JPH11344858A - Blade for forming toner thin layer, manufacture of the same, and developing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blade for forming toner thin layer for a single-component system dry type developing device with a superior reliability, capable of forming the uniform toner thin layer provided with the satisfactory triboelectric quantity, and made possible to form an image with high quality as a result thereof. SOLUTION: The blade 10 for forming the toner thin layer is, composed of a blade shape elastic member 12 provided with an edge part 12a for forming the toner thin layer on the developer carrier, and the supporting member 11 that the blade shape elastic member 12 is adhered to a main plane edge part 12d on the opposite side via an adhesive, and moreover the edge part 12a is formed in the curved plane with a radius of 0.05 to 2.0 mm, and an angle formed by two planes connected with this curved plane is 90 to 110 angular degrees.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blade for forming a thin toner layer, a method of manufacturing the same, and a developing device.

[0002]

2. Description of the Related Art As a developing device used in an electronic copying machine, an electrostatic recording device, various other recording devices, and the like, there are a one-component dry developing device and a two-component developing device. Unlike a two-component developing device, a one-component dry developing device does not use a carrier, so there is no need to consider the deterioration of the carrier and the mixing ratio of the carrier and the toner. Since a replenishment control mechanism, a stirring mechanism for stirring the toner and the carrier, and the like are not required, there is an advantage that the configuration of the apparatus can be simplified.

[0003] The toner used in this one-component dry developing device
Has a volume resistivity of 10^Ten-10 ¹³Ωcm or more and ratio
It is relatively expensive. This toner has a predetermined polarity
And the frictional charging of the developing device during development
Friction charge is given from the member, and it is charged even higher
Things.

The frictional charging member includes a toner carrier for carrying toner, a toner thin layer forming blade for uniformly thinning the toner on the toner carrier, and a charging member used only for frictional charging of the toner. It is composed of Among these, the simplest configuration using a blade for forming a thin toner layer and triboelectrically charging the toner can reduce the cost of a one-component dry developing device. It is.

Hereinafter, a conventional toner thin layer forming blade will be described with reference to the drawings. FIG. 6 shows a configuration in which a blade 67 for forming a thin toner layer is formed by a leaf spring 66 and an elastic blade 65 made of a rubber material attached to the tip of the leaf spring 66. The elastic blade 65 has a contact surface 65a with the developing roller 2. Has a predetermined radius of curvature, and the leaf spring 6
6 is pressed against the developing roller 2 at a constant pressure by the resilience of 6. In addition, as shown in FIG.
Is supplied from the toner supply roller 4 and thinned by the toner thin layer forming blade 67,
Is transported to a region where it rotates while approaching or in contact with the developing roller 2, and a part thereof adheres to the electrostatic latent image portion of the photosensitive drum 1, and visualizes the electrostatic latent image portion.

FIG. 7 shows an example in which an elastic blade 75 made of a rubber material is bonded to a developing bat 78 made of a highly rigid member or the like. The elastic blade 75 is applied to the developing roller 2 at a predetermined pressure by its elastic force. It is something to press.

FIG. 8 shows a blade 85 made of a resin or a metal having relatively high hardness supported by a blade guide 86 via a coil spring 87.
Is for pressing the developing roller 2 with a constant pressure.

FIG. 9 shows a state in which a metal leaf spring 96 is mounted on the developing bat 98. The leaf spring 96 is pressed against the developing roller 2 at a constant pressure by its elastic force. FIG. 10 shows a configuration in which a blade 107 for forming a thin toner layer is formed by a leaf spring 106 and an elastic blade 105 made of a rubber material attached to the distal end thereof, and R is provided at at least one edge of the distal end of the elastic blade 105. The edge portion is pressed against the developing roller 2 with a constant pressure by the elastic force of the leaf spring 106.

The conventional blade for forming a thin toner layer has the following problems. 6, since the elastic blade 65 has a large radius, it is difficult to uniformly press the contact surface 65a against the developing roller 2, and the thickness of the thin toner layer formed by the toner 3 is small. Also, there is a problem that unevenness in toner triboelectric charge amount causes background smear, line width unevenness, and image density unevenness in the print width direction.

