Display covering material, in-vehicle display device, method for manufacturing display covering material, and method for manufacturing in-vehicle display device

Abstract

The display cover material includes a transparent substrate having a first main surface and a second main surface, and a first printed layer laminated on the second main surface and having a first opening. In the display cover material, a second printed layer is laminated on a part of the surface of the first printed layer, the second printed layer has a different color from the first printed layer, and the second printed layer has a second opening. The first printing layer is exposed at the second opening portion, and a plurality of irradiation marks are formed on the surface of the first printing layer at the second opening portion.

Description

Technical Field

[0001] The present invention relates to a display covering material with a printed layer, a vehicle-mounted display device, a method for manufacturing a display covering material with a printed layer, and a method for manufacturing a vehicle-mounted display device. Background Art

[0002] In vehicle-mounted display devices such as instrument panels and portable display devices such as smartphones, a covering material is used on the front surface of a touch panel or a display panel. As such a covering material, a configuration is known in which a printed layer having a light-shielding property is provided at a peripheral portion of a transparent substrate such as glass. In addition, in order to perform alignment when bonding the covering material to a liquid crystal panel, it is known to provide alignment marks on the printed layer (for example, Patent Document 1).

[0003] In addition, in recent years, as a vehicle-mounted display device, for the purpose of improving the visual recognition of a driver or improving the design, it is required to bend the covering material into a three-dimensional shape (for example, Patent Document 2).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2017-87618

[0007] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2018-95553 Summary of the Invention

[0008] However, in the technology of Patent Document 1, there is a problem that the positional accuracy of the alignment marks is insufficient and a positional deviation occurs during bonding to a liquid crystal panel. In addition, in a three-dimensional shaped covering material such as that of Patent Document 2, it is particularly difficult to improve the positional accuracy of the alignment marks.

[0009] The present invention has been made in view of the above problems, and an object thereof is to provide a display covering material and a vehicle-mounted display device in which marks are formed with high positional accuracy, and a method for manufacturing a display covering material and a method for manufacturing a vehicle-mounted display device in which marks are formed with high positional accuracy.

[0010] The display covering material according to the present invention includes: a transparent substrate having a first main surface and a second main surface, and a first printed layer laminated on the second main surface and having a first opening portion. A second printed layer is laminated on a part of the surface of the first printed layer. The second printed layer has a color different from that of the first printed layer. The second printed layer has a second opening portion. In the second opening portion, the first printed layer is exposed. In the second opening portion, a plurality of irradiation marks are formed on the surface of the first printed layer.

[0011] The in-vehicle display device according to the present invention includes the above-described display cover material and a display.

[0012] The method for manufacturing the display cover material according to the present invention includes: laminating a first printing layer having a first opening on the second main surface of a transparent substrate having a first main surface and a second main surface, laminating a second printing layer having a color different from that of the first printing layer on a part of the surface of the first printing layer, and forming a second opening by irradiating the surface of the second printing layer with a laser to remove the second printing layer, so that the first printing layer is exposed from the second opening.

[0013] The method for forming the in-vehicle display device according to the present invention includes attaching the above-described display cover material to a display.

[0014] The attachment of the above-described display is performed by aligning the display with the display cover material by using the pattern formed by the second opening as an alignment mark.

[0015] According to the present invention, a display cover material for forming a mark with high positional accuracy and a method for manufacturing a display cover material for forming a mark with high positional accuracy can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram showing an in-vehicle display device including the display cover material according to the present embodiment.

[0017] Figure 2 It is a cross-sectional view of the display cover material with a printing layer according to the present embodiment.

[0018] Figure 3 It is a top view of the display cover material with a printing layer according to the present embodiment.

[0019] Figure 4 It is a graph showing the film thickness distribution of the first printing layer.

[0020] Figure 5A It is a top view showing the alignment mark formed in the second opening.

[0021] Figure 5B It is a top view showing the alignment mark formed in the second opening.

[0022] Figure 6A It is a top view showing the irradiation marks on the surface of the first printing layer exposed from the second opening.

[0023] Figure 6B It is a top view showing the irradiation marks on the surface of the first printing layer exposed from the second opening.

[0024] Figure 7 It is a schematic diagram showing an example of the configuration of a laser irradiation device that irradiates a part of the first printing layer with laser light.

[0025] Figure 8 It is a schematic diagram showing an example of a laser irradiation device.

[0026] Figure 9A It is an image obtained by photographing the surface of the second opening in Test Example 2.

[0027] Figure 9B It is an image obtained by photographing the surface of the second opening in Test Example 3.

[0028] Figure 9C It is an image obtained by photographing the surface of the second opening in Test Example 4. Detailed Embodiments

[0029] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0030] <In-vehicle display device>

[0031] Figure 1 It is a schematic diagram of an in-vehicle display device including the display cover material according to the present embodiment. As Figure 1 shown, the in-vehicle display device 2 is a display device provided in a vehicle. For example, it is provided on the front side of the steering shaft 1 in the vehicle interior. The in-vehicle display device 2 includes a display panel 3 and a display cover material 100. The display panel 3 displays images such as various gauges such as a car navigation screen and a speedometer, and a start button. The display cover material 100 is used as a cover material in front of the display panel 3. However, Figure 1 the configuration is an example, and the vehicle display device using the display cover material 100 can have any configuration. In addition, the display cover material 100 is not limited to being used as a cover material for the surface of an in-vehicle display device, and can also be used for any purpose including cover materials for display devices such as smartphones.

[0032] <Display cover material>

[0033] As Figure 2 , Figure 3 shown, the display cover material 100 with a printing layer according to the present embodiment includes: a transparent substrate 10 having a first main surface 10A and a second main surface 10B, a first printing layer 11 laminated on the second main surface 10B and having a first opening 12, and a second printing layer 13 laminated on a part of the surface of the first printing layer 11.

[0034] Among them, the first printing layer 11 and the second printing layer 13 have different colors, and a plurality of irradiation marks 20 are formed on the surface of the first printing layer 11 exposed at the second opening 14 (see Figure 6A , Figure 6B ).

[0035] When the display cover material 100 is mounted on the display device, the second main surface 10B side is attached to the display panel 3, and the first opening 12 serves as the display portion of the display. The pattern formed by the second opening 14 and the first printing layer 11 exposed from the second opening 14 is used, for example, as an alignment mark for alignment when the display cover material 100 is attached to the display panel 3.

[0036] The configuration of each layer will be described below.

[0037] (Transparent Substrate)

[0038] The transparent substrate 10 is not particularly limited in material as long as it has a high visible light transmittance and can protect the display panel 3, and can be resin or glass. From the viewpoints of strength, safety, heat resistance, and weather resistance, glass is preferred.

[0039] Examples of the resin include polyethylene terephthalate, polycarbonate, polymethyl methacrylate, etc.

[0040] As the glass, alkali-free glass, soda-lime glass, soda-lime silicate glass, aluminosilicate glass, borosilicate glass, lithium aluminosilicate glass, borosilicate glass, etc. can be used, and aluminosilicate glass and lithium aluminosilicate glass that are preferably easy to introduce large stress through strengthening treatment even when the thickness is thin to obtain high-strength glass are preferred.

[0041] The glass is preferably chemically strengthened glass that is strengthened by chemical strengthening treatment.

