Patent Application
20060071388
The present invention relates to a recording material guiding device for preventing frictional contact between a recording material and a recording material guiding member by displacing the recording material guiding member during recording, as well as a recording apparatus having the same.
Conventionally, after paper is set, a user guides a paper guide by moving the paper guide to a side end of the paper, so that there have been variations in the gap between the side end of the paper and the paper guide. For this reason, if the gap is large, the paper is skewed during paper feeding, and there are possibilities of the occurrence of a paper jam or a skew of the print on the paper. In a case where the aforementioned gap is small the frictional resistance between the paper and the paper guide becomes large, so that the paper becomes difficult to be fed, and there has been a possibility of causing a decline in the recording quality.
Accordingly, in JP-UM-A-5-12428, a paper guide of an automatic feeder is provided with a limiter mechanism. The limiter mechanism sets a fixed gap between each side end of the stacked paper and the paper guide on each side when the paper is set. By virtue of this gap, it is possible to reduce the frictional force between the paper and the paper guide.
However, if a fixed guide is always set, there is a possibility of a variation occurring in the main scanning direction due to the vibration during recording and the friction between the sheets of paper. Accordingly, there is a possibility of the paper coming into contact with the paper guide during recording, resulting in the occurrence of friction. Namely, since the friction hereafter referred to as the back tension) during recording is only reduced, the image quality can possibly decline in the case of A3 or the like having a large paper since in which the back tension is likely to occur.
Accordingly, the present invention has been devised in view of such problems, and its object is to provide a recording material guiding device which sets friction to nil instead of reducing the friction at least between one side end of the recording material and a side end guiding member during recording, as well as a recording apparatus having the recording material guiding device.
To attain the above object, in accordance with a first aspect of the invention there is provided a recording material guiding device comprising: a feed tray in which a recording maternal is stacked; a first side end guiding member and a second side end guide member for restricting the movement of the recoding material in a main scanning direction; and a hopper having the first side end guiding member and the second side end guide member and capable of causing the stacked recording material to be brought into contact with and move away from a feed roller so as to transport the stacked recording material to the feed roller, wherein the hopper has frictional contact preventing means for preventing frictional contact at least between one side end of the recording material and one of the first side end guiding member and the second side end guide member.
According to the first aspect of the invention, since the recording material guiding device has the frictional contact preventing means, it is possible to prevent frictional contact at least between one side end of the recording material and one of the first side end guiding member and the second side end guide member. Namely, back tension can be set to nil at least at one side end of the recording material. Accordingly, it is possible to improve the recording image quality since back tension can be reduced remarkably even in the case of the large A3 or the like having a large paper size in which the back tension is likely to occur.
According to a second aspect of the invention, in the first aspect, the recording material guiding device is characterized in that the frictional contact preventing means is comprised of: a first guide member which has the first side end guiding member and whose sliding movement in the main scanning direction is restricted; and a second guide member which has the second side end guide member, and is slidable in the main scanning direction with respect to the first side end guiding member up to a first position and a second position, wherein the first position is a position where the second side end guide member and the one side end of the recording material abut, and the second position is a position for forming a gap between the second side end guide member and the one side end of the recording material.
According to the second aspect of the invention, in addition to an operational effect similar to that of the first aspect, since the hopper is comprised of the first guide member and the second guide member which is slidable in the main scanning direction with respect to the first guide member up to the first position and the second position, and a gap can be formed between the second side end guide member and the side end of the recording material, there is no possibility of frictional contact occurring at the side end of the recording material on the second side end guide member side.
According to a third aspect of the invention, in the second aspect, the recording material guiding device is characterized in that the frictional contact preventing means has a moving direction converting mechanism for converting a force for causing the hopper to be brought into contact with and move away from the feed roller into a force for causing the second guide member to slide in the main scanning direction.
According to the third aspect of the invention, in addition to an operational effect similar to that of the second aspect since the frictional contact preventing means has the moving direction converting mechanism, the force for causing the hopper to be brought into contact with and move away from the recording material can be converted into the force for causing the second guide member to slide in the main scanning direction. Accordingly, by causing the hopper to move toward and away from the feed roller (hereafter, this motion will be referred to as the swinging motion), the second guide member can be slid to the first position or the second position.
In addition, since it is possible to make use of the power source for swinging the hopper toward the feed roller, a new power source is not required.
According to a fourth aspect of the invention, in the third aspect, the recording material guiding device is characterized in that the moving direction converting mechanism has a guide projection provided on the second guide member and a guide groove provided in the feed tray and adapted to engage the guide projection.
According to the fourth aspect of the invention, in addition to an operational effect similar to that of the third aspect, the moving direction converting mechanism can be constructed simply by merely providing the guide projection on the second guide member and the guide groove in the feed tray for engagement with the guide projection.
According to a fifth aspect of the invention, in the fourth aspect, the recording material guiding device is characterized in that the guide groove includes: a rectilinear portion provided on a side of the feed roller and extending in the same direction as a direction in which the hopper is brought into contact with and moves away from the feed roller; and an inclined portion provided on a side away from the feed roller and inclined with respect to the rectilinear portion.
