Patent Grant
7681969
1. Field of the Invention
The present invention relates to a liquid ejection apparatus such as an ink-jet recording apparatus for ejecting a liquid such as ink ejecting from a head thereof on a medium (herein after, referred to “recording medium”).
Here, the liquid ejection apparatus is not limited to a printer, a copying machine, a facsimile, etc., using a recoding head for recording on a recording medium by ink ejecting from the head. The liquid ejection apparatus includes an apparatus for ejecting a fluid which may be used instead of the ink from a fluid ejection head corresponding to the recording head on a recording medium corresponding to the recording medium.
The fluid ejection head includes a colorant ejection head used for manufacturing a color filter of a liquid crystal display, an electrode material (conductive paste) ejection head used for forming electrodes of an organic EL display, a field emission display (FED), etc., and a bio-organic substance ejection head used for manufacturing a bio chip, a sample material ejection head such as a precision pipette, etc., in addition to the recording head.
2. Description of the Related Art
There is an ink-jet printer (herein after, referred to “printer”) as an example of the liquid ejection apparatus or the recording apparatus. The printer is provided with a guiding member (which may be called “platen”) at a position opposite to the recording head for ejecting ink drops to a printing paper which is an example of the recording medium or the recording medium, wherein the guiding member predetermines a distance between the printing paper and the recording head. The guiding member extends in the main scanning direction of the recording head and predetermines the distance between the printing paper and the recording head by supporting the printing paper from the underside.
A transfer (paper transfer) roller for transferring the printing paper to the side of the recording head is provided upstream of the guiding member and a discharge (paper discharge) roller for discharging the recorded printing paper is provided downstream of the guiding member. The transfer roller includes a driving transfer roller which is formed by a shaft extending in the width direction of the printing paper and drives rotation and a driven transfer roller which is adjacent to and rotates following the driving transfer roller. Moreover, the discharge roller includes: a driving discharge roller which is localized on a rotation axis extending in the width direction of the printing paper and drives rotation; and a driven discharge roller which is adjacent to and rotates following the driving discharge roller. The driven discharge roller is provided so that it is localized on a driven discharge roller supporting frame of a shape extending in the direction of the main scanning direction of the recording head in the direction of the main scanning direction.
Japanese Patent Application Laid Open No. 2002-19204 discloses a paper transfer apparatus of a recording apparatus in which a vertex of a platen is lower than a line connecting a nip point of a paper transfer roller and a nip point of a paper discharge roller and the paper transfer speed of the paper transfer roller is the same as the paper discharge speed of the paper discharge roller and which performs printing with a good quality even after the end of a paper gets out of the paper transferring roller.
Japanese Patent Application Laid Open No. 2002-248819 discloses restricting the position of a platen in the direction opposite to a recording head of the platen by the planet's colliding with a restricting means by an energizing force of an energizing means and consequently determining a platen gap.
Japanese Patent Application Laid Open No. 1998-211748 discloses moving a gap regulating unit on a shaft of a paper discharge roller driven by a paper transfer motor to the side of engaging with a middle gear by shifting to a platen gap switching position of a carriage, engaging one side of a planet gear with the middle gear according to a rotational direction of the paper transfer motor, rotating a pair of guide rods in the same directions and by the same amounts through a sector gear according to the rotational direction, and shifting a carriage parallel to a printing reference plane.
Each of Japanese Patent Application Laid Open Nos. 2002-19204 and 1998-211748 discloses an apparatus having a function of switching the height of a recording head in order to prevent the rear end of a paper from floating, which makes the configuration of the apparatus complicated because the apparatus should include means for moving a carriage mechanism in the vertical direction. Moreover, Japanese Patent Application Laid Open No. 2002-248819 discloses an apparatus having function of translating a platen in the vertical direction in order to prevent a recording medium for contacting with a recording head, and a constitution performing the function is also complicated.
The elements such as the guiding member, the driving transfer roller, the driving discharge roller, and the driven discharge roller supporting frame described above are installed on a frame material forming the body of the printer like a sub-frame disclosed in Japanese Patent Application Laid Open No. 2002-347304.
However, in case the plurality of elements are installed on one frame material, the elements need to be installed sequentially which is not effective.
Moreover, the frame material is generally made of metal in order to acquire strength and the guiding member is sometimes made of resin because of complexity of its shape and construction. In this case, due to the difference in the rate of thermal expansion between the both, a shear stress is generated in the guiding member and thus the guiding member is deformed. In this case, there is a problem that the distance between the printing paper and the recording head (which may be called “platen gap”) is not uniform and thus quality of recording gets worse. These kinds of problems may be caused by low initial precision of components in addition to the temperature variation. Furthermore, if the driven discharge roller supporting frame is fixed to the frame material by a screw, warpage is generated due to the size change as time goes by and thus a shear stress is generated in the driven discharge roller supporting frame. Thus, similarly with the guiding member, there is a problem that the driven discharge roller supporting frame may also be deformed. If the driven discharge roller supporting frame is deformed, the position of the driven discharge roller is varied. By this, the driven discharge roller contacts the printing paper strongly and there is a problem that contact traces are formed on the printing surface.
Therefore, it is an object of the present invention to provide a fluid ejection apparatus which can prevent the rear end of a paper from contacting with a fluid ejection head by preventing the rear end of a paper from floating with a relatively simple configuration.