In the embodiment shown in FIG.
Is pressed against the developing roller 2 for a long time, a creep phenomenon occurs, the pressing force gradually decreases, and the ability to triboelectrically charge the toner decreases, and the image gradually deteriorates.

In the apparatus shown in FIG. 8, the precision of the press-contact surface and the edge of the blade 85 must be increased, so that the cost is increased. If the precision is insufficient, the axial direction of the developing roller 2 is reduced. In addition, there is a problem in that unevenness in the layer thickness of the toner and unevenness in the triboelectric charge amount of the toner occur, resulting in uneven image density and partial background contamination. Further, since a force in the rotation direction of the developing roller 2 is applied to the pressure contact surface of the blade 85, the blade 85 is inclined in the blade guide 86, and the blade 85 does not slide smoothly in synchronization with deflection due to the rotation of the developing roller 2. There is also a problem that a problem occurs, and unevenness in toner layer thickness and uneven triboelectric charging occur in synchronism with the rotation cycle of the developing roller 2, resulting in image density unevenness and background contamination.

In the configuration shown in FIG. 9, the parallelism between the leaf spring 96 and the developing roller 2 is limited, and it is extremely difficult to make the toner layer thickness uniform. There have been problems such as streaky image density unevenness and background stains. Further, there is also a problem that the toner is easily fixed and a streak is generated in an image.

FIG. 10 shows a leaf spring 106 and an elastic blade 10 made of rubber material attached to the leaf spring 106.
5, the contact between the thin toner layer forming blade 107 and the developing roller 2 is made uniform, so that the toner layer thickness can be made relatively uniform. However, at the contact position shown in FIG. 10, the contact width A between the thin toner layer forming blade 107 and the developing roller 2 is too narrow, and at the position shown in FIG. 11, the contact width B is too large. Even when the layer thickness is uniform, the contact width of the R portion of the blade 107 for forming a thin toner layer with the developing roller 2 varies in the axial direction of development, and the amount of triboelectric charge of the toner becomes non-uniform in the print width direction. There were problems such as background contamination, uneven line width, and uneven image density in the printing width direction.

[0014]

SUMMARY OF THE INVENTION In view of the above, the present invention makes it possible to form a uniform thin toner layer having a sufficient amount of triboelectric charge, and therefore to form a high image quality and to have excellent reliability. A toner thin layer forming blade for a one-component dry developing device, a method for manufacturing a toner thin layer forming blade capable of efficiently and inexpensively manufacturing the toner thin layer forming blade, and a method for manufacturing the toner thin layer. It is an object of the present invention to provide a developing device using a layer forming blade.

[0015]

A blade for forming a thin toner layer according to the present invention comprises a plate-like elastic member having an edge portion for forming a toner thin layer on a developer carrying member; A toner thin layer forming blade comprising a support member adhered to an end of a main surface opposite to the edge portion via an adhesive, wherein the edge portion has a radius of 0.05 to 2.0.
mm, and an angle between two surfaces connected to the curved surface is 90 to 110 °. Also,
The method for manufacturing a blade for forming a thin toner layer according to the present invention is directed to a drum having a groove formed over the entire outer periphery thereof, wherein the cross section of the groove is part of a cross section perpendicular to the edge of the plate-like elastic member. While rotating a continuous molding die having a drum formed in the same shape as above and a belt body running along a part of the outer periphery of the drum and covering the groove,
Injecting the liquid composition for forming the plate-like elastic member into the groove portion, molding, forming a continuous band-like body, and cutting the continuous band-like body to a predetermined length to prepare a plate-like elastic member. It is characterized by doing. Hereinafter, the present invention will be described in detail.

The blade for forming a thin toner layer according to the present invention includes a plate-like elastic member having an edge portion for forming a toner thin layer on a developer carrier, and the plate-like elastic member being opposite to the edge portion. And a supporting member adhered to an end of the main surface via an adhesive, and the edge has a radius of 0.05 to 2.0.
It forms a curved surface of 0 mm, and an angle between two surfaces connected to the curved surface is 90 to 110 °. FIG. 1A is a cross-sectional view schematically showing a state in which development is performed using the blade for forming a thin toner layer of the present invention, and FIG. FIG. 5 is a partially enlarged cross-sectional view schematically showing a part of a plate-like elastic member to be formed. FIG.
FIG. 4 is a cross-sectional view showing a state in which the plate-like elastic member 12 and the developing roller 3 are in proximity to each other during development.

