Patent Application
20140049516
This invention relates to touch panels, namely to touch panels including an arrangement of sensors which enables spatial locations whereat tactile contacts onto the panels occur to be determined. Moreover, the embodiments described herein concern methods of manufacturing aforesaid touch panels. Furthermore, the present embodiments concern software products recorded on machine-readable data storage media, wherein the software products are executable upon computing hardware associated with aforesaid touch panels for processing measurement signals generated by the panels from which the spatial location whereat tactile contact onto the panels occurs.
Touch screens are well known from contemporary mobile telephones (also known as “cell phones”) and also from portable navigation aids, for example as manufactured by Tom Tom and Garmin. Moreover, touch-screen computer monitors are also known and are manufactured by contemporary companies such as liyama, HP-Compaq, Dell, Acer, Elo and others; such monitors are expected to make devices such as computer mice ultimately redundant as input devices.
Many different approaches to implementing touch panels are known in the technical art. For example, in a published PCT patent application no. WO/2010/122233 (PCT/FI2010/050339, Applicant—Teknologian Tutkimuskeskus VTT), there is described a user input arrangement and related method of manufacture. The arrangement, for example implemented as a touch-screen or touch-pad, comprises a substrate, such as an optically substantially transparent flex film or a multilayer film. The substrate includes support electronic circuits for providing power, control and/or communications connection to further electronic components, a number of emitters and detectors arranged in respect of the substrate into contact with the support electronic circuits, for emitting and detecting light respectively, and a light-guide. The electronic circuits, emitters, detectors and light-guides are provided laminated onto the substrate such that the emitters and detectors are optically coupled to the light-guide. Properties of the light-guide include a refractive index of the light-guide material being selected, and the emitters and detectors being configured, so as to enable, when in use, total internal reflection (TIR) of propagating light to occur within the waveguide between the emitters and the detectors; recognition of touching is determined on a basis of a drop in TIR performance from the light received at the detectors. There is also described a related method of manufacturing the user input arrangement.
In a published PCT patent application no. WO/2010/046539 (PCT/FI2009/050852, Applicant—Valtion Teknillinen Tutkimuskeskus), there is described an arrangement for a touch-screen and a related method of manufacture. The arrangement is intended for use with a touch-screen. The arrangement includes a substrate, for example an optically substantially transparent film or a film defining a through-hole. The substrate comprises support electronic circuits, for example printed electronic circuits including a plurality of printed conductors, for providing power, control and/or communications connection to further electronic components. Moreover, the arrangement includes a plurality of emitters and detectors arranged on the substrate into contact with the support electronic circuits, for emitting and detecting light, respectively. A light-guide is arranged on the substrate, such that the emitters and detectors, and optionally at least a part of the support electronic circuits, are substantially immersed in the light-guide material. Properties of the light-guide material are such that include its refractive index 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 light-guide between the emitters and detectors. Recognition of a touch is determined on a basis of a drop (FTIR) in the TIR performance as determined from the detected light at the detectors. An associated method of manufacture is also described.
The aforementioned touch panels are complex to manufacture which potentially prevents them being widely employed for data input, for example to replace use of known input devices such as computer mice and similar pointing devices.
According to a first aspect of the present invention, there is provided a touch-panel as defined in appended claim 1: there is provided a touch panel including a first planar substrate for receiving tactile contact from one or more objects, wherein the first planar substrate is operable to guide light radiation therein by total internal reflection, wherein electronic circuits are provided to transmit and detect the light radiation guided within the first planar substrate and to detect spatial positions of the tactile contact of the one or more objects by a corresponding disturbance in the light radiation propagating within the first planar substrate, characterized in that the electronic circuits are implemented by way of printed and/or deposited electronic elements onto at least one of: a decorative trim of the touch panel, the first planar substrate, a second planar protective substrate which is operable to provide protection to the electronic circuits.
The invention is of advantage in that the touch panel is simpler and easier to manufacture, and thus potentially of lower cost in manufacture. The touch-panel is manufactured to a higher degree of integration, thereby potentially increasing its reliability and/or decreasing its weight
Optionally, the touch panel is implemented such that the electronic circuits have associated therewith a connector tail for enabling the electronic circuits to be coupled externally.
Optionally, the touch panel is implemented such that the electronic circuits are formed by at least one of: printing, vacuum sputtering, vacuum evaporation, aqueous deposition, electroplating, etching, amorphous semiconductor deposition, organic semiconductor deposition.
Optionally, the touch panel is implemented such that the electronic circuits are disposed substantially at a peripheral region of the first substrate when the touch panel is assembled. More optionally, the touch panel is implemented such that transmitter elements (tx1, tx2) of the electronic circuits are included at a first set of mutually-abutting peripheral edges of the first substrate, and wherein detector elements (rx1, rx2) of the electronic circuits are included at a second set of mutually-abutting peripheral edges of the first substrate. More optionally, the touch panel is implemented such that the transmitter elements and detector elements, for reducing an influence from ambient illumination external to the touch panel, are in operation at least one of: multiplexed, strobed.
Optionally, the touch panel is implemented such that the second planar substrate has a central hole therein.
Optionally, the touch panel is implemented such that the first planar substrate is fabricated from glass, and the second planar substrate is fabricated from a plastics material.
Optionally, the touch panel is implemented such that at least one of the first and second planar substrates have major planar surfaces which are substantially rectangular in form.
Optionally, the touch panel is implemented such that the panel is configured to operate when overlaid onto a pixel graphics screen.
