Patent Publication Number: US-2005122489-A1

Title: Printing medium

Description:
BACKGROUND  
      The present invention relates to a printing medium.  
      Conventionally, as a three-dimensional image, it has been widely known that a plurality of images shot from a plurality of directions are synthesized in a stripe, and parallax images recorded on a backside of a lenticular sheet (printing medium), where a plurality of cylindrical aspherical lenses is arranged on a surface, are transmitted from the surface side of the lenticular sheet through the cylindrical aspherical lens of the lenticular sheet and viewed with left and right eyes, so that the images are seen in three dimension.  
      In addition to the above-mentioned three-dimensional image, when the plurality of different images is converted into parallax images and recorded according to an observation direction, different images can be viewed according to a direction to be viewed.  
      Further, in addition to the above-mentioned lenticular sheet, the three-dimensional image can be obtained by using a so-called integral photography that uses a plurality of convex lenses (fly-eye lens) arranged in a planar shape.  
      Such three-dimensional images are obtained by arranging parallax images at positions corresponding to each of the plurality of lenses made of the cylindrical aspherical lens or fly-eye lens, so that it has a merit that special glasses such as glasses having different color for two eyes are not required.  
      However, in the case in which the position relationship of the parallax images to the plurality of lenses is not exact, left and right eyes observes different three-dimensional images of parallax images. As a result, the three-dimensional image or image may not be exactly viewed. For this reason, a technology for printing parallax images in the precise position relationship with the plurality of lenses has been suggested (for example, see Patent Documents 1 and 2).  
      [Patent Document 1] Japanese Unexamined Patent Application Publication No. 7-281327.  
      [Patent Document 2] Japanese Patent No. 3420394.  
      In the Patent Document 1, a backside of the lenticular lens is formed in a convex curve shape in the same pitch as that of the arrangement of the cylindrical aspherical lens (hereinafter, referred to as lenticular lens), and an ink absorption layer is formed at the backside thereof. Specifically, the parallax images are printed on the ink absorption layer of the lenticular lens and the position of the convex curve surface is detected by a sensor. As a result, a deviation factor of positions of the parallax images to the plurality of lenses is excluded so that the printing can be performed according to the precise position relationship.  
      In addition, in the Patent Document 2, a backside of the lenticular lens is provided with a rib in the same pitch as that of the arrangement of the lenticular lens and the inkjet recording layer for absorbing ink is formed in the backside thereof. Specifically, the parallax images are printed on the inkjet recording layer of the lenticular lens and position of the rib is detected by a sensor. As a result, a deviation factor of the parallax images to the plurality of lenses is excluded so that the printing can be performed in the precise position relationship.  
      However, for the direct printing of the lenticular sheet, there is a problem in that, even when the lenticular sheet made of a resin is coated with the ink absorption layer or the inkjet recording layer, the absorption of printed ink into the ink absorption layer etc. is not enough and the quality of parallax images is typically unsatisfactory.  
      Furthermore, when the print paper is used as a printed object to obtain the quality of the parallax images, the position of the parallax images with regard to the plurality of lenses becomes deviated. Therefore, the exact three-dimensional image or image may not be viewed.  
      In addition, the technology of adhering a protective sheet to the parallax images to protect the printed parallax image has been proposed. However, when the convex surface or the rib is formed as described in the above-mentioned Patent Document 1 and Patent Document 2, there are problems in that it is difficult to adhere the protective sheet to the print surface of the parallax image and the protective sheet is easily removed.  
      In addition, since the bask side of the lenticular lens is formed as the convex surface or the rib in both the above-mentioned Patent Document 1 and Patent Document 2, the its fabrication process is difficult due to its particular shape.  
     SUMMARY  
      The present invention has been achieved in view of the drawbacks inherent in the prior arts, and it is an object of the present invention to provide a printing medium capable of printing parallax images in a precise positional relationship to the lens, as well as improving the quality of the parallax images.  
