Glass member, input device, pen input device, mobile device, and method for manufacturing a glass member

Abstract

To provide a glass member that is excellent in touch feeling such as feeling of writing by an input pen and feeling of touch by a finger tip, an input device having the glass member, a pen input device, a mobile apparatus, and a method for manufacturing the glass member.SOLUTION: A glass member has minute unevenness 10 in at least part of a primary face (a surface) 21a. A regression straight line L (La) is obtained by performing single regression analysis by a minimum square method in a range of a load area ratio of 10% to 99% in a load curve T (Ta) of a surface in a square region with a side of 5 μm in the minute unevenness 10. A determination coefficient R2 of the regression straight line is equal to or larger than 0.600 and equal to or smaller than 0.960.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a glass member, an input device including the glass member, a pen input device, a mobile device, and a method for manufacturing the glass member.

Background Art

[0002] Conventionally, an input device that can perform input operations such as characters and figures by an input pen or a fingertip, such as a touch panel, is known. In such an input device, a transparent glass substrate made of a glass member is disposed as a cover member on the front side (front surface side) of a display device such as a liquid crystal display. Various input operations can be performed by contacting and moving an input pen or a fingertip with respect to the surface (main surface) of the glass substrate. Here, on the surface of the cover member, for example, minute irregularities are provided in advance for the purpose of improving the touch feeling such as the writing feeling by an input pen and the touch feeling by a fingertip. In recent years, the demand for a higher-quality touch feeling has been increasing.

[0003] Therefore, as a technique for further improving the touch feeling (writing feeling), for example, in Patent Document 1, a glass substrate for a pen input device having an uneven shape on the surface with an arithmetic mean roughness Ra of 0.19 μm or more and 0.45 μm or less and an average period Sm of 30 μm or more and 80 μm or less is disclosed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the glass substrate described in Patent Document 1, although it is easy to obtain a good writing feel with respect to a stylus tip made of polyacetal, which is a relatively hard material, with respect to a stylus tip or a fingertip made of an elastomer, which is a relatively soft and low-elastic material, rather, the unevenness is too large, the catching force becomes strong, and there is a risk that the writing feel and the touch feel will deteriorate.

[0006] The present invention has been made in view of the above-described problems of the current situation, and an object thereof is to provide a glass member having excellent tactile sensations such as a writing feel by an input pen and a touch feel by a fingertip, an input device including the glass member, a pen input device, a mobile device, and a method for manufacturing the glass member.

Means for Solving the Problems

[0007] The problems to be solved by the present invention are as described above. Next, means for solving these problems will be described.

[0008] That is, the glass member according to the present invention has minute irregularities on at least a part of the surface, and in the surface load curve in a region of a square having a side of 5 μm in the minute irregularities, the load area ratio ranges from 10% to 99%, and the coefficient of determination R of the regression line obtained by performing simple regression analysis by the least squares method 2 is 0.600 or more and 0.960 or less. By having such a configuration, according to the glass member of the present invention, when the pen tip or fingertip of the input pen is brought into contact with and moved on the surface of the glass member, the contact area is appropriately reduced due to the presence of recesses (valleys) in the minute irregularities, so that these pen tips or fingertips become appropriately easy to slide, and due to the presence of protrusions (peaks) in the minute irregularities, an appropriate catching feeling is felt, and the frictional force between the surface of the glass member and the pen tip or fingertip of the input pen can be appropriately adjusted, and the tactile sensations such as the writing feel by the input pen and the touch feel by the fingertip can be improved.

[0009] Further, the glass member according to the present invention has minute irregularities on at least a part of its surface. In the load curve of the surface within a square region with a side length of 5 μm in the minute irregularities, the ratio (d / h) of the root mean square error d between the load curve and the regression line obtained by performing simple regression analysis by the least squares method for the range from a load area ratio of 10% to 99% with respect to the maximum height h (= ha - hb), which is the difference between the height ha when the load area ratio is 1% and the height hb when the load area ratio is 99%, is 0.045 or more and 0.165 or less. By having such a configuration, according to the glass member of the present invention, when the pen tip of the input pen or the fingertip contacts and moves on the surface of the glass member, due to the presence of the concave portions (valley portions), the contact area is appropriately reduced, so that excessive adhesion during contact can be suppressed. Therefore, these pen tips or fingertips become appropriately slippery, and due to the presence of the convex portions (hill portions), an appropriate catching feeling can be felt, and the tactile sensations such as the writing feel by the input pen and the touch feel by the fingertip can be improved.

[0010] Further, the glass member according to the present invention has minute irregularities on at least a part of its surface. In the load curve of the surface within a square region with a side length of 5 μm in the minute irregularities, when the load area ratio indicating the boundary between the core portion and the protruding hill portion in the minute irregularities is 10% and the load area ratio indicating the boundary between the core portion and the protruding valley portion in the minute irregularities is 80%, the ratio (Vvv / Vmp) of the volume Vvv of the space of the protruding valley portion to the volume Vmp of the protruding hill portion is 2.4 or more and 15 or less. By having such a configuration, according to the glass member of the present invention, the effect of reducing the contact area between the pen tip of the input pen or the fingertip and the concave portions (valley portions) can be sufficiently expected. When the pen tip of the input pen or the fingertip contacts and moves on the surface of the glass member, these pen tips or fingertips become appropriately slippery, and due to the presence of the convex portions (hill portions), an appropriate catching feeling can be felt, and the tactile sensations such as the writing feel by the input pen and the touch feel by the fingertip can be improved.

[0011] Further, in the micro unevenness of the glass member according to the present invention, it is preferable that the arithmetic mean height Sa of the elements of the roughness curve is 1 nm or more and 100 nm or less. With such a configuration, according to the glass member of the present invention, due to the reduction effect of the contact area between the micro unevenness provided on the surface of the glass member and the pen tip of the input pen or the fingertip, and the appropriate hooking feeling due to the uneven shape, the writing feeling by the input pen and the touch feeling such as the touch feeling by the fingertip can be more reliably improved. In addition, it is possible to minimize the light scattering due to the uneven shape of the micro unevenness, and the visibility on the surface of the glass member on which the micro unevenness is formed can be more reliably ensured.

[0012] Further, the input device according to the present invention is characterized by including a glass substrate made of any of the above-described glass members, a display device that displays an image, and a detection circuit that detects an input position. With such a configuration, it is possible to realize an input device excellent in touch feeling such as writing feeling by an input pen and touch feeling by a fingertip.

[0013] Further, the pen input device according to the present invention is characterized by including the above-described input device and an input pen that performs an input operation on the input device by moving while contacting the surface of the glass substrate. With such a configuration, it is possible to realize a pen input device excellent in touch feeling such as writing feeling by an input pen and touch feeling by a fingertip.

[0014] Further, the mobile device according to the present invention is characterized by including a back cover member made of any of the above-described glass members. With such a configuration, it is possible to realize a mobile device excellent in touch feeling such as touch feeling by a fingertip.

