Electrophotography – Image formation – Development
Reexamination Certificate
2000-01-24
2001-05-01
Grimley, Arthur T. (Department: 2852)
Electrophotography
Image formation
Development
C399S109000, C399S274000
Reexamination Certificate
active
06226485
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
The present invention relates to toner metering blades used for metering toner in imaging processing equipment. The invention further relates to a novel process for manufacturing toner metering blades.
By way of background, toner metering blades are used in the toner cartridges of photocopy machines, laser printers, and other image processing equipment to perform the useful function of controlling the amount of toner that is transferred from a toner reservoir onto an image forming component. As is known, the image forming component, which is typically a photosensitive drum, is first rotated past an image forming area, where a latent image is formed thereon by laser imaging or other means. The image forming component is then advanced through the toner reservoir, where toner adheres to the portions of the image forming component that bear the latent image, forming a toner image pattern. As the image forming component continues to rotate, the toner image pattern is brought into contact with a print medium, such as paper, to which the toner is transferred to form a permanent image.
A typical prior art toner metering blade includes an elongated blade holder with a thin elongated blade element attached thereto. The blade holder mounts to a fixed structure on the toner cartridge such that a free edge portion of the blade element is positioned in close proximity to the moving image forming component, at a location where the image forming component enters the toner reservoir. The toner metering blade thus serves to remove excess toner remaining on the image forming component following a printing operation and prior to its re-entry into the toner reservoir. A strip made from silicone rubber or the like is usually secured to the toner blade at the free edge thereof. This provides the additional function of statically charging the image forming component to assist in the transfer of toner to the latent image.
In the past, toner metering blades have been manufactured by bonding the blade element to the blade holder in an adhesive bonding operation. Prior to or after the adhesive bonding operation, the silicone strip is applied to the free edge of the blade element in a separate manufacturing operation. In some cases, the silicone strip is a calendared strip that is placed on the blade element and secured thereto by appropriate curing. More recently, applicant's assignee has developed a technique for molding the silicone strip to the blade element. This provides a secure attachment between the blade element and the strip and obviates the strip calendaring, strip placement and strip curing steps referred to above.
A remaining deficiency of prior art toner metering blades is that several processing operations are still required to fabricate such products. Moreover, the relative placement of the blade element onto the blade holder is not controllable with complete precision. In particular, when the blade element and the blade holder are joined together with the soft adhesive sandwiched therebetween, the components can “float” relative to one another in three-dimensional space until the adhesive sets up. This can increase manufacturing tolerances to unsatisfactory levels.
It is with overcoming the foregoing deficiencies of the prior art that the present invention is concerned.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved toner metering blade with an improved bond between the blade holder and the blade element.
Another object of the present invention to provide an improved toner metering blade with an improved bond between the blade holder and the blade element, in combination with a well defined blade element strip.
Still another object of the present invention is to provide an improved process for manufacturing toner metering blades wherein the manufacturing steps are reduced in number and the manufacturing cycle time (per-unit) is held to a minimum.
In accordance with the present invention, a toner metering blade has an elongated blade holder and an elongated blade element. These components are bonded together—and a strip is optionally formed on one face of the blade element—in a single molding and material injection operation in which the blade holder is configured to provide a hot runner system.
In the preferred embodiment of the invention disclosed herein, the foregoing is accomplished by providing an elongated blade holder that is constituted, in part, by an elongated base member. The base member has a first blade holder face, a second blade holder face that is substantially parallel to the first blade holder face, a first longitudinal blade holder side edge, a second longitudinal blade holder side edge, a first blade holder end and a second blade holder end. An open blade holder cavity is formed in the first blade holder face for receiving an adhesive material, and at least one blade holder injection port extends from the second blade holder face to the cavity.
There is further provided an elongated blade element having a first blade element face, a second blade element face that is substantially parallel to the first blade element face, a first longitudinal blade element edge, a second longitudinal blade element edge, a first blade element end and a second blade element end.
During assembly of the foregoing components, the blade holder base member is placed onto the blade element such that the first blade element face is in facing engagement with the first blade holder face, and with the blade element covering the blade holder cavity. A mold is then closed around the blade holder and the blade element, the mold being shaped to receive the blade holder and the blade element therein and including a first mold gate that is located so as to be in fluid communication with the blade holder injection port when the mold is closed. There then follows the injection of a quantity of adhesive material into the first mold gate, the injecting of the adhesive material being sufficient to fill the blade holder cavity with the adhesive and to bond the blade holder to the blade element.
In a most preferred embodiment of the invention, the blade element includes plural blade element injection ports extending from the first blade element face to the second blade element face. The mold also includes (a) a strip-forming cavity located so as to be adjacent to the second blade element face and in fluid communication with the blade element injection ports when the mold is closed, and b) a set of second mold gates located so as to be in fluid communication with the blade element injection ports at the first blade element face when the mold is closed.
The manufacturing method then also includes injecting a quantity of strip-forming material into the second mold gates, the injecting of the strip-forming material being sufficient to fill the strip-forming cavity with the strip-forming material and form a strip on the blade element. Preferably, the strip is made from the same material as the adhesive. This material is preferably injected into the first and second mold gates substantially simultaneously.
The various aspects of the present invention will be more fully understood when the following portions of the specification are read in conjunction with the following drawings wherein:
REFERENCES:
patent: 6029031 (2000-02-01), Yokomori et al.
patent: 6117395 (2000-09-01), Ploug et al.
patent: 6141513 (2000-02-01), Nishiuwatoko et al.
patent: 60-69678 (1985-04-01), None
Duft Walter W.
Grimley Arthur T.
Ngo Hoang
TMP Technologies, Inc.
LandOfFree
Toner metering blade and manufacturing process therefor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Toner metering blade and manufacturing process therefor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Toner metering blade and manufacturing process therefor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2461528