JP2001066860A - Exposure device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make obtainable excellent latent image formation, transfer and separation in respective stages even though the processing speed in the device is made high without adding a new light source, a driving circuit therefor and a wiring. SOLUTION: The scanning range by a laser beam is extended not only to a reflecting mirror 19 but also to a 1st convex mirror 19'. The mirror 19' reflects incident light to a 2nd convex mirror 19", and the mirror 19" reflects the incident light to an area having width more than image forming width at a specified rotational angle position on a photoreceptor drum 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus having a recording material conveying apparatus for passing various kinds of recording materials, and more particularly to an image forming apparatus having an exposure apparatus such as an electrophotographic printer, a copying machine, a facsimile machine, and the like. Related to the device.

[0002]

2. Description of the Related Art Conventionally, an outline of an image forming process in an apparatus such as a printer, a copying machine, a facsimile or the like using an electrophotographic system is as shown in FIG. That is, after the surface of the photosensitive drum 2 is uniformly charged to a certain polarity by the charging roller 1 to which DC and AC biases are superimposedly applied, the photosensitive drum is de-charged only by an exposure means 3 such as a laser in a region under exposure. To form a latent image, and
Is frictionally charged between the developing blade 4a and the developing sleeve 4b to have the same polarity as the charged surface of the photosensitive drum, and a DC and AC bias is superimposed and applied in a developing gap portion where the photosensitive drum and the developing sleeve are opposed to each other. After the toner is selectively attached to the latent image forming portion of the photosensitive drum while floating and vibrating, the toner is conveyed by rotation of the photosensitive drum to a transfer nip portion formed by the transfer roller 7 and the photosensitive drum.

On the other hand, a recording material 6 such as paper on which an image is recorded
Is transported to a transfer nip by means of a transport roller or the like (not shown), and a high voltage having a polarity opposite to that of the toner is recorded so that the toner on the photosensitive drum is electrostatically attracted and moved toward the recording material at the transfer portion. The image is transferred by being applied to the transfer roller on the backside of the recording material and electrostatically attracting the toner to the backside of the recording material, and the backside of the recording material is charged to a polarity opposite to that of the toner, so that the transferred toner is maintained. Is applied to the back surface of the recording material.

Finally, the recording material onto which the toner image has been transferred is heated by a pressure roller 1 forming a nip with a heating rotator 10.
The toner image is conveyed to the fixing device 9 constituted by the fixing device 1 and is heated and pressurized in the nip portion to permanently fix the toner image on the surface of the recording material. On the other hand, since a small amount of deposits such as toners having different polarities remain on the surface of the photosensitive drum after the transfer, the surface of the photosensitive drum after passing through the transfer nip portion is cleaned by the cleaning container 8 in counter-contact with the photosensitive drum surface. After the attached matter is scraped off and cleaned by the blade 8a, the apparatus stands by for the next image formation.

[0005] In the above steps, the configuration of an optical system using a laser widely used for forming a latent image is specifically shown in FIG.
As shown in (B), the laser light diffusely radiated from the laser diode 3 as the light source is converted into parallel light through the collimator lens 12, and the parallel light is reflected by the minute surface of the reflection surface of the polygon mirror 15. To avoid the effect of tilt,
Once a cylindrical lens 13 for so-called surface tilt correction
Irradiates the reflecting surface of the polygon mirror which is rotating at high speed by the motor 14 only in the vertical direction, and the reflected light is used for restoring this light to parallel light again. The angular velocity according to the rotation of the polygon mirror An aspherical surface having the function of an f-θ lens having a distribution of refractive indices so that light scanned uniformly is focused at a constant speed in the horizontal direction when focusing on a flat latent image forming surface. The scanning is performed via the lens 16, the optical path is bent by a folding mirror 19 provided for the purpose of increasing the optical path length in order to reduce the size of the apparatus, and then the scanning is performed while focusing on the photosensitive drum. I have. In addition, in order to generate a reference signal (beam detect signal: hereinafter, abbreviated as “BD”) for synchronizing the scanning start timing with the next scanning during one scanning in the above steps, it is turned back. This light is guided to a BD sensor 18 by a BD mirror 17 that reflects scanning light that is not necessary for image formation on the scanning start side before being incident on the mirror, and a sensor output responsive to this light is used as a BD signal. Is controlled to write image data based on the BD signal.

