Apple enlightens us with 34 new touchscreen patents
If you’ve been thinking of suing Apple for their touch technologies lately, then be prepared to have your Fourth of July weekend ruined. It’ll take that long just to get through Apple’s 34 lengthy new touch screen related patents that were published today by the US Patent & Trademark Office. Then again, some of you that may be sitting in a cell at this very moment - may actually have the extra time on your hands to do just that. This report highlights some of the more interesting patents of the day covering such topics as flex circuit bonding, multi-event input systems and multiple sensors.
Patent: Multi-Touch Surface Stackup Arrangement
Apple’s patent relates to covers for electronic devices, and more particularly, to a cover that is able to provide light-transmissive apertures required for various sensors and display devices in an electronic device, while hiding them from the user to provide a seamless, uncluttered visual appearance.
Apple’s patent FIG. 2 illustrates a top view of an exemplary electronic device incorporating the computing system of FIG. 1 according to one embodiment of this invention.
Going into a little more depth, Apple’s patent discusses a multi-layer cover for an electronic device having one or more of a sensor panel, a proximity sensor, an ambient light sensor, and a display device can include an outer hardcoat, a structural layer, an IR transmissive ink layer, a mask layer, and a backside hardcoat. The backside hardcoat can reduce cover warpage, enable full surface lamination of the cover to the sensor panel, prevent bubbles from forming in transparent windows in the cover, enable a wider range of functional inks to be applied in various layering orders to allow certain types of light to pass through while blocking others, and hide the sensors to provide a seamless, uncluttered visual appearance.
Electronic devices can include a sensor panel, a display device, ambient light sensors, discrete proximity sensors, and other openings. To accommodate the sensor panel and display device, a transparent aperture can be formed on the cover of the electronic device. In addition, to allow light to be detected by the ambient light sensor, an ambient light aperture can be substantially aligned with the ambient light sensor. Furthermore, to allow IR light to be transmitted from and received by the proximity sensor, an IR aperture can be substantially aligned with the proximity sensor. All other areas on the cover can present a uniform appearance, such as a black finish, to the user. In addition, it can be desirable to extend this uniform appearance over the ambient light aperture and the IR aperture to hide these apertures and give a simple, uncluttered appearance to the device.
The cover can include, from outside to inside, an outer hardcoat, which can be substantially transparent and be capable of preventing moisture absorption, followed by a structural layer, which can also be substantially transparent and formed from a plastic such as polymethyl methacrylate (PMMA). The next layer of the cover can be an IR transmissive ink, which can pass IR light and some amount of visible (ambient) light, and can also provide a uniform color (e.g. black) representing the primary color of the cover. The next layer of the cover can be a mask layer, which can be generally opaque and capable of blocking both IR and visible light. The mask layer can be the same color as the IR transmissive ink to further maintain the uniform appearance of the cover. The next layer of the cover can be a backside hardcoat, which can be a different type of hardcoat from the outer hardcoat. The backside hardcoat can be substantially transparent, can have a thermal coefficient of expansion similar or identical to that of the outer hardcoat, and can act as a moisture barrier for the cover.
With the IR transmissive ink applied directly to the structural layer, and the mask layer applied to the IR transmissive ink, a single, unbroken, uniform layer of IR transmissive ink is present at the user side of the cover. As a result, the apertures in the mask layer cannot be seen, and a uniform appearance is presented.
Patent: Multi-Event Input System
Apple’s patent relates generally to input systems, methods, and devices, and more particularly, to multi-event input systems, methods, and devices for use in connection with touch-sensitive electronic devices.
Unlike conventional touch screens, the touch screens (noted below as #120 in Figures 1A, B and C collectively) are capable of recognizing multiple types of touch inputs. The touch screen allows for handling of different events depending on what is used to touch the touch screen. In accordance with various embodiments of the present disclosure, the touch screen is capable of distinguishing between a contact made by a flesh surface of a finger and a contact made by a non-flesh surface of the finger, such as a fingernail.
The fingernail 150 may provide a more precise contact than a fleshy surface such as a fingertip. In other embodiments, the non-flesh surface may comprise an electrically insulative material of a suitable thickness coupled to the finger. For example, as depicted in FIG. 1B, the non-flesh surface may comprise a rubber finger cap or sleeve having a suitable thickness. As another example, the non-flesh surface may comprise a partially fingerless glove, i.e., a glove that is missing one or some of its fingers or fingertips. In some embodiments, at least one of the glove fingers may have an insulated fingertip area, and at least another of the glove fingers may lack a fingertip portion to allow at least one of the user’s fingers to be uncovered. An uncovered finger may be used to drive a first event system, i.e., one class of events, and a covered finger may be used to drive a second event system, i.e., a different class of events.
