 | JP | national |