This relates to electronic devices and, more particularly, to touch sensitive displays for electronic devices.
Electronic devices such as cellular telephones, handheld computers, and portable music players often include displays. A display includes an array of controllable pixels that are used to present visual information to a user. To protect a display from damage, the display may be mounted behind a protective layer of cover glass. The active portion of a display may be formed using backlit liquid crystal display (LCD) technology. Displays may also be formed using pixels based on organic light-emitting diode (OLED) technology.
It is often desirable to provide displays with touch sensor capabilities. For example, personal digital assistants have been provided with touch screens using resistive touch sensing technology. Touch screens of this type have a pair of opposing flexible plastic panels with respective sets of transparent electrodes. When touched by an object, the upper panel flexes into contact with the lower panel. This forces opposing electrodes into contact with each other and allows the location of the touch event to be detected.
Resistive touch screens can have undesirable attributes such as position-dependent sensitivity. Accordingly, many modern touch screens employ touch sensors based on capacitance sensing technology. In a capacitive touch screen, a capacitive touch sensor is implemented using an array of touch sensor electrodes. When a finger of a user or other external object is brought into the vicinity of the touch sensor electrodes, corresponding capacitance changes can be sensed and converted into touch location information.
In conventional capacitive touch screens, capacitive electrodes are formed on a glass substrate. The glass substrate is interposed between the active portion of the display and an outer cover glass. Although efforts are made to ensure that the glass substrate on which the capacitive electrodes are formed is not too thick, conventional glass substrates may still occupy about half of a millimeter in thickness. Particularly in modern devices in which excessive overall device thickness is a concern, the glass substrate thickness that is associated with conventional capacitive touch sensors can pose challenges.
It would therefore be desirable to be able to provide improved touch screens for electronic devices.
An electronic device may have a touch screen display. The display may have a touch sensor structure that determines the location at which external objects touch the display. The touch sensor structure may have a clear substrate on which conductive capacitive touch sensor electrodes are formed. The electrodes may be formed from a transparent conductive material such as indium-tin oxide. The clear substrate may be formed from a flexible material such as a polymer. The polymer may be a clear polyimide. Copper traces or other conductive traces may be used to route sensor signals from the capacitive touch sensor electrodes to processing circuitry in the electronic device over a flex circuit path that is formed as an integral part of the touch sensor structure.
Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments.
Electronic devices such as computers, handheld devices, computer monitors, televisions, cellular telephones, media players, and other equipment may have displays. An example is presented in
As shown in
A display such as display 14 may be mounted within housing 12. Display 14 may be, for example, a liquid crystal display (LCD), an organic light emitting diode (OLED) display, or a plasma display (as examples). Touch sensor electrodes may be included in display 14 to provide display 14 with touch sensing capabilities (i.e., so that display 14 operates as a touch screen). Display 14 may contain a number of layers of material. For example, the outermost surface of display 14 may be protected using a layer of plastic or glass. This protective layer is sometimes referred to as a cover glass (whether formed from plastic, glass, or other transparent materials).
In the interior of device 10, display 14 may be provided with an array of controllable display pixels. In an LCD display, each display pixel is associated with a circuit that controls the polarization of a small volume of liquid crystal material. In light-emitting diode displays, each image pixel contains an individually controllable light-emitting diode.
The image pixels of display 14 may be formed as part of a display module. A liquid crystal display module may have layers of polarizer, light diffusing elements, light guides for backlight structures, and a liquid crystal layer with individual pixel-sized control elements. An organic light-emitting diode (OLED) display may have organic materials that are used in producing light. The outermost layer of the display module may be formed from a transparent material such as glass.
A cross-sectional view of display 14 of
The structures of display 14 may be protected using a protective cover such as cover glass 18. Cover glass 18 may be formed from a layer of glass, plastic, or other clear material. Cover glass 18 may, for example, be formed from a transparent layer of glass that is about 0.75 mm to 1 mm thick.
To provide display 14 with touch sensing capabilities and thereby allow display 14 to serve as a touch screen, an array of touch sensor electrodes may be interposed between display module 24 and cover glass 18. In the illustrative side view of
Touch sensor electrodes 22 may be formed on one or both sides of the flexible substrate in touch sensor 20 and may have any suitable shapes. In a typical two-sided configuration, perpendicular elongated rectangular touch sensor electrodes 22 are formed on the top and bottom of the touch sensor substrate. In a typical single-sided configuration, square patches of transparent conductor may be used in forming the electrodes. Other configurations may also be used (e.g., single-sided arrangements based on diagonal electrode patterns, etc.).