      In addition, it is another object of the present invention to provide a printing medium capable of printing parallax images in a precise positional relation to the lens, and being easily fabricated to adhere a sheet that protects the parallax images on a print surface.  
      In order to achieve the objects, according to an aspect of the present invention, there is provided a printing medium having a print surface on which an image is printed and a surface on which lenses are arranged, the print image being viewed through the arranged lenses, wherein, at the time of printing, at least some of the arranged lenses are located at the print surface side.  
      Specifically, the printing medium of the present invention can print images based on a shape and an arrangement interval of each of the lenses arranged on the same side with the print surface. Therefore, the images can be printed at a precise position with regard to the lens. Further, after printing, the images printed at the precise position can be viewed through lens. Moreover, when the lens is arranged on the printed images, the printed images can be protected with the lens, so that the image quality can be improved. In addition, when the lens is arranged at a surface other than the print surface, since there is no arranged on the printed surface, the printed images are easily protected using a protecting member such as a protective sheet. Thus, the image quality is easily improved.  
      In addition, in order to achieve the objects, according to another aspect of the present invention, there is provided a printing medium comprising: a print base material having a print surface on which an image is printed; and a lens sheet, wherein a lens is arranged on one side of the lens sheet, a surface on which the print surface of the print base material is provided and a surface of the other side of the lens sheet are fixed to each other at least at a partial area, and in the case of printing an image on the print surface, at least a part of the print base material and at least a part of the lens sheet are relatively moved to expose the print surface.  
      In other words, another printing medium of the present invention has a lens sheet and a print base material having a print surface, respectively, so that the print ink is easily absorbed into the print surface, and the quality of the printed images can be easily improved.  
      In addition, when the images are printed on the print base material, at least a part of the print base material is moved relative to at least part of the lens sheet to expose the print surface. Therefore, the images can be printed on the print surface without interfering with the lens sheet.  
      In addition, the print base material and the lens sheet are fixed to the part of the region, so that their positional relationship is not changed before and after printing. Moreover, even when the exposed printed surface is covered again with the lens sheet, the relative positional relationship between the print base material and the lens sheet is not changed. As a result, the images can be printed with a precise positional relationship to the lens.  
      To achieve the above configuration, more specifically, a turning unit that moves the print base material relative to the lens sheet to expose the print surface may be provided, at least at one side of the print base material or the lens sheet.  
      According to this configuration, since the turning unit is provided on at least one of the print base material and the lens sheet, the print base material and the lens sheet can be relatively moved from the turning unit. Therefore, it is ensured that the print surface is exposed.  
      To achieve the above configuration, more specifically, the turning unit may be formed at the remaining area of the lens sheet, and may be a folding unit folded to one side of the lens sheet.  
      According to this configuration, the lens sheet can be folded from the folding unit provided in the remaining region of the lens sheet. As a result, when the images are printed on the print base material, the lens sheet is folded to expose the print surface, thereby printing the images. In addition, the print base material and the lens sheet are combined at the port of region, so that their positional relationship is not changed before and after printing. Moreover, the lens sheet, which was folded, is not changed in the positional relationship even when it is combined into the print base material. As a result, the images can be printed with the exact relationship to the image lens.  
      To achieve the above configuration, more specifically, the remaining area of the lens sheet may be divided by at least one cut, and the divided part of the lens sheet is fixed to the print base material.  
      According to this configuration, since the part of lens sheet is fixed to the print base material in advance, the print position of the images can be determined based on the arrangement of the lens of the portion of lens sheet when the images are printed on the print surface. As a result, the print position of the images and the position of the lens can be more exactly determined.  
      To achieve the above configuration, more specifically, the fixing of the lens sheet to the print base material at the partial area may be performed using a fixing unit.  
      According to this configuration, the fixing of the lens sheet to the print base material at the part of the area is performed using a fixing unit, so that the lens sheet can be easily fixed to the print base material.  
