JP2018123030A - Glass substrate for pen input device, pen input device and manufacturing method of glass substrate for pen input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass substrate for pen input device excellent in writing feeling by an input pen and capable of maintaining high resolution of a display device.SOLUTION: There is provided a glass substrate 20 for pen input device constituted by a crystallized glass sheet having crystal C, in which the crystallized glass sheet has crystallization degree of 50% or more, haze is 10% or less in a wavelength region of visible lights, a main surface 20a of the crystallized glass sheet has a convexoconcave due to a crystal by etching a glass original sheet constituted by the crystallized glass and the main surface 20a is constituted by crystal C. There is provide a glass substrate for pen input device having particle diameter of the crystal C of 5 to 10 nm.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a glass substrate for a pen input device, a pen input device, and a method for manufacturing a glass substrate for a pen input device.

2. Description of the Related Art Conventionally, a pen input device that can input characters and figures using an input pen is known.
In such a pen input device, a transparent cover member composed of a glass substrate or the like is disposed 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 with respect to the cover member. Thus, various input operations can be performed. When a glass substrate is used as a cover member for a pen input device, the surface of the glass substrate is generally smooth with small irregularities, so the pen tip when the input pen is brought into contact with the surface of the glass substrate and moved. Slipped and the problem of poor writing comfort occurred.

  For example, in Patent Document 1, in order to enhance the writing quality of an input pen in a pen input device, a resin layer (antiglare layer) made of an active energy ray-curable resin composition and having irregularities on the surface of a cover member is formed. It is disclosed.

JP 2009-151476 A

However, the resin layer having the unevenness as described above tends to have a high haze indicating the haze in the index related to transparency, and when the cover member on which the resin layer having the unevenness is formed is arranged on the front side of the display device. As a result, the resolution of the display device is lowered. The decrease in resolution is particularly remarkable in a high-resolution display device.
Moreover, when the resin layer which has an unevenness | corrugation is formed in the surface of a cover member like patent document 1, the glare called sparkling generate | occur | produces.
Furthermore, since the resin layer is generally soft and has low scratch resistance, the resin layer is easily scratched, and the scratch on the resin layer causes a reduction in the resolution of the display device.
That is, in the conventional examination of the material of the antiglare layer, it is difficult to improve the writing quality with the input pen and to maintain the resolution of the display device.

  Therefore, the present invention provides a pen input device glass substrate and a pen input device that have high scratch resistance, excellent writing performance with an input pen, and can maintain high resolution of a display device.

A glass substrate for a pen input device and a pen input device that solve the above problems have the following characteristics.
That is, the glass substrate for pen input devices according to the present invention is constituted by a crystallized glass plate having crystals, and the main surface of the crystallized glass plate is formed with irregularities by the crystals.
With such a configuration, the scratch resistance is high, the high resolution of the display device in the pen input device is maintained, and the writing quality of the input pen that performs input to the pen input device can be improved.

The crystal preferably has a particle size of 5 nm or more and 100 nm or less.
Thereby, the writing quality of the input pen which performs input with respect to a pen input device can be made more excellent.

The crystallized glass plate preferably has a crystallinity of 50% or more.
Thereby, the writing quality of the input pen which performs input with respect to a pen input device can be made more excellent.

Moreover, it is preferable that a haze is 10% or less in the wavelength range of visible light.
Thereby, the transparency of the glass substrate for pen input devices can be maintained, and the high resolution of the display device can be maintained.

The crystal is preferably a β-quartz solid solution.
Thereby, the high resolution of the display device can be maintained.

Further, as represented by mass _{percentage, SiO 2 55~75%, Al 2} O 3 15~25%, Li 2 O 3~4%, Na 2 O 0~1%, K 2 O 0~1%, MgO 0~ _{3%, BaO 0.5~2%, TiO} 2 1~3%, ZrO 2 0~3%, TiO 2 + ZrO 2 3~5%, P 2 O 5 0~3%, SnO 2 0~0.5 %, Fe ₂ O ₃ 0.003 to 0.02% of the composition is preferable.
Thereby, the high resolution of a display apparatus can be hold | maintained and the writing quality of the input pen which performs the input with respect to a pen input apparatus can be made more excellent.

The pen input device includes any of the glass substrates for pen input devices described above, a display device, and a detection circuit that detects pen input.
With such a configuration, the scratch resistance is high, the high resolution of the display device in the pen input device is maintained, and the writing quality of the input pen that performs input to the pen input device can be improved.

Moreover, the manufacturing method of the glass substrate for pen input devices is a manufacturing method of the glass substrate for pen input devices comprised by the crystallized glass plate which has a crystal | crystallization, Comprising: The said crystallized glass substrate is crystallized glass which has a crystal | crystallization. Etching is performed on the glass base plate constituted by the above, and irregularities due to the crystals are formed on the main surface.
Thereby, the above-mentioned glass substrate for pen input devices can be manufactured easily.

  ADVANTAGE OF THE INVENTION According to this invention, scratch resistance is high, the high resolution of the display apparatus in a pen input device can be hold | maintained, and the writing quality of the input pen which performs the input with respect to a pen input device can be made excellent.

It is a schematic side sectional view showing a pen input device. It is a schematic side surface sectional view which shows the side surface of the glass substrate 20 for pen input devices. It is a photograph of the scanning electron microscope of the main surface 20a of the glass substrate 20 for pen input devices. It is a schematic sectional side view which shows the glass substrate 60 with a film | membrane. It is a schematic side sectional view showing a crystallized glass base plate.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described. However, the present invention is not limited to the following embodiments, and is based on ordinary knowledge of a person skilled in the art without departing from the gist of the present invention. It should be understood that modifications and improvements as appropriate to the following embodiments also fall within the scope of the present invention.

A pen input device 10 shown in FIG. 1 is an embodiment of a pen input device including a glass substrate for a pen input device according to the present invention.
The pen input device 10 includes a display panel 30 for displaying an image, a glass substrate 20 for a pen input device as a cover glass disposed on the front side of the display panel 30, and a digitizer circuit disposed on the back side of the display panel 30. 40 and an input pen 50. The glass substrate 20 for pen input devices is an example of the glass substrate for pen input devices according to the present invention, and the digitizer circuit 40 is an example of a detection circuit that detects pen input according to the present invention.
The “front side” of the display panel 30 refers to the side on which the video is displayed, and the “back side” of the display panel 30 refers to the side opposite to the side on which the video is displayed. In FIG. 1, the “front side” of the display panel 30 is above the paper surface, and the “back side” is below the paper surface.

The pen input device 10 can input characters, figures, and the like by moving the input pen 50 in contact with the pen input device glass substrate 20.
The pen input device 10 is, for example, a tablet terminal. This tablet terminal broadly means a display device for pen input having a display function and a pen input function. The tablet terminal includes devices such as a tablet PC, a mobile PC, a smartphone, and a game machine.

  The glass substrate 20 for pen input devices is formed of a transparent glass plate having irregularities formed on at least one main surface 20a. The glass substrate 20 for pen input devices is a crystallized glass plate. The details of the glass substrate 20 for a pen input device will be described later.

  The display panel 30 is configured by a known display panel such as a liquid crystal display, a plasma display, and an organic EL display. In the display panel 30, the glass substrate 20 for pen input devices is arranged so that the main surface 20a on which the irregularities are formed is a surface on the side where the input pen 50 contacts.

The digitizer circuit 40 includes a detection sensor that detects input from the 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 for a pen input device is made of a synthetic resin material such as an elastomer or a polyacetal resin, or felt. It is configured. The nib 51 composed of these members is easily caught by the unevenness. Therefore, the writing quality when the pen tip 51 of the input pen 50 is moved in contact with the main surface 20a of the glass substrate 20 for pen input device on which irregularities are formed is particularly excellent.

Next, the glass substrate 20 for pen input devices will be described.
The glass substrate 20 for pen input devices is composed of a crystallized glass plate, and as shown in FIG. 2, the main surface 20a of the glass substrate 20 for pen input devices is composed of crystals C and a glass matrix AM. Yes. That is, the glass substrate 20 for pen input devices is configured such that the crystal C is exposed. And since the unevenness | corrugation comprised with the crystal | crystallization C with higher hardness compared with the glass matrix AM is formed in the main surface 20a of the glass substrate for pen input devices, the main surface 20a of the glass substrate 20 for pen input devices is formed. Has high scratch resistance, and the pen tip 51 is easily caught on the crystal C.

