摘要:
Provided is a field emission display (FED) capable of driving on the basis of current and preventing leakage current caused by thin film transistors (TFTs). The FED includes: a plurality of unit pixels including an emission element in which cathode luminescence of a phosphor occurs and a TFT for driving the emission element; a current source for applying a scan signal to each unit pixel; and a voltage source for applying a data signal to each unit pixel. Here, the on-current of the current source is high enough to take care of the load resistance and capacitance of a scan row within a given writing time, and the off-current of the current source is so low that the electron emission of each pixel can be ignored. In addition, the pulse amplitude or pulse width of the data signal applied from the voltage source is changed, and thereby the gray scale of the display is represented.
摘要:
Provided is a field emission display (FED) capable of driving on the basis of current and preventing leakage current caused by thin film transistors (TFTs). The FED includes: a plurality of unit pixels including an emission element in which cathode luminescence of a phosphor occurs and a TFT for driving the emission element; a current source for applying a scan signal to each unit pixel; and a voltage source for applying a data signal to each unit pixel. Here, the on-current of the current source is high enough to take care of the load resistance and capacitance of a scan row within a given writing time, and the off-current of the current source is so low that the electron emission of each pixel can be ignored. In addition, the pulse amplitude or pulse width of the data signal applied from the voltage source is changed, and thereby the gray scale of the display is represented.
摘要:
Provided is a field emission display (FED) in which field emission devices are applied to a flat panel display. The FED includes: a cathode plate including a substrate, first and second thin film transistors (TFTs) that are serially connected on the substrate, a field emitter disposed on a drain electrode of the second TFT, a gate insulating layer having a gate hole surrounding the field emitter, and field emission gate electrodes disposed on the gate insulating layer; and an anode plate including a substrate, and red, green, and blue phosphors disposed on the substrate, wherein the cathode plate and the anode plate are vacuum-packaged parallel and opposite to each other. According to the present invention, uniformity of the FED panel can be significantly improved, and an inherent source-drain leakage current of the TFT can be significantly reduced, so that a contrast ratio of the FED can be significantly enhanced.
摘要:
A field emission pixel includes a cathode on which a field emitter emitting electrons is formed, an anode on which a phosphor absorbing electrons from the field emitter is formed, and a thin film transistor (TFT) having a source connected to a current source in response to a scan signal, a gate receiving a data signal, and a drain connected to the field emitter. The field emitter is made of carbon material such as diamond, diamond like carbon, carbon nanotube or carbon nanofiber. The cathode may include multiple field emitters, and the TFT may include multiple transistors having gates to which the same signal is applied, sources to which the same signal is applied, and drains respectively connected to the field emitters. An active layer of the TFT is made of a semiconductor film such as amorphous silicon, micro-crystalline silicon, polycrystalline silicon, wide-band gap material like ZnO, or an organic semiconductor.
摘要:
A discretely addressable large-area X-ray system is provided. The large-area X-ray system can output a uniform flux of X-rays over a large area using discrete addressing operation of transistors connected to cathodes of electron emitters. Thus, when applied to a medical device, the system can minimize damage inflicted upon the human body because it enables effective imaging of only a desired specific portion of the body. Furthermore, the large-area X-ray system can be simply implemented by current switching using transistors. Thus, the system can be very easily applied to other applications.
摘要:
Provided is a field emission device (FED) capable of fine local dimming. In the FED, a cathode substrate is comprised of a plurality of cathode layers, and a plurality of interconnections are disposed on each of the cathode layers, so that fine local dimming is enabled using a plurality of cathode blocks without limiting the number of the cathode blocks. Also, since RC delays of the respective cathode blocks can be synchronized according to the design of the interconnections, current control signals can be simultaneously transmitted to the respective cathode blocks, thereby improving the characteristics of the FED.
摘要:
Provided is a field emission device, and more particularly, a field emission back light unit which makes an interconnection connected with an external electrode simple and capable of local dimming. To this end, a cathode structure for the field emission back light unit includes a plurality of data electrodes formed on a cathode substrate and spaced apart from one another, an insulating layer formed on the data electrodes, and having exposure regions exposing the predetermined data electrodes, cathode electrodes formed on the insulating layer and electrically connected with the data electrodes through the exposure regions, and at least one field emitter formed on the cathode electrodes, wherein a cathode block is defined based on the cathode electrodes electrically isolated from one another, and brightness of each cathode block can be controlled according to current supplied through the data electrode.
摘要:
Provided are methods of manufacturing carbon nanotube (CNT) paste, to which a nano-sized particle is added, and a CNT emitter with high reliability for a field emission display (FED). The method includes the steps of: (i) dispersing CNT powder in a solvent; (ii) adding an organic binder to the solution in which the CNT powder is dispersed; and (iii) performing a milling process to adjust viscosity of the dispersion solution to which the organic binder is added, wherein a nano-sized metal particle is added in step (i) or (iii). Accordingly, the nano-sized metal particle is added as a metal filler of the CNT paste, and thus a metal may be melted at a low temperature at which CNTs do not deteriorate. Thus, adhesion between the CNT paste and a cathode may be improved, and resistance between the cathode and the CNT or between CNTs may be reduced. Further, the CNT paste manufactured by the above method is employed in manufacturing the CNT emitter to thereby obtain uniform emission of electrons from the CNT emitter and increase electron emission sites, and thus the reliability of the CNT emitter may be further improved.
摘要:
A microminiature X-ray tube with a triode structure using a nano emitter is provided, which can increase a field emission region as much as possible by means of nano emitters fine-patterned in a cathode to not only increase an emission current per unit area as much as possible but secure high electrical characteristics, reliability, and structural stability by means of a cover and a bonding material. In addition, gate holes having a macro structure can be formed in the gate to promote electron beam focusing by means of the gate without using a separate focusing electrode and to prevent a leakage current from occurring on the gate. Further, an auxiliary electrode can be formed on a top or an inner surface of a cover applied for structural stability to further promote the electron beam focusing and to control the output amounts per individual X-ray tubes output according to current switching to be equal to each other.
摘要:
A microminiature X-ray tube with a triode structure using a nano emitter is provided, which can increase a field emission region as much as possible by means of nano emitters fine-patterned in a cathode to not only increase an emission current per unit area as much as possible but secure high electrical characteristics, reliability, and structural stability by means of a cover and a bonding material. In addition, gate holes having a macro structure can be formed in the gate to promote electron beam focusing by means of the gate without using a separate focusing electrode and to prevent a leakage current from occurring on the gate. Further, an auxiliary electrode can be formed on a top or an inner surface of a cover applied for structural stability to further promote the electron beam focusing and to control the output amounts per individual X-ray tubes output.