Laser recording medium

Abstract

To provide a laser recording medium having a variable information recording part formed by disposing a lenticular lens on a laser sensitive layer, having a constitution capable of easily improving separability of a strip-shaped fragment image recorded on the variable information recording part.SOLUTION: In a variable information recording part 2, a laser sensitive layer 11 is joined with a surface of a base material layer 10, and the base material layer 10 is constituted so as to transmit a laser beam for recording. In such a constitution, the laser beam for recording is not reflected on an interface of the laser sensitive layer 11 and the base material layer 10, and only a portion where the laser sensitive layer 11 is directly irradiated with the laser beam for recording is made to become colored. Thus, compared to a conventional constitution, the strip-shaped fragment image can be recorded with high definition, and the separability of adjacent strip-shaped fragment images can be improved.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a laser recording medium on which characters and images can be recorded by using a laser beam. [Background technology]

[0002] Laser recording media that record characters and images using laser light are used for identification cards, etc., because the recorded information is difficult to erase and has excellent anti-tampering properties. Among such laser recording media, there have been proposals for recording variable information, called MLI (Multiple Laser Image) and CLI (Changeable Laser Image), which change depending on the viewing angle, using laser light (for example, Patent Document 1).

[0003] Specifically, in the variable information recording section for recording the variable information, a lenticular lens is disposed on the laser-sensitive layer. The lenticular lens is in the form of a sheet made up of a plurality of elongated convex lenses arranged side by side. Then, when a plurality of images constituting the variable information are subdivided into elongated rectangular fragmentary images and recorded on the laser-sensitive layer below the lenticular lens, the action of the lenticular lens allows one of the images to be viewed when viewed from a certain angle, and another image to be viewed when viewed from another angle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2008-537244 Summary of the Invention [Problem to be solved by the invention]

[0005] In the variable information recording section described in the above Patent Document 1, the more clearly the boundaries between adjacent rectangular fragment images are recorded and the more the separability of the two images is improved, the faster the images can be switched in response to changes in viewing angle. Also, by improving the separability of adjacent rectangular fragment images, the rectangular fragment images can be made finer, making it easier to increase the number of images recorded in the variable information recording section. However, there is a high cost burden and technical limitations in recording the rectangular fragment images in high resolution using a high-performance laser recording device.

[0006] The present invention has been made in consideration of the current situation, and aims to provide a configuration for a laser recording medium having a variable information recording section formed by arranging a lenticular lens on a laser-sensitive layer, which can easily improve the separability of the rectangular fragmented images recorded in the variable information recording section. [Means for solving the problem]

[0007] The inventor, after intensive research to solve the above problems, discovered that when recording to the variable information recording section, a part of the recording laser light that is obliquely irradiated to the laser sensitive layer is not completely absorbed by the laser sensitive layer, and a part of it is reflected at the interface with the base layer, causing the peripheral area of ​​the area directly irradiated with the recording laser light to develop color. Based on this knowledge, the inventor then completed the present invention after repeated trial and error.

[0008] That is, the present invention is a sheet-shaped laser recording medium configured to record information by irradiating a recording laser light in a predetermined wavelength region, comprising a base layer and a laser-sensitive layer disposed on the base layer and absorbing the recording laser light to develop color, a lenticular lens disposed on the laser-sensitive layer, and a variable information recording section capable of recording variable information that changes depending on the viewing angle by irradiating the recording laser light, wherein in the variable information recording section, the laser-sensitive layer is bonded to the surface of the base layer, and the base layer is configured to be transparent to the recording laser light.

[0009] In this configuration, reflection of the recording laser light at the interface between the laser sensitive layer and the base layer is suppressed, and the color-developing portion of the laser sensitive layer is limited to the portion directly irradiated with the recording laser light, so that it is possible to record a strip-shaped fragment image with higher resolution than in the conventional configuration, and the separation of adjacent strip-shaped fragment images can be improved. In particular, the present invention has the advantage that it can be easily realized without changing the configuration of the laser recording device. The base layer according to the present invention is not limited to one having a transmittance of approximately 100% for the recording laser light. Even if the transmittance of the recording laser light is not 100%, the effect of reducing the reflection of the recording laser light at the interface between the laser sensitive layer and the base layer can be expected compared to the conventional configuration. According to the inventor's research, as long as the base layer transmits at least 60% or more of the recording laser light, it is possible to record a strip-shaped fragmented image with higher resolution compared to the conventional configuration.

[0010] As a specific configuration of the present invention, a configuration is proposed in which a lenticular lens is not provided, and a fixed information recording section is provided in which information can be recorded by irradiating the recording laser light, the base layer is transparent or translucent, the fixed information recording section has a light-opaque printing layer formed on the surface of the base layer, and the laser-sensitive layer is disposed on the printing layer, and the variable information recording section does not have the printing layer formed, and the laser-sensitive layer is bonded to the surface of the base layer.

[0011] With this configuration, a laser recording medium having a fixed information recording section and a variable information recording section can be suitably realized while using a relatively inexpensive transparent or semi-transparent resin sheet as the base layer.

[0012] As another aspect of the present invention, a sheet-like laser recording medium configured to record information by irradiation with a recording laser light in a predetermined wavelength region is proposed, comprising a base layer and a laser-sensitive layer disposed on the base layer and absorbing the recording laser light to develop a color, a lenticular lens is disposed on the laser-sensitive layer, and the laser-sensitive layer is equipped with a variable information recording section capable of recording variable information that changes depending on the viewing angle by irradiation with the recording laser light, and a fixed information recording section not equipped with a lenticular lens and capable of recording information by irradiation with laser light in the predetermined wavelength region, characterized in that in the variable information recording section, the laser-sensitive layer is not supported from the back side, and an air gap is formed on the back side of the laser-sensitive layer.

[0013] Even in the case where, as in this configuration, the laser-sensitive layer in the variable information recording section is not supported by the base layer and there is a gap on the back side of the laser-sensitive layer, the recording laser light is not reflected at the interface between the laser-sensitive layer and the base layer, so that it is possible to improve the separation of adjacent rectangular fragment images without changing the configuration of the laser recording device. Effect of the Invention

[0014] As described above, according to the present invention, it is possible to record strip-shaped fragment images with higher resolution than conventional methods in the variable information recording section without changing the configuration of the laser recording device, thereby making it possible to easily improve the separability of adjacent strip-shaped fragment images. [Brief description of the drawings]

[0015] [Figure 1] 1A is a front view of the laser recording medium 1 of Example 1, and FIG. 1B is a front view of an identification card 100 issued using the laser recording medium 1. FIG. [Diagram 2] 1B is an explanatory diagram showing the variable information visible when viewed from the front and the variable information visible when viewed from below. FIG. [Diagram 3] 1 is an explanatory diagram showing a layer structure of a laser recording medium 1 of Example 1. FIG. [Figure 4] FIG. 11 is an explanatory diagram showing a method for recording variable information. [Diagram 5] 1 is an explanatory diagram showing a recording mode of variable information in a conventional configuration and a recording mode of variable information in the first embodiment. FIG. [Figure 6] FIG. 11 is an explanatory diagram showing a layer structure of a laser recording medium 1a of Example 2. [Figure 7] FIG. 11 is an explanatory diagram showing a layer structure of a laser recording medium 1b of Example 3. [Figure 8] FIG. 11 is an explanatory diagram showing a layer structure of a laser recording medium 1c of Example 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Embodiments of the present invention are illustrated by the following examples. EXAMPLES

[0017] The laser recording medium 1 of this embodiment is a sheet-like identification paper used for issuing a card-type identification card. As shown in FIG. 1(A), characters, borders, and background patterns (not shown) are pre-printed on the front side of the laser recording medium 1. The front side of the laser recording medium 1 is configured so that characters and images can be recorded by irradiating a recording laser light in a predetermined wavelength range, and as shown in FIG. 1(B), an identification card 100 is issued by recording a facial image and attribute information of a person to be identified by the recording laser light. Although not shown, the back side of the laser recording medium 1 is blank and configured so that it is difficult to record information with the recording laser light.

[0018] The front side of the laser recording medium 1 is made up of a variable information recording section 2 capable of recording variable information that changes depending on the viewing angle by a recording laser beam, and a fixed information recording section 3 capable of recording information that does not change depending on the viewing angle. Specifically, as shown in Fig. 1(A), the variable information recording section 2 is a relatively narrow rectangular area provided in the lower center of the laser recording medium 1, and the part excluding the variable information recording section 2 is the fixed information recording section 3.

[0019] A lenticular lens 4 is disposed on the surface of the variable information recording section 2. The lenticular lens 4 is in the form of a sheet with a plurality of elongated convex lenses arranged side by side on the front side, and variable information that changes depending on the viewing angle can be recorded by the action of the lenticular lens 4. For example, FIG. 1B shows an example of an identification card 100 issued using the laser recording medium 1 of this embodiment, and in this identification card 100, the surname (Kobayashi) and face image of the person to be certified are recorded as variable information in the variable information recording section 2. Specifically, the convex lens of the lenticular lens has an elongated shape extending horizontally, and when the variable information recording section 2 is viewed from approximately the front as shown in FIG. 2A, the face image of the person to be certified is visible, and when the variable information recording section 2 is tilted and viewed from diagonally above or below as shown in FIG. 2B, the surname (here, "Kobayashi") of the person to be certified can be recorded so that it can be viewed. The variable information recording section 2 is transparent, and the variable information is recorded in black in the variable information recording section 2 by the recording laser light.

[0020] The surface of the fixed information recording section 3 is flat without the lenticular lens 4. Therefore, the information recorded in the fixed information recording section 3 by the recording laser light does not change depending on the viewing angle. The face image and attribute information of the person to be certified are recorded in the fixed information recording section 3 when the identification card is issued. Specifically, the fixed information recording section 3 includes a face image recording section 5 for recording the face image of the person to be certified, and a character information recording section 6 for recording and displaying the attribute information of the person to be certified. The face image recording section 5 is a plain white rectangular area, and is configured to record the face image of the person to be certified in monochrome by the recording laser light when the identification card is issued, as shown in FIG. 1(B). The character information recording section 6 has the item names of the attribute information pre-printed on it, as shown in FIG. 1(A), and the attribute information is recorded in black characters by the recording laser light when the identification card is issued, as shown in FIG. 1(B). Although not shown in FIG. 1, a background pattern having an anti-counterfeiting effect is printed on the fixed information recording section 3 in the area other than the face image recording section 5.

[0021] 3 shows the layer structure of the laser recording medium 1. The laser recording medium 1 includes a transparent substrate layer 10 and a transparent laser-sensitive layer 11 disposed on the substrate layer 10.

[0022] The substrate layer 10 is a layer that is the base of the laser recording medium 1, and is made of a resin sheet that is thicker than the laser sensitive layer 11 and the coating layer 12. The substrate layer 10 may be a single sheet, or may be made by laminating a plurality of sheets. Materials that constitute the substrate layer 10 include polyvinyl chloride (PVC), glycol-modified polyethylene terephthalate (PETG), polyethylene terephthalate (PET), polypropylene (PP), polycarbonate (PC), and the like. The substrate layer 10 may have a strength according to the application of the laser recording medium 1, and the thickness thereof can be freely set. The substrate layer 10 is transparent, and also transmits a recording laser beam. Specifically, the laser recording medium 1 of this embodiment uses a laser beam in the near infrared region as the recording laser beam, and the substrate layer 10 is configured to transmit light in the visible region and the near infrared region.

[0023] As shown in FIG. 3, opaque printed layers 14, 15 are formed on the surface of the base layer 10. The printed layers 14, 15 are composed of a base printed layer 14 formed on the surface of the base layer 10 and a decorative printed layer 15 printed on the base printed layer 14. The base printed layer 14 is an opaque white-out print using white ink that forms the background of the decorative printed layer 15, and is formed over the entire area of ​​the fixed information recording section 3. The decorative printed layer 15 forms the characters, frame lines, and background pattern of the fixed information recording section 3. The printed layers 14, 15 are formed only on the fixed information recording section 3 and not on the variable information recording section 2, so that the fixed information recording section 3 is opaque and the variable information recording section 2 is transparent.

[0024] The laser sensitive layer 11 is a layer made of a transparent resin sheet, and absorbs the irradiated recording laser light and turns black due to carbonization of the resin. The composition of the laser sensitive layer 11 includes a composition consisting of a photothermal conversion agent that absorbs the recording laser light and generates heat, and a resin that is carbonized by the heat generated by the photothermal conversion agent. Such a composition can be widely adopted from known compositions. As shown in FIG. 3, the laser sensitive layer 11 is bonded to the surface of the base layer 10 in the variable information recording section 2, and is bonded to the surfaces of the printing layers 14, 15 in the fixed information recording section 3. The thickness of the laser sensitive layer 11 is not particularly limited, and it is sufficient if it is thick enough to clearly record information in black. The laser sensitive layer 11 is not limited to a resin sheet, and may be coated on the surface of the base layer 10.

[0025] As shown in FIG. 3, the fixed information recording section 3 has a transparent covering layer 12 provided on a laser sensitive layer 11. The covering layer 12 is a layer made of a resin sheet, and is provided for the purpose of preventing damage or deterioration of the laser sensitive layer 11 and falsification of the recorded information. The covering layer 12 is made of a substantially transparent material that transmits the recording laser light and allows the recorded information to be visually recognized. The covering layer 12 can be suitably made of a material that is impermeable to water and air. Examples of materials that constitute the covering layer 12 include polyvinyl chloride (PVC), glycol-modified polyethylene terephthalate (PETG), polyethylene terephthalate (PET), polypropylene (PP), polycarbonate (PC), and the like. The thickness of the covering layer is not particularly limited, but is preferably about 10 μm to 100 μm.

[0026] As shown in FIG. 3, in the variable information recording section 2, a transparent lenticular lens 4 is disposed on a laser-sensitive layer 11. The lenticular lens 4 is in the form of a sheet in which a plurality of elongated convex lenses 8 are arranged side by side, and variable information that changes depending on the viewing angle can be recorded in the laser-sensitive layer by irradiation with a recording laser beam. The lenticular lens 4 is provided integrally with the cover layer 12. That is, the lenticular lens 4 and the cover layer 12 are formed of a common resin sheet in which the convex lenses 8 are formed only in the variable information recording section 2. The lenticular lens 4 can be made of a wide variety of known shapes and materials. The lenticular lens 4 may not be integral with the cover layer 12, but may be formed of a resin sheet separate from the cover layer 12.

[0027] The laser recording medium 1 of this embodiment can be manufactured, for example, by sequentially carrying out the following steps (1) to (3). (1) The base printing layer 14 and the decorative printing layer 15 are printed on the resin sheet constituting the substrate layer 10. (2) The resin sheet constituting the base layer 10, the resin sheet constituting the laser sensitive layer 11, and the resin sheets constituting the cover layer 12 and the lenticular lens 4 are laminated and integrally bonded by thermocompression bonding. (3) The joined resin sheets are punched out to the size of the laser recording medium 1.

[0028] The laser recording medium 1 of this embodiment can issue an identification card by using a known laser recording device used for issuing identification cards and the like. Specifically, the laser recording device irradiates the variable information recording section 2 and the fixed information recording section 3 with a recording laser beam to cause the laser sensitive layer 11 to develop a color, thereby recording the certification information of the person to be certified and the like. Here, a strip-shaped fragment image of variable information is recorded in the variable information recording section 2 under the convex lens 8 of the lenticular lens 4. Specifically, as shown in FIG. 4, a strip-shaped fragment image C1 in which the face image of the person to be certified is fragmented into elongated pieces is recorded in a portion of the variable information recording section 2 that is visible from approximately the front, and a strip-shaped fragment image C2 in which the surname of the person to be certified ("Kobayashi") is fragmented into elongated pieces is recorded in a portion that is visible when the variable information recording section 2 is tilted up and down. Here, when recording variable information in the variable information recording section 2, the recording laser light is refracted by the lenticular lens 4, and therefore, as shown in Figures 4(A) and 4(B), the angle at which the recording laser light is irradiated is changed according to the recording portion of the laser sensitive layer 11. The variable information recording method and the laser recording device are well known techniques, and therefore detailed explanations are omitted here.

[0029] The essential configuration of the present invention will be described below. 4, the recording laser light irradiated to the laser sensitive layer 11 is absorbed by the laser sensitive layer 11, causing the laser sensitive layer 11 to develop a black color. However, since the laser sensitive layer 11 is thin, the recording laser light is not completely absorbed by the laser sensitive layer 11, and a part of the recording laser light reaches the interface with the base layer 10.

[0030] In the case of the conventional configuration, the base layer reflects the recording laser light, so that the recording laser light that reaches the interface with the base layer is reflected by the surface of the base layer and re-enters the laser-sensitive layer, as shown in Fig. 5(A). Therefore, in the conventional configuration, the reflected recording laser light causes the laser-sensitive layer to develop color up to the periphery of the area directly irradiated with the recording laser light.

[0031] In contrast, in this embodiment, the base layer transmits the recording laser light, so that the recording laser light that reaches the interface with the base layer does not reflect at the interface, but enters the base layer and is transmitted to the back side of the base layer, as shown in Fig. 5(B). Therefore, in this embodiment, the color-developing portion of the laser-sensitive layer is limited to the portion directly irradiated with the recording laser light.

