Overall structure

Abstract

To improve the stain-resistant performance of the moth-eye structure. [Solution] The display structure includes a first layer of a moth-eye structure formed on a base material of the display panel using a first material with a first refractive index, and a second layer formed on the first layer using a second material with a second refractive index lower than the first refractive index, and having a complementary structure that fills the irregularities of the moth-eye structure on the first layer side. Furthermore, the outermost surface of the multiple layers formed on the base material is flat.

Description

[Technical Field]

[0001] The present invention relates to a display structure. [Background Art]

[0002] Conventionally, a water tank comprising a layer having a moth-eye structure has been proposed (for example, Patent Document 1). The water tank has a transparent wall, and comprises, on the inner surface of the transparent wall, a first moth-eye layer having a moth-eye structure and a protective layer covering the moth-eye structure of the first moth-eye layer in this order from the transparent wall side. Further, it is stated that preferably, the liquid storage tank comprises a second moth-eye layer having a moth-eye structure on an outer surface of the transparent wall, and the second moth-eye layer is provided in a region facing the first moth-eye layer. [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] International Publication No. 2010 / 073881 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] Incidentally, low-reflection technologies for displays include a low-reflection film structure using thin-film interference of light and a moth-eye structure in which fine protrusions smaller than the wavelength of light are arranged. The moth-eye structure can reduce reflection because the refractive index approaches that of air on the tip side of the protrusions, and has excellent low-reflection performance. However, when the moth-eye structure is arranged on the outermost surface of a product, there is a problem that it is difficult to remove if sebum from fingers or dirt in the air adheres to the protrusions. Accordingly, an object of the present technology is to provide a technology for improving the antifouling performance of a moth-eye structure. [Means for Solving the Problem]

[0005] The disclosed display structure includes a first layer of a moth-eye structure formed on a base material of a display panel using a first material with a first refractive index, and a second layer formed on the first layer using a second material with a second refractive index lower than the first refractive index, and having a complementary structure on the first layer side that fills in the irregularities of the moth-eye structure. Furthermore, the outermost surfaces of the multiple layers formed on the base material are planar. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a technology for improving the antifouling performance of a moth-eye structure. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a perspective view showing an example of a display structure according to the first embodiment. [Figure 2] Figure 2 is a plan view showing an example of a display structure. [Figure 3] Figure 3 is a cross-sectional view (end view) showing an example of a display structure. [Figure 4] Figure 4 shows an example of a method for producing a display structure. [Figure 5] Figure 5 is an end view showing an example of a display structure according to the second embodiment. [Figure 6] Figure 6 is an end view showing an example of a display structure according to the third embodiment. [Modes for carrying out the invention]

[0008] Embodiments of the present invention will be described below with reference to the drawings.

[0009] <Embodiment 1> Figure 1 is a perspective view showing an example of a display structure. Figure 2 is a plan view showing an example of a display structure. Figure 3 is a cross-sectional view (end view) showing an example of a display structure. The display structure 100 according to this embodiment includes a moth-eye structure 1 provided on the surface side (display surface side) of the base material 2 of the display. For convenience, the base material 2 side of the display is referred to as the downward direction, and the moth-eye structure 1 side as the upward direction. The display is a display device using methods such as OLED (Organic Electro Luminescence Diode) or LCD (Liquid Crystal Display), and may particularly have a touch panel laminated on it. The base material 2 of the display is a component that the display has on its surface side, such as a cover glass (glass substrate) or a polarizing filter, which is surface-treated in this embodiment.

[0010] The moth-eye structure 1 according to this embodiment includes a moth-eye structure layer (also referred to as the "first layer") 11 containing a plurality of protrusions 111 that constitute a general moth-eye structure, and a complementary structure layer (also referred to as the "second layer") 12 having a complementary structure that fills the irregularities of the plurality of protrusions 111. The protrusions 111 of the moth-eye structure layer 11 are formed by repeatedly creating minute protrusions that are smaller than the wavelength of visible light, for example, on the order of tens of nanometers, and Figure 1 etc. shows a part of the display structure 100. Furthermore, the shape of the protrusions 111 shown in Figure 1 etc. is schematic, and the shape of the moth-eye structure 1 may be spindle-shaped or the like. The moth-eye structure layer 11 is made of a transparent material with a relatively high refractive index (in other words, a refractive index close to that of the base material 2 of the display). The complementary structure layer 12 is made of a transparent material with a relatively low refractive index (in other words, a refractive index close to that of air). The materials of the moth-eye structure layer 11 and the complementary structure layer 12 may specifically be UV-curable resin, acrylic resin, polycarbonate, etc.

