JP2008275608A - Device and method for measuring electrostatic latent image - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device for forming an electrostatic latent image and a method for measuring the electrostatic latent image capable of measuring the electrostatic latent image within a very short time after the image is formed and measuring the image without destructing it by using a means for irradiating charged particle beams and forming the electrostatic latent image in a measuring device. <P>SOLUTION: This invention scans the surface of a sample with a charged particle beam and measures the electrostatic latent image of the sample surface by a detection signal obtained by this scanning. A charge distribution is formed on the sample 30 within a scanning apparatus by charging the sample 30 and exposing the charged sample by means of an optical system. It is possible to measure the electrostatic latent image on the sample surface while moving the charge-distributed sample. The charging means is a means 10 to irradiate electron beams. A means 18 is provided to detect secondary electrons from the sample. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method and apparatus for forming an electrostatic latent image, a method and apparatus for measuring an electrostatic latent image, and is applicable to measurement of surface potential distribution and surface charge distribution of a sample.

In order to obtain an output image in an electrophotographic image forming apparatus such as a copying machine or a laser printer, the following processes are usually performed. An example of an electrophotographic apparatus that obtains an output image by executing each process is shown in FIG. Hereinafter, a description will be given with reference to FIG.
1. Charging: The electrophotographic photosensitive member is uniformly charged.
2. Exposure: The photosensitive member is irradiated with light, and charges are partially released corresponding to the image to form an electrostatic latent image.
3. Development: A visible image is formed on the electrostatic latent image with charged fine particles (hereinafter referred to as “toner”).
4). Transfer: Move the developed and visualized toner image to paper or other transfer material.
5. Fixing: The toner forming the transfer image is fused to fix the image on the transfer material.
6). Cleaning: Cleans residual toner on the photoreceptor.
7). Static elimination: Eliminates residual charge on the photoreceptor.

The process factor and process quality in each of the above steps greatly affect the final output image quality. For this reason, in order to obtain a higher quality image, it is necessary to improve the process quality of each process. In particular, evaluating the quality of the electrostatic latent image after exposure is necessary for obtaining a high quality image. Very important.
In particular, the design of the writing optical system used in the exposure process is optimized as the beam spot diameter on the surface of the photoreceptor. However, in spite of the fact that it should be designed so that an optimum electrostatic latent image on the photoreceptor that directly affects the behavior of the toner particles should be formed, such a design is performed. I don't mean. In addition, a clear mechanism for converting exposure energy into an electrostatic latent image has not been established. Therefore, if information obtained from the electrostatic latent image can be taken into the optical system design, higher image quality can be obtained, and it can be expected to design the image forming apparatus at a low cost.

However, it is extremely difficult to measure an electrostatic latent image, and the actual situation is that it cannot be measured at all in actual use.
A well-known method for measuring an electrostatic latent image is to bring a sensor head such as a cantilever close to a sample having a potential distribution, and at that time, electrostatic attraction generated as an interaction between the electrostatic latent image and the cantilever. Or an induced current is measured and converted into a potential distribution. The electrostatic attraction type is commercially available as SPM (scanning probe microscope), and the induced current type is described in Patent Literature 1, Patent Literature 2, and the like.

However, in order to use these methods, it is necessary to bring the sensor head close to the sample. For example, in order to obtain a spatial resolution of 10 μm, the distance between the sensor and the sample needs to be 10 μm or less. Under these conditions,
・ Absolute distance measurement is required.
• Measurement takes time, and the state of the latent image changes during that time.
・ Discharge and adsorption occur.
・ The sensor itself disturbs the electric field.
Even if it can be used for other purposes, an electrostatic latent image cannot be measured in actual use.

  Therefore, as a realistic measurement method, for visualization of the electrostatic latent image, a charge is applied to the toner, which is a colored fine powder, and development is performed by the Coulomb force acting between the toner having this charge and the electrostatic latent image. In general, a method of transferring the toner image onto paper or tape is generally used. However, in this case, the electrostatic latent image itself is not measured because the development and transfer processes are performed.

