In our last post, we introduced you to a modern technology i.e Pico projector. A hand held projector that does not need to be connected to wired power source every time. Carrying it is so convenient that you can even keep it in your pockets. What more one can ask for?? Now, in this post we will concentrate on the various “technologies behind Pico projector” .
Still to date, a whole lot of money is continuously being spent for R&D (Research & development) of the Pico projectors. Every day, new inventions are being made. Some companies have even started the full fledged production of these Pico projectors also. Keeping apart the technologies under test, we will take a look on the Pico projector’s technologies under use only. Accordingly, we can categorise the “technologies behind Pico projector” to three main technologies:
Digital-light-processing technology (D.L.P)
This technology uses very small mirrors that are placed on the specific chip which manages the direction of light. Every mirror has its own specific function to control the value of light which a pixel will have in the picture. This mirror has two conditions i.e. ON/OFF and its refreshing speed is very high per unit second. It should be noted that this ON/OFF time percentage of the mirror defines the brightness of the pixels. For example – if the ON time percentage of the mirror is 60%, then the brightness of the pixel will be 60%. The different colours are achieved with the help of a colour-wheel which is placed between mirror and the white light-source. This colour wheel carryout the splitting of light into three colours i.e. Red, Blue and Green. The mirror then does the controlling of these beam of lights on the assigned pixel’s spot.
Liquid-crystal-on-Silicon technology (L.C.oS.)
In this technology, a tiny liquid crystal display (L.C.D.) is used for controlling the value of light which a pixel will get in the picture. The white light-source for L.C.oS. may be a laser (diffused type) or an LED. We can achieve various colours in this technology through two methods :
Colour Filter L.C.oS. –
In this method three sub-pixels are used. Every sub-pixel is assigned with its own clour (in between Red, Blue and Green).
Field sequencial Colour L.C.oS. –
In this method, a relatively more active L.C.D. is used. The picture is split into three basic colours (i.e. Red, Blue and Green ) and the L.C.D. is refreshed three times ( one time for every colour).
Laser beam steering Technology (L.B.S.)
In this technology, a directable laser beam is used which generates an image with a single pixel per unit time. There are three lasers with basic colour for each one (i.e. Red, Blue and Green) The beams are later directed with the help of mirrors. The basic advantage of this projector is that it is focus-free i.e. it does not lose its focus even on curved surfaces. Yes…. you heard it right.