Patent Application
20120230728
Reference is made to commonly-assigned copending U.S. patent application Ser. No. ______ (Attorney Docket No. 96606/NAB), filed herewith, entitled METHOD FOR MOUNTING A PHOTOCONDUCTOR, by Pitas et al.; the disclosure of which is incorporated herein.
The invention relates to electrophotography in general and in particular to an apparatus for mounting a photoconductor in an electrophotographic apparatus.
The electrophotographic process is used as a means of creating an image on paper or other suitable printing media. The electrophotographic process uses various components assembled into a print engine to enable printing. In order for those components to function correctly they must be mounted within the printer precisely and rigidly. The more precisely the components are mounted, the less correction is necessary for an accurate, well focused image placement on paper. Some components need to be replaced as part of normal operations. During this process, they must be positioned in a proper functional orientation. There is, therefore, a need to accurately locate components relative to a photoreceptive cartridge in a manner which minimizes necessary image registration correction. There is also a need for the process to be repeatable, and which minimizes variation when assemblies are interchanged.
Briefly, according to one aspect of the present invention an apparatus for mounting a cylindrical photoreceptor includes a gudgeon attached to a photoconductor; a stationary mount attached to the photoconductor; and wherein a diameter of the stationary mount matches a diameter of the photoconductor.
The invention and its objects and advantages will become more apparent in the detailed description of the preferred embodiment presented below.
The present invention will be directed in particular to elements forming part of, or in cooperation more directly with the apparatus in accordance with the present invention. It is to be understood that elements not specifically shown or described may take various forms well known to those skilled in the art.
An electrophotographic printer includes components necessary to print an image on paper. The printer is comprised of various sub-assemblies which perform specific functions.
An imaging module in the printer consists of components to print a single color image. Multiple imaging modules may be assembled to enable the printing of multiple color images.
Primary charging subsystem 210 uniformly electrostatically charges photoreceptor 206 of photoreceptive member 111, shown in the form of an imaging cylinder. Charging subsystem 210 may include a grid 213 having a selected voltage, or may be in the form of a roller with conductive properties.
Additional necessary components provided for control may be assembled around the various process elements of the respective printing modules. Meter 211 measures the uniform electrostatic charge provided by charging subsystem 210, and meter 212 measures the post-exposure surface potential within a patch area of a latent image formed from time to time in a non-image area on photoreceptor 206.
Image writer 220 is used to expose photoreceptor 206 and may be a light emitting diode (LED) array or other similar mechanisms. Toning unit 225, comprising elements 226 and 227 is used to develop the latent image created by image writer 220 on photoreceptor 206. Cleaning unit 230 removes residual toner from photoreceptor 206 after transfer of the image to a secondary receiver. Other meters and components may be included.
Within the printing module 31, periodic replacement of critical components is necessary to ensure proper function. It may be desired to cluster multiple components to enable simultaneous replacement.
Referring to
Referring now to
Referring now to
The stationary mount 242 is made with a precisely controlled inner and outer diameter. Suitable materials are chosen to enable low torque and long bearing surface life. The gudgeon 241 has precisely controlled bearing surface and outer diameter. The photoreceptor has precisely controlled inner diameter, which the gudgeon 241 presses into, and precisely controlled outer diameter. The construction is designed to provide precise spacing “B” between the outside of the stationary mount 242 and the photoreceptor 206. If materials with similar thermal expansion characteristics are chosen the spacing change is minimal with temperature change.
An image writer 220 is maintained at a certain distance from the photoreceptor 206 with critical spacing feature 248. The spacing feature 248 is precisely located to the image writer 220, such that the overall spacing C between the writer and photoreceptor 206 is precisely controlled. A similar approach can be used for the toning unit 225, cleaning unit 230, charging subsystem 210 and other features requiring precise location. The means of accurate, well controlled spacing between the photoreceptor surface and electrophotographic elements ensure a well focused image and proper function of the electrophotographic printer.
Because many of the subsystems are not part of the replacement cartridge 200, it is necessary to retract them from engagement with the stationary mount 242 prior to replacing the cartridge. It is convenient to make the outer diameter of the stationary mount similar in diameter to the photoreceptor to limit the refraction distance needed for clearance to spacing feature 248. For some systems this may not be a factor so a more appropriate diameter according to the particular design may be chosen.
Referring now to
Referring now to
The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the scope of the invention.
