Apple has been granted patents by the US Patent & Trademark Office involving touch sensor panels, keystroke tactility arrangements,

Patent number 7918019 is for 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. The inventors are Shih Change Chang, John Z. Zhong, Liki Hugang, Seung Jae Hong and Lynn Youngs.

Patent number 792129 is for a double-sided, touch-sensitive panel with a shield and drive-combined layer. A multi-touch capacitive touch sensor panel can 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 can be widened to shield the column traces, and the row traces can be placed closer to the LCD.

In particular, the rows can be widened so that there is spacing of about 30 microns between adjacent row traces. In this manner, the row traces can 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 Richards Land.

Patent number 7920134 involves periodic sensor autocalibration and emulation by varying stimulus level. Per the patent, the automatic calibration of a sensor panel is disclosed by varying the amplitude of an input stimulus Vstim to simulate a full-touch condition and calibrating each pixel of the sensor panel in accordance with the difference between the simulated full-touch condition and a baseline full-touch condition. To accomplish this, a baseline full scale output FS_targ_cal can be measured at during pre-delivery calibration for each pixel using a test fixture capable of applying a no-touch to full-touch condition given a nominal Vstim.

A full-touch condition can then be emulated for each pixel by lowering Vstim until the current full scale output FS_targ_current equals FS_targ_cal, and determining the Vstim value Vstim_cal at that point. During field calibration, Vstim_cal can be applied to each pixel to simulate a full-touch condition, and FS_targ_current can be obtained and compared against FS_targ_cal. Each analog channel can then be tuned so that in subsequent full-touch conditions, FS_targ_current will approximately equal FS_targ_cal. Christoph Horst Krah is the inventor.

Patent number 7920131 is for keystroke tactility arrangement on a smooth touch surface. Disclosed are 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. Wayne Carl Westerman is the inventor.

-- Dennis Sellers