As yet another illustrative example, in a media player application, while playing a movie or song, or other audio or video content, dragging with the second surface of the finger may be used to scrub through the content, i.e., move the currently viewed or heard part of it backwards or forwards in order to locate something in it quickly, as depicted in FIGS. 10A-10C.
The foregoing examples are provided as illustrative examples of uses in which a first surface of a finger can be used to drive a first event system and a second, distinguishable surface of a finger can be used to drive a second event system. In various embodiments, the first surface may generally correspond to a flesh surface of a finger, while the second surface may generally correspond to a non-flesh surface of a finger (such as a fingernail or finger cap, etc.), or vice versa. The examples provided in the present specification are examples only and are not intended to be exhaustive or limiting. Furthermore, additional gestures may be implemented in accordance with the principles of the present disclosure. For example, a combination of finger surfaces may be used to implement additional gestures in connection with a multipoint touch screen which is capable of sensing multiple points at the same time. The combination may comprise, for example, a combination of two or more flesh surfaces, a combination of two or more non-flesh surfaces, or a combination of at least one flesh surface and at least one non-flesh surface, etc.
Patent: Advanced Frequency Calibration
Apple’s patent relates to tuned oscillation circuits for electronic devices, and more particularly to tuning a variable oscillator to produce a precise oscillating signal.
Apple’s patent FIG. 2c is a side view of the exemplary capacitive touch sensor or pixel in a dynamic (touch) condition in accordance with one embodiment of the present invention.
According Apple’s background documentation, there are many types of input devices that are presently available for performing operations in a computing system - such as buttons or keys, mice, trackballs, touch panels, joysticks, touch screens and the like. Touch screens, in particular, are becoming increasingly popular because of their ease and versatility of operation as well as their declining price. Touch screens may include a touch panel, which may be a clear panel with a touch-sensitive surface. The touch panel may be positioned in front of a display screen so that the touch-sensitive surface covers the viewable area of the display screen. Touch screens may allow a user to make selections and move a cursor by simply touching the display screen via a finger or stylus. In general, the touch screen may recognize the touch and position of the touch on the display screen, and the computing system may interpret the touch and thereafter perform an action based on the touch event.
One limitation of many conventional touch panel technologies is that they are only capable of reporting a single point or touch event, even when multiple objects come into contact with the sensing surface. That is, they lack the ability to track multiple points of contact at the same time. Thus, even when two points are touched, these conventional devices only identify a single location, which is typically the average between the two contacts (e.g., a conventional touchpad on a notebook computer provides such functionality). This single-point identification is a function of the way these devices provide a value representative of the touch point, which is generally by providing an average resistance or capacitance value.
Moreover, many touch-panel devices use oscillating signals to power and clock electronic elements. Examples of their use include providing clock signals, or providing carrier signals which can later be modified to include information. For example, an oscillating signal can be used to drive a row in a capacitive touch sensor panel. Changes to the sensed signal indicate a touch event at the panel.
There are various known ways to create an oscillating signal. For example, persons of skill in the art would recognize that a simple circuit including an inductor and a capacitor would create such a signal. However, most circuit based oscillators suffer from the fact that they do not provide a signal with a precise and predictable frequency. Apple’s patent presents a solution in respect to tuning a variable oscillator to produce a precise oscillating signal.
Patent: Noise Reduction Within an Electronic Device using Automatic Frequency Modulation
Apple’s patent relates to tuned oscillation circuits for electronic devices, and more particularly to providing a precise oscillating signal without using a crystal as a reference.
The oscillator circuit of FIG. 1, illustrated above, is typically a fast startup oscillator to allow fast lock after the system wakes up from a lower power management state to scan the multi-touch panel. To reduce the time between wake-up, scanning the multi-touch panel and going back into a lower power state, it is advantageous for the oscillating signal to become stable in a relatively short period in order to minimize the time the system is active and thus to conserve power.
According to Apple’s background information, oscillating signals are widely used in electronics. Examples of their use include providing clock signals, or providing carrier signals which can later be modified to include information. For example, an oscillating signal can be used to drive a row in a capacitive touch sensor panel. Changes to the sensed signal indicate a touch event at the panel.
There are various known ways to create an oscillating signal. For example, persons of skill in the art would recognize that a simple circuit including an inductor and a capacitor would create such a signal. However, most circuit based oscillators suffer from the fact that they do not provide a signal with a precise and predictable frequency and phase.
