1. Technical Field
The present invention relates to a feeding device such as a paper feeding device and a recording device including the feeding device, such as an ink jet-type printer.
2. Related Art
From the past, as disclosed in JP-A-8-91612, a recording device such as a printer includes a paper feeding device (feeding device) which automatically feeds plural sheets of paper placed in a stacked state (overlap state) to a recording portion by separating the paper sheet by sheet so that the recording is continuously performed on the paper (recording medium).
The paper feeding device disclosed in JP-A-8-91612 is equipped with a paper feeding cassette (mounting portion) allowing the plural sheets of paper to be stacked therein, a paper feeding roller delivering the top sheet of paper by a rotation motion thereof while it is in contact with the top sheet of paper from the stack of paper in a feeding direction, and a gate member for preventing the second top sheet (underlying sheet) of paper from being fed in the feeding direction along with the top sheet of paper.
In more detail, the gate member is movably supported so that is can move such that one end thereof serves as a support point and the other end thereof is in contact with the outer circumferential surface of the paper feeding roller at a predetermined pressure due to urging force of a compression spring. At the other end of the gate member, the inclined surface is provided at a position where the leading end of the paper delivered by the paper feeding roller can hit up. Therefore, if the leading end of the paper delivered by the paper feeding roller in the paper feeding direction hits up against the inclined surface, the gate member having the inclined surface pushed by the paper shakes in a direction in which it moves away from the outer surface of the paper feeding roller, while resisting against the urging force of the compression spring, and a gap is formed between the paper feeding roller and the gate member in a size such large as only one sheet of paper can pass. With such an operation, only the top sheet of paper is fed through the gap in the feeding direction. In the case in which double feeding occurs such that the sheet underlying the top sheet of the paper is fed along with the top sheet of paper due to frictional force between the top sheet and the underlying sheet of paper, the underlying sheet of paper is stopped by the inclined surface of the gate member, thus preventing the double feeding.
In such a paper feeding device, the paper feeding roller is typically configured such that the outer surface is made of a soft material, such as rubber, in order to generate frictional force for the delivery of the paper. Accordingly, as disclosed in JP-A-8-91612, if the other end of the gate member pressed up against the paper feeding roller, a problem that the outer surface of the paper feeding roller deforms arises particularly in conditions of high temperature and humidity. Here, the angle of the delivered paper to the inclined surface of the other end of the gate member is important when forming the gap between the gate member and the outer surface of the paper feeding roller, which allows only one sheet of paper to pass through, when the inclined surface of the gate member is shaken du to the being pushed by the paper. However, there is possibility that the outer surface of the paper feeding roller comes to be dented by the pushing pressure of the gate member, so that the contact angle between the paper and the inclined surface changes. Further, since the gate member rotates around the support point when the gate member is shaken due to being pushed by the paper, the contact angle between the paper and the inclined surface may change if the gate member is vigorously shaken. If the contact angle between the paper and the inclined surface changes, it is impossible to precisely form the gap and double feeding of paper is more likely to occur.
Such a problem commonly arises in feeding devices which feed a plurality of stacked recording media while separating them one by one as well as in the above-mentioned paper feeding device of the printer.
An advantage of some aspects of the invention is to provide a feeding device capable of precisely preventing the double feeding of recording media and a recording device including such a feeding device.
According to an aspect of the invention, there is provided a feeding device including: a mounting portion capable of allowing a plurality of recording media to be mounted thereon in a stacked state; a delivering member which performs delivery of the top recording medium by performing a feeding motion in a state in which a contact surface thereof is in contact with the top recording medium of the recording media mounted on the mounting portion so that the top recording medium is delivered in a feeding direction of the recording media due to the frictional force generated between the top recording medium and the contact surface of the delivering member, the frictional force being used as transporting force; and a separating member having an inclined surface, against which a leading end of the recording medium delivered by the delivering member hits up against, and fixed in place at a downstream side of the mounting portion in the feeding direction of the recording media and at a portion at which the separating member can be in contact with the contact surface of the delivering member. The delivering member is structured such that the contact surface of the delivering member is formed by a contact surface forming member which elastically deforms when it is pressed, and the top recording medium, which is delivered by the delivering member and of which the leading end hits up against the inclined surface of the separating member, is fed, resisting against elastic recovery force of the contact surface forming member by pressing the contact surface of the delivering member so as to elastically deform the contact surface forming member so that a gap is formed between the contact surface and the separating member through which only the top recording medium can pass.
