US20050225029A1 - Recording medium feeding device - Google Patents
Recording medium feeding device Download PDFInfo
- Publication number
- US20050225029A1 US20050225029A1 US11/090,296 US9029605A US2005225029A1 US 20050225029 A1 US20050225029 A1 US 20050225029A1 US 9029605 A US9029605 A US 9029605A US 2005225029 A1 US2005225029 A1 US 2005225029A1
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- US
- United States
- Prior art keywords
- roll body
- feed roller
- recording medium
- feeding device
- roll
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H16/00—Unwinding, paying-out webs
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H18/00—Winding webs
- B65H18/08—Web-winding mechanisms
- B65H18/26—Mechanisms for controlling contact pressure on winding-web package, e.g. for regulating the quantity of air between web layers
Definitions
- the present invention relates to a recording medium feeding device and, more particularly, to a recording medium feeding device for feeding a recording medium by rotating a roll body formed by winding a recording medium in a roll form.
- a device As a recording medium feeding device of this type, a device is known in which a roll paper formed by rolling recording paper used as a recording medium is charged in a paper feed unit, and the roll paper is rotated by rotating a feed roller that is in contact with the peripheral surface of the roll paper, by which the roll paper tip end peeled off the roll paper is fed to an image forming location.
- FIG. 5 is a view showing the positional relationship between the roll paper and the feed roller in a conventional recording medium feeding device. For convenience, this figure shows a case where a roll paper 1 and a feed roller 2 are arranged perpendicularly.
- the roll paper 1 and the feed roller 2 are in contact with each other at a contact point 3 .
- the roll paper 1 is rotated in the direction indicated by the arrow a, by which a roll paper tip end 1 a is fed and conveyed.
- the roll paper 1 can always be brought into contact with the fixed feed roller 2 at the contact point 3 by moving in the direction indicated by the arrow b.
- support shafts of the roll paper 1 is guided by guide members, not shown, so as to be movable in the direction of a line segment connecting the centers of rotation of the roll paper 1 and the feed roller 2 (the direction indicated by the arrow b).
- the movement direction of the roll paper 1 is the same as the direction of the above-described line segment, and is perpendicular to a tangential line 4 at the contact point 3 (the paper feed direction) because the contact point 3 also lies on this line segment.
- the feeding device is provided with one feed roller 2 in the above-described conventional example, some feeding devices are provided with two feed rollers as in other conventional examples (for example, Japanese Patent Application Laid-open No. 10-139239).
- the roll paper 1 is subjected to forces in the directions indicated by the arrows c 1 and c 2 from the feed roller 2 when the feed roller is rotated in the reverse direction, and in particular, the contact pressure at the contact point 3 between the roll paper 1 and the feed roller 2 is lowered by the force in the direction indicated by the arrow c 2 , which poses a problem in that winding slack occurs.
- the force in the direction indicated by the arrow c 2 is a force in the direction such that the roll paper 1 is movable (retractable) when the roll paper 1 is rotated by the feed roller 2 , and acts as a force in the direction such that the load of the feed roller 2 is reduced.
- the paper feeding device described in Japanese Patent Application Laid-open No. 10-139239 requires two feed rollers the respective speeds of which can be controlled, which requires extra cost and space. Also, this paper feeding device has a problem in that the occurrence of winding slack caused by the decrease in contact pressure between the roll paper and the feed roller cannot be prevented.
- the present invention has been made in view of the above circumstances, and accordingly an object thereof is to provide a recording medium feeding device capable of preventing the winding slack of a recording medium wound on a roll body when the roll body is rewound by one feed roller.
- a first aspect of the present invention provides a recording medium feeding device in which one of right and left support shafts for holding a roll body formed by winding a recording medium in a roll form and one feed roller for rotating the roll body in such a manner as to be in contact with a peripheral surface of the roll body is fixed, and the other thereof is moved as the diameter of the roll body decreases, wherein an angle is formed between the direction of a line segment connecting the centers of rotation of the roll body and the feed roller and the movement direction in which the roll body or the feed roller moves as the diameter of the roll body decreases, so that when the recording medium is rewound on the roll body by the feed roller, a contact pressure at a contact point between the roll body and the feed roller increases.
- the relative movement direction between the roll body and the feed roller and the direction of the line segment connecting the centers of rotation of the roll body and the feed roller are not caused to coincide with each other, and an angle is formed.
- the above-described angle can be formed by arranging the feed roller at a predetermined position (on the downstream side of the roll body from the prolongation of the movement direction of roll body). Inversely, with the arrangement position of feed roller being a reference, the above-described angle can be formed by making the roll body movable in a predetermined direction (direction different from the direction of the line segment connecting the centers of rotation).
- the above-described angle can be formed by arranging the support shafts of the roll body at predetermined positions. Also, with the arrangement positions of the support shafts of the roll body being a reference, the above-described angle can be formed by making the feed roller movable in a predetermined direction.
- a rotational driving force of the feed roller acts so that the contact pressure between the roll body and the feed roller increases when the roll body is rewound by the feed roller, so that the winding slack of the roll body can be prevented.
