Patent Publication Number: US-2022221909-A1

Title: Information handling system variable feel input device

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates in general to the field of information handling system input devices, and more particularly to an information handling system variable feel input device. 
     Description of the Related Art 
     As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems. 
     Information handling systems include processing components that cooperate to process information. Desktop or other stationary systems have a housing that contains the processing components and interacts with end users through peripheral devices, such as a peripheral keyboard and display. Portable systems integrate a display and a power source in a portable housing to support mobile operations. Portable information handling systems allow end users to carry a system between meetings, during travel, and between home and office locations so that an end user has access to processing capabilities while mobile. Convertible configurations typically include multiple separate housing portions that couple to each other so that the system converts between closed and open positions. For example, a main housing portion integrates processing components and a keyboard and rotationally couples with hinges to a lid housing portion that integrates a display. In a clamshell configuration, the lid housing portion rotates approximately ninety degrees to a raised position above the main housing portion so that an end user can type inputs at an integrated keyboard while viewing the display. After usage, convertible information handling systems rotate the lid housing portion over the main housing portion to protect the keyboard and display, thus reducing the system footprint for improved storage and mobility. Typically, portable systems will also interface with peripheral devices, such as a peripheral keyboard and display. 
     Generally, keyboards provide a common input device for information handling systems that allow end users to interact with a wide variety of applications. Peripheral keyboards typically comply with ANSI and/or ISO standards that define how keyboard keys are arranged and the type of key movements that will generate an input, such as a 4.0 mm key depression. In some portable systems, keyboard keys can have a smaller size and reduced key depression to help reduce the housing size. Typically, keyboard keys tend to have a uniform expected “feel” for the resistance to end user press, the amount of depression to indicate an input and the feedback once an input is completed. A uniform keyboard feel lets an end user have a predictable input environment, however, different applications and end users may have improved performance from non-uniform key press responses, such as the resistance to an input and the depression to complete an input. For example, gamers often desire responsive keyboards that match the end user&#39;s input style, while typists who perform word processing may be satisfied with a uniform keyboard key response. Some keyboards offer key modules that have specified key travel actuating and operating forces, such as the CHERRY modules available from KeyMouse. An end user selects a key module with desired operating conditions and inserts the key modules into the keyboard. Although this allows an end user to customize key response, changing key response for specific conditions can be a time consuming process as key modules are swapped out at the keyboard. 
     SUMMARY OF THE INVENTION 
     Therefore, a need has arisen for a system and method which provides a programmable adjustment of key response in a keyboard. 
     In accordance with the present invention, a system and method are provided which substantially reduce the disadvantages and problems associated with previous methods and systems for adapting a keyboard key response. Input device characteristics, such as a keyboard key, are customized by adjusting a magnetic field proximate to a chamber of magneto-rheological fluid in which a member of the input device is disposed. Keystroke distance to an input and key resistance to compression are managed by adjusting a current applied to a magnetizing coil based upon key position and/or velocity. 
     More specifically, a portable information handling system processes information with a processor and memory disposed in a portable housing and accepts inputs through a keyboard integrated in the portable housing. The keyboard has plural keys with each key&#39;s input characteristics managed by a variable stroke module. The variable stroke module forms a chamber that holds magneto-rheological fluid and controls the viscosity of the magneto-rheological fluid with a magnetizing coil disposed around the chamber. A member extends out from the chamber to accept a key and translate key inputs to work against the magneto-rheological fluid and a biasing mechanism that biases the key upward and away from the variable stroke module. For example, the member terminates as a piston within the chamber that has openings to manage the resistance provided by the magneto-rheological fluid to the key based upon the viscosity as set by the strength of a magnetic field formed at the chamber. A position sensor, such as time of flight sensor, a rheostat or a Hall sensor, detects a position of the key and/or velocity of the key to control the magnetic field to target desired key characteristics, such as completing a key stroke at an input press distance by increasing the magnetic field, releasing the key to bias upward after the input and detection of upward movement, such as by turning off the magnetic field, and changing the keystroke characteristics as the key descends downward with a press, such as by linearly increasing current applied to the magnet. In alternative embodiments, inputs at alternative inputs devices may be controlled, such as other push button input devices. 
     The present invention provides a number of important technical advantages. One example of an important technical advantage is that a keyboard key has a customizable response that enhances an end user experience by adapting keyboard response based upon end user preference for specific use cases, such as different types of applications. An end user may customize the keystroke length from full extension upward by a biasing device to an input detection so that the compression distance can adjust, for example, from 4 mm to 3 mm or less. The end user may also customize how the key feel changes through course of a key input. An end user is provided with customizable key response without having physically change out key modules or adjust physical key settings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention may be better understood, and its numerous objects, features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. The use of the same reference number throughout the several figures designates a like or similar element. 
