Mesh sensor design for reduced visibility in touch screen devices

An input device having a plurality of low-visibility sensor electrodes and method for fabricating the same are provided. In one embodiment, an input device includes a plurality of sensor electrodes disposed over a display device. A first sensor electrode of the plurality of sensor electrodes includes a conductive mesh having a first periodicity defined by intersections of conductive traces forming the mesh. A terminal portion of one of the conductive traces terminating at an edge of the first sensor electrode has an orientation that is different than an orientation of a corresponding portion of the mesh defining the first periodicity. An end of the terminal portion proximate the edge laying over a subpixel has the same color as a subpixel of the display device which the end would lay over if the end had the same orientation as the corresponding portion of the mesh defining the first periodicity.

FIELD OF INVENTION

Embodiments of the invention generally relate to an input device having a plurality of low-visibility sensor electrodes and method sensing an input object using the same.

BACKGROUND

Some proximity sensor devices proximity sensor devices utilize microscopic wiring patterns made from opaque conductive materials to form conductive sensor elements. When used over a display of the touch screen, these conductive traces or wires can block some of the pixels or sub-pixels in the display. Certain patterns interfere with the display more than others. For example, if the sensor periodicity is close to the display periodicity, a moiré pattern may be visible when the display is illuminated. Because the eye is more sensitive to some pattern sizes than others, the moiré pattern has a different appearance depending on its size. In the size range of typical displays, small features are less visible. Because of this, fabricators have conventionally attempted to minimize the moiré pattern by reducing the size and width of each conductive trace. Cost effective processing precludes making the conductive traces so small that they cannot be seen under any condition, rendering simple size reduction as an ineffective solution.

Therefore, there is a need for an improved an input device having a plurality of low-visibility sensor electrodes for sensing an input object relative to a sensing region of the input device.

SUMMARY OF INVENTION

An input device having a plurality of low-visibility sensor electrodes and method for using the same are provided. In one embodiment, an input device includes a plurality of sensor electrodes disposed over a display device having an array of pixels. Each pixel including at least a first subpixel having a first color and a second subpixel having a second color that is different than the first color. The plurality of sensor electrodes are configured to sense objects in a sensing region of the input device. At least a first sensor electrode of the plurality of sensor electrodes further includes plurality of spaced apart conductive traces forming a conductive mesh having a first periodicity defined by intersections of the conductive traces forming the mesh. A terminal portion of one of the conductive traces terminating at an edge of the first sensor electrode has an orientation that is different than an orientation of a corresponding portion of the mesh defining the first periodicity. An end of the terminal portion of the conductive trace proximate the edge of the first sensor electrode laying over a subpixel has the same color as a subpixel which the end would lay over if the end had the same orientation as the corresponding portion of the mesh defining the first periodicity.

In another embodiment, an input device is provided that includes a display device having an array of pixels and a plurality of sensor electrodes disposed over the display device. The sensor electrodes are configured to sense objects in a sensing region of the input device. The plurality of sensor electrodes further include a first sensor electrode comprising a plurality of spaced apart conductive traces forming a conductive mesh, a second sensor electrode comprising a plurality of spaced apart conductive traces forming a conductive mesh, a first unit area having a visually resolvable plan area defined within the first sensor electrode, and a second unit area having a visually resolvable plan area defined partially within the first sensor electrode and partially within the second sensor electrode. A first blockage area defined within the first unit area is substantially equal to a second blockage area defined within the second unit area.

In yet another embodiment, a method for making a sensor device is provided that includes receiving display information and generating mesh sensor fabrication instructions for creating a trace pattern for a plurality of sensor electrodes, the trace pattern having reduce visibility. For example in one embodiment, the trace pattern may include first unit area having a visually resolvable plan area defined within a first sensor electrode of the plurality of sensor electrodes, and a second unit area having a visually resolvable plan area defined partially within the first sensor electrode and partially within a second sensor electrode of the plurality of sensor electrodes, wherein a first blockage area defined within the first unit area is substantially equal to a second blockage area defined within the second unit area.

In another embodiment, the trace pattern may include a conductive mesh having a first periodicity defined by intersections of the traces forming the mesh, a terminal portion of one of the conductive traces terminating at an edge of the a sensor electrode of the plurality of sensor electrodes, the sensor electrode having an orientation that is different than an orientation of a corresponding portion of the conductive mesh, and wherein an end of a terminal portion of the conductive trace proximate an edge of the sensor electrode laying over a subpixel having the same color as a subpixel which the end would lay over if the end had the same orientation as a corresponding portion of the conductive mesh at an interior of the sensor electrode.

DESCRIPTION OF EMBODIMENTS

The following Description of Embodiments is merely provided by way of example and not of limitation. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. Various embodiments of the present invention provide input devices and methods that facilitate improved usability of a touch screen device.

In various embodiments, an input device is formed from conductive traces (i.e., micro-traces) arranged at an angle and periodicity such that the traces are substantially invisible, thus allowing larger assemblies of small traces to form sensor elements that do not substantially diminish the quality of light transmission through the input device. Advantageously, the low-visibility traces can be utilized to form sensor elements in virtually any arbitrary shape, size or orientation, thereby allowing the design of the sensor elements to focus on device performance instead of trying to minimize disruption of light transmission or other undesirable visual effects.

InFIG. 1, the input device100is shown as a proximity sensor device (also often referred to as a “touchpad” or a “touch sensor device”) and includes a sensor device150having sensing elements configured to sense input provided by one or more input objects140in a sensing region120. Example input objects include fingers and styli, as shown inFIG. 1.

The input device100may utilize any combination of sensor components and sensing technologies to detect user input in the sensing region120. The input device100comprises one or more sensing elements (i.e., sensor electrodes of the sensor device150) for detecting user input. As several non-limiting examples, the input device100may use ultrasonic, capacitive, elastive, resistive, inductive, surface acoustic wave, and/or optical techniques to provide one or more resulting signals which include positive and negative polarities, the one or more resulting signals including effects indicative of the input object relative to the sensing region.

Some implementations are configured to provide images that span one, two, three or higher dimensional spaces. Some implementations are configured to provide projections of input along particular axes or planes.

In some resistive implementations of the input device100, a flexible and conductive first layer is separated by one or more spacer elements from a conductive second layer. During operation, one or more voltage gradients are created across the layers. Pressing the flexible first layer may deflect it sufficiently to create electrical contact between the layers, resulting in voltage outputs reflective of the point(s) of contact between the layers. These voltage outputs may be used to determine positional information.

Some capacitive implementations utilize “mutual capacitance” (or “transcapacitance”) sensing methods based on changes in the capacitive coupling between sensor electrodes. In various embodiments, an input object near the sensor electrodes alters the electric field between the sensor electrodes, thus changing the measured capacitive coupling. In one implementation, a transcapacitive sensing method operates by detecting the capacitive coupling between one or more transmitter sensor electrodes (also “transmitter electrodes” or “transmitters”) and one or more receiver sensor electrodes (also “receiver electrodes” or “receivers”). Transmitter sensor electrodes may be modulated relative to a reference voltage (e.g., system ground) to transmit transmitter signals. Receiver sensor electrodes may be held substantially constant relative to the reference voltage to facilitate receipt of resulting signals. A resulting signal may comprise effect(s) corresponding to one or more transmitter signals, and/or to one or more sources of environmental interference (e.g. other electromagnetic signals). Sensor electrodes may be dedicated transmitters or receivers, or may be configured to both transmit and receive.