  Therefore, the main surface 20a of the glass substrate 20 for a pen input device is against the pen tip 51 that is formed of a member that is easily caught by irregularities such as the above-described elastomer, resin material such as polyacetal resin, and felt. The writing quality is particularly excellent.

In the present embodiment, the crystal C is a β-quartz solid solution. The crystals of β- quartz solid solution, meaning crystallized glass precipitated _Li 2 O as a constituent component, _Al 2 _{O 3} and SiO ₂ required to crystals (LAS-based crystals) as a main crystal, _Li 2 O · Al ₂ O ₃ .nSiO ₂ (where 4> n ≧ 2). The crystalline, beta-besides crystal quartz solid solution, is LAS-based crystal beta-spodumene _{[Li 2 O · Al 2 O} 3 · nSiO 2 ( provided that n ≧ 4)] and the crystals other than LAS-based crystals It may be deposited. As crystals other than LAS-based crystal, for example, mullite _{[2SiO 2 · 3Al 2 O 3} ], β- willemite [ZnO · 2SiO _2], gahnite _{[ZnO · Al 2 O 3]} , forsterite [2MgO · SiO _2] is Can be mentioned.

In the case of this embodiment, the particle diameter of the crystal C contained in the glass substrate 20 for pen input devices is 5 nm or more and 100 nm or less.
When the particle diameter of the crystal C is in such a range, the occurrence of glare called sparkling due to interference of scattered light can be suppressed. Further, the pen tip 51 is easily caught on the glass substrate 20 for pen input device, and the writing quality is more excellent.

In the case of this embodiment, the lower limit value of the particle diameter of the crystal C of the glass substrate 20 for pen input devices is set to 5 nm, but is preferably set to 10 nm, and more preferably set to 15 nm.
Moreover, although the upper limit of the particle diameter of the crystal | crystallization C of the glass substrate 20 for pen input devices is set to 100 nm, it is preferable to set to 50 nm, and it is more preferable to set to 40 nm.
The particle diameter of the crystal C can be measured, for example, by observing the main surface 20a of the glass substrate 20 for a pen input device with a scanning electron microscope. In this case, the magnification of the scanning electron microscope is preferably 100,000 to 300,000 times. The particle diameter of the crystal C on the main surface 20a of the glass substrate 20 for pen input device and the particle diameter of the crystal C inside the glass substrate 20 for pen input device (in FIG. 2, below the main surface 20a) are as follows. Are almost identical. Moreover, it is also possible to confirm whether or not the main surface 20a is made of the crystal C by observing and measuring the main surface 20a of the glass substrate 20 for pen input device with a scanning electron microscope. For example, FIG. 3 is a scanning electron microscope image of the main surface 20a of the glass substrate 20 for a pen input device, and the massive object is a crystal C on the main surface 20a of the glass substrate 20 for a pen input device. Indicates. In addition, before observing the main surface 20a of the glass substrate 20 for pen input devices with a scanning electron microscope, in order to remove dust, a foreign material, etc., the glass substrate 20 for pen input devices is used for 1 minute with an ultrasonic cleaner. After cleaning, the measurement was performed after drying for 1 hour in a sealed desiccator so that no foreign matter such as dust adhered to the main surface 20a.
In addition, as a method for determining whether or not the massive object in the image is the crystal C, for example, an approximate value of the particle diameter of the crystal is obtained by an X-ray diffractometer, and 1/3 to 3 times the approximate value. The particles may be determined to be crystals C.

In the case of this embodiment, the glass substrate 20 for pen input devices has a crystallinity of 50% or more.
Since the crystallinity is in such a range, the crystal C is easily formed uniformly on the main surface 20a of the glass substrate 20 for a pen input device, so that the pen tip 51 of the input pen 50 is uneven. The writing quality is particularly excellent when moved in contact with the main surface 20a of the glass substrate 20 for pen input device.

