JP2009231183A - Tough panel, display device with input function, and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: a touch panel in which even when fine irregularities for preventing a neutron ring are formed, good images can be displayed by appropriating the form of the irregularities; a display device with an input function provided with the touch panel; and an electronic equipment provided with the display device with the input function. <P>SOLUTION: A tough panel 1 comprises a first substrate 10 in which a first electrode 15 is formed on a first surface 11, and a second light-transmitting substrate 20 in which a second electrode 25 is formed on a first surface 21, and fine irregularities 21a are formed on the first surface 21 of the second substrate 20. The irregularities 21a have an arithmetic average roughness Ra of ≤0.1 μm, and a mean interval Sm between the surface irregularities is 10-60 μm. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a touch panel capable of detecting a position touched by a finger or the like, a display device with an input function including the touch panel, and an electronic apparatus including the display device with an input function.

  In recent years, in electronic devices such as mobile phones, car navigation systems, personal computers, ticket vending machines, bank terminals, etc., as shown in FIG. 6, a touch panel 1 is arranged on the surface of a liquid crystal device 5 or the like, and an image display area of the liquid crystal device 5 In some cases, information can be input by pressing a predetermined part of the touch panel 1 with a finger or the like while referring to the instruction image displayed on the screen.

  Among such touch panels, in the resistive film type, the translucent first substrate 10 in which the first electrode 15 is formed on the first surface 11 and the second electrode 25 are formed on the first surface 21. The translucent second substrate 20 is disposed so that the first surfaces 11 and 21 face each other with a predetermined gap therebetween, and the second surface 22 side of the second substrate 20 is pushed down. . At this time, if the interval between the first substrate 10 and the second substrate 20 is narrowed and Newton rings are generated, the image displayed on the liquid crystal device 5 becomes difficult to see.

Therefore, a configuration has been proposed in which fine irregularities 21a having an arithmetic average roughness Ra of 0.06 to 3.0 μm are formed on the first surface 21 of the second substrate 20 made of a PET film or the like to prevent the occurrence of Newton rings. (See Patent Document 1).
JP 7-169367 A

  However, in the display device 100 with the input function provided with the touch panel 1, when the unevenness 21 a is formed on the first surface 11 of the second substrate 20 when the image of the liquid crystal device 5 becomes high definition, depending on how the unevenness 21 a is formed. In addition, the visibility of information displayed on the liquid crystal device 5 is lowered due to the microlens effect of the unevenness 21a, but the display quality is lowered due to turbidity. That is, in the display device 100 with an input function provided with the touch panel 1, there is a problem that it is not sufficient to control only the arithmetic average roughness Ra in forming the unevenness 21a for preventing the occurrence of Newton rings.

  In view of the above problems, the problem of the present invention is to provide a touch panel that can display a good image by optimizing the form even when fine irregularities for preventing Newton rings are formed, and the touch panel. And a display device with an input function, and an electronic device including the display device with an input function.

  In order to solve the above-described problems, in the present invention, when the surfaces on the opposite sides of the substrate are the first surface and the second surface, respectively, the first substrate on which the first electrode is formed on the first surface; The second electrode having the second electrode formed on the first surface is disposed so that the first surfaces face each other with a predetermined gap, and the second surface side of the second substrate is pressed down. In at least one of the first surface of the first substrate and the first surface of the second substrate, the arithmetic average roughness Ra is 0.1 μm or less and the average interval Sm of surface irregularities is 10 Fine irregularities of ˜60 μm are formed.

