Systems and methods for reducing light shock to a photoreceptive member

Information

  • Patent Grant
  • 6456805
  • Patent Number
    6,456,805
  • Date Filed
    Wednesday, March 7, 2001
    24 years ago
  • Date Issued
    Tuesday, September 24, 2002
    23 years ago
Abstract
A light source within a photocopy machine continuously shines high level, wide band fluorescent light on the photoreceptor to maintain the photoreceptor in a uniformly light-shocked condition. This constant level of light shock has no adverse effects on either the life or performance of the photoreceptor in normal operation. Thus, the photoreceptor becomes less sensitive to unintentional, uneven ambient room light and random, long lasting delta voltages within the print area are reduced so that print quality defects are minimized.
Description




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.











BRIEF DESCRIPTION OF THE DRAWINGS




Various exemplary embodiments of this invention will be described in detail, with reference to the following figures, wherein:





FIG. 1

is a side view showing the structure of an image forming system incorporating a first exemplary embodiment of a light shock reduction system according to this invention;





FIG. 2

is a side view showing the structure of an image forming system incorporating a second exemplary embodiment of a light shock reduction system according to this invention;





FIG. 3

is a side view showing the structure of an image forming system incorporating a third exemplary embodiment of a light shock reduction system according to this invention; and





FIGS. 4A-4C

show a flowchart outlining one embodiment of a control routine using the light shock reduction system of this invention.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS




For simplicity and clarification, the operating principles, design factors, and layout of the light shock reduction systems and methods according to this invention are explained with reference to various exemplary embodiments of light shock reduction systems and methods according to this invention, as shown in

FIGS. 1-4C

. The basic explanation of the operation of the illustrated light shock reduction systems and methods is applicable for the understanding and design of the constituent components employed in the light shock reduction systems and methods of this invention.





FIG. 1

shows an image forming system incorporating a first exemplary embodiment of a light shock reduction system


100


according to this invention. As shown in

FIG. 1

, the light shock reduction system


100


includes a light source


110


that is positioned adjacent to a photoreceptor


115


and a controller


112


. In various exemplary embodiments, the light source


110


is one or more florescent lights. The photoreceptor


115


is a belt-type device that rotates in the direction A, and advances sequentially through various xerographic process steps.




A charger


120


is mounted adjacent to the photoreceptor


115


. The charger


120


charges the photoreceptor to a predetermined potential and polarity. A toner dispenser/developer housing


125


is also mounted adjacent to the photoreceptor


115


. The toner dispenser/developer housing


125


stores toner particles and dispenses the toner particles to the photoreceptor


115


to develop the latent image in an imaging/exposure/developing zone


145


. A transfer dicorotron


155


is also mounted adjacent to the photoreceptor


115


. The area between the transfer dicorotron


155


and the photoreceptor


115


form an image transfer zone


135


. A cleaner


130


is also mounted adjacent to the photoreceptor


115


. The cleaner


130


removes residual toner particles from the surface of the photoreceptor


115


after the developed image is transferred to an image recording medium from the photoreceptor


115


.




In various exemplary embodiments, the light source


110


includes two or more lights. In various exemplary embodiments, the light source


110


includes a wide band florescent light. In various exemplary embodiments, the wide band florescent light has an output intensity of 25000 μW per centimeter of length. In various exemplary embodiments, the wide band florescent light has a wavelength that is tuned to optimize the performance of the particular photoreceptor


115


that the light source


110


is used with. In various exemplary embodiments, the light source


110


is a high intensity light source, such as, for example, an incandescent light.




If the light shock reduction system


100


includes multiple modes, the controller


112


is used to control which mode is active and to controllably turn on and off the light source


110


. However, if the light reduction system


110


does not have either multiple modes or a mode that requires controllably turning on and off the light source


110


, the controller


112


can be omitted. It should be appreciated that the controller


112


can be implemented as an independent control device or as a portion of the main controller of the image forming system in which the light shock reduction system


100


is implemented.




During operation of the light shock reduction system


100


according to this invention, as a portion of photoreceptor


115


passes by the charger


120


, the charger


120


charges the photoconductive surface of photoreceptor


115


to a relatively high, substantially uniform potential V


0


. Next, the charged portion of the photoconductive surface of photoreceptor


115


advances through an imaging/exposure/developing zone


145


. In the imaging/exposure/developing zone


145


, portions of the photoconductive surface of photoreceptor


115


are selectively discharged to form a latent electrostatic image. This latent image is developed on the photoconductive surface of the photoreceptor


115


.




The photoreceptor


115


, which is initially charged to a voltage V


0


by the charger


120


, undergoes dark decay to a voltage level V


dd


. In various exemplary embodiments, the dark decay voltage V


dd


is equal to about −500V. When developed at the imaging/exposure/developing zone


145


, the exposed portions of the photoreceptor


115


are discharged to an exposure voltage V


e


. In various exemplary embodiments, the exposure voltage V


e


is equal to about −50V. Thus, after exposure, the photoreceptor


115


has a bipolar voltage profile of high and low voltages. In various exemplary embodiments, the high voltages correspond to charged areas and the low voltages correspond to discharged or background areas. Thus, the photoreceptor


115


now has an electrostatic latent image formed on the surface of the photoreceptor


115


.




As the photoreceptor


115


continues to move, the imaged portion of the photoreceptor


115


passes the toner dispenser/developer housing


125


. The toner dispenser/developer housing


125


transfers charged toner particles to the imaged portions of the photoreceptor


115


.




As the photoreceptor


115


continues to move, the developed image arrives at the image transfer zone


135


. In the image transfer zone


135


, a recording medium moves along a sheet path


150


in a timed sequence so that the developed image developed on the surface of the photoreceptor


115


contacts the advancing recording medium at image transfer zone


135


.




In various exemplary embodiments of the image forming system, the image transfer zone


135


includes a transfer dicorotron


155


, which applies a bias to the recording medium. In various exemplary embodiments, the dicorotron


155


sprays positive ions onto the backside of the recording medium. This attracts the charged toner particles of the developed image from the surface of the photoreceptor


115


to the recording medium.




After transfer, the recording medium continues to move along the sheet path


150


. The recording medium is separated from the photoconductive surface of the photoreceptor


115


. Then, the recording medium continues to move along the sheet path


150


. A fusing station permanently affixes the toner particles of the transferred image to the recording medium.




As the photoreceptor


115


continues to move, the photoreceptor


115


passes the light source


110


. The light source


110


shines high level, wide band light onto the photoreceptor


115


. This wide band light uniformly light shocks the photoreceptor


115


. This light shock reduces the photoreceptor's sensitivity to ambient room light and other stray light that may enter the image forming system or otherwise impinge on the photoreceptor


115


.




In various exemplary embodiments, the high level, wide band light from the light source


110


also aids in neutralizing any remaining voltages remaining from the electrostatic latent image formed on the surface of the photoreceptor


115


. Thus, any remaining charged toner particles carried on the photoconductive surface of the photoreceptor


115


will no longer be as strongly attracted to the surface of the photoreceptor


115


. As the photoreceptor


115


continues to move, the photoreceptor


115


passes the cleaner


130


. The cleaner


130


removes any remaining toner particles from the surface of the photoreceptor


115


.




In other exemplary embodiments, the light source


110


may be two or more light sources. One or more of the light sources may be oriented to expose a portion of photoreceptor


115


to the high-level wide band light before that portion of the photoreceptor


115


reaches the cleaner


130


. The other one or more light sources may be oriented to expose the portion of the photoreceptor


115


to the high-level wide band light after that portion of the photoreceptor


115


travels past the cleaner


130


. Using two sets of one or more light sources each in this manner tends to make the cleaner


130


more effective and reduce the chance that remaining toner particles will shadow the photoreceptor


115


.




In yet other exemplary embodiments, the light source


110


may be located in another portion of the photocopy machine. In such exemplary embodiments, the high-level wide band light from the light source


110


could shine on the photoreceptor


115


through the use of, for example, a light pipe.





FIG. 2

shows an image forming system incorporating a second exemplary embodiment of a light shock reduction system


200


. As illustrated in

FIG. 2

, light shock reduction system


200


includes a controller


212


and a light source


210


, which is positioned relative to a photoreceptor


215


, a charger


220


, a toner dispenser/developer housing


225


, a cleaner


230


, and a transfer dicorotron


255


. Each of these elements corresponds to one of the elements discussed above with respect to FIG.


1


.




However, light shock reduction system


200


further includes a number of light sealing elements


245


,


250


and


255


. The light sealing elements


250


and


255


are attached to a housing of the light source


210


. The light sealing element


245


is positioned on the side of the photoreceptor


215


opposite the light source


210


. The light sealing elements


245


,


250


and


255


are positioned to reduce, if not prevent, any stray light from the light source


210


from entering other areas of the imaging forming device that incorporates the light shock reduction system


200


according to this invention. In various exemplary embodiments, at least one of the light sealing elements


245


,


250


and


255


has a reflective surface where the reflective surface faces the photoreceptor


215


. In various exemplary embodiments, the reflective surface of at least one of the light sealing elements


245


,


250


and


255


reflects light from the light source


210


toward the photoreceptor


215


.




If the light shock reduction system


200


includes multiple modes, the controller


212


is used to control which mode is active and to controllably turn on and off the light source


210


. However, if the light reduction system


210


does not have either multiple modes or a mode that requires controllably turning on and off the light source


210


, the controller


212


can be omitted. It should be appreciated that the controller


212


can be implemented as an independent control device or as a portion of the main controller of the image forming system in which the light shock reduction system


200


is implemented.




In other exemplary embodiments, the light sources


110


and/or


210


may be located inside the circumference of the photoreceptor


115


.





FIG. 3

shows an image forming system incorporating a third exemplary embodiment of a light shock reduction system


300


according to this invention. As illustrated in

FIG. 3

, the light shock reduction system


300


includes a light source


310


that is positioned adjacent to a drum-type photoreceptor


315


and a controller


312


. In various exemplary embodiments, the light source


310


is one or more florescent lights. The photoreceptor


315


is a drum-type device that rotates in the direction B and advances sequentially through various xerographic process steps.




A charger


320


is mounted adjacent to the photoreceptor


315


. The charger


320


charges the photoreceptor to a predetermined potential and polarity. A toner dispenser/developer housing


325


is also mounted adjacent to the photoreceptor


315


. The toner dispenser/developer housing


325


stores toner particles and dispenses the toner particles to the photoreceptor


315


to develop the latent image. A transfer dicorotron


355


is also mounted adjacent to the photoreceptor


315


. The area between the transfer dicorotron


355


and the photoreceptor


315


forms an image transfer zone


335


. A cleaner


330


is also mounted adjacent to the photoreceptor


315


. The cleaner


330


removes residual toner particles from the surface of the photoreceptor


315


after the developed image is transferred to an image recording medium from the photoreceptor


315


.




The light source


310


, the photoreceptor


315


, the charger


320


, the toner dispenser/developer housing


325


, the cleaner


330


, and the transfer dicorotron


355


correspond to and operate similarly to the same elements discussed above with respect to FIGS.


1


and/or


2


.




If the light shock reduction system


300


includes multiple modes, the controller


312


is used to control which mode is active and to controllably turn on and off the light source


310


. However, if the light reduction system


310


does not have either multiple modes or a mode that requires controllably turning on and off the light source


310


, the controller


312


can be omitted. It should be appreciated that the controller


312


can be implemented as an independent control device or as a portion of the main controller of the image forming system in which the light shock reduction system


300


is implemented.




During operation of the light shock reduction system


300


according to this invention, as a portion of the photoreceptor


315


rotates by the charger


320


, the charger


320


charges the photoconductive surface of photoreceptor


315


to a relatively high, substantially uniform potential V


0


. Next, the charged portion of the photoconductive surface of photoreceptor


315


rotates through an imaging/exposure/developing zone


345


. In imaging/exposure/developing zone


345


, portions of the photoconductive surface of the photoreceptor


315


are selectively discharged to form a latent electrostatic image. This latent image is then developed on the photoconductive surface of photoreceptor


315


.




The photoreceptor


315


, which is initially charged to a voltage V


0


by charger


320


, undergoes dark decay to a voltage level V


dd


. In various exemplary embodiments, the dark decay voltage V


dd


is equal to about −500V. When exposed at the imaging/exposure/developing zone


345


, the exposed portions of the photoreceptor


315


are discharged to an exposure voltage Ve. In various exemplary embodiments, the exposure voltage V


e


. is equal to about −50V. Thus, after exposure, the photoreceptor


315


has a bipolar voltage profile of high and low voltages. In various exemplary embodiments, the high voltages correspond to charged areas and the low voltages correspond to discharged or background areas. Thus, the photoreceptor


315


now has an electrostatic latent image formed on the surface of the photoreceptor


315


.




