This Nonprovisional application claims priority under 35 U.S.C. ยง119(a) on Patent Application No. 2007-233575 filed in Japan on Sep. 10, 2007, the entire contents of which are hereby incorporated by reference.
The present technology relates to a toner supplier including a toner stirrer. The technology also relates to a development unit including such a toner supplier. The technology further relates to an image forming apparatus including such a development unit.
In general, a toner supplier includes a toner container and a toner stirrer, which includes a shaft and an auxiliary member. The shaft needs to be strong enough to support the auxiliary member stirring the toner in the container. The auxiliary member needs to be strong enough to stir the toner, and be flexible when this member comes into contact with a wall of the container. Therefore, the shaft and the auxiliary member are made of different materials.
JP 2004-286939 A discloses a method of separately molding a shaft and an auxiliary member as parts of a toner stirrer and bonding them together.
A shaft and an auxiliary member as parts of a toner stirrer may be bonded together by being welded thermally to each other with a jig. The thermal welding is liable to cause defective calking, thereby resulting in a low manufacturing yield and low accuracy of parts.
An object is to provide a toner supplier including a toner stirrer that can be manufactured at a high yield with high part accuracy.
A toner supplier includes a toner stirrer. The toner stirrer includes a shaft, an auxiliary member, and a fixture. The melting point of the auxiliary member is higher than the melting points of the shaft and fixture. The shaft and fixture are welded to each other with the auxiliary member interposed between them.
Because the melting point of the auxiliary member is higher than the melting points of the shaft and fixture, this member is not influenced by heat when the shaft and fixture are welded thermally to each other. This prevents the auxiliary member from waving when the shaft and fixture are welded thermally to each other. Because the shaft and fixture can melt sufficiently without the auxiliary member waving, the shaft and fixture can be welded firmly to the auxiliary member. Accordingly, the toner stirrer can be manufactured at a high yield with high part accuracy.
The best mode of carrying out the technology will be described below in detail with reference to the accompanying drawings.
With reference to
The charger 300 charges the cylindrical surface of the photosensitive drum 200 uniformly to a preset electric potential. The exposure unit 400 exposes the drum surface to light based on image data. The exposure forms an electrostatic latent image on the drum surface. The development unit 500 includes a development roller 505, which carries toner on its cylindrical surface and makes the latent image visible with the toner. The intermediate transfer roller 600 gives a transfer bias for transferring the toner image on the drum surface onto the intermediate transfer belt 610. The cleaner 700 recovers the toner remaining on the drum surface downstream from the intermediate transfer roller 600.
With reference to
With reference to
With reference to
At a secondary molding step, the same kind of resin as the shaft 532 is made of is poured into the molding machine so as to form a fixture 536. This produces a toner stirrer 530, with its auxiliary member 534 molded integrally between its shaft 532 and fixture 536.
When the auxiliary member 534 is molded integrally, the shaft 532 and fixture 536 melt and are welded thermally to each other with the auxiliary member 534 sandwiched between them. This keeps these parts 532, 534 and 536 fixed together and prevents them from becoming rickety. The integral molding differs from the common manufacturing method in that the parts 532, 534 and 536 are not calked. This makes the manufacturing yield of the toner stirrer 530 less liable to decrease and the precision of parts of the stirrer less liable to decrease. The molding temperature at the secondary molding step is lower than the melting point of the auxiliary member 534. This prevents the auxiliary member 534 from waving. If the shaft 532 and fixture 536 are made of PS resin, they contract at a rate of about 1 mm for a size of 300 mm at the primary molding step, but at a rate of about 0.2 or less mm for the same size at the secondary molding step.
With reference to
The auxiliary member 534 has holes 538 formed through it, through which toner passes. If toner is left at a high temperature in the toner supplier 510, the toner may become tapping. While the tapping toner is stirred, very high torque would, without the holes 538, be exerted on the auxiliary member 534. This would make it impossible to rotate the toner stirrer 530 by means of a general motor. Therefore, the holes 538 are formed so that part of the toner can escape through them.
When the auxiliary member 534 is molded integrally, it does not wave. This enables the toner stirrer 530 to stir toner uniformly. As a result, the development unit 500 and image forming apparatus 100 provide developed perfect images easily for a long period.
It will be obvious that the technology may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the technology, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
Number | Date | Country | Kind |
---|---|---|---|
2007-233575 | Sep 2007 | JP | national |
Number | Name | Date | Kind |
---|---|---|---|
6456810 | Deguchi et al. | Sep 2002 | B1 |
7349657 | Sato et al. | Mar 2008 | B2 |
20040062574 | Isomura et al. | Apr 2004 | A1 |
Number | Date | Country |
---|---|---|
3-260678 | Nov 1991 | JP |
07-261525 | Oct 1995 | JP |
11058518 | Mar 1999 | JP |
2001075343 | Mar 2001 | JP |
2003-287949 | Oct 2003 | JP |
2004-198800 | Jul 2004 | JP |
2004-286939 | Oct 2004 | JP |
2006001065 | Jan 2006 | JP |
2006-78992 | Mar 2006 | JP |
Number | Date | Country | |
---|---|---|---|
20090067884 A1 | Mar 2009 | US |