Granted Patent: Method for Fabricating Thin Touch Sensor Panels

Apple's first granted patent of the day generally relates to the fabrication of touch sensor panels, and more particularly, to the fabrication of thin double and single sided touch sensor panels.

More specifically, Apple's Patent covers a method for fabricating thin DITO or SITO touch sensor panels with a thickness less than a minimum thickness tolerance of existing manufacturing equipment. In one embodiment, a sandwich of two thin glass sheets is formed such that the combined thickness of the glass sheets does not drop below the minimum thickness tolerance of existing manufacturing equipment when thin film process is performed on the surfaces of the sandwich during fabrication. The sandwich may eventually be separated to form two thin SITO/DITO panels. In another embodiment, the fabrication process involves laminating two patterned thick substrates, each having at least the minimum thickness tolerance of existing manufacturing equipment. One or both of the sides of the laminated substrates are then thinned so that when the substrates are separated, each is a thin DITO/SITO panel having a thickness less than the minimum thickness tolerance of existing manufacturing equipment.

Apple credits Shih Chang, John Zhong, Lili Huang, Seung Hong and Lynn Youngs as the inventors of Granted Patent 7,918,019 originally filed in Q 2009.

Granted Patent: Double-Sided Touch-Sensitive Panel with Shield and Drive Combined Layer

Apple has been granted a patent for multi-touch sensor panels and their associated sensor panel circuitry that could detect multiple touches (touch events or contact points) that occur at about the same time while identifying and tracking their locations.

Apple's patent covers multi-touch capacitive touch sensor panels that could be created using a substrate with column and row traces formed on either side of the substrate. To shield the column (sense) traces from the effects of capacitive coupling from a modulated Vcom layer in an adjacent liquid crystal display (LCD) or any source of capacitive coupling, the row traces could be widened to shield the column traces, and the row traces could be placed closer to the LCD.

In particular, the rows could be widened so that there is spacing of about 30 microns between adjacent row traces. In this manner, the row traces could serve the dual functions of driving the touch sensor panel, and also the function of shielding the more sensitive column (sense) traces from the effects of capacitive coupling.

For more information about this technology, see Granted Patent 7,920,129. Apple credits Steve    Hotelling and Brian Land as the inventors of this patent which was originally filed in Q1 2007, just prior to Steve Jobs Keynote introducing the coming iPhone.

Granted Patent: Periodic Sensor Autocalibration and Emulation by Varying Stimulus Level

In order to even remotely understand the nature of Apple's latest multi-touch related granted patent, a little background is required. Apple states that a display screen could be located beneath the sensor panel. A user interface (UI) algorithm could generate a virtual keypad or other virtual input interface beneath the sensor panel that could include virtual buttons, pull-down menus and the like. By detecting touch events at locations defined by the virtual buttons, the UI algorithm could determine that a virtual button has been "pushed." The magnitude of analog channel output values, indicating the "degree" of touch, could be used by the UI algorithm to determine whether there was a sufficient amount of touch to trigger the pushing of the virtual button.

Ideally, a particular amount of touch should generate an analog channel output value of the same magnitude regardless of where the touch event occurred on a sensor panel. However, because the electrical characteristics of the sensors in a sensor panel are likely to vary due to processing variations, manufacturing tolerances, assembly differences (which could be due to the location of the sensors in relation to the edges and shape of the sensor panel), aging, stress, dirt, moisture, deformation due to pressure, temperature, expansion of materials and geometries, and the like, the magnitude of the analog channel output values can vary from location to location within the sensor panel. This could lead to inconsistent or false triggering of virtual buttons or non-triggering of virtual buttons, and a difficult user experience as the user discovers that certain areas of the sensor panel require more or less touching in order to trigger a virtual button.

Apple's invention attempts to remedy this problem by introducing automatic calibration of a sensor panel by varying the amplitude of an input stimulus to simulate a full-touch condition. It then calibrates the sensor panel in accordance with the difference between the simulated full-touch condition and a baseline full-touch condition.

To get a detailed account of this technology, see granted patent 7,920,134. Apple credits as the inventors of Granted Patent originally filed in Q 2009.

Granted Patent: Keystroke Tactility Arrangement on a Smooth Touch Surface

In January of this year, we reported on a new patent application titled "Apple Gets Closer to a Virtual Keyboard for the iMac." This is an area that Apple is working very hard on to achieve. Today's granted patent is important because it quickly establishes Apple's technology as being protected early on in the game. Although Apple may use variations of this technology for a final product, the fact remains that this is a key pioneering virtual keyboard patent that gives and gave Apple a foundation for designing a future virtual keyboard.

Apple's granted patent discloses four arrangements for providing tactility on a touch surface keyboard. One approach is to provide tactile feedback mechanisms, such as dots, bars, or other shapes on all or many keys. In another embodiment, an articulating frame may be provided that extends when the surface is being used in a typing mode and retracts when the surface is used in some other mode, e.g., a pointing mode. The articulating frame may provide key edge ridges that define the boundaries of the key regions or may provide tactile feedback mechanisms within the key regions. The articulating frame may also be configured to cause concave depressions similar to mechanical key caps in the surface. In another embodiment, a rigid, non-articulating frame may be provided beneath the surface. A user will then feel higher resistance when pressing away from the key centers, but will feel a softer resistance at the key center.

For more information on this technology, see granted patent 7,920,131. Apple credits Wayne Westerman as the sole inventor of this patent. As a side note, it should be made aware that Apple is also working on an alternative or in-between design that we covered in our report titled "Apple Pushes Research into Motion Keyboards for MacBooks." To review Apple's other multi-touch related patents, check out our Archives.

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