TWM502898U - Low chromatic aberration touch substrate - Google Patents

Description

Low color difference touch substrate

The present invention relates to a substrate, and more particularly to a low color difference touch substrate.

Common touch substrates are mainly divided into resistive, capacitive, infrared, and surface acoustic wave types. In structure, a transparent conductive layer (ITO) is formed on the transparent plate to form a spot. However, as the size of the touch panel increases, it is necessary to lengthen the length of the transparent conductive layer distributed in a pattern so that it can be distributed over a large-sized transparent plate. However, when the length is lengthened, the resistance increases. .

In order to overcome the aforementioned technical obstacles, the most common practice is to increase the thickness of the transparent conductive layer to reduce its electrical resistance. Although this method can solve the problem of resistance, the thickening of the transparent conductive layer may cause serious dispersion phenomenon, resulting in uneven transmittance of the touch panel, making the transparent conductive layer have a clear outline and exhibiting electrical conductivity in appearance. The color difference between the film and the light-transmissive plate affects the appearance quality of the product.

In order to solve the problem of chromatic aberration caused by thickening of the transparent conductive layer, referring to FIG. 1 , the conventional touch substrate includes a transparent plate 91 and a transparent conductive layer 92 spaced apart from each other, and is disposed on the transparent plate 91 and the transparent Film layers 93, 94 between conductive layers 92. The effect of adjusting the optical chromatic aberration is provided by forming the two film layers 93, 94 having different refractive indices from each other. However, the effect of adjusting the optical chromatic aberration of the film layers 93 and 94 is limited. Under the condition that the thickness of the transparent conductive layer is thick to reduce the electric resistance, the existing touch substrate still cannot satisfy the optical transmittance, low chromatic aberration and electrical requirements.

Therefore, the object of the present invention is to provide a low chromaticity touch substrate capable of satisfying optical transmittance, low chromatic aberration and electrical requirements under conditions of a thick transparent conductive layer.

Therefore, the novel low chromaticity touch substrate comprises: a transparent plate, a transparent conductive layer spaced apart from the transparent plate, and an optical adjustment unit disposed between the transparent plate and the transparent conductive layer.

The optical adjustment unit includes a first low refractive index layer disposed on the light transmissive sheet, and at least two high refractive index layers disposed between the first low refractive index layer and the transparent conductive layer and at least two Two low refractive index layers. The high refractive index layers and the second low refractive index layers are staggered from adjacent to the first low refractive index layer. The first low refractive index layer has a first surface contacting the light transmissive sheet and a second surface opposite the first surface and contacting one of the high refractive index layers. The refractive index of the first low refractive index layer is 1.4 to 1.8, the refractive index of each of the second low refractive index layers is 1.3 to 1.6, and the refractive index of each of the high refractive index layers is 1.9 to 2.42.

The effect of the novel is to pass the refractive index of the first low refractive index layer, the high refractive index layer and the second low refractive index layer of the optical adjustment unit. Selecting a specific arrangement order of the layer body, through the layer structure, the low color difference touch substrate can have a lower overall color difference and a higher optical transmittance at a wide viewing angle, and the appearance is closer to a natural color, thereby improving the product. Appearance quality.

1‧‧‧Transparent sheet

2‧‧‧Transparent conductive layer

3‧‧‧Optical adjustment unit

31‧‧‧First low refractive index layer

311‧‧‧ first surface

312‧‧‧ second surface

32, 32'‧‧‧ high refractive index layer

33, 33'‧‧‧ second low refractive index layer

Other features and effects of the present invention will be apparent from the following description of the drawings, wherein: FIG. 1 is a side view of a conventional touch substrate; and FIG. 2 is a view of the novel low color difference touch substrate. A side view of an embodiment.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same reference numerals.

Referring to FIG. 2, an embodiment of the novel low-difference touch substrate includes a light-transmitting sheet 1, a transparent conductive layer 2 spaced apart from the light-transmitting sheet 1, and a transparent conductive layer 1 disposed on the transparent conductive sheet 1 and the transparent conductive layer Optical adjustment unit 3 between layers 2.

The light-transmitting sheet 1 has a refractive index of 1.5 to 1.8 for light having a wavelength of 633 nm. In practice, the material of the transparent plate 1 may be plastic, glass or sapphire.

