How transparent displays work

Transparent display

A transparent smartphone concept

A Transparent display is an electronic display that allows the user to see what is shown on the glass screen while still being able to see through it.Transparent Electroluminescent display has been around for a decade or two.It has been an inevitable part oif sci-fi movies since 90's.Always Hollywood is a step ahead of science.But,only after 2010 companies have started thinking about it seriously.By the end of 2011 few companies had finished their transparent display prototypes.

Types of Transparent/see through displays

There are two major transparent display technologies, LCD and LED.Transparent LCD display is of absorptive nature and transparent LED display is emissive in nature.Let us have a look at the working principle behind both type of see-through dispalys.

How transparent displays work?

Transparent LCD display

Transparet LCD display from EVOLUCE(a German company)

Hope you are familiar with the working of LCD display.If don't please go through and come back.

• Working of LCD.

Different Layers of an LCD unit

Refer the diagram given above.You can see different layers of LCD display unit.If you remove the mirror(A) ,then remaining layers can be made transparent.Standard LCD screens,have backlit components built into them to help illuminate the pixels on the screen. This backlighting help make the screen visible to viewers, but thicken the screens so that they’re no longer see-through.onverting these standard LCD screens into transparent LCD screens requires an alternative light source that doesn’t block the display. Transparent LCD panel utilizes ambient light such as sun light, which consequently reduces the dependency on electricity for generating power.Usually for transparent LCD system LED illuminated boxes with integrated electronics and connections are used.

A transparent LCD display can be integrated into store windows, display cases, billboards, and more to make static words and images more kinetic. Products can be placed behind a clear transparent screen that shows advertising and provide the opportunity to showcase real products while providing interactive information with an transparent LCD display.

Transparent LED display.

Samsung transparent OLED panel

Transparent OLED displays are self-emitting  and utilize cutting edge Organic Light Emitting Diode [OLED] technology to eliminate the need for a backlight or enclosure.

A transparent OLED pixel

Each pixel in a transparent OLED is made up of 4 sub-pixels. Color is created by the combination of red, green and blue sub- pixels and the remaining area of the pixel is clear. That clear section creates the transparency.This is why there is a direct relationship between resolution and transparency. Ff the display contains more active pixels that creates less space for clear pixels,it results in less see-through.So,in OLED transparent panel design,there is a need for transmission and resolution optimization.Unlike transparent LCD displays,black or dark content on the display is clear and white or bright content is opaque.Just like any glass surface ,ambient light effects that appearance of transparency.The more you light the item behind,more transparent the screen.Transparent cathode and electronics components also add to the transparency of panel.Transparent electronics are made using a special class of material called Transparent Conductive Oxides(TCO).In2O3,SnO2,CdO,ZnO are some of the commonly used TCOs.

• What is OLED and How it works?

Transparency in eletronics can also be achieved by graphene.Graphene is single atom thick carbon sheet which is highly transparent and super flexible.[Read more about graphene]Researches in this field is going around the world.Scientist claim that graphene will be the key to future electronics.

sources:http://www.evoluce.com/,www.planar.com