The electronic device in which display 14 is mounted may contain storage and processing circuitry such as storage and processing circuitry 30. Display driver circuitry may be coupled to display module 24 using a path such as path 32. Path 32 may be used to route image data to display drivers in module 24. In response, image pixels 26 in module 24 are configured to display a desired image. Because the layers of material in touch sensor 20 and cover glass 18 are transparent, the image that is created by display 24 may be viewed by a user, as indicated schematically by light ray 28.
Storage and processing circuitry 30 may contain circuitry that measures and analyzes the capacitance of electrodes 22. This circuitry may be coupled to electrodes 22 using path 34. By monitoring the capacitances of electrodes 22, changes in capacitance can be measured. These changes in the capacitance associated with electrodes 22 can then be correlated with touch events. Capacitance changes can be detected when an external object is brought within the vicinity of touch sensor 20, so situations in which an external object comes into direct contact with cover glass 18 and situations in which an external object is merely brought into close proximity to cover glass 18 are both generally referred to as touch events.
A conventional glass-based touch sensor structure of the type that may be interposed between a cover glass layer and liquid crystal display module in a portable media player is shown in
Transparent electrodes 40 and 42 are electrically connected to traces in flexible printed circuit 46 (sometimes referred to as a “flex circuit”) using conductive lines 44 on the front surface of glass substrate 38 and conductive lines 48 on the rear surface of glass substrate 38. Flexible printed circuit 46, which is formed from conventional colored polyimide, is used to couple the electrodes and traces on glass substrate 38 to processing circuitry located on system board 60 (
Conductive lines 44 and 48 are formed from screen-printed silver paste. Silver-paste conductive lines exhibit high conductivity, which helps ensure proper operation of the touch sensor.
As shown in the cross-sectional side view of touch sensor 36 of
The minimum thickness for sensor 36 is also limited by the need to provide clearance between adjoining material layers. This is illustrated in the cross-sectional side view of touch sensor structure 36 that is shown in
A top view of an illustrative touch sensor structure of the type that may be used in display 14 of device 10 of
Transparent sensor electrodes can be formed on one or both sides of substrate 76. Transparent sensor electrodes may be formed from a transparent conductive material such as indium-tin oxide or other transparent conductive substance in rows, squares, diagonally oriented groups, or other suitable layouts. In the example of
Conductive paths are formed between electrodes 78 and 80 and tail portion 86 of substrate 76. For example, conductive lines 82 that are connected to respective electrodes 80 may be formed on the front surface of substrate 76, whereas conductive lines 84 that are connected to respective electrodes 78 may be formed on the rear surface of substrate 76. Conductive lines such as lines 82 and 84 may be formed from copper or other suitable conductors. An advantage of using copper to form lines 82 and 84 is that copper is compatible with flexible substrate materials such as polyimide and has a high conductivity. Copper may be deposited by sputtering, evaporation, chemical vapor deposition, screen printing, electroplating, photolithographic patterning techniques, combinations of these fabrication techniques or any other suitable fabrication process. To prevent corrosion, copper lines may be covered with a coating of a corrosion resistant material such as gold.
When substrate 76 is formed from a flexible polymer such as polyimide and is coated with conductive traces such as copper traces, substrate 76 can serve as both a transparent substrate for touch screen electrodes and as a flex circuit path (e.g., all or part of path 34 of
With the unitary flex circuit approach of
Board 90 may be a rigid or flexible printed circuit board. For example, board 90 may be a main logic board that contains integrated circuits and discrete components for implementing storage and processing circuitry 30 of
As shown in the cross-sectional diagram of
The lower surface of touch sensor structure 20 may be coated with antireflection layer 94 to reduce reflections that might otherwise arise from the presence of air gap 96 as light exits the surface of display 24.
Layer 94 may be an antireflection (AR) film such as a polyethylene terephthalate (PET) film or other clear polymer. An AR polymer film that is used for antireflection film layer 94 may have a thickness of about 0.11 mm (as an example) and may have an index of refraction n having a value that lies between that of air (n=1) and substrate 76 (e.g., n=1.4-1.5).
Layer 94 may also be formed by depositing thinner layers of material. For example, layer 94 may be formed form a layer of silicon oxide, a layer of titanium oxide, a layer of a unidirectional nano-structured coating, or other transparent coating that has a thickness of a fraction of a wavelength (e.g., 1 μm or less).
