Abstract:
A radio frequency identification tag to be attached to printing paper includes an upper face that is opposite to a face to be attached to the printing paper, the upper face being made of a paper material substantially equal to the printing paper.

Description:
BACKGROUND 
   1. Technical Field 
   The present invention relates to radio frequency identification (RFID) tags, printing paper, printers, and RFID systems. 
   2. Related Art 
   RFID data carriers that include a coil antenna pattern arranged on a substrate made of plastic or the like and that form a resonance circuit by the antenna pattern and a capacitance element so as to receive and transmit radio waves at a constant frequency have been available. Some of such RFID data carriers (RFID tags) are provided with a memory. Depending on the capacity of the memory, an RFID data tag is capable of storing only a unique ID number or capable of storing other information as well as a unique ID number. 
   In order to make handling of RFID tags in which invisible information is stored easier, label paper including RFID is proposed, for example, in Japanese Unexamined Patent Application Publication No. 2004-202894, on which information or the like stored in an RFID tag can be printed. In addition, a technology for providing a liquid crystal display or a microcapsule electrophoretic display that displays information stored in an RFID tag is proposed, for example, in Japanese Unexamined Patent Application Publication No. 2003-271911. 
   In the above-mentioned technologies, information stored in an RFID tag is simply printed or displayed as character information. In addition, a dedicated printer is needed for printing such information on label paper including an RFID tag. 
   SUMMARY 
   An advantage of the invention is that it provides a printer and the like capable of printing an image, a character, or the like on paper including an RFID tag and capable of storing information on the printed image or character or related information in the RFID tag. 
   In order to solve the above problems, according to an aspect of the invention, an RFID tag to be attached to printing paper includes an upper face that is opposite to a face to be attached to the printing paper, the upper face being made of a paper material substantially equal to the printing paper. 
   Accordingly, printing (drawing) can be performed on an RFID tag. Thus, even if an RFID tag is attached to printing paper, a printing area is not reduced. 
   In addition, when the RFID tag to be attached to printing paper has a total length substantially equal to a width of the printing paper, the maximum antenna adjusted to printing paper can be acquired. Thus, a communication area can be increased. 
   In addition, when the RFID tag to be attached to printing paper includes an upper face that is opposite to a face to be attached to the printing paper, the upper face being made of a paper material substantially equal to the printing paper, and has a total length substantially equal to a width of the printing paper, even if the RFID tag is attached to the printing paper, a printing area is not reduced, and at the same time, a communication area can be increased. 
   According to an aspect of the invention, printing paper includes the foregoing radio frequency identification tag. Accordingly, a character or an image can be satisfactorily drawn, and information related to the character or the image can be satisfactorily stored (written). 
   According to an aspect of the invention, a printer for drawing a character or an image on printing paper including a radio frequency identification tag includes a drawing unit that draws the character or the image on the printing paper, and a communication unit that writes information related to the character or the image into the radio frequency identification tag. 
   Accordingly, drawing of a character or an image on printing paper and writing of the character or the image into an RFID tag can be performed at substantially the same time. Thus, a discrepancy between a drawn object and stored information in an RFID tag can be prevented easily and reliably. 
   In addition, when the above-described printing paper is used as the printing paper, even if an RFID is attached later, drawing of a character or an image and writing of the character or the image into the RFID tag can be performed satisfactorily. 
   According to an aspect of the invention, a radio frequency identification system stores information related to an image or a character drawn on printing paper including a radio frequency identification tag in the radio frequency identification tag, reads the stored information by using an external communication unit, and displays or outputs the stored information by using an external apparatus connected to the external communication unit. 
   Accordingly, since information related to a character or an image printed (drawn) on printing paper is displayed or output, information that cannot be represented by printing can be added. Thus, this technology can be used in a wider field, such as business advertising. 
   In addition, when the stored information is character information, sound information, static image information, or moving image information, for example, a photograph with syllabic sound can be provided. In addition, a printed image can be used as an index. 
