Patent Publication Number: US-2020301517-A1

Title: Input device with capacitive touch and proximity sensing

Description:
FIELD OF THE DISCLOSURE 
     This disclosure relates generally to touch sensing input devices and methods of operation. More particularly, this disclosure relates to systems and methods for touch sensing input devices to locate an input device user&#39;s hands or fingers on or near the device. 
     BACKGROUND 
     In many situations input devices, such as keyboards, game controllers, joysticks, directional pads (D-pads), and the like need to be used without the user being able to view the input device. For example, in virtual reality (VR) or augmented reality (AR) environments, a headset, helmet, goggles, or the like often precludes or limits viewing of the input device. Some existing systems have provided a camera or the like to augment the users view of the input device, however, these systems can be unduly complicated and expensive to implement. Other drawbacks, inconveniences, and issues with existing devices and methods also exist. 
     SUMMARY 
     Accordingly, disclosed embodiments address the above-noted, and other, drawbacks, inconveniences, and issues with existing devices and methods. Disclosed embodiments include an input device for a VR or AR system, the input device having at least one input controller for providing user input to the VR or AR system, and a touch sensor adjacent to the at least one input controller and configurable to sense an object touching or proximate to the at least one input controller. 
     In further disclosed embodiments, the input device is a keyboard and the at least one input controller is a key. In further disclosed embodiments, the touch sensor is located beneath the key. In still further embodiments, the touch sensor is located within the key. In still further embodiments, the touch sensor is located on a top surface of the key. In still further embodiments, the touch sensor is an in-mold conductive plastic. 
     In further disclosed embodiments, the input device is a keyboard that has a wrist rest region and a second touch sensor located within the wrist rest region that is configurable to sense an object touching or proximate to the wrist rest region. In further disclosed embodiments, the second touch sensor is a capacitive touch sensor. 
     Further disclosed embodiments, include a keyboard having a plurality of keys and a touch sensor associated with each of the plurality of keys and that senses a touch or proximity of a user&#39;s finger on specific ones of the plurality of keys. In further disclosed embodiments, the touch sensor includes a touch sensor substrate positioned beneath the plurality of keys, and a plurality of electrodes on the touch sensor substrate and positioned to substantially outline a perimeter of each of the plurality of keys. 
     Further disclosed embodiments include a game controller for a VR or AR system, the game controller including at least one input controller for providing user input to the VR or AR system, and a touch sensor adjacent to the at least one input controller and configurable to sense an object touching or proximate to the at least one input controller. 
     In further disclosed embodiments, the at least one input controller is a button. In further disclosed embodiments, the touch sensor is located within the button. In still further embodiments, the touch sensor is located on a top surface of the button. In still further embodiments, the touch sensor comprises in-mold conductive plastic. In still further embodiments, the at least one input controller comprises a joystick. Other advantages, conveniences, and embodiments are also possible. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic block diagram of an example of a capacitive touchpad system. 
         FIG. 2  is a schematic of an input device with capacitive touch sensors in accordance with disclosed embodiments. 
         FIG. 3  is a schematic illustration of an input device with capacitive touch sensors in accordance with disclosed embodiments. 
         FIG. 4  is an exploded, schematic, cross-sectional illustration of a portion of an input device with capacitive touch sensors in accordance with disclosed embodiments. 
         FIG. 5  is a schematic illustration of an input device of the type shown in  FIG. 4  showing exemplary electrode routing for capacitive touch sensors in accordance with disclosed embodiments. 
         FIG. 6  is an exploded, schematic, cross-sectional illustration of a portion of an input device with capacitive touch sensors in accordance with disclosed embodiments. 
         FIG. 7  is a schematic diagram of an input device of the type shown in  FIG. 6  showing exemplary locations of capacitive touch sensors in accordance with disclosed embodiments. 
         FIG. 8  is a schematic diagram of a system implementing a VR or AR input device with capacitive touch sensing in accordance with disclosed embodiments. 
     
    
    
     While the disclosure is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, it should be understood that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the appended claims. 
     DETAILED DESCRIPTION 
     It should be understood that use of the terms “touch pad” and “touch sensor” throughout this document may be used interchangeably with “capacitive touch sensor,” “capacitive sensor,” “capacitive touch and proximity sensor,” “proximity sensor,” “touch and proximity sensor,” “touch panel,” “touchpad,” and “touch screen.” 
