US20080315497A1

US20080315497A1 - Feeding apparatus and recording apparatus

Info

Publication number: US20080315497A1
Application number: US12/142,508
Authority: US
Inventors: Satoshi Kobayashi
Original assignee: Seiko Epson Corp
Current assignee: Seiko Epson Corp
Priority date: 2007-06-20
Filing date: 2008-06-19
Publication date: 2008-12-25
Also published as: JP4826812B2; JP2009001366A

Abstract

The invention provides, as an aspect thereof, a feeding apparatus that includes: a target-medium feeding roller that feeds a target medium; a target-media placement unit on which target media are placed, the target-media placement unit being able to move toward and away from the target-medium feeding roller; a first urging unit that urges the target-media placement unit toward the target-medium feeding roller; a target-media-placement-unit retraction movement unit that moves the target-media placement unit away from the target-medium feeding roller; a movement unit that is provided at a downstream position as viewed from the target-media placement unit in a target-medium-feed direction and is able to move toward and away from the target-medium feeding roller; and a second urging unit that urges the movement unit toward the target-medium feeding roller.

Description

BACKGROUND

1. Technical Field
The present invention relates to a feeding apparatus that has a target-medium feeding roller that feeds a target medium and further has a target-media placement section on which target media are placed, where the target-media placement section of the feeding apparatus is able to move toward and away from the target-medium feeding roller thereof. In addition, the invention further relates to a recording apparatus that is provided with such a feeding apparatus.
2. Related Art
In the following description of this specification, the term “recording apparatus” according to the present invention encompasses various kinds of apparatuses, devices, machines, equipment, and the like such as an ink-jet printer, a wire dot printer, a laser printer, a line printer, a copying machine, and a facsimile machine, though not limited thereto. In addition, in the following description of the present invention, the term “liquid ejecting apparatus” encompasses various kinds of apparatuses, devices, machines, equipment, and the like that ejects liquid specific to each application/use onto a liquid ejection target medium from a liquid ejecting head, thereby causing the liquid to adhere to the liquid ejection target medium. A non-limiting example thereof is a recording apparatus such as an ink-jet printer, a copying machine, or a facsimile machine, though not limited thereto, that ejects ink, which is an example of the above-mentioned various kinds of liquid, onto a recording target medium, which is an example of the above-mentioned various kinds of liquid ejection target medium, from a recording head, which is an example of the above-mentioned various kinds of liquid ejecting head, thereby performing recording such as printing on the recording target medium.
Examples of a liquid ejecting head used in such a variety of liquid ejecting apparatuses include, without any limitation thereto: a color material ejection head that is used in the production of a color filter for a liquid crystal display device or the like; an electrode material (i.e., conductive paste) ejection head that is used for electrode formation for an organic EL display device, a surface/plane emission display device (FED), and the like; a living organic material ejection head that is used for production of biochips; and a sample ejection head that functions as a high precision pipette, in addition to the recording head described above.
In the configuration of a recording apparatus of the related art, a feeding apparatus that is provided therein has a recording-target-medium feeding roller that transports a recording target medium and further has a recording-target-media placement unit on which recording target media are placed, where the recording-target-media placement unit of the feeding apparatus of the related art is able to move toward and away from the recording-target-medium feeding roller thereof. Specifically, the feeding apparatus of the related art is provided with a hopper, which constitutes an example of the above-mentioned recording-target-media placement unit thereof. Examples of a recording apparatus of the related art as well as a feeding apparatus provided therein are disclosed in JP-A-2005-200141 and JP-A-2006-089276. In the configuration of the feeding apparatus of the related art, sheets of printing paper, which constitute an example of the above-mentioned recording target media, are placed, or, in other words, set, on the hopper (i.e., recording-target-media placement unit). In such a configuration of the feeding apparatus of the related art, the recording-target-medium feeding roller, or simply said, a paper-feed roller, feeds a sheet of printing paper that is placed on the hopper in a so-called “hopper-up” state/position. The hopper-up state/position is a positional state in which the hopper has moved close to the paper-feed roller.
FIG. 18 is an enlarged side view that schematically illustrates an example of the essential components of a feeding apparatus provided in a recording apparatus of the related art. As illustrated in FIG. 18, a feeding apparatus 501 of the related art is provided with a base body portion 505, a paper-feed roller 502, and a hopper 504. In the configuration of the feeding apparatus 501 of the related art, the hopper 504 constitutes an example of the above-mentioned recording-target-media placement unit. An urging member, which is not shown in the drawing, applies an urging force to the hopper 504 toward the paper-feed roller 502. In the following description of the feeding apparatus 501 of the related art, this urging force is referred to as an urging force A. The feeding apparatus 501 of the related art is further provided with a hopper-down mechanism, which is also not illustrated in the drawing. As the hopper-down mechanism operates, the hopper 504 moves away from the paper-feed roller 502 against the urging force A that is applied by the above-mentioned urging member. In addition to the above-described components, the feeding apparatus 501 of the related art is further provided with a bank separation portion 507. The bank separation portion 507 is formed on the base body portion 505 at a downstream position as viewed from the hopper 504 in (i.e., along) the paper-feed direction. The bank separation portion 507 is an example of a non-preparatory paper separation unit.
In a hopper-up state in which the hopper 504 has been lifted/raised to a position in the proximity of the paper-feed roller 502, the paper-feed roller 502 rotates in a clockwise direction as shown in the drawing. As the paper-feed roller 502 rotates in a clockwise direction, the uppermost sheet of printing paper 503 among a plurality of sheets thereof that are placed on the hopper 504 is fed in a downstream direction as viewed along the course of paper transportation. It should be particularly noted that, in the configuration of the feeding apparatus 501 of the related art described herein, it is only one point at which the sheet of printing paper 503 is urged toward the paper-feed roller 502. Accordingly, the magnitude of a paper feeding force (i.e., paper-feed force) B that is applied to the sheet of printing paper 503 for transport thereof is determined on the basis of the aforementioned urging force A that is applied by the above-mentioned urging member and further on the basis of a coefficient of friction between the paper-feed roller 502 and the sheet of printing paper 503. In this example, it is assumed that the urging force A that is applied by the above-mentioned urging member is two hundred (200) gram force (i.e., gram-force, or gram-weight). It is further assumed that the coefficient of friction between the paper-feed roller 502 and the sheet of printing paper 503 is one point eight (μ=1.8). Specifically, the magnitude of the paper feeding force B that is applied to the sheet of printing paper 503 for transport thereof is mathematically expressed as the product (multiplication result) of the urging force A that is applied by the above-mentioned urging member and the coefficient of friction between the paper-feed roller 502 and the sheet of printing paper 503 (Paper Feeding Force B=Urging Force A (200 gram force)×Coefficient of Friction (μ=1.8)). As the paper feeding force B of three hundred and sixty gram force (360 gf) is applied to the sheet of printing paper 503 for transport thereof, the sheet(s) of printing paper 503 starts to be fed in a downstream direction as viewed along the course of paper transportation. A paper-feed gap limitation portion 506 is formed on the base body portion 505. When the sheet(s) of printing paper 503 starts to be fed in a downstream direction as viewed along the course of paper transportation under the paper feeding force B applied thereto, the paper-feed gap limitation portion 506 functions to prevent, if it works successfully, any remaining sheets of printing paper 503 other than the uppermost one thereof from being transported together with the uppermost one thereof. This is called as preparatory paper separation.
Thereafter, the front edge of the sheet(s) of printing paper 503 arrives at the bank separation portion 507. Since the preparatory paper separation of the paper-feed gap limitation portion 506 may not be successful, there is a possibility that some sheets of printing paper 503 including the uppermost one and other one(s) are fed together so as to reach the bank separation portion 507. The bank separation portion 507 performs non-preparatory paper separation in a case where some sheets of printing paper 503 including the uppermost one and other one(s) are fed together to arrive thereat. Specifically, as the front edge of the sheet(s) of printing paper 503 is brought into contact with the bank separation portion 507, it is possible for the uppermost sheet of printing paper 503 only to be fed forward by the paper-feed roller 502 in a reliable operation. Such a configuration makes it possible to stop the undesired transport of the second sheet of printing paper 503 counted from the uppermost one and any subsequent sheets thereof that were placed under the second sheet thereof at the bank separation portion 507. The feeding apparatus 501 of the related art is further provided with a pair of paper pushback levers, which is not illustrated in the drawing. At the time when the hopper 504 retracts to its hopper-down position, these paper-returning levers push the second sheet of printing paper 503 counted from the uppermost one and the subsequent sheets thereof that were placed under the second sheet thereof, which were stopped at the bank separation portion 507, if any, back onto the hopper 504, which is provided at an upstream position as viewed from the bank separation portion 507 (or, paper-returning levers) in the paper-feed direction.
In order for the front edge of the uppermost sheet of printing paper 503 to successfully overpass the bank separation portion 507, it is necessary that the sheet of printing paper 503 should be transported/fed with a force that is greater than a certain overpass barrier force C. Herein, it is assumed that the magnitude of the overpass barrier force C is two hundred and fifty (250) gf (i.e., abbreviation of gram force). That is, it is necessary that the paper feeding force B (360 gf) should be greater than the above-mentioned certain overpass barrier force C (250 gf). In the configuration of the feeding apparatus 501 of the related art described herein, a rubber, which is an example of a high-friction member, is provided on the outer circumferential surface of the paper-feed roller 502 in order to increase the coefficient of friction between the paper-feed roller 502 and the sheet of printing paper 503. In such a configuration, when determining the magnitude of a paper feeding force B that is applied to the sheet of printing paper 503 for transport thereof, which is three hundred and sixty gram force (360 gf) as explained above, the aforementioned urging force A that is applied by the above-mentioned urging member, which is two hundred gram force (200 gf) as explained above, is adjusted with the rubber-enhanced coefficient of friction between the paper-feed roller 502 and the sheet of printing paper 503 (μ=1.8).
Since there is a limit in increasing the coefficient of friction between the paper-feed roller 502 and the sheet of printing paper 503, it is necessary to set the urging force A that is applied by the above-mentioned urging member at a large value (e.g., 200 gf) in order to obtain a sufficient magnitude of a paper feeding force B that is applied to the sheet of printing paper 503 for transport thereof. That is, in the configuration of the feeding apparatus 501 of the related art described herein, the urging force A that is applied by the above-mentioned urging member is set at a large value (e.g., 200 gf) in order to ensure that the paper feeding force B (360 gf) is greater than the above-mentioned certain overpass barrier force C (250 gf). For this reason, at the time when the hopper 504 is lifted/raised to a position in the proximity of the paper-feed roller 502, there is an adverse possibility that the sheets of printing paper 503 that are placed on the hopper 504 collide with the paper-feed roller 502 so as to generate a large collision noise. In addition, since the urging force A that is applied by the above-mentioned urging member is set at a large value (e.g., 200 gf), it is likely that the burden/load of the aforementioned hopper-down mechanism (which is not illustrated in the drawing) placed/imposed at the time when the hopper 504 moves away from the paper-feed roller 502 against the urging force A that is applied by the above-mentioned urging member is substantially large, which is not desirable. For example, if a motor drives the hopper-down mechanism, a motor torque will be large, resulting in large power consumption.

