Patent Publication Number: US-2013241863-A1

Title: Touch-sensitive display with molded cover and method

Description:
FIELD OF TECHNOLOGY 
     The present disclosure relates to electronic devices including but not limited to portable electronic devices having touch-sensitive displays and their control. 
     BACKGROUND 
     Electronic devices, including portable electronic devices, have gained widespread use and may provide a variety of functions including, for example, telephonic, electronic messaging and other personal information manager (PIM) application functions. Portable electronic devices include several types of devices including mobile stations such as simple cellular telephones, smart telephones (smart phones), Personal Digital Assistants (PDAs), tablet computers, and laptop computers, with wireless network communications or near-field communications connectivity such as Bluetooth® capabilities. 
     Portable electronic devices such as PDAs, or tablet computers are generally intended for handheld use and ease of portability. Smaller devices are generally desirable for portability. A touch-sensitive display, also known as a touchscreen display, is particularly useful on handheld devices, which are small and may have limited space for user input and output. The information displayed on the display may be modified depending on the functions and operations being performed. 
     Improvements in electronic devices with touch-sensitive displays are desirable. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a portable electronic device in accordance with the disclosure. 
         FIG. 2  is a flowchart illustrating a method of molding a cover on touch sensors in accordance with the present disclosure. 
         FIG. 3  through  FIG. 7  are sectional side views illustrating the manufacture of a touch-sensitive display in accordance with the present disclosure. 
         FIG. 8  is an example of a touch-sensitive display with a molded cover on a display with a polarizer in accordance with the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The following describes a touch-sensitive display, an electronic device, and method including disposing capacitive touch sensors on a display and molding a cover over the touch sensors such that the touch sensors are disposed between the display and the cover. 
     For simplicity and clarity of illustration, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. Numerous details are set forth to provide an understanding of the examples described herein. The examples may be practiced without these details. In other instances, well-known methods, procedures, and components are not described in detail to avoid obscuring the examples described. The description is not to be considered as limited to the scope of the examples described herein. 
     The disclosure generally relates to an electronic device, such as a portable electronic device as described herein. Examples of electronic devices include mobile, or handheld, wireless communication devices such as pagers, cellular phones, cellular smart-phones, wireless organizers, personal digital assistants, wirelessly enabled notebook computers, tablet computers, mobile internet devices, electronic navigation devices, and so forth. The portable electronic device may also be a portable electronic device without wireless communication capabilities, such as a handheld electronic game device, digital photograph album, digital camera, media player, e-book reader, and so forth. 
     A block diagram of an example of a portable electronic device  100  is shown in  FIG. 1 . The portable electronic device  100  includes multiple components, such as a processor  102  that controls the overall operation of the portable electronic device  100 . Communication functions, including data and voice communications, are performed through a communication subsystem  104 . Data received by the portable electronic device  100  is decompressed and decrypted by a decoder  106 . The communication subsystem  104  receives messages from and sends messages to a wireless network  150 . The wireless network  150  may be any type of wireless network, including, but not limited to, data wireless networks, voice wireless networks, and networks that support both voice and data communications. A power source  142 , such as one or more rechargeable batteries or a port to an external power supply, powers the portable electronic device  100 . 
     The processor  102  interacts with other components, such as a Random Access Memory (RAM)  108 , memory  110 , a touch-sensitive display  118 , one or more actuators  120 , one or more force sensors  122 , an auxiliary input/output (I/O) subsystem  124 , a data port  126 , a speaker  128 , a microphone  130 , short-range communications  132  and other device subsystems  134 . The touch-sensitive display  118  includes a display  112  and touch sensors  114  that are coupled to at least one controller  116  that is utilized to interact with the processor  102 . Input via a graphical user interface is provided via the touch-sensitive display  118 . Information, such as text, characters, symbols, images, icons, and other items that may be displayed or rendered on a portable electronic device, is displayed on the touch-sensitive display  118  via the processor  102 . The processor  102  may also interact with an accelerometer  136  that may be utilized to detect direction of gravitational forces or gravity-induced reaction forces. 
