JP2000105297A - Electrostatic recording body, electrostatic latent image recording apparatus and electrostatic latent image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To record and read an electrostatic latent image with high sharpness at high speed by a simple record and read apparatus in electrostatic recording for recording image information as an electrostatic latent image. SOLUTION: This electrostatic recording body 10 is formed by sequentially stacking a conductor layer 1 having permeability to recording light 1, a recording photoconductive layer presenting photoconductivity by recording light 1L1, a charge transport layer 3 having non-sensitivity to light, serving as an insulator for negative charges and as a conductor for positive charges, a reading photocondutive layer presenting photoconductivity by read light L2, and a conductor layer 5 translucent to the read light L2 in order. After a D.C. voltage is applied to the electrostatic recording body 10 by a power supply 60 to charge both conductor layers 1, 5, an object 9 is exposed by a recording illuminating means 90 to record an electrostatic latent image on the interface between the recording photoconductive layer 2 and the charge transport layer 3. Read light L2 is scanned by a reading exposure means 92 and a current flowing out of the electrostatic recording body 10 is detected by a current detecting means 70 to read the electrostatic latent image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic recording medium capable of recording image information as an electrostatic charge pattern (electrostatic latent image) formed by irradiation with radiation such as X-rays, and an electrostatic recording medium. The present invention relates to an apparatus for recording image information on an electrophotographic recording medium and an apparatus for reading image information from an electrostatic recording medium on which image information is recorded.

[0002]

2. Description of the Related Art Conventionally, in medical X-ray photography, a photoconductor (for example, a selenium plate or the like) sensitive to X-rays is used as a photoreceptor in order to reduce the exposure dose received by a subject and improve diagnostic performance. A system for reading an electrostatic latent image formed by X-rays on the selenium plate with a laser beam or a large number of electrodes as an (electrostatic recording medium) is disclosed (for example, US Pat. No. 4,176,275, US Pat. No. 4,176,275). No. 5268569, No.5354982
No. 4535468, "23027 Method and devisce for
recording and transducing an electromagnetic ener
gy pattern "; Research Disclosure June 1983, JP-A-9
No.-5906, U.S. Pat.No. 4,961,209, "X-ray imaging using
amorphous selenium "; Med Phys.22 (12) etc.).

[0003] These methods have a higher resolution than an indirect imaging method using a TV image pickup tube, which is a well-known imaging method, and require X-rays required for imaging as compared with a zero radiography method (electro X-ray photography method). It is excellent in that the radiation dose is small.

[0004]

However, in each of the above systems, the reading speed decreases when the film thickness is increased in order to compensate for the defect of the selenium plate having a low X-ray absorption capability. It has a common problem that it is easy to pick up noise (structure noise) caused by geometric accuracy in the vertical direction.

Also, US Pat. Nos. 4,176,275 and 5,268,569
No. 5,354,982, the detection speed is slow because the recording X-ray photoconductive layer that requires a thickness is commonly used as the photoconductive layer for reading, and at least reading is performed after the latent image is formed. Since a high voltage is applied to the photoconductive layer from the start to the end, the charge due to the dark current is added to the latent image charge, and there is a problem that the contrast in a low dose range is reduced. Furthermore, there is an inherent problem that re-recording requires an erasing process.

[0006] Japanese Patent Application Laid-Open No. 9-5906 and Research Disclosu
In the system according to re June 1983, the X-ray photoconductive layer for recording and the photoconductive layer for reading are provided separately,
Although the detection speed has been improved and erasing is not required, a high voltage is applied from the start of reading to the end of reading (generally several seconds) after the formation of the latent image. There is a problem that the charge is added to the latent image charge and the contrast in a low dose range is reduced.

On the other hand, there is also described a method in which a high voltage is not applied at the time of reading and the electrodes on the recording side and the reading side are short-circuited and reading is performed. A uniform charge distribution is previously formed by the accumulated charges on the interface, and at the time of short-circuit, a high voltage due to the accumulated charges is applied to the reading photoconductive layer. For this reason, there is a problem that the contrast in the low dose region is also reduced due to the leakage of the charge due to the dark current.

Further, Japanese Patent Application Laid-Open No. 9-5906 and Research Disclosu
In the system according to re June 1983, a floodlight source for primary exposure is required, which increases costs, increases the size of the apparatus, and makes it difficult to provide uniform floodlighting. There is a problem that it is difficult to match the timing of light illumination and X-ray imaging.

No. 4,535,468 discloses a system having a three-layer structure of an X-ray photoconductive layer, a reading photoconductive layer, and an intermediate layer in which charges are accumulated as traps. This system applies a high voltage during recording to irradiate X-rays, accumulates latent image charges in the intermediate layer, and then reads out by short-circuiting. The speed is improved by making the photoconductive layer for reading thinner. Also, after the X-ray latent image is stored in the intermediate layer, short-circuiting occurs without applying a high voltage, and the state is short-circuited during reading. Therefore, the stored latent image charge leaks (decays) due to dark current. Unlike the above, since the leakage occurs in accordance with the amount of the latent image charge, the decrease in the contrast in the low dose range is reduced.

However, it is common to apply a high voltage for a long time before irradiating the recording X-ray. In this case, the high voltage is applied before the recording X-ray is applied. An offset charge component due to the accompanying dark current exists and cannot be removed. Further, since the reading photoconductive layer is thinner than the X-ray photoconductive layer, there is a problem that the amount of signal charges detected outside is small. Further, since the charge mobility of both the electrons and holes is small, the intermediate layer cannot be made thick. This is because if the charge mobility is increased, the response becomes slow or an afterimage occurs. That is,
In this system, it is difficult to achieve both the response, the charge storage capability, and the efficient extraction of the signal charge.

In each of the above systems, the recording is performed by scanning a spot light such as a laser beam, and the location where the latent image charge is accumulated, that is, the pixel is not fixed. Difficult to do.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it has been made possible to shorten the reading time (improve the reading speed) with a simple device and to maintain a high sharpness while maintaining a high sharpness. It is an object of the present invention to provide an electrostatic recording medium capable of achieving an S / N ratio, an apparatus for recording image information on the electrostatic recording medium, and an apparatus for reading image information from the electrostatic recording medium on which the image information is recorded. It is the purpose.

[0013]

According to the present invention, there is provided an electrostatic recording medium for recording radiation image information as an electrostatic latent image, comprising: a recording photoconductive layer and a reading photoconductive layer;
Image information is converted into an electrostatic latent image by laminating via a charge transport layer that acts as a conductor only for charges of one polarity, and accumulating charge at the interface between the recording photoconductive layer and the charge transport layer. The basic feature is that it is configured to be recordable. That is, the first electrostatic recording medium according to the present invention has a first conductive layer that is permeable to radiation such as recording X-rays, and has a photoconductive property by being irradiated with recording radiation. A photoconductive layer for recording, which acts substantially as an insulator with respect to charges of the same polarity as the charge charged on the first conductor layer, and substantially acts as a charge with a polarity opposite to this charge. A charge transport layer acting as a conductor, a photoconductive layer for reading that exhibits photoconductivity by being irradiated with electromagnetic waves for reading, and a second conductor layer having transparency to the electromagnetic waves for reading, It is characterized by being laminated in this order.

The recording photoconductive layer of the first electrostatic recording medium is composed of a-Se, PbO, PbI ₂ , Bi ₁₂ (Ge, S
i) It is preferable that at least one of O ₂₀ and Bi ₂ I ₃ / organic polymer nanocomposite is used as a main component, and that the thickness of the layer is 50 μm or more and 1000 μm or less.

Further, in the first electrostatic recording medium, it is preferable that the reading photoconductive layer exhibit photoconductivity even when irradiated with the recording radiation.

The term “electromagnetic wave” in the above description also includes so-called light such as infrared light and visible light, and is not limited as long as it can be used for reading an electrostatic latent image described later. It may be of a wavelength. The same applies hereinafter.

A second electrostatic recording medium according to the present invention is an electrostatic recording medium for recording radiation image information as an electrostatic latent image. And a conductive layer, which is laminated via a charge transport layer that acts as a conductor only for one polarity of charge,
In addition, the radiation such as the X-rays may be wavelength-converted once by a wavelength conversion layer into light in another wavelength region, and the wavelength-converted light may be applied to the recording photoconductive layer to record an electrostatic latent image. The basic feature of the present invention is that it is configured as follows. That is, the third electrostatic recording medium according to the present invention has a wavelength conversion layer such as an X-ray scintillator that converts recording radiation into visible light in the first wavelength region, and has transparency to the visible light. A first conductive layer, a recording photoconductive layer that exhibits photoconductivity by being irradiated with the visible light transmitted through the first conductive layer, and a charge that is charged on the first conductive layer. A light-insensitive charge transport layer that acts substantially as an insulator for charges of the same polarity, and also acts as a conductor for charges of the opposite polarity to the charge, irradiates electromagnetic waves for reading. A reading photoconductive layer exhibiting photoconductivity upon receiving and a second conductor layer having transparency to the reading electromagnetic wave are laminated in this order.

In the second electrostatic recording medium, the wavelength conversion layer converts the recording electromagnetic radiation into visible light in a second wavelength range, and the reading photoconductive layer is It is desirable that the layer exhibit photosensitivity when irradiated with visible light in the second wavelength region.

In any of the above electrostatic recording media, the reading photoconductive layer is made of a-Se, Se-Te, Se-As-T.
e, metal-free phthalocyanine, metal phthalocyanine, Mg
It is preferable that at least one of Pc, VoPc, and CuPc is a main component.

In any of the above-mentioned electrostatic recording media,
The reading photoconductive layer has a wavelength in the near ultraviolet to blue region (300
550 nm), and more preferably those having a low sensitivity to electromagnetic waves having a wavelength in the red region (700 nm or more).
-Se, PbI2, Bi12 (Ge, Si) O20, perylene bisimide (R = n-propyl), and perylene bisimide (R = n-neopentyl) are preferably used as the main component. .

The reading photoconductive layer of the electrostatic recording medium which exhibits photoconductivity even when irradiated with the recording radiation is at least one of a-Se, Se-Te, Se-As-Te. It is more preferable that the main component is (A).

Further, in any of the above electrostatic recording media,
The charge transport layer preferably contains at least one of PVK, TPD, a polymer dispersion of TPD, and a-Se doped with 10 to 200 ppm of Cl.

Further, in any of the above electrostatic recording media, it is desirable that the charge mobility in the thickness direction of the charge transport layer be larger than the charge mobility in the film thickness horizontal direction.

Further, in any of the above-mentioned electrostatic recording materials, the charge transport layer has a property of substantially acting as an insulator with respect to charges of the same polarity as the charges charged on the first conductive layer. A first charge transport layer made of a material, and a second charge transport layer made of a material having a property of substantially acting as a conductor with respect to a charge having a polarity opposite to that of the charge to be charged; It is preferable that the layer is laminated so that the transport layer is on the recording photoconductive layer side and the second charge transport layer is on the read photoconductive layer side. More preferably, the first charge transport layer is made of an organic material, and the second charge transport layer is made of a Se material.
Specifically, the first charge transport layer is made of PVK or TPD
Preferably, the second charge transport layer is an a-Se layer doped with 10 to 200 ppm of Cl. In this case, it is desirable that the second charge transport layer be thicker than the first charge transport layer.

Further, in any of the above electrostatic recording media,
A first blocking layer for preventing injection of charges charged in the first conductor layer into the recording photoconductive layer is laminated between the first conductor layer and the recording photoconductive layer. Or a second blocking layer for preventing the charge charged in the second conductive layer from being injected into the reading photoconductive layer, the second blocking layer and the reading photoconductive layer. It is desirable that they are stacked between the two.

Further, the sum of the thickness of the reading photoconductive layer and the thickness of the charge transporting layer is one of the thickness of the recording photoconductive layer.
/ 2 or less is more preferable, 1/10 or less is more preferable, and 1/20 or less is more preferable.

Further, in any of the above electrostatic recording media,
In the charge transport layer, the mobility of the charge of the same polarity as the charge charged to the first conductor layer is preferably 1/10 ² or less with respect to the mobility of the charge of the opposite polarity, 1/1
It is more preferable that the value be 0 ³ or less.

Further, in any of the above electrostatic recording media,
It is preferable that the second conductive layer has a comb electrode for reading formed in a comb shape.

