Patent Publication Number: US-2011063393-A1

Title: Printer and method for recording/erasing image

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2009-212274, filed on Sep. 14, 2009, the entire contents of which is incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate generally to a printer and a method for recording and/or erasing a visible image with respect to a rewritable-type recording medium including a wireless communicable IC inlet. 
     BACKGROUND 
     Recently, technologies for wirelessly short-range communicating among IC inlets of articles have rapidly been distributed. Some types of printers use a print paper (recording medium) having a recording surface where a visible image is recordable, as an article. The print paper is mounted with an IC inlet, and the printers record the IC inlet along with printing the recording surface. 
     In some rewritable-type recording medium, visible images may be repeatedly recorded and erased in response to the application of heat energy. Such a recording medium has characteristics that a visible image is recorded by heating, the visible image is fixed by rapid cooling after heating, and the once-visualized image is erased by slow cooling after heating. If a recording medium is re-heated, a fixed visible image starts to be erased when the recording medium reaches a lower temperature than when the visible image is formed, and it is possible to repeatedly record and erase the visible image many times. 
     Additionally, some rewritable-type recording mediums are embedded with an IC inlet. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an illustration of an overall perspective view showing a paper feeder and a printer. 
         FIG. 2  is an illustration of a longitudinal side view thereof. 
         FIG. 3  is an illustration of a graph showing color developing characteristics of rewritable paper (recording medium). 
         FIG. 4  is a block diagram showing a hardware configuration of a printer, 
         FIGS. 5A to 5C  are schematic diagrams illustrating a method of varying heat energy to be assigned to a recording surface of a rewritable paper (recording medium). 
         FIGS. 6A to 6C  are schematic diagrams illustrating another method of varying heat energy to be assigned to a recording surface of a rewritable paper (recording medium). 
         FIG. 7  is a schematic diagram showing a state of heat energy assigned to a recording surface of a rewritable paper (recording medium) at the time of erasing a visible image. 
         FIG. 8  is a schematic diagram illustrating a control method for implementing the assignment of heat energy. 
         FIG. 9  is a flowchart showing a flow of a process of erasing a visible image. 
         FIG. 10  is an illustration of a view showing a rewritable paper embedded with an IC inlet. 
         FIG. 11  is a flowchart showing a flow of a process of erasing a visible image. 
     
    
    
