JP2002148549A - Scanner unit and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a situation that origin detecting light radiated to the vicinity of a sensor is finally emitted from an emitting port part in a scanner unit and an image forming device equipped with the scanner unit. SOLUTION: A perpendicularly sheer wall part 51d is formed on a housing in front of a slit plate 73 for a BD sensor 71. The wall part 51d is designed so that a laser beam Lb reflected on the plate 73 and a laser beam Lc directly cast to the wall part 51d without being cast to the plate 73 may be reflected in different directions from a reflecting mirror as well as a polygon mirror. Then, the origin detecting laser beam is prevented from being finally emitted from the emitting port part of the scanner unit, whereby ghost is satisfactorily prevented from being formed on recording paper in an image forming part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanner unit for irradiating light emitted from a light source in a scanning manner and an image forming apparatus using the scanner unit, and more particularly, to a sensor for detecting the scanning origin. The present invention relates to a scanner unit and an image forming apparatus provided with the scanner unit.

[0002]

2. Description of the Related Art Conventionally, as this type of scanner unit, a deflecting means for deflecting light from the light source in a predetermined scanning direction and a housing of the scanner unit are provided.
It is conceivable to provide an emission port for emitting the light deflected by the deflecting means to the outside of the housing, and a sensor fixed in the housing and for detecting the scanning origin. . In such a scanner unit, light generated by a light source such as a laser light emitting unit is deflected in a predetermined scanning direction by a deflecting unit such as a polygon mirror and emitted from an emission port to irradiate the light in a scanning manner. Can be.

In this type of scanner unit, light deflected by a deflecting means such as a polygon mirror is reflected by a folding mirror having a long shape along the scanning direction, and the polygon mirror is reflected from an exit port. It is also considered to emit light in a direction that is not orthogonal to the rotation axis.
Further, in the above-mentioned scanner unit, the light in the direction corresponding to the scanning origin can be detected by the above-described sensor, and if the ON / OFF timing of the light source is set according to the detection timing, the light irradiation direction can be further increased. It can be specified exactly. In particular, when this type of scanner unit is used to expose a photosensitive drum or the like in an image forming apparatus such as a laser printer, for example, by precisely defining the light irradiation direction as described above, Image can be formed.

[0004]

However, when the light applied to the vicinity of the sensor is reflected by the inner surface of the housing or the like and is emitted from the emission port, the image formed by the image forming apparatus becomes a ghost image. A called image is formed. That is, an unnecessary image is formed by the light for detecting the origin which should not contribute to the image formation.

Accordingly, the present invention provides a scanner unit and an image forming apparatus provided with the scanner unit, which prevent origin-detecting light emitted near the sensor from being finally emitted from the emission port. Made for purpose.

[0006]

According to the first aspect of the present invention, there is provided a scanner unit for irradiating light generated by a light source in a scanning manner, wherein the scanner unit emits light from the light source. Deflecting means for deflecting light in a predetermined scanning direction; an emission port provided on a housing of the scanner unit for emitting light deflected by the deflecting means to the outside of the housing; and fixed inside the housing. And a sensor for detecting the origin of the scanning, and standing in the housing,
A wall portion for reflecting light emitted near the sensor in a direction not finally emitted from the emission port.

According to the present invention, the light generated by the light source is deflected by the deflecting means in a predetermined scanning direction, and emitted from the light exit, so that the light can be irradiated in a scanning manner. Further, in the present invention, since the light in the direction corresponding to the scanning origin can be detected by the above-mentioned sensor, the ON / OF of the light source can be detected according to the detection timing.
If the F timing is set, the light irradiation direction can be more accurately defined.

Here, in the present invention, the light irradiated to the vicinity of the sensor is reflected in a direction in which the wall portion is not finally emitted from the emission port. Therefore, in the present invention, it is possible to satisfactorily prevent the light for origin detection which is applied to the vicinity of the sensor from being finally emitted from the emission port.
For this reason, when the scanner unit of the present invention is used to expose a photosensitive member of an image forming apparatus, an accurate image can be formed on a recording medium by detecting light in a direction corresponding to the scanning origin by the sensor. At the same time, the formation of a ghost by the light for detecting the origin can be favorably prevented.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the light deflected by the deflecting means is once reflected by a first mirror which is elongated in the scanning direction. Then, the light is emitted from the emission port. The present invention includes a first mirror configured to be long along the scanning direction of the deflecting unit, and the light deflected by the deflecting unit is once reflected by the first mirror, and then is reflected by the emission port. Released from the department. For this reason, in the present invention, in addition to the effect of the first aspect of the invention, an effect that the light emission direction can be freely set is generated.

