JP7549817B2 - Decorative sheet, display device with decorative sheet, and method for manufacturing decorative sheet - Google Patents

Description

The present invention relates to a decorative sheet, a display device with a decorative sheet having the decorative sheet, and a method for manufacturing the decorative sheet.

For example, as described in Patent Document 1, a decorative sheet illuminated with light from behind is known. When this decorative sheet is not illuminated with light from behind, it displays a pattern provided on a layer forming its surface. Meanwhile, it is said that the decorative sheet may be formed with minute openings to allow light to pass through. Light projected onto the rear surface of the decorative sheet passes through the decorative sheet at the positions where the openings are formed. Therefore, when the decorative sheet is illuminated with light in a predetermined pattern, the decorative sheet can display the predetermined pattern.

With such a decorative sheet, a display can be made by illuminating the decorative sheet from behind, while a specific pattern can be displayed when no display is being made. Therefore, when not illuminated from behind, the pattern on the decorative sheet allows the decorative sheet to blend in with its surroundings. This makes it possible to impart excellent display value to devices that display some kind of information.

JP 2000-132126 A

The openings in the decorative sheet can be formed by melting and removing a portion of the sheet-like material that will form the decorative sheet with laser light. However, since the openings are so minute that they are not visible, it is difficult to form openings in a highly precise arrangement by irradiating only a portion of the decorative sheet with laser light. For this reason, in many cases, conventional decorative sheets have openings formed with the entire area as a transparent region. In other words, conventional decorative sheets have not been able to improve the design expression when illuminated from behind by changing the arrangement pattern of the openings, and it has been difficult, for example, to express a high degree of correspondence between the design of the pattern on the decorative sheet and the design displayed by illuminating it from behind.

The present invention was made in consideration of the above points, and aims to improve the design of decorative sheets that are illuminated from behind.

The first decorative sheet according to the present invention comprises:
A decorative sheet disposed opposite a surface light source device,
A base design layer;
A pattern layer provided on a portion of the base design layer;
An opening is provided that penetrates the base design layer and reaches the pattern layer,
The infrared ray absorptivity of the pattern layer is higher than that of the base design layer.

In the first decorative sheet according to the present invention, the absorption spectrum of the pattern layer may have a peak in the infrared region.

The second decorative sheet according to the present invention is
A decorative sheet disposed opposite a surface light source device,
A base design layer;
A pattern layer provided on a portion of the base design layer;
An opening is provided that penetrates the base design layer and reaches the pattern layer,
The absorption spectrum of the patterned layer has a peak in the infrared region.

In the first or second decorative sheet according to the present invention, the absorption spectrum of the pattern layer may have a peak at a wavelength of 900 nm or more and 1300 nm or less.

In the first or second decorative sheet according to the present invention, the peak of the absorption spectrum of the pattern layer in the infrared region may be 3% or more.

In the first or second decorative sheet according to the present invention, the peak of the absorption spectrum in the infrared region of the pattern layer may be higher than the peak of the absorption spectrum in the infrared region of the base design layer.

The third decorative sheet according to the present invention is
A decorative sheet disposed opposite a surface light source device,
A base design layer;
A pattern layer provided on a portion of the base design layer;
An opening is provided that penetrates the base design layer and reaches the pattern layer,
The peak of the absorption spectrum of the pattern layer in the infrared region is higher than the peak of the absorption spectrum of the base design layer in the infrared region.

In the first to third decorative sheets according to the present invention, the visible light transmittance in the area where the pattern layer is provided may be higher than the visible light transmittance in the area where the pattern layer is not provided.

A fourth decorative sheet according to the present invention is
A decorative sheet disposed opposite a surface light source device,
A base design layer;
A pattern layer provided on a portion of the base design layer;
a visible light transmittance in a region where the pattern layer is provided is higher than a visible light transmittance in a region where the pattern layer is not provided;
The infrared ray absorptivity of the pattern layer is higher than that of the base design layer.

A fifth decorative sheet according to the present invention is
A decorative sheet disposed opposite a surface light source device,
A base design layer;
A pattern layer provided on a portion of the base design layer;
a visible light transmittance in a region where the pattern layer is provided is higher than a visible light transmittance in a region where the pattern layer is not provided;
The absorption spectrum of the patterned layer has a peak in the infrared region.

A sixth decorative sheet according to the present invention is
A decorative sheet disposed opposite a surface light source device,
A base design layer;
A pattern layer provided on a portion of the base design layer;
a visible light transmittance in a region where the pattern layer is provided is higher than a visible light transmittance in a region where the pattern layer is not provided;
The peak of the absorption spectrum of the pattern layer in the infrared region is higher than the peak of the absorption spectrum of the base design layer in the infrared region.

In the first to sixth decorative sheets according to the present invention, the aperture ratio in the area where the pattern layer is provided may be higher than the aperture ratio in the area where the pattern layer is not provided.

In the first to sixth decorative sheets of the present invention, the pattern layer may be colored.

In the first to sixth decorative sheets of the present invention, the pattern layer may be colorless and transparent.

In the first to sixth decorative sheets according to the present invention, a recess may be provided in an area of the base design layer where the pattern layer is not provided.

In the first to sixth decorative sheets according to the present invention, the base design layer may contain an inorganic material.

In the first to sixth decorative sheets according to the present invention, the inorganic material may be in the form of flakes.

In the first to sixth decorative sheets according to the present invention, the maximum length of the inorganic material may be 5 μm or more.

In the first to sixth decorative sheets according to the present invention, the pattern layer may contain particles, and the maximum length of the particles may be smaller than the maximum length of the flake-like inorganic material.

In the first to sixth decorative sheets according to the present invention, the inorganic material may contain any one of aluminum, titanium oxide, and mica.

In the first to sixth decorative sheets according to the present invention, the visible light reflectance of the base design layer may be 5% or more.

In the first to sixth decorative sheets according to the present invention, the visible light absorptance of the base design layer may be 3% or less.

The first to sixth decorative sheets according to the present invention are
Further comprising a light-shielding layer provided on the opposite side of the base design layer to the pattern layer,
The visible light transmittance of the light-shielding layer may be lower than the visible light transmittance of the base design layer.

The display device with a decorative sheet according to the present invention comprises:
A surface light source device;
The decorative sheet according to any one of the first to sixth decorative sheets of the present invention described above is disposed so as to face the surface light source device.

The method for producing a decorative sheet according to the present invention includes the steps of:
A method for producing any one of the first to sixth decorative sheets according to the present invention,
preparing a first film which will form the pattern layer and a second film which will form the base design layer;
and removing a portion of the first film and the second film by irradiating the second film with laser light to form an opening.

In the method for manufacturing a decorative sheet according to the present invention, the absorptivity of the first film at the wavelength of the laser light may be higher than the absorptivity of the second film at the wavelength of the laser light.

In the method for manufacturing a decorative sheet according to the present invention, the absorptance of the first film at the wavelength of the laser light may be 3% or more.

In the method for manufacturing a decorative sheet according to the present invention, the wavelength of the laser light may be 900 nm or more and 1300 nm or less.

The objective of the present invention is to improve the design of decorative sheets that are illuminated from behind.