InFIG. 1, the processing system (or “processor”)110is shown as a part or subsystem of the input device100. The processing system110is configured to operate the hardware of the input device100to detect input in the sensing region120utilizing resulting signals provided to the processing system110from the sensor device150. The processing system110comprises parts of or all of one or more integrated circuits (ICs) and/or other circuitry components; in some embodiments, the processing system110also comprises electronically-readable instructions, such as firmware code, software code, and/or the like. In some embodiments, components composing the processing system110are located together, such as near sensing element(s) of the input device100. In other embodiments, components of processing system110are physically separate with one or more components close to sensing element(s) of input device100, and one or more components elsewhere. For example, the input device100may be a peripheral coupled to a desktop computer, and the processing system110may comprise software configured to run on a central processing unit of the desktop computer and one or more ICs (perhaps with associated firmware) separate from the central processing unit. As another example, the input device100may be physically integrated in a phone, and the processing system110may comprise circuits and firmware that are part of a main processor of the phone. In some embodiments, the processing system110is dedicated to implementing the input device100. In other embodiments, the processing system110also performs other functions, such as operating display screens, driving haptic actuators, etc.

For example, in some embodiments, the processing system110operates the sensing element(s) of the sensor device150to produce electrical signals indicative of input (or lack of input) in the sensing region120. The processing system110may perform any appropriate amount of processing on the electrical signals in producing the information provided to the electronic system. For example, the processing system110may digitize analog electrical signals obtained from the sensor electrodes of the sensor device150. As another example, the processing system110may perform filtering or other signal conditioning. As yet another example, the processing system110may subtract or otherwise account of a baseline, such that the information reflects a difference between the electrical signals and the baseline. As yet further examples, the processing system110may determine positional information, recognize inputs as commands, recognize handwriting, and the like.

In some embodiments, the input device100comprises a touch screen interface, and the sensing region120overlaps at least part of an active area of a display screen that is part of a display device160shown inFIG. 2and described further below. For example, the sensor device150of the input device100may comprise substantially transparent sensor electrodes overlaying the display screen and provide a touch screen interface for the associated electronic system. The display screen may be any type of dynamic display capable of displaying a visual interface to a user, and may include any type of light emitting diode (LED), organic LED (OLED), cathode ray tube (CRT), liquid crystal display (LCD), plasma, electroluminescence (EL), or other display technology. The input device100and the display screen may share physical elements. For example, some embodiments may utilize some of the same electrical components for displaying and sensing. As another example, the display screen may be operated in part or in total by the processing system110.

FIG. 2is an exploded schematic of one embodiment of the sensor device150disposed over a display device160. As discussed above, a portion or all of the sensor device150may optionally be incorporated into the display device160. Together, the input device100having the sensor device150and the display device160may be part of an electronic system250.

The display device160may have monochromatic pixels, each formed from single subpixels, or multi-colored pixels, each formed from multiple subpixels. Three or four subpixels per color pixel are common, with color pixels formed from red-green-blue subpixels, red-green-blue-white subpixels, red-green-blue-yellow subpixels, or some other combination of differently-colored subpixels. In embodiments where the display device160includes multiple subpixels per pixel, the display device160typically has a pixel pitch along the directions that the display device spans. For example, square or rectangular display screens typically has “X” and “Y” pixel pitches. These pitches may be equal (resulting in square pixels) or not equal. In the embodiment depicted inFIG. 2, the display device160includes an array of square pixels206comprised of red (R), green (G), and blue (B) subpixels, but in other embodiments, other subpixels and subpixels groupings may be used.

The sensor device150includes a plurality of sensor elements, for example, a sensor electrode pattern, configured to sense the presence of (or lack thereof) input objects140in the sensing region120adjacent the sensor device150. For clarity of illustration and description,FIG. 2shows a pattern of simple rectangles, and does not show various components. In various embodiments, the sensor electrode pattern comprises a plurality of first sensor electrodes2021,2022, . . .202n(collectively referred to as first sensor electrodes202), and a plurality of second sensor electrodes2041,2042, . . .204m(collectively referred to as second sensor electrodes204) disposed adjacent the plurality of first sensor electrodes202, wherein N and M are positive integers representative of the last electrode in the array, and wherein N may, or may not, equal M. In the embodiment depicted inFIG. 2, all of the second sensor electrodes204designed by the same subscript are linearly aligned to form M parallel rows, three of which are shown. Likewise, the first sensor electrodes202are linear and parallel to each other, and oriented perpendicular to the rows of second sensor electrodes2041-M. It is also contemplated that the sensor electrodes202,204may have different orientations.

In the embodiment depicted inFIG. 1, the sensor electrodes202,204are shown disposed on a single substrate216. It is contemplated that the sensor electrodes202,204may be disposed on the same or opposite sides of the substrate216. It is also contemplated that the first sensor electrodes202may be disposed second sensor electrodes204different substrates.

The first sensor electrodes202and second sensor electrodes204are coupled to the processing system110by conductive routing lines262,264, wherein at least a portion of at least one of the conductive routing lines262,264is disposed on the substrate216on which the electrodes202,204are formed. The conductive routing lines262,264may be formed from ITO, aluminum, silver and copper, among other suitable materials. The conductive routing lines262,264may be fabricated from opaque or non-opaque materials. In the embodiment depicted inFIG. 2, at least a portion260of the conductive routing lines262is routed on the substrate216between the electrodes202,204, and such portion260of the conductive routing lines262may be configured as discussed below with reference to the construction of the electrodes202,204.

In a transcapacitive configuration, the first sensor electrodes202and second sensor electrodes204may be configured to sense the presence of (or lack thereof) input objects140in the sensing region120adjacent the sensor device150by driving a signal onto one of the sensor electrodes (i.e., transmitter electrode), while at least one of the other sensor electrodes is configured as a receiver electrode. The capacitive coupling between the transmitter sensor electrodes and receiver sensor electrodes change with the proximity and motion of input objects (140shown inFIG. 1) in the sensing region120associated with the first and second sensor electrodes202,204. By monitoring the capacitive coupling between the transmitter sensor electrodes and receiver sensor electrodes, the location and/or motion of the input object140may be determined.

Alternatively in an absolute sensing configuration, first sensor electrodes202and second sensor electrodes204may be configured to sense the presence of input objects140in the sensing region120adjacent the sensor device150based on changes in the capacitive coupling between sensor electrodes202,204and an input object140. For example, the sensor electrodes202,204may be modulated with respect to a reference voltage (e.g. system ground), and by detecting the capacitive coupling between the sensor electrodes202,204and input objects, the location and/or motion of the input object140may be determined. In other embodiments, other sensing methods may be used, including but not limited to, optical sensing, resistive sensing, acoustic wave sensing, ultrasonic sensing and the like.

In some touch screen embodiments, first sensor electrodes202comprise one or more common electrodes (e.g., “V-com electrode”) used in updating the display of the display device160. These common electrodes may be disposed on an appropriate display screen substrate of the display device160. For example, the common electrodes may be disposed on the TFT glass in some display screens (e.g., In-Plane Switching (IPS) or Plane to Line Switching (PLS)), on the bottom of the color filter glass of some display screens (e.g., Patterned Vertical Alignment (PVA) or Multi-domain Vertical Alignment (MVA)), etc. In such embodiments, the common electrode can also be referred to as a “combination electrode”, since it performs multiple functions. In various embodiments, each first sensor electrode202comprises one or more common electrodes. In other embodiments, at least two first sensor electrodes202may share at least one common electrode.

