DVST stands for Direct View Storage Tube. It is one of the display devices in which an electron flood gun and writing gun is present. The flood gun floods electrons to a wire grid on which already the writing gun has written some image. The electrons from the flood gun will be repelled back by the negatively charged wire grid which has been charged so by the writing electron beam. The part of the wire grid which has not been charged -ve will allow the electrons to pass through and the electrons will collide on the screen and produce the image.
Adv.-1)Refreshing CRT is not required.
2)Complex picture can be displayed in high resolution without flicker
3)It has flat screen
basically this device is based on inherent image storage capability.plasma panel and laser scan display is based on this technology but DVST is most widely used in graphical displays
chuitya giri
1) Primary gun 2) Flood gun
DIRECT VIEW TUBE CATHODE RAY TUBE dvst-1)it has flatscreen crt-1)it maybe ormaynotbe flat screen 2)it has poor contrast 2)better contrast then dvst 3)refreshing not allowed 3)refreshing allowed 4)selecting or part erasing of screen 4) in this erasing is allowed not allowed 5)performance is inferior to CRT 5)verybetter performance then DVST 6)high resolution for complex pictures
Good frend for Iesvs sake forbeare, To digg the dvst encloased heare. Bleste be ye man yt spares thes stones, And cvrst be he yt moves my bones
The contrast in a DVST monitor is not sharp They ordinarily do not display color . Selected part of the picture can not be erased The erasing and redrawing process can take several seconds for complex pictures.
The contrast in a DVST monitor is not sharp They ordinarily do not display color . Selected part of the picture can not be erased The erasing and redrawing process can take several seconds for complex pictures.
DVST has inherent image storing capacity so that it avoids flickering of image which has been displayed on computer screen.
Good frend for Iesvs sake forbeare,To digg the dvst encloased heare.Bleste be ye man yt spares thes stones,And cvrst be he yt moves my bonesRead more: What_did_William_Shakespeare_have_written_on_his_gravestone
Shakespeare is buried beneath the floor of Trinity Church in his hometown of Stratford. The following doggerel verse is engraved on the paving stone:Good frend for Iesvs sake forbeare,To digg the dvst encloased heare.Bleste be man spares thes stones,And cvrst be he moves my bones
There is no reason to think that Shakespeare wrote his own epitaph, especially as he probably could have done a better job of writing a poem than this:Good frend for Iesvs sake forbeare,To digg the dvst encloased heare.Bleste be the man thatspares thes stones,And cvrst be he thatmoves my bones
Conceptually the Direct View Storage Tube(DVST) behaves like a CRT with highly persistent phosphor. Pictures drawn on will be seen for several minutes (40-50 minutes) before fading. It is similar to CRT as far as the electronic gun and phosphor coated mechanisms are concerned. But instead of the electron beam directly writing the pictures on the phosphor coated CRT screen, the writing is done with the help of fine-mesh wire grid. The grid made of very thin, high quality wire is located with a dielectric and is mounted just before the screen on the path of the electron beam from the gun. A pattern of positive charges is deposited on the grid and this pattern is transferred to the phosphor coated CRT by a continuous flood of electrons'. This flood of electrons' is produced by a "flood gun" (This is separate frame the electron gun that produces the main electron beam). Just behind the storage mesh is a second grid called the collection. The function of the collector is to smooth out the flow of flood electrons. Since large number of electrons are produced at high velocity by the flood gun, the collector grid, which is also negatively charged reduces, the acceleration on these electrons and the resulting low velocity flood pass through the collector and get attracted by the positively charged portions of the storage mesh (Since the electrons are negatively charged), by are repelled by the other portions of the mesh which are negatively charged (Note that the pattern of positive charges residing on the storage mesh actually defines the picture to be phosphor-coated screen and display the picture. Since the collector has slowed down the electrons, they may not be able to produces sharpand bright images. To over come this problem, the screen itself is maintained at a high positive potential be means of a voltage applied to a thin aluminum coating between the tube face and the phosphor. The other popular display device is the plasma panel device, which is partly similar to the DVST in principle, but over comes some of the undesirable features of the DVST.