Moreover, it is another object of the present invention to provide the fluid ejection apparatus which can adjust a medium gap by bending a transfer path a little with a relatively simple configuration in order to prevent the rear end of the paper from contacting with the liquid ejection head or adjust the medium gap without moving the liquid ejection head.
Furthermore, it is another object of the present invention to provide the fluid ejection apparatus which can improve assembling efficiency and prevent deformation of members due to a difference in rate of thermal expansion and warpage generated by the size change.
The above and other objects can be achieved by combinations described in the independent claims. The dependent claims define further advantageous and exemplary combinations of the present invention.
According to the first aspect of the present invention, a liquid ejection apparatus for discharging a medium on which liquid is ejected by a discharge roller after ejecting liquid on the medium by a liquid ejection head includes a medium pressing roller for controlling floatation of the medium between the liquid ejection head and the discharge roller, the medium pressing roller being provided on a rotatable discharge frame, wherein the liquid ejection apparatus operates by switching between a first mode where the medium pressing roller moves to an upper position by rotation of the discharge frame and a second mode where the medium pressing roller moves to a lower position than the first mode to press the medium downward.
According to the first aspect of the present invention, it is possible to prevent the rear end of the recording medium for contacting with the liquid ejection head by pressing down the rear end of the recording medium by the medium pressing roller in case the rear end of the recording medium floats upward and thus contacts with the liquid ejection head during discharging the recording medium on which the liquid is ejected.
According to the second aspect of the present invention, the liquid ejection apparatus of the first aspect further includes a first rotating member rotatable about an axis in a main scanning direction on a position facing with the liquid ejection head, a surface facing the liquid ejection head forming a transfer path; and a second rotating member rotatably connected to the first rotating member via a connecting unit, the second rotating member forming the transfer path and being rotatable about an axis in the main scanning direction, wherein the first and second rotating members vary a gap between the liquid ejection head and the surface of the first rotating member facing with the liquid ejection head by rotating in opposite directions and bending on the connecting unit.
According to the second aspect of the present invention, the transfer path is formed by the first and second rotating members rotatably connected via the connecting unit. Thus, it is possible to form a small recess on the transfer path by bending it on a part of the connecting unit. As a result, it is possible to increase or decrease a gap between the surface of the first rotating member facing the liquid ejection member and the liquid ejection member, that is, a medium gap by forming small recess on the transfer path the without moving the liquid ejection head. Thus, in case there is a problem that the rear end of the recording medium floats and thus contacts with the liquid election head or the recording medium is thick, it is possible to overcome the problem by enlarging the medium gap. Moreover, since the recess due to the bending of the transfer path is very small, the smooth transfer of the recording medium is not disturbed.
According to the third aspect of the present invention, a platen of a platen unit rotating with the first rotating member is provided on a position facing with the liquid ejection head, and the platen unit varies a gap between the platen and the liquid ejection head by rotating in a direction opposite to a direction in which the discharge frame rotates in association with rotation of the discharge frame into the second mode.
According to the third aspect of the present invention, the platen unit rotates to move downward in association with the rotation of the discharge frame. As a result, the gap between the platen and the liquid ejection head, that is, a medium gap is enlarged by switching the mode without moving the liquid ejection head and thus there is not a problem that the rear end of the recording medium contacts with the liquid ejection nozzle.
According to the forth aspect of the present invention, a liquid ejection apparatus for discharging a medium on which liquid is ejected by a discharge roller after ejecting liquid on the medium by a liquid ejection head includes a first rotating member rotatable about an axis in a main scanning direction on a position facing with the liquid ejection head, a surface facing the liquid ejection head forming a transfer path; and a second rotating member rotatably connected to the first rotating member via a connecting unit, the second rotating member forming the transfer path and being rotatable about an axis in the main scanning direction, wherein the first and second rotating members vary a gap between the liquid ejection head and the surface of the first rotating member facing with the liquid ejection head by rotating in opposite directions and bending on the connecting unit.
According to the forth aspect of the present invention, the transfer path is formed by the first and second rotating members rotatably connected via a connecting unit. Therefore, it is possible to form a small recess on the transfer path by bending it on a part of the connecting unit. As a result, it is possible to increase or decrease a gap between the surface of the first rotating member facing the liquid ejection member and the liquid ejection member, that is, a medium gap by forming small recess on the transfer path the without moving the liquid ejection head. Thus, in case there is a problem that the rear end of the recording medium floats and thus contacts with the liquid election head or the recording medium is thick, it is possible to overcome the problem by enlarging the medium gap. Moreover, since the recess due to the bending of the transfer path is very small, the smooth transfer of the recording medium is not disturbed.
According to the fifth aspect of the present invention, the connecting unit is provided on a downstream side of a downstream side end of the liquid ejection head in a medium transfer direction.
According to the fifth aspect of the present invention, the connecting unit is provided on the downstream side of the downstream side end of the liquid ejection head in the transfer direction of the recording medium and does not face the liquid ejection head. As a result, even if a gap between the front end or the rear end and the liquid ejection head, that is, a medium gap is varied due to the recess of the transfer path based on the bending of the connecting unit during ejecting the liquid, recording quality does not become worse because the variation is uniformly continuous and very small in a region in which the recording head performs recording.
