# How Foldable Screens Use Electrochromic Layers to Improve Color and Contrast > A method for foldable display panels to adjust their light-filtering properties using electrochromic layers that change color or opacity based on whether the screen is stretched or folded. - **Patent:** US 12354567 - **Original title:** Driving method of display panel, display panel, and display device - **Owner:** HKC Co Ltd - **Granted:** 2025 - **Status:** Active - **Times cited:** 0 - **Field:** consumer_electronics, semiconductors, mechanical ## What it does This patent describes a way to manage light in foldable OLED displays by placing electrochromic layers on either side of a standard color filter. These layers use materials that change their optical properties when an electric field is applied. When the device is in a stretched or flat state, the system turns these layers into color filters to enhance the display's color output. When the device is in an unstretched or folded state, the system switches these layers to an opaque mode to prevent light leakage or adjust contrast. This allows the display to dynamically adapt its filtering characteristics based on the physical configuration of the screen. ## What it does NOT cover - Does not cover displays that lack electrochromic layers on both sides of the color filter. - Does not cover mechanical folding mechanisms that do not involve electronic light-filtering adjustments. - Does not cover standard OLED panels that rely solely on pixel-level voltage control without additional electrochromic filters. ## The clever bit Instead of relying only on the OLED pixels themselves to compensate for color shifts, the patent uses active, switchable filter layers that physically change their color or opacity in response to the screen's deformation. ## Real-world examples 1. Foldable smartphone displays 2. Flexible OLED tablet screens 3. Rollable display panels ## Why it matters As foldable smartphones and tablets become more common, managing image quality during the transition between folded and flat states is a significant engineering hurdle. This technology provides a way to maintain color accuracy and contrast in flexible displays by physically altering the light path, potentially solving issues with light bleeding or color shifts that occur when flexible substrates are deformed. ## Frequently asked questions ### What does How Foldable Screens Use Electrochromic Layers to Improve Color and Contrast cover? A method for foldable display panels to adjust their light-filtering properties using electrochromic layers that change color or opacity based on whether the screen is stretched or folded. ### Who owns patent US 12354567? HKC Co Ltd owns this patent, granted in 2025. ### When does this patent expire? This patent is expected to expire on July 8, 2045, when the invention enters the public domain. ### What problem does this patent solve? As foldable smartphones and tablets become more common, managing image quality during the transition between folded and flat states is a significant engineering hurdle. This technology provides a way to maintain color accuracy and contrast in flexible displays by physically altering the light path, potentially solving issues with light bleeding or color shifts that occur when flexible substrates are deformed. ### What does this patent NOT cover? Does not cover displays that lack electrochromic layers on both sides of the color filter. **Full plain-English explainer:** https://patentbrief.org/patent/us/12354567/sea-level-raptor **Original patent:** https://patents.google.com/patent/US12354567 --- _Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._ ## Related patents Semantically similar inventions in the PatentBrief corpus: - [How to Fix Color Uniformity in Digital Screens Using Math](https://patentbrief.org/patent/us/12277890/kestrel-engine) — A method for smoothing out color and brightness inconsistencies across a display screen by mathematically adjusting pixels based on their distance from a reference point. - [How Organic Diodes Make Light Using Special Molecules](https://patentbrief.org/patent/us/4356429/oled-organic-light-emitting-diode) — Eastman Kodak's 1982 patent on creating light-emitting diodes (OLEDs) using organic materials, specifically a layer of porphyrinic compounds to help inject electrical charges. - [How Liquid Crystal Displays (LCDs) Were Invented](https://patentbrief.org/patent/us/3322485/lcd-liquid-crystal-display) — This 1962 patent describes the first practical way to use organic liquid crystals to create a display that scatters light when an electric current is applied. - [Tiny Capsules for Electronic Paper Displays](https://patentbrief.org/patent/us/5961804/e-ink-electronic-paper-display) — MIT's 1999 patent on a special ink made of tiny capsules that can change color when an electric field is applied, forming the basis for early e-readers. - [How LG Chem Makes Plastic Films That Block UV Light](https://patentbrief.org/patent/us/12031028/starship-eclss) — A specialized plastic film made of alternating chemical segments that blocks harmful ultraviolet light while remaining perfectly clear.