Table of Contents
- 1 What is the working principle of direct view storage tube?
- 2 Where is DVST used?
- 3 What is shadow mask method?
- 4 What is the function of writing gun in DVST?
- 5 What is working principle of shadow mask tube?
- 6 How does raster scan work?
- 7 How does direct view storage tube ( DVST ) work?
- 8 What is the purpose of a storage tube?
What is the working principle of direct view storage tube?
Direct View Storage Tube (DVST) resembles CRT as it uses electron gun to draw picture and phosphor coated screen to display it. The phosphor used in this is of high persistence. DVST does not use refresh buffer or frame buffer to store picture definition.
Where is DVST used?
Difference between DVST and CRT :
| Sr. No. | Basis | DVST |
|---|---|---|
| 8. | Use of Collector mesh | To control the flow of electrons, it uses collector mesh. |
| 9. | Application | DVST is only used for the line drawing applications. |
What is storage tube display in computer graphics?
The term “storage tube” refers to the ability of the screen to retain the image which has been projected against it, thus avoiding the need to rewrite the image constantly. Primary guns: It is used to store the picture pattern. Flood gun or Secondary gun: It is used to maintain picture display.
What is DVST explain?
(Direct View Storage Tube) An early graphics screen that maintained an image without refreshing.
What is shadow mask method?
Shadow masks are made by photochemical machining, a technique that allows for the drilling of small holes on metal sheets. Three electron guns at the back of the screen sweep across the mask, with the beams only reaching the screen if they pass through the holes.
What is the function of writing gun in DVST?
The writing gun scans across a wire grid, charging the grid to create the negative image. The flood gun then floods the grid. Previously charged areas repel the incoming electrons so that electrons only pass through the grid to the phosphor in those areas not previously charged.
What is the role of segment in computer graphics?
Segmentation allows to organize display files in sub-picture structure. It allows to apply different set of attributes to different portions of image. It makes it easier to the picture by changing/replacing segments.
What is the purpose of refreshing a CRT?
Refesh CRT : The electron beam must sweep the whole area of the screen and then repaint it numerous times per second in order to maintain a steady image. Refreshing the screen is the term for this procedure. If the electron beam takes too much time to refresh, it looks like the flickering of the image.
What is working principle of shadow mask tube?
How does raster scan work?
In a raster scan system, the electron beam is swept across the screen, one row at a time from top to bottom. As the electron beam moves across each row, the beam intensity is turned on and off to create a pattern of illuminated spots.
What is the function of the control electrode in a CRT?
Control Electrode: It is used to turn the electron beam on and off.
How does flood gun work?
A flood gun is an electromechanical device that provides a steady flow of low-energy electrons to a desired target or “flood area.” Typically, the target is an area on an insulator or semiconductor where another “writing gun” has just left a net positive charge. This is called “charge neutralization.” …
How does direct view storage tube ( DVST ) work?
Direct View Storage Tube (DVST) resembles CRT as it uses electron gun to draw picture and phosphor coated screen to display it. The phosphor used in this is of high persistence. DVST does not use refresh buffer or frame buffer to store picture definition.
What is the purpose of a storage tube?
The term “storage tube” refers to the ability of the screen to retain the image which has been projected against it, thus avoiding the need to rewrite the image constantly. Primary guns: It is used to store the picture pattern.
Where is the picture definition stored in DVST?
Picture definition is stored in inside CRT in form positive charged distribution. Because of this reason DVST is knows as Storage Type CRT. In DVST no refreshing is required as result picture drawn on DVST will be seen for several minutes before fading.
What are the advantages and disadvantages of DVST?
Figure – Direct View Storage Tube . Advantages of DVST : For picture display it does not require refreshing. Display complex pictures at high resolution without any flicker. No use of frame buffer or refresh buffer. Disadvantages of DVST : Not used for dynamic graphic such as animation. These systems do not display colors.