JP3465899B2 - Electrostatic latent image reading method and apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to the reading of an electrostatic latent image formed on a charge image holding medium such as an electrostatic recording medium or an electrostatic latent image holding medium for electrophotography, or electrostatic force such as electrostatic charge or polarization. The present invention relates to a method and apparatus for reading an electrostatic latent image, such as signal reading of a high-density recording apparatus using the.

[0002]

2. Description of the Related Art Conventionally, it has been proposed to form an electrostatic latent image on a charge holding medium having an insulating layer formed on a conductive layer by voltage application exposure, ion flow, beam exposure or the like.
This charge holding medium has the advantages of extremely high resolution and being capable of semi-permanently storing image information. However, contact with water or the like apparently attenuates the potential and makes it undetectable. Alternatively, it is difficult for a third party to read the image information, but the security is not yet perfect.

As a countermeasure against this, the applicant of the present invention attaches a charge having a polarity opposite to that of the charge of the electrostatic latent image, attenuates the surface potential and makes it impossible to read the image information from the outside, and reads the image information. In this case, a PET film or the like is brought into close contact with the surface of the charge holding medium, and by removing the film, the opposite polarity charges are removed to restore the image information so that the information can be read. -110447
issue).

The above proposal will be described with reference to FIG. In the figure,
1 is a charge holding medium, 1c is an insulating layer, 1b is a conductive layer, 1
d is an electrostatic latent image, 1e is a charge having a polarity opposite to 1d, 1f is P
It is an ET film. The charge holding medium 1 is formed by laminating an insulator (trade name CYTOP) 1c made of a fluororesin on a conductive layer 1b forming an electrode to a thickness of about 2.6 μm. Of course, the charge holding medium 1 may be laminated on a glass substrate or the like (not shown). With respect to such a charge holding medium 1, a photoconductor is arranged to face a conventionally known, for example, corona charging or charge holding medium, and the conductive layer 1b is formed.
An electrostatic latent image 1d is recorded as shown in FIG. 13A by so-called voltage application exposure, in which image exposure is performed while applying a voltage between and. By wetting the surface of the insulating layer of the charge holding medium 1 on which the electrostatic latent image is recorded with water or the like, or by disposing the charge holding medium 1 in a high humidity environment, as shown in FIG. On the surface of the layer 1c, charges 1e of opposite polarity are attached. At this time, the electric charges 1e of the opposite polarity attached cancel the electric potential due to the electrostatic latent image, the surface potential cannot be detected from the outside, and the electrostatic latent image cannot be read.
FIG. 13C shows the charge holding medium in such a state.
As shown in, PET with a thickness of about 12 μm vapor-deposited with Al
The opposite surface of the film 1f from the Al vapor deposition is placed, and by applying pressure or rubbing, the film is adhered and then peeled off, whereby the electric charge 1e having the opposite polarity attached to the insulating layer 1c is attached to the PET film 1f. Then removed. In this case, since the charges forming the electrostatic latent image 1d are trapped in the insulating layer 1c, it becomes apparent when the charges of opposite polarity are removed by the PET film 1f, and the electrostatic latent image can be read.

[0005]

As described above, by adhering a charge having a polarity opposite to that of the latent image charge, there are advantages such as improved security and long-term stable storage.
Since it is necessary to remove charges of opposite polarities during reading, the reading operation is troublesome, and image distortion may occur when removing the charges. The present invention is intended to solve the above problems, and by adhering a charge having a polarity opposite to that of a latent image charge, it enables security improvement and long-term stable storage, and also causes image disturbance during latent image reading. An object of the present invention is to provide a method and apparatus for reading an electrostatic latent image that does not exist.

[0006]

According to the present invention, a latent image is read by the principle and means described below, using a probe having a microscopic action cross section for detecting potential. Although the electrostatic latent image formed on the charge holding medium is charged on the surface of the insulating layer, it is actually accumulated at a position slightly inside the insulating layer. If you attach this charge holding medium to water,
Charges of opposite polarity are attached to the electrostatic latent image, but since these charges are attached to the surface of the insulating layer, there is a minute gap on the order of sub-μm between the latent image charges and the charges of opposite polarity on the surface. Even if the potential detecting probe is brought closer to a distance farther than the minute distance, the influences of the charges of opposite polarities on the electrostatic latent image and the surface cancel each other out, and nothing can be detected electrically. But,
When the probe is brought close to the above-mentioned minute interval, an induced charge is induced in the probe in accordance with the difference in the distance between the latent image charge and the surface opposite charge. At this time, if a probe with a sharp tip such as a needle is used as the probe, the induced charge is induced at the tip portion.

