ARRANGEMENT FOR A TOUCHSCREEN AND RELATED METHOD OF MANUFACTURE

• US 20110199340A1
• Filed: 10/23/2009
• Published: 08/18/2011
• Est. Priority Date: 10/24/2008
• Status: Active Grant

• Current Assignee: TactoTek Oy
• Original Assignee: Teknologian tutkimuskeskus VTT Oy
• Inventors: Aikio, Janne, Keranen, Antti
• Granted Patent: US 9,864,127 B2
• Time in Patent Office: Days
• US Class Current: 345/175
• CPC Class Codes: G02B 6/0021 for housing at least a part of the light source, e.g. by forming holes or recesses
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: G02B 6/0083 Details of electrical connections of light sources to drivers, circuit boards, or the like
• CPC Class Codes: G06F 2203/04109 FTIR in optical digitiser, i.e. touch detection by frustrating the total internal reflection within an optical waveguide due to changes of optical properties or deformation at the touch location
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49146 with encapsulating, e.g., potting, etc.

Abstract

Arrangement for use with a touchscreen, includes a substrate, such as an optically substantially transparent film or a film defining a through hole, the substrate including support electronics, such as printed electronics including a number of printed conductors, for providing power, control and/or communications connection to further electronic components, a number of emitters and detectors arranged on the substrate into contact with the support electronics, for emitting and detecting light, respectively, and a lightguide arranged onto the substrate such that the emitters and detectors, and optionally at least part of the support electronics, are substantially immersed in the lightguide material, the properties of the lightguide including the refractive index of the lightguide material being selected and the emitters and detectors being configured so as to enable, when in use, total internal reflection (TIR)-type propagation of light within the lightguide between the emitters and detectors and recognition of a touch on the basis of a drop in the TIR performance as determined from the detected light. A related method of manufacture is presented.

Claims

1. An arrangement (202, 502) for a touchscreen, comprising:

a substrate (206), such as an optically substantially transparent film, said substrate comprising support electronics (212), such as roll-to-roll processed printed electronics including a number of printed conductors, for providing power, control and/or communications connection to further electronic components (210),

a number of emitters and detectors (210) arranged on said substrate into contact with the support electronics, for emitting and detecting light, respectively, and

a lightguide (208) arranged onto the substrate such that said emitters and detectors, and optionally at least part of said support electronics, are substantially embedded in the lightguide material, the properties of the lightguide including the refractive index of the lightguide material being selected and the emitters and detectors being configured so as to enable, when in use, total internal reflection (TIR)-type propagation of light within the lightguide between the emitters and detectors and recognition of a touch on the basis of a drop in the TIR performance as determined from the detected light.

2. The arrangement of claim 1, wherein the lightguide is over-moulded onto the substrate carrying the electronics (204, 210, 212).

3. The arrangement of claim 1, wherein the substrate includes at least one element selected from the group consisting of:

an optically substantially transparent flex film, and a substrate portion provided with an opening such as a through hole.

4. The arrangement of claim 1, wherein at least a predetermined touch surface (606) of the lightguide has been provided with an additional protective material layer or a layer configured to improve the touch feel.

5. The arrangement of claim 1, wherein the configuration enables recognizing the touch, optionally locating the touch and further optionally determining the touch pressure, from FTIR (frustrated TIR)—

induced drop in the light intensity level and/or distribution as captured by one or more detectors in contrast to a predetermined or adaptively determined basic reception level and/or distribution during a TIR condition.

6. The arrangement of claim 1, wherein the emitters include at least one LED (light emitting diode) or OLED (organic LED).

7. The arrangement of claim 1, wherein the detectors include at least one element selected from the group consisting of:

a photodiode, a phototransistor, and an image sensor.

8. The arrangement of claim 1, wherein the lightguide includes at least one material selected from the group consisting of:

PC (polycarbonate), PA (polyamide, nylon), COC (cyclo olefin copolymer), COP (cyclo olefin polymer), and PMMA (polymethyl methacrylate).

9. The arrangement of claim 1, wherein the substrate includes at least one material selected from the group consisting of:

PET (polyethylene terephthalate), PC (polycarbonate), PEN (polyethylene naphthalate), PI (polyimide), LCP (liquid crystal polymer), PE (polyethylene), and PP (polypropylene).

10. The arrangement of claim 1, comprising a plurality of emitters and detectors configured to sequentially activate and deactivate (604) in groups such that in one group at least one emitter is associated with a plurality of detectors to increase the resolution in locating the touch relative to the surface of the lightguide.

11. An electronic apparatus (501) comprising the arrangement of claim 1 and optionally comprising a display or a touchpad associated with the arrangement, wherein said apparatus further optionally comprises one element selected from the group consisting of:

a mobile terminal, a personal digital assistant, a music player, a multimedia player, a portable computer, a desktop computer, a palmtop computer, a portable radio, and a control device for an industrial application.

12. A method for manufacturing a touchscreen arrangement, said method comprising:

providing a substrate (308), such as an optically substantially transparent film,

arranging support electronics (302, 322, 310), such as printed electronics including a number of printed conductors, on the substrate for providing power, control and/or communications connection to further electronic components,

arranging a number of emitters and detectors (302, 322, 312) on said substrate into contact with the support electronics, for emitting and detecting light, respectively, and

producing a lightguide onto the substrate (304, 314) such that said emitters and detectors, and optionally at least part of the support electronics, are substantially immersed in the lightguide material, the properties of the lightguide including the refractive index of the lightguide material being selected and the emitters and detectors being configured so as to enable, when in use, total internal reflection (TIR) -type propagation of light within the lightguide between the emitters and detectors and recognition of a touch on the basis of a drop in the TIR performance as determined from the detected light.

13. The method of claim 12, wherein the lightguide material is over-moulded onto the substrate carrying said emitters, detectors and support electronics.

14. The method of claim 13, wherein said substrate is utilized as an insert in an injection-moulding process.

15. The method of claim 12, wherein roll-to-roll manufacturing is utilized for producing the substrate or providing the substrate with at least some of the support electronics, emitters, or detectors, or for providing the substrate with the lightguide or some other functional layer.