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:
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. 
    
    
     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&#39;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&#39;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&#39;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.