FIG. 1 is a diagram for explaining one embodiment, and is an exploded perspective view that shows a schematic diagram of a display device with a decorative sheet. FIG. 2 is a cross-sectional view of the display device with the decorative sheet of FIG. FIG. 2A is a cross-sectional view of a base design layer of a decorative sheet. FIG. 2B is a cross-sectional view of the base design layer and the pattern layer of the decorative sheet. FIG. 3 is a plan view showing the decorative sheet of the display device with the decorative sheet of FIG. 1 in a state where the surface light source device is turned off. FIG. 4 is an enlarged view of region Z in FIG. FIG. 5 is a cross-sectional view taken along line VV in FIG. FIG. 6 is a plan view showing the decorative sheet in the display device with the decorative sheet of FIG. 1 in a state where the surface light source device is turned on. FIG. 7 is a diagram for explaining an example of a method for manufacturing a decorative sheet. FIG. 8 is a diagram for explaining an example of a method for manufacturing a decorative sheet. FIG. 9 is a diagram for explaining an example of a method for manufacturing a decorative sheet. FIG. 10 is a diagram for explaining an example of a method for manufacturing a decorative sheet. FIG. 11 is a diagram for explaining an example of a method for manufacturing a decorative sheet. FIG. 12 corresponds to FIG. 3 and is a diagram for explaining a modified example of the decorative sheet. FIG. 13 corresponds to FIG. 4 and shows an enlarged view of region Z in FIG. FIG. 14 corresponds to FIG. 5 and is a diagram for explaining another modified example of the decorative sheet. FIG. 15 corresponds to FIG. 10 and is a diagram for explaining a reference example of a method for producing a decorative sheet. FIG. 16 corresponds to FIG. 11 and is a diagram for explaining a reference example of a method for producing a decorative sheet.

One embodiment of the present invention will now be described with reference to the drawings. Note that in the drawings accompanying this specification, the scale and aspect ratios have been appropriately altered and exaggerated from those of the actual product for the sake of ease of illustration and understanding.

In this specification, the terms "layer," "sheet," and "film" are not distinguished from one another solely on the basis of differences in name. For example, the term "layer" is a concept that includes members that may be called sheets or films.

In addition, terms used in this specification that specify shapes, geometric conditions, and the degree of those conditions, such as "parallel," "orthogonal," and "same," as well as values of lengths and angles, are to be interpreted without being bound by strict meanings, but rather to include the range in which similar functions can be expected.

Figure 1 is an exploded perspective view showing a schematic diagram of a display device with a decorative sheet 1 according to an embodiment of the present invention. As shown in Figure 1, the display device with a decorative sheet 1 has a surface light source device 10 having a light-emitting surface 11, and a decorative sheet 20 arranged facing the light-emitting surface 11. In the display device with a decorative sheet 1, the decorative sheet 20 is arranged so that the side on which a light-shielding layer 24 (described later) is provided faces the surface light source device 10. Note that, in the example shown in the figure, the display device with a decorative sheet 1 is shown in a flat plate shape, but the display device with a decorative sheet 1 may have a curved shape by curving each component of the display device with a decorative sheet 1.

The surface light source device 10 is a device that emits light in a planar manner. The surface light source device 10 is not particularly limited, and various types, such as edge light type and direct type devices, can be used. The illustrated surface light source device 10 has a light emitting surface 11 on the front surface facing the decorative sheet 20. In addition, of the front surface of the surface light source device 10 facing the decorative sheet 20, the area surrounding the light emitting surface 11 is a non-light emitting surface 12 formed by a frame (bezel). In other words, the front surface of the surface light source device 10 facing the decorative sheet 20 includes the light emitting surface 11 and the non-light emitting surface 12 located around the light emitting surface 11.

The decorative sheet 20 is disposed facing the light-emitting surface 11 of the surface light source device 10, and covers at least the entire light-emitting surface 11 so that the light-emitting surface 11 is not directly observed from the outside. The decorative sheet 20 has dimensions equal to or larger than the light-emitting surface 11 so as to cover the entire light-emitting surface 11 of the surface light source device 10. The illustrated decorative sheet 20 has dimensions covering the entire front area of the surface light source device 10, including the light-emitting surface 11 and the non-light-emitting surface 12 located around the light-emitting surface 11. In other words, the decorative sheet 20 conceals the entire surface light source device 10. In the example shown in FIG. 1, the decorative sheet 20 is a flat member that extends in the same direction as the light-emitting surface 11 of the surface light source device 10 as a whole. The thickness of the decorative sheet 20 can be, for example, 20 μm or more and 550 μm or less.

The decorative sheet 20 displays a design and imparts design to the display device 1 with the decorative sheet. In this embodiment, the decorative sheet 20 has a base design layer 22 and a pattern layer 23 provided on a portion of the base design layer 22. The base design layer 22 is formed as a so-called solid layer, which is a layer that extends two-dimensionally, or in other words, a layer that extends in a planar shape. On the other hand, the pattern layer 23 is formed on a portion of the base design layer 22. For example, the pattern layer 23 is provided in a predetermined pattern on one surface of the base design layer 22.

As shown in Figs. 2 and 3, the decorative sheet 20 includes a first region A1 and a second region A2. The illustrated decorative sheet 20 is divided into a first region A1 and a second region A2. The pattern layer 23 is provided in the first region A1, but not in the second region A2 outside the first region A1. In the illustrated example, the first region A1 is provided in the center of the decorative sheet 20, as shown in Fig. 3, and is an area that forms the pattern of the alphabet "D."

The illustrated decorative sheet 20 further includes a base film 21 and a light-shielding layer 24 in addition to the base design layer 22 and the pattern layer 23, as shown in FIG. 2. In the decorative sheet 20 shown in FIG. 2, the pattern layer 23 is provided in a first region A1 on one side of the base film 21. The base design layer 22 is formed so as to cover one side of the base film 21 and the entire area of the pattern layer 23. In other words, the illustrated base design layer 22 extends over the entire area of the base film 21. The light-shielding layer 24 is laminated on the side of the base design layer 22 opposite the pattern layer 23. The light-shielding layer 24 extends over the entire area of the base design layer 22. Below, each component included in the decorative sheet 20 will be described in order.

The substrate film 21 supports the base design layer 22, the pattern layer 23, and the light-shielding layer 24 laminated thereon. The substrate film 21 is a transparent film-like member. The substrate film 21 may be any material that transmits visible light and can adequately support the base design layer 22, the pattern layer 23, and the light-shielding layer 24, and examples of such materials include polymethylmethacrylate, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polystyrene, cyclic polyolefin, and ABS (acrylonitrile butadiene styrene copolymer). In addition, the substrate film 21 preferably has a thickness of 10 μm or more and 500 μm or less, taking into consideration visible light transmittance and adequate support for the base design layer 22, the pattern layer 23, and the light-shielding layer 24.

Transparent means that the visible light transmittance, specified as the average value of the transmittance at each wavelength, is 80% or more when measured using a spectrophotometer (Shimadzu Corporation's UV-3100PC, compliant with JIS K 0115) in the measurement wavelength range of 380 nm to 780 nm.

The base design layer 22, together with the pattern layer 23, forms the design displayed by the decorative sheet 20. The base design layer 22 can form designs such as figures, patterns, designs, colors, pictures, photographs, characters, marks, letters, and numbers. In addition, in this embodiment in which the pattern layer 23 is provided separately from the base design layer 22, the base design layer 22 can also express the design as the background of the pattern layer 23. For example, the base design layer 22 may display a wood grain or marble pattern or a geometric pattern as a design that can harmonize with the surrounding environment in which the display device 1 with the decorative sheet is provided. The design formed by the base design layer 22 may be represented by a single color or multiple colors. In addition, the base design layer 22 has a color that does not impair the design of the pattern formed by the pattern layer 23 by mixing with the pattern layer 23 when observed by an external observer, and is preferably, for example, white or silver, which is easy to avoid color mixing.

