JPS6064359A - Method and device for image forming - Google Patents

Abstract

PURPOSE:To obtain an image having high quality by subjecting the conductive toner coated uniformly on a photosensitive body to image exposing, removing at the same time the toner in said part, impressing a DC voltage to the electrode facing the toner remaining on the photosensitive body and implanting electric charge. CONSTITUTION:A cylindrical photosensitive body 30 laminated with a light transmittable base plate 11, a light transmittable conductive layer 12 and a photoconductive layer 13 from the inside is turned counterclockwise. A toner is coated by a coater 31 onto the body 30 and rays are irradiated from an image exposing device 32 to said body to expose the image and at the same time the toner in the part where the image is formed is removed by a toner remover 33. The toner is conveyed 37 to the original position. The image corresponding to the dark part where no light is received is formed on the body 30 and is turned. The body 30 is irradiated with the transfer lamp of a transfer device 36 and a voltage is applied to a counter electrode 34 to transfer the toner onto a transfer material 38 consisting of general purpose paper. The material 38 on which the toner is transferred is fixed in a fixing part 39 and is thereafter discharged. The image having good quality without drop-out and edge effect is thus easily formed.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an image forming method and apparatus for printers, copying machines, etc., and particularly to an image forming method for forming a toner image using a photoreceptor having a photoconductive layer. and regarding equipment.

[Technical background of the invention and its problems] In recent years, with the development of office automation, printers, copiers, facsimile machines,
There is an increasing demand for improved performance of hard copy devices and the like as computer output terminals. In particular, the ability to use plain paper as recording paper; 1. The image quality is high;
There are strong demands for excellent maintenance and reliability. Inkjet recording and thermal transfer recording were developed to meet these demands.

Recording devices using various methods such as electrophotographic recording have been developed.

Among these, inkjet recording has maintenance and reliability problems such as nozzle clogging due to ink, and thermal transfer recording has the ink film consumed while leaving unused ink behind, leaving a negative image on the ink film.
There are problems with economy and confidentiality. Furthermore, it is relatively difficult to obtain high image quality in both cases. In contrast, electrophotographic recording is attracting attention as a technology that can relatively easily obtain high quality images.

A typical image forming method currently in practical use that applies electrophotographic recording is to develop an electrostatic latent image formed on a photoreceptor by image exposure, and then print a toner image on plain paper. Examples include the xerographic method, in which a toner image is transferred onto a transfer material such as, to obtain a copy, and the electrofax method, in which a toner image is formed on a photoreceptor to obtain a copy. All of these methods require a development step, making the equipment complex and expensive. In addition, there are fundamental problems caused by developing an electrostatic latent image, such as blanking due to the edge effect that occurs due to the difference in electric field strength between the center and the edge of the latent image, even though the latent image has a uniform charge distribution. It has image quality deterioration factors such as ghosting.

As an attempt to eliminate these drawbacks of electrophotographic recording, US Pat.
-22645, JP-A-49-76531, etc. are known. All of the techniques described in these publications uniformly apply a charged photoconductive toner onto a grounded conductive support and perform imagewise exposure to form a bond between the support and the photoconductive toner. The photoconductive toner is transferred from the support to the transfer material after the electrostatic attraction is weakened or removed according to the image configuration.

However, in this method, the light does not sufficiently reach the lower part of the photoconductive toner (conductive support) during image exposure, and the contact resistance between the photoconductive toners is large, so the charge on the toner is For reasons such as the fact that the light does not reach the conductive support during exposure, the photosensitivity is 10 to 100 times lower than that of general electrophotography using a normal photoreceptor that uses a binder in the toner. This poor photosensitivity manifests itself in image quality deterioration such as a =9-9 decrease in image density and the occurrence of fog. For this reason, the development of photoconductive toners and processes with high photosensitivity is progressing (Japanese Patent Application Laid-open No. 103739/1983, etc.).
The reality is that nothing that can be put to practical use has yet been obtained.

[Objective of the Invention] The object of the present invention is to have a simple process without a developing step, and to obtain sufficient photosensitivity without using special toner.
It is an object of the present invention to provide an image forming method and apparatus capable of forming high-quality images with sufficiently high density without image quality deterioration or fogging due to edge effects.

Another object of the present invention is to provide an image forming method and apparatus capable of transferring an image onto a transfer material such as plain paper.

Still another object of the present invention is to provide an image forming method and apparatus with high toner usage efficiency.