According to the fifth aspect of the invention, in addition to an operational effect similar to that of the fourth aspect, since the guide groove has the rectilinear portion and the inclined portion, it is possible to control the sliding motion of the second guide member in the main scanning direction on the basis of one cycle of the swinging motion of the hopper toward the feed roller.
Furthermore, since the guide groove has the rectilinear portion on the feed roller side and the inclined portion on the side away from the feed roller, there is no possibility of hampering the pressing of the recording material against the feed roller, which is the essential operational effect of the hopper.
According to a sixth aspect of the invention, in any one of the second to fifth aspects, the recording material guiding device is characterized in that the second guide member has a guide member control portion for providing control such that when the second guide member is at the second position, the second guide member slides from the second position to the first position until ensuing recording material to be recorded is fed.
According to the sixth aspect of the invention, in addition to an operational effect similar to that of any one of the second to fifth aspects, since the second guide member has the guide member control portion, the second guide member can be slid from the second position to the first position until the ensuing recording material to be recorded is fed. Namely, the second side end guide member and the side end of the stacked recording material assume their original state of abutting against each other. Accordingly, in the case where the ensuing recording material (stacked recording material) has offset in the main scanning direction due to the aforementioned gap during recording, the second side end guide member is capable of pushing back the side end of the offset recording material to rearrange the side end of the recording material until the next feeding.
According to a seventh aspect of the invention, in the sixth aspect, the recording material guiding device is characterized in that the guide member control portion has a throughput control unit which provides control such that when a rear end in a transporting direction of the recording material is fed from the hopper to a downstream side, the second guide member slides from the second position to the first position.
According to the seventh aspect of the invention, in addition to an operational effect similar to that of any one of the second to fifth aspects, since the throughput control unit is provided, when the rear end in the transporting direction of the recording material is fed from the hopper to the downstream side, the second guide member can be moved from the second position to the first position. Namely, regardless of whether or not recording is being effected, the second guide member can be returned to the first position to prepare for the feeding of the ensuing recording material. In other words, since the second guide member is returned to the first position at an early timing, it is possible to improve the throughput.
According to an eighth aspect of the invention, in the seventh aspect, the recording material guiding device is characterized in that the throughput control unit has a recording material detector provided on the downstream side of the hopper to detect the rear end of the recording material.
According to the eighth aspect of the invention, in addition to an operational effect similar to that of the seventh aspect, since the recording material detector is provided, it is possible to reliably detect that the rear end of the recording material has been transported to the downstream side from the hopper.
According to a ninth aspect of the invention, in any one of the second to eighth aspects, the recording material guiding device is characterized by further comprising: a cam disposed coaxially with the feed roller to control the hopper, wherein the cam is provided with a projection which extends at least a length from the first position to the second position in the main scanning direction so as to abut against the second abutment portion at the second position.
According to the ninth aspect of the invention, in addition to an operational effect similar to that of any one of the second to eighth aspects, since the cam is provided with a projection which extends at least a length from the first position to the second position in the main scanning direction so as to abut against the second abutment portion at the second position, even if the second guide member is at the second position, control can be provided by the guide member control potion.
According to a 10th aspect of the invention, in any one of the second to ninth aspects, the recording material guiding device is characterized by further comprising: a liftup preventing guide disposed on the second side end guide member and adapted to prevent the lifting up of the stacked recording material, wherein the liftup preventing guide extends at least the length from the first position to the second position in the main scanning direction so as to be capable of abutting against a surface of the stacked recording material even if the second guide member is at the second position.
According to the 10th aspect of the invention, in addition to an operational effect similar to that of any one of the second to ninth aspects, the liftup preventing guide extends at least the length from the first position to the second position in the main scanning direction so as to be capable of abutting against the surface of the stacked recording material even if the second guide member is at the second position. Accordingly, it is possible to prevent the lifting up of the recording material stacked on the feed tray even if the second guide member is at the second position.
According to an 11th aspect of the invention, in any one of the second to 10th aspects, the recording material guiding device is characterized in that the second guide member is arranged to slide to a third position after sliding to the second position, and the third position is a position which is displaced slightly from the first position toward a side of the recording material.
As described before, even in a case where the second guide member is returned from the second position to the first position, there is a possibility that the side ends of the randomly oriented sheets of recording material fail to be arranged neatly.
Therefore, according to the 11th aspect of the invention, in addition to an operational effect similar to that of any one of the second to 10th aspects, the second guide member is arranged to slide to the third position which is a position displaced slightly from the first position toward the side of the recording material. Accordingly, even in the case where the side ends of the stacked sheets of recording material are randomly oriented at the second position, the second guide member slides to the third position, thereby making it possible to neatly arrange the side ends of the randomly oriented sheets of recording material by pushing them in.
According to a 12th aspect of the invention, in any one of the second to 11th aspects, the recording material guiding device is characterized in that the feed roller is disposed in such a manner as to be offset toward the first side end guiding member, the retard roller further comprising: a transport roller extending in the main scanning direction on the downstream side in the transporting direction of the feed roller and forwardly and reversely rotatable to transport the recording material; and unskewing means which unskews the recording material before feeding by means of the feed roller and the transport roller.
