JP5089067B2 - Sample mounting device and electrostatic latent image measuring device - Google Patents

Description

The present invention relates to a sample mounting device and an electrostatic latent image measuring device, and can be applied to measurement of a surface potential distribution and a 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 executes each process and obtains an output image 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: Removes 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.
Japanese Patent No. 3009179 JP-A-11-184188 JP 03-49143 A

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,
1 Absolute distance measurement is required.
2 Measurement takes time, and the state of the latent image changes during that time.
3 Discharge and adsorption occur.
4 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, the electrostatic latent image is visualized by applying a charge to the toner, which is a colored fine powder, and developing it by the Coulomb force acting between the charged toner 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.

  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 irradiating a charged particle beam to form an electrostatic latent image in an apparatus for performing measurement, thereby forming a latent image. It is an object of the present invention to provide an electrostatic latent image measuring apparatus capable of performing measurement within a short time later and a sample mounting apparatus used in the apparatus .

  In addition, it is intended to facilitate attachment / detachment of the vacuum sample stage unit to / from the vacuum chamber and to improve workability outside the chamber for setting the installation conditions of the photoconductor as the test object, setting of the exposure optical system, etc. To do.

In order to solve the above problems, the invention of claim 1, comprising a sample stage that can move the sample in any direction, the sample stage device capable of positioning and attachment and detachment of the sample, the sample is cylindrical A sample mounting table on which the sample is placed, the sample mounting table having a surface having a curvature only in one direction, and the curvature radius of the surface having the curvature is greater than the curvature radius of the sample. The surface having the curvature and the base portion of the sample are in contact with each other and provided with a pressing member that presses the sample mounting table, and the pressing member is made of an elastic member and is pressed by the pressing member And an abutting reference member for receiving the surface of the surface .

The invention of claim 2 is the sample stage apparatus according to claim 1, wherein said specimen table is characterized in that for centering the bus in line contact at least two sides to the base portion of the sample.

A third aspect of the present invention is the sample mounting apparatus according to the first aspect , further comprising a sample mounting table receiving member that receives the sample mounting table, wherein the abutting reference member is smaller than the length of the sample in the generatrix direction. In addition, a rectangular hole is formed in a substantially central portion, and is fastened to the sample mounting table receiving member via a resin member .

According to a fourth aspect of the present invention, in the sample mounting device according to the third aspect, the abutting reference member has a sample abutting surface other than the rectangular hole.

A fifth aspect of the present invention, the sample stage apparatus according to claim 4, characterized in that abutting a generatrix direction of the side surface of the sample to the resin member.

According to a sixth aspect of the invention, the sample stage device according to claim 1, wherein the pressing member, the setting between the specimen table and said specimen table receiving member vignetting, groups of the sample The material portion is electrically connected to the sample mounting table receiving member via the pressing member and the sample mounting table .

The invention according to claim 7 is the sample mounting apparatus according to claim 6 , wherein the elastic member is a compression spring.

The invention according to claim 8 is the sample mounting apparatus according to any one of claims 1 to 7 , wherein the adjusting means for pressing down both ends in the generatrix direction of the sample mounting table against the pressing direction of the pressing member when the sample is attached or detached. Is provided.

A ninth aspect of the present invention is the sample mounting device according to the eighth aspect , wherein the adjusting means includes projecting portions provided at both ends in the busbar direction and pins fastened to the projecting portions, and at least the sample is disposed. The detachable pin has a tapered shape .

A tenth aspect of the invention is characterized in that, in the sample mounting device according to the eighth aspect , the protrusion serves as a guide for sliding the sample mounting table .

The invention according to claim 11 is the sample mounting apparatus according to any one of claims 1 to 10 , wherein contact means for contacting the abutting reference member is provided in conjunction with attachment / detachment of the sample stage, and the contact means The surface of the sample is electrically grounded or a bias potential is applied .

A twelfth aspect of the present invention is the sample mounting apparatus according to the eleventh aspect , wherein the contact means is a contact terminal.

A thirteenth aspect of the invention includes the sample mounting device according to any one of the first to twelfth aspects, a vacuum chamber that accommodates the sample, means for scanning a charged particle beam that charges the sample, and the charging Means for forming an electrostatic latent image for generating a charge distribution on the sample, exposure optical system for exposing the charged sample to generate a charge distribution, means for scanning the sample with a charged particle beam, The charge distribution generated in the sample is measured by a detection signal obtained by this scanning .

