JP2008014967A - Characteristic evaluating device for electrophotographic photoreceptor and characteristic evaluating method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a characteristic evaluating device for an electrophotographic photoreceptor where, even in the case emission spectrum is changed by deterioration in a light source, the structural difference in apparatus or the like, influence is not exerted on the measured result of the characteristics, and to provide a characteristic evaluating method using the same. <P>SOLUTION: Prior to the evaluation of the characteristics of a photoreceptor drum 1, in such a manner that exposed light from an exposure lamp 13 is made fixed as possible, using a light spectroanalyzer, the emission spectrum of the exposed light and its intensity are measured. The measured value is compared with the initial characteristic value of the exposure lamp 13, then, the lamp lighting voltage to be fed to the exposure lamp 13 is changed in accordance with the difference in these values, and is controlled to the one same as the exposed state of the exposure lamp in the initial state, and the characteristics of the photoreceptor drum 1 are evaluated in the exposed state of the exposure lamp in the initial state. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a device for evaluating characteristics of an electrophotographic photoreceptor and a method for evaluating properties using the same.

  Conventionally, in electrophotographic photoreceptors used in image forming apparatuses such as laser printers and copiers, characteristics such as chargeability and sensitivity are important. In order to obtain the physical properties, charging is performed while moving the photoreceptor. Followed by exposure to measure the surface potential of the photoreceptor. At this time, the exposure amount for exposing the photosensitive member is an important factor for determining the sensitivity of the photosensitive member, and it is necessary to know an accurate value of the exposure amount. However, the exposure surface of the photoconductor exposed by exposure light is usually the outer periphery of the photoconductor, so that the exposure amount cannot be accurately known. For this reason, conventionally, a method has been adopted in which the amount of light is measured in advance at a position corresponding to the exposure surface, or an illuminance measurement sensor is placed around the exposure surface and the measured value is used as the exposure amount.

However, in the former case, there is a drawback that even if the exposure amount changes due to deterioration of the light source, voltage fluctuation, etc., it cannot be detected. In the latter case, the exposure amount is reduced due to the deviation of the optical system. There was a fear of change. In order to remedy these drawbacks, a half mirror that partially divides the light to be exposed is used, the amount of light branched by this half mirror is measured by a light amount sensor, and the exposure amount is corrected from this measured value to accurately expose the light. It has been proposed to evaluate the characteristics of the body. (For example, see Patent Document 1)
JP-A-6-236090

  However, although it is possible to measure deterioration of the light source and the like in the method described in Patent Document 1, when characterization is performed using white light such as a tungsten lamp or a halogen lamp as the light source, the same illuminance is set. Even if the light source deteriorates, the emission spectrum also changes, and even if the same photoconductor is measured, the photoconductor white light sensitivity may change. Therefore, the characteristics of the photoconductor should be measured with high accuracy. There is a problem that is difficult.

  The present invention has been made in consideration of the above circumstances, and is an electrophotographic photoreceptor that is not affected by the measurement results of characteristics even when the emission spectrum changes due to deterioration of the light source or structural differences of the apparatus. It is an object to provide a characteristic evaluation apparatus and a characteristic evaluation method using the same.

  In order to solve the above-mentioned problems, the invention described in claim 1 is an electrophotographic photosensitive member characteristic evaluation apparatus provided with a charging device, an exposure device, and a surface potential detection device around the photosensitive member. And a measuring means for measuring the illuminance and optical spectrum of the exposure light at a position outside the optical path of the exposure light applied to the irradiation surface of the photoconductor.

  Further, the invention of claim 2 is the electrophotographic photosensitive member characteristic evaluation apparatus according to claim 1, wherein the exposure apparatus has a light power of a reference optical spectrum held in advance and an optical spectrum at the time of measurement. A determination unit that determines whether or not the difference is within a preset allowable range is provided, and the lamp lighting voltage of the exposure apparatus is controlled based on the determination.