The base design layer 22 can be a layer containing an inorganic material, as shown in FIG. 2A. The base design layer 22 shown in FIG. 2A has a binder resin 22a and an inorganic material 22b dispersed in the binder resin 22a. The inorganic material contained in the base design layer 22 is not particularly limited, but can be any of aluminum, titanium oxide, and mica. The base design layer 22 containing these inorganic materials can be, for example, white or silver, and can effectively suppress changes in the color of the pattern layer 23. The inorganic material made of aluminum or mica can be a flake-shaped material with a maximum length of 5 μm or more. Such large flake-shaped inorganic materials allow the base design layer 22 to provide an active design expression.

In order to brightly display the design formed by the base design layer 22, the visible light reflectance of the base design layer 22 is preferably 5% or more, and more preferably 10% or more. The visible light reflectance can be determined by measuring the reflectance (total reflectance) in the visible range of 380 nm to 780 nm at an incident angle of 8° using an ultraviolet/visible/near-infrared spectrophotometer (Shimadzu UV-3600) and an integrating sphere accessory (ISR-3100), and determining the average reflectance.

Furthermore, from the viewpoint of making the design expression by the base design layer 22 more effective, the visible light absorptance of the base design layer 22 may be 3% or less. When the visible light absorptance of the base design layer 22 is 3% or less, the base design layer 22 can display a white color or a white color close to white, and the design quality of the design formed by the base design layer 22 can be improved. The visible light absorptance can be determined as the average value of the absorptance at each wavelength when measured within the measurement wavelength range of 380 nm to 780 nm using, for example, an ultraviolet-visible-near infrared spectrophotometer (for example, "V-770" manufactured by JASCO Corporation).

On the other hand, since the wavelengths of visible light and infrared light are close, materials with low visible light absorptance generally also have low infrared absorptance. If the visible light absorptance of the base design layer 22 is low, the infrared absorptance of the base design layer 22 will also be low. Specifically, the infrared absorptance of the base design layer 22 tends to be 3% or less.

As described above, the pattern layer 23 is provided only in the first region A1 of the decorative sheet 20. The pattern layer 23 is provided on a portion of the base design layer 22 to form a pattern. The shape of the first region A1 forming the pattern of the pattern layer 23 is not particularly limited and can be selected as appropriate. The pattern layer 23 may display figures, designs, colors, pictures, characters, marks, pictograms, letters, numbers, etc., by the pattern itself. Furthermore, the pattern layer 23 may display images such as figures, designs, colors, pictures, characters, marks, pictograms, letters, numbers, etc., within the first region A1 in which the pattern layer 23 is provided.

In one illustrated specific example, the pattern layer 23 is formed in an area forming the letter "D" located in the center of the decorative sheet 20, as shown in FIG. 3. The illustrated pattern layer 23 is a monochromatic layer. In other words, this pattern layer 23 displays the letter "D" in a single color. On the other hand, the illustrated base design layer 22 is a monochromatic layer different from the pattern layer 23. In other words, the base design layer 22 displays the background of the letter "D" in a color different from that of the pattern layer 23.

The pattern layer 23 also has the property of absorbing infrared rays. As described later, the first film 31 that will form the pattern layer 23 in the manufacturing process of the decorative sheet 20 absorbs laser light in the infrared region that is not absorbed by the second film 32 that will form the base design layer 22. For this reason, the pattern layer 23 is more likely to absorb infrared rays than the base design layer 22. In other words, the infrared absorption rate of the pattern layer 23 is higher than that of the base design layer 22. Here, the infrared absorption rate means the average absorption rate of infrared rays with wavelengths of 900 nm to 1300 nm. Such wavelengths are the wavelengths of laser light irradiated from an infrared laser light source that is generally available at low cost and has sufficient output, and are suitable for the wavelengths of laser light used in the manufacturing process of the decorative sheet 20. The infrared absorption rate can be specified as the average value of the absorption rate at each wavelength when measured within the measurement wavelength range of 900 nm to 1300 nm using, for example, an ultraviolet-visible-near infrared spectrophotometer V-770 manufactured by JASCO Corporation.

In order for the pattern layer 23 to easily absorb infrared rays, the absorption spectrum of the pattern layer 23 has an absorptivity peak in the infrared region (wavelength range of 780 nm to 15,000 nm). Specifically, the absorption spectrum of the pattern layer 23 preferably has an absorptivity peak at a wavelength of 780 nm to 15,000 nm, more preferably has an absorptivity peak at a wavelength of 800 nm to 10,000 nm, and even more preferably has an absorptivity peak at a wavelength of 900 nm to 1,300 nm. In addition, the absorptivity peak of the absorption spectrum of the pattern layer 23 is preferably 3% or more, and more preferably 5% or more. Here, the absorption spectrum means the distribution of the absorptivity [%] of light at each wavelength [nm]. In addition, in order for the pattern layer 23 to easily absorb infrared rays, it is preferable that the absorption spectrum peak of the pattern layer 23 in the infrared region is higher than the absorption spectrum peak of the base design layer 22 in the infrared region.

The base design layer 22 and the pattern layer 23 can be formed as layers containing pigments and the like in a binder resin. As described above, the base design layer 22 and the pattern layer 23 can also be layers containing inorganic materials such as aluminum, titanium oxide, and mica in a binder resin.

The thickness of the base design layer 22 and the pattern layer 23 is preferably at least as thick as sufficient design expression can be achieved. On the other hand, the thickness of the base design layer 22 and the pattern layer 23 is preferably at most as thick as sufficient for removal by laser light, as described below. Specifically, the thickness of the base design layer 22 can be 1 μm or more and 40 μm or less. The thickness of the pattern layer 23 can be 1 μm or more and 20 μm or less. In the illustrated example, the thickness of the base design layer 22 in the second region A2 is the sum of the thickness of the base design layer 22 in the first region A1 and the thickness of the pattern layer 23 in the first region A1.

The light-shielding layer 24 is provided so as to cover the base design layer 22 from the side facing the surface light source device 10. The light-shielding layer 24 has a visible light-shielding property so that visible light from the surface light source device 10 does not enter the base design layer 22. Therefore, it is preferable that the visible light transmittance of the light-shielding layer 24 is lower than the visible light transmittance of the base design layer 22. The light-shielding layer 24 may contain, for example, light-absorbing particles in a binder resin. Examples of light-absorbing particles include black pigments such as carbon black and titanium black. When the light-shielding layer 24 is sufficiently thick to cover the base design layer 22, the design formed by the base design layer 22 can be formed thick and clear. As a specific example, the thickness of the light-shielding layer 24 may be 1 μm or more and 20 μm or less.

As mentioned above, the visible light transmittance can be determined as the average value of the transmittance at each wavelength when measured using a spectrophotometer (Shimadzu Corporation's "UV-3100PC", compliant with JIS K 0115) in the measurement wavelength range of 380 nm to 780 nm.

2, the decorative sheet 20 has an opening H formed in the region where the pattern layer 23 is provided, i.e., the first region A1, which penetrates the light-shielding layer 24 and the base design layer 22 to reach the pattern layer 23. By forming such an opening H, the decorative sheet 20 can promote the transmission of light in the first region A1. From the viewpoint of transmitting visible light, the depth DH of the opening H is preferably 90% or more of the thickness T1 excluding the base film 21 in the first region A1 of the decorative sheet 20, and typically, the opening H penetrates the pattern layer 23 to reach the base film 21 (see FIG. 5). That is, typically, an opening (through hole) H is formed that penetrates the light-shielding layer 24, the pattern layer 23, and the base design layer 22. This opening H functions as a transmission section 28 for light emitted by the surface light source device 10 when illuminated from behind by the surface light source device 10. As shown in FIG. 5, in the illustrated example, the opening H in the first area A1 is formed as a through hole that penetrates the decorative sheet 20.