According to the 12th aspect of the invention, in addition to an operational effect similar to that of any one of the second to 11th aspects, unskewing means is provided, and the unskewing means unskews the recording material before feeding by means of the feed roller disposed in such a manner as to offset toward the first side end guide member side and the transport roller extending in the main scanning direction on the downstream side in the transporting direction of the feed roller and forwardly and reversely rotatable to transport the recording material. Therefore, the recording material can be moved slightly toward the opposite side to the first side end guide member side, i.e., toward the second side end guide member side. Accordingly, since a gap is produced between the side end of the recording material and the first side end guide member, it is possible to prevent frictional contact. As a result, during recording, it is possible to prevent the frictional contact of the recording material on both sides of the first side end guide member and the second side end guide member.
According to a 13th aspect of the invention, there is provided a recording apparatus comprising: a feeding section for feeding a stacked recording material by holding the stacked recording material; a recording section for effecting recording on the recording material fed from the feeding section; and a discharge section for discharging the recording material from the recording section, wherein the feeding section has the recording material guiding device according to any one of claims 1 to 12.
According to the 13th aspect of the invention, in the recording apparatus it is possible to obtain an operational effect similar to that of any one of the second to 12th aspects.
The present disclosure relates to the subject matter contained in Japanese patent application No. 2004-280743 fed on Sep. 27, 2004, which is expressly incorporated herein by reference in its entirety.
Hereafter, a description will be given of the embodiments of the invention with reference to the drawings.
As shown in
As shown in the drawing, an automatic feeder 20 is disposed in the rear of the ink jet recording apparatus 100, and an upwardly openable paper feed tray cover 6 is disposed in an upper portion of the automatic paper feeder 20. The paper feed tray cover 6 is used in an open state during the execution of recording, and the recording paper P before execution of recording is adapted to be stacked on a paper feed tray 22 forming a supporting surface for the recording paper P integrally with the paper feed tray cover 6 in the open state. The recording paper P stacked on the paper feed tray 22 is pressed against an outer peripheral surface of a paper feed roller 21 by a hopper 23 which swings toward the paper feed roller 21 side at a predetermined timing during paper feeding. The sheets of recording paper P pressed against the outer peripheral surface of the paper feed roller 21 are automatically fed one sheet at a time toward nips between an outer peripheral surface of a transport drive roller 41 and outer peripheral surfaces of transport driven rollers 42 by the rotative driving of the paper feed roller 21 disposed rotatably with a paper feed roller shaft 211 serving as a rotating shaft.
The main framework of a housing of the ink jet recording apparatus 100 is formed by a main frame 11, a left side frame 12, a right side frame 13, a right side outer frame 13a, and a rear frame 19. The left side frame 12 (through a member 191), the right side frame 13, and the right side outer frame 13a are connected by the rear frame 19 on the front side of the ink jet recording apparatus 100. Both ends of the transport drive roller 41 are respectively supported by the left side frame 12 and the right side frame 13 so as to be rotatable in the transporting direction (sub scanning direction Y) of the recording paper P. The left end of the transport drive roller 41 is rotatably supported by the left side frame 12 by means of a rotating bush 17, while the right end of the transport drive roller 41 is rotatably supported by the right side frame 13 by means of a rotating bush 18. In addition, a supporting portion formed in the vicinity of a center of the transport drive roller 41 is rotatably supported by an intermediate supporting member 15. The intermediate supporting member 15 is adapted to be capable of vertically moving a supporting position in the vicinity of the center of the transport drive roller 41 by the rotational position of an adjustment member 16 disposed rotatably on a sub frame 14. A high-friction resisting film is formed on that portion of the outer peripheral surface of the transport drive roller 41 where the recording paper P is pressed and brought in close contact, excluding the portion which is rotatably supported by the intermediate supporting member 15.
Two transport driven rollers 42 are supported in each transport driven roller holder 43 in such a manner as to be drivenly rotatable in the transporting direction of the recording paper P. The transport driven rollers 42 are disposed in such a manner as to be juxtaposed in parallel to the transport drive roller 41, and are respectively swingably supported by the main frame 11. Each transport driven roller holder 43 is pressed and urged against the transport drive roller 41 by a spring 431, with the result that each transport driven roller 42 is pressed against the outer peripheral surface of the transport drive roller 41 with a substantially fixed pressing force. In addition, auxiliary roller holders 43S are respectively disposed on the downstream side of the transport driven roller holders 43 in the sub scanning direction Y, and an auxiliary roller 42S is supported by each auxiliary roller holder 43S in such a manner as to be drivenly rotatable in the transporting direction of the recording paper P. The recording paper P which is fed from the automatic paper feeder 20 is guided toward the outer peripheral surface of the transport drive roller 41 by a paper guide front member 44, is nipped between the outer peripheral surface of the transport drive roller 41 and the outer peripheral surfaces of the transport driven rollers 42, and is pressed to be brought into close contact with the high-friction resisting film surface of the transport drive roller 41. As the transport drive roller 41 is rotated in the sub scanning direction Y, the recording paper P is transported in the sub scanning direction Y at a rate of transport corresponding to the amount of rotation of the transport drive roller 41.
