Patent Publication Number: US-8967756-B2

Title: Printer and print system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2011-128332, filed on Jun. 8, 2011, the entire contents of which is incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate generally to a printer, a print system and a printing method. 
     BACKGROUND 
     Some thermal printers form an image by melting an ink of an ink ribbon with the heat of a thermal head and thermally transfers the ink to a medium. 
     However, this kind of printer suffers from a problem in that the image formation quality is reduced if the environmental temperature around the thermal head and the ink ribbon changes sharply. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view showing a schematic configuration of a printer according to a first embodiment. 
         FIGS. 2A and 2B  are views illustrating one example of the temperature-sensitive properties of a temperature-sensitive ink. 
         FIG. 3  is an assembled perspective view showing a deterring unit in an assembled state. 
         FIG. 4  is an exploded perspective view showing the deterring unit in an exploded state. 
         FIG. 5  is a side view of the deterring unit shown in  FIG. 3 . 
         FIG. 6  is a block diagram showing a hardware configuration of a control system of the printer according to the first embodiment. 
         FIG. 7  is a block diagram showing a software configuration of the printer according to the first embodiment. 
         FIGS. 8A and 8B  are views showing one example of a product label as a medium obtained in the printer. 
         FIG. 9  is a side view showing a schematic configuration of a print system. 
         FIG. 10  is a perspective view showing a modified example of the deterring unit shown in  FIG. 3 . 
         FIG. 11  is a side view showing a modified example of the printer shown in  FIG. 1 . 
         FIG. 12  is a side view showing a schematic configuration of a printer according to a second embodiment. 
         FIG. 13  is an assembled perspective view showing a deterring unit and an electricity-removing unit in an assembled state. 
         FIG. 14  is an exploded perspective view showing the deterring unit and the electricity-removing unit in an exploded state. 
         FIG. 15  is a side view of the deterring unit and the electricity-removing unit shown in  FIG. 13 . 
         FIG. 16  is a side view showing a schematic configuration of a print system. 
         FIG. 17  is a front view of the deterring unit, the cooling device and the electricity-removing unit shown in an assembled state in  FIG. 13 . 
         FIG. 18  is a side view showing a schematic configuration of a printer according to a third embodiment. 
         FIG. 19  is a front view showing a cooling mechanism of the printer shown in  FIG. 18 . 
         FIGS. 20A and 20B  are section views showing a spouting portion included in the cooling mechanism shown in  FIG. 19 ,  FIG. 20A  illustrating a state in which a gas is spouted at a right angle with respect to a medium and  FIG. 20B  illustrating a state in which the gas is obliquely spouted with respect to the medium. 
         FIG. 21  is a plan view of a portion of the spouting portion of the cooling mechanism shown in  FIG. 19 , which is seen at the side of a backing paper. 
         FIG. 22  is a perspective view schematically showing a deterring unit of the printer according to the third embodiment. 
         FIG. 23  is a side view of the deterring unit shown in  FIG. 22 . 
         FIG. 24  is a block diagram showing a hardware configuration of a control system of the printer according to the third embodiment. 
         FIGS. 25A and 25B  are side views schematically showing portions of ink ribbon cartridges included in the printer,  FIG. 25A  illustrating an ink ribbon cartridge having a long contact section over which an ink ribbon makes contact with a medium and  FIG. 25B  illustrating an ink ribbon cartridge having a short contact section over which an ink ribbon makes contact with a medium. 
         FIG. 26  is a plan view showing a movable plate included in a printer according to a modified example. 
         FIG. 27  is a view showing one example of a product label as a medium obtained in the printer according to the modified example. 
         FIG. 28  is a perspective view schematically showing a deterring unit according to a modified example. 
         FIG. 29  is a side view showing a configuration of a printer according to a modified example of the third embodiment. 
         FIG. 30  is a block diagram showing a hardware configuration of a control system of the printer shown in  FIG. 29 . 
         FIG. 31  is a flowchart illustrating a printing process according to one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     According to one embodiment, a printer includes an image forming unit, a coloring conversion unit, and a deterring unit. The image forming unit forms an image from a temperature-sensitive ink whose color is changed depending on a temperature on a medium. The coloring conversion unit converts a coloring state of the image of the temperature-sensitive ink by heating or cooling the image of the temperature-sensitive ink. The deterring unit provided between the coloring conversion unit and the image forming unit deters an air heated or cooled by the coloring conversion unit from flowing toward the image forming unit. 
     Certain embodiments will now be described in detail with reference to the drawings. 
       FIG. 1  is a side view showing a schematic configuration of a printer  1  according to a first embodiment. 
     The printer  1  of the present embodiment is made up of, e.g., a thermal printer configured to heat an ink ribbon and transfer ink to a medium M such as paper. 
     The medium M used in the present embodiment may be, e.g., a label shown in  FIGS. 8A and 8B . A plurality of media M is attached to, e.g., a surface of a strip-shaped backing paper  2  at a specified interval (pitch). 
     As shown in  FIG. 1 , the printer  1  includes a body unit  1   a  to which a plurality of (four, in the present embodiment) ink ribbon cartridges  3  ( 3 A through  3 D) can be attached in a removable manner. The ink ribbon cartridges  3  are arranged side by side along a conveyance path P of the strip-shaped backing paper  2  defined inside the printer  1 . 
     Each of the ink ribbon cartridges  3  includes a head (thermal head)  3   a  and an ink ribbon  3   d . By causing the head  3   a  to heat the ink of the ink ribbon  3   d , each of the ink ribbon cartridges  3  forms images of different inks on the medium M conveyed along the conveyance path P. 
     In the printer  1  of the present embodiment, the head (thermal head)  3   a  of each of the ink ribbon cartridges  3  corresponds to an image forming unit. 
     The number of ink ribbon cartridges  3  is not limited to four but may be set differently. 
     A roll  2   a  of the backing paper  2  is removably and rotatably mounted to the body unit  1   a  at the most upstream side of the conveyance path P. Upon rotation of conveying rollers  4 , the backing paper  2  is drawn away from the roll  2   a  and conveyed through the conveyance path P. The conveyance path P is defined not only by the arrangement of the ink ribbon cartridges  3  but also by the arrangement of conveying rollers  4  and auxiliary rollers  5 . 
     The printer  1  includes a plurality of conveying rollers  4  rotationally driven by a motor  6 . Rotation of the motor  6  is transmitted to the respective conveying rollers  4  through a rotation-transmitting mechanism (or a speed-reducing mechanism)  7 . The printer  1  includes auxiliary rollers  5  arranged in such positions that the auxiliary rollers  5  nip the backing paper  2  in cooperation with the conveying rollers  4  or in such positions that the backing paper  2  is stretched between the conveying rollers  4  or between the auxiliary rollers  5 . 
     The printer  1  further includes a sensor  8  for detecting the medium M and a tension detecting mechanism  9  for detecting the tension of the backing paper  2 . 
     In the printer  1  of the present embodiment, the conveying rollers  4 , the auxiliary rollers  5 , the motor  6  and the rotation-transmitting mechanism  7  make up a conveying mechanism for conveying the backing paper  2  (or the medium M). 
     The printer  1  can be mounted with an ink ribbon cartridge  3  having an ink ribbon of a non-temperature-sensitive ink whose color does not change depending on temperature, an ink ribbon cartridge  3  having an ink ribbon of temperature-sensitive ink whose color changes depending on the temperature and an ink ribbon cartridge  3  having a differently-colored ink ribbon (of a non-temperature-sensitive ink and a temperature-sensitive ink). 
     Each of the ink ribbon cartridges  3  can be removably mounted in one of the mounting positions of the ink ribbon cartridges  3  ( 3 A through  3 D) provided in the body unit  1   a.    
     Among the temperature-sensitive inks is an ink whose coloring state varies above and below a threshold temperature Th as depicted in  FIG. 2A . 
     For example, the temperature-sensitive ink depicted in  FIG. 2A  becomes white (S 2 ) if the temperature T exceeds the threshold temperature Th but gets colored (S 1 ) if the temperature T is equal to or lower than the threshold temperature Th. If the medium M is white in color and if the temperature-sensitive ink remains white (S 2 ), the temperature-sensitive ink images formed on the medium M are hard to see or invisible. The temperature-dependent change of the coloring state of the temperature-sensitive ink is reversible. 
     Among the temperature-sensitive inks, there is also an ink whose coloring state varies above and below two different threshold temperatures Th 1  and Th 2  when the temperature T goes up and down as depicted in  FIG. 2B . 