As the photoreceptor


315


continues to rotate, the imaged portion of the photoreceptor


315


passes the toner dispenser/developer housing


325


. The toner dispenser/developer housing


325


transfers charged toner particles to the imaged portions of the photoreceptor


315


.




As the photoreceptor


315


continues to rotate, the developed image arrives at the image transfer zone


335


. In the image transfer zone


335


, a recording medium moves along a sheet path


350


in a timed sequence so that the developed image developed on the surface of the photoreceptor


315


contacts the advancing recording medium at image transfer zone


335


.




In various exemplary embodiments of the image forming system, the image transfer zone


335


includes a transfer dicorotron


355


, which applies a bias to the recording medium. In various exemplary embodiments, the dicorotron


355


sprays positive ions onto the backside of the recording medium. This attracts the charged toner particles of the developed image from the surface of the photoreceptor


315


to the recording medium.




After transfer, the recording medium continues to move along the sheet path


350


. The recording medium is separated from the photoconductive surface of the photoreceptor


315


. Then, the recording medium continues to move along the sheet path


350


. A fusing station permanently affixes the toner particles of the transferred image to the recording medium.




As the photoreceptor


315


continues to rotate, the photoreceptor


315


passes the light source


310


. The light source


310


shines high level, wide band light onto the photoreceptor


315


. This wide band light uniformly light shocks the photoreceptor


315


. This light shock reduces the photoreceptor's sensitivity to ambient room light.




In various exemplary embodiments, the high level, wide band light from the light source


310


also aids in neutralizing any remaining voltages remaining from the electrostatic latent image formed on the surface of the photoreceptor


315


. Thus, any remaining charged toner particles carried on the photoconductive surface of the photoreceptor


315


will no longer be as strongly attracted to the surface of the photoreceptor


315


. As the photoreceptor


315


continues to rotate, the photoreceptor


315


passes the cleaner


330


. The cleaner


330


removes any remaining toner particles from the surface of the photoreceptor


315


.




In other exemplary embodiments, the housing of light source


310


may include the light sealing elements discussed above with respect to FIG.


2


.




In other exemplary embodiments, the light source


310


may include two or more light sources. One or more of the light sources may be oriented to expose a portion of photoreceptor


315


to the high-level wide band light before that portion of the photoreceptor


315


reaches the cleaner


330


. The other one or more light sources may be oriented to expose the portion of the photoreceptor


315


to the high-level wide band light after that portion of the photoreceptor


315


travels past the cleaner


330


. Using two sets of one or more light sources each in this manner tends to make the cleaner


330


more effective and reduce the chance that remaining toner particles will shadow the photoreceptor


315


.




In yet other exemplary embodiments, the light source


310


may be located in another portion of the photocopy machine. In such exemplary embodiments, the high-level wide band light from the light source


310


could shine on the photoreceptor


315


through the use of, for example, a light pipe.





FIGS. 4A-4C

are a flowchart outlining one exemplary embodiment of a method for controllably light shocking a photoreceptor according to this invention. A user can toggle between various light shock reduction modes, such as, for example, a “continuous” mode, a “diagnostic” mode, a “non-interference” mode, or an “analysis” mode. In the “continuous” mode, the light source constantly shines on an adjacent photoreceptor. In the “diagnostic” mode, the light source only shines on the adjacent photoreceptor when 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 the “non-interference” mode, the light source only shines on the adjacent photoreceptor during a time period 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. Finally, in the “analysis” mode, the light source shines on the adjacent photoreceptor if 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.




As shown in FIGS.


4


A—


4


C, beginning in step S


100


, control continues to step S


110


, where a determination is made whether a light shock reduction mode has been selected. If, in step S


110


, a light shock reduction mode has not been selected, control advances to step S


120


. Otherwise control jumps to step S


140


.




In step S


120


, the light source is operated in a default light shock reduction mode. In the default light shock reduction mode, the light source is turned on. Then, in step S


130


, a determination is made whether there has been a change to the selected light shock reduction mode. If there is a change in the selected light shock reduction mode control routine returns to step S


110


. Otherwise, if there is no change to the selected light shock reduction mode, control returns to step S


120


, and the light source continues to be operated in the predetermined default light shock reduction mode.




In step S


140


, a determination is made whether a “continuous” light shock reduction mode has been selected in step S


110


. If the “continuous” light shock reduction mode was selected in step S


110


, control advances to step S


150


. Otherwise, control jumps to step S


170


.




In step S


150


, the light source is turned on. Next, in step S


160


, a determination is made whether there has been a change to the selected light shock reduction mode. If there is a change to the selected light shock reduction mode, control returns to step S


110


. Otherwise, if there is no change to the light shock reduction mode input, control returns to step S


150


, and the light source continues to be operated on the continuous light shock reduction mode.




In step S


170


, a determination is made whether a “diagnostic” light shock reduction mode was selected in step S


110


. If the “diagnostic ” light shock reduction mode was selected in step S


110


, control advances to step S


180


. Otherwise, control jumps to step S


220


.




In step S


180


, a determination is made whether a diagnostic cycle is operating in the image forming system. If so, control jumps to step S


210


. Otherwise, control advances to step S


190


.




In step S


190


, the light source is turned off. Then, in step S


200


, a determination is made whether there has been a change to the selected light shock reduction mode. If there is a change to the selected light shock reduction mode input, control returns to step S


110


. Otherwise, if there is no change to the selected light shock reduction mode, control returns to step S


180


.




In step S


210


, the light source is turned on for a limited period of time. Once the light source has been on for the limited period of time, control returns to step S


110


.




In step S


220


, a determination is made whether a “non-interference” light shock reduction mode was selected in step S


110


. If the “non-interference ” light shock reduction mode was selected in step S


110


, control advances to step S


230


. Otherwise, control jumps to step S


270


.




In step S


230


, a determination is made whether the image forming system is printing. If the image forming system is printing, the control advances to step S


240


. Otherwise, control jumps to step S


250


.




In step S


240


, the control routine turns the light source off control directly then jumps to step S


260


. In contrast, in step S


260


, the control routine turns the light source on. Then, in step S


260


, a determination is made whether there has been a change to the selected light shock reduction mode. If there is a change in the light shock reduction mode input, control returns to step S


110


. If there is no change to the selected light shock reduction mode input, control returns to step S


230


.




Once the light source is turned on, the control system returns to step S


110


.




In step S


270


, a determination is made whether an “analysis” light shock reduction mode was selected in step S


110


. If the “analysis” light shock reduction mode was selected in step S


110


, control advances to step S


280


. Otherwise, control returns to step S


110


.




In step S


280


, a determination is made whether a fault diagnostic system has determined that the image forming system is in an analysis or problem solving condition requiring actions, such as, for example, a door to be opened, that will permit ambient light to illuminate the photoreceptor member. If in step S


280


, the image forming device is not in an analysis or problem solving condition, control advances to step S


290


. Otherwise, control jumps to step S


300


.




In step S


290


, the light source is turned off. Control then jumps to step S


310


. In contrast, step S


300


, the light source is turned on. Then, in step S


300


, a determination is made whether there has been a change to the selected input light shock reduction mode. If there is a change to the selected light shock reduction mode, control returns to step S


110


. Otherwise, if there is no change to the selected light shock reduction mode, control returns to step S


280


.




It should be appreciated that, if any one of the above described light shock reduction modes is omitted from any particular embodiment, the flowchart outlined in

FIGS. 4A-4C

will be modified accordingly. Similarly, should the implemented light shock reduction system include additional light shock reduction modes, the flowchart outlined in

FIGS. 4A-4C

will be adjusted accordingly to incorporate steps similar to those described above for these additional light shock reduction modes. Similarly, the default light shock reduction mode could in fact be any one of the implemented light shock reduction modes.




Furthermore, it should be appreciated that, rather than the user selecting the light shock reduction mode, the light shock reduction mode could be determined automatically by the image forming system based on various control parameters, such as, for example, the light shock reduction mode could be automatically selected based on any number of control criteria. Such control criteria could include, for example, the age of the photoreceptor, the length of time since the image forming system was last serviced, the diagnostic history of the image forming apparatus and/or any other desired control criteria.