- the recording medium feeding device has a pair of right and left guide members for movably guiding the support shafts of the roll body in the radial direction of the roll body and an urging device for urging the roll body to the movement direction of the roll body guided by the guide members, so that the support shaft of the roll body is moved by the guide members and the urging device as the diameter of the roll body decreases, and the feed roller is arranged so that the contact point at which the feed roller is in contact with the roll body shifts from a tangential position at which the movement direction of the roll body moved by being guided by the guide members is a normal to the downstream side of the rotating direction of the roll body.
- the contact pressure between the roll body and the feed roller is provided by the gravity of the roll body and an urging force generated by the urging device.
- a rotational force of the feed roller acts so as to increase the contact pressure, so that the winding slack of the roll body can be prevented.
- the feed roller is arranged at a position at which taking the maximum radius of the roll body as R 1 , the minimum radius thereof as R 2 , and the radius of the feed roller as Rf, an angle ⁇ between a line segment connecting the centers of rotation of the roll body with the maximum radius and the feed roller and a normal corresponding to the movement direction of the roll body is represented by the following inequality. 0 ⁇ sin ⁇ 1 ⁇ ( R 2 + Rf )/( R 1 + Rf ) ⁇
- the angle ⁇ on the upper limit side in the aforementioned inequality exhibits a condition necessary for the feed roller to be in contact with the roll body even if the roll body comes to have the minimum radius.
- the feed roller sends out the recording medium wound on the roll body at the time of normal rotation and rewinds the recording medium on the roll body sent out from the roll body at the time of reverse rotation, and some of a force acting on the roll body from the feed roller at the time of reverse rotation acts in the direction such that the contact pressure between the roll body and the feed roller is increased.
- the recording medium is a recording paper in which a coloring layer, which is colored by heat and is fixed by light with a predetermined wavelength, is formed on the surface thereof.
- a coloring layer which is colored by heat and is fixed by light with a predetermined wavelength
- an angle is formed between the direction of the line segment connecting the centers of rotation of the roll body and the feed roller and the movement direction in which the roll body or the feed roller moves as the diameter of the roll body decreases.
- the contact point between the roll body and the feed roller shifts to the downstream side of the roll body from the line segment connecting the centers of rotation of the roll body and the feed roller. Therefore, when the roll body is rewound by the feed roller, the contact pressure between the roll body and the feed roller can be increased, and thereby the winding slack of the roll body can be prevented.
- FIG. 1 is a view showing the positional relationship between a roll paper and a feed roller, which is used for illustrating the principle of the present invention
- FIG. 2 is a view showing one example of an internal construction of a printer to which a recording medium feeding device in accordance with the present invention is applied;
- FIG. 3 is a view showing an embodiment of an internal construction of the feeding device in FIG. 2 ;
- FIG. 4 is a view used for illustrating another embodiment of a recording medium feeding device in accordance with the present invention.
- FIG. 5 is a view showing the positional relationship between a roll paper and a feed roller in a conventional recording medium feeding device.
- FIG. 6 is a view used for illustrating a problem arising when a roll paper is rewound in the conventional recording medium feeding device shown in FIG. 5 .
- a feed roller 12 for rotating a roll paper 10 in the normal or reverse direction is arranged on the downstream side of the roll paper 10 with respect to the position of the conventional feed roller 2 indicated by a broken line (refer to FIGS. 5 and 6 ).
- the roll paper 10 can always be brought into contact with the fixed feed roller 12 at a contact point 13 by moving in the direction indicated by the arrow b due to the gravity of the roll paper 10 and an urging force applied by an urging device, not shown.
- the contact point 13 between the roll paper 10 and the feed roller 12 is shifted to the downstream side in the roll paper feed direction from the prolongation of the movement direction of the roll paper 10 .
- forces applied to the roll paper 10 by the feed roller 12 at the contact point 13 can be represented by the arrows d 1 and d 2 .
- the force in the direction indicated by the arrow d 1 is a force in the direction connecting the centers of rotation of the roll paper 10 and the feed roller 12 , and corresponds to the contact pressure at the contact point 13 .
- the force in the direction indicated by the arrow d 2 is a force in the direction of a tangential line 14 at the contact point 13 , and corresponds to a rotational driving force transmitted from the feed roller 12 to the roll paper 10 .
- the force in the direction indicated by the arrow d 2 can further be represented by component forces of a force in the direction indicated by the arrow d 2 v , which is the same direction as the movement direction of the roll paper 10 (the direction indicated by the arrow b) and a force in the direction indicated by the arrow d 2 h , which is perpendicular to the force in the direction indicated by the arrow d 2 v .
- the component force in the direction indicated by the arrow d 2 v acts as a force for restraining a force of separation of the roll paper 10 from the feed roller 12 .
- the rotational driving force can normally be transmitted from the feed roller 12 to the roll paper 10 .
- the winding slack of the roll paper 10 which is caused by a phenomenon that the rotational driving force is not transmitted to the roll paper 10 normally and thus the recording paper on the surface of the roll paper 10 is returned much, can be prevented.