     For example, the temperature-sensitive ink depicted in  FIG. 2B  remains white (S 2 ) if the temperature T, when going down, is higher than a first threshold temperature Th 1  but gets colored (S 1 ) if the temperature T, when going down, becomes equal to or lower than the first threshold temperature Th 1 . If the medium M has a white color and if the temperature-sensitive ink remains white (S 2 ), the temperature-sensitive ink images formed on the medium M are hard to see or invisible. The temperature-sensitive ink depicted in  FIG. 2B  remains colored (S 1 ) if the temperature T, when going up, is equal to or lower than a second threshold temperature Th 2  but becomes white (S 2 ) if the temperature T, when going up, is higher than the second threshold temperature Th 2 . 
     In this regard, the second threshold temperature Th 2  is higher than the first threshold temperature Th 1  as can be seen in  FIG. 2B . Therefore, as long as the temperature T stays between the first threshold temperature Th 1  and the second threshold temperature Th 2 , the coloring state of the temperature-sensitive ink in the falling process of the temperature T differs from the coloring state of the temperature-sensitive ink in the rising process of the temperature T. 
     Since many different kinds of temperature-sensitive inks are available, it is possible to appropriately change the threshold temperatures Th, Th 1  and Th 2  and the colors in the respective coloring states. 
     In the case of a thermal printer, the temperature T goes up during an image forming process (heat transfer process). Therefore, if images of a temperature-sensitive ink whose color is changed to the same color as the medium M at a temperature higher that the threshold temperatures Th, Th 1  and Th 2  mentioned above are formed on the medium M through the use of the printer  1 , it is often impossible or difficult to determine whether the temperature-sensitive ink images are successfully formed on the medium M. Depending on the kinds of temperature-sensitive inks, it is sometimes the case that the temperature-sensitive ink images formed on the medium M are hardly visible at normal temperature. 
     In view of this, the printer  1  of the present embodiment includes a cooling device  10 A that serves as a coloring conversion mechanism for converting the coloring state of temperature-sensitive ink images formed on the medium M. 
     In the present embodiment, the temperature T is reduced by, e.g., cooling the temperature-sensitive ink images with the cooling device  10 A. Thus, the temperature-sensitive ink images become readily visible, thereby making it easy to check the formation situation of the temperature-sensitive ink images on the medium M. 
     In other words, the cooling device  10 A may be said to be a coloring conversion mechanism or a visualizing mechanism of temperature-sensitive ink images. 
     In the present embodiment, a Peltier element (or a thermo-module) that can perform cooling through the use of a Peltier effect is employed as the cooling device  10 A. 
     The printer  1  of the present embodiment further includes deterring unit  30 . The deterring unit  30  and the cooling device  10 A as a coloring conversion unit are arranged at the downstream side of the ink ribbon cartridges  3  as an image forming unit along the conveying direction of the medium M. The deterring unit  30  serves to deter at least a part of the air cooled by the cooling device  10 A from reaching the ink ribbon cartridges  3  (the heads  3   a  and the ink ribbons  3   d ) as an image forming unit and the environmental temperature sensor  8  or from staying in a specific area. The deterring unit  30  is supported on the body unit  1   a  by, e.g., a support member (not shown) arranged inside the body unit (housing)  1   a . In other words, the printer  1  of the present embodiment is characterized by providing the cooling device  10 A as a coloring conversion mechanism so that visual recognition of the image of the temperature-sensitive ink can be increased and further provides deterring unit  30  so that the temperature of the ink ribbon cartridge  3  can be constantly maintained without being affected by the cooling device  10 A, which is important in maintaining superior printing capability. Further, as described below, the cooling device  10 A, which is not limited to the present embodiment and may be provided in various forms, has a superior effect of more easily controlling air flow in the present embodiment. 
       FIGS. 3 through 5  are views for explaining the configuration of the deterring unit  30 .  FIG. 3  is an assembled perspective view showing the deterring unit  30  in an assembled state.  FIG. 4  is an exploded perspective view showing the deterring unit  30  in an exploded state.  FIG. 5  is a side view of the deterring unit  30  shown in  FIG. 3 . 
     As shown in  FIGS. 3 through 5 , the deterring unit  30  includes a blower unit (or a fan motor)  31  for blowing the air cooled by the cooling device  10 A and a guide unit  32  for guiding the air blown by the blower unit  31  so as not to reach the ink ribbon cartridges  3 . 
     The blower unit  31  includes, e.g., a fan case  31 A having an air intake surface  31   a  and an air exhaust surface  31   b  arranged at the opposite ends thereof. Within the fan case  31 A, there are arranged a blower unit controller  31   c  (see  FIG. 6 ), a motor  31   d  electrically connected to the blower unit controller  31   c  and a fan  31   e  rotationally driven about an axis by the motor  31   d.    
     The blower unit  31  includes a cylindrical case portion  31   f  for accommodating the fan  31   e . The case portion  31   f  is inserted into an insertion hole  32   a  formed on one surface (the upper surface) of the guide unit  32 . The blower unit  31  is fixed to a top surface portion  32 C of the guide unit  32  by screws V threadedly coupled to screw holes  31   g  formed in the fan case  31 A and screw holes  32   b  formed in the guide unit  32 . 
     The guide unit  32  is a member shaped to define a guide route along which the air blown by the blower unit  31  is guided toward the downstream side in a conveying direction X of the medium M (particularly, toward a discharge port (not shown) for the discharge of the medium M formed in the body unit  1   a  at the downstream side of the conveyance path P in the conveying direction X). The guide unit  32  is also a member for holding the cooling device  10 A. The guide unit  32  is made of, e.g., a metallic material or a resin material. 
     More specifically, the guide unit  32  includes a front wall portion  32 A arranged near the downstream end of the conveyance path P in the conveying direction X (near the discharge port of the medium M not shown), a rear wall portion  32 B arranged in opposing relationship with the front wall portion  32 A and a top surface portion  32 C configured to interconnect the front wall portion  32 A and the rear wall portion  32 B and arranged above the conveyance path P to extend parallel to a conveying plane of the conveyance path P. As can be seen in  FIG. 5 , the guide unit  32  is formed to have a generally trough-like side cross section. 
     In the present embodiment, the rear wall portion  32 B of the guide unit  32  of the deterring unit  30  is provided between the cooling device  10 A as a coloring conversion unit and the ink ribbon cartridges  3  as an image forming unit so that the deterring unit  30  can deter at least a part of the air cooled by the cooling device  10 A from flowing toward the ink ribbon cartridges  3 . 
     The length of the guide unit  32  in a width direction Z is substantially equal to the width of the conveyance path P. The guide unit  32  is arranged close to one surface (the upper surface) of the conveyance path P in alignment with the width of the conveyance path P. 
     In other words, the guide unit  32  having the shape set forth above guides the air (wind) blown by the fan  31   e  of the blower unit  31  toward the cooling device  10 A arranged below the fan  31   e  and discharges at least a part of the air (cold air) cooled by the cooling device  10 A from an outlet O defined between the front wall portion  32 A and the upper surface of the cooling device  10 A. 
     The cooling device  10 A is fixed to the guide unit  32  by connector members  10 A- 1  and screws V threadedly coupled to screw holes  10 A- 2  of the connector members  10 A- 1 . 
     Although not particularly shown in the drawings, it may be possible to provide a guide wall portion extending from an open end (lower end) of the front wall portion  32 A of the guide unit  32  to the discharge port (not shown) of the medium M formed in the body unit  1   a  in a generally parallel relationship with the conveying plane of the conveyance path P. 
     Although not particularly shown in  FIGS. 1 and 3  through  5 , in some embodiments the opposite open ends in the width direction Z of the guide unit  32  (see  FIG. 3 ) are closed by the opposite side wall portions (not shown) in the width direction Z of the body unit  1   a  or are connected to vent holes (not shown) formed in the opposite side wall portions (not shown) of the body unit  1   a . This makes it possible to deter the cold air leaked from the opposite open ends in the width direction Z of the guide unit  32  from flowing toward the ink ribbon cartridges  3  as an image forming unit. 
       FIG. 6  is a block diagram showing a hardware configuration of the printer  1  of the present embodiment, particularly the details of a control circuit  20  as a control system. 