A transport gear 54 is integrally attached to the transport drive roller 41 so as to be capable of transmitting the rotation, the rotative driving of a drive pulley 52 of a transport motor 51 (see
The ink jet recording apparatus 100 has a carriage 62 for causing a recording head 63 for effecting recording by injecting ink to the recording paper P to scan the recording paper P in the main scanning direction X. The carriage 62 is pivotally supported by a carriage guide shaft 61 so as to be reciprocatable in the main scanning direction X, and reciprocates in the main scanning direction X as the rotatively driving force of an unillustrated carriage motor is transmitted thereto by an unillustrated belt transmission mechanism. The carriage guide shaft 61 is disposed with its both ends supported by the left side frame 12 and the right side outer frame 13a. An ink cartridge (not shown) in which inks of various colors are filled is detachably mounted on the carriage 62, and the inks of various colors are supplied from the ink cartridge to the recording head 63. The head surface of the recording head 63 reciprocates in the main scanning direction X at a position opposing the platen 46, and the inks are injected from nozzles arranged in the head surface of the recording paper P being transported on the platen 46, so as to execute recording. The gap between the head surface of the recording head 63 and the recording surface of the recording paper P is defined by the platen 46. In addition, a known linear encoder for detecting the moved position of the carriage 62 is disposed in the ink jet recording apparatus 100. The linear encoder has a linear scale 64 disposed in parallel to the carriage guide shaft 61 and a linear scale sensor (not shown) for detecting slits formed at equal intervals in the linear scale 64.
Meanwhile, as means for discharging the recording paper P after the execution of recording, a first paper exit drive roller shaft 47 and a second paper exit drive roller shaft 48, which are supported by the paper guide rear member 45 so as to be rotatable in the sub scanning direction Y, are disposed on the downstream side of the platen 46 in the sub scanning direction Y. As shown in the drawings, a plurality of fit paper exit drive rollers 471 are provided at substantially equal intervals on the first paper exit drive roller shaft 47, and a plurality of second paper exit drive rollers 481 are similarly provided at substantially equal intervals on the second paper exit drive roller shaft 48 as well. The second paper exit drive rollers 481 rotates in the discharging direction tub scanning direction Y) as the rotatively driving force of the transport motor 51 is transmitted to the second paper exit drive roller shaft 48 through the transport gear 54, an intermediate gear 55, and a paper exit gear 56. The first paper exit drive rollers 471 rotate in the discharging direction (sub scanning direction Y) as the rotatively driving force of the transport motor 51 is transmitted to a gear 58 attached to the first paper exit drive roller shaft 47, through a gear 57 attached to the second paper exit drive roller shaft 48 so as to be capable of transmitting rotation as well as an unillustrated intermediate gear.
A paper exit frame 49 (
In the ink jet recording apparatus having such a construction, the blank recording paper P before recording is first automatically fed by the automatic paper feeder 20. Subsequently, the operation in which the automatically fed blank recording paper P before recording is transported with a predetermined amount of transport in the sub scanning direction Y by the rotation of the transport drive roller 41 while coming into sliding contact with the platen 46 opposing the head surface of the recording head 68 and the operation in which ink is injected from the recording head 63 reciprocating over the platen 46 in the main scanning direction X are alternately executed repeatedly to execute recording on the recording surface. Then, the recording paper P after execution of recording is discharged onto the discharged paper stacker 3 in the open state by the rotation of the first paper exit drive rollers 471 and the first paper exit driven rollers 472 in the discharging direction. This series of recording execution operations is executed as an automatic paper feed motor (not shown) serving as a driving force source of the automatic paper feeder 20, the transport motor 51, and a carriage driving motor (not shown) are controlled by an unillustrated recording controller.
Next, referring to FIGS. 5 to 7, a description will be given of a schematic construction of the automatic paper feeder 20 serving as an “automatic feeding device” in accordance with the invention.
A supporting surface 221 for supporting the recording paper P stacked on the paper feed tray 22 in a state in which leading ends of the stacked sheets of recording paper P abut is formed on the paper feed tray 22 serving as the “recording material stacking means” on which the recording paper P before execution of recording is stacked The hopper 23 which swings toward the paper feed roller 21 side at a predetermined timing during paper feeding is swingably disposed on the paper feed tray 22 swingably with a shaft 233 as a swinging shaft. The hopper 23 is urged by an unillustrated urging means in a direction of pressing an uppermost sheet P1 of the recording paper against the outer peripheral surface of the paper feed roller 21 from a lowermost sheet side of the recording paper P stacked in the hopper 23. A non-slip member 231 for the recording paper P is disposed in that portion of the hopper 23 where the outer peripheral surface of the paper feed roller 21 abuts. The hopper 23 undergoes cam engagement with a pair of hopper cams 213 respectively formed integrally in vicinities of both ends of the paper feed roller shaft 211, and its swinging position is defined by the hopper cams 213 so that the hopper 23 swings in correspondence with the rotational position of the paper feed roller shaft 211.