Further, the width of the comb teeth is preferably 75% or less of the pitch of the comb teeth, and the gap between the comb teeth has a shielding property against the electromagnetic wave for reading. More preferably, it is desirable that the space between the pixels in the longitudinal direction of the comb tooth has a shielding property against the electromagnetic wave for reading.

The sum of the thickness of the read photoconductive layer and the thickness of the charge transport layer of the electrostatic recording medium having the read comb electrodes is preferably substantially equal to or less than the pitch of the comb teeth.

Further, in the electrostatic recording medium having the reading comb electrodes, the insulating layer and the third conductive layer, both of which are transparent to the reading electromagnetic wave, are formed in this order on the second conductive layer. Wherein the third conductive layer has a recording comb electrode formed in a comb-like shape substantially orthogonal to the comb teeth of the second conductor layer. It would be even more desirable.

Further, it is desirable that the space between the comb teeth of the third conductive layer has a shielding property to the electromagnetic wave for reading, and the comb of the third conductive layer is desirably provided. More preferably, the width of the teeth is no more than 75% of the pitch of the comb teeth.

The sum of the thickness of the reading photoconductive layer and the thickness of the charge transport layer of the electrostatic recording medium having the recording comb electrode is the third.
It is preferable that the pitch is substantially equal to or less than the pitch of the comb teeth of the conductor layer.

A first electrostatic latent image recording apparatus according to the present invention is an apparatus for recording radiation image information as an electrostatic latent image on any one of the above-mentioned electrostatic recording media. A power supply for applying a predetermined DC voltage between the first conductor layer and the second conductor layer, and a recording radiation carrying the image information is irradiated onto the recording photoconductive layer of the electrostatic recording medium A recording irradiating means for irradiating the recording photoconductive layer of the electrostatic recording medium with a charge having the same polarity as the charge charged on the first conductive layer by the irradiation of the radiation. The image information is recorded as an electrostatic latent image by accumulating it at a substantially interface with the transport layer.

A second electrostatic latent image recording apparatus according to the present invention is an apparatus for recording radiation image information as an electrostatic latent image on any of the electrostatic recording members having the recording comb electrodes. A power supply for applying a predetermined DC voltage between a first conductor layer and a third conductor layer of the electrostatic recording medium, and a recording radiation for carrying the image information, A recording irradiating means for irradiating the recording medium with a charge having the same polarity as the charge charged on the first conductive layer by the irradiation of the radiation. By accumulating at the approximate interface between the layer and the charge transport layer,
The image information is recorded as an electrostatic latent image.

Each of the above electrostatic latent image recording apparatuses further includes a pre-exposure means for irradiating a predetermined amount of electromagnetic radiation to the second conductor layer before irradiating the recording radiation. It is desirable.

An electrostatic latent image reading apparatus according to the present invention is an apparatus for reading an electrostatic latent image from any one of the above-mentioned electrostatic recording media in which radiation image information is recorded in advance as an electrostatic latent image,
A reading exposure unit that scans and exposes an electromagnetic wave for reading on the second conductive layer side of the electrostatic recording body, and the electrostatic exposure according to the electrostatic latent image by scanning exposure with the electromagnetic wave for reading. Current detecting means for detecting a current flowing out of the recording medium via the first or second conductive layer.

In the above-described electrostatic latent image reading device,
The electrostatic recording medium further includes connection means for selectively connecting the first conductor layer and the second conductor layer or the current detecting means, and the first conductor After connecting the layer and the second conductor layer to charge both conductor layers to the same potential, the current is detected by connecting the first conductor layer and the current detection means. It is desirable.

In any of the above electrostatic latent image reading devices, the reading photoconductive layer of the electrostatic recording medium has high sensitivity to electromagnetic waves having wavelengths in the near ultraviolet to blue range (300 to 550 nm). In the case where the reading exposure means has low sensitivity to an electromagnetic wave having a wavelength in the red region (700 nm or more), the scanning exposure means scans and exposes an electromagnetic wave having a wavelength in the near ultraviolet to blue region. Is desirable.

In this case, it is preferable that the reading exposure means performs scanning exposure while forming the reading electromagnetic radiation into a beam.

In an apparatus for reading an electrostatic latent image from an electrostatic recording medium having the reading comb electrodes, the reading exposure means applies the electromagnetic waves for reading, which are substantially uniform in a line, to the first electromagnetic wave. While making it approximately perpendicular to the comb teeth of the conductor layer 2
It is preferable that scanning exposure is performed in the longitudinal direction of the comb teeth of the second conductive layer, and the current detection means detects a current flowing out of the electrostatic recording medium for each of the comb teeth.

Further, in the apparatus for reading an electrostatic latent image from an electrostatic recording medium having the recording comb electrodes, the second conductive layer and the third conductive layer of the electrostatic recording medium are connected. It is desirable to have two connection means.

In the above electrostatic latent image reading device,
Further, it is preferable that the reading exposure means irradiates the reading electromagnetic wave in a pulse shape substantially every pixel.

In this case, the current detecting means further comprises:
An integration capacitor for accumulating the electric charge by the current flowing in the current detection means; and a discharging means for selectively discharging the electric charge accumulated in the integration capacitor, and detecting the electric charge accumulated in the integration capacitor for each pixel. It is more preferable that the current detecting means or the first conductive layer and the current detecting means are connected via a bias power supply having a predetermined DC voltage.
More preferably, the bias power supply is a power supply used for recording the electrostatic latent image.

[0045]

According to the electrostatic recording medium, the electrostatic latent image recording apparatus and the electrostatic latent image reading apparatus according to the present invention, first, the electrostatic recording medium is separated from the recording photoconductive layer and the reading A photoconductive layer, for example, having a three-layer structure in which a charge transport layer acting as a conductor only for positive charges is interposed, and charges are accumulated at the interface between the recording photoconductive layer and the charge transport layer. Since the image information can be recorded as an electrostatic latent image, when recording an electrostatic latent image on the electrostatic recording medium, both conductor layers sandwiching the three-layer structure are charged to a predetermined potential. All that is required is to irradiate the recording photoconductive layer with recording radiation,
Since there is no need to perform uniform exposure prior to recording to primary charge the electrostatic recording medium, it is not necessary to provide an exposure unit for uniform exposure, and the recording apparatus can be simplified. .

Further, according to the electrostatic recording medium, the electrostatic latent image recording device and the electrostatic latent image reading device of the present invention, prior to irradiating the recording photoconductive layer with the recording radiation, When both conductor layers sandwiching the structure are charged to a predetermined potential, dark current generated in the recording photoconductive layer, particularly dark current injected from the first conductor layer into the recording photoconductor layer (for example, , Electronic)
Reaches the charge transport layer interface and accumulates. Further, a dark current generated in the reading photoconductive layer, particularly a dark current (a hole in the example of the electron) injected from the second conductive layer into the reading photoconductive layer passes through the charge transport layer and accumulates. Neutralize the electrons. Here, if the conditions (material, thickness, etc.) of the two conductor layers or the two photoconductive layers are adjusted, it is possible to make the condition that the number of holes is slightly larger than the number of electrons reaching the interface. . If there are many holes, the surplus holes are injected into the recording photoconductor and drift to reach the electrodes without accumulating at the interface. In this case, dark electrons added to the latent image charges of the recording radiation in an offset manner can be suppressed to an extremely low level, so that an S / N having a good S / N can be easily realized.

Further, it is possible to adjust the condition that the number of holes reaching the interface is slightly smaller than the number of electrons. If there are a large number of electrons, the surplus electrons accumulate at the interface, but just before irradiating the recording radiation, an appropriate amount of holes are generated by uniformly performing a predetermined amount of preexposure on the reading photoconductor. As a result, surplus electrons at the interface can be neutralized. Of course, at this time, the surplus holes do not accumulate at the interface as described above and reach the electrodes.

In this case, also in this case, the dark electrons added in an offset manner can be kept extremely low.
Good N can be easily realized.

The latter is more preferable in terms of S / N. This is because, in the latter case, the dark resistance of the photoconductive layer for reading is large, so that the signal can be prevented from attenuating (fading) in the time course until the reading is completed.

Further, when the remaining latent image of the previous recording remains, the latter is preferable.

When a small charge (hole) injection barrier is formed between the transport charge layer and the recording photoconductive layer, a small amount of holes are accumulated therein. However, this often has a positive effect. That is, the accumulated small holes flatten the band structure of the reading photoconductive layer, cancel out the photoelectromotive force generated at the contact interface between the light incident electrode and the photoconductive layer, and have the effect of reducing noise current.

On the other hand, when reading the recorded electrostatic latent image, the reading electromagnetic wave can be irradiated from the relatively thin reading photoconductive layer side, so that it can be applied under a strong electric field without applying a high voltage. The electrostatic latent image can be read at high speed,
Furthermore, since there is almost no charge accumulation in the electrostatic recording medium after reading, it is necessary to provide an exposure means for the erasing process without needing an erasing process when recording again after reading. Therefore, the reading device can be simplified.

The recording photoconductive layer has a thickness of 50 μm
When the thickness is 1000 μm or less, the recording photoconductive layer can sufficiently absorb the recording radiation, and the amount of latent image charge can be increased, so that the S / N can be improved. .

Furthermore, in the above-mentioned electrostatic recording medium, if the reading photoconductive layer is made to exhibit photoconductivity with respect to the recording radiation, it is possible to prevent the accumulation of excess charges,
This makes it possible to reduce the dark current which is substantially proportional to the amount of accumulated charge when reading the electrostatic latent image, and consequently the S / S of the read image.
N can be improved.

As in the second electrostatic recording medium according to the present invention, radiation such as X-rays is once wavelength-converted to visible light in another wavelength region by a wavelength conversion layer, and then the wavelength-converted visible light is converted to visible light. When the recording photoconductive layer is configured to be able to record an electrostatic latent image by irradiating the recording photoconductive layer, the generation efficiency of the charge pairs generated in the recording photoconductive layer by the visible light can be increased. The amount of irradiation can be reduced, so the subject (subject)
Radiation dose can be kept low.

Further, the recording photoconductive layer which exhibits photoconductivity by irradiation with visible light can be made relatively thin, so that the signal extraction efficiency can be increased.

Further, the radiation such as X-rays is further wavelength-converted to second visible light in a different wavelength region so that the reading photoconductive layer exhibits photoconductivity with respect to this second visible light as well. In the same manner as described above, it is possible to prevent the accumulation of excess charges, thereby reducing the dark current that is substantially proportional to the amount of accumulated charges when reading the electrostatic latent image, and thereby improving the S / N of the read image. You can plan.

As the reading photoconductive layer of the electrostatic recording medium, various types can be used as described above, but the photoconductive layer has high sensitivity to electromagnetic waves having a wavelength in the near ultraviolet to blue region (300 to 550 nm). However, if a material having low sensitivity to an electromagnetic wave having a wavelength in the red region (700 nm or more) is used, a reading photoconductive layer having a large band gap and a small generation of dark current due to heat can be obtained. Noise due to dark current can be reduced.

Assuming that the charge mobility in the vertical direction of the film thickness of the charge transport layer is greater than the charge mobility in the horizontal direction of the film thickness,
The charge can move at a high speed in the vertical direction of the film thickness, that is, in the thickness direction, and it is difficult for the charge to move in the horizontal direction, that is, the horizontal direction of the film thickness. Therefore, the sharpness can be improved.

The charge transport layer is formed of a first charge made of a material having a property of substantially acting as an insulator with respect to charges having the same polarity as charges (latent image charge) charged on the first conductive layer. A first charge transport layer including at least a transport layer and a second charge transport layer made of a material having a property of substantially acting as a conductor with respect to a charge having a polarity opposite to the polarity of the latent image (transport polarity charge); Is laminated on the recording photoconductive layer side and the second charge transporting layer is on the reading photoconductive layer side. Since the first charge transport layer can be provided with a strong insulating property against the latent image polar charge, it can be made ideal as the charge transport layer.

It is to be noted that the present invention is not limited to the two layers, and may be formed of a plurality of layers. In this case, when the respective layers are laminated, the first conductive property is determined when the respective properties are compared. The layer having a relatively strong property of acting substantially as an insulator with respect to the electric charge having the same polarity as the electric charge charged on the body layer is located on the recording photoconductive layer side, and is substantially opposite to the electric charge having the opposite polarity to the electric charge. What is necessary is just to laminate | stack so that the layer which has a relatively strong property which acts as a conductor may be on the reading photoconductive layer side.

