(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2010/0123670 A1
`
`
` Philipp (43) Pub. Date: May 20, 2010
`
`US 20100123670A1
`
`(75)
`
`(54) TOUCH SCREEN SENSOR
`.
`.
`Harald Philipp, Hamble (GB)
`Inventor:
`Correspondence Address:
`igg‘gEGMAN’ LUNDBERG & WOESSNER /
`PO. BOX 2938
`
`MINNEAPOLIS’ MN 55402 (US)
`
`(73) Assignee:
`
`.
`(21) Appl. NO"
`.
`(22) File(1‘
`
`firsnel corporation’ San Jose, CA
`(
`)
`
`12/421’696
`.
`,
`Apr 10 2009
`
`Related US. Application Data
`
`(60) Provisional application No. 61/ 1 1 5,032, filed on Nov.
`15, 2008.
`
`Publication Classification
`
`(
`
`51
`
`Int. Cl.
`(2006.01)
`) G06F 3/041
`888288
`2%}; é/ggzo
`(52) US. Cl. .............................. 345/173; 702/82; 29/832
`(57)
`ABSTRACT
`
`A two-dimensional touch sensor comprising a plurality of
`electrodes arranged in a mesh pattern on a substrate. Each
`electrode is formed by interconnected metal traces, the metal
`being intrinsically opaque, but the metal traces being sufli-
`ciently narrow to be practically invisible. The metal traces
`have a width less than or equal to 10 um and occupy less than
`or equal to 5% of the area of each electrode. The electrodes
`can be deposited additively Via a printing process,
`for
`example using copper as the metal. The narrow width of the
`tracks allows the film to be highly transparent, since the
`electric field used in capacitive touch screens can be made to
`propagate with very low metal densities.
`
`
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`PETITIONERS
`
`Exhibit 1010, Page 1
`
`PETITIONERS
`Exhibit 1010, Page 1
`
`

`

`Patent Application Publication May 20, 2010 Sheet 1 0f 7
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`US 2010/0123670 A1
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`Exhibit 1010, Page 2
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`

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`Patent Application Publication May 20, 2010 Sheet 2 0f 7
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`Exhibit 1010, Page 3
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`

`

`Patent Application Publication May 20, 2010 Sheet 3 0f 7
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`US 2010/0123670 A1
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`Exhibit 1010, Page 4
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`PETITIONERS
`Exhibit 1010, Page 4
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`

`

`Patent Application Publication May 20, 2010 Sheet 4 0f 7
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`US 2010/0123670 A1
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`Patent Application Publication May 20, 2010 Sheet 5 0f 7
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`PETITIONERS
`Exhibit 1010, Page 6
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`

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`Patent Application Publication May 20, 2010 Sheet 6 0f 7
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`US 2010/0123670 A1
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`Exhibit 1010, Page 7
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`

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`Patent Application Publication May 20, 2010 Sheet 7 0f 7
`
`US 2010/0123670 A1
`
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`PETITIONERS
`Exhibit 1010, Page 8
`
`

