JP2009169837A - Liquid crystal display with touch panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display with a touch panel, which does not cause rainbow color nonuniformity in display of a liquid crystal panel, having high visibility even when a person operating a touch panel wears polarized sunglasses. <P>SOLUTION: In the liquid crystal display 1 with a touch panel, an angular difference 12 between the angle 10 of an optical axis of 1/4 wavelength retardation plate 2 and the angle 11 of an absorption axis of a polarizing plate of the liquid crystal display 9 is arranged in the range of 45±5°. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid crystal display with a resistive film type touch panel.

  A touch panel formed by facing an upper electrode plate having a transparent conductive film such as an oxide of indium and tin and a lower electrode plate with a predetermined gap therebetween is formed by pressing the upper electrode plate with a fingertip etc. The transparent conductive film of the plate and the lower electrode plate is brought into contact with each other, and the pressed position is detected by electrical connection. Therefore, the upper electrode plate that is directly pressed by a fingertip or the like needs to have some flexibility, and the lower electrode plate needs to have rigidity that can withstand depression. Therefore, the upper electrode plate is composed of a plastic film such as polyethylene terephthalate (PET) with a transparent conductive film formed by a method such as sputtering, and the lower electrode plate is a glass plate with a transparent conductive film formed in a similar manner. It is generally composed of And the liquid crystal display is attached to the surface on the opposite side to the surface which has the transparent conductive film of the lower electrode plate of this touch panel, and the liquid crystal display with a touch panel is comprised.

  In Patent Document 1, a λ / 4 plate and a polarizing plate are stacked on the surface of the upper electrode plate opposite to the surface facing the lower electrode plate, and the surface of the lower electrode plate opposite to the surface facing the upper electrode plate. A touch panel having a liquid crystal panel on a surface opposite to the surface contacting the second retardation plate of the first retardation plate, wherein the first retardation plate and the second retardation plate are laminated An attached liquid crystal panel is disclosed. When a λ / 4 plate and a polarizing plate are combined, a circularly polarizing plate is obtained. This circularly polarizing plate functions as an antireflection filter that efficiently absorbs internal reflection due to incident light from the outside.

  In Patent Document 2, a λ / 4 plate and a linear polarizing plate are laminated on the surface of the upper electrode plate opposite to the surface facing the lower electrode plate, and the surface of the lower electrode plate opposite to the surface facing the upper electrode plate is laminated. Disclosed is a liquid crystal display device with a touch panel, in which a λ / 4 plate is laminated on the surface, and the λ / 4 plate laminated on the lower electrode plate has a liquid crystal display device on the surface opposite to the surface in contact with the lower electrode plate Has been. When a λ / 4 plate and a linear polarizing plate are combined, a circularly polarizing plate is obtained. This circularly polarized plate has a function of preventing reflection of external light incident on the touch panel through the plate.

JP 2002-72214 A JP 2005-346046 A

  The liquid crystal panel with a touch panel of Patent Document 1 has a circularly polarizing plate on the upper electrode plate, but the light transmitted to the outside of the touch panel through the circularly polarizing plate is combined with the first polarizing plate and the second polarizing plate. As a result, it is in a linearly polarized state. When the electrode plate is made of an optically isotropic material such as glass, the polarized display light emitted from the liquid crystal panel is not distorted, and rainbow-colored unevenness does not occur. Depending on the polarization angle of the polarized sunglasses with respect to the polarization angle, that is, the viewing angle of the operator, the screen becomes so dark that the liquid crystal panel cannot be seen (crossed Nicols state), and visibility may be hindered.

  The liquid crystal display device with a touch panel of Patent Document 2 also has a circularly polarized plate on the upper electrode plate, but the light transmitted to the outside of the touch panel through the circularly polarizing plate is combined with λ / 4 on the lower electrode plate, It is in a linearly polarized state. If the electrode plate is made of an optically isotropic material such as glass, the polarized display light emitted from the liquid crystal panel will not be distorted and rainbow-colored unevenness will not occur. Depending on the polarization angle of the polarized sunglasses with respect to the polarization angle of the device, that is, the viewing angle of the operator, the screen becomes so dark that the liquid crystal display device cannot be viewed (crossed Nicol state), and visibility may be hindered.

