Prior art — US Patent 9280220

As a senior US patent analyst, I have reviewed the prior art cited for US patent 9,280,220, titled "Pulse- or frame-based communication using active stylus." Below is an analysis of the most relevant prior art references and their potential impact on the patent's claims under 35 U.S.C. § 102, which pertains to anticipation. A claim is anticipated if every single element of that claim is disclosed in a single prior art reference.

Analysis of Most Relevant Prior Art for US Patent 9,280,220

The core invention of US Patent 9,280,220 revolves around a method for an active stylus to communicate sensor data to a touch-sensitive device. This is achieved by the stylus receiving a carrier signal from the device's touch sensor, modulating that signal with its sensor data, and transmitting the modulated signal back to the touch sensor. The communication can be structured on a pulse-by-pulse or a frame-by-frame basis.

After a thorough review of the cited art, the following references have been identified as most pertinent.

1. US Patent No. 8,432,163 B2

Full Citation: US Patent 8,432,163 B2, "Sensing system including stylus," assigned to Apple Inc.
Publication Date: April 30, 2013
Filing Date: June 24, 2008
Brief Description: This patent describes a sensing system that includes a stylus and a touch sensor panel. The stylus can generate a stimulus signal that is detected by the touch sensor panel. The system can determine the location of the stylus and can also support communication of data from the stylus to the touch sensor panel. This data can include information such as stylus pressure, orientation, or button presses. The communication can be achieved by modulating the stimulus signal from the stylus.
Potential Anticipation under 35 U.S.C. § 102:
- Claim 1: This reference potentially anticipates claim 1. US 8,432,163 discloses a stylus that transmits data to a touch sensor device. It describes modulating a signal to encode this data, which is then received by the touch panel. This aligns with the core elements of claim 1 of US 9,280,220, which recites receiving sensor data at a stylus, generating a carrier signal, modulating it with the sensor data, and transmitting it to the device's touch sensor.
- Dependent Claims (e.g., 2-10): The anticipation of the dependent claims would hinge on whether the specific modulation techniques (amplitude, frequency, phase shift keying), the types of sensor data (pressure, accelerometer), and the communication protocols (pulse-by-pulse, frame-by-frame) are explicitly or inherently disclosed in the '163 patent. The '163 patent does discuss various data types from the stylus and the modulation of signals, making it highly relevant.

2. US Patent Application Publication No. 2011/0205169 A1

Full Citation: US Patent Application Publication No. 2011/0205169 A1, "Methods and Systems for Synchronizing a Stylus with a Touch System," assigned to Synaptics Inc.
Publication Date: August 25, 2011
Filing Date: February 24, 2010
Brief Description: This publication details methods for synchronizing communication between a stylus and a touch-sensitive device. It describes a touch system that can transmit synchronization signals to a stylus. The stylus can then transmit data back to the touch system in synchronization with the system's timing. This data can be modulated onto a signal transmitted by the stylus. The publication discusses using different frequencies or modulation schemes for communication.
Potential Anticipation under 35 U.S.C. § 102:
- Claim 1 & Related Claims: This reference is highly relevant as it addresses the core concept of synchronized communication between a stylus and a touch system, which is a key aspect of the '220 patent's frame-based communication. It discloses a stylus transmitting modulated data back to a touch sensor. The disclosure of a synchronized transmission in response to signals from the touch system presents a strong case for the anticipation of the method described in claim 1.
- Claims related to synchronization and timing: Claims in the '220 patent that relate to the timing of the signal transmission, such as responding within a specific time window or in sync with the touch sensor's scan, are particularly vulnerable to anticipation by this reference.

3. US Patent No. 7,928,963 B2

Full Citation: US Patent 7,928,963 B2, "Touch-sensitive device with active stylus," assigned to Wacom Co., Ltd.
Publication Date: April 19, 2011
Filing Date: March 28, 2008
Brief Description: This patent describes a touch-sensitive device that interacts with an active stylus. The stylus includes a signal processing circuit that can transmit signals to the touch-sensitive device. The transmitted signals can contain data from the stylus, such as pen pressure. The communication is based on capacitive coupling between the stylus and the electrodes of the touch sensor.
Potential Anticipation under 35 U.S.C. § 102:
- Claim 1: The '963 patent discloses an active stylus transmitting data (pen pressure) to a touch-sensitive device via signals, which is the foundational concept of claim 1 of the '220 patent. It describes the use of a signal processing circuit within the stylus to generate and transmit these signals. This disclosure of a stylus actively sending modulated information to a touch panel makes it a strong anticipatory reference.
- Apparatus Claims: For any apparatus claims in the '220 patent that describe the components of the stylus (sensors, controller, transmitter), the detailed description of the active stylus in the '963 patent could potentially anticipate these claims by disclosing a similar hardware configuration.

It is important to note that a final determination of anticipation requires a rigorous legal analysis and comparison of the specific claim language with the disclosures of these prior art references. This analysis is provided for informational purposes based on a technical review of the documents.