`

`US 2010/0123670 A1
`
`May 20, 2010
`
`TOUCH SCREEN SENSOR
`
`BACKGROUND OF THE INVENTION
`
`[0001] The present invention relates to the manufacture and
`application of capacitive touch screen electrode layers by the
`use of single layer fine-line metal mesh electrodes printed
`onto a substrate. The method includes a simple way to self-
`test the electrodes from a connector so as to avoid the need for
`
`more elaborate test methodologies.
`[0002] Most touch screens today, capacitive or otherwise,
`use a sputtered layer of Indium Tin Oxide (ITO) deposited
`onto a thin plastics film (such as PET film) or directly onto a
`glass layer. The ITO is uniformly deposited then etched using
`a subtractive process which involves numerous process steps.
`Finally, layers of silver ink and dielectric are used to make
`connections to the ITO on film or glass, which adds yet more
`process steps.
`[0003]
`ITO films are clear to about 92% (single layer), but
`have a relatively high resistance and are known to be quite
`fragile. A relatively high percentage of films become dam-
`aged during production, requiring an expensive and time-
`consuming test stage. Also, ITO films are expensive and there
`are only a few suppliers who can competently manufacture
`such films, causing logistical problems for users of these
`films. Finally, Indium is a scarce metal which is increasingly
`in demand, yet production of this metal is limited by the few
`mines which produce it.
`[0004] Other materials can replace these films, such as poly
`(3,4-ethylenedioxythiophene) or PEDOT conductive poly-
`mer. However PEDOT is not as optically clear as ITO, is
`difficult to deposit uniformly, and degrades rapidly under
`adverse environmental conditions.
`
`[0005] Therefore there is a need for a new material and/or
`method for producing touch screens which overcomes the
`above limitations.
`
`SUMMARY OF THE INVENTION
`
`[0006] The invention provides an improved touch sensor
`comprising a substrate with a sensitive area defined by a
`pattern of conductive electrodes arranged in a mesh pattern.
`[0007] The invention, in its most inexpensive form, com-
`prises the use of fine-line printed metal deposited additively
`via a printing process onto a PET layer. It is now possible to
`inexpensively print metal traces that are highly conductive
`using copper, which are 10 um wide or less. The narrow width
`of these tracks allows the film to be highly transparent, since
`the electric field used in capacitive touch screens can be made
`to propagate with very low metal densities. In tests, it has been
`found that fine line electrodes comprising less than 5% metal
`coverage of the total screen area, are nearly as effective in
`propagating fields as the solid surfaces they replace. In addi-
`tion to copper, other metals or alloys thereof with high elec-
`trical conductivity may also be used, for example silver or
`gold.
`[0008] As a result, a mesh offine metal lines ofabout 10 um
`width can be applied to a substrate such as PET film, which is
`98% clear, better than ITO. The metal lines are so narrow as
`to be optically invisible. Also, the mesh configuration allows
`for robust performance, since a break in the metal is ‘cured’
`by alternate paths around the defect. Furthermore, copper is
`malleable unlike ITO and can be readily flexed or kinked
`
`without damage. Unlike PEDOT, fine line copper has no
`problems with environmental deterioration under normal
`conditions of anticipated use.
`[0009] The method applies to single-layer and two-layer
`film designs, the latter being commonly employed for higher
`resolution and for multi-touch sensing applications. Any
`number of pattern designs can be used.
`[0010]
`Self-test is also optionally incorporated by the use of
`loop-back testing built into a film as will be described here-
`inafter.
`
`[0011] One aspect of the invention provides a two-dimen-
`sional
`touch sensor comprising a plurality of electrodes
`arranged in a pattern on a substrate, each electrode being
`formed of an interconnected mesh of metal traces, the metal
`being intrinsically opaque, but the metal traces being suffi-
`ciently narrow to be practically invisible.
`[0012] The metal traces preferably have a width less than or
`equal to 10 um, or alternatively less than or equal to 50 um, 40
`um, 30 um, 20 um or 5 pm.
`[0013] The metal traces preferably occupy less than or
`equal to 5% ofthe area of each electrode, or alternatively less
`than or equal to 10%, 8%, 6%, 4%, 2% or 1% of the area of
`each electrode.
`
`In some embodiments, the electrodes are arranged
`[0014]
`in a single layer. In other embodiments, the electrodes are
`arranged in two layers, the two layers being separated by a
`dielectric.
`
`[0015] Adjacent electrodes may be spaced apart by a plu-
`rality of islands also made of interconnected metal traces, the
`metal traces of the islands being visually and electrically
`similar to the metal traces of the electrodes. These islands
`
`in-fill between electrodes to provide visual continuity.
`[0016]
`To provide a self-test capability, each electrode is
`preferably subdivided into upper and lower parts, in that the
`metal traces from the upper and lower parts are connected
`only at a distal end ofthe electrode, there being no connection
`between metal traces in the upper and lower parts from the
`distal end to first and second proximal ends of the electrode.
`First and second electrical connections for each electrode are
`
`connected to respective first and second proximal ends
`thereof. If the electrode pattern is rotated through an angle of
`90 degrees the upper and lower parts of each electrode may be
`referred to as the left and right parts respectively.
`[0017]
`In some embodiments, there are a plurality of X
`electrodes spaced apart by a plurality of Y electrodes. The
`second proximal end of each X electrode is electrically con-
`nected to the first proximal end ofthe adjacent X electrode via
`a resistive element. The second proximal end of eachY elec-
`trode is electrically connected to the first proximal end of the
`adjacent Y electrode.
`[0018] Another aspect of the invention provides a method
`of manufacturing a capacitive touch sensor, the method com-
`prising the steps of: providing a substrate; and depositing a
`plurality of electrodes on at least one side of the substrate,
`each electrode being formed of an interconnected mesh of
`metal traces, the metal being intrinsically opaque, but the
`metal traces being sufficiently narrow and of low visual den-
`sity so as to be practically invisible.
`[0019] Each electrode is advantageously subdivided into
`upper and lower parts, in that the metal traces from the upper
`and lower parts are connected only at a distal end of the
`electrode, there being no connection between metal traces in
`the upper and lower parts from the distal end to first and
`PETITIONERS
`
`Exhibit 1010, Page 9
`
`PETITIONERS
`Exhibit 1010, Page 9
`
`