SUMMARY

An advantage of some aspects of the invention is to provide a feeding apparatus that is capable of reducing an urging force that is applied by an urging section for shortening the distance between a target-medium feeding roller that feeds a target medium and a target-media placement section on which target media are placed. In addition, the invention further relates to a recording apparatus that is provided with such a feeding apparatus.
In order to address the above-identified problem without any limitation thereto, the invention provides, as a first aspect thereof, a feeding apparatus that includes: a target-medium feeding roller that feeds a target medium; a target-media placement section on which target media are placed, the target-media placement section being able to move toward and away from the target-medium feeding roller; a first urging section that urges the target-media placement section toward the target-medium feeding roller; a target-media-placement-section retraction movement section that moves the target-media placement section away from the target-medium feeding roller; a movement section that is provided at a downstream position as viewed from the target-media placement section in a target-medium-feed direction and is able to move toward and away from the target-medium feeding roller; and a second urging section that urges the movement section toward the target-medium feeding roller.
A feeding apparatus according to the first aspect of the invention is provided with the second urging section. With such a configuration, a feeding apparatus according to the first aspect of the invention is capable of generating a plurality of target-medium-feed forces at a plurality of places along the target-medium-feed direction, where each of the plurality of target-medium-feed forces acts to transport a target medium due to contact with the target-medium feeding roller. Therefore, in comparison with the configuration of a feeding apparatus of the related art in which a target-medium-feed force is generated at only one place, the configuration of a feeding apparatus according to the first aspect of the invention described above makes it possible to reduce the magnitude of an urging force applied by the first urging section. Or, in other words, it is possible to reduce the load of the first urging section. Thus, a feeding apparatus according to the first aspect of the invention described above makes it possible to reduce a collision noise that is generated due to the collision of target media that are placed on the target-media placement section with the target-medium feeding roller as a result of so-called hopper-up operation, which is the movement of the target-media placement section toward the target-medium feeding roller.
In addition, since a feeding apparatus according to the first aspect of the invention described above makes it possible to reduce the magnitude of an urging force applied by the first urging section in comparison with that of a feeding apparatus of the related art in which a target-medium-feed force is generated at only one place, it is possible to reduce the load of the target-media-placement-section retraction movement section. For example, if the target-media placement section is moved away from the target-medium feeding roller under motive power supplied by a motor, a feeding apparatus according to the first aspect of the invention described above makes it possible to make the size of the motor smaller in comparison with that of a feeding apparatus of the related art in which a target-medium-feed force is generated at only one place. As a result thereof, a feeding apparatus according to the first aspect of the invention described above makes it possible to reduce power consumption in comparison with that of a feeding apparatus of the related art in which a target-medium-feed force is generated at only one place. In such an advantageous configuration of a feeding apparatus according to the first aspect of the invention described above, the aggregate target-medium-feed force that is the sum of the plurality of target-medium-feed forces that are generated at the plurality of places is greater, in magnitude, than a counteractive force that occurs at a counteractive region that lies at a downstream position as viewed from the plurality of places in the target-medium-feed direction.
It is preferable that the feeding apparatus according to the first aspect of the invention described above should further include a separating section that is provided at a downstream position as viewed from the target-medium feeding roller in the target-medium-feed direction, the separating section being able to separate target media that might be fed together one over another to the above-mentioned downstream position as viewed from the target-medium feeding roller in the target-medium-feed direction, wherein the target-media-placement-section retraction movement section starts to move the target-media placement section away from the target-medium feeding roller at a certain point in time within a time period from a point in time immediately after the front edge of the target medium that is now being fed has passed over the separating section to a point in time at which the front edge of the target medium that is now being fed reaches a pair of target-medium transport rollers that is provided at a downstream position as viewed from the separating section in the target-medium-feed direction.
In the preferred configuration of a feeding apparatus described above, which may be hereafter referred to as the “preferred second configuration”, in addition to the same advantageous configuration (and thus advantageous effects) of the feeding apparatus according to the first aspect of the invention described above, the target-media-placement-section retraction movement section starts to move the target-media placement section away from the target-medium feeding roller at a certain point in time within a time period from a point in time immediately after the front edge of the target medium that is now being fed has passed over the separating section to a point in time at which the front edge of the target medium that is now being fed reaches a pair of target-medium transport rollers that is provided at a downstream position as viewed from the separating section in the target-medium-feed direction. That is, in the preferred second configuration of a feeding apparatus described above, a point in time (i.e., timing) at which the target-media-placement-section retraction movement section starts to move the target-media placement section away from the target-medium feeding roller is earlier than that of a feeding apparatus of the related art in which a target-medium-feed force is generated at only one place.
Therefore, a feeding apparatus having the preferred second configuration of the invention described above makes it possible to arbitrarily set the start timing of the movement of the target-media placement section away from the target-medium feeding roller by the target-media-placement-section retraction movement section, resulting in greater design flexibility in comparison with that of a feeding apparatus of the related art in which a target-medium-feed force is generated at only one place. As a result thereof, it is possible to lower the peak value of the load of the target-media-placement-section retraction movement section so as to achieve load distribution. For example, if the preferred second configuration of a feeding apparatus described above is adopted, it is possible to start the movement of the target-media placement section away from the target-medium feeding roller by the target-media-placement-section retraction movement section at an earlier timing while taking a longer time for the execution thereof by moving the target-media placement section away from the target-medium feeding roller more slowly. By this means, it is possible to lower the peak value of the load of the target-media-placement-section retraction movement section so as to achieve load distribution.
It is preferable that the feeding apparatus according to the first aspect of the invention described above should further include a movement-section retraction movement section that moves the movement section away from the target-medium feeding roller. Such a configuration may be hereafter referred to as the “preferred third configuration”. In the preferred third configuration of a feeding apparatus described above, in addition to the same advantageous configuration of the feeding apparatus according to the first aspect (or the preferred second configuration) of the invention described above, a movement-section retraction movement section that moves the movement section away from the target-medium feeding roller is provided. For example, if the preferred third configuration of a feeding apparatus described above is adopted, and further if the target-medium feeding roller has the cross-sectional shape of a circle, at the time when the pair of target-medium transport rollers nips the front edge of the target medium that is now under transportation, it is possible to reduce an adverse possibility that the target-medium feeding roller damages the target medium, which is achieved by moving the movement section away therefrom.
If the preferred third configuration of a feeding apparatus described above is adopted, and further if the target-medium feeding roller has the cross-sectional shape of not a circle but an alphabet D, at the time when the pair of target-medium transport rollers nips the front edge of the target medium that is now under transportation, it is possible to reduce a frictional force that is generated between the target medium and the movement section, which is achieved by moving the movement section away therefrom. In addition, if more than one paper feeding forces is generated at three or more places, which act along the paper-feed direction, it is possible to control a combined (i.e., aggregate) paper-feed force in an appropriate manner.
In the configuration of the feeding apparatus according to the first aspect of the invention, it is preferable that the separating section should be a target-medium separating portion with which the front edges of target media are brought into contact, if fed together one over another, so that the separating section is able to separate the uppermost target medium from other target media that are fed together with the uppermost target medium; and a front-end region of the movement section that is formed on one end of the movement section that is closer to the target-medium feeding roller than the other end thereof should be able to move toward and away from the rotation fulcrum of the target-medium feeding roller. Such a configuration may be hereafter referred to as the “preferred fourth configuration”.
In the preferred fourth configuration of a feeding apparatus described above, in addition to the same advantageous configuration of the feeding apparatus according to the first aspect (or the preferred second or third configuration) of the invention described above, the separating section is a target-medium separating portion with which the front edges of target media are brought into contact, if fed together one over another, so that the separating section is able to separate the uppermost target medium from other target media that are fed together with the uppermost target medium; and a front-end region of the movement section that is formed on one end of the movement section that is closer to the target-medium feeding roller than the other end thereof is able to move toward and away from the rotation fulcrum of the target-medium feeding roller. Such a configuration may be hereafter referred to as the “preferred fourth configuration”. With such a preferred fourth configuration of a feeding apparatus, it is possible to ensure that the orientation (i.e., position) of a part of the target medium that is now being fed, which partially lies at a downstream position as viewed from the point of nip between the movement section and the target-medium feeding roller in the target-medium-feed direction, follows the tangential direction/projection of a virtual line that passes through the nip point on the circumference of the target-medium feeding roller. By this means, a feeding apparatus having the preferred fourth configuration of the invention described above determines the angle of approach of the target medium viewed with respect to the separating section when the target medium approaches (i.e., arrives at) the separating section at a constant value (i.e., constant angle).
As a result thereof, it is possible to considerably improve the reliability of non-preparatory separation; that is, the uppermost target medium with respect to the target-medium feeding roller can reliably overpass the separating section. That is, there is no risk that the uppermost target medium fails to pass over the separating section because of any variance/variation/difference between one angle of approach and another. In addition, with the preferred fourth configuration of a feeding apparatus described above, in a case where target media are fed together one over another, the separating section is able to separate the uppermost target medium from other target media that are fed together with the uppermost target medium in a reliable manner.
In the configuration of the feeding apparatus according to the first aspect of the invention, it is preferable that the movement section should have a sloped region that is formed at an upstream position as viewed from the front-end region of the movement section in the target-medium-feed direction; and the sloped region of the movement section is inclined with respect to the target-medium-feed direction. Such a configuration may be hereafter referred to as the “preferred fifth configuration”. In the preferred fifth configuration of a feeding apparatus described above, in addition to the same advantageous configuration of the feeding apparatus according to the first aspect (or the preferred second, third, or fourth configuration) of the invention described above, the movement section has a sloped region that is formed at an upstream position as viewed from the front-end region of the movement section in the target-medium-feed direction; and the sloped region of the movement section is inclined with respect to the target-medium-feed direction. Thanks to the presence of the sloped region, a feeding apparatus having the preferred fifth configuration of the invention described above can perform so-called preparatory target-medium separation at the time when target media are fed. Through the successful preparatory target-medium separation, the target-medium feeding roller feeds the uppermost target medium only. By this means, a feeding apparatus having the preferred fifth configuration of the invention described above can perform target-medium feeding operation in a reliable manner.
In the configuration of the feeding apparatus according to the first aspect of the invention, it is preferable that the front-end region of the movement section that is formed on the above-mentioned one end of the movement section that is closer to the target-medium feeding roller than the above-mentioned other end thereof should be provided along the width direction of the target medium at a position that faces the target-medium feeding roller. Such a configuration may be hereafter referred to as the “preferred sixth configuration”. In the preferred sixth configuration of a feeding apparatus described above, in addition to the same advantageous configuration of the feeding apparatus according to the first aspect (or the preferred second, third, fourth, or fifth configuration) of the invention described above, the front-end region of the movement section that is formed on the above-mentioned one end of the movement section that is closer to the target-medium feeding roller than the above-mentioned other end thereof is provided along the width direction of the target medium at a position that faces the target-medium feeding roller. With such a preferred sixth configuration of a feeding apparatus, it is possible to obtain the target-medium-feed force easily at the movement section.
In the preferred sixth configuration of a feeding apparatus described above, it is further preferable that a roller should be provided at the front-end region of the movement section. Such a configuration may be hereafter referred to as the “preferred seventh configuration”. In the preferred seventh configuration of a feeding apparatus described above, in addition to the same advantage of the feeding apparatus having the sixth configuration of the invention described above, a roller is provided at the front-end region of the movement section. With such a preferred seventh configuration of a feeding apparatus, it is possible to reduce a frictional force that is generated between the target medium that is now being fed and the movement section. Moreover, at the time when the target medium that is now being transported is released from the nip between the target-medium feeding roller and the movement section, it is possible to avoid any adverse effects that arise due to contact of the target-medium feeding roller and the movement section.
In the preferred seventh configuration of a feeding apparatus described above, it is further preferable that the axis of the roller should be made of a bar spring; and the target-medium feeding roller should have the cross-sectional shape of an alphabet D. Such a configuration may be hereafter referred to as the “preferred eighth configuration”. In the preferred eighth configuration of a feeding apparatus described above, in addition to the same advantage of the feeding apparatus having the seventh configuration of the invention described above, the axis of the roller is made of a bar spring; and the target-medium feeding roller has the cross-sectional shape of an alphabet D. If such a preferred eighth configuration of a feeding apparatus is adopted, it is possible to make the roller, which is provided at the front-end region of the movement section, protrude toward the target-medium feeding roller at the time when the chord portion of the target-medium feeding roller, which has the cross-sectional shape of an alphabet D, faces the roller in comparison with the state/position of the roller that is obtained when the arc portion of the target-medium feeding roller having the shape of D in its cross section faces the roller. Therefore, at the time when the chord portion of the D-shaped target-medium feeding roller faces the roller and further when the pair of target-medium transport rollers is feeding the target medium, it is possible to reduce so-called back tension, which is a friction between the target medium that is now under transportation/feeding and the movement section.
In order to address the above-identified problem without any limitation thereto, the invention provides, as a second aspect thereof (which constitutes the ninth configuration), a recording apparatus that includes: a recording-target-medium feeding section that feeds a recording target medium placed for recording; and a recording section that performs recording onto the recording target medium that is fed from the recording-target-medium feeding section by means of a recording head, wherein the recording-target-medium feeding section is provided with the feeding apparatus according to the first aspect (or the preferred second, third, fourth, fifth, sixth, or seventh configuration) of the invention described above. In the configuration of a recording apparatus according to the second aspect (i.e., ninth configuration) of the invention, the recording-target-medium feeding section is provided with the feeding apparatus according to the first aspect (or the preferred second, third, fourth, fifth, sixth, or seventh configuration) of the invention described above. Having such a configuration, a recording apparatus according to the second aspect of the invention offers the same advantageous effects as those offered by the feeding apparatus according to the first aspect or the preferred second, third, fourth, fifth, sixth, or seventh configuration of the invention described above.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.