[0015] The manufacturing method of the glass member according to the present invention is a manufacturing method for manufacturing any of the above-described glass members, and is characterized in that wet blasting treatment or sand blasting treatment is performed on the surface of the glass member. With such a configuration, according to the manufacturing method of the glass member according to the present invention, a glass member having minute irregularities formed on its surface can be manufactured, and compared with a smooth flat surface having no such minute irregularities, a glass member excellent in touch feeling such as writing feel by an input pen and touch feel by fingertips can be manufactured.

Effects of the Invention

[0016] As effects of the present invention, the following effects are exhibited. That is, according to the glass member according to the present invention, the input device including the glass member, the pen input device, the mobile device, and the manufacturing method of the glass member, the touch feeling such as writing feel by an input pen and touch feel by fingertips can be made excellent.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

[0018] Next, one embodiment of the present invention will be described with reference to FIGS. 1 to 9.

[0019] [Overall Configuration of Pen Input Device 1] First, the overall configuration of the pen input device 1 implemented according to this embodiment will be described with reference to FIG. 1. The pen input device 1 includes an input device 2 having a glass substrate 21 made of a glass member according to the present invention, and an input pen 3 that performs an input operation on the input device 2 by moving while contacting the surface of the glass substrate 21 (more specifically, the main surface 21a).

[0020] The input device 2 mainly includes a glass substrate 21 provided as a cover member, a display element 22 that is an example of a display device and displays an image, and a digitizer circuit 23 that is an example of a detection circuit and detects information input by the input pen 3 or the fingertip 4 (more specifically, the input position of the input pen 3 or the fingertip 4).

[0021] The glass substrate 21, the display element 22, and the digitizer circuit 23 are configured to be laminated on each other. The glass substrate 21 is disposed on the front side of the display element 22, and the digitizer circuit 23 is disposed on the back side of the display element 22.

[0022] In the above description, the "front side" of the display element 22 means the side on which the image is displayed, and the "back side" of the display element 22 means the side opposite to the side on which the image is displayed. In this embodiment, for example, the "front side" of the display element 22 is the upper side of the paper surface in FIG. 1, and the "back side" of the display element 22 is the lower side of the paper surface in FIG. 1.

[0023] Then, the pen input device 1 moves with the pen tip 3a of the input pen 3 or the fingertip 4 in contact with the surface of the glass substrate 21 (the main surface 21a on the side opposite to the display element 22 with respect to the glass substrate 21), so that the positions of these pen tip 3a and fingertip 4 (input positions) are detected by the digitizer circuit 23, and an input operation such as characters and figures can be executed. An example of such a pen input device 1 is, for example, a tablet terminal.

[0024] Note that the above tablet terminal widely refers to an input display device having both a display function and an input function, and includes devices such as a liquid crystal pen tablet, a tablet PC, a mobile PC, a smartphone, and a game machine.

[0025] The glass substrate 21 is formed of a plate-shaped transparent glass member having minute irregularities (hereinafter, appropriately referred to as "minute irregularities 10") formed on at least one surface (in this embodiment, the main surface 21a). Further, the glass substrate 21 is arranged such that the main surface 21a on which the minute irregularities 10 are formed is the surface on the side where the input pen 3 or the fingertip 4 contacts.

[0026] Here, examples of the material of the glass substrate 21 include quartz glass, soda lime glass, alkali-free glass, aluminosilicate glass, borosilicate glass, and chalcogenide glass. Further, when the glass substrate 21 is constituted by a glass member made of alkali-containing aluminosilicate glass, the glass substrate 21 may have a chemical strengthening layer on the main surface 21a.

[0027] Also, a functional film for imparting a specific function can be provided on the main surface 21a of the glass substrate 21. For example, an antireflection film for reducing the reflectance on the side where the input pen 3 or the fingertip 4 contacts, and / or an antifouling film for preventing fingerprint adhesion and imparting water repellency and oil repellency may be formed.

[0028] As the antireflection film, for example, a low refractive index film having a lower refractive index than the glass substrate 21, or a dielectric multilayer film in which a low refractive index film having a relatively low refractive index and a high refractive index film having a relatively high refractive index are alternately laminated is used. Also, the antireflection film can be formed by a sputtering method, a CVD method, or the like.

[0029] On one hand, as the antifouling film, it is preferable to include an organosilicon compound, a fluoropolymer containing silicon in the main chain, and the like.

[0030] In addition, when the glass substrate 21 has an antireflection film and an antifouling film on the main surface 21a on the surface side, it is preferable to form the antireflection film on the main surface 21a of the glass substrate 21 and form the antifouling film on the antireflection film. Further, when forming a functional film on the main surface 21a of the glass substrate 21, minute irregularities 10 on the main surface 21a of the glass substrate 21 are formed so that the irregularities on the surface of the functional film fall within a predetermined surface roughness range described later. Details of the glass substrate 21 will be described later.

[0031] The digitizer circuit 23 includes a detection sensor that detects an input operation by the input pen 3 or the fingertip 4. Here, the input pen 3 is an input instrument having a shape similar to a writing instrument such as a pencil or a ballpoint pen, and has a pen tip 3a which is an example of a friction member that contacts the glass substrate 21. The pen tip 3a is made of a synthetic resin material such as an elastomer or a polyacetal resin, or a conductive fiber or felt.

[0032] In the input pen 3, if the pen tip 3a is made of the above members, it is likely to catch on the minute irregularities 10 provided on the main surface 21a of the glass substrate 21. Therefore, when the pen tip 3a of the input pen 3 is brought into contact with and moved on the main surface 21a of the glass substrate 21 on which the minute irregularities 10 are formed, particularly excellent writing feeling can be realized.

[0033] [Configuration of Glass Substrate 21] Next, the configuration of the glass substrate 21 will be described in detail with reference to FIGS. 1 to 8. As described above, the glass substrate 21 is an example of the glass member according to the present invention, and is formed in a rectangular flat plate shape as shown in FIG. 1, for example.

[0034] Note that the shape of the glass substrate 21 is not limited to the present embodiment. For example, it may be a flat plate shape with a circular or polygonal contour, or a shape in which a flat plate shape is curved as a whole, or any other shape.

[0035] On one surface of the glass substrate 21 (in the present embodiment, the main surface 21a), minute unevenness 10 is formed. Here, the minute unevenness 10 is mainly provided on the main surface 21a of the glass substrate 21 for the purpose of appropriately adjusting the frictional force generated between the pen tip 3a of the input pen 3 and the fingertip 4. Therefore, the minute unevenness 10 may be formed in at least a part of the region of the main surface 21a where it is necessary to improve the tactile sensation such as the writing feel by the input pen 3 and the touch feel by the fingertip 4 according to the final use state of the glass substrate 21. In the present embodiment, it is formed on the entire main surface 21a.

[0036] As shown below, the shape of the minute unevenness 10 is set using the surface load curve T (see FIG. 2) representing the ratio of the surface unevenness and various three-dimensional surface roughness parameters (the volume Vvv of the space of the protruding valleys, the volume Vmp of the protruding peaks, and the arithmetic mean height Sa) defined by ISO25178.

[0037] Here, the surface load curve T is a curve representing the ratio of the convex portions (peaks) and concave portions (valleys) of the surface unevenness shape in the height direction, and is a cumulative distribution function representing the area ratio occupied by the convex portions (peaks).

[0038] Specifically, as shown in FIG. 2, the surface load curve T is represented by the vertical axis indicating the height of the unevenness shape and the horizontal axis indicating the load area ratio of the convex portions (peaks). In the contour curve 10a representing the shape of the minute unevenness 10, for example, when the uppermost end portion 10a1 of the convex portion (peak) is set to a load area ratio of 0% and the lowermost end portion 10a2 of the concave portion (valley) is set to a load area ratio of 100%, it is expressed as a substantially S-shaped curve. Note that the above load area ratio represents the ratio of the area occupied by the region where the convex portions (peaks) having a certain height or more exist.

[0039] And the minute unevenness 10 is composed of a protruding peak portion that occupies a region with a height h1 or more when the load area ratio is t1 (%) on the surface load curve T, a protruding valley portion that occupies a region with a height h2 (>h1) or less when the load area ratio is t2 (%) higher than t1 (%), and a core portion that occupies a region between these protruding peak portions and protruding valley portions.

[0040] [Coefficient of determination R 2 Setting conditions] As shown in FIG. 3, the shape of the minute unevenness 10 in the present embodiment is such that in the surface load curve T (the surface load curve Ta shown in FIG. 3(b)) within a region of a square with a side length of 5 μm in the minute unevenness 10, the coefficient of determination R of the regression line L (the regression line La shown in FIG. 3(b)) obtained by performing simple linear regression analysis by the least squares method for the range where the load area ratio is from 10% to 99% 2 is set to be 0.600 or more and 0.960 or less.

[0041] Here, the coefficient of determination R 2 is represented by the following mathematical formula (Equation 1), and is obtained by subtracting from 1 the value obtained by dividing the sum of the squares of the residuals d i between the above-mentioned load curve T and the regression line L by the sum of the squares of the differences between the height h i and the average height H of the height h i . Note that the above-mentioned average height H is the average value of the heights hi ((h 1 +h 2 +···hi) / i) in the range where the load area ratio is from 10% to 99%.

[0042]

Equation

[0043] Then, as shown in Fig. 4(a), in the micro unevenness 10, when the convex part (ridge part) of the contour curve 10a has a sharply rising shape, the surface load curve T of the micro unevenness 10 (the surface load curve Tb1 shown in Fig. 4(b)) rapidly increases the load area ratio at a low height position. For example, when the load area ratio t1 at the boundary between the protruding ridge part and the core part is 10% (t1 = 10%), the shape of the surface load curve Tb1 in the range where the load area ratio is from 10% to 99% excluding the protruding ridge part approximates the regression line L (the regression line Lb1 shown in Fig. 4(b)) as shown in Fig. 4(b).

[0044] Also, as shown in Fig. 5(a), in the micro unevenness 10, when the convex part (ridge part) and the concave part (valley part) of the contour curve 10a are in a substantially regular repeating triangular wave shape, similarly, the surface load curve T of the micro unevenness 10 (the surface load curve Tb2 shown in Fig. 5(b)) increases the load area ratio at a substantially constant rate as the height decreases. Therefore, for example, when the load area ratio t1 at the boundary between the protruding ridge part and the core part is 10% (t1 = 10%), the shape of the surface load curve Tb2 in the range where the load area ratio is from 10% to 99% excluding the protruding ridge part approximates the regression line L (the regression line Lb2 shown in Fig. 5(b)) as shown in Fig. 4(b).

[0045] On the other hand, as shown in Fig. 6(a), in the micro unevenness 10, when the concave part (valley part) of the contour curve 10a is deeply and sharply cut and the convex part (ridge part) has a relatively smooth rounded shape, the surface load curve T of the micro unevenness 10 (the surface load curve Tc shown in Fig. 6(b)) rapidly increases the load area ratio at a high height position. For example, when the load area ratio t1 at the boundary between the protruding ridge part and the core part is 10% (t1 = 10%), the shape of the surface load curve Tc in the range where the load area ratio is from 10% to 99% excluding the protruding ridge part becomes a curve that greatly deviates from the regression line L (the regression line Lc shown in Fig. 6(b)) as shown in Fig. 6(b).

[0046] Thus, in the relationship between the surface load curve T and the regression line L in the contour curve 10a of the minute unevenness 10, the shape of the contour curve 10a tends to be an uneven shape with sharp convex portions (ridge portions) or a triangular wave-shaped uneven shape as the shape of the surface load curve T in the range of 10% to 99% of the load area ratio, excluding the protruding peak portions, approximates the regression line L. On the other hand, as the deviation from the regression line L increases, the shape of the contour curve 10a tends to be an uneven shape in which the concave portions (valley portions) are deeply and sharply cut and the convex portions (ridge portions) have relatively smooth roundness.

[0047] And in the present embodiment, based on such an opinion, the coefficient of determination R of the regression line L (La), which is an index of the linearity of the surface load curve T (Ta) in the range of 10% to 99% of the load area ratio, 2 is set within a predetermined range, and minute unevenness 10 having an appropriate uneven shape in which the convex portions (ridge portions) are not too sharp and deep concave portions (valley portions) are provided is imparted to the main surface 21a of the glass substrate 21.

[0048] Specifically, as shown in FIGS. 4 and 5, when the coefficient of determination R of the regression line L (Lb1 and Lb2) 2 exceeds 0.96 (R 2 > 0.96), the shape of the minute unevenness 10 provided on the main surface 21a of the glass substrate 21 becomes an uneven shape in which there are convex portions (ridge portions) with steeply sharpened tip portions. Therefore, when the pen tip 3a of the input pen 3 or the fingertip 4 (see FIG. 1) is brought into contact with and moved on the main surface 21a of the glass substrate 21, the catching feeling felt becomes too strong, and the writing feeling by the input pen 3 and the touch feeling such as the touch feeling by the fingertip 4 deteriorate.

[0049] On the other hand, as shown in FIG. 6, when the coefficient of determination R of the regression line L (Lc) 2 is less than 0.600 (R 2When the micro unevenness 10 provided on the main surface 21a of the glass substrate 21 has an uneven shape in which there are recesses (valleys) that are deeply and sharply cut, and the ratio of the area of the recesses (valleys) in the entire micro unevenness 10 is relatively small, the reduction effect of the contact area with the pen tip 3a of the input pen 3 or the fingertip 4 cannot be expected much, and the input pen 3 or the fingertip 4 becomes difficult to slide on the main surface 21a of the glass substrate 21. Also, since the protruding portions (hill portions) of the micro unevenness 10 have a relatively smooth shape at the protruding ends, when the pen tip 3a of the input pen 3 or the fingertip 4 is brought into contact with and moved on the main surface 21a of the glass substrate 21, the feeling of snagging is not felt much. Therefore, the tactile sensation such as the writing feel by the input pen 3 and the touch feel by the fingertip 4 deteriorates.

[0050] For this reason, as shown in FIG. 3, in the present embodiment, the coefficient of determination R of the regression line L (La) 2 is set to be 0.600 or more and 0.960 or less (0.600 ≤ R 2 ≤ 0.960). By such a simple method, by controlling the shape of the micro unevenness 10 provided on the main surface 21a of the glass substrate 21, the micro unevenness 10 is formed into an uneven shape including recesses (valleys) cut with appropriate gaps and protruding portions (hill portions) with appropriately sharp protruding ends.