According to a third aspect of the present invention, in addition to the configuration of the second aspect, the wall reflects the light in a direction different from that of the deflecting means and the first mirror. When the light for detecting the origin is reflected toward the deflecting means, there is a high possibility that the light is emitted from the emission port. Further, when the first mirror is provided as described in claim 2, even if the light for detecting the origin is reflected toward the first mirror, there is a high possibility that the light is emitted from the emission port.

According to the present invention, since the wall reflects light in a direction different from that of the deflecting means and the first mirror, in addition to the effect of the second aspect, the light is emitted from the emission port. Is more effectively prevented. Therefore, when the scanner unit of the present invention is used for exposing the photoconductor of the image forming apparatus,
Ghosts can be more effectively prevented from being formed.

According to a fourth aspect of the present invention, in addition to the configuration according to any one of the first to third aspects, a slit plate is provided in front of the sensor, and the wall portion reflects light reflected by the slit plate. Is reflected in the above-mentioned direction. In the present invention, since the slit plate is provided in front of the sensor, light in the direction corresponding to the scanning origin can be detected more accurately. Also, when a slit plate is provided in this way,
Although the light irradiated near the sensor is reflected by the slit plate, the wall portion of the present invention causes the light reflected by the slit plate to move in the above-described direction (the direction not finally emitted from the emission port, or the deflection means). (A direction different from that of the first mirror).

Therefore, according to the present invention, in addition to the effect of any one of the first to third aspects of the present invention, the light in the direction corresponding to the scanning origin can be detected more accurately and the origin for detecting the origin can be detected. There is an effect that the light can be more preferably prevented from being emitted from the emission port. Therefore, when the scanner unit of the present invention is used for exposing a photosensitive member of an image forming apparatus, a more accurate image can be formed by detecting light in a direction corresponding to the scanning origin more accurately, and the image can be formed. The formation of a ghost by the light for detecting the origin can be more favorably prevented.

According to a fifth aspect of the present invention, in addition to the configuration according to any one of the first to fourth aspects, the wall portion absorbs the light, thereby attenuating the reflected light from the wall portion. Features. In the present invention, since the wall absorbs the light, the light reflected from the wall is attenuated.
The reflected light can be more preferably prevented from being emitted from the emission port. Therefore, in the present invention, claims 1 to
In addition to the effect of the invention described in any one of 4 above, there is an effect that the light for detecting the origin can be more preferably prevented from being emitted from the emission port. For this reason, when the scanner unit of the present invention is used for exposing the photosensitive member of the image forming apparatus, it is possible to more favorably prevent the formation of a ghost.

According to a sixth aspect of the present invention, in addition to any one of the first to fifth aspects, the light deflected by the deflecting means in the direction corresponding to the origin of the scanning is reflected toward the sensor. And a light path from the second mirror to the sensor is disposed in a direction intersecting a plane containing light in each direction deflected by the deflector. Features.

In the present invention, the second mirror reflects the light deflected by the deflecting means in the direction corresponding to the scanning origin, toward the sensor. Further, an optical path from the second mirror to the sensor is disposed in a direction intersecting a plane containing light in each direction deflected by the deflector. For this reason, in the present invention, the optical path of the light for detecting the origin irradiated to the vicinity of the sensor is not arranged on the same plane as the plane containing the light in each direction deflected by the deflecting means. If the optical path of the light for detecting the origin is arranged on the same plane as the plane containing the light in each direction deflected by the deflecting means, when the light is reflected by some member, the exit port is finally formed. However, in the present invention, since the optical path is not arranged on the same plane,
It is possible to more favorably prevent the light from being emitted from the emission port.