     It should also be understood that, as used herein, the terms “vertical,” “horizontal,” “lateral,” “upper,” “lower,” “left,” “right,” “inner,” “outer,” etc., can refer to relative directions or positions of features in the disclosed devices and/or assemblies shown in the Figures. For example, “upper” or “uppermost” can refer to a feature positioned closer to the top of a page than another feature. These terms, however, should be construed broadly to include devices and/or assemblies having other orientations, such as inverted or inclined orientations where top/bottom, over/under, above/below, up/down, and left/right can be interchanged depending on the orientation. 
     The present invention utilizes touchpad technology from CIRQUE® Corporation. Accordingly, it is useful to understand operation of the touchpad technology to a degree. The touchpad technology from CIRQUE® Corporation is a mutual capacitance sensing device  100  and an example is illustrated in  FIG. 1 . For this device  100  a touchpad  10  having a grid of row  12  and column  14  electrodes is used to define the touch-sensitive area of the touchpad  10 . Typically, the touchpad is configured as a rectangular grid of an appropriate number of electrodes (e.g., 8-by-6, 16-by-12, 9-by-15, or the like). 
     As shown in  FIG. 1 , the mutual capacitance sensing device  100  also includes a touch controller  16 . Touch controller  16  typically includes at least one of a central processing unit (CPU), a digital signal processor (DSP), an analog front end (AFE) including amplifiers, a peripheral interface controller (PIC), another type of microprocessor, and/or combinations thereof, and may be implemented as an integrated circuit, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a combination of logic gate circuitry, other types of digital or analog electrical design components, or combinations thereof, with appropriate circuitry, hardware, firmware, and/or software to choose from available modes of operation. 
     Typically, touch controller  16  also includes at least one multiplexing circuit to alternate which of the row  12  or column  14  electrodes are operating as a drive electrode or a sense electrode. The driving electrodes can be driven one at a time in sequence, or randomly, or all at the same time in encoded patterns. Other configurations are possible such as self-capacitance mode where the electrodes are driven and sensed simultaneously. Electrodes may also be arranged in non-rectangular arrays, such as radial patterns, linear strings, or the like. Other configurations are also possible. 
     Typically, no fixed reference point is used for measurements. Touch controller  16  generates signals that are sent directly to the row  12  and column  14  electrodes in various patterns. 
     The touchpad  10  does not depend upon an absolute capacitive measurement to determine the location of a finger (or stylus, pointer, or other object) on the touchpad  10  surface. The touchpad  10  measures an imbalance in electrical charge to the electrode functioning as a sense electrode (exemplarily illustrated as row electrode  121  in  FIG. 1 , but can be any of the row  12 , column  14 , or other dedicated-sense electrodes). When no pointing object is on or near the touchpad  10 , the touch controller  16  is in a balanced state, and there is no signal on the sense electrode (e.g., electrode  121 ). When a finger or other pointing object creates imbalance because of capacitive coupling, a change in capacitance occurs on the plurality of electrodes  12 ,  14  that comprise the touchpad electrode grid. What is measured is the change in capacitance, and not the absolute capacitance value on the electrodes  12 ,  14 . 
       FIG. 2  is a schematic of an input device with capacitive touch sensors in accordance with disclosed embodiments. As shown input device may comprise a keyboard  20  with a typical QWERTY layout for alphabet keys  22 , directional keys  24 , numeric keys  26 , function keys  28 , and the like. Of course, as one of ordinary skill in the art having the benefit of this disclosure would understand, other layouts (e.g., ergonomic or split layouts), key arrangements, types of keys, key functions, number of keys, and the like, may be used. As disclosed herein, keyboard  20  includes touch sensors underneath, or incorporated within, the keyboard as indicated by touch sensor region  30 . Additionally, some keyboards (e.g., laptop keyboards) may include a wrist rest region  32  that includes additional touch sensor regions  30 . In some embodiments, touch sensors  30  may comprise proximity sensing sensors to detect when a user&#39;s hands are near (i.e., in proximity to) a touch sensor region  30 . This is particularly useful for touch sensors  30  in the wrist rest region  32  where a user will often rest or hover their hands without touching the keys. 