     DETAILED DESCRIPTION 
     A printer prints on a recording medium having a recording surface whose visible image is recordable and erasable by the assignment of heat energy, and the recording medium has a wireless communicable IC inlet therein. The printer includes a guide conveying unit configured to convey the recording medium along a guide path, an image recording/erasing unit configured to record and erase a visible image by assigning heat energy of a thermal print head to the recording surface of the recording medium, and a control unit configured to control the image recording/erasing unit so as to assign a first temperature to a region where the IC inlet is not arranged, and so as to assign a second temperature higher than the first temperature to a region where the IC inlet is arranged when a visible image is erased. 
     Embodiments will now be described in detail with reference to the drawings. 
     Embodiments provide printer  201  using rewritable paper P (see  FIGS. 2 ,  7 , and  8 ) as a recording medium, and an image erasing method for printer  201 . Rewritable paper P has recording surface  51  whose visible image is recordable and erasable by assigning heat energy and has wireless communicable IC inlet  52  within recording surface  51 . 
       FIG. 1  is an overall perspective view showing paper feeder  101  and printer  201 . Printer  201  of this embodiment is separate from paper feeder  101 . Printer  201  includes operation display unit  202  and front panel  204  on the front-left side and the front-right side, respectively. Front panel  204  has paper discharging port  203  of rewritable paper P. Paper feeder  101  is combined to the backside of printer  201  to be internally connected to printer  201 . 
       FIG. 2  is a longitudinal side view of paper feeder  101  and printer  201 . Paper feeder  101  includes built-in paper storage unit  103  where each rewritable paper P is loaded, stored, and retained in a stack state on lifter  102 . Paper storage unit  103  is connected to feed port  105  via paper feed path  104 . Rewritable paper P is loaded on lifter  102  with recording surface  51  of rewritable paper P directed upwardly. Paper feeder  101  includes built-in pickup unit  106  for separating the top piece from a plurality of rewritable papers P stored in paper storage unit  103 , and feeding the separated piece to paper feed path  104 . Lifter  102  lifts a plurality of the stacked rewritable papers P by the amount of the consumption as pickup unit  106  feeds rewritable paper P. 
     Printer  201  includes paper feed port  205  on the rear. Paper feed port  205  is connected to feed port  105  installed at the end of paper feed path  104  built in paper feeder  101 . Paper feed port  205  is connected to paper discharging port  203  formed on front panel  204  via guide path  206  for guiding rewritable paper P. Along guide path  206 , two pairs of conveying rollers  207  (guide conveying unit) are arranged to convey rewritable paper P. 
     Printer  201  includes a built-in image recording/erasing unit  208  for recording and erasing a visible image by assigning heat energy to rewritable paper P. Image recording/erasing unit  208  is disposed around paper discharging port  203  at the end of guide path  206 . Image recording/erasing unit  208  includes, among others, platen  209  (guide conveying unit) installed in guide path  206  and linear type thermal print head  210  in contact with platen  209  via guide path  206 . Thermal print head  210  includes a plurality of heating elements  210   a  arranged in a line (see  FIG. 7 ). If voltage is applied to heating elements  210   a , heating elements  210   a  generate heat. Thermal print head  210  is installed above recording surface  51  of rewritable paper P. Thermal print head  210  may cause heating elements  210   a  to generate relatively high heat to an extent that recording surface  51  of rewritable paper P may be rapidly cooled after heating. Thereby, recording surface  51  of rewritable paper P may be rapidly cooled after heating elements  210   a  selectively generate heat, so that a visible image may be recorded on recording surface  51 . Also, thermal print head  210  may cause heating elements  210   a  to generate relatively low heat to an extent that recording surface  51  of rewritable paper P may be slowly cooled after heating. Thereby, recording surface  51  of rewritable paper P may be slowly cooled after heating elements  210   a  collectively generate heat, so that a visible image may be erased. Platen  209  is installed below recording surface  51  of rewritable paper P, and rotates to convey rewritable paper P. In this configuration, thermal print head  210  is responsible for recording image in a main scan direction, and platen  209  is responsible for recording image in a sub scan direction. 
     Printer  201  includes a built-in antenna holding body  212  for holding antenna  211  of wireless communication unit  251 . Antenna holding body  212  is arranged between pairs of conveying rollers  207  and image recording/erasing unit  208 , which are located in the downstream of guide path  206 . Wireless communication unit  251  uses antenna  211  to perform short-range wireless communication with IC inlet  52  in rewritable paper P. Antenna holding body  212  for holding antenna  211  is disposed below guide path  206 , When IC inlet  52  is positioned opposite to antenna  211 , wireless communication unit  251  wirelessly communicates with IC inlet  52 . 