According to the structure, the top recording medium, the leading end of which has hit up against the inclined surface of the separating member after being delivered by the delivering member, is fed while elastically deforming the contact surface forming member by pushing the contact surface of the delivering member and forming a gap, through which only the top recording medium can pass, between the contact surface and the separating member, by resisting against the elastic recovery force of the contact surface forming member. Accordingly, it is possible to prevent double feeding by separating the top recording medium from the underlying recording medium lying under the top recording medium. Further, since the separating member is fixed in place, it is possible to maintain a constant contact angle between the recording medium and the inclined surface. As a result, it is possible to reliably prevent the double feeding of the recording media.
The feeding device of the invention may further include an urging member capable of urging the contact surface forming member in a direction in which the contact surface gets close to and away from the separating member.
According to the structure, when the contact surface forming member is elastically deformed by being pushed by the top recording medium which has hit up against the inclined surface of the separating member by the urging member which urges the contact surface forming member in a direction in which the contact surface forming member gets closer to the separating member, it is possible to obtain an urging force acting as a load applied to the recording medium which pushes the contact surface. Accordingly, even in the case in which the rigidity of the contact surface forming member changes under the condition of, for example, high temperature, the elastic recovery force can be compensated, so that it is possible to reliably prevent the double feeding of the recording media.
In the feeding device, the urging member may be a spring member which urges the contact surface forming member via a slider.
According to the structure, the urging force can be reliably applied to the contact surface forming member by the urging of the contact surface forming member via the slider by the spring. Further, since the urging member is a spring, it is possible to precisely set the urging force by suppressing the change of the urging force which is accompanied by the change in the environment, such as temperature.
In the feeding device, the delivering member may be a feeding roller having a rigid base portion supported so as to be able to rotate around a rotary shaft, an outer side of the rigid base portion covered with the contact surface forming member.
According to the structure, since it is possible to realize the feeding operation of the delivering member by the rotation of the feeding roller, it is possible to smoothly and continuously performing delivery of the recording media. Further, in the feeding roller, since the outer surface of a base portion having a rigidity is covered with the contact surface forming member having elasticity, it is possible to direct any repulsive force outside the feeding roller when the contact surface forming member is elastically deformed by external pressure applied thereto.
In the feeding device, the feeding roller may have an outer surface formed by the contact surface forming member, the outer surface being composed of a circumferential surface having a radius equal to the distance from the rotary shaft and a non-circumferential surface which is distanced shorter than the distance between the rotary shaft than the circumferential surface, in which the circumferential surface forms the contact surface.
According to the configuration, since the feeding roller has a circumferential surface and a non-circumferential surface as the outer surface, it is possible to have a configuration such that the delivery of the recording medium is performed on the circumferential surface and the non-circumferential surface does not come into contact with the recording medium or the separating member. Accordingly, as the feeding roller is separated from the recording medium at the non-circumferential surface after the top recording medium is delivered, it is possible to suppress back tension is unnecessarily applied to the recording medium delivered to the downstream side.
According to another aspect of the invention, there is provided a recording device including: a recording portion performing recording on a recording medium; and the feeding device for feeding the recording medium to the recording portion.
According to the configuration, it is possible to attain the same operative advantage of the above feeding device.
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
Hereinafter, an ink jet printer (hereinafter, refer to as “printer”) which is a concrete example of a recording device including a feeding device according to the invention is described with reference to the accompanying drawings 1 to 5. In the description, “longitudinal direction,” “lateral direction,” and “vertical direction” must be understood with reference to directions indicated by arrows of the accompanying drawings.
As shown in
The inside of the main body 12 is provided with a carriage 18 reciprocating in a main scan direction (lateral direction in
Next, description about the automatic paper feeding device 13 will be made with reference to
The paper feeding tray 14 placed obliquely to the rear surface of the main body 12 is installed such that a lower end thereof is supported by the rear side of a base portion 21 and a nearly midway position of the upper surface thereof is provided with the hopper 15. Further, a lower end portion of the hopper 15 is provided with a compression spring 22 interposed between the hopper 15 and the paper feeding tray 14. The hopper 15 is configured to be able to reciprocate between a paper feeding position shown in
A paper feeding roller (feeding roller) 23, which has an almost D-shape in a side view and serves as a delivering member, is in front of the lower end portion of a hopper 15 which is a paper feeding device disposed so as to be able to rotate around a rotary shaft 24. The paper feeding roller 23 includes a base portion 23a made of a resinous material having rigidity and a contact surface forming member 25 which covers the outer surface of the base portion 23a and is made of rubber having elasticity. The contact surface forming member 25 of the paper feeding roller 23 forms the outer surface of the paper feeding roller 23, in which the outer surface is composed of a circumferential surface 25a which serves as a contact surface and has a radius equal to distance r1 from the center C of the rotary shaft 24, and a flat surface 25b, i.e. non-circumferential surface, which is separated from the center C of the rotary shaft 24 by distance r2 (r2<r1) which is shorter than the distance r1 between the circumferential surface 25a and the center C of the rotary shaft 24. Further, the paper feeding roller 23 performs the paper feeding operation (feeding operation) of paper P by rotating along with the rotary drive of the rotary shaft 24.
