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intro_screen [2026/06/05 14:33] – [Emissive technologies] yusufabdillahintro_screen [2026/06/30 11:40] (current) – [Life Cycle - Inventory] antoine
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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, and pixel resolution. 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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   * **[[intro_OLED|OLEDs]] (Organic Light Emitting Diodes)**: These screens are based on the electroluminescence of organic semiconductor materials, which emit light when an electric current passes through them   * **[[intro_OLED|OLEDs]] (Organic Light Emitting Diodes)**: These screens are based on the electroluminescence of organic semiconductor materials, which emit light when an electric current passes through them
 [([[https://en.wikipedia.org/wiki/Electroluminescent_display|Wikipedia - Elecroluminescent displays]])]. Unlike LCD screens, each pixel is self-illuminating and therefore no backlight is required: high contrast ratios and thinner screens can be obtained  [([[https://en.wikipedia.org/wiki/Electroluminescent_display|Wikipedia - Elecroluminescent displays]])]. Unlike LCD screens, each pixel is self-illuminating and therefore no backlight is required: high contrast ratios and thinner screens can be obtained 
-[([[https://en.wikipedia.org/wiki/OLED| Wikipedia - OLED]])]. However, OLED screens consume more power than LCDs in bright conditions as organic molecules need to be excited. Similarly, they consume less energy than LCDs in dark conditions as each pixel can be switched-off completely. This technology is used in smartphones, televisions, smartwatches and high-end flexible screens. Increasingly popular since the 2000s, OLED is considered a newer technology than LCD and CRT screens.+[([[https://en.wikipedia.org/wiki/OLED| Wikipedia - OLED]])]. However, OLED screens consume more power than LCDs in bright conditions as organic molecules need to be excited. Similarly, they consume less energy than LCDs in dark conditions as each pixel can be switched off completely. This technology is used in smartphones, televisions, smartwatches and high-end flexible screens. Increasingly popular since the 2000s, OLED is considered a newer technology than LCD and CRT screens.
  
-  * **E-paper** or **Electronic Paper**: E-paper (or electronic paper) screens work using small capsules containing charged particles that move under the influence of an electric field. By changing their position, these particles either lighten or darken certain areas of the screen by reflecting ambient light+  * **E-paper** or **Electronic Paper**: E-paper (or electronic paper) screens work using small capsules containing charged particles that move under the influence of an electric field. By changing their position, these particles either brighten or darken certain areas of the screen by reflecting ambient light
 [([[https://en.wikipedia.org/wiki/Electronic_paper|Wikipedia - Electronic paper]])]. This technology, used in e-readers, in certain digital labels and low-power devices, does not produce light but operates in reflective mode.  [([[https://en.wikipedia.org/wiki/Electronic_paper|Wikipedia - Electronic paper]])]. This technology, used in e-readers, in certain digital labels and low-power devices, does not produce light but operates in reflective mode. 
  
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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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 Display performance depends in part on the transistor technology used to drive the pixels. There are several technologies whose characteristics directly influence the optoelectronic performance of displays, including refresh rate, luminance, pixel density and energy efficiency.  Display performance depends in part on the transistor technology used to drive the pixels. There are several technologies whose characteristics directly influence the optoelectronic performance of displays, including refresh rate, luminance, pixel density and energy efficiency. 
  
-  * **Amorphous silicon (a-Si)**: It is the most mature and widely used backplane technology due to its straightforward manufacturing and scalability to massive substrate sizes. It involves depositing an unorganized silicon film via plasma-enhanced chemical vapor deposition (PECVD), which is highly cost-effective. While it is excellent for general applications, a-Si has low electron mobility (around 0.5 to 1.0 cm²/Vs), limiting its use in ultra-high-resolution or high-refresh-rate displays [( Flay_Panel_Display_Manufacturing>[[https://www.wiley.com/en-es/Flat+Panel+Display+Manufacturing-p-9781119161363|Flat Panel Display Manufacturing, Jun Souk, Shinji Morozumi, Fang-Chen Luo, Ion Bita, 2018]]). Additionally, it lacks the bias stability required for current-driven devices like OLEDs. Despite these limitations, a-Si remains the benchmark for mainstream TVs, budget notebooks, and desktop monitors. Recent efforts have focused on reducing mask counts (to 4 or 5) to further lower production costs +  * **Amorphous silicon (a-Si)**: It is the most mature and widely used backplane technology due to its straightforward manufacturing and scalability to massive substrate sizes. It involves depositing an amorphous silicon film via plasma-enhanced chemical vapor deposition (PECVD), which is highly cost-effective. While it is excellent for general applications, a-Si has low electron mobility (around 0.5 to 1.0 cm²/Vs), limiting its use in ultra-high-resolution or high-refresh-rate displays [( Flay_Panel_Display_Manufacturing>[[https://www.wiley.com/en-es/Flat+Panel+Display+Manufacturing-p-9781119161363|Flat Panel Display Manufacturing, Jun Souk, Shinji Morozumi, Fang-Chen Luo, Ion Bita, 2018]]). Additionally, it lacks the bias stability required for current-driven devices like OLEDs. Despite these limitations, a-Si remains the benchmark for mainstream TVs, budget notebooks, and desktop monitors. Recent efforts have focused on reducing mask counts (to 4 or 5) to further lower production costs 
 [( Flay_Panel_Display_Manufacturing>[[https://www.wiley.com/en-es/Flat+Panel+Display+Manufacturing-p-9781119161363|Flat Panel Display Manufacturing, Jun Souk, Shinji Morozumi, Fang-Chen Luo, Ion Bita, 2018]])]. [( Flay_Panel_Display_Manufacturing>[[https://www.wiley.com/en-es/Flat+Panel+Display+Manufacturing-p-9781119161363|Flat Panel Display Manufacturing, Jun Souk, Shinji Morozumi, Fang-Chen Luo, Ion Bita, 2018]])].
  