[Summary of the Invention] In order to achieve the above object, the present invention uses a photoconductor formed by laminating a light-transmissive conductive layer and a photoconductive layer on a light-transmissive substrate. Apply conductive toner to the surface. Next, image exposure is performed on the photoreceptor from the light-transmitting substrate side, and at the same time, a DC voltage is applied to a toner removal electrode provided opposite to the light-transmitting conductive layer via the photoconductive layer. , removing toner on the image-exposed areas of the photoreceptor. This image exposure and toner removal leave a toner image on the photoreceptor corresponding to the dark areas that were not irradiated with light during the image exposure. Then, a DC voltage having the same polarity as the voltage applied to the toner removal electrode is applied to a counter electrode provided opposite to the light-transmitting conductive layer via the photoconductive layer, and at the same time, the light-transmitting substrate side is The toner image remaining on the photoreceptor is transferred onto a counter electrode or onto a transfer material held between the counter electrode and the photoconductive layer to obtain a toner image. Note that when a toner image is formed on the counter electrode, this may be transferred onto a transfer material after that.

[Effects of the Invention] According to this invention, charge is selectively injected only to toners 1 to 1 on the image-exposed area of the photoreceptor, and at the same time, the toner is removed to form a toner image on the photoreceptor, and then transferred. Since a toner image is obtained by transferring the toner image onto the material, compared to the conventional method which includes a development process of an electrostatic latent image, there are essentially no gaps in the middle due to the edge effect,
There are no image quality deterioration factors such as ghosts. Moreover, special toners such as photoconductive toners are not required.
Toners similar to those conventionally used in electrophotographic recording can be used. Furthermore, it is possible to form extremely high-quality images that eliminate the reduction in image density and the occurrence of fog caused by insufficient photosensitivity in systems using photoconductive toner.

In addition, in this invention, Infusiera! is used as a transfer material, that is, a recording paper.・Plain paper can be used in the same way as recording and thermal transfer recording.

Further, according to the present invention, toner that has not been transferred onto the counter electrode or the transfer material and has not contributed to the formation of a toner image can be recovered and reused, and there is an advantage that toner usage efficiency is high.

Further, according to the present invention, the elements of each process can be arranged along the rotating or moving photoreceptor, the image exposure section and the transfer section can be arranged facing each other in the same place, and the toner application means and toner Since the collecting and transport means can be integrated, the apparatus can be realized compactly.

[Embodiments of the Invention] FIG. 1 is a sectional view showing the structure of a photoreceptor used in the present invention. This photoreceptor 10 has a light-transmissive conductive layer 12 made of Nesa film, indium film, etc. formed on a light-transparent substrate 11 made of transparent glass, a transparent sheet, etc., and further coated with amorphous selenium, ZnO, OPC, etc. This structure has a photoconductive layer 13 made of a-8i, CdS, or the like. Note that the term "light transmittance" used herein means that the material is transparent to at least the wavelength of light used in imagewise exposure, and is not necessarily required to be colorless and transparent. The photoconductive layer 13 has appropriate spectral sensitivity including the wavelength of light used for imagewise exposure. Furthermore, regarding the thickness of the photoconductive layer 13, in the case of a photoreceptor used in conventional electrophotography, for example, a 13-selenium photoreceptor, the thickness is about 50 to 60 μm, whereas in this invention, the thickness of the photoconductive layer 13 is approximately 50 to 60 μm. Since the light needs to reach near the surface layer of the photoconductive layer 13, it is better to make it thinner than this (for example, 1 to 20 μm in the case of a selenium photoreceptor), although this is also related to the wavelength of the light. is obtained.

Next, the image forming process according to the present invention will be explained with reference to FIG. First, as shown in FIG. 2(a), toner 21 is uniformly applied onto the photoreceptor 10 shown in FIG. The toner 21 has conductivity (approximately 106 to 108 Ω/crs), and methods for applying this toner include a method using a magnetic roller, a method using a blade, a method using a fur brush, and a method using a metal RLH tube with a small diameter. Examples include a method of spraying it from a spray bottle and applying it in the form of a mist.