[0051] As a result, according to the glass substrate 21 in the present embodiment, when the pen tip 3a of the input pen 3 or the fingertip 4 is brought into contact with and moved on the main surface 21a of the glass substrate 21, the contact area is appropriately reduced due to the presence of the recesses (valleys), so that these pen tips 3a or fingertips 4 become appropriately easy to slide, and an appropriate feeling of snagging is felt due to the presence of the protruding portions (hill portions). The frictional force between the main surface 21a of the glass substrate 21 and the pen tip 3a of the input pen 3 or the fingertip 4 can be appropriately adjusted, and the tactile sensation such as the writing feel by the input pen 3 and the touch feel by the fingertip 4 can be improved.

[0052] Note that the coefficient of determination R of the regression line L (La) 2Regarding the upper limit value in [it], it is set to 0.960, but 0.950 is preferable, and 0.940 is more preferable. Also, the coefficient of determination R of the regression line L(La) 2 Regarding the lower limit value in [it], it is set to 0.600, but 0.630 is preferable, and 0.650 is more preferable.

[0053] [Setting conditions of ratio (d / h)] As shown in FIG. 7, the shape of the micro unevenness 10 in the present embodiment is such that, in the load curve T(Ta) of the surface described above, the ratio (d / h) of the root mean square error d between the load curve T(Ta) and the regression line L(La) to the maximum height h within the range of the load area ratio from 1% to 99% is set to be 0.045 or more and 0.165 or less. Note that the maximum height h is the difference (h = ha - hb) between the height ha when the load area ratio in the load curve T(Ta) of the surface is 1% and the height hb when the load area ratio is 99%. Also, as described above, the regression line L(La) is a regression line obtained by performing simple linear regression analysis by the least squares method on the range of the load area ratio from 10% to 99% in the load curve T(Ta) of the surface.

[0054] Here, the above-mentioned root mean square error d indicates the amount of deviation between the load curve T of the surface and the regression line L (how much the load curve T of the surface deviates from the regression line L within the range of the load area ratio from 10% to 99%) as shown by the following mathematical formula (Formula 2). However, as the roughness of the micro unevenness 10 (the difference in height between the convex part (peak part) and the concave part (valley part)) increases, the root mean square error d also increases. Therefore, it is difficult to simply compare between the micro unevenness 10 having different surface roughnesses.

[0055]

Equation

[0056] Therefore, in the present embodiment, by using the ratio (d / h) of the maximum height h within the range of 1% to 99% of the load area ratio in the surface load curve T(Ta), as an index indicating the deviation amount between the surface load curve T in the range of 10% to 99% of the load area ratio and the regression line L, even between minute irregularities 10 having different surface roughnesses, it is made possible to easily compare the deviation amounts. Note that the above ratio (d / h) serves as an index of the linearity of the surface load curve T in the range where the load area ratio is from 10% to 99%.

[0057] When the above ratio (d / h) is less than 0.045 ((d / h) < 0.045), the surface load curve T tends to be extremely close to the regression line L. Therefore, the minute irregularities 10 provided on the main surface 21a of the glass substrate 21 have an uneven shape with recesses (valleys) that are deeply and sharply cut, and since the ratio of the area of the recesses (valleys) in the entire minute irregularities 10 is relatively small, the effect of reducing the contact area with the pen tip 3a of the input pen 3 or the fingertip 4 (see FIG. 1) cannot be expected much, and the input pen 3 or the fingertip 4 becomes difficult to slide on the main surface 21a of the glass substrate 21. Alternatively, since the recesses (valleys) in the minute irregularities 10 have a relatively smooth shape at the protruding ends, when the pen tip 3a of the input pen 3 or the fingertip 4 is brought into contact with and moved on the main surface 21a of the glass substrate 21, the feeling of snagging is not felt much. Therefore, the tactile sensations such as the writing feel with the input pen and the touch feel with the fingertip deteriorate.

[0058] On the other hand, when the above ratio (d / h) exceeds 0.165 ((d / h) > 0.165), the surface load curve T tends to deviate relatively greatly from the regression line L. Therefore, the shape of the minute irregularities 10 provided on the main surface 21a of the glass substrate 21 has an uneven shape with convex portions (peaks) having sharp and steep protruding ends, so that when the pen tip 3a of the input pen 3 or the fingertip 4 is brought into contact with and moved on the main surface 21a of the glass substrate 21, the feeling of snagging becomes too strong, and the tactile sensations such as the writing feel with the input pen 3 and the touch feel with the fingertip 4 deteriorate.

[0059] Therefore, in the present embodiment, by setting the above ratio (d / h) to be 0.045 or more and 0.165 or less (0.045 ≦ (d / h) ≦ 0.165), the minute unevenness 10 provided on the main surface 21a of the glass substrate 21 is surely constituted by a recess (valley portion) cut with an appropriate gap and a convex portion (hill portion) with a moderately sharp tip portion.

[0060] As a result, according to the glass substrate 21 in the present embodiment, when the pen tip 3a of the input pen 3 or the fingertip 4 is brought into contact with and moved on the main surface 21a of the glass substrate 21, due to the presence of the above recess (valley portion), the contact area is appropriately reduced, so that excessive adhesion during contact can be suppressed. Therefore, these pen tips 3a or fingertips 4 become appropriately easy to slide, and due to the presence of the above convex portion (hill portion), an appropriate catching feeling can be felt, and the touch feeling such as the writing feeling by the input pen 3 and the touch feeling by the fingertip 4 can be improved.

[0061] Note that, regarding the upper limit value of the above ratio (d / h), although it is 0.165, 0.160 is preferable, and 0.150 is more preferable. Also, regarding the lower limit value of the above ratio (d / h), although it is 0.045, 0.050 is preferable, and 0.055 is more preferable.

[0062] [Setting conditions for ratio (Vvv / Vmp)] The shape of the minute unevenness 10 in the present embodiment is such that, in the surface load curve T (Ta) described above, when the load area ratio indicating the boundary between the core portion and the protruding hill portion in the minute unevenness 10 is 10% (t1 = 10%) and the load area ratio indicating the boundary between the core portion and the protruding valley portion in the minute unevenness 10 is 80% (t2 = 80%), the ratio (Vvv / Vmp) of the volume Vvv of the space of the protruding valley portion to the volume Vmp of the protruding hill portion is set to be 2.4 or more and 15 or less.

[0063] Here, the volume Vmp of the protruding mountain part and the volume Vvv of the space of the protruding valley part are both parameters defined by ISO 25178 and are derived based on the surface load curve T.

[0064] Specifically, as shown in FIG. 2, the volume Vmp of the protruding mountain part represents the actual volume of the convex part (mountain part) when the load area ratio of the surface load curve T is t1 (%). In this embodiment, as the volume Vmp of the protruding mountain part, the actual volume of the convex part (mountain part) when the load area ratio t1 is 10% is obtained. That is, the load area ratio t1 indicating the boundary between the core part and the protruding mountain part in the micro unevenness 10 is set to 10%. Note that, as the value of the volume Vmp increases, the uneven shape of the micro unevenness 10 tends to have more steep and pointed convex parts (mountain parts).