In the case of this embodiment, the lower limit value of the crystallinity of the glass substrate 20 for a pen input device is set to 50%, but is preferably set to 55%, and more preferably set to 60%.
Moreover, although the upper limit of the crystallinity degree of the glass substrate 20 for pen input devices is not set, it is preferable to set to 90% and it is more preferable to set to 85%.

In the case of this embodiment, it is preferable that the average transmittance | permeability of visible light (380 nm-780 nm) of the glass substrate 20 for pen input devices is 30% or more.
By setting the average visible light transmittance of the glass substrate 20 for pen input devices to 30% or more, the transparency of the glass substrate 20 for pen input devices can be maintained, and the high resolution of the display panel 30 can be maintained. it can.

  In the case of the present embodiment, the average transmittance of visible light of the glass substrate 20 for a pen input device is set to 30% or more, but is preferably 50% or more, and more preferably 60% or more. 80% or more is more preferable.

The glass substrate 20 for a pen input device has a haze that represents haze as an index related to transparency from the viewpoint of the resolution of the image when the image of the display panel 30 is viewed through the glass substrate 20 for a pen input device. It is preferable that it is 10% or less in the wavelength range (380 nm-780 nm).
By setting the haze of the glass substrate 20 for pen input devices to 10% or less, the transparency of the glass substrate 20 for pen input devices can be maintained, and the high resolution of the display panel 30 can be maintained.

  In the case of this embodiment, the haze of the glass substrate 20 for pen input devices is set to 10% or less, preferably 7% or less, more preferably 5% or less, and 4% or less. More preferably.

  Further, the main surface 20a of the glass substrate 20 for pen input device is provided with an antireflection film for reducing the reflectance on the side in contact with the input pen 50, or water repellency and oil repellency to prevent adhesion of fingerprints. An antifouling film may be formed.

When the glass substrate 20 for a pen input device is used as a cover glass for the pen input device 10, the antireflection film is at least the main surface 20a on the front side of the pen input device glass substrate 20 (the side on which the input pen 50 contacts). Have. When there is a gap between the glass substrate 20 for pen input device and the display panel 30, an antireflection film is also provided on the main surface 20a on the back side (display panel 30 side) of the glass substrate 20 for pen input device. It is preferable.
As the antireflection film, for example, a low refractive index film having a lower refractive index than the glass substrate 20 for a pen input device, or a low refractive index film having a relatively low refractive index and a high refractive index film having a relatively high refractive index, A dielectric multilayer film in which are alternately stacked is used. The antireflection film can be formed by a sputtering method, a CVD method, or the like.

  In the case where the main surface 20a of the glass substrate 20 for pen input device has an antireflection film, the glass substrate 20 for pen input device has a haze of the glass substrate 20 for pen input device having the antireflection film in the above range. Unevenness of the main surface is formed.

When the glass substrate 20 for a pen input device is used as a cover glass for the pen input device 10, the antifouling film is formed on the main surface 20a on the front side of the pen input device glass substrate 20 (the side on which the input pen 50 contacts). Have.
The antifouling film preferably contains a fluoropolymer containing silicon in the main chain. As the fluorine-containing polymer, for example, a polymer having —Si—O—Si— units in the main chain and 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 condensation of silanol.
When the front-side main surface 20a of the pen input device glass substrate 20 has an antireflection film and an antifouling film, an antireflection film is formed on the main surface 20a of the pen input device glass substrate 20 to prevent reflection. An antifouling film is formed on the film.

  When the main surface 20a of the pen input device glass substrate 20 has an antifouling film, or when the main surface 20a of the pen input device glass substrate 20 has an antireflection film and an antifouling film, an antifouling film was formed. A glass substrate for pen input device so that the haze of glass substrate 20 for pen input device after that, or the haze of glass substrate 20 for pen input device after forming an antireflection film and an antifouling film is in the above-mentioned range. Unevenness of 20 main surfaces 20a is formed.

  FIG. 4 shows a glass substrate 60 with a film having an antireflection film AR and an antifouling film AF on the main surface 20a of the glass substrate 20 for a pen input device.