     Printer  201  further includes paper registration sensors  213  disposed ahead of antenna holding body  212  in the guide path  206 . Paper registration sensors  213  detect rewritable paper P being conveyed by pairs of conveying rollers  207 . After paper registration sensors  213  detects, wireless communication unit  251  connected to antenna  211  performs short-range wireless communication and image recording/erasing unit  208  records or erases a visible image in synchronization with the wireless communication based on the detection of paper registration sensors  213 . For example, paper registration sensors  213  use transmission photo sensors. 
       FIG. 3  is a graph showing color developing characteristics of rewritable paper P. Rewritable paper P is a recordable/erasable medium whose visible image is recordable or erasable by applying heat energy. Specifically, rewritable paper P is formed of reversibly thermo-sensitive recording layers including a leuco dye, or a color developer. The reversibly thermo-sensitive recording layers are multilayered on a medium surface of paper, or a resin film. Rewritable paper P has characteristics that print content is fixed by rapid cooling after heating and print content is erased by slow cooling after heating. Any medium capable of supporting information as an image may be used as a medium other than paper or a resin film. In rewritable paper P, reversibly thermo-sensitive recording layers are multilayered to form recording surface  51  whose visible image is recordable or erasable. 
     More specifically, as shown in  FIG. 3 , when a composite of reversibly thermo-sensitive recording layers in a decolored state is heated to exceed melting point temperature T 1  of a color developer, the composite is melted to react with pigment of a leuco dye so as to be colored. When it is slowly cooled thereafter (see arrow a), the composite is decolored on the way of cooling and returns to be in the original decolored state. When it is rapidly cooled (see arrow b), a colored state is fixed. On the other hand, when a composite of reversibly thermo-sensitive recording layers in a colored state is heated from the state and a temperature increases (see arrow c), the composite is decolored at temperature T 2 , which is lower than coloring temperature as melting point temperature T 1  of the color developer. If the increased temperature does not exceed melting point temperature T 1  of the color developer, the composite remains in an original decolored state. 
     As described above, rewritable paper P whose visible image is recordable and erasable has built-in IC inlet  52  (see  FIGS. 7 and 8 ). IC chip  52   a  is combined with antenna  52   b  to form IC inlet  52  (see  FIGS. 7 and 8 ), and IC inlet  52  is built in rewritable paper P. In IC chip  52   a , a processor and a memory are integrated as an integrated circuit. A passive type where electromotive force is supplied from an outside source is used as IC chip  52   a  in IC inlet  52 . 
       FIG. 4  is a block diagram showing the hardware configuration of printer  201 . Printer  201  includes control unit  252  as a hardware resource for processing information. Control unit  252  is configured to connect SRAM  254 , flash ROM  255 , and EEPROM  256  to CPU  253  via bus line BL. The SRAM is used as a work area where variable data such as temporary storage data is rewritable and storable. ROM  255  is operable to rewrite and permanently store various types of variable data. EEPROM  256  stores a control program. CPU  253  of control unit  252  executes various processes according to the control program and causes printer  201  to record and erase visible information by controlling to drive individual parts. 
     Via bus line BL, CPU  253  is connected to head control circuit  257  for controlling thermal print head  210 , motor controller  258  for controlling to drive pairs of conveying rollers  207  of a conveying system and a motor (not shown) for rotating platen  209  as a drive source, operation display unit  202 , and sensor input circuit  259  for receiving a signal from paper registration sensor  213 . Further, CPU  253  is connected to I/O  260  for connecting paper feeder  101  and communication interface  261  via bus line BL. Communication interface  261  may be connected to an external device (not shown), and allows printer  201  to communicate with the external device by supporting a communication protocol. 
     When printer  201  receives an image formation command from the external device via communication interface  261 , printer  201  outputs an activation command to paper feeder  101  connected to I/O  260 . In response to the activation command, paper feeder  101  picks up the top piece from pieces of rewritable papers P loaded on lifter  102  by pickup unit  106 . Pickup unit  106  separates the top piece from other pieces of rewritable papers P located therebelow, and feeds the top piece to paper feed port  205  of printer  201  via feed port  105 . 