`

`US 2010/0123670 A1
`
`May 20, 2010
`
`second proximal ends of the electrode. The upper and lower
`parts of each electrode may also be referred to as left and right
`parts respectively.
`[0020] The invention in another aspect covers a method of
`testing a capacitive touch sensor manufactured as above,
`comprising: applying a first voltage to the first proximal end
`of one of the plurality of electrodes while connecting the
`proximal ends ofall other electrodes to ground and measuring
`a second voltage at the second proximal end of the one elec-
`trode; repeating the previous step for all other electrodes; and
`failing the sensor if the second voltage is anomalously low
`compared to the first voltage for any of the electrodes, and
`passing the sensor otherwise. This provides self-test by the
`use of loop-back testing around the loop formed by each
`‘split’ electrode.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`For a better understanding of the invention and to
`[0021]
`show how the same may be carried into effect reference is
`now made by way of example to the accompanying drawings.
`[0022]
`FIG. 1A shows a single-layer design according to an
`embodiment of the invention;
`[0023]
`FIG. 1B shows the same pattern as in FIG. 1A, but
`with shading over the electrodes so as to aid the reader in
`viewing the electrode areas, for purposes of demonstration
`only;
`FIG. 2A shows a metal mesh configuration with
`[0024]
`self-test built in, using the loop-back principle;
`[0025]
`FIG. 2B shows the electrode pattern shown in FIG.
`2A connected to a processor;
`[0026]
`FIG. 2C shows a flow chart for testing continuity of
`the electrode pattern shown in FIG. 2A;
`[0027]
`FIG. 2D shows a flow chart for testing continuity of
`the electrode pattern shown in FIG. 2A;
`[0028]
`FIG. 3A shows a 2-layer diamond pattern (or a
`l-layer pattern with cross-overs) implemented using the
`method, including the use of self-test loop back paths;
`[0029]
`FIG. 3B shows the electrode pattern shown in FIG.
`3A connected to a processor;
`[0030]
`FIG. 4A shows the same pattern as FIG. 2A, but with
`two termination resistors on the Y lines, which offers a
`method to reduce the connection count to the electrodes for
`
`self-test purposes;
`[0031]
`FIG. 4B shows the electrode pattern shown in FIG.
`4A connected to a processor; and
`[0032]
`FIG. 4C shows a flow chart for testing continuity of
`the electrode pattern shown in FIG. 4A.
`
`DETAILED DESCRIPTION
`
`Processes have been recently developed which
`[0033]
`allow the printing of ultra-fine metal traces on plastic films
`and glass, as thin as 10 um or even less. The metals used
`include copper, which is highly conductive and has a darker
`color than other metals, for example chrome. The technology
`has been developed using standard photolithographic pro-
`cesses and can be used to mass produce films on a roll-to-roll
`process for extremely low cost. No expensive, rare, or exotic
`materials are used in the manufacture of these metal traces.
`
`The technology has been developed specifically for use in
`micro-circuit applications, for example RFID tags, smart
`cards, displays, and the like.
`[0034] These fine metal traces can also be used to develop
`field-emitting structures, using a sparse mesh configuration
`
`which has been shown to emit copious amounts of electric
`field, almost the same as a solid electrode shape. A sparse
`mesh allows for high optical clarity; if the traces are 10 pm or
`less, and the mesh covers only 5% of the surface area, the
`optical properties will equal or exceed the best available ITO
`films which can only achieve 93% light transmission. Visu-
`ally the film will only appear to have an extremely light shade
`of gray, imperceptible to the untrained eye. At 10 microme-
`ters, the metal traces are invisible to the naked eye. A uniform
`density or uniform sparse distribution of these traces over the
`surface of a touch screen would not generate a noticeable
`visual pattern.
`[0035] However, it is usually advisable to have a substantial
`gap between the electrodes to allow for proper field propaga-
`tion. These gaps can create a visual effect by showing up as
`lighter areas; as a consequence, it is desirable to ‘fill in’ these
`areas with fine lines ofa similar density as the electrode areas.
`The caveat is that these fill areas should be disconnected from
`
`the electrodes and broken up into small islands or made up of
`isolated small metal traces, so that the average density across
`the screen area is visually similar.
`[0036]
`FIG. 1A shows a basic pattern according to the
`invention, with horizontal bars of mesh labeled X which are
`connected together, to form one of the field electrode group-
`ings, and two sets of mesh triangles, one extending from each
`side, labeledY0 and Y1. The bars X and triangles Y0, Y1 are
`solid mesh electrodes 6. Also shown are spacer areas com-
`posed of disconnected mesh 4, having an areal density
`approximating the electrode mesh areas. Where cuts have
`been made in the mesh to isolate each small cell, some metal
`tracking is added to compensate for the metal missing in the
`cuts. The pattern as shown still has visual gap areas which can
`be fixed by the use of more judicious artwork design.
`[0037] Triangles Y0, Y1 and bars X of metallic material 6
`are shown in the figure, together with spacer areas. The spacer
`areas may be unfilled or void of any metal pattern so as to
`allow electric fields to propagate optimally into an overlying
`panel during use. However, the metal mesh, while largely
`transparent, would under certain light conditions cause the
`gap or spacer areas to become more noticeable, even though
`the lines themselves are too fine to be visible.
`
`[0038] Accordingly, the spacer areas may be optionally
`filled with a metal pattern 4 that mimics the metal mesh
`electrode areas, but in such a manner as to provide an elec-
`trical discontinuity with the electrode areas. The spacer areas
`4 contain metal filling that is ‘disconnected’ so that all the
`small metal segments are floating. The metal is shaped so that
`the average density of the spacer areas is approximately the
`same as the electrode areas so that visually the spacer areas
`blend in and cannot be distinguished from the electrodes.
`[0039]
`FIG. 1B shows graphically the electrodes them-
`selves using shading to outline the bars (X’s) and triangles
`(Y’s). The un-shaded areas are the gap filler regions which
`contain disconnected islands of material matched in areal
`
`density to the electrodes so as to provide for visual continuity.
`[0040] Reliability of the electrodes is very important and
`may be compromised by micro-fractures of the electrodes or
`a defective metal printing process. Therefore, it is a preferred
`feature of the invention for electrical pathways of the elec-
`trode array to be tested from end to end. Using fine line
`connections and a split electrode technique,
`this can be
`readily accomplished, as shown in FIG. 2A and discussed
`below. Shown here is the same basic pattern as shown in FIG.
`1A, however electrodes are cut in such a way as to create a ‘U’
`PETITIONERS
`
`Exhibit 1010, Page 10
`
`PETITIONERS
`Exhibit 1010, Page 10
`
`