In this embodiment, the pen input device glass substrate 20, as represented by mass _{percentage, SiO 2 55~75%, Al 2} O 3 15~25%, Li 2 O 3~4%, Na 2 O 0~1 %, K ₂ O 0-1%, MgO 0-3%, BaO 0.5-2%, TiO ₂ 1-3%, ZrO ₂ 0-3%, TiO ₂ + ZrO ₂ 3-5%, P ₂ O _{5 0~3%, SnO 2 0~0.5%} , preferably contains _Fe 2 O 3 _0.003~0.02%.

  Hereinafter, the reason which prescribed | regulated content of each component of the glass substrate 20 for pen input devices as mentioned above is demonstrated. In the description of the glass composition, “%” means “mass%” unless otherwise specified.

SiO ₂ is a component that forms a glass skeleton and constitutes a β-quartz solid solution that is a precipitated crystal. The content of SiO ₂ is 55 to 75% in terms of mass percentage. When the content of SiO ₂ is too small, crystals are unlikely to precipitate and grow, the number of crystals C on the main surface 20a of the glass substrate 20 for pen input devices tends to decrease, and the effect of improving the writing quality is difficult to obtain. On the other hand, if the content of SiO ₂ is too large, deteriorated the meltability of the glass, the viscosity of the glass melt becomes higher, there is a tendency that molding becomes difficult for the glass may become difficult to clear. A preferable range of SiO ₂ is 58 to 70%, and a more preferable range is 60 to 68%.

Al ₂ O ₃ is a component that forms a glass skeleton and constitutes a β-quartz solid solution that is a precipitated crystal. The content of Al ₂ O ₃ is 15 to 25% in terms of mass percentage. When the content of Al ₂ O ₃ is too small, crystals are difficult to precipitate and grow, the number of crystals C on the main surface 20a of the glass substrate 20 for pen input devices tends to decrease, and the effect of improving writing quality is difficult to obtain. Become. On the other hand, when the content of Al ₂ O ₃ is too large, it deteriorated the meltability of the glass, higher viscosity of the glass melt, may become difficult to clear, there is a tendency to forming of glass difficult. Moreover, the crystal | crystallization of a mullite precipitates and the transparency of the glass substrate 20 for pen input devices becomes easy to fall. A preferable range of Al ₂ O ₃ is 18 to 25%, and a more preferable range is 20 to 24%.

Li ₂ O is a component constituting a β-quartz solid solution that is a precipitated crystal, and greatly affects the crystallinity of the glass substrate 20 for a pen input device. The content of Li ₂ O is 3 to 4% in terms of mass percentage. When the Li 2 _O content is too small, crystals of mullite is precipitated transparency of the pen input device glass substrate 20 tends to decrease. Further, when the glass is crystallized, the β-quartz solid solution is difficult to precipitate and grow, the number of crystals C on the main surface 20a of the glass substrate 20 for pen input devices is likely to be reduced, and an effect of improving writing quality is obtained. It becomes difficult. On the other hand, when the content of Li 2 _O is too large, too strong crystallinity of the pen input device for a glass substrate 20, the glass tends to be devitrified. A preferable range of Li ₂ O is 3.5 to 4%.

Na ₂ O is a component that dissolves in the β-quartz solid solution and greatly affects the crystallinity. The content of Na ₂ O is 0 to 1% in terms of percentage. When the content of Na 2 _O is too large, crystallinity becomes too strong, the glass tends to be devitrified. Further, when the glass is crystallized, the β-quartz solid solution is difficult to precipitate and grow, the number of crystals C on the main surface 20a of the glass substrate 20 for pen input devices is likely to be reduced, and an effect of improving writing quality is obtained. It becomes difficult. A preferable range of Na ₂ O is 0 to 0.8%.

K ₂ O, like Na ₂ O, is a component that dissolves in the β-quartz solid solution, and greatly affects crystallinity. The content of K ₂ O is 0 to 1% as a percentage. When the content of K 2 _O is too large, crystallinity becomes too strong, the glass tends to be devitrified. A preferable range of K ₂ O is 0 to 0.8%.