  An object of the present invention is to provide a liquid crystal display with a touch panel with good visibility, in which rainbow-colored unevenness does not occur in the liquid crystal display even when the touch panel is viewed with polarized sunglasses.

  In order to achieve the above object, according to the present invention, a liquid crystal display with a touch panel having the following characteristics is provided.

  In the first aspect of the invention, the quarter-wave retardation plate and the upper electrode plate provided with the transparent conductive film provided on the surface of the quarter-wave retardation plate, the substrate made of an optically isotropic material, and the optical isotropic A lower electrode plate provided with a transparent conductive film provided on the surface of the substrate made of a conductive material, and the upper electrode plate and the lower electrode plate are opposed to and spaced apart from each other so that the respective transparent conductive films can be in conductive contact with each other In a touch panel having a liquid crystal display on the surface opposite to the surface facing the upper electrode plate of the lower electrode plate in a relative arrangement, the optical axis angle of the quarter-wave retardation plate and the polarizing plate absorption of the liquid crystal display The angle difference from the shaft angle is arranged in a range of 45 ± 5 degrees.

  According to a second aspect of the present invention, there is provided a substrate made of an optically isotropic material, an upper electrode plate provided with a transparent conductive film provided on a surface of the substrate made of an optically isotropic material, a substrate made of an optically isotropic material, and an optical member. A lower electrode plate provided with a transparent conductive film provided on the surface of a substrate made of an isotropic material, and the upper electrode plate and the lower electrode plate face each other so that the respective transparent conductive films can be in conductive contact with each other. In a touch panel having a liquid crystal display on a surface opposite to the surface facing the upper electrode plate of the lower electrode plate, which is combined in a spaced apart relative arrangement, the surface opposite to the surface having the transparent conductive film of the upper electrode plate The surface has a 1/4 wavelength phase difference plate, and the angle difference between the optical axis angle of the 1/4 wavelength phase difference plate and the polarizing plate absorption axis angle of the liquid crystal display is arranged in the range of 45 ± 5 degrees. It is characterized by that.

  According to a third aspect of the present invention, there is provided a substrate made of an optically isotropic material, an upper electrode plate provided with a transparent conductive film provided on a surface of the substrate made of an optically isotropic material, and a substrate made of an optically isotropic material and an optical member. A lower electrode plate provided with a transparent conductive film provided on the surface of a substrate made of an isotropic material, and the upper electrode plate and the lower electrode plate face each other so that the respective transparent conductive films can be in conductive contact with each other. In a touch panel having a liquid crystal display on the surface opposite to the surface facing the upper electrode plate of the lower electrode plate, which is combined in a spaced apart relative arrangement, the surface opposite to the surface having the transparent conductive film of the lower electrode plate A 1/4 wavelength phase difference plate is provided between the surface and the liquid crystal display, and the angle difference between the optical axis angle of the 1/4 wavelength phase difference plate and the polarizing plate absorption axis angle of the liquid crystal display is 45 ± 5. This is located in the range of degrees And features.

  In the invention of claim 4, the optically isotropic material of claim 2 or 3 is any one of glass, PC (polycarbonate), PES (polyether sulfone), PSF (polysulfone) and PO (polyolefin). It is characterized by that.

  According to the first aspect of the present invention, the angle difference between the optical axis angle of the quarter-wave retardation plate and the polarizing plate absorption axis angle of the liquid crystal display is disposed in the range of 45 ± 5 degrees. The linearly polarized light emitted from the liquid crystal display is converted into circularly polarized light. When the touch panel is viewed with polarized sunglasses, the occurrence of iridescent unevenness is suppressed, and the liquid crystal display becomes so dark that the screen cannot be seen depending on the viewing angle. Can also be prevented.

