Patent Abstract:
An image erasing apparatus includes a heating member and a pressure member positioned adjacent one another, such that a sheet having an erasable image thereon may be passed between the heating member and the pressure member with the pressure member pressing the image on the sheet against the heating member, and a separation member positioned adjacent to the heating member and adjacent to a portion of a transport path of a sheet to be erased in the erasing apparatus.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority from U.S. Provisional Application No. 61/622,431 filed on Apr. 10, 2012; the entire contents of which are incorporated herein by reference. 
    
    
     FIELD 
     Embodiments described herein relate to an erasing apparatus that decolors the color of an image previously made visible by developing a developer having a coloring material therein. 
     BACKGROUND 
     There is an erasing apparatus that erases the color of the image by decoloring the color of the coloring material so that the sheet can be reused. 
     In the erasing apparatus, a developed coloring material is heated so as to reduce the effect of the developing agent on the coloring compound (the precursor compound of the pigment) that generates color by a developing material, thereby eliminating the colored state of the coloring material. 
     In an apparatus for heating the coloring material, the sheet carrying the coloring material, and the coloring material carried thereon, are conveyed to an erasing region including a heating roller and a pressing roller pressed toward the heating roller for heat treatment. The sheet to be decolored or erased is passed through the nip region of the two rollers, which presses the imaged side of the sheet against the heating roller to “decolor” or erase the image thereon. In this case, in order to prevent the sheet from winding around the heating roller, a separating hook is adopted. 
     When heated, the sheet that carries the coloring material curls due to the heat imparted thereto during decoloring. When separating hook is adopted to ensure that the sheet does not wrap or wind around the heating roller, to reliably separate a thin sheet or a sheet having color of the image erased therefrom the separating hook has to make contact with the surface of the heating roller. As a result, the coating of the surface of the heating roller becomes scratched, degrading the durability of the heating roller. 
     The purpose of the present disclosure is to solve the aforementioned problems of the related art by providing an erasing apparatus that decolors the color of the image developed by a developing material, while it maintaining high durability of the heating roller. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an example of the erasing apparatus of the present embodiment. 
         FIG. 2  shows an example of a main section of the erasing apparatus of the present embodiment. 
         FIG. 3  shows an example of a decoloring apparatus of the erasing apparatus of the present embodiment. 
         FIG. 4A  and  FIG. 4B  shows an example of the decoloring apparatus of the erasing apparatus of the present embodiment. 
         FIG. 5A  and  FIG. 5B  shows an example of the decoloring apparatus of the erasing apparatus of the present embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     As an embodiment of the present disclosure, an erasing apparatus includes a decoloring section and a separating section. The decoloring section has a first unit, which has the first heating source in contact with the sheet that carries the image of the color generated by the developing material so that the developing material on the sheet is heated, and a second unit, which has a second heating source in contact with the second surface of the sheet to heat the developing material on the sheet, as a result, the color generated by developing material on either side of the sheet is decolored. A separating section separates the sheet from the heating source, by contacting the sheet at non-image bearing regions of the sheet in at least one of the first unit and the second unit. 
     In the following, embodiments of the present disclosure will be explained with reference to the drawings. 
     As shown in  FIGS. 1 and 2 , the erasing apparatus  101  at least contains a paper feeding section  10 , an erasing section  20 , a reading section  30 , a conveying section  40 , a decoloring device control section  50 , a paper discharge section  60 , and a display unit  70  and an operation section  80  shown functionally in blocks on  FIG. 2 . In addition,  FIG. 2  is a block diagram illustrating the main functions of the erasing apparatus  101  in block diagram form.  FIG. 1  is a schematic diagram of the erasing apparatus  101  explaining with an emphasis on conveying of the sheet (paper sheet) and the circulation (conveying) of the sheet to the decoloring apparatus. 