At least one of the sensor electrodes202,204comprises one or more conductive traces having a diameter less than about 10 um. In the embodiment depicted inFIG. 2, a portion of the second sensor electrode2041is enlarged such that conductive traces210are shown. In various embodiments, the conductive traces210may be fabricated from a material sufficiently conductive enough to allow charging and discharging of the sensor electrodes202,204. Examples of materials suitable for fabricating the conductive traces210include ITO, aluminum, silver and copper, among others. The conductive traces210may be fabricated from opaque or non-opaque materials, and may be one of a metal mesh and/or thin metal wires. Suitably conductive carbon materials may also be utilized. Advantageously, using metallic materials for the conductive traces210provides much lower electrical resistance as compared to substantially transparent conductors, thereby improving device performance. Although the traces210are shown as being linear, the traces210may also be wavy, for example, sinusoidal, along its length.

In at least some embodiments, the traces210may be arranged in an orientation that is substantially invisible and/or produces an acceptable moiré pattern, the width of the traces210may be increased, thereby allowing simpler and more efficient processing. For example, the conductive traces210may be arranged with at least one of an angle and periodicity selected to render the traces substantially invisible. This allows a number of small traces210to be locally grouped to form larger sensor elements (such as the second sensor electrode2041and other electrodes illustrated inFIG. 2) in any arbitrary shape, size and orientation. In this manner, the second sensor electrode204(and/or similarly constructed first sensor electrode202) may be linear, curved, circular, polygonal or other desirable geometric shape.

As mentioned above, the angle of individual traces210relative to the axes of the display device160will also affect the visibility of the traces210. Not all of the traces210grouped to form a single sensor electrode need have the same angular orientation, as long as combined arrangement of the traces210will not detrimentally affect the visibility of an image displayed on the display device160. Thus, in many embodiments, the traces210are predominantly orientated at angles selected to reduce the visibility of the moiré patterns that may result.

In the embodiment depicted inFIG. 2, the axes of pixels206comprising the display device160are aligned with the X and Y coordinate axes, as are lateral edges212,214of the transparent substrate216on which the second sensor electrodes204of the sensor device150is disposed. Thus, primary angles218,220of individual traces210thus may be referenced relative to one of the lateral edges, for example edge212, which is aligned with the axis of the pixels206. The angles218,220of individual traces210in which the traces210may be rendered substantially invisible may be determined by a variety of methods. For example, one method to render the traces210substantially invisible is to rotate a physical embodiment of the sensor pattern and visually identify angle(s) that results in an acceptable or optimal subjective appearance. As another example, the spatial frequencies for color aliasing between the display and the opaque traces may be calculated to determine the angles and/or the trace pitches that reduce the calculated visibility. Examples of how to calculate the spatial frequencies are described in literature on human vision, for example, “Contrast Sensitivity of the Human Eye and its Effects on Image Quality” by Peter G. J. Baden. As yet another example, geometric construction may be utilized to choose a path for the traces that passes over red, green, and blue subpixels in a sequence that results in an acceptable or optimal subjective appearance. Generally, the angles218,220which provide a substantially invisible appearance need not be at a maximum value of the spatial frequency for a given trace210and pixel206. The eye is most sensitive to spatial frequencies of about 1-10 cycles per degree at typical touch screen viewing distances, for example about 500 to about 1000 mm. A contrast modulation of about 1 percent may be visible at the most visible spatial frequencies. To remain invisible, with for example 10 percent contrast modulation, the spatial frequency of the moiré pattern should be greater than about 40 cycles per degree, or about 50 per-cm (cm−1). The angles218,220that produce a moiré pattern with a spatial frequency greater than about 50 cm have sufficiently low visibility with a typical 10 percent modulation.

In the embodiment depicted inFIG. 2, the angle218of the traces210may be at an orientation relative to the edge212(and the first orientation of pixels206(e.g., aligned with the X axis) comprising the display device160) that is within about +/−5 degrees of an orientation that provides maximized spatial frequency. In another embodiment, the angle218of the traces210may be, but not limited to, any one of about 30, 36, 56, or 71 degrees+/− about 5 degrees relative to the edge212(and the first orientation of pixels206(e.g., aligned with the X axis) comprising the display device160). Although the first sensor electrodes202of the sensor device150in the embodiment depicted inFIG. 2is disposed at an angle222that is perpendicular to the X axis and edge212of the sensor device150, the angle222of the first sensor electrodes202may be disposed at angles other than 90 degrees.

In the embodiment depicted inFIG. 2, the angle220of the traces210may be at an orientation relative to the edge212(and the first orientation of pixels206(e.g., aligned with the X axis) comprising the display device160) that is within about +/−5 degrees of an orientation that provides maximized spatial frequency. In another embodiment, the angle220may be, but not limited to anyone of about 109, 124, 144, or 150 degrees+/− about 5 degrees relative to the edge212(and the first orientation of pixels206(e.g., aligned with the X axis) comprising the display device160).

Adjacent traces210having the same angular orientation (e.g., either angle218or angle220) may have a spacing (i.e., periodicity)224,226selected to render the traces substantially invisible. In one embodiment, not all of adjacent traces210are spaced similarly. In various embodiments, the second sensor electrodes204may be fabricated using in a similar manner using conductive traces as described above in reference to the first sensor electrodes202.

It is noted that both the spacing224and angles220,222may be selected together to produce the above effects. The conductive traces210may also be oriented using any one or combination of spacing224and angles220,222relative to plurality of pixels206form a moiré pattern with the display device160, wherein said moiré pattern comprises a pitch in a direction parallel to the first orientation smaller than the pitch of 3 cycles of pixels206.

Other attributes of the traces210comprising the sensor electrodes202,204also affect how visually detectable of the sensor electrodes202,204are to the human eye. For example, variation in the edges of the sensor electrodes202,204, the variation in amount of occlusion of a particular color pixel, and the density of the traces210(factoring other light occluding material as further discussed below) across the sensor device150may all individually influence if undesirable visual patterns are formed.FIGS. 3-16describe embodiments of sensor devices150which provide sensor electrodes202,204having reduced visual patterns achieved through the configuration of the various of attributes of the traces210comprising the sensor electrodes202,204.

FIG. 3is one embodiment of one of the second sensor electrodes204superimposed over an imaginary grid330. The neighboring sensors electrodes202,204are omitted fromFIG. 3to enhance the ease of understanding during the following description of the second sensor electrode204in relation to the imaginary grid330. The imaginary grid330extends beyond the bounds of the second sensor electrodes204across the sensing region of the substrate such that one or more of the other electrodes202,204comprising the input device100may be configured with reference to the same singular grid330. Although only one second electrode204is shown inFIG. 3, it is intended that one or more other second sensor electrodes204, and optionally one or more of the first sensor electrodes202, may be similarly constructed.

The second sensor electrodes204includes a body302formed by the traces210. The body302is connected to the processing system110by the conductive routing line264, which includes the portion260disposed on the substrate216.

The traces210forming the body302are arranged in a conductive mesh306that includes an interior portion308bounded by a terminal portion310. The interior portion308includes traces210intersecting at interior intersections304and boundary intersections312. The boundary intersections312circumscribe the interior intersections304and separate the terminal portion310from the interior intersections304. For clarity, the boundary intersections312are illustrated interconnected by dashed line340.

