Organic Light Emitting Display And Method Of Fabricating The Same
Patent No. US11251394 (titled "Organic Light Emitting Display And Method Of Fabricating The Same") was filed by Lg Display Co Ltd on Jun 22, 2020.
What is this patent about?
’394 is related to the field of organic light-emitting diode (OLED) displays with integrated touch sensors. Traditional touchscreens are manufactured separately and then attached to the display, increasing thickness and manufacturing complexity. This patent addresses the need for thinner, lighter, and more cost-effective OLED displays with integrated touch functionality.
The underlying idea behind ’394 is to integrate the touch sensing elements directly into the OLED display's encapsulation layer . By using the existing encapsulation layers as the insulating layer between the touch driving and sensing lines, the need for a separate touch insulating layer is eliminated. This simplifies the structure, reduces thickness and weight, and streamlines the manufacturing process.
The claims of ’394 focus on an OLED display comprising light emitting elements, an encapsulation unit, and touch sensors. The touch sensors include first and second touch electrodes connected by first and second bridges, respectively. First conductive lines are connected to the touch sensors, and second conductive lines are connected to the first conductive lines. At least one insulating film, formed of an inorganic or organic film, is disposed between the first and second conductive lines. A key feature is that at least one of the bridges overlaps a bank that exposes the anodes of the light emitting elements. Another key feature is that the second conductive lines are disposed along a side surface of the encapsulation unit.
In practice, the touch sensors operate based on mutual capacitance . The touch driving lines are supplied with a pulse, which charges the mutual capacitance formed at the intersection of the driving and sensing lines. When a user touches the screen, the capacitance changes, and this change is detected by the sensing lines. The location of the touch is then determined based on the signals from the sensing lines. The routing lines and pads connect the touch sensors to external circuitry for processing the touch signals.
This design differentiates itself from prior approaches by eliminating the need for a separate touch insulating layer. Instead, the existing encapsulation layers, which are already present to protect the OLED elements from moisture and oxygen, are utilized as the insulating layer between the touch driving and sensing lines. Furthermore, the overlapping of the bridges with the bank prevents the lowering of the aperture ratio. This integration reduces the overall thickness and weight of the display, simplifies the manufacturing process, and potentially improves the display's flexibility and transmittance.
How does this patent fit in bigger picture?
Technical landscape at the time
In the mid-2010s when ’394 was filed, organic light-emitting diode (OLED) displays were increasingly used in mobile devices and televisions at a time when touch screen functionality was often achieved by adding a separate touch sensor panel to the display. At that time, reducing the thickness and weight of such devices was a common engineering goal, and integrating the touch sensor directly into the display stack was a known approach to achieve this. When systems commonly relied on capacitive touch sensing, the design and fabrication of transparent conductive layers and insulating layers within the display structure were critical for performance.
Novelty and Inventive Step
The examiner approved the application because the prior art references failed to teach or suggest the specific combination of features in claim 1, which includes touch sensors with a plurality of first and second touch electrodes, first and second bridges connecting these electrodes, first and second conductive lines connected to the touch sensors, an insulating film between the conductive lines, and a bank configured to expose anodes of the light emitting elements, where at least one of the bridges overlaps the bank. Claims 2-5, 7-9 and 12-20 were also allowable because they depend from claim 1 and share the same reasons for allowance. The examiner also stated that the prior art failed to teach or suggest the combination of limitations set forth in claim 21, specifically comprising the limitation of an encapsulation unit disposed on the light emitting elements; touch sensors disposed on the encapsulation unit; first conductive lines connected to the touch sensors; second conductive lines connected to the first conductive lines; and at least one insulating film formed of at least one of an inorganic film or an organic film and disposed between the first and second conductive lines, wherein the second conductive lines are disposed along a side surface of the encapsulation unit.
Claims
This patent contains 19 claims, with independent claims 1 and 19 directed to an organic light emitting display including light emitting elements, an encapsulation unit, touch sensors, first and second conductive lines, at least one insulating film, and a bank (claim 1) or second conductive lines disposed along a side surface of the encapsulation unit (claim 19). The dependent claims generally elaborate on the specific configurations, materials, and connections of the components described in the independent claims.
Key Claim Terms New
Definitions of key terms used in the patent claims.
Patent Family
File Wrapper
The dossier documents provide a comprehensive record of the patent's prosecution history - including filings, correspondence, and decisions made by patent offices - and are crucial for understanding the patent's legal journey and any challenges it may have faced during examination.
Date
Description
Get instant alerts for new documents
US11251394
- Application Number
- US16907966
- Filing Date
- Jun 22, 2020
- Status
- Granted
- Expiry Date
- Jun 29, 2037
- External Links
- Slate, USPTO, Google Patents