This application claims the right of priority under 35 U.S.C. § 119(a)-(d) of Korean Patent Application No. 10-2005-0115866, filed on Nov. 30, 2005, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to an image drum for use in a printing apparatus, and more particularly to an image drum and a method of manufacturing the image drum, in which an image drum including a ring conductor can be easily fabricated and associated manufacturing costs can be reduced.
2. Description of the Related Art
Referring to
An elongate-shaped control unit 16 is mounted inside of the hollow drum body 12 such that a terminal array 18 formed at a longitudinal edge of the control unit 16 adjoins the internal wall of the drum body 12. The control unit 16 is arranged for individually applying a suitably high voltage to each of the electrodes 14 via the terminal array 18 in accordance with the image formation. As shown in
In order to manufacture the image-forming element 10, the cylindrical drum body 12 is provided. The grooves are cut into the outer circumferential surface of the drum body, for example, by means of a diamond chisel in such a fashion as to have a pitch of approximately 40 μm and a width of approximately 20 μm in order to form the electrodes 14. Alternatively, these grooves may be formed on the outer circumferential surface of the drum body by means of a laser beam or an electron beam.
In the next step, the large-diameter holes 26 are cut into the wall of the drum body 12 from the inside by, for example, a laser beam. The small-diameter holes 24 may also be formed with a laser beam, either from the inside or outside of the drum body, to thereby form the through-holes 22. After the through-holes 22 including the small-diameter holes 24 and the large-diameter holes 26 have been formed, the whole drum body 12 is anodized so as to form the insulating metal oxide layer 34 on the whole surface of the drum body. Thereafter, the electrically conductive material 32 fills in the grooves 14 and the through-holes 22. The outer or inner circumferential surface of the drum body 12 is cut to a predetermined depth through grinding so as to effectuate the electrodes 14 and electrical connection portions inside of the through-holes 22. An insulating layer is formed on the outer circumferential surface of the drum body 12 and the control unit 16 is disposed inside of the drum body 12 so as to complete the manufacture of the image-forming element 10.
As described above, in order to form the electrodes 14 on the outer circumferential surface of the drum body 12, the grooves are densely formed over the whole length of the drum body 12 using a precise cutting tool and the through-holes 22 must be formed at regular intervals either from the inside or outside of the drum body 12. Also, after the formation of the anodized surface layer on the outer circumferential surface of the drum body 12 and at the internal wall of the through-holes 22, the electrically conductive material 32 is filled into the grooves and the through-holes and is removed until a desired thickness of the drum body 12 remains. Specifically, since it is very difficult to evenly form the grooves on the outer circumferential surface of the drum body 12 in such a fashion as to have a pitch of approximately 40 μm and a width of approximately 20 μm and to fabricate the through-holes 22, the manufacturing cost of the image-forming element 10 is very high and a defects regularly occur. As mentioned above, there is at present a disclosed direct-induction-type, image-forming method and apparatus using a ring conductor such as the image-forming element as described above. However, the conventional image-forming method and apparatus entails a problem in that a printer made by using such a method and apparatus is high priced, which makes it difficult for the printer to be popularized.
Accordingly, the present invention has been made in view of the aforementioned problems occurring in the conventional art. An exemplary embodiment of the present invention provides an image drum which can be easily fabricated and can enable an excellent quality of printing, and a method of manufacturing the image drum.
Another exemplary embodiment of the present invention provides an image drum which can be rapidly and easily fabricated, is advantageous for mass production, and can reduce manufacturing costs, and a method of manufacturing the image drum.
A further exemplary embodiment of the present invention provides an image drum which can effectively discharge heat generated in the image drum so that it can be utilized for a long time period without inconvenience.
To accomplish the above, according to one exemplary embodiment of the present invention, there is provided a image drum which has long-lasting, good heat conductive characteristics.
According to an exemplary embodiment of the present invention, the novel image drum includes a drum body and an electrode member. The electrode member includes a flexible substrate, ring-shaped electrodes for a ring conductor, and a control unit. The ring-shaped electrodes are formed on the flexible substrate and the control unit is joined to the flexible substrate. An image drum for selectively adsorbing a toner on the image drum so as to form an image in a printing apparatus may include, for example, a hollow cylindrical drum body and an electrode member. The electrode member may include a flexible substrate adapted to surround an outer circumferential surface of the drum body, a plurality of ring-shaped electrodes formed circumferentially on a top surface of the flexible substrate so as to be electrically insulated from one another, and a control unit disposed on a bottom surface of the flexible substrate for independently applying a voltage to each of the ring-shaped electrodes. The electrode member may be disposed on the outer circumferential surface of the drum body.
As mentioned above, a conventional image drum is constructed such that grooves are formed on the outer circumferential surface of the drum body by using a diamond cutting tool, etc., and an electrically conductive material is filled into the grooves so as to form ring-shaped conductors. Further, through-holes are formed in the drum body using a laser beam, etc., so as to electrically interconnect an inside and an outside of the drum body, and an electrically conductive material fills in the through-holes to form an electrical connection portion.