     Referring to  FIG. 6 , the control circuit  20  of the printer  1  includes a CPU (Central Processing Unit)  20   a  as a control unit, a ROM (Read Only Memory)  20   b , a RAM (Random Access Memory)  20   c , an NVRAM (Non-Volatile Random Access Memory)  20   d , a communication interface (I/F)  20   e , a conveying motor controller  20   f , a head controller  20   g , a ribbon motor controller  20   h , an input unit controller  20   j , an output unit controller  20   k , a sensor controller  20   m , a cooling device controller  20   p  and a blower unit controller  31   c , all of which are connected to one another through a bus  20   n  such as an address bus or a data bus. 
     The CPU  20   a  controls individual units of the printer  1  by executing various kinds of computer-readable programs stored in the ROM  20   b  or other places. The ROM  20   b  stores, e.g., various kinds of data processed by the CPU  20   a  and various kinds of programs (such as a basic input/output system abbreviated as BIOS, an application program and a device driver program) executed by the CPU  20   a . The RAM  20   c  temporarily stores data and programs while the CPU  20   a  executes various kinds of programs. The NVRAM  20   d  stores, e.g., an OS (Operating System), an application program, a device driver program and various kinds of data which are to be kept intact even when the power is turned off. 
     The communication interface (I/F)  20   e  controls data communication with other devices connected through telecommunication lines. 
     The conveying motor controller  20   f  controls the motor  6  pursuant to an instruction supplied from the CPU  20   a . The head controller  20   g  controls the head  3   a  (see  FIG. 1 ) in response to an instruction supplied from the CPU  20   a . The ribbon motor controller  20   h  controls a ribbon motor  3   b  provided in each of the ink ribbon cartridges  3  according to an instruction supplied from the CPU  20   a.    
     The input unit controller  20   j  transmits to the CPU  20   a  signals inputted through an input unit  12  for inputting manual operations or voices of a user (e.g., push buttons, a touch panel, a keyboard, a microphone, knobs or DIP switches). The output unit controller  20   k  controls an output unit  13  for outputting images or voices (e.g., a display, a light-emitting unit, a speaker or a buzzer) pursuant to an instruction supplied from the CPU  20   a.    
     The sensor controller  20   m  transmits to the CPU  20   a  signals indicative of the detection results of sensors  8  including various kinds of sensors such as an environmental temperature sensor. In the printer  1  of the present embodiment, the environmental temperature sensor ( 8 ) is arranged near the ink ribbon cartridges  3  and at the upstream side of the deterring unit  30  and the cooling device  10 A in the conveying direction X. 
     Pursuant to an instruction received from the CPU  20   a , the cooling device controller  20   p  controls the electric power supplied to the cooling device (Peltier element)  10 A, thereby controlling the cooling operation of the cooling device (Peltier element)  10 A. 
     Responsive to an instruction received from the CPU  20   a , the blower unit controller  31   c  controls the operation of the motor  31   d , thereby controlling the rotation of the fan  31   e  of the blower unit  31 . 
     The printer  1  of the present embodiment includes a power supply unit  40  for supplying necessary electric power from a commercial power source to the respective loads (e.g., the control circuit  20 , the cooling device  10 A and the motor  31   d  of the blower unit  31 ). 
       FIG. 7  is a block diagram for explaining a functional configuration (software configuration) of the printer  1  realized when the programs stored in the ROM  20   b  are expanded onto the RAM  20   c  and executed by the CPU  20   a.    
     As shown in  FIG. 7 , the CPU  20   a  as a control unit works as the print control unit  21   a , the coloring conversion setting unit  21   b , the counter unit  21   c , the determination unit  21   d , the coloring conversion control unit  21   e  and the blowing control unit  21   f  according to the programs. The programs include modules corresponding to at least the print control unit  21   a , the coloring conversion setting unit  21   b , the counter unit  21   c , the determination unit  21   d , the coloring conversion control unit  21   e  and the blowing control unit  21   f.    
     The print control unit  21   a  controls the motor  6 , the head  3   a  and the ribbon motor  3   b  through the conveying motor controller  20   f , the head controller  20   g  and the ribbon motor controller  20   h . Images such as letters or pictures are formed on the medium M under the control of the print control unit  21   a.    
     The coloring conversion setting unit  21   b  performs various kinds of setting operations associated with the coloring conversion of the temperature-sensitive ink images formed on the medium M (the cooling performed by the cooling device  10 A in the present embodiment). More specifically, the coloring conversion setting unit  21   b  can cause the storage unit such as the NVRAM  20   d  to store a pitch (frequency) at which coloring conversion (cooling) is performed with respect to the media M and a parameter for setting the operation conditions of the cooling device  10 A (e.g., the cooling timing and the cooling time period), which are inputted through the input unit  12 . 
     The counter unit  21   c  counts the number of media M (or the number of image formation areas) detected by the sensor  8 . 
     The determination unit  21   d  compares the count value counted by the counter unit  21   c  with the pitch (frequency) stored in the storage unit and determines whether to perform coloring conversion (cooling in the present embodiment). 
     The coloring conversion control unit  21   e  controls the operation of the cooling device  10 A in order to perform coloring conversion (cooling) with respect to the medium M (the temperature-sensitive ink images formed on the medium M) which is determined by the determination unit  21   d  to be subjected to coloring conversion. In the present embodiment, pursuant to the setting of the pitch (frequency), the coloring conversion can be performed with respect to the temperature-sensitive ink images formed on all the media M or some of the media M. 
     The blowing control unit  21   f  controls the operation of the motor  31   d  of the blower unit  31  to deter at least a part of the air (cold air) cooled by the cooling device  10 A from staying around the cooling device  10 A or flowing toward the ink ribbon cartridges  3  as an image forming unit when coloring conversion (cooling) is performed by the coloring conversion control unit  21   e.    
     In the present embodiment, the coloring conversion control unit  21   e  and the blowing control unit  21   f  are configured to switch, under the control of the CPU  20   a , the operations of the cooling device  10 A and the blower unit  31  to one of an intermittent operation and a continuous operation depending on the image formation interval. 
     Under the control of the CPU  20   a , the blowing control unit  21   f  stops the operation of the blower unit  31  (the rotation of the motor  31   d ) if a specified times lapses after the operation of the cooling device  10 A as a coloring conversion unit is stopped. 
     In other words, the cooling device  10 A remains cold for a specified time after the stoppage of the operation thereof. Thus, the blower unit  31  is continuously operated for the specified time after the stoppage of the operation of the cooling device  10 A. This makes it possible to deter at least a part of the air (cold air) cooled by the cooling device  10 A from staying around the cooling device  10 A or flowing toward the ink ribbon cartridges  3  as an image forming unit. 
     In the printer  1  configured as above, it is possible to obtain, e.g., a medium M as illustrated in  FIG. 8A  or  8 B. 
       FIG. 8A  illustrates a product label as a medium M outputted from the printer  1  with no cooling performed by the cooling device  10 A.  FIG. 8B  illustrates a product label as a medium M outputted from the printer  1  with the cooling performed by the cooling device  10 A. 
     As illustrated in  FIG. 8B , the temperature-sensitive ink images Im 1  and Im 2  are visualized when the cooling is performed by the cooling device  10 A. Accordingly, as user or an operator of the printer  1 , it is easy to visually recognize the formation of the temperature-sensitive ink images Im 1  and Im 2  on the medium M. 
       FIGS. 8A and 8B  illustrate a case where images Im 1  and Im 2  of two kinds of temperature-sensitive inks differing in threshold temperature Th are formed on the medium M. Moreover, an image Im 3  (e.g., a barcode) formed by a typical ink whose coloring state is not changed depending on a temperature is also formed on the medium M. 
     As one example, the medium M illustrated in  FIGS. 8A and 8B  can be used for temperature management when refrigerating or freezing a product. 
     More specifically, the medium M on which the images Im 1  and Im 2  of the temperature-sensitive ink having the temperature-sensitive property depicted in  FIG. 2A  are formed by the printer  1  is used as a product label. The printer  1  utilizes a temperature-sensitive ink having a threshold temperature Th equal to a management temperature (e.g., 5 degrees C.) that a product to be refrigerated or frozen is not allowed to exceed. As a result, if a product temperature exceeds the threshold temperature Th, the medium M comes into the state as illustrated in  FIG. 8A . Thus, the temperature-sensitive ink images Im 1  and Im 2  become hard to see or invisible (S 2  in  FIG. 2A ). 
