JP2007065472A - Blade for restricting developer amount - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blade for restricting developer amount, capable of suppressing image defects due to high-speed rotation of a developer carrier of a developing device over a long period by suppressing image unevenness, image stripes, ghosts, etc., due to the high-speed rotation of the developer carrier that accompanies faster electrophotographic process. <P>SOLUTION: The developer amount restricting blade is equipped with a blade member with rubber elasticity, which is provided in the developing device of an electrophotographic device and is brought into contact with the developer carrier carrying a developer stored in a developer container and supplying the developer to an electrostatic latent image and a support member which supports the blade member, and makes the amount of the developer that the developer carrier carries constant and imparts specified frictional charges to the developer. The blade member has tanδ of that is ≤1.0 at 15°C, and ≥0.03 at 40°C, with respect to the frequency 10 Hz. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a developer amount regulating blade provided in a developing device in an image forming process of an electrophotographic apparatus such as an electrophotographic copying machine, a laser beam printer, and a facsimile machine.

  Conventionally, as a developing device in an image forming process of an electrophotographic apparatus such as an electrophotographic copying machine, a laser beam printer, a facsimile, etc., a part of the developing device is provided in an opening of a developer container for storing developer (toner). A developer having a developer carrying member such as a roller and a developer amount regulating blade provided with a blade member formed of a rubber material that comes into contact with the surface of the developer carrying member is widely used. In such a developing device, the developer carrying member carrying the developer on the surface rotates, and the developer is carried out to the surface of the electrophotographic photosensitive member that contacts and rotates at a portion exposed from the developer container. It is like that. When the developer passes between the developer carrier and the blade member of the developer amount regulating blade, the excess is removed from the surface of the developer carrier and returned to the developer container, and the friction with the blade member. As a result, a triboelectric charge (also referred to as tribo) having a polarity opposite to that of the electrostatic latent image formed on the surface of the electrophotographic photosensitive member is imparted, and a certain amount of the toner adheres to the surface of the developer carrying member. Then, at the contact portion between the developer carrying member and the electrophotographic photosensitive member, the developer is electrostatically attracted to the electrostatic latent image and moved from the surface of the developer carrying member to the surface of the electrophotographic photosensitive member. The image is developed.

  Such a developer amount regulating blade is composed of a blade member that is in contact with the surface of the developer carrying member and a support member that supports the developer member in a predetermined position. For a negative developer, for example, A blade member of a plate material such as urethane resin or polyamide elastomer is used by being attached to a support member such as a metal plate. For positive developers, a blade member of a plate material such as silicon rubber is a support member such as a metal plate. It is attached to and used. The surface of the blade member that is in contact with or pressed against the developer carrier has a function of controlling the triboelectric charge of the developer, so it is called a charge control surface, and its surface layer is called a charge control layer. There is also.

  In recent years, in the electrophotographic process, higher image quality and higher speed have been advanced, and in the developing device, the rotation speed of the developer carrier has been increased. There may be a bumping phenomenon that the blade member bounces at the contact portion. A situation in which the amount of developer transported by the developer carrying member is not properly performed due to the bumping phenomenon has occurred, and a technique for suppressing image unevenness, image streaks, and ghosts resulting from this has been developed.

  Specifically, by setting the dynamic loss coefficient (tan δ) of the elastic body at room temperature to a specific range in the developer amount regulating blade, it is possible to prevent bumping phenomenon and wear at high speed, and a good image Has been reported (Patent Document 1). However, if the loss coefficient (tan δ) at normal temperature is set within a specific range, toner adhesion or fusion may occur at low or high temperatures, resulting in image streak problems.

In addition, it is reported that a blade with high mechanical properties can be obtained by including a perfluoroalkyl component in polyurethane and setting the loss coefficient (tan δ) peak temperature and the loss coefficient (tan δ) at 55 ° C. within a specific range. (Patent Document 2). However, toner adheres to the blade at low temperatures, or the contact pressure is low and the tribo is not uniformly applied to the toner, resulting in image unevenness and ghosting.
JP 2000-352870 A JP 2003-12752 A

  The present invention suppresses image unevenness, image streaks, ghosts, and the like caused by high-speed rotation of a developer carrier in a developing device as the electrophotographic process increases in speed, and causes image defects due to high-speed rotation of the developer carrier. It is an object of the present invention to provide a developer amount regulating blade capable of suppressing the occurrence of toner over a long period of time.

