WO2019221756A1

WO2019221756A1 - Anti-sparkle layers

Info

Publication number: WO2019221756A1
Application number: PCT/US2018/033486
Authority: WO
Inventors: Kuan-Ting Wu; Hang Yan YUEN; Chi-Hao Chang
Original assignee: Hewlett Packard Development Co LP
Current assignee: Hewlett Packard Development Co LP
Priority date: 2018-05-18
Filing date: 2018-05-18
Publication date: 2019-11-21
Anticipated expiration: 2020-11-18

Abstract

The present subject matter relates to anti-sparkle layers. In an example implementation, an anti-sparkle layer may include an optically clear adhesive (OCA) resin with homogenously dispersed titanium dioxide gel particles.

Description

ANTI-SPARKLE LAYERS

BACKGROUND

[0001] Display units, such as liquid crystal displays (LCDs), plasma displays, and light emitting diode (LED) based displays, may be provided with a touch functionality. Such display units include a display panel and a touch sensor panel attached together by an optically clear adhesive (OCA) As the OCAs are transparent, the OCAs do not affect optical characteristics of the display unit while bonding the touch sensor panel with the display panel.

BRIEF DESCRIPTION OF DRAWINGS

[0002] The following detailed description references the drawings, wherein:

[0003] FIG. 1 illustrates a sectional view of an anti-sparkle film, according to an example;

[0004] FIG. 2 illustrates a sectional view of a display unit implementing an anti-sparkle layer, according to an example;

[000S] Fig. 3 illustrates another sectional view of a display unit implementing anti-sparkle layers, according to an example; and

[0006] Fig. 4 illustrates a sectional view of an electronic device implementing an anti-sparkle layer, according to an example.

DETAILED DESCRIPTION

[0007] The display units may be provided with antiglare surfaces to reduce glare or reflection of ambient light from a surface of the display unit. The antiglare surfaces are generally rough surfaces which scatter incident light, thereby reducing glare. The antiglare surfaces are often provided at a front surface of the display unit. The antiglare surfaces may cause a sparkling effect on an image on the display unit. The sparkling effect is caused by randomized light diffraction leading to non-uniform lighting which results in appearance of small bright spots in an image through the antiglare surface. Thus, the sparkling effect gives a grainy appearance to the image, which may be distracting for the user. [0008] To reduce the sparkling effect, anti-spark!e films are used in the display units. Anti-sparkle OCA films may include a layer of an optical structure, such as a diffraction grating structure. The optical structure facilitates in splitting and diffracting light into several beams that travel in different directions. The optical structure may be sandwiched between two layers of OCA. As a result, an anti-sparkle OCA film is multi-layered, thereby resulting in increase in thickness of the anti-sparkle OCA film. Further, forming a multi-layered anti-sparkle OCA film as described above is a complex and time-consuming process.

[0009] Certain anti-sparkle OCA films include a matrix of an adhesive material, such as an OCA, embedded with admixtures of dense particles. As the dense particles may not be evenly embedded in the matrix of the adhesive material, the anti-sparkle OCA films may not provide uniform distribution of light in the display unit. In addition, the dense particles may reduce a brightness of the display unit.

[0010] The present subject matter describes an anti-sparkle layer for being implemented in a display unit. The anti-sparkle layer includes homogenously dispersed gel particles that facilitate in uniform distribution of light in the display unit as well as maintaining the brightness of the display unit.

[0011] In an example, the display unit includes a display panel having the anti-sparkle layer disposed on the display unit. The anti-sparkle layer includes an optically clear adhesive (OCA) resin mixed with homogenously dispersed titanium dioxide gel particles. The gel particles provide transparency to the anti-sparkle layer, thereby maintaining brightness of the display unit. Further, the display unit includes a glass panel disposed on the anti-sparkle layer. The glass panel may act as a protective cover for the display unit

[0012] in an example, the OCA resin and the titanium dioxide gel particles have different refractive indices. Due to the difference in the refractive indices and homogenous dispersion of the titanium dioxide gel particles in the OCA resin, a uniform lighting is produced in the display unit thereby preventing the undesired sparkling effect. In addition, as the anti-sparkle layer includes a single layer of OCA mixed with titanium dioxide gei pariicies, the anti-spark!e layer of the present subject matter is suitable for thin layer solutions.

[0013] The following detailed description refers to the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the following description to refer to the same or similar parts. While several examples are described in the description, modifications, adaptations, and other implementations are possible. Accordingly, the following detailed description does not limit the disclosed examples. Instead, the proper scope of the disclosed examples may be defined by the appended claims.