- an angle ⁇ between a line segment L 1 connecting the centers of rotation of the roll paper 10 with the maximum radius and the feed roller 12 and a normal L 2 corresponding to the movement direction of the roll paper 10 is represented by the following inequality. 0 ⁇ sin ⁇ 1 ⁇ ( R 2 + Rf )/( R 1 + Rf ) ⁇ (1) Wherein, the angle ⁇ on the upper limit side in Inequality (1) exhibits a condition necessary for the feed roller 12 to be in contact with the roll paper 10 even if the roll paper 10 comes to have the minimum radius.
- FIG. 2 is a view showing one example of an internal construction of a printer to which the recording medium feeding device in accordance with the present invention is applied.
- a printer 100 is a digital color printer of a thermo-autochrome type (hereafter referred to TA type), mainly including a feeding device 20 for the roll paper 10 and an image forming device 50 for forming images on the recording paper fed from the feeding device 20 .
- TA type thermo-autochrome type
- the details of the feeding device 20 are described later.
- the roll paper 10 is a continuous paper formed by winding recording paper 44 on a paper tube 42 so that the image forming surface is directed to the inside.
- the image forming surface is configured so that, for example, a three coloring layers of cyan (C), magenta (M), and yellow (Y) are formed on a support body, and a heat-resistant protective layer is formed on the uppermost layer.
- the image forming device 50 includes a pinch roller 52 , a capstan 54 , a thermal head 56 , a platen roller 58 , a cutter portion 60 , a Y fixing lamp 62 , and an M fixing lamp 64 .
- the recording paper 44 fed from the feeding device 20 is conveyed at a constant speed by being held between the pinch roller 52 and the capstan 54 in the image forming device 50 .
- the thermal head 56 presses on the recording paper 44 to form images on the image forming surface of the recording paper 44 .
- the recording paper 44 is conveyed reciprocatingly three times to form coloring layers of YMC on the image forming surface of the recording paper 44 .
- the thermal head 56 is controlled by a Y signal to form a yellow layer on the image forming surface.
- the yellow color is fixed by the Y fixing lamp 62 .
- the thermal head 56 is controlled by an M signal to form a magenta layer on the image forming surface, and the magenta color is fixed by the M fixing lamp 64 .
- the thermal head 56 is controlled by a C signal, and the cyan layer is formed on the image forming surface. Thereby, color images are printed on the image forming surface of the recording paper 44 .
- the cutter portion 60 disposed at the rear stage of the thermal head 56 is used to cut the recording paper 44 on which images have been formed into a predetermined size.
- the recording paper 44 is cut off by being held between upper and lower edges.
- FIG. 3 is a view showing an embodiment of an internal construction of the feeding device 20 of the roll paper 10 .
- the feeding device 20 includes a roll paper case 22 for housing the roll paper 10 , the feed roller 12 , a guide plate 30 for movably guiding a support shaft 46 attached to the paper tube 42 of the roll paper 10 , a pressurizing lever 32 one end of which is turnably attached to the guide plate 30 , a coil spring 34 for urging the pressurizing lever 32 in the clockwise direction in FIG. 3 , a tip end detector 36 for detecting a roll paper tip end, and a peeling plate 38 , which is in contact with the outer peripheral surface of the roll paper 10 , for peeling the roll paper tip end from the roll paper 10 to guide a delivery port 37 .
- the roll paper case 22 being of a substantially cylindrical shape covering the roll paper 10 from upper and lower sides, consists of an upper case 22 A serving as a top cover and a lower case 22 B.
- the upper case 22 A is opened and closed by a hinge 23 .
- the guide plate 30 disposed in the roll paper case 22 is formed with a guide groove 30 A for guiding the support shaft 46 of the roll paper 10 .
- the roll paper 10 moves along the guide groove 30 A when the roll diameter is decreased by the consumption of the recording paper.
- the pressurizing lever 32 is in contact with the support shaft 46 of the roll paper 10 , and pressurizes the roll paper 10 in the direction such that the roll paper 10 moves downward along the guide groove 30 A.
- the feed roller 12 is fixedly arranged in the roll paper case 22 so as to be rotatable in the forward and reverse directions, and the outer peripheral surface of the roll paper 10 is always in contact with the feed roller 12 under an appropriate contact pressure.
- the contact pressure between the roll paper 10 and the feed roller 12 is produced by the gravity of the roll paper 10 and the urging force for urging the roll paper 10 by using the pressurizing lever 32 .
- the direction of the line segment connecting the centers of rotation of the roll paper 10 and the feed roller 12 does not coincide with the movement direction of the roll paper 10 (the direction of the guide groove 30 A), and the contact point between the roll paper 10 and the feed roller 12 shifts to the downstream side (in the feed direction of the recording paper 44 ) from the position on the outer peripheral surface at the prolongation of the movement direction of the roll paper 10 .
- the tip end detector 36 provided in a bottom part of the lower case 22 B detects the roll paper tip end by detecting the difference in height of the outer periphery of roll paper 10 when the roll paper 10 is rotated.
- a detection signal from the tip end detector 36 is used to determine whether or not all of the recording paper 44 has been stored in the roll paper case 22 and the rewinding operation has been finished when the roll paper 10 is rewound, and also to determine whether or not the roll paper tip end has been peeled off the outer peripheral surface of the roll paper 10 by the peeling plate 38 and has been sent out to a delivery port 37 .
- the guide groove 30 A in the guide plate 30 shown in FIG. 3 is inclined to guide the roll paper 10 movably downward and slantwise to the right.
