简体中文
 
繁體中文
 
Projector jdcUser 2018-01-04T15:20:32+00:00
  • What about current LCoS projector market?( Suggest Delete this FAQ)
  • Current LCoS occupy <5% of total projection product market mainly for high end/ high resolution home theater projector.
  • Why is LCoS projection better than DLP technology?
  • LCoS technology can provide much higher resolution than DLP for the same panel size. For example, unlike DLP, which needs to utilize one or two dimensional pixel warbling to increase resolution to 4K (3840×2160), LCoS directly implements native 4096×2400 resolution instead, which provides higher picture quality.
    Current LCoS occupy <5% of total projection product market mainly for high end/ high resolution home theater projector.
  • What are the advantages of JDC’s LCoS projection technology?
  • We are using digital silicon backplane technology which provides high yield rate, lower cost, accurate gray scale control, and high pixel density, e.g. JDC’s unique 0.7” diagonal 4096×2400 LCoS panel.
  • How to classify current microdisplay technologies?
  • Technologically, there are presently two ways of classifying display components and the systems which use them:

    (1)  Based on the composition of microdisplay panel: using LCoS technology vs. using DLP technology.

    (2)  The system light source light used to illuminate the microdisplay: illumination by LED or laser.

    Functionally, the display systems can be distinguished by their intended use: for example pico projectors may be produced to be embedded into other devices for stand-alone operation, using an external direct connection to devices without embedded capabilities. Both these types bring more convenient and comfortable viewing experiences than possible with traditional displays by projecting pictures, movies, streaming videos, and presentations from newer and more personal mobiles such as an iPhone, an iPad, a laptop, a digital camera, a camcorder, simulation systems, etc. – the list keeps growing.

  • Why is LCOS projection better than DLP projection technology?
  • (1) Color performance of LCoS is better than one-panel DLP .

      Due to the inherent limitations of single-panel structure, one-panel DLP has yet to reach the color performance of LCoS display.

    (2) Raising resolution is difficult for DLP .

      Because DLP is using by MEMS (Micro-Electro-Mechanical Systems), raising its resolution is very difficult. This is the Achilles’ heel.

    (3) Three-panel DLP is expensive.

      Three-panel DLP can avoid unfavorable flare seen on one-panel DLP . It can give better color performance. However, the cost of three-panel DLP projector is extremely high, which makes difficult its widespread use for home theater entertainments.

  • What are the advantages of LCOS projection technology?
  • (1) Project high-resolution, sharp and smooth images

       LCoS microdisplays’ merits of high aperture ratio and tiny pixel size contribute to smaller pixel pitch on projected images. The images look sharper and smoother, which makes LCoS very suitable for big-screen projection.

    (2) High contrast ratio

      Excellent contrast brings richer gray scale performance. LCoS projected images are more natural, more stereoscopic.

    (3) Great for playing sport events

      As the technology advances, the liquid crystal layer on LCoS microdisplays gets thinner, which reduces the viscosity. As a result, when watching sporting events, LCoS gives faster and clearer images.

  • How to choose the right resolution?
  • The resolution of a projector determines the number of pixels on a projected image. When choosing projectors, a user needs to take the resolution of the video input into account. If a user only needs a projector to go with a DVD player or Wii video game, it is not necessary to buy a Full HD projector.

    Projector Resolution Type of Video Input
    480p 854×480 DVD(720X480)、Wii
    SVGA 800×600 PC, PowerPoint Presentation
    XGA 1024×768 PC, PowerPoint Presentation
    720p 1280×720 HD Movie
    WXGA 1366×768、1366×800、1400×788、1280×768、1280×800 Wide-screen PC, PowerPoint Presentation
    SXGA/SXGA+ 1280×1024、1400×1050 High-end PC, PowerPoint Presentation
    Full HD 1080p 1920×1080 Blue-ray Disc、PS3、HDTV (MOD), PowerPoint Presentation
  • What is throw ratio?
  • Throw ratio (D/W) is an important feature of projection lens. It is defined as the distance between the projector and the screen (D) divided by the width of the projected image (W).

    For example, a projector is equipped with zoom lens of throw ratio 2.0 ~ 2.5. When the desired width of the projected image is 160cm, how far away should the projector be from the screen?
    Here the W is 160. D/160 = 2.0 ~ 2.5. D should be 3.2 ~ 4 meters.

    What if the distance is set to 4 meters? What is an appropriate size for the screen?
    4/W = 2.0 ~ 2.5. The width (W) of the screen should be 1.6 ~ 2 meters.

  • What is DMD?
  • A Digital Micromirror Device, or DMD , is a key element in DLP projection system developed by Texas Instruments. The DMD is a spatial light modulator, on which millions of tiny mirrors control the incident light so that it is reflected either into or away from the projection lens. Electrostatic force is responsible for tilting the mirrors. Each mirror represents a single pixel. The entire array of mirrors directly decides the resolution of a DMD . A DMD is fabricated by one of a type of techniques known as Micro-Electro-Mechanical Systems ( MEMS ). The mirrors are connected to base SRAM cells by yokes and torsion hinges. The mechanical structure is pictured in the following diagram.

     

  • What is transmissive LCD?
  • A transmissive LCD is a flat, thin liquid crystal display. The light transmits from the back of the panel, through the liquid crystal layer, and reaches the viewers in the front. Each pixel on the display consists of two polarizers, two electrodes, and in between a layer of liquid crystal. When there is no applied voltage, the backlight transmits through both polarizers, and the LCD appears bright. On the other hand, when voltage is applied to electrodes, the liquid crystal molecules align themselves parallel to the electric field, thus preventing the backlight from passing the second polarizer. The result is a dark LCD .

     

  • What is the difference between a front projection system and a rear projection system?
  • In a front projection system, the light source and the audience are on the same side of the viewing screen. On the contrary, for a rear projection system, the light source and the audience are on opposite sides of the viewing screen. The configuration is shown as the pictures below.

     Normal front projection.

     Suspended front projection.

     Normal rear projection.

     Suspended back projection.

  • What is color temperature?
  • At different absolute temperatures, a black-body radiator emits light of different hues, some commonly referred as to the color red, yellow, green, blue and purple, etc. The color temperature is an attribute of a light source. It is defined as the absolute temperature (unit: Kelvin, symbol: K) of the black-body radiator when a light source emits the color hue similar to that of black-body radiator. The color temperature of daylight, which by convention is called ‘white’, is 6500K. The hues of low and high color temperatures look red and blue, respectively. When a projector is set to a high color temperature , the normally white color looks bluish, whereas at a low color temperature , the normally white color looks a bit reddish.
  • What is brightness versus luminous flux?
  • Brightness is a qualitative property based on human visual perception of light emitted from a source. It is not a measured (quantitative) thing. On the other hand, luminous flux can be measured. Luminous flux is the total amount of light emitted through a projected area from a light source. The unit of luminous flux is lumen. A standard incandescent lamp measures 1300 lumens in areas using 220V voltage and 1700 lumens in North America.
  • What is contrast?
  • In projectors, contrast is defined as the ratio of the brightest area to the darkest area of the projected image.

    For example, a contrast of 2000:1 means the brightest white area of the image is 2000 times brighter than the darkest black area. The contrast  determines how much detail a projector can show in a dark movie scene. The higher the contrast , the more easily the   detail in a dark scene can be discerned.

  • What is light?
  • Electromagnetic waves are everywhere in the world. Cosmic rays, cell phone signals, satellite signals and microwaves are some examples of electromagnetic waves. Light is a kind of electromagnetic wave that humans are able to see. The wave length of light ranges from 400nm to 700nm. Blue light has the shortest wave length, from 420nm to 480nm. Green light is slightly longer, from 500nm to 560nm. For red light, it is the longest, from 580nm to 700nm. Human eyes are most sensitive to green lights, especially to those of 550nm.