As described above, it is possible to increase the charge mobility of the transport polar charge by selecting the material to be used for the charge transport layer or to form the charge transport layer into a multilayer structure. And the charge storage stress can be compatible. In addition, since trapping of transport carriers in the charge transport layer can be reduced, an afterimage hardly remains even when the film thickness is increased.

If a blocking layer is laminated between the conductive layer and the recording or reading photoconductive layer, charge injection from the conductive layer, which is a noise component of the read image, can be prevented. By adjusting the material, thickness, and the like, the balance of charge injection from both conductor layers can be effectively adjusted, thereby improving the S / N of the read image.

The sum of the thickness of the read photoconductive layer and the thickness of the charge transport layer is made smaller than the thickness of the recording photoconductive layer (for example, 以下 or less, further 1/1
(0 or less, more preferably 1/20 or less), and the accumulated charge (electrostatic latent image) can be read under a strong electric field, so that the electrostatic latent image can be read at high speed.

Furthermore, if the mobility of the charge accumulated as the electrostatic latent image in the charge transport layer is sufficiently smaller than the mobility of the charge of the opposite polarity (specifically, 1/10 ² or less, more preferably, 1/10 ³ or less), so that the accumulation property of the accumulated charge is improved, so that the preservability of the electrostatic latent image can be improved.

Further, if the conductive layer laminated on the reading photoconductive layer is formed as a comb-shaped reading comb electrode, the accumulated electric charges can be concentrated on the comb teeth, and the accumulated electric charge between the comb teeth can be accumulated. As a result, the charge can be separated, and the sharpness of the electrostatic latent image in the arrangement direction of the comb teeth can be improved. In this case, if the sum of the thickness of the charge transport layer and the thickness of the reading photoconductive layer is substantially equal to or less than the pitch of the comb teeth corresponding to the pixel pitch, the sharpness of the electrostatic latent image can be further improved. it can.

Further, the area of the reading electrode is reduced due to the comb-shaped conductor layer, and the capacitance formed between the reading photoconductive layer and the latent image forming interface via the charge transport layer is substantially reduced. Decrease.

On the other hand, the capacitance formed at the interface between the other electrode and the latent image via the recording photoconductive layer has substantially no significant effect. As a result, it is possible to increase the signal extraction efficiency at the time of reading despite the fact that the charge transport layer and the reading photoconductive layer are thinner than the recording photoconductive layer.

Further, since the reading exposure means can be used for scanning and exposing uniform light in a line shape in the longitudinal direction of the comb teeth, the reading exposure means can have a simple structure. . Further, the area of the reading electrode is reduced due to the comb-shaped conductor layer, the distribution capacitance is reduced, the influence of noise is reduced, and pixel pixels can be fixed at least at the comb-tooth spacing. The image data of the electrostatic latent image can be corrected according to the arrangement of the comb teeth, and the structure noise can be corrected.

Further, the intensity of the electric field at the time of reading is also concentrated on the comb teeth, and the electric field becomes stronger and separated, so that the sharpness and the signal intensity at the time of reading are improved. In particular, if the width of the comb teeth is set to 75% or less of the comb pitch, the effect is increased. In addition, if the longitudinal direction of the comb tooth has a blocking property at the pixel interval, the scanning exposure is performed with a substantially small beam spot despite the scanning exposure with the linear light source, which is higher. A read image with sharpness can be obtained. Furthermore, if the sum of the thickness of the reading photoconductive layer and the thickness of the charge transport layer is approximately equal to or less than the pitch of the comb teeth, an electric field is approximately generated at the interface between the recording photoconductive layer and the charge transport layer. The non-existing portion can be clearly formed, and the sharpness can be further improved.

When the recording comb electrodes are stacked so as to be orthogonal to the reading comb electrodes, the distribution of the electric field during recording is converged at the intersection of both comb teeth, and the electric charges are concentrated at the converged points. Therefore, an electrostatic latent image with high sharpness can be recorded also in the longitudinal direction of the comb teeth. Further, it is possible to substantially reduce the capacity of the charge transport layer and the reading photoconductive layer, thereby increasing the signal extraction efficiency at the time of reading. In this case, if the width of the comb teeth is 75% or less of the comb pitch, or if the space between the recording comb teeth is blocked, the effect is further increased.

The electrostatic latent image recording apparatus according to the present invention is for recording image information as an electrostatic latent image on the above-mentioned various types of electrostatic recording media. As described above, the recording photoconductive layer and the charge transport layer It is only necessary to charge both conductor layers sandwiching the three-layer structure of the reading photoconductive layer to a predetermined potential, so that an extremely simple recording apparatus can be realized. In particular, even in the case of recording an electrostatic latent image on an electrostatic recording medium provided with a recording comb electrode, the recording device does not need to be particularly changed and only the electrode to which the voltage is applied needs to be changed. Thus, the sharpness can be remarkably improved in the longitudinal direction of the comb teeth, so that the recording device plays an extremely important role.

Further, before irradiating the recording radiation,
By irradiating a predetermined amount of electromagnetic radiation to the second conductive layer, unnecessary charges accumulated in the electrostatic recording medium before the recording light is irradiated can be erased. Thus, problems such as an afterimage phenomenon and S / N deterioration caused by the above problem can be solved.

The electrostatic latent image reading apparatus according to the present invention reads an electrostatic latent image from the above-mentioned various electrostatic recording media on which an electrostatic latent image is recorded. Since scanning exposure for reading can be performed from the photoconductive layer side, an electrostatic latent image can be read at a high speed under a strong electric field. Since there is no accumulation, an erasing process is not required when recording is performed again after reading, and an extremely simple reading device can be realized without having to include an exposure unit for the erasing process. Further, a so-called laser beam can be used as an exposure means (light source) for scanning exposure for reading, or in the case of reading an electrostatic latent image from an electrostatic recording medium provided with a comb electrode for reading. It is also possible to use a linear light source, and there is no need for a special light source device or scanning exposure device.

If the reading light is scanned and exposed in a pulsed manner, the electrostatic latent image can be read with a large detection current, thereby improving the S / N of the read image. become able to.

Further, as a more specific electrostatic latent image reading device, a current amplifier using an operational amplifier is used, the electric charge accumulated in the integrating capacitor is detected for each pixel,
Further, the detection can be performed by applying a bias voltage, and the electrostatic latent image can be read with an extremely simple configuration.

[0077]

Embodiments of the present invention will be described below with reference to the drawings. First, an embodiment of the electrostatic recording medium according to the present invention will be described in detail.

FIG. 1 is a sectional view of the electrostatic recording medium according to the first embodiment of the present invention. This electrostatic recording medium
Reference numeral 10 denotes a first conductor layer 1 having transparency to recording radiation (for example, X-rays, etc .; hereinafter, referred to as “recording light”) L1 described below, and radiation transmitted through the conductor layer 1 A recording photoconductive layer 2 exhibiting conductivity when irradiated with L1;
A charge (latent image charge; for example, a negative charge) charged on the conductive layer 1 substantially acts as an insulator, and a charge of the opposite polarity to the charge (transport polarity charge; positive in the above example). (A charge), a charge transporting layer 3 acting substantially as a conductor, and a reading photoconductive layer 4 exhibiting conductivity when irradiated with a reading electromagnetic wave (hereinafter referred to as "reading light") L2 described later. , A second conductive layer 5 having transparency to the electromagnetic wave L2 is laminated in this order.

Here, as the conductor layers 1 and 5, for example, a material in which a conductive substance is uniformly applied on a transparent glass plate (such as a Nesa film) is suitable. , Amorphous selenium (a-Se), PbO, Pb
Lead (II) oxide such as I ₂ , lead (II) iodide, Bi ₁₂ (G
_{e, Si) O 20, Bi} 2 I 3 / photoconductive material containing as a main component at least one organic polymer nanocomposite and the like are suitable.

As the charge transport layer 3, the larger the difference between the mobility of the negative charge charged on the conductor layer 1 and the mobility of the positive charge having the opposite polarity (for example, 10 ² or more, preferably 10 ² or more). ³ or more) poly N-vinyl carbazole (PV
K), N, N'-diphenyl-N, N'-bis (3-methylphenyl)-[1,1'-biphenyl] -4,4'-diamine (TP
D) or organic compounds such as discotic liquid crystals, or TPD polymers (polycarbonate, polystyrene,
PUK) dispersion, a semiconductor material such as a-Se doped with 10 to 200 ppm of Cl is suitable. In particular, organic compounds (PVK, TPD, discotic liquid crystal, etc.) are preferable because they have photosensitivity, and the dielectric constant is generally small, so that the capacities of the charge transport layer 3 and the photoconductive layer 4 for reading become small, so Can be increased in signal extraction efficiency. Note that “having light insensitivity” means that the recording light L1
And that it hardly exhibits conductivity even when irradiated with the reading light L2.

As the reading photoconductive layer 4, a-Se, S
e-Te, Se-As-Te, metal-free phthalocyanine,
Metal phthalocyanine, MgPc (Magnesium phtalocyanine)
ine), VoPc (phase II of Vanadyl phthalocyanin)
e), a photoconductive substance mainly containing at least one of CuPc (Cupper phtalocyanine) and the like is preferable.

The thickness of the recording photoconductive layer 2 should be not less than 50 μm and not more than 1000 μm so that the recording light L 1 can be sufficiently absorbed.
μm or less, and in this example, about 500 μm.
m. Further, the thickness of the charge transport layer 3 and the photoconductive layer 4 is desirably not more than １ ／ of the thickness of the recording photoconductive layer 2, and the thinner (for example, 1/10 or less, more preferably 1/20 or less) Responsiveness at the time of reading described later is improved.

Next, a basic method of recording image information as an electrostatic latent image on the electrostatic recording medium 10 having the above-described structure and reading out the recorded electrostatic latent image will be briefly described.

FIG. 2 is a schematic configuration diagram of a recording and reading system (integrating an electrostatic latent image recording device and an electrostatic latent image reading device) using the electrostatic recording medium 10. This recording and reading system includes an electrostatic recording medium 10, a recording irradiation unit 90, a power supply 6
0, current detection means 70, reading exposure means 92, and connection means S
1 and S2, and the electrostatic latent image recording device
0, a power source 60, a recording irradiating unit 90, and a connecting unit S1. The electrostatic latent image reading unit includes an electrostatic recording body 10, a current detecting unit 70, and a connecting unit S2.

The conductor layer 1 of the electrostatic recording medium 10 is connected to the negative electrode of the power source 60 via the connecting means S1 and the connecting means S2
Is also connected to one end. One end of the other end of the connecting means S2 is connected to the current detecting means 70, and the other end of the conductive layer 5 of the electrostatic recording medium 10, the positive electrode of the power supply 60, and the other end of the connecting means S2 are grounded. The current detection means 70 includes a detection amplifier 70a composed of an operational amplifier and a feedback resistor 70b, and forms a so-called current-voltage conversion circuit.

An object 9 is disposed on the upper surface of the conductor layer 1. The object 9 has a portion 9a having transparency to the recording light LI and a blocking portion (light shielding portion) 9b having no transparency. I do. The recording irradiating means 90 uniformly blasts the recording light L1 onto the subject 9, and the reading exposing means 92 scans and exposes the reading light L2 such as infrared laser light in the direction of the arrow in FIG. It is preferable that the reading light L2 has a beam shape converged to a small diameter.

Hereinafter, an electrostatic latent image recording process and an electrostatic latent image reading process in the recording and reading system having the above-described configuration will be described. First, the process of recording an electrostatic latent image will be described with reference to a charge model (FIG. 3). Connection means in FIG.
With S2 in an open state (not connected to any of the ground and the current detection means 70), the connection means S1 is turned on, and a DC voltage Ed from the power source 60 is applied between the conductor layer 1 and the conductor layer 5, Power supply
From 60, a negative charge is applied to the conductive layer 1, and a positive charge is applied to the conductive layer 5.
(See FIG. 3 (A)). Thereby, the electrostatic recording medium
In 10, a parallel electric field is formed between the conductor layers 1 and 5.