An electrostatic force acts between the probe and the recording medium due to the induced electric charge induced and the electric field generated between the recording medium. Therefore, if the probe is mechanically displaceable, the probe may not be bent. Mechanical displacement occurs. Since the mechanical displacement indicates the amount of displacement corresponding to the electrostatic force, the electrostatic force acting on the mechanical displacement, that is, the electrostatic image of the portion can be read by detecting the mechanical displacement.

Further, in this method, since it is sufficient to obtain a measurable mechanical displacement due to the electrostatic force due to the induced electric charge, the material, shape, configuration, or mechanical displacement detecting means of the probe is used. By selecting it, the electrostatic latent image can be read with the resolution of the probe up to the size of molecule or atom. Further, the electrostatic latent image can be read two-dimensionally by scanning the recording medium or the probe two-dimensionally.

The above is the case where the probe in the stationary state is used, but the same measurement can be performed by bringing the probe vibrated by an external force to approach the recording medium. The probe is made to approach the recording medium while being vibrated by an external force so as to maintain a constant amplitude at its mechanical natural frequency. Then, similarly to the case described above, induced charges are induced, and electrostatic force acts on the probe. A new external force, which is the electrostatic force of the probe, acts to change the natural frequency or amplitude of the probe. Since the change in the natural frequency or the amplitude changes depending on the electrostatic force acting on the probe, the electrostatic force, that is, the electrostatic latent image of the part can be read by measuring the natural frequency or the amplitude. . The reading by two-dimensional scanning and the resolution are the same as in the case of the mechanical displacement described above.

As described above, by using the potential detecting probe and directly utilizing the phenomenon of mechanical displacement, change in natural frequency, or change in amplitude, which is caused by electrostatic force, an electrostatic latent image of a minute portion is obtained. Can be read.

These actions are influenced not only by the potential of the recording medium but also by the distance between the probe and the recording medium. When measuring while scanning on the recording medium, if the distance between the probe and the recording medium is controlled so that the state of the probe does not change due to the action of these electrostatic forces, this control amount corresponds to the electrostatic force acting on the probe. The electrostatic latent image can be read by scanning while measuring this value.

In addition to the electric field generated by the recording medium, the electrostatic force acting between the probe and the recording medium is
It can also be operated by externally applying a voltage between the recording media. Therefore, when measuring while scanning on the recording medium, a bias voltage is applied between the probe and the recording medium, and the bias voltage is controlled so that the state of the probe is not changed by the electrostatic force generated from the recording medium. This control amount corresponds to the electrostatic force acting on the probe, and the electrostatic latent image can be read from this value.

The present invention uses a potential detecting probe to mechanically displace the probe due to an electrostatic force acting when it approaches a recording medium on which an electrostatic latent image charge having a polarity opposite to that of the latent image charge is applied. Control when the distance between the probe and the recording medium and the bias voltage between the probe and the recording medium are controlled so that the state of the probe does not change due to the action of electrostatic force by using the change in frequency or the change in amplitude. From the quantity, it becomes possible to read an electrostatic latent image shielded by charges of opposite polarities with a finer resolution than the conventional method of directly measuring induced charges.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 is a diagram showing a basic configuration of electrostatic latent image reading by a recording medium and a probe described in each of the following embodiments. As shown in FIG. 1A, the recording medium 1 is
The charge holding layer 1c is laminated on the support 1a with the conductive layer 1b interposed therebetween, and recording charges are formed in the charge holding layer 1c. Not limited to the recording medium having such a configuration, electrostatic charge, induced charge,
Any medium having a potential distribution due to dipole polarization or the like can be a measurement target in the present invention. When such a recording medium 1 is dipped in water or placed in a humid environment,
As shown in FIG. 1B, the shield charge 1e having the opposite polarity adheres only to the surface on which the recording charge is formed. For such a recording medium 1, as shown in FIG. 1C, a minute gap between the recording charge 1d and the seal charge 1e, for example, 0.1.
When the probe 2 is brought closer to about μm, the recording charge and the shield charge act on the probe 2, and the charge based on the difference between the acting forces of the two is induced to act the electrostatic force. The recording charge 1d of the recording medium 1 is read by utilizing the action of this electrostatic force. [Embodiment 1] FIG. 2 is a view showing an embodiment in which an electrostatic latent image on a recording medium is read from the mechanical displacement of a probe. 1 in the figure
Is a recording medium, 2 is a probe, 3 is a probe fixing jig, 4
Is a mechanical displacement measuring device, 5 is a Z-direction moving device, and 6 is X-.
A Y scanning device, 7 is a Z direction control device, 8 is an XY scanning control device, and 9 is a recording processing device. Since the recording medium 1 scans on the XY plane and approaches the probe 2,
It is installed on the Y scanning device 6 and the Z direction moving device 5.
At this time, if the recording medium 1 has a card-like form,
As the XY scanning device 6, an XY stage or the like using a piezoelectric element, an electromagnetic motor or the like as a drive source can be used. If the recording medium 1 is disk-shaped, the XY scanning device 6 is a rotating mechanism and a moving device in the direction of the rotation center, and if the recording medium 1 is cylindrical shaped formed on a drum or the like, XY scanning is performed. The device 6 is a moving device in a direction parallel to the rotation mechanism and the rotation axis. The Z-direction moving device 5 uses a piezoelectric element, an electromagnetic motor, or the like as a drive source.
Stage available.