  Further, the invention of claim 3 is the electrophotographic photosensitive member characteristic evaluation apparatus according to claim 1 or 2, wherein the exposure apparatus includes a reflection mirror for guiding the exposure light out of the optical path, The measuring means measures the illuminance and optical spectrum of the exposure light reflected by the reflecting mirror.

  According to a fourth aspect of the present invention, in the apparatus for evaluating characteristics of an electrophotographic photosensitive member according to the first or second aspect, the exposure apparatus includes a half mirror for guiding the exposure light out of the optical path. The measuring means measures the illuminance and optical spectrum of the exposure light reflected by the half mirror.

  According to a fifth aspect of the present invention, in the electrophotographic photosensitive member characteristic evaluation apparatus according to any one of the first to fourth aspects, the exposure apparatus uses a plurality of light beams from an exposure light source of the exposure apparatus. The light is branched by a light guide that can be branched, and one of the lights branched by the light guide is used as exposure light for irradiating the photosensitive member, and the other is used as measurement light supplied to the measuring means.

  According to a sixth aspect of the present invention, there is provided an electrophotographic photosensitive member characteristic evaluation method using an electrophotographic photosensitive member characteristic evaluation device including a charging device, an exposure device, and a surface potential detection device around the photosensitive member. It is determined whether or not a difference in optical power between a reference optical spectrum held in advance and an optical spectrum of the exposure light of the exposure apparatus at the time of measurement is within a preset allowable range, and the exposure apparatus is based on the determination The characteristics of the electrophotographic photosensitive member are evaluated by controlling the lamp lighting voltage.

  According to the present invention, with the above-described configuration, the characteristics evaluation of the electrophotographic photoreceptor is not affected by the measurement result of the characteristics even when the emission spectrum is changed due to the deterioration of the light source or the difference in the structure of the apparatus. It is possible to provide a device and a characteristic evaluation method using the device.

  FIG. 1 is a diagram showing a schematic configuration of an electrophotographic photoreceptor characteristic evaluation apparatus according to an embodiment of the present invention. In the figure, 1 is a photosensitive drum, 13 is an exposure lamp for exposing the photosensitive drum 1, 3 is a surface potential meter probe for measuring the potential of the photosensitive drum 1, 6 is a corona charger for charging the photosensitive drum 1, 7 is a power source for supplying a voltage to the corona charger 6, 8 is a light source for static elimination that neutralizes the photosensitive drum 1, 12 is a lamp box that covers the exposure lamp 13, and 2 is irradiation of the photosensitive drum 1 with the exposed light. An exposure guide box for guiding the surface to the surface, 16 an aperture for adjusting the illuminance from the exposure lamp 13, 14 a mirror for reflecting the exposure light applied to the photosensitive drum 1, 11 a sensor for receiving the light reflected by the mirror 14, Reference numeral 10 denotes an optical spectrum analyzer for receiving light received by the sensor 11, and 15 denotes a light guide 15 for guiding the light to the optical spectrum analyzer 10.

  In the characteristic evaluation apparatus according to the present embodiment, the photosensitive drum 1 is rotated in the direction of arrow A, a high voltage is output from the power source 7, and the photosensitive drum 1 is charged by the corona charger 6. Thereafter, the passing current in the photosensitive drum 1 is fed to the signal processing circuit 5, and the passing current is smoothed by a smoothing circuit (not shown) in the signal processing circuit 5. Thereafter, the signal output from the signal processing circuit 5 is converted into a digital signal by the A / D converter 20, and this digital signal is sent to the controller 21 for arithmetic processing to calculate a passing charge amount.

  Further, the surface potential of the photosensitive drum 1 is sent from the surface potential meter probe 3 to the surface potential meter 4 which is a monitor unit and monitored, and the measured surface potential is sent to the signal processing circuit 9. Thereafter, it is converted into a digital signal by an A / D converter, and then sent to the controller 21 for calculation processing to calculate a charge amount, a residual potential in the photosensitive member, and the like.

  The exposure lamp 13 is connected to the controller 21, and the lamp lighting voltage of the exposure lamp 13 can be controlled by the controller 21. Further, the units such as the charger 6 and the static elimination light source 8 around the photosensitive drum 1 and the exposure lamp 13 are ON / OFF controlled by the digital relay output 22. Further, the post-exposure potential of the photosensitive drum 1 can be measured by using the exposure lamp 13, and when removing the surface potential of the photosensitive drum 1, this light source 8 is used by using the light source 8 for static elimination. Can be removed by irradiating the photosensitive drum 1 with.

  In the apparatus for evaluating characteristics of the photosensitive drum 1 according to the present embodiment, it is possible to evaluate characteristics such as charging characteristics and light attenuation characteristics of the photosensitive drum 1 as described above. However, when the exposure lamp 13 of the exposure apparatus is used for a long time, the exposure lamp 13 is deteriorated and the exposure amount is changed, and when the characteristics are evaluated using white light such as a tungsten lamp or a halogen lamp, Even when the same illuminance is set, if the light source deteriorates, the emission spectrum also changes, and even if the same photoconductor is measured, the photoconductor white light sensitivity changes, so that the characteristics of the photoconductor drum 1 can be evaluated with high accuracy. There are things that cannot be done.

  Next, these points will be described. First, a tungsten lamp is used as the exposure lamp 13, and the light spectrum on the irradiated surface of the photosensitive drum 1 is confirmed with respect to the time transition of the color temperature of the tungsten lamp. The ratio of the emission spectrum measurement results of 500 nm and 700 nm The color temperature was calculated and measured based on the radiation formula. Table 1 shows the results of investigation on the color temperature change. The tungsten lamp used was FP8DC 120V100 Watt manufactured by Fuji Electric Bulb Co., Ltd., and the optical spectrum analyzer used at the time of emission spectrum measurement was Q8381A manufactured by ADVANTETS. Further, the lamp lighting voltage of the tungsten lamp was set to 106 V and measured.

  From the results in Table 1, it can be seen that the color temperature changes as the usage time becomes longer, and the emission spectrum changes. In the management method in which the lamp operating voltage is fixed, the emission spectrum changes with the usage time and the color temperature changes. When the same tungsten lamp is used for a long time, it is the same as the initial color temperature. It is understood that white light sensitivity may not be obtained.

  Next, the influence of the light guide when the characteristics of the photosensitive drum 1 are evaluated using the light guide when the exposure light from the exposure lamp 13 is irradiated onto the photosensitive drum 1 will be described.

  As shown in FIG. 1, when an exposure apparatus in which the exposure lamp 13 is directly connected to the exposure guide box 2 is used (condition 1), the exposure is performed as shown in FIG. Changes in the case where the exposure light from the lamp 13 is supplied to the exposure guide box 15 using the light guide 17 (condition 2) were examined. A tungsten lamp (FP8DC 120V100 Watt manufactured by Fuji Electric Bulb Co., Ltd.) was used as the exposure lamp. Further, the tungsten lamp was set to a lamp lighting voltage of 106 V at a brightness of 2856K, and the emission spectrum was measured using Q8381A manufactured by ADVANTETS Co., Ltd. as an optical spectrum analyzer used at the time of emission spectrum measurement. Moreover, the light guide 17 shown in FIG. 2 used the multicomponent glass fiber by Hayashi Clock Co., Ltd.

  The result of comparing the emission spectra is shown in FIG. Note that the Y-axis in FIG. 3 was calculated with the maximum light amount at 400 nm to 1000 nm as 1. Also, white light sensitivity (time (s) required for the potential to decay) and exposure illuminance (lx) until the potential of the photoreceptor is attenuated from −800 V to −80 V in the characteristic evaluation apparatuses of Condition 1 and Condition 2. Table 2 shows the result of calculating the exposure amount (lx · s) calculated by multiplying by. As conditions for calculating the sensitivity, both the conditions 1 and 2 use a high voltage power source 610E manufactured by TREK as a power source for supplying voltage to the corona charger 6, and a surface potential meter manufactured by TREK for measuring the surface potential. It measured using Model344 and the surface potential meter probe Model6000B-7C by TREK. Further, as the photosensitive drum 1, the same material and prescription configuration as those of the Ricoh PC LASER SP-90 photosensitive member are used. As measurement conditions, the illuminance (measured by T-1M manufactured by Minolta Co., Ltd.) on the photoreceptor surface was 19.7 lux, and the photoreceptor rotation speed was 1800 rpm.

  From the results shown in FIG. 1, even when the same lamp is used at the same lamp temperature and the same color temperature, when the light guide such as a light guide is used (condition 2), the exposure lamp 13 is directly connected to the exposure guide box 2. It can be seen that the optical spectrum at a wavelength of 400 to 1000 nm is changed as compared with the case (condition 1).

  In addition, it can be seen from the results in Table 2 that even when the same lamp is used, the white light sensitivity measurement result varies depending on whether or not the light guide 17 is used.

  As described above, when the characteristics are evaluated using white light such as a tungsten lamp or a halogen lamp as the exposure lamp 13, the emission spectrum changes due to deterioration of the light source or use of the light guide. Therefore, it is understood that the characteristic evaluation of the photosensitive drum 1 cannot be performed with high accuracy.

  In this embodiment, the exposure light from the exposure lamp 13 is evaluated prior to or during the characteristic evaluation of the photosensitive drum 1 in order to improve such a problem caused by the deterioration of the exposure lamp 13 with the passage of time. The emission spectrum of the exposure light and its intensity are measured by using the optical spectroanalyzer 10 so as to be as constant as possible, and the measured values are compared with the characteristic values of the initial exposure lamp 13 to obtain these values. The lamp lighting voltage supplied to the exposure lamp 13 is changed according to the difference, and the exposure state of the exposure lamp in the initial state is controlled to be the same as the exposure state of the exposure lamp in the initial state. Thus, the characteristics of the photosensitive drum 1 are evaluated.

  Specifically, as shown in FIG. 1, the exposure light emitted from the exposure lamp 13 is reflected upward by a mirror 14 such as a reflection mirror or a half mirror before or during the evaluation of the characteristics of the photosensitive drum, It is detected by the sensor 11 and sent to the optical spectrum analyzer 10 by the light guide 15. The exposure light thus sent is measured for wavelength and intensity by the optical spectrum analyzer 10, and the measured spectrum is sent to the arithmetic unit 19. In the arithmetic unit 19, the power ratio with the irradiation surface of the photosensitive drum 1 (the ratio between the power of the irradiation surface of the photosensitive drum and the power of the optical spectrum analyzer 10), the spectrum result, and the relative luminous efficiency curve are obtained. Illuminance is calculated and output. In this way, the initial illuminance is calculated, and the diaphragm 16 and the like of the exposure lamp 13 are adjusted so that the initial illuminance is maintained.

  After the initial illuminance is set in this way, the exposure lamp 13 is set according to the flowchart shown in FIG. 4 prior to the characteristic evaluation of the photosensitive drum 1. In other words, the lamp is turned on by supplying a lighting voltage to the exposure lamp 13 with the start. The exposure light of the exposure lamp 13 is reflected by the mirror 14 and the spectrum of the exposure light is measured by the optical spectrum analyzer 10. (Step S1) The spectrum measured by the optical spectrum analyzer 10 is compared with the initial spectrum, and it is determined by the arithmetic unit 19 whether the difference is within the determination criteria. (Step S2) In this case, the determination criterion is based on whether or not the difference in optical power is within ± 3% in the wavelength region of 400 nm to 800 nm, for example. Next, when it is determined in step S2 that it is within the determination criterion, it is determined by the arithmetic unit 19 whether or not the power of the wavelength of 700 nm or more in the measurement spectrum is strong. Is increased (step S4), and in the case of yes, the operation of decreasing the lamp operating voltage (step S5) is automatically performed. The exposure light whose exposure intensity has been changed by adjusting the lighting voltage in this way returns to step S1 again, and the spectrum is measured.

  Next, in step S2, when the observed spectrum is not within the determination criterion, in step S6, it is determined by the arithmetic device 19 whether or not the illuminance output by the arithmetic device 19 is within an allowable range. If the determination result is no, it is determined whether or not the illuminance is larger than the set illuminance (step S7). If yes, the diaphragm 16 in the lamp box 12 is narrowed (step S8). For this, the aperture 16 is widened (step S9), the spectrum of the exposure light with the light quantity changed in this way is measured again (step S10), and the illuminance is determined in step S6. As a result, in the case of YES, the setting of the light source of the exposure lamp 13 is completed. In this way, by controlling, it is possible to measure even when the emission spectrum changes within the criterion of ± 3% compared to the initial sensitivity value.

  Next, specific measurement conditions are set as follows, a reflection mirror is used as a mirror 14, and when adjusting the exposure lamp 13, the entire amount of exposure light is introduced into the optical spectrum analyzer 10, and the exposure lamp 13 After the adjustment setting, when the mirror 14 is flipped up and the entire amount is irradiated onto the photosensitive drum 1 (Example 1a), the mirror 14 is a half mirror (as a half mirror, both the reflection surface and the transmission surface are 400 nm to 800 nm. Using a half mirror with a flat spectral characteristic in the wavelength region of (1) and supplying exposure light to the optical spectrum analyzer 10 and the photosensitive drum 1 simultaneously (Example 1B), and a mirror and an optical spectrum as a comparative example The analyzer 10 is not used, and only the illuminance is measured with the illuminometer (T-1M manufactured by Minolta) on the irradiated surface of the photosensitive drum 1 before measuring the illuminance. Was measured (Comparative Example 1). In Examples 1a and 1b, before the sensitivity measurement, the lamp lighting voltage was adjusted according to the flowchart shown in FIG.

  As the characteristic evaluation apparatus, the characteristic evaluation apparatus shown in FIG. 1 is used. As the exposure lamp 13, a tungsten lamp (Fuji Electric Bulb Co., Ltd. FP8DC 120V100 Watt) is used, and the initial use tungsten lamp has a color temperature of 2856K. The lamp operating voltage is 106.0 V, the power supply for supplying voltage to the corona charger 6 is a high voltage power supply 610E manufactured by TREK, and the surface potential is measured by a surface potential meter Model 344 manufactured by TREK and manufactured by TREK. The surface potential meter probe Model6000B-7C was used, and the emission spectrum was measured using an optical spectrum analyzer Q8381A manufactured by ADVANTETS. The photoconductor used was the same material and composition as the photoconductor for Ricoh PC LASER SP-90. As measurement conditions, the set illuminance calculated by the calculation device 19 was set to 20 lux, and the characteristics of the photosensitive drum 1 were evaluated at 1800 rpm. The white light sensitivity (exposure amount calculated by multiplying the time required for the potential to decay and the exposure illuminance) until the potential of the photoreceptor was attenuated from −800 V to −80 V was calculated by the characteristic evaluation apparatus.

  Table 3 shows the results of measuring the white light sensitivity for each usage time of the white light lamp every 20 hours.

  From the results in Table 3, as shown in Comparative Example 1, the sensitivity of the lamp that has been used for a long time with the lamp lighting time constant (106 V) is reduced, and the characteristic results are obtained in the initial case and after 100 hours. You can see the difference. However, as shown in the present embodiment 1a, the reflection mirror is used, the light spectrum is confirmed before measurement, and when the change is confirmed in the spectrum, the lamp lighting is controlled by controlling the lamp lighting voltage. Even after 100 hours of use, it is clear that the sensitivity is within ± 3% of the original sensitivity value (initial sensitivity value) and measurement is possible even if the emission spectrum changes. is there.