      To achieve the above configuration, more specifically, the fixing of the print base material to the portion of the lens sheet may be performed using a fixing member.  
      According to this configuration, the fixing of the print base material to the part of the lens sheet is performed using a fixing member, so that the portion of the lens sheet can be easily fixed to the print base material.  
      To achieve the above configuration, more specifically, one side of the lens sheet may comprise a fixing member.  
      According to this configuration, since the other surface of the lens sheet comprises a fixing member, the fixing of the lens sheet to the print base material can be easily performed.  
      In addition, since the print surface of the print base material does not comprise the fixing member, degradation in the quality of image printed on the print surface can be prevented.  
      To achieve the above configuration, more specifically, the print base material may comprise a fixing member at the edge of the print surface.  
      According to this configuration, since the print base material comprises the fixing member at the edge of the print surface, the fixing of the lens sheet to the print base material can be easily performed.  
      In addition, since the fixing member is arranged only at the edge of the print surface, the center portion of the print surface where most images are printed is not affected. Therefore, degradation in the quality of image printed on the print surface can be prevented.  
      To achieve the above configuration, more specifically, the fixing member may be made of a paste or double-sided tape.  
      According to this configuration, since the fixing member is made of the paste or double-sided tape, the fixing of the lens sheet to the print base material can be easily performed.  
      To achieve the above configuration, more specifically, the fixing of the lens sheet to the print base material at the partial area may be performed using a pin.  
      According to this configuration, since the fixing of the lens sheet to the print base material at the partial area is performed using a pin, the lens sheet can be tightly adhered to the print base material.  
      To achieve the above objects, there is provided a printing medium having one surface on which lenses are arranged and the other surface on which a planar-shaped print surface on which an image is printed is formed, wherein at least one folding unit is provided substantially perpendicular to the lenses and is thinner than other regions.  
      In other words, in the printing medium of the present invention, the side other than that where the print face is formed has a planar shape. Therefore, for example, a sheet protecting images printed on the print surface can be easily adhered. In addition, since the other side has the planar shape, it can be easily fabricated without a specific process. As a result, the printing medium having the other surface can also be easily fabricated.  
      By forming the folding unit substantially perpendicular to the lenses, the printing medium can be folded from the folding unit so that the lens of the folded printing medium becomes suitable to the print surface. As a result, the position of the images printed on the print surface can be determined based on the arrangement position and arrangement pitch of the lens, so that the images can be printed in a precise positional relation to the lens.  
      Here, a substantial perpendicular to the lenses refers to a substantial perpendicular to the longitudinal rectangular axis direction of the lenticular lens in the case of the lenticular lens, which is a cylindrical aspherical lens, and a substantial perpendicular to the straight line binding the center of each fly-eye lens in the case of the integral sheet on which the fly-eye lens is arranged.  
      To achieve the above configuration, more specifically, the folding unit may a cut opening toward the one side.  
      According to this configuration, the printing medium can be easily folded from the folding unit to the other side of the print surface, so that the lens of the folded printing medium is easily turned.  
      To achieve the above configuration, more specifically, a fixing member may be arranged to fix the other surface in at least a part of a region in which folded faces of the other surface oppose to each other when folded by the folding unit.  
      According to this configuration, since the fixing member is arranged at least at a part of the region, the printing medium folded from the folded back portion can be easily fixed. As a result, when the parallax images are printed on the print surface, the arrangement position and the arrangement pitch of the folded lens are easily measured so that the parallax images can be easily printed with a precise positional relationship to the lens.  
      To achieve the above configuration, more specifically, the fixing member may be a paste or double-sided tape.  