         FIG. 1  depicts an exploded perspective view of a portable information handling system having an integrated keyboard with variable stroke modules to vary key feel; 
         FIG. 2  depicts a side perspective view of an example embodiment of a variable stroke module. 
         FIG. 3  depicts a side perspective sectional view of the variable stroke module with the piston in a raised position; 
         FIG. 4  depicts a side perspective view of an example embodiment of a piston that inserts in the module housing; 
         FIG. 5  depicts a side perspective view of plural keys arranged as a part of a keyboard with each key&#39;s movement defined by a variable stroke module; and 
         FIG. 6  depicts a block diagram of a feedback control loop that manages key input customization. 
     
    
    
     DETAILED DESCRIPTION 
     An input device, such as a key of a keyboard, provides a variable feel input response by adjusting a magnetic field proximate a chamber of the input device having a magneto-rheological fluid. For purposes of this disclosure, an information handling system may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an information handling system may be a personal computer, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system may include random access memory (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of the information handling system may include one or more disk drives, one or more network ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, and a video display. The information handling system may also include one or more buses operable to transmit communications between the various hardware components. 
     Referring now to  FIG. 1 , an exploded perspective view depicts a portable information handling system  10  having an integrated keyboard  36  with a variable stroke module  40  to vary key feel. In the example embodiment, information handling system  10  processes information with processing components disposed in a housing  12  having a lid housing portion  14  rotationally coupled to a main housing portion  16  by a hinge  18 . Lid housing portion  14  integrates a display  20  that presents information as visual images. In the depicted clamshell open position, main housing portion  16  holds display  20  is a viewing position with keyboard  36  supported on a cover  34  to accept inputs typed by an end user. A motherboard  22  couples to main housing portion  16  to support communication between processing components that cooperate to process information. For instance, a central processing unit (CPU)  24  executes instructions that process information. A random access memory (RAM)  26  stores the instructions and information. A graphics processing unit (GPU)  28  further processes the information to generate pixel values that define visual images presented at display  20 . A solid state drive (SSD)  30  or other persistent storage device stores the instructions and information during power down states of the system, such as an operating system and applications that are retrieved at power up to RAM  26  for execution on CPU  24 . An embedded controller  32  manages operating conditions for the processing components, such as power supply and thermals. In addition, embedded controller  32  is a keyboard controller that receives inputs from keyboard  36  for communication to CPU  24 . 
     In the example embodiment, keyboard  36  and a touchpad  38  couple to an upper surface of a cover housing portion  34  that, in turn, couples to main housing portion  16 . Keyboard  36  is exposed at the upper surface of main housing portion  16  to accept an end user&#39;s typed inputs with presses at keys  38  that translate into inputs through variable stroke modules  40 . Variable stroke modules  40  have a programmable response to key inputs so that the feel to an end user at a key input is selectable, such as the compression load needed to depress the key and the compression extension needed to complete an input. For example, an end user programs embedded controller  32  to customize the touch response to a key input, and variable stroke module  40  adjusts the response to key touches to achieve the end user selection. For example, a key touch may have a light initial resistance that increases as the key depresses with a very high resistance once an input is recorded. The amount of resistance may change based on context, such as the application executing on the system or the types of presses detected at the keys over time. For example, a gaming application may have a greater or lesser compression resistance to presses and smaller or larger compression stroke than a word processing application. As another example, inputs at keys may be monitored over time to determine a desired key response of the end user making the key inputs, and then variable stroke module  40  may gradually adjust the key response by changing the settings for the variable stroke modules  40  for keyboard  36 , such as through embedded controller  32 . In the example embodiment, keyboard  36  integrates in portable information handling system  10 ; however, in alternative embodiments, keyboard  36  may be a peripheral keyboard separate from the information handling system and interfaced through a cable or a wireless interface. In addition variable stroke module  40  may adjust input feel associated with other types of input devices, such as push buttons. 
     Referring now to  FIG. 2 , a side perspective view depicts an example embodiment of a variable stroke module  40 . A piston  42  extends out of a module housing  46  through a seal  44  that seals a fluid within a chamber defined by module housing  46 . A red/green/blue LED  48  is disposed at the upper side of module housing  46  to provide illumination effects. A time of flight sensor  50  is disposed at the base of module housing  46  to detect a position of the key coupled to piston  42 . In alternative embodiments, other position sensors may be used, such as rheostat, a Hall sensor with an opposing magnet coupled to the key or other sensors that measures a physical position of the key or piston relative to module housing  46 . When an end user presses on a key to depress piston  42  into module housing  46 , time of flight sensor  50  detects the reduced distance to set a viscosity of fluid in module housing  46  and to detect when an input distance has been traveled for reporting the press as an input. In addition, time of flight sensors  50  can determine a rate of change of distances over time to estimate a velocity of the key movement up or down. In one embodiment, time of flight sensor  50  includes a processing element, such as a microcontroller with flash memory and stored instructions that manages viscosity of fluid in module housing  46  and reports key inputs to an embedded controller. In an alternative embodiment, time of flight sensor  50  reports detected distance and/or velocities to the embedded controller or other processing resources that manage fluid viscosity and input determinations. Similarly, a Hall sensor may be used to detect position and velocity based upon a magnet coupled to the key. 