[0014] FIG. 1 illustrates a sectional view of an anti-sparkle film 100, according to an example. The anti-sparkle film 100 may be implemented in display units of electronic devices as well as automobiles. Examples of the electronic devices include, but are not limited to, a personal computer, a laptop, a phone, and a television.

[001 S] The anti-sparkle film 100 includes a substrate 102 and an anti-sparkle layer 104 disposed thereon. The anti-sparkle layer 104 may be deposited on the substrate 102 by a roller-coating process in an example, the substrate 102 is of a material from one of polyethylene, polypropylene, polyester, or a combination thereof.

[0016] In an example implementation, the anti-sparkle layer 104 includes an optically clear adhesive (OCA) resin 106 mixed with homogeneously dispersed nanogei particles, such as titanium dioxide gei particles 108. in an example, the OCA resin 106 may be blended with the titanium dioxide gei particles 108 to form the anti-sparkle layer 104. The blending process ensures uniform dispersion of the titanium dioxide gei particles 108 in the OCA resin 106. In an example, the titanium dioxide gei particles 108 are formed by a sol-gel process. The titanium dioxide gei particles 108 are added in the OCA resin 106 in about 0.1 weight percent to about 3 weight percent of the OCA resin 106. Thus, the formation of the anti-sparkle layer 104 as described in the present subject matter does not include complex processes and is cost effective. As the anti-sparkle layer 104 already contains an adhesive, the anti-sparkle layer 104 may be releasab!y attached to the substrate 102. For example, the anti-sparkle layer 104 may be peeled off from the substrate 102 before being used in a display unit.

[0017] Upon blending the titanium dioxide gel particles 108 in the OCA resin 108, the anti-sparkle layer 104 is formed as a single layer. The anti-sparkle layer 104 may have a thickness in a range of about 10 pm to 50 p . Thus, the anti sparkle layer 104 may be implemented in thin film applications.

[0018] In an example, the OCA resin 108 may include a cyclo-olefin polymer (COP), polycarbonate and poly-methyl methacrylate (PMMA), or a combination thereof. Further, examples of the nanogei particles include, but are not limited to, titanium dioxide gel particles 108. The titanium dioxide gel particles 108 are porous in nature and have a porosity percentage greater than about 90 percent. The porous nature facilitates in allowing light to pass though the titanium dioxide gel particles 108. Further, the titanium dioxide gel particles 108 are semi transparent and have a light transmittance value in a range of about 90% to about 95%. Thus, the titanium dioxide gel particles 108 allow light to pass through them thereby maintaining brightness of the display unit. In addition, the titanium dioxide gel particles 108 have a size in a range of about 3 nm to about 15 nm.

[0019] Further, the titanium dioxide gel particles 108 have a gel density in a range of about 0.021 g/cm³ to about 0.025 g/cm³. The gel density indicates that the titanium dioxide gel particles 108 have a low mass per unit volume. Thus, the titanium dioxide gel particles 108 are less dense and are homogenously dispersed in the OCA resin 108.

[0020] in an example, the OCA resin 108 and the titanium dioxide gel particles 108 have different refractive indices. As a result, when a light beam falls on the anti-sparkle layer 104, the incident light beam gets reflected between the OCA resin 106 and the titanium dioxide gel particles 108. Further, as the titanium dioxide gel particles 108 are semi-transparent, the incident light gets partially transmitted and partially reflected after striking the titanium dioxide gel particles 108. The partial transmission of the light maintains brightness in the display unit. [0021] F!G. 2 illustrates a sectional view of a display unit 200 implementing an anti-sparkle layer, such as the anti-sparkle layer 104, according to an example. The anti-sparkle layer 104 is the same as the anti-sparkle layer described through the description of FIG. 1. Examples of the display unit 200 include, but are not limited to, liquid crystal displays (LCDs), plasma displays, and light emitting diode (LED) based displays. The display unit 200 may be implemented in electronic devices as well as in the automotive industry.

[0022] in an example, the display unit 200 includes a display panel 202. Further, the display unit 200 includes an anti-sparkle layer 104 disposed on the display panel 202. in an example implementation, the anti-sparkle layer 104 may be in a form of a sheet. As described with reference to FIG. 1 , the anti-sparkle layer 104 may be disposed on a substrate, such as the substrate 102. To use the anti-sparkle layer 104 in the display unit 200, the anti-sparkle layer 104 is peeled off or separated from a substrate and placed over the display panel 202, such that the anti-sparkle layer 104 overlaps the display panel 202. For example, while assembling the display unit 200, the anti-sparkle layer 104 may be placed on or applied to the display panel 202.

[0023] in an example, the anti-sparkle layer 104 may have a thickness in a range of about 10 pm to 50 pm. In an aspect, the anti-sparkle layer 104 may be in a liquid form. In the liquid form, the anti-sparkie layer 104 may be coated over the display panel 202 to form a film.