      According to this configuration, the paste or double-sided tape is used for the fixing member. At this time, since the particular process and method is not required in preparing the paste or double-sided tape on the one side, the printing medium can be easily fabricated. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is an exploded perspective view showing an example of a lenticular sheet according to a first embodiment of the present invention;  
       FIG. 2  is a plan view showing a lens sheet of the lenticular sheet shown in  FIG. 1 ;  
       FIG. 3  is a perspective view showing an example of the lenticular sheet shown in  FIG. 1 ;  
       FIG. 4  is an exploded perspective view showing a modified example of the lenticular sheet shown in  FIG. 1 ;  
       FIG. 5  is a cross sectional view showing a behavior of the lenticular sheet shown in  FIG. 1 ;  
       FIG. 6  is an exploded perspective view showing a modified example of the lenticular sheet shown in  FIG. 1 ;  
       FIG. 7  is a perspective view showing an example of a lenticular sheet according to a second embodiment of the present invention;  
       FIG. 8  is a perspective view of an example of the lenticular sheet shown in  FIG. 7 ; and  
       FIG. 9  is a cross sectional view for explaining a behavior of the lenticular sheet shown in  FIG. 9 . 
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS  
      A lenticular sheet according to a first embodiment of the present invention will now be described with reference to FIGS.  1  to  5 .  
       FIG. 1  is an exploded perspective view showing an example of a lenticular sheet according to a first embodiment of the present invention.  
      As shown in  FIG. 1 , a lenticular sheet (printing medium)  10  schematically comprises a print paper (print base material)  20  on which parallax images are printed, and a lens sheet  30  on which a plurality of lenticular lenses (lenses)  31 , i.e., a cylindrical aspherical lens (cylindrical lens), is formed.  
      The print paper  20  has a print surface  21  on which parallax images are printed using ink. As the print paper  20 , the well-known sheet used for printing, such as a photo paper and an OHP film, can be used.  
       FIG. 2  is a plan view of a lens sheet according to the present invention.  
      As shown in  FIGS. 1 and 2 , the lens sheet  30  has the plurality of lenticular lenses  31  provided almost over one side of the lens sheet in parallel or at the same interval in a longitudinal axis direction (in a direction of arrow A in  FIG. 1 ), and an attaching unit (a part of region)  32  arranged in a portion adjacent to the one side on which the lenticular lens  31  is not formed. The region where the lenticular lens  31  is formed can be divided into an observation lens sheet  34  at the center and detection lens sheets (a part of lens sheet)  35  at both sides of the observation lens sheet  34 , by two cuts  33  formed in a direction substantially perpendicular to the lenticular lens  31 . As a result, shapes, arrangement positions and arrangement pitches of the lenticular lenses  31  are equal to each other for the observation lens sheet  34  and the detection lens sheets  35 .  
      In addition, two cuts  33  may be provided as described above, or one cut  33  may be provided. In the latter case, the observation lens sheet  34  can be fabricated to have a large area so that the printable area of the parallax images for the lenticular sheet  10  can be made large.  
      A folding unit (turning unit)  36  is provided between the attaching unit  32  and the observation lens sheet  34  in substantially parallel to the lenticular lens  31  to fold back the observation lens sheet  34  into the side of the lenticular lens  31 .  
      Moreover, the surface of the one side of the attaching unit  32  may be formed with the lenticular lens  31  as described above, and may not be formed with the lenticular lens  31 . In this case, the lenticular lens  31  is easily fabricated so that the lenticular sheet  10  is also easily fabricated.  
      The surface of the other side of the lens sheet  30  where the lenticular lens  31  is not formed is formed in a planar shape so as to facilitate the close adherence to the print paper  20  and is provided with a double-sided tape (fixing member)  37  for attaching to the print paper  20 .  
      Further, as described above, the double-sided tape  37  may be prepared on the lens sheet  30  to adhere to the print paper  20 , and a paste instead of the double-sided tape  37  may be prepared on the lens sheet  30  to adhere to the print paper  20 . In addition, instead of arranging the double-sided tape  37  on the lens sheet  30 , the double-sided tape  37  may be provided around the edge of the print paper  20  as shown in  FIG. 4 , or alternatively, the paste may be provided around the edge of the print paper  20 . Since the paste or double-sided tape is provided only around the edge of the printing side, there is little influence on the center of the print surface where most images are printed. Therefore, degradation of the image quality can be prevented.  