  BaO is a component that lowers the viscosity of the glass and improves the meltability and moldability of the glass. The content of BaO is 0.5 to 2% in terms of mass percentage. When there is too much BaO content, the crystal | crystallization containing Ba will precipitate easily and glass will devitrify. A preferable range of BaO is 0.8 to 1.8%, and a more preferable range is 1 to 1.5%.

TiO ₂ is a component that serves as a nucleating agent for precipitating crystals. The content of TiO ₂ is 1 to 3% by mass in terms of mass percentage. When the content of TiO ₂ is too small, it tends to be devitrified when melted glass. On the other hand, when the content of TiO ₂ is too large, increasingly colored glass, the transparency is lowered. Moreover, it becomes easy to devitrify glass. A preferable range of TiO ₂ is 1.5 to 3%, and a more preferable range is 1.5 to 2.5%.

ZrO ₂ is a component serving as a nucleating agent for precipitating crystals, like TiO ₂ . The content of ZrO ₂ is 0 to 3% in terms of mass percentage. When the content of ZrO ₂ is too large, there is a tendency to devitrification during melting the glass, forming the glass becomes difficult. A preferable range of ZrO ₂ is 0.5 to 2.5%, and a more preferable range is 1 to 2.5%.

Incidentally, ZrO ₂ and TiO ₂ is a nucleation agent is preferably 3-5% in total. When the total amount of ZrO ₂ and TiO ₂ is too small, crystals are difficult to precipitate. On the other hand, when the total amount of ZrO ₂ and TiO ₂ is too large, the glass tends to devitrify, forming of glass difficult. A more preferable range of the total amount of ZrO ₂ and TiO ₂ is 3.5 to 5%, and a more preferable range is 4 to 5%.

P ₂ O ₅ is a component that promotes the phase separation of glass and assists the formation of crystal nuclei. The content of P ₂ O ₅ is 0 to 3% in terms of mass percentage. When the content of P ₂ O ₅ is too large, the glass tends to undergo phase separation in the melting process, the homogeneity of the glass tends to decrease. A preferable range of P ₂ O ₅ is 0.5 to 3%, and a more preferable range is 1 to 2%.

SnO ₂ is a component that acts as a fining agent. The content of SnO ₂ is 0 to 0.5% in terms of mass percentage. When the content of SnO ₂ is too small, it is difficult to obtain the effect as the heat resistance improved and a fining agent. On the other hand, when the content of SnO ₂ is too large, in addition to the glass tends to be devitrified, leading to increase in raw material costs. Furthermore, coloring tends to be strong when crystallized. A preferable range of SnO ₂ is 0.1 to 0.4%, and a more preferable range is 0.15 to 0.35%.

Further, Fe ₂ O ₃ is a component to be mixed as an impurity, is a component to enhance the coloration of the glass. The content of Fe ₂ O ₃ is 0.003 to 0.02% in terms of mass percentage. When the content of Fe ₂ O ₃ is too large, coloring of the glass becomes too strong, the transparency of the glass tends to decrease. The content of Fe ₂ O ₃ is preferably as low as possible, but the removal cost of Fe ₂ O ₃ as an impurity increases as the content decreases. A preferable range of Fe ₂ O ₃ is 0.003 to 0.018%, and a more preferable range is 0.003 to 0.015%.

In addition to the above components, various components can be contained. For example, trace elements such as H ₂ , CO ₂ , CO, H ₂ O, He, Ne, Ar, and N ₂ are each added to 0.1%, and noble metal elements such as Ag, Au, Pd, and Ir are included up to 10 ppm each. May be.
Furthermore, B ₂ O ₃ , CaO, SrO, ZnO, Cr ₂ O ₃ , Sb ₂ O ₃ , SO ₃ , MnO, CeO ₂ , Cl as long as the transparency of the glass substrate 20 for pen input device is not adversely affected. ₂ , La ₂ O ₃ , WO ₃ , Nd ₂ O ₃ , Nb ₂ O ₅ , Y ₂ O _{3 and the} like may be contained up to 2% in total.

  Next, the manufacturing method of the glass substrate 20 for pen input devices is demonstrated.