Next, the recording light L1 is uniformly emitted from the recording irradiation means 90 toward the subject 9. The recording light L1 transmits through the transmitting portion 9a of the subject 9, and further transmits through the conductor layer 1. The photoconductive layer 2 receives the transmitted recording light L1 and becomes conductive. This can be understood by acting as a variable resistor that shows a variable resistance value according to the light amount of the recording light L1, and the resistance value generates a charge pair of an electron (negative charge) and a hole (positive charge) by the recording light L1. Therefore, if the light amount of the recording light L1 transmitted through the subject 9 is small, the resistance value becomes large (see FIG. 3B). When the X-ray is used as the recording light L1, it should be expressed as a dose, but here, it is expressed as a light amount including the dose. Also, the recording light
Negative (-) and positive (+) charges generated by L1
Is represented by enclosing-or + in the drawing.

The positive charges generated in the photoconductive layer 2
It moves at a high speed toward the conductor layer 1 through the inside, and recombine with the negative charges charged in the conductor layer 1 at the interface between the conductor layer 1 and the photoconductive layer 2 to disappear (FIG. C), (D)). On the other hand, the negative charges generated in the photoconductive layer 2 move toward the charge transfer layer 3 in the photoconductive layer 2. The charge transfer layer 3 has the same polarity as the charge on the conductor layer 1 (negative charge in this example).
Act as an insulator, the negative charges moving in the photoconductive layer 2 stop at the interface between the photoconductive layer 2 and the charge transfer layer 3 and are accumulated at this interface. (See FIGS. 3 (C) and (D)). The amount of charge stored is determined by the photoconductive layer 2
It is determined by the amount of negative charge generated therein, that is, the amount of recording light L1 transmitted through the subject 9.

On the other hand, since the recording light L1 does not pass through the light-shielding portion 9b of the subject 9, the portion corresponding to the lower portion of the light-shielding portion 9b of the electrostatic recording medium 10 does not change at all (see FIGS. 3B to 3D). reference).

In this manner, the recording light L1 is bombarded onto the subject 9, so that charges corresponding to the subject image are transferred to the photoconductive layer 2.
And the charge transfer layer 3 can be accumulated at the interface. The image of the subject due to the accumulated charges is called an electrostatic latent image. As is apparent from the above description, the configuration of the apparatus for recording an electrostatic latent image on the electrostatic recording medium 10 according to the present invention is extremely simple, and the recording operation is also extremely simple.

Next, the process of reading an electrostatic latent image will be described with reference to a charge model (FIG. 4). The connection means S1 is opened to stop the power supply, and S2 is once connected to the ground side, and the electrostatic recording medium 10 on which the electrostatic latent image is recorded as described above.
After the electric conductor layers 1 and 5 are charged to the same potential and the electric charges are rearranged (see FIG. 4A), the connecting means S2 is connected to the current detecting means 70 side.

When the reading light L2 is scanned and exposed to the conductive layer 5 side of the electrostatic recording medium 10 by the reading exposure means 94, the reading light L2 is transmitted through the conductive layer 5, and the transmitted reading light L2 is irradiated. The photoconductive layer 4 becomes conductive in response to the scanning exposure. This depends on the fact that the photoconductive layer 2 exhibits conductivity by receiving the recording light L1 to generate a positive and negative charge pair, and similarly, the photoconductive layer 2 generates a positive and negative charge pair by receiving the reading light L2. (See FIG. 4B). Note that, similarly to the recording process, the negative charge (-) and the positive charge (+) generated by the reading light L2 are represented by enclosing-or + in the drawing.

It is desirable that the thickness of the photoconductive layer 4 and the charge transport layer 3 be as thin as possible (eg, 1/10 or less, more preferably 1/20 or less). A very strong electric field (strong electric field) is formed between the interface and the conductive layer 5 by the accumulated charge (negative charge) according to the thickness. Further, since the charge transport layer 3 acts as a conductor for positive charges, the positive charges generated in the photoconductive layer 4 rapidly move through the charge transport layer 3 so as to be attracted to the accumulated charges. Then, at the interface between the photoconductive layer 2 and the charge transport layer 3, the accumulated charge and the charge recombination disappear and disappear (see FIG. 4C). On the other hand, the negative charges generated in the photoconductive layer 4 recombine with the positive charges in the conductive layer 5 and disappear (see FIG. 4C). The photoconductive layer 4 has the reading light L2
, The scanning exposure is performed with a sufficient amount of light, and the accumulated charges accumulated at the interface between the photoconductive layer 2 and the charge transport layer 3, that is, all the electrostatic latent images are eliminated by charge recombination. As described above, the disappearance of the charges stored in the electrostatic recording medium 10 means that the current I due to the movement of the charges flows in the electrostatic recording medium 10, and this state is the The recording medium 10 can be represented by an equivalent circuit as shown in FIG. 4D in which the current amount is represented by a current source whose current amount depends on the accumulated charge amount.

As described above, as the sum of the thicknesses of the reading photoconductive layer 4 and the charge transport layer 3 is smaller than the thickness of the recording photoconductive layer 2, the stronger the electric field is at the time of reading. Formed,
Since the movement of the charges is also performed rapidly, the reading can be performed at a high speed. Further, if the mobility of the negative charge in the charge transport layer 3 is sufficiently smaller than the mobility of the positive charge (for example, 1/10 ³ or less), the accumulation property of the accumulated charge is improved, and the preservability of the electrostatic latent image is improved. Will be done.

The electrostatic latent image recording process and the electrostatic latent image reading process described above will be briefly described using a capacitor model. FIG. 5 shows the electrostatic recording medium 10 by an electrical equivalent circuit diagram based on a capacitor model. In FIG. 5, C _{* a} is the distributed capacitance of the photoconductive layer 2, C _{* b} is the distributed capacitance between the charge transport layer 3 and the photoconductive layer 4, SW _{* a} is the optical switch of the photoconductive layer 2, and SW _{* b} is the charge. An optical switch between the transport layer 3 and the photoconductive layer 4,
R _{* a} indicates a variable resistor of the photoconductive layer 2 depending on the light amount, and R _{* b} indicates a variable resistor of the charge transport layer 3 and the photoconductive layer 4 depending on the light amount. The suffix * such as C _{* a} is 1,2, ..., n
And basically indicates a pixel. FIG. 6 illustrates the electrostatic recording medium 10 shown in FIG. 5 in which a transmission part 9a and a light-shielding part 9b of the subject 9 are separately illustrated based on an electrical equivalent circuit diagram based on a capacitor model. In the recording process, since the DC voltage Ed is first applied to the electrostatic recording medium 10, the distributed capacitances C _{* b} and C _{* b} are charged (see FIG. 6A).

In the transmission section 9a, the optical switch SW _{* a} is turned on by the irradiation of the recording light L1, and the resistance value of the variable resistor R _{* a} changes according to the amount of light, so that only the distribution capacitance C _{* b} is charged. (See FIG. 6 (B)). This is the electrostatic latent image recording process,
This means that the electrostatic latent image has been recorded on the distribution capacitance C _{* b} . Next, after the power source 60 is removed, the distribution capacitors C _{* a} and C _{* b} are connected, and both distribution capacitors are set to the same potential (charge rearrangement) (FIG. 6C).
reference). Here, by exposing the reading light L2, the optical switch SW _{* b} is turned on, the resistance value of the variable resistor R _{* b} changes according to the light amount, and the current I flows from the distributed capacitance C _{* a} , and The electric latent image is read out (see FIG. 6D).

On the other hand, the light shielding section 9b is connected to the recording light L1 by the optical switch SW.
_{* a} is not turned on, and neither distribution capacitance C _{* a} nor C _{* b} is changed (see FIG. 6E). For this reason, when the distribution capacitances C _{* a} and C _{* b} are connected at the time of reading, both the distribution capacitances are discharged (see FIG. 6 (F)). Even if the reading light L2 is exposed in such a state, no current flows from the distributed capacitance C _{* a} (see FIG. 6 (G)).

As described above, by detecting the current flowing from the electrostatic recording medium 10 while scanning and exposing the reading light L2, the accumulated charge amount of each portion (corresponding to the pixel) that has been scanned and exposed can be sequentially read. To read an electrostatic latent image. Further, since a very strong electric field is formed between the interface between the photoconductive layer 2 and the charge transport layer 3 and the conductor layer 5, the accumulated charges can be eliminated at a very high speed. Means that the response of reading the electrostatic latent image is extremely high.

In general, when reading an electrostatic latent image, a dark current proportional to the amount of the total charge stored in the electrostatic recording medium flows in addition to the signal current due to the disappearance of the stored charge. The signal current is detected by being superimposed on the dark current. This means that the read electrostatic latent image contains noise due to dark current. In this example, the accumulated charge amount is proportional to the intensity of the recording light L1 transmitted through the subject 9. When the recording light L1 is weak, the accumulated charge amount is small, and when the accumulated charge amount is small, the dark current decreases. Thus, the read image has high image quality. Furthermore, since the accumulated charge does not exist in the electrostatic recording medium 10 after the electrostatic latent image is read out in this manner, when the electrostatic latent image is newly recorded on the electrostatic recording medium 10, No erasing process is required,
The above recording process can be performed immediately.

The material used for the electrostatic recording medium according to the present invention is not limited to the above-described example, and various materials can be changed.

For example, if the charge transport layer 3 has a charge mobility in the direction perpendicular to the film thickness larger than the charge mobility in the film thickness horizontal direction, the transport polarity charges can move at a high speed in the thickness direction. Since the charge transport layer 3 is not easily moved in the lateral direction, the sharpness can be improved. Specific materials include discotic liquid crystal and hexapentyloxytriphylene.
enylene (see Physical Review LETTERS 70.4, 1933), discotic liquid crystal group whose central core contains π-conjugated condensed rings or transition metals (EKISHO VOL No.1 19
97 P55).

The charge transport layer 3 is formed of a material having a property of substantially acting as an insulator against charges charged on the recording conductor layer 2, that is, charges having the same polarity as the latent image polarity charge. A first charge transport layer, and a second charge transport layer made of a material having a property of substantially acting as a conductor with respect to a charge having a polarity opposite to the polarity of the latent image, that is, a transport polarity charge; The transport layer is a recording photoconductive layer 4
If the second charge transport layer is laminated so as to be on the side of the reading photoconductive layer 2, the second charge transport layer is provided with high-speed transportability of transport polar charges, and the first charge transport layer is provided with the first charge transport layer. Since the transport layer can be provided with a strong insulating property against the latent image polarity charge, the charge transport layer can be made ideal. Specifically, the first charge transport layer is a layer composed of at least one of PVK and TPD,
The second charge transporting layer may be an a-Se layer doped with 10 to 200 ppm of Cl. At this time, it is desirable that the second charge transport layer be thicker than the first charge transport layer.

Further, comparing the layer made of PVK with the layer made of TPD, the layer made of PVK acts almost as an insulator for a charge having the same polarity as the latent image polarity charge (negative polarity in the above example). The property is stronger than the layer composed of TPD,
The layer made of PD has a transport polarity charge (positive in the above example).
Is stronger than the layer made of PVK, so that the layer made of TPD and the layer made of PVK are different from each other in that the layer made of TPD becomes the reading photoconductive layer side.
The charge transport layer may be stacked such that the layer made of K is on the recording photoconductive layer side.

It is to be noted that the present invention is not limited to the two layers, and may be composed of a plurality of layers. In this case, when the respective layers are laminated, when the respective properties of the respective layers are compared, the latent image polarity charge The layer that has a relatively strong property of substantially acting as an insulator for charges of the same polarity as the recording photoconductive layer is on the recording photoconductive layer side, and the layer that has a relatively strong property of substantially acting as a conductor for the transport polarity charge is read. What is necessary is just to laminate so that it may become the photoconductive layer side for use.

The reading photoconductive layer 4 has high sensitivity to electromagnetic waves having a wavelength in the near ultraviolet to blue range (300 to 550 nm) and is sensitive to electromagnetic waves having a wavelength in the red range (700 nm or more). One having a low sensitivity, specifically, a-Se, PbI2, Bi12 (Ge, Si) O2
If a photoconductive material containing at least one of 0, perylene bisimide (R = n-propyl) and perylene bisimide (R = n-neopentyl) as a main component is used, the band gap is large and the dark current due to heat is increased. Can be obtained as the reading photoconductive layer 4 in which the occurrence of the light is small.
By scanning and exposing an electromagnetic wave having a wavelength in the range from near ultraviolet to blue, noise due to dark current can be reduced.

Next, a second embodiment of the electrostatic recording medium according to the present invention will be described in detail with reference to FIGS. In FIG. 8, the same elements as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted unless otherwise required.