[0011] Figure 3 is an example of an AA end view shown in the plan view of Figure 2. The projections 111 of the moth-eye structure layer 11 have a cross-sectional diameter that decreases from the base 113 side towards the tip 112 side in the protruding direction. Note that the shape of the projections 111 shown in Figure 3 is schematic, and the outer shape of the projections 111 may be curved in cross-sectional view. This shape allows for a continuous change in the effective refractive index in the vertical direction, thereby reducing reflection. The complementary structure layer 12 is also provided to fill the recesses between the projections 111 so as to fill the irregularities caused by the projections 111 of the moth-eye structure layer 11. The upper surface of the complementary structure layer 12 (the outermost surface of the display structure 100) is flat.

[0012] Here, the reflectance R for normal incidence can be calculated using the following equation (1). Note that n1 is the refractive index of the incident light medium, and n2 is the refractive index of the transmitted light medium. R = ((n1 - n2) / (n1 + n2)) 2 ...(1) When light is incident on the complementary structural layer 12 from the air side (above the complementary structural layer 12), the reflectance R is low because the complementary structural layer 12 is made of a material with a refractive index close to that of air, as described above. Furthermore, when light is incident on the moth-eye structural layer 11 from the complementary structural layer 12, reflection can be reduced due to the natural characteristics of the moth-eye structure. In addition, since the material of the moth-eye structural layer 11 is close to the refractive index of the display base material 2, as described above, the reflectance R of light incident on the display base material 2 from the moth-eye structural layer 11 is also low. Thus, according to the display structure 100 of this embodiment, the reflection of light from the display to the user can be reduced.

[0013] Furthermore, since the complementary structural layer 12 fills in the irregularities of the moth-eye structural layer 11, it ensures the strength of the protrusions 111 and prevents dirt from getting into the irregularities of the moth-eye structural layer 11, thereby improving the stain-resistant performance of the display structure 100. Therefore, the display structure 100 can be used particularly suitably in displays with stacked touch panels that are touched by the user's fingers.

[0014] FIG. 4 is a diagram illustrating an example of a method for producing display structure 100. In step S1 shown in FIG. 4, an ultraviolet curable resin made of a high-refractive-index material for forming a moth-eye structure layer 11 is filled into a moth-eye structure mold 8 formed of UV (ultraviolet) transmissive glass or the like in advance by a method such as etching or lithography. In step S2, a base material 2 such as a cover glass is placed on the ultraviolet curable resin, and UV is irradiated from the direction of the mold 8 to form the moth-eye structure layer 11. In step S3, an ultraviolet curable resin made of a low-refractive-index material for forming a complementary structure layer 12 is filled into a mold 9 formed of UV transmissive glass or the like and having a flat surface side, and the moth-eye structure layer 11 formed in step S2 is superimposed thereon. Further, UV is irradiated from the direction of the mold 9 to form the complementary structure layer 12, thereby obtaining the display structure 100. In step S4, the display structure 100 is taken out from the mold 9. The production method shown in FIG. 4 is merely an example, and the display structure 100 may be obtained using printing technology or other methods.

[0015] <Embodiment 2> FIG. 5 is an end view illustrating an example of a display structure according to a second embodiment. Constituent elements corresponding to those of the first embodiment shown in FIG. 3 and other figures are denoted by the same reference numerals, and descriptions thereof are omitted. In the example of FIG. 5, a moth-eye structure 1A of a display structure 100A further includes an anti-fingerprint layer 13 on a complementary structure layer 12. The anti-fingerprint layer 13 is formed by performing an existing anti-fingerprint treatment using a film, coating, or the like. For the anti-fingerprint treatment, for example, a water-repellent and oil-repellent coating such as a fluorine-based (fluororesin) coating may be applied directly or indirectly via a film.

[0016] Even when the outermost surface of the complementary structure layer 12 is finished to be flat, fingerprints and the like may still adhere thereto. According to the second embodiment, the antifouling performance of the display structure 100 can be further improved.

[0017] <Embodiment 3> FIG. 6 is an end view illustrating an example of a display structure according to a third embodiment. Components corresponding to those in the above-described embodiments are denoted by the same reference numerals, and descriptions thereof are omitted. In the moth-eye structure 1B of the display structure 100B of FIG. 6, moth-eye structure layers 11 and complementary structure layers 12 are repeatedly laminated. In the display structure 100B of FIG. 6, a first moth-eye structure layer 11A, a first complementary structure layer 12A, a second moth-eye structure layer 11B, a second complementary structure layer 12B, a third moth-eye structure layer 11C, a third complementary structure layer 12C, a fourth moth-eye structure layer 11D, and a fourth complementary structure layer 12D are laminated on a base material 2. Note that the number of laminated layers is not limited to the example shown in FIG. 6, but the outermost surface (topmost surface) shall be a flat surface.