FIG. 1 is a general perspective view that schematically illustrates an example of the configuration of a recording apparatus, which is a non-limiting example of a liquid ejecting apparatus according to an exemplary embodiment of the invention.

FIG. 2 is a general plan view that schematically illustrates an example of the configuration of the recording apparatus, which is a non-limiting example of the liquid ejecting apparatus according to an exemplary embodiment of the invention.

FIG. 3 is a perspective view that schematically illustrates an example of the configuration of a slider portion of a paper-feed unit according to an exemplary embodiment of the invention.

FIG. 4 is a downward view that schematically illustrates an example of the configuration of the slider portion of the paper-feed unit according to an exemplary embodiment of the invention.

FIG. 5 is a side view that schematically illustrates an example of an operation state of the paper-feed unit according to an exemplary embodiment of the invention; more specifically, FIG. 5 illustrates a hopper-down state, which is the standby state of the paper-feed unit.

FIG. 6 is a side view that schematically illustrates an example of an operation state of the paper-feed unit according to an exemplary embodiment of the invention; more specifically, FIG. 6 illustrates a state of paper-feed operation at the instant when a paper-feed roller according to an exemplary embodiment of the invention picks up a sheet of printing paper during a time period when a hopper according to an exemplary embodiment of the invention is in a hopper-up state.

FIG. 7 is a side view that schematically illustrates an example of an operation state of the paper-feed unit according to an exemplary embodiment of the invention; more specifically, FIG. 7 illustrates a state of paper-feed operation at the instant when the front edge of the sheet of printing paper P is brought into contact with a preparatory paper separation portion.

FIG. 8 is a side view that schematically illustrates an example of an operation state of the paper-feed unit according to an exemplary embodiment of the invention; more specifically, FIG. 8 illustrates a state of paper-feed operation at the instant when the front edge of the sheet of printing paper P has passed through the preparatory paper separation portion.

FIG. 9 is a side view that schematically illustrates an example of an operation state of the paper-feed unit according to an exemplary embodiment of the invention; more specifically, FIG. 9 illustrates a state of paper-feed operation at the instant when the front edge of the sheet of printing paper P is brought into contact with a bank separation portion.

FIG. 10 is a side view that schematically illustrates an example of an operation state of the paper-feed unit according to an exemplary embodiment of the invention; more specifically, FIG. 10 illustrates a state of paper-feed operation at the instant when the front edge of the sheet of printing paper P has passed over the bank separation portion.

FIG. 11 is a side view that schematically illustrates an example of an operation state of the paper-feed unit according to an exemplary embodiment of the invention; more specifically, FIG. 11 illustrates a state of paper-feed operation after the hopper-down operation has been initiated.

FIG. 12 is a graph that shows an example of the motor torque value of a paper-feed motor provided in the paper-feed unit according to an exemplary embodiment of the invention and further shows, for comparison, an example of the motor torque value of a paper-feed motor provided in a paper-feed apparatus of the related art.

FIG. 13 is a perspective view that schematically illustrates an example of the configuration of a slider portion of a paper-feed unit according to another embodiment 1 of the invention.

FIG. 14 is a downward view that schematically illustrates an example of the configuration of the slider portion of the paper-feed unit according to another embodiment 1 of the invention.

FIG. 15 is a sectional side view that schematically illustrates an example of the configuration of the slider portion of the paper-feed unit according to another embodiment 1 of the invention.

FIG. 16 is a perspective view that schematically illustrates an example of the configuration of a slider portion of a paper-feed unit according to another embodiment 2 of the invention.

FIG. 17 is a downward view that schematically illustrates an example of the configuration of the slider portion of the paper-feed unit according to another embodiment 2 of the invention.

FIG. 18 is an enlarged side view that schematically illustrates an example of the essential components of a feeding apparatus provided in a recording apparatus of the related art.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