The electrostatic recording medium according to the second embodiment
11 is the same as the electrostatic recording medium 10 according to the first embodiment in the laminated structure, but the reading photoconductive layer 4a is
A material exhibiting conductivity even when irradiated with L1 (for example, a-Se, Se-Te, Se-As, S
e-As-Te alloy).

A method of recording an electrostatic latent image on the electrostatic recording medium 11 using the same recording and reading system as described above will be described. Although the operation method of the system is not different from the above description, the amount of charge accumulated at the interface between the recording photoconductive layer 2 and the charge transport layer 3 when a large amount of the recording light L1 is irradiated is determined by electrostatic recording. This is different from the case where the body 10 is used. Hereinafter, this point will be described in detail.

The amount of electric charge accumulated at the interface between the recording photoconductive layer 2 and the charge transport layer 3 is substantially proportional to the amount of the recording light L1. The larger the irradiation amount, the larger the accumulated charge amount (see the straight line a in FIG. 7). On the other hand, when reading an electrostatic latent image, it is known that the dark current increases as the total amount of accumulated charges on the electrostatic recording medium increases, which causes a problem of deteriorating the S / N during reading.

When the light quantity of the recording light L 1 is sufficiently large, the recording light L 1 generates a charge pair in the recording photoconductive layer 2, and a large number of charges are generated at the interface between the recording photoconductive layer 2 and the charge transport layer 3. Some of them not only accumulate but also partially do not contribute to charge accumulation, but pass through the photoconductive layer 2 or the charge transport layer 3 and reach the reading photoconductive layer 4.

The reading photoconductive layer 4 of the electrostatic recording medium 11 exhibits conductivity even when irradiated with the recording light L1.
Inside the photoconductive layer 4 for reading, the recording light L1 transmitted through the charge transport layer 3 receives the recording light L1 to generate positive and negative charge pairs (see FIG. 8A). Note that, similarly to the first embodiment, the negative charge (−) and the positive charge (+) generated by the irradiation of the recording light L1 are represented by enclosing-or + in the drawing.

In the charge transport layer 3, an electric field is generated due to the charge accumulated at the interface between the recording photoconductive layer 2 and the charge transport layer 3 and the charge of the conductor layer 5. Since it acts as a conductor against the charges, the positive charges generated in the reading photoconductive layer 4 are attracted to the interface between the recording photoconductive layer 2 and the charge transport layer 3 (see FIG. 8B). Charge recombination is performed between the positive charge that has reached and the negative charge accumulated at the interface, and both charges disappear (see FIG. 8C). This effect can occur even when the light amount is small, but since the amount increases in accordance with the increase in the light amount of the recording light L1, that is, the amount of the accumulated charge, the accumulated charge is substantially proportional to the light amount. The amount is still increasing.

On the other hand, the recording light reaching the reading photoconductive layer 4
When the light amount of L1 becomes larger than a predetermined light amount, an action similar to the so-called avalanche effect comes to work, and the generation of positive and negative charge pairs inside the reading photoconductive layer 4 rapidly increases (FIG. 7 curve b). Therefore, when the recording light L1 is irradiated in a large amount exceeding a predetermined light amount, the amount of accumulated charge does not increase almost in proportion to the light amount of the recording light L1, but the degree of increase rapidly decreases. Therefore, the accumulated charge amount does not excessively increase (see the curve c in FIG. 7).

In general, in order to record an electrostatic latent image that faithfully reflects an image of a subject, if the accumulated charge amount changes linearly within a predetermined range (effective image range) of the recording light L1. The area irradiated with the recording light L1 that is sufficient and equal to or more than a predetermined amount is a so-called plain portion, and is not important as image information, and the amount of accumulated charge is proportional to the recording light L1. Does not need to increase.
Rather, an increase in dark current due to the large amount of accumulated charge,
As a result, the deterioration of the S / N of the read image becomes more problematic.

For this reason, by using the electrostatic recording medium 11 according to the second embodiment, even when the recording light L1 is irradiated in a large amount, the amount of accumulated charges is not excessively increased, and the static electricity is reduced. It is possible to reduce the dark current when reading the electrostatic latent image, thereby contributing to an improvement in S / N at the time of reading the electrostatic latent image. Further, the recording and reading system using the electrostatic recording body 10 according to the first embodiment can be used as it is, and the electrostatic recording body 10 is changed to the electrostatic recording body 11 according to the second embodiment. In addition, since the stacked structure of the electrostatic recording body 11 can be easily formed, it is extremely easy to improve the S / N at the time of reading the electrostatic latent image when the recording light L1 is irradiated in a large amount. Can be realized.

Next, a third embodiment of the electrostatic recording medium according to the present invention will be described in detail with reference to FIG. In FIG. 9, the same elements as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted unless otherwise required.

The electrostatic recording medium according to the third embodiment
Reference numeral 12 denotes a wavelength conversion layer called a so-called X-ray scintillator, which converts the wavelength of X-rays (recording light) L1 into light (for example, blue light) L3 in another wavelength region on the surface of the conductor layer 1 as shown in FIG. 6 are laminated. As the wavelength conversion layer 6, for example, cesium iodide (CsI) or the like is preferably used.

The conductor layer 1 has transparency to the blue light L3, and the recording photoconductive layer 2 exhibits conductivity when irradiated with the blue light L3.
Alternatively, a member similar to the electrostatic recording member 10 according to the second embodiment can be used. In this example, the electrostatic latent image is recorded by the blue light L3, the conductor layer 1 does not need to transmit X-rays, and the recording photoconductive layer 2 is formed of X-ray. It does not need to exhibit conductivity when irradiated. Hereinafter, a method of recording an electrostatic latent image on the electrostatic recording medium 12 using the same recording and reading system as that of FIG. 2 will be described.

The recording light L 1 passes through the transmitting portion 9 a of the subject 9 and enters the wavelength conversion layer 6. The wavelength conversion layer 6 converts the wavelength of the recording light L1 into blue light L3, and the higher the conversion efficiency, the better (for example, cesium iodide (CsI) has a higher conversion efficiency). The wavelength-converted blue light L3 transmits through the conductive layer 1 and irradiates the photoconductive layer 2. The photoconductive layer 2 using amorphous selenium exhibits conductivity to blue light L3 very efficiently. Therefore, the electrostatic recording medium
When the recording medium 10 was used, a part of the recording light L1 did not contribute to the charge accumulation and some of the recording light L1 passed through the photoconductive layer 2. Positive and negative charge pairs can be generated very efficiently in the photoconductive layer 2 not by the light L1 but by the wavelength-converted blue light L3. Further, when cesium iodide (CsI) is used as described above, the conversion efficiency of the wavelength conversion layer is high, so that even if the irradiation amount of the recording light L1 is reduced, it is possible to store a sufficiently large amount of charges. Thus, the exposure dose to the subject can be kept low.

As the wavelength conversion layer 6, one that converts the wavelength of the recording light L1 into light L4 in another wavelength region (for example, red light) is used (for example, Y ₂ O ₃ : Eu, YVO ₄ : A scintillator in which a phosphor emitting red light such as Eu and a phosphor emitting blue light such as CsI are mixed),
If a material exhibiting photoconductivity by L4 (for example, metal-free phthalocyanine, metal phthalocyanine, etc.) is used,
The photoconductive layer 2 using amorphous selenium does not exhibit photoconductivity with respect to the red light L4 and the photoconductive layer 2 and the charge transfer layer 3
Therefore, some of the wavelength-converted red light L4 that irradiates the photoconductive layer 4 exists, and the red light L4 causes the photoconductive layer 4 to exhibit conductivity. Therefore, similarly to the electrostatic recording medium 11 according to the second embodiment, even when the recording light L1 is irradiated in a large amount, the accumulated charge amount does not excessively increase. It is also possible to reduce the dark current when reading an image, thereby contributing to an improvement in S / N when reading an electrostatic latent image.

Next, a fourth embodiment of the electrostatic recording medium according to the present invention will be described in detail with reference to FIG. In FIG. 10, the same elements as those in FIG. 1 are denoted by the same reference numerals, and a description thereof will be omitted unless otherwise required.

The electrostatic recording medium according to the fourth embodiment
13 is different from the electrostatic recording medium 10 according to the first embodiment in that a blocking layer 7a is laminated between the conductor layer 1 and the photoconductive layer 2 as shown in FIG. The blocking layer 7a is a barrier such as Al ₂ O _{3 of} about 500 ° and has a barrier potential. In the case where the blocking layer 7a is not provided as in the case of the electrostatic recording medium 10, for example, some of the negative charges charged on the conductive layer 1 are directly injected into the photoconductive layer 2 and the negative charge is present on the photoconductive layer 2. The negative charge directly injected into the photoconductive layer 2 is accumulated as an accumulated charge at the interface between the photoconductive layer 2 and the charge transport layer 3. Since this electric charge is not generated by the irradiation of the recording light L1, it becomes a so-called noise component.
On the other hand, when a barrier potential is provided by the blocking layer 7a, charges (negative charges in this example) charged on the conductor layer 1 may be injected into the photoconductive layer 2 due to the barrier potential. As a result, generation of noise due to direct injection of negative charges can be prevented.

On the other hand, some of the charges (positive charges in this example) charged on the conductor layer 5 include those which are directly injected into the photoconductive layer 4. The charges move through the charge transport layer 3 and recombine with the stored charges to make the stored charges disappear. Since the disappearance of the accumulated charges due to the charge recombination does not occur due to the irradiation of the reading light L2, it becomes a so-called noise component. For this reason, as shown in FIG. 10 (B), a blocking layer 7b such as CeO _{2 of} about 500 ° is laminated between the conductive layer 5 and the photoconductive layer 4 as in the electrostatic recording medium 14 to form the conductive layer. Similarly to the above, the positive charge charged to 5 is prevented from being injected into the photoconductive layer 4 due to the barrier potential, so that the generation of noise due to the direct injection of the positive charge can be prevented.

Next, a fifth embodiment of the electrostatic recording medium according to the present invention will be described in detail with reference to FIG. In FIG. 11, the same elements as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted unless otherwise required.

FIG. 11 is a perspective view of the electrostatic recording medium 15 according to the fifth embodiment, which is different from the first embodiment in that the conductive layer 5 is formed in a comb-like shape. Different from the electrostatic recording medium 10 and the like. Note that between the comb teeth 5a, 5b is the reading light L2.
It is preferable to have a light shielding property.

To record an electrostatic latent image on the electrostatic recording medium 15, a recording and reading system similar to that shown in FIG. 2 can be used, but the electrostatic latent image is recorded at the interface between the photoconductive layer 2 and the charge transport layer 3. The method of accumulating charges is different from that of the above-described electrostatic recording medium 10 or the like. Hereinafter, a method for recording an electrostatic latent image will be described in detail with reference to a cross-sectional view of the electrostatic recording medium 15 (FIG. 12). When recording an electrostatic latent image, a DC voltage is first applied between the conductor layer 1 and the comb teeth 5a of the conductor layer 5 to charge both conductor layers, as in FIG. Thereby, the comb teeth 5a of the conductor layer 1 and the conductor layer 5 are formed.
A U-shaped electric field is formed between the photoconductive layer 2 and a substantially parallel electric field existing at most portions of the photoconductive layer 2, but an electric field is generated at the interface between the photoconductive layer 2 and the charge transport layer 3. A portion that does not exist is generated (see the arrow Z in FIG. 12A). The smaller the total thickness of the charge transport layer 3 and the photoconductive layer 4 compared to the thickness of the photoconductive layer 2 and the smaller the ratio between the width and the pitch of the comb teeth 5a (even if the ratio is 75% or less). If the thickness of the charge transport layer 3 and the photoconductive layer 4 is substantially equal to or less than the pitch of the comb teeth 5a, the portion where such an electric field does not exist is clearly formed.

When the recording light L1 is bombarded on the subject 9 in such a state, the negative charges of the positive and negative charge pairs generated by the recording light L1 transmitted through the transmitting portion 9a are changed along the electric field distribution to the comb teeth 5a. (See FIG. 12 (B)), and an electrostatic latent image is recorded centering on the comb teeth 5a (see FIG. 12 (C)). It should be noted that the positive charge of the positive / negative charge pair generated by the exposure of the recording light L1 is attracted to the conductive layer 1 and disappears, similarly to the electrostatic recording medium 10.

