JP2021077032A - Cover member for input device, and input device - Google Patents

Abstract

To provide a cover member for an input device, etc., capable of improving the writing feeling of input means such as an input pen to an input device.SOLUTION: A cover member for an input device arranged at a front side of a display device 30 in an input device 10 has irregularity on at least one principal surface 20a. In the principal surface 20a having the irregularity, when the size of interval width of the irregularity is regarded as A and the diameter of a tip part of an input medium is regarded as B when a cut-off value of a high-pass filter λc is regarded as a value of 1.6 times the interval width of the irregularity of a measurement cross-sectional curve and a cut-off value of a low-pass filter λs is regarded as 25 μm, the relation between them satisfies 0.02<[A/B]<1.SELECTED DRAWING: Figure 2

Description

The present invention relates to a cover member for an input device and an input device including the cover member.

Conventionally, a pen input device capable of inputting characters, figures, and the like using an input pen or the like has been known.
In such a pen input device, a transparent cover member composed of a glass substrate or the like is arranged on the front side of a display device such as a liquid crystal display, and the input pen is brought into contact with and moved to the cover member. Therefore, it is possible to perform various input operations. When a glass substrate is used as a cover member of a pen input device, the surface of the glass substrate is generally formed smoothly with small irregularities, so that the pen is moved when the input pen is brought into contact with the surface of the glass substrate and moved. The tip slipped, causing the problem of uncomfortable writing.

For example, Patent Document 1 discloses that the surface of the cover glass of an input device is made uneven to improve friction in order to improve the writing quality of the input pen in the pen input device. The maximum valley depth of the unevenness is 10 to 400 nm, and the average interval is 500 to 2000 nm.

JP-A-2018-20942

However, when the concave-convex layer formed on the surface of the cover glass described above is moved by bringing the input pen into contact with the surface of the cover glass member, the pen tip becomes too caught and becomes hard to slip, and good writing like paper and a ballpoint pen. It was difficult to get the taste.

Therefore, in the present invention, a cover member for an input device, which is made in view of the current problems and has an even better writing quality of an input means using an input medium such as an input pen, and an input device including the cover member are provided. It is to provide.

The problem to be solved by the present invention is as described above, and next, the means for solving this problem will be described.

The cover member for an input device that solves the above problems and the input device provided with the cover member have the following features.
That is, the input device cover member according to the present invention is an input device cover member arranged on the front side of the display device in the input device, and has unevenness on at least one main surface, and the main having the unevenness. On the surface, the cutoff value of the high frequency filter λc is 1.6 times the spacing width of the unevenness of the measurement cross-sectional curve, and the cutoff value of the low frequency filter λs is 25 μm. When the size of is A and the diameter of the tip of the input medium is B, the relationship between the two satisfies 0.02 << [A / B] <1.
With such a configuration, the contact area between the tip of the input medium and the cover member can be reduced, and an excessive increase in friction can be reduced. As a result, the writing quality of an input medium such as an input pen can be improved.

Further, in the cover member for an input device according to the present invention, the cutoff value of the high frequency filter λc is set to 1.6 times the interval width of the unevenness of the measurement cross-sectional curve on the main surface having the unevenness, and is low. When the cutoff value of the region filter λs is 25 μm, the maximum height width of the unevenness is 3 to 1000 nm, and the interval width A of the unevenness is 50 to 1000 μm.
With such a configuration, it is possible to prevent the operation of the input means by the input medium such as the input pen on the input device from becoming too slippery, and the writing quality of the input means by the input medium such as the input pen is excellent. can do.

Further, in the cover member for an input device according to the present invention, when the cutoff value of the high frequency filter λc is 25 μm on the main surface having the unevenness, the surface roughness (three-dimensional) arithmetic average height Sa of the unevenness Is 1 to 50 nm and the spacing width of the unevenness is 0.01 to 10 μm.
With such a configuration having two types of unevenness, it is possible to prevent the operation of the input means by the input medium such as the input pen for the input device from being too slippery and not too slippery. The writing quality of the input means using the input medium can be improved.

Further, in the cover member for an input device according to the present invention, the diameter of the tip portion of the input medium is 0.5 mm to 10 mm.

Further, the cover member for an input device according to the present invention has a haze of less than 10% in the wavelength range of visible light.
As a result, the transparency of the cover member for the input device can be maintained, and the visibility of the display device can be maintained.

Further, the input device according to the present invention includes the cover member for the input device according to any one of claims 1 to 4, the display device, and the detection circuit for detecting the input.
As a result, the writing quality of the input means using an input medium such as an input pen for inputting to the input device can be improved.