Next, as shown in FIG. 2(b), light 22 corresponding to image information to be recorded on the photoconductive layer 13 from the light-transparent substrate 11 side through the light-transparent conductive layer 12 is applied to an image surface such as the document surface. At the same time, a DC power supply 24 is applied to a toner removal electrode 23 provided opposite to the light-transmitting conductive layer 12 via the photoconductive layer 13 (14-) to perform image exposure by irradiating light corresponding to the original image from the photoconductive layer 13. Apply a DC voltage (negative polarity in the example shown). At this time, the light 22 of the photoconductive layer 13
The irradiated area, that is, the image-exposed area becomes conductive, and positive charges are injected into the toner on the image-exposed area on the surface of the photoconductive layer 13. Then, the toner on this image exposure area adheres to the electrode 23 and is removed by the action of an electric field caused by a DC voltage applied between the toner removal electrode 23 and the light-transmitting conductive layer 12 by the DC power supply 24. .

Other methods for removing toner include a method using a conductive roller, a method using a combination of a conductive roller and a dielectric roller, and a method using a dielectric thin film and a corona charger to charge it. .

In this way, toner is selectively left on the photoreceptor 10 corresponding to the dark areas to which no light has been irradiated.

Next, as shown in FIG. 2(C), a counter electrode 25 disposed opposite the light-transmitting conductive layer 12 with the photoconductive layer 13 in between is connected to a counter electrode 25 having the same polarity as the DC power supply 24 for toner removal. A polar DC voltage is applied by a DC power supply 26. Simultaneously with the application of the DC voltage to the counter electrode 25, the photoconductive layer 13 is irradiated with light from the light-transmissive substrate 11 side through the light-transmissive conductive layer 12 using the transfer lamp 27, so that the photoconductive layer 13 is exposed to light in the same manner as when removing the toner. Charge is injected into the toner on the photoreceptor 10 , and the toner image on the photoreceptor 10 is transferred to the photoconductive layer 13 by the action of the electric field between the light-transmitting conductive layer 12 and the counter electrode 25 .
The toner acid is transferred onto the counter electrode 25 or onto a transfer material (not shown) held between the counter electrode 25 and the photoconductive layer 13.

In this way, a toner image is formed on the counter electrode 25 or the transfer material. The magnitude of the voltage applied by the DC power source 26 varies depending on the type and structure of the counter electrode 25 and the type of transfer material, but generally a lower voltage is required than in the case of toner image transfer in conventional electrophotographic recording.

On the other hand, the toner removed in the step of FIG. 2(b) is collected and transported to be reused in the toner application step of FIG. 2(a). In this way, a series of image forming processes is completed.

Next, a printer as an example of an image forming apparatus that implements the above-described image forming process will be described.

FIG. 3 shows an embodiment in which the present invention is applied to an LED printer. In FIG. 3, photoreceptor color O is a so-called photoreceptor drum formed in a cylindrical shape, and the photoconductive layer is made of, for example, selenium with a thickness of 5 μm, and the light-transmitting conductive layer is made of, for example, In0z. A vapor deposited film is used. The photoconductive layer is arranged on the outer peripheral surface side of the photoreceptor drum 30. This photosensitive drum 30 is rotated counterclockwise in the figure in accordance with the recording speed, and along this rotational direction, a toner application device 31. Image exposure device 32 and toner removal/collection device 3
3. A transfer device 36 consisting of a counter electrode 34 and a transfer lamp 35 is arranged in sequence, and a toner removal/collection device 3
A toner transport device 37 is provided between the toner application device 3 and the toner application device 31 . Note that 38 is a transfer material, and 39 is a fixing section 17-.

Next, the detailed structure and operation of each part shown in FIG. 3 will be explained. First, the toner in the toner application device 31 is stirred by the charging roller 31a and uniformly applied onto the photoreceptor 30 by the blade 31b. At this time, it is preferable to use conductive rubber or the like for the blade 31b.
By applying a DC voltage from the DC power source 31c via b, charges are injected into the toner applied onto the photoreceptor drum 30. In this case, the toner applied onto the photoreceptor drum 30 generates an adhesion force due to the injected charges to assist the adhesion of the toner to the photoreceptor 30. Therefore, as shown in FIG. 3, even in an apparatus whose processes and arrangement are such that it is affected by gravity between the toner application process and the image exposure/toner removal process, toner cannot peel off or fall from the photoreceptor drum 30. This enables stable toner application and transportation. The polarity of the charge injected in this toner application step is preferably opposite to the polarity of the charge injected in the image exposure/toner removal step.