  Similarly, in the method using the half mirror (Example 1b), even after the lamp lighting time was used for 100 hours, the emission spectrum changed within ± 3% of the original sensitivity value compared to the original sensitivity value. It is clear that even if it is possible to measure. Further, the illuminance on the irradiation surface of the photosensitive drum 1 can be easily calculated, and the time spent for illuminance measurement is shortened. Furthermore, in the case of using a half mirror, the illuminance and spectrum can always be predicted.

  As described above, the apparatus for evaluating characteristics of the photosensitive drum 1 according to the present embodiment can make the sensitivity substantially constant and the deterioration of the exposure lamp 13 as compared with the comparative example that does not use the mirror and the optical spectrum analyzer 10. It is possible to satisfactorily prevent erroneous measurement associated with.

  For the exposure apparatus, fluorescent materials such as fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LEDs), semiconductor lasers (LDs), and electroluminescence (ELs) can be used. And to irradiate only light in the desired wavelength range, various filters such as sharp cut filter, band pass filter, near infrared cut filter, dichroic filter, interference filter, color temperature conversion filter can be used, Neutral Density Fuller can be used to lower

  In addition, a neutral density filter that can adjust the illuminance without using the diaphragm can be used as the diaphragm for adjusting the illuminance.

  The mirror can be a reflection mirror or a half mirror. When the reflection mirror is used, a changeover switch for guiding light to the photosensitive drum 1 side and guiding light to the optical sensor 11 side is provided. The structure is easily switchable (not shown).

  The charging device power supply circuit control means for charging the surface of the photoconductor drum 1 as the sample to be tested and the light source power supply circuit control means for irradiating the photoconductor drum 1 with light are not shown. As these, conventionally known ones can be used as they are.

  The characteristic evaluation apparatus according to the present invention is covered with a dark box or a black curtain that does not transmit light. If it is not covered with a dark box or a black curtain, it will be affected by the external environment (wind, light, temperature) during testing, making accurate characterization difficult. However, things that do not affect the evaluation of the photosensitive drum, such as a controller and signal processing circuit, do not need to be covered with a dark box or black curtain.

  The photoreceptor used in the present invention is not limited to a drum but may be in the form of a belt. A charge generating layer, a charge transport layer formed on a conductive support, and a protective layer on the charge transport layer. The one formed with is used. As the conductive support, the charge generation layer, and the charge transport layer, any known ones can be used.

  (Embodiment 2) Using the characteristic evaluation apparatus according to another embodiment of the present invention shown in FIG. 2, a tungsten lamp (Fuji Electric Bulb Co., Ltd. FP8DC 120V100 Watt) is used as the exposure lamp 13, and the initial tungsten lamp The lamp lighting voltage at a color temperature of 2856K was 106.0V. The power supply for supplying voltage to the corona charger 6 uses a high voltage power supply 610E manufactured by TREK, and the surface potential is measured using a surface potential meter Model 344 manufactured by TREK and a surface potential meter probe Model 6000B-7C manufactured by TREK. The light guide 17 was a multicomponent glass fiber manufactured by Hayashi Watch Industry, and the light emission spectrum was measured using an optical spectrum analyzer Q8381A manufactured by ADVANTETS. The photoconductor used was the same material and composition as the photoconductor for Ricoh PC LASER SP-90. As measurement conditions, the set illuminance calculated by the calculation device was 20 lux, and the characteristics of the photosensitive drum 1 were evaluated at 1800 rpm. The white light sensitivity (exposure amount calculated by multiplying the time required for the potential to decay and the exposure illuminance) until the potential of the photoreceptor was attenuated from −800 V to −80 V was calculated by the characteristic evaluation apparatus. In this case, when the reflection mirror is used as the mirror 14 (Example 2a), when the half mirror is used (Example 2b), and without using the mirror, only the illuminance is measured on the photosensitive member irradiation surface before the white light sensitivity measurement. A method in which white light sensitivity is measured with an illuminometer (manufactured by Minolta, T-1M) is referred to as Comparative Example 2. In Examples 2a and 2b, before measuring the white light sensitivity, light was guided to the optical sensor 11 side by the reflection mirror and the half mirror, and the white light lamp lighting voltage was adjusted according to the flowchart shown in FIG. Thereafter, the white light sensitivity was measured by adjusting the illuminance. However, as the half mirror, a half mirror having a flat spectral characteristic in a wavelength region of 400 nm to 800 nm on both the reflection surface and the transmission surface was used.

  Since the original sensitivity of the used photosensitive drum 1 is 1.14 (lx · s), the light in the path from the result of Table 4 until the light from the light source is guided to the irradiation surface of the photosensitive drum 1 is written. When an object that may change the light spectrum such as the guide 17 is used, as is apparent from the results of Comparative Example 2, the white light sensitivity may be different between the initial time and after 100 hours of use. I understand. However, as shown in Examples 2a and 2b, the light spectrum is confirmed before measurement, and when a change is confirmed in the spectrum, the light spectrum of the light guide 17 and the like is changed by changing the lamp lighting voltage and measuring. Even when an object that may be changed is used, it can be measured even if the emission spectrum changes, within the criteria of ± 3% compared to the original sensitivity value (initial sensitivity value). The thing is clear. Furthermore, it is clear that even if the lamp usage time is 100 hours in that situation, it is within the criterion of ± 3% compared to the original sensitivity value (initial sensitivity value).

  Further, as shown in Example 2b, even when a half mirror is used, similarly, it falls within the determination standard within ± 3% compared to the original sensitivity value, and can be measured even when the emission spectrum changes. The thing is clear. Further, the illuminance on the photosensitive member irradiation surface can be easily calculated, and the time spent for illuminance measurement can be shortened. Furthermore, in the case of using a half mirror, the illuminance and spectrum can always be predicted.

  (Example 3) The characteristic evaluation apparatus according to another embodiment of the present invention shown in FIG. 5 was used, and a tungsten lamp (FP8DC 120V100 Watt) was used as the exposure lamp. The power supply for supplying voltage to the corona charger 6 uses a high voltage power supply 610E manufactured by TREK, and the surface potential is measured using a surface potential meter Model 344 manufactured by TREK and a surface potential meter probe Model 6000B-7C manufactured by TREK. The light guide 18 was made of a multicomponent glass fiber manufactured by Hayashi Watch Industry Co., Ltd., and the emission spectrum was measured using an optical spectrum analyzer Q8381A manufactured by ADVANTETS Corporation. The photosensitive drum 1 used the same material and formulation as the Ricoh PC LASER SP-90 photoreceptor. As measurement conditions, characteristic evaluation was performed with a set illuminance of 20 lux and a photosensitive member rotation speed of 1800 rpm. The white light sensitivity (exposure amount calculated by multiplying the time required for the potential to decay and the exposure illuminance) until the potential of the photoreceptor was attenuated from −800 V to −80 V was calculated by the characteristic evaluation apparatus. The illuminance was set as a value calculated by a calculation device. In this measurement, when the light spectrum is measured by the optical spectrum analyzer 10 using the branched light guide 18 to control the lighting voltage of the exposure lamp 13 (Example 3), the light guide is branched. The white light sensitivity was measured every 20 hours when the white light lamp was used as a measurement using a multi-component glass fiber manufactured by Hayashi Watch Industry (Comparative Example 3). The results are shown in Table 5.

  Since the original sensitivity of the used photoconductor is 1.14 (lx · s), a light guide or the like is included in the path from the result shown in Table 5 until the light from the light source is guided to the irradiation surface of the photoconductor drum 1. As shown in Comparative Example 3, it can be seen that there is a difference in white light sensitivity when an object that may change the light spectrum is used. However, there is a possibility of changing the light spectrum of the light guide etc. by measuring the light spectrum using a branching light guide, and changing the lamp lighting voltage when a change in the spectrum is confirmed. Even when a certain object is used, it can be seen that it can be measured even when the emission spectrum changes, within the judgment standard within ± 3% of the original sensitivity value (initial sensitivity value). Furthermore, it can be seen that even if the lamp usage time is 100 hours in this situation, it falls within the criterion of ± 3% compared to the original sensitivity value (initial sensitivity value). Further, the illuminance on the photosensitive member irradiation surface can be easily measured, and the operability is also good.

