1. Field of the Invention
The present invention relates to a corona wire cartridge for a corona discharger that is applied to a charger, a transcriber, and a static eliminator of an image forming apparatus.
2. Background Art
A corona discharger where high voltage is applied to an electrode having a wire shape, a corona wire, to generate corona discharging is applied to, for example, a charger, a transcriber, and a static eliminator of a printer or a copier that forms images by using an electrography process.
In the corona wire, discharging efficiency may be reduced or local discharging may occur due to oxidation coming from the discharging or deterioration coming from attachment of floating toners resulting from static electricity during the discharging, and nonuniform charging of an object to be charged (photoreceptor, intermediate transfer body, paper, and so on) incurs poor printing including nonuniform concentration of black lines, white lines, and images.
Therefore, it is necessary to regularly replace the corona wire, and a structure where the corona wire is easily replaced is proposed in, for example, JP-A-62-131274
JP-A-62-131274 discloses a corona wire cassette where corona wires are wound around a reel member having a spiral spring therein and drawn from a casing and wound into the casing.
Even though the above-mentioned configuration provides improved handling of the corona wires, it is disadvantageous in that since parts such as switch rollers or felt rings for providing the spiral spring into the reel member or guiding the corona wires from the casing are required, costs of parts and assembling are increased.
Additionally, tension is continuously applied to the corona wires in the casing due to the spring or a transverse load is applied to the corona wires due to the switch roller, causing inferior effects such as lengthening or cutting of the corona wires.
A corona wire cartridge includes: a reel around which a corona wire is wound; a reel holder that rotatably supports the reel; a casing having a receiving portion which receives the reel and the reel holder and a wire drawing opening through which the corona wire is drawn; and an elastic member that movably connects the casing to the reel holder.
According to an aspect of the invention, it is possible to provide a corona wire cassette that has reduced costs of parts and assembling due to the small number of parts.
Furthermore, it is possible to prevent corona wires from being lengthened and cut, as an unnecessary load is not applied to the corona wires.
The present invention may be more readily described with reference to the accompanying drawings:
In
A radial groove 31d extending from the recess 31b to the circumference of the reel 31 is formed in a portion of a thick portion 31c.
As to the reel 31 having the above-mentioned configuration, a wheel a that is provided at an end of the wire is hanged on the reel shaft 31a so that the corona wire W is supported by the reel 31. A portion other than the end of the wire W is drawn from the groove 31d and wound around the circumference of the reel 31. Meanwhile, an annular member b is provided at another end of the wire W.
Turning to
A receiving portion 33a is formed in a casing 33 of the corona wire cartridge to receive the reel 31 supported by the reel holder 32, and the reel 31 and the reel holder 32 are provided in the receiving portion 33a like the arrangement of
The connection between the reel holder 32 and the casing 33 is performed using a spring 34 extending between a protrusion 33b provided in the receiving portion 33a and the reel holder 32.
Since the reel holder 32 is always biased by the spring 34 in the direction of the arrow x, the reel 31 is also drawn in the same direction due to the reel holder 32. For this, the reel 31 is supported by inclined sides 33c provided in the receiving portion 33a to stop the drawing of the reel and to regulate the position of the reel 31 in the receiving portion 33a, so that excessive force (excessive tension) is not applied to the corona wire W.
A supporting portion 33e is provided at a wire drawing opening 33d of the casing 33 to support an annular member b provided at the wire W.
As shown in
Next, the cartridge longitudinally moves in relation to the corona discharger 40 to unwind the wire W. As shown in
Since the supporting portion 33e which supports the annular member b is provided to the casing 33 to stabilize the posture of the annular member b, it is easy to hook the annular member b on the hook member 40a of the corona discharger and the replacement of the wire W is efficiently performed.
Furthermore, since a piece 33h having the latch 33g is flexible, if the cartridge is to be separated from the corona discharger, an operator pushes the piece 33h counterclockwise in
In the modification of the embodiment, as shown in
According to the above-mentioned configuration, since the winding of the wire W around the reel 31 may be performed outside, the assembling of the cartridge is efficiently performed, and, even if the wire is loosened, the wire may be tightly wound outside.
In
A polygonal rotating mirror 3 starts to rotate immediately after power is supplied to the laser beam printer 1, and rotates highly precisely at a constant speed while the power is supplied. A laser beam emitted from a light source 4 that is formed of a semiconductor laser and so on reflects from the polygonal rotating mirror 3 and is radiated through an fθ lens 5 onto the photosensitive drum 21 while scanning is performed.
If letter data or figure data converted into dot images are transmitted from the controller 22 to the laser beam printer 1 as on/off signal of the laser beam, portions onto which the laser beam is and is not radiated are formed on the surface of the photosensitive drum 21 to form the so-called electrostatic latent image.
When the photosensitive drum having the electrostatic latent image reaches a portion facing a developing device 6, a toner is supplied to the electrostatic latent image so that the positively charged toner is absorbed by static electricity, thus forming toner images at a portion from which electric charges are removed by radiation of the laser beam onto the photosensitive drum 21.
Paper 7 that continuously extends and is received in a paper hopper 11 is transported between the photosensitive drum 21 and a transcriber 10 by using a paper transportation tractor 8 in synchronization with the arrival of the toner images of printed data formed on the upper surface of the photosensitive drum 21 to a transcription position. Furthermore, the transcriber 10 is a kind of corona discharger which is equipped with the corona wire cartridge of the invention.
The toner images formed on the photosensitive drum 21 are absorbed on the paper 7 by using the transcriber 10 that provides electric charges having the polarity opposite to that of toner images on a rear side of the paper 7.
Therefore, the paper 7 that is provided in the paper hopper 11 is transported through the paper transportation tractor 8, the transcriber 10, the paper transportation tractor 9, and a buffer plate 24 to a fixing device 12. After the paper 7 transported to the fixing device 12 is preheated by a preheating plate 13, the paper 7 is transported while being heated and pressed by using a nip portion formed by a pair of fixing rollers that is formed of a heating roller 14 provided with a heater lamp 25 and a pressing roller 15 to fix the toner images on the paper 7 by fusing.
The paper 7 which has been already transported by using the heating roller 14 and the pressing roller 15 is moved to a stacker table 19 by using a transportation roller 16 and accordion-folded along a roulette due to the swing of a swing fin 17. Furthermore, the folded paper is adjusted by using rotating paddles 18 and stacked on the stacker table 19. A portion of the photosensitive drum 21 that passes a transcription position is cleaned by using a cleaning device 20, and then waits for the next printing.
In
In the above-mentioned embodiment, a description is given of the application of the corona discharger provided with the corona wire cartridge of the invention to the charger 2 and the transcriber 10. However, a corona static electricity remover may be provided to remove static electricity from a portion of the surface of the photosensitive drum 21 between the transcriber 10 and the cleaning device 20, or a corona discharger for pre-electrification may be provided to perform pre-electrification of the surface of the photosensitive drum 21 between the cleaning device 20 and the charger 2. In this connection, the invention may be applied to the corona static electricity remover and the corona discharger for pre-electrification.
Number | Date | Country | Kind |
---|---|---|---|
P2006-117808 | Apr 2006 | JP | national |
P2006-256968 | Sep 2006 | JP | national |
P2006-256969 | Sep 2006 | JP | national |
P2006-256970 | Sep 2006 | JP | national |
P2007-042094 | Feb 2007 | JP | national |
Number | Name | Date | Kind |
---|---|---|---|
4320957 | Brown et al. | Mar 1982 | A |
4746796 | Heigl | May 1988 | A |
5337131 | Sagiv et al. | Aug 1994 | A |
5528808 | Holubek et al. | Jun 1996 | A |
Number | Date | Country |
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62-131274 | Jun 1987 | JP |
Number | Date | Country | |
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20070248379 A1 | Oct 2007 | US |