Next, L as a light emitting element array arranged in a line in the axial direction of the photosensitive drum 3o (perpendicular to the paper surface)
The image exposure device 3°2, which combines an ED array and a rod lens array as a light guiding system,
Light is irradiated onto the photoconductive layer through the light-transmissive conductive layer from the inside of the photoconductive layer, that is, from the light-transparent substrate side. In this case, the LED array is driven according to an image information signal to be recorded given from an external drive circuit. The image exposure device 32 is also adjusted so that the photoconductive layer is located within its depth of focus. In this way, image exposure is performed on the photoreceptor drum 3o. Simultaneously with this image exposure, the toner on the image exposure area is removed from the photoreceptor drum 30 by the action of an electric field caused by a negative DC voltage applied from the DC power supply 33b to the toner removal roller 33a in the toner removal/recovery device 233. It peels off from above and adheres to the surface of the roller 33a. In this example, the roller 33a is
The volume resistivity value of the smφ A1 roller is 10,000.
- A conductive roller with a thickness of about 13 amφ wrapped with conductive rubber of about cjI, arranged so that the gap with the photoreceptor drum 3o is about 300 μm, and rotates in accordance with the rotation of the photoreceptor drum 30. and rotate. This roller 33
Appropriately, the voltage applied to a is around -600V.

The toner attached to the toner removal roller 33a is removed and collected by the collection blade 33c, and the toner conveying device 37
The toner is conveyed and supplied to the toner application device 31 by the conveyance chain 37a inside, and the toner is reused.

In this way, through the image exposure and toner removal steps, a toner image corresponding to the dark area that is not exposed to light is formed on the photoreceptor 30, and this toner image is transferred to the transfer device 30.
The image is transferred onto a transfer material 38 made of plain paper by light irradiation from the opposing electrode 34 in the transfer lamp 35 and the transfer lamp 35 . In this example, a flat plate electrode was used as the counter electrode 34, and the distance from the photoreceptor drum 30 was 300 μm, and the voltage applied to the flat plate electrode was -800V.

The toner image formed on the transfer material 38 in this way is
The image is outputted via the fixing section 39. This toner image, that is, the output image, has a uniform image density in the so-called solid printing area, and clear lines in the line drawing area.
Good images were obtained for various image patterns.

FIG. 4 shows an embodiment in which the present invention is applied to a laser printer, and unlike the case of FIG. 3, a web-like photoreceptor is used. Compared to a cylindrical photoreceptor drum, such a web-like photoreceptor has an open side on one side, so it can escape from limitations such as the size and optical path length of an image exposure system, and can be used as described in this example. In addition to easily realizing a copying machine or the like, it is also possible to combine the present invention with an image exposure system that requires a relatively large space, such as a light scanning optical system using laser light.

In FIG. 4, the web-like photoreceptor 40 has a thickness of, for example, 50 μm.
Palladium was vapor-deposited as a light-transmitting conductive layer on a Mylar (trade name of polyethylene terephthalate) film with a thickness of about 5 μm. Then, the supply roller 5o moves to the take-up roller 54 in accordance with the recording speed. At this time, an appropriate tension is applied to the photoreceptor 40, and the rollers 51, 5
2.53, the flatness is regulated to be maintained well in each process. Along the moving direction of the web-like photoreceptor 40, a toner coating device @41. Image exposure device 42 and toner removal/collection device 43. Transfer devices 46 are sequentially arranged. 47 is a toner conveying device, 48 is a transfer material, and 49 is a fixing section.

In the above configuration, the web-like photoreceptor 4o is moved in accordance with the recording speed as described above, and the elements of each process operate at a constant timing in accordance with this movement. That is, first, the agitation roller 41 in the toner application device 41 is applied onto the photoreceptor 40.
The toner stirred by the blade 41b is uniformly coated with its coating thickness regulated by the blade 41b, and a charge is injected by the DC power source 41c.

Next, the photoreceptor 4o coated with the toner is transferred to an image exposure device 42.
Image exposure is carried out by The image exposure device @42 is 22- In this example, several originals 42b are placed with the original surface facing down on a transparent original platen 42a, the original surface is illuminated with illumination light a 142c, and the photoreceptor 40 is exposed by the imaging lens 42d. is arranged and adjusted so that an image is formed on the photoconductive layer of the photoconductive layer. In this case, image formation on the document surface covers the entire document size in the direction perpendicular to the ring 1 with respect to the paper surface, and is limited in the direction perpendicular to this. Image exposure corresponding to the size is performed.