Further, the input device according to the present invention includes an input pen for inputting to the input device by moving while contacting the main surface of the cover member for the input device.
With such a configuration, it is possible to improve the writing quality of the input device using an input medium such as an input pen.

According to the present invention, the writing quality of an input means using an input medium such as an input pen for inputting to an input device can be improved.

It is a schematic side sectional view which shows the input device. It is a figure which shows the relationship that the size of the interval width of the unevenness of the measurement cross-sectional curve of a main surface is A, and the diameter of the tip of an input medium such as an input pen is B. It is a figure which shows the measurement cross-sectional curve of the main surface, the unevenness of a large spacing width, and the unevenness of a small spacing width. It is a figure which shows the cut-off value of the high region filter λc and the low region filter λs. It is a figure which shows the state in which the pen tip comes into contact with the main surface of the glass substrate which formed the two types of unevenness, large and small, which have different widths of spacing of unevenness. It is a figure which shows the state that the pen tip comes into contact with the main surface of the glass substrate which does not have a small unevenness among the two types of unevenness of large and small which the spacing width of the unevenness is different. The glass substrate has two types of irregularities, large and small, having different irregularities, and the pen tip is in contact with the main surface of the glass substrate in which the interval width of the large irregularities is larger than the diameter of the pen tip.

Next, a cover member for an input device according to the present invention and a mode for carrying out an input device including the cover member will be described with reference to the accompanying drawings.

The input device 10 shown in FIG. 1 is an embodiment of an input device provided with a cover member for an input device according to the present invention.
The input device 10 includes a display element 30 for displaying an image, a glass substrate 20 as a cover member arranged on the front side of the display element 30, a digitizer circuit 40 arranged on the back side of the display element 30, and an input pen. With 50. The glass substrate 20 is an example of a cover member for an input device according to the present invention, and the digitizer circuit 40 is an example of a detection circuit for detecting an input according to the present invention.
The "front side" of the display element 30 means the side on which the image is displayed, and the "back side" of the display element 30 means the side opposite to the side on which the image is displayed. In FIG. 1, the “front side” of the display element 30 is above the paper surface, and the “back side” is below the paper surface.

The input device 10 can input characters, figures, and the like by moving the input pen 50 in contact with the glass substrate 20. Input to the input device 10 can also be performed by an input means other than the input pen 50. For example, by moving the user's finger in contact with the glass substrate 20, it is possible to input characters and figures.
The input device 10 is, for example, a tablet terminal. This tablet terminal broadly means an input display device having a display function and an input function. Tablet terminals include devices such as tablet PCs, mobile PCs, smartphones, and game consoles.

The glass substrate 20 is formed of a transparent glass plate having irregularities formed on at least one main surface 20a. As the glass substrate 20, for example, a glass plate made of aluminosilicate glass or borosilicate glass can be used. When the glass substrate 20 is a glass plate made of alkali-containing aluminosilicate glass, the glass substrate 20 may have a chemically strengthened layer on its surface. The details of the glass substrate 20 will be described later.

The glass substrate 20 is arranged so as to be a surface on the side where the input pen 50 comes into contact with the main surface 20a on which the unevenness is formed.

The digitizer circuit 40 includes a detection sensor that detects an input by an input means such as an input pen 50. The input pen 50 is an input tool having a shape similar to a writing instrument such as a pencil or a ballpoint pen, and the pen tip 51 in contact with the glass substrate 20 is made of an elastomer, a synthetic resin material such as polyacetal resin, fibers, or the like. .. The diameter of the pen tip 51 composed of these members is easily affected by the width of the unevenness. Therefore, when the pen tip 51 of the input pen 50 is moved in contact with the main surface 20a of the glass substrate 20 on which the unevenness is formed, which defines the ratio between the diameter of the pen tip 51 and the interval width of the unevenness, the writing taste is improved. Especially excellent.

In the present embodiment, the glass substrate 20 is used as the cover member for the input device, but the present invention is not limited to this, and the cover member covers a resin substrate formed of synthetic resin and having irregularities formed on at least one main surface. It can also be used as. In this case, the unevenness of the resin substrate can be formed by, for example, blasting the main surface of the resin substrate with wet blasting or the like, or embossing the main surface of the resin substrate.

Further, it is also possible to use a resin layer having irregularities formed on the surface formed on at least one main surface of the glass substrate as a cover member. In this case, the cover member can be formed by attaching a resin sheet having irregularities formed on the surface to the main surface of the glass substrate. The unevenness of the resin sheet can be formed, for example, by embossing the surface of the resin sheet or forming a synthetic resin mixed with powders and granules into a sheet shape. Further, the resin layer can also be formed by a spray method in which a synthetic resin is sprayed onto the main surface of a glass substrate.