     The paper feeding section  10  at least contains a pre-decoloration sheet holding section (hereinafter to be referred to as paper feeding cassette)  11  that has the pre-decoloration sheets (paper sheets) which may have images (coloring material) to be decolored on the sheets loaded therein (the sheets are set therein), a conveying path  41  (conveying section  40 ) that guides the pre-decoloration sheet loaded in the paper feeding cassette  11  to the erasing section  20  to be explained in detail later, and a paper feeding roller  12 , a conveying roller  13 , and a conveying roller  14  that provide the pushing force (conveying force) to the pre-decoloration sheet so that the pre-decoloration sheet can be conveyed (driven to move) in the conveying path  41 . 
     The conveying path  41  is connected to a conveying path  42  (conveying section  40 ) that partially overlaps and is shared with the reading section  30  to be explained in detail later. 
     By the conveying path  42  (conveying section  40 ), a sheet having a decolorable image thereon is guided through the reading section  30 , and if an image is present on the sheet, to the erasing section  20  erased (to have the color of the coloring material decolored) in the erasing section  20 , and thus guides the sheet after decoloration (hereinafter to be referred to as decolored sheet) again through the reading section  30  and then on to the decolored sheet holding section (hereinafter to be referred to as discharged paper section)  60 . The conveying path  42  at least contains conveying rollers  33  and  34  that provide the pushing force that allows the sheet to be conveyed in the conveying path  42  to the pre-decoloration sheet and the decolored sheet, respectively. 
     The erasing section  20  at least contains a branching unit  22 , which branches the pre-decoloration sheet from the conveying path  42  to a decoloring apparatus  21  on the basis of the reading result by the reading section  30 , i.e., if an image is present on the sheet, the sheet is fed to the erasing section  2   d , if an image is not present on the sheet, the sheet is fed to the discharged paper section  60 , a conveying path  47  (conveying section  40 ) that guides the pre-decoloration sheet branched by the branching unit  22  to the decoloring apparatus  21  of the erasing section  20 , conveying rollers  23  to  25  that provide a pushing force to the pre-decoloration sheet so that the pre-decoloration sheet can be conveyed to the decoloring apparatus  21 , and conveying rollers  26  to  28  that guide the decolored sheet after decoloration by the decoloring apparatus  21  to the conveying path  42 . The decoloring apparatus  21  works as follows: a decoloring temperature (heat) over a prescribed temperature is applied on the sheet passing between two rollers arranged with their axes that define their rotating centers substantially parallel with each other, or through the nip region defined by the adjacent portions of one roller and an endless belt, so that the effect of the developing agent on the coloring compound (the precursor compound of the coloring material) which caused the color to be is substantially reduced, and the coloring state is cancelled, that is, the sheet is decolored. Here, the decoloring temperature (heat) is provided by a heat lamp, a heated metal layer on a belt, or an IH (inductive heating) heater that generates heat by inductive heat generated in the metal surface of a roller, or the like. In the following, for the decoloring apparatus  21 , a detailed explanation will be made with reference to  FIGS. 3 to 5 . 
     Referring still to  FIG. 1 , the reading section  30  at least contains a first image sensor  31  and a second image sensor  32  that detect whether the sheet going through the conveying path  42  is a pre-decoloration sheet, in other words, the sensors  31  and  32  detect the presence of an image on one or the other sides of a sheet passing there past. The first image sensor  31  and the second image sensor  32  may be sensors for measuring reflection density from the sheet, the dielectric constant or a material passing the sensor, or the like, and thereby detect the presence (or not) of an image on each of the two surfaces of the sheet passing therethrough. 
     The first image sensor  31  and the second image sensor  32  of the reading section  30  may be CMOS sensors, which acquire the image information of the sheet going through the conveying path  42 . The image information acquired by the first image sensor  31  and the second image sensor  32  is stored in a memory device  36 . The image information stored in the memory device  36  is subject to A/D conversion (analog/digital conversion), and the converted data are sent to the page memory  35  in page units, i.e., the data is associated with a particular sheet as if passed through the decoloring apparatus. 
     The conveying path  42  is connected to a conveying path  43 , at that the branching unit  22  guides a decolored sheet to the paper discharge section  60 , rather than back through the erasing apparatus  20 . 