  In the present invention, since fine irregularities are formed on at least one of the first surface of the first substrate and the first surface of the second substrate, the irregularities are also reflected on the electrode surface. Therefore, even when the second substrate is pressed, Newton rings are unlikely to occur between the first substrate and the second substrate. Further, in the present invention, since the upper limit of the arithmetic average roughness Ra of the unevenness is set to 0.1 μm, even when the image displayed on the image generating device has a high definition, the turbidity like frosted glass does not occur. Furthermore, in the present invention, since the average interval Sm of the unevenness is also defined and the value is set to 10 to 60 μm, the information displayed on the image generation device is visually recognized due to the microlens effect of the unevenness. Sex does not decrease as a feeling of glare. That is, when the arithmetic average roughness Ra is larger than 0.1 μm, a turbid feeling like a frosted glass is generated, and the visibility of information displayed on the image generating device is lowered. Since the upper limit of the average roughness Ra is set to 0.1 μm, such a problem does not occur. Further, if the average interval Sm between the surface irregularities is larger than 60 μm, an effect like a microlens due to the irregularities occurs, and the visibility of the information displayed on the image generation device decreases as a glare feeling, while the surface irregularities If the average interval Sm is smaller than 10 μm, it overlaps with the small arithmetic average roughness Ra to increase the flatness and make it easy to see the Newton ring. However, in the present invention, the average interval Sm of unevenness is set to 10 to 60 μm. This problem does not occur.

  In the present invention, it is preferable that the unevenness is formed at least on the first surface of the second substrate. In the present invention, since the arithmetic average roughness Ra of the unevenness is set to 0.1 μm or less, there is a possibility that some Newton rings may be generated between the first substrate and the second substrate, but the first surface of the second substrate If irregularities are formed on the surface, there is an advantage that it does not stand out even if Newton rings occur.

  In this invention, it is preferable that arithmetic mean roughness Ra of the said unevenness | corrugation is 0.02-0.06 micrometer, and the average space | interval Sm of surface unevenness | corrugation is 20-60 micrometers. By adopting such conditions, it is possible to more reliably prevent display quality degradation such as turbidity like frosted glass, glare feeling caused by the influence of microlenses due to unevenness, and display quality degradation such as Newton ring caused by reflection. Can do.

  In the present invention, the second substrate preferably has a haze value (turbidity value) of 2 to 4%. If comprised in this way, the image produced | generated with the image production | generation apparatus can be seen with high quality.

  In the present invention, when forming the unevenness, when the substrate on which the unevenness is formed is the glass substrate among the first substrate and the second substrate, the unevenness is formed by frost processing on the glass substrate. be able to.

  The present invention is effective when applied when the second substrate is a glass substrate having a thickness of 0.2 mm or less. In such a thin glass substrate, the first substrate and the second substrate are bonded together, and then the substrate is thinned by etching. However, in the present invention, the unevenness is the first substrate and / or the inner surface of the second substrate ( Since the first surface is formed on the first surface, the unevenness does not disappear even when etching for thinning the substrate is performed.

  When a display device with an input function is configured using a touch panel to which the present invention is applied, an image generation device is arranged on the first substrate side of the touch panel. The present invention is effective when applied when the dot pitch (pixel pitch) in the image generating apparatus is 60 μm or less, for example, about 30 μm.

  The display device with an input function to which the present invention is applied can be used for electronic devices such as a mobile phone, an electronic notebook, and a terminal device such as a POS terminal.

  Embodiments of the present invention will be described with reference to the drawings. In the drawings to be referred to in the following description, the scales are different for each layer and each member so that each layer and each member have a size that can be recognized on the drawing. Further, in order to make the correspondence relationship easy to understand, portions having the same functions as those in the configuration shown in FIG.

[Embodiment 1]
(overall structure)
1 and 2 are explanatory diagrams schematically showing the configuration of a display device with an input function to which the present invention is applied. In FIG. 2, the shape of the touch panel, the substrate of the liquid crystal panel, the electrode, and the like are simplified and the thickness is shown to be easily understood.

  1 and 2, the display device with an input function 100 according to the present embodiment generally includes a liquid crystal device 5 as an image generating device and a touch panel disposed on the surface of the liquid crystal device 5 that emits display light. 1 (input device).

  The liquid crystal device 5 includes a transmissive active matrix liquid crystal panel (hereinafter simply referred to as a liquid crystal panel 5a). In the case of the transmissive liquid crystal panel 5a, a backlight device ( (Not shown). Further, in the liquid crystal device 5, the first polarizing plate 81 is disposed on the liquid crystal panel 5a on the display light emission side, and the second polarizing plate 82 is disposed on the opposite side. The liquid crystal panel 5 a includes a translucent element substrate 50, a translucent counter substrate 60 that is bonded to the element substrate 50 with a sealing material 71 in a state of being opposed to the element substrate 50, and the counter substrate 60 and the element substrate 50. And a liquid crystal layer 55 held between them. In the element substrate 50, a driving IC 75 is COG mounted in an overhanging region 59 projecting from the edge of the counter substrate 60, and a flexible substrate 73 is connected to the overhanging region 59. Note that a drive circuit may be formed on the element substrate 50 simultaneously with the switching elements on the element substrate 50.

(Detailed configuration of touch panel 1)
The touch panel 1 is a resistance film type, and a translucent first substrate in which a translucent first electrode 15 made of a translucent conductive film such as an ITO film (Indium Tin Oxide) is formed on the first surface 11. 10 and a light-transmitting second substrate 20 on which a second electrode 25 made of a light-transmitting conductive film such as an ITO film is formed on the first surface 21, and the first surfaces 11 and 21 have a predetermined gap between them. The seal material 31 is attached so as to face each other, and the inside is an air layer. As the first substrate 10 and the second substrate 20, a light-transmitting thin plastic substrate or a thin glass substrate can be used. In this embodiment, the thickness of the first substrate 10 is 0.4 to 1.1 mm. The second substrate 20 is a thin glass substrate having a thickness of 0.2 mm or less, for example, 0.1 mm. In the first substrate 10, a flexible substrate 33 is connected to the overhang region 19 that projects from the edge of the second substrate 20.

  The touch panel 1 configured as described above is arranged so as to overlap the first polarizing plate 81 of the liquid crystal device 5 and constitutes the display device 100 with an input function. In the display device with an input function 100, the liquid crystal device 5 can display a moving image or a still image in the image display area 100a, and when the input device 100 with the input function is input via the touch panel 1. An instruction image is also displayed. Accordingly, if the user presses the touch panel 1 with a finger while viewing the instruction image displayed on the liquid crystal device 5, the second substrate 20 is bent, and the first electrode 15 and the second electrode 25 are pressed at the pressed position. Touch. Therefore, if the location where the first electrode 15 and the second electrode 25 are in contact with each other is detected, the input information can be determined.

(Detailed configuration of the second substrate 20)
3A, 3B, and 3C are graphs showing the arithmetic average roughness Ra of the unevenness, the average interval Sm of the surface unevenness, and the relationship between the haze value and the reflectance. The reflectance of raw glass is about 9%.

  In the display device 100 with the input function and the touch panel 1 of the present embodiment, the fine unevenness 21a is formed on the first surface 21 of the second substrate 20, and the unevenness 21a is reflected on the surface of the second electrode 25. Also, fine irregularities 25 a are formed on the surface of the second electrode 25. In contrast, the first surface 11 of the first substrate 10, the second surface 12 of the first substrate 10, and the second surface 22 of the second substrate 20 are all smooth surfaces. The unevenness 21a is formed by frosting the second substrate 20, and in order to form the unevenness 21a, a predetermined region of the glass substrate is covered with a mask and hydrofluoric acid and hydrogen phosphate. Immerse the glass substrate in an acid treatment solution composed of an aqueous solution of ammonium, etc. to roughen the surface, then immerse the glass substrate again in an etching solution composed of an aqueous solution of hydrofluoric acid and ammonium fluoride acid, etc. Etching is performed to form fine irregularities 21a having a uniform shape.

  In the display device with an input function 100 configured as described above, in this embodiment, as a preferable embodiment, the arithmetic average roughness Ra of the unevenness 21a is set to 0.1 μm or less, and the average interval Sm of the surface unevenness is set to 10 to 60 μm. ing. As a more preferred form, the unevenness 21a has an arithmetic average roughness Ra of 0.02 to 0.06 μm, for example, 0.05 μm, and an average interval Sm of surface unevenness of 20 to 60 μm, for example, 40 to 60 μm. is there.

  Here, as shown in FIG. 3 (a), the arithmetic average roughness Ra is extracted from the roughness Ra curve in the direction of the average line by a reference length l and from the average line of the extracted portion to the measurement curve. The absolute value of the deviation is summed and averaged. Further, as shown in FIG. 3 (b), the average interval Sm of the surface irregularities is extracted from the roughness Ra curve by the reference length l in the direction of the average line. The sum of the lengths of the average lines corresponding to one adjacent valley is obtained and averaged. In other words, if the average line is crossed n times within the reference length l, Sm = 1 / n.