Here, the distances r1 and r2 of the outer surface from the center C of the rotary shaft 24 are set such that, in the case in which the paper feeding roller 23 rotates in a state in which the hopper 15 resides at a paper feeding position, the flat surface 25b is not brought into contact with the paper P but the circumferential surface 25a is brought into contact with the paper P, so that the paper P is pushed toward the circumferential surface 25a by receiving the urging force of the compression spring 22. The frictional force, which is generated between the circumferential surface 25a and the paper P when the paper feeding roller 23 rotates in the state in which the circumferential surface 25a and the paper P are in contact with each other, is set to be larger than the frictional force generated between stacked sheets of paper P. Accordingly, if the paper feeding roller 23 rotates in the state in which the circumferential surface 25a serving as the contact surface of the outer surface formed by the contact surface forming member 25 is in contact with the paper P, the urging force of the compression spring 22 becomes the vertical resistance force, and the frictional force generated between the circumferential surface 25a and the paper P becomes the transporting force. As a result, the paper P is delivered.
A separating member 29 is attached to the base portion 21 at a position at the downstream side of the hopper 15 residing at the paper feeding position in the transporting direction of the paper P indicated by the arrow in
In the case in which the separating member 29 faces almost the center portion of the flat surface 25b of the paper feeding roller 23, the separating member 29 is in contact with the contact surface forming member 25 which forms the outer surface of the paper feeding roller 23. However, in the case in which the separating member 29 faces the circumferential surface 25a, the separating member is brought into contact with the contact surface forming member 25 which forms the outer surface of the paper feeding roller 23. In the case in which the separating member 29 is in contact with the circumferential surface 25a of the outer surface formed by the contact surface forming member 25 of the paper feeding roller 23, the contact surface forming member 25 elastically deforms to overlap the contact surface forming member 25 by about 0.5 mm, and the overlap portion of the separating member 29 receives the elastic recovery force of the contact surface forming member 25.
When feeding the paper P, after the paper feeding roller 23 rotates in the clockwise direction in
The top sheet of paper P, which has the leading end which hits up against the inclined surface 29a, is fed by elastically deforming the contact surface forming member 25 by pushing the circumferential surface 25a formed by the contact surface forming member 25 of the paper feeding roller 23 and forming a gap between the circumferential surface 25a and the separating member 29, resisting against the elastic recovery force of the contact surface forming member 25. That is, the contact angle between the separating member 29 and the top sheet of paper P, and elasticity and repulsive characteristics of the contact surface forming member 25 are set such that a gap, through which only the top sheet of paper P can pass, is formed between the circumferential surface 25a and the separating member 29 by the pushing force of the top sheet of paper P delivered by the paper feeding roller 23.
It sometimes happens that the underlying sheet of paper P lying under the top sheet of paper P is transported in the feeding direction along with the top sheet of paper P due to the frictional force generated between sheets of paper P when the paper feeding roller 23 delivers the top sheet of paper P. In such a case, the underlying sheet of paper P which hits up against the inclined surface 29a of the separating member 29 receives the elastic recovery force of the contact surface forming member 25 via the top sheet of paper P but does not have a transporting force strong enough so that it can pass through between the circumferential surface 25a and the separating member 29, resisting against the elastic recovery force. Accordingly, even in the case in which the sheet of paper P underlying the top sheet of paper P is pulled by the top sheet of paper P delivered by the paper feeding roller 23 due to the frictional force, feeding of the underlying sheet of paper P is stopped when the underlying sheet of paper P hits up against the inclined surface 29a of the separating member 29, and the underlying sheet of paper P is separated from the top sheet of paper P.