[0042] As a method for obtaining chemically strengthened glass by chemically strengthening the glass, typically, a method of immersing the glass in a KNO3 molten salt, performing ion exchange treatment, and then cooling to near room temperature can be cited. The treatment conditions such as the temperature of the KNO3 molten salt and the immersion time can be set so that the surface compressive stress and the thickness of the compressive stress layer become desired values.

[0043] The surface compressive stress (CS) of the compressive stress layer is preferably 500 MPa or more, more preferably 600 MPa or more, and further preferably 700 MPa or more. On the other hand, CS is preferably 1300 MPa or less.

[0044] The thickness (DOL) of the compressive stress layer is preferably 10 μm or more, more preferably 15 μm or more, still more preferably 20 μm or more, and particularly preferably 25 μm or more. In addition, DOL is preferably 50 μm or less, more preferably 40 μm or less.

[0045] When chemical strengthening is carried out, examples of the glass type include soda-lime glass, aluminosilicate glass (SiO2-Al2O3-Na2O-based glass), etc. Among them, aluminosilicate glass is preferred from the viewpoint of strength.

[0046] Examples of the glass material include a glass material containing 50% to 80% of SiO2, 1% to 20% of Al2O3, 6% to 20% of Na2O, 0% to 11% of K2O, 0% to 15% of MgO, 0% to 6% of CaO, and 0% to 5% of ZrO2 in terms of mol% based on oxides.

[0047] It is also preferable to use a chemically strengthened glass based on aluminosilicate glass. For example, "Dragontrail (registered trademark)" manufactured by AGC Inc. can be cited.

[0048] More specifically, the more preferable composition of the glass for the transparent substrate 10 is as follows. It should be noted that, for example, "containing 0 to 25% of MgO" means that MgO is not essential, but it can contain 25% or less of MgO. The glass in the following (i) is included in soda-lime silicate glass, the glasses in the following (ii) and (iii) are included in aluminosilicate glass, and the glasses in the following (iv) to (vi) are included in lithium aluminosilicate glass.

[0049] (i) A glass containing 63 to 73% of SiO2, 0.1 to 5.2% of Al2O3, 10 to 16% of Na2O, 0 to 1.5% of K2O, 0 to 5.0% of Li2O, 5 to 18% of MgO, and 1 to 10% of CaO in the composition expressed in mol% based on oxides.

[0050] (ii) A glass containing 50 to 74% of SiO2, 5 to 15% of Al2O3, 10 to 20% of Na2O, 0 to 8% of K2O, 0 to 5.0% of Li2O, 2 to 15% of MgO, 0 to 6% of CaO, and 0 to 5% of ZrO2 in the composition expressed in mol% based on oxides, and the total content of SiO2 and Al2O3 is 65 to 85%, the total content of Na2O and K2O is 12 to 25%, and the total content of MgO and CaO is 1 to 15%.

[0051] (iii) A glass whose composition expressed in mole % based on oxides contains 68 - 80% of SiO2, 4 - 10% of Al2O3, 5 - 15% of Na2O, 0 - 1% of K2O, 0 - 5.0% of Li2O, 4 - 15% of MgO, and 0 - 1% of ZrO2.

[0052] (iv) A glass whose composition expressed in mole % based on oxides contains 67 - 75% of SiO2, 0 - 4% of Al2O3, 7 - 15% of Na2O, 1 - 9% of K2O, 0 - 5.0% of Li2O, 6 - 14% of MgO, and 0 - 1.5% of ZrO2, and the total content of SiO2 and Al2O3 is 71 - 75%, the total content of Na2O and K2O is 12 - 20%, and when CaO is contained, its content is less than 1%.

[0053] (v) A glass whose composition expressed in mole % based on oxides contains 50 - 73% of SiO2, 5 - 20% of Al2O3, 0 - 6% of B2O3, 0 - 10% of P2O5, 4 - 12% of Li2O, 3 - 20% of Na2O, 0 - 5% of K2O, 0 - 8% of MgO, 0 - 2% of CaO, 0 - 5% of SrO, 0 - 5% of BaO, 0 - 5% of ZnO, 0 - 2% of TiO2, 0 - 4% of ZrO2.

[0054] (vi) A glass whose composition expressed in mole % based on oxides contains 58 - 80% of SiO2, 13 - 18% of Al2O3, 0 - 5% of B2O3, 0.5 - 4% of P2O5, 3 - 10% of Li2O, 5 - 20% of Na2O, 0 - 2% of K2O, 0 - 11% of MgO, 0 - 20% of CaO, 0 - 20% of SrO, 0 - 15% of BaO, 0 - 10% of ZnO, 0 - 1% of TiO2, 0 - 2% of ZrO2.

[0055] The thickness of the glass is not particularly limited. For effective chemical strengthening treatment, it is usually preferably 5 mm or less, more preferably 3 mm or less. In addition, when used as a cover glass for in-vehicle display devices such as car navigation, from the viewpoint of strength, the thickness of the glass is preferably 0.2 mm or more, more preferably 0.8 mm or more, and further preferably 1 mm or more. It should be noted that the thickness of the glass refers to the distance in the normal direction between the first main surface 10A and the second main surface 10B of the transparent substrate 10. In addition, when the transparent substrate 10 is made of a material other than glass, it may have the same thickness as the above-mentioned glass.

[0056] The size of the transparent substrate 10 can be appropriately selected according to the intended use. When used as a covering material for an in-vehicle display device, the length of the short side is, for example, 50 mm to 500 mm, preferably 100 mm to 300 mm, and the length of the long side is, for example, 50 mm to 1500 mm, preferably 100 mm to 1200 mm.

[0057] The shape of the transparent substrate 10 can be Figure 2 the flat shape shown, or can be a shape including a three-dimensional curved surface having one or more bent portions or folded portions.

[0058] Here, the curved surface in the present embodiment means that the radius of curvature is 10,000 mm or less. On the contrary, the flat surface means that the radius of curvature is greater than 10,000 mm.

[0059] When the transparent substrate 10 has a curved surface, the radius of curvature of the curved surface is preferably 50 mm or more, more preferably 100 mm or more, and still more preferably 200 mm or more. The radius of curvature is, for example, 10,000 mm or less, preferably 5,000 mm or less, and more preferably 3,000 mm or less.

[0060] When the display covering material 100 is used for an in-vehicle display device, in order to improve visual recognition or design, a shape having a curved surface is preferred. However, in a shape having a curved surface, it is difficult to align the display covering material 100 and the display panel 3 during bonding, and it is difficult to form marks with good positional accuracy in existing methods. In particular, when the minimum radius of curvature of the curved surface is 800 mm or less, it is increasingly difficult to improve the positional accuracy of the marks in existing printing methods, and it is preferable to use the display covering material 100 of the present embodiment.

[0061] The planar shape of the transparent substrate 10 can be Figure 3 the rectangle shown, but is not limited thereto, and can be a substantially rectangular shape, a shape in which each side is curved, or a shape in which each side has a recess or a protrusion. In particular, in an in-vehicle display device, the demand for a complex shape is increasing from the viewpoint of improving design or visual recognition. In such a complex shape, it is difficult to align the display covering material 100 and the display panel 3 during bonding, and particularly high positional accuracy of the alignment marks is required.

