Patent Application
20130267412
The embodiments described herein relate generally to a color erasing apparatus and a color erasing heat source unit.
In an image forming apparatus, such as an MFP (a Multi-Function Peripheral), an image is formed on a sheet recording medium such as paper or the like (hereinafter will be referred to as “paper”). In order to erase the image formed on the paper and reuse the paper, the image is printed on the paper using an erasable coloring material such as ink containing a leuco dye. The erasable coloring material is erased by applying heat thereto at a high temperature.
The color erasing apparatus is configured to have a heat roller, into which a roller type heat source is built-in similar to a fuser (fixing) unit, and a press roller with an interposing paper transporting path. The heat roller and the press roller are arranged to face each other. The color erasing apparatus transports the printed paper by rotating the heat roller (the heat source) along with the press roller with the paper pinched therebetween. The image that had been formed on the paper is erased by heating the printed paper as it rolls moves between the press roller and a heat roller.
However, the printed paper being transported to the heat source (the color erasing unit) of the color erasing apparatus has been used at least once. Unlike new paper, the printed (used) paper may be guided to the color erasing unit in a deformed state, such as being wrinkled, folded, having a hole therein, or the like. The color erasing is achieved by heating the toner on the surface of the transported paper. The surface of the used paper is rapidly heated as it passes through the color erasing unit, vaporizing the moisture in the paper, and causing a subtle change in the size of the paper. Further wrinkling of the paper may occur when the used paper is heated and pressed by the rollers while passing through the color erasing unit. Therefore, transporting the paper becomes extremely unstable and paper jamming may occur.
The probability of a paper jam increases for used paper transported while applying roller pressure and heat. When a paper jam occurs at the color erasing unit, the paper is freed by releasing the pressure from the press roller or by turning a knob connected to the press roller for rotating it to release the jammed paper therefrom.
According to an embodiment of a color erasing apparatus, paper with an image formed by a coloring material which is erasable by heating thereof, is transported on a transporting path. A first color erasing unit includes a first heat roller, with a first heat source therein, and a first press roller, facing the first heat roller. The paper is sandwiched between the first heat roller and the first press roller during transport. The first color erasing unit is provided in the upstream side of the transporting path for erasing a first side of the paper. A second color erasing unit includes a second heat roller, with a second heat source therein, and a second press roller, facing the second heating member. The paper is sandwiched between the second heat roller and the second press roller during transport. The second color erasing unit is provided downstream of the first color erasing unit for erasing a second side of the paper. A gear drive train connects the first heat roller with the second heat roller, and includes a plurality of gears transmitting a driving force from a transporting motor to the first heat roller and the second heat roller. An opening and closing mechanism for the heat source moves from a first position to a second position while maintaining the connected state of the drive train gears coupled to the rotating axis of any one of the heat source rollers. The first heat roller is separated (spaced) from the first press roller and the second heat roller is separated (spaced) from the second press roller, in a first position. The first press roller is in close proximity to the first heat roller and the second press roller is in close proximity to the second heat roller in the second position.
The embodiments will be described below with reference to the drawings. Identical reference numbers have been used, where possible, to designate identical elements or locations that are common to the figures.
Referring to
The transporting paths 141 to 145 have a plurality of motors 18 for driving a plurality of conveyor rollers 17 to transport a paper S therethrough. Furthermore, a plurality of gates 19 is provided for accurately transporting the paper S along each of the transporting paths 141 to 145.
The first transporting path 141 transports the paper S from the paper feed unit 12 to the scanner 13. The second transporting path 142 transports the paper S in the direction shown by arrow A from the scanner 13 to the color erasing unit 20. The third transporting path 143 transports the paper S from the color erasing unit 20 back to the scanner 13. The fourth transporting path 144 transports the paper S from the scanner 13 to the first paper discharge tray 15, and the fifth transporting path 145 transports the paper S from the scanner 13 to the second paper discharge tray (the reject box) 16.
The first paper discharge tray 15 accommodates the paper S which can be reused after an image has been erased. The second paper discharge tray (the reject box) 16 accommodates the paper S that cannot be reused and normally would be discarded and recycled.
The color erasing apparatus 10 carries out the following operations:
(1) The paper S supplied from the paper feed unit 12 along the first transporting path 141 is read by the scanner 13. The scanner 13 has a first scanner 131 and a second scanner 132 for reading both sides of the paper. The scanner 13 reads image data from a paper S to determine a printed status of both sides of the paper S. The image data read by the scanner 13 is saved.