As shown in FIG. 1, a blade 10 for forming a thin toner layer is a plate-like elastic member having an edge portion 12a for forming a thin layer with a toner 3 on a developing roller 2 as a developer carrier. And a support member 11 in which a plate-like elastic member 12 is bonded to an upper main surface end 12d opposite to the edge 12a via an adhesive.

As shown in FIGS. 1 and 2, a toner supply roller (see FIG.
The toner 3 carried by the developing roller 2 is charged by the charging friction between the developing roller 2 and the toner supply roller and adheres to the surface of the developing roller 2, and the toner thin layer forming blade existing near the surface of the developing roller 2 10 is carried near the edge portion 12a.

Next, the toner 3 carried near the edge portion 12a of the toner thin layer forming blade 10
2a, it is further triboelectrically charged and formed into a uniform thin layer. The thin toner 3 is then carried to a region where the photosensitive drum is rotating with the photosensitive drum approaching or in contact with the developing roller 2, and a part of the toner 3 adheres to the electrostatic latent image portion of the photosensitive drum, The electrostatic latent image portion is visualized (see FIG. 6).

As described above, the edge portion 12a of the blade 10 for forming a thin layer of toner plays an important role in pressing the toner 3 and forming a uniform thin layer, and its shape is a problem. However, in the present invention, the edge portion 12a of the toner thin layer forming blade 10 has a radius R
Form a curved surface of 0.05 to 2.0 mm, and the angle θ between two surfaces connected to the curved surface is 90 to 110 °,
When used in a developing device, a uniform thin toner layer having a sufficient amount of triboelectric charge can be formed, and therefore, high image quality can be formed.

When the radius of the curved surface is less than 0.05,
When the radius of the curved surface exceeds 2.0 mm, the thickness of the toner 3 becomes too large, and the excessive developer causes a tendency to scrape off the toner. Formation becomes difficult.

If the angle θ between the two surfaces connected to the curved surface is less than 90 °, the toner 3 is
When the angle θ exceeds 110 °, the edge portion 12
a and the lower main surface 12c facing the developing roller 2 easily becomes clogged with the toner 3, and the aggregation of the toner 3 makes it difficult to form a uniform thin layer.

The hardness of the plate-like elastic member 12 is preferably 30 to 80 ° in Walles hardness. Wallace hardness 30 °
If less than, the elasticity of the plate-like elastic member is weakened, it is easy to bend in the rotation direction of the developing roller 2, it is difficult to form a uniform thin layer, and if the Wallace hardness exceeds 80 °,
The pressing force against the developing roller 2 becomes too strong, and the toner 3 tends to fuse and agglomerate due to frictional heat between the developing roller 2 and the thin layer. further,
The surface of the developing roller 2 is easily damaged.

The material of the plate-like elastic member is not particularly limited, and examples thereof include polyurethane, silicone rubber, and ethylene-propylene-diene copolymer (EPDM). Of these, polyurethane is
It is preferable because the contamination of the mating member is small, the permanent set is small, and the wear resistance is excellent. As the polyurethane, those obtained by a reaction between a polymer polyol and a diisocyanate are preferable.

Examples of the high molecular polyol include:
Polyethylene glycol, polypropylene glycol,
Polyoxyalkylene glycols such as polyoxytetramethylene glycol; polyether-type polyols of bisphenol A and glycerin ethylene oxide adduct; dibasic acids such as adipic acid, phthalic anhydride, isophthalic acid, maleic acid, fumaric acid and ethylene glycol ,
Propylene glycol, 1,4-butanediol, 1,
Polyester-type polyols obtained by a polymerization reaction with glycols such as 6-hexanediol and trimethylolpropane; polycaprolactone diol, polycarbonate diol and the like. The number average molecular weight of the high molecular polyol is preferably from 500 to 5,000, more preferably from 1,000 to 3,000. The above polymer polyols may be used alone or in combination of two or more.

Examples of the diisocyanate compound include tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and 1,4-cyclohexane diisocyanate. The diisocyanate compounds may be used alone or in combination of two or more.