`

`US 2010/0123670 A1
`
`May 20, 2010
`
`shaped conduction path; the first X bar and first Y triangle in
`this figure have the cuts highlighted (cut lines). Each elec-
`trode also has two connections, one for each endpoint of the
`‘U’. In this way, an electrical current can be passed through
`each electrode shape to determine whether there is continuity
`or not. This is discussed further below.
`
`comparators. Each of the connections Y0a, Y0b, Yla, Y1b,
`Xa and Xb of the processor 10 could be configured as inputs
`or outputs, or both depending on the test strategy that is used.
`[0046] The presence of short and open circuits can be
`detected using the processor 10 with the steps shown in FIGS.
`2C and 2D.
`
`FIG. 2A shows ‘X’ lines, where it is common prac-
`[0041]
`tice to wire several electrodes together for the purpose of
`interpolation of the emitting field. Resistors are used (Rxa,
`Rxb, Rxc) to interconnect these electrodes in order to provide
`a potential gradient. For testing purposes, these resistors can
`be wired with split electrodes in such a way as to be able to test
`all the ‘X’ electrodes in one step with no added external
`connection count. As shown, lines Xa and Xb loop through
`the fourX electrodes using three resistors (Rxa, Rxb, Rxc), so
`that if any one electrode has a failure, the electrical disconti-
`nuity and failure can be detected and the film and/or device
`rejected. FIG. 2A shows a metal mesh configuration with
`self-test built in, using the loop-back principle. In the case of
`‘Y’ lines Y0, Y1, it is typical that these are wired together as
`columns. In the case of FIG. 2A, there are two ‘columns’ of
`triangles, one left, and one right. In order to test the continuity
`of these triangles with a minimum of external connections, it
`is possible to take advantage of the fact that they are typically
`connected to each other anyway during use as a touch screen,
`by wiring the ends of the triangles in series. FIG. 2A shows
`lines Y0a, Y0b, andY1a, Y1b; each pair being connected to
`its respective column using a series of connection of lines 2.
`By measuring continuity between the pair ends (i.e. between
`Y0a, Y0b, anlea, Y1b), all the triangles in a screen can be
`tested at the same time. This arrangement requires but one
`extra connection to the device perY electrode set; in the case
`of FIG. 2A, there are therefore only two more connections to
`be made than normal.
`
`It should also be noted that the arrangement shown
`[0042]
`in FIG. 2A can also be used to determine short circuits
`
`between adjacent ones of the electrodes, for example due to
`inadvertently deposited metal connecting an X electrode to a
`Y electrode. The manner of such testing should be obvious to
`one skilled in the art.
`
`[0043] Using the method described above, the electrodes
`are sliced along their long axis and ‘looped back’ at the distal
`end from the connections, so that the touch screen processor
`can test the integrity ofall the metal mesh electrodes, for short
`circuits as well as open circuits. Only a few added connection
`lines or test points are required to do this.
`[0044]
`FIG. 2B shows the electrode arrangement shown in
`FIG. 2A connected to a processor 10. The processor 10 could
`be a purpose built testing processor or could be the same
`processor that is used to operate the electrode pattern in a
`touch screen for example. A testing processor could be used
`during manufacture to test if the electrode pattern contains
`any short circuits or open circuits that would result in poor or
`no operation of the electrode pattern when used as a part of a
`touch screen. If an open circuit or short circuit is detected
`during manufacture the electrode pattern could be discarded.
`Alternatively, a touch screen processor could test the elec-
`trode pattern during use, for example during start-up. If a