[0065] Also, the volume Vvv of the space of the protruding valley part represents the volume of the void of the concave part (valley part) when the load area ratio of the surface load curve T is t2 (%). In this embodiment, as the volume Vvv of the space of the protruding valley part, the volume of the void of the concave part (valley part) when the load area ratio t2 is 80% is obtained. That is, the load area ratio t2 indicating the boundary between the core part and the protruding valley part in the micro unevenness 10 is set to 80%. Note that, as the value of the volume Vvv increases, the uneven shape of the micro unevenness 10 tends to have more deep and sharp concave parts (valley parts).

[0066] And since the ratio (Vvv / Vmp) is the ratio of the parameters composed of these volumes Vmp and Vvv, it becomes an index representing the balance between the steep and pointed convex parts (mountain parts) that contribute to the catching feeling and the deep and sharp concave parts (valley parts) that contribute to the reduction of the contact area with respect to the pen tip 3a of the input pen 3 and the fingertip 4 (see FIG. 1).

[0067] When the above ratio (Vvv / Vmp) is less than 2.4 ((Vvv / Vvp) < 2.4), in the micro unevenness 10 provided on the main surface 21a of the glass substrate 21, since the proportion occupied by the concave portions (valley portions) is relatively small, the effect of reducing the contact area with the pen tip 3a of the input pen 3 or the fingertip 4 cannot be expected much. With respect to the main surface 21a of the glass substrate 21, these pen tips 3a or fingertips 4 are difficult to slide and tend to adhere, deteriorating the tactile sensations such as the writing feel by the input pen 3 and the touch feel by the fingertip 4.

[0068] On the other hand, when the above ratio (Vvv / Vmp) exceeds 15 ((Vvv / Vvp) > 15), in the micro unevenness 10 provided on the main surface 21a of the glass substrate 21, since the proportion occupied by the convex portions (hill portions) is relatively small, with respect to the main surface 21a of the glass substrate 21, when the pen tip 3a of the input pen 3 or the fingertip 4 is brought into contact with and moved, the feeling of snagging is not felt much, deteriorating the tactile sensations such as the writing feel by the input pen 3 and the touch feel by the fingertip 4.

[0069] For this reason, in the present embodiment, the above (ratio Vvv / Vvp) is set to be 2.4 or more and 15 or less (2.4 ≤ (Vvv / Vvp) ≤ 15), and in the micro unevenness 10 provided on the main surface 21a of the glass substrate 21, the proportion occupied by the convex portions (hill portions) and the proportion occupied by the concave portions (valley portions) are configured to be an appropriate distribution with respect to each other.

[0070] As a result, according to the glass substrate 21 in the present embodiment, the effect of reducing the contact area with the pen tip 3a of the input pen 3 or the fingertip 4 by the concave portions (valley portions) can be sufficiently expected. When the pen tip 3a of the input pen 3 or the fingertip 4 is brought into contact with and moved with respect to the main surface 21a of the glass substrate 21, these pen tips 3a or fingertips 4 become moderately easy to slide, and due to the presence of the convex portions (hill portions), a moderate feeling of snagging is felt, improving the tactile sensations such as the writing feel by the input pen 3 and the touch feel by the fingertip 4.

[0071] Note that regarding the upper limit value of the above ratio (Vvv / Vmp), it is set to 15, but 14 is preferable and 13 is more preferable. Also, regarding the lower limit of the ratio (Vvv / Vmp), it is set to 2.4, but 2.5 is preferable and 2.6 is more preferable.

[0072] [Setting conditions for arithmetic mean height Sa] In the micro unevenness 10 in the present embodiment, the arithmetic mean height Sa of the elements of the roughness curve is set to be 1 nm or more and 100 nm or less.

[0073] Here, the arithmetic mean height Sa is a parameter defined by ISO 25178, and is a parameter obtained by expanding the elements of the contour curve 10a, which is a line, into a plane. Specifically, as shown in FIG. 8, the arithmetic mean height Sa represents the average of the absolute values of the distances between the respective points of the uneven shape constituting the micro unevenness 10 with respect to the average plane Z on the main surface 21a of the glass substrate 21 (for example, the height Xh to the apex of the convex portion (hill portion) Xa and the depth Yh to the apex of the concave portion (valley portion) Ya) (Sa = ((Xh 1 + Xh 2 + ··· + Xh n )) + (Yh 1 + Yh 2 + ··· + Yh n )) / 2n).

[0074] When the arithmetic mean height Sa is less than 1 nm (Sa < 1 nm), the frictional force between the micro unevenness 10 provided on the main surface 21a of the glass substrate 21 and the pen tip 3a of the input pen 3 or the fingertip 4 becomes too large, and the writing feel by the input pen 3 and the touch feel such as the touch feel by the fingertip 4 deteriorate.

[0075] On the other hand, when the arithmetic mean height Sa exceeds 100 nm (Sa > 100 nm), light scattering is likely to occur due to the uneven shape of the micro unevenness 10 provided on the main surface 21a of the glass substrate 21, the transparency on the main surface 21a of the glass substrate 21 is impaired, and there is a risk that the visibility deteriorates. Also, the haze of the glass substrate 21 tends to deteriorate.

[0076] For this reason, in the present embodiment, the arithmetic mean height Sa is set to be 1 nm or more and 100 nm or less (1 nm ≤ Sa ≤ 100 nm). By appropriately adjusting the frictional force between the minute irregularities 10 provided on the main surface 21a of the glass substrate 21 and the pen tip 3a of the input pen 3 or the fingertip 4, the reduction effect of the contact area between the minute irregularities 10 provided on the main surface 21a of the glass substrate 21 and the pen tip 3a of the input pen 3 or the fingertip 4, and the appropriate catching feeling due to the irregular shape can more reliably improve the touch feeling such as the writing feeling by the input pen 3 and the touch feeling by the fingertip 4. In addition, it is possible to minimize the light scattering due to the irregular shape of the minute irregularities 10, and more reliably ensure the visibility on the main surface 21a of the glass substrate 21 where the minute irregularities 10 are formed.

[0077] Note that, although the upper limit value of the arithmetic mean height Sa is 100 nm, 80 nm is preferable and 60 nm is more preferable. Also, although the lower limit value of the arithmetic mean height Sa is 1 nm, 2 nm is preferable and 3 nm is more preferable.

[0078] The irregular shape of the minute irregularities 10 set using the surface load curve T (Ta) and various three-dimensional surface roughness parameters (the volume Vvv of the space of the protruding valleys, the volume Vmp of the protruding peaks, and the arithmetic mean height Sa) according to ISO 25178 as described above is not limited to the present embodiment.

