Technology

Characteristics of JOLED Display

JOLED display is an advanced display that realizes superb picture quality, energy efficient, and simple structure that enables ultra-thin profile and light weight.

Ultra-thin and light weight

JOLED display realizes ultra-thin form of 1.3mm thickness and light weight of 500g, as a result of its simple panel structure with no backlight.*

Energy efficient

JOLED display is energy efficient because it does not need backlight and is self-illuminating device that each EL element can be ON/OFF as needed.

Superb picture quality and accurate color reproduction

JOLED display has various advantages that can realize superb picture quality. It has 130% sRGB coverage that realizes greater color accuracy.*

High resolution and high definition

JOLED display has capacity to realize superb picture quality of 4K resolution with 3,840(RGB) x 2,160, 204ppi.*

Perfect jet-black

JOLED display is self-illuminating device that each EL element can be ON/OFF as needed. When it is OFF, it displays perfect black (jet-black). There is no light leakage like LCD. It also accurately displays color fineness with contrast ratio of 1,000,000:1 for darker blacks and brighter whites.*

Fast response time

Fast in responding, it displays movies smoothly and beautifully, taking advantage of self-illuminating device.

*In the case of 21.6 inch 4K JOLED display

What is OLED?

Organic Light Emitting Diode (OLED) is a kind of light-emitting diode (LED) that uses organic compound to emit light. In OLED, the emissive electroluminescent (EL) layer is formed by a film of organic compound that emits light in response to the current flow.
OLED device is composed of two electrodes and several functional layers: electron transport layer (ETL), emitting layer (EML), and hole transport layer (HTL), etc. When a bias is applied between anode and cathode electrodes, electron and hole recombine in the EML and emit light in response to the current flow.

Proprietary RGB Printing Technology

JOLED display is manufactured by JOLED proprietary RGB printing technology, which can produce excellent performance displays in effective production process.

Performance Advantages

Features of JOLED display are: “RGB Printing” to realize great light efficiency, “Microcavity Structure” to realize high color purity by sharpening RGB lights, and “Top Emission” to realize high light utilization.

Top Emission

High color output without obstacles

Microcavity Structure

Selectively strengthen RGB peak light waves

RGB Printing

RGB side by side to realize high color purity

Process Advantages

JOLED RGB printing technology has many advantages compared to conventional evaporation technologies. It is highly productive because it can be manufactured under atmospheric pressure without vacuum chamber nor mask. It is also highly efficient in material utilization because it puts necessary quantity of materials onto target points by printing. RGB printing technology has scalability that can produce panels of different sizes or different resolutions with a single printing system.

Difference of OLED Manufacturing Methods

There are two types of method to manufacture OLED display; “evaporation technology” and “printing technology”. There are also two types of technologies to form EL layer; “White OLED” in which three layers are deposited in laminated structure to emit white color, and “RGB side by side” in which three different light emitting layers are deposited side-by-side through a fine mask. In the case of “White OLED” technology, color is produced by color filter that causes loss of 3/4 light, and color reproductivity contradicts light utilization efficiency.
Actually major companies use “evaporation technology” in which EL layer is formed with vaporized EL material in vacuum chambers. It requires large vacuum chambers to accommodate panel and vapor deposition source and fine metal mask to form the EL layer on target points.
Especially “RGB side by side” technology, it deposits each RGB layer individually and requires three times of fine mask. When the screen size becomes bigger or number of pixels rises, it becomes more difficult to align the mask. In addition, extremely low efficiency in material utilization and the difficulty in depositing uniform thin films are the issues for this technology.
JOLED put into practical use the competitive RGB printing technology, and strives to popularize JOLED display into the market.

Vapor deposition method : White deposition

・Requires high degree of vacuum
・Requires mask

Vapor deposition method : 3-color deposition

・Requires high degree of vacuum
・Requires high-definition mask

JOLED Technologies that Enable Further Advanced Displays

Flexible Display

Flexible display is a display that can be rolled, folded, or bended like a paper or cloth. With its ultra-thin and light profile, it can realize displays more freely designed or easy to store.
JOLED is researching and developing various flexible displays. A super light in weight, flexible and high performance display can be realized by replacing the conventional glass substrate to the plastic substrate, and using the oxide TFT. We are aiming at developing flexible OLED for practical use in near future.

TAOS TFT Technology

To realize excellent performance of OLED, it is required high current flow to run for the thin film transistor (TFT).
Actually JOLED display uses low temperature poly-silicon (LTPS) TFT. LTPS TFT has good performance to run the high current flow but has same tasks such as non-uniform TFT performance due to the crystallization process and high manufacturing cost.
JOLED is now focusing on developing TAOS TFT (Transparent Amorphous Oxide Semiconductor) which has high electron mobility for high current flow and is uniformly formed on the large substrate.
We have developed a novel self-aligned top-gate TFT and realized superior reliability, by using a technology to passivate TFT electrode by metallic reaction. Also putting our unique correction circuit technology, we will realize high quality but reasonable OLED displays using our TAOS TFT.

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