  The inventor examined the adhesion and fusion of the developer to the surface of the developer amount regulating blade, which causes image unevenness, image streaks, and ghosts accompanying the high speed rotation of the developer carrying member. When the developer amount adheres to the surface of the blade by the developer, the viscosity of the blade member or the viscosity of the developer is caused as a factor. When development is performed with the blade member to which the developer is attached, image streaks and image unevenness occur. It has been found that the developer adheres to the blade member at an early stage after the start of image formation by the electrophotographic apparatus. When image formation is further advanced from this state, image streaks and the like are improved in the image output by the electrophotographic apparatus. Therefore, the developer once adhered to the blade member is accompanied with the progress of image formation by the electrophotographic apparatus. The knowledge of falling off from the blade member surface was obtained. On the other hand, once the developer fuses and adheres to the blade member surface during image formation by the electrophotographic apparatus, the solidified developer is unlikely to fall off the blade member surface and can impart sufficient frictional charge to the developer. In addition, even when image formation was advanced, the image streaks and the like were not improved, and it was found that they tend to deteriorate. For this reason, in the initial stage after the start of image formation in the electrophotographic apparatus, by suppressing the adhesion of the developer to the blade member, and further, by suppressing the fusion of the developer when the image formation proceeds, In the image formation by the electrophotographic apparatus, it has been found that adhesion and sticking to the developer on the blade member can be suppressed, and troubles such as image unevenness and image streaks can be suppressed. The present inventor assumes that the blade member has a specific loss factor (tan δ) with respect to charges of a specific frequency at 15 ° C. and 40 ° C., so that the developer adheres to the blade member, and is fused and solidified. As a result, it has been found that image unevenness, image streaks, ghosts and the like in the output image from the electrophotographic apparatus can be suppressed. The reason for this is that by setting the tan δ of the blade member in a specific range, the viscosity of the blade member at 15 ° C. can be set in a specific range, so that adhesion of the developer to the blade member surface can be prevented. it can. Further, since the elastic modulus at 40 ° C. of the blade member can be set within a specific range, the contact pressure is set within an appropriate range, and the developer is not pressed more than necessary, thereby suppressing the fusion of the developer. Based on this knowledge, the present invention has been completed.

  That is, the present invention provides a blade member that is provided in a developing device of an electrophotographic apparatus and that contacts a developer carrying member that carries a developer contained in a developer container and supplies the developer to an electrostatic latent image, and the blade In the developer amount regulating blade for providing a predetermined triboelectric charge to the developer, the blade member comprising: a support member that supports the member; and a constant amount of the developer carried by the developer carrier. The present invention relates to a developer amount regulating blade having a tan δ of 1.0 or less at 15 ° C. and 0.03 or more at 40 ° C. for a frequency of 10 Hz.

  The developer amount regulating blade of the present invention can suppress the occurrence of adhesion and fusion of the developer to the surface, and can impart a sufficient triboelectric charge (tribo) to the developer. Along with higher speeds, image irregularities, image streaks, ghosts, etc. caused by high speed rotation of the developer carrier in the developing device are suppressed, and image defects due to high speed rotation of the developer carrier are suppressed over a long period of time. can do.

  The developer amount regulating blade of the present invention is provided in a developing device of an electrophotographic apparatus, and is a blade member that contacts a developer carrying member that carries a developer contained in a developer container and supplies it to an electrostatic latent image. And a support member that supports the blade member, and a developer amount regulating blade that applies a predetermined triboelectric charge to the developer while maintaining a constant amount of developer carried by the developer carrier, the blade member includes: As long as it has a tan δ of 1.0 or less at 15 ° C. and 0.03 or more at 40 ° C. for a frequency of 10 Hz, there is no particular limitation.

  The developer amount regulating blade of the present invention is provided in a developing device of an electrophotographic apparatus, and as such an electrophotographic apparatus, any apparatus can be used as long as it forms an image using an electrophotographic process. Specifically, an electrophotographic copying machine, a laser beam printer, a facsimile, etc. can be mentioned.