[0079] That is, regarding the irregular shape of the minute irregularities 10, the coefficient of determination R of the regression line L (La) obtained by performing simple regression analysis by the least squares method on the surface load curve T (Ta) of the surface with a load area ratio of 10% to 99% 2 should be set to be 0.600 or more and 0.960 or less. Also, the root mean square error d between the surface load curve T (Ta) and the regression line L (La) in the range where the load area ratio is from 10% to 99% and the ratio (d / h) of the maximum height h within the range where the load area ratio is from 1% to 99% should be set to be 0.045 or more and 0.165 or less. Furthermore, the ratio (Vvv / Vmp) of the volume Vvv of the recessed valleys and the volume Vmp of the protruding ridges may be set to be 2.4 or more and 15 or less. These each identify the concavo-convex shape of the minute unevenness 10 only by each feature, and it is not necessary to satisfy each parameter simultaneously. For example, the coefficient of determination R of the regression line L (La) obtained by performing simple regression analysis by the least squares method on the load curve T (Ta) of the surface with a load area ratio ranging from 10% to 99% 2 When it is 0.600 or more and 0.960 or less, even if other parameters, that is, the root mean square error d from the regression line L (La) in the range of a load area ratio of 10% to 99%, the ratio (d / h) of the maximum height h within the range of a load area ratio of 1% to 99%, and the ratio (Vvv / Vmp) of the volume Vvv of the recessed valleys and the volume Vmp of the protruding ridges are outside the above set ranges, it may be acceptable.

[0080] [Method for manufacturing the glass substrate 21] Next, the method for manufacturing the glass substrate 21 will be described with reference to FIG. 1. The minute unevenness 10 formed on at least a part of the surface (main surface 21a) of the glass substrate 21 is formed by subjecting the main surface 21a to wet blasting treatment, sandblasting treatment, or the like.

[0081] The wet blasting treatment is a process of forming a minute uneven shape on a workpiece made of the glass substrate 21 by uniformly stirring abrasive grains made of solid particles such as alumina and a liquid such as water using compressed air to form a slurry and then injecting the slurry from an injection nozzle at high speed.

[0082] In the wet blasting treatment, when the slurry injected at high speed collides with the workpiece, the abrasive grains in the slurry scrape, strike, or rub the surface of the workpiece, thereby forming a minute uneven shape on the surface of the workpiece. In this case, the abrasive grains sprayed onto the workpiece and the fragments of the workpiece cut by the abrasive grains are washed away by the liquid sprayed onto the workpiece, so that the particles remaining on the workpiece are reduced.

[0083] Also, in wet blasting, when slurry is sprayed onto the workpiece, the liquid transports the abrasive grains to the workpiece. Therefore, compared with dry sandblasting, finer abrasive grains can be used, the impact when the abrasive grains collide with the workpiece is reduced, and precise machining can be performed.

[0084] In this way, by performing wet blasting on the workpiece (glass substrate 21), it is possible to easily form an uneven shape of an appropriate size on the main surface 21a of the glass substrate 21, and without impairing the transparency of the glass substrate 21, the friction force when the pen tip 3a of the input pen 3 or the fingertip 4 comes into contact can be appropriately adjusted, and the tactile sensations such as writing feel and touch feel can be surely improved.

[0085] Sandblasting is a process of forming minute uneven shapes on a workpiece made of a glass substrate 21 by directly spraying abrasive grains made of solid particles such as alumina from a spray nozzle at high speed onto the workpiece using compressed air.

[0086] By also performing sandblasting on the workpiece (glass substrate 21), similar to the above-described wet blasting, it is possible to easily form an uneven shape of an appropriate size on the main surface 21a of the glass substrate 21, and without impairing the transparency of the glass substrate 21, the friction force when the pen tip 3a of the input pen 3 or the fingertip 4 comes into contact can be appropriately adjusted, and the tactile sensations such as writing feel and touch feel can be surely improved.

[0087] In this way, the manufacturing method of the glass substrate 21 in the present embodiment is characterized in that minute unevenness 10 satisfying the above-described predetermined conditions is formed by performing wet blasting or sandblasting on at least a part of the surface (main surface 21a) of the glass substrate 21. According to the manufacturing method having such a configuration, a glass substrate 21 having minute irregularities 10 formed on the main surface 21a can be manufactured. Compared with a smooth plane without the minute irregularities 10, the glass substrate 21 has excellent tactile sensations such as writing feel by the input pen 3 and touch feel by the fingertip 4.

[0088] In addition, in forming the minute irregularities 10 on the main surface 21a of the glass substrate 21, as processing methods other than the wet blasting process and the sandblasting process described above, it is also possible to use chemical etching processing, sol-gel method, nanoimprint method, and the like. Here, the chemical etching processing is a process of chemically etching the main surface 21a of the glass substrate 21 with hydrogen fluoride (HF) gas, an acid such as hydrofluoric acid, hydrochloric acid, sulfuric acid, or an alkaline aqueous solution such as sodium hydroxide.

[0089] [Another Embodiment] By the way, in FIG. 9, regarding the glass substrate 21 in the present embodiment, paying attention to the point that the touch feel by the fingertip 4 is improved, it can be used as a back cover member 101 that constitutes the exterior of the mobile device 100. That is, as another embodiment of the present invention, the mobile device 100 includes the back cover member 101 made of the glass substrate 21 described above.

[0090] Here, examples of the mobile device 100 having the back cover member 101 include a mobile phone, a smartphone, a PDA (Personal Data Assistance), a PND (Portable Navigation Device), a notebook computer, and a tablet PC, which are communication terminals.

[0091] And by having such a configuration, a mobile device 100 having excellent tactile sensations such as touch feel by the fingertip 4 can be realized.

Example

[0092] Next, the glass member with micro unevenness according to the present invention will be described in detail using examples and comparative examples. Note that the configuration of the glass member according to the present invention is not limited to the examples shown below.

[0093] [Preparation of Samples] First, as examples of the glass member according to the present invention, Samples 1 to 11 were each prepared. In addition, as comparative examples for these examples, Samples 12 to 15 were each prepared.

[0094] Regarding the materials of Samples 1 to 11 which are examples, aluminosilicate glass (manufactured by Nippon Electric Glass Co., Ltd., product name: T2X-1) in the form of a rectangular plate with a thickness of 0.5 mm was used. Note that the materials of Samples 12 to 15 which are comparative examples will be described later.

[0095] Regarding the glass members of Samples 1 to 7 which are examples, micro unevenness was formed on one main surface by performing wet blasting treatment. Specifically, as an abrasive, abrasive grains composed of alumina (Al 2 O 3 ) and water were uniformly stirred to prepare a slurry. While moving the nozzle at a predetermined scanning speed, the slurry was scanned over the entire one main surface of each glass member, and wet blasting was performed to inject the prepared slurry from the nozzle using air at a predetermined processing pressure.

[0096] Here, for the glass members of Samples 1 to 3, polygonal abrasive grains with an average particle size of 1.2 μm were used. For the glass members of Samples 4 and 5, polygonal abrasive grains with an average particle size of 3.0 μm were used. For the glass members of Samples 6 and 7, polygonal abrasive grains with an average particle size of 6.9 μm were used. Note that the above average particle size is the abrasive particle size measured with the median diameter as D 50 .

[0097] Also, regarding the glass members of Samples 1 to 7 in terms of the slurry concentration, a slurry with an abrasive grain concentration of 6.0 wt% was used.

[0098] And in terms of the treatment pressure of the air in the nozzle, for the glass members of Samples 1 and 2, it was set to 0.22 MPa, for the glass member of Sample 3, it was set to 0.13 MPa, for the glass members of Samples 4 and 6, it was set to 0.15 MPa, and for the glass members of Samples 5 and 7, it was set to 0.25 MPa.