The terminal portions310extend from the boundary intersection312of the interior portion308to a terminal end314. The terminal end314defines the outer perimeter (extents) of the body302. Each portion of the trace210disposed in the terminal portions310extend from one of the boundary intersections312and ends at the terminal end314. The terminal end314of the trace210may be free and unattached to other traces210, for form an intersection with a neighboring adjacent trace210disposed in the terminal portions310. Other than traces210intersecting at a terminal end314, the traces210do not intersect within the terminal portion310between the boundary intersections312and the terminal ends314.

As discussed above, the body302is defined in size by the terminal ends314, which together, form the perimeter of the body302. The perimeter of the body302depicted inFIG. 3includes edges316,318,320,322arranged to form a rectangle. Of course, the body302may have any number of edges and be shaped in other polygonal or other geometrical forms. For example, an adjacent pair of the edges316,318,320,322on neighboring sensor electrodes may be interleaved, parallel, linear, wavy or have another geometrical interface. As shown in the enlarged portion ofFIG. 3, the terminal ends314defining the edges316,318may include one or more closed terminations324, i.e., formed by the coupling of neighboring terminal end314, and/or one or more open terminations326, i.e., formed by a terminal portion310having an unconnected and free terminal end314. It is desirable, in at least some embodiments, that one or more of the terminal ends314of adjacent traces210are connected at the edges316,318,320,322of the body302. It is also desirable, in at least some embodiments, that one or more of the connected terminal ends314of adjacent traces210are aligned with the imaginary grid330. By ending adjacent traces210of the body302at connected terminal ends314in alignment with the imaginary grid330, the conductor density, and thus performance, of the sensor electrode may be enhanced.

As illustrated inFIG. 3, the orientation of the angles218,220and spacing224,226of the traces210forming the body302defines the imaginary grid330. The grid330, illustrated by unfilled lines332inFIG. 3, is defined by the periodicity, angles and configuration of the traces210forming the interior portion308of the conductive mesh306, wherein indices334of the grid330align with interior intersections304of the traces210within the interior portion308of the conductive mesh306. The terminal portion310of the body302, and optionally the portion260of the conductive routing line264may not necessarily conform, e.g., overlay, the grid330as further discussed below. The interior intersections304of the traces210within the interior portion308of the conductive mesh306define a first periodicity370and a second periodicity372which align with the imaginary grid330. As such, the imaginary grid330has the same periodicity370,372. In at least some embodiments, it is desirable that one or both of the width (in the X direction) of the body302be a 0.5 multiple of distance defined by the periodicity370and the height (in the Y direction) of the body302be a 0.5 multiple of distance defined by the periodicity372, which enhances density uniform of the traces210across the body302, and between adjacent bodies302of neighboring sensor electrodes. In at least some embodiments, it is also desirable that one or both of the periodicity370and the periodicity372be a 0.5 multiple of the periodicity of the pixels206.

FIG. 4is a plan view of a portion of the sensor device150shown disposed over a portion of the display device160. Although the display device160is shown with pixels206segmented into RGB subpixels, other subpixel configurations may be utilized. The imaginary grid330is also depicted inFIG. 4. In the portion of the sensor device150shown inFIG. 4, portions of two first sensor electrodes202, portions260of three conductive routing lines264, and portion of one second sensor electrode204are shown with the grid330overlaying the array of pixels206.

It is desirable to have high conductor density within the sensor electrodes202,204to enhance performance, but is conversely undesirable for the conductor density to be so high as to undesirably make the sensor electrodes202,204visible or to create moiré patterns. Unfortunately, increasing the conductor density undesirably makes the sensor electrodes202,202block an excessive amount of light. To obtain desirable conductor density, the sensor electrodes202,204and portions260of the conductive routing lines264are closely packed. To obtain desirable low visibility, sensor electrodes202,204and portions260of the conductive routing lines264may be configured to block only a small fraction, such as less than about 20 percent, or even less than 10 percent, of the light emitted by the display device160. To prevent moiré pattern generation, it is desirable for each trace210to repeat the coverage pattern of the underlying pixels206across the sensor electrodes202,204. In such a closely packed configuration, the traces210at the adjacent edges318,322of neighboring bodies302must not be so close as to allow arcing or other electrical communication which would reduce the performance of the input device100.

In some embodiments of the invention, the terminal portions310of the traces210are “displaced” relative the interior portion of the traces210comprising the body302of at least one of the electrodes202,204. As utilized herein with reference to the portion of the traces210comparing the terminal ends314, the term “displaced” means that at least a portion if not all of the terminal portions310of the traces210diverges, i.e., is not aligned with or is offset, from the imaginary grid330. As utilized herein with reference to the portion of the traces210comparing the terminal ends314, the term “non-diverged” means the theoretical position that the displaced terminal ends314would have occupied if the trace210was not displaced, i.e., the theoretical position is aligned with the imaginary grid330. For example, one or more of the terminal ends314of the terminal portions310shown in the enlarged portion of the body302of the second electrodes202Nand204Mare displaced, i.e., offset from, the grid330.

In at least some embodiments, it is advantageous for the displaced terminal ends314to cover a subpixel of the same color that would have been covered it the terminal end314had been in its “non-diverged” theoretical position in alignment with the imaginary grid330.

Referring to the enlarged portion ofFIG. 4labeledFIG. 4A, the displaced terminal ends314of the first sensor electrode2022that terminate in the closed termination324are illustrated in a displaced position430. That is, the displaced position430is offset from a non-diverged position432coinciding with the imaginary grid330. Likewise, the displaced terminal end314of the first sensor electrode2022that terminates in the open termination326is illustrated in a displaced position434. That is, the displaced position434is offset from a non-diverged position436coinciding with the imaginary grid330. As illustrated in Detail4A, the displaced positions430,434of the displaced terminal ends remain within (i.e., over) the same respective subpixel as would the trace210cover if the trace210had been positioned in the non-diverged position432,436. In this manner, the amount of light blockage by the trace210for a given subpixel color substantially does not change across the body302of the first sensor electrode2022. The amount and direction of the displacement of the trace210allows a gap460defined between sensor electrodes to be tailored with minimal effect on light blockage or moiré pattern generation. Other sensor electrodes and/or conductive routing lines may be similarly configured.

Referring now to a second enlarged portion ofFIG. 4labeledFIG. 4B, the traces210comprising the adjacent portions260of conductive routing lines264are illustrated. In the embodiment depicted inFIG. 4B, the traces210comprising at least one of the portions260of the conductive routing lines264are substantially displaced form the imaginary grid330. For example, the conductive routing line264indicated as480inFIG. 4Bincludes traces210which have the same periodicity370,372as the interior portion308of the body302of the second sensor electrode204M, and substantially aligns with the imaginary grid330. For example, ends484of the traces210comprising conductive routing line480are aligned with the indices334of the lines332forming the imaginary grid330. The conductive routing line264indicated as482immediately adjacent to conductive routing line480has substantially the same periodicity370,372as the conductive routing line480, but at least some of the traces210comprising the conductive routing line482are displaced relative the imaginary grid330. For example, ends486of the traces210comprising conductive routing line482are displaced from the imaginary grid330by a predefined amount which is substantially uniform over lengths of with the lines480,482are adjacent. In other words, a distance between adjacent ends484,486of the conductive routing lines480,482are substantially equal. Moreover, since the displaced ends486remain over the same subpixel (G in the example illustrated inFIG. 4B) as would the trace210if in a non-diverged position488, the traces210of the conductive routing line482block substantially the same fraction of light from each subpixel, which contributes to reducing the visibility of the conductive routing line482.