       FIG. 3  is a schematic illustration of another input device with capacitive touch sensors in accordance with disclosed embodiments. As shown in  FIG. 30 , an input device may also comprise a game controller  40  with left and right front buttons  42 , a directional pad  44 , A-B-X-Y selection buttons  46 , left and right joysticks  48 , and the like. Of course, as one of ordinary skill in the art having the benefit of this disclosure would understand, other configurations for game controller  40 , button arrangements, types of buttons, button functions, number of buttons, and the like, may be used. Game controller  40  is indicated as being wired  49 , but need not be so, and the disclosed embodiments include wireless controllers  40  as well. As also indicated, each region of the game controller may include touch sensors  30  as exemplarily indicated for joysticks  48  and directional pad  44 . As disclosed above for keyboard  20 , the touch sensors  30  may be underneath the surfaces of, or integrated into, the various buttons, joysticks, and the like on the game controller  40 . Touch sensors  30  can also be integrated into various locations of the game controller  40  housing. 
     While  FIGS. 2-3  show exemplary input devices of a keyboard  20  and game controller  40 , one of ordinary skill in the art having the benefit of this disclosure would understand other input devices such as steering wheels, cockpit joysticks, sporting game paddles, rackets, fishing poles, fighting game weapons, and the like may also be implemented as disclosed herein. 
       FIG. 4  is an exploded, schematic, cross-sectional illustration of a portion of an input device with capacitive touch sensors  30  in accordance with disclosed embodiments. As shown in close-up, for an input device comprising a keyboard  20 , a key (e.g., alphabet key  22 ) may include a shaft  52  or other mechanism for contacting a switch  54  or contact to record presses of the key  22  as is known. A dome  56  or other resilient member (such as a spring, or the like) may cause the shaft  52  and key  22  to return to an initial or un-pressed state. Keyboard  20  may also include a base  58  and a cover  62 . In accordance with disclosed embodiments, a touch sensor  30  may be included on a touch sensor substrate  50  that is positioned in between the keyboard cover  62  and the base  58 . Though not illustrated in  FIG. 4 , one of ordinary skill in the art having the benefit of this disclosure would understand that touch sensor substrate  50  may be suspended, supported, or otherwise anchored to not interfere with the operation of switch  54  and dome  56  or other resilient member and the normal operation of the keys  22 . Likewise, touch sensor substrate  50  includes apertures  51  or other pass-throughs, contacts, or the like to enable presses of the keys  22  to properly operate the switch  54  and dome  56  or other contact mechanisms. Further, keyboard cover  62  is shown spaced above touch sensor substrate  50  for ease of illustration but may be in contact with touch sensor substrate  50 , may be in the same plane as the substrate  50 , may have openings to allow the keys  22  to contact the substrate  50 , or the like. It is also understood that the touch sensor substrate  50  may be combined with the base  58  into one substrate, or they may be laminated together as a composite substrate, or the like. 
     Touch sensor substrate  50  may comprise a printed circuit board (PCB), a flexible printed circuit (FPC), conductive ink printed on a flexible surface (e.g., mylar), an in-mold conductive plastic sensor, or the like. As also indicated schematically, a touch sensor  30  may be included on the top surface of the touch sensor substrate  50 . As also indicated, touch sensor  30  may comprise a number of electrodes (e.g.,  12 ,  14 ) that are etched, printed, or otherwise positioned on the top surface of touch sensor substrate  50 . As better illustrated in  FIG. 5 , the electrodes (e.g.,  12 ,  14 ) are routed to avoid the apertures  51  and shaft  52  and not impede the normal operation of the keys  22  and switches  54 . 
