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intro_screen [2026/06/05 14:47] – [Article 2: Life cycle assessment of organic light emitting diode display as emerging materials and technology, Amasawa & al] yusufabdillahintro_screen [2026/09/11 15:17] (current) – [Definition] lucas.burlot.ext
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 Screens are electronic devices designed **to display visual content** by creating electronic pictures with illuminated pixels. Each pixel has three separate sub-pixels (red, blue, and green) that are individually controlled to create a color and brightness. Screens are electronic devices designed **to display visual content** by creating electronic pictures with illuminated pixels. Each pixel has three separate sub-pixels (red, blue, and green) that are individually controlled to create a color and brightness.
  
-Screens are the **main interface** between people and machines in integrated devices, such as laptops, smartphones, and tablets, or as external displays for desktop computers. The screen's technology has progressed from large, bulky cathode ray tubes (CRTs) to thin, lightweight flat panel displays (FPDs) like LCDs and OLEDs.+Screens are the **main interface** between people and machines in integrated devices, such as laptops, smartphones, and tablets, or as external displays for desktop computers. The screen's technology has progressed from large, bulky cathode ray tubes (CRTs) to thin, lightweight flat panel displays (FPDs) like [[intro_lcd|LCDs]] and [[intro_oled|OLEDs]].
  
  
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-A screen can be described as a **graphical interface** which converts electronic signals to a displayable form for the end-user. The technology consists of pixels that have been laid out in a matrix and can be controlled independently to display texts, images, or video sequences. Some of the properties of a screen include the type of technology (LCD, OLED), aspect ratio, dimension, and pixel resolution. In a life cycle assessment study of screen systems, all elements necessary for the performance of the screen will be included.+A screen can be described as a **graphical interface** which converts electronic signals to a displayable form for the end-user. The technology consists of pixels that have been laid out in a matrix and can be controlled independently to display texts, images, or video sequences. Some of the properties of a screen include the type of technology ([[intro_lcd|LCD]], [[intro_oled|OLED]]), aspect ratio, dimension, pixel resolution and density (PPI, Pixels Per Inch). In a life cycle assessment study of screen systems, all elements necessary for the performance of the screen will be included.
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   * **CRTs (Cathode Ray Tubes)**: They operate by generating an electron beam within a vacuum tube and projecting it onto a layer of phosphor materials. When these materials are struck by the electrons, they emit light through a process known as cathodoluminescence, thereby forming the image on the screen   * **CRTs (Cathode Ray Tubes)**: They operate by generating an electron beam within a vacuum tube and projecting it onto a layer of phosphor materials. When these materials are struck by the electrons, they emit light through a process known as cathodoluminescence, thereby forming the image on the screen
-[([[https://en.wikipedia.org/wiki/Cathode_ray_tube|Wikipedia - Cathode Ray Tube]])]. This technology was widely used in televisions, computer monitors and oscilloscopes during the 20th century. It is an older technology and has now largely been replaced by flat-panel displays (LCD, OLED) due to its bulkiness, high energy consumption and limitations in terms of miniaturisation.+[([[https://en.wikipedia.org/wiki/Cathode_ray_tube|Wikipedia - Cathode Ray Tube]])]. This technology was widely used in televisions, computer monitors and oscilloscopes during the 20th century. It is an older technology and has now largely been replaced by flat-panel displays ([[intro_lcd|LCD]], [[intro_oled|OLED]]) due to its bulkiness, high energy consumption and limitations in terms of miniaturisation.
  
   * **[[intro_LCD|LCDs]] (Liquid Crystal Displays)**: They use a backlight source whose rays pass through a layer of electrically controlled liquid crystals. Depending on their orientation, these crystals modify the passage of light through polarising filters, which allows the different colours and brightness levels of the image to be formed    * **[[intro_LCD|LCDs]] (Liquid Crystal Displays)**: They use a backlight source whose rays pass through a layer of electrically controlled liquid crystals. Depending on their orientation, these crystals modify the passage of light through polarising filters, which allows the different colours and brightness levels of the image to be formed 
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 <figure center| fig_screen_types> <figure center| fig_screen_types>
-{{ :display_panel_taxonom.png?600 |}}+{{ :display_panel_taxonom.png?800 |}}
 <caption> Classification of screen types </caption> <caption> Classification of screen types </caption>
 </figure> </figure>
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 Generic substrates of specialty glasses form the base for the layers of the display in practically all flat panel displays. The matrix of the thin film transistors (TFT) represents yet another universal family component that regulates each pixel in the active matrix. Generic substrates of specialty glasses form the base for the layers of the display in practically all flat panel displays. The matrix of the thin film transistors (TFT) represents yet another universal family component that regulates each pixel in the active matrix.
  
-An ordinary LCD assembly usually comprises several significant sub-assemblies, including the LCD panel, the backlight module, and the electronic controller. +An ordinary [[intro_lcd|LCD]] assembly usually comprises several significant sub-assemblies, including the [[intro_lcd|LCD]] panel, the backlight module, and the electronic controller. 
  
-The OLED assembly includes a substrate, a TFT matrix, an anode, multiple organic layers, a cathode, and an essential protective encapsulation layer. Ancillary sub-assemblies common to both families include the chassis, internal wiring, and stand. This is illustrated on {{ref>fig_screen_components}}. +The [[intro_oled|OLED]] assembly includes a substrate, a TFT matrix, an anode, multiple organic layers, a cathode, and an essential protective encapsulation layer. Ancillary sub-assemblies common to both families include the chassis, internal wiring, and stand. This is illustrated on {{ref>fig_screen_components}}. 
  
 <figure center|fig_screen_components> <figure center|fig_screen_components>
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 **Included in the LCA** **Included in the LCA**
  
-The scope of this life cycle assessment study involves the complete screen unit, encompassing the screen panel itself. This also extends back to upstream production processes such as the mining and refinement of materials used to create the screen, as well as the manufacturing of sub-units such as backlighting and the screen glass. Distribution is considered as part of the perimeter as it involves transport from the manufacturing facility to the end-user.+The scope of this life cycle assessment study involves the complete screen unit, encompassing the screen panel itself. This also extends back to upstream production processes such as the mining and refinement of materials used to create the screen, as well as the manufacturing of sub-units such as backlighting and the screen glass. 
  
 **Excluded from the LCA** **Excluded from the LCA**
  
-The housing, internal wiring, any cables, CPU of the computer and any accessories such as keyboards or mice are not included in the scope of many life cycle assessments for screens+The housing, internal wiring, any cables, CPU of the computer and any accessories such as keyboards or mice are not included in the scope of many life cycle assessments for screens. 
 +"Factory gate to user" distribution is not considered as part of the perimeter.
  
 ===== Functional unit and reference flows ===== ===== Functional unit and reference flows =====
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-The functional unit of this study is " ? one rigid display panel without touchscreen"+The functional unit of this study is "manufacture a rigid display unit without touchscreen interface". The term ‘manufacture’ as used here refers to the extraction and processing of raw materials, as well as the manufacturing processes required to produce a screen. 
  
 ====  Reference flow ==== ====  Reference flow ====
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-===== Life Cycle - Inventory =====+===== Life Cycle - Inventory (⚠️WORK IN PROGRESS⚠️)===== 
 + 
  
 => Goal: Define state of the art on life cycle stages to be considered. => Goal: Define state of the art on life cycle stages to be considered.