In particular, when the light amount of the recording light L1 is small,
The negative charges are attracted to the center of the comb teeth 5a, and the accumulated charges are separated for each comb tooth, and the accumulated charges are accumulated together with each comb tooth 5a. Makes it possible to record an electrostatic latent image with high sharpness (spatial resolution). In today's advanced semiconductor formation technology, it is easy to form the comb teeth 5a at sufficiently small intervals, so that the electrostatic recording medium 15 according to the present invention can be easily manufactured. it can.

Next, the process of recording and reading an electrostatic latent image on the electrostatic recording medium 15 will be described with reference to a recording and reading system shown in FIG. As shown in FIG. 13A, this system comprises an electrostatic recording medium 15, a flow detecting means 71, and a recording irradiating means 90.
And reading exposure means 93.
Is to apply a substantially uniform reading light L2 in a line shape to the comb teeth of the conductive layer 5.
Scanning exposure is performed in the longitudinal direction (the direction of the arrow in the figure) of the comb teeth 5a while being substantially orthogonal to 5a (such an exposure means is referred to as a linear exposure means). Thus, the electrostatic recording medium
With the use of 15, it is possible to configure the reading exposure means 93 by a linear exposure means without using a laser beam, and configure the reading apparatus with a very simple and low-cost scanning optical system. It becomes possible. In addition, since an incoherent light source can be used, it is possible to prevent the occurrence of interference fringe noise. It is also possible to use a device for scanning and exposing the beam-like reading light as shown in FIG.

The current detecting means 71 is provided for each of the comb teeth 5a of the conductor layer 5.
It has a large number of current detection amplifiers 71a connected to each of them, and detects the current flowing through each comb tooth 5a by exposure of the reading light L2 in parallel for each comb tooth 5a. Electrostatic recording medium 15
Of the connection means 71b and the power supply 71
c is connected to the negative electrode, and the positive electrode of the power supply 71c is connected to the connecting means.
Connected to the other input of 71b. The output of the connection means 71b is connected to each current detection amplifier 71a (see FIG. 13).
(B)).

FIG. 13B is a block diagram showing the current detecting means 71 in detail along with a side cross section of the electrostatic recording medium 15.
Hereinafter, a method of recording an electrostatic latent image on the electrostatic recording medium 15 and reading the electrostatic latent image from the read electrostatic recording medium 15 will be described with reference to FIG.

First, the connecting means 71b is connected to the positive electrode side of the power supply 71c, and an electrostatic latent image is recorded on the electrostatic recording medium 15 in the same manner as in the first embodiment. After the recording is completed, the connecting means 71b is connected to the conductor layer 1 side of the electrostatic recording medium 15. The scanning exposure of the reading light L2 by the reading exposure means 93 causes a current I to flow from the conductive layer 1 of the electrostatic recording medium 15 to the comb teeth 5a of the conductive layer 5 via the current detection amplifier 71a. Each current detection amplifier
71a, the integration capacitor 71
e is charged and the integration capacitor 71
The charge is accumulated in e, and the voltage across the integrating capacitor 71e rises. Therefore, the connection means 71f is turned on between the pixels during the scanning exposure to discharge the electric charge accumulated in the integration capacitor 71e, thereby making the integration capacitor 71e.
, A change in voltage is observed one after another in accordance with the accumulated charge of each pixel. Since this change in voltage corresponds to the electric charge of each pixel stored in the electrostatic recording medium 15, the electrostatic latent image can be read out by detecting the change in voltage.

As described above, if the electrostatic latent image is read from the electrostatic recording medium 15 by the reading exposure means 93 using the line exposure means, the conductive layer 5 has a comb-like shape. As a result, the distribution capacity of the charge transport layer 3 and the photoconductive layer 4 is reduced, and the current detecting means 71 is less affected by noise. The image data is corrected in accordance with the arrangement of the image data, and the structure noise can be accurately corrected.

Further, the comb teeth 5a of the conductor layer 5 and the accumulated charges are attracted, and the positive charges generated by the irradiation of the reading light L2 according to the electric field make it easier to erase the accumulated charges, and the electrostatic latent image reading It is possible to maintain a high sharpness even when recording, and the effect is particularly high on the low light amount side during recording (that is, when the accumulated charge amount is small). Further, since the electric field strength of the photoconductive layer 4 is increased in the vicinity of the comb teeth 5a, a charge pair is generated by the reading light L2 in this strong electric field, so that the ion dissociation efficiency of excitons increases, and the charge pair The quantum efficiency of generation can be made closer to 1, and the light energy density can be reduced. Furthermore, the capacity of the charge transport layer 3 and the capacity of the reading photoconductive layer 4 can be reduced, and the signal extraction efficiency at the time of reading can be increased.

Further, as shown in FIG. 14, between the comb teeth 5a 5b
It is also possible to provide a light-shielding portion and a light-transmitting portion at predetermined intervals in the longitudinal direction (scanning direction) of the comb teeth 5a as well as to have a light-shielding property with respect to the reading light L2. The portion corresponding to the eyes is formed as a reading light transmitting portion, and even in the longitudinal direction of the comb teeth 5a, it is possible to avoid a decrease in spatial resolution due to light leakage with an adjacent reading light transmitting portion at the time of reading the electrostatic latent image. As a result, scanning and exposure are performed in parallel with a substantially small spot beam, and a read image with extremely high sharpness can be obtained without converging the read light L2 so much.

Next, a sixth embodiment of the electrostatic recording medium according to the present invention will be described in detail with reference to FIG. In FIG. 15, elements that are the same as the elements in FIG. 11 are given the same reference numerals, and descriptions thereof will be omitted unless otherwise necessary.

FIG. 15A is a perspective view of an electrostatic recording medium 16 according to the sixth embodiment. The electrostatic recording medium 15 is read on the surface of the comb-like conductive layer 5 and further together. An insulating layer 8c having transparency to the light L2 and a comb-shaped conductor layer 8 are laminated, and the comb teeth 8a are comb teeth 5a of the conductor layer 5.
Are formed substantially orthogonally. FIGS. 15B and 15C are cross-sectional views of the XZ plane and the XY plane of FIG. 15A, respectively.

A method for recording an electrostatic latent image on the electrostatic recording medium 16 will be described with reference to FIG. When recording an electrostatic latent image, first, a DC voltage is applied between the conductor layer 1 and the comb teeth 8a of the conductor layer 8 to charge both conductors. In addition,
It is desirable that no DC voltage be applied to the comb teeth 5a of the conductor layer 5. In this way, an electric field having a distribution as shown in FIGS. 16B and 16C is formed between the conductor layers 5 and 8. That is, as shown in FIG. 16 (B), from the comb teeth 8a of the conductor layer 8 to the comb teeth 5a of the conductor layer 5 by the longitudinal direction of the comb teeth 8a of the conductor layer 8 and the comb teeth 5a of the conductor layer 5. The electric field converged in a U-shape and the comb teeth of the conductor layer 8 due to the longitudinal direction of the comb teeth 8a of the conductor layer 8 and the comb teeth 5a of the conductor layer 5 as shown in FIG. An electric field which is diffused in a U-shape from 8a toward the comb teeth 5a of the conductor layer 5 is formed. The manner of forming the electric field distribution between the conductor layer 5 and the conductor layer 1 is the same as in the case of the electrostatic recording member 15 according to the fifth embodiment. Therefore, the conductor layer 5
The final distribution of the electric field formed by the comb teeth 5a and 8a of the conductor layer 8 is shown in FIG.
As shown in (D), a substantially contoured electric field is formed around the intersection of the comb teeth 5a and 8a.

In this state, when the recording light L1 is bombarded onto the subject 9 in the same manner as in the recording and reading system shown in FIG.
The charge accumulated by the recording light L1 transmitted through the transmission portion 9a is
As a result, the electrostatic latent image can be recorded with a higher sharpness than the electrostatic recording medium 15. The sharpness can be further increased by reducing the ratio of the width and pitch of the comb teeth (for example, 75% or less), and the comb teeth 8a
This effect becomes even more pronounced if the portion 8b is made of a material having a light-shielding property against the reading light L2 (for example, a polymer material (eg, polyethylene) in which a pigment (eg, carbon black) is slightly dispersed).

In order to read out the electrostatic latent image from the electrostatic recording medium 16 on which the electrostatic latent image has been recorded in this manner, using the same method as the above-described electrostatic recording medium 15 and the like, And conductor layer 5a
What is necessary is just to detect the electric current which flows between. At this time, the comb teeth of the conductor layer 8a are preferably left as it is. By reading out the electrostatic latent image from the electrostatic recording medium 16 in this way, in particular, the pixel pixels can be fixed in the direction of both comb teeth, so that the structure noise is adjusted in accordance with the arrangement of both comb teeth. Can be corrected more accurately.

Next, another embodiment of the electrostatic latent image reading apparatus according to the present invention will be described. Note that a reading device using the electrostatic recording medium 10 according to the first embodiment is referred to as an electrostatic latent image reading device according to the first embodiment, and the reading device according to the fifth embodiment.
The reading apparatus using the electrostatic recording medium 15 according to the second embodiment is referred to as an electrostatic latent image reading apparatus according to the second embodiment.

In each of the electrostatic latent image reading apparatuses according to the first and second embodiments, it is assumed that the reading exposure means 92 or 93 emits the reading light L2 constantly. Although the electrostatic latent image reading device according to the third embodiment does not differ in the configuration as the reading device from the electrostatic latent image reading device according to the first or second embodiment (the drawing of the configuration is This is different in that the reading exposure means 94 emits the reading light L2 in a pulsed manner. FIG. 17 shows the operation.
This will be described with reference to FIG.

When an electrostatic latent image is read from an electrostatic recording medium (for example, the electrostatic recording medium 10) on which an electrostatic latent image is recorded as accumulated charges, as described above, it is substantially proportional to the total amount of accumulated charges of each pixel. This dark current flows uniformly during current detection irrespective of the pixel to be read, and becomes a noise component of the read image. Therefore, assuming that the accumulated charge Q is as shown in FIG. 17A corresponding to the readout pixel (pixel width W, pitch P), this accumulated charge is read out by the reading light L2 which is constantly emitting light. The current detected when reading at the read time T1 can be expressed as a signal current superimposed on a dark current proportional to the total amount of accumulated charges as shown in FIG. 17 (B).

On the other hand, as shown in FIG. 17C, when the reading exposure means 94 emits sufficiently strong light in a pulse form (T1> T2) in accordance with the read light L2 in accordance with the pixel, As shown in D), the accumulated charges are read when the pulse light is exposed. Here, since the current is represented by the time derivative of the charge, even if the amount of charge read out corresponding to each pixel is the same, the current is detected as a larger current as the charge is read out in a shorter time. That is, when reading with pulsed light, FIG.
As shown in FIG. 17, a current larger than that in FIG. 17B is detected. In this way, by reading out the electrostatic latent image by emitting the reading light in a pulsed manner at a short interval corresponding to the pixel, a pixel having a small accumulated charge amount can be detected as a sufficiently large current. , S /
N can be dramatically improved.

Next, a fourth embodiment of the electrostatic latent image reading apparatus according to the present invention will be described in detail with reference to FIG. In FIG. 18, elements that are the same as the elements in FIG. 2 are given the same reference numerals, and descriptions thereof will be omitted unless otherwise necessary. The electrostatic latent image reading apparatus according to the fourth embodiment is obtained by replacing the current detecting means 70 in FIG. 2 with a current detecting means 72 shown in FIG. , The current detecting means 70 in FIG. 2 may be considered as the current detecting means 72 and the electrostatic recording body 10 may be considered as the electrostatic recording body 17). FIG. 18 is a schematic block diagram at the time of reading an electrostatic latent image.
72, and a reading exposure means 95. The electrostatic recording body 17 may be any of the electrostatic recording bodies described above, and the reading exposure means 95 may be any of the above-described one that performs scanning exposure in the form of a beam and the one that performs scanning exposure in the form of a line. It does not matter whether the light is emitted in a pulsed manner.

The current detecting means 72 includes a detection amplifier 72a composed of an operational amplifier, an integrating capacitor 72b connected between the output of the operational amplifier and one of the input terminals, and a selectively openable / closable connected in parallel with the integrating capacitor 72b. Connection means 72c
Consists of One end of the input terminal is connected to the conductive layer 1 of the electrostatic recording medium 17, and the other of the input terminals is connected to the conductive layer 5 of the electrostatic recording medium 17.