     The conveying path  43  (conveying section  40 ) at least contains a discharged paper branching unit  16  and a conveying roller  15 . The decolored sheet branched by the branching unit  22  is guided to a first decolored sheet holding section (hereinafter to be referred to as the reuse cassette)  61  or a second decolored sheet holding section (hereinafter to be referred to as stocker)  62  of the paper discharge section  60 . A decolored sheet to be placed in the reuse cassette  61  is guided by a conveying roller  63  and a conveying path  44  (conveying section  40 ). The decolored sheets to be placed in the stocker  62  are guided to the conveying rollers  63  to  65  and conveying paths  45 ,  46  into the stocker  62 , (conveying section  40 ). 
     At a prescribed position of the conveying path  42  where the sheet can be fed, such as at the position on the upstream side with respect to the conveying path  41  that conveys the sheet fed by the paper feeding cassette  11  or the conveying path  47  that conveys the decolored sheet after decoloration by the decoloring apparatus  21  to the conveying path  42  with respect to the conveying path  42 , a manual conveying path  48  is provided. This manual conveying path contains a conveying roller  18  and a manual paper feeding section  17  to manually feed a pre-decoloration sheet to the decoloring apparatus  21 , and then to the erasing section  20 , without going through the paper feeding cassette  11 . 
     Referring now to  FIGS. 1 and 2 , a control section  50  at least contains, for example, a CPU (Central Processing Unit, main controller)  51 , a ROM (Read-Only Memory)  52 , a RAM (Random Access Memory)  53 , an input/output (I/O) port  54 , a motor driver  56 , a conveying path switching control section (branching unit driving section)  57 , a temperature control section  58 , and a power supply section  59 . Here, the display unit  70  and the operation section  80  are connected to the control section  50 . Also, the display unit  70  and the operation section  80  may be made of touch panel or the like formed monolithically. 
     The main controller (CPU)  51  controls the operation of the various parts according to an operation program stored in the ROM  52 . 
     The ROM  52  holds the operation program for operation of the decoloring apparatus  21  and the reference values for comparing with the results detected by the first image sensor  31  and the second image sensor  32 , and the like. 
     The RAM  53  stores, for example, the results of determining the presence of an image on a sheet detection by the first image sensor  31  and the second image sensor  32  which is input via the I/O port  54 , and the input from the jam sensors arranged at the prescribed sites on the various conveying paths  41  to  48  (conveying section  40 ) via the I/O port  54 , and, it stores the temporary data (such as individual data relating to a specific sheet) when the processing routine is executed according to the instruction input (operation information) of the operation section  80 , and the like. 
     The I/O port  54  converts, for example, the detection results of the first image sensor  31  and the second image sensor  32  to a format that can be processed by the CPU  51  (the main control section). Also, the I/O port  54  converts the instruction input from the operation section  80  to a format that can be processed by the CPU  51 . Also, the I/O port  54  receives the control instructions to the various elements, such as the paper feeding section  10 , the erasing section  20 , the reading section  30 , the conveying section  40  and the paper discharge section  60 , as well as the motor and the branching unit, and the detected values of the various sensors, and the like. 
     The motor driver  56  drives the rollers of a conveying motor  29  that drives the conveying rollers  23  to  28  arranged before and after (on the upstream side and downstream side) the decoloring apparatus  21 , and other motors. 
     As shown in  FIG. 1 , the paper discharge section  60  guides a decolored sheet sent via the conveying path  43  via the discharged paper branching unit  16  to the reuse cassette  61  (the first decolored sheet holding section) or the stocker  62  (the second decolored sheet holding section). 
     The operation section  80  receives control instructions input by the user, and it outputs control commands corresponding to the control instructions so that the CPU  51  can read them. 
     As shown in  FIGS. 3 and 4 , the decoloring apparatus  21  contains a first heating unit  210  and a second heating unit  220 . The side of the second conveying path, that is, the side of the conveying rollers  23  to  25  of the conveying path  47 , is called the conveying upstream side. The side of the conveying rollers  26  to  28  of the second conveying path, that is, the conveying path  47 , is called the conveying downstream side. 