  On the other hand, a method for measuring a potential pattern using an electron beam is known. This has already been put to practical use for LSI failure analysis. This measurement method is a case where the sample is a conductor, and a measurement object is completely different from a dielectric material such as a photoconductor intended by the present invention, and cannot be applied to measurement of a dielectric material such as a photoconductor. . If the object to be measured is a conductor, the potential distribution can be maintained for a long time by passing a constant current through the conductor, and the potential amount is a narrow range of 0 to 5 V at most, so that no charge-up phenomenon occurs. The potential state does not change by irradiation with the electron beam.

As a method for observing an electrostatic latent image with an electron beam, there is one described in Patent Document 3, but the sample is limited to an LSI chip or a sample that can store and hold an electrostatic latent image. That is, a normal photoconductor that causes dark decay cannot be measured.
Since a normal dielectric can hold a charge semipermanently, even if measurement is performed over time after forming a charge distribution, the measurement result is not affected. However, in the case of a photoconductor, since the resistance value is not infinite, the charge cannot be held for a long time, dark decay occurs, and the surface potential decreases with time. The time that the photoconductor can hold the charge is at most several tens of seconds even in the dark room. Therefore, even if an attempt is made to observe in an electron microscope (SEM) after charging and exposure, the electrostatic latent image disappears at the preparation stage.

Japanese Patent No. 3009179 Japanese Patent Application No. 11-184188 Japanese Patent Application No. 03-49143

  By the way, a photoconductor sample used in an electrophotographic process has a generally cylindrical shape, and it is desired to measure the electrostatic latent image distribution generated on the cylindrical photoconductor in a non-destructive manner with high resolution. Even if the charge distribution forming means is the same, the electrostatic latent image changes due to the deterioration of the photoreceptor over time. For this reason, it is desired to evaluate the variation of the electrostatic latent image over time.

The present invention has been made to solve the above-described problems of the prior art, and has a means for forming an electrostatic latent image in an apparatus for performing measurement by irradiating a charged particle beam and forming a latent image. It is an object of the present invention to provide an electrostatic latent image forming method and apparatus, an electrostatic latent image measuring method and a measuring apparatus capable of performing measurement within a short time later.
Another object of the present invention is to provide a method and an apparatus for measuring an electrostatic latent image that can be measured nondestructively.

The invention according to claim 1 relates to a method of forming an electrostatic latent image, and in a device that scans a charged particle beam, the surface of the sample is scanned with the charged particle beam, a charge distribution is generated on the sample, and the electrostatic latent image is generated. An image is formed.
The invention according to claim 2 relates to an electrostatic latent image forming apparatus, wherein the surface of the sample is scanned with the charged particle beam in the apparatus that scans the charged particle beam, and a charge distribution is generated on the sample to generate an electrostatic latent image. An apparatus for forming an image is provided.

The invention according to claim 3 is a method of scanning a sample surface with a charged particle beam and measuring the sample surface by a detection signal obtained by the scanning, and charging the sample surface in an apparatus for scanning the charged particle beam. Scanning with a particle beam generates a charge distribution on the sample.
The invention described in claim 4 is a method of scanning a sample surface with a charged particle beam and measuring the sample surface with a detection signal obtained by the scanning, charging the sample, and exposing the sample surface with an exposure optical system. And a charge distribution is generated.

According to a fifth aspect of the present invention, there is provided an apparatus for scanning a sample surface with a charged particle beam and measuring the sample surface based on a detection signal obtained by the scanning, a means for charging the sample, and an optical for exposing the sample. And means for generating a charge distribution by the system means.
The invention described in claim 6 is characterized in that, in the invention described in claim 5, the means for charging the sample comprises means for irradiating the sample with an electron beam.
According to a seventh aspect of the invention, in the sixth aspect of the invention, the means for charging the sample is irradiated with an electron beam at an acceleration voltage larger than the acceleration voltage at which the secondary electron emission ratio of the sample is 1. It is characterized in that the sample is charged.