The hopper 23 is provided with a reference end guide 24 for defining one end side in the main scanning direction X of the recording paper P stacked on the paper feed tray 22 at a reference end serving as a “recording material reference end” in the main scanning direction X, as well as an edge guide member 25 for guiding the other end side in the main scanning direction X of the recording paper P stacked on the paper feed tray 22. The edge guide member 25 is hooked at its arm portion 252 to an upper end of the hopper 23, and engages thereat an elongated hole 232 elongated in the main scanning direction X and formed in the hopper 23, such that the edge guide member 25 is disposed slidably in directions indicated by reference sign S in correspondence with the size of the recording paper P. A liftup preventing guide 241 for preventing the recording paper P fed from the paper feed tray 22 from lifting up is formed on the reference end guide 24, as shown in the drawings. Similarly, a liftup preventing guide 251 for preventing the recording paper P fed from the paper feed tray 22 from lifting up is formed on the edge guide member 25 as well, as shown in the drawings.
The paper feed roller 21 has its both end portions supported rotatably in the feeding direction of the recording paper P, and is disposed concentrically and integrally with the paper feed roller shaft 211 serving as a “feed roller shaft” which rotates as the rotatively driving force of an automatic paper feed motor 27 (see
The first paper feed auxiliary roller 214, the second paper feed auxiliary roller 215, and the third paper feed auxiliary roller 216 are thin plate-shaped rotators having substantially the same D-shaped cross-sectional shapes as that of the paper feed roller 21, but a high friction member is not provided on their outer peripheral surfaces. These paper feed auxiliary rollers 214, 215, and 216 are formed with the same phase as that of the paper feed roller 21, and their outside diameters are set to be about 1 to 2 mm smaller than that of the paper feed roller 21. When the recording paper P is fed by the rotation of the paper feed roller 21 disposed in the vicinity of the one end side in the main scanning direction X, the respective outer peripheral surfaces of the first paper feed auxiliary roller 214, the second paper feed auxiliary roller 215, and the third paper feed auxiliary roller 216 abut against the recording surface (upper surface) on the other end side in the main scanning direction X. As a result, the leading end of the recording paper P is guided toward the nips between the transport drive roller 41 and the transport driven rollers 42 while the lifting up of the recording paper P at the other end side in the main scanning direction X is being prevented, and the feeding attitude of the recording paper P fed is being restricted. The recording paper P is fed in a state of being in uniform surface contact with a paper feed guide surface 222 formed on the paper feed tray 22 and a paper feed guide surface 444 formed on the paper feed guide member 44, thereby preventing a skew and the like of the recording paper P during paper feeding.
The first paper feed auxiliary roller 214 is formed at a position corresponding to a vicinity of the other end side in the main scanning direction X of the recording paper P in a case where A3-size recording paper P is stacked on the paper feed tray 22. The second paper feed auxiliary roller 215 is formed at a position corresponding to a vicinity of the other end side in the main scanning direction X of the recording paper P in a case where A4-size recording paper P is stacked on the paper feed tray 22. The third paper feed auxiliary roller 216 is formed at a position corresponding to recording paper P of a size smaller than the A4 size recording paper P. Further, a fourth paper feed auxiliary roller 212 is formed on the paper feed roller shaft 211 at a position closer to an end portion of the reference end side than the paper feed roller 21, thereby preventing the lifting up of the recording paper P in the vicinity of the one end side in the main scanning direction X. The fourth paper feed auxiliary roller 212 demonstrates a large effect particularly in the case of small recording paper P such as a name card size.
A retard roller 26 and a retard roller holder 261 are disposed at a position corresponding to the outer peripheral surface 21a and the outer peripheral surface 21b of the paper feed roller 21. The retard roller 26 and the retard roller holder 261 serve as “recording material separating means” for separating from the recording paper P1 being fed the other recording paper P which tends to enter the feeding path by being dragged by the recording paper P1 being fed when the recording paper P1 abutting against the outer peripheral surface 21a of the paper feed roller 21 is fed by the rotation of the paper feed roller 21 in the feeding direction. The retard roller 26 is a rotator provided with a high friction member such as a rubber material on its outer peripheral surface, has a substantially fixed resistance against driven rotation in the paper feeding direction, and is disposed by being rotatably supported by the retard roller holder 261. The retard roller holder 261 is pivotally supported by the paper bed tray 22 swingably with a shaft 262 as a swinging shaft, and one end side of a spring 263 whose other end side is retained by a portion of the paper feed tray 22 is connected thereto. Hence, the retard roller holder 261 is disposed by being urged such that the outer peripheral surface of the retard roller 26 presses the outer peripheral surface 21a of the paper feed roller 21 with a predetermined pressing force.
As for the retard roller holder 261, its swung position at which the outer peripheral surface of the retard roller 26 assumes a state of slightly projecting from the paper feed guide surface 222 is set as its position of a displacement limit in the pressing direction. For this reason, in a state of opposing the outer peripheral surface 21a of the paper feed roller 21 (during the paper feeding operation), the outer peripheral surface of the retard roller 26 abuts against the outer peripheral surface 21a with an appropriate pressing force, whereas in a state of opposing the outer peripheral surface 21b of the paper feed roller 21 (after the leading end of the recording paper P fed has been nipped by the transport drive roller 41 and the transport driven rollers 42), the outer peripheral surface of the retard roller 26 is spaced away from the outer peripheral surface 21b. As a result, back tension by the retard roller 26 is prevented from being applied to the recording paper P being nipped by the transport drive roller 41 and the transport driven rollers 42 and being transported in the sub scanning direction Y.