- the guide groove 30 A may be arranged so as to guide the roll paper 10 movably in the vertical direction as shown in FIG. 1 .
- the relative positional relationship between the direction of the guide groove 30 A and the arrangement position of the feed roller 12 has only to be kept so that the feed roller 12 lies on the downstream side of the centerline of the guide groove 30 A.
- the configuration may be such that the roll paper is provided at a fixed position, and the feed roller is moved so as to come into contact with the roll paper under an appropriate contact pressure as the diameter of the roll paper decreases.
- a feed roller 12 ′ is provided so as to be movable in the direction indicated by the arrow e with respect to the roll paper 10 provided at the fixed position.
- the feeding device is configured so that the contact point between the roll paper 10 and the feed roller 12 ′ lies on the upstream side of the outer peripheral position of the roll paper 10 at the prolongation of the movement direction e of the feed roller 12 ′.
- the rotational driving force due to the feed roller 12 ′ at the time when the roll paper 10 is rewound acts so as to increase the contact pressure of the feed roller 12 ′, so that the winding slack of the roll paper 10 can be prevented.
- the roll paper formed by winding the recording paper is not limited to this, but can be applied to a feeding device for a roll body formed by winding a resin sheet, cloth, or any other recording medium.
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- Unwinding Webs (AREA)
- Handling Of Continuous Sheets Of Paper (AREA)
Abstract
Description
- 1. Field of the Invention
- The present invention relates to a recording medium feeding device and, more particularly, to a recording medium feeding device for feeding a recording medium by rotating a roll body formed by winding a recording medium in a roll form.
- 2. Description of the Related Art
- As a recording medium feeding device of this type, a device is known in which a roll paper formed by rolling recording paper used as a recording medium is charged in a paper feed unit, and the roll paper is rotated by rotating a feed roller that is in contact with the peripheral surface of the roll paper, by which the roll paper tip end peeled off the roll paper is fed to an image forming location.
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FIG. 5 is a view showing the positional relationship between the roll paper and the feed roller in a conventional recording medium feeding device. For convenience, this figure shows a case where aroll paper 1 and afeed roller 2 are arranged perpendicularly. - As shown in
FIG. 5 , theroll paper 1 and thefeed roller 2 are in contact with each other at acontact point 3. By rotating thefeed roller 2 in the direction indicated by the arrow in the figure (clockwise direction), theroll paper 1 is rotated in the direction indicated by the arrow a, by which a rollpaper tip end 1 a is fed and conveyed. - Although the diameter of the
roll paper 1 decreases as paper is consumed, theroll paper 1 can always be brought into contact with the fixedfeed roller 2 at thecontact point 3 by moving in the direction indicated by the arrow b. - Specifically, support shafts of the
roll paper 1 is guided by guide members, not shown, so as to be movable in the direction of a line segment connecting the centers of rotation of theroll paper 1 and the feed roller 2 (the direction indicated by the arrow b). The movement direction of theroll paper 1 is the same as the direction of the above-described line segment, and is perpendicular to atangential line 4 at the contact point 3 (the paper feed direction) because thecontact point 3 also lies on this line segment. - Although the feeding device is provided with one
feed roller 2 in the above-described conventional example, some feeding devices are provided with two feed rollers as in other conventional examples (for example, Japanese Patent Application Laid-open No. 10-139239). - In the paper feeding device described in the aforementioned Laid-open, two feed rollers are provided in parallel, and roll paper is placed on these feed rollers. When the roll paper is sent out, the downstream-side feed roller is rotated faster than the upstream-side feed roller. On the other hand, when the roll paper is rewound, the upstream-side feed roller is rotated faster than the downstream-side feed roller, which prevents the paper from slackening.
- In the conventional recording medium feeding device having the configuration shown in
FIG. 5 , in the case where the rollpaper tip end 1 a is rewound by rotating thefeed roller 2 in the reverse direction (counterclockwise direction) as shown inFIG. 6 , theroll paper 1 is subjected to forces in the directions indicated by the arrows c1 and c2 from thefeed roller 2 when the feed roller is rotated in the reverse direction, and in particular, the contact pressure at thecontact point 3 between theroll paper 1 and thefeed roller 2 is lowered by the force in the direction indicated by the arrow c2, which poses a problem in that winding slack occurs. Specifically, if the contact pressure at thecontact point 3 lowers, a frictional force between paper on the surface of theroll paper 1 and paper just inside the surface paper decreases, so that the surface paper is much returned by thefeed roller 2. As a result, there occurs a phenomenon that the winding of roll paper is slackened. The force in the direction indicated by the arrow c2 is a force in the direction such that theroll paper 1 is movable (retractable) when theroll paper 1 is rotated by thefeed roller 2, and acts as a force in the direction such that the load of thefeed roller 2 is reduced. - Also, the paper feeding device described in Japanese Patent Application Laid-open No. 10-139239 requires two feed rollers the respective speeds of which can be controlled, which requires extra cost and space. Also, this paper feeding device has a problem in that the occurrence of winding slack caused by the decrease in contact pressure between the roll paper and the feed roller cannot be prevented.