     The first heating unit  210  (on the conveying upstream side) includes a heating roller  211  and pressing roller  212 . The heating roller  211  has a heating source lamp  213  inside the roller thereof, and a temperature detecting section  214  is located on the outer periphery of the roller. 
     The second heating unit  220  (on the conveying downstream side) includes a pair of rollers, that is, a heating roller  221  and a pressing roller  222 . The heating roller  221  has a heating source lamp  223  inside the roller thereof and a temperature detecting section  224  is located on the outer periphery of the roller. 
     To prevent wrapping or winding of the sheet around the heating rollers  211  and  221 , separating guides  215  are located between the heating roller  211  and the pressing roller  212  of the first heating unit  210  and between the heating roller  221  and the pressing roller  222  of the second heating unit  220 . The separating guides  215  guide the paper sheet between the heating roller  221  and the pressing roller  222  of the second heating unit  220 , and, at the same time, ensure separation of the sheet from the surface of the heating roller  211  of the first heating unit  210 . Also, on the downstream side (the conveying roller  26  side) of the heating roller  221  and the pressing roller  222  of the second heating unit  220 , separating guides  225  are arranged to ensure separation of the sheet from the surface of the heating roller  221  of the second heating unit  220 . 
     The heat capacity of the heating source lamp  213  in the heating roller  211  of the first heating unit  210  is nearly equal to the heat capacity of the heating source lamp  223  in the heating roller  221  of the second heating unit  220 . 
     The first heating unit  210  and the second heating unit  220  have the positions of the heating roller  211  and the heating roller  221  inverted from each other with respect to the second conveying path, i.e., the heating rollers  211  and  221  are located to engage opposite sides of a sheet passing through the erasing apparatus  20 . In the configuration in the embodiment, the heating roller  211  is in contact with one surface of the sheet passing through the second conveying path (the side on the second image sensor  32  side, to be referred to as the outer surface as needed). Consequently, the heating roller  221  is in contact with the other surface of the sheet passing through the second conveying path (the side on the first image sensor  31  side, to be referred to as the back surface as needed). 
     The first heating unit  210  or the second heating unit  220  or both of them may have a configuration in which one roller and an endless belt together form a nip. The heating source lamp  213  of the first heating unit  210  or the heating source lamp  223  of the second heating unit  220  may also be replaced by an IH (inductive heating) heater that generates the inductive heat in the metal surface of the heat roller (or the metal layer of the belt). 
       FIG. 4A  and  FIG. 4B  shows an example of a heating roller  211  or  221  of the embodiment. In this example, on the heating roller  211  of the first heating unit  210  or the heating roller  221  of the second heating unit  220 , at the sites corresponding to the opposed sides of a sheet to be decolorated, there are provided recesses  211 A for receiving the separating guides  215  therein, respectively, or recesses  221 A in roller  221  for receiving the separating guides  225 , respectively. That is to say, the separating guides  215  extend within the recesses  211 A of the heating roller  211  of the first heating unit  210 , and the separating guides  225  extend within the recesses  221 A of the heating roller  221  of the second heating unit  220 . Consequently, the separating guides  215  and the separating guides  225  are located adjacent to the outer diameter of the heating roller or at the positions inwardly thereof. 
     The recessions  211 A or recessions  221 A are arranged at the portions on the heating roller  211  (heating roller  221 ) corresponding to the non-printing/non-decoloring regions of the sheet, where an image is not present or is unlikely to be present. The recessions  211 A or the recessions  221 A are formed to overlap the sides of a sheet moving therepast by a few mm, e.g., 2 mm, from the end portions in the width direction of the sheet, respectively. Consequently, the separating guides  215  or the separating guides  225  are located at the sites of the recessions  221 A or the recessions  221 A, and they may contact the sides of the sheet for, e.g., about 2 mm. 
