Chapter 7
Imaging Devices
In the following chapters, we will discuss what specifically has to be done to
the map of a system to make the system useful for a specific task. In many
cases, this requires that certain matrix elements vanish, or sometimes assume
specific values. The most important device is probably the imaging device,
in which final positions are independent of initial angles, as shown
schematically in Fig. 7.1. Represented in the language of the transfer map,
this entails that
(x|a) = 0, (y|b) = 0.
It is apparent the final angles a f and b f are unimportant since it does not
matter at what angle the rays strike at the image position; so all terms of the
form (a| . . .) or (b| . . .) are insignificant. Additional requirements usually exist
for the various subclasses of imaging systems.
There are many types of devices that form images of charged particles. The
following are a few types that are widely used.
7.1 The Cathode Ray Tube (CRT)
The cathode ray tubes (CRT) are a class of imaging that have seen wide
use in electronic displays, such as the television tube and the oscilloscope.
As far as practical use, impact on society, and revenues are concerned, the TV
FIGURE 7.1: Sketch of an imaging system.
161
DOI:10.1201/b12074-7
Imaging Devices
In the following chapters, we will discuss what specifically has to be done to
the map of a system to make the system useful for a specific task. In many
cases, this requires that certain matrix elements vanish, or sometimes assume
specific values. The most important device is probably the imaging device,
in which final positions are independent of initial angles, as shown
schematically in Fig. 7.1. Represented in the language of the transfer map,
this entails that
(x|a) = 0, (y|b) = 0.
It is apparent the final angles a f and b f are unimportant since it does not
matter at what angle the rays strike at the image position; so all terms of the
form (a| . . .) or (b| . . .) are insignificant. Additional requirements usually exist
for the various subclasses of imaging systems.
There are many types of devices that form images of charged particles. The
following are a few types that are widely used.
7.1 The Cathode Ray Tube (CRT)
The cathode ray tubes (CRT) are a class of imaging that have seen wide
use in electronic displays, such as the television tube and the oscilloscope.
As far as practical use, impact on society, and revenues are concerned, the TV
FIGURE 7.1: Sketch of an imaging system.
161
DOI:10.1201/b12074-7