     To identify a subscriber for network access, the portable electronic device  100  may utilize a Subscriber Identity Module or a Removable User Identity Module (SIM/RUIM) card  138  for communication with a network, such as the wireless network  150 . Alternatively, user identification information may be programmed into memory  110 . 
     The portable electronic device  100  includes an operating system  146  and software programs, applications, or components  148  that are executed by the processor  102  and are typically stored in a persistent, updatable store such as the memory  110 . Additional applications or programs may be loaded onto the portable electronic device  100  through the wireless network  150 , the auxiliary I/O subsystem  124 , the data port  126 , the short-range communications subsystem  132 , or any other suitable subsystem  134 . 
     A received signal such as a text message, an e-mail message, or web page download is processed by the communication subsystem  104  and input to the processor  102 . The processor  102  processes the received signal for output to the display  112  and/or to the auxiliary I/O subsystem  124 . A subscriber may generate data items, for example e-mail messages, which may be transmitted over the wireless network  150  through the communication subsystem  104 . For voice communications, the overall operation of the portable electronic device  100  is similar. The speaker  128  outputs audible information converted from electrical signals, and the microphone  130  converts audible information into electrical signals for processing. 
     The touch-sensitive display  118  may be any suitable touch-sensitive display, such as a capacitive, resistive, infrared, surface acoustic wave (SAW) touch-sensitive display, strain gauge, optical imaging, dispersive signal technology, acoustic pulse recognition, and so forth. A capacitive touch-sensitive display includes one or more capacitive touch sensors  114 . The capacitive touch sensors may comprise any suitable material, such as indium tin oxide (ITO). 
     The touch-sensitive display  118  is a capacitive touch-sensitive display that includes capacitive touch sensors  114 . The capacitive touch sensors may comprise any suitable material, such as indium tin oxide (ITO). 
     One or more touches, also known as touch contacts or touch events, may be detected by the touch-sensitive display  118 . The processor  102  may determine attributes of the touch, including a location of the touch. Touch location data may include data for an area of contact or data for a single point of contact, such as a point at or near a center of the area of contact. The location of a detected touch may include x and y components, e.g., horizontal and vertical components, respectively, with respect to one&#39;s view of the touch-sensitive display  118 . A touch may be detected from any suitable input member, such as a finger, thumb, appendage, or other objects, for example, a stylus, pen, or other pointer, depending on the nature of the touch-sensitive display  118 . Multiple simultaneous touches may be detected. 
     One or more gestures may also be detected by the touch-sensitive display  118 . A gesture, such as a swipe, also known as a flick, is a particular type of touch on a touch-sensitive display  118  and may begin at an origin point and continue to an end point, for example, a concluding end of the gesture. A gesture may be identified by attributes of the gesture, including the origin point, the end point, the distance travelled, the duration, the velocity, and the direction, for example. A gesture may be long or short in distance and/or duration. Two points of the gesture may be utilized to determine a direction of the gesture. A gesture may also include a hover. A hover may be a touch at a location that is generally unchanged over a period of time or is associated with the same selection item for a period of time. 
     The optional actuator(s)  120  may be depressed or activated by applying sufficient force to the touch-sensitive display  118  to overcome the actuation force of the actuator  120 . The actuator(s)  120  may be actuated by pressing anywhere on the touch-sensitive display  118 . The actuator(s)  120  may provide input to the processor  102  when actuated. Actuation of the actuator(s)  120  may result in provision of tactile feedback. When force is applied, the touch-sensitive display  118  is depressible, pivotable, and/or movable. Such a force may actuate the actuator(s)  120 . The touch-sensitive display  118  may, for example, float with respect to the housing of the portable electronic device, i.e., the touch-sensitive display  118  may not be fastened to the housing. A mechanical dome switch actuator may be utilized. In this example, tactile feedback is provided when the dome collapses due to imparted force and when the dome returns to the rest position after release of the switch. Alternatively, the actuator  120  may comprise one or more piezoelectric (piezo) devices that provide tactile feedback for the touch-sensitive display  118 . 