       FIG. 3  is a perspective view of the lenticular sheet according to the present invention.  
      The print paper  20  is arranged such that the print surface  21  faces the lens sheet  30 , and the lens sheet  30  is arranged such that the surface of the other side where the lenticular lens  31  is not formed faces the print paper  20 .  
      As shown in  FIG. 1 , the print paper  20  and the lens sheet  30  are attached to the attaching unit  32  and the detection lens sheet  35 . The observation lens sheet  34  is folded from the folding unit  36  into the side of the lenticular lens  31 , as shown in  FIG. 3 , so that the central portion of the print surface  21  of the print paper  20  is exposed.  
      Next, a function of the lenticular sheet  10  having the above structure will be described.  
       FIG. 5  is a sectional view for explaining a method of printing the lenticular sheet according to the present invention.  
      The printing of the above-mentioned lenticular sheet  10  is performed as follows. First, in a state in which the print surface  21  is exposed by folding the observation lens sheet  34  of the lens sheet  30  toward the side of the lenticular lens  31  as shown in  FIG. 1 , the lenticular sheet  10  is set to a printing device  40  using an inkjet method as shown in  FIG. 5 .  
      Next, the printing device  40  detects an arranged position of the lenticular lens  31  of the detection lens sheet  35  at least at one side of the detection lens sheets  35  arranged at both sides of the print surface  21 , using a sensor  41  provided in the printing device  40 .  
      The printing device  40  prints parallax images on the print surface  21  with print ink, based on arrangement position information of the lenticular lens  31  detected by the sensor  41 .  
      When the parallax images are printed on the print surface  21 , the lenticular sheet  10  is removed from the printing device  40 . In addition, the observation lens sheet  34  of the lens sheet  30  folded toward the side of the lenticular lens  31  is unfolded to attach the printing side  21  to the observation lens sheet  34  of the lens sheet  30  using the double-sided tape  37  arranged at the lens sheet  30 . Therefore, the printing of the lenticular sheet  10  is ended.  
      According to the above-mentioned configuration, since the print paper  20  and the lens sheet  30  are respectively provided so as to print images, the printing ink is easily absorbed into the print surface  21  of the print paper  20 , and the image quality printed on the lenticular sheet  10  can be easily improved.  
      In addition, the print paper  20  and the lens sheet  30  are adhered to the attaching unit  32  so that the observation lens sheet  34  is folded toward the lenticular lens  31  from the folding unit  36 . As a result, when the parallax images are printed on the print paper  20 , the observation lens sheet  34  is folded to expose the print surface  21  as shown in  FIG. 3 , so that the parallax images can be printed on the print surface  21 .  
      In addition, since the print paper  20  and the lens sheet  30  are adhered to the attaching unit  32 , the positional relationship is not changed before and after printing the parallax images. Moreover, even when the observation lens sheet  34  is adhered to the print paper  20 , the positional relationship is not changed. As a result, the parallax images can be printed in a precise positional relationship to the lens sheet  30 .  
      Since the detection lens sheet  35  is previously adhered to the print paper  20 , the print position of the parallax images can be determined based on the lens arrangement of the detection lens sheet  35  when the parallax images are printed on the print surface  21 . As a result, the print position of the parallax image and the position of the lenticular lens  31  can be more accurately determined.  
      In the attaching unit  32 , the adhering of the print paper  20  to the lens sheet  30  is performed using the paste or double-sided tape  37 , so that the lens sheet  30  can be easily adhered to the print paper  20 . In addition, the adhering of the print paper  20  to the detection lens sheet  35  is performed using the paste or double-sided tape  37 , so that the print paper  20  can be easily adhered to the detection lens sheet  35 .  