By potentially reducing the thicknesses of adhesive layer 92, touch sensor substrate layer 76, and/or antireflection coating layer 96, the overall thickness of touch sensor structure 20 may be reduced considerably relative to conventionally constructed touch sensor structures.
If desired, the transparent conductive structures that are used as capacitive touch screen electrodes may be formed on a single side of substrate 76. As shown in
As shown in
a and 10b are simplified diagrams of a layered touch substrate, in accordance with one embodiment. The layered touch substrate arrangement may include multiple touch substrates that are stacked, such as in the example of
Described embodiments may include touch I/O device 1001 that can receive touch input for interacting with computing system 1003 (
Touch I/O device 1001 may include a touch sensitive panel which is wholly or partially transparent, semitransparent, non-transparent, opaque or any combination thereof. Touch I/O device 1001 may be embodied as a touch screen, touch pad, a touch screen functioning as a touch pad (e.g., a touch screen replacing the touchpad of a laptop), a touch screen or touchpad combined or incorporated with any other input device (e.g., a touch screen or touchpad disposed on a keyboard) or any multi-dimensional object having a touch sensitive surface for receiving touch input.
In one example, touch I/O device 1001 embodied as a touch screen may include a transparent and/or semitransparent touch sensitive panel partially or wholly positioned over at least a portion of a display. According to this embodiment, touch I/O device 1001 functions to display graphical data transmitted from computing system 1003 (and/or another source) and also functions to receive user input. In other embodiments, touch I/O device 1001 may be embodied as an integrated touch screen where touch sensitive components/devices are integral with display components/devices. In still other embodiments a touch screen may be used as a supplemental or additional display screen for displaying supplemental or the same graphical data as a primary display and to receive touch input.
Touch I/O device 1001 may be configured to detect the location of one or more touches or near touches on device 1001 based on capacitive, resistive, optical, acoustic, inductive, mechanical, chemical measurements, or any phenomena that can be measured with respect to the occurrences of the one or more touches or near touches in proximity to device 1001. Software, hardware, firmware, or any combination thereof may be used to process the measurements of the detected touches to identify and track one or more gestures. A gesture may correspond to stationary or non-stationary, single or multiple, touches or near touches on touch I/O device 1001. A gesture may be performed by moving one or more fingers or other objects in a particular manner on touch I/O device 1001 such as tapping, pressing, rocking, scrubbing, twisting, changing orientation, pressing with varying pressure and the like at essentially the same time, contiguously, or consecutively. A gesture may be characterized by, but is not limited to a pinching, sliding, swiping, rotating, flexing, dragging, or tapping motion between or with any other finger or fingers. A single gesture may be performed with one or more hands, by one or more users, or any combination thereof.
Computing system 1003 may drive a display with graphical data to display a graphical user interface (GUI). The GUI may be configured to receive touch input via touch I/O device 1001. Embodied as a touch screen, touch I/O device 1001 may display the GUI. Alternatively, the GUI may be displayed on a display separate from touch I/O device 1001. The GUI may include graphical elements displayed at particular locations within the interface. Graphical elements may include but are not limited to a variety of displayed virtual input devices including virtual scroll wheels, a virtual keyboard, virtual knobs, virtual buttons, any virtual UI, and the like. A user may perform gestures at one or more particular locations on touch I/O device 1001 which may be associated with the graphical elements of the GUI. In other embodiments, the user may perform gestures at one or more locations that are independent of the locations of graphical elements of the GUI. Gestures performed on touch I/O device 1001 may directly or indirectly manipulate, control, modify, move, actuate, initiate or generally affect graphical elements such as cursors, icons, media files, lists, text, all or portions of images, or the like within the GUI. For instance, in the case of a touch screen, a user may directly interact with a graphical element by performing a gesture over the graphical element on the touch screen. Alternatively, a touch pad generally provides indirect interaction. Gestures may also affect non-displayed GUI elements (e.g., causing user interfaces to appear) or may affect other actions within computing system 1003 (e.g., affect a state or mode of a GUI, application, or operating system). Gestures may or may not be performed on touch I/O device 1001 in conjunction with a displayed cursor. For instance, in the case in which gestures are performed on a touchpad, a cursor (or pointer) may be displayed on a display screen or touch screen and the cursor may be controlled via touch input on the touchpad to interact with graphical objects on the display screen. In other embodiments in which gestures are performed directly on a touch screen, a user may interact directly with objects on the touch screen, with or without a cursor or pointer being displayed on the touch screen.