  According to an eighth aspect of the present invention, in the fifth, sixth or seventh aspect, a known reference potential is arranged in the scanning region of the charged particle beam, and the secondary electron signal intensity of the reference potential and the measurement sample are measured. Means is provided for calculating a potential amount by comparing the signal intensities.

According to a ninth aspect of the present invention, in the method of scanning the sample surface with a charged particle beam and measuring the electrostatic latent image on the sample surface based on the detection signal obtained by this scanning, the electrostatic latent image on the sample surface is moved while moving the sample. It is characterized by measuring an image.
According to a tenth aspect of the present invention, in a method of scanning a sample surface with a charged particle beam and measuring an electrostatic latent image on the sample surface based on a detection signal obtained by the scanning, the sample surface is moved while moving a sample having a charge distribution. The electrostatic latent image is measured.

  According to the eleventh aspect of the present invention, in a device that scans a sample surface with a charged particle beam and measures an electrostatic latent image on the sample surface based on a detection signal obtained by this scanning, while moving a sample having a charge distribution, It has a means for measuring the electrostatic latent image on the sample surface.

According to a twelfth aspect of the present invention, in a device that scans a sample surface with a charged particle beam and measures an electrostatic latent image on the sample surface based on a detection signal obtained by the scanning, a static image forming an electrostatic latent image on the sample is measured. Electrostatic latent image forming means, and measuring means for measuring by moving a sample having a charge distribution to a charged particle beam irradiation position.
A thirteenth aspect of the invention is characterized in that, in the second aspect of the invention, an exposure means is provided as the electrostatic latent image forming means.
The invention described in claim 14 is characterized in that, in the invention described in claim 13, the sample and the exposure means are arranged in the same chamber.

  According to the first and second aspects of the present invention, it is possible to form an electrostatic latent image by forming a charge distribution on a sample in an apparatus that scans a charged particle beam.

  According to the third aspect of the present invention, the surface charge distribution of the sample, which has been extremely difficult in the past, is measured by having means for forming a charge distribution on the sample in the apparatus for scanning the charged particle beam. It becomes possible.

  According to the fourth and fifth aspects of the present invention, since the charging means and the exposure means necessary for forming the electrostatic latent image are provided in the same apparatus as the measuring means, real-time measurement can be performed, and the surface charge with time. It is possible to measure the electrostatic latent image of the photoreceptor whose amount is attenuated with high resolution on the order of microns.

According to the invention described in claim 6, in the invention described in claim 5, since charging is performed by irradiating an electron beam used for measurement, it is not necessary to use another means for charging.
According to the invention described in claim 7, in the invention described in claim 6, the sample can be negatively charged.
According to the invention described in claim 8, in the inventions described in claims 5, 6 and 7, it is possible to quantitatively measure the surface potential distribution of the sample.

According to the ninth, tenth and eleventh aspects of the present invention, by providing means for forming a charge distribution on the sample in the apparatus for scanning the charged particle beam, the surface of the sample, which has been extremely difficult in the past, It becomes possible to measure the charge distribution with high accuracy.
Further, by measuring the electrostatic latent image on the sample surface while moving the sample, it is possible to measure in a wider range than the region irradiated with the charged particle beam.

According to the twelfth aspect of the invention, by providing the means for forming the charge distribution on the sample in the apparatus for scanning the charged particle beam, the surface charge distribution of the sample, which has been extremely difficult in the past, is increased. It becomes possible to measure with high accuracy.
Further, since the electrostatic latent image formation position and the measurement position can be arranged at a distance, there is an advantage that the degree of freedom in layout is increased.
According to the thirteenth aspect of the present invention, an electrostatic latent image can be formed by an exposure means that is often used conventionally.