The transparent conductive layer 2 is disposed on the optical adjustment unit 3 in a patterned manner. The specific planar structure of the pattern is not a modification of the present invention and will not be described in detail herein. The transparent conductive layer 2 has a refractive index of 1.7 to 2.2, a thickness of 50 to 300 nm, and a sheet resistance of 5 to 150 Ω/□. The material of the transparent conductive layer 2 may specifically be indium tin oxide (ITO), aluminum zinc oxide (AZO), indium zinc oxide (IZO), manganese zinc oxide (MZO), gallium-doped zinc oxide (GZO) or gallium-doped aluminum. Zinc oxide (GAZO).

It should be noted that when the thickness of the transparent conductive layer 2 is less than 50 nm, the sheet resistance is greater than 150 Ω/□; when the thickness of the transparent conductive layer 2 is greater than 300 nm, the sheet resistance may be lower than 5 Ω/□, but will result in Manufacturing costs increase. Therefore, the thickness of the transparent conductive layer 2 is preferably 50 to 300 nm, and the sheet resistance is preferably 5 to 150 Ω/□.

The optical adjustment unit 3 includes a first low refractive index layer 31 disposed on the transparent plate 1 and two high refractive index layers disposed between the first low refractive index layer 31 and the transparent conductive layer 2 32, 32' and two second low refractive index layers 33, 33'. In practice, the number of the high refractive index layers 32, 32' and the second low refractive index layers 33, 33' may be two or more, respectively, and is not limited to the example of the embodiment.

The high refractive index layers 32, 32' and the second low refractive index layers 33, 33' are staggered from adjacent to the first low refractive index layer 31, in the present embodiment from adjacent to far away. The specific arrangement order of the first low refractive index layer 31 is the high refractive index layer 32, the second low refractive index layer 33, the high refractive index layer 32' and the second low refractive index layer 33'. The first low refractive index layer 31 has a first surface 311 contacting the light transmissive sheet 1, and a second surface 312 opposite to the first surface 311 and contacting the high refractive index layer 32.

The first low refractive index layer 31 has a refractive index of 1.4 to 1.8 for a light having a wavelength of 633 nm and a thickness of 5 to 40 nm, and the material thereof may specifically be silicon oxynitride (SiO _x N _y ) or cerium oxide ( SiO ₂ ).

Each of the high refractive index layers 32, 32' has a refractive index of 1.9 to 2.42 for a light having a wavelength of 633 nm and a thickness of 5 to 55 nm, and the material thereof may specifically be niobium oxide (Nb ₂ O _X ) or titanium oxide (TiO _X ). ), tantalum nitride (SiN _X ) or zirconia (ZrO _X ).

Each of the second low refractive index layers 33, 33' has a refractive index of 1.3 to 1.6 for a light having a wavelength of 633 nm and a thickness of 10 to 55 nm, and the material thereof may specifically be cerium oxide (SiO ₂ ) or magnesium fluoride (MgF). ₂ ).

The present invention will be further described in the following Experimental Examples 1 to 12 and Comparative Examples 1 to 12, but it should be understood that the Experimental Examples 1 to 12 are for illustrative purposes only and should not be construed as being limit.

The structures of the test articles of Experimental Examples 1 to 12 are shown in Fig. 2 .

The material of the light-transmitting sheet 1 of Experimental Examples 1 to 12 was glass, and had a refractive index of 1.52 and a thickness of 3.2 mm.

The material of the transparent conductive layer 2 of Experimental Examples 1 to 12 was indium tin oxide, and the refractive index was 1.8. The transparent conductive layers 2 of Experimental Examples 1 to 3 and 7 to 9 were formed at a room temperature of about 25 ° C, and the sheet resistance was 25 to 100 Ω / □. The transparent conductive layer 2 of Experimental Examples 4 to 6, 10 to 12 was produced at a high temperature of about 320 ° C, and its sheet resistance was 10 to 40 Ω / □.

The material of the first low refractive index layer 31 of Experimental Examples 1 to 12 was cerium oxide, and the refractive index was 1.46.

The materials of the high refractive index layers 32 and 32' of Experimental Examples 1 to 6 were yttrium oxide and had a refractive index of 2.42; the materials of the high refractive index layers 32 and 32' of Experimental Examples 7 to 12 were tantalum nitride and had a refractive index of 2.0. .

The materials of the second low refractive index layers 33, 33' of Experimental Examples 1 to 12 were cerium oxide and had a refractive index of 1.46.

