Touch panel
Technical Field
The present invention relates to a touch panel, and more particularly, to a touch panel with improved circular polarization efficiency by planarization.
Background
In recent years, Touch panels (Touch panels) have been widely applied to various electronic products, such as: global Positioning System (GPS), Personal Digital Assistant (PDA), cellular phone (cellular phone), and Hand-held PC (Hand-held PC) to replace the conventional input devices (e.g., keyboard and mouse). The great change in the design not only improves the human-computer interface affinity of the electronic devices, but also saves more space for installing a display panel with a larger size for the convenience of users to browse data because of omitting the traditional input equipment. In the conventional touch panel, a plurality of transparent photo resists are formed on a single-layer indium tin oxide (SITO) structure to form a plurality of grooves, which causes structural defects and further affects the display effect.
Therefore, the present invention provides a touch panel to solve the above problems.
Disclosure of Invention
The main objective of the present invention is to provide a touch panel, which utilizes a transparent protection layer to fill up the groove of a touch sensing layer, so as to enhance the circular polarization effect.
To achieve the above object, the present invention provides a touch panel, which includes a transparent substrate, a touch sensing layer, a transparent protection layer and a circular polarization layer. For example, the transparent substrate is made of polyethylene terephthalate (PET), inorganic transparent polyimide (CPI), glass, Cyclic Olefin Polymer (COP), polyvinylidene chloride (HPVDF), Cyclic Block Copolymer (CBC) or Polycarbonate (PC), the transparent protective layer is a polymer resin layer or an acrylic coating layer, and the thickness of the transparent protective layer is 3-8 μm. The touch sensing layer is arranged on the transparent substrate, and the top of the touch sensing layer is provided with a plurality of grooves. The transparent protective layer is arranged on the touch sensing layer and fills the groove, and the top surface of the transparent protective layer is a flat surface. The circular polarization layer is arranged on the flat surface of the transparent protection layer.
In an embodiment of the present invention, the circular polarizing layer further includes a quarter-wave plate and a linear polarizing layer, the quarter-wave plate is disposed on the flat surface of the transparent protection layer, and the linear polarizing layer is disposed on the quarter-wave plate. For example, the quarter-wave plate has a thickness of 1-3 microns (μm), and the linearly polarizing layer has a thickness of 1-3 μm.
In an embodiment of the invention, the touch sensing layer further includes a plurality of transparent electrode blocks, a patterned transparent insulating layer and a transparent electrode layer. For example, the transparent electrode block is a metal mesh (metal mesh) of copper or silver or a nano silver wire (AgNWs), the material of the transparent electrode block may be Indium Tin Oxide (ITO), poly (3, 4-ethylenedioxythiophene) (PEDOT) or Carbon Nanotube (CNT), and the material of the patterned transparent insulating layer is a transparent photoresist. The transparent electrode blocks are arranged on the transparent substrate and are separated from each other. The patterned transparent insulating layer is arranged on the transparent electrode blocks and fills gaps among the transparent electrode blocks, and the patterned transparent insulating layer is provided with a plurality of concave holes penetrating through the patterned transparent insulating layer so as to respectively expose the transparent electrode blocks. The transparent electrode layer is arranged on the patterned transparent insulating layer and covers the transparent electrode block through the concave hole, the top surface of the transparent electrode layer in the concave hole is provided with a groove, and the transparent protective layer is arranged on the transparent electrode layer.
In order to provide further understanding and appreciation of the structural features and advantages of the invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which:
drawings
Fig. 1 is a cross-sectional view of a touch panel according to an embodiment of the invention.
Fig. 2 is a cross-sectional structural view of an embodiment of a touch display device according to the present invention.
Reference numerals:
36 transparent substrate 38 touch sensing layer
40 transparent protective layer 41 circular polarizing layer
42 quarter-wave plate 44 linearly polarizing layer
46 groove 48 transparent electrode block
50 patterned transparent insulating layer 52 transparent electrode layer
54 gap 56 pit
58 luminous module 60 optical cement layer
62 optical adhesive layer 64 light shielding layer
66 glass cover plate
Detailed Description
Embodiments of the present invention will be further explained by referring to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings and the description to refer to the same or like parts. In the drawings, the shape and thickness may be exaggerated for simplicity and convenience. It is to be understood that elements not specifically shown in the drawings or described in the specification are of a type well known to those of ordinary skill in the art. Many variations and modifications may be made by one of ordinary skill in the art in light of the teachings of the present invention.
