JP2020104471A - Protective sheet - Google Patents

Abstract

To provide a protective sheet capable of suppressing reduction of an image quality of portable electronic equipment and suppressing occurrence of an interference fringe.SOLUTION: A protective sheet 10 comprises: an outer layer part 12; a middle layer part 14 comprising a holding part 18 and a moth-eye structure 20; and an inner layer part 16. The outer layer part 12 is formed into a plate-shape for protecting a screen 104 of portable electronic equipment 100, an outer periphery of the outer layer part 12 is formed to be curved to the portable electronic equipment 100 side. The holding part 18 is provided on a main surface of the outer layer part 12 for holding the outer layer part 12. The moth-eye structure part 20 comprises a plurality of conical salient parts 24 which are smaller than a wavelength of visible light, and is provided on a main surface on an opposite side of the outer layer part 12 on the holding part 18 so as to expose the salient parts 24. The inner layer part 16 is provided in a plane direction of the outer layer part 12 so as to hold the moth-eye structure part 20 and is provided along an outer periphery of the outer layer part 12, and fixes the outer layer part 12 to the portable electronic equipment 100 so that the salient parts 24 face the screen 104.SELECTED DRAWING: Figure 3

Description

The present invention relates to a protective sheet, and more specifically to a protective sheet for protecting a screen of a mobile electronic device.

As an example of this type of conventional technology, Patent Document 1 discloses a screen protection sheet for protecting the screen of a portable electronic device such as a tablet or a smartphone. The screen protection sheet has an outer surface layer, an intermediate layer provided so as to overlap with the outer surface layer, and an adhesive layer provided so as to overlap with the intermediate layer. The intermediate layer is formed of a so-called dot film, and a plurality of convex portions (dots) are formed on the surface of the intermediate layer opposite to the outer surface layer. The screen protection sheet is attached to the mobile electronic device such that the plurality of convex portions of the intermediate layer face the screen of the mobile electronic device. Therefore, when the user operates the portable electronic device through the screen protective sheet, even if the screen protective sheet and the screen of the portable electronic device come into contact with each other, the screen protective sheet can be easily separated from the screen of the portable electronic device. This makes it easier to eliminate interference fringes generated by the contact between the screen protection sheet and the screen of the mobile electronic device.

JP, 2018-182641, A

However, in Patent Document 1, since a plurality of convex portions formed in the intermediate layer are visually recognized by the user, when the screen protection sheet is attached to the mobile electronic device, the convex portions become unsightly and the image quality of the mobile electronic device deteriorates. Resulting in. Further, if the number of convex portions is increased in order to make the interference fringes easier to disappear, the screen appears white and turbid (hazy), and the image quality of the portable electronic device further deteriorates.

Therefore, a main object of the present invention is to provide a protective sheet capable of suppressing the occurrence of interference fringes while suppressing the deterioration of the image quality of portable electronic devices.

In order to achieve the above-mentioned object, an outer layer portion formed in a plate shape for protecting the screen of the portable electronic device, a moth-eye structure portion having a plurality of conical convex portions smaller than the wavelength of visible light, And, the middle layer portion provided on the main surface of the outer layer portion so that the convex portion is exposed, and the convex portion of the moth-eye structure portion facing the screen, the inner layer portion for fixing the outer layer portion to the mobile electronic device is provided, A protective sheet is provided.

In the present invention, the outer layer portion is fixed to the mobile electronic device by the inner layer portion so that the plurality of convex portions of the moth-eye structure portion face the screen of the mobile electronic device. Therefore, when the user operates the portable electronic device through the protective sheet (when the protective sheet bends toward the screen), even if the protective sheet comes into contact with the screen, the plurality of convex portions of the moth-eye structure portion The protective sheet can be easily removed from the screen. As a result, it is possible to suppress the occurrence of interference fringes caused by the contact between the protective sheet and the screen. Further, since the size of the plurality of convex portions of the moth-eye structure portion is smaller than the wavelength of visible light and so small that the user cannot visually recognize it, it is possible to prevent the screen of the mobile electronic device from appearing cloudy in white. Further, since each convex portion of the moth-eye structure portion is formed in a conical shape and the refractive index changes gently, the moth-eye structure portion is unlikely to reflect light, and it is possible to prevent the screen of the portable electronic device from being hard to see. Therefore, the deterioration of the image quality of the mobile electronic device can be suppressed.