As shown in FIG. 4, the transmissive portion 28 consisting of the through openings H is a non-formed portion of the base design layer 22, the pattern layer 23, and the light-shielding layer 24 when the decorative sheet 20 is observed from the front. In order to sufficiently transmit the light emitted by the surface light source device 10, the ratio of the area of the through openings H to the area of the first region A1 of the decorative sheet 20, i.e., the aperture ratio, is preferably 10% or more, more preferably 15% or more, and even more preferably 20% or more. On the other hand, in order to sufficiently ensure the visibility of the pattern layer 23 when the surface light source device 10 is turned off, the aperture ratio in the first region A1 is preferably 50% or less.

Note that Figure 4 shows an enlarged view of area Z in Figure 3.

In this way, in the first region A1 of the decorative sheet 20, light transmission is promoted when the surface light source device 10 is turned on. On the other hand, in the second region A2 of the decorative sheet 20, light transmission is restricted when the surface light source device 10 is turned on. For this reason, the aperture ratio, which is the proportion of the area occupied by the through-hole openings H, is greater in the first region A1 than in the second region A2. As a result, the visible light transmittance in the first region A1 where the pattern layer 23 is provided is higher than the visible light transmittance in the second region A2 where the pattern layer 23 is not provided. In other words, the through-hole openings H are concentrated in the first region A1 of the decorative sheet 20.

In the decorative sheet 20 shown in Figures 4 and 5, in the area where the pattern layer 23 is not provided, i.e., the second area A2, no openings H penetrating the base design layer 22 are formed. In the illustrated example, no through holes are provided in the second area A2 of the decorative sheet 20. Therefore, the opening ratio in the illustrated second area A2 of the decorative sheet 20 is 0%, and the transmission of visible light in the second area A2 of the decorative sheet 20 is effectively restricted.

As shown in FIG. 5, a recess (opening that does not penetrate) R that does not penetrate the base design layer 22 may be formed in the second region A2 of the decorative sheet 20. As described later, this recess R is formed in the second region A2 in conjunction with the creation of the opening H in the first region A1. From the viewpoint of effectively blocking the transmission of light emitted by the surface light source device 10 when illuminated from behind by the surface light source device 10, the depth DR of the recess R is preferably 80% or less of the thickness T2 excluding the base film 21 at the position where the recess R is not formed in the second region A2 of the decorative sheet 20, and more preferably 70% or less. By forming the recess R in the second region A2 and adjusting its depth DR, the brightness of the second region A2 when the decorative sheet 20 is turned on can be controlled. As a result, the brightness balance between the first region A1 and the second region A2 can be adjusted to adjust the display contrast of the pattern layer 23, enabling a variety of design expressions.

In the example shown in FIG. 4, the multiple openings H provided in the first region A1 are spaced apart from each other. The multiple openings H provided in the first region A1 are also regularly arranged. By regularly arranging the openings H that form the transmission portion 28, the light emitted by the surface light source device 10 can be transmitted through the first region A1 of the decorative sheet 20 with a generally uniform brightness. Similarly, the multiple recesses R provided in the second region A2 are spaced apart from each other. The multiple recesses R provided in the second region A2 are also regularly arranged. By regularly arranging the recesses R, the second region A2 of the decorative sheet 20 can be made uniformly bright when the surface light source device 10 is turned on and emitting visible light.

Furthermore, in the decorative sheet 20, the openings H and recesses R are arranged regularly together. In the illustrated example, the multiple openings H and multiple recesses R are arranged in a square array, but this is not limited thereto, and they may be arranged in a honeycomb array or a staggered array, or may be arranged irregularly. The arrangement of the multiple openings H and the arrangement of the multiple recesses R may be different.

In the example shown in FIG. 4, the multiple openings H provided in the first region A1 have the same shape in plan view. Specifically, each opening H has a circular shape in plan view. By having the multiple openings H forming the transmission portion 28 have a uniform shape, the light emitted by the surface light source device 10 can be transmitted through the first region A1 of the decorative sheet 20 with approximately uniform brightness. Similarly, in the example shown in FIG. 4, the multiple recesses R provided in the second region A2 have the same shape in plan view. Specifically, each recess R has a circular shape in plan view. By having the recesses R have a uniform shape, the second region A2 of the decorative sheet 20 can be made uniformly bright when the surface light source device 10 is turned on and emitting visible light.

In addition, in the example shown in FIG. 4, the openings H and the recesses R have the same shape in a plan view. However, this is not limited to the illustrated example, and the plan view shapes of the openings H may be different among the multiple openings H. Also, the plan view shapes of the recesses R may be different among the multiple recesses R. Furthermore, the plan view shape of the openings H may be different from the plan view shape of the recesses R.

From the viewpoint of the design of the decorative sheet 20, it is preferable that each opening H is not visible. Similarly, it is preferable that each recess R is not visible. From this viewpoint, the arrangement pitch PH of the multiple openings H can be set to 60 μm or more and 160 μm or less. The maximum width WH of each opening H can be set to 30 μm or more and 130 μm or less. The area of each opening H can be set to 900 μm ² or more and 16900 μm ² or less. In addition, the arrangement pitch PR of the multiple recesses R can be set to 60 μm or more and 160 μm or less. The maximum width WR of each recess R can be set to 30 μm or more and 130 μm or less. The area of each recess R can be set to 900 μm ² or more and 16900 μm ² or less.

Next, we will explain the operation of the display device 1 with decorative sheet of this embodiment.

When the surface light source device 10 is turned off and no visible light is emitted from the light-emitting surface 11, as shown in FIG. 3, the pattern of the first area A1 in which the pattern layer 23 is formed is visible due to the difference in color between the base design layer 22 and the pattern layer 23 of the decorative sheet 20. In other words, the pattern of the pattern layer 23 becomes visible. The decorative sheet 20 can also conceal the surface light source device 10. Furthermore, the design of the base design layer 22 itself can harmonize the decorative sheet 20 with the surrounding environment in which the display device with decorative sheet 1 is installed.

On the other hand, when the surface light source device 10 is turned on and visible light is emitted from the light-emitting surface 11, the visible light transmittance of the first region A1 in which the openings H are formed is higher than that of the second region A2. As a result, the pattern of the first region A1 in which the pattern layer 23 is formed can be seen brighter than when the surface light source device 10 is turned off, as shown in FIG. 6. On the other hand, since the openings H are not formed in the second region A2, the visible light emitted by the surface light source device 10 does not penetrate the decorative sheet 20 in the second region A2 with high transmittance. For this reason, the base design layer 22 is only visible due to the reflection of ambient light, and is not observed as brightly as the pattern layer 23. In other words, the pattern layer 23 can be clearly seen with high contrast.

The base design layer 22 is covered from the side of the surface light source device 10 by the light-shielding layer 24. Therefore, the light-shielding layer 24 can effectively restrict the visible light emitted by the surface light source device 10 from entering the base design layer 22. Therefore, in the first region A1, it is possible to effectively prevent the pattern layer 23 from being viewed in an unintended color due to the mixing of the base design layer 22 and the pattern layer 23 by visible light passing through the base design layer 22 and the pattern layer 23. Furthermore, in the illustrated example, the boundary B between the light-emitting surface 11 and the non-light-emitting surface 12 of the surface light source device 10 is located within the second region A2 of the decorative sheet 20, but since visible light does not actively pass through the second region A2, this boundary B can be made invisible.

Next, we will explain an example of a manufacturing method for the decorative sheet 20.