   In addition, when the external apparatus is a portable information terminal, use of a cellular phone or a portable game terminal allows many people to acquire information and enables representation using an image, sound, and the like. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
       FIG. 1  is an exploded perspective view of an RFID tag. 
       FIG. 2  is a schematic diagram showing an inkjet printer. 
       FIG. 3  is a cross-sectional view showing the inkjet printer. 
       FIG. 4  schematically shows an RFID system. 
   

   DESCRIPTION OF EXEMPLARY EMBODIMENTS 
   An RFID tag, printing paper, a printer, and an RFID system according to an embodiment of the invention will be described with reference to the drawings. 
     FIG. 1  is an exploded perspective view of an RFID tag  10 . The RFID tag  10  includes an inlet  13  covered with protection films  15  and  16 . The inlet  13  is provided with an integrated circuit (IC) chip  11  and an antenna  12 . 
   The inlet  13  is a flexible printed-circuit board (FPC) formed by sandwiching a wiring electrode between cover films. The IC chip  11 , the antenna  12 , and various wires are arranged on the upper face of the inlet  13 . 
   The IC chip  11  includes a central processing unit (CPU) performing various operations, a read-only memory (ROM), a random-access memory (RAM), a memory, a transmission and reception unit, and the like. In accordance with an instruction from the CPU, the IC chip  11  receives information from outside via the transmission and reception unit, stores the received information in the memory, and transmits information stored in the memory to the outside. 
   The antenna  12  is arranged in a coil shape along the periphery on the inlet  13  arranged in a rectangular shape. Liquid metal droplets may be sprayed by inkjet printing to form the antenna  12  and to connect the antenna  12  and the IC chip  11 . 
   Although the protection films  15  and  16  are provided for protecting the IC chip  11  and the antenna  12  from ultraviolet rays and external force, the protection films  15  and  16  may be omitted. 
   In addition, a paper sheet  17  is attached to the protection film  15 . The paper sheet  17  is made of a material substantially equal to that of printing paper, which will be described below. In contrast, an adhesive sheet  18  is attached to the protection film  16 . The adhesive sheet  18  is used for attaching the RFID tag  10  to the printing paper. In other words, when the RFID tag  10  is attached to the printing paper via the adhesive sheet  18 , the paper sheet  17  made of a material substantially equal to that of the printing paper is exposed to the surface. Thus, even if the RFID tag  10  is attached to the printing paper, the RFID tag  10  does not stand out. In addition, printing can be performed on the RFID tag  10 . 
   The RFID tag  10  has a strip-like rectangular shape. The length of the RFID tag  10  is substantially equal to or slightly shorter than the width of printing paper to which the RFID tag  10  is attached. For example, the RFID tag  10  to be attached to A4 printer paper (210 mm×297 mm) has a length of 210 mm, and is attached to an edge of the printing paper, as shown in  FIG. 2 . 
   The RFID tag  10  need not be attached to an edge of printing paper. In addition, the width of the RFID tag  10  is, for example, between about 5 mm and about 10 mm. 
   In addition, the size of paper to which the RFID tag  10  is attached need not necessarily be A4 paper. The RFID tag  10  may have various lengths so as to be attached to paper of standardized sizes, such as an A5 size, a B5 size, a postcard size, an envelope size, a photograph size (including an L size and a double-L size), a business card size, and a CD jacket size. 
   In addition, printing paper may be, for example, a newspaper, a magazine, or a poster. If the size of paper is defined by a standard, the RFID tag  10  suitable for the paper can be formed and attached. 
   As described above, a plurality of lengths can be set as the length of the RFID tag  10 . The number of turns and the shape of the antenna  12  are optimized in accordance with the length of the RFID tag  10 . This is because since the communication distance changes depending on the size of the antenna  12 , necessary communication quality cannot be ensured. 
