Touch panel for display device integrated with front light unit

• US 20020075245A1
• Filed: 12/18/2001
• Published: 06/20/2002
• Est. Priority Date: 12/20/2000
• Status: Active Grant

• Current Assignee: Minebea Mitsumi, Inc.
• Original Assignee: Minebea Company Limited (MinebeaMitsumi Inc.)
• Inventors: Kawashima, Satoshi, Asakawa, Toshiaki
• Granted Patent: US 6,654,006 B2
• Time in Patent Office: Days
• 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, which has one resistive layer of a pair of resistive layers, that are disposed facing each other across a plurality of insulating dot spacers, being laid on a flat translucent hard plate, is disposed along a display device with said translucent hard plate facing toward a display surface of said display device while a 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 is interposed therebetween, and which is adapted to generate a signal by touching an outer surface of the other resistive layer according to a position touched, wherein said light conductive plate and said translucent hard plate are integrally combined with each other sandwiching elastic spacers.

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.