`short circuit or open circuit is detected in the electrode pat-
`tern, the user could be informed.
`[0045] The processor shown in FIG. 2B is shown as a single
`microprocessor, but it will be appreciated that several sepa-
`rate circuits could be combined to form the processor, such as
`drive units, sense units including one or more ADCs and
`
`FIG. 2C shows the steps to test the triangular elec-
`[0047]
`trodesY0. In step 812, the bar electrodes (i.e. connections Xa
`and Xb) and triangular electrodes Y1 (i.e. connections Y1a
`and Y1b) are grounded. In step 814, a voltage is applied or
`connected to connection Y0a. In step 816, the voltage at
`connection Y0b is detected or measured. In step 818, if there
`is no voltage detected or measured at connectionY0b, there is
`either an open circuit in the electrode pattern Y0 or there is a
`closed circuit to the bar electrodes X or the triangular elec-
`trodesY1. That is to say ifthe voltage measured at connection
`Y0b is anomalously low compared to the voltage applied to
`connection Y0a no voltage is measured or detected.
`[0048]
`To test the triangular electrodes Y1 the same steps
`are used as described above except the connections to trian-
`gular electrodes Y0 and Y1 are reversed. First, the bar elec-
`trodes (i.e. connections Xa and Xb) and triangular electrodes
`Y0 (i.e. connectionsY0a andY0b) are grounded or connected
`to a ground connection. A voltage is then applied to Y1a. The
`voltage is then measured at connection Y1b. If there is no
`voltage detected at Ylb, there is either an open circuit in the
`electrode pattern Y1 or there is a closed circuit to the bar
`electrodes X or the triangular electrodes Y0. That is to say if
`the voltage measured at connection Y1b is anomalously low
`compared to the voltage applied to connectionY1a there is no
`voltage measured or detected at connection Y1b.
`[0049]
`FIG. 2D shows the steps to test the bar electrodes X.
`In step S20, the triangular electrodesY0, Y1 (i.e. connections
`Y0a, Y0b, Y1a anleb) are grounded. In step S22, a voltage
`is applied or connected to connection Xa. In step S24, the
`voltage at connection Xb is measured. In step S26, if there is
`no voltage detected at connection Xb, there is either an open
`circuit in the electrode bar pattern X or there is a closed circuit
`to the triangular electrodesY0,Y1. That is to say ifthe voltage
`measured at connection Xb is anomalously low compared to
`the voltage applied to connection Xa no voltage is measured
`or detected at connection Xb.
`
`Furthermore, in order to test the resistors Rxa, Rxb,
`[0050]
`Rxc, a load resistor Rxd may be applied to terminal Xb to
`ground and the voltage across it measured in a final step. Rxd
`serves to produce a voltage that is inversely related to the
`resistance of the other three resistors in accordance with
`Ohm’s law, so that their values can be ascertained to ensure
`they are correct within a predefined tolerance band.
`[0051]
`It will be appreciated in the above, that the voltages
`could be equally applied to connections Xb, Y0b or Y1b
`respectively and the voltage detected at Xa, Y0a and Y1a
`respectively. If the resistors Rxa, Rxb, Rxc are optionally
`tested using the method described above resistor Rxb would
`be connected to terminal Xa to ground.
`[0052]
`FIG. 3A shows a more conventional 2-layer geom-
`etry of electrodes composed of diamond patterns as is well
`known in the art, but formed from an outline of the electrode
`shapes using fine line metal. With this pattern there are ver-
`tical columns 32, 40 and horizontal rows 34, 42 of diamonds
`which are interconnected so as to form an interleaved elec-
`
`trode set in both the x and y axis. Some in—fill is used to
`increase the effective surface area as shown, using inward
`‘spikes’ of metal 38 emanating from each corner. This figure
`PETITIONERS
`
`Exhibit 1010, Page 11
`
`PETITIONERS
`Exhibit 1010, Page 11
`
`