   As described above, the RFID tag  10  has a strip-like rectangular shape, and the length of the RFID tag  10  is set to be substantially equal to the width of printing paper to which the RFID tag  10  is attached. This is because the communication distance is increased as much as possible and the size of the RFID tag  10  is reduced so as to be inconspicuous as much as possible when the RFID tag  10  is attached to printing paper. Thus, although the RFID tag  10  having a length substantially equal to the length in the long side direction of paper may be attached, trouble is likely to occur in paper feeding in an inkjet printer  60 , which will be described below. 
   The RFID tag  10  is not necessarily attached to a printed side of printing paper P. The RFID tag  10  may be attached to a rear side. In addition, the RFID tag  10  is not necessarily attached to the printing paper P. The RFID tag  10  may be inserted (woven) inside the printing paper P in advance. In this case, the paper sheet  17  and the adhesive sheet  18  are not necessarily used. 
   In addition, a plurality of RFID tags  10  may be attached to a sheet of paper. 
   A printer for printing (drawing) a desired character, image, or the like on the printing paper P to which the RFID tag  10  is attached is described next. 
     FIG. 2  is a schematic diagram showing the inkjet printer  60  according to this embodiment. In the following description, an upper side in a Z direction is referred to as an “upper portion” and a lower side in the Z direction is referred to as a “lower portion”. 
   The inkjet printer  60  includes a tray  621  provided at the upper back of a printer main unit  62 , an outlet slot  622  provided at the lower front of the printer main unit  62 , and an operation panel  67  provided on the upper face of the printer main unit  62 . The printing paper P is set in the tray  621 , and the printing paper P is ejected from the outlet slot  622 . 
   The operation panel  67  is a display device, such as a liquid crystal display, an organic electroluminescent display, or a light-emitting diode (LED) lamp display. The operation panel  67  includes a display unit (not shown) for displaying an error message or the like and an operation unit (not shown) including various switches. 
   The printer main unit  62  contains therein a printing device  64  including a head unit  63  mainly performing reciprocating motion, a paper feeder  65  for feeding sheets of printing paper P one by one to the printing device  64 , a controller  66  for controlling the printing device  64  and the paper feeder  65 , and the like. 
   In accordance with an instruction from the controller  66 , the paper feeder  65  intermittently feeds sheets of printing paper P one by one. The intermittently fed printing paper P passes near the lower portion of the head unit  63 . Here, the head unit  63  performs reciprocating motion in a direction substantially orthogonal to the fed direction of the printing paper P, and printing on the printing paper P can be performed. In other words, reciprocating motion of the head unit  63  and intermittent feeding of the printing paper P are main scanning and sub scanning in printing. Accordingly, inkjet printing is performed. 
   The printing device  64  includes the head unit  63 , a carriage motor  641  functioning as a driving source of the head unit  63 , and a reciprocating mechanism  642  causing the head unit  63  to reciprocate in response to rotation of the carriage motor  641 . 
   The head unit  63  includes an inkjet head provided with many nozzles, an ink cartridge  631  for supplying ink to the inkjet head, and a carriage  632  on which the inkjet head and the ink cartridge  631  are mounted. The inkjet head, the ink cartridge  631 , and the carriage  632  are provided at a lower portion of the head unit  63 . 
   When the ink cartridge  631  is filled with ink of four colors, yellow, cyan, magenta, and black, full-color printing can be performed. In this case, inkjet heads for the respective colors are provided in the head unit  63 . However, the color of ink is not necessarily yellow, cyan, magenta, or black. 
   The reciprocating mechanism  642  includes a carriage guide shaft  644  whose both ends are supported by a frame (not shown) and a timing belt  643  extending in parallel to the carriage guide shaft  644  and performing a traveling operation. The carriage  632  is reciprocatably supported by the carriage guide shaft  644  and is fixed by part of the timing belt  643 . When an operation of the carriage motor  641  causes the timing belt  643  to travel forward and backward via a pulley, the head unit  63  reciprocates, guided by the carriage guide shaft  644 . 
   In the reciprocation operation, ink is ejected from the inkjet head in an appropriate fashion. Accordingly, printing (drawing) on the printing paper P is performed. 