The XY scanning device 6 and the Z direction moving device 5 are connected to an XY scanning control device 8 and a Z direction control device 7, respectively, and driven and controlled. The XY scanning device 6 and the Z-direction moving device 5 are integrally formed by a piezoelectric element or the like and are movable in the X, Y, and Z directions other than the case where they are separated as shown in FIG. You may use what was done. The probe 2 is installed near the recording medium 1 with one end fixed by the probe fixing jig 3. The material and form of the probe 2 may be any as long as induced charges are induced when the probe is placed in a field where an electric field exists and mechanical displacement is caused by the action of electrostatic force.

FIG. 3 shows an example of a probe prepared by using a conductive metal foil (Ni or the like). The thickness of the metal foil is 10 μm, and the tip portion is sharpened to increase the lateral resolution during measurement. In addition to this, a wire-shaped metal wire, a needle made of a material having ferroelectricity, or the like can be used as the probe of the present device as long as it causes mechanical displacement by an electric field.

When a conductive material such as metal is used as the probe, in order to enhance the effect of electrostatic force,
As shown in FIG. 2, the probe 2 and the conductive layer 1 b of the recording medium 1
May be short-circuited. Also, instead of short-circuiting, both may be connected to ground respectively. As a result, the charges having the opposite polarity to the recording charges induced in the conductive layer 1b are distributed to the probe, so that the electrostatic force can be increased.

In FIG. 2, the probe fixing jig 3 is not provided with a moving mechanism, but the recording medium 1 is installed in X.
The Y scanning device 6 and the Z direction moving device 5 may be provided on the probe fixing jig 3, respectively. Of course, they may be provided in both. The recording medium 1 and the probe 2 are brought close to each other by the Z-direction moving device 5 to a distance where electrostatic force is exerted by the interaction between them. One end of the probe 2 is fixed by the probe fixing jig 3, and the tip end portion receives a force by the electrostatic force due to the interaction with the recording medium, so that mechanical displacement such as bending occurs. This is a mechanical displacement measuring device 4
Detect with.

The mechanical displacement detector 4 is generally an AFM.
The method used in (atomic force microscope) can be used. That is, an STM that is provided with a needle for detecting a tunnel current above the probe 2 and detects the displacement of the probe 2 from the tunnel current between the probe 2 and the needle for detecting the tunnel current.
A method using the principle of (scanning tunneling microscope), or the displacement of the probe 2 is measured by irradiating the upper surface of the probe 2 with a light beam such as a laser beam from any one direction and measuring the positional displacement of the reflected light. It is possible to use an optical lever method for knowing the above, a light wave interference method for recognizing the displacement of the probe 2 by irradiating the upper surface of the probe with laser light, and an interference phenomenon with the reflected light.