According to the fourteenth aspect of the present invention, the charging means and the exposure means necessary for forming the electrostatic latent image are arranged in the same apparatus as the measuring means, so that real-time measurement is possible, and the surface charge amount with time. It is possible to measure the electrostatic latent image of the photoconductor on which the dampens with high resolution on the order of microns.
In addition, since the photoconductor sample and the exposure optical system are arranged in the same chamber, it is possible to measure an electrostatic latent image in a state close to a real machine. In addition, the device configuration becomes easy.

Hereinafter, embodiments of a method and an apparatus for measuring an electrostatic latent image according to the present invention will be described with reference to the drawings.
FIG. 1 shows an embodiment of an electrostatic latent image measuring apparatus according to the present invention. The electrostatic latent image measuring apparatus includes a charged particle irradiation unit 10 that irradiates a charged particle beam, an exposure unit 20, a sample setting unit 16, and a secondary electron detection unit 18. These are all placed in the same chamber, and the inside of the chamber is evacuated.
Here, the charged particles refer to particles that are affected by an electric field or a magnetic field, such as an electron beam or an ion beam.

Hereinafter, the charged particle irradiation unit will be described as an embodiment including an electron beam irradiation unit.
The electron beam irradiation unit 10 includes an electron gun 11 for generating an electron beam, a condenser lens 12 for focusing the electron beam emitted from the electron gun 11, and a beam blanker 13 for turning on / off the electron beam. The scanning lens 14 for scanning the electron beam that has passed through the beam blanker 13 and the objective lens 15 for condensing the electron beam that has passed through the scanning lens 14 are provided. The scanning lens 14 is a so-called deflection coil. A driving power source (not shown) is connected to each of the other lenses.
In the case of an ion beam, a liquid metal ion gun or the like is used instead of an electron gun.
The secondary electron detector 18 uses a scintillator, a photomultiplier tube, or the like.

  The exposure unit 20 includes a light source 21 of a wavelength having sensitivity with respect to a photoconductor configured as described below, a collimate lens 22, an aperture 23, an imaging lens 25, and the like, and is placed on the sample setting unit 16. A desired beam diameter and beam profile can be generated on the sample 30. As the light source 21, an LD (laser diode) or the like can be used. Further, the light source 21 is controlled by LD control means or the like so that an appropriate exposure time and exposure energy can be irradiated. In order to form a line pattern composed of an electrostatic latent image on the sample 30, a scanning mechanism using a galvano mirror or a polygon mirror may be attached to the optical system of the exposure unit 20.

  As shown in FIG. 4, the structure of the photoconductor constituting the actual state of the sample 30 is formed by forming a charge generation layer (CGL) and a charge transport layer (CTL) on a conductive support. When the surface is exposed in a charged state, light is absorbed by the charge generation material (CGM) of the charge generation layer CGL, and positive and negative charge carriers are generated. One of the carriers is injected into the charge transport layer CTL and the other into the conductive support by an electric field. The carriers injected into the charge transport layer CTL move in the charge transport layer CTL to the surface of the charge transport layer CTL by an electric field, and are combined with charges on the surface of the photoreceptor to disappear. Thereby, a charge distribution is formed on the surface of the photoreceptor. That is, an electrostatic latent image is formed.

Next, an electrostatic latent image forming method and an electrostatic latent image measuring method will be described together with the operation of the embodiment shown in FIG.
First, the charged particle beam irradiation unit 10 irradiates the photoconductor sample 30 with an electron beam. The relationship between the acceleration voltage and the secondary electron emission ratio δ at this time is shown in FIG. The acceleration voltage E1 is set to an acceleration voltage higher than the acceleration voltage E0 at which the secondary electron emission ratio δ is 1, so that the amount of incident electrons exceeds the amount of emitted electrons, so that electrons are accumulated in the sample 30, Causes a charge-up. As a result, the sample 30 can be negatively charged uniformly. A desired charging potential can be formed by appropriately setting the acceleration voltage and the irradiation time.
Once the charged potential is formed, the electron beam is once turned off.

Next, the photosensitive member sample 30 is exposed via the optical system of the exposure unit 20. The optical system is adjusted to form a desired beam diameter and beam profile. By performing exposure, an electrostatic latent image can be formed on the photoreceptor sample 30.
After forming the electrostatic latent image, the mode is changed to the observation mode. In the observation mode, the photoconductor sample 30 is scanned with an electron beam, and the emitted secondary electrons are detected by the secondary electron detector 18 including a scintillator, a photomultiplier tube, etc., and converted into an electrical signal. Observe the potential contrast image.

In order to convert a potential contrast image into a potential, a conversion table representing the correlation between the potential and the signal intensity may be prepared in advance, and the potential may be calculated from the signal intensity based on the conversion table.
Further, a method of calculating a potential distribution by arranging a known reference potential in the electron beam scan region and comparing the secondary electron signal intensity with the reference potential may be used.
As a method of arranging the reference potential, as shown in FIG. 5, there is a method of arranging a plurality of conductive substrates 34 on an insulator 33 and setting a reference potential to each of the conductive substrates 34. Specifically, the voltage of the reference voltage source is divided by a resistor, and a reference potential is applied to each conductive substrate 34. In general, a portion having a lower potential than a portion having a high potential becomes brighter because the amount of secondary electrons emitted increases. In FIG. 5, a portion having a relatively low potential is displayed in white, and a portion having a high potential is displayed in black. In FIG. 5, reference numeral 30 denotes a sample, 31 denotes an electrostatic latent image, and 32 denotes an electron beam scan area. Secondary electrons are detected by the detector 18 while scanning the surface of the sample 30 with an electron beam. The state of change in the detection signal intensity at that time is shown in the lower part of FIG.

The signal intensity on the detector 18 may be corrected when it changes depending on the setting conditions. Further, calibration may be performed in advance.
After the measurement is completed, the residual charge of the sample 30 can be removed by irradiating the entire surface of the sample 30 with light using the light source 17 shown in FIG.

  FIG. 6 shows an example of the control unit of the above embodiment. In FIG. 6, an LD control unit 36 that controls the light source 21, a charged particle control unit 37 that controls the scanning lens 14, an LED control unit 38 that controls the light source 17 for residual charge removal, and a sample that controls the movement of the sample stage 16. A table control unit 39 is provided, and the LD control unit 36, charged particle control unit 37, LED control unit 38, and sample table control unit 39 are controlled by the host computer 35. Further, the output of the detector 18 is detected by the secondary electron detector 41, and this detection signal is processed by the signal processing unit 42 so that the measurement result output unit 43 outputs the secondary electron measurement result. Yes.

The secondary electron emission ratio δ is
Secondary electron emission ratio δ = emitted electron / incident electron, but more strictly speaking, it is necessary to consider transmission electron and reflection electron,
Emission electron = transmission electron + reflection electron + secondary electron is preferable.

  When positive charging is desired, irradiation with an accelerating voltage with a secondary electron emission ratio of 1 or more as shown in FIG. In general sample observation by SEM, in order to avoid the influence of charge-up, observation is generally performed under the condition of δ = 1, and it is known that no other acceleration voltage is used. One of the features of this embodiment is that the charged potential is formed by intentionally charging up.

In the above method, after the charged potential is formed, the electron beam is once turned off, but without turning it off, the acceleration voltage is converted to an acceleration voltage at which δ = 1, and the observation condition is such that no charge-up occurs. A method of exposing in a state may be used.
As a charging method, another means such as contact charging may be used.

Next, another embodiment of the present invention will be described. In this embodiment, the electrostatic latent image distribution can be measured within a short time after the electrostatic latent image is formed on the photoconductor, and the photoconductor sample is non-destructive and close to the actual machine. It is possible to measure.
In addition, the same code | symbol is attached | subjected to the same component as the above-mentioned embodiment.