Feedback may be provided to the user via communication channel 1002 in response to or based on the touch or near touches on touch I/O device 1001. Feedback may be transmitted optically, mechanically, electrically, olfactory, acoustically, or the like or any combination thereof and in a variable or non-variable manner.
Attention is now directed towards embodiments of a system architecture that may be embodied within any portable or non-portable device including but not limited to a communication device (e.g. mobile phone, smart phone), a multi-media device (e.g., MP3 player, TV, radio), a portable or handheld computer (e.g., tablet, netbook, laptop), a desktop computer, an All-In-One desktop, a peripheral device, or any other system or device adaptable to the inclusion of system architecture 2000, including combinations of two or more of these types of devices. FIG. 12 is a block diagram of one embodiment of system 2000 that generally includes one or more computer-readable mediums 2001, processing system 2004, Input/Output (I/O) subsystem 2006, radio frequency (RF) circuitry 2008, and audio circuitry 2010. These components may be coupled by one or more communication buses or signal lines 2003.
It should be apparent that the architecture shown in
RF circuitry 2008 is used to send and receive information over a wireless link or network to one or more other devices and includes well-known circuitry for performing this function. RF circuitry 2008 and audio circuitry 2010 are coupled to processing system 2004 via peripherals interface 2016. Interface 2016 includes various known components for establishing and maintaining communication between peripherals and processing system 2004. Audio circuitry 2010 is coupled to audio speaker 2050 and microphone 2052 and includes known circuitry for processing voice signals received from interface 2016 to enable a user to communicate in real-time with other users. In some embodiments, audio circuitry 2010 includes a headphone jack (not shown).
Peripherals interface 2016 couples the input and output peripherals of the system to processor 2018 and computer-readable medium 2001. One or more processors 2018 communicate with one or more computer-readable mediums 2001 via controller 2020. Computer-readable medium 2001 can be any device or medium that can store code and/or data for use by one or more processors 2018. Medium 2001 can include a memory hierarchy, including but not limited to cache, main memory, and secondary memory. The memory hierarchy can be implemented using any combination of RAM (e.g., SRAM, DRAM, DDRAM), ROM, FLASH, magnetic and/or optical storage devices, such as disk drives, magnetic tape, CDs (compact disks) and DVDs (digital video discs). Medium 2001 may also include a transmission medium for carrying information-bearing signals indicative of computer instructions or data (with or without a carrier wave upon which the signals are modulated). For example, the transmission medium may include a communications network, including but not limited to the Internet (also referred to as the World Wide Web), intranet(s), Local Area Networks (LANs), Wide Local Area Networks (WLANs), Storage Area Networks (SANs), Metropolitan Area Networks (MAN), and the like.
One or more processors 2018 run various software components stored in medium 2001 to perform various functions for system 2000. In some embodiments, the software components include operating system 2022, communication module (or set of instructions) 2024, touch processing module (or set of instructions) 2026, graphics module (or set of instructions) 2028, and one or more applications (or set of instructions) 2030. Each of these modules and above noted applications correspond to a set of instructions for performing one or more functions described above and the methods described in this application (e.g., the computer-implemented methods and other information processing methods described herein). These modules (i.e., sets of instructions) need not be implemented as separate software programs, procedures, or modules, and thus various subsets of these modules may be combined or otherwise re-arranged in various embodiments. In some embodiments, medium 2001 may store a subset of the modules and data structures identified above. Furthermore, medium 2001 may store additional modules and data structures not described above.
Operating system 2022 includes various procedures, sets of instructions, software components, and/or drivers for controlling and managing general system tasks (e.g., memory management, storage device control, power management, etc.) and facilitates communication between various hardware and software components.
Communication module 2024 facilitates communication with other devices over one or more external ports 2036 or via RF circuitry 2008 and includes various software components for handling data received from RF circuitry 2008 and/or external port 2036.
Graphics module 2028 includes various known software components for rendering, animating and displaying graphical objects on a display surface. In embodiments in which touch I/O device 2012 is a touch sensitive display (e.g., touch screen), graphics module 2028 includes components for rendering, displaying, and animating objects on the touch sensitive display.
One or more applications 2030 can include any applications installed on system 2000, including without limitation, a browser, address book, contact list, email, instant messaging, word processing, keyboard emulation, widgets, JAVA-enabled applications, encryption, digital rights management, voice recognition, voice replication, location determination capability (such as that provided by the global positioning system (GPS)), a music player, etc.