     Control unit  252  of printer  201  inputs a drive signal into motor controller  258  in time. Thereby, pairs of conveying roller  207  and platen  209  of image recording/erasing unit  208  are driven to rotate. At this point, printer  201  receives rewritable paper P delivered from paper feeder  101  and conveys rewritable paper P using pairs of conveying rollers  207 . Control unit  252  acquires the timing when paper registration sensor  213  detects rewritable paper P, and synchronously controls image recording/erasing unit  208  to record a visible image to recording surface  51  of rewritable paper P based on print data received along with the image formation command from the external device. Alternatively, if an image erasure command is received from the external device, image recording/erasing unit  208  is controlled to erase a visible image recorded on recording surface  51  of rewritable paper P. Thereafter, printer  201  discharges rewritable paper P whose visible image has been recorded or erased from paper discharging port  203 . 
     In the course of recording a viable image on rewritable paper P or erasing a viable image from rewritable paper P, control unit  252  of printer  201  controls wireless communication unit  251  to perform short-range wireless communication with IC inlet  52  on which rewritable paper P is mounted. Control unit  252  uses wireless communication unit  251  to write IC chip  52   a  with record information for IC inlet  52 , which is received along with the image formation command or the image erasure command from the external device. Otherwise, control unit  252  uses wireless communication unit  251  to read or erase information stored in IC chip  52   a.    
       FIGS. 5A to 5C  are schematic diagrams illustrating a method for varying heat energy to be assigned to recording surface  51  of rewritable paper P. Head control circuit  257  has a circuit configuration where current flows according to a strobe pulse for each of individual heating elements  210   a  in thermal print head  210 . In this configuration, a pulse width of the strobe pulse defines current flowing time of head control circuit  257  for individual heating elements  210   a . In this respect, for example, current for individual heating elements  210   a  flows in accordance with three types of strobe pulse widths of  FIGS. 5A ,  5 B, and  5 C. 
       FIG. 5A  shows a strobe pulse width when a visible image is recorded on rewritable paper P. Each of heating elements  210   a  is driven with the strobe pulse to assign heat energy to recording surface  51  of rewritable paper P, which is sufficient to record a visible image. That is, recording surface  51  reaches more than melting point temperature T 1  of a color developer included in a reversibly thereto-sensitive recording medium by the heat energy (see  FIG. 3 ). As a result, recording surface  51  of rewritable paper P is rapidly cooled after heating elements  210   a  selectively generate heat, so that a visible image may be recorded on recording surface  51 . 
       FIG. 5B  shows a strobe pulse width when a visible image recorded on rewritable paper P is erased. For example, the strobe pulse width illustrated in  FIG. 5B  has 50% duty of the strobe pulse width illustrated in  FIG. 5A . Thereby, heat energy assigned to recording surface  51  of rewritable paper P decreases less than the heat energy when heating elements  210   a  is driven with the strobe pulse width illustrated in  FIG. 5A . At this point, the heat energy may erase a visible image recorded on recording surface  51 . That is, when the heat energy is assigned, the temperature of recording surface  51  does not exceed melting point temperature T 1  of a color developer included in a reversibly thermo-sensitive recording medium, but exceeds temperature T 2  necessary for decoloring (see  FIG. 3 ). As a result, recording surface  51  of rewritable paper P is slowly cooled after heating elements  210   a  collectively generate heat, so that a visible image recorded on recording surface  51  may be erased. 
       FIG. 5C  also shows a strobe pulse width when a visible image recorded on rewritable paper P is erased. In a region where IC inlet  52  is installed in rewritable paper P, IC inlet  52  absorbs heat energy supplied from heating elements  210   a . Thus, even though heating elements  210   a  are driven with the strobe pulse width illustrated in  FIG. 5B , the temperature of recording surface  51  may not reach temperature T 2  necessary for decoloring. In this respect, for example, in the region where IC inlet  52  is installed, heating elements  210   a  are driven with 70% duty of the strobe pulse width illustrated in  FIG. 5A , which is greater than the strobe pulse width illustrated in  FIG. 5B . Thereby, the heat energy absorbed by IC inlet  52  is supplemented to allow the temperature of recording surface  51  to reach temperature T 2  necessary for decoloring. As a result, even in the region where IC inlet  52  is installed, recording surface  51  of rewritable paper P is slowly cooled after heating elements  210   a  generate heat, so that a visible image recorded on recording surface  51  may be erased. 
     In this respect, for the sake of convenience, it is assumed that the heat energy of heating elements  210   a  driven with the strobe pulse illustrated in  FIG. 5A  is E 1 , the heat energy of heating elements  210   a  driven with the strobe pulse illustrated in  FIG. 5B  is E 2 , and the heat energy of heating elements  210   a  driven with the strobe pulse illustrated in  FIG. 5C  is E 3 . 
       FIGS. 6A to 6C  are schematic diagrams illustrating another method for varying heat energy to be assigned to recording surface  51  of rewritable paper P. In an example shown in  FIGS. 6A to 6C , a strobe pulse per line is divided into a plurality of strobe pulses and heating elements  210   a  generate heat in response to the number of strobe pulses so that heat energy is controlled to be assigned to the recording surface of rewritable paper P. In this embodiment, for example, current flows for individual heating elements  210   a  with three types of strobe pulse number of  FIGS. 6A ,  6 B, and  6 C. 