In the state in which the outer peripheral surface 21a of the paper feed roller 21 abuts against the outer peripheral surface of the retard roller 26 with an appropriate pressing force, and a plurality of sheets of recording paper P in an overlapped state are being nipped between the outer peripheral surface 21a of the paper feed roller 21 and the retard roller 26, the driven rotation resistance of the retard roller 26 is set to be smaller than the frictional resistance between the outer peripheral surface 21a of the paper feed roller 21 and the outer peripheral surface of the retard roller 26 and to be greater than the frictional resistance between the sheets of recording paper P in the overlapped state. As a result, only the recording paper P1 which abuts against the outer peripheral surface 21a of the paper feed roller 21 and is to be fed is fed by the rotation of the paper feed roller 21. The other overlapping sheets of recording paper P below the recording paper P1 to be fed are separated from the recording paper P1 to be fed by the driven rotation resistance of the retard roller 26, and their entry into the farther side of the nip between the outer peripheral surface 21a of the paper feed roller 21 and the outer peripheral surface of the retard roller 26 is prevented. Therefore, it is possible to prevent a plurality of sheets of recording paper P from being fed in the overlapping state.
As for the other sheets of recording paper P separated from the recording paper P1 to be fed by the driven rotation resistance of the retard roller 26, there are cases where their leading ends remain in the vicinity of the retard roller 26. For this reason, the automatic paper feeder 20 is provided with a paper return lever 28 (
Next, referring to FIGS. 8 to 11, a description will be given of an outline of the operation of the automatic paper feeder 20.
FIGS. 8 to 11 are side elevational views of essential portions of the automatic paper feeder 20.
When the paper feed roller 21 starts to rotate in the rotating direction indicated by reference character A, the hopper 23 swings in the swinging direction indicated by reference character B. As a result, the uppermost recording paper P1 among the sheets of recording paper P stacked in the paper feed tray 22 is pressed and abutted against the outer peripheral surface 21a of the paper feed roller 21. Meanwhile, the paper return lever 28 swings in the swinging direction indicated by reference character C, and its paper returning surface 282, which advanced toward the paper feeding path side relative to the paper feed guide surface 222 in such a manner as to block the paper feeding path, retreats from the paper feeding path (
When the paper feed roller 21 further rotates in the rotating direction indicated by the reference character A, the recording paper P1 which is abutting against the outer peripheral surface 21a of the paper feed roller 21 and is to be fed is fed in the paper feeding direction. As described before, the other sheets of recording paper P in the overlapping state below the recording paper P1 to be fed are separated from the recording paper P1 to be fed by the driven rotation resistance of the retard roller 26, and their entry into the farther side of the nip between the outer peripheral surface 21a of the paper feed roller 21 and the outer peripheral surface of the retard roller 26 is prevented (
When the paper feed roller 21 further rotates in the rotating direction indicated by the reference character A, the recording paper P1 is fed while being guided toward the paper feed guide surface 444 of the paper feed guide member 44 in a state in which the leading end of the recording paper P1 to be fed is brought into surface contact with the paper feed guide surface 222. In addition, in the meanwhile, at a point of time when the paper feed roller 21 has rotated to a predetermined rotated position, the hopper 23 swings in the swinging direction indicated by reference character D. At this time, most of the sheets of recording paper P return to the predetermined position in the paper feed tray 22, but there are cases where leading ends of some of the sheets of recording paper P separated from the recording paper P1 to be fed by the driven rotation resistance of the retard roller 26 still remain in the vicinity of the retard roller 26 (
When the paper feed roller 21 further rotates in the rotating direction indicated by the reference character A, the paper return lever 28 swings in the swinging direction indicated by reference character E, and its paper returning surface 282 advances to the paper fed guide surface 222. The sheets of recording paper P whose leading ends still remain in the vicinity of the retard roller 26 are pushed back toward the predetermined position in the paper feed tray 22 by the paper returning surface 282 of the paper return lever 28. Meanwhile, the recording paper P1 to be fed reaches the nip between the transport drive roller 41 and the transport driven rollers 42 while its leading end is being guided by being brought into surface contact with the paper feed guide surface 444 of the paper feed guide member 44, and the recording paper P1 is set in a nipped state by being brought into contact with and is drawn by the outer peripheral surface of the transport drive roller 41 which rotates in the rotating direction indicated by reference character F. The paper feed roller rotates until its outer peripheral surface 21b reaches a rotated position opposing the outer peripheral surface of the retard roller 26, and the nipped state of the recording paper P1 to be fed by the paper feed roller 21 and the retard roller 26 is released, thereby completing the series of the paper feeding operation. Control of the recording execution with respect to the recording paper P1 fed is started, and the recording paper P1 is transported in the sub scanning direction Y by the rotation of the transport drive roller 41 in the rotating direction indicated by the reference character F (
Thus, the plurality of sheets of recording paper P stacked on the paper feed tray 22 are automatically fed one sheet at a time toward nips between the outer peripheral surface of the transport drive roller 41 and the outer peripheral surfaces of the transport driven rollers 42.
Next, referring to FIGS. 12 to 14, a farther description will be given of the construction of the recording material guiding device in accordance with the invention.
