Stmicroelectronics Asia Pacific Pte Limited

Manivannan Ponnarasu

Mythreyi Nagarajan

Praveesh Chandran

Kusuma Adi Ningrat

Lokesh Kumar Korapati

Ade Putra

Leo Lee

In one embodiment, a method for operating an electronic device includes determining that a touch sensitive display is being contacted. The touch sensitive display includes a plurality of mutual-sensing capacitive sensor regions and an array of self-sensing capacitive sensor regions. The plurality of mutual-sensing capacitive sensor regions is arranged in rows and columns on the touch sensitive display. The array of self-sensing capacitive sensor regions is arranged in a row or a column on the touch sensitive display. The method may include obtaining mutual sensing touch values for each of the rows and the columns and self-sensing touch values for the row or the column. Based on the mutual sensing touch values and self-sensing touch values, the method includes determining whether a contacted region of the touch sensitive display is an impression of a single finger, multiple fingers, a single thumb, or multiple thumbs.

Electronic device with finger touch detection and related methods

A touch screen controller identifies an island in a matrix of acquired touch data values. A first sharpness of the island is calculated and a second sharpness of the island is calculated if the calculated first sharpness is greater than a sharpness threshold. A dynamic strength threshold is then determined as a function of the second sharpness if a variance of the island is greater than a dynamic variance threshold. A determination is then made that the identified island is a valid stylus island if a peak strength of the island is greater than the dynamic strength threshold.

Support of narrow tip styluses on touch screen devices

Disclosed herein is a touch screen controller operable with a touch screen. The touch screen controller includes input circuitry to receive touch data from the touch screen, and processing circuitry. The processing circuitry acquires mutual capacitance touch strength values from the touch screen, determines when the mutual capacitance touch strength values define a pre-validated donut touch pattern, and reads self capacitance touch strength values for lines that are contained within bounds of the pre-validated donut touch pattern. If the self capacitance touch strength values for lines contained within bounds of the pre-validate donut touch pattern contain a singular peak value, the processing circuitry validates the pre-validated donut touch pattern as representing a single touch.

Electronic device validating multiple finger touch detection through donut shaped touch islands, and related methods

Disclosed herein is a touch screen controller that calculates a variance of an island in acquired touch data values. Where the variance exceeds a variance threshold, the island is validated as a representing touch. Where the variance does not exceed the variance threshold, whether the island represents a touch or a hover is determined by calculating a sharpness by applying weights to nodes of the island, where neighboring nodes adjacent to a peak node are weighted less than non-neighboring nodes not adjacent to the peak node. An island strength threshold is determined as a function of a product of the variance and the sharpness. It is determined that the island represents a touch where a highest touch data value of the island is greater than the island strength threshold, and a hover where the highest touch data value of the island is less than the island strength threshold.

Hover rejection through dynamic thresholding

A touch screen controller includes input circuitry receiving touch data from a touch screen, and processing circuitry. The processing circuitry determines first coordinates of a touch at a first time, based upon the received touch data. A first threshold window is set about the first coordinates, with the first threshold window having a central point at the first coordinates, and a second threshold window is set about the first coordinates, with the second threshold window having a central point at the first coordinates and being larger than the first threshold window. Second coordinates of the touch are determined at a second time, based upon the received touch data, and where the second coordinates are not within the first threshold window but are within the second threshold window, the second coordinates are corrected based upon a distance between the second coordinates and the central point of the second threshold window.

Multiple threshold motion tolerance to filter coordinate jitter in touch sensing

A method of foreign matter rejection for multi-touch capacitive touch screens includes performing touch detection in both self-capacitance mode and mutual capacitance mode. By combining information from both modes, a distinction is identified between wanted touches, such as by a finger or stylus, and unwanted touches such as by foreign matter.

Water rejection for capacitive touch screen

Disclosed herein is a touch screen controller operable with a touch screen. The touch screen controller includes input circuitry configured to receive touch data from the touch screen, and processing circuitry. The processing circuitry is configured to identify an island in the touch data, determine whether a horizontal groove is present in the island, determine whether a vertical groove is present in the island, and determine whether a diagonal groove is present in the island. The processing circuitry determines the island to indicate a single elongated touch where a diagonal groove is present in the island but horizontal and vertical grooves are not present in the island.

Use of groove analysis in a touch screen device to determine occurrence of an elongated touch by a single finger

An electronic device disclosed herein includes a touch screen controller to identify an island i.e., a matrix of acquired touch data values, the island including adjacent touch data values indicating a potential touch of a touch sensitive screen. A first sharpness of the island is calculated using a first normalization type and not a second normalization type. A second sharpness of the island is calculated using the first and second normalization types if the first sharpness is greater than the sharpness threshold. A dynamic variance threshold is determined as a function of the second sharpness. A dynamic strength threshold is determined as a function of the second sharpness if a variance of the island is greater than the dynamic variance threshold, and the island is determined to be a valid stylus island if the peak strength is greater than the dynamic strength threshold.

Groove analysis in a device having a tactile input surface suited to detect more than one tactile input at a time. Using groove analysis allows a touch screen device a more robust and efficient algorithm for distinguishing between two different tactile inputs. The touch screen device may include a touch screen controller that includes an analysis circuit for determining grooves between touch inputs. Generally, when a touch input is received at the surface of a touch screen device, the touch screen may register touch strength signals at each of a plurality of touch regions. A groove may be generally defined as a touch region that exhibits a touch strength signal that is less than surrounding touch regions. Once all touch regions are analyzed by a groove analysis, various touch regions determined to grooves may be eliminated from a further analysis to determine the XY coordinates of actual touch inputs.

Determining finger separation through groove analysis in a touch screen device

An electronic device includes a processor that acquires touch data values corresponding to different locations of a touch display, and identifies an island in the touch data that has touch data values acquired from adjacent locations of the touch display that indicate a potential touch. A first area of the island is determined from touch data values that exceed a first threshold value, and a second area of the island is determined from touch data values that exceed a second threshold value. If the first area is less than a multiple of the second area, coordinates of a location of the island are determined from the touch data values indicating the potential touch. If the first area is at least the multiple of the second area, coordinates of a location of the island are determined from the touch data values indicating the potential touch that exceed a third threshold value.

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Singapore, Singapore

Manivannan Ponnarasu