       FIG. 5  is a schematic illustration of an input device of the type shown in  FIG. 4  showing exemplary electrode routing for capacitive touch sensors in accordance with disclosed embodiments.  FIG. 5  is a simplified schematic showing a mutual capacitance electrode layout to sense individual finger locations. As discussed herein, tighter or looser spacing, different pitch, and different layouts may also be used. As shown, an exemplary input device may be a keyboard  20  that is positioned over a touch sensor substrate  50 . As shown, touch sensor substrate  50  may include a number of apertures  51  to enable key shafts or other mechanisms to contact switches for key presses. As also shown, a number of row electrodes  12  (dotted lines) and column electrodes  14  (dashed lines) may be located on the substrate  50  to provide touch or proximity sensing as disclosed herein. As shown in  FIG. 5 , the electrodes  12 ,  14  generally surround the locations of each key of the keyboard  20  so that when the keyboard  20  is in place above the touch sensor substrate  50  a determination of which keys have been touched, or which keys the fingers are located near, can be made as disclosed herein. While the electrodes  12 ,  14  in  FIG. 5  are generally shown as a rectangular layout, they need not be so, and other patterns may be implemented. For example, the column electrodes  14  may be a continuous electrode that is routed in a step-wise fashion as exemplarily indicated at electrodes  14 A, or the electrodes  14  may be of a more free-form layout as indicated at electrodes  14 B, or the electrodes may be free-form or step-wise but be laid out in other directions as indicated at  14 C and  14 D respectively. Similarly, column electrodes  14  may be laid out generally straight and row electrodes  12  may be laid out step-wise, free-form, or the like. Again, other patterns and electrode layouts may also be implemented. As indicated schematically, a main bus or other connector  64  may be used to connect the various electrodes  12 ,  14  to a touch controller or other component systems (not shown in  FIG. 5 ). 
       FIG. 6  is an exploded, schematic, cross-sectional illustration of a portion of an input device with capacitive touch sensors in accordance with disclosed embodiments. As shown in close-up, for an input device comprising a keyboard  20 , a key (e.g., alphabet key  22 ) may include a shaft  52  or other mechanism for contacting a switch  54  or contact to record presses of the key  22  as is known. A dome  56  or other resilient member (such as a spring, or the like) may cause the shaft  52  and key  22  to return to an initial or un-pressed state. Keyboard  20  may also include a base  58  and a cover  62 . In accordance with disclosed embodiments, a touch sensor  30  may be included within each key  22 . In other embodiments, a touch sensor  30 ′ may be included on top of or overlaying each key  22 . In still other embodiments a touch sensor (e.g.,  30 ′) may be included as part of the top surface of each key  22  as, for example, a portion of in-mold conductive plastic or the like. In any case, a flexible or otherwise moveable connection  66  may connect each touch sensor  30 ,  30 ′ with a touch controller  16  and may operate in a self-capacitance, mutual capacitance, or mixed mode. 
       FIG. 7  is a schematic diagram of an input device of the type shown in  FIG. 6  showing exemplary locations of capacitive touch sensors in accordance with disclosed embodiments. As shown, an input device comprising a keyboard  20  may have a touch sensor  30  on or within each key  22  for finger sensing. As also indicated, some keys (e.g., function keys  28 ) may not have touch sensors  30  as desired. 
       FIG. 8  is a schematic diagram of a system  600  implementing a VR or AR input device with capacitive touch sensing in accordance with disclosed embodiments. As indicated, system  600  may include an input device  602  (e.g., keyboard  20 , game controller  40 , or the like) that includes a touch sensor  30  as disclosed herein. Touch sensor  30  is in communication with touch controller  16  to enable various touch and proximity sensing functions as disclosed herein. As also indicated, touch sensor  30 , input device  602 , and touch controller  16  are also in communication with other control systems  604  that may comprise parts of the AR or VR system (e.g., other processors, processor-based devices, controllers, audio systems, input/output devices, or the like) and display  606  which may be a headset or the like worn by a user. 
     As a person of ordinary skill in the art having the benefit of this disclosure would understand, one advantage of the system  600  is that touches or proximity of hands and fingers on the input device  602  are sensed by touch sensor  30  and communicated to the display  606  so that the user may virtually “see” or otherwise receive and indication of hand and finger positions in the VR or AR environment. The system  600  may show the input device  602  as it appears in reality (e.g., to enable typing or the like), may incorporate the input device  602  into the AR or VR environment (e.g., displaying the input device  602  as a tool, weapon, game object, or the like on display  606 ), or combinations thereof as dictated by the VR or AR environment. 
     Although various embodiments have been shown and described, the present disclosure is not so limited and will be understood to include all such modifications and variations would be apparent to one skilled in the art.