According to the first aspect of the present invention, the sample can be positioned with high accuracy in the vacuum chamber and the sample can be easily exchanged, so that highly reproducible measurement is possible.
In addition, by setting the radius of curvature of the sample mounting table to be greater than or equal to the radius of curvature of the sample, it is possible to measure a plurality of samples with a single sample mounting table. Efficiency can be improved.

  According to the second aspect of the present invention, the photoconductor bus can be adjusted to a predetermined position by making the mounting table small with respect to the sample obtained by cutting the photoconductor drum so as to have a curvature only in one direction.

  According to the third, fourth, and fifth aspects of the invention, the end portion of the sample obtained by cutting the photosensitive drum is abutted against a resin reference frame, and the surface of the photosensitive member is abutted against a metal reference plate. The sample mounting table unit prevents leakage.

According to the inventions of claims 6 , 7 , 8 , 9 , and 10 , the sample mounting table is pressed against the reference plate by an elastic member such as a compression spring, thereby ensuring the contact pressure between the sample and the reference plate, and the sample base Therefore, it is possible to obtain electrical continuity with respect to the device, and to make the device more compact.

According to the eleventh and twelfth aspects of the present invention, a bias potential can be independently applied to the surface of the photosensitive member (photosensitive layer) and the photosensitive member base portion without leaking each other.

According to the thirteenth aspect of the present invention, it is possible to measure the surface charge distribution of the sample, which has been extremely difficult in the past, by providing means for forming a charge distribution on the sample in a vacuum apparatus that scans a charged particle beam. It becomes possible.

  Embodiments according to the present invention will be described below with reference to the drawings. First, an embodiment of an electrostatic latent image measurement method will be described.

  FIG. 12 shows an embodiment of a method for measuring an electrostatic latent image according to the present invention. This electrostatic latent image measuring method 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 collimating 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. 15, 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 measuring apparatus will be described based on 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 E ₁ is set to an acceleration voltage higher than the acceleration voltage E _{0 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 accumulate in the sample 30. Is caused to 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. 16, 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. 16, a portion having a relatively low potential is displayed in white, and a portion having a high potential is displayed in black. In FIG. 16, 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 shown in FIG. 12 while scanning the surface of the sample 30 with an electron beam. The state of change of 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 completion of the measurement, 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. 17 shows an example of the control unit of the above embodiment. In FIG. 17, 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, it is known that observation is performed under the condition of δ = 1 in order to avoid the influence of charge-up, and other acceleration voltages are not 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. However, without turning it off, the acceleration voltage is converted to an acceleration voltage at which δ = 1, and the observation condition is such that charge-up does not occur. A method of exposing in a state may be used. As a charging method, another means such as contact charging may be used.

FIGS. 1-11 is the figure which showed the Example of the sample mounting apparatus of this invention, and a vacuum chamber apparatus.
FIG. 1 is a view showing a state in which a vacuum sample stage unit 60 is mounted in the vacuum chamber 50.
The vacuum chamber 50 forms an opening and a flange attachment portion 61 by performing inner diameter processing of the material on the cylinder and D-cutting from above. A guide rail mounting portion is provided on a surface parallel to the bottom surface of the vacuum chamber 50, and the guide rail 52 is mounted in a direction orthogonal to the opening. In the present invention, two guide rails 52 and a reinforcing plate 53 are configured to improve the positioning accuracy and load resistance of the vacuum sample stage unit 60. One guide 54 is set on the guide rail 52, and the guide rail 52 and the reinforcing plate 53 are screwed together.

  The vacuum sample stage unit 60 will be described with reference to FIGS. A stage unit 62 for moving the sample in three directions is attached to the flange 61. A box-shaped structure 69 is formed on the opposite surface of the flange 61 to the stage 62 side, and the drive unit 63 of the stage 62, in this embodiment, a stepping motor, a microhead, or the like is attached with an O-ring to prevent leakage. It has become. A harness for power supply and signal extraction to the inside of the vacuum chamber 50 can be relayed with a feedthrough 64 while maintaining a vacuum. A positioning member 65 having an L-shaped cross section is fastened to the bottom of the box-shaped structure 69, the corners on both sides on the short side are chamfered, and the height of the bottom of the end and the bottom of the bottom of the flange are substantially the same. As a result, even when the work is performed on the desk before the vacuum sample table unit is placed on the vacuum sample table unit mounting table 55 (hereinafter, unit mounting table), the substantially horizontal state can be maintained.

