LCD Projector Manufacturer
Provides audio-visual integration for residential and commercial projects. Offers front screen projection projectors, touch panels, media recording systems and home theater equipment. Also provides system design and installation services.
BOE has positioned itself as a formidable LCD supplier that excels where DLP projectors are unable to. This includes superior brightness levels, color accuracy and cost-effectiveness.
History
While LCD TVs and computer monitors have been around for a while now, the LCD projector is still relatively new. So, how did this technology come to be?
New York inventor Gene Dolgoff began working on the LCD projector while he lcd projector manufacturer was in college in 1968. His goal was to produce a multimedia projector that was brighter and less bulky than the 3-CRT projectors available at the time. He envisioned using an element known as a light valve to control the amount of light that passed through and a powerful external light source to produce his video image. However, the technology he needed – direct driven and matrix-addressable LCDs with high enough resolution to produce video images – wasn’t available until 1984.
In the meantime, researchers were developing new materials that could be used in light valves, and one of those, cyanobiphenyls, worked well at room temperature. This allowed Dolgoff to finally get his projector working, though it wasn’t without flaws. He had to correct problems such as major light losses and very noticeable pixels (also called the screen-door effect).
Now, nearly two decades later, LCD projectors are the dominant technology in the business and home entertainment markets. While there are still other technologies vying for those markets, such as micromirrors, LCDs have proven to be the most efficient and cost-effective.
Technology
In a projector, images are transmitted through the lens and projected onto a screen. The vibrant, full-color image is produced by using a light source and a series of specialized electronic circuits that control the amount of light passing through each pixel in the imager. The result is an extremely bright, high-resolution display that looks very similar to a traditional overhead projector, but can be much more compact and affordable.
A CCFL (cold cathode fluorescent lamp) or a parallel array of LEDs provide the light source in most projectors. CCFLs are used because they produce much more stable light than LEDs and offer an easier-to-control color gamut. They also require an external inverter to convert whatever DC voltage is applied to the projector into the 1000 V needed to light a CCFL panel.
The imagers in most modern projectors are LCDs, with a few models that use LCoS (liquid crystal on silicon) instead. LCoS projects tend to have the best inherent contrast and blacks among today’s projection displays.
Some home-theater LCD projectors with 1080p imagers simulate true UHD resolution by shifting the final image pixels diagonally by half a pixel each frame. This technology is called pixel-shifting, and it allows the pixels to be switched between two levels of transparency much faster than any human can see, doubling the effective number of visible pixels on the screen and dramatically reducing the dreaded “screen door” effect.
Specifications
A projector’s specifications determine how large an image it can display and its contrast ratio. A higher resolution supports a larger image size, while a higher contrast ratio increases sharpness and brightness. Some projectors have a zoom lens that can adjust the image size based on distance from the screen.
A wide range of specifications are available for LCD projectors, allowing users to customize the device to their specific needs and applications. For example, many projectors have multiple input and output ports for connecting various devices, such as computers, speakers, audio mixers, and control systems. Some also support multiple projection formats, ensuring compatibility with the latest digital content.
The display technology inside a projector determines its quality and price. For instance, some models outdoor projection tv use three DMDs—one for red, one for green, and one for blue—to produce full-color images. However, this type of projector is usually more expensive than its counterparts that use only one DMD.
Contrast ratio is another important specification, but it should be noted that ambient room light can reduce contrast performance dramatically. It is therefore essential to match a projector’s contrast ratio spec with the intended usage conditions.
Applications
In a projector, the light from the lamp is directed onto a projection screen by a lens. The image can be a single color or multiple colors. In LCD projectors, the light passes through three separate LCD-based imagers (each with a different color filter). The colored filters in the imagers allow red, green and blue images to be separated out and projected one at a time.
The first working prototypes of LCD projectors appeared in 1971, but digitally addressed LCD matrix devices with high enough resolution to display video did not become available until 1984. Early LCD projectors used a series of dichroic mirrors to split the white light from the lamp into the red, green, and blue components that would pass through their respective imagers. Then, the imagers recombined those channels into a full-color video image.
LCD projectors use small lamps, so they are lighter and more portable than other types of projection systems. They also require a blank white or black (which blocks ambient light) surface for best results.
Some LCD projectors use a spinning wheel with phosphor coatings to produce yellow light instead of using a laser. This allows them to produce higher brightness levels and more color combinations. For example, JVC’s 1080p home-theater model uses this technology, which it calls e-Shift. The e-Shift system doubles the number of pixels that are projected on the screen by shifting each imager’s red, green, and blue images by half a pixel 120 times per second.