Crt - cathode ray tube, Computer Graphics

Assignment Help:

CRT - Cathode Ray Tube

  • Electron gun is used to send an electron beam aimed at a particular point on the screen. Deflection system is used to make the beam strike the screen on a precise point.
  • When electron beam strikes the screen, coated phosphor emits light due to the natural phenomenon called phosphorescence. Output decays rapidly approximately within 10 - to 60 microseconds.
  • As a result of this decay, the entire screen must be refreshed at least 30-60 times per second. This is called the refresh rate. If the refresh rate is low, screen will tend to flicker.
  • CFF (Critical Fusion Frequency) is the minimum refresh rate needed to avoid flicker. It depends on the persistence of the phosphors and the human vision system.
  • Electron beam traces out a path on the screen, hitting each pixel once per cycle. Tracing out of the entire picture once is called a cycle. In case of a raster scan display we call the horizontal path of the beam a scan line. In case of random scan display, the path is a directed set of line segment, which are called vector lines.
  • On a raster scan display, refresh rate is fixed as mentioned above. On a vector display, a scan is in the form of a list of directed line segments to be drawn, so the time to refresh is dependent on the length of the display list. For small and simple object displays, some kind of delay is introduced to avoid un-necessary refreshing of the screen.
  • In color CRT, shadow-mask method is most common since it produces a wide range of colors. In this method, each pixel consists of a group of three phosphor dots (one each for red, green, and blue), arranged in a triangular form called a triad. The shadow mask is a grid structure with one hole per pixel. To excite one pixel, three electron guns are used one for each of red, green, and blue. Each gun fires its electron stream through the hole in the mask to hit that pixel.

Related Discussions:- Crt - cathode ray tube

C++ programming, self test exercise 17 asked you to overload the operator >...

self test exercise 17 asked you to overload the operator >> and the operator Overload biinary operator + to add pairs according to the rule (a, b) + (c, d) = (a + c, b, + d) overl

Write a note on mpeg-2, Question 1 Write a note on digitizers Quest...

Question 1 Write a note on digitizers Question 2 Discuss on line drawing algorithm Question 3 Explain 3D viewing Question 4 Explain different types of cohe

Transformation for 3-d translation, Suppose P be the point object along wit...

Suppose P be the point object along with the coordinate (x,y,z). We want to translate such object point to the new position as, P'(x',y',z') through the translation Vector as V=t x

Please give me ans, Differences between digital differential analyzer and ...

Differences between digital differential analyzer and VECGEN line algorithm?

What colour depths are basically used, Q. What Colour depths are basically ...

Q. What Colour depths are basically used? Basically the number of colours are an exponential power of 2 as for Colour Depth n, colours can be showed. The most popular colour mo

Briefly explain the term density range, QUESTION a) Explain with the he...

QUESTION a) Explain with the help of a diagram, how a thermal inkjet printer works. b) Briefly explain the term density range. c) Distinguish between scaling and resampli

Benefits of computer simulation - computer aided design, Benefits of Comput...

Benefits of Computer Simulation The benefit of Simulation is: even for simply solvable linear systems: a uniform model execution technique can be utilized to resolve a large v

Design a graphical user interface, 1. Implement proper exception handling m...

1. Implement proper exception handling mechanism for this application. 2. Display all data a. Search specific data (depending of the user selection, your application should e

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd