Disclosure of Invention
The invention provides a field emission display pixel unit, which solves the technical problem of uneven brightness of the pixel unit in the prior art.
To solve the above technical problem, the present invention provides a field emission display pixel unit, comprising: the electron source comprises a gate electrode, an electron collecting electrode, an emission tip, a driving circuit and a constant current source circuit;
the gate electrode is a circular electrode and is connected with the driving circuit;
the electron collecting electrode is connected with the constant current source circuit;
wherein the emission tip is disposed below an inner circumference of the gate electrode and the electron collection electrode is located above the gate electrode.
Further, the drive circuit and the constant current source circuit are arranged within the shadow of the emission angle between the emission tip and the electron collecting electrode.
Further, the driving circuit and the constant current source circuit are separated by an STI isolation process.
Further, the driving circuit is connected with a driving circuit power supply.
Further, the electron collecting electrode is connected with an electron collecting power supply.
Further, a cover plate is arranged on the top of the electron collecting electrode.
Further, a fluorescent layer is arranged on the cover plate.
Further, the gate electrode, the electron collecting electrode, the emission tip, the driving circuit, and the constant current source circuit are completed in the same process flow.
One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:
the field emission display pixel unit provided by the embodiment of the application is based on a field emission technology, and is provided with a driving circuit and a constant current source circuit for a gate electrode, an electron collecting electrode and an emission tip for compensation; the current of the emission tip is dynamically sensed by using a driving circuit and a constant current source circuit, the current of the emission tip and the voltage of a gate electrode are automatically adjusted according to external input, the electric field of the gate electrode and the emission tip is finally changed, the emission efficiency of the emission tip is changed, and the emission number of electrons on the emission tip, namely the current flowing in the emission tip is controlled; the current source control circuit is used for controlling the current flowing in the emission tip, so that the distance deviation between the gate electrode and the emission tip caused by the processing deviation in the process can be compensated, the emission efficiency among different pixels is unified by controlling the current of the emission tip, and the uniformity of the pixel brightness is achieved. Meanwhile, the emission tip is protected from being damaged by process deviation, and the phenomenon that the emission tip is burnt due to overhigh emissivity of certain pixels is avoided.
Detailed Description
The embodiment of the application provides a field emission display pixel unit, and solves the technical problem of uneven brightness of the pixel unit in the prior art.
In order to better understand the technical solutions, the technical solutions will be described in detail below with reference to the drawings and the specific embodiments of the specification, and it should be understood that the embodiments and specific features of the embodiments of the present invention are detailed descriptions of the technical solutions of the present application, and are not limitations of the technical solutions of the present application, and the technical features of the embodiments and examples of the present application may be combined with each other without conflict.
Referring to fig. 1, 2 and 3, a field emission display pixel cell includes: the electron source comprises a gate electrode, an electron collecting electrode, an emission tip, and a driving circuit and a constant current source circuit which are matched.
The gate electrode is a circular electrode and is connected with the driving circuit; the electron collecting electrode is connected with the constant current source circuit; wherein the emission tip is disposed below an inner circumference of the gate electrode and the electron collection electrode is located above the gate electrode.
In order to compensate the problem of uneven brightness caused by the manufacturing distance deviation of the gate electrode and the emission tip in the process, the emission current of the emission tip is controlled by a constant current source circuit and is controlled at a certain value according to an externally input instruction. The emitter is realized by a cross current source circuit, and the constant current source circuit can provide the state of a grid control tube through negative feedback action to control the electric field of an emission tip.
The current of the emission tip is dynamically sensed by utilizing a driving circuit and a constant current source circuit, and the current of the emission tip is automatically regulated according to external input, the control of the current is automatically regulated by the constant current source circuit, the automatic regulation comprises the control of the voltage of a driving tube of a gate electrode, the voltage of the gate electrode is further changed, the electric fields of the gate electrode and the emission tip are finally changed, the emission efficiency of the emission tip is changed, and the emission number of electrons on the emission tip, namely the current flowing in the emission tip is controlled. The current flowing in the emission tip is controlled by the current source control circuit to compensate for the distance deviation between the gate electrode and the emission tip due to the process deviation, thereby unifying the emission efficiency between different pixels by controlling the current of the emission tip. Uniformity of pixel brightness is achieved.
Meanwhile, the emission tip is protected from being influenced by process deviation, and the phenomenon that the emission tip is burnt due to overhigh emissivity of certain pixels is avoided.
It should be noted that the increase of the current source control portion inevitably occupies the pixel area, thereby affecting the optical performance of the pixel. This embodiment utilizes the emission angle phenomenon between emission point and the electron collector, can the emission point with make drive circuit and constant current source circuit in the shadow of emission angle between the electron collecting electrode, like this can be when not influencing the pixel area integrated circuit part, along with the promotion of processing technology ability, drive circuit's line size constantly reduces, its territory area that occupies also correspondingly reduces, thereby cover the shared light emitting area who has of drive circuit constant current source circuit, and can not influence luminous effective area, reduce the influence to luminance.
Further, the driving circuit and the constant current source circuit are separated by an STI isolation process, and the STI isolation process is realized by the STI isolation in a standard silicon process.
The connection area of the emission tip and the driving circuit can be isolated by a shallow STI, and the high-doped region at the lower part of the emission tip is directly connected with the constant current source circuit. Due to the distance between the electron collecting electrode and the emission tip, the emission tip will generate an emission angle, so that the interconnection layer region of the circuit can be made outside the emission angle.
In the process, the driving voltage can be adjusted by controlling the distance between the gate metal and the emitting metal, and the discrete distance deviation in the manufacturing process can be compensated by the compensation circuit.
Generally, the driving circuit is connected with a driving circuit power supply, and the electron collecting electrode is connected with an electron collecting power supply.
Furthermore, a cover plate is arranged on the top of the electron collecting electrode, and a fluorescent layer is arranged on the cover plate.
Further, the gate electrode, the electron collecting electrode, the emission tip, the driving circuit, and the constant current source circuit are completed in the same process; and the emission angle design technology is utilized to realize that the circuit does not occupy the display area. The processing is completed at one time, so that the reassembly cost is saved, the technology of coating the fluorescent layer on the collector cover plate can realize color, and the mature process has low manufacturing cost.
Referring to fig. 4, in the present embodiment, the height influence of the Electron collecting electrode and the emission tip provides an emission angle, and the emission angle is mainly calculated by using Simulation software, for example, the EBS software is a set of 3-dimensional particle Simulation software under the full name of Electron Beam Simulation.
One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:
the field emission display pixel unit provided by the embodiment of the application is based on a field emission technology, and is provided with a driving circuit and a constant current source circuit for a gate electrode, an electron collecting electrode and an emission tip for compensation; the current of the emission tip is dynamically sensed by using a driving circuit and a constant current source circuit, the current of the emission tip and the voltage of a gate electrode are automatically adjusted according to external input, the electric field of the gate electrode and the emission tip is finally changed, the emission efficiency of the emission tip is changed, and the emission number of electrons on the emission tip, namely the current flowing in the emission tip is controlled; the current source control circuit is used for controlling the current flowing in the emission tip, so that the distance deviation between the gate electrode and the emission tip caused by the processing deviation in the process can be compensated, the emission efficiency among different pixels is unified by controlling the current of the emission tip, and the uniformity of the pixel brightness is achieved. Meanwhile, the emission tip is protected from being damaged by process deviation, and the phenomenon that the emission tip is burnt due to overhigh emissivity of certain pixels is avoided.
Finally, it should be noted that the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to examples, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.