First, as represented by mass _{percentage, SiO 2 55~75%, Al 2} O 3 15~25%, Li 2 O 3~4%, Na 2 O 0~1%, K 2 O 0~1%, MgO 0~ _{3%, BaO 0.5~2%, TiO} 2 1~3%, ZrO 2 0~3%, TiO 2 + ZrO 2 3~5%, P 2 O 5 0~3%, SnO 2 0~0.5 %, Fe ₂ O ₃ 0.003 to 0.02% is prepared glass raw material. In addition, you may add the component for improving the meltability and moldability of glass, a clarifying agent, etc. as needed.

  Next, after the prepared glass raw material is melted at a temperature of 1550 to 1750 ° C., the molten glass is formed into a predetermined shape such as a plate shape. Examples of the molding method include molding methods such as a float method, a rollout method, a press method, and an overflow downdraw method. In this way, crystalline glass is obtained.

  The crystalline glass obtained by the above procedure is heat-treated at 600 to 800 ° C. for 1 to 5 hours to form crystal nuclei, and further subjected to heat treatment at 800 to 950 ° C. for 0.5 to 3 hours to obtain a main crystal. To precipitate crystals of β-quartz solid solution. In this way, a crystallized glass base plate 21 as shown in FIG. 5 is obtained. In addition, before or during the crystallization treatment, bending may be performed by a method such as applying a load to the heated crystalline glass. Further, the crystalline glass may be polished before the crystallization treatment. In addition, although a heating furnace can be used for the heat treatment of crystalline glass, a gas burner or an electric heater can be used as a heating source of the heating furnace. In consideration of promoting crystal growth in the vicinity of the main surface, it is preferable to use a gas burner as a heating source.

  As shown in FIG. 5, the main surface 21a of the crystallized glass base plate 21 is mainly composed of a glass matrix AM. Then, the glass substrate 20 for pen input devices by which the main surface 20a was comprised by the crystal | crystallization C is obtained by etching the main surface 21a of the crystallized glass base plate 21 obtained.

Etching of the crystallized glass base plate 21 is performed by immersing the crystallized glass base plate 21 in an etchant such as hydrogen fluoride (HF) gas or hydrofluoric acid.
When hydrofluoric acid is used as the etchant, the etchant temperature is 10 to 40 ° C., the hydrogen fluoride concentration is 0.5 to 10 wt%, and the crystallized glass base plate 21 is 0.5. It is preferable to immerse in an etching solution for 10 minutes.

  Hereinafter, an example of the glass substrate 20 for the pen input device in which the main surface 20a is configured by the crystal C will be described. However, the glass substrate 20 for pen input devices is not limited to this.

[Preparation of sample]
In this example, Sample 1 was prepared as an example of the glass substrate 20 for a pen input device, and Sample 2 was prepared as a comparative example.
First, each raw material was prepared in the form of an oxide, hydroxide, carbonate, nitrate or the like so as to obtain a glass having the composition shown in Table 1, and mixed uniformly to obtain a glass batch. The obtained glass batch was put into a refractory kiln by oxygen combustion and melted at 1650 ° C. to obtain a glass melt. After stirring the glass melt with a platinum stirrer, the glass melt is roll-formed to a thickness of 4 mm with a molding device to form a plate-like product, and further, the plate-like product is gradually cooled to room temperature with a slow cooling furnace, A crystalline glass plate was obtained by molding so as to be 2000 mm long × 1200 mm wide. This crystalline glass plate is Sample 2.
Next, the crystalline glass plate is crystallized by heat treatment at room temperature to 780 ° C., which is the nucleation temperature, for 3 hours with a roller hearth kiln, and then crystallized by heat treatment at 890 ° C. for 1 hour. A glass substrate was obtained. Finally, the crystallized glass substrate was etched by being immersed in hydrofluoric acid having a temperature of 25 ° C. and a concentration of 2 wt% for 1 sample.

[Measurement of crystal particle size]
About the sample 1 and the sample 2, the particle diameter of the crystal | crystallization of a main surface was measured using Hitachi High Technology Co., Ltd. scanning electron microscope S-4300SE. Specifically, the magnification is set at 180,000 times, a photograph of an arbitrary place of the glass substrate 20 for pen input device is taken, and the range of the particle diameter of arbitrary 10 crystals at 0.74 μm × 0.55 μm is set. It confirmed from the photograph.