     Optional force sensors  122  may be disposed in conjunction with the touch-sensitive display  118  to determine or react to forces applied to the touch-sensitive display  118 . The force sensor  122  may be disposed in line with a piezo actuator  120 . The force sensors  122  may be force-sensitive resistors, strain gauges, piezoelectric or piezoresistive devices, pressure sensors, quantum tunneling composites, force-sensitive switches, or other suitable devices. Force as utilized throughout the specification, including the claims, refers to force measurements, estimates, and/or calculations, such as pressure, deformation, stress, strain, force density, force-area relationships, thrust, torque, and other effects that include force or related quantities. Optionally, force information related to a detected touch may be utilized to select information, such as information associated with a location of a touch. For example, a touch that does not meet a force threshold may highlight a selection option, whereas a touch that meets a force threshold may select or input that selection option. Selection options include, for example, displayed or virtual keys of a keyboard; selection boxes or windows, e.g., “cancel,” “delete,” or “unlock”; function buttons, such as play or stop on a music player; and so forth. Different magnitudes of force may be associated with different functions or input. For example, a lesser force may result in panning, and a higher force may result in zooming. 
     In known devices, touch sensors are included in a touch-sensitive overlay that is adhered to a display and a plastic or glass cover is adhered to the touch sensors to protect the touch sensors. As described herein, a touch-sensitive display, which may be disposed in an electronic device, includes capacitive touch sensors disposed on a display with a cover imolded over the touch sensors such that the touch sensors are disposed between the display and the cover. 
     A flowchart illustrating a method of manufacturing a touch-sensitive display of an electronic device is shown in  FIG. 5 . The method may contain additional or fewer processes than shown and/or described, and may be performed in a different order. The order of the elements may differ from the one in the examples shown herein. 
     The capacitive touch sensors  114  are disposed  202  on the display  112 . For example, the capacitive touch sensors  114  may be deposited on a polarizer of the display  112 . The touch sensors  114 , or electrodes, may be deposited, for example, by depositing a conductive material such as indium tin oxide (ITO) on the display  112 , followed by laser patterning of the conductive material into desired shape(s) and arrangement. 
     A flex connector may be coupled  204  to the touch sensors  114 , for example, by soldering the flex connector conductors to bond pads of the touch sensors  114 . 
     A cover is molded  206  on the touch sensors, for example, by placing the display  112 , including the capacitive touch sensors  114  and the flex connector, in a mold and injection molding or overmolding plastic onto the touch sensors  114 . Materials other than plastic and other processes may be utilized to overmold the cover. 
     Sectional side views illustrating one example of a touch-sensitive display  118  are shown in  FIG. 3  through  FIG. 7 . A display  112  is shown in  FIG. 3 . The display  112  may be, for example, a liquid crystal display (LCD), a light-emitting diode (LED) display, or an organic light-emitting diode (OLED) display. 
     In this example, the touch sensors  114  include first touch sensors  402  disposed directly on the display  112 , as illustrated in  FIG. 4 . The first touch sensors  402  may be disposed on a polarizer of the display  112  by depositing a conductive material such as indium tin oxide (ITO) on the polarizer, followed by patterning the conductive material. In this example, the first touch sensors  402  include a plurality of touch sensors that are parallel touch sensors or electrodes. 
     A dielectric  502  disposed on the first touch sensors  402  is illustrated in  FIG. 5 . The dielectric  502  may be disposed on the first touch sensors  402 , for example, by plasma enhanced chemical vapor deposition or sputter coating. 
