BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is schematic illustrating the internal configuration of a traditional laser printer;
FIG. 2 is schematic illustrating the internal configuration of a field emission based photosensitive drum printer according to a preferred embodiment of the present invention;
FIG. 3 is schematic illustrating the filed emission based apparatus according to a preferred embodiment of the invention; and
FIGS. 4A-4C are schematics illustrating the process of fusing after the photoelectric conversion layer adsorbed toner.
DETAILED DESCRIPTION OF THE INVENTION
The characteristics and the technical contents of the present invention will be explained with reference to the detailed description and the accompanying drawings. However, it should be understood that the drawings are illustrative but not used to limit the scope of the present invention.
FIG. 2 is schematic illustrating the internal configuration of a field emission based photosensitive drum printer according to a preferred embodiment of the present invention. As shown in the figure, the printer of the present invention at least includes a photosensitive drum 1, a toner cartridge 2, a fusing unit 3, a roller assembly 4, and an erasing unit 5. Photosensitive drum 1 is manufactured with built-in field emission. Namely, the light is generated from within photosensitive drum 1 and converted into electrical energy such that the surface of photosensitive drum 1 is covered with electrostatic charges. When photosensitive drum 1 rotates and comes into contact with toner cartridge 3, toner powder is transferred to the surface of photosensitive drum 1 by electrostatic charge attraction. When the photosensitive drum 1 with toner powder then rotates and comes into contact with paper 6, the toner image is transferred to the surface of the paper 5a by fusing unit 3. Then, the remaining toner and electrostatic charges on the surface of photosensitive drum 1 is removed by erasing unit 5.
Photosensitive drum 1 includes an inner roller 11, an outer roller 12, and a photoelectric conversion layer 13. Inner roller 11 is a circular cylinder 111 formed by a cathode substrate. The outer surface of circular cylinder 111 is configured with a plurality of cathode units disposed in a matrix array (not shown). Outer roller is a hollow circular cylinder 121 formed by an anode substrate. The inner diameter of hollow circular cylinder 121 is greater than the outer diameter of inner roller 11, such that inner roller 11 is snugly fitted to the outer surface of outer roller 12. An electric potential difference is applied between inner roller 11 and outer roller 12, to cause the cathode unit of the cathode substrate to generate electron beam 10 which directly impinges the anode unit of outer roller 12 to generate light. The generated light is then converted by the photoelectric conversion layer 13, on the surface of which a layer of electrostatic is formed capable of adsorbing toner.
Toner cartridge 2 is disposed in correspondence with photosensitive drum 1. Fusing unit 3 is a roller wheel 31, and the interior of which contains a heating element 32. When paper 6 is fed in by roller wheel 31 and comes into contact with the toner adsorbed on the surface of photosensitive drum 1, both paper 6 and the toner are heated by heating element 32 of roller wheel 31, and the toner on the surface of photosensitive drum 1 is subsequently transferred and fused on the surface of paper 6 to form image.
Roller wheel assembly 4 is composed of a plurality of roller wheels 41 disposed in correspondence with above-described photosensitive drum 1. When image is formed on the surface of paper 6, paper 6 is output from the printer by roller wheels 41.
Erasing unit 5 is disposed in correspondence with photosensitive drum 1, for discharging the electrostatic. That is, when image is fused, photosensitive drum 1 rotates and comes into contact with erasing unit 6, the erasing unit 5 removes the remaining toner and electrostatic on the surface of photosensitive drum 1, allowing which to return to initial conditions and the next round of xerographic process can begin.
FIG. 3 is schematic illustrating the filed emission based apparatus according to a preferred embodiment of the invention. As shown in the figure, the above-mentioned light generated between inner roller 11 and outer roller 12 can be implemented by more than two electrodes of field emission based structure. In this preferred embodiment of the invention, a three-electrode field emission based structure is described. The structure includes an anode structure 7 and a cathode structure 8, and a spacer 9 lies therebetween to provide both vacuum spatial isolation and support. Anode structure 7 includes an anode substrate 71, an anode conduction layer 72, and a phosphors layer 73. The above-mentioned anode substrate 71 is constituted of conductive glass material. The anode conduction layer 72 is constituted of ITO (Indium Tin Oxide). The cathode structure 8 includes a cathode substrate 81, a cathode conduction layer 82, an electron emitter layer 83, a dielectric layer 84, and a gate electrode layer 85. Gate electrode layer 85 is applied an electric potential difference to induce the emission of electron beam 10 of electron emitter layer 83. Through the high voltage provided by anode conduction layer 72, electron beam 10 is accelerated to accrue enough momentum to impinge on the phosphors layer of anode structure 7 to cause illumination on the surface of anode substrate 71. The cathode conduction layer 82, electron emitter layer 83, dielectric layer 83, and gate electrode layer 85 shown in the figure collectively form a cathode unit, which is constituted of carbon nanotubes. The above-described anode unit is implemented using anode conduction layer 72 and phosphors layer 73.
After passing through anode substrate 71, the light is converted into electricity by photoelectric conversion layer 13 adhered on the surface of anode substrate 71. Hence, a layer of electrostatic charges capable of adsorbing toner 21 is formed on the surface of photoelectric conversion layer 13, solving the problem of O3 pollution and power consumption caused by traditional laser printer while disassociating (electrolyzing) the air molecules surrounding the photosensitive drum during the charging process.
FIGS. 4A-4C are schematics illustrating the process of fusing after the photoelectric conversion layer adsorbed toner. Gate electrode layer 85 is applied an electric potential difference to induce the emission of electron beam 10 of electron emitter layer 83. The gate electrode layer 85 of substrate 81 is provided an electrical potential induce emission of the electron beam of electron emitter layer 83. Through the high voltage provided by anode conduction layer 72, electron beam 10 is accelerated to accrue enough momentum to impinge on the phosphors layer of anode structure 7 to cause illumination on the surface of anode substrate 71. After photoelectric conversion layer 13 converts light into electrical energy such that the surface of photoelectric conversion layer 13 is covered with electrostatic charges capable of adsorbing toner 21. When photoelectric conversion layer 13 rotates and comes into contact with paper 6, the toner image is then transferred and fused on the surface of paper 6.
Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.
Patent Application
20080043086