`

`US 2010/0123670 A1
`
`May 20, 2010
`
`shows both layers superimposed, however it should be under-
`stood that there is an insulating layer between the vertical and
`horizontal sets of diamond-shaped electrodes. As with FIG.
`2A, the electrode sets have two connections each and a loop-
`back structure 30 that permits testing for continuity and short
`circuits.
`
`FIG. 3B shows the electrode arrangement shown in
`[0053]
`FIG. 3A connected to a processor 36. The processor 36 is
`similar in structure and operation to the processor shown in
`FIG. 2A.
`
`[0054] The test strategy shown in FIGS. 2C and 2D can be
`applied to the electrode pattern shown in FIG. 3B using the
`processor 36. For example, to test vertical column electrode
`32, the connections (X111, X119, Y0a, Y0b, Y1a andY1b) of
`the other electrodes are connected to ground. A voltage is
`applied or connected to connection X01; and then the voltage
`at connection X0!) is measured. If there is no voltage mea-
`sured at connection Xb, there is either an open circuit in the
`vertical column electrode 32 or there is a short circuit to one
`
`of the other electrodes. That is to say if the voltage measured
`at connection Xb is anomalously low compared to the voltage
`applied to connection Xa no voltage is measured or detected
`at connection Xb.
`
`FIG. 4A shows a method of reducing the required
`[0055]
`number of added external connections required to perform
`the loop-back test on the ‘Y’ lines with regard to the electrode
`pattern of FIG. 2A. Resistors Ryt0 and Ryt1 are added to the
`endpoints of each set on triangles, and connected together to
`form connection Yt. This eliminates one of the Y line end-
`
`wires for each pair ofY triangle sets. The resistors are pref-
`erably of a high value so as not to cause interference with the
`sensing function of the electrodes. For example, the resistors
`can be 100 KS2 or greater.
`[0056]
`FIG. 4B shows the electrode pattern shown in FIG.
`4A connected to processor 40. The processor 40 is similar in
`structure and operation to that described for the processor
`shown in FIG. 2B. However, as described above there is a
`reduced number ofconnections, namely connections Y0!) and
`Y1!) are replaced by a single connection Yt.
`[0057] The testing strategy for testing the bar electrodes is
`similar to that shown in the flow chart in FIG. 2D. For
`
`example, connections Yt, Y0 and Y1 are all connected to
`ground. A voltage is then applied to connection Xa. The
`voltage is then measured at Xb. If there no voltage measured
`at connection Xb, there is either an open circuit in the bar
`electrode pattern or there is a closed circuit to the triangular
`electrodes. That is to say if the voltage measured at connec-
`tion Xb is anomalously low compared to the voltage applied
`to connection Xa no voltage is measured or detected at con-
`nection Xb.
`
`[0058] The test procedure for testing theY lines of FIG. 4A
`involves:
`
`4) ground Y0 while holding the voltage on Yt,
`
`1) ground all X connections, then,
`2) put a voltage on connection Yt, then,
`3) measure the voltage on each of Y0 and Y1,
`
`[0059]
`[0060]
`[0061]
`then,
`[0062]
`then,
`5) measure the output ofY1.
`[0063]
`If in step 3 there is no voltage on either Y0 or Y1,
`[0064]
`there is a fault, either due to a short circuit from aY electrode
`to an X electrode or an open circuit in theY electrode pattern.
`If in step 5 there is no voltage on Y1, there is a short circuit
`
`between Y1 and Y0. The above sequence tests all known
`combinations of possible faults.