       FIG. 6A  shows the number of strobe pulses per line when a visible image is recorded on rewritable paper P. Each of heating elements  210   a  is driven with the strobe pulses to assign heat energy to recording surface  51  of rewritable paper P, which is sufficient to record a visible image. That is, recording surface  51  reaches more than melting point temperature T 1  of a color developer included in a reversibly thermo-sensitive recording medium by the heat energy (see  FIG. 3 ). As a result, recording surface  51  of rewritable paper P is rapidly cooled after heating elements  210   a  selectively generate heat, so that a visible image may be recorded on recording surface  51 . 
       FIG. 6B  shows the number of strobe pulses per line when a visible image recorded on rewritable paper P is erased. For example, the number of strobe pulses illustrated in  FIG. 6B  is the half the number of strobe pulses illustrated in  FIG. 6A . Thereby, the heat energy assigned to recording surface  51  of rewritable paper P decreases as compared with when heating elements  210   a  are driven with the number of strobe pulses illustrated in  FIG. 6A . At this point, the heat energy is that of an extent to which a visible image recorded on recording surface  51  is erasable. That is, by the heat energy, the temperature of recording surface  51  does not exceed melting point temperature T 1  of a color developer included in a reversibly thermo-sensitive recording medium, but exceeds temperature T 2  necessary for decoloring (see  FIG. 3 ). As a result, recording surface  51  of rewritable paper P is slowly cooled after heating elements  210   a  collectively generate heat, so that a visible image recorded on recording surface  51  may be erased. 
       FIG. 6C  also shows the number of strobe pulses per line when a visible image recorded on rewritable paper P is erased. The number of strobe pulses is for the region where IC inlet  52  is installed. That is, in the region where IC inlet  52  is installed, heating elements  210   a  are driven with the number of strobe pulses which is greater than the number of strobe pulses illustrated in  FIG. 6B . Thereby, the heat energy absorbed by IC inlet  52  is supplemented to allow the temperature of recording surface  51  to reach temperature T 2  necessary for decoloring. As a result, even in the region where IC inlet  52  is installed, recording surface  51  of rewritable paper P is slowly cooled after heating elements  210   a  generate heat, so that a visible image recorded on recording surface  51  may be erased. 
     Here, for the sake of convenience, it is assumed that the heat energy of heating elements  210   a  driven with the strobe pulses illustrated in  FIG. 6A  is E 1 , the heat energy of heating elements  210   a  driven with the strobe pulses illustrated in  FIG. 6B  is E 2 , and the heat energy of heating elements  210   a  driven with the strobe pulses illustrated in  FIG. 6C  is E 3 . 
     In order to vary the heat energy to be assigned to recording surface  51  of rewritable paper P, the adjustment of strobe pulse width illustrated in  FIGS. 5A to 5C  and the adjustment of the number of strobe pulses per unit time illustrated in  FIGS. 6A to 6C  may be appropriately combined. 
       FIG. 7  is a schematic diagram showing a state of heat energy to be assigned to recording surface  51  of rewritable paper P at the time of erasing a visible image.  FIG. 7  schematically shows a state where rewritable paper P is conveyed to be directed to heating elements  210   a  of thermal print head  210  in the direction of an arrow. In this case, in view of a sub scan direction, rewritable paper P has region L 1  from the leading end of rewritable paper P in the conveying direction to a portion where IC inlet  52  is not installed, regions L 2  to L 4  where IC inlet  52  is installed, and region L 5  from a portion excluding IC inlet  52  to the rear end of rewritable paper P in the conveying direction. In this embodiment, both ends of IC inlet  52  have the lengths longer than the one of the center portion in a sub scan direction. Depending on the points where the length of IC inlet  52  changes in a sub scan direction, the region of IC inlet  52  is divided into three types of L 2 , L 3 , and L 4 . 
     When a visible image is erased, heating elements  210   a  of thermal print head  210  are respectively driven so that heat energy becomes E 2  for the region where IC inlet  52  is not installed and heat energy becomes E 3  for the region where IC inlet  52  is installed (see  FIGS. 5 and 6 ). Regions L 2  to L 4  are where IC inlet  52  is installed in view of a sub scan direction of rewritable paper P, and region R 1  and two regions R 2  are where IC inlet  52  is installed in view of a main scan direction. That is, regions L 2  and L 4  of rewritable paper P in a sub scan direction are interconnected with two regions R 2  in a main scan direction, and region L 3  of rewritable paper P in a sub scan direction is interconnected with region R 1  in a main scan direction. 
     Accordingly, control unit  252  of printer  201  drives heating elements  210   a  of thermal print head  210  as shown in Table 1. 
     