According to the sixth aspect of the present invention, the liquid ejection apparatus of the second aspect further includes a driving sending roller for transferring the medium to an upstream side of the platen unit, wherein a platen of a platen unit rotating with the first rotating member is provided on a position facing with the liquid ejection head, and a rotation axis of the first rotating member is provided on an upstream side of an axis of the driving sending roller.
According to the sixth aspect of the present invention, since the rotation axis of the first rotating member is provided on the upstream side of the axis of the driving sending roller, it is possible to make a rotation radius connecting the platen and the rotation axis of the first rotating member large. As a result, it is possible to make a difference in the angle of the recording medium around the platen smaller. Thus, it is possible to prevent a banding phenomenon because variation in the relation between a printing pitch and the sending amount becomes small.
Here, the banding phenomenon is that the spacing between printing lines becomes narrow or empty contrarily if printing by the print head and the nozzle for a line and paper sending are performed continuously during printing a line.
According to the seventh aspect of the present invention, the discharge roller includes a driving discharge roller and driven discharge roller, the driven discharge roller is provided on the discharge frame, the discharge frame and the driving discharge roller are provided on the second rotating member, and the driving and driven discharge rollers rotate in association with the rotation of the second rotating member by rotating the second rotating member without variation in relative position.
According to the seventh aspect of the present invention, when the second rotating member rotates into the second or B mode, the discharge frame rotates with the second rotating member and the medium pressing roller presses down the rear end of the recording medium. Moreover, since the driving discharge roller and the driven discharge roller rotate together by the rotation of the second rotating member, their relative positions is not varied. Thus, the recording medium can be discharged in same states in the first or A mode and the second or B mode.
According to the eighth aspect of the present invention, the liquid ejection apparatus according to the second aspect further includes a locking mechanism for fixing a position of the first rotating member in the first mode or mode A and the second mode or mode B, wherein the gap is either narrow one in the mode A or wide one in mode B, and the second rotating member is adapted to be rotated by operating a operation lever usually energized on the side of the second mode or mode B.
According to the eighth aspect of the present invention, since the recess of the transfer path is very small, it is possible to enlarge the gap between the surface of the first rotating member facing the recording head, that is, the medium gap without moving the liquid ejection head when the A mode is switched to the B mode. Thus, it is possible to switch the medium gap by switching the mode. In addition, after switching the first or A mode and the second or B mode, the switched mode is fixed immediately. Therefore, it is possible to perform switching and fixing the mode by one-touch. Moreover, since the position of the first rotating member is fixed directly, it is possible to stably maintain the gap between the surface of the first rotating member facing the liquid ejection head and the liquid ejection head.
According to the ninth aspect of the present invention, a liquid ejecting apparatus of the eighth aspect further includes a link lever moving in association with the rotation of the first rotating member via an engaging unit; and a lock lever pressed in a direction to the link lever by an all-time pressing means, wherein two stable positions, where rotation of the link lever is prohibited by the lock lever, are to be defined.
According to the ninth aspect of the present invention, it is possible to realize low cost and small space because the locking mechanism is formed with a small number of elements. Moreover, sometimes a moving distance of the platen is short and a user cannot recognize easily the moving when the first or A mode and the second or B mode are switched to each other. In this case, it is possible to acquire two stable positions by prohibiting the rotation of the link lever by the lock lever pressed toward the link lever. Thus, it is possible to make a good feeling of clicking and the user can operate easily.
According to the tenth aspect of the present invention, the link lever is formed in order for a distance between a rotating fulcrum and the engaging unit to be shorter than a distance between the rotating fulcrum and a contact point of the lock lever.
According to the tenth aspect of the present invention, since the distance between the rotating fulcrum and the engaging unit to be shorter than the distance between the rotating fulcrum and the contact point of the lock lever, it is possible to properly increase a lever ratio while maintaining the difference between the distances. Thus, it is possible to prohibit the first rotating member from rotating even if unexpected external force is applied to the first rotating member. Moreover, even if the user contacts the platen forming one body with the first rotating member, the first rotating member does not move easily.
According to the eleventh aspect of the present invention, a liquid ejecting apparatus according to the ninth aspect further includes a sensing device provided on a moving path of the engaging member accompanied by the rotation of the first rotating member, wherein the sensing device senses the link lever in any one of the first or second mode or mode A or B.
According to the eleventh aspect of the present invention, since the sensing device is provided on a moving path of the engaging member accompanied by the rotation of the first rotating member, it is possible to surely sense the rotating member via the link lever.
According to the twelve aspect of the present invention, a liquid ejection apparatus includes a liquid ejection head for ejecting liquid on a medium; a guiding member for regulating a distance between the medium and the liquid ejection head, the guiding member being formed to be elongated in a main scanning direction of the liquid ejection head and provided on a position facing with the liquid ejection head; a driving discharge roller for rotating in contact with and discharging the medium on which liquid ejection is performed, the driving discharge roller being provided on a driving discharge roller axis elongated in the main scanning direction of the liquid ejection head on a downstream side of the liquid ejection head; a driven discharge roller for rotating in contact with the driving discharge roller; a driven discharge roller supporting frame for supporting the driven discharge roller, the driven discharge roller supporting frame being formed to be elongated in the main scanning direction of the liquid ejection head; and a main frame for supporting a rotation axis of the driving discharge roller together with the guiding member and the driven discharge roller supporting frame, wherein the guiding member includes a first guiding member provided on an upstream side of the liquid ejection head in a medium transfer direction, and a second guiding member provided on a downstream side of the liquid ejection head in the medium transfer direction, the second guiding member being able to be connected to the first guiding member with a snap type connecting unit, the second guiding member and the driven discharge roller supporting frame are integrated to form a unit, and the unit is adapted to be installed on the main frame by connecting the second guiding member to the first guiding member supported by the main frame.