  In FIG. 7, an electron beam irradiation unit 10, a sample 30 made of a cylindrical photoconductor, an electrostatic latent image forming unit for forming a charge distribution on the surface of the sample 30, and secondary electrons are contained in one housing. A detector 18 is arranged. The electron beam irradiation unit 10 includes an electron gun 11 for generating an electron beam, a condenser lens 12 for focusing the electron beam emitted from the electron gun 11, and a beam blanker 13 for turning the electron beam on / off. And a scanning lens (deflection coil) 14 for scanning the electron beam that has passed through the beam blanker 13 and an objective lens 15 for refocusing the electron beam that has passed through the scanning lens 14. A driving power source (not shown) is connected to each lens. The detector 18 is a scintillator, a photomultiplier tube, or the like.

  The electrostatic latent image forming unit includes a charging unit 45, an exposure unit 46, and a charge removal unit 47 arranged around the cylindrical photoconductor sample 30. The charging unit 45 irradiates the surface of the sample 30 with an electric charge to uniformly charge, and the exposure unit 46 exposes the uniformly charged surface of the sample 30 with a predetermined pattern to form a charge distribution. The charge eliminating portion 47 is for erasing charges. The photosensitive member 30 is provided with a driving unit attached to the central axis of the photosensitive member, and the photosensitive member 30 is rotationally driven by the driving unit. As the driving means, a stepping motor, a DC servo motor, or the like can be used. Examples of the charging unit 45 include charging by electron beam irradiation, contact charging, and charge injection charging. The neutralization unit 47 can be configured by an LED or the like that irradiates light on the entire surface of the photoreceptor 30.

The operation or measurement method of the embodiment shown in FIG. 7 is as follows.
1. The photoreceptor 30 is rotated.
2. In the charging unit 45, the photosensitive member 30 is uniformly charged so that the surface of the photosensitive member 30 has a desired potential.
3. In the exposure unit 46, the surface of the photoconductor 30 is irradiated with light to partially release the charges and form an electrostatic latent image.
4). In the measurement unit 18, the acceleration voltage of the electron beam irradiation unit 10 is set so that the secondary electron emission ratio is 1. The surface of the photoreceptor sample 30 is scanned with an electron beam, and the emitted secondary electrons are detected by a detector 18 such as a scintillator and converted into an electric signal to observe a potential contrast image.
5. In the static eliminating unit 47, the residual charge on the photoconductor 30 is erased by irradiating light onto the surface of the photoconductor 30 from an LED or the like.
By using such a method, it is possible to dynamically measure the electrostatic latent image on the photoreceptor 30.

The rotation driving mechanism may be a means for driving the photosensitive member 30 once. By attaching driving means capable of rotating once, it is possible to dynamically measure the electrostatic latent image over the entire circumference of the photoreceptor 30.
When evaluating the change of the photoconductor 30 over time, the photoconductor 30 is continuously rotated, and the above operations 1 to 5 are repeated and measured.
According to this embodiment, since the photoconductor 30 as a sample is the same as the cylindrical photoconductor used in the electrophotographic apparatus, the photoconductor used in the actual machine or the photoconductor used in the actual machine is used as it is. That is, it can be measured as a sample without destruction. Therefore, a photoconductor used over the years can also be easily measured.

  8 and 9 show examples of the exposure unit 46. FIG. In the example shown in FIGS. 8 and 9, the light emitting element array 51 is used as the exposure light source. As the light emitting element, an LED, an EL, or the like can be used. The light emitted from the light emitting element array 51 is irradiated to the photosensitive member 30 by the equal magnification imaging element 52 including a rod lens array in which rod lenses 53 are arranged, and is exposed. A scanning optical system is used as a general photoconductor exposure apparatus. By using an exposure unit 46 including a light emitting element array 51 and a unity imaging element 52 as in the examples shown in FIGS. Compared to a general scanning optical system, the space in the chamber 50 can be saved. Therefore, it becomes easy to arrange the cylindrical photoconductor 30 and the exposure apparatus in the same chamber 50. In FIG. 9, reference numeral 54 denotes an opaque member that fills the periphery of the rod lens 53, and 55 denotes an opaque member 54 and a side plate disposed outside the rod lens 53 that is solidified by the opaque member 54.