  Further, as a developing device of these electrophotographic apparatuses, a developer carrying member that carries a developer contained in a developer container and supplies the developer to an electrostatic latent image, a blade member that contacts the developer carrying member, and the blade member And a developer amount regulating blade provided with a supporting member for supporting the toner. As an example, for example, as shown in the schematic configuration diagram of FIG. A developer container 10 to be stored, an electrophotographic photosensitive member 12 in which a part of the developer container is exposed to the outside of the developer container, and an electrostatic latent image is formed on the surface portion of the exposed part. A developer amount regulating blade 13 having a roller-like developer carrier 11 arranged so as to be in contact with the developing member, and a blade member formed of a rubber material or the like that comes into contact with the surface of the developer carrier. You can list those with .

  As an example of the developer amount regulating blade of the present invention, FIG. 2 shows an example of a developer amount regulating blade comprising a blade member 20 that slides on the developer carrier and a support member 21 to which the blade member is bonded. Here, the blade member 20 is bonded to the support member 21 between 20 and 21, and 25 is a surface (sliding surface) on which the developer slides on the developing carrier and the blade member, and also charges the developer. This is the surface to be controlled (charge control surface). Further, the developer amount regulating blade 22 produced by laminating the blade member 20 and the support member 21 is fixed to the developer container, and is pressed against the developer carrier 11 on the sliding surface 25 to slide. The amount of developer particles passing through the surface 25 is regulated.

  As developer carrier 11 is rotated in the direction of the arrow, developer particles 23 are conveyed to sliding surface 25. At this time, since the surface (charge control surface) for controlling the charge of the developer amount regulating blade 22 is in contact with the developer carrier 11, the developer particles are given a predetermined triboelectric charge, and pass through the sliding surface 25. The amount of developer particles conveyed to the photoreceptor can be regulated.

  As the support member 21 of the developer amount regulating blade, any member may be used as long as it supports the blade member, and the material may be any of metal, ceramic, resin and the like. Specific examples include steel plates subjected to chromate treatment and surface treatment with a lubricating resin, elastic metal plates such as phosphor bronze and spring steel, plastics, and ceramics.

  Further, the blade member 20 of the developer amount regulating blade is provided in pressure contact with the surface of the developer carrier 11, and an excess of developer carried by the developer carrier is used for the surface of the developer carrier. The toner particles of the developer passing between the developer carrying member and the developer carrier are given a predetermined triboelectric charge with a polarity opposite to that of the electrostatic latent image formed on the photosensitive member of the electrophotographic apparatus. It is given.

  Such a blade member has a tan δ of 1.0 or less at 15 ° C. and 0.03 or more at 40 ° C. with respect to a charge of a frequency of 10 Hz. When the tan δ at 15 ° C. is 1.0 or less with respect to a charge of 10 Hz, the viscosity of the blade member can be kept low, and the toner particles adhere to the blade member surface and move to the electrostatic latent image. As a result, the occurrence of image streaks in the image output from the electrophotographic apparatus can be suppressed. Furthermore, since it is possible to suppress adhesion of additives and lubricants other than the developer, it is possible to suppress damage to the surface of the development carrier. Further, the impact resilience of the blade member can be maintained, the contact pressure with respect to the developing carrier can be maintained high, a sufficient charge can be imparted to the toner particles of the developer, and ghost and image unevenness can be prevented. Occurrence can be suppressed.

  In addition, when the tan δ at 40 ° C. is 0.03 or less with respect to a charge of a frequency of 10 Hz, an excessive increase in the resilience of the blade member can be suppressed, and the contact pressure against the developing carrier is appropriately maintained. It is possible to suppress the adhesion of the developer to the blade member surface and to suppress the occurrence of image streaks. In the electrophotographic process, vibrations with a frequency of about 100 to 10000 Hz are generally applied to the blade member. However, it is generally difficult to measure tan δ by applying a charge with a frequency of 100 to 10000 Hz. Whether the developer adheres to the blade member surface, whether it is fused or solidified, and whether it is solidified can be determined using tan δ due to the 10 Hz charge that can be measured as an index, and the tan δ due to the 10 Hz charge is within the above range. Thus, it is possible to suppress the adhesion and fusion of the developer to the blade member.

  tan δ can be obtained by a method of measuring at a measurement temperature of −50 ° C. to 130 ° C. and a measurement frequency of 10 Hz with a viscoelasticity measuring device such as DMS6100 manufactured by Seiko Instruments Inc.