Therefore, in the present invention, in addition to the effect of the invention according to any one of the first to fifth aspects, it is possible to further effectively prevent the light for detecting the origin from being emitted from the emission port. There is an effect that it can be done. For this reason, when the scanner unit of the present invention is used for exposing the photoreceptor of the image forming apparatus, the formation of a ghost can be more favorably prevented.

According to a seventh aspect of the present invention, there is provided a scanner unit for irradiating light emitted from a light source in a scanning manner, comprising: a deflecting means for deflecting light from the light source in a predetermined scanning direction;
An emission port provided in the housing of the scanner unit and emitting light deflected by the deflecting means to the outside of the housing, and a sensor fixed in the housing and for detecting an origin of the scanning. A second mirror for reflecting, toward the sensor, light in a direction corresponding to the scanning origin deflected by the deflecting unit, and an optical path from the second mirror to the sensor is provided by the deflecting unit. Are arranged in a direction intersecting with a plane containing light in each direction deflected by.

By providing the second mirror as in the sixth aspect of the present invention, the optical path of the light for detecting the origin is arranged on the same plane as the surface containing the light in each direction deflected by the deflecting means. In order to prevent the light for detecting the origin from being emitted from the emission port portion when the light emission is not performed, it is possible to prevent the light from being emitted from the emission port portion.
The configurations of the wall portions described in Nos. To 5 are not necessarily required. In the present invention, although the configuration of the wall portion is not included as an essential requirement, since the configuration of the second mirror similar to that of the sixth aspect is provided, the light for detecting the origin is emitted from the emission port portion. Can be satisfactorily prevented. For this reason, when the scanner unit of the present invention is used to expose a photosensitive member of an image forming apparatus, an accurate image can be formed on a recording medium by detecting light in a direction corresponding to the scanning origin by the sensor. At the same time, the formation of a ghost by the light for detecting the origin can be favorably prevented.

[0020] The image forming apparatus according to the eighth aspect is the first aspect.
7. A scanner unit according to any one of claims 1 to 7, a photoconductor exposed by light emitted from the scanner unit, a developing unit for attaching a developing material to the exposed photoconductor, and a photoconductor by the developing unit. Transfer means for transferring an image of the developer adhered to the recording medium to form an image.

In the image forming apparatus of the present invention, when the photosensitive member is exposed by the light emitted from the scanner unit,
Developing means attaches a developing material to the exposed photoconductor,
A transfer unit transfers the developing material to a recording medium. Therefore, an image corresponding to the light emitted from the scanner unit can be formed on the recording medium. Further, since the scanner unit is a scanner unit according to any one of claims 1 to 7, a more accurate image can be formed by detecting light in a direction corresponding to the origin of scanning, and the origin can be detected. Can be satisfactorily prevented from being emitted from the emission port. For this reason, in the image forming apparatus of the present invention, it is possible to improve the accuracy of image formation and to prevent ghosts from being formed satisfactorily.

[0022]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view illustrating a configuration of a main body unit 1 of a laser printer as an image forming apparatus to which the present invention is applied. The laser printer according to the present embodiment is configured such that a tray unit (not shown) including a paper feed tray configured similarly to the paper feed tray 3 can be stacked below the main body unit 1 shown.

As shown in FIG. 1, a support plate 5 urged upward by a spring (not shown) is provided inside a paper feed tray 3 which is removably inserted below the main unit 1. Further above the plate 5, a paper feed roller 9 that separates the recording paper (corresponding to a recording medium: not shown) held on the support plate 5 one by one and feeds it toward the image forming unit 7. Are arranged. Further, in the conveyance path of the recording paper from the paper feed roller 9 to the image forming section 7, two pairs of conveyance rollers 11 and 13 for conveying the recording paper are stopped appropriately to lock the leading end of the recording paper. And a registration roller 15 for correcting the skew of the recording paper. Furthermore,
The recording paper disposed on the manual feed tray 17 can be conveyed to the registration roller 15 by the paper feed roller 19.