- The present invention has been made in view of the above circumstances, and accordingly an object thereof is to provide a recording medium feeding device capable of preventing the winding slack of a recording medium wound on a roll body when the roll body is rewound by one feed roller.
- To achieve the above object, a first aspect of the present invention provides a recording medium feeding device in which one of right and left support shafts for holding a roll body formed by winding a recording medium in a roll form and one feed roller for rotating the roll body in such a manner as to be in contact with a peripheral surface of the roll body is fixed, and the other thereof is moved as the diameter of the roll body decreases, wherein an angle is formed between the direction of a line segment connecting the centers of rotation of the roll body and the feed roller and the movement direction in which the roll body or the feed roller moves as the diameter of the roll body decreases, so that when the recording medium is rewound on the roll body by the feed roller, a contact pressure at a contact point between the roll body and the feed roller increases.
- That is to say, unlike the conventional example, the relative movement direction between the roll body and the feed roller and the direction of the line segment connecting the centers of rotation of the roll body and the feed roller are not caused to coincide with each other, and an angle is formed. For example, in the case where the feed roller is fixed, and the diameter of the roll body decreases due to the consumption of recording medium and accordingly the roll body is moved, with the movement direction of roll body being a reference, the above-described angle can be formed by arranging the feed roller at a predetermined position (on the downstream side of the roll body from the prolongation of the movement direction of roll body). Inversely, with the arrangement position of feed roller being a reference, the above-described angle can be formed by making the roll body movable in a predetermined direction (direction different from the direction of the line segment connecting the centers of rotation).
- Similarly, in the case where the support shafts of the roll body are fixed, and the diameter of the roll body decreases due to the consumption of recording medium and accordingly the feed roller is moved, with the movement direction of feed roller being a reference, the above-described angle can be formed by arranging the support shafts of the roll body at predetermined positions. Also, with the arrangement positions of the support shafts of the roll body being a reference, the above-described angle can be formed by making the feed roller movable in a predetermined direction.
- If the above-described angle is formed, a rotational driving force of the feed roller acts so that the contact pressure between the roll body and the feed roller increases when the roll body is rewound by the feed roller, so that the winding slack of the roll body can be prevented.
- According to a second aspect of the present invention, in the recording medium feeding device of the first aspect of the present invention, the recording medium feeding device has a pair of right and left guide members for movably guiding the support shafts of the roll body in the radial direction of the roll body and an urging device for urging the roll body to the movement direction of the roll body guided by the guide members, so that the support shaft of the roll body is moved by the guide members and the urging device as the diameter of the roll body decreases, and the feed roller is arranged so that the contact point at which the feed roller is in contact with the roll body shifts from a tangential position at which the movement direction of the roll body moved by being guided by the guide members is a normal to the downstream side of the rotating direction of the roll body.
- The contact pressure between the roll body and the feed roller is provided by the gravity of the roll body and an urging force generated by the urging device. When the roller body is rotated in the rewinding direction by the feed roller, a rotational force of the feed roller acts so as to increase the contact pressure, so that the winding slack of the roll body can be prevented.
- According to a third aspect of the present invention, in the recording medium feeding device of the second aspect of the present invention, the feed roller is arranged at a position at which taking the maximum radius of the roll body as R1, the minimum radius thereof as R2, and the radius of the feed roller as Rf, an angle θ between a line segment connecting the centers of rotation of the roll body with the maximum radius and the feed roller and a normal corresponding to the movement direction of the roll body is represented by the following inequality.
0<θ<sin−1{(R 2+Rf)/(R 1+Rf)} - The angle θ on the upper limit side in the aforementioned inequality exhibits a condition necessary for the feed roller to be in contact with the roll body even if the roll body comes to have the minimum radius.
- According to a fourth aspect of the present invention, in the recording medium feeding device of any one of the first to third aspects of the present invention, the feed roller sends out the recording medium wound on the roll body at the time of normal rotation and rewinds the recording medium on the roll body sent out from the roll body at the time of reverse rotation, and some of a force acting on the roll body from the feed roller at the time of reverse rotation acts in the direction such that the contact pressure between the roll body and the feed roller is increased.
- According to a fifth aspect of the present invention, in the recording medium feeding device of any one of the first to fourth aspects of the present invention, the recording medium is a recording paper in which a coloring layer, which is colored by heat and is fixed by light with a predetermined wavelength, is formed on the surface thereof. For the recording paper of this type, if winding slack occurs and the coloring layer is exposed, the image quality is adversely influenced at the subsequent time of image formation. In the present invention, however, since the winding slack is prevented, a cause for adverse influence on the image quality is eliminated, so that high image quality can be obtained.
- According to the present invention, in the device for feeding the recording medium by rotating the roll body by using one feed roller, an angle is formed between the direction of the line segment connecting the centers of rotation of the roll body and the feed roller and the movement direction in which the roll body or the feed roller moves as the diameter of the roll body decreases. For example, in the case where the roll body is moved, the contact point between the roll body and the feed roller shifts to the downstream side of the roll body from the line segment connecting the centers of rotation of the roll body and the feed roller. Therefore, when the roll body is rewound by the feed roller, the contact pressure between the roll body and the feed roller can be increased, and thereby the winding slack of the roll body can be prevented.