With reference to the accompanying drawings, exemplary embodiments of the present invention are explained below. FIG. 1 is a general perspective view that schematically illustrates an example of the configuration of a recording apparatus, which is a non-limiting example of a liquid ejecting apparatus according to an exemplary embodiment of the invention. FIG. 2 is a general plan view that schematically illustrates an example of the configuration of the recording apparatus, which is a non-limiting example of the liquid ejecting apparatus according to an exemplary embodiment of the invention. A recording apparatus 100 according to the present embodiment of the invention has a recording apparatus main assembly (i.e., recording apparatus body) 101. A cassette unit 300 is provided on the back of the recording apparatus body 101. The cassette unit 300 is a part of a target-media placement unit 145. Sheets of recording paper P, which constitutes a non-limiting example of a (recording) target medium, are placed and stacked on the target-media placement unit 145. In the following description, the recording paper P is referred to as printing paper P. A cassette hopper 301, which is illustrated in FIGS. 5-11, is provided inside the cassette unit 300. The cassette hopper 301 is provided in such a manner that it can move toward and away from a paper-feed roller 190, which is illustrated in FIGS. 3-11. The paper-feed roller 190 is a component of a paper-feed unit (i.e., paper feeder) 144. A more detailed explanation on the paper-feed roller 190 will be given later. The cassette hopper 301 is provided in such a manner that it can swing with a certain point on the upper portion thereof as a fulcrum.
The paper-feed unit 144 feeds the uppermost sheet of printing paper P among a plurality of sheets thereof that are placed on the cassette hopper 301 in a downstream direction as viewed along the course of paper transportation, that is, toward a recording unit. Being driving by a paper-feed motor 104, the paper-feed roller 190 (refer to FIGS. 3-11) of the paper-feed unit 144 feeds the uppermost sheet of printing paper P among a plurality of sheets thereof that are placed on the cassette hopper 301 toward a pair of paper transport rollers 241, which is provided at a downstream position as viewed from the paper-feed roller 190 in the paper-feed (i.e., paper-transport) direction. The pair of paper transport rollers 241 is illustrated in FIGS. 6-10. After the sheet of printing paper P has been transported to the pair of paper transport rollers 241 (refer to FIGS. 6-10), a paper-transport motor, which is not illustrated in the accompanying drawings, drives the pair of paper transport rollers 241. As the pair of paper transport rollers 241 rotates under the driving force of the paper-transport motor, the sheet of printing paper P is further transported to a recording unit 143, which is provided at a downstream position as viewed from the pair of paper transport rollers 241 in the paper-transport (i.e., paper-feed) direction.
The recording unit 143 is made up of, though not necessarily limited thereto, a platen 105 and a carriage 107. The platen 105 provides a support to the sheet of printing paper P from the back thereof. The carriage 107 is provided over the platen 105 in such a manner that the carriage 107 and the platen 105 face each other. A carriage motor 102 supplies a driving force to the carriage 107 in such a manner that the carriage 107 travels in a main scan direction as guided by a carriage axis that extends along the main scan direction. It should be noted that the main scan direction is the direction of the width (i.e., width direction X) of the sheet of printing paper P, which is the target of transportation. It should be further noted that the carriage guide axis is not shown in the accompanying drawings. A recording head 106 is provided on the bottom surface of the carriage 107. The recording head 106 discharges ink drops onto the sheet of printing paper P. After the recording unit 143 has performed recording such as printing on the sheet of printing paper P, the sheet of printing paper P is further transported in a downstream direction. Then, a paper-eject roller, which is not illustrated in the accompanying drawings, ejects the sheet of printing paper P from the front of the recording apparatus 100.
Ink cartridges, which are not illustrated in the accompanying drawings, are provided on the lower region of the recording apparatus main assembly 101 of the recording apparatus 100. Ink contained in each of the ink cartridges enters through an ink-supply needle into an ink-supply passage. It should be noted that the ink-supply needles are not illustrated in the accompanying drawings. The ink-supply passages are also not illustrated in the accompanying drawings. Ink that has flowed into the ink-supply passage is supplied to the recording head 106 of the carriage 107 via an ink-supply tube 110. The forcible discharging of ink and suction thereof are carried out at an ink suction apparatus 200 at the time of the flushing operation of the recording head 106 and the cleaning operation thereof, respectively. The ink suction apparatus 200, which is provided at a one-digit side thereof, functions as an ink-discharging characteristic preservation/maintenance unit that keeps the ink-discharging characteristics of the recording unit 143 at an appropriate level. The ink suction apparatus 200 is provided with a cap unit 204. The cap unit 204 of the ink suction apparatus 200 can be elevated in a vertical direction, or, in other words, can move up and down, so as to seal the recording head 106.
FIG. 3 is a perspective view that schematically illustrates an example of the configuration of a slider portion of a paper-feed unit according to an exemplary embodiment of the invention. FIG. 4 is a downward view that schematically illustrates an example of the configuration of the slider portion of the paper-feed unit according to an exemplary embodiment of the invention. Each of FIGS. 5-11 is a side view that schematically illustrates an example of an operation state of the paper-feed unit according to an exemplary embodiment of the invention. Specifically, FIG. 5 illustrates a hopper-down state, which is the standby state of the paper-feed unit. FIG. 6 illustrates a state of paper-feed operation at the instant when a paper-feed roller according to an exemplary embodiment of the invention picks up a sheet of printing paper during a time period when a hopper according to an exemplary embodiment of the invention is in a hopper-up state. FIG. 7 illustrates a state of paper-feed operation at the instant when preparatory paper separation is being executed. FIG. 8 illustrates a state of paper-feed operation immediately after the preparatory paper separation has been completed. FIG. 9 illustrates a state of paper-feed operation at the instant when non-preparatory paper separation is being executed. FIG. 10 illustrates a state of paper-feed operation immediately after the non-preparatory paper separation has been completed. FIG. 11 illustrates a state of paper-feed operation after the hopper-down operation has been initiated. FIG. 12 is a graph that shows an example of the motor torque value of a paper-feed motor provided in the paper-feed unit according to an exemplary embodiment of the invention and further shows, for comparison, an example of the motor torque value of a paper-feed motor provided in a paper-feed apparatus of the related art.
As illustrated in FIGS. 3, 4, and 5, the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention is provided with a base body portion 210, the paper-feed roller 190, a hopper 250, and a slider portion 230. The paper-feed roller 190 is provided in such a manner that it can rotate around a paper-feed roller axis 193. The hopper 250 is provided at the front end of a hopper lever 252. The hopper 250 is provided in such a manner that it can move toward and away from the paper-feed roller 190. Specifically, the hopper lever 252 can move in a rotary manner so that the hopper 250 approaches the paper-feed roller 190 due to a first urging force F1 applied thereto. A helical torsion coil spring (i.e., torsion coil spring), which is not shown in the accompanying drawings applies the first urging force F1 to the hopper 250 and the hopper lever 252 so that they come closer to the paper-feed roller 190. The helical torsion coil spring is a non-limiting example that constitutes at least a part of a “first urging section” according to the invention. The application of the first urging force F1 is illustrated in each of FIGS. 6-10. In the description of an exemplary embodiment of the invention made in this specification, it is assumed that the magnitude of the first urging force F1 is one hundred gram force (100 gf).
A cam portion of a hopper-down mechanism according to an exemplary embodiment of the invention operates so that the hopper lever 252 moves, in a rotary manner, away from the paper-feed roller 190. It should be noted that the hopper-down mechanism, which is provided with a motor, is not illustrated in the accompanying drawings. Specifically, as the cam portion of the hopper-down mechanism operates, it is brought into engagement with a cam-follower portion of the hopper lever 252. As a result of the engagement of the cam portion thereof with the cam-follower portion thereof, the hopper-down operation is performed. It should be noted that the cam-follower portion of the hopper lever 252 is not illustrated in the accompanying drawings. When the cam portion of the hopper-down mechanism is brought into disengagement with the cam-follower portion of the hopper lever 252, or, in other words, when the cam portion of the hopper-down mechanism is released from the cam-follower portion of the hopper lever 252, the hopper-up operation is performed due to the above-mentioned first urging force F1 of one hundred gram force (100 gf) in magnitude.
A cork member 251 is provided on one surface of the hopper 250 that is closer to the paper-feed roller 190 than the other surface thereof. The cork member 251 constitutes a non-limiting example of a high-friction member. The cork member 251 is brought into contact with the lowermost sheet of printing paper P so as to support the sheets of printing paper P. The cork member 251 prevents the sheets of printing paper P from sliding down over the paper-transport channel like an “avalanche” due to their own weight or for any other reason, or reduces the risk thereof. The sheets of printing paper P are placed on the cassette hopper 301 of the cassette unit 300. As will be described in detail later, the cassette hopper 301 is provided in such a manner that it is brought into engagement with the hopper 250 so that it can move toward and away from the paper-feed roller 190.
The slider portion 230 of the paper-feed unit 144 according to the present embodiment of the invention is provided along the width direction X of the sheet of printing paper P at a position that faces the paper-feed roller 190, as illustrated in FIGS. 3 and 4. The slider portion 230 is provided in such a manner that it can move toward and away from the paper-feed roller 190 within a predetermined movement range. Specifically, the slider portion 230 is urged toward the paper-feed roller 190 under a second urging force F2 applied thereto. A slider spring, which is not shown in the accompanying drawings, applies the second urging force F2 to the slider portion 230 so that the slider portion 230 comes closer to the paper-feed roller 190. The slider spring is a non-limiting example of a “second urging section” according to the invention. The application of the second urging force F2 is illustrated in each of FIGS. 9, 10, and 11. A position-stopper unit determines the maximum movement range of the slider portion 230, that is, one maximum position thereof at which the slider portion 230 lies closest to the paper-feed roller 190 and the other maximum position thereof at which the slider portion 230 lies remotest to the paper-feed roller 190. It should be noted that the position-stopper unit is not illustrated in the accompanying drawings. The above-mentioned one maximum position at which the slider portion 230 lies closest to the paper-feed roller 190 is a positional state illustrated in each of FIGS. 3, 4, and 5. In the description of an exemplary embodiment of the invention made in this specification, it is assumed that the magnitude of the second urging force F2 is one hundred gram force (100 gf). A front-end region 231 is formed on one end of the slider portion 230 that is closer to the paper-feed roller 190 than the other end thereof. In addition, a sloped region 232 is formed on the slider portion 230 at an upstream position as viewed from the front-end region 231 in the paper-feed direction. The sloped region 232 of the slider portion 230 is inclined with respect to the paper-feed direction. The sloped region 232 of the slider portion 230 is provided so that the preparatory separation of the sheets of printing paper P can be performed thereat, as will be described later. In addition to the above-described components, the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention is further provided with a bank separation portion 240. The bank separation portion 240 is formed on the base body portion 210 at a downstream position as viewed from the slider portion 230 in the paper-feed direction. The bank separation portion 240 is a non-limiting example of a non-preparatory paper separation unit according to an exemplary embodiment of the invention. The bank separation portion 240 is provided so that it can perform “bank separation”, which is known in the technical field to which the present invention pertains. A more detailed explanation of the bank separation that is performed by the bank separation portion 240 will be given later. Moreover, the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention is further provided with a guiding-surface portion 211. The guiding-surface portion 211 is formed at a downstream position as viewed from the bank separation portion 240 of the base body portion 210 in the paper-feed direction. The guiding-surface portion 211 guides the sheet of printing paper P to the recording unit 143.
In the following description, the operation of the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention is explained. Hopper-down State (Standby State)
As illustrated in FIG. 5, the paper-feed roller 190 has the cross-sectional shape of an alphabet D, which is made up of a chord portion 191 and an arc portion 192. The reset position of the paper-feed roller 190 is defined as a positional state in which the chord portion 191 thereof faces the slider portion 230 and regional components of the base body portion 210 including but not limited to the bank separation portion 240. When the paper-feed roller 190 is in the reset position thereof, the hopper 250 is in the aforementioned hopper-down state in which the hopper 250 has moved away from the paper-feed roller 190.