(2) Torn or wrinkled paper S, as categorized by the image data, is guided along the fifth transporting path 145 to the reject box 16. The paper S, without tears or wrinkles, is transported along the second transporting path 142 to the color erasing unit 20.
(3) The paper S transported to the color erasing unit 20 is heated while passing through the color erasing unit 20. The color erasing unit 20 thereby erases the image on the paper, formed by an erasable color material, by applying heat and pressure to the paper at a relatively high temperature, for example, 180 to 200° C. A structure for the color erasing unit 20 will be described later herein.
(4) After passing through the color erasing unit 20, the paper is transported along the third transporting path 143 back to the scanner 13. The scanner 13 re-reads the printing status to confirm whether the image, formed by an erasable coloring material, has been erased by the color erasing unit 20.
(5) The paper S, determined to be free of an image, and that can be reused, is transported along fourth transporting path 144 to the first paper discharge tray 15. Paper S containing a residual image, or paper S containing tears or wrinkles, is transported along the fifth transporting path 145 to the reject box 16.
The paper S is transported along the second transporting path 142 in the direction of arrow A. The direction of arrow A is equivalent to the direction of arrow A in
The press rollers 301 and 302 are cylindrically shaped rotating rollers and rotate about axis 303 and 304. The press rollers 301 and 302 contact heat rollers 213 and 214 in the longitudinal direction thereof. The paper S is transported while being heated by biasing the rotating axis 303 and 304 (or the rollers 301, 302) in the direction of the heat rollers 213 and 214, sandwiching the paper S between the heat roller 213 and the press roller 301, as well as between the heat roller 214 and the press roller 302 as the paper S passes therethrough.
F1 denotes a biasing pressure (pinch pressure) of the press roller 301 in the direction of the heat roller 213, in the first color erasing unit 201. F2 denotes a biasing pressure (pinch pressure) of the press roller 302 in the direction of the heat roller 214, in the second color erasing unit 202. In one embodiment, the ratio of the pinch pressure F1 to the pinch pressure F2 is 3:2.
The rotating axis 303 is configured to bias, by use of a spring, press roller 301 towards the heat roller 213 in order to apply the pinch pressure F1. Furthermore, the rotating axis 304 is configured to bias, by use of a spring, press roller 302 towards the heat roller 214 in order to apply the pinch pressure F2.
Next, the color erasing operation for the paper S by the heat rollers 213 and 214 and the press rollers 301 and 302 will be explained. The paper S is guided via the second transporting path 142 through the guide plates 31 and 33 into the color erasing apparatus 20. Paper S is transported through the color erasing apparatus 20 in the direction of arrow A, at a speed set in advance, by rotating clockwise the press roller 301 of the first color erasing unit 201 while rotating counterclockwise the press roller 302 of the second color erasing unit 202.
In the first color erasing unit 201, which is situated upstream in the transporting path, the press roller 301 is biased to be in contact with the heat roller 213 by the pinch pressure F1. A nip area for applying heat to the paper S is created at the contact point (the dashed line X01) of the press roller 301 and the heat roller 213. When paper S passes through the nip area X01, the surface of the paper is heated to erase the image formed on a first surface of the paper S.
When an image has been formed on the paper S using an erasable coloring material, the coloring material can be erased by heating the erasable coloring material at a predetermined temperature. The heat roller 213 is provided with a uniform heat by the cylindrically shaped halogen heat lamp 241 and is maintained thereby at the erasable temperature. The temperature of the heat roller 213 is detected by thermistors (not shown) and maintained at the appropriate temperature based on the detected temperature.
The paper S, discharged from the first color erasing unit 201, is guided by guide plates 32 and 34 and transported into the second color erasing unit 202. In the second color erasing unit 202, downstream on the transporting path from first color erasing unit 201, the relationship between the upper position for the press roller 302 and lower position for the heat roller 214 is reversed from that in the first color erasing unit 201. Additionally, press roller 302 is biased to be in contact with the heat roller 214 by pinch pressure F2.
The contact point of the press roller 302 and the heat roller 214 forms the nip area from which the heat is applied to paper S. The surface of the paper is heated by passing the paper through the nip area to erase the image formed on the second surface of the paper S. The paper S, in which both surfaces have been erased, is discharged from guide plate 34 and sent along third transporting path 143.