Examples of the chain extender include low molecular weight diols such as ethylene glycol, 1,4-butanediol, diethylene glycol, 1,6-hexanediol and neopentyl glycol; diamines such as ethylenediamine, hexamethylenediamine and isophoronediamine And the like. Of these, low molecular weight diols are preferred. Further, if necessary, as a multifunctional component, trimethylolpropane, triethanolamine,
Glycerin and their ethylene oxide and propylene oxide adducts may be added. Regarding the method of manufacturing a toner thin layer forming blade using these materials,
It will be described later.

The support member used in the present invention is not particularly limited, and includes, for example, a rigid metal, an elastic metal;
Those manufactured from plastics, ceramics and the like can be mentioned. Among these support members, a rigid metal is preferably used. As a method of bonding the plate-like elastic member and the support member, for example, polyamide-based,
Polyurethane-based hot melt adhesives, epoxy-based, and phenol-based adhesives can be used.
Among these, a bonding method using a hot melt adhesive is preferable.

In the blade for forming a thin toner layer according to the present invention, the edge of the plate-like elastic member forms a curved surface having a radius of 0.05 to 2.0 mm, and an angle formed between two surfaces connected to the curved surface is as follows.
Since the angle is 90 to 110 °, when used in a one-component dry developing apparatus, high image quality can be formed and the reliability is excellent.

The method of manufacturing a blade for forming a thin toner layer according to the present invention is directed to a drum having a groove formed over the entire outer periphery thereof, wherein the cross section of the groove is perpendicular to the edge of the plate-like elastic member. A drum formed in the same shape as a part of the drum, and along a part of the outer periphery of the drum, a rotating continuous molding die having a belt body running over the groove is rotated. After injecting the liquid composition for forming the plate-like elastic member, performing molding, and producing a continuous belt-like body,
A plate-like elastic member is produced by cutting the continuous strip into a predetermined length.

FIG. 3 is a perspective view schematically showing an apparatus for manufacturing a plate-like elastic member used in the method for manufacturing a blade for forming a thin toner layer according to the present invention. As shown in FIG. 3, the manufacturing device 20 for the plate-like elastic member includes a liquid composition injection device (not shown) including a mixing head 21, a drum 41, an endless belt (belt body) 22, and the like. And a rotating continuous molding die 40, a cooling belt conveyor 30, a cutting device 38, and the like.

Although not shown, the liquid composition injecting apparatus is provided with two tanks for storing a prepolymer and a cross-linking agent, respectively, which are raw materials for producing polyurethane. A pipe provided via a pump is connected to the mixing head 21. In the mixing head 21, the raw materials flowing from each tank are mixed therein, and the mixed liquid composition can be discharged to the molding grooves (grooves) 42.

The drum 41 has a molding groove 42 formed over the entire outer periphery thereof. The cross section of the molding groove 42 shown in FIG. 4 is perpendicular to the edge 12 a of the plate-like elastic member 12. It is formed in the same shape as the part except the upper main surface 12b (see FIG. 1B). Also, the molding groove 4
No. 2 is formed very precisely, and its surface is formed extremely smooth. Furthermore, the forming groove 4
On both sides of 2, overflow grooves 43 and 44 are provided.

A heating facility is disposed inside the drum 41, and its outer peripheral surface is heated to a predetermined temperature in order to promote a polymerization reaction of the discharged liquid composition. A heater 23 is also provided in the upper left half of the outer peripheral portion of the drum 41 so that heating can be performed from the outside.
The center of the drum 41 is supported by a rotating shaft 45 and rotates counterclockwise at a predetermined slow rotation speed.

An endless belt 22 running at the same speed as the drum 41 is provided so as to cover the forming groove 42 so as to be in close contact with the lower half of the outer periphery of the drum 41.
The endless belt 22 is hung around a driving roll 24 and driven rolls 25 and 26. The endless belt 22 also includes a plurality of heaters 23 for heating the formed body. Disposed at the upper right of the drum 41 is a release agent spraying device for preventing the compact from adhering to the drum 42.

A cooling belt conveyor 3 is provided adjacent to the drive roll 24 for cooling the continuous strip 120 after molding.
0 is installed, and the belt 31 is rolled 32, 33,
34, 35, 36, and 37. The rolls 36 and 37 are disposed inside a cooling device (not shown), and the belt 31 is cooled by passing through the cooling device.