FIG. 5Adepicts another embodiment of traces210comprising the adjacent portions260of the conductive routing lines264wherein the conductive routing lines264have a width less than the periodicity370of the interior portion308of the body302of the sensor electrode to which the conductive routing lines264is attached, here shown as the second sensor electrode204M. In the embodiment depicted inFIG. 5A, the portion260of the conductive routing line264, now referred to as conductive routing line502, has a width less than the periodicity370of the interior portion308of the body302to which the conductive routing line502is attached, for example, the second sensor electrode204M. For example, the width of the conductive routing line502may be 0.5 (or other fraction) of the periodicity370. The periodicity in the long (Y direction) of the conductive routing line502may be substantially equal to the periodicity372. In this manner, the traces210comprising the conductive routing line502are substantially aligned with the imaginary grid330and the traces210comprising the body302. An immediately adjacent portion260of the conductive routing line264, now referred to as conductive routing line504, has a width similar to the width of the conductive routing line502. The conductive routing line504also has the same periodicity as the conductive routing line502, but at least some of the traces210comprising the conductive routing line504are displaced relative the imaginary grid330. In other words, the periodicity of the conductive routing line504is the same as the periodicity in both the X and Y directions as the conductive routing line502, but only the conductive routing line502and not the conductive routing line504overlays the imaginary grid330.

For example, the traces210comprising conductive routing line502have the same geometrical configuration and dimensions as the traces210comprising conductive routing line504, but only one of the conductive routing lines502,504is displaced from the imaginary grid330. Since the displaced traces210of the conductive routing line504remain over the same subpixel (G in the example illustrated inFIG. 5A) as would the trace210if a non-diverged position aligned with the imaginary grid330, the traces210of the conductive routing line504block substantially the same fraction of light from each subpixel, which contributes to reducing the visibility of the conductive routing line504.

In some embodiments, the longer traces210comprising the conductive routing line504are oriented favoring the long direction of the routing line504. In this manner, the resistance is minimized to improve sensor response time. Additionally, by configuring the conductive routing line504with the same periodicity (370,372) as the body302, the visual differences between the conductive routing line504and sensor electrodes202,204are reduced.

FIG. 5Bdepicts another embodiment of traces210comprising the adjacent portions260of the conductive routing lines264wherein the conductive routing lines264have a width less than the periodicity370of the interior portion308of the body302of the sensor electrode to which the conductive routing lines264is attached, here shown as the second sensor electrode204M. In the embodiment depicted inFIG. 5B, the portion260of the conductive routing line264, now referred to as conductive routing line512, has a width less than the periodicity370of the interior portion308of the body302to which the conductive routing line512is attached, for example, the second sensor electrode204M. For example, the width of the conductive routing line512may be 0.5 (or other fraction) of the periodicity370. The periodicity in the long (Y direction) of the conductive routing line512may be substantially equal to the periodicity372. At least some of the traces210comprising the conductive routing line512are displaced relative the imaginary grid330. However, displaced ends516of the traces210comprising the conductive routing line512remain over the same subpixel (G in the example illustrated inFIG. 5B) as would the trace210if a non-diverged position aligned with the imaginary grid330. Thus, the traces210of the conductive routing line512block substantially the same portion (or fraction) of light from each subpixel, which contributes to reducing the visibility of the conductive routing line512.

An immediately adjacent portion260of the conductive routing line264, now referred to as conductive routing line514, has a width similar to the width of the conductive routing line512. The conductive routing line514also has the same periodicity as the conductive routing line512, and at least some of the traces210comprising the conductive routing line514are displaced relative the imaginary grid330. In the embodiment depicted inFIG. 5B, displaced ends518of the traces210comprising the conductive routing line514remain over the same subpixel (G in the example illustrated inFIG. 5B) as would the trace210if a non-diverged position aligned with the imaginary grid330. Thus, the traces210of the conductive routing line514block substantially the same portion (or fraction) of light from each subpixel, which contributes to reducing the visibility of the conductive routing line514. Additionally, as adjacent ends516,518of the traces210comprising neighboring conductive routing lines512,514are displaced to opposite sides of the indices334of the lines332forming the imaginary grid330overlaying the interface between the lines512,514, the conductor density of the lines512,514may be better balanced across the sensing region120while ensuring that substantially the same portion (or fraction) of light is blocked from each subpixel, which contributes to reducing the visibility of the conductive routing lines512,514.

The displaced terminal ends314of the first sensor electrode2021(or other sensor electrode) may have many alternative configurations.FIGS. 6-9discussed below are provided by way of example, and are not intended to be inclusive of all variations in which the invention may be practiced or to limit the scope of the claims.

FIG. 6is a plan view of facing edges320,316of one embodiment of the second sensor electrode204Mand first sensor electrode2021. The displaced terminal portions310of the first sensor electrode2021, illustrated inFIG. 6as terminal portions602, are at least partially displaced from the imaginary grid330. Adjacent terminal portions602are joined at closed terminations606. The displaced terminal portions310of the second sensor electrode204M, illustrated inFIG. 6as terminal portions604, are also at least partially displaced from the imaginary grid330. Adjacent terminal portions604are joined at closed terminations608. The closed terminations606,608have the same periodicity372as the body302of the sensor electrodes2021,204M. However, the closed terminations606are 180 degrees out of phase with the closed terminations608. That is, the closed terminations606are aligned horizontally (in the X-direction) with the boundary intersections312of the second sensor electrode204M, while the closed terminations608are aligned horizontally with the boundary intersections312of the first sensor electrode2021. The relation between the closed terminations606,608can also be described as being mirrored in the x-direction, and shifted ½ the periodicity372in the y-direction. The closed terminations606,608remain over the same subpixel (G and R, respectively in the example illustrated inFIG. 6) as would the trace210if a non-diverged position aligned with the imaginary grid330. Thus, the traces210in the terminal portions310of the sensor electrodes2021,204Mblock substantially the same portion (or fraction) of light from each subpixel, which contributes to reducing the visibility of the sensor electrodes2021,204M.

FIG. 7is a plan view of facing edges320,316of another embodiment of the second sensor electrode204Mand first sensor electrode2021. The displaced terminal portions310of the first sensor electrode2021, illustrated inFIG. 7as terminal portions702, are at least partially displaced from the imaginary grid330. Adjacent terminal portions702are joined at closed terminations706uniformly displaced to a first side of the indices334of the lines332forming the imaginary grid330. The displaced terminal portions310of the second sensor electrode204M, illustrated inFIG. 7as terminal portions704, are also at least partially displaced from the imaginary grid330. Adjacent terminal portions704are joined at closed terminations708uniformly displaced to a second side of the indices334of the lines332forming the imaginary grid330, that is, to a side opposite of the closed terminations706(in the Y direction). The closed terminations706,708have the same periodicity372as the body302of the sensor electrodes2021,204M. The closed terminations706,708substantially remain over the same subpixel (G and R, respectively in the example illustrated inFIG. 7) as would the trace210if a non-diverged position aligned with the imaginary grid330. Thus, the traces210in the terminal portions310of the sensor electrodes2021,204Mblock substantially the same portion (or fraction) of light from each subpixel, which contributes to reducing the visibility of the sensor electrodes2021,204M.