The thickness and sheet resistance of the transparent conductive layer 2 of Experimental Examples 1 to 12, and the respective thicknesses of the first low refractive index layer 31, the high refractive index layers 32, 32' and the second low refractive index layers 33, 33' are as follows. They are organized in Table 1.

The structures of the test pieces of Comparative Examples 1 to 12 are shown in Fig. 1 .

Comparative Examples 1 to 6 are the control groups of Experimental Examples 1 to 6, respectively, and the difference between the two is that Comparative Examples 1 to 6 form two film layers 93 between the light-transmitting sheet 91 and the transparent conductive layer 92, 94, the material of the film layer 93 is yttrium oxide, the refractive index is 2.42; the material of the film layer 94 is yttrium oxide, and the refractive index is 1.46. .

Comparative Examples 7 to 12 are the control groups of Experimental Examples 7 to 12, respectively, and the difference between the two is that in Comparative Examples 7 to 12, two film layers 93 are formed between the light-transmitting sheet 91 and the transparent conductive layer 92, 94, the material of the film layer 93 is tantalum nitride, the refractive index is 2.0; the material of the film layer 94 is yttrium oxide, and the refractive index is 1.42.

Hereinafter, the thickness and sheet resistance of the transparent conductive layer 92 of Comparative Examples 1 to 12, and the thicknesses of the film layers 93 and 94, are respectively summarized in Table 2.

The sheet resistances described in Tables 1 and 2 were measured using a four-point probe, and the measurement results were approximately ±10 Ω/□.

In the measurement, the color difference value (ΔEab*) was calculated using the standard set by CIE1976.

Referring to Figures 1 and 2, it should be noted that the transparent conductive layer 2, 92 is a graphically distributed arrangement, that is, the transparent conductive layer 2 92 is not a complete and continuous layer. Therefore, the light-transmitting sheet 1, 91 has a portion overlapping the transparent conductive layers 2, 92, and a portion not overlapping the transparent conductive layers 2, 92.

Moreover, since the present invention is to solve the problem that the pattern outline of the transparent conductive layers 2, 92 is conspicuous, the portions where the light-transmitting sheets 1, 91 overlap the transparent conductive layers 2, 92, and the light-transmitting sheet 1, respectively. 91 is measured at a portion that does not overlap the transparent conductive layers 2, 92. By comparing the chromatic aberration of the region where the transparent conductive layers 2, 92 are formed with or without the above, the pattern outline of the transparent conductive layers 2, 92 is known.

In the measurement process, the light intensity of the CIE1976 chromaticity coordinate L*, the red-greenness coordinate value a* and the yellow-blueness coordinate value b* are measured by using the light of the D65 source incident at a 2 degree angle, and the experimental example is compared. The darkness value L ₁ *, the red-greenness coordinate value a ₁ * and the yellow-blueness coordinate value b ₁ *, and no formation were measured in the regions 1 to 12 and Comparative Examples 1 to 12 where the transparent conductive layer 2 was formed. The area of the transparent conductive layer 2 is measured to have a brightness value L ₂ *, a red-green degree coordinate value a ₂ * and a yellow-blueness coordinate value b ₂ *, and the difference between the measured chromaticity values is squared. The total opening number is the color difference ΔEab*. (The formula is as follows:)

Color difference values (ΔEab*) and yellow-blueness coordinate values displayed in Experimental Examples 1 to 12 and Comparative Examples 1 to 12 at different viewing angles (0, 20, 40, 60, and 80 degrees) b*) is organized in Table 3. Among them, the color difference value (△Eab*) is used to check the color difference ability. The closer to 0, the more chromatic aberration is observed; the yellow-blueness coordinate value (b*) is used to check the chromaticity ability. The closer to 0, the optical penetration. rate Preferably, the appearance is closer to the natural color and the image absorbing ability is better.

Referring to Table 3, the comparative examples 1 to 12 are the structures of the conventional touch substrate shown in FIG. 1 , and it is shown that only the two refractive index films are formed between the transparent plate 1 and the transparent conductive layer 2, and the color difference is obtained. The value (△Eab*) is the worst at 7.47, indicating that the chromatic aberration is obvious, and the yellow-blueness coordinate value (b*) is the worst at -8.9, indicating that the optical transmittance is poor and the appearance is not close to the natural color and the opacity effect is poor. Therefore, the appearance quality of the products of Comparative Examples 1 to 12 is poor. In addition, for different perspectives, only in the case of a viewing angle of 80 degrees, Comparative Examples 1 to 12 The color difference value (ΔEab*) can be compressed below 1 and the yellow-blueness coordinate value (b*) is compressed below ±1. The remaining viewing angles have poor image-dipping ability, the appearance is not close to natural color, and the color difference is not good. .