Touch processing module 2026 includes various software components for performing various tasks associated with touch I/O device 2012 including but not limited to receiving and processing touch input received from I/O device 2012 via touch I/O device controller 2032.
I/O subsystem 2006 is coupled to touch I/O device 2012 and one or more other I/O devices 2014 for controlling or performing various functions. Touch I/O device 2012 communicates with processing system 2004 via touch I/O device controller 2032, which includes various components for processing user touch input (e.g., scanning hardware). One or more other input controllers 2034 receives/sends electrical signals from/to other I/O devices 2014. Other I/O devices 2014 may include physical buttons, dials, slider switches, sticks, keyboards, touch pads, additional display screens, or any combination thereof.
If embodied as a touch screen, touch I/O device 2012 displays visual output to the user in a GUI. The visual output may include text, graphics, video, and any combination thereof. Some or all of the visual output may correspond to user-interface objects. Touch I/O device 2012 forms a touch-sensitive surface that accepts touch input from the user. Touch I/O device 2012 and touch screen controller 2032 (along with any associated modules and/or sets of instructions in medium 2001) detects and tracks touches or near touches (and any movement or release of the touch) on touch I/O device 2012 and converts the detected touch input into interaction with graphical objects, such as one or more user-interface objects. In the case in which device 2012 is embodied as a touch screen, the user can directly interact with graphical objects that are displayed on the touch screen. Alternatively, in the case in which device 2012 is embodied as a touch device other than a touch screen (e.g., a touch pad), the user may indirectly interact with graphical objects that are displayed on a separate display screen embodied as I/O device 2014.
Touch I/O device 2012 may be analogous to the multi-touch sensitive surface described in the following U.S. Pat. No. 6,323,846 (Westerman et al.), U.S. Pat. No. 6,570,557 (Westerman et al.), and/or U.S. Pat. No. 6,677,932 (Westerman), and/or U.S. Patent Publication 2002/0015024A1, each of which is hereby incorporated by reference.
Embodiments in which touch I/O device 2012 is a touch screen, the touch screen may use LCD (liquid crystal display) technology, LPD (light emitting polymer display) technology, OLED (organic LED), or OEL (organic electro luminescence), although other display technologies may be used in other embodiments.
Feedback may be provided by touch I/O device 2012 based on the user's touch input as well as a state or states of what is being displayed and/or of the computing system. Feedback may be transmitted optically (e.g., light signal or displayed image), mechanically (e.g., haptic feedback, touch feedback, force feedback, or the like), electrically (e.g., electrical stimulation), olfactory, acoustically (e.g., beep or the like), or the like or any combination thereof and in a variable or non-variable manner.
System 2000 also includes power system 2044 for powering the various hardware components and may include a power management system, one or more power sources, a recharging system, a power failure detection circuit, a power converter or inverter, a power status indicator and any other components typically associated with the generation, management and distribution of power in portable devices.
In some embodiments, peripherals interface 2016, one or more processors 2018, and memory controller 2020 may be implemented on a single chip, such as processing system 2004. In some other embodiments, they may be implemented on separate chips.
As shown in the cross-sectional diagram of
Curved (bent) tail portion 86, which is an integral portion of substrate 76, does not generally lie in the plane of cover glass 18 and is therefore not coplanar with the planar portion of substrate 76. Tail portion 86 may be received within connector 88 on printed circuit board 90. Printed circuit board 90 may be a main logic board (e.g., a system board), a daughter card, or any other suitable printed circuit board structure. Connector 88 may be, for example, a zero-insertion-force (ZIF) connector or any other suitable connector. Connector 88 may include contacts that mate with traces on opposing sides of tail portion 86 or may include contacts that mate with a single side of traces on tail portion 86. In configurations in which tail portion 86 contains single-sided traces, vias may be used to form connections that route signals from traces on one surface of substrate 76 to traces on an opposing surface of substrate 76. In lieu of connector 88, tail portion 86 may be attached with to printed circuit board 90 using conductive adhesive or solder joints.
Printed circuit board 90 may be a rigid or flexible printed circuit board. Printed circuit board 90 may be parallel to cover glass 18. For example, board 90 may be a main logic board that contains components 130 such as integrated circuits and discrete components implementing storage and processing circuitry 30 of
The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.
This application claims the benefit of provisional patent application No. 61/227,054, filed Jul. 20, 2009, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | |
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61227054 | Jul 2009 | US |