Touch-sensitive display device and method

Patent No. US8243045 (titled "Touch-sensitive display device and method") on Mar 10, 2009. The application was issued on Aug 14, 2012.

'045 is related to the field of touch-sensitive displays, specifically those used in electronic devices like mobile phones and computer monitors. Traditional touch screens often involve a separate sensor panel placed over or under a display, requiring calibration to ensure accurate touch registration. This adds complexity to manufacturing and can lead to user frustration due to misalignment over time.

The underlying idea behind '045 is to integrate the touch-sensing functionality directly into the display itself, eliminating the need for a separate touch sensor panel. This is achieved by using the display's existing circuitry for both displaying images and detecting touch events. The key insight is that the display elements, such as OLED pixels, can be leveraged to sense changes in electrical characteristics caused by a user's touch.

The claims of '045 focus on a device comprising a display with a plurality of touch-sensitive locations, measurement circuitry electrically coupled to both the display and each of the touch-sensitive locations, and a processor. The processor receives signals from the measurement circuitry corresponding to the touch-sensitive locations affected by a touch, and determines the location of the touch by identifying the touch-sensitive location with the highest magnitude signal change.

In practice, the invention works by applying a sub-threshold voltage to the display elements, creating a reference capacitance field. When a user touches the screen, their finger introduces a change in capacitance, which is detected by the measurement circuitry. The processor then analyzes the signals from multiple display elements to pinpoint the touch location based on the magnitude of the capacitance change at each location. The harder the touch, the greater the signal distortion.

This approach differs from prior solutions by eliminating the need for a separate touch sensor panel and the associated calibration process. By sharing the display circuitry for both display and touch sensing, the manufacturing process is simplified, and the device becomes more robust against misalignment. Furthermore, the use of a sub-threshold signal allows the touch-sensing functionality to operate even when the display is not actively illuminated, enabling always-on touch detection.

How does this patent fit in bigger picture?

Technical Landscape

In the late 2000s when ’045 was filed, touch-sensitive interfaces were typically implemented using discrete sensor panels layered atop or beneath a separate display unit at a time when the display components themselves did not participate in touch detection. When systems commonly relied on external touch controllers to translate physical contact into data for a central processor, hardware constraints made the integration of sensing and display functions within a single organic light-emitting diode (OLED) matrix non-trivial. This era was characterized by architectures where touch sensing and image generation were treated as distinct electrical operations, often requiring separate drive circuitry and dedicated substrate layers.

Prosecution Position

Following the filing of this application, the examiner issued a Final Office Action rejecting claims 1–8, 17, and 19–21 under 35 U.S.C. § 103 as being unpatentable over the prior art. The applicant had previously submitted amendments and arguments on December 19, 2011, which the examiner found unpersuasive regarding the ability of the prior art to teach specific measurement circuitry and processor configurations for determining touch location. While the application later proceeded to allowance, the prosecution record provided does not describe the specific technical reasoning or claim changes that ultimately led to that allowance.

Claims

There are 19 claims in total. Claims 1, 13, and 16 are independent. The independent claims focus on a device and method for determining the location of a touch on a touch-sensitive display. The dependent claims generally elaborate on the specific components, configurations, and steps of the device and method described in the independent claims.

Key Claim Terms New

Definitions of key terms used in the patent claims.

Term (Source)	Support for Specification	Interpretation
Measurement circuitry (Claim 1, Claim 13, Claim 16)	The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several examples in accordance with the disclosure and are, therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings, in which:	Electronic circuits that measure signals generated by touch-sensitive locations.
OLED pixel (Claim 13)	The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several examples in accordance with the disclosure and are, therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings, in which:	An organic light-emitting diode pixel that emits light and provides touch signals.
Respective signal change (Claim 1)	The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several examples in accordance with the disclosure and are, therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings, in which:	A change in an electrical signal that corresponds to the strength of a touch at a specific touch-sensitive location.
Sub-threshold signals (Claim 16)	The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several examples in accordance with the disclosure and are, therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings, in which:	Signals provided to the display at the touch-sensitive locations that are below a certain threshold.
Touch-sensitive locations (Claim 1, Claim 16)	In prior art touch screen applications, a touch screen sensor panel is disposed over or under a display, but the display does not play a role in determining the location of a touch. Rather, by touching the touch screen, a change is sensed in the touch screen panel, and a touch screen controller couples the sensor to a driver and/or computer processing unit (“CPU”) and translates information from the touch sensor into data usable by the driver/CPU.	Specific areas on the display that can detect a touch.

Litigation Cases New

US Latest litigation cases involving this patent.

Case Number	Filing Date	Title
1:22-cv-00127	Jan 28, 2022	Vibrant Licensing LLC v. TTE Technology, Inc.

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US8243045

Application Number: US12401124A
Filing Date: Mar 10, 2009
Publication Date: Aug 14, 2012
External Links: Slate, USPTO, Google Patents

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