[0062] It should be noted that when the transparent substrate 10 has a curved surface, the first printing layer 11, the second printing layer 13, and other decorative layers described later are deformed following the shape of the transparent substrate 10.

[0063] (The first printing layer and the first opening)

[0064] As Figure 2 、 Figure 3As shown, a first printing layer 11 having a first opening 12 is formed on the second main surface 10B of the transparent substrate 10. The second main surface 10B of the transparent substrate 10 is exposed in the first opening 12. Figure 3 The display is omitted. Figure 3 In this case, the first printing layer 11 is provided on the outer peripheral portion of the transparent substrate 10 and has one first opening 12. However, it is not limited thereto. For example, when two display areas of a display are to be provided, it may be in a shape independently having two first openings 12. The first printing layer 11 functions to shield wiring components and the like disposed in the peripheral portion of the display panel 3 so that the area other than the display area cannot be visually recognized from the observer side.

[0065] The first printing layer 11 is formed, for example, by a method of printing ink. From the viewpoint of improving durability, it is preferably formed by curing a thermosetting or photocurable ink. The color of the first printing layer 11 is not particularly limited. From the viewpoint of high light-shielding property, a color with low brightness is preferably used. For example, the color of the first printing layer 11 is black, brown, dark blue, etc., and pattern printing such as wood grain may also be used. In addition, in order to improve the light-shielding property, the first printing layer 11 preferably contains carbon black.

[0066] The first printing layer 11 may be a single layer or may be composed of multiple layers. When composed of multiple layers, the same ink may be coated and overlapped in multiple layers, or different inks may be overlapped. For example, by coating and overlapping the same ink in multiple layers, the light-shielding property can be improved. For example, after forming a first layer that imparts design on glass, a second layer with a higher light-shielding property can be overlapped with a different ink. In addition, the number of layers of the first printing layer 11 may be locally different. For example, when an infrared transmission area is provided in a part of the printing layer, after forming a first layer that shields visible light and transmits infrared light on the glass, a second layer with a higher shielding property may be further formed in the area other than the infrared transmission area.

[0067] The film thickness of the first printing layer 11 is preferably formed to be 2.0 μm to 20.0 μm, and more preferably 5.0 μm to 15.0 μm. If the film thickness is thicker than 20 μm, when the transparent substrate 10 and the display panel 3 ( Figure 1 ) are bonded using an optical adhesive, air bubbles are likely to remain at the printing step. By making the film thickness 2.0 μm or more, the light-shielding property of the first printing layer 11 can be sufficiently ensured, and it is easy to prevent wiring from being seen through from the first main surface 10A side or the pattern formed by the second opening 14.

[0068] Here, as the film thickness of the first printing layer 11, the average value of the film thickness measured at multiple points in the area other than the 4 mm around the first opening 12 and the first printing layer 11 exposed in the second opening 14 is preferably used. As the number of measurement points, for example, 3 or more points are preferred, and they are preferably selected evenly within the main surface.

[0069] There is no particular limitation on the shape of the end portion of the first printing layer 11 at the boundary with the first opening 12, and it preferably has a steep slope in a cross-sectional view. The slope of the end portion is preferably 0.1 or more, more preferably 0.5 or more, and further preferably 1.0 or more. If the slope of the end portion is within the above range, in the first printing layer 11, the region with a thin film thickness and low light-shielding property becomes narrower, light leakage at the end portion can be further suppressed, the boundary becomes clearer, and the designability is more excellent when the display device covering material 100 is used for a display device.

[0070] As Figure 4 shown, the slope of the end portion of the first printing layer 11 is obtained by setting two points P1 and P2 with different thicknesses on the surface of the end portion 11A and calculating the ratio (Lt / Lh) of the distance Lt in the thickness direction to the distance Lh in the in-plane direction between these two points P1 and P2. Among them, point P1 is the point where the thickness of the first printing layer 11 reaches 10% of the average thickness t of the first printing layer 11, and point P2 is the point where the thickness of the first printing layer 11 reaches 50% of the average thickness t of the first printing layer 11. The first printing layer 11 with the slope of the end portion within the above range can be formed by, for example, performing laser trimming described later and adjusting the conditions of the laser trimming.

[0071] (Second printing layer and second opening)

[0072] As Figure 2 , Figure 3 shown, the second printing layer 13 is formed on a part of the first printing layer 11 and has a second opening.

[0073] By having a color different from that of the first printing layer 11, the second printing layer 13 can form a pattern detectable by a camera or the like in the second opening 14. Here, the different colors in this embodiment refer to the color difference ΔE in the L * a * b colorimetric system (ΔE = { (ΔL * ) 2 + (Δa * ) 2 + (Δb * ) 2} 1 / 2 ) with a value difference of 1.5 or more.

[0074] The color of the second printing layer 13 preferably has a color difference ΔE value different from that of the first printing layer 11 by 2.0 or more, and more preferably by 3.0 or more. The greater the color difference from the first printing layer 11, the clearer the contour of the formed pattern and the higher the detectability using a camera or the like.

[0075] Here, the hues of the first printing layer 11 and the second printing layer 13 can be measured by using a colorimeter such as the SCI method (e.g., CM-5 manufactured by Konica Minolta) on their respective surfaces. The measurement is preferably carried out at three points uniformly selected in the target area, and the average value is adopted.

[0076] In addition, as described above, the first printing layer 11 preferably uses a color with low brightness. Therefore, the color of the second printing layer 13 preferably uses a color with relatively high brightness, more preferably white or a color close to white.

[0077] The second printing layer 13 is formed, for example, by a method of printing ink. In order to make the color of the second printing layer 13 a color with relatively higher brightness compared to the first printing layer 11, it is preferred that the second printing layer 13 does not contain carbon black or the content of carbon black is less than that of the first printing layer 11. In addition, the second printing layer 13 preferably contains, for example, titanium oxide or the like as a white-based material.

[0078] In addition, as described below, the second printing layer 13 is preferably formed by a printing method that does not include a step of curing by heating or light irradiation. From this viewpoint, the second printing layer 13 is preferably formed by curing a non-thermosetting and non-photocurable ink. As a substance having such properties, the main component of the second printing layer 13 is preferably a non-crosslinkable resin.

[0079] The formation position of the second printing layer 13 is not particularly limited as long as it is on the first printing layer 11. When the transparent substrate 10 is rectangular, it can be provided on the side or in a corner shape. The second printing layer 13 can be one or a plurality can be formed. When using the pattern formed by the second opening 14 as an alignment mark, from the viewpoint of improving the alignment accuracy, the second printing layer 13 is preferably formed at two or more places, more preferably at three or more places.

[0080] The shape of the second printing layer 13 is not particularly limited and can be rectangular or circular. The size of the second printing layer 13 is not particularly limited as long as it is a sufficient size relative to the desired size of the second opening 14.

[0081] The pattern formed in the second opening 14 is used, for example, as an alignment mark for alignment when bonding to the display panel 3. The shape of the second opening is not particularly limited. For example, in addition to the Figure 5A shown cross shape, it can also be a quadrangle, a circle, or any other arbitrary shape. In addition, a plurality of second openings 14 can be provided in one second printing layer 13. For example, as shown in Figure 5B a pattern of display information such as a QR code (registered trademark), a barcode, or other character strings can be formed.