A support table 39 is provided in the vicinity of the roll 33, and a cutting device 38 is provided on the support table 39. The continuous belt 120 transported by the cooling belt conveyor 30 is subjected to the cutting. The cutter 38a of the device 38
Is cut into a predetermined length.

Next, a method for manufacturing the plate-like elastic member 12 using the apparatus for manufacturing a plate-like elastic member will be described. First, two liquids are sent from a tank storing a prepolymer and a cross-linking agent to a mixing head 21 via a pipe, mixed by the mixing head, and a liquid composition 27 for molding is prepared. The liquid composition 27 is discharged from the mixing head 21 into a molding groove 42 formed in the drum 41. The discharge amount is adjusted by the rotation speed of the drum 41 and the capacity of the forming groove 42.

The liquid composition 27 is mixed with the mixing head 21.
Is discharged in the vicinity of the point a directly below the point a, moves in the direction of the point b with the rotation of the drum 41, is heated from the point a to the point b, and the reaction proceeds. From point c to point c, heating and pressurization by the endless belt 22 substantially complete the polyurethane polymerization reaction, and a continuous belt-like body 120 having the same cross-sectional shape as the plate-like elastic member 12 is produced. This continuous belt 120 is then cooled by the cooling belt conveyor 3.
The plate-like elastic member 12 is transported while being cooled by the heat treatment and cut to a predetermined length by the cutter 38a, and has a very smooth surface and a precisely shaped edge portion 12a.

The obtained plate-like elastic member 12 is then adhered to the support member 11 via an adhesive at the upper main surface end 12d as shown in FIG. Is completed.

According to the method for manufacturing the blade for forming a thin toner layer, the plate-like elastic member is continuously and efficiently manufactured using the plate-like elastic member manufacturing apparatus, so that it is efficient and inexpensive. It is possible to manufacture a blade for forming a toner thin layer having an accurate shape.

Further, the blade for forming a thin toner layer is
Developer carrier (developing roller), toner supply roller,
When mounted on a developing device provided with a photosensitive drum or the like, a uniform thin toner layer having a sufficient amount of triboelectric charge can be formed, so that high image quality can be formed. The above-mentioned developing device is also one of the present invention.

[0043]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 As a polymer polyol, polycaprolactone ester diol (average molecular weight: 2000) was added at 70 ° C. for 3 hours.
After heating and stirring under reduced pressure (5 mmHg) and dehydrating,
This was charged into a reactor, and subsequently, 4,4-diphenylmethane diisocyanate was added as a diisocyanate, and the mixture was stirred at 70 ° C. for 1 to 4 hours under a nitrogen gas atmosphere to obtain a liquid urethane prepolymer. The amount of the polymer polyol and diisocyanate added, the content of residual isocyanate groups, and the equivalent ratio (isocyanate group /
(Hydroxyl groups) are shown in Table 1 below.

Further, 1,4-butanediol, trimethylolpropane, and 1,2-dimethylimidazole as a reaction accelerator were reduced at 70 ° C. for 3 hours under reduced pressure (5 mm
Hg), followed by dehydration after heating and stirring to obtain a crosslinking agent having a hydroxyl equivalent of 45. The amounts of 1,4-butanediol, trimethylolpropane, and 1,2-dimethylimidazole are shown in Table 1 below.

The prepolymer and the cross-linking agent obtained as described above were respectively charged into a raw material tank, temperature-adjusted to a temperature shown in Table 1, and then mixed with a mixing head to obtain a liquid composition. An article is prepared, and after discharging the liquid composition from the mixing head 21 into the molding groove 42 of the apparatus for manufacturing a plate-like elastic member shown in FIG. The plate-like elastic member 12 was manufactured by the method described in the description. The manufacturing conditions are shown in Table 1 below.

Example 2 Example 1 was repeated except that polyethylene adipate diol (average molecular weight: 2000) was used instead of polycaprolactone ester diol as the polymer polyol, and the shape of the plate-like elastic member to be produced was changed. Similarly, the plate-like elastic member 12 was manufactured. Table 1 below shows the amount of each raw material to be added and the production conditions when the production apparatus for the plate-like elastic member is used.