  FIG. 10 shows another example of the exposure apparatus. This exposure apparatus is configured in the same manner as the general scanning optical system described above. In FIG. 10, a light source 61 such as an LD (laser diode), a collimate lens 62, a cylinder lens 63, an aperture, a polygon mirror 65 as a deflector, and a scanning lens 66 having a wavelength having sensitivity with respect to the cylindrical photosensitive member 30. , 67 and the like. An electrostatic latent image can be generated by irradiating the surface of the photoreceptor 30 as a sample with a light beam having a desired beam diameter and beam profile. Reference numerals 64 and 68 denote mirrors. The light source 61 is controlled by LD control means (not shown) so that the photoconductor 30 can be irradiated with an appropriate exposure time and exposure energy. As described above, by adding a scanning mechanism using the polygon mirror 65, an arbitrary latent image pattern including a line pattern can be formed in the generatrix direction of the photoreceptor 30.

  Yet another embodiment of the present invention is shown in FIG. Unlike an electron beam, an optical system for exposure behaves basically in the same way in a vacuum and in the air, so that the exposure optical system can be arranged in the air. In the embodiment of FIG. 11, an exposure unit 46 composed of an exposure optical system is arranged in the atmosphere outside the chamber 50. The chamber 50 is evacuated, and an entrance window 51 with high transmission wavefront accuracy is placed at the boundary between the vacuum and the atmosphere. The entrance window 51 is fixed with an O-ring or the like interposed in order to maintain the degree of vacuum in the chamber 50. The configuration other than the exposure unit 46 is the same as that of the embodiment shown in FIG.

  Yet another embodiment of the present invention is shown in FIG. The difference between this embodiment and the embodiment shown in FIGS. 9 and 11 is that the photoreceptor sample is not a cylindrical one but a planar photoreceptor sample 30 and a sample on which the photoreceptor sample 30 is placed. The installation unit 16 can move horizontally to move between a position where the photosensitive sample 30 is irradiated with an electron beam and an exposure position by the electrostatic latent image forming unit 20 for forming a charge distribution on the photosensitive sample 30. It is that.

As a method of forming an electrostatic latent image on the surface of the photosensitive member by the electrostatic latent image forming unit 20, a method of forming a latent image pattern by directly drawing electrons or ions, or charging the surface of the photosensitive member uniformly once. In addition, there is a method of partially releasing electric charges to form a latent image pattern. As a measurement method, the sample 30 is first moved to a position facing the electrostatic latent image forming unit 20, and an electrostatic latent image is formed by the above method. Thereafter, the sample 30 having a charge distribution is moved to a measurement unit that irradiates a charged particle beam, the charged particle beam is irradiated onto the sample 30 from the charged particle irradiation unit 10, and secondary electrons are detected by the detector 18.
Other configurations, operations, and measurement methods are the same as those in the above-described embodiment, and thus description thereof is omitted.

It is an optical arrangement | positioning figure which shows embodiment of the measuring method and measuring apparatus of an electrostatic latent image concerning this invention. It is a graph which shows the relationship between the acceleration voltage in the charged particle beam irradiation part of the said embodiment, and secondary electron emission ratio (delta). 1 is a front view schematically showing an example of an image forming apparatus in which a photoconductor as a measurement target of the present invention is used. It is sectional drawing which expands and shows the structure of the photoreceptor which is a measuring object of this invention. It is a top view which shows the example which has arrange | positioned the known reference potential in the measurement example by this invention, and an electron beam scanning area | region. It is a block diagram which shows the example of each part control system applied to the said embodiment of this invention. It is an optical arrangement | positioning figure which shows another embodiment of the measuring method and measuring apparatus of an electrostatic latent image concerning this invention. It is a front view which shows the example of the exposure optical system which can be used for the said embodiment. (A) which shows the example of the rod lens array which makes a part of said exposure optical system is an end view, (b) is a perspective view. It is a perspective view which shows the example of the scanning optical system which can be used for this invention. It is an optical arrangement | positioning figure which shows another embodiment of the measuring method and measuring apparatus of an electrostatic latent image concerning this invention. It is an optical arrangement | positioning figure which shows another embodiment of the measuring method and measuring apparatus of an electrostatic latent image concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electron beam irradiation part 11 Electron gun 12 Condenser lens 13 Beam blanker 14 Scan lens 16 Sample installation part 18 Detector 20 Exposure part 30 Sample (photoconductor)