However, in the present invention, ring-shaped electrodes may be formed on the flexible substrate and the control unit may be joined to the flexible substrate to correspond to each of the ring-shaped electrodes so as to form the electrode member. Generally, a conventional flexible printed circuit board (“FPCB”) technology may be used, and it is possible to form a copper line having a width of approximately 20 μm in FPCB. Thus, in the electrode member of the present invention, a copper pattern having a pitch of approximately 40 μm and a width of approximately 20 μm may also be formed on the flexible substrate. An application-specific integrated circuit (“ASIC”) chip may be used as the control unit. In this case, a needed number of ASIC chips can be joined to the flexible substrate by means of bonding, for example. The electrode member including the ring-shaped electrodes and the control unit is disposed on the outer circumferential surface of the drum body so as to form an image drum.
The above and other features and advantages of the present invention will be apparent from the following detailed description of the exemplary embodiments of the invention in conjunction with the accompanying drawings, in which:
Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.
Referring to
The magnetic cutter 220 includes a rotary sleeve 224, and a magnet 222 disposed within the magnetic cutter 220 for applying an attractive magnetic force to the toner 1. The magnet 222 is positioned adjacent to the image drum 100, and can attract the toner 1 adhered to the surface of the image drum 100 using the magnetic force. The magnet 222 has a sufficient magnetic force so that it can collect the toner 1 from the electrodes of the image drum 100 that is not attracted to the image drum 100 by a voltage. The toner 1 collected by the magnet 222 is fed back to the toner storage section or the toner feed roller 210 via the rotary sleeve 224.
The toner 1 that is not fed back to the toner storage section or the toner feed roller 210 by the magnetic cutter 220 is transferred to the image transfer section 230 from the outer circumferential surface of the image drum 100. Then, the toner 1 transferred to the image transfer section 230 is moved to a printing paper sheet which is in turn heat-treated so as to allow the toner to be adhered to the surface of the printing paper sheet. To this end, the image drum 100 controls the voltage applied to the electrodes to conform to an image signal. Then, the image drum 100 generates a electrostatic force larger than the magnetic force of the magnet 222 so as to prevent the toner 1 from being collected to the magnetic cutter 220.
Approximately five thousand electrodes are controlled independently so as to represent a two dimensional image on the image drum 100. The image represented on the image drum 100 through the toner 1 can be transferred to the printing paper sheet by using the image transfer section 230 as a relay means. After the toner 1 has been adhered to the surface of the printing paper sheet, the printing paper sheet passes through a heat-treatment apparatus. At this time, the toner is adsorbed to the surface of the printing paper sheet to complete a corresponding printing.
As shown in
The electrode member 120 includes the flexible substrate 125, ring-shaped electrodes 130 formed on the top surface of the flexible substrate 125, and the control chip 140 formed beneath the bottom surface of the flexible substrate 125. The electrode member 120 may be formed of a thin insulating film made of a material such as polyimide, etc. Conductive patterns may be circumferentially formed on the outer circumferential surface of the flexible substrate 125. The conductive patterns are evenly formed as ring-shaped electrodes 130 in such a fashion as to have a pitch of approximately 40 μm and a width of approximately 20 μm. The ring-shaped electrodes 130 covering the circumference of the drum body 110 are formed to have a width corresponding to the printing width of the printing paper sheet. For example, assuming the printing paper sheet is of A4 size, the drum body 110 is formed to have a length of at least 20 cm to 22 cm over its whole width. At this time, each of the ring-shaped electrodes 130 may be formed to have a pitch of approximately 40 μm in order to achieve about five thousand lines. The ring-shaped electrodes can be formed in a ring structure which is closed as one piece or partially opened. That is, both ends of each of the ring-shaped electrodes 130 may be electrically interconnected to form a closed ring structure, but it is possible to electrically insulate both ends of the each ring-shaped electrode 130 according to circumstances.
Since the ring-shaped electrodes 130 can be formed by patterning copper or other thin conductive film in a flat state, a groove cutting step or a conductive material filling step employed in a conventional image drum manufacturing process can be eliminated in this exemplary embodiment. First of all, since it is possible to form the ring-shaped electrodes 130 on the planar flexible substrate 125, the level of work difficulty is greatly lowered as compared to a formation of the ring-shaped electrodes 130 on the outer circumferential surface of the cylindrical drum body 110, as well as remarkably reducing the generation rate of defective ring-shaped electrodes.