FIG. 8is a plan view of facing edges320,316of another embodiment of the second sensor electrode204Mand first sensor electrode2021. The displaced terminal portion310of the first sensor electrode2021, illustrated inFIG. 8as terminal portions802, have a first portion801aligned with the imaginary grid330and a second portion805extending from the first portion801and terminating in terminal ends314. The second portion805of the terminal portion802is displaced from the imaginary grid330. Adjacent ends314of the terminal portions802are joined at closed terminations806uniformly displaced to a first side of the indices334of the lines332forming the imaginary grid330. The displaced terminal portions310of the second sensor electrode204M, illustrated inFIG. 8as terminal portions804, have a first portion803aligned with the imaginary grid330and a second portion807extending from the first portion803and terminating in terminal ends314. The second portion807of the terminal portion804is displaced from the imaginary grid330. Adjacent ends314of the terminal portions804are joined at closed terminations808uniformly displaced to a second side of the indices334of the lines332forming the imaginary grid330, that is, to a side opposite of the closed terminations806(in the Y direction). The closed terminations806,808have the same periodicity372as the body302of the sensor electrodes2021,204M. The closed terminations806,808substantially remain over the same subpixel (G and R, respectively in the example illustrated inFIG. 8) as would the trace210if a non-diverged position aligned with the imaginary grid330. Thus, the traces210in the terminal portions310of the sensor electrodes2021,204Mblock substantially the same portion (or fraction) of light from each subpixel, which contributes to reducing the visibility of the sensor electrodes2021,204M.

FIG. 9is a plan view of facing edges320,316of another embodiment of the second sensor electrode204Mand first sensor electrode2021. The terminal portion310of the first sensor electrode2021are illustrated inFIG. 9as displaced terminal portions902and aligned terminal portions903. The displaced terminal portions902have a portion at least partially displaced from the imaginary grid330. The aligned terminal portions903are at least partially aligned with the imaginary grid330. Adjacent ends314of the terminal portions902,903are not joined and end at open terminations906. The displaced ends314of the displaced terminal portions902are uniformly displaced to a first side of the lines332forming the imaginary grid330.

As discussed above, other attributes of the traces210such as the density uniformity of the traces210(and other light occluding material) across the sensor device150comprising the sensor electrodes202,204, will affect how visually detectable of the sensor electrodes202,204are to the human eye. Thus, in at least some embodiments, it is desirable to maintain a substantially uniform density of light occluding material (i.e., the traces210and other light occluding elements) per unit area across the sensing region120. The unit area can be an area of a single pixel, or an area that can be resolved by the eye. For example, approximately 1 minute of arc is about the smallest useful area human vision may resolve. Thus, for sensor devices150disposed at arm's length (approximately 500 mm), a unit area may have a mean diameter of 0.14 mm or greater (about 0.0154 mm2). For a sensor devices150held closer the eye, a reasonable unit area may have a mean diameter of about 0.1 mm in diameter or greater (about 0.0073 mm2). Of course, the above examples of unit area are not intended to limit the scope of the claims, and larger unit areas may be utilized.

FIG. 10is a partial plan schematic view of one embodiment of a sensor device150having sensor electrodes202,204. The sensor electrodes202,204may be constructed as described herein, or in another manner which provides density uniformity of light occluding material, i.e., the traces210and other light occluding elements, across the sensor device150as further described below. The sensor device150includes the portions260of the conductive routing lines264disposed on the substrate216and connected to sensor electrodes2041,2042, and204M. The portion260of the conductive routing line262connected to sensor electrodes2021may be similarly configured.

The sensor device150illustrated inFIG. 10includes 5 imaginary boxes demarking unit areas in different regions of the sensor device150which overlay the display device160. The size of the unit areas is generally an area that can be resolved by the eye as described above. The unit areas encompass different combinations of sensor electrodes and or conductive routing lines, and some of the unit area also encompass portions of the black matrix (e.g., interpixel area) or are entirely within the body. In the embodiment depicted inFIG. 10, unit area1002encompasses portions of the first sensor electrode2021and the second sensor electrode2041, wherein only two edges316,320of the sensor electrodes (e.g., one from each electrodes2021,204M) pass are within the boundaries of the unit area1002. Unit area1004encompasses portions of the first sensor electrode2021, the second sensor electrodes2041and the second sensor electrode2042, wherein three or more edges (shown as four edges, edge316of the first sensor electrode2021, edges320,322of the second sensor electrode2041, and edges318,320of the second sensor electrode2042) of the sensor electrodes pass are within the boundaries of the unit area1004. Unit area1006encompasses only portions of the interior portion308of one of the sensor electrodes202,204, shown inFIG. 10over the first sensor electrode2021. Unit area1008encompasses portions of the second sensor electrodes204Mand the portion260of the conductive routing line264disposed on the substrate216(not shown in FIG.10). Unit area1010encompasses portions of neighboring portions260of conductive routing lines264disposed on the substrate216.

In the example described with reference toFIG. 10and other embodiments described herein, the plan area of the light occluding materials (i.e., the traces210and light occluding elements) within a predefined unit area, i.e., specific areal density, will be referred to as the “blockage area”. The blockage area is intended encompass all light occluding material, such as the traces210alone, the traces210and other light occluding elements, and light occluding elements alone. The blockage area for the traces210may be determined using the width, spacing and angular orientation of the traces210within a given unit area. Examples of light occluding elements are described below with reference toFIGS. 12-17. The blockage area in at least two or more, including any combinations, of the units areas1002,1004,1006,1008,1010are substantially equal, for example, within less than about 5%, and wherein less visibility is desired, less than about 2%. At equal to or less than about 1%, the traces and light occluding elements will be substantially invisible. For example, the blockage area within unit area1006may be substantially equal to the blockage area attributable to the traces210and other light occluding elements, if present, within one or more of the unit areas1002,1004,1008, and1010. By having the blockage area be substantially equal across least two or more of the units areas1002,1004,1006,1008,1010, the amount of pixel light blocked, for example by the traces210, is substantially uniform across these areas, thus reducing and/or eliminating perceptible visual differences across the sensor device150, and thus enhancing the performance of the display device160without diminishing touch sensing performance of the input device100.

To compensate of the lack of traces210across the gap460defined between sensor electrodes202,204and/or conductive routing traces264, the plan area of light occluding material in the terminal portions310of the sensor electrodes202,204may differ, for example be greater, than the blockage area solely attributable to the traces210within the interior portion308of the body302. This may be accomplished by increasing one or more of the width, decreasing the spacing and changing the angular orientation of the traces210within terminal portions310relative to the traces210present in the interior portion308of the body302. Additionally or in the alternative, the plan area of light occluding material in the terminal portions310of the sensor electrodes202,204may be increased, thereby increasing the plan area attributable to light occluding elements in the terminal portions310of the sensor electrodes202,204.

FIG. 11is a schematic plan view of two crossing traces210having substantially uniform trace width. The crossing traces210may be formed as a single layer of material on the substrate216, or on different layers stacked in the input device100. At the intersection of the traces210, an intersecting portion1102has a plan area equivalent to the portion of a single trace that is shared (e.g., overlaps) the intersecting second trace. Accordingly, the total plan area of the intersecting traces210is less than that of two non-intersecting traces210of equal length, or for example when traces intersect at 90 degrees, the product of the widths of each trace. Thus, the plan area the intersecting portion1102may be modified to increase the total plan area of the two crossing traces210to substantially that of two non-intersecting traces210of equal length within a unit area. Increasing the total plan area of the two crossing traces210may be realized by modifying the traces210at or near the intersecting portion1102, and alternatively or in addition, adding light occluding at or near the intersecting portion1102.