The image forming section 7 includes the process cartridge 2
1, a photosensitive drum 23 as a photosensitive member provided in
And a transfer roller 25 as a transfer unit that is disposed opposite to the photosensitive drum 23.
The recording paper, which has passed between the transfer roller 3 and the transfer roller 25 and has an image formed of toner as described later, is supplied to the fixing unit 31 via the transport belt 27. In the fixing unit 31, the toner image formed on the recording paper is thermally fixed by being sandwiched between the heating roller 33 and the pressing roller 35, and the recording paper on which the image is fixed is conveyed by three pairs of discharge rollers 37, The paper is discharged to a paper discharge tray 39 provided on the upper surface of the main unit 1.
A scanner unit 41 that exposes the photosensitive drum 23 with the laser light L is provided between the paper discharge tray 39 and the process cartridge 21.

FIG. 2 shows the process cartridge 21.
It is a longitudinal cross-sectional view showing the internal structure of FIG. As shown in FIG.
The process cartridge 21 rotatably includes a photosensitive drum 23 having a photosensitive layer on its surface, and further includes a charging roller 43 for uniformly charging the surface of the photosensitive drum 23.
It has. On the surface of the photosensitive drum 23 charged by the charging roller 43, an electrostatic latent image is formed by a laser beam L (see FIG. 1) incident from the scanner unit 41 via the exposure opening 21a. The developing roller 45 as a means supplies the toner as a developing material to the surface of the photosensitive drum 23, so that the electrostatic latent image is developed. In this way, the toner adhered to the photosensitive drum 23 is transferred to the recording paper passing between the above-described transfer roller 25 and an image is formed on the recording paper.

The charging roller 43 and the developing roller 45
Rotates following the photosensitive drum 23. In addition, the process cartridge 21 further includes a toner feeding member 47 that feeds the toner contained in the toner container 21b toward the developing roller 45 while stirring the toner, and a developing device that frictionally charges the toner attached to the surface of the developing roller 45. Blade 49
Various known configurations are provided.

Next, the configuration of the scanner unit 41 will be described. FIG. 3 is a plan view showing the configuration of the scanner unit 41, and FIG. 4 is a longitudinal sectional view thereof. Figures 3 and 4
As shown in FIG. 3, the scanner unit 41 includes an upwardly open housing 51 having a substantially flat bottom plate 51a and a side wall 51b provided upright around the bottom plate 51a. A collimator lens 55, a polygon mirror 57 as a deflecting means, an fθ lens 59, and a return mirror 61 as a first mirror are fixed as optical elements constituting an optical path of the laser light L where the laser light L is generated.

With this configuration, the laser beam L generated by the laser light emitting section 53 is deflected in a predetermined scanning direction by the polygon mirror 57 and is turned back by the turn-back mirror 61 so that the emission port 51 c formed on the bottom surface of the housing 51 is formed.
(See FIG. 4). In addition, as shown in FIG.
There is provided a cylindrical lens 63 through which the laser light L reflected by the light passes, and a cover glass 65 that covers the emission port 51c from below. Thus, the fθ lens 59
Folding mirror 6 between the lens and the cylindrical lens 63
1 can be prevented from being arranged in a straight line, and
In this case, the influence of the airflow generated during the rotation of can be eliminated well.

Further, a first BD mirror 67 is provided adjacent to the folding mirror 61 as shown in FIG.
By cooperating with the second BD mirror 69 provided at a position deviated from the optical path of the deflected laser beam L toward the photosensitive drum 23, the laser beam La in the direction corresponding to the scanning origin is used as a BD as a sensor. The light is reflected toward the sensor 71. Further, a slit plate 73 and a BD lens 75 are provided in front of the BD sensor 71. This BD
The sensor 71, the slit plate 73, and the BD lens 75 also
The deflected laser light L is provided at a position deviated from an optical path toward the photosensitive drum 23. With this configuration, if the ON / OFF timing of the laser light emitting unit 53 is set in accordance with the timing at which the BD sensor 71 detects the laser light La, the irradiation direction of the laser light L can be accurately defined, and the recording paper An accurate image can be formed.

FIG. 5 is a perspective view showing the structure of the housing 51 in detail. As shown in FIG. 5, the housing 51 includes a support member 80 for supporting the laser emission unit 53 on the outside, and a first B
A supporting member 81 supporting the D mirror 67, a supporting member 82 supporting the second BD mirror 69, a supporting member 83 supporting the BD sensor 71, and a supporting member 8 supporting the slit plate 73.
A support member 85 for supporting the BD lens 75 is integrally formed.