     On the other hand, if the product temperature is equal to or lower than the threshold temperature Th as the management temperature, the medium M is kept in the state illustrated in  FIG. 8B  (S 1  in  FIG. 2A ). This enables a worker or other persons to determine whether the product temperature is higher than or lower than the management temperature, depending on whether the temperature-sensitive ink images Im 1  and Im 2  are easy to see (visible) or hard to see (invisible). 
     In the example illustrated in  FIGS. 8A and 8B , the images Im 1  and Im 2  of two kinds of temperature-sensitive inks differing in the threshold temperature Th are formed on the medium M to thereby indicate the product management results with respect to the two kinds of management temperatures (first and second management temperatures). In this example, the formation condition of the temperature-sensitive ink images Im 1  and Im 2  on the medium M can be visually recognized by cooling the medium M with the cooling device  10 A. 
     As another example, images Im 1  and Im 2  of a temperature-sensitive ink with a temperature-sensitive property showing a hysteresis in temperature rising and falling processes as depicted in  FIG. 2B  can be formed by the printer  1  on a product label as a medium M illustrated in  FIGS. 8A and 8B . 
     In this case, the printer  1  forms the images Im 1  and Im 2  on the medium M through the use of a temperature-sensitive ink having a threshold temperature Th 2  equal to a management temperature (e.g., −5 degrees C.) that a product to be refrigerated or frozen is not allowed to exceed and a threshold temperature Th 1  equal to a temperature (e.g., −30 degrees C.) that cannot be realized in a specified refrigerating or freezing state. 
     In the printer  1 , the cooling device  10 A cools the images Im 1  and Im 2  to the threshold temperature Th 1  or less (e.g., −40 degrees C.) so that the images Im 1  and Im 2  formed by the printer  1  can be visualized on the medium M. 
     In this example, all the media M are cooled by the cooling mechanism  10  to first reduce the temperature of the media M to the threshold temperature Th 1  or less. As a result, if a product temperature exceeds the threshold temperature Th 2  as the management temperature even just once, the medium M comes into the state as illustrated in  FIG. 8A . Thus, the temperature-sensitive ink images Im 1  and Im 2  become hard to see or invisible (S 2  in  FIG. 2B ) and continue to remain in this state (S 2 ). 
     On the other hand, if the product temperature is equal to or lower than the threshold temperature Th 2  as the management temperature, the medium M is kept in the state illustrated in  FIG. 8B  (S 1  in  FIG. 2B ). This enables a worker or other persons to determine whether the product temperature has ever exceeded the management temperature before, depending on whether the temperature-sensitive ink images Im 1  and Im 2  are easy to see (visible) or hard to see (invisible). 
     In this example, the images Im 1  and Im 2  of two kinds of temperature-sensitive inks differing in the threshold temperature Th 2  are formed on the medium M to thereby indicate the product management results with respect to the two kinds of management temperatures (first and second management temperatures). 
     According to the present embodiment described above, it is possible to deter at least a part of the air (cold air) cooled by the cooling device  10 A from flowing toward (or reaching) the ink ribbon cartridges  3  (the heads  3   a  and the ink ribbons  3   d ) as an image forming unit and the environmental temperature sensor ( 8 ). This helps restrain or prevent the occurrence of a sharp change in the environmental temperature detected by the environmental temperature sensor ( 8 ). Accordingly, it is possible to accurately control the heating operation of the head  3   a  and to restrain or prevent the temperature-sensitive ink from being unnecessarily hardened. Moreover, it is possible to prevent reduction of an image formation quality (print quality). 
     According to the present embodiment, the deterring unit  30  (including the blower unit  31  and the guide unit  32 ) can deter at least a part of the air (cold air) cooled by the cooling device  10 A from staying in a specific area (e.g., around the cooling device  10 A), which helps prevent the occurrence of dew condensation in the body unit  1   a . This makes it possible to prevent the conveyance path P and the medium M from getting wet and to prevent the finger or the hand of an operator from getting wet when touching the body unit  1   a.    
     While one illustrative embodiment has been described above, the present disclosure is not limited to this embodiment. 
     The embodiment described above is directed to an all-in-one printer  1  in which the ink ribbon cartridges  3  as an image forming unit, the cooling device  10 A as a coloring conversion unit and the deterring unit  30  (including the blower unit  31  and the guide unit  32 ) are accommodated within the body unit  1   a . However, the present disclosure is not limited thereto. Alternatively, it may be possible to provide a print system in which the respective components (particularly, the image forming unit and the coloring conversion unit) are arranged independently of each other. 
     More specifically, as shown in  FIG. 9 , it may be possible to provide a print system  100  including a printer  1 B and a coloring conversion device  15 . The printer  1 B includes a CPU  20   a , a plurality of ink ribbon cartridges  3  as an image forming unit capable of forming, on a medium M, images of a temperature-sensitive ink whose color changes depending on temperature, and a conveying unit which includes conveying rollers  4 , auxiliary rollers  5 , a motor  6  and a rotation-transmitting mechanism (or a speed-reducing mechanism)  7 . The coloring conversion device  15  includes a control unit  15   a  for receiving a control signal issued from the CPU  20   a , a coloring conversion unit (e.g., a cooling device  10 A) for heating or cooling the images formed by the image forming unit of the printer  1 B and converting the coloring states of the images under the control of the control unit  15   a  and a deterring unit  30  for deterring at least a part of the air heated or cooled by the coloring conversion unit from flowing toward the image forming unit or staying in a specific area. 
     In the print system  100 , if the printer  1 B and the coloring conversion device  15  are arranged close to each other, the deterring unit  30  can provide an enhanced effect of deterring at least a part of the air heated or cooled by the coloring conversion unit from flowing toward the image forming unit. 
     In the embodiment described above, as shown in  FIG. 3 , the guide unit  32  has no wall at the opposite ends in the width direction Z and engages with the body unit  1   a . Alternatively, as illustrated in  FIG. 10 , the guide unit  32  may have side wall portions  32 D and  32 E at the opposite ends thereof. As compared with the guide unit  32  shown in  FIG. 3 , this configuration makes it possible to more accurately deter at least a part of the air (cold air) cooled by the cooling device  10 A from flowing toward the ink ribbon cartridges  3  as an image forming unit. 
     In the embodiment described above, as shown in  FIG. 1 , the deterring unit  30  is arranged on one surface (the upper surface) of the cooling device  10 A, namely on one surface (the upper surface) of the conveyance path P. Alternatively, as illustrated in  FIG. 11 , an additional deterring unit  30  may be arranged on the other surface (the lower surface) of the cooling device  10 A, namely on the other surface (the lower surface) of the conveyance path P. 
     This configuration can deter at least a part of the cold air generated below the cooling device  10 A and the conveyance path P from flowing toward the ink ribbon cartridges  3  (the heads  3   a  and the ink ribbons  3   d ) as an image forming unit or from staying at the lower side of the cooling device  10 A and the conveyance path P. 
     As another alternative example, only an additional guide unit  32  for deterring at least a part of the cold air generated below the cooling device  10 A and the conveyance path P from flowing toward the ink ribbon cartridges  3  as an image forming unit may be arranged below the cooling device  10 A and the conveyance path P without installing any blower unit  31 . In this case, the shape of the additional guide unit  32  is not limited to the generally trough-like shape but may be a flat plate shape orthogonal to the conveying surface of the conveyance path P or other shapes. 
     In the embodiment described above, the printer  1  employs a cooling device (the cooling device  10 A) for cooling the images formed on the medium M as the coloring conversion unit for converting the coloring states of the images formed on the medium M. However, the present disclosure is not limited thereto. Alternatively, it may be possible to provide a printer  1  that employs, as the coloring conversion unit, a heating device for heating the images formed on the medium M. 
     In the printer  1  including the heating device stated above, the deterring unit  30  can deter at least a part of the air (hot air) heated by the heating device from flowing toward the ink ribbon cartridges  3  (the heads  3   a  and the ink ribbons  3   d ) as an image forming unit, thereby preventing the ink ribbons  3   d  from being melted unnecessarily. This makes it possible to restrain or prevent reduction of an image formation quality. With the configuration set forth just above, it is possible to deter the hot air from staying in a specific area (e.g., around the heating device). This makes it possible to prevent occurrence of various kinds of trouble (reduction of an image formation quality or occurrence of an erroneous operation of the respective control unit) which may otherwise be caused by the stagnant hot air. 
     In the embodiment described above, the Peltier element is used as the cooling device for cooling the images formed on the medium M. However, the present disclosure is not limited thereto. It may be possible to use other kinds of cooling devices. 
