Electrophotography – Supplemental electrophotographic process – Exposure or charging
Reexamination Certificate
2001-03-07
2002-09-24
Ngo, Hoang (Department: 2852)
Electrophotography
Supplemental electrophotographic process
Exposure or charging
C399S051000
Reexamination Certificate
active
06456805
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to image forming systems that incorporate light sensitive photoreceptors.
2. Description of Related Art
Generally, electrophotographically forming an image includes charging a photoconductive member to a substantially uniform potential. This sensitizes the surface of the photoconductive member. The charged portion of the photoconductive surface is then exposed to a light image from either a modulated light source or from light reflected from an original document being reproduced. This creates an electrostatic latent image on the photoconductive surface. After the electrostatic latent image is created on the photoconductive surface, the latent image is developed. During development, toner particles are electrostatically attracted to the latent image recorded on the photoconductive surface. The toner particles form a developed image on the photoconductive surface. The developed image is then transferred to a copy sheet. Subsequently, the toner particles in the developed image are heated to permanently fuse the toner particles to the copy sheet.
SUMMARY OF THE INVENTION
Ambient room light is made of various wavelengths of light. Thus, when a photoconductive member is exposed to room light, for example, when the image forming system is serviced, random areas on the surface of the photoconductive member become light-shocked by the ambient room light. As a result, these light-shocked areas of the photoconductive member become more sensitive to the light used to form the latent image. Thus, the non-uniform room light causes non-uniform exposure voltages to accrue on imaging areas of the photoconductive member. Non-uniform exposure voltages across the imaging areas of the photoconductive member cause distortions in the electrostatic latent image developed on the imaging areas of the photoconductive member. Thus, the developed image on the photoconductive member includes image density variations, or distortions. As a result, when the developed image is subsequently transferred to a recording medium, the resulting image is distorted. These image distortions create images that would be objectionable to a customer.
Additionally, photoreceptors are relatively expensive. Unfortunately, during servicing, photoreceptors are often exposed to ambient room light. Thus, many photoreceptors are needlessly discarded by service personnel during servicing because of expected poor performance after these photoreceptors are exposed to ambient room light.
This invention provides apparatuses, systems and methods to maintain a photoreceptor in a uniformly light-shocked condition.
This invention separately provides apparatuses, systems and methods to supply a light source within a photocopy machine that will shine light on the photoreceptor.
This invention separately provides apparatuses, systems and methods to supply a light source within a photocopy machine that will shine high level, wide band fluorescent light on the photoreceptor.
This invention separately provides apparatuses, systems and methods that reduce the photoreceptor's sensitivity to ambient room light.
This invention separately provides apparatuses, systems and methods that limit a level of light shock to reduce the non-uniform voltages within the print area of the photoreceptor.
This invention separately provides apparatuses, systems and methods that limit a level of light shock to reduce defects in resulting images.
This invention separately provides apparatuses, systems and methods that limit a level of light shock to reduce adverse effects on the life of the photoreceptor.
This invention separately provides apparatuses, systems and methods that limit a level of light shock to reduce adverse effects on the performance of the photoreceptor
This invention separately provides apparatuses, systems and methods for more effectively removing undeveloped toner particles from the surface of a photoreceptor.
In accordance with the apparatuses, systems and methods of this invention, various exemplary embodiments of the light exposure systems according to this invention use a light that constantly shines on the photoreceptor during normal printing. In various exemplary embodiments, the light includes a wide band fluorescent light.
Other exemplary embodiments of this invention include systems and methods that turn on a fluorescent light only during specific time periods. In various exemplary embodiments, the specific time periods include times during which special diagnostic routines are being performed. This allows a user or service personnel to operate the wide band fluorescent light if print quality appears to be poor, or after, or as part of, a servicing routine. In various exemplary embodiments, the specific time periods include time periods when the image forming system is not printing. The time periods when the image forming system is not printing could include, for example, time periods when the image forming system is in a warm-up or a shut-down cycle. In various exemplary embodiments, the specific time periods include time periods when a fault diagnostic system determines that the image forming system is in a condition requiring analysis or problem solving, such as, for example, any time that the doors of the image forming system are open.
Other exemplary embodiments of this invention include systems and methods that use a bank of lights that constantly shine light on the photoreceptor.
Other exemplary embodiments of this invention include systems and methods that use a bank of wide band fluorescent lights that constantly shine wide band fluorescent light on the photoreceptor.
These and other features and advantages of this invention are described in or are apparent from the following detailed description of various exemplary embodiments of the apparatuses, systems and methods of this invention.
REFERENCES:
patent: 4110026 (1978-08-01), Farley et al.
patent: 4119373 (1978-10-01), Frishman et al.
patent: 4477179 (1984-10-01), Inuzuka et al.
patent: 5631727 (1997-05-01), Ehara et al.
patent: 5701560 (1997-12-01), Tsujita et al.
patent: 6070032 (2000-05-01), Rokutanda et al.
Buttles Patrick J.
Desmore John D.
Wagner Moritz P.
Ngo Hoang
Oliff & Berridg,e PLC
Xerox Corporation
LandOfFree
Systems and methods for reducing light shock to a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Systems and methods for reducing light shock to a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Systems and methods for reducing light shock to a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2848644