The first color erasing unit 201 and the second color erasing unit 202 are structurally the same; however the units are arranged with the heat roller and press roller in opposing locations with respect to the paper S path. The opposing locations for the heat rollers enable erasing an image on the first side of the paper S with the first color erasing unit 201 and an image on the second side of the paper S with the second color erasing unit 202. Therefore, the images on both sides of the paper S can be erased efficiently.
However, a paper jam may occur when the paper passes through the inside of the color erasing unit 20 with a structure of twin or two different color erasing units as described above. The color erasing unit 10 heats printed or previously used paper while an image forming apparatus may print on virgin paper. Therefore, the color erasing unit 10 has a higher probability of a jamming paper than an image forming apparatus. The following section will describe a heat source opening and closing mechanism provided to address this problem in the color erasing apparatus 10.
As has been explained above, the heat source opening and closing mechanism is divided into an upper and a lower unit that have been integrated into a single body. The upper unit has the heat roller 213 of the first color erasing unit 201 and the press roller 302 of the second color erasing unit 202. The lower unit has the heat roller 214 of the second color erasing unit 202, the press roller 301 of the first color erasing unit 201, and the gear drive train 22.
In the upper unit, the heat roller 213 of the first color erasing unit 201 is arranged adjacent to gear 22A and arranged in the downstream side of the paper transporting direction from gear 22A arranged at the beginning of gear drive train 22. The press roller 302 of the second color erasing unit 202, facing heat roller 214, is arranged in the downstream side of the paper transporting direction from heat roller 213.
In the lower unit, the press roller 301, of the first color erasing unit 201, is adjacent to the gear 22A and arranged in the downstream side of the paper transporting direction from gear 22A. A gear 22B is connected to a lower portion of gear 22A and arranged in the downstream side of the paper transporting direction from gear 22A. Similarly, gear 22C is connected to a lower portion of gear 22B and arranged in the downstream side of the paper transporting direction from gear 22B. Gear 22D is connected in the upper portion of gear 22C and is arranged in the downstream side of the paper transporting direction from gear 22C. Gear 22D is adjacent to heat roller 214, in second color erasing unit 202, and arranged in the downstream side of the paper transporting direction from gear 22D.
That is to say, the gear drive train arranged inside of the gear bracket 23 has a gear structure that sequentially connects gears 22B, 22C, and 22D with gear 22A. Gear 22A serves as the head gear and is connected to heat roller 213 of the first color erasing unit 201. Heat roller 214, of the second color erasing unit 202, is connected to gear 22D, arranged as the last gear. The amount of clearance between mated gear teeth is controlled for backlash.
As shown in
When a paper jam occurs, the jammed paper is taken out by releasing the heat source (heat rollers 213 and 214) from the press rollers 301 and 302. When the heat source is closed again, the heat source opening and closing mechanism maintains the gear coupling for the gear drive train 22. For this reason, backlash control among the gears that constitute the gear drive train 22 is unnecessary. Furthermore, a quit high conveyance speed can be achieved by maintaining the gear coupling for the gear drive train 22. Color erasing unit 20, which is the color erasing heat source, can achieve high rigidity since the color erasing unit has a structure that maintains the gear coupling for the gear drive train 22, which drives heat rollers 213 and 214, even when opening the heat source by supporting the gear drive train 22. In the embodiment described above, the color erasing unit 20 is configured as a dual unit structure for efficiently erasing the color from both sides of the paper. However, the same release structure can also be applied to a single-unit structure. The embodiment also described a structure for opening around a rotating axis of gear 22A, connected to the heat roller 213 of the first color erasing unit 201. However, the structure may also swing open around the rotating axis of other gears that constitute the gear drive train. Furthermore, described is an example in which the gear drive train 22 is formed by four gears; however, the gear drive train may also be a structure of coupling an even number of gears such as two or six gears. The number and size of the gear can be designed and modified arbitrarily depending on the size of the gear combined or the size of the apparatus.
While certain embodiments have been described, these embodiments have been presented by way of example only, and they are not intended to limit the scope of the invention. Indeed, the novel embodiments described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the invention.
This application is based upon and claims the benefit of priority from U.S. provisional Patent Application No. 61/622,429, filed Apr. 10, 2012; the entire contents of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61622429 | Apr 2012 | US |