  According to invention of Claim 2, it has a 1/4 wavelength phase difference plate in the surface opposite to the surface provided with the transparent conductive film of an upper electrode plate, and the optical axis of a 1/4 wavelength phase difference plate Since the angle difference between the angle and the polarizing plate absorption axis angle of the liquid crystal display is arranged in the range of 45 ± 5 degrees, it is difficult to provide a transparent conductive film on the quarter-wave retardation plate. However, the linearly polarized light emitted from the liquid crystal display is converted to circularly polarized light, and when the touch panel is viewed with polarized sunglasses, the occurrence of iridescent unevenness is suppressed, and the liquid crystal display is such that the screen cannot be seen depending on the viewing angle. Can also be prevented from becoming dark.

  According to invention of Claim 3, it has a 1/4 wavelength phase difference plate between the surface opposite to the surface provided with the transparent conductive film of a lower electrode plate, and a liquid crystal display. Since the angle difference between the optical axis angle of the phase difference plate and the polarizing plate absorption axis angle of the liquid crystal display is arranged in the range of 45 ± 5 degrees, there is no 1/4 wavelength phase difference plate on the operation surface of the touch panel. The 1/4 wavelength phase difference plate is not easily damaged, and linearly polarized light emitted from the liquid crystal display is converted into circularly polarized light, and when the touch panel is viewed with polarized sunglasses, the occurrence of iridescent unevenness is suppressed. In addition, it is possible to prevent the liquid crystal display from becoming so dark that the screen cannot be visually recognized depending on the viewing angle.

  According to the invention described in claim 4, the substrate made of an optically isotropic material is any one of glass, PC (polycarbonate), PES (polyether sulfone), PSF (polysulfone) and PO (polyolefin). Since it is comprised with material, according to the use of a touch panel, material can be selected.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Corresponding components are denoted by common reference symbols throughout the drawings. FIG. 1 shows a liquid crystal display 1 with a touch panel according to a first embodiment of the present invention. FIG. 2 shows an angle difference 12 between the optical axis angle 10 of the quarter-wave retardation plate 2 and the polarizing plate absorption axis angle 11 of the liquid crystal display 9 in the plan view of the liquid crystal display 1 with a touch panel according to the first embodiment. FIG. A liquid crystal display 1 with a touch panel includes a quarter-wave retardation plate 2 and an upper electrode plate 4 having a transparent conductive film 3 provided on the surface of the quarter-wave retardation plate 2 and a substrate made of an optically isotropic material. 5 and a lower electrode plate 6 provided with a transparent conductive film 3 provided on the surface of a substrate 5 made of an optically isotropic material. The upper electrode plate 4 and the lower electrode plate 6 are combined in a relative arrangement in which the transparent conductive films 3 face each other so as to be in conductive contact with each other and are separated by a spacer 7. The liquid crystal display 1 with a touch panel has a liquid crystal display 9 on the surface opposite to the surface facing the upper electrode plate 4 of the lower electrode plate 6. An angle difference 12 between the optical axis angle 10 of the quarter-wave retardation plate 2 and the polarizing plate absorption axis angle 11 of the liquid crystal display is arranged in a range of 45 ± 5 degrees.

  Since the angle difference 12 between the optical axis angle 10 of the ¼ wavelength phase difference plate 2 and the polarizing plate absorption axis angle 11 of the liquid crystal display 9 is disposed in the range of 45 ± 5 degrees, the liquid crystal display 9 emits light. The linearly polarized light is converted into circularly polarized light, and when the liquid crystal display 1 with a touch panel is viewed with polarized sunglasses, the occurrence of iridescent unevenness is suppressed, and the liquid crystal display 9 is so dark that the screen cannot be seen depending on the viewing angle. Can also be prevented.