[0082] The size of the second opening 14 is not particularly limited. When used as an alignment mark, for example, in the circumscribed circle of the formed pattern, a diameter of 1 mm to 20 mm is preferred. In particular, when the alignment mark is quadrilateral, the diagonal length is preferably 1 mm to 20 mm.

[0083] (Irradiation mark 20)

[0084] The second opening 14 is formed by removing the second printing layer 13 by laser irradiation as described below. Therefore, an irradiation mark 20 as shown in Figure 6A 、 Figure 6B and in the following embodiments is formed on the surface of the first printing layer 11 exposed in the second opening 14. The irradiation mark 20 refers to a portion where the surface of the first printing layer 11 is modified by laser irradiation and the color appears to change, and has a substantially circular shape.

[0085] The irradiation mark 20 is generated in a part of the region irradiated with the laser. The cross-sectional intensity distribution of the laser is generally based on a Gaussian distribution, and the intensity at the center near the optical axis becomes higher. Therefore, near the center of the optical axis, in particular, the portion where the surface of the first printing layer 11 is damaged becomes the irradiation mark 20.

[0086] The arrangement of the irradiation marks 20 is not particularly limited. From the viewpoint of balancing the suppression of damage to the first printing layer 11 and the removal of the second printing layer 13, it is preferably arranged along a regular pattern. For example, it can be in the form of a checkerboard grid as shown in Figure 6A , or in a staggered form as shown in Figure 6B .

[0087] For example, from the viewpoint of productivity, the diameter d of the irradiation mark 20 is preferably 10 μm or more, more preferably 30 μm or more. On the other hand, from the viewpoint of making the contour of the alignment mark shape clear, the diameter d of the irradiation mark 20 is preferably 200 μm or less, more preferably 100 μm or less.

[0088] The interval p between the irradiation marks 20 is preferably greater than 1.0 times the diameter d of the irradiation mark 20. The irradiation mark 20 is a portion where the first printing layer 11 is particularly damaged. By irradiating the laser in such a way that the regions do not overlap, damage to the first printing layer can be suppressed, and a decrease in the light shielding property of the printing layer due to a reduction in film thickness or light leakage can be suppressed. The interval p between the irradiation marks 20 is more preferably 1.1 times or more the diameter d of the irradiation mark 20.

[0089] On the other hand, if the interval p between the irradiation marks 20 is, for example, 2.6 times or less the diameter d of the irradiation marks 20, the area where the second printing layer 13 remains without being removed can be made less than 30%. The interval p between the irradiation marks 20 is preferably 2.0 times or less the diameter d of the irradiation marks 20. If the interval p between the irradiation marks 20 is within the above range, the area where the second printing layer 13 remains without being removed can be made almost non-existent, and the recognition of the pattern can be improved. The interval p between the irradiation marks 20 is more preferably 1.8 times or less the diameter d of the irradiation marks 20, and further preferably 1.5 times or less.

[0090] That is, by providing the irradiation marks 20 in the first printing layer 11 at the second opening 14, the positional accuracy of the second opening 14 can be improved. In addition, by making the interval p between the irradiation marks 20 within the above range, damage to the first printing layer 11 can be suppressed, and the recognition of the pattern can be improved.

[0091] Here, the positional accuracy in the present embodiment refers to the deviation between the predetermined formation position and the actually formed position of the second opening 14. The predetermined formation position or the actually formed position can, for example, take a part of the boundary line between the first opening 12 and the first printing layer 11 as a reference point, and the position can be evaluated using the distance from this point. With the display cover material 100 according to the present embodiment, the positional accuracy can be made ±50 μm or less.

[0092] Here, the light leakage in the present embodiment means a decrease in the light-shielding property of the printing layer or the generation of pinholes. The decrease in the light-shielding property can be evaluated, for example, using the OD value (Optical Density) of the printing layer, etc. It is generally known that the reduction in film thickness is related to the OD value.

[0093] The deviation of the irradiation marks 20 is preferably 0.4 times or less the diameter d of the irradiation marks 20. Here, the deviation of the irradiation marks 20 refers to the amount of deviation from the predetermined formation position of the irradiation marks. By making the deviation of the irradiation marks 20 within the above range, there are advantages such as the contour becoming clear when recognizing the pattern formed by the second opening 14 with a camera, and the recognition accuracy can be ensured.

[0094] The thickness difference between the first printing layer 11 at the second opening 14 and the first printing layer 11 outside the second opening is preferably 3.0 μm or less, more preferably 2.5 μm or less, and further preferably 2.3 μm or less. By comparing the thickness of the first printing layer 11 at the second opening 14 with the thickness of the first printing layer 11 outside the second opening 14, the reduction amount of the first printing layer 11 before and after laser irradiation can be known. By making the thickness difference between the first printing layer 11 at the second opening 14 and the first printing layer 11 outside the second opening 14 particularly 3.0 μm or less, damage to the second printing layer 13 caused by laser irradiation can be suppressed, and light leakage can be prevented.

[0095] Here, the film thickness of the first printing layer 11 of the second opening 14 is the film thickness measured for the first printing layer 11 exposed in the second opening 14. As the film thickness of the first printing layer 11 other than the second opening 14, it is preferable to use the average value of the film thicknesses measured at multiple points in a region other than the 4 mm around the first opening 12 and the first printing layer 11 exposed in the second opening 14. As the number of measurement points, for example, it is preferably 3 or more, and it is preferably selected uniformly within the target area.

[0096] (Decoration layer on the first main surface 10A)

[0097] A decorative layer such as an antiglare layer, an antireflection layer, and an antifouling layer can be provided on the first main surface 10A of the transparent substrate 10. The following antiglare layer, antireflection layer, and antifouling layer are examples, and can be appropriately changed within the range of having the functions of each layer. In addition, the antiglare layer, antireflection layer, and antifouling layer are not essential components, and depending on the configuration of the display cover material 100, a part of the antiglare layer, antireflection layer, and antifouling layer may not be provided.

[0098] The antiglare layer is provided on the first main surface 10A side of the transparent substrate 10 to impart antiglare properties to the transparent substrate 10. The antiglare layer has an uneven shape formed on the first main surface 10A side of the transparent substrate 10. The uneven shape can be one directly formed with unevenness on the first main surface 10A of the transparent substrate 10, or can be formed by a layer made of a material different from the transparent substrate 10. In addition, it can be provided on both the first main surface 10A and the second main surface 10B. The surface roughness (root mean square roughness, RMS) of the uneven shape is preferably 10 nm to 1000 nm, more preferably 15 nm to 500 nm. The antiglare layer can be realized by the uneven shape imparted by performing an antiglare treatment and an etching treatment on the first main surface 10A of the transparent substrate 10. In addition, a coating film in which particles having an arbitrary refractive index are dispersed can be used on the first main surface 10A of the transparent substrate 10, or an uneven shape can be formed on the main surface of the adhered transparent resin film, and the uneven shape can be used to realize it.