   The paper feeder  65  includes a paper feed motor  651  functioning as a driving source of the paper feeder  65  and a paper feed roller  652  rotating around the shaft in accordance with the operation of the paper feed motor  651 . The paper feed roller  652  includes a slave roller  652   a  and a driving roller  652   b  that face each other in the vertical direction across a feed path for the printing paper P. The driving roller  652   b  is connected to the paper feed motor  651 . With this configuration, the paper feed roller  652  is capable of feeding to the printing device  64  many sheets of paper set in the tray  621  one by one. 
   Instead of the tray  621 , a paper feed cassette accommodating the printing paper P may be detachably installed. 
   The controller  66  controls a printing operation by driving the printing device  64 , the paper feeder  65 , and the like in accordance with print data input from a host computer, such as a personal computer or a digital camera. Although not illustrated, the controller  66  includes a memory mainly storing a control program and the like for controlling each unit, a head driving circuit for driving the inkjet head to control timing for ejecting ink, a control circuit for driving the printing device  64  (that is, the carriage motor  641 ), a driving circuit for driving the paper feeder  65  (that is, the paper feed motor  651 ), a communication circuit receiving print data from the host computer, and a CPU electrically connected to the above-mentioned units in the controller  66  and performing various control in the units. 
   Various sensors that can detect printing environment, such as the remaining ink level of the ink cartridge  631 , the position of the head unit  63 , the temperature, and the humidity, are electrically connected to the CPU. The controller  66  receives print data via the communication circuit and stores the received print data in the memory. The CPU processes the print data, and outputs a driving signal to each driving circuit in accordance with the processed data and input data received from each sensor. The driving signal causes the inkjet head, the printing device  64 , and the paper feeder  65  to operate. Accordingly, desired printing (drawing) can be performed on the printing paper P. 
     FIG. 3  is a cross-sectional view of the inkjet printer  60  according to this embodiment. 
   The inkjet printer  60  also includes a communication unit  69 . The communication unit  69  transmits predetermined information to the RFID tag  10  in accordance with an instruction from the controller  66 . The communication unit  69  is arranged in the immediately previous position of the head unit  63 , as shown in  FIG. 3 . 
   Since the communication unit  69  is provided in the inkjet printer  60 , a desired character or image can be printed (drawn) on the printing paper P, and at the same time, predetermined information can be transmitted to the RFID tag  10  by communicating with the RFID tag  10  attached to the printing paper P. The communication unit  69  may be arranged in any position as long as the communication unit  69  can communicate with the RFID tag  10  attached to the printing paper P. 
   Information, such as an ID number of the RFID tag  10 , is transmitted from the RFID tag  10  to the communication unit  69 . In contrast, information related to a character or an image printed (drawn) on the printing paper P, such as character information including an ID number and photographed (produced) date and time of image information, is transmitted from the communication unit  69  to the RFID tag  10 . In addition, sound information related to the image information and other types of image information (irrespective of static images or moving images) related to the image information may be transmitted from the communication unit  69  to the RFID tag  10 . Character information or image information equal to a character or an image printed (drawn) on the printing paper P may be transmitted from the communication unit  69  to the RFID tag  10 . The information transmitted to the RFID tag  10  is stored in a readable/writable random access nonvolatile memory of the RFID tag  10 . The nonvolatile memory is, for example, a flash memory or a ferroelectric RAM (FeRAM). 
   As described above, the inkjet printer  60  is capable of printing (drawing) a desired character or image on the printing paper P and capable of storing predetermined information in the RFID tag  10  attached to the printing paper P (writing the predetermined information to the nonvolatile memory). 
   Thus, an image photographed by a digital camera or a digital video camera is printed on the printing paper P, and at the same time, character information, such as the photographed date of the image, sound information when being photographed, other images photographed at substantially the same time, a moving image including the printed image, and the like are stored in the RFID tag  10 . In other words, information that cannot be represented only by printing can be stored and kept by being attached to a printed image. 
