TWI486674B - A manufacturing method of a protective layer for a display panel, and a protective layer structure - Google Patents

Description

Protective layer manufacturing method and protective layer structure of display panel

The invention relates to a protective layer manufacturing method and a protective layer structure on a display panel, in particular to a transparent protective layer used on a portable electronic device, above the display panel, which can reduce the colored printing layer and adhesion around the protective layer. The method of layer thickness and its structure.

In recent years, portable electronic display devices such as smart phones, notebook computers, tablet computers or other devices with display panels have been required to be lightweight and ultra-thin, and this must further reduce the thickness of the display panel itself. As shown in FIG. 1 , it is a schematic structural diagram of a conventional electronic display panel. A transparent protective layer is disposed above a conventional display panel (which may include an LCD 10 or a Touch Sensor Panel (TSP) 20). 30, such as transparent plastic (PET) or glass (Glass), which is coated with a hard coat layer (Hard Coat, HC layer), which has the characteristics of abrasion resistance, scratch resistance, high light transmittance and surface hardness. Slide your finger or stylus over it.

Around the lower side of the protective layer 30, an electronic circuit for the LCD 10 or the TSP 20 is hidden, and for fear of being seen, a colored layer is printed around the back surface of the protective layer 30 and above the electronic circuit. 31, and a surface difference is generated between the colored layer 31 and the surface of the protective layer 30 having no colored layer inside, so that the optical coating adhesive (Optical Coating Adhesive) is used on the display panel (the LCD 10 and the touch panel 20). When the OCA 40 is adhered to the protective layer 30, the unevenness of the air layer 32 may occur due to the surface drop.

To this end, the OCA adhesive 40, which is much thicker than the printed layer 31, is usually applied to hide the unevenness. Nevertheless, the air layer 32 remains in the surface of the colored layer 30, and the center of the colored layer 30 does not have a collapsed shape at the center of the colored layer, which is unacceptable to the first-class customers who have high taste requirements. Case.

In order to further reduce the thickness of the electronic display device, the protective layer 30, the colored layer 31 and the OCA adhesive 40 must be thinner. The following table is the structural thickness table of the current general display panel:

The above table is usually adhered to the touch panel using OCA, while the OCA adhesive uses a thickness of 75 μm. Although the problem of the air layer is solved, the cost of the OCA is quite high, and the center still has a collapsed condition, and the appearance is It is not beautiful, not to mention that it is more difficult to solve this problem when the market demand is thinner.

Therefore, the inventor of the present invention solves the above-described problem that the thickness of the OCA adhesive cannot be lowered by the surface of the printed layer of the conventional electronic display panel, and when the color layer is printed on the back surface of the protective layer 30 in the assembly process of the display panel, Simultaneous printing of a transparent layer on the back side of the protective layer 30 does not have a colored layer, so that the OCA adhesive requires only a thin layer and does not cause a central collapse.

The main purpose of the present invention is to provide a protective layer manufacturing method and a protective layer structure for a display panel, which are used for reducing the thickness of the colored printing layer and the adhesive layer around the protective layer, thereby reducing manufacturing cost, thereby reducing the thickness of the display panel, and solving the problem. It is known that there is a collapse in the center of the adhesive layer.

The main technical feature of the present invention is to provide a method for manufacturing a protective layer of a display panel, which firstly provides a transparent protective layer having a hard coat layer on its upper surface, and then printing a colored printed layer around the lower surface of the transparent protective layer. Then, a transparent printing layer is printed to cover the transparent protective layer and the exposed surface of the colored printing layer, and is substantially horizontal; finally, an optical coating adhesive layer (OCA) is coated to cover the surface of the transparent printing layer. And adhering the transparent protective layer to the display panel.

The second technical feature of the present invention is to provide a protective layer structure on a display panel, comprising a transparent protective layer having a hard film layer on the upper surface thereof; and a colored printed layer disposed around the lower surface of the transparent protective layer; a transparent printed layer covering the transparent protective layer and the exposed surface of the colored printed layer, substantially horizontal; and an optically coated adhesive layer (OCA) covering the surface of the transparent printed layer to adhere the transparent protective layer to the display On the panel.

The detailed description of the present invention and the accompanying drawings are not to be construed as limiting the invention.

Please refer to FIG. 2A to D, which are schematic diagrams of the process of the protective layer embodiment on the display panel of the present invention. The protective layer manufacturing method of the display panel of the present invention is first provided with a transparent protective layer 50. The upper surface of the transparent protective layer 50 has a hard layer (HC layer) 51. As shown in FIG. 2A, the transparent protective layer 50 can be transparent. The transparent protective layer 50 preferably has a thickness of 50 μm to 125 μm, and the hard coat layer 51 has wear resistance, scratch resistance, high light transmittance and surface hardness. Characteristic, the thickness of the hard coat layer 51 may preferably be 7 μm.

Then, a colored printed layer 52 is printed around the lower surface of the transparent protective layer 50. As shown in FIG. 2B, the color of the colored printed layer 52 may preferably be an opaque color such as black, dark blue, or dark green. The thickness of the colored printed layer 52 may preferably be 5 μm to 20 μm, which is mainly used to cover the electronic circuit of the LCD or the touch panel underneath.

Then, a transparent printed layer 53 is printed to cover the exposed surface of the transparent protective layer 50 and the colored printed layer 52, and is substantially horizontal. As shown in FIG. 2C, the transparent printed layer 53 may optionally use a heat-curable transparent ink or UV. The curable clear ink may have a thickness of preferably 6 μm to 35 μm.

Finally, an optically coated adhesive layer (OCA) 54 is applied to cover the surface of the transparent printed layer 53. As shown in FIG. 2D, the transparent protective layer 50 is adhered to the display panel. The thickness of the optically coated adhesive layer 54 is higher. Good place can be 10μm~15μm.

Referring to FIG. 3, it is a schematic diagram of the first example of the thickness of the protective layer formed by the present invention. The present invention actually uses a thermosetting transparent ink as the screen printing of the transparent printed layer under the conditions of FIG. 3 and Table 1 below.

The thickness of the colored printed layer 52 is defined as (A), the thickness of the transparent printed layer 53 is defined as (B), and the total thickness of the colored printed layer 52 and the optically coated adhesive layer 54 is defined as (C). The total thickness of the transparent printed layer 53 and the optically-coated adhesive layer 54 is defined as (D), the range of the surface difference between the colored printed layer (A) and the transparent printed layer (B), or the adhesion of the colored printed layer. The range of the surface difference between the layer (C) and the adhesive layer (D) of the transparent printed layer satisfies at least the following formula: 0 < ((A) - (B)) / (B) < 0.50 or 0 < ((C) -(D))/(D)<0.30.

The range of surface drop of the test results is: ((A)-(B))/(B)=0.16 ((C)-(D))/(D)=0.1

It conforms to the range of the aforementioned surface drop formula, so that there is no collapse in appearance, and the thickness is reduced by at least 150 μm or more.

Please refer to FIG. 4 , which is a schematic diagram of a second example of the thickness of the protective layer formed by the present invention. The present invention actually uses a thermosetting transparent ink as a screen printing of the transparent printed layer under the conditions of FIG. 4 and Table 2 below.

The range of surface drop of the test results is:

((A)-(B))/(B)=0.33

((C)-(D))/(D)=0.18

It conforms to the range of the aforementioned surface drop formula, so that there is no collapse in appearance, and the thickness is reduced by at least 140 μm or more.

The present invention is capable of providing a design that is quite different from the prior art by the above-mentioned disclosed technology, which can improve the overall use value, and is not found in the publication or public use before the application, and has already met the requirements of the invention patent. , 提出 filed an invention patent application in accordance with the law.

10‧‧‧LCD

20‧‧‧ Trackpad

30‧‧‧Protective layer

31‧‧‧Printing layer

32‧‧‧ air layer

40‧‧‧Adhesive

50‧‧‧Transparent protective layer

51‧‧‧dural layer

52‧‧‧Colored printing layer

53‧‧‧Transparent printed layer

54‧‧‧Optical coated adhesive layer

Figure 1 is a schematic view of the structure of a conventional electronic display panel.

2A to D are schematic diagrams showing the process of the embodiment of the protective layer on the display panel of the present invention.

Figure 3 is a schematic view showing the first example of the thickness of the protective layer formed in the present invention.

Figure 4 is a schematic view showing a second example of the thickness of the protective layer formed in the present invention.

50‧‧‧Transparent protective layer

51‧‧‧dural layer

52‧‧‧Colored printing layer

53‧‧‧Transparent printed layer

54‧‧‧Optical coated adhesive layer

Claims (20)

A method for manufacturing a protective layer of a display panel comprises the steps of: providing a transparent protective layer having a hard coat layer (Hard Coat, HC layer) on the upper surface; and printing a colored printed layer on the lower surface of the transparent protective layer a transparent printing layer covering the transparent protective layer and the exposed surface of the colored printing layer, and substantially horizontal; coating an optically coated adhesive layer (OCA) to cover the surface of the transparent printing layer; And bonding the transparent protective layer to the display panel; wherein the thickness of the colored printed layer is defined as (A), and the thickness of the transparent printed layer is defined as (B), defining the colored printed layer and the optically coated adhesive layer The total thickness is (C), and the total thickness of the transparent printed layer and the optically coated adhesive layer is defined as (D), and the surface difference between (A) and (B) or (C) and (D) is defined. It is necessary to satisfy the following formula: 0 < ((A) - (B)) / (B) < 0.50 or 0 < ((C) - (D)) / (D) < 0.30. The method for manufacturing a protective layer of a display panel according to claim 1, wherein the transparent protective layer is a transparent plastic (PET) or transparent glass. The method for producing a protective layer of a display panel according to claim 1, wherein the hard coat layer has a thickness of 7 μm. The method for manufacturing a protective layer of a display panel according to claim 1, wherein the transparent protective layer has a thickness of 50 μm to 125 μm. The method for manufacturing a protective layer of a display panel according to claim 1, wherein the color of the colored printed layer is black, dark blue, or dark green. Wait for opaque colors. The method for producing a protective layer of a display panel according to claim 1, wherein the colored printed layer has a thickness of 5 μm to 20 μm. The method for manufacturing a protective layer of a display panel according to claim 1, wherein the colored printed layer is used to cover an electronic circuit therebelow. The method for producing a protective layer of a display panel according to claim 1, wherein the transparent printed layer has a thickness of 6 μm to 35 μm. The method for producing a protective layer of a display panel according to claim 1, wherein the transparent printed layer is a thermosetting transparent ink or an ultraviolet curable transparent ink. The method for manufacturing a protective layer of a display panel according to claim 1, wherein the optically-coated adhesive layer has a thickness of 10 μm to 15 μm. A protective layer structure on a display panel includes at least: a transparent protective layer having a hard coat layer (Hard Coat, HC layer) on the upper surface; and a colored printed layer disposed around the lower surface of the transparent protective layer; a transparent printed layer covering the transparent protective layer and the exposed surface of the colored printed layer, substantially horizontal; and an optically coated adhesive layer (OCA) covering the surface of the transparent printed layer to adhere the transparent protective layer to On the display panel, wherein the thickness of the colored printed layer is defined as (A), the thickness of the transparent printed layer is defined as (B), and the total thickness of the colored printed layer and the optically coated adhesive layer is defined as (C) Defining the total thickness of the transparent printed layer and the optically coated adhesive layer to be (D), and the surface difference between (A) and (B) or (C) and (D) It is necessary to satisfy the following formula: 0 < ((A) - (B)) / (B) < 0.50 or 0 < ((C) - (D)) / (D) < 0.30. The protective layer structure of the display panel according to claim 11, wherein the transparent protective layer is a transparent plastic (PET) or transparent glass. The protective layer structure of the display panel according to claim 11, wherein the hard coat layer has a thickness of 7 μm. The protective layer structure of the display panel according to claim 11, wherein the transparent protective layer has a thickness of 50 μm to 125 μm. The protective layer structure of the display panel according to claim 11, wherein the color of the colored printed layer is an opaque color such as black, dark blue, or dark green. The protective layer structure of the display panel according to claim 11, wherein the colored printed layer has a thickness of 5 μm to 20 μm. The protective layer structure of the display panel according to claim 11, wherein the colored printed layer is used to cover the electronic circuit underneath. The protective layer structure of the display panel according to claim 11, wherein the transparent printed layer has a thickness of 6 μm to 35 μm. The protective layer structure of the display panel according to claim 11, wherein the transparent printing layer is a thermosetting type clear ink or an ultraviolet curing type clear ink. The protective layer structure of the display panel according to claim 11, wherein the optically coated adhesive layer has a thickness of 10 μm to 15 μm.