     In the embodiment described above, a single cooling device  10 A is employed as the coloring conversion unit. Alternatively, it may be possible to employ a plurality of cooling devices. 
     In the embodiment described above, the cooling device  10 A is fixed to the portion protruding frontwards from the lower end of the rear wall portion  32 B of the guide unit  32 . However, the present disclosure is not limited thereto. It may be possible to fix the cooling device  10 A in other attachment positions. For example, the cooling device  10 A may be fixed to the upper surface of the protruding portion of the rear wall portion  32 B or the inner surface of the rear wall portion  32 B. In other words, the cooling device  10 A may be fixed to the inner portion of the guide unit  32 . 
     The programs executed in the printer  1  are offered in a state that the programs are preliminarily incorporated in the storage unit such as the ROM  20   b . Alternatively, the programs may be offered by recording the programs in a computer-readable recording medium in the form of installable or executable files. In addition, the programs may be offered or disseminated via a network such as the Internet. 
     In the embodiment described above, the hardware configuration and software configuration of the printer  1 , the hardware configuration and outward configuration of the blower unit  31 , the shape of the guide unit  32  and the hardware configuration and outward configuration of the cooling device  10 A are presented merely by way of example. The present disclosure is not limited thereto. 
     Next, a description will be made of a second embodiment. The same elements in the figures used to describe the first embodiment will be designated by like reference symbols and will not be described in detail. 
     The printer  1 A of the second embodiment (see  FIG. 12 ) differs from the printer  1  of the first embodiment in that an electricity-removing unit  50  for removing static electricity is attached to the deterring unit  30 . The configurations (the hardware configuration and the software configuration) of the printer  1 A of the present embodiment other than the electricity-removing unit  50  remain the same as those of the printer  1  of the first embodiment. 
       FIG. 12  is a side view showing a schematic configuration of the printer  1 A according to the second embodiment, which is configured by adding the electricity-removing unit  50  to the printer  1  of the first embodiment shown in  FIG. 1 .  FIGS. 13 through 15  are views for explaining the configurations of the deterring unit  30  and the electricity-removing unit  50 .  FIG. 13  is an assembled perspective view showing the deterring unit  30  and the electricity-removing unit  50  in an assembled state.  FIG. 14  is an exploded perspective view showing the deterring unit  30  and the electricity-removing unit  50  in an exploded state.  FIG. 15  is a side view of the deterring unit  30  and the electricity-removing unit  50  shown in  FIG. 13 . 
     As shown in  FIGS. 13 through 15 , just like the deterring unit  30  described with respect to the first embodiment, the deterring unit  30  includes a blower unit (or a fan motor)  31  for blowing the air cooled by the cooling device  10 A and a guide unit  32  for guiding the air blown by the blower unit  31  so as not to reach the ink ribbon cartridges  3 . The configuration of the deterring unit  30  is substantially the same as the configuration of the deterring unit  30  of the first embodiment and therefore will not be described herein. 
     The electricity-removing unit  50  is fixed to the guide unit  32  by connector members  53  and screws V threadedly coupled to screw holes  53   a  of the connector members  53 . 
     The electricity-removing unit  50  is an electricity-removing brush (static-electricity-removing brush) for air-discharging and removing static electricity frictionally generated when the air blown by the blower unit  31  is guided within the guide unit  32  and static electricity charged in the medium M. 
     More specifically, the electricity-removing unit  50  of the present embodiment includes a plurality of thin wires  51   a  composed of electrically conductive fibers capable of corona-discharging static electricity and a parallelepiped support body  52  for supporting the thin wires  51   a . The support body  52  has a length substantially equal to the length in the width direction Z of the guide unit  32 . 
     In the electricity-removing unit  50  of the present embodiment, wire bundles  51  each having a predetermined number of (e.g., ten) thin wires  51   a  that are arranged along the substantially full length in the width direction Z of the support body  52  at a specified pitch P 0 . Further, the specified pitch P 0  is provided not to deter the flow of the air blown by the blower unit  31 . 
     The electricity-removing unit  50  is arranged in the outlet O of the guide unit  32 . The electricity-removing unit  50  causes a part of the cooled air to flow back into the guide unit  32  and temporarily stay within the guide unit  32  and causes a part of the cooled air (including the air flowing back into the guide unit  32 ) to be discharged from the outlet O to the outside of the guide unit  32 . In other words, the electricity-removing unit  50  serves to solve a problem that the cooled air existing around the cooling device  10 A is unnecessarily removed by the wind of the blower unit  31 , as a result of which the cooling effect of the cooling device  10 A is reduced. 
     When the electricity-removing unit  50  is attached to the body unit  1   a  of the printer  1 A in a usable state, the wire bundles  51  (the thin wires  51   a ) make contact with the conveyance path P (particularly, the medium M conveyed along the conveyance path P). 
     Thus, the electricity-removing unit  50  of the present embodiment removes the static electricity generated in the deterring unit  30  and the static electricity charged in the medium M conveyed along the conveyance path P (particularly, the medium M on which the images are formed). 
     According to the present embodiment, the electricity-removing unit  50  can remove the static electricity generated by the action of the deterring unit  30 , which helps restrain or prevent the medium M and various kinds of electronic parts such as the cooling device controller  20   p  and the blower unit controller  31   c  from being charged with static electricity. This makes it possible to prevent the electronic parts from being erroneously operated or broken and to prevent dust from adhering to the medium M on which the images are formed. 
     According to the present embodiment, the thin wires  51   a  of the electricity-removing unit  50  can restrain the cooled air existing around the cooling device  10 A from being unnecessarily removed by the wind of the blower unit  31 . This makes it possible to prevent reduction of the cooling effect of the cooling device  10 A. 
     While one illustrative embodiment has been described above, the present disclosure is not limited to this embodiment. 
     For example, as set forth with respect to the first embodiment, it may be possible to provide a print system in which the respective components (particularly, the image forming unit and the coloring conversion unit) are arranged independently of each other. 
     More specifically, as shown in  FIG. 16 , it may be possible to provide a print system  100 A including a printer  1 B and a coloring conversion device  15 . The printer  1 B includes a CPU  20   a , a plurality of ink ribbon cartridges  3  as an image forming unit capable of forming, on a medium M, images of a temperature-sensitive ink whose color is changed depending on a temperature, and a conveying unit which is composed of conveying rollers  4 , auxiliary rollers  5 , a motor  6  and a rotation-transmitting mechanism (or a speed-reducing mechanism)  7 . The coloring conversion device  15  includes a control unit  15   a  for receiving a control signal issued from the CPU  20   a , a coloring conversion unit (e.g., a cooling device  10 A) for heating or cooling the images formed by the image forming unit of the printer  1 B and converting the coloring states of the images under the control of the control unit  15   a , a deterring unit  30  for deterring at least a part of the air heated or cooled by the coloring conversion unit from flowing toward the image forming unit or staying in a specific area and an electricity-removing unit  50  for removing the static electricity generated by the action of the deterring unit  30 . 
     In the electricity-removing unit  50  of the embodiment described above, the wire bundles  51  each having a predetermined number of (e.g., ten) thin wires  51   a  are arranged along the substantially full length in the width direction Z of the support body  52  at a specified pitch P 0 . Alternatively, it may be possible to use an electricity-removing unit  50  in which an individual thin wire  51   a  is arranged along the substantially full length in the width direction Z of the support body  52  at a specified pitch P 0 . 
     In the electricity-removing unit  50  of the embodiment described above, the wire bundles  51  each having a predetermined number of thin wires  51   a  are fixed to the support body  52  at a specified pitch P 0 . However, the present disclosure is not limited thereto. The wire bundles  51  may be fixed at other pitches. For example, as shown in  FIG. 17 , the wire bundles  51  may be fixed to support body  52  at different pitches in a plurality of transverse sections divided along the width direction Z of the electricity-removing unit  50 .  FIG. 17  is a front view of the deterring unit  30 , the cooling device  10 A and the electricity-removing unit  50  shown in an assembled state in  FIG. 13 . 
     More specifically, the flow of the air blown by the fan  31   e  of the blower unit  31  is strong in, e.g., a transverse section T 1  corresponding to the attachment position of the blower unit  31  of the deterring unit  30 . With a view to restrain the air cooled by the cooling device  10 A from being unnecessarily removed by the fan  31   e  of the blower unit  31 , the wire bundles  51  are arranged at a relatively small first pitch P 1  in the transverse section T 1 . On the other hand, the flow of the air is weak in transverse sections T 2  and T 3  that do not correspond to the attachment position of the blower unit  31  of the deterring unit  30 . Thus, the wire bundles  51  are arranged at a relatively large second pitch P 2  in the transverse sections T 2  and T 3 . The first pitch P 1  is set smaller than the second pitch P 2 . 