The displacement signal output from the mechanical displacement detection device 4 and the position signal output from the XY scanning control device 8 are taken into the recording processing device 9. A recorder, a computer or the like is used as the recording processing device. Here, by converting the displacement signal into a potential on the recording medium and making it correspond to the position signal obtained from the XY scanning control device 8, the electrostatic latent image at an arbitrary position on the recording medium can be read. The position signal may use a signal obtained by providing an independent device for measuring the relative position of the probe and the recording medium without using the XY scanning control device.

After the measurement at any position, X-
The recording medium 1 is scanned by the Y scanning device 6. As a scanning method, after measuring one point, move to the next position, stop and then perform the measurement, along with an intermittent scanning method, there is also a method of performing measurement in a state of continuously moving without stopping It is possible. Further, it is possible to actually move either the recording medium, the probe, or both.

Although the example of detecting the mechanical displacement of the probe has been described above, another configuration is possible within the scope of the present invention, depending on the shape of the recording medium, the scanning direction, and the like. [Embodiment 2] FIG. 4 is a diagram showing an embodiment in which a probe is vibrated and the potential distribution is measured from its amplitude. The basic configuration is the same as that of [Embodiment 1]. Device 11 has been added. The vibration excitation device 10 is
It is for vibrating the probe 2 at its natural frequency. As a means for vibrating, a piezoelectric element or the like is connected to the probe 2 or the probe fixing jig 3, and the piezoelectric element is vibrated by applying a piezoelectric pulse at a frequency corresponding to the natural frequency. Further, there is a method in which a heat pulse is applied to a part of the probe by a laser beam, a heating element, or the like at a frequency corresponding to the natural frequency to cause thermal expansion in the frequency to vibrate.

The recording medium 1 and the probe 2 in a vibrating state are brought close to each other by the Z-direction moving device 5. When the probe 2 is brought close to the distance where the electrostatic force works, the vibration state of the probe changes due to the electrostatic force and the amplitude changes. These changes are detected by the mechanical displacement detecting device 4, pass through the amplitude measuring device 11, and are recorded as an amplitude signal in the recording processing device 9.
Is taken into. The amplitude measuring device 11 is composed of, for example, a circuit that detects an AC component of an input signal.

The electrostatic latent image can be read by converting the amplitude signal input in the recording processing device 9 into the potential on the recording medium. The above is the same as the case of [Example 1] except for the points described above. [Embodiment 3] FIG. 5 is a view showing an embodiment in which a probe is vibrated and a potential distribution is measured from its natural frequency. The basic configuration is the same as that of [Embodiment 2], and the amplitude of [Embodiment 2] is the same. A natural frequency measuring device 12 is added instead of the measuring device. When the recording medium 1 and the probe 2 in the vibrating state are brought close to each other by the Z-direction moving device 5 and brought close to the distance where the electrostatic force works, the natural frequency of the probe changes according to the strength of the electrostatic force. . This is measured by the natural frequency measuring device 12. As a method, for example, while monitoring the vibration state by the mechanical displacement measuring device 4,
There is a method of determining the natural frequency by scanning the frequency at which the probe is vibrated by the vibration excitation device 10 and selecting the frequency at which the maximum amplitude is obtained.

The information on the natural frequency obtained by the natural frequency measuring device 12 is transmitted to the recording processing device 9. The electrostatic latent image can be read by converting the signal input in the recording processing device 9 into the potential on the recording medium. that's all,
Except for the points described above, it is the same as the case of [Example 1]. [Embodiment 4] FIG. 6 shows that the mechanical displacement is detected and the distance between the recording medium and the probe is controlled so that the value is kept constant.
In the figure which shows the example which measures the electric potential distribution from the control quantity,
The basic configuration is the same as that of [Embodiment 1], but the signal of the mechanical displacement detection device 4 enters the Z direction control device 7, and the control signal of the Z direction control device 7 is taken in by the recording processing device 9. ing. The probe 2 causes a mechanical displacement due to the electrostatic force due to the interaction between the probe 2 and the recording medium 1. The displacement amount also changes by changing the distance between the probe and the recording medium. That is, even if the potential on the recording medium is the same, the magnitude of the electrostatic force that works depends on the distance from the probe.