In this embodiment, the haze value of the second substrate 20 is set to 2 to 4% in the relationship between the haze value and the reflectance shown in FIG. For this reason, the second substrate 20 has a high reflectance of 7 to 8%, but has a transmittance close to that of raw glass because the scattering is small. Therefore, an image generated by the liquid crystal device 5 can be viewed with high quality. Here, the haze value is a value indicating the degree of turbidity (cloudiness) when the translucent substrate is not completely transparent but has turbidity (cloudiness). Ratio / total light transmittance) × 100 (%)
It is represented by

(Main effects of this form)
As described above, in this embodiment, since the fine unevenness 21a is formed on the first surface 21 of the second substrate used in the touch panel 1, the unevenness 21a is also formed on the surface of the second electrode 25 as the unevenness 25a. It is reflected. Therefore, even if the second substrate 20 is pressed, a Newton ring is unlikely to occur between the first substrate 10 and the second substrate 20.

  In this embodiment, since the upper limit of the arithmetic average roughness Ra of the unevenness 21a is set to 0.1 μm, the dot pitch of the liquid crystal device 5 is narrowed to 60 μm or less, for example, about 30 μm, and the image becomes high definition. Even in this case, the turbidity such as frosted glass does not occur.

  Furthermore, in this embodiment, since the average interval Sm of the irregularities 21a is also defined and the value is set to 10 to 60 μm, it is possible to reliably prevent the display quality from being deteriorated due to reflection, The visibility of information displayed on the liquid crystal device 5 does not deteriorate due to the microlens-like influence of the unevenness 21a. That is, when the arithmetic average roughness Ra is larger than 0.1 μm, the turbidity such as frosted glass is generated, and the visibility of information displayed on the liquid crystal device 5 is lowered. Since the upper limit of the arithmetic average roughness Ra is set to 0.1 μm, such a problem does not occur. Further, if the average interval Sm between the surface irregularities is larger than 60 μm, an effect like a microlens due to those irregularities occurs, and the visibility of the information displayed on the liquid crystal device 5 decreases as a feeling of glare. If the average interval Sm is smaller than 10 μm, it overlaps with the small arithmetic average roughness Ra to increase the flatness and make it easy to see the Newton ring, but in this embodiment, the average interval Sm of the irregularities 21a is set to 10 to 60 μm. Therefore, such a problem does not occur.

  As a more preferable form, in this embodiment, if the arithmetic average roughness Ra of the unevenness 21a is 0.02 to 0.06 μm and the arithmetic average roughness Ra of the surface unevenness is 20 to 60 μm, it becomes turbid like rubbed glass. It is possible to more surely prevent display quality deterioration such as glittering feeling caused by the influence of microlenses due to feeling and unevenness, and display quality deterioration such as Newton ring caused by reflection.

  Further, in this embodiment, since the unevenness 21a is formed on the first surface 21 of the second substrate 20, it is not noticeable even when Newton rings are generated. That is, when the arithmetic average roughness Ra of the unevenness 21a is 0.1 μm or less, there is a possibility that Newton's ring may occur somewhat. However, if the unevenness 21a is formed on the first surface 21 of the second substrate 20, the Newton ring There is an advantage that it does not stand out even if it occurs.

  In the present embodiment, the second substrate 20 is a glass substrate having a thickness of 0.2 mm or less, for example, 0.1 mm or less, and such a thickness is a thickness of 0.4 to 1.1 mm. Although it is realized by etching after bonding the first substrate 10 and the second substrate 20, in this embodiment, the unevenness 21 a is formed on the inner surface (first surface 21) of the second substrate 20. Even when etching for thinning is performed, the unevenness 21a does not disappear. In addition, when the second substrate 20 is a thin glass substrate and the surfaces of the first electrode 15 and the second electrode 25 are flat, the second electrode 25 is the first electrode even when the second substrate 20 is pressed and bent. When the second electrode 20 returns to its original shape from the state where the second substrate 20 is pressed and bent, the noise is generated when the second electrode 25 is pulled away from the first electrode 15. However, in this embodiment, since the unevenness 25a is reflected on the surface of the second electrode 25, such a problem does not occur.