     In the embodiment described above, the self-discharged electricity-removing brush capable of discharging static electricity in the air is used as the electricity-removing unit  50 . However, the present disclosure is not limited thereto. Other types of electricity-removing brushes may be used. For example, it may be possible to use an electricity-removing brush of the type in which the static electricity charged in the thin wires  51   a  is discharged from the electrically conductive support body  52  to the outside of the printer  1 A via an earth wire of the body unit  1   a  of the printer  1 A. 
     In the embodiment described above, the electricity-removing brush (static-electricity-removing brush) is employed as the electricity-removing unit  50  for removing static electricity. However, the present disclosure is not limited thereto. Other types of electricity-removing members may be employed. For example, it may be possible to employ an electricity-removing sheet for discharging static electricity in the air. The electricity-removing sheet is formed by combining ultrafine fibers with an electrically conductive polymer matrix so that the tip ends of the ultrafine fibers can serve as conductor needles. 
     Next, a description will be made of a third embodiment. The same elements used in the figures to describe the first embodiment will be designated by like reference symbols and will not be described in detail. 
     The printer  1 C of the third embodiment (see  FIG. 18 ) greatly differs from the printer  1  of the first embodiment in that the printer  1 C includes a visual recognition enabling unit. In the third embodiment, the unit removably mounted with a plurality of (four, in the present embodiment) ink ribbon cartridges  3  ( 3 A through  3 D) will be called a print block  300 . In the third embodiment, the unit for conveying the backing paper (the medium M) through the use of the conveying rollers  4 , the auxiliary rollers  5 , the motor  6  and the rotation-transmitting mechanism  7  will be called a conveying unit  50 A. 
     In the third embodiment, the cooling device  10 A is changed to a cooling mechanism  10 . The cooling mechanism  10  is arranged along and below the conveyance path P. 
     In the present embodiment, the cooling mechanism  10  is configured to spout, e.g., a gas, and reduce the temperature of the medium M, namely the temperature of temperature-sensitive ink images, using the adiabatic expansion or the latent heat of the gas. More specifically, the cooling mechanism  10  includes a mounting portion  10   a  for holding a gas cartridge  11  of a gas cylinder, a spouting portion  10   b , a tube  10   c , a valve  10   d  and a cooling fin  10   e.    
     The gas cartridge  11  is removably mounted to the mounting portion  10   a . The mounting portion  10   a  serves as a connector for receiving a connector  11   a  of the gas cartridge  11 . The mounting portion  10   a  may include a movable lever (not shown) used in removing the gas cartridge  11  and a lock mechanism (not shown) for fixing the gas cartridge  11  in a mounting position. 
     The gas cartridge  11  may be made up of, e.g., a gas cylinder (gas bomb) filled with a liquefied gas. As the gas (coolant), it is possible to use, e.g., tetrafluoroethane. 
     As shown in  FIGS. 18 and 19 , the spouting portion  10   b  is arranged to extend in the width direction of the backing paper  2  along the rear surface of the backing paper  2 . The spouting portion  10   b  is a gas pipe having a gas flow path formed therein. Referring to  FIG. 21 , the spouting portion  10   b  has an upper wall  10   f  and a plurality of nozzle holes  10   g  formed side by side in the upper wall  10   f  at a regular interval (pitch). The gas is spouted from the nozzle holes  10   g  toward the rear surface of the backing paper  2 . The nozzle holes  10   g  may be arranged in plural rows. 
     The spouting portion  10   b  is supported by brackets  10   h  to rotate about a rotation axis Ax extending in the width direction of the backing paper  2  and is capable of changing the spouting angle (spouting direction) of the gas G as illustrated in  FIGS. 20A and 20B . More specifically, as shown in  FIG. 19 , the spouting portion  10   b  can be fixed at an arbitrary angle by arranging the spouting portion  10   b  at a specified spouting angle and then tightening nuts  10   j  to the male thread portions  10   i  of the spouting portion  10   b  inserted into the through-holes (not shown) of the brackets  10   h . The cooling degree of the backing paper  2  cooled by the gas G can be variably set by variably setting the spouting angle. For instance, cooling is more heavily performed in the arrangement shown in  FIG. 20A  than in the arrangement shown in  FIG. 20B . Thus, the temperature-sensitive ink images formed on the medium M have a lower temperature in the arrangement shown in  FIG. 20A  than in the arrangement shown in  FIG. 20B . In the present embodiment, the spouting portion  10   b  includes a spouting condition adjusting mechanism as set forth above. 
     The tube  10   c  has pressure resistance and flexibility required for the tube  10   c  to serve as a gas conduit between the mounting portion  10   a  and the spouting portion  10   b  regardless of the change of the angle of the spouting portion  10   b.    
     The valve  10   d  can switch the spouting of the gas from the spouting portion  10   b  and the blocking of the gas by opening or closing a gas flow path extending from the gas cartridge  11  to the spouting portion  10   b . The valve  10   d  may be made up of, e.g., a solenoid valve which is opened in response to an electric signal supplied from a CPU  20   a  (see  FIG. 24 ). The valve  10   d  can be attached to the mounting portion  10   a . The spouting condition of the gas can be variably set by controlling the opening and closing of the valve  10   d  (e.g., the length of opening time, the number of times for opening and closing, and the period for opening and closing). 
     The cooling fin  10   e  includes a base portion  10   k  close to or adjoining to the outer circumferential surface  11   b  of the gas cartridge  11  and a plurality of plate-shaped portions  10   m  extending in the medium conveying direction and protruding from the base portion  10   k  toward positions near the rear surface of the backing paper  2 . When the temperature of the gas cartridge  11  is reduced by spouting the gas, the cooling fin  10   e  can enhance the cooling performance for the medium M. The cooling mechanism  10  can be removably mounted to the body unit  1   a.    
     The body unit  1   a  of the printer  1 C includes a front panel  15 A positioned above a paper discharge port  40 A. The front panel  15 A is formed of, e.g., a transparent resin. The reason for forming the front panel  15 A with a transparent resin is to enable a user or other persons to confirm, at the outside of the printer  1 C, the surface condition of the medium M existing near the cooling mechanism  10 . In other words, the front panel  15 A serves as a visual recognition enabling unit that enables a user or other persons to visually recognize, from outside of the printer  1 C, the temperature-sensitive ink images formed on the medium M and subjected to coloring state conversion in the cooling mechanism  10 . 
     The printer  1 C of the present embodiment further includes a deterring unit  70  positioned between the cooling mechanism  10  and the print block  300 . The deterring unit  70  is configured to deter at least a part of the air cooled by the cooling mechanism  10  from flowing toward the print block  300  and to deter the air cooled by the cooling mechanism  10  from staying in a specific area. The deterring unit  70  includes a blower unit  71  for blowing the air cooled by the cooling mechanism  10  and a guide unit  72  for guiding the air blown by the blower unit  71  so as not to reach the print block  300 . 
       FIG. 22  is a perspective view schematically showing the deterring unit  70 . As shown in  FIG. 22 , the guide unit  72  of the deterring unit  70  is a member shaped to form a portion of the conveyance path P and configured to guide the air blown by the blower unit  71  toward the downstream side along the conveying direction of the medium M. The guide unit  72  is made of, e.g., a transparent resin. Thus, the deterring unit  70  can maintain a visually recognizable state in which the temperature-sensitive ink images formed on the medium M and subjected to coloring state conversion in the cooling mechanism  10  can be visually recognized from the front panel  15 A as a visual recognition enabling unit. The guide unit  72  includes a front wall portion  72 A arranged near the downstream end of the conveyance path P in the medium conveying direction, a rear wall portion  72 B arranged in opposing relationship with the front wall portion  72 A and a top surface portion  72 C configured to interconnect the front wall portion  72 A and the rear wall portion  72 B and arranged above the conveyance path P to extend parallel to the conveying plane of the conveyance path P. As can be seen in  FIG. 22 , unlike the deterring unit  30  of the first embodiment, the cooling device  10 A is not fixed to the guide unit  72  in the deterring unit  70  of the third embodiment. 