First, as shown in FIG. 8, a first film 31 that will form the pattern layer 23 is formed in the first region A1 of the base film 21. Next, as shown in FIG. 9, a second film 32 that will form the base design layer 22 is formed so as to cover the base film 21 and the first film 31. Thereafter, as shown in FIG. 10, a third film 33 that will form the light-shielding layer 24 is formed so as to cover the second film 32. The first film 31, the second film 32, and the third film 33 can be formed by applying and drying a resin composition that contains inorganic materials, pigments, etc. that will be contained in each corresponding layer. The application of the resin composition can be carried out using a known coating technique. At this time, the resin composition that forms the first film 31 can also be applied only to the first region A1 on the base film 21 using a known technique, very easily, quickly, and accurately.

In the laminate 34 thus formed, the infrared absorption rate of the first film 31 is preferably higher than that of the second film 32. The peak of the absorption spectrum of the first film 31 is preferably higher than that of the second film 32. The absorption spectrum of the first film 31 preferably has a peak in the infrared region. The absorption spectrum of the first film 31 may have a peak at a wavelength of 900 nm or more and 1300 nm or less. The peak of the absorption spectrum of the first film 31 in the infrared region may be 3% or more.

Next, as shown in FIG. 11, the laser device 40 irradiates the laser light Lx at the position where the opening H is to be formed. The laser light is irradiated from the opposite side to the base film 21 side, that is, from the side of the second film 32 and the third film 33. The wavelength of the laser light Lx is 780 nm or more and 1300 nm or less in the infrared region, for example, 900 nm or more and 1300 nm or less. As a specific example of the laser light Lx, a laser light of an Nd:YAG laser with a wavelength of 1064 nm can be used. By making the laser light Lx emitted from the laser device 40 infrared, the influence of the color and pattern of the base design layer 22 and the pattern layer 23 is weakened, and it becomes easier to set the absorption rate of the laser light Lx in the first film 31 that forms the pattern layer 23 higher than the absorption rate of the laser light Lx in the second film 32 that forms the base design layer 22.

In the example shown in FIG. 11, the laser light Lx is irradiated from the third film 33 side to the laminate 34 while shifting the emission part of the laser device 40 at a certain pitch. At this time, the irradiation area of the laser light Lx on the third film 33 of the laminate 34 can be irradiated with the laser light Lx without performing any particularly complicated control, and the laser light Lx can be irradiated to almost the entire area of the third film 33 or to an area of the third film 33 other than the peripheral area that is clearly outside the first area A1. In other words, the irradiation area of the laser light Lx, which has an extremely fine spot diameter because it forms a fine opening, is not controlled with high precision, for example, without being controlled so as to be limited to only the first area A1, but the laser light Lx is irradiated from the laser device 40 by controlling only the pitch and output of the laser device 40. Since the first film 31 indicating the first area A1 is hidden by the third film 33, it is expected that the positioning control for irradiating the laser light Lx only to the first area A1 will be complicated, but by being able to omit such complicated work, productivity can be significantly improved.

The output of the laser light Lx emitted from the laser device 40 is set to a level that does not melt and remove all of the second film 32 in the second region A2. In other words, the output of the laser device 40 is suppressed so that an opening penetrating the third film 33 and the second film 32 is not formed in the second region A2. In the example shown in FIG. 11, the third film 33 and the second film 32 are removed to about half of the total thickness of the third film 33 and the second film 32 in the second region A2. As a result, a recess R is formed that penetrates the third film 33 and extends partway through the second film 32.

On the other hand, in the first region A1, the third film 33, the second film 32, and the first film 31 are all removed at the position where the laser light Lx is irradiated, and a through opening 29 leading to the base film 21 is formed. In the first region A1, the first film 31 arranged at the position farthest from the incident side of the laser light Lx can absorb the laser light Lx in the wavelength range projected from the laser device 40 with a high absorption rate (for example, an absorption rate of 3% or more, more preferably 5% or more). Therefore, even if the laser light Lx is irradiated with an output that does not completely remove the second film 32 on the first film 31, as shown in FIG. 12, a part of the laser light Lx reaches the first film 31 and is efficiently absorbed by the first film 31, melting the first film 31. Accordingly, first, the second film 32 adjacent to the melted first film 31 also melts. Furthermore, the melted second film 32 also evaporates with the evaporation of the melted first film 31.

In this manner, by irradiating the laser light Lx, a recess R can be formed in the second region A2 of the laminate 34, and an opening H can be formed in the first region A1 of the laminate 34 where the first film 31 is provided. In this manufacturing method, the irradiation conditions of the laser light Lx when irradiating the first region A1 and the irradiation conditions of the laser light Lx when irradiating the second region A2 can be made the same. Therefore, it is not necessary to specify the region of the first region A1 of the laminate 34. Since the laser light Lx is irradiated from the side of the third film 33 that can hide the first film 31, it is complicated to specify the first region A1 where the first film 31 is provided and irradiate only the first region A1 with the laser light Lx. In this respect, in the above-mentioned manufacturing method, the specification of the first region A1 is omitted, and the laser light Lx is irradiated to the entire area of the third film 33 under certain irradiation conditions, so that an opening H can be selectively formed in the first region A1 and a recess R can be selectively formed in the second region A2. This greatly simplifies the manufacture of the decorative sheet 20, which has excellent design qualities.

The third film 33, the second film 32, and the first film 31 that were not irradiated with the laser light Lx and thus not removed form the light-shielding layer 24, the base design layer 22, and the pattern layer 23, respectively. Through the above steps, the decorative sheet 20 is manufactured.

The decorative sheet 120 not including the pattern layer 23 can be manufactured by laminating the second film 132 and the third film 133 on the base film 121 and irradiating the position where the transparent portion 128 is to be formed with laser light Ly with adjusted output, as shown in FIG. 15. When the decorative sheet 120 is manufactured in this manner, as shown in FIG. 16, the second film 132 that will form the base design layer 122 may not be sufficiently removed, and residues 132r of the second film 132 may remain in some of the transparent portions 128. There may be a difference in design between the transparent portion 128 with such residues 132r remaining and the transparent portion 128 without residues 132r remaining. Specifically, the residues 132r may cause the design to be displayed darker than the design that should be displayed. Due to this difference in design, a shading pattern will appear in the design displayed by the decorative sheet 120, which may impair the design that the decorative sheet 120 is intended to display and deteriorate the design provided by the decorative sheet 120.

As a result of careful investigation by the inventors of the present invention, it was found that such residue 132r is caused by the second film 132 not absorbing the laser light Ly sufficiently. Specifically, due to the second film 132 not absorbing the laser light Ly sufficiently, the second film 132 does not melt or evaporate sufficiently, and some of the second film 132 remains in the transparent portion 128. It was also confirmed that the second film 132 that absorbs the laser light Ly and the second film 132 that does not absorb the laser light Ly sufficiently can be caused by, for example, differences in color and pattern at each position of the base design layer 122 that is formed by the second film 132 at each position.

On the other hand, in the decorative sheet 20 of this embodiment, in the first region A1 where the opening H is to be formed, a pattern layer 23 that absorbs infrared rays is arranged between the base film 21 and the base design layer 22. That is, in the manufacturing process of the decorative sheet 20, a first film 31 that will form the pattern layer 23 is arranged between the base film 21 and the second film 32. The infrared absorption rate of the pattern layer 23 is higher than that of the base design layer 22. That is, in the manufacturing process of the decorative sheet 20, the infrared absorption rate of the first film 31 is higher than that of the second film 32. For this reason, even if the laser light that forms the opening H is not sufficiently absorbed in the second film 32, the laser light can be sufficiently absorbed in the first film 31. The first film 31 that absorbs the laser light melts and evaporates, so that the second film 32 and the third film 33 stacked on the first film 31 can be removed with almost no residue left behind. In other words, in the first area A1 of the decorative sheet 20, it is possible to make it difficult for residue to remain in the opening H.