In various exemplary embodiments described above, the light exposure systems have been described with reference to a florescent light source. However, it should be appreciated that any known or later developed high intensity light source can be used in conjunction with, or in place of, the light source described above. Furthermore, the light exposure systems described above have been described within a single color electrophotographic marking process. However, it should be appreciated that any known or later developed image forming system that uses a photoconductive member could be modified to incorporate the light exposure systems and methods according to this invention.




The controllers


112


,


212


, and


312


shown in

FIGS. 1-3

, if implemented as independent control devices, can be implemented using a programmed microprocessor or microcontroller and peripheral integrated circuit elements, and ASIC or other integrated circuit, a digital signal processor, a hardwired electronic or a logic circuit such as a discrete element circuit, a programmable logic device such as a PLV, PLA, FPGA or PAL or the like. In other exemplary embodiments, where the controllers


112


,


212


and/or


312


are implemented as part of the control system of the image forming apparatus in which the light shock reduction system


100


,


200


or


300


, respectively is implemented, the controllers


112


,


212


and/or


312


can be implemented using a programmed general purpose computer or any other device capable of implementing the general control system for the image forming system. Such other devices include a special purpose computer, a programmed microprocessor or microcontroller and a peripheral integrated circuit elements, and ASIC or other integrated circuit, a digital signal processor, a hardwired electronic or logic circuit such as discrete element circuit, a programmable logic device such as a PLV, PLA, FPGA or PAL or the like. In general, any device, capable of implementing a finite state machine that is in turn capable of implementing the flowchart shown in

FIGS. 4A-4C

, can be used to implement the controllers


112


,


212


and/or


312


.




While this invention has been described in conjunction with the exemplary embodiments outlined above, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the exemplary embodiments of the invention, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention.



Claims
  • 1. An image forming apparatus, comprising:a light-sensitive photoconductive member; and a light source positioned adjacent to the photoconductive member without obstruction that supplies high-intensity light to the photoconductive member, the high-intensity light emitted by the light source placing the photoconductive member in a controlled, light-shocked state.
  • 2. The image forming apparatus of claim 1, wherein the light source is a wide band fluorescent light.
  • 3. The image forming apparatus of claim 2, wherein the wide band fluorescent light is tuned to maximize the performance of the photoconductive member.
  • 4. The image forming apparatus of claim 1, wherein the high intensity light is tuned to maximize the performance of the photoconductive member.
  • 5. The image forming apparatus of claim 1, wherein the light constantly shines on the photoconductive member during printing.
  • 6. The imaging forming apparatus of claim 1, wherein the image forming apparatus is one of a laser printer, a xerographic copier, an analog copier, a digital copier, a color copier, a color printer, and a facsimile machine.
  • 7. The imaging forming apparatus of claim 1, wherein the light-sensitive photoconductive member comprises at least one of at least one photoconductive drum and at least one photoconductive belt member.
  • 8. A method for improving print quality of an image forming device, comprising:positioning a light source adjacent to a light-sensitive photoconductive member without obstruction; shining high-intensity light from the light source on the light-sensitive photoconductive member; and maintaining the light-sensitive photoconductive member in a controlled, light-shocked state by shining the high-intensity light on the light-sensitive photoconductive member.
  • 9. The method of claim 8, wherein shining the light includes shining a wide band fluorescent light.
  • 10. The method of claim 8, wherein shining the light includes shining wide band fluorescent light that is tuned to maximize a performance of the photoconductive member.
  • 11. The method of claim 8, wherein shining the light includes continuously shining a light on the photoconductive member during printing.
Parent Case Info

This is a continuation of application Ser. No. 09/449,345 filed Nov. 24, 1999. The entire disclosure of the prior application(s) is hereby incorporated by reference herein in its entirety.

US Referenced Citations (6)
Number Name Date Kind
4110026 Farley et al. Aug 1978 A
4119373 Frishman et al. Oct 1978 A
4477179 Inuzuka et al. Oct 1984 A
5631727 Ehara et al. May 1997 A
5701560 Tsujita et al. Dec 1997 A
6070032 Rokutanda et al. May 2000 A
Continuations (1)
Number Date Country
Parent 09/449345 Nov 1999 US
Child 09/799614 US