[Results of crystal particle size measurement]
In sample 1, the crystal particle size was in the range of 20-30 nm. On the other hand, no crystal was observed in Sample 2.

[X-ray diffraction measurement]
About the sample 1, the crystallinity degree of the glass substrate 20 for pen input devices was measured using Rigaku Co., Ltd. X-ray-diffraction apparatus RINT-2100.

[X-ray diffraction measurement results]
In Sample 1, the precipitated crystals were only β-quartz solid solution, the crystallinity was 70%, and the crystallite size was 26 nm. In sample 2, no crystal peak was confirmed, and only a halo peak indicating an amorphous state was confirmed.

[Measure haze]
Samples 1 and 2 were measured for haze. The haze was measured based on JIS K7361-1 (1997) using an ultraviolet-visible near-infrared spectrophotometer (UV-3100PC) manufactured by Shimadzu Corporation.

[Measurement result of haze]
The haze was 10% or less for both samples 1 and 2.

[Resolution Evaluation]
The resolution of the image displayed on the display panel 30 when the pen input device glass substrate 20 of Samples 1 and 2 was placed on the front side of the display panel 30 in the pen input device 10 was evaluated. As an evaluation method, whether or not bleeding is seen in an image displayed on the display panel 30 was evaluated in three stages as follows. ◯: A clear image can be seen and no blur is observed in the image. ×: The image is unclear and the image blur is conspicuous.

[Resolution evaluation results]
The resolution of the images was ◯ for both samples 1 and 2.

[Evaluation of writing quality]
The writing taste when characters, figures, and the like were input to the glass substrate 20 for a pen input device with the input pen 50 was evaluated by a sensory test. As an evaluation method, a Wacom Propen (KP-503E) is used as the input pen 50, and the writing on the glass substrate 20 for pen input device is sensibly similar to the writing of an HB mechanical pencil on paper. Judgment of writing quality was performed by setting “X” when close, and “x” when different sensibly such as being slippery and less slippery than the writing quality.

[Writing evaluation result]
The writing taste was ◯ for sample 1 as an example, and x for sample 2 as an untreated comparative example.

[Comprehensive evaluation of each sample]
As shown in Table 1, with respect to Sample 1 as an example, an evaluation result with good writing quality and good resolution was obtained.
On the other hand, Sample 2 as a comparative example was poor in writing.

DESCRIPTION OF SYMBOLS 10 Pen input device 20 Glass substrate for pen input devices 20a Main surface 30 Display panel 40 Digitizer circuit 50 Input pen

Claims (8)

It is composed of a crystallized glass plate having crystals,
The main surface of the crystallized glass plate is formed with irregularities by the crystals,
Glass substrate for pen input device. The crystal has a particle size of 5 nm or more and 100 nm or less.
The glass substrate for pen input devices according to claim 1. The crystallized glass plate has a crystallinity of 50% or more.
The glass substrate for pen input devices according to claim 1 or 2. The haze is 10% or less in the wavelength range of visible light.
The glass substrate for pen input devices of any one of Claims 1-3. The crystal is a β-quartz solid solution,
The glass substrate for pen input devices of any one of Claims 1-4. Represented by mass _{percentage, SiO 2 55~75%, Al 2} O 3 15~25%, Li 2 O 3~4%, Na 2 O 0~1%, K 2 O 0~1%, MgO 0~3% _{, BaO 0.5~2%, TiO 2 1~3} %, ZrO 2 0~3%, TiO 2 + ZrO 2 3~5%, P 2 O 5 0~3%, SnO 2 0~0.5%, containing Fe ₂ O ₃ 0.003~0.02%,
The glass substrate for pen input devices of any one of Claims 1-5. A glass substrate for a pen input device according to any one of claims 1 to 6, a display device, and a detection circuit for detecting pen input,
Pen input device. A method for producing a glass substrate for a pen input device comprising a crystallized glass plate having crystals,
The crystallized glass substrate is
The manufacturing method of the glass substrate for pen input devices which etches the glass base plate comprised by the crystallized glass which has a crystal | crystallization, and forms the unevenness | corrugation by the said crystal | crystallization on the main surface.