However, when the glass substrate 20 is used as the cover member, the surface hardness is higher than that when the resin substrate or the one having the resin layer formed on the main surface of the glass substrate is used, so that the surface is less likely to be scratched. It is advantageous in that.

Next, the glass substrate 20 will be described.
The glass substrate 20 is an embodiment of a cover member for an input device according to the present invention. Concavities and convexities are formed on the main surface 20a of the glass substrate 20.

As shown in FIG. 2, the glass substrate 20 has a main surface 20a having irregularities, and the cutoff value of the high frequency filter λc is 1.6 times the interval width of the irregularities of the measurement cross-sectional curve, although the details will be described later. When the value is set and the cutoff value of the low frequency filter λs is 25 μm, the size of the gap width of the unevenness is A, and the diameter of the tip of the input medium such as an input pen is B, [A / B] is in the range of 0.02 to 1 (however, 1 is not included). It is preferably 0.03 to 0.99, more preferably 0.05 to 0.95, and particularly preferably 0.07 to 0.90. If the value of [A / B] is too small or too large, an appropriate frictional force cannot be obtained, so that a good writing quality cannot be obtained.

As shown in FIG. 3, the unevenness is composed of two different types of unevenness, large and small. The unevenness having a large interval width has a maximum height width Rz of 3 nm to 1000 nm and an unevenness interval width RSm of 50 μm to 10000 μm. Further, the unevenness having a small spacing width has a three-dimensional arithmetic mean height Sa of 1 nm to 50 nm and an spacing width RSm of the unevenness of 0.01 μm to 10 μm. The maximum height width Rz is preferably larger than the three-dimensional arithmetic mean height Sa. Further, the maximum height width Rz is more preferably 1.1 to 500 times the three-dimensional arithmetic mean height Sa.

Here, in the unevenness with a large interval width, the maximum height width Rz is the sum of the height of the highest mountain and the depth of the deepest valley in the unevenness, and the interval width RSm of the unevenness is the unevenness at a predetermined reference length. It is the average of each cycle length Xs of. Further, in the unevenness with a small interval width, the three-dimensional arithmetic average height Sa is the average of the absolute values of the height Z1 of the peak and the depth Z2 of the unevenness in the predetermined three-dimensional region, and the interval width RSm of the unevenness. Is the average of each period length Xs of the unevenness at a predetermined reference length.

As shown in FIGS. 3 and 4, the values of the maximum height width Rz and the gap width RSm of the unevenness in the above-mentioned unevenness having a large spacing width are the heights for blocking the long wavelength component from the measurement cross-sectional curve of the main surface 20a. The cut-off value λc1 of the region filter λc is set to a value 1.6 times the interval width of the unevenness of the measurement cross-section curve, and the low-frequency filter λs for blocking short wavelength components from the measurement cross-section curve of the main surface 20a. This is a value obtained when the cutoff value λs1 of is set to 25 μm.

Further, the values of the three-dimensional arithmetic mean height Sa and the spacing width RSm of the unevenness in the unevenness of the small spacing width described above are the cutoffs of the high frequency filter λc for blocking the long wavelength component from the measurement cross-sectional curve of the main surface 20a. It is a value obtained when the value λc2 is set to 25 μm. In the measurement cross-sectional curve of the main surface 20a, by applying the high frequency filter λc having the cutoff value λc2, the waviness component and the unevenness component having a large interval width of the main surface 20a are removed. An uneven curve with a small spacing width can be obtained.

When the shape of the unevenness having a large spacing width and the shape of the unevenness having a small spacing width on the main surface 20a of the glass substrate 20 are within such a range, the visibility of the display element 30 is maintained in the input device 10. It is possible to improve the writing quality of the input means such as the input pen 50. In addition, it is possible to suppress the occurrence of glare called sparkling due to the interference of scattered light due to the formed unevenness. Further, if the resin layer is not formed on the main surface 20a of the glass substrate 20 and the concave-convex shape is directly formed, the scratch resistance is high and the scratches are hard to be made, which may reduce the visibility of the display element 30. Absent.

The unevenness with a large spacing affects the contact between the main surface 20a and the pen tip 51 of the input pen 50. The pen tip 51 comes into contact with the main surface 20a of the glass substrate 20 at the convex portion of the unevenness having a large spacing width, but does not contact the concave portion of the unevenness having a large spacing width. As a result, the combination of an appropriate increase and decrease in the frictional force between the pen tip 51 and the main surface 20a prevents an excessive increase and decrease in the frictional force between the pen tip 51 and the main surface 20a. This makes it possible to improve the writing quality of the input pen 50. Further, even when the user's finger is moved in contact with the glass substrate 20, the finger can be moved appropriately and smoothly, and the writing taste when inputting with the finger is improved. Can be done. In this way, it is possible to improve the writing quality of the input means such as the input pen 50 and the finger.