Preferably, the outer peripheral portion of the outer layer portion is formed so as to curve toward the portable electronic device side in a state where the outer layer portion is fixed to the portable electronic device, and the inner layer portion sandwiches the moth-eye structure portion in the surface direction of the outer layer portion. It is provided along the outer peripheral portion of the outer layer portion. In this case, even when the outer peripheral portion of the screen is curved, the outer peripheral portion of the outer layer portion is curved toward the mobile electronic device, so that the screen can be appropriately protected. Further, the inner layer part is provided along the outer peripheral part of the outer layer part while sandwiching the moth-eye structure part in the surface direction of the outer layer part, so that it is possible to suppress the occurrence of interference fringes while suppressing the deterioration of the image quality of the portable electronic device. The curved outer layer portion can be fixed to the portable electronic device without impairing the function of the structure portion.

Further preferably, the middle layer portion further has a holding portion provided on the main surface of the outer layer portion for holding the outer layer portion, and the moth-eye structure portion is provided on a main surface of the holding portion opposite to the outer layer portion. .. In this case, the moth-eye structure section suppresses the occurrence of interference fringes while suppressing the deterioration of the image quality of the mobile electronic device, and the holding section holds the outer layer section, so that even if the outer layer section is damaged, It is possible to suppress scattering of fragments.

More preferably, the protrusion has a size of nanometer level. In this case, the moth-eye structure portion can more effectively suppress the occurrence of interference fringes while suppressing the deterioration of the image quality of the mobile electronic device.

In the present invention, the "moth-eye structure portion" means a plurality of conical convex portions that are smaller than the wavelength of visible light (400 to 800 nm) and are arranged at intervals of approximately 100 nm to 200 nm. In addition, the term “conical” for the convex portion of the moth-eye structure portion means that the top portion may be a curved surface and the generatrix is limited to a straight line as long as it is formed so as to gradually thicken from the top portion to the bottom surface. Instead, it may be a curve.

According to the present invention, it is possible to obtain a protective sheet that can suppress the occurrence of interference fringes while suppressing the deterioration of the image quality of the mobile electronic device.

It is a perspective view showing a protection sheet and a portable electronic device concerning one embodiment of this invention. It is a disassembled perspective view which shows the protective sheet of FIG. (A) is an AA line sectional schematic view in the state which attached the protection sheet of FIG. 1 to a portable electronic device, (b) is an expanded schematic diagram which shows a moth-eye structure part. (A) is a figure containing the photograph which shows the protective sheet of a comparative example, (b) is a figure containing the photograph which shows the protective sheet of FIG. It is a figure containing the photograph which shows the state which attached the protective sheet of a comparative example, and the protective sheet of FIG. 1 side by side to the portable electronic device. (A) is a graph showing the brightness of the place where the protective sheet is not attached, the place where the protective sheet of FIG. 1 is attached, and the place where the protective sheet of the comparative example is attached, and (b) is the center of each place. It is a table showing the brightness of.

Embodiments of the present invention will be described below with reference to the drawings. In the embodiment of the present invention, the lateral direction is the direction indicated by arrow X in FIGS. 1, 2 and 3(a), and the longitudinal direction is the direction indicated by arrow Y in FIGS.

1 to 3, the protective sheet 10 is used to protect the screen 104 of the display unit 102 of the mobile electronic device 100, and includes an outer layer portion 12, a middle layer portion 14, and an inner layer portion 16. In this embodiment, the mobile electronic device 100 is a smartphone. In this embodiment, the display unit 102 is configured using an OLED (Organic Light Emitting Diode), and a portion of the outer peripheral portion of the screen 104 extending in the longitudinal direction is orthogonal to the longitudinal direction and the lateral direction. Slightly curved in the direction.

2 and 3A, the outer layer portion 12 is formed in a rectangular shape and a plate shape in order to protect the screen 104 of the mobile electronic device 100. Both ends in the lateral direction of the outer layer portion 12 are slightly curved in a direction orthogonal to the longitudinal direction and the lateral direction. That is, the portion of the outer peripheral portion of the outer layer portion 12 that extends in the longitudinal direction is slightly curved in the direction orthogonal to the longitudinal direction and the lateral direction. The outer layer portion 12 is made of glass, preferably tempered glass.

The middle layer portion 14 has a holding portion 18 and a moth-eye structure portion 20, and is provided on one main surface of the outer layer portion 12 so that a convex portion 24 (described later) is exposed.

The holding portion 18 is formed in a rectangular shape and a film shape, and is attached to substantially the entire one main surface of the outer layer portion 12 to hold the outer layer portion 12. The holding portion 18 is made of engineering plastic, preferably polyethylene terephthalate (PET).

