Microdisplay Technology

Epson Microdisplays Are the Heart of a Projector

Projectors have become essential tools for both business and home-theater. Epson projectors employ a 3LCD system to project bright images that are easy on the eyes. The 3LCD method is a method in which images of red, green, and blue created using three liquid crystal displays are combined with a dichroic prism and projected. Read on to learn about the Epson microdisplay technology that makes beautiful projected images possible.

HTPS panels, which are essential for 3LCD

HTPS panels

HTPS (High-Temperature Poly-Silicon TFT liquid crystal)panel

HTPS panels are essential for bright, easy-on-the-eyes 3LCD projectors

The light emitted from the light source in a 3LCD projector is split into its red, green, and blue components (the primary colors of light) by dichroic mirrors. Each of these beams is sent to its own LCD panel, where an image of each respective color is created. LCDs for projectors come in two types: reflective and transmissive. Epson uses the transmissive type. These LCDs are called high-temperature polysilicon thin-film transistor (TFT) liquid crystal display panels, or "HTPS panels" for short. There is one TFT for each dot, and the amount of light transmitted from each dot can be precisely controlled using electric signals. Images are displayed by smoothly controlling the brightness from black to white. For this reason, HTPS panels are extremely important devices that determine 3LCD projector performance. HTPS panels must both efficiently transmit or block light as needed. Panels must also demonstrate high photostability, high resolution, and high resolution. Epson leverages its original technology to manufacture small, high-performance HTPS panels with integrated driver circuits.

Aperture ratio

Aperture ratio

Bright images achieved by increasing the aperture ratio by 50% using microfabrication technology

High-definition HTPS panels must have a high transmittance. HTPS panels require certain parts that do not transmit light, such as pixel bus lines, transistors, and a black matrix (a light-shielding framework). The panels also must have areas (apertures) through which light passes. These apertures need to occupy as large an area as possible; that is, the aperture ratio must be as high as possible. Epson maximizes the aperture ratio of its HTPS panels by leveraging advanced microfabrication technology, which is also used in semiconductor manufacturing, along with Epson-engineered bus lines and pixel elements. Epson was able to increase the aperture ratio of a 0.76-inch WUXGA panel, for example, by more than 30% in the first five years after 2005 and by more than 50% over the first 10 years.


Optical efficiency increased by 30% with Epson double-microlens arrays

Epson's microlens arrays are one of the technologies that enable high-performance HTPS panels.HTPS panels must transmit as much light as possible to produce bright images. However, each tiny pixel has an aperture through which light can pass and opaque parts such as bus lines that block light. Therefore, Epson provides a microlens array, with a tiny lens for each pixel. The microlens array also covers the bus lines and other light-blocking parts of the black matrix. The lenses refract the light that would otherwise bounce off the light-shielding parts and send it through the apertures. In addition, Epson disposes a double-microlens array over the entire surface of the HTPS panel. By providing a pair of opposing lenses over each aperture, Epson increased the light utilization efficiency of the panels by 30% compared to panels that are not equipped with a microlens array.

Vertical integration provides creative products

Epson develops and manufactures all the key parts to ensure beautiful images

HTPS panels are not the only technology underpinning Epson's high-performance projectors. Our projectors also require a light source, such as a laser light source engine, dichroic mirrors that split the light from the light source into the three beams of the primary colors, a dichroic prism for combining the images created on each of the LCDs to create a single full-color image, and an image processing engine IC.

Epson is able to provide unique, high-performance projectors because it has the core technologies that enable it to develop and manufacture nearly all the core components.

Page Top

Page Top