According to a second aspect of the present invention, there is provided a method of manufacturing a touch panel pursuant to the first aspect of the invention, characterized in that the method includes:
It will be appreciated that features of the invention are susceptible to being combined in various combinations without departing from the scope of the invention as defined by the appended claims.
Embodiments of the present invention will now be described, by way of example only, with reference to the following diagrams wherein:
In the accompanying diagrams, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.
In overview, the present embodiments are concerned with touch panels, wherein each touch panel includes first and second planar substrates: these substrates provide two-dimensional major planar surfaces. The first planar substrate is fabricated from a material, for example glass, which is substantially optically transparent and capable of operating as a waveguide to confine light propagation within boundaries defined by major planar surfaces of the first planar substrate; the light propagation is confined by way of total internal reflection (TIR) resulting from the first panel being surrounded by a medium having a significantly lower optical refractive index in comparison to that of the first planar substrate. Moreover, the second planar substrate can be a planar structure that is manufactured to overlay onto at least a peripheral edge region of the first planar substrate. At least one of the first and second planar substrates includes printing electronic circuits thereon which are operable to generate light radiation for propagating within the first substrate as aforementioned, and which are operable to receive light radiation which has propagated within the first substrate, and which are operable to process signals corresponding to the received light. When an object, for example a stylus or a human finger is held in contact with the first substrate, light propagating within the first substrate is disturbed which influences the light propagation as received by the electronic circuits. By printing the electronic circuits, rapid low-cost manufacture of the touch panel is feasible, whilst also providing a compact and reliable touch panel. The electronic circuits beneficially employ devices such as thin-film-transistors (TFT), OLEDs and printed metallic or amorphous semiconductor conductors. Organic electronics and so-called flexible electronics allow benefits of flexibility and cost effective manufacturing and versatile products. Beneficially, the second substrate, when attached to the first substrate, protects the electronic circuits from damage or degradation, for example from degradation due to exposure to ambient air and moisture. Beneficially, the electronic circuits include multiplexers, analogue-to-digital converters, a microcontroller unit, latches, memory buffers and similar necessary for operation of the touch panel.
Referring to
Details of manufacture of the touch screen 10 will now be described with reference to
A method of manufacturing the touch panel 10 illustrated in
STEP 1: preparing the first planar substrate 30 so that its surfaces are clean, and so that its internal material is capable of guiding light as aforementioned by way of total internal reflection;
STEP 2: forming connector tracks onto the first planar substrate 30 for receiving the connector tail 100; such forming is beneficially achieving using printing and/or deposition techniques, for example vacuum deposition techniques such as electrostatic deposition, spraying, sputtering or vacuum evaporation of metal, ambient electrostatic deposition, aqueous deposition, electroplating, or any combinations of such processes;
STEP 3: attaching the connector tail 100 to the connector tracks formed in STEP 2; the connector tail 100 is beneficially implemented as a flex foil, for example as selectively-metalized multilayer Kapton (trade mark) (polyimide) film assembly;
STEP 4: printing and/or depositing the transmitters tx1 , tx2 and detectors rx1 , rx2 onto the first planar substrate 30 in a manner so that they connect to the connector tracks associated with the connector tail 100; such forming is beneficially achieving using printing and/or deposition techniques, for example electrostatic deposition, spraying, vacuum deposition techniques such as sputtering or vacuum evaporation of metal, ambient electrostatic deposition, aqueous deposition, electroplating, or any combinations of such processes; optionally, polysilicon and/or amorphous Silicon is employed when fabricating the transmitters tx1, tx2 and detectors rx1, rx2 onto the first planar substrate 30; and
STEP 5: attaching the second planar protector substrate 20 onto the first planar substrate 30, for example using suitable bonding adhesives, so that components printed, deposited and/or attached in STEPS 2 to 4 are protected to the second planar protector substrate 20.
Referring next to
Referring to
Referring next to
Optionally, major planar surfaces of the first substrate 30 are patterned, for example with periodic grating features whose physical size is of a similar order to a wavelength of the light radiation 310 propagating within the first substrate 30, for example by way of shallow photo-etching or by additive printing processes, to cause the rays of light radiation 310 to propagate preferably in orthogonal general directions within the first substrate 30 by way of total internal reflection (TIR), so that the electronic circuits 220 of the touch panel 10 receive signals from the detectors rx1, rx2 which are more straightforward to decode in respect of determining one or more spatial positions on one or more major surfaces of the substrate whereat tactile contact of an object, for example a given user's finger or pointing stylus, has occurred.
According to an embodiment, the touch panel can be curved as shown in
According to an alternative embodiment, the aforementioned electronic circuits, for example including the transmitters tx1, tx2, the detectors rx1, rx2 and the connector 100, can be formed onto a peripheral decorative trim 200. The peripheral decorative trim and the electronic circuits can be then connected to the second planar protector substrate 20 or to the first planar substrate 30 as a complete assembly.
According to an alternative embodiment, the first substrate 30, the second substrate 20 and the decorative trim 200 are manufactured from a flexible material to enable the resulting touch panel to provide a tactile sensor element present in a curved surface.
Modifications to embodiments of the invention described in the foregoing are possible without departing from the scope of the invention as defined by the accompanying claims. Expressions such as “including”, “comprising”, “incorporating”, “consisting of”, “have”, “is” used to describe and claim the present invention are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural. Numerals included within parentheses in the accompanying claims are intended to assist understanding of the claims and should not be construed in any way to limit subject matter claimed by these claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1214771.6 | Aug 2012 | GB | national |