In the Z direction control device 7, when a value different from the initially set displacement amount is input from the mechanical displacement detection device 4, the Z direction moving device 5 causes the probe to move so that the initially set displacement amount is obtained. — Control the spacing between recording media. This control amount corresponds to the amount of static electricity that acts between the probe and the recording medium. What is moved at this time is the recording medium,
Alternatively, it may be a probe or both. Then, the control amount signal is sent to the recording processing device 9, where it is converted into a potential on the recording medium. The above is the same as the case of [Example 1] except for the points described above. [Embodiment 5] FIG. 7 is a diagram showing an embodiment in which the potential distribution is measured by vibrating the probe and controlling the interval between the probe and the recording medium so as to keep the amplitude constant. Example 2], but the output signal of the amplitude measuring device 11 enters the Z direction control device 7,
The control signal is taken into the recording device 9.

An electrostatic force due to the interaction between the probe 2 and the recording medium 1 changes the vibration state of the probe and changes the amplitude. The amount of change in the amplitude also changes by changing the interval between the probe and the recording medium. . That is, even if the potential on the recording medium is the same, the magnitude of the electrostatic force that works depends on the distance from the probe. In the Z-direction control device 7, when an amplitude different from the initially set vibration amplitude is input from the amplitude measuring device 11, the Z-direction moving device 5 causes the gap between the probe and the recording medium so that the amplitude becomes the initially set amplitude. To control. This control amount corresponds to the amount of static electricity that acts between the probe and the recording medium. What is moved at this time may be a recording medium, a probe, or both. Then, the control amount signal is sent to the recording processing device 9, where it is converted into a potential on the recording medium. The above is the same as the case of [Example 1] except for the points described above. [Embodiment 6] FIG. 8 is a view showing an embodiment in which the potential distribution is measured by vibrating the probe and controlling the interval between the probe and the recording medium so as to keep its natural frequency constant. As in the case of [Embodiment 3], the output signal of the natural frequency measuring device 12 enters the Z direction control device 7, and the control signal is taken into the recording device 9.

Although the natural frequency of the probe changes due to the electrostatic force due to the interaction between the probe 2 and the recording medium 1, this change amount also changes depending on the distance between the probe and the recording medium. That is, even if the potential on the recording medium is the same, the magnitude of the electrostatic force that works depends on the distance from the probe.

In the Z-direction control device 7, when a natural frequency different from the natural frequency initially set is input from the natural frequency measuring device 12, the Z-direction controller 7 sets the initial frequency to be Z.
The direction moving device 5 controls the distance between the probe and the recording medium. This control amount corresponds to the amount of static electricity that acts between the probe and the recording medium. What is moved at this time may be a recording medium, a probe, or both. Then, the control amount signal is sent to the recording processing device 9, where it is converted into a potential on the recording medium. The above is the same as the case of [Example 1] except for the points described above. [Embodiment 7] FIG. 9 is a diagram showing an embodiment in which a mechanical displacement is detected, the bias voltage between the recording medium and the probe is controlled so as to maintain the value at a constant value, and the potential distribution is measured from the control amount. The basic configuration is the same as that of the first embodiment, but the signal of the mechanical displacement detection device 4 enters the bias voltage control device 13, and the control signal of the bias voltage control device 13 is taken into the recording processing device 9. A bias voltage is applied between the probe 2 and the dielectric layer 1b of the recording medium 1.

The probe 2 is mechanically displaced by an electrostatic force due to the interaction between the probe 2 and the recording medium 1. The displacement amount is also changed by applying a bias voltage between the probe and the recording medium. That is, even if the potential on the recording medium is the same, the magnitude of the electrostatic force acting on the probe differs depending on the external bias voltage.

In the bias voltage control device 13, when a value different from the initially set displacement amount is input from the mechanical displacement detection device 4, the bias between the probe and the recording medium is adjusted so that the initially set displacement amount is obtained. Control the voltage. This control amount corresponds to the potential on the recording medium. The control amount signal is sent to the recording processing device 9, where it is converted into a potential on the recording medium. Except for the points described above, it is the same as the case of the first embodiment. [Embodiment 8] FIG. 10 is a view showing an embodiment in which the potential distribution is measured by vibrating the probe and controlling the bias voltage between the probe and the recording medium so as to keep the amplitude constant. Example 2], but the output signal of the amplitude measuring device 11 enters the bias voltage control device 13, and the control signal is taken into the recording processing device 9, and the probe 2 and the dielectric layer 1b of the recording medium 1 are processed. The point is that a bias voltage can be applied between the two.