In contrast, the experimental examples 1 to 12 are the structures of the low color difference touch substrate shown in FIG. 2, and the experimental examples 1 to 12 and the comparative examples 1 to 12 are respectively compared, and the experimental example 1 is observed at a viewing angle of 0 to 80 degrees. The color difference value (ΔEab*) of 12 is not more than 2.39 and the absolute value of the yellow-blueness coordinate value (b*) is not more than 5.01.

Compared with Comparative Examples 1 to 12, the color difference values (ΔEab*) and the yellow-blueness coordinate values (b*) of Experimental Examples 1 to 12 were closer to 0 at different viewing angles, respectively. That is, the experimental results show that the optical adjustment unit 3 is formed between the transparent plate 1 and the transparent conductive layer 2, and the first low refractive index layer 31 and the high refractive index layer 32 of the optical adjustment unit 3 are transmitted through the optical adjustment unit 3. The selection of the refractive index of the 32' and the second low refractive index layers 33, 33' and the specific arrangement order of the layer bodies, the above-mentioned layer structure makes the overall color difference and optical transmittance of the experimental examples 1 to 12 at a wide viewing angle. And the ability to eliminate shadows is higher, so that the appearance is closer to the natural color. It can be seen that the appearance quality of the novel low color difference touch substrate is better, so the purpose of the novel can be achieved.

However, the above description is only for the embodiments of the present invention, and the scope of the present invention cannot be limited thereto, that is, the simple equivalent changes and modifications made by the present patent application scope and the contents of the patent specification are still It is within the scope of this new patent.

1‧‧‧Transparent sheet

2‧‧‧Transparent conductive layer

3‧‧‧Optical adjustment unit

31‧‧‧First low refractive index layer

311‧‧‧ first surface

312‧‧‧ second surface

32, 32'‧‧‧ high refractive index layer

33, 33'‧‧‧ second low refractive index layer

Claims (10)

A low color difference touch substrate comprises: a light transmissive plate; a transparent conductive layer spaced apart from the transparent plate; and an optical adjustment unit disposed between the transparent plate and the transparent conductive layer and including a setting a first low refractive index layer of the light transmissive sheet, and at least two high refractive index layers and at least two second low refractive index layers disposed between the first low refractive index layer and the transparent conductive layer; The equal high refractive index layer and the second low refractive index layers are staggered from adjacent to the first low refractive index layer; the first low refractive index layer has a first surface contacting the transparent plate, and a second surface opposite to the first surface and contacting one of the high refractive index layers; the first low refractive index layer has a refractive index of 1.4 to 1.8, and each of the second low refractive index layers has a refractive index of 1.3 to 1.6 Each of the high refractive index layers has a refractive index of 1.9 to 2.42. The low chromaticity touch substrate of claim 1, wherein the first low refractive index layer has a thickness of 5 to 40 nm. The low chromaticity touch substrate of claim 1, wherein the first low refractive index layer is bismuth oxynitride or cerium oxide. The low chromaticity touch substrate of claim 1, wherein each of the high refractive index layers has a thickness of 5 to 55 nm. The low chromaticity touch substrate according to claim 1, wherein each of the high refractive index layers is ruthenium oxide, titanium oxide, tantalum nitride or zirconium oxide. The low color difference touch substrate as claimed in claim 1, wherein each of the second The low refractive index layer has a thickness of 10 to 55 nm. The low chromaticity touch substrate of claim 1, wherein the material of each of the second low refractive index layers is cerium oxide or magnesium fluoride. The low chromaticity touch substrate of claim 1, wherein the transparent conductive layer is made of indium tin oxide, aluminum zinc oxide, indium zinc oxide, manganese manganese oxide, gallium-doped zinc oxide or gallium-doped aluminum zinc oxide. The low chromaticity touch substrate of claim 1, wherein the transparent conductive layer has a thickness of 50 to 300 nm. The low chromaticity touch substrate of claim 1, wherein the transparent conductive layer has a sheet resistance of 5 to 150 Ω/□.