      The surface where the lenticular lens  31  of the lens sheet  30  is not formed is provided with the paste or double-sided tape  37 , so that the adhering of the print paper  20  to the lens sheet  30  can be easily performed. In addition, since the print surface  21  of the print paper  20  is not provided with the paste or double-sided tape  37 , degradation in the quality of image printed on the print surface  21  can be prevented.  
      The detection lens sheets  35  are arranged at both sides of the print surface  21 , so that when the parallax images are printed on the print surface  21 , the arrangement position and the arrangement pitch of the lenticular lens  31  can be detected from both sides of the detection lens sheets  35 . As a result, the print can be started from both sides of the detection lens sheets  35 , thereby improving the print speed.  
      Moreover, in the attaching unit  32 , the adhering of the print paper  20  to the lens sheet  30  may be performed using the paste or double-sided tape as described above. In addition, in the attaching unit  32 , the adhering of the print paper  20  to the lens sheet  30  may be performed using pins  51  as shown in  FIG. 6 . In this case, the adhesive strength of the print paper  20  to the lens sheet  30  is improved, so that until the parallax images are completely printed on the print paper  20 , the removing of the lens sheet  30  from the print paper  20  can be effectively prevented.  
      Moreover, the present invention is not limited to the above-mentioned embodiment, and a variety of modification can be made without departing from the spirit of the present invention.  
      For example, while, in the above-mentioned embodiment, the lenticular lens  31  is arranged as the lens sheet  30 , the present invention is not limited to the above-mentioned embodiment in which the lenticular lens  31  is arranged as the lens sheet  30 . A fly-eye lens and other various lenses may be used as the lens sheet.  
      Next, a lenticular sheet according to a second embodiment of the present invention will now be described with reference to FIGS.  7  to  9 .  
       FIG. 7  is a perspective view of a lenticular sheet according to a second embodiment of the present invention as viewed from a backside.  
      As shown in  FIG. 7 , a lenticular sheet (printing medium)  110  comprises a plurality of lenticular lenses (lenses)  131  which are cylindrical aspherical lenses (cylindrical lens) on a surface of one side, and a print surface  121  made of an ink absorption layer on a surface of the other side. The lenticular lenses  131  are arranged parallel or at the same interval in a longitudinal axis direction (in a direction of arrow A in  FIG. 7 ).  
      The lenticular sheet  110  is provided with folding units  133  formed in substantially parallel to each other, as two cuts opening toward the side of the lenticular lens  131 , and the folding units  133  are formed so as to extend in a direction (in a direction of arrow B in  FIG. 7 ) substantially perpendicular to the longitudinal axis direction of the lenticular lenses  131 . By using two folding units  133 , the lenticular sheet  110  can be divided into an observation lenticular sheet  134  at the center and detection lenticular sheets  134  at both sides. As a result, for the observation lenticular sheet  134  and the detection lenticular sheets  135 , a shape, an arrangement position and an arrangement pitch of the lenticular lens  131  are equal to each other.  
      Moreover, the two folding units  133  may be provided as described above, or alternatively, only one folding unit  133  may be provided. In the latter case, the observation lenticular sheet  134  can be fabricated with a large area so that the printable area of the parallax images for the lenticular sheet  110  can be made large.  
       FIG. 8 ( a ) is a perspective view of the lenticular sheet folded from the folding units, and  FIG. 8 ( b ) is a perspective view of the lenticular sheet folded from the folding unit as viewed from a backside.  
      Since the folding unit  133  opens toward the side of the lenticular lens  131 , the detection lenticular sheet  135  can be folded back around the print surface  121  of the observation lenticular sheet  134  in reference to the folding unit  133 , as shown in FIGS.  8 ( a ) and  8 ( b ).  