[0099] Also, in terms of the distance between the glass member and the injection port of the nozzle (nozzle distance), for the glass members of Samples 1 to 7, it was adjusted to be 4.0 mm.

[0100] Furthermore, in terms of the scanning speed during the movement of the nozzle, for the glass member of Sample 1, it was set to 1 mm / s, for the glass members of Samples 2 and 3, it was set to 40 mm / s, for the glass members of Samples 4 and 6, it was set to 20 mm / s, and for the glass members of Samples 5 and 7, it was set to 10 mm / s.

[0101] Regarding the glass members of Samples 8 to 11 which are examples, micro unevenness was formed on one main surface by performing sandblasting treatment. Specifically, as the abrasive, abrasive grains composed of alumina (Al 2 O 3 ) were scanned while moving the nozzle at a predetermined scanning speed over the entire one main surface of each glass member, and sandblasting was performed to inject the abrasive grains from the nozzle using air at a predetermined treatment pressure.

[0102] Here, for the glass member of Sample 8, polygonal abrasive grains with an average particle size of 1.2 μm were used, for the glass member of Sample 9, polygonal abrasive grains with an average particle size of 2.0 μm were used, for the glass member of Sample 10, polygonal abrasive grains with an average particle size of 3.0 μm were used, and for the glass member of Sample 11, polygonal abrasive grains with an average particle size of 4.0 μm were used. Incidentally, the above average particle size is the abrasive particle size measured with the median diameter being D 50 Also, the abrasive particles used in the polishing process are spherical particles having a size distribution such that the cumulative distribution of the particle size measured by a laser diffraction / scattering method satisfies the following relationship:

[0103] In addition, regarding the treatment pressure of the air in the nozzle, for the glass members of Samples 8 to 11, it was set to 0.40 MPa.

[0104] In addition, regarding the distance from the glass member to the injection port of the nozzle (nozzle distance), for the glass members of Samples 8 to 11, it was adjusted to be 4.0 mm.

[0105] Furthermore, regarding the scanning speed in the movement of the nozzle, for the glass members of Samples 8 to 11, it was set to 15 mm / s.

[0106] On the other hand, for the glass member of Sample 12, which is a comparative example, aluminosilicate glass (manufactured by Nippon Electric Glass Co., Ltd., product name: T2X-1) in the form of a rectangular plate with a thickness of 0.5 mm was used, and one main surface was not treated. That is, the glass member of Sample 12 was left untreated without using an abrasive.

[0107] Also, for the glass member of Sample 13, which is a comparative example, non-alkali glass (manufactured by Nippon Electric Glass Co., Ltd., product name: OA-10G) in the form of a rectangular plate with a thickness of 0.5 mm was used, and micro unevenness was formed on one main surface by performing wet etching treatment (HF etching) with hydrofluoric acid. Specifically, one main surface of the glass member was immersed in a hydrofluoric acid solution adjusted to a concentration of 5 wt% and a liquid temperature of 30°C and left for 2000 seconds to form micro unevenness.

[0108] Also, for the glass member of Sample 14, which is a comparative example, non-alkali glass (manufactured by Nippon Electric Glass Co., Ltd., product name: OA-10G) in the form of a rectangular plate with a thickness of 0.5 mm was used, and micro unevenness was formed on one main surface by performing a silica coating by the sol-gel method. Specifically, it was applied by injecting a liquid containing a silica component, and by drying the applied liquid containing the silica component, minute irregularities composed of a silica coating film were formed on the main surface.

[0109] Furthermore, for the glass member of Sample 15 which is a comparative example, an aluminosilicate glass (manufactured by Nippon Electric Glass Co., Ltd., product name: T2X-1) having a rectangular plate shape with a thickness of 0.5 mm was used, and wet blasting treatment was performed to form minute irregularities on one main surface. Specifically, using polygonal alumina abrasive grains with an average particle size of 6.9 μm, the concentration of the slurry was set to 1.0 wt%, the treatment pressure of air was set to 0.10 MPa, the distance between the glass member and the nozzle opening was set to 20.0 mm, and the scanning speed during the movement of the nozzle was set to 40 mm / s, and the treatment was performed.

[0110] Regarding the conditions of the abrasive for the glass members of Samples 1 to 15 shown above, and the conditions of the treatment pressure, nozzle distance, and scanning speed when performing wet blasting treatment or sandblasting treatment, they are described in Tables 1 and 2.

[0111] [Table 1]

[0112] [Table 2]

[0113] [Measurement of surface roughness] Next, the surface roughness of the main surfaces of the glass members of Samples 1 to 15 was measured. The measurement of the surface roughness was performed on the main surfaces subjected to wet blasting treatment for Samples 1 to 7 and 15, on the main surfaces subjected to sandblasting treatment for Samples 8 to 11, on one main surface for Sample 12, on the main surface subjected to wet etching treatment with hydrofluoric acid for Sample 13, and on the main surface provided with a silica coating film for Sample 14.

[0114] The measured surface roughness parameters were the arithmetic mean height Sa, the volume Vvv of the space of the protrusion valleys, and the volume Vmp of the protrusion peaks in the formed micro unevenness, and these measurements were performed using an atomic force microscope (AFM). Also, based on the above measurement values, the ratio (Vvv / Vmp) of the volume Vvv of the space of the protrusion valleys to the volume Vmp of the protrusion peaks was derived.

[0115] Here, the surface load curve T was obtained by equally dividing the interval from the maximum peak height to the maximum valley depth (that is, as described above, in FIG. 2, the interval between the uppermost end 10a1 of the convex part (peak part) and the lowermost end 10a2 of the concave part (valley part)) into 512 equal intervals, and plotting the load area ratio at each height. Also, the regression line L by the least squares method, the coefficient of determination R 2 , the root mean square error d, and the maximum height h within the range of 1% to 99% of the load area ratio were derived from the surface load curve T of the surface based on the above plot.

[0116] The atomic force microscope (AFM) used for the measurement was the atomic force microscope Dimension Icon (SPM unit) and Nano Scope V (Controller unit) manufactured by Bruker, and the measurement was carried out based on ISO 25178. Also, as the measurement conditions, the tapping mode was used, and the measurement was carried out such that the scan rate was 1 Hz and the number of acquired data was 512×512 for a measurement area of 5×5 μm.

[0117] [Measurement of haze] Next, the haze of the glass members of Samples 1 to 14 was measured. The measurement of haze was carried out based on JIS K7361-1:1997 using an ultraviolet-visible-near-infrared analytical photometer (UV-3100PC) manufactured by Shimadzu Corporation.

[0118] [Evaluation of writing feel] Next, in order to confirm the writing feel of the glass members of Samples 1 to 15, evaluation was carried out by the following method. As an evaluation method, first, two types of pens were prepared: pen X made of a Wacom propen (product name "KP-503E") with a refill manufactured by Wacom (product name "ACK-20004: elastomer refill"), and pen Y made of an Apple Pencil 2 manufactured by Apple. On the main surface with minute unevenness, the character "あ" was written using these pens X and Y, and compared with the writing feel between paper and a ballpoint pen. When the writing feel was good, it was evaluated as "○", and when the writing feel was bad, it was evaluated as "×".

[0119] [Evaluation of touch feel] Next, in order to confirm the touch feel of the fingertips on the glass members of Samples 1 to 15, evaluation was conducted by the following method. As an evaluation method, the main surface with minute unevenness was traced several times with the fingertips. When it felt moderately easy to slide, it was evaluated as "○", when it felt slightly easy to slide, it was evaluated as "△", and when a catching feeling was felt on the fingertips, it was evaluated as "×".

[0120] The surface roughness, haze measurement results, writing feel, and touch feel evaluation results for the glass members of Samples 1 to 15 shown above are described in Tables 3 and 4.

[0121] [Table 3]

[0122] [Table 4]

[0123] [Discussion] First, as shown in Table 4, in the glass members of Samples 1 to 11 which are examples, regardless of whether pen X or pen Y was used, the writing feel of the main surface with minute unevenness was "○", resulting in good results. In addition, in the glass members of Samples 1, 2, 4 to 11 which are examples, and the glass member of Sample 3 which is an example, the feel when touched with a fingertip was “○” and “△” respectively, and in both cases, the results were substantially good.

[0124] On the other hand, in the glass members of Samples 12 to 15 which are comparative examples, regardless of whether Pen X or Pen Y was used, the writing feel of the main surface on which minute irregularities were formed was “×”, resulting in a poor result. In addition, in the glass members of Samples 12, 13, and 15 which are comparative examples, the feel when touched with a fingertip was also “×”, resulting in a poor result. In the glass member of Sample 14 in which a silica coating was applied to one main surface, the feel when touched with a fingertip was “○”, resulting in a good result.

[0125] Based on these results, the measurement results of the surface roughness of the glass members of Samples 1 to 15 are considered.

[0126] As shown in Table 3, in the glass members of Samples 1 to 11 which are examples, the coefficient of determination R of the regression line L obtained by performing simple regression analysis by the least squares method on the range from 10% to 99% of the load area ratio in the surface load curve T of the surface 2 was a value within the range of 0.683 to 0.939. On the other hand, in the glass members of the untreated Sample 12, the Sample 13 subjected to wet etching treatment with hydrofluoric acid, and the Sample 14 subjected to silica coating which are comparative examples, the coefficient of determination R of the regression line L 2 was a value within the range of 0.963 to 0.976, and in the glass member of Sample 15 subjected to wet blasting, the coefficient of determination R of the regression line L 2 was 0.521.

[0127] In addition, in the glass members of Samples 1 to 11 which are examples, in the surface load curve T, the ratio (d / h) of the root mean square error d of the regression line L obtained by performing simple regression analysis by the least squares method in the range of the load area ratio from 10% to 99% to the maximum height h in the range of the load area ratio from 1% to 99% was a value in the range of 0.063 to 0.144. On the other hand, in the glass members of the untreated Sample 12, the Sample 13 subjected to wet etching treatment with hydrofluoric acid, and the Sample 14 subjected to silica coating which are comparative examples, the above ratio (d / h) was a value in the range of 0.038 to 0.042, and in the glass member of the Sample 15 subjected to wet blasting, the above ratio (d / h) was 0.166.

[0128] Furthermore, in the glass members of Samples 1 to 11 which are examples, when the load area ratio indicating the boundary between the core part and the protruding peak part in the surface load curve T was 10% and the load area ratio indicating the boundary between the core part and the protruding valley part was 80%, the ratio (Vvv / Vmp) of the volume Vmp of the protruding peak part to the volume Vvv of the space of the protruding valley part was a value in the range of 2.65 to 14.70. On the other hand, in the glass members of the untreated Sample 12, the Sample 13 subjected to wet etching treatment with hydrofluoric acid, and the Sample 14 subjected to silica coating which are comparative examples, the above ratio (Vvv / Vmp) was a value in the range of 0.87 to 2.30, and in the glass member of the Sample 15 subjected to wet blasting, the above ratio (Vvv / Vmp) was 16.00.

[0129] As is clear from the above results, when the concavo-convex shape of the minute irregularities satisfies any one of the following predetermined conditions, that is, at least the coefficient of determination R of the above regression line L 2 is a numerical value in the range of 0.600 to 0.960, the above ratio (d / h) is a numerical value in the range of 0.045 to 0.165, and the above ratio (Vvv / Vmp) is a numerical value in the range of 2.4 to 15, the glass member having such minute irregularities exhibits excellent performance in terms of writing feel and touch feel.

[0130] The embodiments of the present application have been described above. However, the present application is not limited to such embodiments at all, but is merely illustrative, and it goes without saying that the present application can be implemented in various other forms without departing from the gist of the present application. The scope of the present application is indicated by the description in the claims, and further includes the equivalent meaning described in the claims and all modifications within the scope.

Explanation of Reference Numerals

[0131] 1 Pen input device 2 Input device 3 Input pen 10 Micro unevenness 21 Glass substrate (glass member) 21a Main surface (surface) 22 Display element (display device) 23 Digitizer circuit (detection circuit) 100 Mobile device 101 Rear cover member L Regression line T Surface load curve

Claims

1. having minute irregularities on at least a part of the surface, in the surface load curve within a region of a square having a side length of 5 μm in the minute irregularities, The coefficient of determination R of the regression line obtained by performing simple regression analysis by the least squares method in the range where the load area ratio is from 10% to 99% ２ is 0.600 or more and 0.960 or less, a glass member characterized by the following.

2. having minute irregularities on at least a part of the surface, in the surface load curve within a region of a square having a side length of 5 μm in the minute irregularities, the ratio (d / h) of the root mean square error d between the load curve and the regression line obtained by performing simple regression analysis by the least squares method for the range from a load area ratio of 10% to 99% with respect to the maximum height h (= ha - hb) which is the difference between the height ha when the load area ratio is 1% and the height hb when the load area ratio is 99%, is 0.045 or more and 0.165 or less, a glass member characterized by the following.

3. having minute irregularities on at least a part of the surface, in the surface load curve within a region of a square having a side length of 5 μm in the minute irregularities, when the load area ratio indicating the boundary between the core part and the protruding mountain part in the minute irregularities is 10% and the load area ratio indicating the boundary between the core part and the protruding valley part in the minute irregularities is 80%, the ratio (Vvv / Vmp) of the volume Vvv of the space of the protruding valley part to the volume Vmp of the protruding mountain part, is 2.4 or more and 15 or less, a glass member characterized by the following.

4. In the minute irregularities, the arithmetic mean height Sa of the elements of the roughness curve is 1 nm or more and 100 nm or less, a glass member according to any one of Claims 1 to 3, characterized by the following.

5. a glass substrate made of the glass member according to any one of Claims 1 to 4, a display device for displaying an image, and a detection circuit for detecting an input position, an input device characterized by the following.

6. the input device according to Claim 5, and an input pen for performing an input operation on the input device by moving while contacting the surface of the glass substrate, a pen input device characterized by the following.

7. including a back cover member made of the glass member according to any one of Claims 1 to 4, a mobile device characterized by the following.

8. a manufacturing method for manufacturing the glass member according to any one of Claims 1 to 4, wherein a wet blasting treatment or a sand blasting treatment is performed on the surface of the glass member, a manufacturing method of a glass member characterized by the following.

Images