According to the twelve aspect of the present invention, the guiding member is supported by the driving discharge roller rotation axis, the driven discharge roller supporting frame, and the main frame. Moreover, the guiding member is formed by the first guiding member of the upstream side and the second guiding member of the downstream side. The second guiding member and the driven discharge roller supporting frame are integrated to form a unit. Therefore, it is possible to increase an assembling efficiency since the second guiding member and the driven discharge roller supporting frame can be installed on the main frame by installing the unit on the main frame after the unit is configured by forming one body with the second guiding member and the driven discharge roller supporting frame.
Moreover, since the first and second guiding members can be connected by a snap type connecting means, it is enough to connect the second guiding member to the first guiding member in a snap type during installing the unit on the main frame. Therefore, it is possible to install the unit on the main frame in a simple manner without using means such as a screw.
Furthermore, although the first guiding member is directly installed on the main frame, the second guiding member is installed to the main frame via the first guiding member. Therefore, even if temperature variation is generated in the second guiding member, large stress does not generate because the second guiding member is not directly bound to the main frame. Therefore, even if the guiding member is formed by the first guiding member and the second binding member separately, it is possible to lessen risk of stress deformation of the guiding member and maintain good printing quality by lessen or prohibit the variation in the gap between the recording medium and the liquid ejection head because the second guiding member is not directly bound to the main frame.
Similarly, the driven discharge roller supporting frame is also installed on the main frame via the first guiding member. In other words, the driven discharge roller supporting frame is not bound to the main frame. Therefore, it is possible to lessen or prohibit the deformation of the driven discharge roller supporting frame. Thus, since it is possible to maintain the position of the driven discharge roller constantly for a long time, it is possible to prevent printing quality from being worse (forming roller contact traces) due to the driven discharge roller's contacting strongly with the recording medium.
Moreover, in case the unit is removed from the fluid ejection apparatus, it is enough to decouple the first and second guiding members. Therefore, it is possible to improve maintenance and handling of the apparatus and to provide the recording medium in consideration of environmental merits by increasing recycling and/or reusing convenience.
According to the thirteenth aspect of the present invention, the second guiding member and the driven discharge roller support frame are engaged with each other by a snap type fitting means in order to form the unit.
According to the thirteenth aspect of the present invention, assembling efficiency is more improved since second guiding member and the driven discharge roller support frame are engaged with each other by the snap type fitting means in order to form the unit.
According to the fourteenth aspect of the present invention, the second guiding member includes a supporting unit for supporting the rotation axis of the driving discharge roller, and the rotation axis of the driving discharge roller is integrated with the unit to be a part of the unit.
According to the fourteenth aspect of the present invention, since the second guiding member includes the supporting unit for supporting the rotation axis of the driving discharge roller and the rotation axis of the driving discharge roller is integrated with the unit to be a part of the unit, it is possible to install the unit on the main frame after making the driven discharge roller rotation axis supported by the second rotating member and making one body with the driven discharge roller rotation axis. Thus, it is possible to increase working efficiency.
According to the fifteenth aspect of the present invention, the rotation axis of the driving discharge roller is formed to be supported by an axis receiving unit provided on the main frame via a bush member.
According to the fifteenth aspect of the present invention, the rotation axis of the driving discharge roller is supported to the main frame via the bush member. Therefore, it is possible to install easily the rotation axis of the driving discharge roller on the main frame by installing the bush member on the rotation axis of the driving discharge roller in advance.
According to the sixteenth aspect of the present invention, the first guiding member is adapted to swing around a swing axis provided on a upstream side of the connecting unit of the first and second guiding members, the second guiding member is adapted to swing around a swing axis provided on a downstream side of the connecting unit of the first and second guiding members, and a gap between the medium and the liquid ejection head is adjustable by swing operations of the first and second guiding members.
According to the sixteenth aspect of the present invention, since each of the first and second guiding members is adapted to swing, it is possible to adjust the gap between the recording medium and the recording head. Therefore, it is possible to adjust the gap without moving the liquid ejection head up and down and thus it is possible to make a gap adjusting mechanism with a simple configuration and low cost.
According to the seventeenth aspect of the present invention, the liquid ejection apparatus of the sixteenth aspect further includes a rotatable operation lever for performing the swing operation of the second guiding member, the operation lever being provided on a downstream side of the second guiding member, wherein the second guiding member includes a rotation end which is formed to be elongated in a direction toward the operation lever and to be able to deform elastically in a longitudinal direction of the second guiding member, the operation lever and the rotation end are adapted to operate in association with each other by engaging a protrusion formed on the rotation end to protrude in a longitudinal direction of the second guiding member with a hole formed on the operation lever, and an inclined surface for guiding the protrusion into the hole is formed on an upside of the hole.