       
         
           
               
               
             
               
                 TABLE 1 
               
               
                   
               
             
            
               
                 Region L1 (sub) 
                 Drive for heat energy of E2 
               
               
                 Region L2 (sub) 
                 Drive for heat energy of E3 in two R2 (main) 
               
               
                   
                 Drive for heat energy of E2 in other portions 
               
               
                 Region L3 (sub) 
                 Drive for heat energy of E3 in R1 (main) 
               
               
                   
                 Drive for heat energy of E2 in other portions 
               
               
                 Region L4 (sub) 
                 Drive for heat energy of E3 in two R2 (main) 
               
               
                   
                 Drive for heat energy of E2 in other portions 
               
               
                 Region L5 (sub) 
                 Drive for heat energy of E2 
               
               
                   
               
            
           
         
       
     
       FIG. 8  is a schematic diagram illustrating a method for controlling to apply heat energy illustrated in  FIG. 7 . For example, printer  201  stores and holds definition file  231  (position data) illustrated in  FIG. 8  in flash ROM  255 . For individual rewritable papers P for printer  201 , definition file  231  stores distance data and range data R in a main scan direction of IC inlet  52  in association with individual regions L 1  to L 5  in a sub scan direction. For example, the distance data is the number of pulses which motor controller  258  assigns to a motor to convey rewritable paper P. Since paper registration sensor  213  detects the position of leading end of the conveyed rewritable paper P, any position of the conveyed rewritable paper P may be recognized P by managing the number of motor pulses thereafter. At this point, if a value of distance data defined by definition file  231  is recognized, the position of IC inlet  52  in a sub scan direction is immediately determined. The range data defined by definition file  231  is the position where IC inlet  52  is installed in a main scan direction. The positions are in three types including AR indicating a total width of rewritable paper P, R 1  indicating a total width of IC inlet  52 , and R 2  indicating only portions of the end of IC inlet  52 . 
     If control unit  252  recognizes the distance data in association with regions L 1  to L 5  in a sub scan direction and the range date R of IC inlet  52  in a main scan direction defined in definition file  231 , control unit  252  may recognize when the heating elements  210   a  are driven in a sub scan direction with heat energy E 3  and which of the heating elements  210   a  are driven in a main scan direction with heat energy E 3 . In accordance with the recognition, control unit  252  sets the heat energy of heating elements  210   a  to E 2  for the region where IC inlet  52  is not installed, and sets the heat energy of heating elements  210   a  to E 3  for the region where IC inlet  52  is installed. 
       FIG. 9  is a flowchart showing a flow of a process of erasing a visible image. CPU  253  of control unit  252  executes a process shown in  FIG. 9  according to a control program stored in EEPROM  256 . First, if an erasure command is received from the external device via communication interface  261  (Y of ACT  101 ), CPU  253  outputs paper feed instructions to paper feeder  101  to initiate to convey rewritable paper P (ACT  102 ). A process of determining a position of rewritable paper P is executed (ACT  103  to ACT  107 ). At this point, once rewritable paper P is positioned with respect to region L 1  in a sub scan direction, flag F is set to 1 as described later (ACT  109 ), so that rewritable paper P is known to be positioned with respect to region L 1 . On the other hand, if determinations of ACT  103  to ACT  107  are made in a state where rewritable paper P is not yet positioned with respect to region L 1  in a sub scan direction, the state of flag F is checked out in subsequent ACT  108 . If flag F is not 1 (N of ACT  108 ), the process returns to ACT  102 . 
     When rewritable paper P is positioned with respect to region L 1  in a sub scan direction (Y of ACT  103 ), CPU  253  sets flag F to 1 (ACT  109 ). Heating elements  210   a  of thermal print head  210  are driven to generate the heat energy of E 2  according to definition file  231  (ACT  110 ). Thereby, for region L 1  in a sub scan direction, a visible image recorded on recording surface  51  of rewritable paper P is erased. 