As shown in FIG. 6 as an enlarged view of a portion A in FIG. 5, a shutter 91 for blocking the optical path of the laser light L is provided at a position facing the laser emitting section 53 so as to be swingable. . The shutter 91 is fixed to one end 93b of a link member 93 that swings about a shaft 93a, and the other end 93c of the link member 93 has some play at one end 95b of the link member 95 that swings about a shaft 95a. (So-called play). The other end 95c of the link member 95 is configured to abut on a peripheral member (not shown) and swing with the opening and closing of the cover of the main unit 1. With this configuration, when the cover of the main unit 1 is opened, the shutter 91 is provided in front of the laser light emitting unit 53, and the laser light L can be prevented from being emitted from the emission port 51c. Conversely, when the cover is closed, the shutter 91 retracts from the front of the laser light emitting unit 53, and the exposure of the photosensitive drum 23 becomes possible as described above.

If the operation of the cover of the main unit 1 is transmitted to the shutter 91 via one link member, sufficient dimensional accuracy cannot be obtained, and the laser beam L is reliably shut off when the cover is opened. If the link member cannot be formed, or if it is formed, a mechanical load is applied to the link member, causing a problem in its durability. In contrast, in the present embodiment,
Since the operation of the cover is transmitted to the shutter 91 via the plurality of link members 93 and 95 which are engaged with a certain amount of play, the shutter 91 can be moved without applying a mechanical load to the link members 93 and 95. Opening and closing can be performed reliably.

Next, as shown in FIGS. 5 and 7, the housing 51 in front of the slit plate 73 is formed with a wall 51d which is vertically cut. As shown in FIG. 7, the wall portion 51d is formed by the laser light Lb reflected by the slit plate 73,
In addition, the laser beam Lc that directly hits the wall 51d without hitting the slit plate 73 is reflected in a direction different from that of the polygon mirror 57 and the return mirror 61 (in this embodiment, a direction that directly hits the inner wall of the housing 51). Designed to be. The inside of the housing 51 including the wall 51d is formed of matte black resin so as to absorb the laser light L. Further, the scanner unit 4
In 1, the first BD mirror 67 and the second BD mirror 69 as the second mirror (only one of them may be used)
Is slightly forwardly (reflecting side) and supported, as shown in FIG.
The laser beam La incident on a is incident so as to approach the bottom plate 51a of the housing 51 at a small angle a.

According to the present embodiment, the following operations and effects are produced by the above configuration. That is, the laser beam La for detecting the origin irradiated to the vicinity of the BD sensor 71
Can be reflected in directions different from those of the polygon mirror 57 and the return mirror 61 like the laser light Lb and the laser light Lc. Moreover, since the inside of the housing 51 is molded with matte black resin, the laser light La is greatly attenuated by the reflection. For this reason, it is possible to prevent the laser beam La for detecting the origin from being finally emitted from the emission port portion 51c, thereby favorably preventing the image forming section 7 from forming a ghost on the recording paper. it can.

In addition, the laser light La for detecting the origin is used.
Is located close to the bottom plate 51a at the small angle a, and is not arranged on the same plane as the plane (parallel to the bottom plate 51a) that contains the laser light L in each direction reflected by the polygon mirror 57. When the laser light La is disposed on the same plane as the above surface, the laser light La is likely to be finally emitted from the emission port 51c when reflected by some member,
In the present embodiment, since the laser light La is not disposed on the same plane as the above-described surface, it is possible to extremely effectively prevent the laser light La from being finally emitted from the emission port 51c. .

In the present embodiment, the BD sensor 71
Since the slit plate 73 is provided in front of the laser beam La, the laser beam La corresponding to the scanning origin can be detected more accurately. Therefore, the laser printer of the present embodiment has a remarkable effect that a high-precision image can be formed on recording paper without ghost.

It should be noted that the present invention is not limited to the above-described embodiment at all, and can be implemented in various forms without departing from the gist of the present invention. For example, the slit plate 73 is not always necessary, and the slit plate 73 can be omitted by appropriately selecting the BD sensor 71. In addition, the first BD mirror 67 and the second BD mirror 69 (only one of them) may be slightly tilted forward to support the laser beam La so that the small angle a
In this case, only one of the configuration in which the laser beam La is reflected in the direction different from that of the polygon mirror 57 and the folding mirror 61 by providing the wall portion 51d and providing the wall portion 51d may be adopted.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view illustrating a configuration of a laser printer to which the present invention is applied.