According to the seventeenth aspect of the present invention, since the protrusion formed on the rotation end to protrude in a longitudinal direction of the second guiding member is engaged with the hole formed on the operation lever, the operation lever moves in association with the second guiding member. Moreover, since the inclined surface for guiding the protrusion into the hole is formed on an upside of the hole and the rotation end is adapted to deform elastically in the protruding direction of the protrusion (the longitudinal direction of the second guiding member), if the second guiding member is moved downward perpendicularly from the upside of the operation lever, the protrusion is guided to the hole by the inclined surface and they are engaged which is accompanied by the elastic deformation of the rotation end. Therefore, it is possible to simply engage the second guiding member and the operation lever by a simple operation of moving the second guiding member downward from the upside of the operation lever.
The above and other objects, features and advantages of the present invention will become more apparent from the following description of the presently preferred exemplary embodiments of the invention taken in conjunction with the accompanying drawings, in which:
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
A recording apparatus 1 shown in
As described with regard to
The scanner unit 5 includes a cover 15 capable of opening and closing by rotating upward about a rotation axis 13. Under the cover 15A, a glass mounting surface (not shown) for mounting a printed matter which is an object to be scanned is provided. Moreover, a scanning apparatus (not shown) is provided below the glass mounting surface. The scanner unit 5 rotates upward about the rotation axis 17 as one body and thus the top of the apparatus main body is open. Thus, it is possible to perform maintenance of members such as a carriage in a recording unit.
As shown in
In
In addition, in order to guide the recording medium P smoothly, a first rib 39a, a second rib 39b, and a third rib 39c are provided on the upstream side of the transferring direction of the platen 39, on a surface of the platen 39 opposed to the recording head, and on the downstream side of the platen 39, respectively. Moreover, a position indicated by the reference numeral 29b is a nip point of the sending roller 33.
The first, second, and third ribs 39a, 39b, and 39c define a gap between the recording medium P and the recording head 35 (herein after, referred to “medium gap PG”) by supporting the recording medium P from the underside while recording on the recording medium P is performed by the head 35.
The distance between the recording head 35 and the top surface of the platen 39, that is, the medium gap PG, may be properly adjusted according to the thickness of the recording medium P. When the medium gap PG is properly adjusted, the recording medium P passes through the first, second and third ribs 39a, 39b and 39c smoothly, and thus high quality recording is performed. The recording media P on which the recording head 35 records are discharged sequentially by a discharge roller 41. The discharge roller 35 includes a lower driving discharge roller 43 driven to rotate and an upper driven discharge roller 45 (herein after, referred to “notched discharge roller”) which is supported to freely rotate via a holder 45 of a discharge frame 44. The recording medium P is drawn out to be discharged by rotation of the rollers 35. Moreover, on a side of the proximal end of the discharge frame 44 (upstream side of the transferring direction), a medium pressing roller 47, which suppresses floating of the recording medium P, is provided via a holder 47a between the recording head 35 and the discharge roller 41. According to the present embodiment, the discharge frame 44 is made of metal.
Moreover, a guide 93 for guiding the recording medium to the discharge roller 41 is provided on the upstream side of the transferring direction of the driving discharge roller 43.
In
The medium guide front member 49 connects with a connecting unit 95 provided in the medium guide front assistant member 51 and is rotatable about the main scanning direction.
Then, the characteristic configuration of the present invention is described with reference to
A hole 59 is formed in one end of the operation lever 57. By the protrusion 51h (
Thus, the medium pressing roller 47 provided on the upstream side of the axis 43a of the discharge roller 43 moves to an upper position as shown in
On the other hand, the medium guide front assistant member 51 is rotatably connected to the medium guide front member 49 via the connecting unit 95. An axis 29a of the driving sending roller 29 is rotatably connected to the end of the upstream side of the feeding direction of the medium guide front member 49. Thus, when the medium guide front assistant member 51 rotates in the counterclockwise direction from a position shown in
At this time, as shown in
A perforating aperture unit 65a is formed in the link lever 67. A rotation fulcrum 65 passes through the perforating aperture unit 65a so that the link lever 67 rotates about the rotation fulcrum 65 (see
A lever holder 61 is provided to be adjacent to the medium guide front member 49. The protrusion 63 is formed on the medium guide front member 49 and protrudes from a long hole (not shown) formed in the link lever holder 61. The link lever holder 61 is provided with the link lever 67 having the rotation fulcrum 65 on the downstream side of the protrusion 63 in the feeding direction. The link lever 67 is provided with the hole 69 which the protrusion 63 passes through. Due to the above configuration, the protrusion 63 moves upward and downward which is accompanied by the rotation of the medium guide front member 49 and thus the link lever 67 can rotates in the clockwise or counterclockwise direction about the rotation fulcrum 65.