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FIG. 1 is a view showing the positional relationship between a roll paper and a feed roller, which is used for illustrating the principle of the present invention; -
FIG. 2 is a view showing one example of an internal construction of a printer to which a recording medium feeding device in accordance with the present invention is applied; -
FIG. 3 is a view showing an embodiment of an internal construction of the feeding device inFIG. 2 ; -
FIG. 4 is a view used for illustrating another embodiment of a recording medium feeding device in accordance with the present invention; -
FIG. 5 is a view showing the positional relationship between a roll paper and a feed roller in a conventional recording medium feeding device; and -
FIG. 6 is a view used for illustrating a problem arising when a roll paper is rewound in the conventional recording medium feeding device shown inFIG. 5 . - Preferred embodiments of a recording medium feeding device in accordance with the present invention will now be described with reference to the accompanying drawings.
- First, the principle of the present invention will be described with reference to
FIG. 1 . - As shown in
FIG. 1 , afeed roller 12 for rotating aroll paper 10 in the normal or reverse direction is arranged on the downstream side of theroll paper 10 with respect to the position of theconventional feed roller 2 indicated by a broken line (refer toFIGS. 5 and 6 ). - Although the diameter of the
roll paper 10 decreases as recording paper is consumed, theroll paper 10 can always be brought into contact with the fixedfeed roller 12 at acontact point 13 by moving in the direction indicated by the arrow b due to the gravity of theroll paper 10 and an urging force applied by an urging device, not shown. - The
contact point 13 between theroll paper 10 and thefeed roller 12 is shifted to the downstream side in the roll paper feed direction from the prolongation of the movement direction of theroll paper 10. When the recording paper is rewound by rotating theroll paper 10 in the direction indicated by the arrow a by using thefeed roller 12, forces applied to theroll paper 10 by thefeed roller 12 at thecontact point 13 can be represented by the arrows d1 and d2. - The force in the direction indicated by the arrow d1 is a force in the direction connecting the centers of rotation of the
roll paper 10 and thefeed roller 12, and corresponds to the contact pressure at thecontact point 13. The force in the direction indicated by the arrow d2 is a force in the direction of atangential line 14 at thecontact point 13, and corresponds to a rotational driving force transmitted from thefeed roller 12 to theroll paper 10. - The force in the direction indicated by the arrow d2 can further be represented by component forces of a force in the direction indicated by the arrow d2 v, which is the same direction as the movement direction of the roll paper 10 (the direction indicated by the arrow b) and a force in the direction indicated by the arrow d2 h, which is perpendicular to the force in the direction indicated by the arrow d2 v. The component force in the direction indicated by the arrow d2 v acts as a force for restraining a force of separation of the
roll paper 10 from thefeed roller 12. - Thereby, when the
roll paper 10 is rewound, the rotational driving force can normally be transmitted from thefeed roller 12 to theroll paper 10. In other words, the winding slack of theroll paper 10, which is caused by a phenomenon that the rotational driving force is not transmitted to theroll paper 10 normally and thus the recording paper on the surface of theroll paper 10 is returned much, can be prevented. - Also, in
FIG. 1 , taking the maximum radius of theroll paper 10 as R1, the minimum radius thereof as R2, and the radius of thefeed roller 12 as Rf, an angle θ between a line segment L1 connecting the centers of rotation of theroll paper 10 with the maximum radius and thefeed roller 12 and a normal L2 corresponding to the movement direction of theroll paper 10 is represented by the following inequality.
0<θ<sin−1{(R 2+Rf)/(R 1+Rf)} (1)
Wherein, the angle θ on the upper limit side in Inequality (1) exhibits a condition necessary for thefeed roller 12 to be in contact with theroll paper 10 even if theroll paper 10 comes to have the minimum radius. - Next, a printer to which the recording medium feeding device in accordance with the present invention is applied will be described.
