Electronics and Telecommunications Research Institute

Jun Tae Kang

Jin Woo Jeong

Yoon-Ho Song

Yoon Ho Song

Jae-Woo Kim

Jae Woo Kim

Sungyoul Choi

Jin-Woo Jeong

Dong Il Kim

SoRa Park

Ji Seon Kim

Jeong Yong Choi

Jeong Woong Lee

Min-Sik Shin

Ji-Hwan Yeon

Sunghee Kim

Hyo Jin Jeon

Eunsol Go

Young Chul Choi

An electron emission source includes a cathode electrode having a recess region formed in an upper portion thereof and the yarn emitter having a tip shape and provided in the recess region of the cathode electrode. The yarn emitter is spaced from an inner surface of the recess region of the cathode electrode.

Electron emission source and X-ray generator using the same

Provided is an X-ray source including a vacuum closed tube. The X-ray source includes a high voltage connection module, a tube module, and a magnetic lens system into which the tube module is inserted. The tube module includes a vacuum closed tube. The vacuum closed tube includes a cathode electrode provided at one end thereof, a nano-emitter on the cathode electrode, an anode electrode provided at the other end, and a first insulation spacer provided between the cathode electrode and the anode electrode. In addition, the vacuum closed tube includes a first conductive tube and a second conductive tube both provided between the cathode electrode and the anode electrode and separated from each other by the first insulation spacer, and a first collimator block covering an inner surface of the first insulation spacer and having a first opening.

Vacuum closed tube and X-ray source including the same

Provided is an X-ray generator including a thermal electron emission type X-ray generator configured to generate a negative high voltage and a filament current, a field electron emission type X-ray generator including an anode electrode to be grounded, and configured to use the negative high voltage to bias the cathode electrode, and a field emission current control unit configured to convert the filament current to generate an output voltage to be provided to a gate electrode of the field electron emission type X-ray generator and convert the filament current to fix, to a specific level, a level of an emission current flowing through the cathode electrode.

X-ray generator and driving method thereof

Disclosed is a field emission apparatus. The apparatus comprises a cathode electrode and an anode electrode spaced apart from each other, an emitter on the cathode electrode, a gate electrode between the cathode and anode electrodes and including at least one gate aperture overlapping the emitter, and an electron transmissive sheet on the gate electrode and including a plurality of fine openings overlapping the gate aperture.

Field emission apparatus

Provided herein is a field emission device. The field emission device includes a cathode which is connected to a negative power supply and emits electrons, an anode which is connected to a positive power supply and includes a target material receiving the electrons emitted from the cathode, and a ground electrode which is formed to face the anode and has an opening through which the electrons emitted from the cathode pass. The ground electrode is grounded so that when an arc discharge occurs due to high voltage operation of the anode, electric charge produced by the arc discharge is emitted to a ground.

Field emission device with ground electrode

Disclosed is an x-ray tube including a hybrid electron emission source, which uses, as an electron emission source, a cathode including both a field electron emission source and a thermal electron emission source. An x-ray tube includes an electron emission source emitting an electron beam, and a target part including a target material that emits an x-ray as the emitted electron beam collides with the target part, wherein the electron emission source includes a thermal electron emission source and a field electron emission source, and emits the electron beam by selectively using at least one of the thermal electron emission source and the field electron emission source.

X-ray tube including hybrid electron emission source

The present disclosure may provide a micro X-ray tube with a filter tube to filter X-rays and at the same time to serve as an insulator. For this, the X-ray tube may include a filter tube between a second electrode and a gate electrode, hence separating from each other. The second electrode may have a target and the gate electrode may accelerate an electron-beam to collide with the target. The filter tube includes an alumina (AlO). The target is inclined to allow the X-rays to be directed toward the filter tube.

Micro X-ray tube

Provided is an X-ray tube including an anode, a target on the anode, a cathode disposed separate from the target and the anode and comprising an emitter providing an electron beam to the target, and a side wall disposed between the cathode and the anode, and surrounding the target and the emitter. The side wall reflects a light generated by collision of the electron beam with the target to the cathode, and electrically insulates the cathode from the anode.

Photocathode coupled X-ray tube

Disclosed is a field emitter electrode including a bonding unit formed on a substrate, and a plurality of carbon nanotubes fixed to the substrate by the bonding unit, in which the bonding unit includes a carbide-based first inorganic filler and a second inorganic filler formed of a metal.

Field emitter electrode and method of manufacturing the same

Provided are a field emission device and a method of manufacturing the same. The field emission device includes an anode electrode and a cathode electrode which are opposite to each other, a counter layer provided on the anode electrode, and a field emitter provided on the cathode electrode and facing the counter layer. Herein, the field emitter includes a carbon nanotube emitting cold electrons and a photoelectric material emitting photo electrons.

Field emission device having field emitter including photoelectric material and method of manufacturing the same

Provided is a method of driving multi electrical field emission devices. The method includes: respectively connecting first current control circuit devices for current path formation to a plurality of electric field emission devices; commonly connecting a second current control circuit device to the first current control circuit devices to commonly control the first current control circuit devices; and driving the first current control circuit devices at different timings when the second current control circuit device is driven.

Method for driving multi electric field emission devices and multi electric field emission system

Provided is an X-ray tube. The X-ray tube includes an electrode on which an electron beam impacts to generate an X-ray, and a window on which the electrode is disposed and through which the X-ray generated from the electrode is transmitted. The electrode includes a channel passing through the electrode, and the electron beam is provided into the channel to generate the X-ray.

X-ray tube having anode electrode

Provided is a current controlling device for controlling an electric field emission current in connection with an electric field emission device which emits electrons in response to an applied voltage, the device including: a first current controlling transistor forming a current path in response to a first gate voltage; a second current controlling transistor connected between the field emission device and the first current controlling transistor and forming a current path in response to a second gate voltage; and a control logic controlling the first and second gate voltages, wherein the control logic controls a upper limit of the field emission current by using the first gate voltage.

Current controlling device and electric field emission system including the same

Provided is a manufacturing method of a CNT emitter with density controlled CNT, comprising: (i) fabricating a CNT paste by dispersing a carbon nanotube (CNT) powder, two kinds or more of inorganic fillers which have a lower melting temperature than the CNT and different oxidation degrees of the CNT, and an organic binder in a solvent; (ii) coating the CNT paste on an electrode formed above a substrate; (iii) sintering the substrate coated with the CNT paste to selectively oxidize the CNT around one kind of inorganic filler among two kinds or more of the inorganic fillers; and (iv) treating the surface of the CNT paste so that the surface of the CNT paste is activated.

Manufacturing method of CNT emitter with density controlled carbon nanotube

An X-ray tube is provided. The X-ray tube includes a first housing including an X-ray window formed therein, a second housing being rotatable about a rotational shaft installed within the first housing, an anode installed on the rotational shaft within the second housing and positioned in one side of the rotational shaft in an extending direction of the rotational shaft, an emitter installed on the rotational shaft within the second housing, positioned in the other side of the rotational shaft in the extending direction of the rotational shaft, and emitting electron beams, a lens unit installed between the anode and the emitter and focusing the electron beams emitted from the emitter to the anode, and an electron beam deflection unit installed on the rotational shaft to deflect an angle of electron beams moving toward the anode from the lens unit.

Growing community of inventors

Daegu, South Korea

Jun Tae Kang