A sensing device 71 is provided below the link lever 67. The sensing unit 71 senses the distance from the bottom side of the link lever 67 and determines whether the medium pressing roller is in a state of
A perforating aperture unit 75a is formed in a lock lever 73 and a rotation fulcrum 75 passes through the perforating aperture unit 75a so that the lock lever 73 rotates about the rotation fulcrum 75. A protrusion 94 is formed on the lock lever 73 and connected to an end of a tensile coil spring 79 which is a spring pressing the lock lever 73 toward the link lever 67 (see
The lock lever 73, which is rotatable around the rotation fulcrum 75, is provided on the upstream side of the link lever 67 in the feeding direction. A stopping protrusion 77 is formed on the free end of the lock lever 73. Moreover, the tensile coil spring 79 is connected to the free end of the lock lever 73. Thus, the free end of the lock lever 73 is always pressed rotatably in the counterclockwise of
A cam 81 is formed on the free end of the link lever 67. The cam 81 is stopped by the upper side of the stopping protrusion 77 when the link lever 67 rotates upward and this state is maintained (see
As described above, the lock lever 73 is pressed toward the link lever 67 by the tensile coil spring which is an all-time pressing means. Thus, it is possible to obtain two stable positions in which rotation of the link lever 67 is prohibited. Moreover, as the protrusion 63 is formed on the medium guide front member 49, it is possible to directly fix the position of the medium guide front member 49. At this time, as the medium guide front member 49 forms one body with the platen 39, the gap between the platen 39 and the recording head 35, that is, the medium gap PG is maintained stably for the first or A mode and the second or B mode.
When the first or A mode is switched to the second or B mode, it is difficult for a user to recognize the mode switch because the distance variation of the medium gap PG is set to substantially 0.9 mm for the present embodiment. In addition, as described above, the stopping protrusion 77 is formed on the lock lever 73 and the lock lever 73 is pressed toward the link lever 67. By this, the rotation of the link lever 67 is prohibited and two stable positions of the link lever 67 (see
Moreover, it is possible to form the locking mechanism with a small number of elements, realize low cost and small space.
Furthermore, the distance between the rotation fulcrum 65 of the link lever 67 and a point at which the protrusion 63 is engaged to the hole 69 (let the point be the center of the protrusion 63) is shorter than the distance between the rotation fulcrum 65 and the cam 81 which is a contact point of the link lever 67 and the lock lever 73 (see
The sensing device is fixed on the link lever holder 61 so that a protruding piece 71a is opposed to the link lever 67 below the link lever 67. At this time, for the first or A mode, the link lever is not sensed by the sensing device 71. When the mode is changed to the second or B mode, the link lever 67 presses the protruding piece 71a by rotating in the counterclockwise and thus is sensed by the sensing device 71 (see
Moreover, as shown in
According to the present embodiment, the sensing device 71 is provided on the lower side of the link lever 67 and senses the link lever in the second or B mode. However, the sensing device 71 may be provided on the upper side of the link lever 67 and sense the link lever in the first or A mode.
Moreover, according to the present embodiment, the protrusion 63 is formed on the first rotating member 49 and the hole 69 is formed in the link lever 67 so as to engage with the protrusion 63. However, a protrusion and a recess may be formed on the first rotating member and the link lever, respectively and engage with each other.
In the following, the operation of the recording apparatus according to the present invention will be described. After recording on the recording medium P by using the recording apparatus 1, the rear end of the recording medium P does not bend as shown in
In the first or A mode, the operation lever 57 moves downward in opposition to the spring force of the spring member 58 as shown in
In the following, there will be description on the switching operation from the first or A mode to the second or B mode where the medium gap PG is large and the rear end of the recording medium P does not contact with the recording head 35 by moving the pressing roller downward as shown in
By moving the operation lever 57 shown in
Moreover, the medium guide front member 49 rotates about the axis 29a of the driving sending roller in the clockwise direction of
Since a transfer path consists of the medium guide front member 49 and the medium guide front assistant member 51 which are connected so as to be rotatable with respect to each other as described above, it is possible to bend the transfer path. As a result, it is possible to enlarge the gap between the platen 39 and the recording head 35 by bending the transfer path even if the recording head 35 does not move. Therefore, it is possible to adjust the medium gap PG by the mode switch. Thus, it is possible to prevent the rear end of the recording medium for contacting with the recording head. Moreover, since the bending of the transfer path is small, the smooth transfer of the recording medium is not disturbed.
Moreover, according to the description with regard to
In
Since the rotation fulcrum is moved to the upper stream side, it is possible to make a rotation radius connecting the platen 39 and the medium guide front member rotation axis 90 larger.
If the difference between the angles of the recording medium P1 and the recording medium P3 is large in the second or B mode where the medium gap PG is enlarged, a gap between ink drops ejected from each nozzle of the recording head 35 in a width scanning direction (the transfer direction) is constant but the paper transfer amount is varied (decreases) in a direction parallel to a nozzle forming surface by the difference in angle. In other words, since the ink is ejected with an inclination by the difference in angle with respect to a constant amount of the paper transfer, the gap in the width scanning direction is larger (variation in the print pitch). Thus, there is a problem of a banding phenomenon that causes color blur and a white line (part on which printing is not performed).
According to the present embodiment, it is possible to prevent the banding phenomenon by decreasing the difference of the angles of the recording medium P1 and the recording medium P3.
Moreover, according to present embodiment, the connecting unit 95 is provided on the downstream side of an end of the downstream side of the recording head 35 in the transfer direction of the recording medium and is not opposed to the recording head 35. As a result, even if the gap between the front end or the rear end of the recording medium and the recording head 35 during the recording, that is, the medium gap is varied due to a very small recess based on bending of the connecting unit 95, the variation is uniformly continuous and very small in a region in which the recording head 35 performs recording. Thus, there is not a problem of recording quality's becoming worse.