      Moreover, as described above, the detection lenticular sheet  135  may be folded around the print surface  121  of the observation lenticular sheet  134 , or alternatively, by arranging adhesion such as a paste or double-sided tape (fixing member) on at least at the portion of the area where the detection lenticular sheet  135  and the print surface  121  of the observation lenticular sheet  134  overlap, the folded detection lenticular sheet  135  may be adhered to the print surface  121  of the observation lenticular sheet  134 .  
      Next, a function of the lenticular sheet  110  having the above-mentioned configuration will be described.  
       FIG. 9  is a sectional view for explaining a method of printing the lenticular sheet according to the present invention. The printing of the above-mentioned lenticular sheet  110  is performed as follows. First, in a state in which the print surface  121  of the observation lenticular sheet  134  faces upward by folding the detection lenticular sheet  135  toward the print surface  121  of the observation lenticular sheet  134  as shown in FIGS.  8 ( a ) and  8 ( b ), the lenticular sheet  110  is set to a printing device  140  using an inkjet method, as shown in  FIG. 9 .  
      Next, the printing device  140  detects an arranged position of the lenticular lens  131  of the detection lenticular sheet  135  at least at one side of the detection lenticular sheets  135  arranged at both sides of the print surface  121 , using a sensor  141  provided in the printing device  140 .  
      The printing device  140  prints parallax images on the print surface  121  with printing ink, based on arrangement position information of the lenticular lens  131  detected by the sensor  141 .  
      When the parallax images are printed on the print surface  121 , the lenticular sheet  110  is removed from the printing device  140 . Therefore, the printing of the lenticular sheet  110  is ended.  
      Next, the detection lenticular sheet  135  folded along the print surface  121  of the observation lenticular sheet  134  extends again or is cut, and the print surface  121  is provided in a planar shape, and then, a protective sheet for protecting the parallax images may be adhered to the print surface  121 , and a protective layer can be formed through a process of depositing and drying a liquid protective material. In addition, when the detection lenticular sheet  135  is adhered using the paste or double-sided tape, the protective sheet may be adhered only to the exposed print surface  121 , or alternatively, the protective sheet may be adhered after removing the area where the paste or double-sided tape is attached.  
      According to the above-mentioned configuration, since the surface where the print surface  121  is formed has a planar shape, the protective layer (protective sheet), for example, can be easily adhered to the print surface  121  to protect the printed parallax images. In addition, since the print surface  121  has a planar shape, it can be easily fabricated without necessitating a particular process or method of forming the print surface  121 . As a result, the lenticular sheet  110  having the print surface  121  can be easily fabricated.  
      The folding unit  133  that is substantially perpendicular to the lenticular lens  131  is provided. As a result, the detection lenticular sheet  135  can be folded from the folding unit  133  and the lenticular lens  131  of the folded detection lenticular sheet  135  faces to the print surface  121  of the observation lenticular sheet  134 . As a result, the position of the parallax images printed on the print surface  121  can be determined based on the arrangement position and arrangement pitch of the lenticular lens  131  in the detection lenticular sheet  135 , so that the parallax images can be printed with a precise position relationship to the lenticular lens  131 .  
      Since the detection lenticular sheets  135  are arranged at both side of the print surface  121 , the arrangement position and the arrangement pitch of the lenticular lens  131  can be detected from both detection lenticular sheets  135  when the parallax images are printed on the print surface  121 . For this reason, the printing can be started from both detection lenticular sheets  135 , so that the print speed can be improved.  
      Moreover, the scope of the present invention is not limited to the above-mentioned embodiments, and a variety of modifications can be made without departing from the spirit of the present invention.  
      For example, while the above-mentioned embodiments has been described with reference to the lenticular sheet  110  on which the lenticular lens  131  are arranged, the present invention is not limited to the above-mentioned embodiments that the lenticular sheet  110  is used. Therefore, an integral sheet having a fly-eye lens and other lens sheets using various lenses can be also applied.