JP2000231246A - Electrophotographic method and electrophotographic apparatus - Google Patents

Abstract

(57) [Problem] To provide an electrophotographic method and an electrophotographic apparatus which can improve a ghost memory and have a high chargeability even when a process is accelerated or miniaturized. The purpose is to do. SOLUTION: A photoreceptor having a photosensitive layer is provided with static elimination, charging,
In an electrophotographic method in which an image is formed by a series of steps including a latent image exposure step and a toner image development step, the light used in the latent image exposure step is (light before charging) / (sensitivity) of the photosensitive layer. Light having a wavelength within a range of 1.5 times or less the minimum value is used. However, the pre-charging optical memory refers to a charging ability that is reduced by irradiating light before charging.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic method and an electrophotographic apparatus, and more particularly, to an electrophotographic method using an amorphous silicon photoconductor (a-Si photoconductor) and an electrophotographic apparatus having the photoconductor. About.

[0002]

2. Description of the Related Art An a-Si photoreceptor has a high surface hardness, exhibits high sensitivity to long-wavelength light such as a semiconductor laser (770 nm to 800 nm), and is hardly deteriorated by repeated use. And a photoreceptor for electrophotography such as a laser beam printer (LBP).

FIG. 1 is a schematic configuration diagram for explaining an example of an image forming process of an electrophotographic apparatus using an a-Si photosensitive member. A photosensitive member 401 rotating in the direction of arrow R1 is provided around the photosensitive member 401. Main charger 402, electrostatic latent image forming portion 403,
Developing device 405, transfer paper supply system 406, transfer charger 407
(A), a separation charger 407 (b), a cleaner 409, a transport system 410, a static elimination light source 411, and the like are provided. As the main charger 402, a corona charger excellent in uniform chargeability is generally widely used.

Hereinafter, the image forming process will be described with reference to an example. The photosensitive member 401 is uniformly charged by a main charger 402 to which a high voltage of +6 to 8 kV is applied, and is guided from an electrostatic latent image forming portion 403 to be projected. The formed electrostatic latent image is formed, and a negative polarity toner is supplied from the developing device 405 to the latent image to form a toner image. On the other hand, the transfer material P supplied in the direction of the photoconductor through the transfer paper supply system 406 is transferred to the transfer charger 407 (a) to which a high voltage of +7 to 8 kV is applied and the photoconductor 40.
A positive electric field having a polarity opposite to that of the toner is applied to the transfer material P from the rear surface in the gap 1 by the negative polarity, so that the negative polarity toner image on the photoconductor surface is transferred to the transfer material P. 12-14 kVp-p, 3
The transfer material P reaches the fixing device (not shown) through the transfer paper transport system 410 by the separation charger 407 (b) to which a high AC voltage of 00 to 600 Hz is applied, and the toner image is fixed and discharged out of the device. Is done.

In electrophotography, a photoconductive material for forming a photosensitive layer in a photoreceptor has a high sensitivity, a high SN ratio [photocurrent (Ip) / dark current (Id)], and has a low spectral characteristic of an electromagnetic wave to be irradiated. Having a suitable absorption spectrum, fast light response, and having a desired dark resistance value,
Characteristics such as being harmless to the human body during use are required. In particular, in the case of a photoconductor for an image forming apparatus that is incorporated in an image forming apparatus used in an office as an office machine, the above-described non-pollution during use is important. Hydrogenated amorphous silicon (hereinafter abbreviated as "a-Si: H") is a photoconductive material exhibiting such excellent properties. For example, Japanese Patent Publication No. 60-35059 discloses a photosensitive material for an image forming apparatus. Application as a body is described.

A photoreceptor for an image forming apparatus using a-Si: H is generally prepared by heating a conductive support to 50 ° C. to 400 ° C. and depositing the conductive support on the support by a vacuum deposition method, a sputtering method, or the like.
A photoconductive layer made of a-Si is formed by a film forming method such as an ion plating method, a thermal CVD method, a photo CVD method, and a plasma CVD method. Among them, a plasma CVD method, that is, a method in which a raw material gas is decomposed by direct current, high frequency, or microwave glow discharge to form an a-Si deposited film on a support has been put to practical use as a suitable method.

[0007] For example, in Japanese Patent Application Laid-Open No. 54-83746, a conductive support and an a-Si (hereinafter referred to as "a-Si: X") photoconductive layer containing a halogen atom as a constituent element are disclosed. A photoreceptor for an image forming apparatus has been proposed. Here, halogen atoms of 1 to 4 are added to a-Si.
By containing 0 atomic%, heat resistance is high, and good electrical and optical characteristics can be obtained as a photoconductive layer of a photoconductor for an image forming apparatus.

Japanese Patent Application Laid-Open No. 57-11556 discloses that a photoconductive member having a photoconductive layer composed of an a-Si deposited film has an electrical property such as a dark resistance value, a photosensitivity, and a photoresponsive property. In order to improve the use environment characteristics such as optical and photoconductive properties and moisture resistance, as well as the stability over time, silicon atoms and carbon are deposited on a photoconductive layer composed of an amorphous material based on silicon atoms. A technique of providing a surface layer made of a non-photoconductive amorphous material containing atoms is described.

Furthermore, Japanese Patent Application Laid-Open No. 60-67951 describes a technique relating to a photoconductor in which a light-transmitting insulating overcoat layer containing amorphous silicon, carbon, oxygen and fluorine is laminated. 62-168161
Japanese Patent Application Laid-Open Publication No. H11-163,887 describes a technique using an amorphous material containing silicon atoms, carbon atoms, and 41 to 70 atomic% of hydrogen atoms as constituent elements as a surface layer.

Furthermore, in JP-A-57-158650, hydrogen containing 10 to 40 atomic%, 0.2 absorption coefficient ratio of the absorption peak of 2100 cm ^-1 and 2000 cm ^-1 in the infrared absorption spectrum It is described that a photosensitive member for an image forming apparatus having high sensitivity and high resistance can be obtained by using a-Si: H of 1.7 for the photoconductive layer.

On the other hand, Japanese Patent Application Laid-Open No. 60-95551 discloses that in order to improve the image quality of an amorphous silicon photoreceptor, charging, exposing, developing and transferring while maintaining the temperature near the photoreceptor surface at 30 to 40 ° C. By performing such an image forming process, there is disclosed a technique for preventing a reduction in surface resistance due to the adsorption of moisture on the surface of a photoreceptor and an image deletion caused thereby.

[0012] These techniques have improved the electrical, optical, photoconductive and operating environment characteristics of the photoreceptor for an image forming apparatus, and accordingly the image quality.

