JP5059329B2 - Photoconductor performance measuring apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a photoconductor performance measuring apparatus used in an image forming apparatus such as a digital copying machine, a laser printer, a laser plotter, a laser facsimile, or a composite machine of these, and further evaluated by the photoconductor performance measuring apparatus. The present invention relates to an image forming apparatus using a photoconductor.

An example of an image forming apparatus applied to a digital copying machine, a laser printer, a laser facsimile, etc. is shown in FIG.
The image forming apparatus shown in FIG. 9 has a photosensitive drum 111 formed in a cylindrical shape as an image carrier, and a charging means 112 (a contact type using a charging roller is shown in the periphery thereof). In addition, a charging brush, a non-contact type corona charger or the like can also be used), an optical scanning device 117, a developing device 113, a transfer unit 114 (a transfer roller is shown in the figure, but a corona charger or the like is used). The cleaning device 115 may be included. Reference numeral 116 denotes a fixing device.

In the photoconductive drum 111, a photoconductive photoconductive material that becomes a dielectric when exposed to light and a conductor when exposed to light is coated on the outer surface of a conductive cylinder such as a grounded metal.
The photosensitive drum 111 is rotated at a constant speed in the direction of the arrow in the figure, and the charging means 112 uniformly charges the surface of the photosensitive drum.
Next, light is applied to a part of the photosensitive drum 111 by the optical scanning device 117. The exposed portion of the photosensitive drum 111 becomes an electric conductor, and the electric charge on the surface of the photosensitive member is eliminated by escaping the electric charge on the surface of the photosensitive member through the conductive cylinder. In addition, the charge of the portion not exposed to light is held as it is. In this way, an electrostatic latent image is formed.

Next, the toner charged to the same polarity as that of the surface of the photoreceptor by the developing device adheres only to the portion where the charge on the surface of the photoreceptor disappears, and is visualized as a toner image.
The toner image on the photoconductor is transferred by a transfer unit 114 by electrostatic force and pressure onto a sheet-like recording medium S such as a transfer sheet or an OHP sheet fed from a sheet feeding unit (not shown), and heat and pressure are transferred by a fixing device 116. It is fixed by applying pressure.
The sheet-like recording medium S on which the toner image is fixed is discharged out of the apparatus, and the photoreceptor 111 after the toner image is transferred is cleaned by a cleaning device 115 to remove residual toner and paper dust.

  Here, depending on the method of manufacturing the photoconductor, if the above cycle is repeated many times, a portion where the electric charge escapes even in a place where no light is applied by the optical scanning device 117 during the transition from charging to development occurs. Sometimes. This is because the photoconductor is deteriorated or deteriorated while a high voltage is applied many times, and a constant path for electric charge is created. When such a portion is generated, the toner adheres to an unnecessary portion, and the output image becomes soiled and the image quality is remarkably deteriorated.

  Therefore, it is necessary to establish a method for manufacturing such a photoconductor that does not cause scumming. However, in the performance evaluation of a photoconductor so far, whether or not scumming occurs is determined after the image forming apparatus is actually assembled. Therefore, it was necessary to conduct a continuous image output experiment for a long time, which was very inefficient.

JP 2003-295696 A

The present applicant has previously proposed a method and an apparatus for measuring an electrostatic latent image as a technique that can be applied to the performance measurement of a photoreceptor (see Patent Document 1).
In this prior application technique, a charged particle beam is irradiated and a means for forming an electrostatic latent image is formed in the measuring apparatus, and the measurement can be performed within a short time after the latent image is formed. It is an object of the present invention to obtain an electrostatic latent image measuring method and apparatus that can be measured by the above method. In this method and apparatus for measuring an electrostatic latent image, a sample surface such as a photoconductor is scanned with a charged particle beam, and the electrostatic latent image on the sample surface is measured by a detection signal obtained by this scanning. More specifically, an electrostatic latent image (charge distribution) is generated on a sample by charging the sample in an apparatus that scans a charged particle beam and exposing the charged sample through an optical system. Let Then, the electrostatic latent image on the sample surface is measured while moving the sample having the charge distribution. The charging means is means for irradiating an electron beam, and means for detecting secondary electrons from the sample is provided.

  In the above-mentioned prior application technique, the surface of the sample, which has been extremely difficult in the past, has a means (for example, a charging means and an exposure means) for forming a charge distribution on the sample in an apparatus that scans a charged particle beam. Although the charge distribution can be measured, the surface charge distribution of the sample is measured after the latent image is formed by charging and exposure. Therefore, in addition to the charged particle beam irradiation means, the exposure means for latent image formation, etc. There is a problem of increasing the size of the measuring device and taking time for the measurement.

  The present invention has been made in view of the above circumstances, and it is possible to measure the performance of a photoconductor with a simpler configuration and in a short time by applying a technique for measuring performance by scanning the surface of the photoconductor with a charged particle beam. An object of the present invention is to provide a photoconductor performance measuring apparatus having a configuration that can be used. An object of the present invention is to provide an image forming apparatus capable of outputting a good image which is less likely to cause scumming by using a photoconductor whose performance is evaluated by a photoconductor performance measuring device.

As a means for achieving the above object, the invention according to claim 1 of the present invention includes a charged particle beam generating means for generating a charged particle beam, an electron lens for bending the charged particle beam, and the charging. An aperture member for restricting passage of the particle beam, beam deflecting means for deflecting the charged particle beam, secondary charged particle detecting means for detecting secondary charged particles generated when the charged particle beam hits a photoreceptor, In a photoconductor performance measuring apparatus having a light source, the apparatus has reference time generating means for managing timing of transmitting a control command, the charged particle beam generating means, the electron lens, the aperture member, and the beam at least controls the deflection means comprises a programming control means capable to store and execute program when performance measurement Serial least two electron lenses varying the refractive power, an electron lens for changing the the refractive power Yes to at least one disposed in each of said aperture member from the charged particle beam generating means side and the photosensitive member side, the performance measurement In the transition from the first stage to the second stage, the refractive power of the electron lens on the charged particle beam generating means side from the aperture member is adjusted to reduce the electron dose passing through the aperture member.

According to a second aspect of the present invention, in the photosensitive member performance measuring apparatus according to the first aspect, an irradiation range of the charged particle beam irradiated to the aperture member is increased .

According to a third aspect of the invention, the photoreceptor performance measuring device of the mounting according to claim 1 or 2 SL,
The electron lens that changes the refractive power at the time of the performance measurement changes the refractive power by the applied voltage generation means controlled by the programming control means .
According to a fourth aspect of the present invention, there is provided the photosensitive member performance measuring apparatus according to any one of the first to third aspects, wherein the intensity of the secondary electron detection signal from the secondary electron detection means is changed over time. An image conversion means for converting the distribution of the amount of secondary electron generation on the surface of the photosensitive member into an image replaced with a density is provided.
Further, the invention described in claim 5 is the photosensitive member performance measuring apparatus according to claim 3 or 4 , wherein the applied voltage generating means includes a low voltage variable voltage generating means and a voltage amplifying means. The voltage generating means and the voltage amplifying means are connected only by a signal line, separated into separate casings, and electrically separated.

According to the sixth aspect of the present invention, an electrostatic latent image is formed on the image carrier, and the electrostatic latent image is developed and visualized, and then the visible image on the image carrier is transferred to a recording medium. an image forming apparatus for forming an image by, as the image bearing member is evaluated Accordingly performance photoreceptor performance measuring device according to any one of claims 1 to 5, with the sorted photosensitive member It is characterized by that.

In the photoconductor performance measuring apparatus of the present invention, the surface of the photoconductor is uniformly charged by applying a uniformly strong charged particle beam to the photoconductor surface in the first stage of measurement, and the charged particle beam is weakened in the second stage. The secondary charged particles generated by the charged particle beam hitting the photosensitive member are detected by the secondary charged particle detecting means to obtain the distribution of the generation amount of secondary electrons. Therefore, it is possible to measure the performance of the photoreceptor in a short time with a simple configuration. Therefore, it is possible to easily evaluate and sort the performance of the photoreceptor.
Here, the performance is whether or not the charge is maintained without being exposed. If the charge is not maintained (poor performance), the image forming apparatus using this photoconductor is soiled and the image performance is significantly deteriorated.
In the present invention, an image forming apparatus that is capable of outputting a good image that is less likely to cause background contamination by configuring the image forming apparatus using the selected photoconductor, the performance of which is evaluated by the above-described photoconductor performance measuring apparatus. It can be realized.

The photoconductor performance measuring apparatus according to the present invention includes a charged particle beam generating unit that generates a charged particle beam, an electron lens that bends the charged particle beam, an aperture that restricts the passage of the charged particle beam, and the charged particle A beam deflecting means for deflecting the beam, a secondary charged particle detecting means for detecting secondary charged particles generated when the charged particle beam hits the photosensitive member, and a light source. The outline of measurement and evaluation by the photoconductor performance measuring apparatus of the present invention is as follows.
(1) The surface of the photoreceptor is uniformly charged by applying a uniformly charged particle beam uniformly over the entire measurement range of the photoreceptor. At this time, an acceleration test is performed by applying a load to the photoconductor.
(2) Scanning with the charged particle beam weakened to obtain the distribution of the amount of secondary electrons generated.
(3) The performance of the photoreceptor is evaluated from the area ratio of the portion where the charge is lost with respect to the area of the entire measurement range.
(4) A photoconductor with good performance is selected from the evaluation result and incorporated in the image forming unit of the image forming apparatus.

  In the photoreceptor performance measuring apparatus of the present invention, at least two of the electron lenses change the refractive power during the performance measurement, and at least one of the two electron lenses is disposed closer to the charged particle beam generating means side than the aperture ( Alternatively, at least two of the electron lenses change the refractive power during the performance measurement, and the electron lenses are arranged on the charged particle beam generation means side and the photosensitive body side from the aperture), respectively, and the function of the beam deflection means during the performance measurement By switching between the state and the stopped state, it is possible to switch between applying the charged particle beam strongly and uniformly to the entire measurement range and scanning with weakening. Further, an applied voltage generating means is used to change the refractive power of the electron lens.

Furthermore, the photoconductor performance measuring apparatus of the present invention has a programming control device capable of storing and executing a program. By having this programming control device, a series of measurement operations can be automated, and the measurement efficiency can be improved.
In addition, the process of escaping the charge and charge is a transient phenomenon in which the state changes from moment to moment, and time management is important in order to align the conditions when performing comparative measurements.Therefore, there is a reference time generation means. Must be.

  Next, in the photoconductor performance measuring apparatus of the present invention, in order to obtain the distribution of the generation amount of secondary electrons, the secondary on the photoconductor surface is detected from the time change of the intensity of the secondary electron detection signal from the secondary electron detection means. By having an image conversion means that converts the distribution of the amount of electron generation into an image replaced with a density, various existing image processing tools can be used, and the area where the charge is lost with respect to the area of the entire measurement range can be used. The area ratio can also be easily calculated.

  Further, the photoreceptor performance measuring apparatus of the present invention has an applied voltage generating means for changing the refractive power of the electron lens, and this applied voltage generating means comprises a low voltage variable voltage generating means and a voltage amplifying means, The low voltage variable voltage generating means performs voltage variable at a low voltage, the voltage amplifying means amplifies, and the high voltage voltage is varied. Here, it is desirable that the variable voltage generating means and the voltage amplifying means are electrically separated except for the signal line. Electrical separation is a state in which a change in magnetic field generated when a high-voltage current suddenly changes or a radio wave is transmitted to the other side and no induced current is generated. Concretely, they are spatially separated, each means is independently covered with a casing having electrical conductivity, and grounding is performed through separate paths. As a result, it is possible to prevent noise generated by the voltage amplifying means that handles a high voltage from destroying the variable voltage generating means.

In the present invention, an image forming apparatus that is capable of outputting a good image that is less likely to cause background smearing is configured by using the selected photoconductor to evaluate the performance by the above-described photoconductor performance measuring apparatus. It can be realized.
In addition, when the image forming apparatus is discarded, by determining the degree of deterioration of the photoconductor with the photoconductor performance measuring apparatus of the present invention, it is possible to recycle those with a low degree of deterioration and to effectively use resources. Become.

  Hereinafter, specific configurations, operations, and actions of the present invention will be described in detail based on illustrated embodiments.

[Example 1]
FIG. 1 shows a first embodiment of the present invention. The photoconductor 18 whose performance is to be evaluated is arranged in a state where the surface opposite to the electron irradiation side is grounded. Here, the inside of the cylindrical photosensitive member 18 is grounded. In the illustrated example, the entire photoconductor is shown as it is in a vacuum chamber (hereinafter referred to as a chamber) 25 of the measuring apparatus. However, the photoconductor is partially cut out and prepared for testing. It may be a flat plate sample.

On the other hand, a charged particle beam irradiation unit 15 is installed in the chamber 25. At the time of measurement, the inside of the chamber is evacuated to a vacuum state by a vacuum evacuation device (not shown). Note that a trace amount of inert gas or the like can be introduced after evacuation.
The charged particle beam irradiation unit 15 includes a charged particle beam generating means 10, a plurality of electron lenses 11, 13, 14, an aperture 12, and the like. A charged particle beam (in this case, an electron beam is used for measurement). Any particle beam having a charge such as ions may be generated by the charged particle beam generation means 10. Although details of the charged particle beam generating means 10 are not shown, the charged particle beam generating means 10 includes a filament for generating electrons, an electrode for extracting the electrons, an electrode for accelerating, a mechanism for starting and stopping beam irradiation, and the like.

  The electron beam generated by the charged particle beam generator 10 is converged by an electron lens (here, a condenser lens) 11. The condenser lens 11 is composed of a coil or an electrode, and in any case, the degree of convergence of the electron beam can be changed by the applied voltage. The electron beam converged by the condenser lens 11 is limited in passage by the aperture 12, and only the electron beam passing through the opening of the aperture 12 is directed to the photosensitive member 18.

The electron beam that has passed through the opening of the aperture 12 is deflected by an electron lens (hereinafter referred to as a scanning lens) 13 as beam deflecting means. The scanning lens 13 is composed of a plurality of coils or electrodes, and an electron beam is deflected by giving a constant voltage change pattern, so that the photosensitive member can be scanned two-dimensionally.
Further, an electron lens (hereinafter referred to as an objective lens) 14 is also provided after the scanning lens 13, and the electron beam is converged again by the objective lens 14. The structure of the objective lens 14 is basically the same as that of the condenser lens 11.

When the electron beam converged by the objective lens 14 strikes the photoconductor 18, the electrons stay on the photoconductor 18, the surface of the photoconductor is charged, and some electrons jump out of the photoconductor 18 as secondary electrons. The secondary electrons are captured by the secondary charged particle detector 16 and become a detection current proportional to the amount of secondary electrons captured.
An example of the structure of the secondary charged particle detection means 16 is a combination of a scintillator (phosphor) and a photomultiplier tube, and secondary electrons are attracted to the scintillator by an electric field of a drawing voltage applied to the surface of the scintillator. Captured and converted into scintillation light. This light is amplified by a photomultiplier through a light pipe and becomes a secondary electron detection signal.

Here, FIG. 2 is a diagram showing the potential distribution in the space between the secondary charged particle detecting means 16 and the photoconductor 18 by contour lines.
In the negatively charged portions (Q1, Q2) of the photoconductor 18, secondary electrons (e11, e12) that have jumped out of the photoconductor 18 follow the solid line potential contours, and as indicated by arrows G1, G2, 2 It reaches the scintillator 24 of the next charged particle detection means.
On the other hand, in the portion (Q3) where the negative charge amount is small, the potential close to Q3 is higher as indicated by the broken potential contour line, and the secondary electrons (e13) jumping out from the photoreceptor 18 are indicated by the arrow G3. Then, it returns to the photoconductor 18 and does not reach the secondary charged particle detection means. Therefore, the charged state of the photoreceptor surface can be measured by scanning the electron beam and measuring the intensity change of the secondary electron detection signal.

  The secondary electron detection signal from the secondary charged particle detection means 16 is converted by the image conversion means 20 into image data in which the distribution of secondary electron generation amount is replaced with concentration. This image data is recorded in the memory as a still image or a moving image file by the programming control device 22. A light source (for example, a lamp, an LED, etc.) 17 is used to irradiate the photoreceptor 18 with light (to eliminate the charge).

  The charged particle beam generating means 10 and the electronic lens (condenser lens 11, scanning lens 13, objective lens 14) constituting the electron beam irradiation unit 15 of the photosensitive member performance measuring apparatus are capable of storing and executing programming. The control is performed by 22. By configuring the control device 22 to be able to store and execute programming, optimum measurement conditions for various photosensitive members 18 having different sensitivities to charging potential and light are determined and stored in a memory. By calling and using it when necessary, it is possible to perform measurement on various photoconductors under optimum measurement conditions.

Next, a specific measurement procedure using the photoconductor performance measuring apparatus of the present invention will be described.
As a preparation stage, the light source 17 is turned on for a certain period of time in order to eliminate the charge on the surface of the photoconductor 18 and to make the initial state uniform.
As a first stage, the charged particle beam irradiation unit 15 irradiates the photoconductor 18 with a large amount of electron beams to charge the photoconductor 18.
Further, by irradiating a large amount of electron beams for a long time, an effect of accelerating the deterioration of the photoreceptor 18 can be given.
Since the irradiation time determines the amount of damage to the photoconductor 18, it is important to strictly control the irradiation time in order to perform comparative measurement with a plurality of photoconductors.

  In this first stage, as shown in FIG. 1, the electron beam is converged so that the condenser lens 11 is focused in the vicinity of the aperture 12, so that most of the electron beam generated by the charged particle beam generating means 10 is a photosensitive member. 18 is reached. Further, the electron beam is converged by the objective lens 13 so as to focus on the vicinity of the photoconductor, and the surface of the photoconductor is scanned two-dimensionally by the scanning lens 13 to create a uniform charged state.

  Next, as a second stage, the amount of secondary electrons reaching the secondary charged particle detecting means 16 by scanning the electron beam while reducing the amount of electrons irradiated to the photosensitive member to 1/10 to several thousandths. And the performance of the photoreceptor 18 is measured. The portion where the negative charge amount is small is where the charge has escaped, and a photoconductor with a large area in this area is a bad photoconductor that is prone to soiling.

  As a method for reducing the amount of the electron beam applied to the photosensitive member 18 in the second stage, an electron lens on the charged particle beam generating means 10 side from the aperture 12 is used when the measurement is shifted from the first stage to the second stage. This is possible by adjusting the refractive power of a certain condenser lens 11. More specifically, the aperture is reduced by decreasing the refractive power of the condenser lens 11 as shown in FIG. 3A or by increasing the refractive power of the condenser lens 11 as shown in FIG. This is possible by varying the amount of electrons passing through 12.

FIGS. 4A and 4B are time charts of the applied voltage to the light source and the electron lens, and the current reached by the photoreceptor corresponding to FIGS. 3A and 3B, respectively.
As a means for changing the electron irradiation amount, a method of changing the aperture diameter of the aperture 12 is also conceivable. However, for this purpose, a mechanical mechanism is necessary, and the switching time takes several tens of milliseconds. This is not desirable because it is too late to observe a system whose state changes in units of several microseconds.
In addition, even though the amount is small during the measurement, since the electron hits the photoconductor, the deterioration of the photoconductor progresses and the state changes depending on the time. Therefore, the measurement must be performed with time management again.

In this way, time management is important for the measurement by this apparatus. Therefore, it is desirable that the program control device 22 that sends a command to each part of the device is connected to the reference time generating means 23 in order to manage the timing of sending the command.
The reference time generating means 23 includes a portion that generates an electric signal at a constant time interval, such as a crystal oscillator, and a portion that counts the electric signal and generates a new electric signal at a specified count number.

  As a means for controlling the charged particle beam generating means 10 and the electron lens (condenser lens 11, scanning lens 13, objective lens 14), first, a low voltage that generates a voltage of several volts according to a command from the program control device 22 is used. Variable voltage generating means 21 and voltage amplifying means 19 for amplifying the voltage to several hundred volts, and the low voltage variable voltage generating means 21 and the voltage amplifying means 19 are separated into separate casings. desirable. This is because the voltage amplifying means 19 handles high voltage, so that strong noise is likely to occur, and this noise does not destroy the low voltage variable voltage generating means 21 and the weak electric elements of the program control device 22. Because.

[Example 2]
Next, a second embodiment of the present invention will be described. The difference from the first embodiment is that, as shown in FIG. 5, the method of charging the photosensitive member 18 is different in the first stage at the time of measurement, and other configurations and operations are the same as those of the first embodiment. It is the same.
In this embodiment, as shown in FIG. 5, the electron beam is converged so that the condenser lens 11 is focused on the vicinity of the aperture 12, so that most of the electrons generated by the charged particle beam generating means 10 are applied to the photoreceptor 18. Furthermore, the refractive power of the objective lens 14 is weakened so that a wide range of the photoconductor 18 is irradiated with an electron beam. Here, the function of the scanning lens 13 which is a beam deflecting unit is stopped.
FIGS. 6A and 6B show two examples of time charts of the voltage applied to the light source 17 and the electron lens (the condenser lens 11 and the objective lens 14) and the photoreceptor arrival current.

As shown in FIG. 7, the refractive power of the objective lens 14 may be adjusted to converge the electron beam so as to focus on the charged particle beam generating means 10 side from the photosensitive member 18, and the same effect as described above can be obtained. You can get it.
FIGS. 8A and 8B show two examples of time charts of the voltage applied to the light source 17 and the electron lens (condenser lens 11 and objective lens 14) and the current reached by the photosensitive member in this case.

  Now, by measuring the performance of the photoconductor using the photoconductor performance measuring apparatus having the configuration and operation shown in the first embodiment or the second embodiment and evaluating the performance, a photoconductor with good performance can be selected and selected. By configuring the image forming apparatus as shown in FIG. 9 using the photosensitive member, it is possible to realize an image forming apparatus that can output a good image that is less likely to cause background contamination.