  It should be noted that the present invention is not limited to the matters shown in each embodiment, and within the scope of the technical idea of the present invention, each of the above embodiments is appropriately changed in addition to the suggestions in each of the above embodiments. Obviously you get.

It is a figure which shows schematic structure of the characteristic evaluation apparatus of the electrophotographic photoreceptor which concerns on Example 1 by this invention. It is a figure which shows schematic structure of the characteristic evaluation apparatus of the electrophotographic photoreceptor which concerns on Example 2 by this invention. It is a figure which shows the relationship between the optical power of an optical spectrum measured by the optical spectrum analyzer used in the Example by this invention, and a wavelength. 4 is a flowchart illustrating a method for controlling an exposure lamp used in an embodiment of the present invention. It is a figure which shows schematic structure of the characteristic evaluation apparatus of the electrophotographic photoreceptor which concerns on Example 3 by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 3 Surface electrometer probe 4 Surface electrometer 5 Signal processing circuit 6 Corona charger 8 Light source for static elimination 9 Signal processing circuit 10 Optical spectrum analyzer 11 Optical sensor 12 Lamp box 13 Exposure lamp 14 Mirror 15 Light guide 16 Aperture 17 Light guide 18 Branch light guide 19 Arithmetic unit

Claims (6)

In the electrophotographic photoconductor characteristic evaluation apparatus provided with a charging device, an exposure device, and a surface potential detection device around the photoconductor,
The exposure apparatus includes a measuring unit that measures the illuminance and the optical spectrum of the exposure light at a position outside the optical path of the exposure light applied to the irradiation surface of the photosensitive member. Evaluation device. The apparatus for evaluating characteristics of an electrophotographic photoreceptor according to claim 1,
The exposure apparatus includes determination means for determining whether or not a difference in optical power between a reference optical spectrum held in advance and an optical spectrum at the time of measurement is within a preset allowable range, and based on the determination, An apparatus for evaluating characteristics of an electrophotographic photosensitive member, characterized by controlling a lamp lighting voltage of an exposure apparatus. The apparatus for evaluating characteristics of an electrophotographic photoreceptor according to claim 1 or 2,
The exposure apparatus includes a reflection mirror for guiding the exposure light to the outside of the optical path, and measures the illuminance and optical spectrum of the exposure light reflected by the reflection mirror by the measuring means. Photographic photoconductor characteristic evaluation device. The apparatus for evaluating characteristics of an electrophotographic photoreceptor according to claim 1 or 2,
The exposure apparatus includes a half mirror for guiding the exposure light out of the optical path, and measures the illuminance and optical spectrum of the exposure light reflected by the half mirror by the measuring means. Photographic photoconductor characteristic evaluation device. 5. The apparatus for evaluating characteristics of an electrophotographic photoreceptor according to claim 1, wherein:
The exposure apparatus branches light from an exposure light source of the exposure apparatus by a light guide that can be branched into a plurality of light, one of the lights branched by the light guide is used as exposure light for photoconductor irradiation, and the other is measured. An apparatus for evaluating characteristics of an electrophotographic photoreceptor, characterized in that the measurement light is supplied to the means. In a method for evaluating the characteristics of an electrophotographic photoreceptor using an electrophotographic photoreceptor characteristics evaluation apparatus provided with a charging device, an exposure device, and a surface potential detection device around the photoreceptor,
It is determined whether or not a difference in optical power between a reference optical spectrum held in advance and an optical spectrum of the exposure light of the exposure apparatus at the time of measurement is within a preset allowable range, and the exposure apparatus is based on the determination A method for evaluating the characteristics of an electrophotographic photosensitive member, wherein the characteristic of the electrophotographic photosensitive member is evaluated by controlling a lamp lighting voltage.

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