In order to prevent or remove the high-humidity image from the photosensitive member, a heat source, for example, a planar or rod-shaped electric heater is disposed on the inner surface of the photosensitive member.
It is known to heat a photoreceptor.

Nevertheless, always heating with a heater to prevent image deletion causes an increase in power consumption as described above. The capacity of such a heater is not necessarily an impression of a large amount of power, usually about 15 W to 80 W. However, in most cases, the heater is always energized even at night, and the amount of power consumed per day is the entire image forming apparatus. In some cases, power consumption may reach 5 to 15%.

With the versatility of electrophotographic apparatuses and the space saving of offices and the like, there has been a demand for space-saving, multifunctional, high-speed copying apparatuses. Therefore, from the design point of view, high speed, miniaturization,
It is necessary to design in consideration of multifunction.

However, with the increase in speed, miniaturization, and multifunctionality of the electrophotographic apparatus, miniaturization of the charging device,
As the process speed increases, the passage time of the photoconductor in the charger becomes shorter, and it becomes difficult to obtain high charge on the photoconductor surface, that is, to sufficiently charge the photoconductor surface. Further, from the viewpoint of energy saving, it is desired to further reduce the power consumption of the entire electrophotographic apparatus by cutting the drum heater and reducing the current value of the charger.

In particular, when the speed is increased or the diameter of the photosensitive member is reduced, a large problem occurs with respect to charging. In the case of high speed, even when the width of the charger is the same, the time required for a certain point of the photoconductor to pass through the inside of the charger, that is, the time required for charging is shortened, and the charge amount may decrease. . Further, when the diameter of the drum-shaped photoconductor is reduced, the width of the charger is limited, and as a result, a sufficient charging area cannot be obtained and charging may not be sufficiently obtained. is there.

As a common problem of increasing the speed and reducing the diameter of the photosensitive member, the time required for a point on the photosensitive member surface to move from exposure to a charger for charging the next photosensitive member surface may be shortened. When amorphous silicon is used, it has an optical memory phenomenon due to exposure. Since this optical memory decreases with the time after exposure, the shorter the time, the more likely it is to appear as a ghost in an image. To eliminate this ghost, it is possible to give an excessive amount of static elimination exposure, but as the amount of static elimination exposure is increased, the charging ability tends to decrease.

Even if these problems are solved, the temperature control of the photoconductor by the heater cannot be stopped when the temperature dependence of the photoconductor characteristics is large.

Therefore, when designing an image forming apparatus or an electrophotographic image forming method using an electrophotographic method, the electrophotographic characteristics of the photoreceptor for the image forming apparatus can be improved so as to solve the above-mentioned problems. There is a need to improve from a comprehensive point of view such as mechanical durability and to further improve a charging device and an image forming apparatus which have good charging efficiency and uniformly charge.

In order to improve the image quality, the dot diameter is reduced. In this case, it is necessary to increase the reproducibility of the dots, and it is also important to improve the latent image level. It is.

[0022]

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and can improve a ghost memory even when a process is speeded up or downsized. An object of the present invention is to provide an electrophotographic method and an electrophotographic apparatus having high charging ability.

Further, the present invention provides an electrophotographic method and an electrophotographic method capable of reducing the diameter of a photoreceptor, further increasing the speed, and reducing the diameter of an exposure spot to achieve higher image quality. It is intended to provide a device.

[0024]

According to the present invention, there is provided a charge removing step for removing a charge on a surface of a photoreceptor having a photoreceptive layer, a charging step for charging the charge on the surface of the photoreceptor, and a method for exposing the charged charge on the surface of the photosensitive member. A latent image exposure step of forming a latent image, a developing step of supplying a toner to the electrostatic latent image and developing to form a toner image, in an electrophotographic method of forming an image by a series of steps including
The light receiving layer has an amorphous silicon semiconductor, and as a light used in the latent image exposing step, a charge potential and a light of a desired wavelength when the light is not irradiated to the photoreceptor before the photoreceptor is charged. An electron using light having a wavelength in a range in which a value obtained by dividing a difference in charging potential when charged after irradiation with sensitivity at the wavelength that generates the difference in charging potential is 1.5 times or less the minimum value. Provide a photography method.

Further, the present invention provides an electrophotographic apparatus using the electrophotographic method.

In addition, the present invention provides a photoreceptor having a photoreceptor layer, a discharging means for discharging the surface of the photoreceptor, a charging means for charging the surface of the photoreceptor, and a method for exposing the charged photoreceptor surface to static electricity. An electrophotographic apparatus including: a latent image exposure unit that forms an electrostatic latent image; and a developing unit that supplies and develops a toner to the electrostatic latent image to form a toner image. The latent image exposure unit provides an electrophotographic apparatus including a light source having a wavelength of 500 to 680 nm as an image exposure light source.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION As a result of repeated studies, the present inventor has found that
It has been discovered that ghosts can be improved by using light having a predetermined range of wavelengths as light to irradiate the photoreceptor even under severe charging ability conditions such as high speed and small diameter of the photoreceptor. As a result, it has been found that the ghost can be improved without irradiating excessive static elimination exposure, so that the charging ability does not decrease due to excessive static elimination exposure and a sufficient charging potential can be obtained. The details will be described below.

FIG. 2 shows the result of measuring an example of the sensitivity at each wavelength of the amorphous silicon photosensitive member. Here, the amorphous silicon photoreceptor whose surface is charged to 400 V is irradiated with light of each wavelength to have a surface potential of 200 V (△).
The amount of change in surface potential per unit light amount [unit area] (ie, 200 V and 350 V) when the voltage becomes 200 V) and 50 V (△ 350 V) is applied to each of the irradiated light beams. Shown (unit: V · cm ² / μ
J). As a result, the amorphous silicon photoreceptor is 70
It is found that the sensitivity has a peak near 0 nm, and that the sensitivity sharply decreases at a wavelength of 700 nm or more. 7
It is considered that the reason why the sensitivity is reduced at a wavelength of 00 nm or more is that sufficient energy of the band gap or more cannot be applied.

Therefore, if an amorphous silicon photosensitive member is used efficiently, it is desirable to use a wavelength having good sensitivity.

However, simply using a wavelength having good sensitivity as an image exposure light source may not be enough for using an amorphous silicon photosensitive member. That is,
Since amorphous silicon generates optical memory due to photosensitivity, simply using the wavelength with the highest sensitivity as the wavelength for image exposure may cause a problem with the optical memory, for example, a ghost.