Next, positioning of the vacuum sample stage unit 60 and the unit mounting table 55 according to the present invention will be described. 4 and 5 show a guide part 56 for easily setting the vacuum sample stage unit 60, a receiving part for holding the vacuum sample stage unit 60 horizontally, and a part for ensuring stability and safety during mounting. It consists of Two guide portions are provided in a direction orthogonal to the sliding direction. On the vacuum chamber 50 side, a U-shaped projecting portion 56 abuts the projecting portion on the surface opposite to the flange stage while guiding it from the outside. The U-shaped guide part 56 has a notch 56a at the end of the vacuum chamber 50 side. Since the corners of each other are rounded, they can be guided even if there is a deviation in the direction perpendicular to the sliding direction. The other guide portion is guided by providing a notch 55a at the end of the unit mounting table 55, and the positioning member 65 of the vacuum sample table unit 60 is fitted into the notch 55a. Positioning in the direction along the guide rail 52 is performed by sandwiching the unit mounting table 55 between the opposite surface of the stage of the flange 61 and the positioning member 65.
Positioning of the vacuum sample stage unit 60 in the vertical direction is held horizontally by its own weight by appropriately setting the height of the receiving surface of the unit mounting table 55.

  In the present invention, the positioning unit 65 of the unit mounting table 55 and the vacuum sample table unit 60 is sandwiched and fitted to each other in the direction along the guide rail 52 and in the direction perpendicular thereto, so that the load due to loading / unloading or normal impact is applied. The vacuum sample stage unit 60 does not fall from the unit mounting table 55.

  Further, by providing a tap at the rear end portion of the unit mounting table 55, providing a hole in the positioning member 65 of the vacuum sample table unit 60, and fastening them with the knob screws 66, further safety can be ensured. A tap is provided in the center of the unit mounting table 55, and a screw is inserted into a hole of the reinforcing plate 53 with a knob screw 66 or abuts against the surface of the reinforcing plate 53, thereby locking the unit mounting table 55 or braking at an arbitrary position. Can be applied. Since the safety device is provided, various operations such as measurement can be performed in a state in which the vacuum sample table unit 60, which is a heavy object, is removed from the vacuum chamber 50 without being removed from the unit mounting table 55. Can be very effective in terms of performance and work efficiency.

  The vacuum sample stage unit 60 is mounted on the vacuum chamber 50 in such a state that the vacuum sample stage unit 60 is mounted on the unit mounting table 55 and gently pushed by the handles 67 attached to the left and right sides of the box-shaped structure 69, and the reference surface (butting surface) of the flange 61 is pressed. ) Completes the mounting by compressing a predetermined amount of the O-ring on the flange mounting surface (contact surface) of the vacuum chamber 50 and fastening the screw. At this time, a hole serving as a main reference and a slot serving as a secondary reference are formed at a predetermined pitch on the flange mounting surface of the vacuum chamber 50 (reference hole 57), and a tapered reference pin 68 provided on the flange 61 is used as a reference. By fitting with the hole 57, it is positioned with high precision in 57, and the positional relationship with the electron gun provided in the vacuum chamber (not shown) is high without variation due to the attachment / detachment of the vacuum sample stage unit 60 and the vacuum chamber 50. The accuracy can be maintained. In the present embodiment, a tapered pin is used as the adjusting means. However, any member having the adjusting means within a range where the above-described effects can be obtained can be appropriately changed.

  FIG. 5 is an external view of the sample mounting table 70 mounted on the stage unit 62 and shows a state in which the photosensitive drum 71 cut into a substantially square shape is set on the mounting table unit. The reference plate frame 72 is made of a resin material and has a U-shape, and is fastened with screws to three stays 73 erected on the sample mounting table 70. A thin metal reference plate 74 is fastened with three screws in close contact with the upper surface of the reference plate frame 72. A rectangular window 75 is opened at a substantially central portion of the reference plate 74.

  FIG. 6 shows a state in which the photoconductor 71 is positioned on the back surface of the reference plate 74 with the reference plate 74 removed for easy understanding. Oval projections 76 are provided at both ends of the sample mounting table 70 in the axial direction, and can be slid in a direction orthogonal to the axis without rotating by fitting with the prism guide portion 78 of the sample mounting guide 77. ing. Pins 79 are fastened to two portions of the oval projection 76, and at least the pin 79 on the side where the sample is to be attached / detached is tapered so that the maximum diameter thereof is in contact with the abutting portion 80 of the sample mounting table 70. The sample mounting table 70 has a curvature in only one direction on at least one surface. For example, in the present embodiment, the sample mounting table 70 has a cylinder shape.

