JPS62272422A - Electron emitting device - Google Patents

Abstract

PURPOSE:To make it possible to control the quantity of the electron emission, effectively and stably, by using an electron emitting element with a thyristor structure, and controlling a driving current with a trigger signal. CONSTITUTION:As a trigger signal is inputted in a gate electrode G when an anode is in a high potential, a diving current is applied to the electron emitting element 1. Thus, an electron is emitted. By controlling a trigger generating circuit 3 so as to generate the trigger signal in the desired phase of an alternating current, it is possible to set a time-integral value of the driving current to the desired value. Therefore, by changing the time-integral value of the driving current, the time-integral value of the electron emission quantity can be controlled, accurately and effectively.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an electron emitting device using an electron emitting element having a thyristor structure, which emits electrons in a particularly stable manner. The present invention relates to an electron emission device designed to easily and accurately control the amount of electron emission.

[Prior art and its problems] Electron emission elements used in conventional electron emission devices include those that use avalanche breakdown of a PM junction, and those that apply a forward bias to the PM junction and inject electrons into the P layer. Those with a structure in which a thin insulation layer is sandwiched between metals (former
In addition, there are field emission type and surface conduction type elements.

Figure 4 (A) shows that the PN junction is forward biased and the P
FIG. 4B is a schematic explanatory diagram of an electron-emitting device of a type in which electrons are injected into a layer, and FIG. 4B is a graph showing a schematic current-voltage characteristic thereof.

In the same figure (A), when a forward bias voltage V is applied to the PM junction, the forward direction current I as shown in the same figure (B)
flows, and electrons injected from the N layer to the P layer are emitted from the surface of the P layer into vacuum. The surface of this P layer is coated with cesium Cs or the like in order to lower the work function and increase the amount of electron emission.

However, in an electron-emitting device using such an electron-emitting element, it is difficult to control the amount of electron emission.
It was not possible to obtain a stable electron flow despite changes in the external environment or changes in element efficiency. In particular, as shown in FIG. 3B, when the applied voltage V exceeds vf, the change in the current I becomes large, making it difficult to control the amount of electron emission by the voltage.

This difficulty in control is the same for old X-type and surface conduction type electron-emitting devices, devices that utilize PM junction avalanche breakdown, and field-emission devices; when the applied voltage exceeds a certain level, the current decreases. The change became large, making it difficult to control the amount of electron emission.

[Means for Solving the Problems] In order to solve the above-mentioned conventional problems, an electron-emitting device according to the present invention includes an electron-emitting element having a thyristor structure;
The present invention is characterized in that it has a trigger generating means for applying a trigger signal to the gate %L pole of the electron-emitting device, and controls the amount of electron emission by controlling the driving current of the electron-emitting device using the trigger signal.

[Function] As described above, by using the electron-emitting device having a thyristor structure and controlling the drive current by the signal, efficient and stable control of the amount of electron emission can be achieved.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a schematic configuration diagram of an embodiment of an electron emitting device according to the present invention, and FIG. 2 is a waveform diagram for explaining the operation of the embodiment.

In FIG. 1, an electron-emitting device 1 has a thyristor structure as described later, an AC power source 2 is connected to an anode electrode A and a cathode electrode K, and a trigger generation circuit 3 is connected to a gate electrode G. There is.

In such a configuration, it is first assumed that an AC voltage as shown in FIG. 2 is applied to both ends of the electron-emitting device 1 by an AC power supply. At this time, even if the 7-node electrode A is at a high potential, unless a signal is input, the electron-emitting element 1
does not conduct, so no current flows and therefore no electrons are emitted. However, when a trigger signal is input to the gate electrode G when the anode electrode A is at a high potential, a driving current flows to the electron-emitting element 1, and electrons are emitted. is released.

Therefore, as shown in the waveform diagram of the trigger signal in FIG. 2, by controlling the generation circuit 3 so that the trigger signal is generated at a desired phase of the AC voltage, the time integral value of the drive current is set to a desired value. Can be set to . That is, if the drive current flowing through the electron-emitting device l is ■, and the electron emission efficiency is η, then the electron emission amount i=ηI. Therefore, by changing the time integral value of the drive current ■, the electron emission amount can be changed. The time integral value of i can be controlled with high precision and efficiency.

Furthermore, since a desired amount of electron emission can be obtained by shifting the phase of the trigger signal, when applied to a display device that uses electron beams, it is also possible to change the gradation of a displayed image.

FIG. 3 is a schematic cross-sectional view showing the structure of the electron-emitting device 1 in this example.

As shown in the figure, two layers 12. N layer 1
3 and 2 layers 14 are formed, respectively, and an insulating layer 15 is formed. Subsequently, a contact hole and an opening in PMj14I: are formed on the second layer 12, and the gate electrode 1
Six and seven node electrodes 17 are formed, respectively. The surface of the two layers 14 in the opening is coated with cesium Cs or the like in order to lower the work function and increase the amount of electron emission. Also,
A cathode electrode 18 is formed on the opposite side of the N substrate 11.

When the electron-emitting device l having such a thyristor structure becomes conductive and electrons flow into the 2 layer 14, the 2 layer with a low work function
Electrons are emitted from the surface of layer 14.

[Effects of the Invention] As described in detail above, the electron emitting device according to the present invention uses an electron emitting element having a thyristor structure and controls the drive 7L flow using a trigger signal, thereby emitting an efficient and stable amount of electrons. can be controlled.

Further, since the electron-emitting device has a thyristor structure, a special switch means is not required, and accurate electron emission amount control can be achieved with a simple circuit configuration.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of an electron-emitting device according to the present invention, FIG. 2 is a waveform diagram for explaining the operation of this embodiment, and FIG. 3 is an electron-emitting device in this embodiment. A schematic cross-sectional view showing the structure of element 1, FIG.
FIG. 4B is a schematic explanatory diagram of an electron-emitting device of a type in which electrons are injected into a layer, and FIG. 4B is a graph showing a schematic current-voltage characteristic thereof. 1・φ・Electron emitter 2...AC power supply 3・Fist・Trigger generation circuit 16II11 Middle gate electrode 17...-7 Node electrode 18...Cathode electrode Patent attorney Seki Yamashita Hei $1 Figure 2 3 diagrams

Claims (1)

[Claims] (1) It has an electron-emitting device having a thyristor structure and a trigger generation means for applying a trigger signal to the gate electrode of the electron-emitting device, and the driving current of the electron-emitting device is controlled by the trigger signal to emit electrons. An electron emitting device characterized by controlling the amount.