     When rewritable paper P is positioned with respect to region L 2  in a sub scan direction (Y of ACT  104 ), CPU  253  drives heating elements  210   a  of thermal print head  210  to generate the heat energy of E 3  for two regions R 2  in a main scan direction and to generate the heat energy of £ 2  for other portions according to definition file  231  (ACT  111 ). Thereby, a visible image recorded on recording surface  51  of rewritable paper P is erased for region L 2  in a sub scan direction. At this point, IC inlet  52  absorbs the heat energy of heating elements  210   a , but the heat energy for the region is supplemented with the heat energy of E 3 , so that a visible image is well erased without leaving any residual. 
     When rewritable paper P is positioned with respect to region L 3  in a sub scan direction (Y of ACT  105 ), CPU  253  drives heating elements  210   a  of thermal print head  210  to generate the heat energy of E 3  for region R 1  in a main scan direction and to generate the heat energy of E 2  for other portions according to definition file  231  (ACT  112 ). Thereby, a visible image recorded on recording surface  51  of rewritable paper P is erased for region L 3  in a sub scan direction. At this point, IC inlet  52  absorbs the heat energy of heating elements  210   a , but the heat energy for the region is supplemented with the heat energy of E 3 , so that a visible image is well erased without leaving any residual. 
     When rewritable paper P is positioned with respect to region L 4  in a sub scan direction (Y of ACT  106 ), CPU  253  drives the heating elements  210   a  of thermal print head  210  to generate the heat energy of E 3  for two regions R 2  in a main scan direction and to generate the heat energy of E 2  for other portions according to definition file  231  (ACT  113 ). Thereby, a visible image recorded on recording surface  51  of rewritable paper P is erased for region L 4  in a sub scan direction. At this point, IC inlet  52  absorbs the heat energy of heating elements  210   a , but the heat energy for the region is supplemented with the heat energy of E 3 , so that a visible image is well erased without leaving any residual. 
     When rewritable paper P is positioned with respect to region L 5  in a sub scan direction (Y of ACT  107 ), CPU  253  drives heating elements  210   a  of thermal print head  210  to generate the heat energy of E 2  according to definition file  231  (ACT  114 ). Thereby, a visible image recorded on recording surface  51  of rewritable paper P is erased for region L 5  in a sub scan direction. 
     CPU  253  checks out a flag state in ACT  108 , and if flag F is 1 (Y of ACT  108 ), returns the flag to 0 (ACT  115 ). CPU  253  stops heating elements  210   a  (ACT  116 ). Then, CPU  253  determines whether or not the next rewritable paper P to be erased is present (ACT  117 ). If so, the process returns to ACT  102  (Y of ACT  117 ). Otherwise, the process ends (N of ACT  117 ). 
     According to this embodiment, a visible image is erased by setting a temperature assigned to a region where IC inlet  52  is arranged to be higher than a temperature assigned to a region where IC inlet  52  is not arranged when thermal print head  210  is driven with respect to rewritable paper P. Thereby, high-temperature heat energy that may cause to form a visible image is not assigned to a region where IC inlet  52  is not arranged, and heat energy that may erase a visible image by supplementing heat absorbed by IC inlet  52  is assigned to the region where IC inlet  52  is arranged. Accordingly, it is allowed to erase a visible image even in the region where IC inlet  52  is mounted. 
     According to this embodiment, control unit  252  determines a position where IC inlet  52  is arranged according to definition file  231  as preset position data, thereby easily detecting the position of IC inlet  52 . 
     Further, in this embodiment, a visible image is erased by setting a temperature assigned to the region where IC inlet  52  is arranged to be higher than a temperature assigned to the region where IC inlet  52  is not arranged. On the other hand, the temperature assigned to the region where IC inlet  52  is arranged may be set to be higher than the temperature assigned to the region where IC inlet  52  is not arranged even at the time of recording a visible image as well as the time of erasing a visible image. 
     Next, some embodiments are described with reference to  FIGS. 10 and 11 , in which like numerals as mentioned above represent like elements. Further, for sake of simplicity, the above mentioned elements are not described below. 
       FIG. 10  shows rewritable paper P embedded with IC inlet  52 . As described above, antenna  52   b  is combined with IC chip  52   a  integrating a processor, a memory chip, etc. to form IC inlet  52 . 
     In this respect, in view of a sub scan direction, rewritable paper P has region L 1  from the leading end of the conveying direction to a portion where IC inlet  52  is not installed, region L 2  where IC inlet  52  is installed, and region L 3  from a portion excluding IC inlet  52  to the rear end of the conveying direction. 
     When a visual image is erased, heating elements  210   a  of thermal print head  210  is driven to generate the heat energy of E 2  for the regions where IC inlet  52  is not installed, and is driven to generate the heat energy of E 3  for the regions where IC inlet  52  is installed. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 2 
               