     The touch sensors  114  also include second touch sensors  602  disposed on the display  112 , as illustrated in  FIG. 6 . The second touch sensors  602  are disposed on the dielectric  502  such that the dielectric  502  is disposed between the first touch sensors  402  and the second touch sensors  602 . The second touch sensors  602  may be disposed on the dielectric  502  by depositing a conductive material such as indium tin oxide (ITO), followed by patterning of the conductive material. The second touch sensors  602  include a plurality of touch sensors that are parallel touch sensors or electrodes and extend in a direction generally perpendicular to the direction of the first touch sensors  402 . The second touch sensors  602  cross over the first touch sensors  402  in a grid. For example, the first touch sensors  402  may be a plurality of electrodes disposed parallel to a first axis and the second touch sensors  602  may be a plurality of electrodes disposed parallel to a second axis that is perpendicular to the first axis. Typically, the first touch sensors  402  are disposed in a first plane and the second touch sensors  602  are disposed in a second plane that is parallel to the first plane. Other materials or layers may be present that are not shown. 
     A flex connector  604  may be coupled to the first touch sensors  402  and to the second touch sensors  602 . The flex connector  604  may be utilized to couple the first touch sensors  402  and the second touch sensors  602 , for example, to a printed circuit board coupled to the controller  116 . Alternatively, the controller  116  may be coupled to the flex connector  604  and fixed to the connector  604  and the remainder of the touch-sensitive display  118  during molding. The controller  116  may alternatively be integrated with a display controller and coupled to the flex connector  604 . 
     A plastic cover  702  injection molded over the second touch sensors  602  is illustrated in  FIG. 7 . To mold the plastic cover  702 , the display  112 , the first touch sensors  402 , the dielectric  502 , the second touch sensors  602 , and the flex connector are placed into a mold. The plastic cover  702  is overmolded over the second touch sensors  602  and the dielectric  502 . 
     In the example described above, touch sensors  114  are deposited directly on the display  112 . Alternatively, the touch sensors  114  may be deposited on a substrate, such as polyethylene terephthalate, and the substrate may be fixed to the display prior to overmolding. Optionally, the plastic cover  702  may be molded over or around sides of the display  112  to protect the display  112 . Overmolding the cover over or around the sides may fix the substrate to the display, rather than utilizing adhesive. Overmolding over or around the sides may also provide protection from humidity, dust, and other environmental elements. 
     Another example of a cover  702  molded over the touch sensors  602  is illustrated in  FIG. 8 . The first touch sensors  402  are deposited directly on an outer layer or surface of the display  112 . In this example, the outer layer or outer surface of the display  112  is a polarizer  802  or outer surface of the polarizer  802 . As described above, the first touch sensors  402  are deposited directly on the polarizer  802  of the display  112 . A dielectric  502  is disposed on the first touch sensors  402  and the second touch sensors  602  are disposed on the dielectric. The cover  702  is molded directly on the second touch sensors  602 . 
     Although the touch sensors are described in the above examples as capacitive touch sensors, the touch sensors may be any type of touch sensors for any type of touch-sensitive display, such as described above. 
     A method includes disposing touch sensors on a display, and injection molding a cover over the touch sensors such that the touch sensors are disposed between the display and the cover. Other orders of layers are possible. 
     A touch-sensitive display includes a display, touch sensors disposed on the display, and a cover injection molded on the touch sensors such that the touch sensors are disposed between the display and the cover. 
     An electronic device includes a processor, a display coupled to the processor, touch sensors disposed on the display and coupled to the processor via a controller, and a cover injection molded on the touch sensors such that the touch sensors are disposed between the display and the cover. 
     The cover protects the touch sensors from the environment. By depositing the touch sensors onto the display and overmolding the cover over the display and the touch sensors, the cover bonds to the touch sensors. An adhesive is not utilized to couple the cover to the touch sensors on the touch-sensitive display, and the thickness of the touch-sensitive display is reduced. Touches on the touch-sensitive display may be more easily detected and the touch detection may be more easily controlled because of the reduced thickness when the additional adhesive layer is not present. The process of overmolding the cover may also reduce yield losses resulting from defects introduced during manufacture. Overmolding the cover also facilitates manufacturing a touch-sensitive display within tight tolerances, rather than utilizing separate parts that are later adhered to each other, increasing the tolerances and risk of contamination of the touch-sensitive display. 
     The present disclosure may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the present disclosure is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.