Moreover, the medium guide front member 49 rotates in the clockwise direction of
According to the present embodiment, generally, the user conducts printing in the first or A mode. Then, when the user finds out a stain due to contact of the recording medium and the recording head, the user switches the mode to the second or B mode and thus it is possible to prevent the contact of the recording medium and the recording head. Moreover, if the mode is set to the second or B mode, the operation panel 11 displays the second or B mode. By this, the user can distinguish the first or A mode and the second or B mode as occasion demands and return to the first or A mode generally.
By this, according to the present invention, it is possible to easily increase or decrease the medium gap PG only by operating the operation lever 57 without moving a carriage 4 upward and down.
According to the present invention described above, it is possible to move the medium pressing roller downward according to the kind of the recording medium and prevent the rear end of the recording medium from contacting with the recording head by using a relatively simple constitution.
In the following, other features of the present invention will be explained referring to
Here,
As described with regard to
Then, when the operation lever 57 is moved downward as shown in
The end of the upstream side of the first guiding member 49 in the transfer direction is rotatably connected to the main frame 2 (see
Moreover, when the operation lever 57 is moved down, the medium pressing roller 47 is moved to an upper position as shown in
As shown in
In other words, the protrusion 51h of the rotation end 51a is formed to protrude in a longitudinal direction of the second guiding member 51 and engages with the hole 59 formed in the operation lever 57. Thus, the operation lever 57 and the second guiding member 51 are linked to move. Here, the inclined surface 57a for guiding the protrusion 51h to the hole 59 is formed on the upside of the hole 59 and the rotation end 51a is adapted to be elastically deformed in a projecting direction of the protrusion 51h (that is, a longitudinal direction of the second guiding member). Therefore, if the second guiding member 51 is moved downward perpendicularly from the upside of the operation lever 57, the protrusion 51h is guided to the hole 59 by the inclined surface 57a and they are engaged which is accompanied by the elastic deformation of the rotation end 51a. Thus, it is possible to simply engage the second guiding member 51 and the operation lever 57 by a simple operation of moving the second guiding member 51 downward from the upside of the operation lever 57 and assembling efficiency is improved.
In the following, it will be described how the first guiding member 49, the second guiding member 51, the discharge frame 44, and the driving discharge roller rotation axis 43a are to be installed on the main frame 2.
In
Then, as shown in
Moreover, ink waste holes 49a and 49a are formed on the end of the first guiding member 49 in the longitudinal direction. The ink waste holes 49a and 49a is formed to perforate vertically a pipe unit 49e as shown in
Here, one of the ink waste holes 49a takes charge of two nozzle aperture arrays 36 and the size of the ink waste hole 49a is sufficiently large in comparison with the nozzle aperture arrays 36 as shown in
With regard to the absorbing materials 83 and 84 provided in the waste ink tray 85, an aperture 83a is formed in the absorbing materials 83 of the upper layer. The pipe unit 49e in which the ink waste hole 49a is formed gets into the aperture 83a. Therefore, it is possible to prevent that the waste ink drops become mist and the mist diffuses from the lower side of the pipe unit 49e (the ink waste hole 49a) to the outside. Moreover, it is possible to prevent the inside of the apparatus from being stained. Moreover, an aperture 84a and a groove which is not shown and communicates with the aperture 84a are formed in the absorbing materials 84 of the lower layer. Thus, the ink drops fell into the waste ink tray 85 diffuse over the whole tray.
As shown in
In the mean time, axis receiving units 51d, 51e, and 51f are formed in the second guiding member 51 as a supporting unit. The driving discharge roller axis 43a is fitted into the axis receiving unit 51d, 51e, and 51f in a snap type.
The driving discharge roller axis 43a is rotatably supported by axis receiving units 2c and 2d formed in the main frame 2 (
As described above, the driving discharge roller axis 43a is supported by the second guiding member 51 before being installed on the main frame 2 and is engaged with the discharge frame 44. Thus, it is possible to form the unit.
The first guiding member 49 and the second guiding member 51 may be connected by the snap type connecting means. In other words, axes 49b and 49c forming the connecting means are formed on both ends in the longitudinal direction of the first guiding member 49 as shown in
Therefore, when the first guiding member 49, the second guiding member 51, the driving discharge roller axis 43a and the discharge frame 44 are installed on the main frame 2, the second guiding member 51 included in the unit 50 is connected to the first guiding member installed on the main frame 2 in a snap type while they forms the unit 50 and the first guiding member 49 is installed on the main frame 2. By this, the second guiding member 51 and the discharge frame 44 are supported by the main frame 2 via the first guiding member 49. Moreover, at this time, the driving discharge roller axis 43a is fit into the axis receiving units 2c and 2d formed on the main frame 2 via the bush member 46. By this, the driving discharge roller axis 43a is supported by the main frame 2. Therefore, the unit 50 is supported by the main frame 2.