Next, operation of the automatic paper feeding device 13 having the above-described structure will be described with reference to
At the reset position of
If the rotary shaft 24 starts its rotary drive and the paper feeding roller 23 rotates in the clockwise direction in
Moreover, if the paper feeding roller 23 rotates, the leading end of the top sheet of paper P delivered by the paper feeding roller 23 hits up against the inclined surface 29a of the separating member 29. Therefore, by the operation such that the leading end of the top sheet of paper P pushes the circumferential surface 25a of the paper feeding roller 23 and causes the contact surface forming member 25 to elastically deform, the leading end of the top sheet of paper P passes through the separating member 29, forming a gap between the circumferential surface 25a and the separating member 29. At this time, the underlying sheet of paper P is also delivered along with the top sheet of paper P by the frictional force generated between the underlying sheet of paper P and the top sheet of paper P, but feeding of the underlying sheet of paper P is stopped at the stage in which the underlying sheet of paper P hits up against the inclined surface 29a of the separating member 29, and therefore the underlying sheet of paper P is separated from the top sheet of paper P as shown in
Along with the rotation of the paper feeding roller 23, as shown in
According to the first embodiment described above, the following advantages can be attained.
(1) By the operation such that the top sheet of paper P, which is delivered by the paper feeding roller 23 and has the leading end which hits up against the inclined surface 29a of the separating member 29, pushes the circumferential surface 25a of the paper feeding roller 23 and thus causes the contact surface forming member 25 to elastically deform, the top sheet of paper P is fed and a gap is formed between the circumferential surface 25a and the separating member 29 through which only the top sheet of paper P can pass, resisting against the elastic recovery force of the contact surface forming member 25. With such operation, it is possible to prevent the double feeding by performing the separation of the top sheet of paper P and the underlying sheet of paper P. Further, since the separating member 29 is fixed in place, it is possible to maintain a constant contact angle between the paper P and the inclined surface 29a. Accordingly, it is possible to reliably prevent the double feeding of the paper P.
(2) Since the feeding operation is realized by rotation of the paper feeding roller 23, it is possible to perform the delivery of the paper P in a smooth and continuous motion. Further, since the outer surface of the rigid base portion 23a of the paper feeding roller 23 is covered with the contact surface forming member 25 having elasticity, it is possible to direct any repulsive force outside the feeding roller when the contact surface forming member 25 is elastically deformed by external pressure applied thereto.
(3) After the top sheet of paper P is delivered, it is possible to prevent back tension from being unnecessarily applied to the paper P delivered to the downstream side by separating the paper feeding roller 23 from the paper P on the flat surface 25b.
Next, a second embodiment in which the liquid ejecting device of the invention is realized in the form of a serial-type ink jet printer will be described with reference to
In this embodiment, a paper feeding roller 23 and a separating member 29 of an automatic paper feeding device 13 provided in a printer 11 serving as a recording device cooperate to perform the separation of paper P as in the first embodiment. However, this embodiment is different from the first embodiment from the point of view that the paper feeding roller 23 of this embodiment is provided with a spring member which urges a contact surface forming member 25 via a slider.
Hereinafter, description will be made mainly with reference to the differences of this embodiment from the first embodiment.
As shown in
Next, the operation of the automatic paper feeding device 13 which is configured as described above will be described.
The paper feeding roller 23 operates such that the contact surface forming member 25 thereof is pushed by the separating member 29 and elastically deforms if the rotary shaft 24 starts a rotation drive, and the portion of the outer surface of the contact surface forming member 25, which corresponds to the receiving hole 23b in the circumferential direction, i.e. the portion of the paper feeding roller 23 where the slider 35 is contained, is brought into contact with the separating member 29. In such a case, the slider 35 moves in the direction in which the slider 35 gets closer to the rotary shaft 24 and the spring member 36 is compressed. At that time, the contact surface forming member 25 receives the urging force of the spring member 36 via the slider 35.
Further, if the paper feeding roller 23 rotates, the leading end of the top sheet of paper P delivered by the paper feeding roller 23 hits up against the inclined surface 29a of the separating member 29. Then, the contact surface forming member 25 is elastically deformed as the top sheet of paper P pushes the circumferential surface 25a of the paper feeding roller 23, resisting against the urging force of the spring member 36. After that, the top sheet of paper P passes through the separating member 29 while forming a gap between the circumferential surface 25a and the separating member 29, resisting against the elastic recovery force of the contact surface forming member 25 and the urging force of the spring member 36. At that time, the underlying sheet of paper P lying under the top sheet of paper P is delivered along with the top sheet of paper P due to the frictional force generated between sheets of paper. However, the feeding of the underlying sheet of paper P is stopped when it hits up against the inclined surface 29a of the separating member 29, and the underlying sheet of paper P is separated from the top sheet of paper P.