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FIG. 2 is a view showing one example of an internal construction of a printer to which the recording medium feeding device in accordance with the present invention is applied. - As shown in
FIG. 2 , aprinter 100 is a digital color printer of a thermo-autochrome type (hereafter referred to TA type), mainly including afeeding device 20 for theroll paper 10 and animage forming device 50 for forming images on the recording paper fed from thefeeding device 20. The details of thefeeding device 20 are described later. - The
roll paper 10 is a continuous paper formed by windingrecording paper 44 on apaper tube 42 so that the image forming surface is directed to the inside. The image forming surface is configured so that, for example, a three coloring layers of cyan (C), magenta (M), and yellow (Y) are formed on a support body, and a heat-resistant protective layer is formed on the uppermost layer. - The
image forming device 50 includes apinch roller 52, acapstan 54, athermal head 56, aplaten roller 58, acutter portion 60, aY fixing lamp 62, and anM fixing lamp 64. - The
recording paper 44 fed from thefeeding device 20 is conveyed at a constant speed by being held between thepinch roller 52 and thecapstan 54 in theimage forming device 50. When therecording paper 44 is conveyed in the left-to-right direction inFIG. 2 to a predetermined position between thethermal head 56 and theplaten roller 58, thethermal head 56 presses on therecording paper 44 to form images on the image forming surface of therecording paper 44. - Specifically, the
recording paper 44 is conveyed reciprocatingly three times to form coloring layers of YMC on the image forming surface of therecording paper 44. First, while therecording paper 44 is conveyed, thethermal head 56 is controlled by a Y signal to form a yellow layer on the image forming surface. Subsequently, the yellow color is fixed by theY fixing lamp 62. Similarly, thethermal head 56 is controlled by an M signal to form a magenta layer on the image forming surface, and the magenta color is fixed by theM fixing lamp 64. Succeedingly, thethermal head 56 is controlled by a C signal, and the cyan layer is formed on the image forming surface. Thereby, color images are printed on the image forming surface of therecording paper 44. - The
cutter portion 60 disposed at the rear stage of thethermal head 56 is used to cut therecording paper 44 on which images have been formed into a predetermined size. Therecording paper 44 is cut off by being held between upper and lower edges. - Next, the
feeding device 20 will be described. -
FIG. 3 is a view showing an embodiment of an internal construction of thefeeding device 20 of theroll paper 10. - As shown in
FIG. 3 , thefeeding device 20 includes aroll paper case 22 for housing theroll paper 10, thefeed roller 12, aguide plate 30 for movably guiding asupport shaft 46 attached to thepaper tube 42 of theroll paper 10, a pressurizinglever 32 one end of which is turnably attached to theguide plate 30, acoil spring 34 for urging the pressurizinglever 32 in the clockwise direction inFIG. 3 , atip end detector 36 for detecting a roll paper tip end, and a peelingplate 38, which is in contact with the outer peripheral surface of theroll paper 10, for peeling the roll paper tip end from theroll paper 10 to guide adelivery port 37. - The
roll paper case 22, being of a substantially cylindrical shape covering theroll paper 10 from upper and lower sides, consists of anupper case 22A serving as a top cover and alower case 22B. Theupper case 22A is opened and closed by ahinge 23. - The
guide plate 30 disposed in theroll paper case 22 is formed with aguide groove 30A for guiding thesupport shaft 46 of theroll paper 10. Theroll paper 10 moves along theguide groove 30A when the roll diameter is decreased by the consumption of the recording paper. - The pressurizing
lever 32 is in contact with thesupport shaft 46 of theroll paper 10, and pressurizes theroll paper 10 in the direction such that theroll paper 10 moves downward along theguide groove 30A. - The
feed roller 12 is fixedly arranged in theroll paper case 22 so as to be rotatable in the forward and reverse directions, and the outer peripheral surface of theroll paper 10 is always in contact with thefeed roller 12 under an appropriate contact pressure. The contact pressure between theroll paper 10 and thefeed roller 12 is produced by the gravity of theroll paper 10 and the urging force for urging theroll paper 10 by using the pressurizinglever 32. - As described with reference to
FIG. 1 , the direction of the line segment connecting the centers of rotation of theroll paper 10 and thefeed roller 12 does not coincide with the movement direction of the roll paper 10 (the direction of theguide groove 30A), and the contact point between theroll paper 10 and thefeed roller 12 shifts to the downstream side (in the feed direction of the recording paper 44) from the position on the outer peripheral surface at the prolongation of the movement direction of theroll paper 10. - The
tip end detector 36 provided in a bottom part of thelower case 22B detects the roll paper tip end by detecting the difference in height of the outer periphery ofroll paper 10 when theroll paper 10 is rotated. A detection signal from thetip end detector 36 is used to determine whether or not all of therecording paper 44 has been stored in theroll paper case 22 and the rewinding operation has been finished when theroll paper 10 is rewound, and also to determine whether or not the roll paper tip end has been peeled off the outer peripheral surface of theroll paper 10 by the peelingplate 38 and has been sent out to adelivery port 37. - In the case where the
roll paper 10 is rewound by thefeed roller 12 as described with reference toFIG. 1 , by the arrangement position of thefeed roller 12 as configured as described above and the direction of theguide groove 30A in the guide plate 30 (the movement direction of the roll paper 10), some of the rotational driving force of thefeed roller 12 acts as a force for pushing theroll paper 10 against thefeed roller 12, by which rewinding can be performed without the occurrence of winding slack on theroll paper 10. - The
guide groove 30A in theguide plate 30 shown inFIG. 3 is inclined to guide theroll paper 10 movably downward and slantwise to the right. However, the present invention is not limited to this configuration. Theguide groove 30A may be arranged so as to guide theroll paper 10 movably in the vertical direction as shown inFIG. 1 . In sum, the relative positional relationship between the direction of theguide groove 30A and the arrangement position of thefeed roller 12 has only to be kept so that thefeed roller 12 lies on the downstream side of the centerline of theguide groove 30A. - Also, in this embodiment, explanation has been given of the configuration in which the
feed roller 12 is fixed, and theroll paper 10 is moved by theguide groove 30A in theguide plate 30. However, inversely, the configuration may be such that the roll paper is provided at a fixed position, and the feed roller is moved so as to come into contact with the roll paper under an appropriate contact pressure as the diameter of the roll paper decreases. - Specifically, as shown in
FIG. 4 , afeed roller 12′ is provided so as to be movable in the direction indicated by the arrow e with respect to theroll paper 10 provided at the fixed position. As shown in the figure, the feeding device is configured so that the contact point between theroll paper 10 and thefeed roller 12′ lies on the upstream side of the outer peripheral position of theroll paper 10 at the prolongation of the movement direction e of thefeed roller 12′. Thereby, the rotational driving force due to thefeed roller 12′ at the time when theroll paper 10 is rewound acts so as to increase the contact pressure of thefeed roller 12′, so that the winding slack of theroll paper 10 can be prevented. - Further, in this embodiment, explanation has been given of the roll paper formed by winding the recording paper. However, the invention is not limited to this, but can be applied to a feeding device for a roll body formed by winding a resin sheet, cloth, or any other recording medium.
Claims (12)
0<θ<sin−1{(R 2+Rf)/(R 1+Rf)}
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2004-093495 | 2004-03-26 | ||
JP2004093495A JP2005280861A (en) | 2004-03-26 | 2004-03-26 | Supplying device for recording medium |
Publications (1)
Publication Number | Publication Date |
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US20050225029A1 true US20050225029A1 (en) | 2005-10-13 |
Family
ID=35059806
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/090,296 Abandoned US20050225029A1 (en) | 2004-03-26 | 2005-03-28 | Recording medium feeding device |
Country Status (2)
Country | Link |
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US (1) | US20050225029A1 (en) |
JP (1) | JP2005280861A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20070077080A1 (en) * | 2005-09-29 | 2007-04-05 | Brother Kogyo Kabushiki Kaisha | Image recording apparatus that supports conveying roller via rolling bearing |
CN101654027A (en) * | 2009-09-07 | 2010-02-24 | 深圳市润天智图像技术有限公司 | Medium control mechanism and inkjet printer |
US20100244374A1 (en) * | 2005-12-27 | 2010-09-30 | Brother Kogyo Kabushiki Kaisha | Sheet-conveying device |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2007160743A (en) * | 2005-12-14 | 2007-06-28 | Sony Corp | Rolled recording web and printer device using this rolled recording web |
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US5924646A (en) * | 1996-09-26 | 1999-07-20 | Pouya; Amir S. | Display apparatus for carpets |
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JPH07106816B2 (en) * | 1989-01-21 | 1995-11-15 | 三菱電機株式会社 | Recording paper loading mechanism |
JPH10139239A (en) * | 1996-11-08 | 1998-05-26 | Canon Aptecs Kk | Label printer |
JP3787407B2 (en) * | 1997-04-18 | 2006-06-21 | 富士写真フイルム株式会社 | Paper supply cartridge |
JP3812866B2 (en) * | 1998-12-02 | 2006-08-23 | 富士写真フイルム株式会社 | Printer |
JP2002308525A (en) * | 2001-04-18 | 2002-10-23 | Fuji Photo Film Co Ltd | Recording paper tip detecting device |
JP2003048646A (en) * | 2001-08-07 | 2003-02-21 | Canon Aptex Inc | Supply device for recording medium |
JP2003261248A (en) * | 2002-03-08 | 2003-09-16 | Fuji Photo Film Co Ltd | Recording paper holder and printer using the holder |
-
2004
- 2004-03-26 JP JP2004093495A patent/JP2005280861A/en active Pending
-
2005
- 2005-03-28 US US11/090,296 patent/US20050225029A1/en not_active Abandoned
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US3861610A (en) * | 1972-04-03 | 1975-01-21 | Ncr Co | Intermittent drive mechanism |
US5924646A (en) * | 1996-09-26 | 1999-07-20 | Pouya; Amir S. | Display apparatus for carpets |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20070077080A1 (en) * | 2005-09-29 | 2007-04-05 | Brother Kogyo Kabushiki Kaisha | Image recording apparatus that supports conveying roller via rolling bearing |
US7658382B2 (en) * | 2005-09-29 | 2010-02-09 | Brother Kogyo Kabushiki Kaisha | Image recording apparatus that supports conveying roller via rolling bearing |
US20100244374A1 (en) * | 2005-12-27 | 2010-09-30 | Brother Kogyo Kabushiki Kaisha | Sheet-conveying device |
US7992869B2 (en) * | 2005-12-27 | 2011-08-09 | Brother Kogyo Kabushiki Kaisha | Sheet-conveying device |
CN101654027A (en) * | 2009-09-07 | 2010-02-24 | 深圳市润天智图像技术有限公司 | Medium control mechanism and inkjet printer |
Also Published As
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JP2005280861A (en) | 2005-10-13 |
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Legal Events
Date | Code | Title | Description |
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AS | Assignment |
Owner name: FUJI PHOTO FILM CO., LTD., JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:KAWASHIMA, TAKASHI;REEL/FRAME:016720/0472 Effective date: 20050418 |
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AS | Assignment |
Owner name: FUJIFILM CORPORATION, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:FUJIFILM HOLDINGS CORPORATION (FORMERLY FUJI PHOTO FILM CO., LTD.);REEL/FRAME:018904/0001 Effective date: 20070130 Owner name: FUJIFILM CORPORATION,JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:FUJIFILM HOLDINGS CORPORATION (FORMERLY FUJI PHOTO FILM CO., LTD.);REEL/FRAME:018904/0001 Effective date: 20070130 |
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STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |