WO2015194074A1 - Capacitive touch panel - Google Patents

Abstract

A touch panel of the present invention is provided with: a first substrate; a first electrode pattern that is disposed on the first substrate; a second substrate; a second electrode pattern that is disposed on the second substrate; and a first adhesive layer that is disposed between the first electrode pattern and the second electrode pattern. In a region between the first electrode pattern and the second electrode pattern, the first adhesive layer, and the first substrate or the second substrate are disposed. The ratio of the volume of a first adhesive layer portion in the region between the first electrode pattern and the second electrode pattern to the volume of the region is set higher than 0 but equal to or lower than 40 %. The touch panel is capable of highly accurately detecting a touch even in the cases where a rapid temperature change is locally generated at a contact position of an operation surface.

Description

Capacitive touch panel

The present invention relates to a capacitive touch panel in which a substrate on which an electrode pattern is formed and another substrate on which another electrode pattern is formed are stacked with an adhesive layer interposed therebetween.

In display devices for portable electronic devices such as portable terminals and in-vehicle electronic devices such as car navigation and car audio, a touch panel is mounted on a display device such as a liquid crystal display device, and the display on the display element on the back is viewed through this touch panel. However, there are an increasing number of operations and displays that are switched by touching and operating the touch panel with a finger or the like.

In such a display device, a capacitive touch panel that identifies an operation position on the panel surface by detecting a change in capacitance generated by an operation of bringing a finger or the like into contact with the panel surface is frequently used. In this capacitive touch panel, the substrate on which the X electrode pattern is formed and the substrate on which the Y electrode pattern is formed are stacked so that the X electrode pattern and the Y electrode pattern intersect. This electrostatic capacitance type touch panel is a so-called projection type touch panel that detects the operation position on the panel surface from the coordinates of the X electrode pattern and the Y electrode pattern by changing the electrostatic capacity.

A conventional touch panel similar to this touch panel is disclosed in Patent Document 1, for example.

International Publication No. 2013/114945

The touch panel includes a first substrate, a first electrode pattern disposed on the first substrate, a second substrate, a second electrode pattern disposed on the second substrate, a first electrode pattern, and a second electrode pattern. And a first adhesive layer disposed between the two. In the region between the first electrode pattern and the second electrode pattern, any one of the first substrate and the second substrate and the first adhesive layer are disposed. The ratio of the volume of the part in the said area | region of the 1st adhesion layer with respect to the volume of the area | region between a 1st electrode pattern and a 2nd electrode pattern shall be larger than 0 and 40% or less.

This touch panel can detect contact with high accuracy even when a sudden temperature change locally occurs at the contact position on the operation surface.

FIG. 1A is a top view of the capacitive touch panel according to the first embodiment. 1B is a cross-sectional view taken along line IB-IB of the capacitive touch panel shown in FIG. 1A. FIG. 2 is a characteristic diagram of the capacitive touch panel according to the first embodiment. FIG. 3 is a cross-sectional view of a capacitive touch panel according to the second embodiment. FIG. 4 is a sectional view of a capacitive touch panel according to the third embodiment. FIG. 5 is a sectional view of a capacitive touch panel according to the fourth embodiment. FIG. 6 is a cross-sectional view of another capacitive touch panel according to the fourth embodiment.

(First embodiment)
FIG. 1A is a top view of the capacitive touch panel 100 according to the first embodiment. FIG. 1B is a cross-sectional view taken along line IB-IB of the capacitive touch panel 100 shown in FIG. 1A.

A capacitive touch panel 100 shown in FIGS. 1A and 1B includes a substrate 2 on which an electrode pattern 1 is formed, an adhesive layer 3 laminated on the substrate 2, a substrate 5 laminated on the adhesive layer 3, The adhesive layer 6 is laminated on the substrate 5, and the cover lens 7 is laminated on the adhesive layer 6. An electrode pattern 4 is formed on the substrate 5.

Specifically, the electrode pattern 1 is provided on the upper surface 2A of the substrate 2. An electrode pattern 4 is provided on the upper surface 5 </ b> A of the substrate 5. The adhesive layer 3 is provided on the upper surface 2 </ b> A of the substrate 2 so as to cover the electrode pattern 1. The lower surface 5B of the substrate 5 is positioned on the upper surface 3A of the adhesive layer 3. The adhesive layer 3 bonds the upper surface 2A of the substrate 2 to the lower surface 5B of the substrate 5. The adhesive layer 6 is provided on the upper surface 5 </ b> A of the substrate 5 so as to cover the electrode pattern 4. The lower surface 7B of the cover lens 7 is positioned on the upper surface 6A of the adhesive layer 6. The adhesive layer 6 adheres the upper surface 5A of the substrate 5 to the lower surface 7B of the cover lens 7. The electrode patterns 1, 4, the substrates 2, 5, the adhesive layers 3, 6 and the cover lens 7 are laminated in a direction D 102 perpendicular to the upper surfaces 2 A, 5 A of the substrates 2, 5.

The substrate 2 and the substrate 5 are formed of a transparent film-shaped substrate such as polycarbonate (PC), polyethersulfone (PES), or polyethylene terephthalate (PET). The electrode pattern 1 and the electrode pattern 4 are respectively formed of a transparent conductive film such as ITO (Indium Tin Oxide (tin-doped indium oxide)) or tin oxide. The substrate 2 and the electrode pattern 1, and the substrate 5 and the electrode pattern 4 are each formed of a so-called ITO film (film coated with an ITO layer).

The pressure-sensitive adhesive layer 3 and the pressure-sensitive adhesive layer 6 are made of OCA (Optical, which is a translucent adhesive mainly composed of acrylic acid polymer, silicon-based polymer, urethane-based polymer, rubber-based polymer, epoxy-based polymer, or the like, or a mixture thereof. It is formed by the base material 93 which consists of (Clear Adhesive).

The cover lens 7 is disposed on the viewing side of the substrate 5 and is made of a resin having optical transparency such as glass, polymethyl methacrylate (PMMA), PC, or epoxy.

In the capacitive touch panel 100, the adhesive layer 3 is laminated on the substrate 2, the substrate 5 is laminated on the adhesive layer 3, the adhesive layer 6 is laminated on the substrate 5, and the adhesive layer 6 is placed on the adhesive layer 6. The cover lens 7 is laminated.

In the capacitive touch panel 100, the electrode pattern 1 is provided on the upper surface 2A of the substrate 2, and the electrode pattern 4 is provided on the upper surface 5A of the substrate 5.

The electrode pattern 1 is composed of a plurality of electrode patterns (for example, X electrode patterns) arranged at equal intervals in a direction D100 parallel to the upper surfaces 2A and 5A of the substrates 2 and 5, and the electrode pattern 4 is an upper surface 2A and 5A of the substrates 2 and 5. And a plurality of electrode patterns (for example, Y electrode patterns) arranged at equal intervals in a direction D101 orthogonal to the direction D100. Therefore, by laminating the substrate 2 and the substrate 5, the electrode pattern 1 and the electrode pattern 4 are arranged in a matrix.

In the capacitive touch panel 100 having such a stacked configuration, the thickness of each component is 0.1 mm for the substrate 2, 0.025 mm for the adhesive layer 3, 0.1 mm for the substrate 5, and 0.1 mm for the adhesive layer 6. The cover lens 7 is 2.0 mm.

Next, the operation of the capacitive touch panel 100 will be described.

When the operation surface of the upper surface 7A of the cover lens 7 is operated with a finger or the like, the electrode pattern 4 is connected in series with capacitances parasitic on the cover lens 7 and the adhesive layer 6 from the electrode corresponding to the operation position of the electrode pattern 4, respectively. A signal corresponding to the combined capacitance connected to is obtained. On the other hand, in the electrode pattern 1, a signal corresponding to a combined capacitance in which electrostatic capacitances parasitic on the cover lens 7, the adhesive layer 6, the substrate 5, and the adhesive layer 3 from the electrode corresponding to the operation position of the electrode pattern 1 are connected in series. Is obtained.