The vibration state of the probe changes and the amplitude changes due to the electrostatic force due to the interaction between the probe 2 and the recording medium 1. This amplitude change is also caused by applying a bias voltage between the probe and the recording medium. Change. That is, even if the potential on the recording medium is the same, the magnitude of the electrostatic force acting on the probe differs depending on the external bias voltage.

In the bias voltage controller 13, when an amplitude different from the initially set amplitude is input from the amplitude measuring device 11, the bias voltage between the probe and the recording medium is controlled so that the initially set amplitude is obtained. . This control amount corresponds to the potential on the recording medium. The control amount signal is sent to the recording processing device 9, where it is converted into a potential on the recording medium.
Except for the points described above, it is the same as the case of the first embodiment. [Embodiment 9] FIG. 11 is a view showing an embodiment in which the potential distribution is measured by vibrating the probe and controlling the bias voltage between the probe and the recording medium so as to keep its natural frequency constant. Is the same as in the case of [Embodiment 3], but the output signal of the natural frequency measuring device 12 enters the bias voltage control device 13, and the control signal is taken into the recording processing device 9, and the probe 2 and the recording medium 1 Dielectric layer 1b
A bias voltage can be applied between the two.

Although the natural frequency of the probe changes due to the electrostatic force due to the interaction between the probe 2 and the recording medium 1, this change in the frequency also changes when a bias voltage is applied between the probe and the recording medium. To do. That is, even if the potential on the recording medium is the same, the magnitude of the electrostatic force acting on the probe differs depending on the external bias voltage.

In the bias voltage control device 13, when a natural frequency different from the initially set natural frequency is input from the natural frequency measuring device 12, the probe-recording medium is adjusted so that the initially set natural frequency is obtained. Control the bias voltage across. This control amount corresponds to the potential on the recording medium. The control amount signal is sent to the recording processing device 9, where it is converted into a potential on the recording medium. Except for the points described above, it is the same as the case of the first embodiment.

Next, an example of measurement based on Example 5 described in FIG. 8 will be described. The specific system configuration of FIG. 8 is as shown in FIG.

The sample 21 corresponding to the recording medium 1 has a layer structure of insulating layer / ITO / glass, and the insulating layer is F
Using an EP (Fluoro Ethylene propylene) film, an electrostatic latent image (20 μm wide line &
Space) formed. The sample 21 is moved in the Z direction by the piezo actuator 25 which is driven and controlled by the power supply 27.
XY stage 26 driven by -Y controller 28
The laser diode (830 nm) driven by the function generator 31 applied a heat pulse to the cantilever 22 constituting the probe to oscillate it. The optical lever method is used to detect vibration.
The laser diode 24a (670 nm) was irradiated, and the reflected light was detected by the PSD 24b. The detection output is phase-detected by the lock-in amplifier 32, and the detection output drives the piezo actuator 25 from the power supply 27 through the amplifier 33.
The intervals were controlled so that the amplitude of the cantilever was constant. The output of the amplifier 33 at this time and the position information obtained from the XY controller 28 were input to the computer 29 and plotted.

[0038]

As described above, it is possible to read an electrostatic latent image with high resolution in a state where charges having the opposite polarity to the latent image charges are attached on the electrostatic latent image. INDUSTRIAL APPLICABILITY The present invention utilizes electrostatic force between a recording medium and a probe, and can be measured as long as it changes an electric field outside the recording medium such as electrostatic charge amount distribution, induced charge distribution, polarization state distribution, and dielectric constant distribution. It is possible. It can also be used as a reading device of a recording system using the above phenomenon as a memory.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic configuration of electrostatic latent image reading by a recording medium and a probe of the present invention.

FIG. 2 is a diagram illustrating an example in which an electrostatic latent image is read by mechanical displacement.

FIG. 3 is a diagram showing an example of a probe.

FIG. 4 is a diagram illustrating an example in which an electrostatic latent image is read based on a vibration amplitude.

FIG. 5 is a diagram illustrating an example in which an electrostatic latent image is read based on a natural frequency.

FIG. 6 is a diagram showing an example in which an electrostatic latent image is read from a probe-recording medium interval control amount for keeping mechanical displacement constant.

FIG. 7 is a diagram showing an example in which an electrostatic latent image is read from a probe-recording medium interval control amount for keeping the vibration amplitude constant.

FIG. 8 is a diagram showing an embodiment in which an electrostatic latent image is read from a probe-recording medium interval control amount for keeping a natural frequency constant.