[0032] Thus, in the conventional configuration, the laser sensitive layer develops color not only in the area directly irradiated with the recording laser light, but also in the area that absorbs the recording laser light reflected from the substrate layer surface, whereas in this embodiment, the recording laser light is not reflected from the substrate layer surface, and the coloring area of ​​the laser sensitive layer is limited to the area directly irradiated with the recording laser light. Therefore, the variable information recording unit according to this embodiment can record a strip-shaped fragment image with higher resolution than the conventional configuration. In addition, the substrate layer 10 according to this embodiment transmits the recording laser light to the back side, so even if it does not reflect the recording laser light, it will not discolor or deteriorate due to the recording laser light.

[0033] As described above, the laser recording medium 1 of this embodiment can record the rectangular fragment image in the variable information recording section 2 with higher resolution than the conventional configuration, even when the recording laser light is irradiated to the variable information recording section 2 in the same manner. Therefore, the boundary between the rectangular fragment images C1 and C2 recorded adjacent to each other can be made clearer than before, and the separability of both images C1 and C2 can be improved. Therefore, according to this embodiment, variable information that quickly switches depending on the viewing angle can be recorded more easily than the conventional configuration. And if the switching of the variable information is clear, not only is the design improved, but it also becomes easier to determine the authenticity of the variable information by mechanically reading it. Also, the improved separability of the rectangular fragment images makes it easier to record more variable information in the variable information recording section 2.

[0034] Furthermore, as in this embodiment, by forming opaque printed layers 14, 15 on the surface of the base layer 10 made of a transparent resin sheet in the fixed information recording section 3, it is possible to produce an identification card paper having a transparent variable information recording section 2 and an opaque fixed information recording section 3 at a relatively low cost.

[0035] <Evaluation test> A laser recording medium having the layer structure of Example 1 was produced as a test sample. The base layer was made of a transparent PET-G film that transmits laser light in the near-infrared region. The laser sensitive layer was made of a transparent PET-G film that contains a photothermal conversion agent and absorbs laser light in the near-infrared region to develop a black color. The base layer had a thickness of 560 μm, and the laser sensitive layer had a thickness of 100 μm. The base layer and the laser sensitive layer were bonded by thermocompression bonding.

[0036] A laser recording medium having the same structure as the test sample, except that the base layer was made of a white PET-G film that reflects laser light in the near infrared region, was prepared as a comparative sample.

[0037] The variable information recording area of ​​the test product and the comparison product were irradiated with recording laser light under the same conditions to print information (numbers) consisting of rectangular fragment images in black. The recording laser light used was near-infrared laser light (wavelength 1064 nm) that was transmitted through the base layer of the test product and reflected by the base layer of the comparison product. The recording laser light was irradiated from a direction tilted 15° upward from the direction perpendicular to the variable information recording area.

[0038] The visual visibility of the information printed on the variable information recording section of the test product and the comparative product was evaluated by changing the viewing angle up and down. As a result, in both the test product and the comparative product, when viewed from the vicinity of the irradiation direction of the recording laser light, the printed information was clearly visible with the same density. In both the test product and the comparative product, the visible printed information gradually became faint and unclear as the viewing direction was tilted up and down from the irradiation direction of the recording laser light. This is because the visibility of the strip-shaped fragment image changes due to the action of the lenticular lens. Here, in the test product, the printed information became so faint that it was difficult to view it at the stage of tilting 40° from the irradiation direction of the recording laser light, and the printed information became invisible at the stage of tilting 45°. In contrast, in the comparative product, the printed information maintained a visible density even at the stage of tilting 45° from the irradiation direction of the recording laser light. This result suggests that it is easier to form a strip-shaped fragment image with a narrower visible angle range in the variable information recording section in the test product than in the comparative product.

[0039] The test product and the comparative product were cut into the variable information recording section after printing the information, and the cross section was observed under a microscope. As a result, in both the test product and the comparative product, a black colored part extending in the direction of irradiation of the recording laser light was observed on the cross section of the laser sensitive layer. Such a colored part is considered to be a part that absorbed the recording laser light and was carbonized. Here, in the laser sensitive layer of the comparative product, the above-mentioned black colored part expanded so as to bleed near the interface with the base layer. Such an expansion was not observed in the colored part of the laser sensitive layer of the test product. It is considered that the expansion of such a colored part was caused by the recording laser light reflected near the interface with the base layer being absorbed by the peripheral part. And, due to the expansion of such a colored part, it is considered that the angle range in which the strip-shaped fragment image can be viewed is wider in the comparative product than in the test product.