Therefore, many electronic devices use crystals to provide an oscillating signal. Crystals are known to provide signals of more precise frequencies. Since it may desirable to generate a wide range of frequencies in a higher frequency band, the crystal may serve as a frequency reference for a frequency multiplier whose output provides a stable frequency which accurately tracks the crystal frequency and can be a multiple of the crystal frequency, the same or lower frequency Such circuit is referred to as a Phase Locked Loop, or PLL. Using a PLL to generate higher frequencies has the benefit of generating accurate and higher frequencies from a crystal based reference clock that’s much lower in frequency, potentially easing the requirement on the type of crystal used and lowering power consumption.
However, the use of crystals adds significant costs to the system not only because of the crystal itself but also because of associated support circuitry and PCB space., which is usually very limited in some devices such as, for example, small hand held products. Apple’s patent covers the delivery of a precise oscillating signal without using a crystal as a reference. Another of Apple’s patents covering this topic published today is titled Automatic frequency calibration.
Patent: Proximity and Multi-Touch Sensor Detection and Demodulation
Apple’s patent relates to panels used as input devices for computing systems, and more particularly, the detection and processing of multi-touch events (the touching of fingers or other objects upon a touch-sensitive surface at distinct locations at about the same time) and hover events (the no-touch, close proximity hovering of fingers or other objects above a touch-sensitive surface but outside the near-field detection capabilities of touch sensors).
Apple’s patent FIG. 4e illustrates an exemplary concurrent use of proximity sensors 422 and 424 and multi-touch panel 426 according to some embodiments of this invention. In the example of FIG. 4e, two input devices, a standard keyboard 428 and multi-touch panel 426, can be available to a user. If the user uses multi-touch panel 426 as indicated at 430, the presence of the user’s palm can be detected by proximity sensor 424, while proximity sensor 422 does not detect the presence of any finger or palm. In addition, the touch sensors in multi-touch panel 426 can detect the presence of one or more fingers, a palm or other object. In this situation, the computing system can assume that the user is using multi-touch panel 426 but not keyboard 428, and thus input devices related to keyboard 428 can be powered down. However, if the user uses keyboard 428 as indicated at 432, the presence of the user’s palm can be detected by proximity sensor 422, while multi-touch panel 426 and proximity sensor 424 may or may not detect the presence of the user’s wrist and forearm, for example. In this situation, the computing system can assume that the user is using keyboard 428 but not multi-touch panel 426, and multi-touch panel 426 can be powered down accordingly to save on power and prevent false readings.
In some embodiments, one or more infrared (IR) proximity sensors can be driven with a specific stimulation frequency and emit IR light from one or more areas, which can in some embodiments correspond to one or more multi-touch sensor “pixel” locations. The reflected IR signal, if any, can be demodulated using synchronous demodulation. In some embodiments, both physical interfaces (touch and proximity sensors) can be connected to analog channels in the same electrical core.
Patent: Individual Channel Phase Delay Scheme
Apple’s patent relates to phase dependent demodulation and processing of analog signals, and more particularly to processing of an analog signal by generating and using a demodulation signal whose phase is controlled in relation to the analog signal.
Apple’s patent FIG. I illustrates exemplary computing system 100 that uses multi-touch panel 124. Computing system 100 can include one or more multi-touch panel processors 102 and peripherals 104, and multi-touch subsystem 106. One or more processors 102 can include, for example, ARM968 processors or other processors with similar functionality and capabilities. “Other processors” may very well include one from Apple’s own P.A. Semi.
According to Apple’s background information, various electronic devices use oscillating signals to sense external conditions. The external condition can be a user’s voice, an incoming radio frequency communication, a user’s touch of a button, a user’s touch of a touch-screen display, the hover of a finger or another object over a proximity sensitive panel, etc. Received signals that are used to sense external conditions and/or carry information such as audio, video or multi-touch data often pick up undesired noise in the process. Any wireless signal generated by, for example, a wireless device, such as a Bluetooth or WiFi signal may represent such a noise source. Noise makes processing of the signal to discover the external condition more difficult. Therefore, there is a continuing need for noise suppression circuits. In general, the major challenge in designing noise suppression circuits is the need to reduce portions of the signal considered to be noise in comparison to portions of the signal considered to include useful information.
Therefore, in order for a filter to be effective it often must be configured or tuned in phase and frequency to the signal it is processing. This requirement can cause difficulties when the signals being processed vary in some of their attributes. For example, if the signal being processed is not in phase with the demodulating signal, the dynamic range of the demodulator or filter is reduced therefore effectively reducing the signal to noise ratio, thus making the detection of the relevant signal more difficult.