Hopper-Up State

As illustrated in FIG. 6, the paper-feed roller 190 rotates in a clockwise direction from the hopper-down standby state illustrated in FIG. 5. As the paper-feed roller 190 rotates, the aforementioned cam portion that is not illustrated in the accompanying drawings turns. As the cam portion turns, the engagement between the cam portion and the cam-follower portion is released. As a result thereof, the hopper 250 and the hopper lever 252 move in a rotary manner so that they come closer to the paper-feed roller 190 due to the first urging force F1 of one hundred gram force (100 gf) in magnitude, which is applied thereto by the first urging section. This movement is so-called hopper-up operation. When the hopper 250 approaches the paper-feed roller 190 due to the first urging force F1, the hopper 250 is brought into engagement with the cassette hopper 301. By this means, the hopper 250, the cassette hopper 301, and the sheets of printing paper P move together toward the paper-feed roller 190. Then, the uppermost sheet of printing paper P among the plurality of sheets thereof that are placed on the cassette hopper 301 is brought into contact with the paper-feed roller 190.
Herein, it is assumed that a coefficient of friction between the paper-feed roller 190 and the sheets of printing paper P is denoted as μ1. In the following description, it is referred to as the coefficient of friction between the paper-feed roller 190 and the uppermost sheet of printing paper P. It is further assumed that a coefficient of friction between one (e.g., the uppermost) sheet of printing paper P and another (e.g., second from the top) sheet of printing paper P is denoted as μ2 whereas a coefficient of friction between the sheets of printing paper P and the cork member 251 is denoted as μ3. In the following description, the latter of the above (μ3) is referred to as the coefficient of friction between the lowermost sheet of printing paper P and the cork member 251. Under such an assumption, the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention is configured in such a manner that the following mathematical formula holds true: the coefficient of friction μ1>the coefficient of friction μ3>the coefficient of friction μ2. Because of such a frictional relationship, a first paper feeding force (i.e., first paper-feed force) G1 is generated, which is applied to the uppermost sheet of printing paper P as the paper-feed roller 190 rotates. That is, a paper-transport force for transporting the uppermost sheet of printing paper P in a paper-feed downstream direction occurs.
Herein, the magnitude of the first paper feeding force G1 is roughly calculated as the result of multiplication of the coefficient of friction between the paper-feed roller 190 and the uppermost sheet of printing paper P, which is denoted as μ1, by the first urging force F1. That is, roughly speaking, it is mathematically expressed as the product of the coefficient of friction μ1 and the first urging force F1: Magnitude of First Paper Feeding Force G1 (180 gf)=Coefficient of Friction μ1 (1.8)×First Urging Force F1 (100 gf). In order to facilitate the understanding of the invention, a counteractive frictional force that acts in the reverse direction is neglected when calculating a paper feeding force (i.e., paper-feed force). To be exact, if the counteractive frictional force that acts on the back of the uppermost sheet of printing paper P in the reverse direction is taken into consideration, the magnitude of the first paper feeding force G1 is mathematically expressed as follows: Magnitude of First Paper Feeding Force G1=(Coefficient of Friction μ1−Coefficient of Friction μ2)×First Urging Force F1. However, the coefficient of friction μ1 is substantially larger than the coefficient of friction μ2, which can be mathematically expressed as: Coefficient of Friction μ1>>Coefficient of Friction μ2. In view of the fact that its effect is negligible, the counteractive frictional force that acts on the back of the uppermost sheet of printing paper P in the reverse direction is not taken into consideration when calculating a paper feeding force in order to simplify explanation.
As the paper-feed roller 190 further rotates in a clockwise direction from a rotation position illustrated in FIG. 6, the uppermost sheet of printing paper P is fed in a downstream direction as viewed along the course of paper transportation due to the first paper feeding force G1 of one hundred and eighty gram force (180 gf) in magnitude applied thereto as shown in FIG. 7. Then, the front edge of the uppermost sheet of printing paper P is brought into contact with the sloped region 232 of the slider portion 230. At the time when the uppermost sheet of printing paper P is fed in a downstream direction as viewed along the course of paper transportation due to the first paper feeding force G1, there is an adverse possibility that an unwanted paper feeding force is applied to the second sheet of printing paper P counted from the uppermost one and any subsequent sheets thereof that were placed under the second sheet thereof because of the coefficient of friction μ2 between one (e.g., the uppermost) sheet of printing paper P and another (e.g., second from the top) sheet of printing paper P, though the magnitude of such an unwanted paper feeding force is small. If such an unwanted paper feeding force is generated, the second sheet of printing paper P counted from the uppermost one and any subsequent sheets thereof that were placed under the second sheet thereof may be fed together with the uppermost sheet thereof in a downstream direction as viewed along the course of paper transportation. As a result thereof, in the same manner as the front edge of the uppermost sheet of printing paper P is brought into contact with the sloped region 232 of the slider portion 230, the front edges of the second sheet of printing paper P counted from the uppermost one and any subsequent sheets thereof that were placed under the second sheet thereof are brought into contact with the sloped region 232 of the slider portion 230. As has already been described above, the sloped region 232 of the slider portion 230 is inclined with respect to the paper-feed direction. Because of such a configuration, in the above-explained case where, due to the unwanted paper feeding force, the second sheet of printing paper P counted from the uppermost one and any subsequent sheets thereof that were placed under the second sheet thereof are fed together with the uppermost sheet thereof in a downstream direction as viewed along the course of paper transportation, it is possible to ensure that the front edges of these sheets of printing paper P are brought into contact with the sloped region 232 of the slider portion 230 not at the same time but in a sequential order with the lowermost one being the first. Accordingly, the front edges of these sheets of printing paper P become out of alignment with one another at the sloped region 232 of the slider portion 230. That is, the sloped region 232 of the slider portion 230 supports these sheets of printing paper P while making the front edges thereof out of alignment with one another. This operation is called as preparatory paper separation.
As the paper-feed roller 190 further rotates in a clockwise direction from a rotation position illustrated in FIG. 7, as shown in FIG. 8, the largest paper-feed force (i.e., the first paper-feed force G1) is generated on the uppermost sheet of printing paper P because of the above-explained relationship among the magnitudes of the coefficients of friction. Since the first paper feeding force G1 is applied to the uppermost sheet of printing paper P, the uppermost sheet of printing paper P can overpass the front-end region 231 of the slider portion 230. Specifically, as the uppermost sheet of printing paper P moves along the sloped region 232 of the slider portion 230 and then along the front-end region 231 thereof, it moves the slider portion 230 away from the paper-feed roller 190 against the second urging force F2 of one hundred gram force (100 gf) in magnitude, which is applied thereto by the second urging section.
It is assumed herein that the magnitude of the second urging force F2, which is one hundred gram force (100 gf) in this example, is determined at a value that is small enough so that the slider portion 230 can be moved away from the paper-feed roller 190 against the second urging force F2 because of the application of the first paper-feed force G1, which is one hundred and eighty gram force (180 gf) in magnitude, to the uppermost sheet of printing paper P. In addition, it is further assumed herein that the inclination of the sloped region 232 of the slider portion 230 is determined at such a value that is sufficient for the slider portion 230 to be moved away from the paper-feed roller 190 against the second urging force F2. Moreover, it is further assumed herein that the magnitude of the second urging force F2, which is one hundred gram force (100 gf) in this example, is determined at a value that is large enough so that the slider portion 230 cannot be moved away from the paper-feed roller 190 against the second urging force F2 because of the application of the unwanted paper feeding force to the second sheet of printing paper P counted from the uppermost one and any subsequent sheets thereof that were placed under the second sheet thereof.
The uppermost sheet of printing paper P is urged toward the paper-feed roller 190 at the front-end region 231 of the slider portion 230 with the magnitude of the second urging force F2, which is one hundred gram force (100 gf) in this example. Accordingly, concurrently with the passage (i.e., overpass movement) of the front edge of the uppermost sheet of printing paper P over the front-end region 231 of the slider portion 230, a second paper feeding force G2, which is one hundred and eighty in magnitude (180 gf), is generated on, and applied to, the uppermost sheet of printing paper P at the front-end region 231 of the slider portion 230. Herein, with the same approach as taken in the calculation of the magnitude of the first paper feeding force G1 explained earlier, the magnitude of the second paper feeding force G2 can be roughly calculated as the result of multiplication of the coefficient of friction between the paper-feed roller 190 and the uppermost sheet of printing paper P, which is denoted as μ1, by the second urging force F2. That is, roughly speaking, it is mathematically expressed as the product of the coefficient of friction μ1 and the second urging force F2: Magnitude of Second Paper Feeding Force G2 (180 gf)=Coefficient of Friction μ1 (1.8)×Second Urging Force F2 (100 gf). As a consequence of the application of additional paper feeding force (i.e., G2) explained above, the sum of the first paper feeding force G1, which is one hundred and eighty gram force in magnitude (180 gf), and the second paper feeding force G2, which is one hundred and eighty gram force in magnitude (180 gf), that is, the aggregate paper feeding force of three hundred and sixty gram force in magnitude (360 gf), is applied to the uppermost sheet of printing paper P.
As the paper-feed roller 190 further rotates in a clockwise direction from a rotation position illustrated in FIG. 8, as shown in FIG. 9, the front edge of the uppermost sheet of printing paper P approaches (i.e., arrives at) the bank separation portion 240 and is brought into contact with the bank separation portion 240. Herein, it is assumed that the minimum overpass paper-transport force for canceling or offsetting an overpass barrier force G3 that is required for the front edge of the uppermost sheet of printing paper P to successfully pass over (i.e., pass through) the bank separation portion 240 is two hundred and fifty gram force in magnitude (250 gf). The overpass barrier force G3 counteracts, in the reverse direction, the aggregate paper feeding force of three hundred and sixty gram force in magnitude (360 gf) applied to the sheet of printing paper P, which is the sum of the first paper feeding force G1 (180 gf) and the second paper feeding force G2 (180 gf).
The sheet of printing paper P is nipped between the front-end region 231 of the slider portion 230 and the paper-feed roller 190. Therefore, the orientation (i.e., position) of a part of the sheet of printing paper P that partially lies at a downstream position as viewed from the nip point in the paper-feed direction follows the tangential direction/projection of a virtual line that passes through the nip point on the circumference of the paper-feed roller 190. By this means, the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention determines the angle of approach of the sheet of printing paper P viewed with respect to the bank separation portion 240 when the sheet of printing paper P approaches (i.e., arrives at) the bank separation portion 240 at a constant value (i.e., constant angle). That is, the paper-feed unit 144 can perform non-preparatory paper separation at the bank separation portion 240 in a reliable manner, thereby offering stable paper-feed operation.
For example, generally speaking, a so-called “non-feed” error/malfunction could occur if the angle of approach of the sheet of printing paper P viewed with respect to the bank separation portion 240 becomes an excessively steep value that does not fall within a tolerable angular range. The non-feed error/malfunction is an undesirable operation state in which the sheet of printing paper P cannot successfully overpass the bank separation portion 240. In this respect, the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention makes it possible to avoid such an adverse possibility because it ensures that the angle of approach of the sheet of printing paper P viewed with respect to the bank separation portion 240 is constant. On the other hand, generally speaking, in a case where the second sheet of printing paper P counted from the uppermost one and any subsequent sheets thereof that were placed under the second sheet thereof have passed through the front-end region 231 of the slider portion 230 together with the uppermost sheet thereof, there is an adverse possibility that the uppermost sheet of printing paper P is unable to be separated from the second and subsequent sheets thereof if the angle of approach of the sheets of printing paper P viewed with respect to the bank separation portion 240 becomes an excessively gentle value that does not fall within a tolerable angular range. In this respect, the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention makes it possible to avoid such an adverse possibility because it ensures that the angle of approach of the sheet of printing paper P viewed with respect to the bank separation portion 240 is constant.