A method of reading an electrostatic latent image from the electrostatic recording medium 17 will be described below with reference to FIGS. As in the recording and reading system shown in FIG. 2, first, the connection means S1 is opened to stop the power supply, and S2 is once connected to the ground side (see FIG. 2), and the electrostatic latent image is recorded. After the conductive layers 1 and 5 of the electrophotographic recording medium 17 are similarly charged, the connecting means S2 is connected to the current detecting means 72 (this state is shown in FIG. 18).

In the electrostatic latent image reading apparatus having such a configuration, the current I is transmitted from the conductive layer 1 of the electrostatic recording medium 17 to the current detecting Flow out towards. This current charges the integration capacitor 72b, and charges are accumulated in the integration capacitor 72b in accordance with the amount of current flowing into the integration capacitor 72b.
The voltage across b rises. Therefore, by turning on the connecting means 72c between the pixels during the scanning exposure and discharging the electric charge accumulated in the integrating capacitor 72b, both ends of the integrating capacitor 72b correspond to the accumulated electric charge of each pixel one after another. Therefore, a change in voltage is observed. Since this change in voltage corresponds to the electric charge of each pixel stored in the electrostatic recording medium 17, the electrostatic latent image can be read by detecting the change in voltage.

With the electrostatic latent image reading apparatus according to the fourth embodiment, the same operation and effect as those shown in FIG. 2 can be obtained, and the structure of the apparatus is the same as that of the reading apparatus section in FIG. Because of the simplicity, an electrostatic latent image reading device using the above-described various types of electrostatic recording media can be realized with an extremely simple device.

Next, a fifth embodiment of the electrostatic latent image reading apparatus according to the present invention will be described in detail with reference to FIG. In FIG. 19, elements that are the same as the elements in FIG. 2 are given the same reference numerals, and descriptions thereof will be omitted unless otherwise required. The electrostatic latent image reader according to the fifth embodiment has a bias power supply 73a inserted into the current detection input section of the current detection means 70 in FIG. 2 (the configuration diagram is omitted). FIG. 19 is a schematic block diagram at the time of reading an electrostatic latent image, and includes an electrostatic recording medium 17, a current detection unit 73, and a reading exposure unit 95. The electrostatic recording body 17 may be any of the electrostatic recording bodies described above, and the reading exposure means 95 may be any of the above-described one that performs scanning exposure in the form of a beam and the one that performs scanning exposure in the form of a line. It does not matter whether the light is emitted in a pulsed manner.

The current detecting means 73 corresponds to the current detecting means 70 shown in FIG.
The bias power supply 73a is inserted into the power supply, and the reading of the electrostatic latent image is the same as that of FIG. 2 except that the bias power supply 73a is inserted. The bias power supply 73a may be different from the DC power supply 60 used when recording the electrostatic latent image,
The connection method of the connection means S1 and S2 may be changed and shared.

As described above, by applying a voltage from the bias power supply 73a, the reading speed can be further increased, and the electrostatic latent image can be reliably erased. Therefore, no noise is generated even during continuous shooting.

Further, the electrostatic latent image reader according to the fifth embodiment can provide the same operation and effects as those shown in FIG. 2, and the configuration of the apparatus is the same as that of the reader shown in FIG. Similarly, since it is simple, an electrostatic latent image reading apparatus using the above-mentioned various electrostatic recording bodies can be realized with an extremely simple apparatus.

Next, a recording and reading system in which pre-exposure is performed will be described. First, the pre-exposure will be described.

In the recording and reading system according to the present invention, when an electrostatic latent image is read from an electrostatic recording medium, all of the stored latent image charges can be basically read out. The latent image charge may not be completely read out, and may be read out and left on the electrostatic recording medium as a residual charge. When an electrostatic latent image is recorded on an electrostatic recording medium, a high voltage is applied to the electrostatic recording medium before the irradiation of the recording light. At this time, a dark current is generated, and the electric charge (darkness) due to the dark current is generated. Current charge) is also accumulated on the electrostatic recording medium. Further, it is known that various charges are accumulated in the electrostatic recording medium before the irradiation of the recording light due to other causes. Unnecessary charges accumulated before the irradiation of the recording light, such as residual charges and dark current charges, are added to the charges carrying the image information accumulated by irradiating the recording light. When an electrostatic latent image is read from an electrophotographic recording medium, a signal output includes a signal component due to unnecessary charges in addition to a signal based on charges carrying image information. Cause problems.

The "pre-exposure" erases unnecessary charges accumulated in the electrostatic recording medium before irradiating the recording light to the electrostatic recording medium, and eliminates problems such as an afterimage phenomenon and S / N deterioration. It is for.

FIG. 20 shows pre-exposure, recording light and reading light,
5 is a timing chart illustrating a relationship between a high voltage applied to an electrostatic recording medium and electric charges accumulated in the electrostatic recording medium.

Before the period t0, the residual charge Q1 due to the unread signal remains.
Are stored in the electrostatic recording medium. If pre-exposure is performed before applying a high voltage to the electrostatic recording medium (period t0 to t1), this charge Q1
Can be reduced. When a high voltage is applied to the electrostatic recording medium at t1, a dark current charge due to a dark current is further superimposed on the charge accumulated up to that time. Therefore, when pre-exposure is not performed before applying a high voltage to the electrostatic recording medium, charge Q2 is accumulated, and when pre-exposure is performed, charge Q2 'is accumulated. Next, when the pre-exposure is performed in the period t2 to t4, the charge Q2 can be reduced. Depending on the time of pre-exposure,
Of course, the amount of charge remaining on the electrostatic recording medium differs. For example, as shown in FIG. 20, if the pre-exposure is performed from t2 to t4 to completely reduce the charge, and then the recording light is irradiated at t5, the charge Q3 carrying only the image information is accumulated in the electrostatic recording medium. Can be done. Therefore, by irradiating the reading light at t7, a signal can be extracted based on the charge Q3 carrying only image information, and problems such as an afterimage phenomenon and S / N deterioration can be solved.

FIG. 21 is a schematic diagram showing an electrostatic latent image recording and reading system in which the above-mentioned pre-exposure is performed. As shown in FIG. 21, the recording and reading system includes an electrostatic recording medium 10, a recording irradiation unit 90, a power supply 60, a current detection unit 70, a reading exposure unit 92, a pre-exposure unit 96, and connection units S1 and S2. Become.
As is apparent from comparison with FIG. 2, the electrostatic latent image recording and reading system shown in FIG. 2 is further provided with a pre-exposure means 96.

Before applying a high voltage to the electrostatic recording medium 10 and irradiating the recording light L1, a predetermined light L3 is applied to the entire surface of the conductor layer 5 on the reading side of the electrostatic recording medium 10 to perform electrostatic recording. The charge stored in the body 10 is erased. The pre-exposure may be started before applying a high voltage to the electrostatic recording medium 10 (t0 to t1 in FIG. 20).
At this time, the connection means S2 is either open or connected to the ground side. When the connection is made to the ground side, it is needless to say that the connection means S2 needs to be opened before the high voltage is applied to the electrostatic recording medium 10. The predetermined light L3 may be the same electromagnetic wave as the reading light L2, and the amount thereof may be smaller than the reading light L2. Further, the pre-exposure is for eliminating unnecessary charges accumulated in the electrostatic recording medium 10 before the irradiation of the recording light, thereby eliminating problems such as an afterimage phenomenon and S / N deterioration. Thus, if necessary, the pre-exposure may be performed not on the entire surface of the conductive layer 5 but on a specific location.

In the electrostatic latent image recording and reading system, the pre-exposure means 96 is provided separately from the reading exposure means 92, but the reading exposure means 92 also functions as the pre-exposure means 96.
The light L3 for pre-exposure is applied to the conductive layer 5 by the exposure means 92 for reading.
May be applied to the entire surface of the substrate.

The pre-exposure means 96 may be constituted by electric luminescence (EL). In this case, an organic EL or an inorganic EL may be used. Further, a combination of a liquid crystal and a backlight therefor may be used.

In the above description, the first conductive layer of the electrostatic recording medium is charged with a negative charge, and the second or third conductive layer is charged with a positive charge, so that the recording photoconductive layer and the charge transport layer are charged. Although the description has been made of the one that causes negative charges to accumulate at the interface with, the present invention is not necessarily limited to this, and each may be a charge of the opposite polarity. Is to realize a recording and reading device similar to that described above by making a slight change such as changing the hole transport layer of the electrostatic recording medium to the electron transport layer and reversing the polarity of the power supply during recording. Can be.

For example, in the electrostatic recording medium 10, a photoconductive substance such as the above-mentioned amorphous selenium a-Se, lead oxide (II), and lead (II) iodide can be similarly used as the photoconductive layer 2. N-trinitrofluorenylidene aniline (TNFA) dielectric, trinitrofluorenone (TNF) / polyester dispersion, and asymmetric diphenoquinone derivative are suitable for the charge transport layer 3. Phthalocyanine and metal phthalocyanine can be used similarly, and the above-mentioned amorphous selenium a-Se, Se-Te, Se-As, Se-As-Te alloy and the like can be similarly used as the reading photoconductive layer 4a.

In the above description, the recording light is applied to the first conductor layer side, but the present invention is not necessarily limited to this. In particular,
If the second conductive layer, the reading photoconductive layer, and the charge transport layer are permeable to the recording light, the recording light is irradiated from the second conductive layer side, and the recording photoconductive layer is irradiated with the recording light. It is possible for the layer to exhibit conductivity. That is, the electrostatic recording medium according to the present invention can irradiate recording light from any direction of the first conductor layer or the second conductor layer.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an electrostatic recording medium according to a first embodiment of the present invention.

FIG. 2 is a recording / reading system using the above-mentioned electrostatic recording medium (integrating an electrostatic latent image recording device and an electrostatic latent image reading device)
Configuration diagram

FIG. 3 is a view for explaining a method of recording an electrostatic latent image on the electrostatic recording medium.

FIG. 4 is a view for explaining a method of reading an electrostatic latent image recorded on the electrostatic recording medium.

FIG. 5 is an equivalent circuit (capacitor model) of the electrostatic recording medium.

FIG. 6 is a diagram showing a method of recording and reading an electrostatic latent image using the electrostatic recording medium in a capacitor model.

FIG. 7 is a diagram showing the relationship between the amount of recording light transmitted through a subject and the amount of accumulated charges.

FIG. 8 is a view for explaining a method for recording an electrostatic latent image on an electrostatic recording medium according to a second embodiment of the present invention;

FIG. 9 is a view for explaining a method for recording an electrostatic latent image on an electrostatic recording medium according to a third embodiment of the present invention.

FIGS. 10A and 10B are cross-sectional views of an electrostatic recording medium according to a fourth embodiment of the present invention.

FIG. 11 is a perspective view of an electrostatic recording medium according to a fifth embodiment of the present invention.

FIG. 12 is a view for explaining a method of recording an electrostatic latent image on an electrostatic recording medium according to the fifth embodiment.

FIG. 13 is a configuration diagram (A) and a block diagram (B) of a recording and reading system for reading out an electrostatic latent image from an electrostatic recording medium according to the fifth embodiment on which an electrostatic latent image is recorded.

FIG. 14 is a view for explaining an electrostatic recording medium according to the fifth embodiment in which light is shielded in the longitudinal direction of the comb teeth.

FIG. 15 is a perspective view (A) and sectional views (B) and (C) of an electrostatic recording medium according to a fifth embodiment of the present invention.

FIG. 16 is a view for explaining an electric field distribution of the electrostatic recording medium according to the fifth embodiment.

FIG. 17 is a view for explaining a reading method of the electrostatic latent image reading apparatus according to the third embodiment using the electrostatic recording medium according to the present invention;

FIG. 18 is a configuration diagram of an electrostatic latent image reading apparatus according to a fourth embodiment using the electrostatic recording medium according to the present invention.

FIG. 19 is a configuration diagram of an electrostatic latent image reading apparatus according to a fifth embodiment using the electrostatic recording medium according to the present invention.

FIG. 20 is a timing chart showing a relationship between pre-exposure, recording light, and reading light, a high voltage applied to the electrostatic recording medium, and electric charges accumulated in the electrostatic recording medium.

FIG. 21 is a configuration diagram of a recording / reading system that performs pre-exposure.