       FIG. 23  is a side view of the deterring unit  70 . As shown in  FIG. 23 , the guide unit  72  of the deterring unit  70  is formed to have a generally trough-like side cross section. The length of the guide unit  72  in a width direction Z is substantially equal to the width of the conveyance path P. The guide unit  72  is arranged close to one surface (the upper surface) of the conveyance path P in alignment with the width of the conveyance path P. 
     The guide unit  72  having the shape set forth above guides the air (wind) blown by the blower unit  71  toward the cooling mechanism  10  arranged below the blower unit  71  and discharges the air (cold air) Y cooled by the cooling mechanism  10  from an outlet O defined below the front wall portion  72 A. 
     The deterring unit  70  is provided with a conveying roller  4 . The conveying roller  4  is arranged along and above the conveyance path P. The cooling mechanism  10  makes contact with the conveying roller  4  through the conveyance path P in such a manner as to move toward or away from the conveying roller  4 . With this structure, a conveying force is applied to the backing paper  2  (the medium M) as the conveying roller  4  is rotationally driven. Thus, the backing paper  2  (the medium M) is conveyed toward the paper discharge port  40 A. 
     A cutter mechanism  60  as a post-treatment device for cutting the backing paper  2  (the medium M) conveyed along the conveyance path P is provided near the paper discharge port  40 A of the printer  1 C at the downstream side of the cooling mechanism  10  in the medium conveying direction. 
     As shown in  FIG. 18 , the printer  1 C further includes a dew-removing member  16  arranged in the body unit  1   a  near the paper discharge port  40 A. The dew-removing member  16  is made of, e.g., a sponge material or a rubber spatula. By arranging the dew-removing member  16  in the body unit  1   a  near the paper discharge port  40 A, a small amount of moisture generated in the backing paper  2  by dew condensation in the coloring process of the medium M can be removed when the backing paper  2  is discharged from the paper discharge port  40 A. This makes it easy to handle a printed and cut label (to reduce difficulties in affixing the label). 
       FIG. 24  is a block diagram showing a hardware configuration of the printer  1 C of the third embodiment. 
     Referring to  FIG. 24 , the printer  1 C of the third embodiment differs from the printer  1  of the first embodiment in that the control circuit  20  further includes a valve controller  20   i  and a cutter motor controller  20   q  and excludes the cooling device controller  20   p . In this regard, the valve controller  20   i  controls the valve  10   d  (the solenoid of the valve  10   d ) of the cooling mechanism  10  pursuant to an instruction supplied from the CPU  20   a.    
     The cutter motor controller  20   q  controls the operation of a cutter motor  61  as a drive power source of the cutter mechanism  60  in response to an instruction supplied from the CPU  20   a.    
     The software configuration of the printer  1 C of the third embodiment is substantially the same as the software configuration of the printer  1  of the first embodiment (see  FIG. 7 ). 
     In the printer  1 C of the third embodiment, the print control unit  21   a  also controls the cutter motor  61  by way of the cutter motor controller  20   q.    
     The coloring conversion setting unit  21   b  performs various kinds of setting operations associated with the coloring conversion of the temperature-sensitive ink images printed on the medium M (the cooling performed by the cooling mechanism  10  in the present embodiment). More specifically, the coloring conversion setting unit  21   b  can cause the storage unit such as the NVRAM  20   d  to store a pitch (frequency) at which coloring conversion (cooling) is performed with respect to the medium M and a parameter for setting the opening or closing conditions of the valve  10   d  (e.g., the opening/closing timing, the opening/closing duration, the number of opening/closing times and the opening/closing period), which are inputted through the input unit  12 . 
     The counter unit  21   c  and the determination unit  21   d  perform the same processing as set forth with respect to the first embodiment and therefore will not be described in detail. 
     The coloring conversion control unit  21   e  controls individual parts or units (the respective parts of the cooling mechanism  10  in the present embodiment) in order to perform coloring conversion (cooling in the present embodiment) with respect to the medium M (the temperature-sensitive ink images formed on the medium M) which is determined by the determination unit  21   d  to be subjected to coloring conversion. In the third embodiment, the coloring conversion control unit  21   e  performs the coloring conversion of the medium M by controlling the opening/closing condition of the valve  10   d  and consequently controlling the spouting state of the gas. The coloring conversion control unit  21   e  also corresponds to a spouting condition adjusting mechanism. In the present embodiment, pursuant to the setting of the pitch (frequency), the coloring conversion can be performed with respect to the temperature-sensitive ink images formed on all the media M or some of the media M. 
     The printer  1 C configured as above can produce, e.g., a medium M as described in the first embodiment and illustrated in  FIG. 8A  or  8 B. 
     In the printer  1 C of the present embodiment, as shown in  FIGS. 25A and 25B , it is possible to use ink ribbon cartridges  3  that differ from each other in the positions of the ribbon rollers  3   c  with respect to the head  3   a . In the configuration shown in  FIG. 25A , the ink ribbon  3   d  and the medium M make contact with each other for a long period of time. In the configuration shown in  FIG. 25B , the ink ribbon  3   d  and the medium M make contact with each other for a short period of time. One of these configurations can be selected depending on the properties of the temperature-sensitive ink or the typical ink. In the present embodiment, the ink ribbon cartridge  3  corresponds to an ink ribbon holding unit. The ribbon motor  3   b  and the ribbon rollers  3   c  make up a ribbon conveying unit. 
     In the printer  1 C of the present embodiment described above, the head  3   a  of the ink ribbon cartridge  3  as an image forming unit forms temperature-sensitive ink images on the medium M and the cooling mechanism  10  as a coloring conversion mechanism converts the coloring of the images. According to the present embodiment, it is therefore possible to impart desired coloring states to the temperature-sensitive ink images formed on the medium M outputted from the printer  1 C. It is also easy to confirm whether desired temperature-sensitive ink images are successfully formed on the medium M. 
     In the present embodiment, the cooling mechanism  10  as a coloring conversion unit reduces the temperature of the images by spouting a gas. This makes it possible to obtain the cooling mechanism  10  with a relatively simple configuration. 
     In the present embodiment, the printer  1 C includes, as the spouting condition adjusting mechanism for adjusting the spouting condition of the gas, a mechanism for adjusting the posture of the spouting portion  10  (e.g., the spouting direction of the gas G spouted from the nozzle holes  10   g ) and a mechanism for variably setting the gas spouting timing or the gas spouting time period (e.g., the opening/closing period of the valve  10   d ). This makes it possible to suitably adjust the condition of the cooling performed by the gas. 
     As the spouting condition adjusting mechanism, it is possible to employ, e.g., a movable plate  14  for changing the number of effective nozzle holes  10   g  as shown in  FIG. 16 . The movable plate  14  is supported on the upper wall  10   f  of the spouting portion  10   b  to allow the movable plate  14  to slide along the upper wall  10   f . The movable plate  14  has through-holes  14   a  overlapping with all the nozzle holes  10   g  when the movable plate  14  is in one position and through-holes  14   b  overlapping with some of the nozzle holes  10   g  when the movable plate  14  is in another position. By sliding the movable plate  14 , it is possible to switch a state in which the gas is spouted from all the nozzle holes  10   g  through the through-holes  14   a  and a state in which the gas is spouted from some of the nozzle holes  10   g  through the through-holes  14   b . This makes it possible to variably set the amount of the spouting gas, thereby variably setting the cooling degree of the temperature-sensitive ink images. 
     In the present embodiment, the printer  1 C includes the heads  3   a  of the ink ribbon cartridges  3  as a plurality of image forming units for forming images of different temperature-sensitive inks on the medium M. Accordingly, a plurality of ink images differing in the temperature-sensitive property can be formed on the medium M, which makes it possible to perform temperature management in multiple stages. 
     In the present embodiment, the cooling mechanism  10  cools the temperature-sensitive ink image extracted (selected or designated) and converts the coloring state thereof. This configuration can reduce energy consumption as compared to when all the temperature-sensitive ink images are cooled. 
     In the printer  1 C, it is also possible to use a temperature-sensitive ink having a property opposite to the property of the temperature-sensitive ink stated above, namely a temperature-sensitive ink having such a property that the temperature-sensitive ink is visualized when the temperature thereof exceeds a management temperature. For example, as shown in  FIG. 27 , if the ink temperature is higher than the threshold temperature, a message of “caution” or “warning” indicating that the temperature of temperature-sensitive ink image Im 4  or Im 5  has exceeded the management temperature appears on the medium M as a product label. In this example, images Im 4  and Im 5  of temperature-sensitive inks differing in the threshold temperature are formed on the medium M, which makes it possible to manage a product at different temperatures. In the printer corresponding to the example shown in  FIG. 27 , a heating mechanism instead of the cooling mechanism  10  can be provided as the coloring conversion unit. In this example, the temperature-sensitive ink images Im 4  and Im 5  are visualized to issue a caution notice or a warning notice when a specified temperature condition is not satisfied. 