First, a description will be given with reference to
A recording material guiding device 601 in accordance with the invention has the paper feed tray serving as the “feed tray” in which the recording paper P serving as the “recording material” is stacked; a first side end guiding member 24a and a second side end guide member 25a for restricting the movement of the recording paper P in the main scanning direction; and the hopper 23 having the first side end guiding member 24a and the second side end guide member 25a and capable of causing the stacked recording paper P to be brought into contact with and move away from the paper feed roller 21 serving as a “feed roller.”
The hopper 23 in accordance with the invention has a frictional contact preventing means 602 for preventing frictional contact at least between one side end (opposite side to Pa) of the recording paper P and the first side end guiding member 24a or between the other side end Pa and the second side end guide member 25a during recording.
The frictional contact preventing means 602 is comprised of a first guide member 603 which has the first side end guiding member 24a and whose sliding movement in the main scanning direction is restricted, as well as a second guide member 606 which has the second side end guide member 25a, is engaged with the first guide member 603, and is slidable in the main scanning direction with respect to the first side end guiding member 24a up to a first position 604 (see
The second guide member 606 in accordance with this embodiment is comprised of a hopper swinging surface 23c, the edge guide member 25 including the second side end guide member 25a, and the liftup preventing guide 251, and the hopper singing surface 23c is engaged in an opening (not shown) provided in a side surface of the reference end guide 24 serving as the first guide member 603. Accordingly, the second guide member 606 can be slid in the main scanning direction with respect to the reference end guide 24 (first guide member 603). Namely, during recording, the gap d1 can be formed between the second side end guide member 25a and the side end Pa of the recording paper P by sliding the second side end guide member 25a from the first position 604 to the second position 605, so that fictional contact can be prevented at the side end Pa of the recording paper P on the second side end guide member side.
Consequently, back tension can be set to nil at least at the one side end Pa of the recording paper P. Accordingly, it is possible to improve the recording image quality since back tension can be reduced remarkably even in the case of the large A3 or the like having a large paper size in which the back tension is likely to occur.
In this embodiment, the swinging position of the hopper 23 is defined as the hopper 23 abuts against a first cam 213C and a second cam 213b so as to swing in correspondence with the rotational position of the paper feed roller shaft 211.
Here, the frictional contact preventing means 602 has a moving direction converting mechanism 607 for converting the force for causing the hopper 23 to be brought into contact with and move away from the paper feed roller 21 into the force for causing the second guide member 606 to slide in the main scanning direction. Accordingly, by causing the hopper 23 to move toward and away from the paper feed roller, the second guide member 606 can be slid to the first position 604 or the second position 605. Next, a detailed description will be given of the moving direction converting mechanism 607 in accordance with this embodiment.
Here, the moving direction converting mechanism 607 in accordance with the invention has a guide projection 608 provided on the second guide member 606 and a guide groove 609 provided in the supporting surface 221 of the paper feed tray 22 for engagement with the guide projection 608. As shown in
It should be noted that a description will be given later of an unskewing means denoted by reference numeral 619.
The guide groove 609 in accordance with this embodiment includes a rectilinear portion 610 provided on the paper feed roller side and extending in the same direction as the direction in which the hopper 23 is brought into contact with and moves away from the paper feed roller 21, as well as an inclined portion 611 provided on the side away from the paper feed roller 21 and inclined with respect to the rectilinear portion 610.
As shown in
In addition, it is possible to make use of the power source for swinging the hopper 23 toward the paper feed roller 21, and a new power source is not required.
Thus, the moving direction converting mechanism 607 can be constructed simply by merely providing the guide projection 608 on the second guide member 606 and the guide groove 609 in the supporting surface 221 of the paper feed tray 22 for engagement with the guide projection 608.
Further, since the guide groove 609 has the rectilinear portion 610 and the inclined portion 611, it is possible to control the sliding motion of the second guide member 606 in the main scanning direction on the basis of one cycle of the swinging motion of the hopper 23 toward the paper feed roller 21.
Furthermore, since the guide groove 609 has the rectilinear portion 610 on the paper feed roller side and the inclined portion 611 on the side away from the paper feed roller 21, there is no possibility of hampering the pressing of the recording paper P against the paper feed roller 21, which is the essential operational effect of the hopper 23.
In this embodiment, the liftup preventing guide 251 disposed on the second side end guide member 25a for preventing the lifting up of the stacked recording paper P extends at least the length from the first position 604 to the second position 605 in the main scanning direction. Accordingly, the liftup preventing guide 251 is capable of abutting against the surface of the stacked recording paper P even if the second guide member 606 is in the state of being located at the second position 605. As a result, it is possible to prevent the lifting up of the recording paper P even if the second guide member 606 is in the state of being located at the second position 605.
When the second guide member 606 slides from the first position 604 to the second position 605, control is provided by the cams. Accordingly, in the second guide member 606 on the sliding side, the first abutment portion 23b which abuts the cam also slides. Namely, there is a possibility of the cam engagement between the second cam 213b and the first abutment portion 23b becoming disengaged due to the sliding of the second guide member 606.