In recent years, various image forming apparatuses such as printers using the above-described structure have been required to have higher printing speed and lower cost as well as to improve image quality. Adverse effects and new issues are increasing. For example, a problem point in promoting the high speed operation is that the margin of the capability around the transfer process is reduced. In the transfer process, it is necessary to supply to the back of the paper a charge of the opposite polarity to that of the toner that can sufficiently attract and hold the toner on the paper surface. It is necessary to increase the amount of charge supplied to the transfer bias, and therefore the transfer bias intensity must be increased.However, if the bias intensity is simply increased, the effect of the electric field causes the toner to change in accordance with the image pattern in a low humidity environment. In other words, the transfer bias may be induced on the surface of the photosensitive drum in the area where no toner is present, or the transfer charge may penetrate the paper and be injected into the photosensitive drum surface in the area where there is no toner in a high humidity environment. If the potential unevenness is formed at a certain bias intensity or more, the potential unevenness cannot be corrected in the next charging step. In this case, the influence of the potential unevenness appears on the next image, and in the former case, a positive ghost appears. There is. Conventionally, as a countermeasure against such an adverse effect, as shown in FIG. 3A, an LED is used as an exposure means different from an exposure means for image formation between a transfer step and a charging step.
A method of providing a pre-charging exposure unit 20 using an array or the like and using the exposure unit to uniformly lower the potential of the entire photosensitive drum has been used. Another disadvantage of the transfer unit is that, even when the charging speed needs to be increased due to the increase in the speed of the apparatus, if an image pattern having a large margin is output, the surface of the photosensitive drum that is strongly charged to a negative polarity is output. The positively charged paper in the transfer section was strongly attracted and became difficult to separate, and the speed of paper transport accelerated the paper tip to the photosensitive drum side before the paper was peeled off the photosensitive drum surface by its own weight. Since the paper is easily conveyed, there is a problem that the risk of causing a so-called separation failure, that is, a conveyance failure while the paper is stuck to the photosensitive drum after the transfer, is increased. In this case, as shown in FIG. 3 (B), a pre-transfer exposure means 21 using an LED array or the like is conventionally provided as an exposure means different from the exposure means for image formation between the development step and the transfer step. A method has been used in which the exposure means uniformly lowers the potential of the entire photosensitive drum within a range in which no adverse effect occurs in the transfer portion, thereby weakening the action of electrostatically adsorbing the paper. In addition to the adverse effects related to the transfer process described above, FIG. 4 shows the purpose of simplifying the structure of the apparatus to reduce the cost and eliminating the scraping of the surface of the photosensitive drum due to the AC charging to extend the life of the photosensitive drum. Even when the DC charging roller 1 ′ is used to charge only the DC component, the unevenness of the potential due to the ineffectiveness of the potential caused by the alternating electric field of the AC component cannot be eliminated. During this period, the DC charging potential equalizing exposure means 22 must be provided so as to expose the light in a weak light amount range that does not affect the formation of the latent image on the downstream side.

However, if such a measure is used, it is necessary to newly provide an exposure means in addition to the conventional basic structure. For this purpose, it is necessary to add a light source, a drive circuit, a routing wiring, and the like, and the cost is reduced. Was a factor to raise.

[0008]

The problem to be solved by the present invention is that exposure such as pre-charging exposure, pre-transfer exposure, and DC post-charging exposure, etc., has been accompanied by the increase in the speed of the apparatus, the simplification of the structure and the improvement of the durability. This requires a process, which necessitates the provision of a new exposure means, which increases the cost.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and to form a good latent image, transfer and separate even if the apparatus is operated at a high speed without adding a new light source, a driving circuit thereof, and wiring. An exposure apparatus and an image forming apparatus are provided.

[0010]

According to the present invention, an object of the present invention is to charge a surface of an image carrier made of a photoreceptor to the same polarity as a developer by a charging means, and then scan light with an image signal. A latent image is formed on the surface of the image carrier by exposing the surface of the image carrier by light scanning means, and an electric field is applied to the developer with respect to the potential of the latent image to form an image by the developer. After the image is electrostatically developed on the surface of the image carrier, the image is transferred to a transfer material by a transfer unit, and the surface of the image carrier after the transfer is charged again to repeat the same process. The light scanning range of the light scanning means is wider than the image forming range, and the scanning light in a range not used for image formation is guided to an area on which the latent image is formed and another image carrier surface via an optical system, and the exposure area At least a scanning area necessary for forming the latent image. By exposure is enlarged to the width, the surface of the image bearing member to stabilize to a desired potential.

