Touch panel for display device integrated with front light unit

• US 6,654,006 B2
• Filed: 12/18/2001
• Issued: 11/25/2003
• Est. Priority Date: 12/20/2000
• Status: Expired due to Term

• Current Assignee: Minebea Mitsumi, Inc.
• Original Assignee: Minebea Company Limited (MinebeaMitsumi Inc.)
• Inventors: Kawashima, Satoshi, Asakawa, Toshiaki
• Primary Examiner(s): Mengistu, Amare
• Application Number:
  US10/020,204
• Publication Number:
  US 20020075245A1
• Time in Patent Office: 707 Days
• Field of Search: 345/173, 345/176, 349/63, 349/62, 341/20, 341/22, 428/141, 428/143, 428/149, 178/18.05
• US Class Current: 345/173
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A touch panel for a display device is structured such that one resistive layer of a pair of resistive layers disposed opposing each other across a plurality of insulating dot spacers is laid on a flat hard glass plate which is integrally combined with a light conductive plate of a front light unit sandwiching elastic spacers. The total thickness measuring when a touch panel is attached to a display device, is reduced, and the accuracy of the information on the position, the display quality and the durability are improved.

Claims

1. A touch panel for a display device, comprising:

a pair of resistive layers disposed facing each other across a plurality of insulating dot spacers, a first resistive layer being laid on a flat translucent hard plate, said translucent hard plate facing toward a display surface of said display device; and

a front light unit interposed between said display surface of said display device and said pair of resistive layers, said front light unit comprising a light source and a light conductive plate in which an array of prisms, whose respective ridges are parallel to each other, is formed on a surface opposite to a surface facing said display device so as to guide light emitted from said light source toward said display surface of said display device;

the touch panel being adapted to generate a signal by touching an outer surface of a second resistive layer according to a position touched, wherein

said light conductive plate and said translucent hard plate are integrally combined with each other and sandwich elastic spacers therebetween.

2. A touch panel for a display device according to claim 1, wherein said elastic spacers are constituted by a plurality of elastic dot spacers.

3. A touch panel for a display device according to claim 1, wherein said elastic spacers are constituted by a gel translucent substance having a low refractive index.

4. A touch panel for a display device according to claim 1, wherein said elastic spacers are constituted by a liquid translucent substance having a low refractive index.

5. A touch panel for a display device according to claim 1, wherein said elastic spacers are constituted by a gel translucent substance, and a layer formed of a translucent substance having a low refractive index is disposed in a tight contact with a surface of said array of prisms formed on said light conductive plate.

6. A touch panel for a display device according to claim 1, wherein said elastic spacers are constituted by a liquid translucent substance, and a layer formed of a translucent substance having a low refractive index is disposed in a tight contact with a surface of said array of prisms formed on said light conductive plate.