[Explanation of symbols]

 10-17 electrostatic recording medium 1 first conductive layer 2 photoconductive layer for recording 3 charge transport layer 4,4a photoconductive layer for reading 5 second conductive layer 6 wavelength conversion layer 7a, 7b blocking layer 8 3 Conductive layer 9 Subject 60 DC power supply 70-74 Current detection means 90 Recording irradiation means 92-95 Reading exposure means 96 Pre-exposure means S1, S2 Connection means L1 Recording radiation (recording light) L2 Reading Electromagnetic wave (reading light) L3 Light for pre-exposure

Claims (44)

[Claims] 1. An electrostatic recording medium for recording radiation image information as an electrostatic latent image, comprising: a first conductive layer having transparency to recording radiation; A recording photoconductive layer exhibiting photoconductivity, acts substantially as an insulator with respect to a charge having the same polarity as the charge charged in the first conductive layer, and has a polarity opposite to that of the charge. A charge transporting layer that acts as a substantially conductive material, a reading photoconductive layer that exhibits photoconductivity when irradiated with a reading electromagnetic wave, and a second conductive material that is transparent to the reading electromagnetic wave. An electrostatic recording medium comprising layers laminated in this order. 2. The recording photoconductive layer is made of a-Se, Pb.
O, PbI ₂ , Bi ₁₂ (Ge, Si) O ₂₀ , Bi ₂ I ₃ /
2. The electrostatic recording medium according to claim 1, wherein at least one of the organic polymer nanocomposites is a main component. 3. The recording photoconductive layer has a thickness of 50 μm.
3. The structure according to claim 2, wherein the thickness is at least 1000 μm.
The electrostatic recording medium according to the above. 4. The static photoconductor according to claim 1, wherein the read photoconductive layer exhibits photoconductivity even when irradiated with the recording radiation. Electrorecording body. 5. An electrostatic recording medium for recording radiation image information as an electrostatic latent image, comprising: a wavelength conversion layer for converting radiation for recording into visible light in a first wavelength region; A first conductive layer having: a photoconductive layer for recording that exhibits photoconductivity by being irradiated with the visible light transmitted through the first conductive layer; and the first conductive layer is charged. The charge transport layer, which acts as a substantially insulator for electric charges of the same polarity as the electric charge and acts as an electric conductor for electric charges of the opposite polarity to the electric charge, is irradiated with electromagnetic waves for reading. An electrostatic recording member comprising: a reading photoconductive layer exhibiting photoconductivity; and a second conductor layer having transparency to the reading electromagnetic wave, laminated in this order. 6. The wavelength conversion layer for converting the recording radiation into visible light in a second wavelength region, and the reading photoconductive layer includes a visible light in the second wavelength region. 6. The electrostatic recording medium according to claim 5, wherein the electrostatic recording medium exhibits photoconductivity even when irradiated with light. 7. The reading photoconductive layer is made of a-Se, Se.
7. The method according to claim 1, wherein at least one of -Te, Se-As-Te, metal-free phthalocyanine, metal phthalocyanine, MgPc, VoPc, and CuPc is a main component. Electrostatic recording medium. 8. The photoconductive layer for reading has high sensitivity to electromagnetic waves having wavelengths in the near-ultraviolet to blue region and low sensitivity to electromagnetic waves having wavelengths in the red region. The electrostatic recording medium according to any one of claims 1 to 6, wherein: 9. The photoconductive layer for reading comprises a-Se, Pb
I ₂ , Bi ₁₂ (Ge, Si) O ₂₀ , perylene bisimide (R = n-propyl), perylene bisimide (R = n-
9. The electrostatic recording medium according to claim 8, wherein at least one of neopentyl) is a main component. 10. The photoconductive layer for reading is a-Se, S
5. The electrostatic recording medium according to claim 4, wherein at least one of e-Te and Se-As-Te is a main component. 11. The method according to claim 11, wherein the charge transport layer is formed of PVK, TPD,
The electrostatic recording medium according to any one of claims 1 to 10, wherein at least one of a polymer dispersion of TPD and a-Se doped with 10 to 200 ppm of Cl is used as a main component. 12. The electrostatic recording medium according to claim 1, wherein the charge transport layer has a charge mobility in a direction perpendicular to the film thickness direction larger than a charge mobility in the film thickness horizontal direction. . 13. A first charge transport layer, wherein the charge transport layer is made of a material having a property of substantially acting as an insulator with respect to charges of the same polarity as charges charged on the first conductor layer. And a second charge transport layer made of a material having a property of substantially acting as a conductor with respect to the charge of the opposite polarity to the charge to be charged, wherein the first charge transport layer is formed of the recording light. The electrostatic recording medium according to any one of claims 1 to 10, wherein the second charge transport layer is stacked on the conductive layer side so as to be on the reading photoconductive layer side. . 14. The method according to claim 13, wherein the first charge transport layer is made of an organic material, and the second charge transport layer is made of a Se material. Electrostatic recording medium. 15. The method according to claim 1, wherein the first charge transport layer is a layer made of at least one of PVK and TPD, and the second charge transport layer is an a-Se layer doped with 10 to 200 ppm of Cl. The electrostatic recording medium according to claim 14, wherein 16. A first blocking layer which prevents injection of charges charged in the first conductive layer into the recording photoconductive layer, the first blocking layer and the recording photoconductive layer. 16. The electrostatic recording medium according to claim 1, wherein the electrostatic recording medium is laminated between the electrostatic recording medium and the recording medium. 17. A second blocking layer for preventing injection of a charge charged in the second conductive layer into the reading photoconductive layer, wherein the second blocking layer and the reading photoconductive layer are used. 17. The electrostatic recording medium according to claim 1, wherein the electrostatic recording medium is laminated between the electrostatic recording medium and the recording medium. 18. The sum of the thickness of the reading photoconductive layer and the thickness of the charge transport layer is 1/1 / th of the thickness of the recording photoconductive layer.
18. The electrostatic recording medium according to claim 1, wherein the number is 2 or less. 19. The recording medium according to claim 1, wherein the sum of the thicknesses is 1/10 or less of the thickness of the recording photoconductive layer.
8. The electrostatic recording medium according to 8. 20. The recording medium according to claim 1, wherein the sum of the thicknesses is not more than 1/20 of the thickness of the recording photoconductive layer.
9. The electrostatic recording medium according to 9. 21. The charge transport layer, wherein the mobility of the charge of the same polarity as the charge charged on the first conductor layer is 1/10 ² or less of the mobility of the charge of the opposite polarity. The electrostatic recording medium according to any one of claims 1 to 20, wherein: 22. The charge transport layer, wherein the mobility of charges of the same polarity as the charges charged on the first conductor layer is 1/10 ³ or less of the mobility of the charges of the opposite polarity. 22. The electrostatic recording medium according to claim 21, wherein: 23. The electrostatic recording medium according to claim 1, wherein the second conductive layer is formed in a comb shape. 24. The electrostatic recording medium according to claim 23, wherein the width of the comb teeth is 75% or less of the pitch of the comb teeth. 25. A space between the comb teeth of the second conductor layer,
25. The electrostatic recording medium according to claim 23, wherein the electrostatic recording medium has a property of blocking electromagnetic waves for reading. 26. The digital camera according to claim 23, wherein the comb teeth have a blocking property between the pixels in the longitudinal direction of the comb teeth with respect to the electromagnetic wave for reading. Electrostatic recording medium. 27. The method according to claim 23, wherein the sum of the thickness of the read photoconductive layer and the thickness of the charge transport layer is substantially equal to or less than the pitch of the comb teeth.
The electrostatic recording medium according to claim 1. 28. An insulating layer and a third conductor layer, both of which are transparent to the reading electromagnetic wave, are laminated on the second conductor layer in this order. 3. The electric conductor layer of claim 2, wherein the electric conductor layer is formed in a comb shape substantially perpendicular to the comb teeth of the second electric conductor layer.
28. The electrostatic recording medium according to any one of items 3 to 27. 29. A space between the comb teeth of the third conductor layer,
29. The electrostatic recording medium according to claim 28, wherein the electrostatic recording medium has a shielding property against the reading electromagnetic wave. 30. The width of the comb teeth of the third conductor layer is:
30. The electrostatic recording medium according to claim 28, wherein the pitch is 75% or less of the pitch of the comb teeth. 31. The sum of the thickness of the read photoconductive layer and the thickness of the charge transport layer is substantially equal to or less than the pitch of the comb teeth of the third conductive layer. Item 31. The electrostatic recording medium according to any one of Items 28 to 30. 32. An apparatus for recording radiation image information as an electrostatic latent image on an electrostatic recording medium according to any one of claims 1 to 27, wherein the first conductive layer and the second conductive layer of the electrostatic recording medium are provided. A power supply for applying a predetermined DC voltage between the conductive layer and the recording layer; and a recording irradiating unit for irradiating a recording radiation carrying the image information to the recording photoconductive layer of the electrostatic recording body. And accumulating charges having the same polarity as the charges charged on the first conductor layer by the irradiation of the radiation at substantially the interface between the recording photoconductive layer and the charge transport layer of the electrostatic recording medium. Wherein the image information is recorded as an electrostatic latent image. 33. An apparatus for recording radiation image information as an electrostatic latent image on an electrostatic recording medium according to any one of claims 28 to 31, wherein the first conductive layer and the third A power supply for applying a predetermined DC voltage between the first conductive layer and the recording layer, and a recording irradiating means for irradiating the first conductive layer side with recording radiation carrying the image information. By accumulating charges of the same polarity as the charges charged on the first conductor layer by the irradiation of the radiation at substantially the interface between the recording photoconductive layer and the charge transport layer of the electrostatic recording medium. And an image recording apparatus for recording the image information as an electrostatic latent image. 34. Before irradiating the recording radiation,
34. The electrostatic latent image recording apparatus according to claim 32, further comprising a pre-exposure unit that irradiates a predetermined amount of electromagnetic radiation to the second conductive layer. 35. A scanning electromagnetic wave for scanning exposure on the second conductive layer side of the electrostatic recording medium according to claim 1, wherein the radiation image information is recorded in advance as an electrostatic latent image. A scanning exposure unit that detects a current flowing out of the electrostatic recording medium in accordance with the electrostatic latent image through the first or second conductive layer. An electrostatic latent image reading device comprising: a current detection unit. 36. The apparatus according to claim 36, further comprising connecting means for selectively connecting the first conductive layer of the electrostatic recording medium to the second conductive layer or the current detecting means. After connecting the first conductor layer and the second conductor layer to charge both conductor layers to the same potential, the first conductor layer and the current detecting means are connected to each other to thereby obtain the current. 36. The electrostatic latent image reading device according to claim 35, wherein: 37. The electrostatic recording medium according to claim 8, wherein the reading exposure means scans and exposes an electromagnetic wave having a wavelength in a range from near ultraviolet to blue. 37. The electrostatic latent image reading device according to claim 35, wherein: 38. The electrostatic recording medium according to claim 1, wherein the reading exposure unit forms the reading electromagnetic wave in a beam shape. The electrostatic latent image reading apparatus according to any one of claims 35 to 37, wherein the apparatus performs scanning exposure. 39. The electrostatic recording medium according to claim 23, wherein:
The electrostatic recording medium according to claim 1, wherein the reading exposure unit causes the reading electromagnetic wave that is substantially uniform in a line shape to be substantially orthogonal to the comb teeth of the second conductive layer. Scanning exposure in the longitudinal direction of the comb teeth of the second conductive layer, wherein the current detecting means detects a current flowing from the electrostatic recording medium for each of the comb teeth. The electrostatic latent image reading device according to any one of claims 35 to 38. 40. The electrostatic recording medium according to claim 28, wherein:
The electrostatic recording medium according to claim 1, further comprising a second connection unit that connects a second conductor layer and a third conductor layer of the electrostatic recording body. The electrostatic latent image reading device according to claim 39, wherein 41. The electrostatic latent image according to claim 38, wherein the reading exposure means irradiates the reading electromagnetic wave in a pulsed manner substantially every pixel. Reader. 42. The current detecting means comprises: an integrating capacitor for accumulating electric charge due to a current flowing through the current detecting means; and discharging means for discharging the electric charge stored in the integrating capacitor. 42. The electrostatic latent image reading device according to claim 35, wherein the current is detected by detecting a charge accumulated in the pixel for each pixel. 43. The apparatus according to claim 35, wherein the first conductive layer and the current detecting means are connected via a bias power supply having a predetermined DC voltage.
3. The electrostatic latent image reading device according to claim 1. 44. The electrostatic latent image reading device according to claim 43, wherein the bias power source is a power source used when recording the electrostatic latent image.