[0099] The antireflection layer brings an effect of reducing the reflectance to the transparent substrate 10, and in addition to reducing the glare caused by the incident light, when used in a display device, it can improve the visual recognition of the display device. The configuration of the antireflection layer is not particularly limited as long as it can suppress the reflection of light. For example, it can be a configuration in which a high refractive index layer having a refractive index of 1.9 or more at a wavelength of 550 nm and a low refractive index layer having a refractive index of 1.6 or less at a wavelength of 550 nm are alternately laminated. The antireflection layer is provided on the first main surface 10A side of the transparent substrate 10, and can be directly provided on the first main surface 10A, or can be provided on the antiglare layer. In addition, it can also be provided on both the first main surface 10A and the second main surface 10B.

[0100] The anti-fouling layer is an anti-fouling layer that has the function of suppressing the adhesion of fingerprint marks or various dirt such as sweat and dust, making the dirt less conspicuous, or facilitating the cleaning of the adhered dirt, and keeps the display surface clean. The anti-fouling layer is provided on the side of the first main surface 10A of the transparent substrate 10, but from the viewpoint of the characteristics of the anti-fouling layer, it is preferably formed on the outermost surface on the side of the first main surface 10A of the display cover material 100. The anti-fouling layer is composed of a fluorine-containing compound (a compound having a fluorine-containing organic group) that can impart anti-fouling properties, hydrophobicity, and oleophobicity. The fluorine-containing compound is preferably a fluorine-containing organic compound, and more preferably a fluorine-containing organosilicon compound.

[0101] <Manufacturing Method of Display Cover Material>

[0102] Next, the manufacturing method of the display cover material 100 of the present embodiment will be described.

[0103] The manufacturing method of the display cover material 100 of the present embodiment has the following steps: a step of laminating a first printing layer 11 having a first opening 12 on the second main surface 10B of a transparent substrate 10 having a first main surface 10A and a second main surface 10B, a step of laminating a second printing layer 13 having a color different from that of the first printing layer 11 on a part of the surface of the first printing layer 11, and a step of irradiating the surface of the second printing layer 13 with a laser to remove the second printing layer 13, thereby forming a second opening 14 and exposing the first printing layer 11 from the second opening 14.

[0104] The details of each step will be described below.

[0105] (Preparation of Transparent Substrate)

[0106] Prepare a transparent substrate 10 having a first main surface 10A and a second main surface 10B. As the transparent substrate 10, a substrate having the characteristics described in the above (transparent substrate) is prepared. The transparent substrate 10 is preferably glass. In the case of glass, the manufacturing method is not particularly limited. For example, it can be manufactured by putting the required glass raw materials into a melting furnace, heating and melting them at 1500 to 1600 °C, clarifying them, and then supplying them to a forming device to form the molten glass into a flat plate shape and slowly cooling it. It should be noted that the forming method of the glass is not particularly limited. For example, the down-draw method (such as the overflow down-draw method, the slot down-draw method, the redraw method, etc.), the float method, the roll press method, the pressing method, etc. can be used.

[0107] In addition, it may have a forming step of cutting the glass on the above-obtained flat plate into an arbitrary shape and size and bending it into a three-dimensional shape while heating. Through the forming step, a curved surface having the shape described in the above (transparent substrate) can be formed on the transparent substrate 10. In addition, before or after the forming step, the workpiece can be subjected to hole processing or chamfering of the end face.

[0108] When using glass as the transparent substrate 10, in order to improve the strength of the obtained substrate, it is preferable to perform chemical strengthening treatment. The chemical strengthening treatment is preferably carried out after bending forming. The method of chemical strengthening treatment is not particularly limited. Ion exchange is performed on the main surface of the transparent substrate to form a surface layer with residual compressive stress. Specifically, at a temperature below the glass transition temperature, an alkali metal ion with a small ionic radius (e.g., Li ion, Na ion) contained in the glass near the main surface of the substrate is replaced with an alkali metal ion with a larger ionic radius (e.g., Na ion or K ion relative to Li ion, K ion relative to Na ion). Thereby, compressive stress remains on the main surface of the transparent substrate 10, and the strength of the transparent substrate is improved.

[0109] (Lamination of the first printing layer)

[0110] Next, a first printing layer 11 is formed on the second main surface 10B of the transparent substrate 10. The first printing layer 11 is formed, for example, by printing ink, and is preferably printed with a design having a first opening 12. As the printing method, there is no particular limitation. As a preferred method, an inkjet method, a screen printing method, a transfer decoration method, etc. can be cited. Especially when the transparent substrate 10 has a multi-bending shape or a curved surface with a bending angle of 45 degrees or more, it is preferable to perform printing by the transfer decoration method.

[0111] In addition, from the viewpoint of improving the durability of the first printing layer 11, a step of curing the ink by heating or light irradiation is preferably included.

[0112] As the ink, an inorganic ink containing a ceramic calcined body, etc., and an organic ink containing a coloring material such as a dye or a pigment and an organic resin can be used.

[0113] In addition, from the viewpoint of improving the durability of the first printing layer 11, the ink preferably uses a thermosetting or photocurable substance.

[0114] As the inorganic ink, for example, a composition composed of one or more selected from SiO2, ZnO, B2O3, Bi2O3, Li2O, Na2O, and K2O, one or more selected from CuO, Al2O3, ZrO2, SnO2, and CeO2, Fe2O3, and TiO2 can be used.

[0115] As an organic-based ink, various printing materials in which a resin is dissolved in a solvent can be used. For example, as the resin, at least one resin selected from acrylic resins, polyurethane resins, epoxy resins, polyester resins, polyamide resins, vinyl acetate resins, phenolic resins, olefin resins, ethylene-vinyl acetate copolymer resins, polyvinyl acetal resins, natural rubbers, styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, polyester polyols, polyether polyurethane polyols, etc. can be selected and used. In addition, as the solvent, water, alcohols, esters, ketones, aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents can be used. For example, as the alcohols, isopropyl alcohol, methanol, ethanol, etc. can be used, as the esters, ethyl acetate can be used, and as the ketones, methyl ethyl ketone can be used. In addition, as the aromatic hydrocarbon solvents, toluene, xylene, SOLVESSO 100, SOLVESSO 150 manufactured by Exxon Mobil Corporation, etc. can be used, and as the aliphatic hydrocarbon solvents, hexane, etc. can be used. It should be noted that these substances are given as examples, and various printing materials can be used. The above-mentioned organic-based printing material can form a resin layer by evaporating the solvent after coating it on a plate, thereby forming a printing layer.

[0116] The ink used in the first printing layer 11 may contain a colorant. The color of the first printing layer 11 is not particularly limited, and from the viewpoint of high light-shielding property, a color with low brightness is preferably used. For example, black, brown, dark blue, etc., can be used for pattern printing such as wood grain, and the colorant can be arbitrarily selected according to the design of the color of the first printing layer 11. Especially from the viewpoint of improving the light-shielding property, the ink preferably contains carbon black.

[0117] The first printing layer 11 can be a single layer or multiple layers can be laminated. When composed of multiple layers, the same ink can be coated multiple times in an overlapping manner, or different inks can be coated in an overlapping manner. For example, by coating the same ink multiple times in an overlapping manner, the light-shielding property can be improved. For example, after forming a first layer that imparts design on glass, a second layer with a high light-shielding property can be overlapped with a different ink. In addition, the number of layers of the first printing layer 11 can be locally different. For example, when an infrared transmission region is provided in a part of the first printing layer 11, after forming a first layer that shields visible light and transmits infrared light on the glass, a second layer with a high shielding property can be further formed in the region other than the infrared transmission region, etc.

