Touch panel, display device and method of producing touch panel

• US 7,492,347 B2
• Filed: 02/28/2005
• Issued: 02/17/2009
• Est. Priority Date: 10/13/2000
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Mori, Kahoru, Muramatsu, Masayoshi, Sato, Koji, Idogaki, Takaharu, Ozaki, Masaaki
• Primary Examiner(s): Awad; Amr
• Assistant Examiner(s): Pervan; Michael
• Application Number:
  US11/066,314
• Publication Number:
  US 20050156907A1
• Time in Patent Office: 1,450 Days
• Field of Search: 345173-178, 345/102, 178 1801- 1809, 178/18.11
• US Class Current: 345/102
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: G06F 3/0488 using a touch-screen or digitiser, e.g. input of commands through traced gestures
• CPC Class Codes: G09F 13/04 Signs, boards or panels, illuminated from behind the insignia

Abstract

This invention provides a touch panel having excellent durability in a high-temperature high-moisture environment and a production method thereof. In a touch panel 1 including a pair of transparent glass substrates 1a and 2a each having a transparent electrode 1b, 2b and so arranged as to oppose each other through a seal portion 3, a thickness of the seal portion 3 is set to be not greater than 8 μm (exclusive of 0). In this way, moisture permeating through the seal portion 3 and entering a gap between the pair of transparent glass substrates 1a and 2a can be reduced.

Claims

1. A display device for an automobile comprising:

a liquid crystal display device for emitting display light;

a touch panel ranged on a display light outgoing side of the liquid crystal display device and having a pair of mutually opposing electrode substrates each having a transparent conductive film; and

a light diffusion portion provided on a surface of the liquid crystal display device on the display light outgoing side, wherein

a surface of one of the electrode substrates on a side opposite to the display light outgoing side of the liquid crystal display device of the pair of the electrode substrates of the touch panel and on an incidence side of display light from the liquid crystal display device keeps direct touch with air;

the liquid crystal display device is equipped with a pair of polarization plates for liquid crystal display;

the surface of one of the pair of polarization plates on the display light outgoing side from the liquid crystal display device includes the light diffusion portion comprising a concavo-convex portion;

a reflection prevention plate is arranged on the surface of the other electrode substrate of the touch panel;

the reflection prevention plate comprises a polarization plate and a concavo-convex portion formed on the display light outgoing side of the polarization plate;

a spectral transmission factor of the touch panel inclusive of the polarization plate is within +/—

10%, with the mean value being 100%, within the range of the display light outgoing wavelength from the liquid crystal display;

the touch panel inclusive of the polarization plate permits permeation of the display light within the entire display light outgoing wavelength range; and

when the liquid crystal display device equipped with the touch panel is mounted to an automobile, the reflection factor upon incidence of external light is not higher than 5.0%.

2. The display device according to claim 1 wherein an absorption axis of the polarization plate of the reflection prevention plate is in conformity with an absorption axis of the polarization plate on the display light outgoing side of the liquid crystal display device.

3. A display device according to claim 1 wherein the surfaces of both of the transparent electrodes or the touch panel keeping touch with air have a conoavo-convex portion.

4. A display device according to claim 1, wherein the surface of one of the electrode substrates of the touch panel keeping touch with air has a concavo-convex portion.

5. A display device for an automobile comprising:

a liquid crystal display device including a pair of display device polarization plates; and

a touch panel arranged on a light emitting side of the liquid crystal display device and including a pair of mutually opposing electrode substrates, a surface of one of the electrode substrates being in direct contact with air and being on a side opposite to a display light outgoing side of the liquid crystal display and on a incidence side of display light from the liquid crystal display device, and a touch panel polarization plate bonded to the display light outgoing side of the touch panel, wherein

the touch panel polarization plate and an outgoing light polarization plate from the pair of display device polarization plates, located on the display light outgoing side of the liquid crystal display device, form concavo-convexities as a light diffusion portion,

a spectral transmission factor of the touch panel, inclusive of the polarization plate, is within +/—

10%, with the mean value being 100%, within the range of the display light outgoing wavelength from the liquid crystal display, and

the touch panel inclusive of the polarization plate permits permeation of the display light within the entire display light outgoing wavelength range.

6. The display device according to claim 5 wherein

an absorption axis of the touch panel polarization plate is in conformity with an absorption axis of the outgoing light polarization plate.