Embodiments presented within Apple’s patent are directed to demodulating an incoming signal by using a demodulation signal, while controlling the phase of the demodulation signal in relation to the incoming signal.
Other patents relating to Apple’s panel processor include the following: 1) “Periodic sensor panel baseline adjustment: This patent relates to panels used as input devices for computing systems, and more particularly, to the periodic updating of baseline no-touch sensor output values to account for temperature drift; 2) Error compensation for multi-touch surfaces: This patent relates to panels used as input devices for computing systems, and more particularly, to normalizing the outputs of the analog channels that generate values representative of the sensor panels by determining the offset error inherent in the electronics of the analog channels and compensating for the errors in the analog channel outputs.
Patent: Projection Scan Multi-Touch Sensor Array
Apple’s patent relates to touch sensor panels, and more particularly, to multi-touch sensor panels whose elements can be applied to a single surface of a substrate.
According to Apple, a touch sensor panel can be constructed on a single surface of a substrate. The panel can be formed as a plurality of distributed Resistor-Capacitor (RC) lines arranged in an array of rows and columns. Each distributed RC line can include alternating connected transistors and metal pads formed on a single surface of the substrate. During operation, the rows and columns are enabled at different times, and the pulse travel times for each row and column in both directions are measured. Equalized travel times are then computed as the sum of the pulse travel times in both directions, and indicate which rows and columns have a finger touching it. The un-equalized pulse travel time data can then be used to determine the relative positions of the fingers within the rows and columns and un-ambiguously determine the positions of all the finger contacts.
Apple’s patent FIG. 2 above, illustrates how an exemplary distributed RC line can serve as a touch sensor according to one embodiment of this invention. Figs. 13a and 13b illustrate Apple’s iPod and iPhone as the intended applications for these sensors.
Patent: Double-Sided Touch Sensitive Panel and Flex Circuit Bonding
Apple’s patent relates to the bonding of flexible circuits to substrates, and more particularly, to the bonding of flex circuits to directly opposing attachment areas of a substrate, and an improved flex circuit design for enabling more secure and less error-prone bonding.
Apple’s patent FIG. 3 is a perspective view of exemplary sensor panel 300 with rows 302 and columns 304 on opposite sides of substrate 306 according to one embodiment of this invention. In the example of FIG. 3, Indium Tin Oxide (ITO) and metal traces are present on both the top and bottom sides of dielectric substrate 306. It would be desirable for flex circuits (a.k.a. flexible printed circuits (FPCs)) 308 to be bonded to both sides of the dielectric, on directly opposing sides (as illustrated in FIG. 3), to provide electrical connections to PCB 310. Such bonding can help minimize the size of sensor panel 300, because no extra area is needed for non-overlapping bonding areas, and the area reserved for attachments can be minimized. Bonding flex circuits as shown in FIG. 3 also minimizes trace length differences, which can minimize unwanted differences in the modulated output signals appearing on columns if the sensor panel relies on capacitive coupling. Also noted above are devices that will benefit from the flex circuit such as a mobile phone (or iPhone) and a digital player (or iPod).
Also see Apple’s related patent titled ” Double-sided touch-sensitive panel with shield and drive combined layer for more details.
Multi-Touch Coming to More Devices
At the end of the day, Figure 10 of Apple’s patent titled “Simultaneous Sensing Arrangement” confirms that Apple intends to integrate touch screen technologies into more devices over time – be it a desktop, a notebook or more handhelds.
Other Apple Related Patents Published Today
Other multi-touch patents published today include the following: Multi-Touch Input Discrimination; Scan sequence generator; Front-end signal compensation; Master/slave mode for sensor processing devices; Minimizing mismatch during compensation; Analog boundary scanning based on stray capacitance; GPIO mux/dynamic port configuration; Multi-touch auto scanning; Channel scan logic; Multi-touch input discrimination; Irregular input identification; Multi buffer asynchronous scheme for processing incoming information; Memory access without internal microprocessor intervention; On-chip decompression engine; Peripheral Pixel Noise Reduction; Far-Field Input Identification; Noise Detection in Multi-Touch Sensors; Gated power management over a system bus; Full scale calibration measurement for multi-touch surfaces; Minimizing mismatch during compensation; and finally, Storing baseline information in EEPROM.
NOTICE: MacNN presents only a brief summary of patents with associated graphic(s) for journalistic news purposes as each such patent application and/or grant is revealed by the U.S. Patent & Trade Office. Readers are cautioned that the full text of any patent applications and/or grants should be read in its entirety for further details.
Written and researched by Neo.
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