[0118] (Laser trimming)

[0119] After forming the first printing layer 11, a process of irradiating a part of the first printing layer 11 disposed on the main surface of the glass substrate with laser light to remove the irradiated first printing layer 11 (hereinafter also referred to as "laser trimming") can be performed. Especially when the first printing layer 11 is printed by the transfer decoration method, it is preferably implemented in order to correct the shape of the first opening 12.

[0120] This is because by performing laser trimming, it is easy to form the first opening 12 having a desired shape at the correct position, and the inclination of the end portion of the first printing layer 11 is closer to the normal line of the main surface, making the boundary between the first opening 12 and the first printing layer 11 clearer, and the visual recognition when using the glass with the first printing layer 11 for a display device is more excellent.

[0121] Figure 7 FIG. is a schematic diagram showing an example of the configuration of a laser irradiation device that irradiates a part of the first printing layer 11 with laser. It should be noted that the configuration of the laser irradiation device and the processing method of laser trimming are not limited to Figure 7 the configuration shown.

[0122] Figure 7 The laser irradiation device 30 shown irradiates the first printing layer 11 with an absorbable laser L and performs ablation processing on the first printing layer 11.

[0123] The laser irradiation device 30 includes a laser oscillator 31, a mirror 32, and a condenser lens 33. The laser oscillator 31 oscillates a laser L having an absorbable wavelength at a predetermined irradiation time to the first printing layer 11 according to a control signal from a control device (not shown). The condenser lens 33 condenses the laser L oscillated from the laser oscillator 31 and guides it to the first printing layer 11. The mirror 32 is disposed between the laser oscillator 31 and the condenser lens 33 and directs the optical axis of the laser L oscillated from the laser oscillator 31 toward the condenser lens 33. Thus, as Figure 7 shown, the excess portion 11B of the first printing layer 11 irradiated with the laser L is removed to form an end portion 11A.

[0124] The main surface for irradiating the laser can be either the first main surface 10A or the second main surface 10B. As Figure 7 shown, by irradiating from the side of the first main surface 10A opposite to the surface on which the first printing layer 11 is disposed, it is easier to remove the unnecessary portion, so it is preferred.

[0125] The conditions for laser trimming are set as follows.

[0126] The wavelength of the laser L can be appropriately selected according to the absorption wavelength of the coloring agent contained in the first printing layer 11, preferably 300 to 1100 nm, more preferably 500 to 1100 nm.

[0127] The irradiation interval of the laser L is preferably less than 100 μm, more preferably less than 70 μm. In addition, the scanning speed is preferably 1000 to 8000 mm / s, more preferably 1000 to 4000 mm / s. The irradiation interval is the interval of the laser intermittently irradiated on the first printing layer 11 when scanning on the first printing layer 11, and is calculated by dividing the scanning speed by the irradiation frequency of the laser L.

[0128] (Lamination of the second printing layer)

[0129] Next, a second printing layer 13 is formed on the first printing layer 11.

[0130] The second printing layer 13 is formed, for example, by a method of printing ink. The printing method is not particularly limited. As a preferred method, an inkjet method, a pad printing method, etc. can be cited. From the viewpoint of productivity, the inkjet method is more preferred. As the inkjet method, a continuous type is preferred. In addition, it is preferred that there is no curing process by heating or light irradiation after the above printing process. Since there is no curing process, it is easy to remove the second printing layer 13 by continuously irradiating laser, and it is easy to prevent damage to the first printing layer 11. In addition, since no curing process is required, there is also an advantage in terms of productivity.

[0131] As the ink, an inorganic ink containing a ceramic calcined body, etc., and an organic ink containing a coloring material such as a dye or a pigment and an organic resin can be used. From the viewpoint of being easily removed by laser irradiation, it is preferred to use an organic ink. In addition, as the main component of the ink, a resin that is not thermosetting or photocuring is preferably used. For example, a non-crosslinking resin is preferably used.

[0132] The materials preferably used for the inorganic ink and the organic ink are the same as those described for the first printing layer 11, so the description here is omitted.

[0133] The ink used in the second printing layer 13 may contain a colorant. The color of the second printing layer 13 is not particularly limited. A color with relatively higher brightness compared to the first printing layer 11 is preferably used, and the colorant can be arbitrarily selected according to the design of the second printing layer 13. In particular, from the viewpoint of forming a color with high brightness, it is preferred that the content of carbon black is less than that of the first printing layer 11 or carbon black is not contained, and a white material such as titanium oxide is preferably contained.

[0134] (Forming the second opening by laser irradiation)

[0135] Next, by irradiating the second printing layer 13 with laser, the second printing layer 13 is removed so that a part of the first printing layer 11 is exposed, and the second opening 14 is formed.

[0136] Figure 8 It is a schematic diagram showing an example of the laser irradiation device 40. Figure 8 In this, the laser irradiation device 40 irradiates the second printing layer 13 with an absorbable laser L2 and performs ablation processing on the second printing layer 13.

[0137] The laser irradiation device 40 includes a laser oscillator 41, a mirror 42, and a condenser lens 43. The laser oscillator 41 oscillates a laser L2 having an absorptive wavelength from the second main surface B side toward the second printing layer 13 at a specified irradiation timing according to a control signal from a control device (not shown). The condenser lens 43 condenses the laser L oscillated from the laser oscillator 41 and guides it to the second printing layer 13. The mirror 42 is disposed between the laser oscillator 41 and the condenser lens 43, and makes the optical axis of the laser L2 oscillated from the laser oscillator 41 face the condenser lens 43.

[0138] The mirror 42 is preferably a galvanometer mirror (galvo mirror). By rotating the galvo mirror around an axis, the laser L2 deflected by the galvo mirror is scanned on the second printing layer 13.

[0139] It should be noted that the laser scanning method is not limited to this. For example, a scanning head including the mirror 42 and the condenser lens can be scanned in the XY direction, which is two orthogonal axial directions. By using a galvo mirror as the mirror 42, the deviation of the irradiation mark 20 can be suppressed, the recognition of the pattern formed by the second opening 14 using a camera or the like can be improved, and the position accuracy of the second opening 14 can be further improved.

[0140] The wavelength of the laser L2 is not particularly limited, and is preferably 300 nm to 1100 nm. In addition, the oscillation mode of the laser L2 is not particularly limited, and pulse oscillation is preferred. For example, the pulse width is preferably 1 ns to 100 ns. If it is within the above range, ablation can occur effectively and the second printing layer 13 can be removed effectively.

[0141] The scanning speed is preferably 100 mm / s to 8000 mm / s, more preferably 1000 mm / s to 4000 mm / s. The output power of the laser L2 is preferably 10 W or less. The spot diameter of the laser L2 is preferably 10 μm to 200 μm. The irradiation interval of the laser L2 is preferably 10 μm to 200 μm. In addition, it is more preferably 0.5 times to 1.3 times the spot diameter, and further preferably 0.5 times to 1.0 times. By making the irradiation interval of the laser 0.5 times or more the spot diameter, the overlap of the irradiation marks 20 can be suppressed and the damage to the first printing layer 11 can be suppressed, thereby suppressing light leakage at the second opening 14. By making the irradiation interval of the laser 1.0 times or less the spot diameter, the situation where the second printing layer 13 is not removed and remains can be suppressed.