The upper limit of the maximum height width Rz of the unevenness having a large interval width is set to 1000 nm, but it is preferably set to 500 nm, and more preferably 200 nm. Further, although the lower limit of the maximum height width Rz of the unevenness having a large interval width is set to 3 nm, it is preferably set to 4 nm, and more preferably set to 5 nm. The upper limit of the spacing width RSm of the unevenness having a large spacing width is set to 10000 μm, but it is preferably set to 9500 μm, and more preferably 9000 μm. Further, although the lower limit value of the interval width RSm of the unevenness having a large interval width is set to 50 μm, it is preferably set to 100 μm, more preferably 500 μm, and further preferably 1500 μm.

The unevenness with a small spacing width contributes to an increase in the frictional force between the main surface 20a of the glass substrate 20 and the pen tip 51. As a result, the pen tip 51 can be prevented from slipping on the main surface 20a of the glass substrate 20, and the writing quality of the input pen 50 can be improved. Further, even when the user's finger is moved in contact with the glass substrate 20, the finger can be moved appropriately and smoothly, and the writing taste when inputting with the finger is improved. Can be done. In this way, it is possible to improve the writing quality of the input means such as the input pen 50 and the finger. The upper limit of the three-dimensional arithmetic mean height Sa of the unevenness having a small interval width is set to 50 nm, but it is preferably set to 40 nm, and more preferably 30 nm. The upper limit of the spacing width RSm of the unevenness having a small spacing width is set to 10 μm, but it is preferably set to 7 μm, and more preferably set to 5 μm. The lower limit of the spacing width RSm of the unevenness having a small spacing width is set to 0.01 μm, but it is preferably set to 0.1 μm, and more preferably 0.5 μm.

Further, the main surface 20a of the glass substrate 20 is made of a pen tip 51 made of a member such as an elastomer such as silicone rubber, a resin material such as polyacetal resin, metal, and fibers which are easily caught by irregularities. The writing quality is particularly excellent. The diameter of the tip of the pen tip or the like is 0.5 mm to 10 mm. The smaller the diameter of the tip portion, the finer the line can be input, but if it is too small, the digitizer circuit 40 cannot be recognized. Therefore, the range of 1 mm to 9.5 mm is preferable, and the range of 1.2 mm to 9 mm is more preferable.

The glass substrate 20 has a haze indicating cloudiness as an index related to transparency in the visible light wavelength range (380 nm to 780 nm) from the viewpoint of visibility of the image when the image of the display element 30 is viewed through the glass substrate 20. ) Is formed to be less than 10%. By setting the haze of the glass substrate 20 to less than 10%, the transparency of the glass substrate 20 can be maintained, and the visibility of the display element 30 can be maintained.

In the case of the present embodiment, the haze of the glass substrate 20 is set to less than 10%, but is preferably less than 7%, more preferably less than 5%, and even more preferably less than 4%. ..

Further, on the main surface 20a of the glass substrate 20, an antireflection film for reducing the reflectance on the side where the input pen comes into contact, or an antifouling film for preventing fingerprints from adhering to impart water repellency and oil repellency. A film can be formed.

When the glass substrate 20 is used as a cover member of the input device 10, the antireflection film is provided on at least the main surface 20a on the front side (the side where the input pen 50 contacts) of the glass substrate 20.
When there is a gap between the glass substrate 20 and the display element 30, it is preferable that the antireflection film is also provided on the main surface 20a on the back side (display element 30 side) of the glass substrate 20. As the antireflection film, for example, a low refractive index film having a refractive index lower than that of the glass substrate 20, or 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. The used dielectric multilayer film is used. The antireflection film can be formed by a sputtering method, a CVD method, or the like.

When the antireflection film is provided on the main surface 20a of the glass substrate 20, the unevenness of the surface of the antireflection film is the above-mentioned surface roughness (the maximum height width Rz of the unevenness having a large spacing width and the spacing width RSm of the unevenness, and the small spacing. The unevenness of the main surface 20a of the glass substrate 20 is formed so as to be within the range of the three-dimensional arithmetic surface height Sa and the interval width RSm) of the unevenness of the width. When the main surface 20a of the glass substrate 20 has an antireflection film, the unevenness of the main surface 20a of the glass substrate 20 is formed so that the haze of the glass substrate 20 having the antireflection film is within the above range. After forming the antireflection film, when measuring the interval width RSm of the unevenness and the three-dimensional arithmetic mean height Sa of the unevenness, an Au film of 10 nm is formed, and then these values are measured.