As the paper-feed roller 190 further rotates in a clockwise direction from a rotation position illustrated in FIG. 9, as shown in FIG. 10, the front edge of the uppermost sheet of printing paper P successfully overpasses the bank separation portion 240. More specifically, as has already been explained earlier, the sum of the first paper feeding force G1, which is one hundred and eighty gram force in magnitude (180 gf), and the second paper feeding force G2, which is one hundred and eighty gram force in magnitude (180 gf), that is, the aggregate (G1+G2) paper feeding force of three hundred and sixty gram force in magnitude (360 gf), is applied to the uppermost sheet of printing paper P. Since the aggregate (G1+G2) paper feeding force of three hundred and sixty gram force in magnitude (360 gf) that is applied to the uppermost sheet of printing paper P is greater than the aforementioned minimum overpass paper-transport force for canceling or offsetting the overpass barrier force G3 that is required for the front edge of the uppermost sheet of printing paper P to successfully pass over the bank separation portion 240, which is two hundred and fifty gram force in magnitude (250 gf), the front edge of the uppermost sheet of printing paper P successfully overpasses the bank separation portion 240.
In addition, as has already been explained earlier, in a case where the second sheet of printing paper P counted from the uppermost one and any subsequent sheets thereof that were placed under the second sheet thereof have passed through the front-end region 231 of the slider portion 230 together with the uppermost sheet thereof, the front edges of the second and subsequent sheets thereof approach the bank separation portion 240 and are brought into contact with the bank separation portion 240. However, because of the above-explained relationship among the magnitudes of the coefficients of friction, there does not occur any unwanted paper-feed force that is greater than the overpass barrier force G3, which is two hundred and fifty gram force in magnitude (250 gf), on the second sheet of printing paper P counted from the uppermost one and any subsequent sheets thereof that were placed under the second sheet thereof. Therefore, the bank separation portion 240 catches the front edges of the second and subsequent sheets of the printing paper P so as to stop the movement, and thus further transport, of the second and subsequent sheets thereof whereas the uppermost sheet of printing paper P only is allowed to overpass the bank separation portion 240.
As the paper-feed roller 190 further rotates in a clockwise direction from a rotation position illustrated in FIG. 10, as shown in FIG. 11, the uppermost sheet of printing paper P is further fed in a downstream direction as viewed along the course of paper transportation. The paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention is configured to start the hopper-down operation immediately after that the front edge of the uppermost sheet of printing paper P has passed over (i.e., through) the bank separation portion 240. When the uppermost sheet of printing paper P is further transported in a downstream direction as viewed along the course of paper transportation at a paper-feed operation state illustrated in FIG. 11, it is not necessary to apply, to the uppermost sheet of printing paper P, a paper feeding force that is greater in magnitude than the overpass barrier force G3, the magnitude of which is two hundred and fifty gram force (250 gf), because the front edge of the uppermost sheet of printing paper P has already passed over the bank separation portion 240. For example, it is possible to perform skew correction with a relatively small paper feeding force of, for example, approximately 50 gf in magnitude. The skew correction is performed as a result of the cooperative rotation of the paper-feed roller 190 and the aforementioned pair of paper transport rollers 241, which is provided at a downstream position as viewed from the paper-feed roller 190 in the paper-feed direction. Therefore, after the front edge of the uppermost sheet of printing paper P has passed over the bank separation portion 240, it is not necessary to apply the aggregate paper feeding force of three hundred and sixty gram force in magnitude (360 gf), which is the sum of the first paper feeding force G1 of one hundred and eighty gram force in magnitude (180 gf) and the second paper feeding force G2 of one hundred and eighty gram force in magnitude (180 gf), to the uppermost sheet of printing paper P.
In the configuration of the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention, the second paper feeding force G2 of one hundred and eighty gram force in magnitude (180 gf) is sufficiently large so that the uppermost sheet of printing paper P can be transported after the front edge of the uppermost sheet of printing paper P has passed over the bank separation portion 240. Therefore, it is possible to start the hopper-down operation even during the execution of paper-feed operation. Moreover, in the configuration of the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention, a plurality of paper-feed forces is generated at a plurality of places. In such a configuration, it is possible for the front edge of the uppermost sheet of printing paper P to successfully overpass the bank separation portion 240 as long as the aggregate paper-feed force that is the sum of the plurality of paper-feed forces that are generated at the plurality of places is greater, in magnitude, than the aforementioned minimum overpass paper-transport force for canceling or offsetting the overpass barrier force G3 that is required for the front edge of the uppermost sheet of printing paper P to successfully pass over the bank separation portion 240, which is two hundred and fifty gram force in magnitude (250 gf). Therefore, in comparison with the configuration of a paper-feed apparatus of the related art in which a paper-feed force is generated at only one place, the configuration of the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention makes it possible to reduce the magnitude of the first urging force F1 that is applied to the hopper 250 by the first urging section.
For this reason, in comparison with the configuration of a paper-feed apparatus of the related art in which a paper-feed force is generated at only one place, the configuration of the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention makes it possible to reduce power load (i.e., burden) required for the hopper-down operation. Therefore, if the configuration of the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention is adopted, it is possible to make the size of the aforementioned hopper-down mechanism smaller in comparison with that of the related art. In addition, if the configuration of the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention is adopted, it is possible to start the hopper-down operation at a point in time (i.e., timing) earlier in comparison with that of the related art. Since the hopper-down operation can be initiated at an earlier point in time, it is possible to achieve motor load (i.e., burden) distribution. Because of the motor load distribution, it is possible to make motor torque load smaller at each moment of motor operation. Moreover, it is further possible to arbitrarily set the execution timing of the hopper-down operation, resulting in increased design flexibility.
Specifically, if the configuration of the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention is adopted, it is possible to complete the hopper-down operation prior to the execution of the paper-returning operation that is performed by a pair of paper pushback levers, which is driven by the same single motor as the power source of the hopper-down operation. In addition, since the hopper-down operation can be initiated at a point in time earlier in comparison with that of the related art, it is possible to reduce the burden (i.e., load) of the motor while performing the hopper-down operation more slowly with an increased gear ratio or the like. A cassette stopper unit 212 stops the hopper-down movement of the cassette hopper 301. The hopper 250 and the hopper lever 252 stop after the hopper 250 has been released from the cassette hopper 301 so as to enter the hopper-down state illustrated in FIG. 5.
FIG. 12 is a graph that shows an example of the motor torque value of a paper-feed motor provided in the paper-feed unit 144 according to an exemplary embodiment of the invention and further shows, for comparison, an example of the motor torque value of a paper-feed motor provided in a paper-feed apparatus of the related art. The vertical axis of the graph shown in FIG. 12 represents motor torque values. On the other hand, the horizontal axis of the graph shown in FIG. 12 represents the rotation angles of the paper-feed roller 190 with respect to the reset position. It should be noted that each rotation angle shown therein is measured from the reset position during a single rotation of the paper-feed roller 190, which starts from the reset position in a clockwise direction. It should be further noted that, in this part of the description, the reference numeral 190 is assigned to denote not only the paper-feed roller according to the present embodiment of the invention but also the paper-feed roller of the related art. In this graph, a broken line shows the motor torque value of a paper-feed motor provided in a paper-feed apparatus of the related art. A solid line shows the motor torque value of a paper-feed motor provided in the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention.
As illustrated in FIG. 12, at the time when the paper-feed roller 190 rotates by a rotation angle of approximately 40°, which is measured from the reset position as explained above, the hopper-up operation is executed in each of the paper-feed apparatus of the related art and the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention. As a result of the execution of the hopper-up operation, the motor torque value of a paper-feed motor provided in a paper-feed apparatus of the related art falls to zero. The motor torque value of a paper-feed motor provided in the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention also falls to zero. Thereafter, in each of the paper-feed apparatus of the related art and the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention, the paper-feed roller 190 feeds the sheet of printing paper P so that preparatory paper separation and non-preparatory paper separation are executed.
Next, at the time when the paper-feed roller 190 rotates by a rotation angle of approximately 70°, which is measured from the reset position as explained above, the front edge of the sheet of printing paper P passes through a preparatory paper separation portion in each of the paper-feed apparatus of the related art and the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention. Next, at the time when the paper-feed roller 190 rotates by a rotation angle of approximately 110°, which is measured from the reset position as explained above, the front edge of the sheet of printing paper P overpasses the bank separation portion 240 in each of the paper-feed apparatus of the related art and the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention. It should be noted that, in this part of the description, the reference numeral 240 is assigned to denote not only the bank separation portion according to the present embodiment of the invention but also the bank separation portion of the related art.
Next, at the time when the paper-feed roller 190 rotates by a rotation angle of approximately 150°, which is measured from the reset position as explained above, the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention starts the hopper-down operation. As a result thereof, the motor torque value of a paper-feed motor provided in the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention goes up to approximately 5.000 (N). When the hopper-down operation is initiated to increase the motor torque value to approximately 5.000 (N), as has already been explained above while making reference to FIG. 11, the sheet of printing paper P is still being transported by the paper-feed roller 190. In contrast, in the configuration of the paper-feed apparatus of the related art, it is not possible to start the hopper-down operation at this moment in time, or, in other words, at this rotation position, because a paper feeding force is generated at only one place, that is, the point of nip between the hopper 250 and the paper-feed roller 190.
Next, at the time when the paper-feed roller 190 rotates by a rotation angle of approximately 260°, which is measured from the reset position as explained above, the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention completes the hopper-down operation. As a result thereof, the motor torque value of the paper-feed motor provided in the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention goes down to approximately 2.000 (N). Next, at the time when the paper-feed roller 190 rotates by a rotation angle of approximately 270°, which is measured from the reset position as explained above, the pair of paper transport rollers 241, which is provided at a downstream position as viewed from the paper-feed roller 190 in the paper-feed direction, nips the front edge of the sheet of printing paper P that is now under transportation in each of the paper-feed apparatus of the related art and the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention. It should be noted that, in this part of the description, the reference numeral 241 is assigned to denote not only the pair of paper transport rollers according to the present embodiment of the invention but also the pair of paper transport rollers of the related art.
At this moment in time, the paper-feed apparatus of the related art starts the hopper-down operation. As has already been described earlier, in the configuration of the paper-feed apparatus of the related art, it is necessary to set the urging force of a hopper-urging spring larger than that (i.e., the first urging force F1 applied by the helical torsion coil spring to the hopper 250 and the hopper lever 252) of the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention. In addition, as has also already been described earlier, in the configuration of the paper-feed apparatus of the related art, the hopper-down operation is started at a point in time later than that of the present embodiment of the invention. For these reasons, if the configuration of the paper-feed apparatus of the related art is adopted, it is necessary to complete the hopper-down operation in a shorter execution time period in comparison with that of the present embodiment of the invention. Since it is necessary to finish the hopper-down operation in a shorter execution time period than that of the present embodiment of the invention, if the configuration of the paper-feed apparatus of the related art is adopted, the motor torque value of a paper-feed motor provided therein increases suddenly and rapidly to approximately 23.000 (N) upon the initiation of the hopper-down operation. That is, the peak motor torque value of the paper-feed motor provided in the paper-feed apparatus of the related art is considerably higher in comparison with the peak motor torque value of the paper-feed motor provided in the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention. Because of such a considerably higher peak value, the burden/load of the paper-feed motor of the related art is significantly larger than that of the paper-feed motor according to the present embodiment of the invention.