[Embodiment 2]
FIG. 4 is an explanatory diagram schematically showing a configuration of a display device with an input function to which the present invention is applied. Since the basic configuration of this embodiment is the same as that of Embodiment 1, common portions are denoted by the same reference numerals and description thereof is omitted.

  In FIG. 4, the display device 100 with an input function according to the present embodiment is also arranged so as to overlap the liquid crystal device 5 as an image generation device and the surface on the display light emitting side in the liquid crystal device 5, as in the first embodiment. Touch panel 1 (input device). The touch panel 1 is of a resistance film type, and a translucent first substrate 10 having a translucent first electrode 15 formed on the first surface 11, and a second electrode 25 made of an ITO film is a first surface 21. The light-transmitting second substrate 20 formed on the first substrate 11 is bonded with a sealing material 31 so that the first surfaces 11 and 21 face each other with a predetermined gap therebetween, and the inside is an air layer. As the first substrate 10 and the second substrate 20, a light-transmitting thin plastic substrate or a thin glass substrate can be used. In this embodiment, the thickness of the first substrate 10 is 0.4 to 1.1 mm. The second substrate 20 is a thin glass substrate having a thickness of 0.2 mm or less, for example, 0.1 mm.

  In this embodiment, fine irregularities 11a are formed on the first surface 11 of the first substrate 10, and the irregularities 11a are reflected also on the surface of the first electrode 15, and as a result, fine irregularities are also formed on the surface of the first electrode 15. 15a is formed. On the other hand, the second surface 12 of the first substrate 10, the first surface 21 of the second substrate 20, and the second surface 22 of the second substrate 20 are all smooth surfaces.

  The irregularities 11a are formed by frost processing on the first substrate 10, and as a preferred form, the arithmetic average roughness Ra is 0.1 μm or less, and the average interval Sm of the surface irregularities is set to 10 to 60 μm. Yes. As a more preferred form, the unevenness 21a has an arithmetic average roughness Ra of 0.02 to 0.06 μm, for example, 0.05 μm, and an average interval Sm of surface unevenness of 20 to 60 μm, for example, 40 to 60 μm. is there.

  Even in such a configuration, since the fine unevenness 11a is formed on the first surface 11 of the first substrate, the unevenness 11a is reflected on the surface of the first electrode 15 as the unevenness 15a. Therefore, as in the first embodiment, even when the second substrate 20 is pressed, Newton rings are unlikely to occur between the first substrate 10 and the second substrate 20. In the present embodiment, the upper limit of the arithmetic average roughness Ra of the unevenness 11a is set to 0.1 μm, and the average interval Sm of the unevenness 11a is set to 10 to 60 μm. It is possible to more reliably prevent display quality degradation such as turbidity, glare sensation due to the influence of microlenses due to unevenness, and display quality degradation such as Newton ring due to reflection.

  Further, the second substrate 20 is a glass substrate having a thickness of 0.2 mm or less, for example, 0.1 mm or less, and such a thinness is obtained after the first substrate 10 and the second substrate 20 are bonded together. In this embodiment, since the unevenness 11a is formed on the inner surface (first surface 11) of the first substrate 10, the unevenness 11a is formed even when etching for thinning the substrate is performed. Does not disappear. Further, although the second substrate 20 is a thin glass substrate, since the unevenness 15a is reflected on the surface of the first electrode 15, when the second substrate 20 is pressed and bent to return to the original shape. Even when the second electrode 25 is separated from the first electrode 15, no abnormal noise is generated.

[Embodiment 3]
In the first embodiment, the unevenness 21a is formed on the first surface 21 of the second substrate 20, and the first surface 11 of the first substrate 10 is flat. In the second embodiment, the first surface of the first substrate 10 is flat. 11, the first surface 21 of the second substrate 20 was flat. However, the first surface 11 of the first substrate 10 was formed with the unevenness 21 a on the first surface 21 of the second substrate 20. Alternatively, a configuration in which the unevenness 11a is formed may be adopted.