[0024] In an example implementation, the anti-sparkie layer 104 includes an optically clear adhesive (OCA) resin 106 mixed with homogeneously dispersed titanium dioxide gel particles 108. The OCA resin 106 may include a cyclo-olefin polymer (COP), polycarbonate and poly-methyl methacrylate (PMMA), or a combination thereof. The titanium dioxide gel particles 108 may have a size in a range of about 3 nm to about 15 nm. Further, the titanium dioxide gel particles 108 may have a gel density in a range of about 0 021 g/cm³ to about 0 025 g/cm³.

[0025] in an aspect, the OCA resin 106 and the titanium dioxide gel particles 108 have different refractive indices. For example, the OCA resin 106 has a refractive index of about 1.46 to about 1.80 and the titanium dioxide gei particles 108 have a refractive index of about 2.49 to about 2.55. Due to the difference in refractive indices, light gets uniformly scattered within the display unit 200, thereby preventing sparkling.

[0026] Further, the display unit 200 includes a glass panel 204 disposed on the anti-sparkle layer 104. In an example, the glass panel 204 may be a protective cover of the display unit 200. As the anti-sparkle layer 104 includes clear or transparent adhesive, the anti-sparkle layer 104 does not hamper optical characteristics of the display unit 200.

[0027] in an example implementation, the display unit 200 may include a touch sensor panel (not shown in FIG. 2) disposed over the anti-sparkle layer 104. Thus, the display unit 200 may include the display panel 202, the anti-sparkle layer 104 disposed over the display panel 202, and the touch sensor panel disposed on the anti-sparkle layer 104.

[0028] FIG. 3 illustrates another sectional view of a display unit 300 implementing multiple anti-sparkle layers 302 and 304, according to an example. The anti-sparkle layers 302 and 304 are same as the anti-sparkle layer described through the description of FIG. 1 Further, the display unit 300 is similar to the display unit 200 described through the description of FIG. 2. The display unit 300 may be implemented in electronic devices as well as in the automotive industry.

[0029] In an example, the display unit 300 includes a display panel, such as the display panel 202. The display panel 202 may be a plasma display panel, an LCD panel, an LED panel, an organic LED (OLED) panel, and so on. The display unit 300 includes a first anti-sparkle layer 302 disposed on the display panel 202. Further, the display unit 300 includes a touch sensor panel 304 disposed on the first anti-sparkle layer 302. The display unit 300 may further include a second anti sparkle layer 308 disposed on the touch sensor panel 304. In addition, the display unit 300 may include a cover lens 308 disposed on the second anti-sparkle layer 306. In an example, the cover lens 308 may be an anti-glare cover lens. [0030] In an example implementation, the first anti-sparkle layer 302 and the second anti-sparkle layer 304 includes an optically clear adhesive (OCA) resin 106 mixed with homogeneously dispersed titanium dioxide gel particles 108. in an example, the titanium dioxide gel particles 108 may be blended with the OCA resin 106 to form the first anti-sparkle layer 302 and the second anti-sparkle layer 304. The titanium dioxide gel particles 108 are porous in nature and have a porosity percentage greater than about 90 percent. In an example, the first and second anti-sparkle layers 302 and 304 may be coated in a liquid state on a surface, such as the display panel 202, the glass panel 204, or the cover lens 306. Alternatively, the anti-sparkle layers 302 and 304 may be fabricated into an anti-sparkle film, such as the anti-sparkle film 100 by applying on a substrate.

[0031] Each of the first and the second anti-sparkle layers 302 and 304 may have a thickness in a range of about 10 pm to 50 pm. Further, the titanium dioxide gel particles 108 may have a gel density in a range of about 0.021 g/cm³ to about 0.025 g/cm³. As a result, when a light beam falls on the anti-sparkle layer 104, the incident light beam gets reflected between the OCA resin 106 and the titanium dioxide gel particles 108. Further, as the titanium dioxide gel particles 108 are semi-transparent and have a light transmittance value in a range of about 90% to about 95%. As a result, the incident light gets partially transmitted and partially reflected after striking the titanium dioxide gel particles 108. The transmission of the light maintains brightness in the display unit 300.