The absorption spectrum of the pattern layer 23 has a peak absorptivity in the infrared region. That is, in the manufacturing process of the decorative sheet 20, the absorption spectrum of the first film 31 has a peak absorptivity in the infrared region. Therefore, the first film 31 can efficiently absorb infrared rays at the peak wavelength. When the peak wavelength of the first film 31 is close to the wavelength of the laser light Lx that forms the opening H, the laser light is efficiently absorbed in the first film 31. The first film 31 that absorbs the laser light melts and evaporates, so that the second film 32 and the third film 33 stacked on the first film 31 can be removed with almost no residue left behind, making it difficult for residue to remain inside the opening H formed in the first area A1 of the decorative sheet 20.

Furthermore, the peak of the absorption spectrum of the pattern layer 23 in the infrared region is higher than the peak of the absorption spectrum of the base design layer 22 in the infrared region. That is, in the manufacturing process of the decorative sheet 20, the peak of the absorption spectrum of the first film 31 in the infrared region is higher than the peak of the absorption spectrum of the second film 32 in the infrared region. Therefore, the first film 31 can absorb infrared rays more efficiently than the second film 32. In other words, the first film 31 can absorb laser light more efficiently than the second film 32. By melting and evaporating the first film 31 that absorbs the laser light, the second film 32 and the third film 33 stacked on the first film 31 can be removed with almost no residue left behind, and residue is less likely to remain inside the opening H formed in the first area A1 of the decorative sheet 20.

The absorption spectrum of the pattern layer 23 has a peak absorptivity at a wavelength of 900 nm or more and 1300 nm or less. That is, in the manufacturing process of the decorative sheet 20, the absorption spectrum of the first film 31 has a peak absorptivity at a wavelength of 900 nm or more and 1300 nm or less. Therefore, the first film 31 can efficiently absorb infrared rays of this wavelength. When the laser light Lx forming the opening H has a wavelength of 900 nm or more and 1300 nm or less, the laser light Lx is absorbed more efficiently in the first film 31. By melting and evaporating the first film 31 that absorbs the laser light Lx, the second film 32 and the third film 33 laminated on the first film 31 can be removed with almost no residue left behind, and residue is less likely to remain in the opening H formed in the first area A1 of the decorative sheet 20.

The peak of the absorption rate of the absorption spectrum of the pattern layer 23 is 3% or more. That is, in the manufacturing process of the decorative sheet 20, the peak of the absorption rate of the absorption spectrum of the first film 31 is 3% or more. Therefore, infrared rays at the peak of the absorption rate of the absorption spectrum of the first film 31 can be absorbed more efficiently. If the laser light forming the opening H has a wavelength at or near the peak of the first film 31, the laser light is absorbed more efficiently in the first film 31. By melting and evaporating the first film 31 that absorbs the laser light, the second film 32 and the third film 33 laminated on the first film 31 can be removed with almost no residue left behind, and residue is less likely to remain in the opening H formed in the first area A1 of the decorative sheet 20.

The base design layer 22 also contains an inorganic material such as titanium oxide. If the second film 32 does not sufficiently absorb the laser light, the inorganic material will remain as a residue and will tend to remain in the opening H. However, as in this embodiment, when a pattern layer 23 that absorbs infrared rays is disposed between the base film 21 and the base design layer 22, the first film 31 that will form the pattern layer 23 will sufficiently absorb infrared rays in the manufacturing process of the decorative sheet 20. Therefore, even if the second film 32 contains such an inorganic material, the first film 31 that absorbs the laser light Lx will melt and evaporate, and the second film 32 can be removed with almost no residue. In other words, it is possible to make it difficult for residue to remain in the opening H formed in the first area A1 of the decorative sheet 20.

In particular, the inorganic material includes aluminum, titanium oxide, or mica. When such materials are included, the visible light reflectance of the base design layer 22 can be 5% or more. Such a base design layer 22 also tends to be less resistant to absorbing infrared rays, and is difficult to remove even when irradiated with laser light. For this reason, it was difficult to form the opening H by irradiating the second film 32 with laser light. On the other hand, if a pattern layer 23 that absorbs infrared rays is disposed between the substrate film 21 and the base design layer 22 as in the present embodiment, in the manufacturing process of the decorative sheet 20, the first film 31 that will form the pattern layer 23 sufficiently absorbs infrared rays Lx, so that even if the second film 32 does not easily absorb infrared rays, the first film 31 that absorbs the laser light melts and evaporates, and the second film 32 can be removed with almost no residue. In other words, it is possible to make it difficult for residue to remain in the opening H formed in the first area A1 of the decorative sheet 20.

In the embodiment described above, the manufacturing method of the decorative sheet includes a step of laminating the first film 31, which will form the pattern layer 23, and the second film 32, which will form the base design layer 22, on the base film 21, and a step of removing a part of the first film 31 and the second film 32 by irradiating laser light from the side of the second film 32 to form an opening H. According to this manufacturing method of the decorative sheet, the laser light Lx for forming the opening H is not sufficiently absorbed in the second film 32, which will form the base design layer 22, while the laser light Lx can be sufficiently absorbed in the first film 31, which will form the pattern layer 23. Therefore, in the first region A1 where the first film 31 is provided, the first film 31 that absorbs the laser light Lx melts and evaporates, thereby removing the second film 32 laminated on the first film 31, and forming an opening H through which visible light can be sufficiently transmitted. On the other hand, in the second region A2 where the first film 31 is not provided, the laser light Lx is not easily absorbed by the second film 32, so that a recess R with a shallow depth DR can be formed. That is, even if the entire area of the second film 32 is irradiated with the laser light Lx, the opening H through which visible light can be sufficiently transmitted can be formed only in the first region A1 where the first film 31 forming the pattern layer 23 is provided. In other words, according to this embodiment, by adjusting the formation area of the first film 31, the formation area of the opening H through which visible light can be sufficiently transmitted can be controlled. Adjusting the formation area of the first film 31 is much easier than adjusting the irradiation area of the laser light Lx. Therefore, the decorative sheet 20 with excellent design can be easily and inexpensively produced.

In one specific example of the embodiment described above, the absorptance of the first film 31 at the wavelength of the laser light Lx is higher than the absorptance of the second film 32 at the wavelength of the laser light Lx. According to this example, the first film 31 that absorbs the laser light Lx melts and evaporates, so that the second film 32 stacked on the first film 31 can be stably removed. Therefore, the opening H that can sufficiently promote the transmission of visible light can be stably formed in the first region A1. On the other hand, in the second region A2 where the first film 31 is not provided, a shallow recess R can be formed instead of the opening H that can sufficiently promote the transmission of visible light. In other words, it is possible to control the formation region of the opening H with high precision by the pattern of the first film 31.

In one specific example of the embodiment described above, the absorption rate of the first film 31 at the wavelength of the laser light Lx used to form the opening H is 3% or more. According to this example, the first film 31 that will form the pattern layer 23 can sufficiently absorb the laser light Lx. Therefore, in the first region A1 where the pattern layer 23 is provided, the first film 31 that absorbs the laser light Lx melts and evaporates, so that the second film 32 stacked on the first film 31 can be stably removed, and the opening H that can sufficiently promote the transmission of visible light can be stably formed in the first region A1. In other words, it is possible to control the formation region of the opening H with high precision by the pattern of the first film 31.