[0018] The shape of the first moth-eye structure layer 11A is the same as, for example, the moth-eye structure layer 11 shown in FIG. 3 and FIG. 5. The lower surface side of the first complementary structure layer 12A has a complementary shape that fills the irregularities of the first moth-eye structure layer 11A, and on the upper surface side thereof, the tips of convex portions (protrusions) or the valleys of concave portions are obtuse than those of the first moth-eye structure layer 11A in cross-sectional view (in other words, the angles of the tips of convex portions and the valleys of concave portions in cross-sectional view are larger on the upper layer side than on the lower layer side), forming a moth-eye structure. Note that, in plan view, the irregularities of the first complementary structure layer 12A are formed at positions corresponding to the irregularities of the first moth-eye structure layer 11A. Further, the first complementary structure layer 12A has irregularities on both the upper layer side and the lower layer side, and the tip of the convex portion on the upper layer side of the first moth-eye structure layer 11A is accommodated in the concave portion on the lower layer side of the first complementary structure layer 12A.

[0019] Further, the lower surface side of the second moth-eye structure layer 11B has a complementary shape that fills the irregularities of the first complementary structure layer 12A, and on the upper surface side thereof, the tips of protrusions or the valleys of concave portions are obtuse than those of the first complementary structure layer 12A in cross-sectional view (in other words, the angles of the tips of convex portions and the valleys of concave portions in cross-sectional view are larger on the upper layer side than on the lower layer side), forming a moth-eye structure. Note that, in plan view, the irregularities of the second moth-eye structure layer 11B correspond to the irregularities of the first complementary structure layer 12A It is assumed that these are formed in corresponding positions. Furthermore, the second moth-eye structure layer 11B has irregularities on both its upper and lower sides, and the tip of the protrusion on the upper side of the first complementary structure layer 12A is housed in the recess on the lower side of the second moth-eye structure layer 11B. In addition, in the example of Figure 6, the tip of the protrusion on the upper side of the first moth-eye structure layer 11A is also housed in the recess on the lower side of the second moth-eye structure layer 11B.

[0020] The second complementary structural layer 12B has a complementary shape on its lower surface that fills in the irregularities of the second moth-eye structural layer 11B, and on its upper surface, in cross-sectional view, the tips of the protrusions or the valleys of the recesses are more obtuse than those of the second moth-eye structural layer 11B (in other words, the angles of the tips of the protrusions and the valleys of the recesses in cross-sectional view are larger on the upper side than on the lower side) forming a moth-eye structure. In plan view, the irregularities of the second complementary structural layer 12B are assumed to be formed in positions corresponding to the irregularities of the second moth-eye structural layer 11B. Furthermore, the second complementary structural layer 12B also has irregularities on both its upper and lower sides, and the tips of the protrusions on the upper side of the second moth-eye structural layer 11B are housed in the recesses on the lower side of the second complementary structural layer 12B.

[0021] Furthermore, the third moth-eye structure layer 11C has a complementary shape on its lower surface that fills in the irregularities of the second complementary structure layer 12B, and its upper surface has a moth-eye structure in which the tips of the protrusions or the valleys of the recesses are more obtuse in cross-sectional view than those of the second complementary structure layer 12B (in other words, the angles of the tips of the protrusions and the valleys of the recesses in cross-sectional view are larger on the upper side than on the lower side). In plan view, the irregularities of the third moth-eye structure layer 11C are assumed to be formed in positions corresponding to the irregularities of the second complementary structure layer 12B. In addition, the third moth-eye structure layer 11C has irregularities on both the upper and lower sides, and the tips of the protrusions on the upper side of the second complementary structure layer 12B are housed in the recesses on the lower side of the third moth-eye structure layer 11C. Furthermore, in the example of Figure 6, the tips of the protrusions on the upper side of the second moth-eye structure layer 11B are also housed in the recesses on the lower side of the third moth-eye structure layer 11C.