     Additionally, the separating guides  215  (separating guides  225 ) are not in contact with the outer surface of the heating roller  211  (heating roller  221 ) in contact with the main portion of the sheet except the overlap portions at the two ends parallel with the conveying direction of the sheet as the decoloration subject. Consequently, the coating on the surface of the heating roller is not scratched by the separation device. As a result, it is possible to prevent the undesired degradation of the durability of the heating roller  211  (heating roller  221 ). 
     Also, the recesses  211 A or recesses  221 A can be positioned to accommodate sheets of different sizes in the same sequence (sequence A or sequence B) with the following scheme: the interval between them is selected with the following effect: for example, when an A4-size sheet is conveyed, the direction parallel with the minor edge direction is taken as the conveying direction, and, for an A3-size sheet, the conveying direction is taken as parallel with the major edge direction. 
     In the example shown in  FIG. 5A  and  FIG. 5B , the separating guides  215  and the separating guides  225  may be formed monolithically on the upstream side and downstream side from the heating roller  211  (heating roller  221 ). 
     In the following, the conveying operation will be explained. 
     In the decoloration and reading mode, the sheet to have the color of the image thereon (the color displayed by the developing material, that is, the coloring material) to be decolored is conveyed from the paper feeding section  10  through the first conveying path, and it is positioned at the reading section  30 . In the reading section  30 , the first image sensor  31  and the second image sensor  32  read the image information on the sheet. The image information on the sheet read by the first image sensor  31  and the second image sensor  32  is stored in the memory device  36 . 
     The sheet that has passed through the reading section  30  then goes through the second conveying path (conveying path  47 ), and it is then positioned at the first heating unit  210  of the decoloring apparatus  21  after going through the conveying roller  25  on the conveying upstream side, and, as it goes through the second heating unit  220  on the conveying downstream side, the color of the image is decolored in the decoloring process. 
     The sheet that has been decolored by the decoloring apparatus  21  then goes through the conveying roller  26  on the conveying downstream side from the second heating unit  220 , and it is positioned in the second conveying path. The decolored sheet located in the second conveying path is again positioned in the first conveying path, and it goes through the first conveying path into the first discharged paper tray (reuse cassette)  61  or the second discharged paper tray (stocker)  62  of the paper discharge section  60 . 
     However, when the decoloring process is carried out by the decoloring apparatus  21 , for the sheet going from the heating roller  211  and the pressing roller  212  of the first heating unit  210  to the heating roller  221  and the pressing roller  222  of the second heating unit  220 , by the separating guides  215  that work together with the recessions  211 A on the first heating roller  211 , it is reliably separated (peeled) from the first heating roller  211 . 
     Also, a sheet moving downstream from the heating roller  221  and the pressing roller  222  of the second heating unit  220  is reliably separated (peeled) from the second heating roller  221  by the separating guides  225  that work together with the recessions  221 A of the second heating roller  221 . 
     Also, as shown in  FIG. 5A  and  FIG. 5B , the separating guides  215  and the separating guides  225  on the upstream side and downstream side of the heating roller  221  of the second heating unit  220  may be formed monolithically, so that it is possible to omit the conveying guides required when they are arranged independently. 
     Consequently, even for a thin sheet or a sheet that has the color of the image erased, it is still possible carry out separation (peeling) without winding on the heating roller. As a result, it is possible to suppress the undesired degradation in the durability of the heating roller. 
     For example, by the manual paper feeding section  17 , when sheets with different lengths are fed, with the same width of the sheets in the direction orthogonal to the sheet conveying direction, such as in the case of A3-size sheets, the input sheet sizes can be tolerated by the operation section  80 . For example, for the length of the sheets, according to the control carried out at the control section  50  corresponding to the input from the operation section  80 , control is carried out so that sheet jam (abnormality in conveying) is not detected up to at least twice the length when an A4-size sheet is conveyed. That is, with the erasing apparatus that carries out decoloration treatment for the minor edge direction (lateral direction) of the A3-size sheet, that is, the major edge direction (longitudinal direction) of the A4-size sheet, it is possible to carry out the decoloration treatment also for the A3-size sheet. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. 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 inventions.

Technology Classification (CPC): 1