In the embodiment described above, the decorative sheet 20 arranged facing the surface light source device 10 has a base design layer 22 and a pattern layer 23 provided on a part of the base design layer 22. In the first region A1 where the pattern layer 23 is provided, an opening H is provided that penetrates the base design layer 22 and reaches the pattern layer 23. The visible light transmittance in the first region A1 where the pattern layer 23 is provided is higher than the visible light transmittance in the first region A1 where the pattern layer 23 is not provided. Here, the infrared absorption rate of the pattern layer 23 is higher than the infrared absorption rate of the base design layer 22, the absorption spectrum of the pattern layer 23 has a peak in the infrared region, or the peak of the absorption spectrum of the pattern layer 23 in the infrared region is higher than the peak of the absorption spectrum of the base design layer 22 in the infrared region. In such a decorative sheet 20, the opening H formed by irradiation with laser light can transmit visible light with a higher transmittance in the first region A1 where the pattern layer 23 is provided. In other words, the openings H formed by irradiating the first area A1 with the pattern layer 23 with the laser light Lx can contribute to improving the visible light transmittance of the decorative sheet 20, compared to the recesses R formed by irradiating the second area A2 with no pattern layer 23 with the laser light Lx. Therefore, when the decorative sheet 20 is illuminated from behind, the first area A1 with the pattern layer 23 can be displayed brighter than the second area A2 with no pattern layer 23. Therefore, the combination of the pattern layer 23 and the base design layer 22 can effectively improve the design and provide a display with excellent design.

In one specific example of the embodiment described above, the aperture ratio in the first region A1 where the pattern layer 23 is provided is higher than the aperture ratio in the second region A2 where the pattern layer 23 is not provided. This allows the visible light transmittance in the first region A1 where the pattern layer 23 is provided to be stably higher than the transmittance in the second region A2 where the pattern layer 23 is not provided.

In one specific example of the embodiment described above, the pattern layer 23 is a colored layer. According to this example, when the decorative sheet 20 is not illuminated from behind, the pattern can be displayed by the color of the pattern layer 23. Furthermore, by illuminating the decorative sheet 20 from behind, the pattern displayed by the pattern layer 23 can be displayed brightly using visible light. This makes it possible to add variation to the display of the pattern, improving the design.

In one specific example of the embodiment described above, a recess R is provided in the second region A2 of the base design layer 22 where the pattern layer 23 is not provided, from the side opposite to the side where the pattern layer 23 is provided. The depth DR of the recess R is 80% or less of the thickness of the decorative sheet 20 excluding the base film 21 at the position where the recess R is not provided in the second region A2. According to this example, a part of the visible light irradiated from the back surface can pass through the second region A2 of the decorative sheet 20 in the part where the recess R is formed as a bottomed hole. In other words, the brightness of the second region A2 where the pattern layer 23 is not provided can be adjusted by the depth DR of the recess R that does not penetrate. This makes it possible to further improve the design.

In one specific example of the embodiment described above, the base design layer 22 contains an inorganic material. According to this example, the base design layer 22 contains an inorganic material, which allows for even richer design expression. On the other hand, it becomes difficult to stably form a penetrating opening H by irradiating laser light on the base design layer 22 that contains an inorganic material. Therefore, this embodiment, which can stabilize the hole shape by providing a pattern layer 23, can be said to be suitable for a decorative sheet 20 having a base design layer 22 that contains an inorganic material.

In one specific example of the embodiment described above, the inorganic material contains titanium oxide. By using titanium oxide as an inorganic material, the design of the decorative sheet 20 can be significantly improved in combination with the pattern layer. On the other hand, the visible light absorptance of the base design layer 22 containing such titanium oxide is reduced to about 3% or less, and the infrared absorptance of the base design layer 22 containing titanium oxide is also reduced to about 3% or less. As a result, it is difficult to stably form a penetrating opening H in such a base design layer 22 by irradiating it with laser light. For this reason, this embodiment, which can stabilize the hole shape by providing a pattern layer 23, can be said to be suitable for a decorative sheet 20 having a base design layer 22 containing titanium oxide as an inorganic material.

In one specific example of the embodiment described above, the visible light reflectance of the base design layer 22 is 5% or more. While a base design layer 22 with high reflectance allows for rich design expression, it is difficult to stably form a penetrating opening H in such a base design layer 22. Therefore, this embodiment, in which the hole shape can be stabilized by providing a pattern layer 23, can be said to be suitable for a decorative sheet 20 having a base design layer 22 containing an inorganic material.

Although one embodiment has been described based on a specific example, the above-mentioned specific example is not intended to limit the one embodiment. The above-mentioned one embodiment can be implemented with various other specific examples, and various omissions, substitutions, modifications, and additions can be made without departing from the spirit of the embodiment.

Below, an example of a modification will be described with reference to the drawings. In the following description and the drawings used in the following description, parts that can be configured similarly to the above-mentioned specific example will be designated by the same reference numerals as those used for the corresponding parts in the above-mentioned specific example, and duplicated descriptions will be omitted.

In the above-mentioned specific example, the pattern layer 23 is a colored layer, but the present invention is not limited to this example, and the pattern layer 23 may be a colorless and transparent layer. For example, the visible light transmittance of the pattern layer 23 can be 80% or more, and even 85% or more. According to this example, when the surface light source device 10 is turned off and does not emit visible light, the pattern layer 23 is not visible as shown in Figs. 12 and 13. Therefore, the first area A1 and the second area A2 of the decorative sheet 20 cannot be separated, and only the base design layer 22 is visible. Here, Fig. 13 corresponds to Fig. 4, and shows an enlarged view of the area Z in Fig. 12. On the other hand, when the surface light source device 10 is turned on and emits visible light, it is possible to display the pattern of the pattern layer 23 brightly and clearly as shown in Fig. 6. According to this example, the decorative sheet 20 can display a pattern that has not been visible until then by being illuminated from behind. In other words, a display with a sense of surprise can be performed, thereby improving the design.

In addition, in the specific example described above, the decorative sheet 20 includes only one base design layer 22, but this is not limited to this. As shown in FIG. 14, the decorative sheet 20 may include one or more further base design layers in addition to the base design layer 22. The further base design layer may be configured in the same manner as the base design layer 22 described above. The further base design layer may extend across the entire area of the decorative sheet 20 as a solid layer, similar to the base design layer 22.

In the example shown in FIG. 14, the decorative sheet 20 has a second base design layer 22B provided on the opposite side of the base design layer 22 from the substrate film 21. In the example shown in FIG. 14, the base design layer 22 is formed as a pattern layer that displays figures, patterns, designs, colors, pictures, photographs, characters, marks, letters and numbers, in particular wood grain and marble patterns and geometric patterns. The second base design layer 22B is formed as a layer containing an inorganic material or a metallic layer containing a metal to enhance the pattern of the base design layer 22. By providing the second base design layer 22B, the design of the base design layer 22 can be enhanced. Such a decorative sheet 20 can be produced by preparing a laminate 34 having a fourth film that will form the second base design layer 22B between the second film 32 that will form the base design layer 22 and the third film 33 that will form the light-shielding layer 33, and irradiating this laminate 34 with laser light.

Even in the decorative sheet 20 having the additional base design layer 22B, the infrared absorption rate of the pattern layer 23 is higher than that of the base design layer 22 adjacent to the pattern layer, or the peak of the absorption spectrum in the infrared region of the pattern layer 23 is higher than the peak of the absorption spectrum in the infrared region of the base design layer 22 adjacent to the pattern layer, so that the above-mentioned action and effect can be achieved. That is, according to such a decorative sheet 20, the opening H formed by irradiation with laser light can transmit visible light with a higher transmittance in the first region A1 where the pattern layer 23 is provided. In other words, the opening H formed by irradiation of the laser light Lx in the first region A1 where the pattern layer 23 is provided can contribute to improving the visible light transmittance of the decorative sheet 20 compared to the recess R formed by irradiation of the laser light Lx in the second region A2 where the pattern layer 23 is not provided. Therefore, when the decorative sheet 20 is illuminated from behind, the first area A1 where the pattern layer 23 is provided can be displayed brighter than the second area A2 where the pattern layer 23 is not provided. Furthermore, the combination of the pattern layer 23 and the base design layer 22 effectively improves the design, allowing for a display with excellent design.