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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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-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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 This article has been published by Yeom JM & al. in 2018 This article has been published by Yeom JM & al. in 2018
-[([[https://link.springer.com/article/10.1007/s41742-018-0106-y|Environmental Effects of the Technology Transition from Liquid–Crystal Display (LCD) to Organic Light-Emitting Diode (OLED) Display from an E-Waste Management Perspective. ]]Yeom, JM., Jung, HJ., Choi, SY. et al., Int J Environ Res 12, 479–488 (2018))] and will be described bellow. +[([[https://link.springer.com/article/10.1007/s41742-018-0106-y|Environmental Effects of the Technology Transition from Liquid–Crystal Display (LCD) to Organic Light-Emitting Diode (OLED) Display from an E-Waste Management Perspective. ]]Yeom, JM., Jung, HJ., Choi, SY. et al., Int J Environ Res 12, 479–488 (2018))] and will be described below. 
  
 **Methodology** **Methodology**
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 <figure center |yeom_results> <figure center |yeom_results>
 {{ ::ttlc_oled_and_lcd.png?direct&400 |https://link.springer.com/article/10.1007/s41742-018-0106-y#citeas}} {{ ::ttlc_oled_and_lcd.png?direct&400 |https://link.springer.com/article/10.1007/s41742-018-0106-y#citeas}}
-<caption>Yeaom et al. results</caption>+<caption>Yeom et al. results</caption>
 </figure> </figure>
  
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 This article has been published by Amasawa & al This article has been published by Amasawa & al
-[([[https://www.sciencedirect.com/science/article/abs/pii/S0959652616309131|Life cycle assessment of organic light emitting diode display as emerging materials and technology]], Eri Amasawa, Tomohiko Ihara, Takashi Ohta, Keisuke Hanaki, Journal of Cleaner Production, Volume 135, 2016, Pages 1340-1350, ISSN 0959-6526)] and is content will be described bellow. +[([[https://www.sciencedirect.com/science/article/abs/pii/S0959652616309131|Life cycle assessment of organic light emitting diode display as emerging materials and technology]], Eri Amasawa, Tomohiko Ihara, Takashi Ohta, Keisuke Hanaki, Journal of Cleaner Production, Volume 135, 2016, Pages 1340-1350, ISSN 0959-6526)] and its content will be described below. 
  
 **Methodology** **Methodology**
  
-[[life_cycle_assessment|Life Cycle Assessment (LCA)]] with the ISO 14040[([[https://www.iso.org/obp/ui/#iso:std:iso:14040:ed-2:v1:fr|ISO 14040, 2006]])] standard, and two criterias : Cumulative Energy Demand (CED) and Global Warming Potential (GWP) based on the IPPC 100-year framework [([[https://www.ipcc.ch/assessment-report/ar4/|IPCC 100-year framework, 2007]])]+[[life_cycle_assessment|Life Cycle Assessment (LCA)]] with the ISO 14040[([[https://www.iso.org/obp/ui/#iso:std:iso:14040:ed-2:v1:fr|ISO 14040, 2006]])] standard, and two criteria : Cumulative Energy Demand (CED) and Global Warming Potential (GWP) based on the IPCC 100-year framework [([[https://www.ipcc.ch/assessment-report/ar4/|IPCC 100-year framework, 2007]])]
  
 ** Types of Technologies Covered (System Definition) ** ** Types of Technologies Covered (System Definition) **
  
-Functional unit: "One assembled 5_inch AMOLED display at the AMOLED manufacturing site in South Korea."+Functional unit: "One assembled 5-inch AMOLED display at the AMOLED manufacturing site in South Korea."
  
 The structure consists of: The structure consists of:
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 **Life Cycle Stages Covered** \\ **Life Cycle Stages Covered** \\
-The scope is a **cradle-to-gate** assessment. It includes :+The scope is a **cradle-to-gate** assessment. It includes:
     * Raw material acquisition     * Raw material acquisition
     * OLED fabrication (pre-treatment, organic/metal layer deposition via vacuum vapor deposition)     * OLED fabrication (pre-treatment, organic/metal layer deposition via vacuum vapor deposition)
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   * Orders of Magnitude: The manufacturing of one 5-inch AMOLED display results in a CED of 22.6 MJ and a GWP of 0.886 kg CO2-eq   * Orders of Magnitude: The manufacturing of one 5-inch AMOLED display results in a CED of 22.6 MJ and a GWP of 0.886 kg CO2-eq
   * Hot Spots: The facility energy is the largest contributor, accounting for 41.5% of the total impact. The organic layer deposition process is the second largest contributor   * Hot Spots: The facility energy is the largest contributor, accounting for 41.5% of the total impact. The organic layer deposition process is the second largest contributor
-  * Process vs. Material: Despite the complexity of specialty chemicals, their synthesis is not a significant contributor; instead, nearly 80% of the impact within the organic layer deposition stage comes from the vacuum vapor deposition process itsef+  * Process vs. Material: Despite the complexity of specialty chemicals, their synthesis is not a significant contributor; instead, nearly 80% of the impact within the organic layer deposition stage comes from the vacuum vapor deposition process itself
   * Comparison: AMOLED displays exhibited a lower GWP for materials when compared to similar-sized Liquid Crystal Displays (LCD)   * Comparison: AMOLED displays exhibited a lower GWP for materials when compared to similar-sized Liquid Crystal Displays (LCD)
  
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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.