[0142] (Formation of other decorative layers)

[0143] In addition, an antiglare layer, an antireflection layer, a stain-resistant layer, or other decorative layers may be formed on the first main surface 10A of the transparent substrate 10, or on both the first main surface 10A and the second main surface 10B. The antiglare layer, the antireflection layer, and the stain-resistant layer can be appropriately formed by known methods. The formation order of the antiglare layer, the antireflection layer, and the stain-resistant layer is not particularly limited. The formation of the antiglare layer is preferably carried out before the formation of the first printing layer 11. The formation of the antireflection layer is preferably carried out after the formation of the second opening 14. The formation of the stain-resistant layer is preferably carried out after the formation of the antireflection layer.

[0144] The display cover material 100 is formed through the above steps.

[0145] (Method for manufacturing a vehicle-mounted display device)

[0146] The display device is manufactured by attaching the display cover material 100 formed by the above manufacturing method to the display panel 3. The display panel 3 is attached to the second main surface 10B side of the display cover material 100. At this time, alignment with the display panel 3 is performed on the first printing layer 11 by using the pattern formed by the second opening 14 as an alignment mark. The positional accuracy of the alignment mark of the display cover material 100 of the present embodiment is high, which can suppress defects during attachment and improve the yield.

[0147] The present disclosure describes the following inventions. It should be noted that it is not limited thereto.

[0148] (1) A display cover material, comprising: a transparent substrate having a first main surface and a second main surface, and a first printing layer laminated on the second main surface and having a first opening. A second printing layer is laminated on a part of the surface of the first printing layer. The second printing layer has a color different from that of the first printing layer. The second printing layer has a second opening. In the second opening, the first printing layer is exposed. In the second opening, a plurality of irradiation marks are formed on the surface of the first printing layer.

[0149] (2) The display cover material according to (1), wherein the interval between the irradiation marks is greater than 1.0 times the diameter of the irradiation marks.

[0150] (3) The display cover material according to (2), wherein the interval between the irradiation marks is 2.6 times or less the diameter of the irradiation marks.

[0151] (4) The display cover material according to any one of (1) to (3), wherein the deviation of the irradiation marks is 0.4 times or less the diameter of the irradiation marks.

[0152] (5) The display covering material according to any one of (1) to (4), wherein the difference between the thickness of the first printing layer in the second opening portion and the thickness of the first printing layer outside the second opening portion is 3.0 μm or less.

[0153] (6) The display covering material according to any one of (1) to (5), wherein the transparent substrate has a curved surface.

[0154] (7) The display covering material according to (6), wherein the minimum radius of curvature of the curved surface is 800 mm or less.

[0155] (8) The display covering material according to any one of (1) to (7), wherein the first printing layer contains carbon black, the second printing layer does not contain carbon black, or contains carbon black and the carbon black content of the second printing layer is less than the carbon black content of the first printing layer.

[0156] (9) The display covering material according to any one of (1) to (8), wherein the transparent substrate is glass.

[0157] (10) The display covering material according to any one of (1) to (9), wherein the pattern formed by the second opening portion is an alignment mark.

[0158] (11) A vehicle-mounted display device, comprising the display covering material according to (9) or (10) and a display.

[0159] (12) A method for manufacturing a display covering material, comprising:

[0160] laminating a first printing layer having a first opening portion on the second main surface of a transparent substrate having a first main surface and a second main surface, laminating a second printing layer having a color different from that of the first printing layer on a part of the surface of the first printing layer, and irradiating the surface of the second printing layer with a laser to remove the second printing layer, thereby forming a second opening portion and exposing the first printing layer from the second opening portion.

[0161] (13) The method for manufacturing a display covering material according to (12), wherein the irradiation interval of the laser is 0.5 times or more of the spot diameter of the laser.

[0162] (14) The method for manufacturing a display covering material according to (13), wherein the irradiation interval of the laser is 1.0 times or less of the spot diameter of the laser.

[0163] (15) The manufacturing method of the display cover material according to any one of (12) to (14), wherein the curing of the second printing layer by heating or light irradiation is not performed before the irradiation of the laser.

[0164] (16) The manufacturing method of the display cover material according to any one of (12) to (15), wherein the laser is scanned by a galvanometer scanner during the irradiation of the laser.

[0165] (17) The manufacturing method of the display cover material according to any one of (12) to (16), wherein the transparent substrate is glass, and the manufacturing method of the display cover material further includes heating the glass to form a curved surface before laminating the first printing layer, and the first printing layer and the second printing layer are laminated on the curved surface.

[0166] (18) A method for forming a vehicle-mounted display device, including attaching the display cover material according to any one of (1) to (10) to a display, and the attachment of the display is performed by aligning the display with the display cover material by using the pattern formed by the second opening as an alignment mark.

[0167] Examples

[0168] Next, the examples will be described. Test example 1 is a comparative example, and test examples 2 to 4 are examples.

[0169] (Test example 1)

[0170] As the transparent substrate 10, aluminosilicate glass (Dragontrail (registered trademark) manufactured by AGC Inc.) was prepared. The first printing layer 11 was made of black ink containing carbon black (Photo Black manufactured by Toray Industries, Inc.), coated to a thickness of 6.4 μm by a spin coater, and then cured by heating at 230 °C for 30 minutes. The second printing layer 13 was made of white ink containing titanium oxide (MW460 manufactured by Markem-Imaje), and the shape of the second opening 14 was directly formed by pad printing. The shape of the second printing layer 13 was a 40 mm × 40 mm square. The second opening 14 was in the shape of the letters "AGC".

[0171] (Test examples 2 to 4)

[0172] The formation conditions of the transparent substrate 10 and the first printing layer 11 are the same as those in Example 1. The second printing layer 13 is printed by the continuous inkjet method using white ink containing titanium oxide (MW460 manufactured by Markem-Imaje). It should be noted that the ink does not contain carbon black, and the curing process after printing is not performed. The shape of the second printing layer 13 is a 40 mm × 40 mm square.

[0173] Next, under the following conditions and the conditions shown in Table 1, the second printing layer 13 is irradiated with a laser to remove the second printing layer 13. The second opening 14 is in the shape of the text "AGC".

[0174] Oscillator: Nanosecond pulsed laser (MD-X1520 manufactured by KEYENCE Corporation)

[0175] Oscillation mode: Pulsed oscillation

[0176] Scanning mechanism: Galvano scanner

[0177] Light wavelength: 1064 nm

[0178] Output power: 3.0 W

[0179] Oscillation frequency: 8 kHz

[0180] Scanning speed in the in-plane direction: 650 mm / s

[0181] The display covering material 100 prepared above is evaluated for position accuracy, irradiation marks, and the film thickness of the first printing layer 11.

[0182] (Position accuracy)

[0183] The deviation between the predetermined formation position and the actual formation position of the second opening 14 is evaluated as the position accuracy. It should be noted that each position is evaluated with the boundary position between the first opening 12 and the first printing layer 11 as the reference point.

