How LASER printer works .....

Laser printers use the property of static electricity in an innovative way. The core part of a laser printer is a rotating photo receptor drum or cylinder, which is made of highly photo conductive material. The corona wire shown in the figure carries electricity which induces positive charge in the drum surface. When a laser beam is fired on the surface of the drum, the the point where the beam is fired, gets negatively changed. The laser beam is controlled by a print controller ( a processor inside the printer ) which determines how to move the laser so that it 'writes' an image of -ve changes on the +vely charged surface (this is called 'electro-static' image). Next step is to draw images on the cylinder with toner - Toner is a fine, black powder which is positively charged. As the drum surface comes under toner hopper, the toner glues to the negative charged 'electro static' image on the drum, but not to the positively charged "background."
With the powder pattern affixed, the drum rolls over a sheet of paper, which is moving along a belt below. Before the paper rolls under the drum, it is given a negative charge by the transfer corona wire (charged roller). This charge is stronger than the negative charge of the electrostatic image, so the paper can pull the toner powder away. Now the paper has the required image drawn with fine toner powder which is required to get etched permanently. The fuser ( see fig B ) heats the paper to melt the toner and make a permanent impression. As the paper moves fast, the paper does not get burnt.
The dischage lamp (fig A) neutralizes all the charges on the surface of the drum so that above steps can be repeated for the next scanline.

A Paradox

Have been reading Simon Singh. The Code Book makes awesome reading. Thanks Kaushik for presenting this wondeful book.
Now if I say - 'I am lying' what does it mean:)

Weekend - running kites!!

After quite a while, I was engrossed in books( not technical stuff which I have to refer anyway) for weeks. Did not come across much readings which would make me feel good, bad or even angry for a long time. Few weekends back, thought of catching a movie but just like my other plans, did not just 'get time' to go for one...instead went to "Sony world" electronic stores...no I did not have plan to buy any electronic item….. thing is that, opposite to the Sony, there is a small make-shift book store which I like to give a visit occasionally. But that day, could not locate the shop...God knows if they'd decided to implement 'Operation sunshine' to get clear of all book/magazine sellers from the narrow strip ( some people call it footpath ). So, had a mixed chaat in a sweet shop there and returned to my flat. After I had the shower, the part of my brain which I call judge saab, opined that I should spend the day with a book. Went to a mall ( now a days they keep books too!) and bought "The Kite Runner" by Khaled Hosseini. Well, next few days I was glued to this book!

It is the story of love, friendship, betrayal, hope. Set against the turmoil in Afganistan in 70s, Hosseini, neatly takes the readers through a wonderful journey. I found a nice line, which describes the devastations of war:
'the desert weed lives on, but
the flower of spring blooms and wilts'

NB: A time, when the protagonist goes to meet a taliban leader....that part appeared somehow Bollywood-movie-like. Nevertless, I liked the book and recommending it to Kaushik, Kunal, Raja...

Some funny laws....

DLF building recently installed a computerised advertising panel, next to the elavators. It keeps on displaying some funny information as well. Here are some of them....
--->The entire Encyclopedia Britannica is banned in Texas because it contains a formula for making beer at home!!!
--->In Alabama- It is illegal to wear a fake mustache that causes laughter in church!
--->In Maryland, it is illegal to take a lion to the movies!
--->In Fairbanks, Alaska, it is illegal to feed alcoholic beverages to a moose!
--->In california, it is illegal to eat oranges in a bathtub!
--->In florida, unmarried women who parachute on sundays may be jailed!
--->In chicago, it is illegal to fish in Pajamas!
--->In Joliet, Illinois, it is illegal to mispronounce the name "joliet"!
--->In Finland, people must be able to read in order to get married!
--->In France, it is forbidden to call a pig Napoleon!
--->The head of any dead whale found on the British coast is legally the property of the King; the tail, on the other hand, belongs to the Queen - in case she needs the bones for her corset!
--->Chewing gum is banned in singapore!

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