Touch panel device

• US 20040032401A1
• Filed: 08/19/2003
• Published: 02/19/2004
• Est. Priority Date: 08/19/2002
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Aritake, Hirokazu, Nakazawa, Fumihiko
• Granted Patent: US 7,489,304 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G02B 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0436 in which generating transducers and detecting transducers are attached to a single acoustic waves transmission substrate
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A substrate made of glass serves both as a substrate for a touch panel and as that for a front light, and has both functions of propagating an ultrasonic wave in order to detect a touched position, and propagating light emitted from a light source to guide the light toward a reflective-type liquid crystal display. In the case where an image on the liquid crystal display is made visible by external light, external light which has been transmitted through the substrate is reflected by the liquid crystal display, and the reflected light is again transmitted through the substrate to be emitted from the front face. In the case where the front light function is used, light which has been introduced into the substrate from the light source is reflected by the liquid crystal display, and the reflected light is transmitted through the substrate to be emitted from the front face.

Claims

1. A touch panel device comprising:

a touch panel for detecting a touched position; and

a lighting device including a light source, a light guiding part on which light is incident from said light source, and a light guiding and emitting part for guiding light propagated through said light guiding part so as to emit the light as planner light to an outside,

wherein the light to be guided to the outside from said light guiding and emitting part is emitted from a side opposite to a side on which the touched position is to be detected.

2. The touch panel device according to claim 1, wherein said touch panel propagates an ultrasonic wave through an optically transparent substrate and senses a change in a propagation state of the ultrasonic wave due to a touch of an object with said substrate so as to detect a position where the object is touched.

3. The touch panel device according to claim 1, wherein

said touch panel senses a change in resistance of a resistance film due to a touch of an object with said resistance film so as to detect a position where the object is touched.

4. The touch panel device according to claim 1, wherein

said light guiding and emitting part is a step-like structure formed on said light guiding part.

5. The touch panel device according to claim 4, wherein

a formation direction of the step-like structure forms an angle of not more than 32.5°

with respect to a normal direction of a face of said light guiding part.

6. The touch panel device according to claim 1, wherein

an optical refractive index of said light guiding and emitting part is not less than an optical refractive index of said light guiding part.

7. The touch panel device according to claim 1, wherein

said light guiding and emitting part is a plurality of protrusions formed on said light guiding part.

8. The touch panel device according to claim 7, wherein

an optical refractive index of said protrusions is not less than an optical refractive index of said light guiding part.

9. The touch panel device according to claim 1, wherein

said light guiding and emitting part is a plurality of grooves formed in said light guiding part.

10. The touch panel device according to claim 9, wherein

a formation direction of said grooves forms an angle of 35°

to 55°

with respect to a normal direction of a face of said light guiding part.

11. The touch panel device according to claim 1, wherein

said light guiding and emitting part is a plurality of prisms formed on said light guiding part.

12. The touch panel device according to claim 2, further comprising an adhesive agent layer for bonding said substrate of said touch panel and said light guiding part of said lighting device together.

13. The touch panel device according to claim 12, wherein,

when optical refractive indices of said substrate, said light guiding part, and said adhesive agent layer are indicated by n1 n2, and n3, respectively, the optical refractive indices n1 n2, and n3 satisfy the following conditions:

n1≈

n3≈

n2.

14. The touch panel device according to claim 1, further comprising an adhesive agent layer for bonding said touch panel and said light guiding part together.

15. The touch panel device according to claim 14, wherein,

when optical refractive indices of said touch panel, said light guiding part, and said adhesive agent layer are indicated by n1, n2, and n3, respectively, the optical refractive indices n1, n2, and n3 satisfy the following conditions:

n1≈

n3≈

n2.

16. A touch panel device in which an ultrasonic wave is propagated through an optically transparent substrate and a change in a propagation state of the ultrasonic wave due to a touch of an object with said substrate is sensed to detect a position where the object is touched, comprising:

a light source for emitting light which is to be incident on said substrate; and

a light guiding and emitting part for guiding the light incident on said substrate from said light source so as to emit the light to an outside.

17. The touch panel device according to claim 16, wherein

said light guiding and emitting part is configured so that the light incident on said substrate from said light source is guided and emitted to the outside from a face of said substrate opposite to a face where the touched position is to be detected.