[0022] The third complementary structural layer 12C has a complementary shape on its lower surface that fills in the irregularities of the third moth-eye structural layer 11C, and its upper surface has a moth-eye structure in which the tips of the protrusions or the valleys of the recesses are more obtuse in cross-sectional view than those of the third moth-eye structural layer 11C (in other words, the angles of the tips of the protrusions and the valleys of the recesses in cross-sectional view are larger on the upper layer than on the lower layer). In plan view, the irregularities of the third complementary structural layer 12C are assumed to be formed in positions corresponding to the irregularities of the third moth-eye structural layer 11C. Furthermore, the third complementary structural layer 12C also has irregularities on both its upper and lower sides, and the tips of the protrusions on the upper side of the third moth-eye structural layer 11C are housed in the recesses on the lower side of the third complementary structural layer 12C.

[0023] Furthermore, the fourth moth-eye structure layer 11D has a complementary shape on its lower surface that fills in the irregularities of the third complementary structure layer 12C, and its upper surface has a moth-eye structure where the tips of the protrusions or the valleys of the recesses are more obtuse in cross-sectional view than those of the third complementary structure layer 12C (in other words, the angles of the tips of the protrusions and the valleys of the recesses in cross-sectional view are larger on the upper side than on the lower side). In plan view, the irregularities of the fourth moth-eye structure layer 11D are assumed to be formed in positions corresponding to the irregularities of the third complementary structure layer 12C. In addition, the fourth moth-eye structure layer 11D has irregularities on both the upper and lower sides, and the tips of the protrusions on the upper side of the third complementary structure layer 12C are housed in the recesses on the lower side of the fourth moth-eye structure layer 11D. Furthermore, in the example of Figure 6, the tips of the protrusions on the upper side of the third moth-eye structure layer 11C are also housed in the recesses on the lower side of the fourth moth-eye structure layer 11D.

[0024] The fourth complementary structural layer 12D has a complementary shape on its lower surface that fills in the irregularities of the fourth moth-eye structural layer 11D, and its upper surface is flat. In plan view, the irregularities on the lower surface of the fourth complementary structural layer 12D are formed in positions corresponding to the irregularities of the fourth moth-eye structural layer 11D. Furthermore, the fourth complementary structural layer 12D also has irregularities on both its upper and lower sides. Furthermore, the tip of the convex portion on the upper side of the fourth moth-eye structure layer 11D is housed in the concave portion on the lower side of the fourth complementary structure layer 12D.

[0025] Furthermore, the material of the moth-eye structure layer 11 (11A to 11D) according to this embodiment is the same as, for example, the moth-eye structure layer 11 according to the first and second embodiments. Similarly, the material of the complementary structure layer 12 (12A to 12D) according to this embodiment is the same as, for example, the complementary structure layer 12 according to the first and second embodiments. However, for example, the material of each layer may be different so that the refractive index gradually approaches that of air from the base material 2 side toward the outermost surface side.

[0026] Some low-reflection films are constructed by alternately stacking high-refractive-index layers and low-refractive-index layers, suppressing reflection through light interference. According to the third embodiment, reflection can be reduced by causing the wavelengths of reflected light to cancel each other out. The display structure shown in Figure 6 can also be manufactured in the same way as the production method shown in Figure 4, for example, by sequentially stacking layers using molds corresponding to the shape of each layer.

[0027] <Other> The configuration of the display structure 100 shown in the embodiment is merely an example, and various modifications can be made without departing from the problems or technical ideas of the present invention. For example, the anti-fingerprint layer 13 shown in Figure 5 may be further provided on the outermost surface of the display structure 100B shown in Figure 6. [Explanation of Symbols]

[0028] 100: Display structure, 1: Moth-eye structure, 11: Moth-eye structure layer (first layer), 111: Protrusion, 112: Tip, 113: Base, 12: Complementary structure layer (second layer), 13: Anti-fingerprint layer, 2: Base material

Claims

1. A first layer of a moth-eye structure formed on the base material of a display panel using a first material with a first refractive index, A second layer is formed on the first layer using a second material having a second refractive index lower than the first refractive index, and has a complementary structure on the first layer side that fills the irregularities of the moth-eye structure, Includes, The outermost surface of the multiple layers formed on the base material is flat. Display structure.

2. The moth-eye structure of the first layer is a first moth-eye structure, A third layer of a second moth-eye structure is formed from the first material and has irregularities at corresponding positions on the irregularities of the first moth-eye structure, A fourth layer formed on the third layer using the second material, having a complementary structure that fills the irregularities of the second moth-eye structure, Includes, The tip of the convex portion on the upper side of the first moth-eye structure is housed in the concave portion on the lower side of the second moth-eye structure. The display structure according to claim 1.

3. The outermost surface of the layer formed on the base material is provided with an anti-fingerprint layer that has been treated to prevent fingerprints. The display structure according to claim 1 or 2.

Images