               
                   
                   
               
             
            
               
                   
                 Region L1 
                 Drive for heat energy of E2 
               
               
                   
                 Region L2 
                 Drive for heat energy of E3 
               
               
                   
                 Region L3 
                 Drive for heat energy of E2 
               
               
                   
                   
               
            
           
         
       
     
       FIG. 11  is a flowchart showing a flow of a process of erasing a visible image. CPU  253  of control unit  252  executes a process shown in  FIG. 11  according to a control program stored in EEPROM  256 . First, if an erasure command is received from the external device via communication interface  261  (Y of ACT  201 ), CPU  253  outputs paper feed instructions to paper feeder  101  to initiate to convey rewritable paper P (ACT  202 ). A process of determining a position of rewritable paper P is executed (ACT  203  to ACT  205 ). At this point, once rewritable paper P is positioned with respect to region L 1  in a sub scan direction, flag F is set to 1 as described later (ACT  207 ), so that rewritable paper P is known to be positioned with respect to region L 1 . On the other hand, if determinations of ACT  203  to ACT  205  are made in a state where rewritable paper P is not yet positioned with respect to region L 1  in a sub scan direction, the state of flag F is checked out in subsequent ACT  206 . If flag F is not 1 (N of ACT  206 ), the process returns to ACT  202 . 
     When rewritable paper P is positioned with respect to region L 1  in a sub scan direction (Y of ACT  203 ), CPU  253  sets flag F to 1 (ACT  207 ). Heating elements  210   a  of thermal print head  210  are driven to generate the heat energy of E 2  according to definition file  231  (ACT  208 ). Thereby, for region L 1  in a sub scan direction, a visible image recorded on recording surface  51  of rewritable paper P is erased. 
     When rewritable paper P is positioned with respect to region L 2  in a sub scan direction (Y of ACT  204 ), CPU  253  drives heating elements  210   a  of thermal print head  210  to generate the heat energy of E 3  according to definition file  231  (ACT  209 ). Thereby, a visible image recorded on recording surface  51  of rewritable paper P is erased for region L 2  in a sub scan direction. At this point, IC inlet  52  absorbs the heat energy of heating elements  210   a , but the heat energy for the region is supplemented with the heat energy of E 3 , so that a visible image is well erased without leaving any residual. 
     When rewritable paper P is positioned with respect to region L 3  in a sub scan direction (Y of ACT  205 ), CPU  253  drives heating elements  210   a  of thermal print head  210  to generate the heat energy of E 2  according to definition file  231  (ACT  210 ). Thereby, a visible image recorded on recording surface  51  of rewritable paper P is erased for region L 3  in a sub scan direction. 
     CPU  253  checks out a flag state in ACT  206 , and if flag F is 1 (Y of ACT  206 ), returns the flag to 0 (ACT  211 ). CPU  253  stops heating elements  210   a  (ACT  212 ). Then, CPU  253  determines whether or not the next rewritable paper P to be erased is present (ACT  213 ). If so, the process returns to ACT  202  (Y of ACT  213 ). Otherwise, the process ends (N of ACT  213 ). 
     As used in this application, entities for executing the actions can refer to a computer-related entity, either hardware, a combination of hardware and software, software, or software in execution. For example, an entity for executing an action can be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and a computer. By way of illustration, both an application running on an apparatus and the apparatus can be an entity. One or more entities can reside within a process and/or thread of execution and an entity can be localized on one apparatus and/or distributed between two or more apparatuses. 
     The program for realizing the functions can be recorded in the apparatus, can be downloaded through a network to the apparatus and can be installed in the apparatus from a computer readable storage medium storing the program therein. A form of the computer readable storage medium can be any form as long as the computer readable storage medium can store programs and is readable by the apparatus such as a disk type ROM and a solid-state computer storage media. The functions obtained by installation or download in advance in this way can be realized in cooperation with an OS (Operating System) in the apparatus. 
     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 device and method described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the device and method 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.