1 is a schematic configuration diagram of a photoreceptor performance measuring apparatus showing a first embodiment of the present invention. It is the figure which showed the electric potential distribution in the space between a secondary charged particle detection means and a photoconductor with the contour line. FIG. 6 is an explanatory diagram when adjusting the refractive power of the condenser lens on the charged particle beam generating means side from the aperture to adjust the amount of electrons on the surface of the photosensitive member during the transition from the first stage to the second stage of measurement. It is a figure which shows the time chart of the applied voltage to a light source and an electronic lens, and the photoreceptor arrival current corresponding to (a) and (b) of FIG. 3, respectively. It is a schematic block diagram of the photoreceptor performance measuring apparatus which shows the 2nd Example of this invention. FIG. 6 is a diagram illustrating two examples of time charts of the voltage applied to the light source and the electron lens (condenser lens and objective lens) and the photoreceptor arrival current in the configuration shown in FIG. 5. It is a schematic principal part block diagram of the photoreceptor performance measuring apparatus which shows another example of a 2nd Example. FIG. 8 is a diagram illustrating two examples of time charts of a voltage applied to a light source and an electronic lens (condenser lens and objective lens) and a photoreceptor arrival current in the configuration illustrated in FIG. 7. 1 is a diagram illustrating an example of an image forming apparatus according to the present invention.

Explanation of symbols

10: Charged particle beam generating means 11: Condenser lens (electron lens)
12: Aperture 13: Scanning lens (beam deflection means)
14: Objective lens (electronic lens)
15: Charged particle beam irradiation unit 16: Secondary charged particle detecting means 17: Light source 18: Photoconductor 19: Voltage amplifying means 20: Image converting means 21: Low voltage variable voltage generating means 22: Program control device 23: Reference time Generation means 25: chamber 111: photosensitive drum 112: charging means 113: developing device 114: transfer means 115: cleaning device 116: fixing device

Claims (6)

Charged particle beam generating means for generating a charged particle beam; an electron lens for bending the charged particle beam; an aperture member for restricting passage of the charged particle beam; beam deflecting means for deflecting the charged particle beam; A reference time for managing the timing of transmitting a control command in a photoconductor performance measuring apparatus having a secondary charged particle detecting means for detecting secondary charged particles generated when a charged particle beam hits the photoconductor and a light source A measuring means for generating a charged particle beam; the electron lens; the aperture member; and the beam deflecting means, and a programming control means capable of storing and executing a program. Sometimes at least two of the electron lenses change their refracting power, which changes the refracting power. Figure Yes to at least one disposed in each of said aperture member from the charged particle beam generating means side and the photosensitive side, the aperture member from the charged particle beam generating means side from the first stage during the transition to the second stage of the performance measurement An apparatus for measuring the performance of a photoreceptor, wherein a refractive power of an electron lens is adjusted to reduce an electron dose passing through the aperture member. In the photoconductor performance measuring device according to claim 1,
An apparatus for measuring the performance of a photosensitive member, wherein an irradiation range of a charged particle beam applied to the aperture member is increased. In the photoconductor performance measuring device according to claim 1 or 2,
The photoconductor performance measuring apparatus, wherein the refractive power of the electron lens that changes the refractive power at the time of the performance measurement is changed by the applied voltage generating means controlled by the programming control means . In the photoconductor performance measuring device according to any one of claims 1 to 3,
An image conversion means for converting a distribution of the amount of secondary electrons generated on the surface of the photosensitive member into an image in which the distribution of the amount of secondary electrons generated on the surface of the photoreceptor is replaced with a density from a change in intensity of a secondary electron detection signal from the secondary electron detection means. Photoconductor performance measuring device. In the photoconductor performance measuring device according to claim 3 or 4 ,
The applied voltage generating means includes a low voltage variable voltage generating means and a voltage amplifying means, and the variable voltage generating means and the voltage amplifying means are connected only by a signal line, separated into separate casings, The photoconductor performance measuring device is characterized by being separated from each other . An image forming apparatus that forms an electrostatic latent image on an image carrier, develops the electrostatic latent image into a visible image, and then transfers the visible image on the image carrier to a recording medium to form an image. In
  6. An image forming apparatus comprising: a photoconductor selected and evaluated by the photoconductor performance measuring apparatus according to claim 1 as the image carrier.

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