Therefore, the present inventors examined the wavelength dependence of the optical memory by irradiating light having different wavelengths before charging in order to see the relationship between the light irradiation before charging and the optical memory. FIG. 3a) shows the amount of decrease in chargeability (unit V) with respect to each wavelength and each light amount irradiated before charging, that is, an optical memory before charging. FIG. 3B shows a pre-charging optical memory at each wavelength when the time from light irradiation before charging to charging is changed.

The longer the time from the exposure to the charging, the smaller the pre-charging optical memory was, but the peak wavelength of the pre-charging optical memory was hardly changed. From these results, it was found that the wavelength at which the charging ability was reduced was around 730 nm.

Based on the results of FIG. 2 and FIG. 3, the present inventor has made it possible to reduce the memory while maintaining the sensitivity.
Decreasing the pre-charge optical memory with respect to the sensitivity of the photoreceptor, that is, the value of (pre-charge optical memory) / (sensitivity), in other words, the value of the optical memory generated at a unit contrast potential,
It has been found that the ghost potential is reduced by using an image exposure in which is as small as possible.

The wavelength of light used for image exposure is most preferably a wavelength at which the value of (pre-charging light memory) / (sensitivity) has a minimum value. However, even if the wavelength is not the minimum value, (pre-charging light memory) / (sensitivity) If the wavelength within the range where the value of ()) is 1.5 times or less of the minimum value is used, the effect of the present invention can be sufficiently obtained.

FIG. 4 shows the difference between the “potential not irradiated with light before charging the photoreceptor” and the “charging potential charged after irradiation with the desired wavelength”, as “sensitivity at the wavelength”. 6 is an example of a graph showing a value divided by. Specifically, the value of the contrast difference of △ 350 V in FIG. 2 was used as the sensitivity (unit: V · cm ² / μJ). As a result, the image exposure wavelength
It can be seen that the use of exposure at 500 nm to 680 nm improves the rank of the ghost memory on the image. Thereby, the charging ability could be improved without lowering the ghost level. Also, more preferably, from 600 nm to 6 nm.
The range of 60 nm was effective. By using an image exposure light source that minimizes the sensitivity of the pre-charging optical memory for sensitivity, it is possible to increase the chargeability of amorphous silicon even under severe conditions such as high-speed and small diameter amorphous silicon drums. It turned out to be effective.

This is because the pre-charging optical memory becomes large when the image exposure becomes 660 nm or more, and the residual potential becomes large when a single wavelength light source such as an LED or a semiconductor laser is used at a wavelength of 600 nm or less. It is considered that the above decrease in sensitivity is caused. Therefore, it is considered that excess light hits and the optical memory increases.

When a semiconductor laser is used, by using these wavelengths, it is possible to reduce the dot diameter at an optical design level, thereby obtaining a higher quality image.

In the present invention, when the above-described image exposure is used, the optimum static elimination exposure will be described below. When the wavelength of the static elimination light is 680 nm or more, the potential unevenness tends to increase rapidly. This is presumably because, when the film quality is uneven, the optical memory is likely to be uneven due to the static elimination light. Further, the reason why the unevenness increases as the wavelength becomes shorter on the short wavelength side is because the residual potential unevenness occurs. In order to reduce the unevenness, the unevenness is reduced to 600 nm to 680 nm, more preferably 630 nm to 680 nm. It turned out that it is good to use static elimination exposure. Next, as a result of performing image exposure to evaluate the ghost potential with respect to the charging ability, it was found that satisfying the above range was effective in improving the ghost memory.

That is, in order to satisfy all three points of charging ability, ghost, and charging potential unevenness, it is more preferable to use image exposure and charge elimination exposure within the scope of the present invention.

In the present invention, the charging can be performed by a generally known corona discharge. However, charging by corona discharge involves generation of ozone.

The generated ozone has been conventionally decomposed and made harmless by an ozone removal filter and discharged. Especially in the case of personal use, the amount of emitted ozone must be reduced as much as possible. As described above, a method for greatly reducing the amount of ozone generated at the time of charging is also demanded from the economical viewpoint. Japanese Patent Application Laid-Open No. Sho 63
There is a contact charging system as described in JP-A-208878. This is to charge a charged surface to a desired potential by bringing a charging member to which a voltage is applied into contact with a member to be charged,
Compared with the corona discharge device, firstly, the applied voltage required to obtain a desired potential on the surface to be charged can be reduced, and secondly, the amount of ozone generated in the charging process is zero to no. It is a very small amount, eliminating the need for an ozone removal filter, simplifying the configuration of the exhaust system of the apparatus, being maintenance-free, and thirdly, eliminating the amount of ozone generated during the charging process to an extremely small amount. Due to the minute amount, ozone and ozone products adhere to the surface of the image carrier, for example, the photoreceptor to be charged, and the surface of the photoreceptor becomes sensitive to humidity due to the influence of the corona product, so that moisture is easily adsorbed. This eliminates the need for dehumidification of the photoreceptor surface by a heater, which is performed to prevent image deletion due to surface resistance reduction, and thus enables a significant reduction in power consumption such as energization at night. Advantages of It has.

As a contact-charging type charging device, there is a charging device in which a fixed charging member in the form of a blade or a sheet is brought into contact with an object to be charged and a charging bias is applied thereto to perform charging.

(A) Charging blade contact charging device FIG. 5 shows an embodiment of a contact charging device using a charging blade. Reference numeral 20 denotes a charging blade as a contact charging member, which comprises an electrode plate 21 and a resistive layer 22 formed on the surface of the photoconductor opposite to the photoconductor. The tip of the charging blade 20 is pressed against the surface of the photoconductor 1 with a predetermined pressing force. Arranged in contact. n is a contact nip portion (charging nip portion).

The electrode plate 21 is generally made of a metal such as aluminum, aluminum alloy, brass, copper, iron, stainless steel, or the like.
An insulating material such as a resin or ceramic is subjected to a conductive treatment, that is, a material obtained by coating a metal or applying a conductive paint.

The resistance layer 22 is generally made of a resin such as polypropylene or polyethylene, or an elastomer such as silicon rubber or urethane rubber in which conductive fillers such as titanium oxide, carbon powder and metal powder are dispersed.

The resistance value of the resistance layer 22 is 1 × 10 ³ Ωcm to 1 × 10 ¹² Ωcm when measured with an MΩ tester manufactured by HIOKI (manufacturer) at an applied voltage of 250 V to 1 kV.
Has a resistance of

It is desirable that the resistance value of the charging member 20 is appropriately selected in accordance with the environment in which the charging member 20 is used, high charging efficiency, withstand voltage characteristics of the photosensitive member surface layer, and the like.

S is a power source for applying a charging bias to the charging blade 20. When a predetermined charging bias voltage is applied to the electrode plate 21 of the charging blade 20 by the power source S, the outer periphery of the photoconductor 1 being driven to rotate is controlled. The surface is charged to a predetermined polarity and potential by a contact charging method.

The charging bias applied to the charging member 20 is a DC application method in which only the DC voltage Vdc is applied,
A for applying an oscillating voltage obtained by superimposing an AC voltage Vac on dc
There is a C application method. Regarding AC application method,
As disclosed in Japanese Patent Application Laid-Open No. 149669, an oscillating voltage obtained by superimposing an AC voltage component having a peak-to-peak voltage that is twice or more the charging start voltage Vth of the member to be charged on a DC voltage Vdc corresponding to a desired charging potential Vd. The method of applying a voltage by applying a voltage whose voltage value changes periodically with time) is intended for the purpose of smoothing out the charging potential by an AC voltage component. It converges to Vd which is the center of the component, and charging is made uniform. The charging start voltage Vth is a voltage value applied to the charging member when a DC voltage is applied to the charging member to start charging the member to be charged.

(B) Magnetic brush contact charging device As a solution to the above, in the course of various improvements of the contact charging member, a magnetic material (magnet, magnet, etc.) as disclosed in JP-A-59-133569, etc. ) And a magnetic powder (or particles), and a magnetic brush contact charging device using a magnetic brush contact charging member has been proposed.

In the magnetic brush contact charging device, characteristics such as the contact property between the member to be charged and the charging member are improved as compared with the case where a roller type, a blade type or the like is used as the contact charging member.

FIG. 6 shows an embodiment of the magnetic brush contact charging device. Reference numeral 23 denotes a magnetic brush charging member. In this embodiment, a core metal 24, a magnet roller 25 as a cylindrical multipolar magnetic body provided concentrically around the core metal,
The outer peripheral surface of the magnet roller 25 was attracted and held as a magnetic brush by the magnetic force of the magnet roller.
A magnet roller rotating type comprising a magnetic brush layer 26 of magnetic powder (or magnetic particles or a magnetic carrier) and disk-shaped spacer rollers 27 which are rotatably fitted to both ends of a core 24, respectively. . The magnetic brush charging member 23 is held substantially parallel to the photoconductor 1, and the spacer rollers 27 at both ends are kept in contact with the surfaces at both ends of the photoconductor 1. Hold the bearings at both ends. Reference numeral 26a denotes a deposit, and 28 denotes a blade for removing the deposit.

The spacer rollers 27 have an outer diameter larger than the outer diameter of the magnet roller 25 and smaller than the outer diameter of the magnetic brush layer 26.
It functions to regulate the closest gap (gap) α between the photoconductor 5 and the photoconductor 1 in a predetermined manner. The gap α is preferably in the range of 50 to 2000 μm, more preferably 100 to 1000 μm.

The magnetic brush layer 26 contacts the surface of the photoconductor 1 between the photoconductor 1 and the magnet roller 25 to form a contact nip n. The closest gap α between the photoreceptor 1 and the magnet roller 25 is equal to the spacer roller 2 as described above.
By the predetermined regulation at 7.27, the width of the contact nip n in the photoconductor rotation direction is stabilized.

Magnet roller 25 of charging member 23
In the present example, the photoconductor 1 at the contact nip n
Is rotated in the clockwise direction indicated by the arrow, which is the opposite direction to the rotation direction, and the surface of the rotating photoconductor 1 is rubbed by the magnetic brush layer 26 at the contact nip n.

A predetermined charging bias voltage is applied by a power source S to the magnetic brush layer 26 via the metal core 24 and the magnet roller 25 by a DC application method or an AC application method, and the photoreceptor 1 being driven to rotate is rotated. Is uniformly charged to a predetermined polarity and potential by a contact charging method. As the magnet roller 25 as a magnetic material, a ferrite magnet, a rubber magnet, or the like is usually used.

As the magnetic powder, magnetic iron oxide (ferrite powder), magnetite powder, a well-known magnetic toner material and the like are generally used.

It is desirable that the resistance value of the charging member 23 is appropriately selected according to the environment in which the charging member 23 is used, high charging efficiency, withstand voltage characteristics of the photosensitive member surface layer, and the like.

An electrode sleeve of a magnetic material is externally fitted to the outside of the magnet roller 25, and the magnetic powder is attracted and held as a magnetic brush on the outer peripheral surface of the sleeve by the magnetic force of the internal magnet roller 25, thereby forming a magnetic brush layer 26. There is also a sleeve rotation type in which the sleeve is rotated by forming and holding the.

With such a magnetic brush contact charging device, the contact and abrasion characteristics of the image bearing member and the contact charging member are improved, and remarkable improvements such as mechanical abrasion against deterioration of durability can be achieved.

(C) Fur brush contact charging device An example in which a fur brush is used as a contact charging member will be described. FIG. 7 shows an embodiment of the fur brush contact charging device. Reference numeral 30 denotes a fur brush charging member, in which a brush-like contact having conductivity, for example, a plated metal brush or a fiber brush in which a conductive material is dispersed is planted on the outer peripheral surface of the roller-shaped electrode member 31. A brush layer (fur brush) 32, and the brush layer 32 is disposed in contact with the photoreceptor 1 as a member to be charged.
By rotating 0, a predetermined charging bias voltage is applied to the electrode member 31 from a power source to charge the photoconductor 1.

In the case of this fur brush contact charging device,
There is no decrease in the magnetic powder as in the magnetic brush contact charging device, and the maintenance interval can be extended. The fur-like charging unevenness of the fur brush is caused by the fur brush charging member 3
By rotating 0 in the direction opposite to the rotation direction of the photoconductor or at a high rotation speed in the contact nip portion n with the photoconductor 1, the image quality can be improved.

Further, when the conditions of the charge removing light were the same and the corona charger and the contact charging were compared, it was found that the contact charging was superior to the ghost. This is considered for the following reasons.

In the case of corona charging, since the potential drops uniformly, charging is applied regardless of the potential difference of the ghost. On the other hand, the contact charging gives a charge to match the potential of the contact member. Therefore, it is considered that it works in a direction to eliminate the potential difference of the generated ghost potential.

When a magnetic powder brush was used as the contact charging member, the amount of magnetic powder was reduced. However,
According to the present invention, the reduction of the magnetic powder can be significantly improved. In other words, it is considered that the ghost level can be improved and the amount of static elimination light, which reduces the charging ability and increases the dark decay, can be suppressed by the present invention. Therefore, it is considered that the dark decay after charging was reduced, and the adhesion of the magnetic powder was significantly improved.

[Image Forming Apparatus] FIG. 8 is a schematic view showing an example of an electrophotographic apparatus using an a-Si photosensitive member. FIG.
A main charger 1302, an electrostatic latent image forming portion 1303, a developing device 1305, a transfer paper supply system 1306, a transfer charger 13 are provided around the photosensitive member 1301 rotating in the direction of arrow R1.
07 (a), separation charger 1307 (b), cleaner 13
09, a transport system 1310, a static elimination light source 1311, and the like. In this example, an example in which a contact charger is used as the main charger 1302 is shown. Hereinafter, the image forming process will be described with reference to an example. The photoconductor 1301 is uniformly charged by a roller-shaped main charger 1302. As the charging member, a material using elastic rubber, a magnetic powder, or a fur brush using metal or graphite fibers can be used according to the resistance value suitable for charging. An electrostatic latent image guided and projected from the electrostatic latent image forming portion is formed on this, and a negative polarity toner is supplied from the developing device 1305 to the latent image to form a toner image. On the other hand, the transfer paper supply system 1306
Transfer material P supplied in the direction of the photoconductor through
In the gap between the transfer charger 1307 (a) to which the high voltage of V is applied and the photosensitive member 1301, a positive electric field having a polarity opposite to that of the toner is applied from the back surface, whereby the negative polarity toner image on the photosensitive member surface is transferred to the transfer material P. Transfer to 12-14kVp
The transfer material P passes through a transfer paper transport system 1310 to a fixing device (not shown) by a separation charger 1307 (b) to which a high AC voltage of 300 to 600 Hz is applied, and the toner image is fixed. It is discharged outside.

[Amorphous silicon-based photoconductor (a-S
i)] Hereinafter, the photoreceptor layer of the photoreceptor suitably used in the present invention will be described in detail with reference to the drawings. FIG. 9 is a schematic configuration diagram illustrating an example of a layer configuration of the photoconductor for an image forming apparatus. In the photoconductor 500 for an image forming apparatus shown in FIG. 9A, a photosensitive layer 502 as a light receiving layer is provided on a support 501 for a photoconductor. The photosensitive layer 502 is made of amorphous silicon (a-Si: H,
X) and a photoconductive layer 503 having photoconductivity. FIG. 9B is a schematic configuration diagram for explaining another layer configuration of the photoconductor for an image forming apparatus. FIG.
In the photoreceptor 500 for an image forming apparatus shown in (b), a photosensitive layer 502 is provided on a support 501 for a photoreceptor. The photosensitive layer 502 has a photoconductive layer 503 made of a-Si: H, X and having photoconductivity, and an amorphous silicon-based or amorphous carbon-based surface layer 504.

FIG. 9C is a schematic configuration diagram for explaining another layer configuration of the photosensitive member for an image forming apparatus. FIG.
In the photoreceptor 500 for an image forming apparatus shown in (c), a photosensitive layer 502 is provided on a support 501 for a photoreceptor. The photosensitive layer 502 includes a photoconductive layer 503 made of a-Si: H, X and having photoconductivity, an amorphous silicon-based or amorphous carbon-based surface layer 504, and an amorphous silicon-based charge injection blocking layer 505.

FIG. 9D is a schematic configuration diagram for explaining still another layer configuration of the photosensitive member for an image forming apparatus.
In the photoconductor 500 for an image forming apparatus shown in FIG. 9D, a photosensitive layer 502 is provided on a support 501 for the photoconductor. The photosensitive layer 502 has a charge generation layer 507 made of a-Si: H, X and a charge transport layer 508 constituting the photoconductive layer 503, and an amorphous silicon-based or amorphous carbon-based surface layer 504.

Hereinafter, the present invention will be described specifically with reference to Experimental Examples and Examples. The present invention is not limited to these experimental examples and examples.

[Experimental Example 1] A charge injection blocking layer and light were applied to a mirror-finished aluminum cylinder having a diameter of 108 mm under the conditions shown in Table 1 using an apparatus for manufacturing a photoreceptor for an image forming apparatus by RF-PCVD. A photosensitive layer was formed by forming a conductive layer and a surface layer.

[0072]

[Table 1]

As a result of obtaining a memory for the pre-charging exposure with respect to the sensitivity of the photoreceptor, the result is as shown in FIG.

The photoreceptor thus prepared is used as an image forming apparatus (NP6060 manufactured by Canon is modified for digital test).
And the ghost potential was evaluated.

A 680 nm LED was used for the charge removal exposure, a 700 nm LED head was used for the image exposure, and the photosensitive member was rotated at a speed of 300 mm / s. For the measurement of the charging ability, the value when the current of the primary charger was 1000 μA was used. In addition, the measurement of the ghost potential was performed at a dark area potential of 400 V
It was determined by measuring the dark area potential after one round of the photoreceptor after exposure at an exposed area potential of 50V.

First, in order to confirm how much a ghost can be eliminated by increasing the amount of charge-discharge exposure, under this condition, the amount of charge-discharge exposure from 1 Lux · s to 11
Lux · s, and the ghost potential and charging ability at each image exposure wavelength were determined. As a result, as shown in FIG. 10, the potential appearing as a ghost was reduced as the light amount of the static elimination exposure was increased, but the charging ability was reduced. That is, it is apparent that simply increasing the light amount of the charge erasing exposure cannot satisfy both the ghost and the charging ability.

Then, the light quantity of the pre-exposure is set to 4 Lux · s
And the wavelength of the image exposure was changed. Ghost potentials were measured using LED heads of 565, 610, 660, and 700 nm as light sources for image exposure. As shown in FIG. 11, the image exposure light source was 565, 610, and 660 L.
When the ED was used, the ghost potential was improved as compared with the case where a 700 nm LED head was used as the image exposure light source.

[Experimental Example 2] The photoreceptor produced in Experimental Example 1 was evaluated for charging ability and ghost potential using the image forming apparatus of Experimental Example 1. 635, 650, 68 for the image exposure light source
A semiconductor laser of 0,788 nm was used. A light source having a wavelength of 680 nm and a light amount of 4 Lux · s was used as a charge removing exposure light source.

From the results shown in FIG. 12, the image exposure light source was 635,
It can be seen that when the semiconductor laser of No. 650 is used, the ghost potential is improved.

As is clear from Experimental Examples 1 and 2, a ghost memory is improved by using an image exposure light source in which the value of the pre-charging light memory with respect to the sensitivity is reduced as much as possible. Can be reduced. Therefore, it is possible to increase the charging ability.

[Experimental Example 3] A study was made on the wavelength of the static elimination light of the potential unevenness of the dark portion potential when no image exposure was performed. FIG. 13 shows potential unevenness when the charging potential is adjusted to 400V. When the wavelength of the static elimination light is 680 nm or more, the potential unevenness tends to increase rapidly. In addition, as the wavelength became shorter, the peripheral unevenness gradually increased. As a result,
It was found that the wavelength of the charge erasing exposure is preferably 600 nm or more and 680 nm or less, more preferably 630 nm or more and 680 nm or less.

[Experimental Example 4] The effect of the charge removal exposure on the ghost was evaluated. The primary current was kept constant at 1000 μA, and the light amounts of the static elimination light sources of each wavelength were matched so that the charging ability was 400 V. A laser light source of 650 nm was used as an image exposure light source, and the exposure portion potential was adjusted to 50 V and the contrast potential was adjusted to 350 V. FIG. 14 shows the ghost potential when the wavelength of the static elimination light is changed at this time. It has been found that the ghost is improved when a charge removal exposure of 600 nm or more and 680 nm or less is used as the charge removal light.

[Experimental Example 5] Using the photosensitive member and the image forming apparatus used in Experimental Example 1, the ghost potential of the charging member was evaluated. In addition, the charge removal light is 680 nm LED light amount 4L.
ux · s, and the ghost potential of the charging member was measured when the wavelength of image exposure was changed. As light sources for image exposure, LED heads of 565, 610, 660, and 700 nm were used. The charging member includes a corona charger-1
Roller charger-2 Fur brush charger-3 Magnetic powder brush charger was used. FIG. 15 shows the results. FIG.
As can be seen, the ghost potential was improved as compared with the case where the contact charger was used, as compared with the case where the corona charger was used.

[Experimental Example 6] Using the magnetic powder brush charger used in Experimental Example 5, an exposure condition was changed and a durability test was performed. The amount of reduction of the magnetic powder of the magnetic powder brush in that case was examined. The conditions were as follows: dark potential 400 V light potential 50
V and the charge removal conditions and the charging conditions were changed so that the ghost potential was constant. Charge removal exposure 700nm Image exposure 700nm
FIG. 16 shows the result of the reduction amount of the magnetic powder when the reduction amount of the magnetic powder was normalized to 10. In this case, there was an effect in preventing the reduction of the magnetic powder.

Example 1 Image evaluation was performed on the photosensitive member manufactured in Experimental Example 1 using the image forming apparatus used in Experimental Example 1. Charging is corona charging, and 635 is used for the image exposure light source.
nm semiconductor laser was used. 660n for static elimination exposure
Using m LEDs, the photoreceptor was rotated at a speed of 300 mm / s. At this time, the charging ability required for image formation was sufficiently obtained.

Next, the dark part potential is set to 400 V and the light part potential is set to 5
The voltage was set to 0 V, and evaluation was performed using images. As an original image for evaluation, a white image, a black image, a 50% reflection image, a ghost image, and 0.5 mm grid paper were used. In each case, good images were obtained. In particular, even when a ghost image was used as the original image for evaluation, no ghost was seen in the electrophotographic image, and a good image was obtained.

Example 2 Image evaluation was performed on the photosensitive member manufactured in Experimental Example 1 using the image forming apparatus used in Experimental Example 1. Charging is corona charging, and 650 is used for the image exposure light source.
nm semiconductor laser was used. 700n for static elimination exposure
The photoreceptor was rotated at a speed of 260 mm / s using m LEDs. At this time, the charging ability required for image formation was sufficiently obtained.

Next, the same evaluation as in Example 1 was performed. In each case, a good image was obtained. In particular, when a ghost image was used, no ghost was observed, and the result was good.

Example 3 Image evaluation was performed on the photoreceptor manufactured in Experimental Example 1 using the image forming apparatus used in Experimental Example 1. Charging is corona charging, and 650 is used for the image exposure light source.
nm LED head was used. 660 nm for static elimination exposure
And the photoreceptor was rotated at a speed of 260 mm / s. At this time, the charging ability required for image formation was sufficiently obtained.

Next, the same evaluation as in Example 1 was performed. In each case, a good image was obtained. In particular, when a ghost image was used, no ghost was observed, and the result was good.

Example 4 The photosensitive member produced in Experimental Example 1 was subjected to image evaluation using the image forming apparatus used in Experimental Example 1. Charging is corona charging, and 630 is used for the image exposure light source.
nm LED head was used. 680 nm for static elimination exposure
And the photoreceptor was rotated at a speed of 360 mm / s. At this time, the charging ability required for image formation was sufficiently obtained.

Next, the same evaluation as in Example 1 was performed. In each case, good images were obtained. In particular, when a ghost image was used, no ghost was observed, and the result was good.

Example 5 Image evaluation of the photoreceptor manufactured in Experimental Example 1 was performed using the image forming apparatus used in Experimental Example 1. Charging is corona charging, and 650 is used for the image exposure light source.
nm semiconductor laser was used. In addition, the charge removal light is 63
Using a 0 nm LED, the photoreceptor was rotated at a speed of 260 mm / s. At this time, sufficient charging ability effective for image formation was obtained. Next, when the same evaluation as in Example 1 was performed, in each case, a good image was obtained. In particular, no ghost was seen in the ghost image, which was favorable.

Example 6 The photosensitive member produced in Experimental Example 1 was subjected to image evaluation using the image forming apparatus used in Experimental Example 1. Charging is corona charging, and 650 is used for the image exposure light source.
nm LED head was used. In addition, 610 is used for static elimination light.
The photoreceptor was rotated at a speed of 260 mm / s using an nm LED. At this time, sufficient charging ability effective for image formation was obtained. Next, when the same evaluation as in Example 1 was performed, in each case, a good image was obtained. In particular, no ghost was observed in the ghost image, which was favorable.

Example 7 An image of the photoreceptor manufactured in Experimental Example 1 was evaluated using the image forming apparatus used in Experimental Example 1. A magnetic powder brush charger was used as a charger, and a 635 nm semiconductor laser was used as an image exposure light source. Note that a 660 nm LED is used for static elimination light, and the photoconductor is 3
It rotated at a speed of 00 mm / s. At this time, sufficient charging ability effective for image formation was obtained. Next, the dark area potential is set to 400
V and the bright portion potential were set to 50 V, and the evaluation was performed using images. The images used were a white image, a black image, a 50% reflection image, a ghost image, and 0.5 mm grid paper. In each case, good images were obtained. In particular, no ghost was observed in the ghost image, which was favorable.

Example 8 The photosensitive member manufactured in Experimental Example 1 was subjected to image evaluation using the image forming apparatus used in Experimental Example 1. A fur brush charger was used as a charger, and a semiconductor laser of 650 nm was used as an image exposure light source. A 630 nm LED was used for the charge removal light, and the
It rotated at a speed of 60 mm / s. At this time, sufficient charging ability effective for image formation was obtained. Next, when the same evaluation as in Example 1 was performed, in each case, a good image was obtained. In particular, no ghost was observed in the ghost image, which was favorable.

Example 9 Image evaluation of the photoreceptor manufactured in Experimental Example 1 was performed using the image forming apparatus used in Experimental Example 1. A roller charger was used as a charger, and a 650 nm LED head was used as an image exposure light source. A 610 nm LED was used for the charge removing light, and the photosensitive member was 260 mm.
/ S speed. At this time, sufficient charging ability effective for image formation was obtained. Next, when the same evaluation as in Example 1 was performed, in each case, a good image was obtained. In particular, no ghost was observed in the ghost image, which was favorable.

Example 10 The photosensitive member produced in Experimental Example 1 was subjected to image evaluation using the image forming apparatus used in Experimental Example 1. A magnetic powder brush charger was used as a charger, and a 630 nm LED head was used as an image exposure light source. Note that a 680 nm LED was used for the charge removing light, and the photoconductor was 3 LEDs.
It rotated at a speed of 60 mm / s. At this time, sufficient charging ability effective for image formation was obtained. Next, when the same evaluation as in Example 1 was performed, in each case, a good image was obtained. In particular, no ghost was observed in the ghost image, which was favorable.

[0099]

According to the present invention, it is possible to provide an electrophotographic method and an electrophotographic apparatus which can improve a ghost memory and have a high charging ability even under conditions of high speed and miniaturization. In particular, the ghost does not appear on the image even if the ghost memory is effectively improved and the amount of charge removal is not increased.

When a semiconductor laser is used as the image exposure light source, the spot diameter can be reduced, and a higher quality image can be realized.

In addition, the present invention exerts a further effect in combination with contact charging. In particular, when a magnetic powder brush is used as a contact charging member, the reduction of magnetic powder can be significantly improved. I can do it.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an example of the configuration of an electrophotographic apparatus.

FIG. 2 is a diagram illustrating an example of sensitivity to wavelength of an amorphous silicon photoconductor.

FIG. 3 is a diagram illustrating an example of a relationship between light irradiated to a photoconductor before charging and a memory. a) Relationship between light intensity for each wavelength b) Relationship between irradiation time for each wavelength

FIG. 4 is a diagram illustrating an example of a relationship between a memory value by light irradiated to a photoconductor before charging with respect to sensitivity of amorphous silicon and a wavelength of the irradiated light.

FIG. 5 is a schematic configuration diagram illustrating an example of a contact charging device.

FIG. 6 is a schematic configuration diagram illustrating an example of a contact charging device.

FIG. 7 is a schematic configuration diagram illustrating an example of a contact charging device.

FIG. 8 is a schematic configuration diagram illustrating an example of the configuration of an electrophotographic apparatus having a contact charging device.

FIG. 9 is a schematic cross-sectional view for explaining an example of a layer configuration of an amorphous silicon photoconductor.

FIG. 10 is a scatter diagram illustrating an example of a relationship between a charging ability and a ghost potential with respect to a difference in the amount of light exposure for exposure.

FIG. 11 is a diagram illustrating an example of a ghost potential with respect to each exposure wavelength.

FIG. 12 is a diagram illustrating an example of a ghost potential with respect to each exposure wavelength.

FIG. 13 is a diagram illustrating an example of potential unevenness with respect to each charge removal exposure wavelength.

FIG. 14 is a diagram illustrating an example of a ghost memory for each charge removal exposure wavelength.

FIG. 15 is a diagram illustrating an example of a ghost potential with respect to each exposure wavelength.

FIG. 16 is a diagram showing an example of a decrease in magnetic powder for each exposure wavelength.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor 20 Charging blade 21 Electrode plate 22 Resistance layer 23 Magnetic brush charging member 24 Core metal 25 Magnet roller 26 Magnetic brush layer 26a Attachment 27 Spacer roller 28 Blade 30 Fur brush charging member 31 Electrode member 32 Brush layer (fur brush) n Contact nip section S Charging bias application power supply 401 a-Si photoreceptor 402 main charger 403 electrostatic latent image forming site 405 developing unit 406 transfer paper supply system 407a) transfer charger 407b) separation charger 409 cleaner 410 transport system 411 Static elimination light source 500 Photoconductor 501 Support 502 Photosensitive layer 503 Photoconductive layer 504 Surface layer 505 Charge injection blocking layer 506 Free surface 507 Charge generation layer 508 Charge transport layer 1301 Photoconductor 1302 Main charger 1303 Electrostatic latent image forming portion 1305 Current Vessel 1306 transfer sheet supply system 1307 (a) transfer charger 1307 (b) separation charger 1309 cleaner 1310 transfer system 1311 light scanning lamp

Continuation of the front page (72) Inventor Yuji Nakayama 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Tetsuya Karaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Toshiyuki Ehara 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H068 DA23 FB07 FB08 FC01 FC05 FC17 2H076 AB05 AB42 DA03 DA06 DA37

Claims (47)

[Claims] 1. A charge removing step for removing charge from a surface of a photoreceptor having a photoreceptor layer, a charging step for charging the surface of the photosensitive member, and a latent image exposure for exposing the charged surface of the photosensitive member to form an electrostatic latent image. An electrophotographic method in which an image is formed by a series of steps including a step of supplying a toner to the electrostatic latent image and developing the toner to form a toner image, wherein the light-receiving layer has an amorphous semiconductor; As light used in the image exposure process,
The difference between the charging potential when the photoreceptor is not irradiated with light before charging the photoreceptor and the charging potential when charging after irradiating light of a desired wavelength is a difference between the charging potentials. An electrophotographic method using light having a wavelength in a range in which a value divided by the sensitivity at the wavelength is 1.5 times or less the minimum value. 2. The electrophotographic method according to claim 1, wherein the light having the wavelength in the range is light from a single wavelength light source. 3. The electrophotographic method according to claim 1, wherein the light having a wavelength within the range has a dominant wavelength within the range. 4. The electrophotographic method according to claim 1, wherein said amorphous semiconductor is amorphous silicon. 5. A light having a wavelength within the above range is not less than 500 nm and not more than 6 nm.
2. The electrophotographic method according to claim 1, wherein the light is 80 or less. 6. The light having a wavelength within the above range is not less than 600 nm and not more than 6 nm.
2. The electrophotographic method according to claim 1, wherein the dominant wavelength is within a range of 60 nm or less. 7. The electrophotographic method according to claim 1, wherein the charge removing step includes performing a charge removing exposure. 8. The method according to claim 1, wherein the charge removing exposure is not less than 600 nm and not more than 680.
The electrophotographic method according to claim 7, wherein light having a wavelength of not more than nm is used. 9. The charge removing exposure has a peak wavelength of 630 n.
The electrophotographic method according to claim 7, which has a wavelength of m to 680 nm. 10. The electrophotographic method according to claim 1, wherein said charging step is performed using corona charging. 11. The electrophotographic method according to claim 1, wherein said charging step is performed using contact charging. 12. The electrophotographic method according to claim 1, wherein the charging step includes applying a voltage to the charging member while the charging member is in contact with the surface of the photoconductor. 13. The electrophotographic method according to claim 12, wherein said charging member is a rubber roller. 14. The electrophotographic method according to claim 12, wherein the charging member is a fur brush. 15. The electrophotographic method according to claim 12, wherein said charging member is a magnetic powder brush. 16. The electrophotographic method according to claim 1, wherein the discharging step includes performing a discharging exposure, and the charging step is performed using corona charging. 17. The exposure for static elimination according to claim 1, wherein the exposure is at least 600 nm and at least 68 nm.
17. The electrophotographic method according to claim 16, wherein light having a wavelength of 0 nm or less is used. 18. The charge removing exposure having a peak wavelength of 630.
The electrophotographic method according to claim 16, having a wavelength of not less than nm and not more than 680 nm. 19. The electrophotographic method according to claim 1, wherein the charge removing step includes performing a charge removing exposure, and the charging step is performed using contact charging. 20. The charge removing step includes performing a charge removing exposure, and the charging step includes applying a voltage to the charging member in a state where the charging member is in contact with the surface of the photoconductor. The described electrophotographic method. 21. The method according to claim 1, wherein the charge removing exposure is not less than 600 nm and not more than 68 nm.
The electrophotographic method according to claim 20, wherein light having a wavelength of 0 nm or less is used. 22. The exposure for static elimination has a peak wavelength of 630.
21. The electrophotographic method according to claim 20, having a wavelength of not less than nm and not more than 680 nm. 23. The electrophotographic method according to claim 20, wherein the charging member is a rubber roller. 24. The electrophotographic method according to claim 20, wherein the charging member is a fur brush. 25. The electrophotographic method according to claim 20, wherein the charging member is a magnetic powder brush. 26. A photoreceptor having a photoreceptor layer, a discharging means for discharging the surface of the photoreceptor, a charging means for charging the surface of the photoreceptor, and a method for exposing the charged photoreceptor surface to electrostatic charge An electrophotographic apparatus comprising: a latent image exposing unit for forming a latent image; and a developing unit for supplying and developing toner to an electrostatic latent image to form a toner image, wherein the light receiving layer includes an amorphous semiconductor. The latent image exposure unit is configured to detect a difference between a charging potential when the photoconductor is not irradiated with light before charging the photoconductor and a charging potential when charging after irradiating light having a desired wavelength. An electrophotographic apparatus having a light source for generating light having a wavelength in a range in which a value obtained by dividing by a sensitivity at the wavelength that generates the difference in the charged potential is 1.5 times or less the minimum value. 27. The light source has a wavelength of 500 nm or more and 680 nm.
27. The electrophotographic apparatus according to claim 26, which is a light source that generates the following wavelengths. 28. The light source has a wavelength of 600 nm or more and 660 nm.
The electrophotographic apparatus according to claim 26, which is a light source that generates the following peak wavelengths. 29. The electrophotographic apparatus according to claim 26, wherein the light source is an LED or a semiconductor laser. 30. The electrophotographic apparatus according to claim 26, wherein said static elimination means has a static elimination light source. 31. The electrophotographic apparatus according to claim 26, wherein said amorphous semiconductor is amorphous silicon. 32. A light source for static elimination of 600 nm or more and 68 nm or more.
31. The electrophotographic apparatus according to claim 30, which is a light source that emits light having a wavelength of 0 nm or less. 33. The light source for static elimination has a peak wavelength of 630.
31. The electrophotographic apparatus according to claim 30, which is a light source that emits light having a wavelength of not less than nm and not more than 680 nm. 34. An electrophotographic apparatus according to claim 26, wherein said charging means is means for performing corona charging. 35. The electrophotographic apparatus according to claim 26, wherein said charging means has a charging member to which a voltage can be applied while being in contact with the surface of said photoreceptor. 36. The electrophotographic apparatus according to claim 35, wherein the charging member is a rubber roller. 37. The electrophotographic apparatus according to claim 35, wherein the charging member is a fur brush. 38. The electrophotographic apparatus according to claim 35, wherein said charging member is a magnetic powder brush. 39. The electrophotographic apparatus according to claim 26, wherein said discharging means has a light source for discharging, and said charging means has a charging member to which a voltage can be applied while being in contact with the surface of said photoreceptor. . 40. The electrophotographic apparatus according to claim 39, wherein the charging member is a rubber roller. 41. The electrophotographic apparatus according to claim 39, wherein the charging member is a fur brush. 42. The electrophotographic apparatus according to claim 39, wherein said charging member is a magnetic powder brush. 43. A light source for static elimination of 600 nm or more and 68 nm or more.
The electrophotographic apparatus according to claim 39, which is a light source that emits light having a wavelength of 0 nm or less. 44. The light source for static elimination has a peak wavelength of 630.
The electrophotographic apparatus according to claim 39, which is a light source that emits light having a wavelength of not less than nm and not more than 680 nm. 45. A photoreceptor having a photoreceptor layer, a discharging means for discharging the surface of the photoreceptor, a charging means for charging the surface of the photoreceptor, and forming an electrostatic latent image by exposing the charged surface of the photoreceptor An electrophotographic apparatus including: a latent image exposing unit that supplies toner to the electrostatic latent image and develops the toner to form a toner image; wherein the light receiving layer includes amorphous silicon; and the latent image exposing unit includes Wavelength of 500 to 680 nm as an image exposure light source
An electrophotographic apparatus provided with a light source. 46. The image exposure light source has a main wavelength of 600 to 6
The electrophotographic apparatus according to claim 45, which is a single-wavelength light source of 60 nm. 47. The electrophotographic apparatus according to claim 45, wherein the single wavelength light source is a semiconductor laser or an LED.