  Furthermore, the international rubber hardness (IRHD) of the blade member of the developer amount regulating blade in the present invention is preferably 60 ° or more and 80 ° or less. When the hardness is 60 ° or more, the developer carrying member has a contact pressure capable of imparting a sufficient charge to the developer, and suppresses the occurrence of ghost and image unevenness in the obtained image. Can do. Further, if it is 80 ° or less, a contact pressure that can form a thin film of the developer with a uniform film thickness on the developer carrying member and that causes the developer to be fused to the blade member surface. In addition, image streaks can be suppressed in the obtained image.

  The hardness of the rubber hardness can be a value measured based on JIS K 6253 using a micro hardness tester.

  Examples of the material of the blade member include thermosetting polyurethane, silicone rubber, liquid rubber, etc. having rubber elasticity from the viewpoint of mechanical properties of wear resistance, and are appropriately selected depending on the polarity with which the developer is frictionally charged. The material of the blade member with respect to the negative developer is particularly preferably a urethane elastomer.

  As a method for producing such a developer amount regulating blade, using the above materials, a method according to a conventional method, specifically, a prepolymer method, a semi-one-shot method, a one-shot method, etc. It can be appropriately selected depending on the material used for the blade member. The case where a urethane elastomer is included as the material of the blade member will be specifically described as an example.

  As a method for producing a urethane elastomer used for the blade member, first, a urethane rubber prepolymer obtained by partially polymerizing a polyisocyanate and a high molecular weight polyol and a curing agent containing a curing catalyst are mixed and stirred to flow the rubber raw material. A neutral isocyanate composition is prepared.

  Specific examples of the polyisocyanate used in the preparation of the urethane rubber prepolymer include 4,4′-diphenylmethane diisocyanate (MDI), isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, trimethylhexamethylene diisocyanate, and tolylene diene. Examples include isocyanate, carbodiimide-modified MDI, polymethylene phenyl polyisocyanate, orthotoluidine diisocyanate, naphthylene diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, paraphenylene diisocyanate, lysine diisocyanate methyl ester, dimethyl diisocyanate, and the urethane rubber obtained MDI is preferred from the viewpoint of the balance of properties of the molded product.

  The high molecular weight polyol used for the preparation of the urethane rubber prepolymer is preferably a polyester polyol, and specific examples of the polyester polyol include polyethylene adipate (PEA) and polybutylene adipate (PBA). And polyhexylene adipate, a copolymer of ethylene adipate and butylene adipate, and the like. The weight average molecular weight of the polyester polyol is preferably 1500 or more and 3000 or less.

  As a curing agent used for preparing a rubber raw material by mixing and stirring with the urethane rubber prepolymer, a low molecular weight polyol having a molecular weight of 300 or less can be used, but it can also be used in combination with the above high molecular weight polyol. Examples of the low molecular weight polyol include ethylene glycol (EG), 1,4-butanediol, 2,3-butanediol, trimethylolpropane (TMP), 3,3-dichloro-4,4-diaminophenylmethane, and hydroquinone. -Bis (β-hydroxyethyl) ether or the like can be used. If necessary, two or more kinds of these low molecular weight polyols can be used.

  Examples of the curing catalyst used to prepare the rubber raw material include amine compounds such as tertiary amines and organometallic compounds. Examples of the tertiary amine include trialkylamines such as triethylamine, tetraalkyldiamines such as N, N, N ′, N′-tetramethyl-1,3-butanediamine, aminoalcohols such as dimethylethanolamine, Ethoxylated amines, ethoxylated diamines, ester amines such as bis (diethylethanolamine) adipate, cyclohexylamine derivatives such as triethyldiamine and N, N-dimethylcyclohexylamine, N-methyl formalin, N- (2-hydroxy Morpholine derivatives such as propyl) -dimethylmorpholine, and piperazine derivatives such as N, N′-diethyl-2-methylpiperazine and N, N′-bis- (2-hydroxypropyl) -2-methylpiperazine. .

  Moreover, various fillers can be added to the isocyanate composition of the rubber raw material as necessary. As the filler, a mechanical property improver such as carbon black, a heat resistance improver such as antimony trioxide, a slidability improver such as polyvinylidene fluoride, and a colorant such as titanium oxide can be used.

  The obtained rubber raw material is poured into a centrifugal molding machine and heat-molded to obtain a urethane elastomer, which is cut into a predetermined dimension to obtain a blade member. The obtained blade member can be fixed to the prepared support member by a method such as adhesion to obtain a developer amount regulating blade.