Referring to fig. 1, a touch panel according to the present invention is described. The touch panel includes a transparent substrate 36, a touch sensing layer 38, a transparent protection layer 40 and a circular polarization layer 41. The touch sensing layer 38 may be a multi-point touch sensing layer. For example, the transparent substrate 36 can be selected to have a birefringence (Re) greater than 5, and the Retardation is Re when two beams of polarized light are polarized perpendicularly to each other. The material with birefringence is polyethylene terephthalate (PET) or inorganic transparent polyimide (CPI). In addition, the transparent substrate 36 may also be made of a material without birefringence, i.e., Re is less than 5. The non-birefringent material is glass, Cyclic Olefin Polymer (COP), polyvinylidene chloride (HPVDF), Cyclic Block Copolymer (CBC) or Polycarbonate (PC). The transparent protective layer 40 is a polymer resin layer or an acryl coating layer, and the polymer resin layer can be a positive photoresist or a negative photoresist. The thickness h of the transparent protection layer 40 is 3-8 μm, the transmittance is greater than 80%, the surface tension is greater than 40 dyne (dyne), and the contact angle is less than 40 degrees. The touch sensing layer 38 is disposed on the transparent substrate 36, and the top of the touch sensing layer 38 has a plurality of grooves 46. The transparent protection layer 40 is disposed on the touch sensing layer 38 and fills the groove 46, and the top surface of the transparent protection layer 40 is a flat surface. The circular polarizing layer 41 is disposed on the flat surface of the transparent protection layer 40. The circular polarizing layer 41 further comprises a quarter-wave plate 42 and a linear polarizing layer 44. The thickness of the quarter-wave plate 42 is 1-3 μm, and the quarter-wave plate 42 is formed by coating a spin-active polymer. The thickness of the linear polarizing layer 44 is 1-3 μm, and the linear polarizing layer 44 is a liquid crystal coating to form a grating. The polarizing angle between the quarter-wave plate 42 and the linear polarizing layer 44 is 45 degrees, the polarizing brightness is 80-99.5%, and the transmittance is 33-45%. A quarter-wave plate 42 is provided on the flat surface of the transparent protective layer 40 and a linear polarizing layer 44 is provided on the quarter-wave plate 42. Since the quarter-wave plate 42 and the linear polarization layer 44 are uniform in thickness and are disposed on the flat surface of the transparent protection layer 40, the top surface of the uppermost linear polarization layer 44 is also flat, thereby increasing the circular polarization efficiency.
The touch sensing layer 38 further includes a plurality of transparent electrode blocks 48, a patterned transparent insulating layer 50 and a transparent electrode layer 52. For example, the transparent electrode block 48 may be a metal mesh (metal mesh) of copper or silver or a nano silver wire (AgNWs), or the material of the transparent electrode block 48 may be Indium Tin Oxide (ITO), poly (3, 4-ethylenedioxythiophene) (PEDOT) or a Carbon Nanotube (CNT), and the material of the patterned transparent insulating layer 50 is a transparent photoresist. The transparent electrode blocks 48 are disposed on the transparent substrate 36 and spaced apart from each other. The patterned transparent insulating layer 50 is disposed on the transparent electrode blocks 48 and fills the gaps 54 between the transparent electrode blocks 48, and the patterned transparent insulating layer 50 has a plurality of cavities 56 penetrating through itself to expose the transparent electrode blocks 48 respectively. The transparent electrode layer 52 is disposed on the patterned transparent insulating layer 50 and covers the transparent electrode block 48 through the cavity 56, the top surface of the transparent electrode layer 52 in the cavity 56 has a groove 46, and the transparent passivation layer 40 is disposed on the transparent electrode layer 52.
Referring to fig. 2, the touch display device of the present invention includes, from bottom to top, a light emitting module 58, an optical adhesive layer 60, a transparent substrate 36, a multi-touch sensing layer 38, a transparent protective layer 40, a quarter-wave plate 42, a linear polarization layer 44, an optical adhesive layer 62, a light shielding layer 64, and a glass cover plate 66. Due to the transparent protection layer 40, the touch display device has a good display effect.
In summary, the invention utilizes the transparent protection layer to fill up the groove of the touch sensing layer, so as to improve the circular polarization effect.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, so that equivalent variations and modifications in the shape, structure, characteristics and spirit of the present invention as described in the claims should be included in the claims of the present invention.