[0032] FIG. 4 illustrates a sectional view of an electronic device 400 implementing an anti-sparkle layer, such as the anti-sparkle layer 104, according to an example. Examples of the electronic device 400 may include, but are not limited to, a personal computer, a laptop, a tablet, and a personal digital assistant (PDA). The electronic device 400 includes a housing 402 for holding and/or at least partially enclosing different components of the electronic device 400. For example, the housing 402 may form an outer casing of the electronic device 400, a frame for holding a display unit 404 of the electronic device 400, a frame for holding keys of the electronic device 400, and so on. [0033] The display unit 404 includes a display panel, such as the display panel 202 Further, the display unit 404 includes the anti-sparkle layer 104 disposed on the display panel 202. The anti-sparkle layer 104 includes an optically clear adhesive (OCA) resin 106 mixed with homogeneously dispersed titanium dioxide gel particles 108 The OCA resin 106 may include a cyclo-olefin polymer (COP), polycarbonate and poly-methyl methacrylate (PMMA), or a combination thereof. The titanium dioxide gel particles 108 may have a size in a range of about 3 nm to about 15 nm.

[0034] in an example implementation, the titanium dioxide gel particles 108 are blended in the OCA resin 106 to form the anti-sparkle layer 104. Other techniques for forming the anti-sparkle layer 104 are contemplated and may include a mixing process or other suitable processes. In an example, the titanium dioxide gel particles 108 are added in the OCA resin 106 in about 0.1 weight percent to about 3 weight percent of the OCA resin 106

[003S] Further, the display unit 404 includes a touch sensor panel 406 disposed on the anti-sparkle layer 104. As the anti-sparkle layer 104 includes clear or transparent adhesive, the anti-sparkle layer 104 does not hamper optical characteristics of the display unit 404.

[0036] Although implementations for anti-sparkle layers, display units, and electronic devices have been described in language specific to methods and/or structural features, it is to be understood that the present subject matter is not limited to the specific methods or features described. Rather, the methods and specific features are disclosed and explained as example implementations for anti-sparkle layers, display units, and electronic devices.

Claims

We claim:

1. A display unit comprising:

a display panel;

an anti-sparkle layer disposed on the display panel, the anti-sparkle layer comprises an optically clear adhesive (OCA) resin with homogenously dispersed titanium dioxide gel particles; and

a glass panel disposed on the anti-sparkle layer.

2 The display unit as claimed in claim 1 , wherein the titanium dioxide gel particles have a gel density in a range of about 0.021 g/cm³ to about 0.025 g/cm³.

3. The display unit as claimed in claim 1 , wherein the OCA resin is selected from a group comprising cyclo-olefin polymer (COP), polycarbonate and poly-methyl methacrylate (PMMA), or a combination thereof

4. The display unit as claimed in claim 1 , wherein the titanium dioxide gel particles have a light transmittance value in a range of about 90% to about 95%.

5. The display unit as claimed in claim 1 , wherein the titanium dioxide gel particles have a size in a range of about 3 nm to about 15 nm.

8. The display unit as claimed in claim 1 , wherein the anti-sparkle layer has a thickness in a range of about 10 p to about 50 pm.

7. An anti-sparkle film comprising:

a substrate; and

an anti-sparkle layer disposed on the substrate, the anti-sparkle layer comprising an optically clear adhesive (OCA) resin with homogenously dispersed titanium dioxide gel particles, wherein the titanium dioxide gel particles have a light transmittance value in a range of about 90% to about 95% and have a size in a range of about 3 nm to about 15 nm.

8. The anti-sparkle film as claimed in claim 7, wherein the substrate is made of polyethylene, polypropylene, polyester, or a combination thereof.

9 The anfi-sparkle film as claimed in claim 7, wherein the titanium dioxide gel particles have a gel density in a range of about 0.021 g/cm³ to about 0.025 g/cm³

10. The anti-sparkle film as claimed in claim 7, wherein the anti-sparkle layer has a thickness in a range of about 10 pm to about 50 pm.

1 1. The anti-sparkle film as claimed in claim 7, wherein amount of titanium dioxide gel particles in the OCA resin is about 0.1 weight percent to about 3 weight percent of the OCA resin.

12. An electronic device comprising:

a housing;

a display unit positioned within the housing, wherein the display unit comprises:

a display panel;

an anti-sparkie layer disposed on the display panel, the anti-sparkle layer comprising an optically clear adhesive (OCA) resin with homogenously dispersed titanium dioxide gel particles; and

a touch sensor pane! disposed on the anti-sparkle layer.

13. The electronic device as claimed in claim 12, wherein the titanium dioxide gei particles have a size in a range of about 3 nm to about 15 nm.

14. The electronic device as claimed in claim 12, wherein the OCA resin comprises a cyclo-olefin polymer (COP), polycarbonate and poly-methyl methacrylate (PMMA), or a combination thereof.

15. The electronic device as claimed in claim 12, wherein the titanium dioxide gei particles in the OCA resin is about 0.1 weight percent to about 3 weight percent of the OCA resin.