  Other manufacturing methods for the developer amount regulating blade member include, for example, a method in which a support member is inserted into a mold and a rubber raw material for molding the blade member is injected to produce an integrally molded blade, or a support member is used. A molding method in which the rubber raw material is poured into the mold and cured and reacted at the same time by being cured and held at the blade member molding die, a method of injecting the rubber raw material into a groove carved in the outer peripheral surface of the molding drum, and heat curing. Can be mentioned.

  The operation of such a developer amount regulating blade in the developing device will be described.

  When the developer carrier 11 rotates in the direction b shown in the figure, the toner particles 23 contained in the developer pass through the sliding portion 25 between the developer carrier 11 and the blade member 20, and the developer carrier. The surplus induced on the surface of the toner is removed from the surface of the developer carrying member and returned to the developer container 10 and is triboelectrically charged to the opposite polarity to the electrostatic latent image formed on the electrophotographic photosensitive member 12. The fixed amount becomes a thin film and adheres to the surface of the developer carrying member. The developer carrying member further rotates, and the developer carried as a thin film on the developer carrying member at the contact portion between the developer carrying member and the electrophotographic photosensitive member is charged on the surface of the electrophotographic photosensitive member. The electrostatic latent image is electrostatically attracted and moved to develop the electrostatic latent image.

  At this time, since the developer amount regulating blade has an appropriate value of tan δ at 15 ° C. with respect to the charge of the frequency of 10 Hz, the developer amount regulating blade is brought into contact with the developing carrier at an appropriate pressure, and the viscosity of the charge control surface of the developer amount regulating blade is Is high, the adhesion of the developer is suppressed, and the occurrence of image streaks in the developed image is suppressed. In addition, since tan δ at 40 ° C. with respect to a frequency of 10 Hz has an appropriate value, the developer amount regulating blade is brought into contact with the developer carrying member at an appropriate pressure, and the developer is fused to the surface of the developer amount regulating blade. Adhesion is suppressed, and a sufficiently charged charge (tribo) can be imparted to the developer. For this reason, the occurrence of image unevenness, image streaks, and ghosts in the output image of the electrophotographic apparatus is suppressed.

Examples of the present invention will be described below, but the technical scope of the present invention is not limited to these examples. Unless otherwise specified, commercially available high-purity products were used as reagents.
[Example 1]
The developer amount regulating blade of the present invention was produced as follows.

  As a support member, an electrogalvanized steel sheet gin coat 21 (trade name: manufactured by Nippon Steel Co., Ltd.) having a non-chromium surface treatment layer containing a urethane-modified olefin resin and an acrylic-modified olefin resin is used. Melt adhesive Elfan-UH (trade name: manufactured by Nippon Matai Co., Ltd.) was temporarily bonded.

  Next, 100 parts by mass of adipate-based urethane prepolymer (Mn2000, NCO content 7.0% by mass), 3.7 parts by mass of 1,4-butanediol, and 1.9 parts by mass of trimethylolpropane were mixed in a casting machine. The rubber raw material mixture was obtained by mixing and stirring inside. The obtained rubber raw material mixture was poured into a centrifugal molding machine, heat-molded at 130 ° C. for 1 hour, demolded and heat-cured to obtain a sheet-like polyurethane elastomer. The obtained polyurethane elastomer was cut into a predetermined size to form a blade member, and this blade member and a support metal plate temporarily bonded with the hot melt adhesive were heated and bonded to obtain a developer amount regulating blade.

  The developer amount regulating blade thus produced was incorporated into a cartridge for LASER SHOT-LBP (manufactured by Canon Inc.), and ghosts and image stripes were evaluated. For ghosts, ◯ indicates that no ghost occurred, △ indicates that a slight ghost was confirmed, and × indicates that a ghost was clearly confirmed. Among image streaks, ○ indicates that no image streak was observed, △ indicates that some image streak was confirmed, but a level that is not a problem for practical use, and occurrence of image streak can be confirmed for a practically problematic level. What was there was marked as x. The results are shown in Table 1.

 The tan δ peak temperature was measured using a Seiko Instruments DMS 6100 as follows. First, a strip-shaped test piece was prepared from the created blade member. Next, after fixing this test piece so that the measurement length is 20 mm, the test piece is distorted at an amplitude of 5 μm and a frequency of 10 Hz, and at about 0.5 ° C. at a heating rate of 2 ° C./min. Tan δ was measured. The value of tan δ at 0 ° C. and 40 ° C. was measured.

The measurement of international rubber hardness (IRHD) was performed based on JIS K 6253 using a Wallace microhardness meter manufactured by H. WALLACE. The obtained results are shown in Table 1.
[Example 2]
A developer amount regulating blade was prepared in the same manner as in Example 1 except that the mixing ratio was 3.4 parts by mass of 1,4-butanediol and 2.2 parts by mass of trimethylolpropane. , Tan δ, and rubber hardness were measured and mounted on an actual machine, and the presence or absence of adhesion and fusion of the developer and the image were evaluated. The results are shown in Table 1.
[Example 3]
A developer amount regulating blade was prepared in the same manner as in Example 1 except that the heat molding time for curing the polyurethane elastomer was changed to 130 ° C. and 30 minutes and the hardness was changed, and the same as in Example 1. In addition, tan δ and rubber hardness were measured and mounted on an actual machine to evaluate the presence / absence of adhesion and fusion of the developer and the image. The results are shown in Table 1.
[Example 4]
A developer amount regulating blade was prepared in the same manner as in Example 1 except that the heat molding time for curing the polyurethane elastomer was changed to 130 ° C. for 5 hours and the hardness was changed, and the same as in Example 1. In addition, tan δ and rubber hardness were measured and mounted on an actual machine to evaluate the presence / absence of adhesion and fusion of the developer and the image. The results are shown in Table 1.
[Example 5]
A developer amount regulating blade was prepared in the same manner as in Example 1 except that the blade member was made of silicon, and tan δ and rubber hardness were measured and mounted on the actual machine in the same manner as in Example 1 to attach and melt the developer. The presence or absence of clothes and the evaluation of images were performed. The results are shown in Table 1.
[Comparative Examples 1-3]
A developer amount regulating blade was prepared in the same manner as in Example 1 except that the adipate-based urethane prepolymer used was Mn2000 and the NCO content was 6.25% by mass. As in Example 1, tan δ, rubber hardness Was measured and mounted on an actual machine, and the presence or absence of adhesion or fusion of the developer and the image were evaluated. The results are shown in Table 1.

  From the above results, in Examples 1 and 2, no toner adhesion / fusion was observed, and good images without image streaks and ghosts were obtained. In Example 3 having a low hardness, a slight ghost was observed, but it was at a level causing no problem on the image. On the contrary, in Example 4 where the hardness is high, some occurrences of image streaks and ghosts were confirmed, but they were at a level with no problem on the image. Further, even in Example 5 in which silicon was used as the blade member, some image streaks and ghosts were confirmed, but the level was satisfactory in terms of image. In contrast, in Comparative Examples 1 and 4, in which tan δ at 15 ° C. was 1.0 or more, toner adhesion was observed in a 15 ° C. environment, and image streaks occurred. In Comparative Example 2 and Comparative Example 4 where tan δ at 40 ° C. was 0.03 or less, toner fusion was observed in an environment of 40 ° C., and image streaks occurred.

FIG. 2 is a schematic configuration diagram illustrating an example of a developing device of an electrophotographic apparatus to which the developer amount regulating blade of the present invention is applied. It is a figure which shows the typical block diagram of the developer amount regulation blade of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Developer container 11 Developer carrier 12 Photoconductor 13 Developer amount control blade 20 Blade member 21 Support member 23 Developer (toner particle)
25 Sliding part

Claims (3)

  A blade member that is provided in a developing device of an electrophotographic apparatus and that contacts a developer carrying member that carries a developer contained in a developer container and supplies the developer to an electrostatic latent image, and a support member that supports the blade member In the developer amount regulating blade that makes the developer carried by the developer carrier a constant amount and imparts a predetermined triboelectric charge to the developer, the blade member has a frequency of 10 Hz, A developer amount regulating blade having a tan δ of 1.0 or less at 15 ° C. and 0.03 or more at 40 ° C.   The developer amount regulating blade according to claim 1, wherein the blade member has an international rubber hardness (IRHD) of 60 ° to 80 °.   The developer amount regulating blade according to claim 1, wherein the blade member includes a urethane elastomer.

Images