The optical scanning means uses laser light reflected and scanned by a rotary polygon mirror.

Further, a reflecting mirror having a convex surface is used as the optical system.

The optical system may include a reflector and a light guide having a function of emitting light incident in one direction from a narrow range to a wider range in another direction. The light is incident on the light guide having a length at least as long as the image forming area in the vicinity of the surface of the image carrier from the side direction of the carrier, and uniform light is emitted from the surface of the light guide facing the image carrier. To expose the surface of the image carrier.

The light guide has a rod shape as a whole, has a light incident surface at an end thereof, and has a light exit surface for emitting a light beam incident from the incident surface on one side surface in the longitudinal direction. In addition, a side surface portion facing the light exit surface has a region for reflecting and diffusing a light beam incident inside.

[0015] Further, a reflection / diffusion area of the light flux of the light guide is a saw-tooth-shaped processing surface arranged in a bar-shaped longitudinal direction,
Further, the saw-toothed processing surface is formed such that the width of the teeth is narrow near the light incident surface, and the width of the teeth increases as the distance from the light incident surface increases.

Further, the light guide has a surface other than the exposure surface covered with a reflecting mirror.

Further, an optical fiber is used as a means for guiding the laser light to the light guide.

Further, by using scanning light in two directions of a scanning start side and a scanning end side as scanning light in a range not used for the image formation, the image carrier is exposed from two directions by exposing the image carrier. Stabilize the surface to the desired potential.

Further, using the scanning light in a range not used for image formation as a pre-charging exposure, and irradiating the latent image forming area and another image carrier surface, the image is formed after the completion of the transfer step and the next time. The surface of the image carrier before receiving the charging step, at this time, during the period of irradiating the scanning light used as the pre-charging exposure, the rear end of the transfer material after the end of the scanning period necessary for forming a latent image of image formation This is extended to a period until the surface of the transferred image carrier reaches the charging step.

In addition, the scanning light in a range not used for image formation is used as exposure before transfer, and the area where the latent image is to be formed and the surface of the image carrier other than the area where the latent image is to be formed are transferred after the development step and the transfer step. The image carrier surface before receiving
At this time, regardless of the scanning period required for forming a latent image for image formation, the period of irradiating the scanning light used as the pre-transfer exposure is such that the surface of the photosensitive drum in contact with the transfer material is on the opposite surface of the exposure unit. Is in the period of passing.

Further, the scanning light in a range not used for image formation is used as exposure means after DC charging, and the area where the latent image is to be irradiated and the surface of the image carrier other than the area are formed after the charging step is completed. The surface of the image carrier before receiving the latent image forming step, at this time, regardless of the scanning period required for the latent image formation of image formation, the period of irradiating the scanning light used as the pre-exposure after the DC charging, This is realized when the DC charging is performed and the photosensitive drum surface after the completion of the DC charging passes through the facing surface of the exposure unit.

[Operation] According to the present invention, the conventional exposure device used for forming a latent image is diverted as it is, and only a slight addition of an optical system and a change in light emission timing are performed. The same effects as the pre-charging exposure, pre-transfer exposure, and DC post-charging exposure, which were performed by adding a drive circuit and wiring, can be obtained. Transfer separability is obtained, and high-quality latent images can be formed by DC charging.

[0023]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(Embodiment 1) FIGS. 1A and 1B are a conceptual view of an exposure optical system of an image forming apparatus and a cross-sectional view of a photosensitive drum peripheral member according to a first embodiment of the present invention. FIG.
In FIGS. 2A and 2B, members having the same reference numerals as those in FIGS. 2A and 2B indicate the same components, and in this embodiment, are provided at the end of the folding mirror 19 on the laser beam scanning end side. A two-dimensional first convex mirror 19 'is provided, and a laser which is turned on in a 5 mm wide scannable blank area existing outside the end side of a laser light scanning area actually required for image formation is formed on the convex part. The light beam is reflected to broaden the beam diameter mainly in the main scanning direction, and at the same time, the light path is changed so that the beam is made incident on a two-dimensional second convex mirror 19 ″ provided behind the charging roller. In the main scanning direction, the surface of the photosensitive drum before charging is extended by one line at the time of forming each latent image by laser scanning for one line in each main image. Irradiate each time, after the latent image formation period This is used as pre-charging exposure by extending the laser lighting only in this scanning area for the period until the surface of the photosensitive drum that has finished transferring the image enters the next charging process, and the exposure intensity is at least expanded by the optical system. The light amount required for the formation of a latent image is reduced to about 1/50 by the ratio of the beam diameter area obtained, but this exposure amount is sufficient depending on the sensitivity of the photosensitive drum and the transfer bias intensity. In this case, the emission amount is doubled by increasing the emission intensity of the laser only during the scanning period for the margin, or by providing a scanning margin portion on the BD mirror side and providing the same optical system as the end portion on the scanning end side. It is also possible to increase.