  FIG. 11 is a central cross-sectional view of the sample mounting table unit. A sample mounting table 70 and a sample mounting table guide 71 are provided with counterbore portions, and a compression spring 81 is bent between them to set the sample plate 74 as the abutting surface. The mounting table 70 can be slid upward and pressed with an appropriate pressing force. When the sample is mounted, the two pins 79 are pushed down against the compression spring 81 and the sample is slid from the front and placed on the sample mounting table 70 to release the push of the pin 79.

  Referring to FIG. 11, it will be described that the center of the reference plate window 75 and the position of the photosensitive member bus 82 substantially coincide with each other, and that the reference plate 74 and the burr at the cut portion of the photosensitive member sample 71 do not contact each other. FIG. 9 is an enlarged view of the sample mounting table. Since the sample mounting table 70 has an axisymmetric shape, the ridge line portion 83 comes into contact with the base material portion of the photoconductor 71 and automatically aligns when the radius of curvature of the photoconductor 71 is smaller than the curvature radius of the sample mounting table 70. It coincides with the photoreceptor bus 82 and further substantially coincides with the center of the window 75 of the reference plate. According to the present invention, a sample having a plurality of drum diameters can be set if the radius of curvature of the photoconductor 71 is equal to or less than the radius of curvature of the sample mounting table and can be set without interference. The photoconductor sample 71 is set against the frame of the resin-made reference plate 72 and the reference plate width in the drawing is made smaller than the width of the photoconductor, so that the burr generated when the aluminum base material is cut contacts the reference plate 74. Troubles such as leaks.

  FIG. 7 shows a contact terminal 84 and an insulating seat 85 necessary for electrically grounding or applying a bias potential to the surface of the photosensitive member. The bent portion of the reference plate 74 slides to the stopper 89 with the sample mounting table guide 77. The contact state is shown in the set state. When applying a bias potential to the aluminum base, the harness is connected to the sample base 86 with a contact terminal as a contact means, for example, a crimp terminal, so that the sample base → the material mounting table guide → the compression spring → the sample mounting A bias potential can be applied in the order of the table → the aluminum base. In this embodiment, the compression spring is used as the elastic member. However, the elastic member may be an elastic member having conductivity, for example, a metal spring, or a resin-based member and a metal member configured to have metal in the contact portion. The composite member spring may be used.

  FIG. 10 shows a state where the sample mounting table guide 77 is set on the sample table base 86 and the vertical direction of the sample mounting table guide 77 is regulated by the holding plate 87. The sample can be exchanged by sliding the sample exchange rod from the sample exchange chamber (not shown) and connecting it to the screw portion 88 of the sample platform guide 77 and pulling out the sample platform unit.

FIG. 4 is a view showing a state in which a vacuum sample stage unit 60 is attached to a vacuum chamber 50. It is a figure which shows the vacuum chamber 50 and the unit mounting base 55. FIG. It is a figure which shows the vacuum sample stand unit. It is the figure which showed the vacuum chamber 50, the vacuum sample stand unit 60, and the stage part 62. FIG. 2 is an external view of a sample mounting table 70. FIG. It is the figure which removed the reference | standard board 74 of the sample mounting base. It is the figure which showed the contact terminal 84 and the insulating seat 85. FIG. FIG. 6 is a diagram in which a sample mounting table is attached to a stage unit. It is an enlarged view of a sample mounting base. FIG. 6 is a view showing a state in which a sample mounting table guide 77 is set on a sample table base 86 and set in a vertical direction with a pressing plate 87. FIG. 6 is a diagram for explaining that the center of a reference plate window 75 and the position of a photoreceptor bus bar 82 are substantially coincident with each other and that the burr at the cutting portion of the reference plate 74 and the photoreceptor sample 71 is not in contact. It is a figure which shows an example of the electrostatic latent image measuring method. It is a figure which shows the relationship between acceleration voltage and secondary electron emission ratio (delta). It is a figure which shows the structure of an electrophotographic apparatus. It is a figure which shows the structure of a photoreceptor. It is a figure which shows an example of the method of arrange | positioning a reference electric potential. It is a figure which shows the structure of an electrostatic latent image measuring device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Electron gun 12 Condenser lens 13 Beam blanker 14 Scan lens 15 Objective lens 16 Sample stand 17 Light source 18 Secondary electron detection part 20 Exposure part 21 Light source 22 Collimating lens 23 Aperture 25 Imaging lens 30 Sample 31 Electrostatic latent image 32 Beam scan Region 33 Insulator 34 Conductive substrate 35 Computer 36 LD control unit 37 Charged particle control unit 38 LED control unit 39 Sample stage control unit 41 Secondary electron detector 42 Signal processing unit 43 Measurement result output unit 50 Vacuum chamber 52 Guide rail 53 Reinforcement plate 54 Moving table 55 Mounting table 56 U-shaped guide unit 57 Reference hole 60 Vacuum sample table unit 61 Flange 62 Stage unit 63 Stage drive unit 64 Field through 65 Positioning member 66 Knob screw 67 Handle 68 Reference pin 69 Box type Structure 70 Sample mounting table 71 Photoconductor 72 Reference plate frame 73 Stay 74 Reference plate 75 Window 76 Oval guide portion 77 Sample mounting table guide 78 Square column guide portion 79 Pin 80 Abutting portion 81 Compression spring 82 Photoconductor bus 83 Edge line 84 Contact terminal 85 Insulation seat 86 Sample base 87 Holding plate 88 Screw hole 89 Stopper 90 Holding spring