In the state where the operation surface of the upper surface 7A of the cover lens 7 is not operated, the electrode pattern 4 and the electrode pattern 1 correspond to the combined capacitance obtained by connecting the parasitic capacitances in the substrate 5 and the adhesive layer 3 in series, respectively. A signal is obtained. Therefore, when the operation surface is operated, the signals obtained from the electrodes corresponding to the operation positions of the electrode pattern 4 and the electrode pattern 1 correspond to the change in capacitance, and thereby the operation position of the operation surface is changed. It is detected by the coordinates of the electrode pattern 4 and the electrode pattern 1.

The electrostatic capacitance parasitic on each constituent member depends on the relative dielectric constant of each constituent member and the volume of each constituent member. In the capacitive touch panel 100, since the area of each component is the same, it depends on the thickness of each component. Further, in the operation guarantee temperature range that guarantees the use of the touch panel, for example, in the range of −30 ° C. to + 90 ° C., the constituent member in which the change in the relative dielectric constant accompanying the temperature change of each constituent member is recognized as the adhesive layer 3 and the adhesive layer Layer 6.

The signal of the detection output obtained by the electrode pattern 4 corresponds to the combined capacitance C1 in which electrostatic capacitances parasitic on the cover lens 7 and the adhesive layer 6 are connected in series. The detection output signal obtained by the electrode pattern 1 is a combined capacitance C2 obtained by connecting in series the parasitic capacitances of the substrate 5 and the adhesive layer 3 in series to the combined capacitance C1 from the surface of the cover lens 7 to the electrode pattern 4. Corresponds to the combined capacitance C3 connected in series. The combined capacity C3 is expressed by the following formula.

1 / C3 = 1 / C1 + 1 / C2
The apparent relative dielectric constant εA of the cover lens 7 and the adhesive layer 6 related to the composite capacitance C1 is determined by the relative dielectric constant ε1 and the thickness d1 of the cover lens 7 and the relative dielectric constant ε2 and the thickness d2 of the adhesive layer 6. It is expressed by Equation 1.

The apparent relative dielectric constant εB of the substrate 5 and the adhesive layer 3 related to the composite capacitance C2 is expressed by the following equation (2) depending on the relative dielectric constant ε3 and the thickness d3 of the substrate 5 and the relative dielectric constant ε4 and the thickness d4 of the adhesive layer 3. It is represented by

In the cover lens 7, the temperature dependence of the relative dielectric constant is not recognized within the guaranteed operating temperature range, and the thickness is one digit larger than that of other components. Therefore, it can be determined that the influence of the temperature dependency of the apparent relative dielectric constant εA of the cover lens 7 and the adhesive layer 6 on the combined capacitance C1 from the surface of the cover lens 7 to the electrode pattern 4 is small.

On the other hand, with respect to the combined capacitance C2 of the substrate 5 and the adhesive layer 3, the substrate 5 shows no temperature dependence of the relative dielectric constant within the guaranteed operating temperature range, and the adhesive layer 3 shows the temperature dependence of the relative dielectric constant. For this reason, the adhesive layer 3 is thinner than the substrate 5, and is thinner than the adhesive layer 6. As a result, the temperature dependence of the apparent relative dielectric constant εB of the substrate 5 and the adhesive layer 3 is higher than that when the adhesive layer 3 has the same thickness as that of the adhesive layer 6. The degree of involvement in is reduced.

In addition, since unevenness remains on the joint surface of the lower surface 7B of the cover lens 7 with the adhesive layer 6, the adhesive layer 6 is thicker than the adhesive layer 3 in order to absorb the unevenness.

In this way, when the rate of change of the synthetic dielectric constant εB by the substrate 5 and the adhesive layer 3 is 10% or less within the guaranteed operating temperature range, it is locally located at the contact position of the operation surface of the upper surface 7A of the cover lens 7. Even when a sudden temperature change occurs, it is possible to suppress the capacitance change that can prevent erroneous detection of a touch operation.

When mounting the above-mentioned conventional capacitive touch panel on a vehicle, it is necessary to consider measures for cold regions and in hot weather environments in the vehicle. The touch panel that follows the ambient temperature and the constant temperature regardless of the ambient temperature. The temperature difference between the finger of a person who operates the touch panel becomes larger. In such a case, a rapid temperature change locally occurs at the contact position on the operation surface of the touch panel, and the contact may not be detected with high accuracy.

Table 1 shows the ratio X of the thickness d4 of the adhesive layer 3 to the total thickness (d3 + d4) of the substrate 5 and the adhesive layer 3 when the thickness d3 of the substrate 5 and the thickness d4 of the adhesive layer 3 are changed within the guaranteed operating temperature range. (= D4 / (d3 + d4)) and the rate of change Y with respect to the temperature of the synthetic dielectric constant εB by the substrate 5 and the adhesive layer 3 are shown.

FIG. 2 is a characteristic diagram showing the characteristics shown in Table 1.

As for the ITO film that forms the substrate 5 and the OCA that forms the adhesive layer 3, options that can be used in existing product groups that are commercially available are limited. In Table 1, the ITO film uses a 0.1 mm-thick PC base material or is not used, and OCA uses 0.1 mm and 0.025 mm-thick products or is not used. Specifically, Sample No. 1 does not include the substrate 5, and the thickness d4 of the adhesive layer 3 is 0.1 mm. Sample No. 2, the thickness d3 of the substrate 5 is 0.1 mm, and the thickness d4 of the adhesive layer 3 is 0.1 mm. Sample No. 3, the thickness d3 of the substrate 5 is 0.1 mm, and the thickness d4 of the adhesive layer 3 is 0.025 mm. Sample No. 4 does not include the adhesive layer 3, and the thickness d3 of the substrate 5 is 0.1 mm.

Table 1 shows that the ratio X of the thickness d4 of the adhesive layer 3 to the total thickness (d3 + d4) of the thickness d3 of the substrate 5 and the thickness d4 of the adhesive layer 3 is 0%, 20%, 50% from the choice of ITO film and OCA. The measurement result of the rate of change Y with respect to the temperature of the synthetic dielectric constant εB by the substrate 5 and the adhesive layer 3 when it is 100% is shown.

FIG. 2 is a characteristic diagram based on Table 1. In FIG. 2, the change rate Y of the synthetic dielectric constant εB with respect to the ratio X of the thickness d4 of the adhesive layer 3 can be regarded as a quadratic curve, and when Y = 10%, the ratio X is between 20% and 50%. It is in. Therefore, when X = 20%, Y≈4%, and when X = 50%, Y≈15%, so the ratio X when Y = 10% is about 40%.

Here, when the rate of change of the synthetic relative permittivity εB by the substrate 5 and the adhesive layer 3 is 10% or less within the guaranteed operating temperature range, the change in capacitance that can prevent erroneous detection of the capacitive touch panel 100. It has been found that it can be controlled within the allowable range.

That is, the thickness of the substrate 5 and the adhesive layer 3 may be selected so that the ratio X of the thickness d4 of the adhesive layer 3 to the total thickness (d3 + d4) of the substrate 5 and the adhesive layer 3 is greater than 0 and 40% or less. . This is because the thickness d4 in the direction D102 of the adhesive layer 3 is larger than 0 and 40% or less with respect to the distance (d3 + d4) in the direction D102 between the lower surface 4B of the electrode pattern 4 and the upper surface 1A of the electrode pattern 1. It shows that it is good.

In the capacitive touch panel 100, the adhesive layer 3 is 0.025 mm and the substrate 5 is 0.1 mm. Therefore, X = 20% and Y≈4%, and the substrate within the guaranteed operating temperature range. 5 and the change rate Y of the synthetic dielectric constant εB due to the adhesive layer 3 are in the range of 10% or less.

In the capacitive touch panel 100, since the area of each constituent member is constant, the difference in thickness of each constituent member directly represents the difference in volume of each constituent member. Therefore, the ratio X of the thickness d4 of the adhesive layer 3 to the total thickness (d3 + d4) of the substrate 5 and the adhesive layer 3 is equivalent to the ratio of the volume of the adhesive layer 3 to the total volume of the substrate 5 and the adhesive layer 3. That is, the ratio of the volume of the portion 3P in the region Ac of the adhesive layer 3 to the volume of the region Ac between the electrode patterns 1 and 4 is greater than 0 and 40% or less.

(Second Embodiment)
FIG. 3 is a cross-sectional view of a capacitive touch panel 200 according to the second embodiment. In FIG. 3, the same components as those of the capacitive touch panel 100 according to the first embodiment shown in FIGS. 1A and 1B are denoted by the same reference numerals. The capacitive touch panel 200 includes an adhesive layer 103 instead of the adhesive layer 3 of the capacitive touch panel 100.

3, the adhesive layer 103 includes a base material 93 made of OCA and a filler 110 mixed in the base material 93. The filler 110 is an additive, and is formed of a material whose relative dielectric constant has a smaller temperature change within an operation guarantee temperature range than the OCA that forms the base material 93 of the adhesive layer 103. The material for forming the filler 110 is formed of the same member as the material for which the change in the relative dielectric constant due to the temperature change is not recognized as a problem within the operation guarantee temperature range, for example, the base material of the ITO film or the constituent material of the cover lens. May be.

As described above, the adhesive layer 103 is mixed with the filler 110 made of a material whose relative dielectric constant has a smaller temperature change than the base material 93 of the adhesive layer 103 within the guaranteed operating temperature range, so that the first embodiment The degree of freedom of thickness is greater than that of the adhesive layer 3 of the capacitive touch panel 100. That is, the capacitive touch panel 200 further includes a filler 110 mixed in the adhesive layer 103. Even in this case, the ratio of the volume of the portion 93P of the adhesive layer 103 (base material 93) excluding the filler 110 in the region Ac to the volume of the region Ac between the electrode pattern 4 and the electrode pattern 1 is larger than 0 and 40%. The following ratio is desirable.

As a result, the change rate Y of the synthetic dielectric constant εB by the substrate 5 and the adhesive layer 103 within the guaranteed operating temperature range is 10% or less, and the capacitance change allowance that can prevent erroneous detection of the capacitive touch panel 200 is allowed. Suppressed within range.

Thus, the configuration in which the filler 110 is mixed into the adhesive layer 103 is advantageous in securing the thickness of the adhesive layer 103 for absorbing floating, foreign matter contamination, or unevenness of the ITO film during the manufacturing process.

In the capacitive touch panel 200, the adhesive layer 6 is the same as that used for the capacitive touch panel 100 and the filler 110 is not mixed. However, in order to use the same member in the adhesive layer 103 and the adhesive layer 6 Similar to the adhesive layer 103, a material in which a filler 110 made of a material whose relative permittivity has a smaller temperature change than the base material may be used.

(Third embodiment)
FIG. 4 is a cross-sectional view of a capacitive touch panel 300 according to the third embodiment. In FIG. 4, the same components as those of the capacitive touch panel 100 according to the first embodiment shown in FIGS. 1A and 1B are denoted by the same reference numerals. A capacitive touch panel 300 shown in FIG. 4 includes an adhesive layer 203 instead of the adhesive layer 3 of the capacitive touch panel 100 according to the first embodiment shown in FIGS. 1A and 1B.

4, the adhesive layer 203 includes a base material 93 made of OCA and a plate-like core material 210 interposed in the center of the base material 93 in the direction D102. The base material 93 constitutes an upper surface 203A of the adhesive layer 203 to which the lower surface 5B of the substrate 5 is bonded and a lower surface 203B to which the upper surface 2A of the substrate 2 is bonded. The core material 210 is made of a material whose relative dielectric constant has a smaller temperature change within the guaranteed operating temperature range than the OCA that forms the base material 93 of the adhesive layer 203. The material forming the core material 210 is formed of the same member as the material of the ITO film base material or the cover lens, for example, in which the change in relative permittivity with temperature change is not recognized as a problem within the guaranteed operating temperature range. May be.

In this way, the adhesive layer 203 has an adhesive layer of the capacitive touch panel 100 by interposing the core material 210 of a material whose relative permittivity has a smaller temperature change than the base material of the adhesive layer 203 within the guaranteed operating temperature range. The degree of freedom of thickness is greater than 3. That is, the capacitive touch panel 300 further includes a core material 210 provided on the adhesive layer 203. Also in this case, the ratio of the volume of the portion 93P of the adhesive layer 203 (base material 93) excluding the core material 210 in the region Ac to the volume of the region Ac between the electrode pattern 4 and the electrode pattern 1 is larger than 0 and 40. % Or less.

As a result, the change rate Y of the synthetic dielectric constant εB by the substrate 5 and the adhesive layer 203 within the guaranteed range of temperature change is 10% or less, and the capacitance change that can prevent erroneous detection of the capacitive touch panel 300 is prevented. It is suppressed within an allowable range.

In this way, the configuration in which the core material 210 is interposed in the adhesive layer 203 increases the stability of the shape as compared with the case where only the base material of the adhesive layer 203 is used, so that the processability of the adhesive layer 203 during the manufacturing process is improved and handling is performed. It is advantageous to improve the above.

In the capacitive touch panel 300, the adhesive layer 6 is the same as that used in the capacitive touch panel 100 and the core material 210 is not mixed, but the adhesive layer 203 and the adhesive layer 6 use the same member. In addition, as in the case of the adhesive layer 203, a material having a core material 210 of a material whose relative permittivity has a smaller temperature change than that of the base material may be used.

(Fourth embodiment)
FIG. 5 is a cross-sectional view of a capacitive touch panel 400 according to the fourth embodiment. The capacitive touch panel 400 includes electrode patterns 301 and 304 instead of the electrode patterns 1 and 4 of the capacitive touch panel 100 according to the first embodiment shown in FIGS. 1A and 1B.

In FIG. 5, the substrate 2 has the electrode pattern 301 disposed on the lower surface 2B, and the substrate 5 has the electrode pattern 304 disposed on the lower surface 5B. The substrate 2 and the substrate 5 are bonded and laminated by the adhesive layer 3. The cover lens 7 is laminated on the substrate 5 with an adhesive layer 6 interposed.

Specifically, an electrode pattern 301 is provided on the lower surface 2B of the substrate 2. An electrode pattern 304 is provided on the lower surface 5B of the substrate 5. The adhesive layer 3 is provided on the lower surface 5B of the substrate 5 so as to cover the electrode pattern 304. The upper surface 2A of the substrate 2 is positioned on the lower surface 3B of the adhesive layer 3. The adhesive layer 3 bonds the upper surface 2A of the substrate 2 to the lower surface 5B of the substrate 5. The adhesive layer 6 is provided on the upper surface 5 </ b> A of the substrate 5. The lower surface 7B of the cover lens 7 is positioned on the upper surface 6A of the adhesive layer 6. The adhesive layer 6 adheres the upper surface 5A of the substrate 5 to the lower surface 7B of the cover lens 7. The electrode patterns 301 and 304, the substrates 2 and 5, the adhesive layers 3 and 6 and the cover lens 7 are laminated in a direction D102 perpendicular to the upper surfaces 2A and 5A of the substrates 2 and 5.

The capacitive touch panel 400 configured as described above is different from the capacitive touch panel 100 in the orientation of the formation surface of the electrode pattern 301 on the substrate 2 and the formation surface of the electrode pattern 304 on the substrate 5. The components are the same.

The material of the electrode patterns 301 and 304 is the same as the electrode patterns 1 and 4 of the capacitive touch panel 100. The board | substrate 2 and the board | substrate 5 are formed with the board | substrates which were light-transmitting in film shape, such as PC, PES, or PET. The electrode pattern 301 and the electrode pattern 304 are each formed of a transparent conductive film such as ITO or tin oxide, and the substrate 2, the electrode pattern 301, the substrate 5 and the electrode pattern 304 are each formed of a so-called ITO film. .

The pressure-sensitive adhesive layer 3 and the pressure-sensitive adhesive layer 6 are formed of OCA whose main material is an acrylic acid polymer, a silicon-based polymer, a urethane-based polymer, a rubber-based polymer, an epoxy-based polymer, or the like. The cover lens 7 is formed of a resin having light transmissivity such as glass or PMMA, PC, or epoxy.

The substrate 2 and the adhesive layer 3 are interposed between the electrode pattern 301 and the electrode pattern 304. The signal of the detection output obtained by the electrode pattern 301 corresponds to a combined capacitance in which electrostatic capacitances parasitic on the substrate 2 and the adhesive layer 3 are connected in series. Therefore, the volume of the base material of the adhesive layer 3 with respect to the total volume of the substrate 2 and the adhesive layer 3 is set to 10% or less of the change rate of the synthetic dielectric constant by the adhesive layer 3 and the substrate 2 within the guaranteed operating temperature range. The ratio is made larger than 0 and 40% or less.

In the capacitive touch panel 400, the adhesive layer 3 has a thickness of 0.025 mm, and the substrate 2 has a thickness of 0.1 mm. That is, the ratio of the volume of the base material of the adhesive layer 3 to the total volume of the substrate 2 and the adhesive layer 3 is 20%, and the change in the synthetic dielectric constant by the substrate 2 and the adhesive layer 3 within the guaranteed operating temperature range. The rate is about 4%.

Therefore, it is possible to provide the capacitive touch panel 400 with good contact detection accuracy even when a local rapid temperature change occurs at the contact position of the operation surface of the upper surface 7A of the cover lens 7.

Similar to the second embodiment, the adhesive layer 3 includes the filler 110 made of a material whose relative dielectric constant has a smaller temperature change than the base material of the adhesive layer 3 within the guaranteed operating temperature range. The volume ratio of the constituent material of the adhesive layer 3 to the material may be smaller than that of the first embodiment.

Similarly to the third embodiment, the adhesive layer 3 is formed by interposing a core material made of a material whose relative dielectric constant has a smaller temperature change than the base material of the adhesive layer 3 within the guaranteed operating temperature range. The volume ratio of the constituent material of the adhesive layer 3 to the constituent material may be smaller than that of the first embodiment.

FIG. 6 is a cross-sectional view of another capacitive touch panel 500 according to the fourth embodiment. In FIG. 6, the same components as those of the capacitive touch panels 100 and 400 shown in FIGS. 1A, 1B, and 5 are denoted by the same reference numerals. A capacitive touch panel 500 shown in FIG. 6 includes an electrode pattern 301 of the capacitive touch panel 400 shown in FIG. 5 instead of the electrode pattern 1 of the capacitive touch panel 100 shown in FIGS. 1A and 1B. In the capacitive touch panel 500 shown in FIG. 6, the electrode pattern 4 is disposed on the upper surface 5 </ b> A of the substrate 5 so that the substrate 2, the substrate 5, and the adhesive layer 3 are disposed between the electrode pattern 301 and the electrode pattern 4. Has been.

Specifically, an electrode pattern 301 is provided on the lower surface 2B of the substrate 2. An electrode pattern 4 is provided on the upper surface 5 </ b> A of the substrate 5. The adhesive layer 3 is provided on the upper surface 2 </ b> A of the substrate 2. The lower surface 5B of the substrate 5 is positioned on the upper surface 3A of the adhesive layer 3. The adhesive layer 3 bonds the upper surface 2A of the substrate 2 to the lower surface 5B of the substrate 5. The adhesive layer 6 is provided on the upper surface 5 </ b> A of the substrate 5 so as to cover the electrode pattern 4. The lower surface 7B of the cover lens 7 is positioned on the upper surface 6A of the adhesive layer 6. The adhesive layer 6 adheres the upper surface 5A of the substrate 5 to the lower surface 7B of the cover lens 7. The electrode patterns 301, 4, the substrates 2, 5, the adhesive layers 3, 6 and the cover lens 7 are laminated in a direction D 102 perpendicular to the upper surfaces 2 A, 5 A of the substrates 2, 5.