(Embodiment 2) FIGS. 5A and 5B and FIGS. 6A and 6B are a conceptual view of an exposure optical system and a light guide of an image forming apparatus according to a second embodiment of the present invention. FIG. 3 is an explanatory diagram of a structure of a body, a cross section of a light guide unit, and a cross sectional view of a photosensitive drum peripheral member using this unit. 5A and 5B, the members having the same numbers as those in FIGS. 2A and 2B indicate the same components, and in the present embodiment, they are folded back as shown in FIG. 5A. Laser light scanning margins are provided at both ends of the mirror, and the laser light applied to the margin area is reflected by the reflecting mirror 2.
The light path is changed so that the light can enter in the direction perpendicular to the side surface of the photosensitive drum 2 behind the charging roller 1 by the combination of the three, and the side surface of the rod-shaped light guide 24 disposed close to the surface of the photosensitive drum 2 behind the charging roller 1 From the part. This light guide is a transparent body made of a material such as an acrylic resin having a structure shown in a top view, a side view, and a back view as shown in FIG. While the light is diffused and guided, and the multiple scattering is repeated on the inner wall of the rod, only the light incident at an appropriate angle on the serrated processing surface provided on the rear side is selectively reflected by the total reflection and Fresnel reflection on the serrated surface. Will be emitted in the opposite direction. With this structure, the laser beam incident from the side surface of the rod is emitted from the other direction substantially perpendicular to the incident direction over the entire region in the longitudinal direction. Furthermore, the size of the saw-tooth surface is small near the light-incident end of the light source, and increases as the distance from the light-incident end. It is possible to correct the non-uniformity of the irradiation light amount in the longitudinal direction (hereinafter, referred to as “shading”). The light guide having such a structure is further covered with an aluminum reflection cover 24 ″ as shown in the cross-sectional view of FIG. 6A, and the surface other than the exposure slit provided on the exposure surface side. All the light leaked from the light is reflected and returned to the light guide, so that the light use efficiency can be further improved, and the desired exposure width and length can be selected by adjusting the size of the slit. It becomes possible.
The light guide unit composed of the light guide 24 and the reflection cover 24 ″ is set at a position as shown in FIG. 6B, and is controlled in the same manner as in the first embodiment to be effectively used as a pre-charge exposure. This makes it possible to realize the optical system in a smaller space than in the first embodiment, and can promote downsizing of the apparatus.

(Embodiment 3) FIG. 7 is a conceptual view of an exposure optical system of an image forming apparatus according to a third embodiment of the present invention. In FIG. 7, members having the same numbers as those in FIG. 5A indicate the same components, and in the present embodiment, instead of changing the optical path of the laser light using a reflecting mirror, the scanning light in the margin is collected. The optical fiber 26 is introduced into the optical fiber 26 via the optical lens 25, and the optical fiber is appropriately routed inside the apparatus to obtain a second embodiment.
Is connected to the same light guide 24 to guide the laser light inside the light guide 24. The effect and control are the same as those of the second embodiment, but by using a flexible fiber. In addition, it is possible to further increase the degree of freedom in the arrangement and configuration of various components inside the apparatus, and to further increase the space efficiency, thereby contributing to further downsizing of the apparatus.

(Embodiment 4) FIG. 8 is a sectional view of a photosensitive drum peripheral member using a light guide unit of an image forming apparatus according to a fourth embodiment of the present invention as a pre-transfer exposure means. In FIG. 8, members having the same numbers as those in FIG. 6B indicate the same components. In the present embodiment, the light guide 24 and the reflection cover 24 ″ using the optical system of the third embodiment are used. The photoconductor unit is arranged in the pre-transfer area, and the surface of the photosensitive drum that comes into contact with the paper surface from the leading edge to the trailing edge of the paper at the transfer unit passes through the surface facing the light guide unit regardless of the presence or absence of an image signal. By controlling the laser to continue emitting light in the scanning margin during the period, the negative potential intensity on the surface of the photosensitive drum in contact with the paper surface, which is positively charged at the transfer unit, can be reduced, resulting in transfer separation Can be secured.