Accordingly, shown in
The second cam 213b in accordance with this embodiment is provided with the cam projection 213a which extends at least a length (d1) from the first position 604 to the second position 605 in the main scanning direction, and the cam projection 213a is arranged to abut against the second abutment portion 23a of the hopper 23 on the other side.
As shown in
Since the above-described arrangement is provided, depending on the shape of the hopper cam 218, i.e., the guide member control portion 612, or depending on the setting of the rectilinear portion 610 and the inclined portion 611 of the moving direction converting mechanism 607, control can be provided such that the second guide member 606 slides from the second position 605 to the first position 604 until the ensuing recording paper P to be recorded is fed. Accordingly, in the case where the ensuing recording paper P (stacked recording paper) has offset in the main scanning direction due to the gap d1 during recording, the second side end guide member 25a is capable of pushing back the side end Pa of the offset recording paper P to rearrange the side end Pa of the recording paper P until the next feeding.
Further, the recording material guiding device 601 in accordance with this embodiment has a recording material detector provided on the transport driven roller holder 43 (
Reference numeral 613 shown in
The recording paper P is fed in the state shown in
When a signal obtained by such a recording material detector 613 is received by a throughput control unit 617, and the rear end Pb of the recording paper P is fed from the hopper 23 to the downstream side, control can be provided such that the second guide member 606 slides from the second position 605 to the first position 604. Namely, regardless of whether or not recording is being effected, when the rear end Pb of the recording paper P is fed from the hopper 23 to the downstream side, the second guide member 606 can be returned to the first position 604 to prepare for the feeding of the ensuing recording paper P. In other words, since the second guide member 606 is returned to the first position 604 at an early timing, it is possible to improve the throughput.
In addition, since the second guide member 606 is returned at an early timing, the moving speed of the second guide member 606 can also be slowed down within a range which does not cause a decline in the throughput. Namely, the operating noise can be made quiet by slowing down the moving speed.
In addition, the recording material guiding device 601 in accordance with this embodiment has an unskewing means 619 (
Since the paper feed roller 21 is disposed in such a manner as to be offset toward the first side end guide member side, as the feeding progresses, the frictional resistance on the second side end guide member side at the side end of the recording paper P becomes greater than the frictional resistance on the first side end guide member side. Accordingly, the leading end of the recording paper P skews toward the opposite side of the first side end guide member side. Then, after the leading end of the recording paper in the skewed state has been fed slightly in the feeding direction by the transport drive roller 41, the transport drive roller 41 is reversely rotated until the state of engagement of the leading end of the recording paper P with the transport drive roller 41 is canceled. Thereupon, since the rotation of the paper feed roller 21 in the opposite direction is restricted, the recording paper P assumes a slightly deflected state in which the paper feed roller 21 lightly grips the recording paper P. Namely, the leading end of the recording paper P assumes a state of abutting in the main scanning direction at the nip line formed in the main scanning direction by the transport drive roller 41 and the transport driven rollers 42.
At this time, the recording paper P slips with respect to the paper feed roller 21 by the returning force of the deflection, so that the side end (opposite side to Pa) of the recording paper P moves away from the first side end guide member 24a.
In other words, the recording paper P can be moved slightly toward the opposite side to the first side end guide member side, i.e., toward the second side end guide member side. Accordingly, since a gap (not shown) is produced between the side end (opposite side to Pa) of the recording paper P and the first side end guide member 24a, it is possible to prevent frictional contact, As a result, during recording, it is possible to prevent the frictional contact of the recording paper P on both sides of the first side end guide member 24a and the second side end guide member 25a.
As described above, even in a case where the second guide member 606 is returned from the second position 605 to the first position 604, there is a possibility that the side ends Pa of the randomly oriented sheets of recording paper P fail to be arranged neatly.
Accordingly, the recording material guiding device in accordance with a second embodiment of the invention is so constructed as to arrange the side ends Pa neatly by pushing in the side ends Pa of the sheets of recording paper P by sliding the second guide member 606 slightly toward the recording paper side away from the first position 604.
The second guide member 606 in accordance with the second embodiment is arranged to slide to the third position 614 after sliding to the second position 605. The third position 614 is a position which is slightly displaced a distance d2 from the first position 604 toward the recording paper side.
As for a specific method of sliding to the third position 614, an inverse chevron-shaped inclined portion 618 which is inclined toward mutually different directions is provided between the rectilinear portion 610 and the inclined portion 611 of the guide groove 609, as shown in
Here, reference numeral 614 shown in
Consequently, even in the case where the side ends Pa of the stacked sheets of recording paper P are randomly oriented at the second position 605, the second guide member 606 slides to the third position 614, thereby making it possible to neatly arrange the side ends Pa of the randomly oriented sheets of recording paper P by pushing them in.
It should be noted that, in the present invention, although the gap d1 is provided with respect to the side ends Pa by sliding only the second guide member 606 on one side to prevent the frictional contact, it goes without saying that it is possible to provide the gap d1 with respect to the side ends of the recording paper P by sliding both sides, i.e., both the first guide member 603 and the second guide member 606 to completely set the frictional contact to zero.
In addition, the present invention is not limited to the foregoing embodiments, and it goes without saying that various modifications are possible within the scope of the invention recited in the claims, and that such modifications are also included in the scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2004-280743 | Sep 2004 | JP | national |