     According to the present embodiment, it is possible to solve a problem that, if the temperature-sensitive ink images formed on the medium M and subjected to coloring state conversion in the cooling mechanism  10  as a coloring conversion unit are erased due to a temperature rise or other causes before the medium M is cut by the cutter mechanism  60 , the formation of desired temperature-sensitive ink images on the medium M cannot be confirmed after the medium M is cut by the cutter mechanism  60 . The provision of the visual recognition enabling unit for enabling a user or other persons to visually recognize, from outside the printer  1 C, the temperature-sensitive ink images formed on the medium M and subjected to coloring state conversion in the cooling mechanism  10  makes it possible to confirm the temperature-sensitive ink images. Accordingly, it is possible to provide a printer in which, when forming temperature-sensitive ink images on the medium M, trouble is hardly caused due to the color change of a temperature-sensitive ink. 
     When the deterring unit for deterring at least a part of the air cooled or heated by the coloring conversion unit from flowing toward the print block  300  is arranged between the visual recognition enabling unit and the medium M, the deterring unit is made of e.g., a transparent resin. This makes it possible to maintain a visually recognizable state in which the temperature-sensitive ink images formed on the medium M and subjected to coloring state conversion in the cooling mechanism  10  can be visually recognized from the visual recognition enabling unit. 
     While the guide unit  72  of the deterring unit  70  is made of a transparent resin in the printer  1 C of the present embodiment, the present disclosure is not limited thereto. As shown in  FIG. 28 , the guide unit  72  may be made of an opaque metal or resin and may have at least one opening  80  through which to visually recognize the surface condition of the medium M existing near the cooling mechanism  10 . 
     While the cutter mechanism  60  for cutting the backing paper (or the medium M) conveyed along the conveyance path P is employed as a post-treatment device in the printer  1 C of the present embodiment, the present disclosure is not limited thereto. It may be possible to employ various kinds of post-treatment devices such as a peeling mechanism for peeling the medium M from the backing paper  2  conveyed along the conveyance path P, a take-up mechanism for winding the backing paper (or the medium M) conveyed along the conveyance path P and a stacker mechanism. 
     In the printer  1 C of the present embodiment, the print block  300 , the cooling mechanism  10  and the cutter mechanism  60  are arranged within the body unit  1   a  in the named order from the upstream side to the downstream side of the medium conveying direction along the conveyance path P. However, the present disclosure is not limited thereto. The print block  300  and the cooling mechanism  10  may be arranged within the body unit  1   a  in the named order (or another order) and the cutter mechanism  60  as a post-treatment device may be installed independently. 
     Next, a description will be made on a modified example of the third embodiment. The same elements used in the figures of the third embodiment will be designated by like reference symbols and will not be described in detail. 
       FIG. 29  is a side view showing a schematic configuration of a printer  1 D as a modified example of the printer  1 C of the third embodiment. As shown in  FIG. 29 , the printer  1 D of the present embodiment includes a cooling element  90  as a coloring conversion unit in place of the cooling mechanism  10  employed in the printer  1 C of the third embodiment. The cooling element  90  is arranged along and below the conveyance path P. Just like the cooling device  10 A described in the first and second embodiments, the cooling element  90  is formed of, e.g., a Peltier element. The Peltier element is cooled by the air blown from the blower unit  71  of the deterring unit  70 . 
     Referring to  FIG. 30 , the cooling element  90  is controlled by a cooling element controller  20   s  pursuant to an instruction supplied from the CPU  20   a.    
     According to the present modified example, the printer  1 D is provided with the cooling element  90  in place of the cooling mechanism  10  employed in the printer  1 C of the third embodiment. Therefore, as compared with the printer  1 C of the third embodiment, the volume of the cooling device is reduced, which assists in reducing the size of the printer. Moreover, it becomes possible to reduce humidity change in the cooling process and to suppress occurrences of noises and vibrations. 
     A printing method according to the printer of the above embodiments is shown in  FIG. 31 . First, the medium M is conveyed to the image forming unit through the conveyance path (Act A 101 ). The medium M, which is for example the backing paper  2  made up of the roll  2   a  of  FIG. 1 , is drawn away from the roll  2   a  in cooperation with the conveying roller  4  and conveyed into the conveyance path. Once the medium M is conveyed to the image forming unit, an image is formed on the medium M by the ink ribbon cartridge of the temperature-sensitive ink (Act A 102 ). The ink ribbon cartridge can be detachably provided in plural in the main body of the printer. As the ink ribbon cartridge, an ink ribbon cartridge of a non-temperature-sensitive ink whose color is not changed depending on a temperature, as well as an ink ribbon cartridge of a temperature-sensitive ink, can be provided. And then the medium M on which an image of a temperature-sensitive ink is formed is subjected to the treatment for converting the coloring state of the image by a coloring conversion unit (Act A 103 ). The coloring conversion unit may be a cooling device or heating device and can be a device provided at an upstream side of the conveyance path as shown in  FIG. 1  or a device provided at a downstream side of the conveyance path as shown in  FIG. 18 . With the coloring state conversion treatment by the coloring conversion unit, the image of the corresponding temperature-sensitive ink is visualized on the medium M and thus is made easier to see. Thus, the state in which the image is formed can be easily confirmed. After, the air cooled or heated by the coloring conversion unit is guided toward to the conveyance direction of the medium M by the deterring unit (Act A 104 ). If the cooled or heated air flows toward the ink ribbon cartridge forming the image forming unit, the image forming quality of the image forming unit can be lowered. Thus, in order to consistently maintain the temperature environment of the image forming unit, the cooled or heated air is guided through the deterring unit toward an opposite side of the ink ribbon cartridge (the conveyance direction of the medium). For example, the deterring unit may be made up of a blower unit for discharging air, a guiding portion for guiding the blown air, etc. Meanwhile, in order to remove static electricity generated by friction of the air guided toward the conveying direction of the medium, an electricity-removing unit, which is for example made up of a static electricity-removing brush, etc., can be provided to remove the generated static electricity. 
     While certain preferred embodiments have been described above, the present disclosure is not limited thereto but may be modified in many different forms. For example, the printer may include three or more image forming units for forming images of different temperature-sensitive inks. The printer may include both the cooling mechanism and the heating mechanism as the coloring conversion unit. In this case, one of the cooling mechanism and the heating mechanism may be caused to act on the temperature-sensitive ink images to first bring the images into an easy-to-see (visible) state. Thereafter, the other may be caused to act on the temperature-sensitive ink images to bring the images into a hard-to-see (invisible) state (namely, to return the images to the original state). This enables a worker or other persons to confirm the temperature-sensitive ink images in the easy-to-see (visible) state. The number of cooling mechanisms and heating mechanisms may be changed to many other numbers. 
     The printer may include a spouting portion for spouting a cold gas or a hot gas as the cooling mechanism or the heating mechanism. A cold gas or a hot gas can be fed from the outside to the spouting portion through a connector and a pipe. In this configuration, it is possible to omit the gas cartridge, which makes it possible to reduce the size of the printer proportionate to the omission of the gas cartridge. 
     The printer may be configured from a printer of another type using ink (e.g., an inkjet printer). In the case of an inkjet printer, an ink head corresponds to the image forming unit. 
     The cutter mechanism (the post-treatment device)  60  and the dew-removing member  16  employed in the third embodiment may be applied to the first and second embodiments. 
     The specifications (type, structure, shape, size, arrangement, position, number, constituent or temperature-sensitive property) of the respective components (the print system, the printer, the medium, the ink ribbon cartridge, the image forming unit, the coloring conversion unit (the cooling mechanism, the heating mechanism, the spouting condition adjusting mechanism and the coloring conversion device), the image or the temperature-sensitive ink) may be appropriately modified and embodied. 
     According to the embodiments and the modified examples described above, it is possible to provide a printer and a print system in which, when forming temperature-sensitive ink images on a medium, trouble is hardly caused due to the color change of a temperature-sensitive ink. 
     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, or 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 printers, print systems and printing methods 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.