[0040] Examples 2 to 4 described below are modifications of Example 1 above, in which the layer structure of the laser recording medium 1 is changed. Since many of the configurations are common to Example 1, common reference numerals are used in the text and drawings for the common configurations, and detailed descriptions thereof will be omitted. EXAMPLES

[0041] In the above-mentioned Example 1, the base layer 10 is exposed on the back side of the laser recording medium 1, whereas in the laser recording medium 1a of this example, as shown in FIG. 6, opaque printed layers 14a, 15a are formed on the back side of the base layer 10, and further, a transparent covering layer 12a is provided so as to cover the entire back side of the base layer 10. The printed layers 14a, 15a are composed of a base printed layer 14a similar to the front side, and a decorative printed layer 15a composed of an arbitrary pattern or information. The covering layer 12a is composed of the same transparent resin sheet as the covering layer 12 on the front side. The back side of the variable information recording section 2 is not formed with a lenticular lens or printed layers 14a, 15a, and is covered with a flat covering layer 12a.

[0042] In this embodiment, the back side of the base layer 10 is covered with the covering layer 12a, which has the advantage of protecting the back side of the base layer 10. Note that the covering layer 12a transmits recording laser light, so variable information can be recorded in the variable information recording section 2 as in embodiment 1. In addition, this embodiment has an advantage that the layer structure is closer to being symmetrical on the front and back than in embodiment 1, which reduces warping of the laser recording medium 1a. EXAMPLES

[0043] This embodiment is characterized in that a fixed information recording section 3b is also provided on the back side of the base layer 10. Specifically, as shown in FIG. 7, in the laser recording medium 1b of this embodiment, opaque printed layers 14b and 15b are formed on the entire back side of the base layer 10, a laser sensitive layer 11b is provided on the printed layers 14b and 15b, and a covering layer 12b is provided so as to cover the laser sensitive layer 11b. As a result, the entire back side of the laser recording medium 1b becomes the fixed information recording section 3b, and information can be recorded on the back side of the laser recording medium 1b by irradiating the recording laser light. The printed layers 14b and 15b are composed of a base printed layer 14b similar to the front side, and a decorative printed layer 15b consisting of an arbitrary pattern or information. The laser sensitive layer 11b is the same as the laser sensitive layer 11 on the front side. The covering layer 12b is made of the same transparent resin sheet as the covering layer 12 on the front side, and no lenticular lens is provided.

[0044] As in this embodiment, the laser recording medium of the present invention may have a variable information recording section and a fixed information recording section disposed on the back side as well. Compared to embodiment 1, this embodiment has the advantage that information can be recorded on the back side with a recording laser beam. In addition, since the layer structure is closer to being symmetrical on the front and back sides, it also has the advantage that warping of the laser recording medium 1a can be reduced. In this embodiment, an opaque base print layer 14b is formed on the back side of the variable information recording section 2, so that the variable information recording section 2 is opaque (white) when viewed from the front side. EXAMPLES

[0045] This embodiment is characterized in that the laser sensitive layer 11 is not supported from the back side in the variable information recording section 2, and a gap 16 is formed on the back side of the laser sensitive layer 11. Specifically, as shown in FIG. 8, in the laser recording medium 1c of this embodiment, the base layer 10c is hollowed out and missing in the variable information recording section 2, and thus a gap 16 is formed on the back side of the laser sensitive layer 11. In this configuration, since nothing is bonded to the back side of the laser sensitive layer 11 in the variable information recording section 2, a part of the recording laser light that is irradiated to the variable information recording section 2 and transmitted through the laser sensitive layer 11 enters the gap 16 without being reflected, and is transmitted to the back side of the laser recording medium 1c. Therefore, even in the configuration of this embodiment, similar to the first embodiment, a strip-shaped fragment image can be recorded in the variable information recording section 2 with high resolution, and the separation of adjacent strip-shaped fragment images can be improved.