Referring also to FIG. 3B, the moth-eye structure portion 20 has a base portion 22 and a plurality of convex portions 24, and is provided on one main surface of the holding portion 18. That is, the moth-eye structure portion 20 is provided on the main surface of the holding portion 18 opposite to the outer layer portion 12. The moth-eye structure 20 is made of engineered plastic, preferably polyethylene terephthalate, polycarbonate or acrylic. The base portion 22 is formed in a rectangular shape and a film shape. The base portion 22 is attached to substantially the entire surface of the one main surface of the holding portion 18 excluding the outer edge portion (the portion surrounded by the one-dot chain line in FIG. 2 ). The plurality of convex portions 24 are formed on substantially the entire one main surface of the base portion 22. Each of the plurality of protrusions 24 has a size smaller than the wavelength of visible light (400 to 800 nm), and is formed in a conical shape so that the protrusions 24 gradually become thicker toward the base 22. Preferably, each protrusion 24 has a size of nanometer level, and the plurality of protrusions 24 are arranged at intervals of about 100 nm to 200 nm.

The inner layer portion 16 has adhesiveness and is formed into a ring shape and a film shape. The inner layer portion 16 preferably comprises a double-sided tape. The inner layer portion 16 is attached to an outer edge portion of the one main surface of the holding portion 18 (a portion outside the one-dot chain line in FIG. 2). Therefore, the inner layer portion 16 surrounds the moth-eye structure portion 20 and is provided along the entire circumference of the outer peripheral portion of the outer layer portion 12. That is, the inner layer portion 16 is provided along the entire circumference of the outer peripheral portion of the outer layer portion 12 while sandwiching the moth-eye structure portion 20 in the longitudinal direction and the lateral direction. In this way, the inner layer portion 16 is provided along the outer peripheral portion of the outer layer portion 12 while sandwiching the moth-eye structure portion 20 in the surface direction of the outer layer portion 12.

With reference to FIGS. 1 to 3, when the protective sheet 10 is attached to the mobile electronic device 100, the outer layer portion 12 is arranged with the plurality of convex portions 24 of the moth-eye structure portion 20 facing the screen 104 of the mobile electronic device 100. Is pressed against the portable electronic device 100. As a result, the inner layer portion 16 is attached to the mobile electronic device 100, and the outer layer portion 12 can be fixed to the mobile electronic device 100. In a state where the outer layer portion 12 is fixed to the mobile electronic device 100, a portion of the outer peripheral portion of the outer layer portion 12 that extends in the longitudinal direction is curved toward the mobile electronic device 100 side. When removing the protective sheet 10 from the mobile electronic device 100, the outer layer portion 12 is pulled to the side opposite to the mobile electronic device 100. Thereby, the inner layer portion 16 is separated from the mobile electronic device 100, and the outer layer portion 12 can be removed from the mobile electronic device 100.

According to such a protective sheet 10, the outer layer portion 12 is fixed to the mobile electronic device 100 by the inner layer portion 16 so that the plurality of convex portions 24 of the moth-eye structure portion 20 face the screen 104 of the mobile electronic device 100. .. Therefore, when the user operates the portable electronic device 100 through the protective sheet 10 (when the protective sheet 10 bends toward the screen 104 ), even if the protective sheet 10 contacts the screen 104, the moth-eye structure unit 20. With the plurality of convex portions 24, the protective sheet 10 can be easily separated from the screen 104. As a result, it is possible to suppress the occurrence of interference fringes that occur due to the contact between the protective sheet 10 and the screen 104. In addition, since the sizes of the plurality of convex portions 24 of the moth-eye structure portion 20 are smaller than the wavelength of visible light and are too small for the user to visually recognize, it is possible to prevent the screen 104 of the mobile electronic device 100 from appearing cloudy in white. it can. Furthermore, each convex portion 24 of the moth-eye structure portion 20 is formed in a conical shape, and the refractive index changes gently. Therefore, the moth-eye structure portion 20 is less likely to reflect light and the screen 104 of the portable electronic device 100 is less visible. Can be suppressed. Therefore, the deterioration of the image quality of the mobile electronic device 100 can be suppressed.

Even if the outer peripheral portion of the screen 104 is curved, a portion of the outer peripheral portion of the outer layer portion 12 that extends in the longitudinal direction is curved toward the portable electronic device 100 side, so that the screen 104 can be appropriately protected. In addition, the inner layer portion 16 is provided along the outer peripheral portion of the outer layer portion 12 while sandwiching the moth-eye structure portion 20 in the surface direction of the outer layer portion 12, thereby suppressing the deterioration of the image quality of the portable electronic device 100 and suppressing the interference fringes. The curved outer layer portion 12 can be fixed to the mobile electronic device 100 without impairing the function of the moth-eye structure portion 20 that can suppress the generation.

The moth-eye structure section 20 suppresses the occurrence of interference fringes while suppressing the deterioration of the image quality of the mobile electronic device 100, and the holding section 18 holds the outer layer section 12 so that even if the outer layer section 12 is damaged, the outer layer section 12 is damaged. It is possible to prevent the fragments of the portion 12 from scattering.