   In addition, since the upper face of the RFID tag  10  is formed by a paper sheet made of paper substantially equal to the printing paper P, a desired character or image can be printed (drawn) on the RFID tag  10 . Thus, a character or image can be printed on the RFID tag  10  similarly to normal paper without reducing a printing area. 
   An RFID system using the printing paper P including the RFID tag  10  is described next. 
   As described above, a desired character or image is printed (drawn) on the printing paper P including the RFID tag  10  by the inkjet printer  60 . Various types of information related to the character or the image are stored in the attached RFID tag  10 . Thus, the various types of information stored in the RFID tag  10  can be read using an external apparatus (reader) that can be communicated with the RFID tag  10 . In other words, when the external apparatus is close to the printing paper P on which the image or the like is printed, communication is performed between the external apparatus and the RFID tag  10 . Accordingly, the information stored in the RFID tag  10  can be acquired. 
   As described above, the information stored in the RFID tag  10  may include sound information and image information as well as character information. Thus, when a speaker and a display are connected to the external apparatus, such information can be reproduced. In other words, not only character information but sound and images can also be output and displayed. 
   More specifically, as shown in  FIG. 4 , in a case where an image photographed by a digital camera, which is not shown, is printed (drawn) on the printing paper P, when an external apparatus  50  is close to the printing paper P, sound related to the printed image or the like, a moving image including the printed image, or character information is output or displayed from a speaker (not shown) or a display  51  connected to the external apparatus  50 . Accordingly, much more information as well as a printed image can be reproduced. 
   Although the external apparatus  50  may be a stationary reader or the like, a portable information terminal, such as a notebook computer, a cellular phone, or a portable game terminal, is suitably used as the external apparatus  50 , as shown in  FIG. 4 . Such a portable information terminal is capable of displaying images and capable of playing back sound. In other words, a reader  52  is installed on a notebook computer, a cellular phone, or a portable game terminal. Accordingly, various types of information can be readily acquired from the printing paper P including the RFID tag  10 . In addition, the reader  52  may be incorporated within such a portable apparatus. 
   Although a case where the printing paper P including the RFID tag  10 , on which a desired character or image is printed by the inkjet printer  60 , is used has been described in the foregoing embodiment, the invention is not limited to this. In other words, printing on the printing paper P may be performed by another printer or the like. 
   For example, in a case where the RFID tag  10  is attached to a so-called direct mail letter, when a cellular phone provided with a reader is close to the direct mail letter, a predetermined advertising image is displayed on a display of the cellular phone or advertising sound is output. 
   In addition, when uniform resource locator (URL) information is stored in the RFID tag  10  using an Internet connection function of a cellular phone and the stored URL information is read by the cellular phone, the cellular phone accesses the homepage of an advertiser by connecting to the Internet. Then, advertising image or sound can be displayed or output. 
   In addition, the RFID tag  10  may be attached to a business card, so that a facial picture, URL information, a telephone number, a facsimile number, company information, and the like can be stored. 
   In addition, in a case where the RFID tag  10  is attached to a newspaper advertisement, a poster, or the like, when an unspecified number of portable information terminals each provided with a reader are close to the RFID tag  10 , an advertisement or route guidance to a shop can be displayed on the portable information terminals. 
   As described above, according to the RFID system, since information stored in the RFID tag  10  is read and reproduced by a portable information terminal or the like, an unspecified number of users are able to acquire various types information via the printing paper P including the RFID tag  10 . In particular, in a case where information that cannot be represented by a printed character or static image is stored, when such information is read and displayed by portable information terminals owned by an unspecified number of users, the information can be provided to many users. 
   Operation procedures, shapes of component members, and combinations of the component members described in the foregoing embodiment are merely examples. Various changes and modifications can be made to the invention without departing from the spirit and the scope thereof. 
   For example, a display unit may be provided in the RFID tag  10 . It is desirable that the display unit be an electrophoretic display device. In addition, it is desirable that character information stored in the RFID tag  10  be displayed on the display unit. 
   The entire disclosure of Japanese Patent Application No. 2005-021136, filed Jan. 28, 2005 is expressly incorporated by reference herein.