When the glass substrate 20 is used as a cover member of the input device 10, the antifouling film is provided on the main surface 20a on the front side (the side that the input pen 50 contacts) of the glass substrate 20. The antifouling film preferably contains a fluorine-containing polymer containing silicon in the main chain. As the fluorine-containing polymer, for example, a polymer having a -Si-O-Si- unit in the main chain and having a water-repellent functional group containing fluorine in the side chain can be used. The fluorine-containing polymer can be synthesized, for example, by dehydrating and condensing silanol. When the antireflection film and the antifouling film are provided on the main surface 20a on the front side of the glass substrate 20, the antireflection film is formed on the main surface 20a of the glass substrate 20, and the antifouling film is formed on the antireflection film. Will be done.

When the main surface 20a of the glass substrate 20 has an antifouling film, or when the main surface 20a of the glass substrate 20 has an antireflection film and an antifouling film, the unevenness of the surface of the antifouling film is the above-mentioned surface roughness ( The glass substrate 20 is provided so as to be within the range of the maximum height width Rz of the unevenness having a large spacing width and the spacing width RSm of the unevenness, and the three-dimensional arithmetic surface height Sa of the unevenness having a small spacing width and the spacing width RSm of the unevenness. The unevenness of the main surface 20a is formed. Further, when the main surface 20a of the glass substrate 20 has an antifouling film, or when the main surface 20a of the glass substrate 20 has an antireflection film and an antifouling film, the glass substrate 20 after the antifouling film is formed. The unevenness of the main surface 20a of the glass substrate 20 is formed so that the haze of the glass substrate 20 after forming the haze or the antireflection film and the antifouling film is within the above range.

Next, a method of manufacturing the glass substrate 20 will be described. The unevenness formed on at least one main surface 20a of the glass substrate 20 is formed by combining at least one kind of treatment methods such as wet blasting treatment, chemical etching treatment, and silica coating treatment on the main surface 20a. In the wet blast treatment, abrasive grains composed of solid particles such as alumina and a liquid such as water are uniformly agitated to form a slurry, which is then subjected to a work made of glass from an injection nozzle using compressed air. This is a process of forming fine irregularities on the work by injecting the work at a high speed. Further, as a nozzle for injecting the slurry, a round nozzle in which the area of the injection port of the slurry is narrowed down with respect to the area of the work is used, and various surface shapes are formed by moving the round nozzle relative to the work. be able to.

In the wet blasting process, when the slurry ejected at high speed collides with the work, the abrasive grains in the slurry scrape, hit, or rub the surface of the work, resulting in fine irregularities on the surface of the work. It will be formed. In this case, the abrasive grains ejected onto the work and the fragments of the work scraped by the abrasive grains are washed away by the liquid ejected onto the work, so that the number of particles remaining on the work is reduced. Further, by arbitrarily scanning the nozzle with respect to the work and partially injecting the slurry onto the surface of the work, it is possible to create unevenness having a large spacing width in addition to unevenness having a small spacing width. The glass substrate 20 can be obtained by preparing a work having two types of irregularities, large and small, having different spacing widths on the surface to a desired size and shape by cutting or the like.

The surface roughness of the unevenness with a small interval width formed on the main surface of the work by the wet blasting process can be adjusted mainly by the particle size distribution of the abrasive grains contained in the slurry and the injection pressure when the slurry is injected into the work. Is. Further, the maximum height width Rz of the unevenness having a large spacing width and the spacing width RSm of the unevenness can be adjusted by adjusting the size of the nozzle for injecting the slurry, the feed pitch width, and the injection pressure.

In the wet blasting process, when the slurry is sprayed onto the work, the liquid carries the abrasive grains to the work, so finer abrasive grains can be used as compared with the dry blasting process, and when the abrasive grains collide with the work. The impact of the slurry is reduced, and precise machining can be performed. By applying the wet blast treatment to the work in this way, it is easy to form two types of irregularities, large and small, on the main surface 20a of the glass substrate 20 with different spacing widths of the irregularities of appropriate size, and the transparency of the glass substrate 20. It is possible to improve the writing quality of the input means such as the input pen 50 without impairing the above.

In the dry blast treatment, processing heat is generated in the work due to friction when the injected abrasive grains collide with the work, but in the wet blast treatment, the liquid constantly cools the surface of the work during the treatment. Therefore, the work is not heated by the blasting process.
Further, it is possible to form irregularities on the main surface 20a of the glass substrate 20 by performing the dry blast treatment, but in the dry blast treatment, the impact when the abrasive grains collide with the main surface 20a of the glass substrate 20 is generated. If it is too large, the surface roughness of the main surface 20a on which the unevenness is formed tends to be large, and the transparency of the glass substrate 20 tends to be impaired.