When the convex portion 24 has a size of nanometer level, the moth-eye structure portion 20 can more effectively suppress the occurrence of interference fringes while suppressing the deterioration of the image quality of the mobile electronic device 100.

With reference to Drawing 4-Drawing 6, the comparison result of protection sheet 10 concerning this invention and protection sheet 1 of a comparative example is explained.

Referring to FIG. 4A, when the central portion of the protective sheet 1 is enlarged with a microscope, a plurality of dots (projections) can be visually recognized. On the other hand, referring to FIG. 4B, even if the central portion of the protective sheet 10 is similarly enlarged with a microscope, the plurality of convex portions 24 of the moth-eye structure portion 20 cannot be visually recognized. Thus, the plurality of convex portions 24 of the protective sheet 10 are much smaller than the dots (convex portions) of the protective sheet 1, and are so small that the user cannot visually recognize them.

Referring to FIG. 5, comparing the location where the protective sheet 1 is attached to the portable electronic device and the location where the protective sheet 10 is attached to the portable electronic device, the protective sheet 10 is attached to the location where the protective sheet 1 is attached. It looks whiter and cloudier than the areas where That is, the place where the protective sheet 10 is attached does not appear white and cloudy than the place where the protective sheet 1 is attached. Therefore, the protective sheet 10 can prevent the screen of the mobile electronic device from appearing cloudy (become hazy) than the protective sheet 1.

When the brightness of the screen of the portable electronic device is measured with reference to FIG. 6, the color becomes lighter in the drawing in the order of the place where the protective sheet is not attached, the place where the protective sheet 10 is attached, and the place where the protective sheet 1 is attached. , The brightness of the screen decreased in this order. It was 354 cd in the center of the place where the protective sheet was not attached, 339 cd in the center of the place where the protective sheet 10 was attached, and 314 cd in the center of the place where the protective sheet 1 was attached. As described above, the screen brightness of the portable electronic device is slightly lowered when the protective sheet 10 is attached, but the protective sheet 10 can suppress the screen brightness lower than that of the protective sheet 1.

In the above-described embodiment, the case where the portion extending in the longitudinal direction of the outer peripheral portion of the outer layer portion 12 is curved in the direction orthogonal to the longitudinal direction and the lateral direction has been described, but the present invention is not limited to this. Depending on the shape of the screen of the mobile electronic device, for example, a portion of the outer peripheral portion of the outer layer portion extending in the lateral direction may be curved in a direction orthogonal to the longitudinal direction and the lateral direction. May be curved in a direction orthogonal to the longitudinal direction and the lateral direction. Further, the outer peripheral portion of the outer layer portion may not be curved.

In the above-described embodiment, the case where the inner layer portion 16 is provided along the entire circumference of the outer peripheral portion of the outer layer portion 12 has been described, but the present invention is not limited to this. For example, the inner layer portion may be provided only along a portion of the outer peripheral portion of the outer layer portion 12 extending in the lateral direction, or may be provided only along a portion of the outer peripheral portion of the outer layer portion 12 extending in the longitudinal direction. Good.

In the above embodiment, the case where the mobile electronic device 100 is a smartphone has been described, but the present invention is not limited to this. The present invention can be applied even when the portable electronic device is a tablet.

DESCRIPTION OF SYMBOLS 10 Protective sheet 12 Outer layer part 14 Middle layer part 16 Inner layer part 18 Holding part 20 Moth eye structure part 22 Base part 24 Convex part 100 Portable electronic device 104 Screen L Distance between the vertices of adjacent convex parts

Claims (4)

An outer layer portion formed in a plate shape to protect the screen of the portable electronic device,
Including a moth-eye structure portion having a plurality of conical protrusions smaller than the wavelength of visible light, and the middle layer portion provided on the main surface of the outer layer portion so that the protrusions are exposed, and the moth-eye structure portion A protective sheet comprising an inner layer portion for fixing the outer layer portion to the portable electronic device such that a convex portion faces the screen. The outer peripheral portion of the outer layer portion is formed to curve toward the portable electronic device side in a state where the outer layer portion is fixed to the portable electronic device,
The protective sheet according to claim 1, wherein the inner layer portion is provided along the outer peripheral portion of the outer layer portion while sandwiching the moth-eye structure portion in the surface direction of the outer layer portion. The middle layer portion further has a holding portion provided on the main surface of the outer layer portion for holding the outer layer portion,
The protective sheet according to claim 1, wherein the moth-eye structure portion is provided on a main surface of the holding portion opposite to the outer layer portion. The said convex part is a protective sheet in any one of Claim 1 to 3 which has a size of a nanometer level.