[0046] In addition, in this embodiment, since the base material layer 10c is absent in the variable information recording section 2, the base material layer 10c does not need to be able to transmit the recording laser light. Therefore, the base material layer 10c in this embodiment is formed of a white resin sheet, not a transparent resin sheet. Therefore, in this embodiment, in the fixed information recording section 3, a white-painted base print is not formed on the surface of the base material layer 10c, and only the decorative print layer 15 is formed. In this way, if the base material layer 10c is made of a white material, it is not necessary to form a base print layer on the base material layer 10c.

[0047] Although examples of the present invention have been described above, the embodiment of the present invention is not limited to the configurations of the above examples, and can be appropriately modified within the scope of the present invention.

[0048] For example, the laser recording medium 1 in the above embodiment is a card-type identification paper, but may be a booklet-type identification. The present invention is not limited to identification paper, and may be applied to any laser recording medium having a variable information recording section using a lenticular lens. The laser recording medium of the present invention may have an IC chip or the like embedded in the base layer.

[0049] Moreover, the laser recording medium 1 of the above embodiment uses a laser beam in the near-infrared region as the recording laser beam, but the laser recording medium of the present invention may use a laser beam in the ultraviolet region or the visible light region as the recording laser beam. Moreover, the base layer 10 of the present invention may not be transparent but may be translucent. Moreover, when the recording laser beam is invisible light such as infrared or ultraviolet light, the base layer 10 may be opaque.

[0050] Furthermore, the variable information recording unit 2 in the above embodiment is configured so that the first image (image of the face of the person to be certified) and the second image (surname of the person to be certified) are switched by tilting the viewing angle up and down, but the variable information recording unit according to the present invention may be one that switches between three or more types of images. Also, the longitudinal direction of the convex lenses of the lenticular lens may be arranged vertically, and the image in the variable information recording unit may be switched when the viewing angle is tilted left and right. Also, the variable information according to the present invention may be an image that appears three-dimensional due to binocular parallax.

[0051] Furthermore, the laser-sensitive layer in the above-mentioned examples is carbonized and develops a black color when irradiated with a recording laser beam, but the laser-sensitive layer according to the present invention may also develop a chromatic color due to a chemical reaction of the leuco dye.

[0052] Furthermore, the laser recording medium 1 in the above embodiment is provided with a variable information recording section 2 and a fixed information recording section 3, but the laser recording medium according to the present invention may be composed of only the variable information recording section 2. [Explanation of symbols]

[0053] 1, 1a, 1b, 1c Laser recording medium 2 Variable information recording section 3,3b Fixed information recording section 4 Lenticular Lens 5. Face image recording section 6. Character information recording section 8 Convex Lens 10,10c base material layer 11,11b Laser sensitive layer 12,12a,12b Covering layer 14, 14a, 14b Base printing layer 15, 15a, 15b Decorative printing layer 16 void 100 ID C1, C2 Strip-shaped fragment images

Claims

1. A sheet-shaped laser recording medium configured to record information by irradiating a recording laser beam in a predetermined wavelength range, a base layer; and a laser-sensitive layer disposed on the base layer and absorbing the recording laser light to develop a color, a lenticular lens is disposed on the laser sensitive layer, and a variable information recording section is provided that can record variable information that changes depending on a viewing angle by irradiation with the recording laser light; In the variable information recording section, the laser sensitive layer is bonded to a surface of the base layer, 2. A laser recording medium, comprising: a substrate layer configured to be transparent to the recording laser beam;

2. a fixed information recording section that is not provided with a lenticular lens and that can record information by irradiating the recording laser light; The substrate layer is transparent or translucent, In the fixed information recording section, a light-opaque printing layer is formed on a surface of the base layer, and the laser-sensitive layer is disposed on the printing layer, 2. The laser recording medium according to claim 1, wherein the print layer is not formed in the variable information recording area, and the laser sensitive layer is bonded to a surface of the base layer.

3. A sheet-shaped laser recording medium configured to record information by irradiating a recording laser beam in a predetermined wavelength range, a base layer; and a laser-sensitive layer disposed on the base layer and absorbing the recording laser light to develop a color, a variable information recording section in which a lenticular lens is disposed on the laser sensitive layer and variable information that changes depending on a viewing angle by irradiation with the recording laser light can be recorded; a fixed information recording section in which a lenticular lens is not provided and information can be recorded by irradiating the laser light in the predetermined wavelength range; Equipped with A laser recording medium, characterized in that in the variable information recording section, the laser sensitive layer is not supported from the rear side, and a gap is formed on the rear side of the laser sensitive layer.

Images