Even in the capacitive touch panel 500, the volume ratio of the portion 3P in the region Ac of the adhesive layer 3 of the volume of the region Ac between the electrode patterns 301 and 4 is set to be larger than 0 and 40% or less. The same effect as the touch panels 100 and 400 can be obtained.

In the above embodiment, the electrode patterns 4 and 304 and the electrode patterns 1 and 301 are formed of ITO, tin oxide or the like, but silver thin wires or the like are dispersed in a resin such as light-transmitting acrylic. Alternatively, it may be made of a light-transmitting conductive resin such as polythiophene or polyaniline.

In the embodiment, terms indicating directions such as “upper surface” and “lower surface” are relative only depending on the relative positional relationship of the components of the touch panel such as the substrates 2, 5, the adhesive layer 3, and the electrode patterns 1, 4. It does not indicate an absolute direction such as a vertical direction.

The capacitive touch panel according to the present invention has good contact detection accuracy even when a sudden temperature change occurs, and is used for operation of electronic devices such as in-vehicle liquid crystal display devices used for car navigation and car audio. Useful.

1,301 electrode pattern (second electrode pattern)
2 Substrate (second substrate)
3,103,203 Adhesive layer (first adhesive layer)
4,304 Electrode pattern (first electrode pattern)
5 Substrate (first substrate)
6 Adhesive layer (second adhesive layer)
7 Cover lens 100, 200, 300, 400, 500 Capacitive touch panel 110 Filler 210 Core material Ac region

Claims (10)

A first substrate;
A first electrode pattern disposed on the first substrate;
A second substrate;
A second electrode pattern disposed on the second substrate;
A first adhesive layer disposed between the first electrode pattern and the second electrode pattern;
With
In the region between the first electrode pattern and the second electrode pattern, any one of the first substrate and the second substrate and the first adhesive layer are disposed,
The capacitive touch panel in which a ratio of a volume of a portion in the region of the first adhesive layer to a volume of the region between the first electrode pattern and the second electrode pattern is greater than 0 and 40% or less. A cover lens disposed on the viewing side of the first substrate;
A second adhesive layer disposed between the cover lens and the first substrate;
Further comprising
The capacitive touch panel according to claim 1, wherein the second adhesive layer is thicker than the first adhesive layer. The second electrode pattern is provided on the upper surface of the second substrate,
The capacitive touch panel according to claim 1, wherein the first electrode pattern is provided on an upper surface of the first substrate. A cover lens disposed on the upper surface of the second substrate so as to cover the second electrode pattern;
A second adhesive layer disposed between the cover lens and the upper surface of the second substrate;
Further comprising
The capacitive touch panel according to claim 3, wherein the second adhesive layer is thicker than the first adhesive layer. The second electrode pattern is provided on the lower surface of the second substrate,
The capacitive touch panel according to claim 1, wherein the first electrode pattern is provided on a lower surface of the first substrate. A cover lens disposed on the upper surface of the second substrate;
A second adhesive layer disposed between the cover lens and the upper surface of the second substrate;
Further comprising
The capacitive touch panel according to claim 5, wherein the second adhesive layer is thicker than the first adhesive layer. Further comprising a filler mixed in the first adhesive layer,
The capacitive touch panel according to claim 1, wherein the filler is made of a material having a smaller change in relative dielectric constant with respect to temperature than the first adhesive layer. Further comprising a core material provided in the first adhesive layer,
The capacitive touch panel according to claim 1, wherein the core material is made of a material having a smaller change in relative dielectric constant with respect to temperature than the first adhesive layer. The capacitive touch panel according to claim 8, wherein the core material is made of the same material as that of the first substrate or the second substrate. The capacitive touch panel according to claim 1, wherein a ratio of a thickness of the first adhesive layer to a distance between the first electrode pattern and the second electrode pattern is greater than 0 and equal to or less than 40%.

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