`[0065] The steps described above for testing theY lines are
`summarized in Steps $1 to SS in FIG. 4C. It will be appreci-
`ated that after steps 3 or 5 (i.e. S3 or SS) above the electrode
`pattern could be discarded. That is to say if the voltage mea-
`sured on connection Y0 or Y1 in step 3, or Y1 in step 5 is
`anomalously low compared to the voltage applied to connec-
`tion Yt in step 2 or 4, the electrode pattern is considered to
`have failed and could be discarded, otherwise the sensor
`baring the electrode pattern is deemed to have passed.
`[0066] The invention can also be used to make resistive
`screens and electroluminescent (EL) lamps, because the
`metal density is high enough that these applications can still
`function but with enhanced transparency when compared
`with ITO or PEDOT based electrodes.
`
`[0067] Different sensing techniques may be employed with
`the invention to determine changes in capacitance and the
`presence or absence of a user in proximity with the touch
`sensor. For example, the apparatus and methods described in
`US. Pat. No. 6,466,036 and US. Pat. No. 6,452,514 may
`each be employed with the invention and are incorporated
`herein in their entirety.
`
`What is claimed is:
`
`1. A two-dimensional touch sensor comprising a plurality
`of electrodes arranged in a pattern on a substrate, each elec-
`trode being formed ofan interconnected mesh ofmetal traces,
`the metal being intrinsically opaque, but the metal traces
`being sufficiently narrow to be practically invisible.
`2. The two-dimensional sensor of claim 1, wherein the
`metal traces have a width less than or equal to 10 um.
`3. The two-dimensional sensor of claim 1, wherein the
`metal traces occupy less than or equal to 5% of the area of
`each electrode.
`
`4. The two-dimensional sensor of claims 1, wherein the
`electrodes are arranged in a single layer.
`5. The two-dimensional sensor of claims 1, wherein the
`electrodes are arranged in two layers separated by a dielectric.
`6. The two-dimensional touch sensor of claim 1, wherein
`adjacent electrodes are spaced apart by a plurality of islands
`also made of interconnected metal traces, the metal traces of
`the islands being visually and electrically similar to the metal
`traces of the electrodes.
`7. The two-dimensional touch sensor of claim 1, wherein
`each electrode is subdivided into upper and lower parts, in
`that the metal traces from the upper and lower parts are
`connected only at a distal end of the electrode, there being no
`connection between metal traces in the upper and lower parts
`from the distal end to first and second proximal ends of the
`electrode.
`8. The two-dimensional touch sensor of claim 7, further
`comprising first and second electrical connections for each
`electrode connected to respective first and second proximal
`ends thereof.
`
`9. The two-dimensional touch sensor of claim 8, wherein
`the electrodes comprise a plurality of X electrodes spaced
`apart by a plurality ofY electrodes;
`wherein the second proximal end of each X electrode is
`electrically connected to the first proximal end of the
`adjacent X electrode via a resistive element; and
`wherein the second proximal end of each Y electrode is
`electrically connected to the first proximal end of the
`adj acentY electrode.
`
`PETITIONERS
`
`Exhibit 1010, Page 12
`
`PETITIONERS
`Exhibit 1010, Page 12
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`

`

`US 2010/0123670 A1
`
`May 20, 2010
`
`10. A method of manufacturing a capacitive touch sensor,
`the meth