Claims (14)

A method of forming an electrostatic latent image, comprising: scanning a surface of a sample with a charged particle beam in an apparatus that scans a charged particle beam; generating a charge distribution on the sample; and forming an electrostatic latent image. A device for scanning a charged particle beam is provided with a device for scanning a sample surface with a charged particle beam, generating a charge distribution on the sample, and forming an electrostatic latent image. Image forming apparatus. A method of scanning a sample surface with a charged particle beam and measuring the sample surface by a detection signal obtained by this scanning,
A method for measuring an electrostatic latent image, comprising: scanning a sample surface with a charged particle beam in an apparatus for scanning a charged particle beam to generate a charge distribution on the sample. A method of scanning a sample surface with a charged particle beam and measuring the sample surface by a detection signal obtained by this scanning,
A method for measuring an electrostatic latent image, comprising charging a sample and exposing the sample with an exposure optical system to generate a charge distribution. An apparatus for scanning a sample surface with a charged particle beam and measuring the sample surface by a detection signal obtained by the scanning,
An electrostatic latent image measuring apparatus comprising means for generating a charge distribution by means for charging a sample and optical means for exposing. 6. The electrostatic latent image measuring apparatus according to claim 5, wherein the means for charging the sample comprises means for irradiating the sample with an electron beam. 7. The electrostatic latent image according to claim 6, wherein the means for charging the sample charges the sample by irradiating the electron beam with an acceleration voltage larger than an acceleration voltage at which the secondary electron emission ratio of the sample is 1. measuring device. It has a means for calculating a potential amount by arranging a known reference potential in the scanning region of the charged particle beam and comparing the secondary electron signal intensity of the reference potential with the signal intensity of the measurement sample. The electrostatic latent image measuring device according to claim 5, 6 or 7. In a method of scanning a sample surface with a charged particle beam and measuring an electrostatic latent image on the sample surface by a detection signal obtained by this scanning,
A method for measuring an electrostatic latent image, comprising: measuring an electrostatic latent image on a sample surface while moving the sample. In a method of scanning a sample surface with a charged particle beam and measuring an electrostatic latent image on the sample surface by a detection signal obtained by this scanning,
A method for measuring an electrostatic latent image, comprising: measuring an electrostatic latent image on a sample surface while moving a sample having a charge distribution. In a device that scans a sample surface with a charged particle beam and measures an electrostatic latent image on the sample surface by a detection signal obtained by this scanning,
An apparatus for measuring an electrostatic latent image, comprising means for measuring an electrostatic latent image on a sample surface while moving a sample having a charge distribution. In a device that scans a sample surface with a charged particle beam and measures an electrostatic latent image on the sample surface by a detection signal obtained by this scanning,
An apparatus for measuring an electrostatic latent image, comprising: an electrostatic latent image forming unit that forms an electrostatic latent image on a sample; and a measuring unit that moves and measures a sample having a charge distribution to a charged particle beam irradiation position . 3. The apparatus for forming an electrostatic latent image according to claim 2, further comprising an exposure unit as the electrostatic latent image forming unit. 14. The apparatus for forming an electrostatic latent image according to claim 13, wherein the sample and the exposure means are arranged in the same chamber.

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