     Referring now to  FIG. 3 , a side perspective sectional view depicts the variable stroke module  40  with piston  42  in a raised position. A biasing mechanism  54 , such as a spring, is disposed in module housing  46  under piston  42  to bias piston  42  towards a raised position. A magnetizing coil  52  is disposed at the outer circumference of a chamber  56  defined within module housing  46  and interfaced with a current source that selectively applies a current to generate a magnetic field. Within chamber  56 , a magneto-rheological fluid is disposed around a piston  42  to dampen and resist movement of piston  42  within chamber  56 . In the raised position as depicted, biasing mechanism  54  biases piston  42  upward to a raised position so that magneto-rheological fluid disposed in chamber  56  flows under the base of piston  42 . Although biasing mechanism  54  is depicted in the example embodiment as a spring disposed in chamber  56 , in alternative embodiments, a spring may be coupled to the plunger or key outside the chamber and may use mechanisms other than a spring. The raised position is the default position of the key, which is raised and prepared to accept an input. In the raised position, magnetizing coil  52  is off so that no magnetic field works to increase the viscosity of the magneto-rheological fluid. An initial press down on piston  42  will result in a base resistance of the magneto-rheological to movement. Once movement of piston  42  is detected by time of flight sensor  50 , a current is applied to magnetizing coil  52  to increase the viscosity of the magneto-rheological fluid. The amount of resistance to piston  42  motion is varied by increasing and decreasing current applied to magnetizing coil  52  so that magnetic field increases and decreases. For example, once key movement is detected, a linear increase in current and associated magnetic force gradually increases resistance to the key press until an input is detected, at which point a high current can increase resistance to feel like a complete key depression has taken place. Once an upward motion is detected under the influence of the biasing mechanism  54 , current at magnetizing coil  52  may be set to zero to reduce resistance of the magneto-rheological fluid to the upward motion of piston  42 . As described above, an end user may customize a key response by establishing variations in current at magnetizing coil  52  based upon positions and or velocities of piston  42  as detected by time of flight sensor  50 . 
     Referring now to  FIG. 4 , a side perspective depicts an example embodiment of a piston  42  that inserts in the module housing. Piston  42  has a member that extends up to a key attachment and a base having plural openings  58 . The circumference of the base fits into the circumference of the module housing chamber so that fluid in the chamber is forced to pass through openings  58  as piston  42  moves up and down. The amount of resistance to movement of piston  42  depends upon the viscosity of the magneto-rheological fluid disposed in the chamber, which in turn is set by the strength of the magnetic field defined at the module housing by the magnetizing coil. Although the piston and chamber arrangement provides a reliable key stroke with good support of the input member extending out of the module housing, in alternative embodiments of internal structures may be used to create a reliable keystroke and predictable resistance to key presses. 
     Referring now to  FIG. 5 , a side perspective view depicts plural keys  38  arranged as a part of a keyboard with each key&#39;s movement defined by a variable stroke module  40 . The key  38  inputs are reported by each key&#39;s time of flight sensor  50  to embedded controller  32  when the key depresses to a programmed depth associated with a completed input. A stroke control module  60  executing on embedded controller  32  manages custom key settings, such as the amount of keystroke to detect an input and the resistance to key movement. For example, an end user inputs desired key customization to an operating system having a driver for a keyboard with available settings for variable stroke modules  40 , such distances to the time of flight sensor at which an input is detected and current setting for application to the magnetizing coil based on key position, key velocity and key direction of movement. Stroke control module  60  programs the customization settings in a processing element of each time of flight sensor for application during operations of the keyboard. In an alternative embodiment, embedded controller  32  may receive sensed conditions of the time of flight sensor and directly control the key input characteristics. 
     Referring now to  FIG. 6 , a block diagram of a feedback control loop is depicted that manages key input customization. In the example embodiment, a key press is managed by embedded controller  32  by applying a current to a coil driver  62  that manages the amount of current applied at the key through a magnetized coil  52 . A positions sensor, such as a time of flight sensor  50 , provides changes in position, velocity and direction of the key back to controller  32 , which applies the key information to adjust management of the coil driver and magnetizing coil output. The control model may vary based upon the type of magneto-rheological fluid, the size and current capacity of the magnetizing coil, the sensitivity of the position sensor, the size of openings in the input device member that pass the magneto-rheological fluid and the spring resilience. Generally, the available force profiles will be the sum of the damping force provided by the input device member passing through the magneto-rheological fluid and the linear spring force. 
     Although the present invention has been described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention as defined by the appended claims.