FIG. 2 is a longitudinal sectional view illustrating a configuration of a process cartridge of the printer.

FIG. 3 is a plan view illustrating a configuration of a scanner unit of the printer.

FIG. 4 is a longitudinal sectional view illustrating a configuration of the scanner unit.

FIG. 5 is a perspective view illustrating a configuration of a housing of the scanner unit in detail.

FIG. 6 is an enlarged view of a portion A showing the configuration of the housing in more detail.

FIG. 7 is an explanatory diagram illustrating a configuration and an operation of a wall provided in the housing.

FIG. 8 is an explanatory diagram illustrating an incident direction of a laser beam for detecting an origin.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Main unit 3 ... Paper feed tray 7 ... Image forming part 9, 19 ... Paper feed roller 21 ... Process cartridge 23 ... Photoconductor drum 25 ... Transfer roller 31 ... Fixing part
39: paper ejection tray 41: scanner unit 45: developing roller
51: housing 51a: bottom plate 51b: side wall
51c ... Outlet 51d ... Wall 53 ... Laser emitting part
55: Collimating lens 57: Polygon mirror 59: fθ lens
61 ... Folded mirror 63 ... Cylindrical lens 65 ... Cover glass
67: first BD mirror 69: second BD mirror 71: BD sensor
73 ... slit plate 73a ... slit 75 ... BD lens 80, 81, 82, 83, 84, 85 ... support member
91: shutter 93, 95: link member L, La, Lb, Lc
… Laser light

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 2C362 BA87 BA89 BB29 BB30 DA28 DA29 2H045 CA89 CB63 DA02 DA04 5B047 AA01 BA02 BC09 BC16 CB05 CB09 CB30 5C072 AA03 CA06 DA04 DA21 HA02 HA13 HB08 HB11 XA01 XA05

Claims (8)

[Claims] 1. A scanner unit for irradiating light emitted from a light source in a scanning manner, comprising: a deflecting unit for deflecting light from the light source in a predetermined scanning direction; An emission port for emitting the light deflected by the deflecting means to the outside of the housing; a sensor fixed in the housing to detect an origin of the scanning; and the sensor standing upright in the housing. And a wall portion for reflecting light irradiated near the end in a direction in which the light is not finally emitted from the emission port. 2. The light deflected by the deflecting means is reflected by a first mirror which is long in the scanning direction, and then emitted from the emission port. The scanner unit according to claim 1. 3. The device according to claim 1, wherein the wall portion and the deflecting means are in the first position.
The scanner unit according to claim 2, wherein the light is reflected in a direction different from that of a mirror. 4. The sensor according to claim 1, wherein a slit plate is provided in front of the sensor, and the wall reflects light reflected by the slit plate in the direction. Scanner unit. 5. The scanner unit according to claim 1, wherein the wall absorbs the light to attenuate the light reflected from the wall. 6. A second mirror for reflecting the light deflected by the deflecting means in a direction corresponding to the scanning origin toward the sensor, wherein an optical path from the second mirror to the sensor is provided. And a direction intersecting with a plane containing light in each direction deflected by the deflecting means.
The scanner unit according to any one of claims 1 to 5, wherein 7. A scanner unit for irradiating light emitted from a light source in a scanning manner, comprising: a deflecting unit for deflecting light from the light source in a predetermined scanning direction; An emission port for emitting the light deflected by the deflecting means to the outside of the housing; a sensor fixed in the housing, for detecting an origin of the scanning; and a sensor for detecting the scanning deflected by the deflecting means. A second mirror that reflects light in a direction corresponding to the origin toward the sensor, wherein an optical path from the second mirror to the sensor includes light in each direction deflected by the deflecting unit. A scanner unit, which is disposed in a direction intersecting a surface. 8. A scanner unit according to claim 1, a photosensitive member exposed by light emitted from the scanner unit, and a developing means for attaching a developing material to the exposed photosensitive member. An image forming apparatus, comprising: a transfer unit configured to transfer a developing material adhered to a photoconductor by the developing unit to a recording medium to form an image.