[Other embodiments]
In the above embodiment, the liquid crystal device 5 is used as the image generating device. However, the present invention may be applied when an organic electroluminescence device or a plasma display device is used as the image generating device.

[Example of mounting on electronic equipment]
Next, an electronic apparatus to which the display device with an input function 100 according to the above-described embodiment is applied will be described. FIG. 5A shows a configuration of a mobile personal computer including the display device 100 with an input function. The personal computer 2000 includes a display device 100 with an input function as a display unit and a main body 2010. The main body 2010 is provided with a power switch 2001 and a keyboard 2002. FIG. 5B shows a configuration of a mobile phone including the display device 100 with an input function. The cellular phone 3000 includes a plurality of operation buttons 3001, scroll buttons 3002, and the display device 100 with an input function as a display unit. By operating the scroll button 3002, the screen displayed on the display device 100 with an input function is scrolled. FIG. 5C shows a configuration of a personal digital assistant (PDA) to which the display device 100 with an input function is applied. The information portable terminal 4000 includes a plurality of operation buttons 4001, a power switch 4002, and the display device 100 with an input function as a display unit. When the power switch 4002 is operated, various kinds of information such as an address book and a schedule book are displayed on the display device 100 with an input function.

  Note that electronic devices to which the display device 100 with an input function is applied include, in addition to those shown in FIG. 5, a digital still camera, a liquid crystal television, a car navigation device, a pager, an electronic notebook, a calculator, a word processor, a workstation, a videophone, Examples thereof include terminal devices such as POS terminals.

It is explanatory drawing which shows typically the structure of the display apparatus with an input function to which this invention is applied. It is explanatory drawing which shows typically the cross-sectional structure of the display apparatus with an input function which concerns on Embodiment 1 of this invention. (A), (b), (c) is a graph which shows the arithmetic mean roughness Ra of unevenness | corrugation, the average space | interval Sm of surface unevenness | corrugation, and the relationship between a haze value and a reflectance. It is explanatory drawing which shows typically the cross-sectional structure of the display apparatus with an input function which concerns on Embodiment 2 of this invention. It is explanatory drawing of the electronic device using the display apparatus with an input function which concerns on this invention. It is sectional drawing of the conventional display apparatus with an input function.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Touch panel, 5 ... Liquid crystal device (image generating apparatus), 10 ... First substrate, 11 .... First surface of first substrate, 12 .... Second surface of first substrate, 11a, 15a, 21a 25a... Fine irregularities 15.. First electrode of first substrate 20.. Second substrate 21.. First surface of second substrate 22.. Second surface of second substrate 25. -Second electrode of second substrate, 100-Display device with input function

Claims (9)

When the surfaces located on opposite sides of the substrate are the first surface and the second surface,
The first substrate having the first electrode formed on the first surface and the translucent second substrate having the second electrode formed on the first surface face each other with a predetermined gap therebetween. In the touch panel where the second surface side of the second substrate is pressed,
At least one of the first surface of the first substrate and the first surface of the second substrate has a fine arithmetic mean roughness Ra of 0.1 μm or less and an average surface roughness Sm of 10 to 60 μm. A touch panel characterized by unevenness.   The touch panel according to claim 1, wherein the unevenness is formed at least on the first surface of the second substrate.   3. The touch panel according to claim 1, wherein an arithmetic average roughness Ra of the unevenness is 0.02 to 0.06 μm, and an average interval Sm of surface unevenness is 20 to 60 μm.   4. The touch panel according to claim 1, wherein the second substrate has a haze value of 2 to 4%. Of the first substrate and the second substrate, the substrate on which the irregularities are formed is a glass substrate,
The touch panel according to any one of claims 1 to 4, wherein the unevenness is formed by frost processing on the glass substrate.   The touch panel according to claim 1, wherein the second substrate is a glass substrate having a thickness of 0.2 mm or less. A display device with an input function comprising the touch panel according to any one of claims 1 to 6,
The display device with an input function, wherein an image generating device is disposed on the first substrate side of the touch panel.   The display device with an input function according to claim 7, wherein a dot pitch in the image generation device is 60 μm or less.   An electronic apparatus comprising the display device with an input function according to claim 7.

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