Now, the result achieved by the above described configuration is described in detail. The recording apparatus 1 includes the recording head 35, the platen unit 40 as the guiding member for regulating a distance between the recording medium P and the recording head 35, the platen unit being formed to be elongated in the main scanning direction of the recording head and provided on the position facing with the recording head 35, the driving discharge roller 43 for rotating in contact with and discharging the recording medium P on which recording is performed, the driving discharge roller 43 being provided on the driving discharge roller axis 43a elongated in the main scanning direction of the recording head 35 on a downstream side of the recording head 35, the driven discharge roller 45 for rotating in contact with the driving discharge roller 43, the discharge frame 44 for supporting the driven discharge roller 45, the discharge frame 44 being formed to be elongated in the main scanning direction of the recording head, and a main frame 2 for supporting the platen unit 40, the discharge frame 44 and the rotation axis 43a of the driving discharge roller 43. According to the recording apparatus 1, the platen unit 40 includes the first guiding member 49 in the upstream side and the second guiding member 51 in the downstream side, and the first and second guiding members 49 and 51 are configured to be connected with each other by a snap type connecting means. Moreover, the second guiding member 51 and the discharge frame 44 are integrated to form the unit 50, and the unit 50 is adapted to be installed on the main frame 2 by connecting the second guiding member 51 to the first guiding member 49 supported by the main frame 2.
Therefore, at first, it is possible to increase an assembling efficiency since the unit 50 can be easily installed on the main frame 2 after the unit 50 is configured by forming one body with the second guiding member 51, the discharge frame 44 and the rotation axis 43a of the driving discharge roller 43.
Moreover, it is enough to connect the second guiding member 51 to the first guiding member 49 in a snap type when the unit 50 is installed on the main frame 2 since the first and second guiding members 49 and 51 are configured to be connected by the snap type connecting means. Therefore, it is possible to simply install the unit 50 on the main frame 2 without using means such as a screw. Moreover, it is required to install the rotation axis 43a on the main frame 2, but it is enough to fit it into the axis receiving units 2c and 2d formed on the main frame 2 via the above described bush member 46.
Moreover, the first guiding member 49 is directly installed on the main frame 2, but the second guiding member 51 is installed via the first guiding member 49. Therefore, a large stress is not generated even when the second guiding member 51 is deformed due to high heat since the second guiding member 51 is not directly restricted by the main frame 2. Therefore, it is possible to maintain high recording quality by preventing or decreasing variation in medium gap PG since it is possible to decrease the risk of stress deformation for the whole platen unit 50.
Additionally, it is possible to prevent deformation of the discharge frame 44 since the discharge frame 44 is also installed on the main frame 2 via the first guiding unit 49, and thus to prevent the recording quality from decreasing, such as generation of notched marks, since it is possible to maintain the position of the driven discharge roller 45 uniformly for the long time.
Moreover, it is possible to increase maintenance efficiency of the recording apparatus 1 since it only needs to decouple the first and second guiding members 49 and 51 in case the unit 50 needs to be separated from the recording apparatus 1. Especially, the members may be stained by the ink mists since a waste ink tray is formed on a location away from the side end of the recording medium P between ribs 39a and 39b and 39b and 39c on the platen unit 40, in other words borderless recording can be performed, but it is easy to exchange the stained member since the unit 50 can be easily removed as described above. Thus, it is possible to provide a recording medium in consideration of environmental merits by increasing recycling and/or reusing convenience since it is enough to decouple the first and second guiding members 49 and 51 in case the unit 50 needs to be separated from the recording apparatus.
Moreover, it is possible to increase working efficiency when the rotation axis 43a of the driving discharge roller 43 is supported by the second guiding member 51 and installed on the main frame 2 since the rotation axis 43a of the driving discharge roller 43 forms one body of the unit 50 as a part of the unit 50 while the second guiding member 51 includes the axis receiving units 51d, 51e and 51f for supporting the rotation axis 43a of the driving discharge roller 43.
Although the liquid ejection apparatus of the present invention is described by way of an embodiment of a recording apparatus with a scanner, it is possible to apply the idea of the present invention to a liquid ejection apparatus including a carriage for supporting a liquid ejection head which performs liquid ejection on a medium and scans in a direction perpendicular to the medium transfer direction.
Although the invention has been described in its preferred form with a certain degree of particularity, obviously many changes and variations are possible therein. It is therefore to be understood that the present invention may be practiced than as specifically described herein without departing from scope and spirit thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2004-039148 | Feb 2004 | JP | national |
| 2004-192676 | Jun 2004 | JP | national |
| 2004-193599 | Jun 2004 | JP | national |
This application is a divisional of U.S. patent application Ser. No. 11/060,369, filed Feb. 16, 2005, issued U.S. Pat. No. 7,481,527, which claims priority to JP 2004-039148 filed on Feb. 17, 2004, JP 2004-193599 filed on Jun. 30, 2004 and JP 2004-192676 filed on Jun. 30, 2004. The contents of each of these applications are incorporated herein by this reference in their entirety.
| Number | Name | Date | Kind |
|---|---|---|---|
| 5852452 | Imai | Dec 1998 | A |
| 6059287 | Bae | May 2000 | A |
| 6273536 | Nozawa | Aug 2001 | B1 |
| 6315468 | Kishida et al. | Nov 2001 | B2 |
| Number | Date | Country |
|---|---|---|
| 10-211748 | Aug 1998 | JP |
| 2000037916 | Feb 2000 | JP |
| 2002-019204 | Jan 2002 | JP |
| 2002-248819 | Sep 2002 | JP |
| 2002-347304 | Dec 2002 | JP |
| 2003063095 | Mar 2003 | JP |
| 2004160844 | Jun 2004 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20090135216 A1 | May 2009 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11060369 | Feb 2005 | US |
| Child | 12316700 | US |