The chemical etching process is a process of chemically etching the main surface 20a of the glass substrate 20 with hydrogen fluoride (HF) gas or hydrofluoric acid.

Further, in the silica coating treatment, a coating agent containing a matrix precursor such as a silica precursor and a liquid medium for dissolving the matrix precursor is applied to the main surface 20a of the glass substrate 20 and heated. It is a process to do.

Next, an example of the glass substrate 20 in which two types of irregularities of different sizes are formed on the main surface 20a with different spacing widths will be described. However, the glass substrate 20 is not limited to this.

[Preparation of sample]
In this example, samples 1 to 9 were prepared as examples of the glass substrate 20, and samples 10 to 12 were prepared as comparative examples. As the glass substrate 20 used for Samples 1 to 12, alkali-containing aluminosilicate glass having a thickness of 1.1 mm was used.

By performing a wet blast treatment on the glass substrates 20 of Samples 1 to 9 as an example and Sample 12 as a comparative example, two types of irregularities, large and small, having different irregularities on one main surface 20a. Was formed. Specifically, it is prepared by uniformly stirring water and abrasive grains composed of alumina having a particle size of # 4000, # 6000 or # 8000 with respect to the glass substrates 20 of Samples 1 to 9 and Sample 12. The glass substrate 20 is placed on a processing table, and a round nozzle of 0.5 mm / mm is applied to the entire one main surface 20a of the glass substrate 20 using air having a processing pressure of 0.1 to 0.3 MPa. Wet blasting was performed by scanning and injecting while moving at a speed of s.
The round nozzle that performs wet blasting is a nozzle that narrows the cross-sectional area of the injection port of the slurry to a small area with respect to the area of the main surface 20a and partially injects the slurry onto the main surface 20a. The spacing width of the unevenness with a large spacing width was changed by changing the scanning distance of the round nozzle. Further, the maximum height width Rz of the unevenness having a large interval width was changed by increasing the number of scans. The three-dimensional arithmetic mean height Sa of the unevenness with a small spacing width was changed by changing the particle size of alumina or changing the processing pressure. As the abrasive grains, abrasive grains having a polygonal shape were used.

In Samples 1 to 9 and Sample 12, samples were prepared by varying the scanning distance of the round nozzle from 500 to 3000 μm for the uneven width of the unevenness having a large spacing width. A sample was prepared by varying the number of scans of the round nozzle to 2 to 5 times that of the sample 1 for the maximum height width Rz of the unevenness having a large interval width. For the three-dimensional arithmetic mean height Sa of the unevenness with a small spacing width, a sample was prepared by changing the particle size of alumina to # 4000-8000 and increasing the processing pressure in the range of 0.1 to 0.2 MPa.

The main surface 20a of the glass substrate 20 of the sample 10 as a comparative example is not treated. That is, the glass substrate 20 of the sample 10 is untreated. For the glass substrate 20 of the sample 11 as a comparative example _{, a SiO 2} coating film was formed on one of the main surfaces 20a by drying a liquid containing a _{SiO 2 component.}

[Measurement of surface roughness]
The surface roughness of the main surface 20a on the glass substrate 20 of Samples 1 to 12 was measured. The surface roughness was measured on the main surface 20a subjected to the wet blast treatment for the samples 1 to 10 and 12, and on one main surface 20a for the sample 11.

The parameters of the measured surface roughness are the maximum height width Rz and the unevenness spacing width RSm for the unevenness with a large spacing width, and the three-dimensional arithmetic surface height Sa and the unevenness spacing width RSm for the unevenness with a small spacing width. Therefore, the surface roughness was measured using a white interference microscope.