The toner on this image exposure area is transferred and adhered to the roller 43a from above the photoreceptor 40 by the action of an electric field caused by a DC voltage applied to the toner removal roller 43a in the toner removal/recovery device 43 at the same time as the image exposure. Toner removal roller 43a
The configuration and the applied voltage are the same as in the case of FIG. The toner adhering to the toner removing row 543a is removed and collected by the collection blade 43C, and is transported and supplied to the toner application device 41 by a transport chain 47a in the toner transport device 47 and reused.

Through this image exposure/toner removal process, a toner image corresponding to the black background portion of the document surface that was not irradiated with light due to image exposure is formed on the photoreceptor 4O, and this toner image is transferred to the transfer device 4O.
The image is transferred onto the transfer material 48 by light irradiation from the counter electrode 44 in the transfer lamp 45 and the transfer lamp 45 . The counter electrode 44 consists of a flat plate electrode as in the case of FIG.

The toner image formed on the transfer material 48 in this way is
The image is output via the fixing section 49. The output image obtained is
Similar to the case shown in FIG. 3, the results were good.

As explained above, the present invention performs image exposure to conductive toner uniformly applied on a photoreceptor, and at the same time,
The toner on the exposed area of the image is removed, and then the toner corresponding to the dark area remaining on the photoreceptor is injected with charge by applying a DC voltage to the counter electrode, and transferred as a toner image onto the counter electrode or transfer material.・It is designed to be formed. Therefore, unlike conventional electrophotographic recording, there is no image quality deterioration such as missing areas or ghosts due to the influence of edge effects, and since the photosensitivity is sufficient compared to methods using photoconductive toner, there is no reduction in image density. It is possible to form extremely high quality images without fogging.

Additionally, this type of image is created by combining traditional electrophotographic processes with image exposure devices such as OFT (optical fiber tubes), LED arrays, etc. that must be placed directly or in close proximity to the photoconductor layer on the photoreceptor. In the forming device, toner adheres to the light exit surface of the image exposure device due to toner scattering and charging, which caused problems in terms of maintenance of the device, but according to the present invention, the image exposure device is Since the toner layer and the toner layer are separated from each other, there is, in principle, no problem of toner adhesion to the image exposure system, and the apparatus can be realized in a compact configuration.

Furthermore, compared to devices using conventional thermal transfer recording methods, it is possible to form images at high speed and high resolution with less energy, and the output images are also excellent in stability. Furthermore, in the thermal transfer recording method, the ink film after transfer is disposable, which poses a problem in terms of confidentiality,25- but in this invention, the toner as a developer is collected and reused, so this There are no such problems and it is especially suitable for office automation printers, copying machines, etc.

It goes without saying that the present invention is not limited to the embodiments described above, and can be implemented with various modifications. For example, the same result can be obtained even if the polarities of the charges injected into the toner in the two steps are reversed to those in the above embodiment. In addition, the photoconductor layer is not limited to selenium-based materials.
ZnO, OPC, Cds, a-8t, etc. may also be used.

As for the image exposure device, in addition to the one using an LED array or a laser beam, it may be one using an OFT and an optical switch array using a liquid crystal or a dielectric material and driven according to an image information signal.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of the photoreceptor used in this invention;
FIG. 2 is a process diagram showing an image forming process according to an embodiment of the invention, and FIGS. 3 and 4 are diagrams showing the configuration of an image forming apparatus according to an embodiment of the invention. 26- 10.30.40... Photoreceptor, 11... Light-transmitting substrate, 12... Light-transmitting conductive layer, 13... Photoconductive layer,
21... Toner, 22... Light, 23... Toner removal electrode, 25.34.44... Counter electrode, 27.3
5.45... Transfer lamp, 31.41... Toner coating device, 32.42... Image exposure device, 33.43.
...Toner removal/collection device, 36.46...Transfer device, 37.47...Toner conveyance device, 38.48...
Transfer material, 39°49...Fixing section. Applicant's agent Patent attorney Takehiko Suzue 271

Claims (24)