FIG. 9 is a diagram showing an embodiment in which an electrostatic latent image is read based on a bias voltage control amount for keeping a mechanical displacement constant.

FIG. 10 is a diagram showing an embodiment in which an electrostatic latent image is read based on a bias voltage control amount for keeping a vibration amplitude constant.

FIG. 11 is a diagram showing an embodiment in which an electrostatic latent image is read from a bias voltage control amount for keeping the natural frequency constant.

FIG. 12 is a diagram showing a specific system configuration of FIG.

FIG. 13 is a diagram illustrating a proposed electrostatic latent image reading method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Recording medium, 1a ... Support body, b ... Dielectric layer, 1c ... Charge holding layer, 2 ... Probe, 3 ... Probe fixing jig, 4 ... Mechanical displacement detection device, 5 ... Z-direction moving device, 6 ... X -Y scanning device, 7 ... Z direction control device, 8 ... XY scanning control device, 9 ... Recording processing device, 10 ... Vibration excitation device, 11 ... Amplitude measuring device, 12 ... Natural frequency measuring device, 13 ... Bias Voltage control device.

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) G11B 9/02 G11B 11/08 G01N 13/10 G01N 13/20

Claims (9)

(57) [Claims] 1. An electrostatic latent image charge having a polarity opposite to that of the electrostatic latent image charge is deposited on an electrostatic latent image formed in the vicinity of the surface of a recording medium, and the electrostatic latent image charge and the opposite polarity charge have a sub-μm order. Minute interval
Bring the probe tip close to the recording medium to a distance near the gap
The electrostatic latent image charge and the surface of the opposite polarity charge and probe
Induced charges are induced in the probe according to the difference in the distance from the tip.
The electrostatic force generated between the probe and the recording medium.
The electrostatic latent image is read by detecting the mechanical displacement of the probe tip.
A method of reading an electrostatic latent image, characterized by taking . 2. A device for reading an electrostatic latent image, wherein a charge having a polarity opposite to that of the electrostatic latent image charge is attached on the electrostatic latent image formed inside the surface of the recording medium, and a potential detection probe. A moving means for three-dimensionally changing the relative positional relationship with the recording medium and a detecting means for detecting the action of the electrostatic force acting between the probe and the recording medium are provided, and the moving means reverses the electrostatic latent image charge and the reverse charge. Near sub-micrometer order micro-distance between polar charges
Rukoto to approximate the probe tip on the recording medium a distance beside
Electrostatic latent image charge and surface opposite charge and probe tip
Induces an induced charge in the probe according to the difference in the distance between
An electrostatic latent image reading device characterized by detecting the action of an electrostatic force acting between a probe and a recording medium by two-dimensionally scanning the recording medium or the probe. 3. The apparatus according to claim 2, further comprising an interval control means for controlling an interval between the probe and the recording medium so as to keep a constant action of an electrostatic force acting between the probe and the recording medium , and the interval control means. An electrostatic latent image reading device that reads an electrostatic latent image based on the control amount by. 4. The electrostatic latent image reading device according to claim 2, wherein the detection means detects an electrostatic force by detecting a mechanical displacement of the probe. 5. The apparatus according to claim 2, further comprising vibration excitation means for vibrating the probe at its natural frequency, and the detection means detects electrostatic force by detecting a change in vibration amplitude of the probe due to electrostatic force. An electrostatic latent image reading device characterized by detecting the. 6. The apparatus according to claim 2, further comprising a vibration excitation means for vibrating the probe at its natural frequency, and the detection means detects static electricity by detecting a change in natural frequency of the probe due to electrostatic force. An electrostatic latent image reading device characterized by detecting force. 7. The electrostatic latent image reading device according to claim 3, wherein the distance control means controls the distance between the probe and the recording medium so as to keep the mechanical displacement of the probe constant. apparatus. 8. The apparatus according to claim 3, further comprising vibration excitation means for vibrating the probe at its natural frequency, and the interval control means between the probe and the recording medium so as to keep the vibration amplitude of the probe constant. An electrostatic latent image reader characterized by controlling the distance between the two. 9. The apparatus according to claim 3, further comprising a vibration excitation means for vibrating the probe at its natural frequency, and the interval control means maintains the natural frequency of the probe constant. An electrostatic latent image reading device characterized by controlling a distance between them.