The white interference microscope used was a white interference microscope (New View 7300) manufactured by Zygo, and measurements were carried out based on JIS B0601-2013. For samples 1 to 10 and 12, the measurement conditions for unevenness with a large spacing width are as follows: an objective lens of 2.5 times and a zoom lens of 1 time are used, and the number of camera pixels is 640 × for a measurement area of 2827 × 2120 μm. It was carried out so that the number of integrations was 480 and the number of integrations was one. When measuring the maximum height width Rz of the unevenness with a large spacing width and the spacing width RSm of the unevenness, the cutoff value λc1 of the high frequency filter λc is set to be about 1.6 times the spacing width RSm of the unevenness. The cutoff value λs1 of the low frequency filter λs was set to 25 μm. The measurement conditions for unevenness with a small spacing width are such that the number of camera pixels is 640 x 480 and the number of integrations is 8 times for a measurement area of 74 x 55 μm using an objective lens of 50 times and a zoom lens of 2 times. Carried out. The cutoff value λc2 of the high frequency filter λc when measuring the three-dimensional arithmetic mean height Sa of the unevenness with a small spacing width and the spacing width RSm of the unevenness was set to 25 μm. Regarding the sample 11, the measurement conditions for the unevenness with a large interval width are that the objective lens is 50 times and the zoom lens is 0.5 times, the number of camera pixels is 640 × 480, and the number of integrations is 640 × 480 for the area of the measurement area 282 × 210 μm. It was carried out so that it would be 8 times. When measuring the maximum height width Rz of unevenness with a large spacing width and the spacing width RSm of unevenness, the cutoff value λc1 of the high frequency filter λc is set to 52.9 μm, and the cutoff value λs1 of the low frequency filter λs is set. It was set to 1.3 μm.

[Measurement result of surface roughness]
The results of surface roughness measurement performed on Samples 1 to 12 will be described. Table 1 shows the measurement results.

As shown in Table 1, the maximum height width Rz of the unevenness having a large interval width is in the range of 25 nm to 125 nm for the samples 1 to 9 as an example and the sample 12 as a comparative example, and the scanning of the wet blast treatment is performed. The maximum height width Rz tends to increase as the number of times increases. In the sample 10 which is an untreated comparative example, unevenness with a large interval width could not be confirmed. The maximum height width Rz of the sample 11 which was a comparative example to which the SiO _{2 coating film was applied was 1225 nm.}

The spacing width RSm of the unevenness in the unevenness having a large spacing width is in the range of 500 μm to 3000 μm for the samples 1 to 9 as an example and the sample 12 as a comparative example. In the sample 10 which is an untreated comparative example, unevenness with a large interval could not be confirmed. The spacing width RSm of the unevenness of the sample 11 which was a comparative example to which the SiO _{2 coating film was applied was 30 μm.}

The three-dimensional arithmetic surface height Sa in the unevenness with a small interval width is in the range of 4.5 nm to 5.3 nm for Samples 1 to 9 as an example and Sample 12 as a comparative example. The three-dimensional arithmetic surface height Sa of sample 10 which is an untreated comparative example is 0.2 nm, which is smaller than that of samples 1 to 9 and 12, and is small for sample 11 which is a comparative example to which a _{SiO 2 coating film is applied.} Unevenness could not be confirmed.

[Measurement of haze]
Haze was measured for Samples 1-12. The haze was measured based on JIS K7361-1-1997 using an ultraviolet-visible near-infrared analysis photometer (UV-3100PC) manufactured by Shimadzu Corporation.

[Measurement result of haze]
As shown in Table 1, the haze was in the range of 1.0% to 1.8% for Samples 1 to 9 as Examples, and was not significantly different from the untreated Samples 10 and 12. On the other hand, for _{sample 11 which is a comparative example to which the SiO 2} coating film was applied, it was as high as 34%.

[Evaluation of visibility]
The visibility of the image displayed on the display element 30 when the glass substrates 20 of the samples 1 to 12 were placed on the front side of the display element 30 in the input device 10 was evaluated. As an evaluation method, whether or not blurring is observed in the image displayed on the display element 30 was evaluated in the following three stages. ⊚: A clear image can be seen and no blurring is seen in the image, ○: The image can be sufficiently visually recognized, but a slight blurring of the image is seen, ×: The image is unclear and the blurring of the image is conspicuous.

[Visibility evaluation result]
As shown in Table 1, the visibility of the image was ⊚ for Samples 1 to 9 as Examples.
Sample 10 which is an untreated comparative example was marked with ⊚, _{sample 11 which was a comparative example coated with a SiO 2} coating film was marked with x, and sample 12 which was a comparative example was marked with ⊚.

[Input medium]
The following input pen was used as the input medium. For Samples 1 to 3 and 10 to 12, Wacom's Bamboo Tip was used. The material of the pen tip was resin, and the diameter of the pen tip was 1.9 mm. For Samples 4 to 5, an Apple Pencil manufactured by Apple Inc. was used. The material of the pen tip was resin, and the diameter of the pen tip was 8.9 mm. For Samples 6 to 7, KP-503E manufactured by Wacom Co., Ltd. was used. Rubber was used as the material of the pen tip, and the diameter of the pen tip was 1.7 mm. For samples 8 to 9, TB-TPG03BK manufactured by Elecom Co., Ltd. was used. The material of the pen tip was conductive fiber, and the diameter of the pen tip was 8 mm.