[Claims] (1) After applying a conductive toner onto a photoreceptor formed by laminating a light-transmitting conductive layer and a photoconductive layer on a light-transmitting substrate, imagewise exposure is performed from the light-transmitting substrate side, and During this image exposure, by applying a DC voltage to a toner removal electrode provided opposite to the light-transmitting conductive layer via the photoconductive layer, the toner on the image exposure area of the photoreceptor is removed. A toner image is formed on the photoreceptor by injecting a charge into the photoreceptor and removing the toner with the toner removing electrode, and then the toner image on the photoreceptor is held facing the photoconductive layer. An image forming method characterized by transferring onto a transfer material. (2) The image forming method according to claim 1, characterized in that when applying the toner onto the photoreceptor, the toner removed from the image exposure area of the photoreceptor is collected and reused. (3) When transferring the toner image on the photoreceptor onto a transfer material, a counter electrode is provided on the light-transmitting conductive layer and faces the photoconductive layer, and a DC voltage is applied to the counter electrode at the same time. The image forming method according to claim 1, characterized in that the layer is irradiated with light. (4) The image forming method according to claim 1, wherein the image exposure is performed by optically forming an original image on a photoreceptor. (5) a photoreceptor that is formed by laminating a light-transparent conductive layer and a photoconductive layer on a light-transparent substrate and rotates or moves in a predetermined direction; and a photoreceptor provided opposite to the photoconductive layer side of the photoreceptor; means for applying conductive toner onto the photoreceptor;
A means is provided in front of the toner application means and performs image exposure on the photoreceptor from the light-transmissive substrate side; means for removing toner on the exposed area; a counter electrode provided in front of the toner removing means to face the photoconductive layer of the photoconductor; and a DC voltage applied to the counter electrode to remove the toner on the photoconductor. An image forming apparatus comprising: a transfer means for transferring toner remaining on the image forming apparatus onto a transfer material held between the counter electrode and the photoreceptor. (6) The image forming apparatus according to claim 5, wherein the light body is formed in a cylindrical shape. (7) The image forming apparatus according to claim 5, wherein the photoreceptor is formed in a web shape. (8) The image forming apparatus according to claim 5, wherein the toner application means applies the toner onto the photoreceptor while injecting charge into the toner. (9) The image forming apparatus according to claim 5, wherein the image exposure means optically forms an original image on an image surface such as a document surface onto a photoreceptor. (10) The image forming apparatus according to claim 5, wherein the t-toner removing means is a conductive roller. (11) The image forming apparatus according to claim 5, wherein the t-toner removing means is a combination of a conductive roller and a dielectric roller. (12) The image forming apparatus according to claim 5, wherein the toner removing means comprises a dielectric thin film and a corona charger for charging the dielectric thin film. (13) The image forming apparatus according to claim 5, wherein the counter electrode is a conductive electrode. (14) The transfer means includes means for applying a DC voltage to the counter electrode and at the same time applying light to the photoconductive layer from the light-transmitting substrate side of the photoreceptor, as set forth in claim 5. Image forming device. (15) a photoconductor which is formed by laminating a light-transmissive conductive layer and a photoconductive layer on a light-transmissive substrate and rotates or moves in a predetermined direction; and a photoconductor provided opposite to the photoconductive layer side of the photoconductor;
means for applying conductive toner onto the photoreceptor; means provided in front of the toner application means for imagewise exposing the photoreceptor from the light-transmissive substrate side; a means for removing toner on the image exposure area of the photoreceptor; a counter electrode provided in front of the toner removing means and facing the photoconductive layer of the photoreceptor; means for applying a DC voltage to the counter electrode to transfer the toner remaining on the photoconductor onto a transfer material held between the counter electrode and the photoconductor to form a toner image; and a means for removing the toner. An image forming apparatus comprising: means for collecting the toner removed by the toner collecting means; and means for transporting the toner collected by the toner collecting means to the toner applying means. (16) The image forming apparatus according to claim 15, wherein the photoreceptor is formed in a cylindrical shape. (17) The image forming apparatus according to claim 15, wherein the photoreceptor is formed in a web shape. (18) The image forming apparatus according to claim 15, wherein the image exposure means optically forms an original image on an image surface such as a document surface onto a photoreceptor. (19) The image forming apparatus according to claim 15, wherein the toner application means applies the toner onto the photoreceptor while injecting charge into the toner. (20) The image forming apparatus according to claim 15, wherein the toner removing means is a conductive roller. (21) The image forming apparatus according to claim 15, wherein the toner removing means is a combination of a conductive roller and a dielectric roller. (22) The image forming apparatus according to claim 15, wherein the toner removing means comprises a dielectric thin film and a corona charger for charging the dielectric thin film. (23) The image forming apparatus according to claim 15, wherein the counter electrode is a conductive roller. (24) Claim 15, characterized in that the transfer means includes means for applying a DC voltage to the counter electrode and at the same time applying light to the photoconductive layer 6- from the light-transmitting substrate side of the photoreceptor. The image forming apparatus described above.