If the portion where the slider 35 is contained gets away from the separating member 29 in the circumferential direction as the paper feeding roller 23 rotates, the top sheet of paper P passes through the separating member 29, receiving the elastic recovery force of the contact surface forming member 25, and is then fed to the recording head 19 side. In such a case, since the inside circumferential surface side of the contact surface forming member 25 is in contact with the base portion 23a having rigidity, the elastic recovery force directing toward the separating member 29 side is reliably maintained and the double feeding of the underlying paper P is inhibited.
According to the above-described second embodiment, the following advantages can be attained besides the advantages (1) to (3) of the first embodiment.
(4) When the contact surface forming member 25 is elastically deformed by being pushed by the top sheet of paper P which hits up against the inclined surface 29a of the separating member 29 due to the spring member 36 which urges the contact surface forming member 25 in the direction in which the contact surface forming member gets closer to the separating member 29, it is possible to obtain a urging force acting like a load applied to the paper P which pushes the circumferential surface 25a. Accordingly, for example, the elastic recovery force can be compensated even in the case in which the rigidity of the contact surface forming member 25 changes, for example, in conditions of a high temperature environment, and thus it is possible to securely prevent the double feeding of the paper P.
(5) Due to the structure of urging the contact surface forming member 25 by the spring member 36 via the slider 35, it is possible to reliably cause the urging force to reach the contact surface forming member 25. Further, the urging of the contact surface forming member by the spring member 36 can suppress changes in urging force accompanied by environmental parameter changes, such as temperature, and therefore it is possible to set the urging force with a high degree of precision.
The above described embodiment can be modified to other forms, such as the following.
The feeding operation is not limited to rotation of the paper feeding roller 23, but may be realized, for example, by the movement of a transporting belt.
The urging member is not limited to the spring member but may be urethane having a high repulsive characteristic. In such a case, for example, a gap between the outer surface of the base portion 23a and the inside circumferential surface of the contact surface forming member 25 is filled with urethane to correspond to the circumferential surface 25a in the circumferential direction. To do so, it is possible to urge the entire circumferential surface 25a in radiation directions.
The spring member is not limited to the coil spring, but may be a leaf spring etc.
The paper feeding roller 23 may be a circular roller having a circular shape in a side view.
In the above-described embodiment, the ink jet printer and the ink cartridge have been used. However, a liquid ejecting apparatus discharging or ejecting another liquid other than ink and a liquid storing unit storing the liquid may be used. The invention is useful for various liquid ejecting apparatuses including a liquid ejecting head for ejecting minute liquid droplets. The liquid droplet refers to a liquid ejected from the liquid ejecting apparatus and includes a liquid having a particle shape, a liquid having a droplet shape, and a liquid having a thread trailing shape. The liquid is a material which can be ejected by the liquid ejecting apparatus. For example, the liquid is a matter in a liquefied state and includes a liquid of a fluid state such as a liquid-like material having high or low viscosity, sol, gel water, other inorganic solvents, an organic solvent, liquid solution, liquid-like resin, and liquid-like metal (metallic melt), a liquid in one state of a matter, and a liquid in which particles of a functional material formed of a solid matter such as colorant or metal particle is dissolved, dispersed, or mixed. Representative examples of a liquid are ink or liquid crystal, as described in the embodiment. Here, the ink includes a liquid composition such as general water-based ink, general oil-based ink, gel ink, and hot-melt ink. Specific examples of the liquid ejecting apparatus include a liquid crystal display, an EL (electro-luminescence) display, a plane emission display, a liquid ejecting apparatus ejecting a liquid containing a material such as an electrode material or a color material used to manufacture a color filter is dispersed or dissolved, a liquid ejecting apparatus ejecting bio organism used to manufacture a bio chip, a liquid ejecting apparatus ejecting a liquid as a sample used by a precise pipette, a printing apparatus, and a micro dispenser. In addition, examples of the liquid ejecting apparatus include a liquid ejecting apparatus ejecting a lubricant to a precision instrument such as a clock or a camera by a pin point, a liquid ejecting apparatus ejecting a transparent resin liquid such as ultraviolet cured resin on a board to form a minute hemispheric lens (an optical lens) used in an optical communication element or the like, and a liquid ejecting apparatus ejecting an acid or alkali etching liquid to etch a board or the like. In addition, the invention is applicable to one liquid ejecting thereof and the liquid storing unit.
Number | Date | Country | Kind |
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2008-196777 | Jul 2008 | JP | national |