A method and apparatus is described to image a body using electric fields.
The electric field is apply to the body from a well controlled electron
beam that deposits charge on a glass plate at a particular time and
spatial location. This is demonstrated by using the ubiquitous CRT
computer monitor. The method is useful in medical imaging and for
nondestructive testing. An advantage of the electric field imaging is it
requires no ionizing radiation. The use of the computer display allows
for proximity detection of a body. A smart control is drawn on the video
screen by a program. The control produces and E-field source that occurs
at known time in the video refresh. A proximate E-field sensor is used to
detect the changes in the signal produced by the button. Changes in the
signal level are associated with a proximate body to the button.
Detection logic is used to instigate the action of the control.