Cathode Ray Tube - Graphics Hardware

Cathode Ray Tube: this is a refreshing display device. The idea of a refreshing display is depicted pictorially is given as:

In fact the picture information is specified through the stream of electrons (e^-) and its flow is controlled through the display controller as the control is according to the information supplied through the picture, initially the controlled e^- flow generates scintillations on the screen of the display device and the image is made. The display is termed as a refreshing display since display is continuously created through the continuous impugnation or striking of e^- on the screen at the similar point. This is same image is continuously made 40 to 50 times per second that is continuous refreshing occurs.

Figure: CRT

For exact image we also need to insert a "Digital to Analog or D/A converter": this is an electronic circuit for digital to analog conversion, between the display device and the display controller.