In the above-explained configuration of the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention, a slider-portion retraction movement unit may be further provided. The slider-portion retraction movement unit moves (i.e., retracts) the slider portion 230 away from the paper-feed roller 190 by means of cams or by means of any other alternative mechanism at the time when the pair of paper transport rollers 241, which is provided at a downstream position as viewed from the paper-feed roller 190 in the paper-feed direction, nips the front edge of the sheet of printing paper P that is now under transportation. If such a slider-portion retraction movement unit is provided, it is possible to retract the front-end region 231 of the slider portion 230 away from the sheet of printing paper P that is being transported. By this means, it is possible to avoid or reduce any unwanted friction between the slider portion 230 and the sheet of printing paper P that is being fed.
In the above-explained configuration of the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention, a plurality of slider portions 230 may be provided. If more than one slider portions 230 is provided, paper feeding forces are generated at three or more places, which act along the paper-feed direction. With such a configuration, it is possible to control a combined (i.e., aggregate) paper-feed force in an appropriate manner. In the above-explained configuration of the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention, the paper-feed roller 190 may have the cross-sectional shape of a circle. With such a configuration, at the time when the pair of paper transport rollers 241 nips the front edge of the sheet of printing paper P that is now under transportation, it is possible to reduce an adverse possibility that the paper-feed roller 190 damages the sheet of printing paper P, which is achieved by moving the slider portion 230 away therefrom.
At the time when the paper-feed roller 190 rotates by a rotation angle of approximately 310°, which is measured from the reset position as explained above, a pair of paper pushback levers 220, 220 starts the paper-returning operation under a driving force supplied by the same single motor as the power source of the hopper-down operation in each of the paper-feed apparatus of the related art and the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention. Subsequently, the paper-feed roller 190 rotates by a rotation angle of 360°, which is measured from the reset position as explained above, thereby returning to the original reset position thereof. Immediately before the paper-feed roller 190 rotates by the rotation angle of 360° so as to return to the original reset position, the paper-feed apparatus of the related art finishes the hopper-down operation and the paper-returning operation. On the other hand, immediately before the paper-feed roller 190 rotates by the rotation angle of 360° so as to return to the original reset position, the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention finishes the paper-returning operation.
As explained above, in the configuration of the paper-feed apparatus of the related art, the hopper-down operation is performed concurrently with the paper-returning operation. In contrast, if the configuration of the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention is adopted, it is possible to shift the execution timing of the hopper-down operation from the execution timing of the paper-returning operation, thereby ensuring that the hopper-down operation and the paper-returning operation are not performed concurrently with each other. As a result thereof, it is possible to ensure that the peak motor torque value of the paper-feed motor provided in the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention is considerably lower in comparison with the peak motor torque value of the paper-feed motor provided in the paper-feed apparatus of the related art. Because of such a considerably lower peak value, the burden/load of the paper-feed motor according to the present embodiment of the invention is significantly smaller than that of the paper-feed motor of the related art. This means that the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention makes it possible to achieve motor load distribution. Because of the motor torque distribution, it is possible to make motor torque burden smaller at each moment of motor operation.
In the foregoing description of the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention, it is explained that the paper-feed unit 144 thereof starts the hopper-down operation at the time when the paper-feed roller 190 rotates by a rotation angle of approximately 150°, which is immediately after the front edge of the uppermost sheet of printing paper P has passed over the bank separation portion 240. However, the scope of the invention is not limited to such an exemplary configuration. For example, the initiation timing of the hopper-down operation may be modified within a range of a time period from a point in time immediately after the front edge of the uppermost sheet of printing paper P has passed over the bank separation portion 240 to a point in time at which the pair of paper transport rollers 241 nips the front edge of the sheet of printing paper P. The same advantageous effects as those offered by the above-explained configuration could be obtained even when such a modified configuration is adopted.
The paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention, which is a non-limiting example of a feeding apparatus according to the invention, includes the following components/elements: the paper-feed roller 190 that feeds a sheet of printing paper P (which is a non-limiting example of a target-medium feeding roller that feeds a target medium); the hopper 250 that constitutes a non-limiting example or part of the target-media placement unit 145 on which sheets of printing paper P are placed, the target-media placement unit 145 being able to move toward and away from the paper-feed roller 190 (which is a non-limiting example of a target-media placement section on which target media are placed, the target-media placement section being able to move toward and away from the target-medium feeding roller); the first urging force F1 of the hopper 250, the hopper lever 252, and the aforementioned helical torsion coil spring that urges the hopper 250 toward the paper-feed roller 190 (which is a non-limiting example of a first urging section that urges the target-media placement section toward the target-medium feeding roller); the aforementioned hopper-down mechanism that moves the hopper 250 away from the paper-feed roller 190 (which is a non-limiting example of a target-media-placement-section retraction movement section that moves the target-media placement section away from the target-medium feeding roller); the slider portion 230 that is provided at a downstream position as viewed from the hopper 250 in the paper-feed direction and is able to move toward and away from the paper-feed roller 190 (which is a non-limiting example of a movement section that is provided at a downstream position as viewed from the target-media placement section in a target-medium-feed direction and is able to move toward and away from the target-medium feeding roller); and the second urging force F2 of the aforementioned slider spring that urges the slider portion 230 toward the paper-feed roller 190 (which is a non-limiting example of a second urging section that urges the movement section toward the target-medium feeding roller).
The paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention is capable of generating a plurality of paper-feed forces at a plurality of places along the paper-feed direction, including but not limited to, the first paper feeding force G1, the second paper feeding force G2, . . . , each of which acts to transport a sheet of printing paper P due to contact with the paper-feed roller 190. In such a configuration, the aggregate paper-feed force that is the sum of the plurality of paper-feed forces that are generated at the plurality of places is greater, in magnitude, than the overpass barrier force G3, which is a counteractive force that occurs at a counteractive region that lies at a downstream position as viewed from the plurality of places in the paper-feed direction. Specifically, in the foregoing explanation of the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention, the aggregate paper-feed force ΣGn (360 gf) that is the sum of the first paper feeding force G1 (180 gf) and the second paper feeding force G2 (180 gf) that are generated at the plurality of places is greater, in magnitude, than the overpass barrier force G3 (250 gf).
It is preferable that the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention should further include the bank separation portion 240, which constitutes a non-limiting example of a non-preparatory paper separating section (240), that is provided at a downstream position as viewed from the paper-feed roller 190 in the paper-feed direction, the non-preparatory paper separating section 240 being able to separate plural sheets of printing paper P that might be fed together one over another to the above-mentioned downstream position as viewed from the paper-feed roller 190 in the paper-feed direction (which is a non-limiting example of a separating section that is provided at a downstream position as viewed from the target-medium feeding roller in the target-medium-feed direction, the separating section being able to separate target media that might be fed together one over another to the above-mentioned downstream position as viewed from the target-medium feeding roller in the target-medium-feed direction), wherein the hopper-down mechanism (which is a non-limiting example of the target-media-placement-section retraction movement section) starts to move the hopper 250 (which is a non-limiting example of the target-media placement section) away from the paper-feed roller 190 (which is a non-limiting example of the target-medium feeding roller) at a certain point in time within a time period from a point in time immediately after the front edge of the sheet of printing paper P (which is a non-limiting example of the target medium) that is now being fed has passed over the non-preparatory paper separating section 240 (which is a non-limiting example of the separating section) to a point in time at which the front edge of the sheet of printing paper P (which is a non-limiting example of the target medium) that is now being fed reaches the pair of paper transport rollers 241 (which is a non-limiting example of a pair of target-medium transport rollers) that is provided at a downstream position as viewed from the non-preparatory paper separating section 240 (which is a non-limiting example of the separating section) in the paper-feed direction (which is a non-limiting example of the target-medium-feed direction). It is preferable that the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention should further include the aforementioned slider-portion retraction movement unit, which constitutes a non-limiting example of a movement-section retraction movement section that moves the slider portion 230 (which is a non-limiting example of the movement section) away from the paper-feed roller 190 (which is a non-limiting example of the target-medium feeding roller)
In the configuration of the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention, it is preferable that the non-preparatory paper separating section 240 (which is a non-limiting example of the separating section) should be a paper separating portion (which is a non-limiting example of a target-medium separating portion) with which the front edges of plural sheets of printing paper P (which is a non-limiting example of target media) are brought into contact, if fed together one over another, so that the non-preparatory paper separating section 240 (which is a non-limiting example of the separating section) is able to separate the uppermost sheet of printing paper P (which is a non-limiting example of the uppermost target medium) from other sheet(s) of printing paper P (which is a non-limiting example of target media) that are fed together with the uppermost sheet of printing paper P; and the front-end region 231 of the slider portion 230 (which is a non-limiting example of a front-end region of the movement section) that is formed on one end of the slider portion 230 (which is a non-limiting example of the movement section) that is closer to the paper-feed roller 190 (which is a non-limiting example of the target-medium feeding roller) than the other end thereof should be able to move toward and away from the rotation fulcrum of the paper-feed roller 190 (which is a non-limiting example of the target-medium feeding roller). In the configuration of the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention, it is preferable that the slider portion 230, which is a non-limiting example of the movement section, should have the sloped region 232 that is formed at an upstream position as viewed from the front-end region 231 of the slider portion 230 in the paper-feed direction; and the sloped region 232 of the slider portion 230 should be inclined with respect to the paper-feed direction.
In the configuration of the paper-feed unit 144 of the recording apparatus 100 according to the present embodiment of the invention, it is preferable that the front-end region 231 of the slider portion 230 that is formed on the above-mentioned one end of the slider portion 230 that is closer to the paper-feed roller 190 than the above-mentioned other end thereof should be provided along the width direction X of the sheet of printing paper P at a position that faces the paper-feed roller 190. The recording apparatus 100 according to the present embodiment of the invention, which constitutes a non-limiting example of a recording apparatus according to the invention, includes the following components: the paper-feed unit 144 that feeds a sheet of printing paper P placed for recording (which is a non-limiting example of a recording-target-medium feeding section that feeds a recording target medium placed for recording); and the recording unit 143 that performs recording onto the sheet of printing paper P that is fed from the paper-feed unit 144 by means of the recording head 106 (which is a non-limiting example of a recording section that performs recording onto the recording target medium that is fed from the recording-target-medium feeding section by means of a recording head).

Another Embodiment 1

FIG. 13 is a perspective view that schematically illustrates an example of the configuration of a slider portion of a paper-feed unit according to another embodiment 1 of the invention. FIG. 14 is a downward view that schematically illustrates an example of the configuration of the slider portion of the paper-feed unit according to another embodiment 1 of the invention (which is illustrated in FIG. 13). FIG. 15 is a sectional side view that schematically illustrates an example of the configuration of the slider portion of the paper-feed unit according to another embodiment 1 of the invention (which is illustrated in FIG. 13). As illustrated in FIGS. 13, 14, and 15, a slider portion 330 according to another embodiment 1 of the invention is provided with a roller 334 that can rotate freely at the front-end portion 231 thereof. Specifically, in the configuration of the slider portion 330 according to another embodiment 1 of the invention, the roller 334 is provided between a pair of convex portions 333, 333 of the front-end portion 231 thereof in such a manner that the roller 334 can rotate around a roller spindle (i.e., support axis) 335. The roller 334 of the slider portion 330 according to another embodiment 1 of the invention is provided along the width direction X of the sheet of printing paper P at a position that faces the paper-feed roller 190. With such a configuration, the outer circumferential surface of the roller 334 can be brought into contact with the paper-feed roller 190. In addition, the roller 334 can follow the rotation of the paper-feed roller 190. Therefore, as the paper-feed roller 190 rotates, the roller 334 rotates as a driven roller. Except for the above-explained components, the basic configuration of the present embodiment of the invention is the same as that of the first exemplary embodiment of the invention described above. Accordingly, in the following description, the same reference numerals are consistently used for the same components as those described in the first exemplary embodiment of the invention so as to omit any redundant explanation thereof.
During so-called “idling” operation, which is an operation state in which no paper is being fed, the outer circumferential surface of the roller 334 can be brought into contact with the paper-feed roller 190 so that the roller 334 can follow the rotation of the paper-feed roller 190 (i.e., driving roller) to turn as a driven roller. Since the slider portion 330 according to another embodiment 1 of the invention has such a configuration, it is possible to prevent the paper-feed roller 190, which is in a rotation state, and the slider portion 330 from being damaged due to contact of the rotating paper-feed roller 190 and the slider portion 330. On the other hand, in a paper-feed operation state, the roller 334 can follow the transport of a sheet of printing paper P that is now being fed so as to turn as a driven roller. Therefore, there is no risk of the generation of unwanted friction between the slider portion 330 according to another embodiment 1 of the invention and the sheet of printing paper P. Thus, the slider portion 330 according to another embodiment 1 of the invention makes it possible to prevent a sheet of printing paper P from being damaged due to unwanted friction between the slider portion 330 according to another embodiment 1 of the invention and the sheet of printing paper P.
In addition, since there is no risk of the generation of unwanted friction between the slider portion 330 according to another embodiment 1 of the invention and the sheet of printing paper P, it is possible to decrease the motor torque of the paper-feed motor 104, which is a driving source that supplies power to the paper-feed roller 190. As a consequence thereof, it is possible to make the size of the paper-feed motor 104 smaller in comparison with a case where the roller 334 is not provided. Moreover, it is possible to reduce power consumption by the reduction amount of motor torque. Furthermore, since there is no risk of the generation of unwanted friction between the slider portion 330 according to another embodiment 1 of the invention and the sheet of printing paper P, it is possible to reduce back tension that acts on a sheet of printing paper P in the above-explained operation state illustrated in FIG. 11. As a result thereof, the recording apparatus 100 according to another embodiment 1 of the invention can execute recording with high performance.
As a non-limiting modification example of the above, the roller spindle 335 may be made of a bar spring. That is, in such a non-limiting modified configuration, the roller 334 can move with respect to the slider portion 330 through the functioning of the bar spring. If the roller spindle 335 is made of a bar spring, it is possible to make the roller 334 protrude toward the paper-feed roller 190 as viewed from the pair of convex portions 333, 333 of the front-end portion 231 of the slider portion 330 at a rotation state/position in which the chord portion 191 of the paper-feed roller 190 faces the slider portion 330. Therefore, there is no risk of contact between a sheet of printing paper P and the pair of convex portions 333, 333 in the above-described rotation state/position. Thus, it is possible to reduce so-called back tension that acts on the rear edge of a sheet of printing paper that is now being fed.
In the configuration of the slider portion 330 according to another embodiment 1 of the invention, it is preferable that the roller 334 should be provided at the front-end portion 231 of the slider portion 330. In the configuration of the slider portion 330 according to another embodiment 1 of the invention, it is preferable that the axis of the roller 334, which is the roller spindle 335, should be made of a bar spring; and the paper-feed roller 190 has the cross-sectional shape of an alphabet D.

Another Embodiment 2

FIG. 16 is a perspective view that schematically illustrates an example of the configuration of a slider portion of a paper-feed unit according to another embodiment 2 of the invention. FIG. 17 is a downward view that schematically illustrates an example of the configuration of the slider portion of the paper-feed unit according to another embodiment 2 of the invention (which is illustrated in FIG. 16). As illustrated in FIGS. 16 and 17, a slider portion 430 according to another embodiment 2 of the invention is provided with a concave portion 435 at the front-end portion 231 thereof. That is, the front-end portion 231 of the slider portion 430 according to another embodiment 2 of the invention has a pair of convex portions 433, 433 and the concave portion 435. The concave portion 435 is formed between the pair of convex portions 433, 433. The concave portion 435 of the slider portion 430 according to another embodiment 2 of the invention is provided along the width direction X of the sheet of printing paper P at a position that faces the paper-feed roller 190. That is, each of the pair of convex portions 433, 433 of the slider portion 430 according to another embodiment 2 of the invention is provided, as viewed along the width direction X of the sheet of printing paper P, at an outside position that does not face the corresponding end of the paper-feed roller 190. Except for the above-explained components, the basic configuration of the present embodiment of the invention is the same as that of the first exemplary embodiment of the invention described above. Accordingly, in the following description, the same reference numerals are consistently used for the same components as those described in the first exemplary embodiment of the invention so as to omit any redundant explanation thereof.
Since the concave portion 435 is formed in the front-end portion 231 of the slider portion 430 according to another embodiment 2 of the invention, it is possible to avoid the paper-feed roller 190 from being brought into contact with the slider portion 430 according to another embodiment 2 of the invention during so-called idling operation, which is an operation state in which no paper is being fed. Since the slider portion 430 according to another embodiment 2 of the invention has such a configuration, it is possible to prevent the paper-feed roller 190, which is in a rotation state, and the slider portion 430 from being damaged due to contact of the rotating paper-feed roller 190 and the slider portion 430. It should be noted that, although each of the pair of convex portions 433, 433 of the slider portion 430 according to another embodiment 2 of the invention is provided, as viewed along the width direction X of the sheet of printing paper P, at an outside position that does not face the corresponding end of the paper-feed roller 190, it is still possible for each of the paper-feed roller 190 and the slider portion 430 according to another embodiment 2 of the invention to nip a sheet of printing paper P by utilizing the rigidity of the sheet of printing paper P. Therefore, even with such a configuration, it is possible to apply a paper-feed force of a certain magnitude to the sheet of printing paper P. That is, the same advantageous effects as those offered by the foregoing first exemplary embodiment of the invention could be obtained even when such a modified configuration is adopted. The present invention should be in no case interpreted to be limited to the specific embodiments described above. The invention may be modified, altered, changed, adapted, and/or improved within a range not departing from the gist and/or spirit of the invention apprehended by a person skilled in the art from explicit and implicit description given herein as well as appended claims. Needless to say, a feeding apparatus and a recording apparatus subjected to such a modification, alteration, change, adaptation, and/or improvement are also within the technical scope of the invention.
The entire disclosure of Japanese Patent Application No. 2007-162894, filed Jun. 20, 2007 is expressly incorporated by reference herein.

Claims

1. A feeding apparatus comprising:

a target-medium feeding roller that feeds a target medium;

a target-media placement section on which target media are placed, the target-media placement section being able to move toward and away from the target-medium feeding roller;

a first urging section that urges the target-media placement section toward the target-medium feeding roller;

a target-media-placement-section retraction movement section that moves the target-media placement section away from the target-medium feeding roller;

a movement section that is provided at a downstream position as viewed from the target-media placement section in a target-medium-feed direction and is able to move toward and away from the target-medium feeding roller; and

a second urging section that urges the movement section toward the target-medium feeding roller.

2. The feeding apparatus according to claim 1, further comprising a separating section that is provided at a downstream position as viewed from the target-medium feeding roller in the target-medium-feed direction, the separating section being able to separate target media that might be fed together one over another to the above-mentioned downstream position as viewed from the target-medium feeding roller in the target-medium-feed direction, wherein the target-media-placement-section retraction movement section starts to move the target-media placement section away from the target-medium feeding roller at a certain point in time within a time period from a point in time immediately after the front edge of the target medium that is now being fed has passed over the separating section to a point in time at which the front edge of the target medium that is now being fed reaches a pair of target-medium transport rollers that is provided at a downstream position as viewed from the separating section in the target-medium-feed direction.

3. The feeding apparatus according to claim 1, further comprising a movement-section retraction movement section that moves the movement section away from the target-medium feeding roller.

4. The feeding apparatus according to claim 1, wherein the separating section is a target-medium separating portion with which the front edges of target media are brought into contact, if fed together one over another, so that the separating section is able to separate the uppermost target medium from other target media that are fed together with the uppermost target medium; and a front-end region of the movement section that is formed on one end of the movement section that is closer to the target-medium feeding roller than the other end thereof is able to move toward and away from the rotation fulcrum of the target-medium feeding roller.

5. The feeding apparatus according to claim 1, wherein the movement section has a sloped region that is formed at an upstream position as viewed from the front-end region of the movement section in the target-medium-feed direction; and the sloped region of the movement section is inclined with respect to the target-medium-feed direction.

6. The feeding apparatus according to claim 1, wherein the front-end region of the movement section that is formed on the above-mentioned one end of the movement section that is closer to the target-medium feeding roller than the above-mentioned other end thereof is provided along the width direction of the target medium at a position that faces the target-medium feeding roller.

7. The feeding apparatus according to claim 6, wherein a roller is provided at the front-end region of the movement section.

8. The feeding apparatus according to claim 7, wherein the axis of the roller is made of a bar spring; and the target-medium feeding roller has the cross-sectional shape of an alphabet D.

9. A recording apparatus comprising:

a recording-target-medium feeding section that feeds a recording target medium placed for recording; and

a recording section that performs recording onto the recording target medium that is fed from the recording-target-medium feeding section by means of a recording head,

wherein the recording-target-medium feeding section is provided with the feeding apparatus according to claim 1.