图形学射线相交算法_计算机图形学中的阴极射线管（CRT）

图形学射线相交算法

什么是阴极射线管(CRT)？ (What is Cathode Ray Tube (CRT)?)

CRT stands for "Cathode Ray Tube".

CRT代表“ 阴极射线管” 。

Cathode Ray Tube is a technology that is used widely in the traditional televisions and screens. An image is created on the screen on Cathode Ray Tube. That image is formed by firing electrons from the backside of the tube with the help of phosphorus which is located towards the screen on Cathode Ray Tube. It accelerates and deflects the electron beam onto the screen to create images. There are three electron guns in the Cathode Ray Tube: Red, Blue, and Green. Every gun streams a steady flow of electrons. Whenever a new line begins at the screen the guns will start from the left and continue right. This is a complex process that is repeated many times until the screen is fully drawn line by line.

阴极射线管是一种在传统电视和屏幕中广泛使用的技术。在阴极射线管的屏幕上创建图像。该图像是通过在阴极射线管上靠近屏幕的磷的作用下从管的背面发射电子形成的。它使电子束加速并偏转到屏幕上以创建图像。阴极射线管中有三支电子枪：红色，蓝色和绿色。每把枪都流着稳定的电子流。每当在屏幕上出现新的一行时，枪支将从左开始，然后继续向右。这是一个复杂的过程，需要重复多次，直到逐行完全绘制屏幕为止。

CRT的组成 (Components of CRT)

Electron Gun
电子枪
Focusing System
调焦系统
Deflection Yoke
偏转线圈
Phosphorus coated Screen
磷涂层筛

Let us explain each of them in detail.

让我们详细解释它们。

1)电子枪 (1) Electron Gun)

The Electron Gun of a Cathode Ray Tube consists of a cathode, a control grid all around the cathode and an anode to focus the electron beam. The main purpose of the Electron Gun is to generate a beam of focused electrons accelerated towards the screen with the coating of phosphorus. The Cathode emits electrons when we supply heat to it. The surface from where the Cathode emits the beam must be as small as possible. The rate of emitted electrons depends upon the current we apply to the cathode.

阴极射线管的电子枪由阴极，围绕阴极的控制栅和聚焦电子束的阳极组成。电子枪的主要目的是产生一束聚焦电子束，该束电子朝着带有磷涂层的屏幕加速。当我们向阴极供电时，阴极会发射电子。阴极发射光束的表面必须尽可能小。发射电子的速率取决于我们施加到阴极的电流。

2)聚焦系统 (2) Focusing System)

The Focusing System of the Cathode Ray Tube helps the electron not to spread. Without this focusing system, the electrons will spread in the shape of a cone because it is the tendency of the electrons. The Focusing System consists of the electric and magnetic fields. All of the Focusing System is adjacent to the electrode which is accelerating the electron beam. There are two main systems inside this focusing system: The Electrostatic system and the Magnetic system. The whole of the electrons are being controlled at the time of emission and once it is controlled the beam goes in a straight line to the phosphorus coated screen.

阴极射线管的聚焦系统有助于电子不扩散。没有这种聚焦系统，电子将以圆锥形扩散，因为这是电子的趋向。聚焦系统由电场和磁场组成。所有的聚焦系统都与正在加速电子束的电极相邻。该聚焦系统内部有两个主要系统：静电系统和磁性系统。整个电子在发射时都受到控制，一旦受到控制，电子束就会直线到达镀磷的屏幕。

3)偏转线圈 (3) Deflection Yoke)

There are two types of deflection needed in the Cathode Ray Tube: One controls the beam horizontally and the other controls the beam vertically. It is also necessary that the beam must be very very thin when it falls on the screen. The electron beam is moved in Raster Scan on the screen. We can adjust the brightness of the screen created by phosphorus by adjusting the electrode current. The Deflection Yoke consists of coils which are present in a set of two. Both the sets are perpendicular to each other and on the neck of the Cathode Ray Tube. These coils are shaped in a way to provide a linear magnetic field distribution.

阴极射线管需要两种偏转方式：一种是水平控制光束，另一种是垂直控制光束。当光束落在屏幕上时，光束也必须非常非常细。电子束在屏幕上的“光栅扫描”中移动。我们可以通过调整电极电流来调整磷所产生的屏幕亮度。偏转线圈由两个线圈组成。两组都彼此垂直，并位于阴极射线管的颈部。这些线圈以提供线性磁场分布的方式成形。

磷镀膜筛 (Phosphorus Coated Screen)

It is the screen of Cathode Ray Tube on which the electron beam falls. Its inner surface is coated by phosphorus. The reason for using phosphorus is that Phosphorus glows whenever a beam of high intensity of electrons hits on it.

这是电子束落在其上的阴极射线管的屏幕。其内表面被磷覆盖。使用磷的原因是，每当高强度电子束撞击磷时，磷就会发光。

阴极射线管的工作 (Working of Cathode Ray Tube)

The electron beam controls the working of Cathode Ray Tube. The electron gun generates an electron beam of high intensity when it is connected to high voltage. When the electron beam emits from the electron gun it passes through a pair of electrostatic and magnetic deflection coil which is on the neck of the electron gun. These coils are responsible for the horizontal and vertical movement of the beam. This beam falls on the screen and creates phosphorescence. This is the working of Cathode Ray Tube.

电子束控制阴极射线管的工作。当电子枪连接到高电压时，它会产生高强度的电子束。当电子束从电子枪发射时，它穿过位于电子枪颈部的一对静电和磁偏转线圈。这些线圈负责光束的水平和垂直运动。该光束落在屏幕上并产生磷光。这是阴极射线管的工作。