Reference is made to commonly-assigned U.S. patent application Ser. No. 12/908,158 (now U.S. Publication No. 2012/0099894), filed Oct. 20, 2010, entitled METHOD FOR PREVENTING DAMAGE TO A PHOTOCONDUCTOR, by Pitas et al.; U.S. patent application Ser. No. 12/849,044 (now U.S. Publication No. 2012/0033992), filed Aug. 3, 2010, entitled METHOD FOR PREVENTING DAMAGE TO A PHOTOCONDUCTOR, by Pitas et al.; and U.S. patent application Ser. No. 12/849,041 (now U.S. Publication No. 2012/0033991), filed Aug. 3, 2010, entitled PREVENTING DAMAGE TO A PHOTOCONDUCTOR, by Pitas et al.; the disclosures of which are incorporated herein.
This invention relates to electrophotography in general and in particular to a replacement cartridge for an electrophotographic printer.
Electrophotographic equipment utilizes sensitive components that must be routinely serviced by either dedicated service personnel or by the end user. Many of these components are easily damaged unless care is exercised during replacement. In some instances, it is considered imprudent to depend upon an individual exercising care as a step in carrying out this critical operation. This is especially important when the risk of error is high, and the cost and machine down-time associated with error is great.
A primary component requiring frequent replacement within an electrophotographic print engine is the photoreceptive member. The function of the photoreceptor is to provide a means of developing an image and transferring that image to paper. The photoreceptor is coated with photosensitive material which is essential to operation of electrographic printers. The photosensitive material is easily scratched and can be damaged by exposure to ambient light if handled imprudently. This type of damage creates unacceptable image quality defects in the transferred image.
In close proximity to the photoreceptive member are many components that support the imaging of the photoreceptor. These components can scratch or abrade the photoreceptive member during replacement. There is a need to eliminate the potential for damage to the photoreceptive member.
Briefly, according to one aspect of the present invention a system for in situ replacement of a cartridge for an electrophotographic printer includes a photoreceptive member in the cartridge; a retractable shield enclosing the photoreceptive member; and a refraction mechanism in the cartridge for retracting the retractable shield when the cartridge is inserted into the printer.
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 all components necessary to accomplish the task of printing an image on paper. A printer is comprised of various sub-assemblies which perform specific functions.
An imaging module in the printer consists of components to enable printing of a single color image. Multiple 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 or laser. Toning unit 225, comprising elements 226 and 227 is used to develop the latent image created by 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 imaging 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
Because of the proximity of subsystems that interface with module 31 and with replacement cartridge 200, it is necessary to have large areas of the photoreceptive member 111 open during use. During insertion into the print engine, these open, unprotected areas can be damaged either mechanically or by light exposure. Therefore it is necessary to protect the photoreceptive member 111 from damage, either from extraneous light, fingerprints or mechanical scrapes. Many designs use paper as a protection means which is removed prior to insertion into the machine. From the time that paper is removed from a photoreceptive member 111, and it is inserted into the machine, it is prone to damage. The windup shield 240 is attached to the replacement cartridge housing 233, and protects from damage, the photoreceptor 206 during the installation process. The windup shield 240 stays in place when the replacement cartridge 200 is installed in the printer. Alternately, if desired the windup shield may be removed and discarded, as dictated by the particular design.
The windup shield consists of housing 241 and shield 242. The shield may be clear, translucent or opaque as dictated by the light sensitivity of components being protected. The shield may or may not rest on the entire surface of the photoreceptor 206. When the cartridge is slid into position the shield 242 is retracted into housing 241 through rotary motion. The windup can be either by turning a manual crank 250 by the installer, or an alternate construction has a torsion spring arrangement and plunger, such that when the plunger is depressed, when the replacement cartridge 200 is installed, a preloaded torsion spring winds the shield 242 into the housing 241.
Active drive means may be incorporated. A particular advantage in the arrangement shown is that the action of the windup shield is in the same direction as the motion of the photoreceptive member 111. The cleaner unit 230 and charger subsystem 210, therefore have a similar interface during windup as to the photoreceptive member 111 during use. By winding the shield in a similar direction, the windup action may be delayed until the machine is started, with the photoreceptive member acting to help wind up the shield. Winding the shield 242 at the same speed as the photoreceptive member 111 eliminates relative motion between the shield and photoreceptor 206 which reduces scuffing the surface. Also, the photoreceptive member 111 may have a one way clutch incorporated such that the windup causes the photoreceptive member to turn.
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.
Number | Name | Date | Kind |
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5231453 | Nakai et al. | Jul 1993 | A |
7184689 | Kang et al. | Feb 2007 | B2 |
20050238386 | Baek | Oct 2005 | A1 |
Number | Date | Country |
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08110744 | Apr 1996 | JP |
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Machine translation of JP08110744. |
Number | Date | Country | |
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20120099895 A1 | Apr 2012 | US |