[0184] (Irradiation marks)

[0185] The surface of the second opening 14 is photographed using an optical microscope (Digital microscope VHX6000 manufactured by KEYENCE Corporation). The image is shown in Fig. 9. The white-changed circular pattern is regarded as the irradiation mark, and the diameter and interval of the irradiation mark are measured. By repeatedly irradiating the laser to the same coordinate, the deviation is obtained from the standard deviation of the error with respect to the coordinate.

[0186] (Maximum film thickness reduction of the first printing layer before and after laser irradiation)

[0187] The thickness of the first printed layer 11 outside the second opening 14 is compared with the thickness of the first printed layer 11 in the second opening 14 in the following procedure to calculate the maximum thickness reduction of the first printed layer 11 before and after laser irradiation.

[0188] (i) A portion of the glass surface was exposed on the first printed layer 11, and a non-contact three-dimensional measuring device (NH-3MAS manufactured by Mitaka Optical Instruments Co., Ltd.) was used to scan the laser probe through the first printed layer 11 and the exposed glass surface using a desktop scanning laser probe method to measure the film thickness of the first printed layer 11. First, the scanning interval of the laser probe was set to 2 mm in the first printed layer 11 other than the second opening 14, and the average film thickness in the scanning interval was calculated.

[0189] (ii) For the first printed layer 11 at the second opening, the scanning interval of the laser probe was set to 2 mm, and the minimum film thickness value in the scanning interval was calculated.

[0190] (iii) The difference between the average thickness of the first printed layer 11 other than the second openings 14 measured above and the minimum thickness of the second openings 14 was used as the maximum thickness reduction of the first printed layer before and after laser irradiation.

[0191] The above results are shown in the following Tables 1 and Figure 9A , Figure 9B , Figure 9C .

[0192]

[0193] As shown in Table 1 and Figure 9A , Figure 9B , Figure 9C As shown, in Test Examples 2 to 4 in which the second opening 14 was formed by laser irradiation, the positional accuracy was improved compared to Test Example 1 in which the second opening 14 was formed by pad printing.

[0194] In addition, in Test Example 3 in which the irradiation interval during laser irradiation is greater than 0.5 times the spot diameter and the irradiation mark interval is greater than 1.0 times the irradiation mark diameter, the maximum film thickness reduction of the first printed layer 11 before and after irradiation can be made less than 3.0 μm, thereby suppressing damage to the first printed layer 11 caused by laser irradiation.

[0195] In Test Example 4 in which the irradiation interval in laser irradiation was 1.3 times or less of the spot diameter and the irradiation mark interval was 2.6 times or less of the irradiation mark diameter, the remaining area of ​​the second printed layer 13 could be reduced to less than 30%, and a pattern could be formed by the second opening.

[0196] In Test Example 3 where the irradiation interval in laser irradiation is 1.0 times or less the spot diameter and the irradiation mark interval is 2.0 times or less the irradiation mark diameter, the remaining area of the second printing layer 13 can be made 0%, and the pattern formed by the second opening is clearer.

[0197] This application is based on Japanese Patent Application No. 2022-185955 filed on November 21, 2022, the content of which is incorporated herein by reference.

[0198] Reference Signs

[0199] 1 Steering Shaft

[0200] 2 In-vehicle Display Device

[0201] 3 Display Panel

[0202] 100 Display Cover Material

[0203] 10 Transparent Substrate

[0204] 10A First Main Surface

[0205] 10B Second Main Surface

[0206] 11 First Printing Layer

[0207] 11A End

[0208] 11B Excess Portion

[0209] 12 First Opening

[0210] 13 Second Printing Layer

[0211] 14 Second Opening

[0212] 20 Irradiation Mark

[0213] 31, 41 Laser Oscillator

[0214] 32, 42 Mirror

[0215] 33, 43 Condensing Lens

[0216] L, L2 Laser

[0217] Lh Horizontal Direction Distance

[0218] Lt Thickness Direction Distance

[0219] t Average Thickness of Film

[0220] p Interval of Irradiation Marks

[0221] d Diameter of Irradiation Marks

Claims

1. A display covering material, characterized in that, Comprising: a transparent substrate having a first major surface and a second major surface, and a first printing layer laminated on the second major surface and having a first opening portion. A second printing layer is laminated on a part of the surface of the first printing layer. The second printing layer has a color different from that of the first printing layer. The second printing layer has a second opening portion, and in the second opening portion, the first printing layer is exposed. In the second opening portion, a plurality of irradiation marks are formed on the surface of the first printing layer.

2. The display covering material according to claim 1, wherein, The interval between the irradiation marks is greater than 1.0 times the diameter of the irradiation marks.

3. The display covering material according to claim 2, wherein, The interval between the irradiation marks is 2.6 times or less the diameter of the irradiation marks.

4. The display covering material according to any one of claims 1 to 3, wherein The deviation of the irradiation marks is 0.4 times or less the diameter of the irradiation marks.

5. The display covering material according to any one of claims 1 to 3, wherein, The difference in thickness between the first printing layer in the second opening portion and the first printing layer outside the second opening portion is 3.0 μm or less.

6. The display covering material according to any one of claims 1 to 3, wherein, The transparent substrate has a curved surface.

7. The display covering material according to claim 6, wherein, The minimum radius of curvature of the curved surface is 800 mm or less.

8. The display covering material according to any one of claims 1 to 3, wherein, The first printing layer contains carbon black, the second printing layer does not contain carbon black, or contains carbon black and the carbon black content of the second printing layer is less than the carbon black content of the first printing layer.

9. The display covering material according to any one of claims 1 to 3, wherein, The transparent substrate is glass.

10. The display covering material according to any one of claims 1 to 3, wherein, The pattern formed by the second opening portion is an alignment mark.

11. A vehicle-mounted display device, comprising the display covering material and the display according to claim 9.

12. A method for manufacturing a display covering material, comprising: Laminating a first printing layer having a first opening portion on the second major surface of a transparent substrate having a first major surface and a second major surface. Laminating a second printing layer having a color different from that of the first printing layer on a part of the surface of the first printing layer, and By irradiating the surface of the second printing layer with a laser, removing the second printing layer to form a second opening portion, so that the first printing layer is exposed from the second opening portion.

13. The manufacturing method of the display covering material according to claim 12, wherein, The irradiation interval of the laser is 0.5 times or more the spot diameter of the laser.

14. The manufacturing method of the display covering material according to claim 13, wherein, The irradiation interval of the laser is 1.0 times or less the spot diameter of the laser.

15. The manufacturing method of the display covering material according to any one of claims 12 to 14, wherein, Before irradiating the laser, curing of the second printing layer by heating or light irradiation is not performed.

16. The manufacturing method of the display covering material according to claim 15, wherein, Including during the irradiation of the laser, using a scanning galvanometer to scan the laser.

17. The manufacturing method of the display covering material according to claim 15, wherein, The transparent substrate is glass. The method for manufacturing the display covering material further includes heating the glass to form a curved surface before laminating the first printing layer. The first printing layer and the second printing layer are laminated on the curved surface.

18. A method for forming a vehicle-mounted display device, comprising attaching the display covering material according to claim 1 to a display. The attachment of the display is performed by aligning the display with the display covering material by using the pattern formed by the second opening portion as an alignment mark.

Images