Control devices, such as joystick navigational pointing devices, are commonplace components related to gaming equipment, cell phones, personal digital assistants, telecommunications equipment, entertainment equipment, digital music players, and other electronic devices. Users now require, to a large degree, the presence of such pointing devices that provide functionality related to touch (e.g. feeling), sight and sound in a dynamic fashion on demand.
For practicality, firmware can be defined as software that is embedded in a hardware device that allows reading and executing the software, but does not allow modification, such as, writing or deleting data by an end user. An example of firmware is a computer program in a read-only memory (ROM) integrated circuit chip. A hardware configuration is usually used to represent the software. Another example of firmware is a program embedded in an erasable programmable read-only memory (EPROM) chip, which program may be modified by special external hardware, but not by an application program.
With regard to navigation devices such as joysticks and computer mice, firmware is used to control the movement of the cursor related to the interaction between the navigation device and the user. For example, as the user moves the navigation device pointer up or North, the cursor moves up or North on the display screen.
Related to haptic feedback, firmware can be used to unify the interaction between a navigation device and user with haptics such as touch sensations, creating the ultimate digital and sensory experience for the user. Using a cell phone joystick as an example, firmware controlling the joystick allows the user to experience all spatial senses such as sight, hearing, and touch making a feature-rich phones easier and more enjoyable to use.
Firmware that adds sight, sound cues, and touch sensations that allows greater realism and intuition in the way people navigate and use joysticks and other navigation pointers in gaming environments (such as when users are playing a game on their cell phone or personal digital assistant) can be defined generally as haptic firmware.
Haptic firmware technologies embedded in such devices help solve the product differentiation problem for handset manufacturers and operators, provide more practical and interactive content options for developers, and redefine the quality of the communication experience for end users.
Variable resistance devices have been used in many applications including joysticks, navigation pointers, sensors, switches, cell phones and transducers. A potentiometer is a simple example of a variable resistance device which has a fixed linear resistance element extending between two end terminals and a slider which is keyed to an input terminal and makes movable contact over the resistance element. The resistance or voltage (assuming constant voltage across the two end terminals) measured across the input terminal and a first one of the two end terminals is proportional to the distance between the first end terminal and the contact point on the resistance element. Resistive elastomers or resistive rubber materials have been used as resistance elements including variable resistance devices. The terms “resistive rubber”, “resistive rubber material” and “resistive material” as used herein, refer to an elastomeric or rubber material which is interspersed with electrically conductive materials including, for example, carbon black, or metallic powder or both.
Examples of pointing devices include U.S. Pat. No. 6,404,323, issued to Schrum et al., titled “Variable Resistance Devices and Methods,” which is hereby incorporated by reference focuses on variable resistance and sensor movement. U.S. Pat. No. 6,352,477, issued to Soma et al., both disclose various types of position reporting devices, joystick, or pointing devices incorporating force related technology.
U.S. Pat. No. 6,404,323, issued to Schrum et al., teaches a variable resistance device that comprises a resistive member having a resistive rubber material. A first conductor is configured to be electrically coupled with the resistive member at a first contact location over a first contact area. A second conductor is configured to be electrically coupled with the resistance member at a second contact location over a second contact area. The first contact location and second contact location are spaced from one another by a distance. The resistance between the first conductor at the first contact location and the second conductor at the second contact location is equal to the sum of a straight resistance component and a parallel path resistance component. At least one of the first location, the second location, the first contact area, and the second contact area is changed to produce a change in resistance between the first conductor and the second conductor. A resistance component increases or decreases as the distance between the first contact location and the second contact location increases or decrease, respectively. The resistance component has predetermined desired characteristics based on selected first and second contact locations and selected first and second contact areas. The first and second contact locations and first and second contact areas can be selected such that the change in the resistance between the first and second contact locations is at least substantially equal to the change in position.
When variable resistance devices similar to those of Schrum et al. are utilized in a gaming environment, a voltage divider value, related to the change in resistance, is determined by a X and Y axis location of the rubber contact across a conductive “read” area. This read area is analogous to the location of a “wiper” across a resistive area in a traditional potentiometer.
The resistance of the rubber used also changes when a Z-axis force is applied. If the Z-axis resistance change differs from the X, Y axis resistance change it can cause counter-intuitive results for the user causing inconsistent positioning reporting. More specifically, when resistive rubber technology is used in gaming devices in high emotion environments, many times device users use extreme amounts of force in handling such gaming devices.
Another example of inconsistent position reporting is also disclosed in U.S. Pat. No. 6,352,477, issued to Soma et al. That problem involved in a force feedback device for sensing the position of the manipulandum near the limits to provided degrees of freedom. For example, force feedback devices typically provide hard stops to limit the motion of the manipulandum to a constrained range. Due to compliance in the mechanical and/or drive system, the problem of sensing the position of the manipulandum is exacerbated at the hard stops. For example, when the user moves the manipulandum fast against the hard stop, the compliance in the system may allow further motion past the hard stop to be sensed by the sensor due to compliance and momentum of the manipulandum. However, when the manipulandum is moved slowly, the momentum inertia is not as strong, and the sensor may not sense extra motion past the hard stop. These two situations can cause problems in sensing an accurate position consistently.
The inconsistent position reporting problem is further exacerbated with variable device joysticks and pointing devices being incorporated into cell phones, digital music players, and personal digital assistants (or PDAs) imposing additional restrictions on the height and size of such devices requiring a miniature form factor or elevation.
As users demand haptic feedback and require dynamic analog performance in a digital environment, the size and height of such conventional devices that meet such criterion are at odds with the user demand for low profile or ultra-thin, high-performance electronic equipment.
There is a need to address these and other drawbacks that are inconsistent with user demands for correct and dynamic position reporting, haptic feedback, and physically thin devices.