After the ring-shaped electrodes 130 have been formed on the flexible substrate 125, the control chip 140 can be joined to the bottom surface of the flexible substrate 125. The control chip 140 is connected to each ring-shaped electrode 130 on a one-to-one corresponding basis, and performs a kind of switch function so as to independently apply a necessary voltage to each electrode 130. The control chips 140 may be mounted at various positions, but in this exemplary embodiment are mounted abuttingly along one end edge of the flexible substrate 125. Owing to this arrangement of components, the present invention provides an advantageous structure for the manufacture of the image drum 100 since it is possible to eliminate interconnection of the control unit disposed inside of the cylindrical drum body 110 to the ring-shaped conductor disposed outside of the drum body 110 by through-holes, which causes problems in the conventional art.
Referring to
As shown in
In addition, as the control chip 140 is made thinner, it becomes more favorable for mounting on the flexible substrate 125. In additional, a thinner control chip 140 generally permits a slight bending of the control chip 140. To this end, the control chip 140 initially may be designed to be thin, and may be formed so as to have a thickness of about 20 μm to 30 μm by partially removing the bottom portion of a conventional ASIC chip.
Now, a manufacturing method of the image drum 100 will be described hereinafter.
First, in order to manufacture the image drum 100, the flexible substrate 125 formed with a plurality of ring-shaped electrodes 130 is fabricated. The flexible substrate 125 may be formed of polyimide material, and copper patterns may be formed on the surface of the flexible substrate 125 through a conventional photolithography, a screen printing, etc. The ring-shaped electrodes 130 are formed in a parallel linear shape on the surface of the flexible substrate 125 in such a fashion as to be regularly arranged while maintaining a width of approximately 20 μm prior to attachment of the flexible substrate 125 on the drum body 110.
After provision of the flexible substrate 125 formed with the ring-shaped electrodes 130, the control chip 140, embodied as an ASIC chip, is joined to the bottom surface of the flexible substrate 125 along one end edge of the flexible substrate 125. The control chip 140 is intended to independently apply a voltage to each of the ring-shaped electrodes 130, and can be electrically connected to the ring-shaped electrodes 130 by means of general die bonding, soldering, or the like.
Generally, an insulating layer is formed on the flexible substrate 125 and the ring-shaped electrodes 130. The insulating layer may be formed of a dielectric material such as, for example, Aluminum Nitride (“AlN”), Al2O3, etc. The ring-shaped electrodes 130 can be electrically insulated from one another by the insulating layer. The insulating layer may be formed on the flexible substrate 125 before and/or after the control chip 140 is joined to the flexible substrate 125.
After the ring-shaped electrodes 130 and the control chip 140 have been integrally formed on the flexible substrate 125, the flexible substrate 125 is attached on the outer circumferential surface of the hollow cylindrical drum body 110. At this time, a recess is formed on the outer circumferential surface of the drum body 110 to receive the control chip therein. Also, although the control chip 140 and the flexible substrate 125 are overlapped with each other in a vertical direction, it is possible to prevent any portion from projecting abnormally from the surface of the image drum.
Referring to
The gear module 150 is centrally formed with a through-hole 152 for allowing the inside and outside of the drum body 110 to be exposed to air. According to this exemplary embodiment, since the control chip 140 is covered by the flexible substrate 125 and the heat-conductivity of polyimide material forming the flexible substrate 125 is relatively poor, heat accumulation phenomenon may occur within the image drum 101. Of course, the drum body 110 is formed of aluminum having good heat-conductivity, but even though the inside of the drum body also is opened at both sides, heat may not be smoothly discharged to the outside.
Therefore, a plurality of blades 154 is radially formed inwardly from the through-hole 152 to improve smooth inflow or outflow of air. In order to rotate the image drum, the gear module must be rotated. At this time, a force may be generated for causing air flow from the blades 154 because of this rotation. By using a structural modification of forming the blades 154 integrally with one another, a forcible flow of air can be induced without power specifically allocated for air flow. In addition, since the structure of the blades is simple and a conventional connection structure can be used as is, it is not difficult to apply the blades to the novel image drum.
Referring to
The image drum of the present invention can easily be manufactured in such a fashion that the control chip is joined to the flexible substrate by forming the FPCB, and the integrally formed FPCB is surrounded on the drum body. Since it is possible the electrodes, which are easily manufactured, have a reduced generation rate of defects and have relatively excellent quality, a superior printing quality can be expected.
In addition, manufacturing of the image drum can be rapidly performed due to its structural simplicity, and the image drum is very favorable for mass production due to easy facilitation of each manufacturing step. Since it is possible to utilize a processing technology which is conventionally well known in the art, the manufacturing cost is reduced and the product cost can be lowered accordingly.
Moreover, because blades are formed at the gear module so as to effectively discharge heat generated from the control chip to the outside, the image drum can be used for a long period without fault or inconvenience.
Although a few exemplary embodiments of the present invention have been shown and described, the present invention is not limited to the described exemplary embodiments. Instead, it would be appreciated by those skilled in the art that changes may be made to these exemplary embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.
Number | Date | Country | Kind |
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10-2005-0115866 | Nov 2005 | KR | national |