[Spacing width A of large spacing unevenness / Diameter B of the tip of the input medium]
When the interval width RSm of the unevenness in the unevenness with a large interval width is A and the diameter of the tip of the input medium is B, the ratio of A and B is expressed by [A / B]. Was in the range of 0.11 to 0.79. On the other hand, the untreated sample 10 which is a comparative example cannot be calculated _{, the sample 11 which is a comparative example coated with the SiO 2} coating film is 0.01, and the sample 12 which is a comparative example is 1.58. It was.

[Evaluation of writing taste]
The writing taste when characters, figures and the like were input to the glass substrate 20 with the input pen 50 was evaluated by a sensory test. As an evaluation method, the above input pen is used as the input pen 50, and the writing taste on the glass substrate 20 is "very comfortable" for a total of 20 men and women in their 20s to 50s. We asked them to score on a 7-point scale up to "very uncomfortable to write," and evaluated the average score.

[Evaluation result of writing taste]
As shown in Table 1, the writing taste was 3.9 or more for Samples 1 to 9 as Examples, Sample 10 which was an untreated Comparative Example, and Sample 11 which was a Comparative Example to which a _{SiO 2 coating film was applied.} And, the sample 12 as a comparative example was 3.7 or less.

[Comprehensive evaluation of each sample]
As shown in Tables 1 and 5, with respect to Samples 1 to 9 as Examples, there are two types of irregularities, large and small, having appropriate irregularities formed on the main surface 20a in contact with the pen tip 51 of the input pen 50 and having different spacing widths. As a result, the pen tip 51 is prevented from slipping on the main surface 20a of the glass substrate 20, and the frictional force between the pen tip 51 and the main surface 20a is appropriately increased and decreased, thereby resulting in a writing taste. Good evaluation results were obtained, such as good visibility and ◎ visibility. On the other hand, in the sample 10 which is an untreated comparative example, the unevenness of the main surface 20a in contact with the input pen 50 is small and slippery, so that the writing quality is poor.

Further, as shown in FIG. 6, _{in the sample 11 which is a comparative example to which the SiO 2} coating film is applied, since there are no two types of irregularities, large and small, in which the spacing width of the irregularities is different, the pen tip 51 is hard to slip and gets caught. The writing taste was bad. On the other hand, as shown in FIG. 7, for sample 12, which is a comparative example in which the value of [A / B] is too large, it was not possible to suppress the catching, and it became difficult to slip and the writing taste was poor.

The present invention can be used for an input device capable of inputting characters, figures, etc. using an input means such as an input pen, and an input device cover member included in the input device, and in particular, a display in the input device. It can be used for an input device provided with a cover member for an input device which is arranged on the front side of the device and has irregularities on at least one main surface, and a cover member for the input device.

10 Input device 20 Glass substrate (Cover member for input device)
20a Main surface 30 Display element 40 Digitizer circuit 50 Input pen

Claims (7)

A cover member for an input device arranged on the front side of the display device in the input device.
On at least one main surface having irregularities, the cutoff value of the high frequency filter λc is set to 1.6 times the interval width of the irregularities of the measurement cross-sectional curve, and the low frequency filter is used. When the cutoff value of λs is 25 μm, the size of the interval width of the unevenness is A, and the diameter of the tip of the input medium is B.
A cover glass member for an input device, wherein the relationship between the two satisfies 0.02 << [A / B] <1. When the cutoff value of the high frequency filter λc is 1.6 times the interval width of the irregularities of the measurement cross-sectional curve and the cutoff value of the low frequency filter λs is 25 μm on the main surface having the unevenness. The cover member for an input device according to claim 1, wherein the maximum height width of the unevenness is 3 to 1000 nm, and the interval width A of the unevenness is 50 to 10000 μm. When the cutoff value of the high frequency filter λc is 25 μm on the main surface having the unevenness, the three-dimensional arithmetic mean height Sa of the unevenness is 1 to 50 nm and the interval width of the unevenness is 0.01 to 10 μm. The cover member for an input device according to claim 1 or 2, wherein the cover member is for an input device. The cover glass member for an input device according to any one of claims 1 to 3, wherein the diameter of the tip portion of the input medium is 0.5 mm to 10 mm. The cover member for an input device according to any one of claims 1 to 4, wherein the haze is less than 10% in the wavelength range of visible light. An input device comprising the cover member for an input device according to any one of claims 1 to 5, a display device, and a detection circuit for detecting an input. The input device according to claim 6, further comprising an input pen for inputting to the input device by moving while contacting the main surface of the cover member for the input device.

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