(Embodiment 5) FIG. 9 is a sectional view of a photosensitive drum peripheral member using a light guide unit of an image forming apparatus according to a fifth embodiment of the present invention as an exposure means after DC charging. In FIG. 9, members having the same numbers as those in FIG. 6B indicate the same constituent elements.
The light guide unit composed of the light guide 24 and the reflection cover 24 ″ is disposed immediately below the charging process by using the optical system of (1) to make the surface potential of the photosensitive drum unevenly charged by DC roller charging uniform. The laser emission period for emitting light in the laser scanning margin is the charging period of the DC charging roller and the period from the end of charging until the photosensitive drum surface passes through the surface facing the light guide unit. By using this configuration, it is possible to avoid a reduction in the life of the photosensitive drum due to AC charging, improve durability, and obtain high image quality with a simple configuration without providing a new exposure unit. .

[0029]

As described above, according to the present invention, the laser is emitted in the marginal area at the end of the scanning area which is not involved in the actual image formation by the laser scanning type exposure means used for the conventional latent image formation. The laser light is guided to the surface of the photosensitive drum other than the latent image forming surface via a simple optical system, and the exposure area is extended to the image forming width to perform exposure, thereby increasing the speed of the apparatus and improving the durability of the photosensitive drum. It can be used as exposure means such as pre-charging exposure, pre-transfer exposure, and DC post-charging exposure that can contribute to cost reduction. The same effects as the pre-charging exposure, the pre-transfer exposure, and the DC post-charging exposure, which were performed by additionally providing a light source and its driving circuit and wiring, can be obtained.

[Brief description of the drawings]

FIG. 1A is a conceptual view of an exposure optical system of an image forming apparatus according to a first embodiment of the present invention. FIG. 3B is a sectional view of a photosensitive drum peripheral member according to the first embodiment of the present invention.

FIG. 2A is a cross-sectional view of a conventional image forming apparatus. (B)... A conceptual diagram of a conventional exposure means configuration.

FIG. 3A is a cross-sectional view of a conventional image forming apparatus having a pre-charging exposure. FIG. 1B is a cross-sectional view of a conventional image forming apparatus having pre-transfer exposure.

FIG. 4 is a cross-sectional view of a conventional image forming apparatus having exposure after DC charging.

FIG. 5A is a conceptual view of an exposure optical system of an image forming apparatus according to a second embodiment of the present invention. (B) ... Light guide structure explanatory drawing showing 2nd Embodiment of this invention.

FIG. 6A is a cross-sectional view of a light guide unit according to a second embodiment of the present invention. FIG. 6B is a cross-sectional view of an image forming apparatus having a pre-charging exposure according to a second embodiment of the present invention.

FIG. 7 is a conceptual diagram of an exposure optical system of an image forming apparatus according to a third embodiment of the present invention.

FIG. 8 is a sectional view of an image forming apparatus having a pre-transfer exposure according to a fourth embodiment of the present invention.

FIG. 9 is a cross-sectional view of an image forming apparatus having exposure after DC charging according to a fifth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Charging roller 2 Photosensitive drum 3 Exposure means 3 'Laser diode 4 Developing device 4a Developing blade 4b Developing sleeve 5 Toner 6 Paper 7 Transfer roller 9 Fixing device 10 Heating rotator 11 Pressure roller 12 Collimator lens 13 Cylindrical lens 14 Motor 15 Polygon Mirror 16 Aspherical lens 17 BD mirror 18 BD sensor 19 Folding mirror 19 ′ First convex mirror 19 ″ First convex mirror 20 Pre-charging exposure unit 21 Pre-transfer exposure unit 22 DC post-exposure unit 23 Reflecting mirror 24 Light guide 24 '' Sawtooth surface 24 '' Reflective cover 25 Condensing lens 26 Optical fiber

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/29 F term (Reference) 2C362 BA03 BA25 BA28 BA83 CB59 CB80 2H045 AA01 CB65 DA21 2H076 AB02 AB12 AB16 AB18 AB61 CA01 CA16 5C072 AA03 BA13 DA04 HA01 HA13 HB15 XA01 XA04 5C074 AA02 AA11 AA12 BB03 BB26 CC22 CC26 DD11 GG04 GG05 GG12 HH02 HH04

Claims (12)

