KYOCERA Develops High-Speed, High-Resolution LED Printhead

The printhead incorporates a newly developed high-intensity 1200dpi LED chip, that at 150μW (1mA drive current), produces four times more light than Kyocera's conventional models. This high-resolution printing is available at the world's fastest speed of 180m/min, with low power consumption. Theoretically, this means it is capable of printing more than 1,000 sheets of standard A4 size paper per minute. It also consumes just a quarter of the power of its predecessors operating at the same printing speed.

High-intensity LED chips provide the optimal light source for amorphous silicon photoreceptor drums*2 — the key device in high-speed electrophotographic printers. Use of LEDs has eliminated memory image and sensitivity shortage — problems that had to be overcome to allow for further improvements in printing speed — leading to the successful development of high-speed, high-resolution LED printheads.

The product is scheduled to launch in April 2010. A package with the amorphous silicon photoreceptor drum for high-speed printing will be released at the same time.

Kyocera began supplying LED printheads for office document equipment in 1992. Starting with this industry leading product, the company will expand its business to the highly promising commercial printing market.

Kyocera will exhibit the product at the Japan Graphic Arts Show (JGAS) 2009 from October 6 (Tue.) - 10 (Sat.) at Tokyo Big Sight.

*1 World's fastest electrophotographic printing speed, based on research by Kyocera as of October 1, 2009.
*2 A photoreceptor drum is a photo conductor that revolves inside a printer and transfers toner to the paper. This device, previously a consumable item, has become a component with long service life due to Kyocera's use of amorphous silicon.

Electrophotographic printing is divided into two types depending on the optical source: laser printing and LED printing. Kyocera engages in development and production for LED printing, which provides the following benefits:
1.) Improvement in printing speed is possible because there is no constraint on mirror revolution speed.
2.) Higher-resolution printing is available as the optical path is short and beams are sharp.
3.) A complicated scanning mechanism is not necessary, which permits compact size and less noise.
Moreover, in recent years the commercial printing market has witnessed a growing call for on-demand digital printing that permits low volume printing of a wide variety of content. Expectations have been raised for LED printheads as a solution for such demands. Kyocera has successfully developed a high-speed printing device as demanded by the commercial printing market by making use of its years of experience in printing devices.

For developing this new product, it was essential to build a high-intensity LED chip that enables high-speed printing. Kyocera employed its own thin-film formation technology to improve the configuration of light-emitting elements on the LED chip and optimize the electrode and wiring structure. This enabled the development of a high-intensity LED with improved luminous efficiency in the low current range, which is required in higher-speed printing. For this LED, Kyocera also improved the high-density packaging process and optimized the design, permitting development of an LED printhead for high-speed, high-resolution printing.

1. High-resolution printing at the world’s highest speed
Use of the new high-intensity LED chip realizes the world’s fastest electrophotographic printing at 180m/min with a resolution of 1200dpi.

2. High-reliability printing with low power consumption
The new printhead produces four times more light than its predecessors, even though the unit consumes only one quarter of the power of conventional printers operating at the same speed. The low power consumption also enables a reduction in heat generation at the LED head; increased heat lowers optical precision and significantly affects the stability of the light amount and emission lifespan. The new product is therefore expected to contribute greatly to quality improvement in digital printers, which have been advancing to higher speeds and resolutions.

3. Stability of printing quality enabled by exclusive technology for light amount correction
Kyocera’s exclusive light amount correction technology permits an optimal light amount for the characteristics of the amorphous silicon photoconductive drum, which enables stable printing quality.