FIG. 12is a schematic plan view of two crossing traces210configured to have a greater plan area relative to the embodiment depicted inFIG. 11that has substantially uniform trace width. In the embodiment depicted inFIG. 12, the crossing traces210may be formed as a single layer of material on the substrate216. The traces210intersect at an intersecting portion1202, wherein the intersecting portion1202includes the plan area1102associated with the widths of the crossing traces210and also includes one or more attached light occluding elements1204formed between at least two adjacent portions of the traces210. The light occluding element1204may have any convenient plan form, and in the embodiment depicted inFIG. 12, the light occluding element1204is in a form of a radius defined between the traces210meeting at the intersecting portion1202. The plan area attributable to the light occluding element1204may be about equal to the plan area of the intersecting portion1102. Thus, the intersecting portion1202has a plan area greater than that of the portion of a single trace that is shared (e.g., overlaps) an intersecting second trace, thereby improving the plan area uniformity and consequently, reducing the visual perceptibility of the sensor electrodes202,204.

FIG. 13is a schematic plan view of two crossing traces210configured to have a greater plan area relative to the embodiment depicted inFIG. 11that has substantially uniform trace width. In the embodiment depicted inFIG. 13, the crossing traces210may be formed as a single layer of material on the substrate216. The traces210intersect at an intersecting portion1302, wherein the intersecting portion1302includes the plan area1102associated with the widths of the crossing traces210and also includes one or more attached light occluding elements1304formed between at least two adjacent portions of the traces210. The light occluding element1304may have any convenient plan form, and in the embodiment depicted inFIG. 13the light occluding element1304is in the form of a web connecting the traces210defining the intersecting portion1302. The light occluding element1304may be of any suitable plan area, and in one embodiment, plan area attributable to the light occluding element1304may be about equal to the plan area of the intersecting portion1102. Thus, the intersecting portion1302has a plan area greater than that of the portion of a single trace that is shared (e.g., overlaps) an intersecting second trace, thereby improving the plan area uniformity and consequently, reducing the visual perceptibility of the sensor electrodes202,204.

FIG. 14is a schematic plan view of two crossing traces210configured to have a greater plan area relative to the embodiment depicted inFIG. 11that has substantially uniform trace width. In the embodiment depicted inFIG. 14, the crossing traces210may be formed as a single layer of material on the substrate216, or on different layers stacked in the input device100. At the intersection of the traces210, an intersecting portion1402has a plan area equivalent to that of the portion of a single trace that is shared (e.g., overlaps) an intersecting second trace, such as the intersecting portion1102, or less than about twice that of the intersecting portion1102. The intersecting portion1402may be similar in plan area to the intersecting portions1102,1202,1302.

One or more detached light occluding elements1410proximate the intersection of the traces210, and contribute to the plan area of the intersecting portion1402. The one or more detached light occluding elements1410may be disposed on the same substrate216as one or more of the traces210comprising the intersecting portion1402as illustrated inFIG. 14, or on a second substrate1502stacked over the substrate216within the input device100as illustrated inFIG. 15. The detached light occluding elements1410are fabricated from a material that is opaque or that blocks the light generated by the pixels206, thus contributing to the total blocked plan area of the light occluding material in a given unit area of the sensor device150. The detached light occluding elements1410may be fabricated from a conductive material, such as a conductive material suitable for fabrication of the traces210. Alternatively, the detached light occluding elements1410may be fabricated from a suitable dielectric material. The detached light occluding elements1410, being spaced from the traces210, are not electrically connected with the traces210.

The detached light occluding elements1410may have any suitable geometry and size. In the embodiment, the plan area, determined by the number and size of the detached light occluding elements1410, may be selected to increase the total blocked plan area of the intersecting portion1402up to about twice the plan area the intersecting portion1102.

In the embodiment depicted inFIG. 14, the traces210and detached light occluding elements1410are disposed on the same substrate216. The traces210and detached light occluding elements1410may be on the same or opposite sides of the substrate216. The detached light occluding elements1410are shown positioned laterally space from the traces210, between the vertices of intersecting portion1402.

In the embodiment depicted inFIG. 15, the traces210comprising at least one of the sensor electrodes202,204are disposed on the substrate216, while the detached light occluding elements1410are disposed on the second substrate1502stacked over the substrate216within the input device100. The detached light occluding elements1410are shown positioned laterally space from the traces210, but between the vertices of intersecting portion1402once the substrates216,1502are vertically stacked.

FIG. 16is a schematic plan view of two crossing traces210configured to have a greater plan area relative to the embodiment depicted inFIG. 11that has substantially uniform trace width. In the embodiment depicted inFIG. 16, the crossing traces210may be formed as a single layer of material on the substrate216. The traces210intersect at an intersecting portion1602, wherein the intersecting portion1602includes one or more attached light occluding elements1604formed between at least two adjacent portions of the traces210. The light occluding element1604may have any form, and in the embodiment depicted inFIG. 16the light occluding element1604is in the form of a trace connecting the traces210defining the intersecting portion1602, such that the light occluding element1604comprising the intersecting portion1602does not align with the web330(not shown inFIG. 16). For example, an open area1608may be bounded within the intersecting portion1602by the light occluding elements1604that couple adjacent traces210. The light occluding elements1604may be of any suitable plan area, and in one embodiment, plan area attributable to the light occluding element1604may be about equal to the plan area of the intersecting portion1102. Thus, the intersecting portion1602has a plan area greater than that of the portion of a single trace that is shared (e.g., overlaps) an intersecting second trace, thereby improving the plan area uniformity and consequently, reducing the visual perceptibility of the sensor electrodes202,204.

FIG. 17is a schematic plan view of two traces210having terminal ends314, one with configured with an attached light occluding element1710. The second terminal end314is disposed adjacent a detached light occluding element1712. Although both attached and detached light occluding elements1710,1712are illustrated inFIG. 17, the sensor electrodes202,204may be configured with solely attached light occluding elements1710, solely detached light occluding elements1712, or combinations thereof.

The attached light occluding element1710is a deviation to the local plan area over a short segment of the trace210. Here, the attached light occluding element1710is illustrated as an increased width of the trace210comprising the terminal end314. The attached light occluding element1710may be utilized to compensate for the reduction in plan area of the terminal end314of a trace210at an edge of a sensor electrode having an open terminations326(as shown inFIG. 4A) which is displaced from the grid330, or to compensate for the absence of traces210in the gap460between neighboring sensor electrodes or conductive routing lines (as shown inFIG. 18). The detached light occluding elements1712may be disposed close to the terminal end314to provide similar effects.

The intersecting portion1702may be configured similar to the similar to the intersecting portion1402. Thus, the attached light occluding elements1710and/or detached light occluding elements1712may have selected with any suitable geometry and size such that the plan area, determined by the number and size of the light occluding elements1710,1712, may be selected to increase the total blocked plan area of a unit area that includes open terminations326such that the blocked plan area is uniform across different areas (such as unit areas illustrated inFIG. 10) to prevent undesired visual effects.

FIG. 18is a schematic plan view of traces210of different sensor electrodes202,204aligned across a gap460. A terminal end314of each trace210includes an attached light occluding element1710. The size and geometry and size of the light occluding element1710may be selected to compensate for the lack of traces210across the460so that the total plan area in a unit area spanning the gap460, such as unit area1002,1004,1006illustrated inFIG. 10, so that the blocked plan area is uniform across different unit area to prevent undesired visual effects.

FIG. 19is an exploded plan view of one embodiment of an input device1900. The input device1900is substantially similar to the input device100described above, except that the sensor elements202,204are disposed on different substrates216,1902. The substrate1902having the sensor elements204may be part of, or on top of, the display device160, and in one embodiment, the sensor elements204comprise the VCOM electrodes of the display device160. With additional reference toFIG. 20, an overlapping region2002is defined where one sensor element202is vertically aligned with another sensor element204. If the overlapping region2002of the sensor elements202,204had the same blocked plan area as non-overlapping regions2004of the sensor elements202,204, the total blocked plan area across larger unit areas (such as illustrated inFIG. 10) would not be uniform. Thus, at least one of the trace pattern, trace width, and use of light occluding elements may be utilized it increase the total blocked plan area such that unit area bounded solely within a single sensor202may be substantially equal to unit area that includes one or more overlapping region2002of adjacent sensor elements202,204.

In addition to input devices having metal mesh sensor electrodes as described above, the invention includes a method for making such sensor electrodes for use in an input device. The method may be utilized by design houses and sensor fabricators.FIG. 21is a schematic diagram of one embodiment of a method2100for making a mesh sensor electrode, such as at least one of the sensor electrodes202,204described above.

The method2100utilizes a design engine2102configured to generate design instructions2110for use by a fabrication device2104. The fabrication device2104may be any device suitable for forming traces210configured and arranged as the sensor electrodes202,204described above. The fabrication device2104may be configured to deposit a sheet of conductive material, then selectively remove portions of the conductive material, leaving traces210in a pattern forming the sensor electrodes202,204. For example, the fabrication device2104may include deposition and removal devices, such as printing devices, inkjet devices, physical vapor deposition devices, plating devices, chemical vapor deposition devices, and spray deposition device, among other suitable deposition devices, while the removal device may include lithographic devices, wet etch devices, dry (plasma) etch devices, and laser ablation devices, among other removal devices. Alternatively, the fabrication device2104may directly form the traces210and sensor electrodes202,204. For example, the fabrication device2104may be an ink jet printing device, stamping devices, and plating devices, among other fabrication devices.

The design instructions2110generated by the design engine2102is in a form suitable for providing and/or generating machine instructions executable by the fabrication device2104to generate the traces210and sensor electrodes202,204. For example, the design instructions2110may be an output CAD or CAM file, such as DXF, Gerber and GDSII, among others. The design instructions2110may reside in the design engine2102and be accessed by the fabrication device2104. The design instructions2110may alternatively loaded into memory of a processor controlling the function of fabrication device2104. The design instructions2110may also be transferred to a memory or processor of the fabrication device2104from the design engine2102, for example, over a network or as computer readable media disposed on a portable digital storage device. The design instructions2110may be for a complete sensing device150, or the design instructions2110may be partial, specifying any portion of the sensing device150.

The design engine2102generally includes a processor2114, memory2116and control circuits2118for the processor2114and facilitates control of the fabrication device2104and, as such, of the sensor electrode design process, as discussed below in further detail. The processor2114may be one of any form of general-purpose computer processor that can be used for generating machine instructions executable by the fabrication device2104. The memory2116of the processor2114may be one or more of readily available memory such as random access memory (RAM), read only memory (ROM), floppy disk, hard disk, or any other form of digital storage, local or remote. The support circuits2118are coupled to the processor2114for supporting the processor in a conventional manner. These circuits2118may include cache, power supplies, clock circuits, input/output circuitry and subsystems, and the like. A program2120is stored in the memory2106or other computer-readable medium accessible to the processor2114and executable as a software routine to generate the fabrication instructions2110. An exemplary program2120which may be adapted to practice the invention include Design Studio™ 4 (DS4), available from Synaptics. Inc., located in Santa Clara, Calif.

The design engine2102allows a user, such as a design house, an input device provider, a sensor fabricator and the like, to input attributes of the sensor electrodes and display device, illustrated as display inputs2130and sensor input2132, to obtain an input device having reduced visual effects. The display inputs2130generally include display size, display type, display orientation (landscape or portrait), pixel pitch, pixel layout and the like.

The design engine2102may be configured to provide an optimal sensor electrode layout (i.e., relative positions of one sensor electrode to another) for a particular mesh configuration, or provide an optimal mesh configuration for a predetermined sensor layout.

For example, the user may indicate as one of the sensor inputs2132that a predefined layout geometry of sensors202,204is desired, which that the design engine2102determines one or more of the mesh pattern attributes, i.e., the spacing224,226, angles218,220, width of the traces210, trace material, trace thickness, position of the terminal ends314relative to the grid330, and the like. The design engine2102may provide sensor reflectance or transmittance, which affects how visible the sensor electrodes are, and sensor conductor density, which affects sensor electrical performance, of the sensor electrode design initially generated by the design engine2102as a feed-back output to the user. Thus, if the user does not wish to utilize the reflectance or transmittance or sensor conductor initial density determined by the design engine2102, the user may set a desired amount of reflectance or transmittance and/or sensor conductor density by inputting a value for the reflectance or transmittance and/or sensor conductor density to the design engine2102as a sensor input2102, for which in turn the design engine2102will recalculate the mesh pattern attributes and/or sensor electrode layout having the desired reflectance or transmittance and/or sensor conductor density. Any one or more of the mesh pattern attributes may also be provided by the user as a sensor input2130, so that the design engine2102provides an output having the desired visual and performance characteristics.

For example, the user may wish for the design engine2102to determine one or more of the mesh pattern attributes along with the layout geometry of sensors202,204. The design engine2102may again provide sensor reflectance or transmittance and sensor conductor density of the mesh electrode design initially generated by the design engine2102as a feed-back output to the user. Thus, if the user does not wish to utilize the reflectance or transmittance or sensor conductor initial density determined by the design engine2102, the user may set a desired amount of reflectance or transmittance and/or sensor conductor density by inputting a value for the reflectance or transmittance and/or sensor conductor density to the design engine2102as a sensor input2102, for which in turn the design engine2102will recalculate the mesh pattern attributes and/or sensor electrode layout having the desired reflectance or transmittance and/or sensor conductor density.

In another example, the user may allow the design engine2102to determine at least one or more of the sensor mesh attributes and the layout geometry of sensors202,204for a particular set of display inputs2130. The design engine2102may determine the sensor mesh attributes and the layout geometry of sensors202,204having a resultant sensor reflectance or transmittance and sensor conductor density. Alternatively one or both of the sensor reflectance or transmittance and sensor conductor density may be provide to the design engine2102as a sensor input2130, so that the design engine2102provides the desired visual and performance characteristics for the outputted sensor mesh attributes and the layout geometry of sensors202,204.

Thus, input device having a plurality of low-visibility sensor electrodes and method for fabricating the same are provided. The traces and/or sensor electrodes are arranged in a manner for minimum pattern perceptibility. In some embodiment, the traces may be electrically connected to one another to form macroscopic (e.g., a single larger) sensor element which, by virtue of the configuration of the attributes of traces and/or occluding material utilized to form the sensor element, can be configured in virtually any arbitrary shape, size or orientation while not detrimentally affecting the visibility of an image displayed on the display device adjacent the sensing region.