[Claims] An image carrier comprising a photoreceptor is charged to the same polarity as that of a developer by a charging means, and the surface of the image carrier is exposed by a light scanning means for scanning light according to an image signal. A latent image is formed on the surface of the image carrier by applying an electric field to the developer with respect to the potential of the latent image to electrostatically develop an image formed by the developer on the surface of the image carrier. In an image forming apparatus in which an image is transferred onto a transfer material by a transfer unit, the surface of the image carrier after transfer is charged again, and the same process is repeated, the light scanning range of the light scanning unit is larger than the image forming range. Broadly, the scanning light in a range not used for image formation is guided to the area where the latent image is formed and another image carrier surface through an optical system, and the exposure area is at least as large as the width of the scanning area required for the latent image formation. The image is exposed by enlarging and exposing An exposure apparatus and an image forming apparatus for stabilizing a surface of a carrier at a desired potential. 2. An exposure apparatus and an image forming apparatus according to claim 1, wherein said optical scanning means uses laser light reflected and scanned by a rotary polygon mirror. 3. An exposure apparatus and an image forming apparatus according to claim 2, wherein a reflection mirror having a convex surface is used as said optical system. 4. The apparatus according to claim 2, wherein the optical system includes a reflecting mirror and a light guide having a function of emitting light incident in one direction from a narrow range to a wide range in another direction. The laser light is used to impinge on the light guide having a length at least as long as the image forming area close to the surface of the image carrier from the side surface direction of the image carrier, and the image carrier of the light guide is And an image forming apparatus for exposing the surface of the image carrier as uniform light from the opposing surface. 5. The device according to claim 4, wherein the light guide has a rod shape as a whole, has a light incident surface at an end thereof, and receives a light beam incident from the incident surface on one side surface in the longitudinal direction. An exposure apparatus and an image forming apparatus having a light emitting surface for emitting light and a region on a side surface facing the light emitting surface for reflecting and diffusing a light beam incident therein. 6. The apparatus according to claim 5, wherein the light beam reflection / diffusion area of the light guide is a bar-shaped saw-toothed processing surface arranged in the longitudinal direction, and the saw-tooth-shaped processing surface is a light beam. An exposure apparatus and an image forming apparatus, wherein the width of the teeth is narrow near the incident surface, and the width of the teeth increases as the distance from the incident surface increases. 7. An exposure apparatus and an image forming apparatus according to claim 6, wherein the light guide has a surface other than the exposure surface covered with a reflecting mirror. 8. An exposure apparatus and an image forming apparatus according to claim 4, wherein an optical fiber is used as means for guiding said laser light to said light guide. 9. The image bearing member according to claim 1, wherein scanning light in two directions, a scanning start side and a scanning end side, is used as scanning light in a range not used for image formation. And an image forming apparatus for stabilizing the surface of the image carrier at a desired potential by performing the exposure. 10. The apparatus according to claim 1, wherein the scanning light in a range not used for the formation is used as a pre-charge exposure, and the surface of the image carrier different from a region where the latent image is formed is irradiated. After the transfer step is completed and before the next charging step, the surface of the image carrier is irradiated with the scanning light used as the pre-charging exposure. An exposure apparatus and an image forming apparatus, wherein the exposure apparatus and the image forming apparatus extend the period from the end of the period until the surface of the image carrier on which the rear end of the transfer material has been transferred reaches a charging step. 11. The apparatus according to claim 1, wherein the scanning light in a range not used for image formation is used as a pre-transfer exposure, and a surface on which the latent image is formed and another image carrier surface are irradiated. This is the surface of the image carrier after the development step and before the transfer step. At this time, the period for irradiating the scanning light used as the pre-transfer exposure is a scanning period necessary for forming a latent image for image formation. Irrespective of this, the exposure apparatus and the image forming apparatus are characterized in that the photosensitive drum surface in contact with the transfer material is in a period of passing over the facing surface of the exposure unit. 12. The image bearing member according to claim 1, wherein the scanning light in a range not used for image formation is used as an exposure unit after DC charging, and the surface on which the latent image is formed is radiated. Is the surface of the image carrier after the completion of the charging step and before the latent image forming step is performed. At this time, the period during which the scanning light used as the pre-exposure after the DC charging is irradiated with the latent image forming step for image formation is used. Irrespective of the scanning period necessary for the exposure, the exposure apparatus and the image processing apparatus are characterized in that during the period of performing the DC charging and until the surface of the photosensitive drum after the completion of the DC charging passes over the facing surface of the exposure unit. Forming equipment.