FIG. 3 shows a touch panel 100 according to the second embodiment of the present invention.
A liquid crystal display 100 with a touch panel includes a substrate 102 made of an optically isotropic material, an upper electrode plate 104 having a transparent conductive film 3 provided on the surface of the substrate 102 made of an optically isotropic material, and an optically isotropic material. And a lower electrode plate 6 provided with a transparent conductive film 3 provided on the surface of the substrate 5 made of an optically isotropic material. The upper electrode plate 104 and the lower electrode plate 6 are combined in a relative arrangement in which the transparent conductive films 3 face each other so as to be in conductive contact with each other and are separated by a spacer 7. The liquid crystal display 100 with a touch panel has a liquid crystal display 9 on the surface of the lower electrode plate 6 opposite to the surface facing the upper electrode plate 104. A ¼ wavelength phase difference plate 13 is provided on the surface of the upper electrode plate 104 opposite to the surface provided with the transparent conductive film 3. The angle difference 12 between the optical axis angle 10 of the quarter-wave retardation plate 13 and the polarizing plate absorption axis angle 11 of the liquid crystal display 9 is arranged in a range of 45 ± 5 degrees (the touch panel 1 in FIG. (Refer to the touch panel 100 by replacing the quarter-wave retardation plate 2 with the quarter-wave retardation plate 13).

  A surface of the upper electrode plate 104 opposite to the surface provided with the transparent conductive film 3 has a quarter-wave retardation plate 13, an optical axis angle of the quarter-wave retardation plate 13, and the liquid crystal display 9. Since the angle difference 12 with respect to the polarizing plate absorption axis angle 11 is in the range of 45 ± 5 degrees, the transparent conductive film 3 is provided on the quarter-wave retardation plate 13 as in the first embodiment. Even when the liquid crystal display 9 is difficult, the linearly polarized light emitted from the liquid crystal display 9 is converted into circularly polarized light. It is also possible to prevent the liquid crystal display 9 from becoming so dark that the screen cannot be visually recognized depending on the viewing angle.

  FIG. 4 shows a liquid crystal display 200 with a touch panel according to a third embodiment of the present invention. A liquid crystal display 200 with a touch panel includes a substrate 102 made of an optically isotropic material, an upper electrode plate 104 having a transparent conductive film 3 provided on the surface of the substrate 102 made of an optically isotropic material, and an optically isotropic material. And a lower electrode plate 6 provided with a transparent conductive film 3 provided on the surface of the substrate 5 made of an optically isotropic material. The upper electrode plate 104 and the lower electrode plate 6 are combined in a relative arrangement in which the transparent conductive films 3 face each other so as to be in conductive contact with each other and are separated by a spacer 7. The liquid crystal display 200 with a touch panel has the liquid crystal display 9 on the surface opposite to the surface facing the upper electrode plate 104 of the lower electrode plate 6. A quarter-wave retardation plate 14 is provided between the surface of the lower electrode plate 104 opposite to the surface opposite to the surface provided with the transparent conductive film 3 and the liquid crystal display 9. An angle difference 12 between the optical axis angle 10 of the plate 14 and the polarizing plate absorption axis angle 11 of the liquid crystal display 9 is arranged in a range of 45 ± 5 degrees (the touch panel 1 in FIG. Replace the four-wavelength phase difference plate 2 with a quarter-wavelength phase difference plate 14 (see, for example).

  Between the surface of the lower electrode plate 6 opposite to the surface provided with the transparent conductive film 3 and the liquid crystal display 9, there is a ¼ wavelength phase difference plate 14, and the optical axis of the ¼ wavelength phase difference plate 14. Since the angle difference 12 between the angle 10 and the polarizing plate absorption axis angle 11 of the liquid crystal display 9 is 45 ± 5 degrees, the ¼ wavelength phase difference plate 14 is not on the operation surface of the touch panel 208 and 1 The 1/4 wavelength retardation plate 14 is not easily damaged, and linearly polarized light emitted from the liquid crystal display is converted into circularly polarized light. When the liquid crystal display 200 with a touch panel is viewed with polarized sunglasses, rainbow-colored unevenness occurs. It is also possible to prevent the liquid crystal display 9 from becoming so dark that the screen cannot be visually recognized depending on the viewing angle.