Furthermore, in the decorative sheet 20 having the further base design layer 22B, the infrared absorption rate of the pattern layer 23 is higher than the infrared absorption rate of the further base design layer (second base design layer 22B), or the peak of the absorption spectrum in the infrared region of the pattern layer 23 is higher than the peak of the absorption spectrum in the infrared region of the further base design layer (second base design layer 22B), thereby making it possible to more significantly achieve the above-mentioned action and effect.

In addition, in the specific example described above, the inorganic material contained in the base design layer 22 may be flake-shaped (thin). Since flake-shaped inorganic materials have high reflectivity, a highly glossy design can be expressed by the base design layer 22. Examples of flake-shaped inorganic materials include aluminum and mica. The maximum length of the flake-shaped inorganic material may be 5 μm or more. From the viewpoint of displaying a lustrous design, it is preferable that the maximum length of the inorganic material is, for example, 20 μm or more. From the viewpoint of circulation resistance, it is preferable that the maximum length of the inorganic material is, for example, 60 μm or less.

In this modified example, as shown in FIG. 2B, the pattern layer 23 may be formed as a layer containing particles 23b in the binder resin 23a, and the maximum length of the particles 23b contained in the pattern layer 23 may be smaller than the maximum length of the flake-shaped inorganic material 22b contained in the binder resin 22a of the base design layer 22. In particular, the maximum length of the particles contained in the pattern layer 23 is preferably less than half the maximum length of the inorganic material contained in the base design layer 22, and more preferably less than one-fifth. Specifically, the maximum length of the particles contained in the pattern layer 23 may be 5 μm or less. When the base design layer 22 contains a flake-shaped inorganic material with a long maximum length, heat is not transferred to the entire binder resin even when irradiated with laser light, and it is difficult to evaporate. On the other hand, the pattern layer 23 using particles with a short maximum length is easily evaporable because heat is easily transferred to the entire binder resin, and the opening H can be formed by involving the base design layer 22 during evaporation. This allows selective formation of openings H in the areas where the pattern layer 23 is formed, and allows the design of the pattern layer 23 to correspond to the design displayed through the openings H by illumination from behind. Examples of the material of the particles contained in the pattern layer 22 include cyanine processed products, phthalocyanine compounds, dithiol metal complexes, lanthanum hexaboride, cesium-doped tungsten oxide, naphthoquinone compounds, and diimonium compounds.

The maximum length of the flake-like inorganic pigment contained in the base design layer 22 and the particles contained in the pattern layer 23 can be calculated, for example, by observing the cross section of each layer in the thickness direction using a scanning electron microscope (Hitachi S-4500) at an accelerating voltage of 15 kV and an observation magnification of 20,000 times, and calculating it as the average of the maximum lengths of 100 inorganic pigments or particles. When exposing the cross section of each layer for observation, it may be cut with a microtome, or it may be rapidly frozen in liquid nitrogen and then cut with a diamond knife or ion beam.

In the specific example described above, the surface light source device 10 has a rectangular light-emitting surface 11, but this is not limited to the example, and the light-emitting surface 11 of the surface light source device 10 may have a shape other than a rectangle. In addition, the display device 1 with the decorative sheet may further include a patterned light-shielding film, which may block a portion of the light emitted from the light-emitting surface 11 of the surface light source device 10, thereby illuminating the decorative sheet 20 in a predetermined pattern.

Reference Signs List 1 Display device with decorative sheet 10 Surface light source device 11 Light-emitting surface 12 Non-light-emitting surface 20 Decorative sheet 21 Substrate film 22 Base design layer 23 Pattern layer 24 Light-shielding layer 28 Transmitting portion 31 First film 32 Second film 33 Third film 34 Laminate 40 Laser device A1 First region A2 Second region H Opening R Recess Lx Laser light

Claims (23)

A decorative sheet disposed opposite a surface light source device,
A base design layer;
A pattern layer provided on a portion of the base design layer;
a visible light transmittance in a region where the pattern layer is provided is higher than a visible light transmittance in a region where the pattern layer is not provided;
A decorative sheet, wherein the infrared absorptivity of the pattern layer is higher than the infrared absorptivity of the base design layer. A decorative sheet disposed opposite a surface light source device,
A base design layer;
A pattern layer provided on a portion of the base design layer;
a visible light transmittance in a region where the pattern layer is provided is higher than a visible light transmittance in a region where the pattern layer is not provided;
A decorative sheet, wherein the peak of the absorption spectrum of the pattern layer in the infrared region is higher than the peak of the absorption spectrum of the base design layer in the infrared region. The decorative sheet according to claim 1 , wherein the absorption spectrum of the pattern layer has a peak at a wavelength of 900 nm or more and 1,300 nm or less. The decorative sheet according to any one of claims 1 to 3 , wherein the pattern layer has an absorption spectrum peak of 3% or more in the infrared region. The decorative sheet according to claim 1 , wherein a peak of the absorption spectrum of the pattern layer in the infrared region is higher than a peak of the absorption spectrum of the base design layer in the infrared region. The decorative sheet according to any one of claims 1 to 5, wherein a visible light transmittance in an area where the pattern layer is provided is higher than a visible light transmittance in an area where the pattern layer is not provided. The decorative sheet according to any one of claims 1 to 6 , wherein an aperture ratio in an area where the pattern layer is provided is higher than an aperture ratio in an area where the pattern layer is not provided. The decorative sheet according to any one of claims 1 to 7 , wherein the pattern layer is colored. The decorative sheet according to any one of claims 1 to 7 , wherein the pattern layer is colorless and transparent. The decorative sheet according to any one of claims 1 to 9 , wherein a recess is provided in an area of the base design layer where the pattern layer is not provided. The decorative sheet according to any one of claims 1 to 10, wherein the base design layer contains an inorganic material. The decorative sheet according to claim 11 , wherein the inorganic material is in a flake form. The decorative sheet according to claim 12 , wherein the maximum length of the flake-like inorganic material is 5 μm or more. The decorative sheet according to claim 12 or 13 , wherein the pattern layer contains particles, and the maximum length of the particles is smaller than the maximum length of the flaky inorganic material. The decorative sheet according to any one of claims 11 to 14 , wherein the inorganic material includes any one of aluminum, titanium oxide, and mica. The decorative sheet according to any one of claims 1 to 15 , wherein the base design layer has a visible light reflectance of 5% or more. The decorative sheet according to any one of claims 1 to 16 , wherein the base design layer has a visible light absorptance of 3% or less. Further comprising a light-shielding layer provided on the opposite side of the base design layer to the pattern layer,
The decorative sheet according to any one of claims 1 to 16, wherein the visible light transmittance of the light-shielding layer is lower than the visible light transmittance of the base design layer. A surface light source device;
A display device with a decorative sheet comprising: the decorative sheet according to any one of claims 1 to 18 , which is arranged to face the surface light source device. A method for producing the decorative sheet according to any one of claims 1 to 18 ,
preparing a first film which will form the pattern layer and a second film which will form the base design layer;
and removing a portion of the first film and the second film by irradiating a laser beam from a side of the second film to form an opening. The method for producing a decorative sheet according to claim 20 , wherein the absorptance of the first film at the wavelength of the laser light is higher than the absorptance of the second film at the wavelength of the laser light. The method for producing a decorative sheet according to claim 20 or 21 , wherein the first film has an absorptance of 3% or more at the wavelength of the laser light. The method for producing a decorative sheet according to any one of claims 20 to 22 , wherein the wavelength of the laser light is 900 nm or more and 1300 nm or less.