Claims (13)

The specimen comprises a specimen stage that can move in any direction, the sample stage device capable of positioning and attachment and detachment of the sample,
The sample is a cylindrical photoreceptor sample;
A sample mounting table for mounting the sample ;
The sample mounting table has a surface having a curvature only in one direction, and the curvature radius of the surface having the curvature is larger than the curvature radius of the sample, and the surface having the curvature and the base portion of the sample are in contact with each other. And
A pressing member that presses the sample mounting table; and the pressing member comprises an elastic member,
A sample mounting device comprising: an abutting reference member that receives the surface of the sample pressed by the pressing member . 2. The sample mounting apparatus according to claim 1, wherein the sample mounting table makes line contact with at least two sides of the sample base to align the bus bar . The sample mounting device according to claim 1, further comprising a sample mounting table receiving member that receives the sample mounting table.
The abutting reference member is smaller than the length of the sample in the generatrix direction, has a rectangular hole at a substantially central portion, and is fastened to the sample mounting table receiving member via a resin member. A sample placement device. 4. The sample mounting apparatus according to claim 3, wherein the abutting reference member has a sample abutting surface other than the rectangular hole. 5. The sample mounting device according to claim 4, wherein an end side surface of the sample in the bus bar direction is abutted against the resin member . In the sample mounting apparatus in any one of Claims 1-5,
The pressing member is set between the specimen table and said specimen table receiving member vignetting,
The sample mounting apparatus is characterized in that the base portion of the sample is electrically connected to the sample mounting table receiving member via the pressing member and the sample mounting table . The sample mounting apparatus according to claim 6 , wherein the elastic member is a compression spring. In the sample stage apparatus according to claim 1-7, wherein the said at detachment of the sample, both ends of the generatrix direction of the specimen table, the possible adjusting means pressing down against the pressing direction of the pressing member is provided A sample placement device. In the sample mounting apparatus according to claim 8 ,
The adjusting means comprises a protrusion provided at both ends in the busbar direction, and a pin fastened to the protrusion,
The sample mounting device characterized in that at least the pin on the side where the sample is attached and detached is tapered . 9. The sample mounting device according to claim 8 , wherein the protrusion serves as a guide for sliding the sample mounting table . In the sample mounting apparatus in any one of Claims 1-10 ,
In conjunction with the attachment and detachment of the sample stage, a contact means for contacting the abutting reference member is provided ,
A sample mounting apparatus, wherein the sample surface is electrically grounded or biased by the contact means . 12. The sample mounting device according to claim 11 , wherein the contact means is a contact terminal. The sample mounting device according to any one of claims 1 to 12 , comprising :
A vacuum chamber containing the sample;
Means for scanning a charged particle beam for charging the sample ;
Means for forming an electrostatic latent image for generating a charge distribution on the charged sample;
An exposure optical system that exposes the charged sample to generate a charge distribution;
Means for scanning the sample with a charged particle beam;
And an electrostatic latent image measuring apparatus for measuring a charge distribution generated on the sample by a detection signal obtained by the scanning .

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