Driving method for electric-field electron emission apparatus

Abstract

A method for driving an electric-field electron emission apparatus without degrading the electron emission characteristics is provided. The method can drive the electric-field electron emission apparatus without degrading the electron emission characteristics by allowing application of the electric field only when the second derivative of the captured electron current density exceeds a certain value.

What is claimed is:  
     
         1 . A method for driving an electric field electron emission apparatus which emits electron by electric field emission from the cathode electrode and captures electrons at the anode electrode, wherein the electric field applied to the cathode electrode is higher than that for generating the field emission and lower than the electric field in which the second derivative of the density of the electron current (hereinafter called the electron current density) to be captured at the cathode electrode with respect to the cathode electrode becomes 0 for the first time after the electric field is applied.  
     
     
         2 . A method of driving an electric field electron emission apparatus, in which electrons emitted from a cathode electrode by the field emission is captured by an anode electrode, wherein the electric field applied to said cathode electrode is higher than the electric field for generating the field emission of electrons, and the second derivative of the density of the electron current (hereinafter, called the electron current density) captured by the anode electrode for the electric field is higher than the electric field in which said second derivative becomes 0 for the first time after the electric field is applied, and wherein the period of time during which the electric field is applied to the cathode electrode satisfies the following two equations:  
         t   ap   =T/|A| E st ≦E  
       where, 
 T: a numeral value within a range higher than 1×10 −9  and lower than 1×10 −6  [sec·cm −2 ·V −2 ·A],  
 A: the second derivative of the electron current density [A·cm −1 ·V −2 ],  
 E: the electric field applied to the cathode electrode, and  
 E st : the minimum electric field in a saturation tendency region,  
 wherein, the minimum electric field in the saturation tendency region is the electric field at which a change of the electron current density changes from an increase to a decrease.  
 
     
     
         3 . A method of driving an electric field electron emission apparatus, wherein, when a cathode electrode standard applied voltage is assumed for the applied voltage to the cathode electrode when the second derivative of said electron current density is 0 and the third derivative of said electron current density is negative, the upper limit of the cathode electrode applied voltage is determined to be in a range of the applied voltages at which the electron emission densities are within a range from one time to two times of the electron current density at the cathode electrode standard applied voltage.  
     
     
         4 . A method of driving an electric field electron emission apparatus, wherein, the electron current density for the upper limit of said cathode electrode applied voltage is 1.5 times of the electron current density at the cathode electrode standard applied voltage.  
     
     
         5 . A method of driving an electric field electron emission apparatus, wherein, the electric field electron emission apparatus comprises a gate electrode formed between said cathode electrode and said anode electrode.