  The substrates (5, 102) made of the optically isotropic material of the liquid crystal display with touch panel (1, 100, 200) of the first to third embodiments are glass, PC (polycarbonate), PES (polyether sulfone), Since it is composed of any one material of PSF (polysulfone) and PO (polyolefin), the material can be selected according to the use of the touch panel.

It is sectional drawing of the liquid crystal display with a touchscreen by 1st embodiment. It is a figure which shows the angle difference of the optical axis angle of the quarter wavelength phase difference plate in the top view of the liquid crystal display with a touch panel of 1st embodiment, and the polarizing plate absorption axis angle of a liquid crystal display. It is sectional drawing of the liquid crystal display with a touchscreen by 2nd embodiment. It is sectional drawing of the liquid crystal display with a touchscreen by 3rd embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal display with a touch panel 2 1/4 wavelength phase difference plate 3 Transparent electrically conductive film 4 Upper electrode plate 5 The board | substrate which consists of an optically isotropic material 6 Lower electrode plate 7 Spacer 8 Touch panel 9 Liquid crystal display 10 1/4 wavelength phase difference plate Optical axis angle 11 Polarizing plate absorption axis angle of liquid crystal display 12 Angle difference

Claims (4)

A quarter-wave retardation plate, an upper electrode plate provided with a transparent conductive film provided on a surface of the quarter-wave retardation plate, a substrate made of an optical isotropic material, and a substrate made of the optical isotropic material A lower electrode plate having a transparent conductive film provided on the surface thereof, and the upper electrode plate and the lower electrode plate are combined in a relative arrangement in which the transparent conductive films are opposed to and separated from each other, In the liquid crystal display with a touch panel having a liquid crystal display on the surface opposite to the surface facing the upper electrode plate of the lower electrode plate,
A liquid crystal display with a touch panel, characterized in that an angle difference between an optical axis angle of the ¼ wavelength phase difference plate and a polarizing plate absorption axis angle of the liquid crystal display is in a range of 45 ± 5 degrees. . From the substrate made of optical isotropic material and the upper electrode plate provided with a transparent conductive film provided on the surface of the substrate made of optical isotropic material, the substrate made of optical isotropic material, and the optical isotropic material A lower electrode plate provided with a transparent conductive film provided on the surface of the substrate, and the upper electrode plate and the lower electrode plate are opposed to and separated from each other so that the transparent conductive films can be in conductive contact with each other. In a liquid crystal display with a touch panel having a liquid crystal display on the surface opposite to the surface facing the upper electrode plate of the lower electrode plate,
A surface of the upper electrode plate opposite to the surface provided with the transparent conductive film has a ¼ wavelength phase difference plate, the optical axis angle of the ¼ wavelength phase difference plate, and the polarization of the liquid crystal display. A liquid crystal display with a touch panel, characterized in that the angle difference from the plate absorption axis angle is in a range of 45 ± 5 degrees. From the substrate made of optical isotropic material and the upper electrode plate provided with a transparent conductive film provided on the surface of the substrate made of optical isotropic material, the substrate made of optical isotropic material, and the optical isotropic material A lower electrode plate provided with a transparent conductive film provided on the surface of the substrate, and the upper electrode plate and the lower electrode plate are opposed to and separated from each other so that the transparent conductive films can be in conductive contact with each other. In a liquid crystal display with a touch panel having a liquid crystal display on the surface opposite to the surface facing the upper electrode plate of the lower electrode plate,
A ¼ wavelength phase difference plate is provided between the surface of the lower electrode plate opposite to the surface provided with the transparent conductive film and the liquid crystal display, and the optical axis angle of the ¼ wavelength phase difference plate And a polarizing plate absorption axis angle of the liquid crystal display are arranged in a range of 45 ± 5 degrees, a liquid crystal display with a touch panel.   The substrate made of the optically isotropic material is made of any one of glass, polycarbonate resin, polyethersulfone, polysulfone, and polyolefin. A liquid crystal display with a touch panel according to item.

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