Apple Inc.

Prathit Bugnait

Isaac W Chan

Albert Lin

John Z Zhong

Sunggu Kang

Chun-Hao Tung

Steven Porter Hotelling

Sumant Ranganathan

Martin Paul Grunthaner

Vivek Pant

Sagar Rajiv Vaze

Alexandre Gourevitch

Seyed Mohammad Navidpour

Yu-Heng Cheng

Differential driving and/or sensing can reduce noise in a touch screen. In some examples, the touch electrodes and/or routing traces can be implemented using metal mesh in first and second metal layers. To mitigate electrical interference at the touch screen from a display, a display-noise shield or sensor can be provided between the display and the touch screen. In some examples, a shield can minimize a noise contribution from the display to signals generated at the touch screen. In other examples, a sensor can enable a differential read out of signals at the touch screen that subtracts a noise component measured by the sensor. Forming the shield or sensor, and the touch screen over the display using an on-cell process can improve touch screen performance and yield. The shield can be connected to a conductive ring and flex circuit via tapping points in a stackup separate from a display stackup.

Touch screen shield layer with ring and tapping points

Touch sensor panel configurations for reducing wobble error for a stylus translating on a surface over and between electrodes of the touch sensor panel are disclosed. In some examples, electrodes with more linear signal profiles are correlated with lower wobble error. In some examples, diffusing elements formed of floating segments of conductive materials can diffuse signal from a stylus to a plurality of electrodes, thus, making the signal profiles associated with the electrodes more linear. In addition, diffusing elements can be configured to improve the optical uniformity of the touch sensor panel. In some examples, the diffusing elements can be formed on the same layer as floating dummy pixels and resemble a plurality of merged floating dummy pixels.

Merged floating pixels in a touch screen

Electrode configurations for reducing wobble error for a stylus translating on a surface of a touch sensor panel is disclosed. Electrodes associated with a more linear signal profile can correlate to lower wobble error. In some examples, electrodes can be configured such that the signal profile associated with each electrode is spread to be wider, and thus, more linear. In some configurations, electrodes can include two or more bars extending along the length of the electrode with each bar electrically connected to one another at one or both ends. Bars can be of non-uniform width or spacing. Some configurations can include a 'split bar,' which can divide a bar lengthwise in order to improve optical uniformity. In some examples, electrodes can include projections which can interleave with corresponding projections in adjacent electrodes.

Multi-bar capacitive sense electrode

Electrode configurations for reducing wobble error for a stylus translating on a surface over and between electrodes of a touch sensor panel is disclosed. In some examples, electrodes associated with a more linear signal profile are correlated with lower wobble error. In some examples, electrodes are coupled to adjacent electrodes via diffusing resistors such that the signal profile for each electrode is spread to be more linear. In some configurations, the value of the diffusing resistors and series resistance associated with an electrode is selected based on a desired signal profile for that electrode. In some examples, the series resistance can include a trace resistance and a compensating resistance. The compensating resistance can compensate for a variance in trace resistance between electrodes, thus making series resistance substantially equal for each of the electrodes.

Sensor with diffusing resistor

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Sunnyvale, CA, United States of America

Prathit Bugnait