Example 3 In preparing the prepolymer, the amount of the polymer polyol used was reduced, and in preparing the cross-linking agent, the above-mentioned polymer polyol was used to change the shape of the plate-like elastic member to be produced. Except for the above, a plate-like elastic member 12 was manufactured in the same manner as in Example 1. The following Table 1 shows the amount of each raw material to be added and the production conditions when the production apparatus for the plate-like elastic member is used.

Example 4 In preparing the prepolymer, the amount of the polymer polyol used was reduced, and in preparing the crosslinking agent, the above-mentioned polymer polyol was used to change the shape of the plate-like elastic member to be produced. Except for this, the plate-like elastic member 12 was manufactured in the same manner as in Example 2. The following Table 1 shows the amount of each raw material to be added and the production conditions when the production apparatus for the plate-like elastic member is used.

Comparative Example 1 The same procedure as in Example 1 was carried out except that polyethylene adipate diol (average molecular weight: 2,000) was used instead of polycaprolactone ester diol as the polymer polyol, and the shape of the plate-like elastic member to be produced was changed. Similarly, the plate-like elastic member 12 was manufactured. Table 2 below shows the amount of each raw material to be added and the manufacturing conditions when the manufacturing apparatus for the plate-like elastic member is used.

Comparative Example 2 In the preparation of the prepolymer, the amount of the polymer polyol was reduced, and in the preparation of the crosslinking agent, the above-mentioned polymer polyol was used, and the shape of the plate-like elastic member to be produced was changed. Except for the above, a plate-like elastic member 12 was manufactured in the same manner as in Example 1. Table 2 below shows the amount of each raw material to be added and the manufacturing conditions when the manufacturing apparatus for the plate-like elastic member is used.

Comparative Examples 3 and 4 Example 1 except that the shape of the plate-like elastic member to be manufactured was changed.
In the same manner as in the above, a plate-like elastic member 12 was manufactured. Table 2 below shows the amount of each raw material to be added and the manufacturing conditions when the manufacturing apparatus for the plate-like elastic member is used.

[0053]

[Table 1]

[0054]

[Table 2]

[0055]Evaluation methods  (1) Dimensions of plate-shaped elastic member, etc.
Method and the like were measured. The results are shown in Tables 3 and 4 below.
You.

(2) Physical properties of the plate-like elastic member The plate-like elastic member obtained according to the above-described embodiment is described in JIS.
Tables 3 and 4 according to the physical test method of the thermosetting polyurethane elastomer molded product of K 7312 (1996)
Were measured. The results are shown in Table 3 below.
And Table 4 below.

[0057]

[Table 3]

[0058]

[Table 4]

(3) Performance Test of Toner Thin Layer Forming Blade The plate-like elastic member obtained in the above example was bonded to a supporting member with an adhesive, and a toner thin layer forming blade 50 having the shape shown in FIG. Produced. The bonding was performed by applying a hot-melt adhesive to the support member 51 side, bonding the bonded portions of the plate-shaped elastic members 52 together, and then fusing them by high frequency. Thereafter, the blade 50 for forming a thin toner layer was mounted on a commercially available developing device, and the state of formation of the thin toner layer on the surface of the developing roller and the copying performance were examined.

As a result of the above-mentioned (3) performance test of the blade for forming a thin toner layer, when the blade 50 for forming a thin toner layer prepared in Examples 1 to 4 was used, the development was performed in any case. A uniform thin toner layer having a sufficient charge amount could be formed on the roller surface, high image quality could be formed, and almost no change in the image was observed even after printing 10,000 sheets. Further, even after printing under the above conditions, the edge portion 5 of the plate-like elastic member 52
In 2a, almost no wear or chipping was observed.

As described above, the blade for forming a thin toner layer according to the present invention has sufficient physical and mechanical characteristics required for a blade for forming a thin toner layer. Was satisfied with the required characteristics.

On the other hand, in Comparative Example 1, the toner thin layer became non-uniform due to the scraping of the toner from the beginning, and image unevenness occurred. In Comparative Example 2, the thickness of the toner layer was increased from the beginning, so that the density of the image was high, and ground fogging frequently occurred. In Comparative Example 3, the toner accumulated on the upper side from the upper side of the toner blade, the toner stirring rate in the developing device was reduced, and the life of the developing device (cartridge) was shortened. In Comparative Example 4, the toner thin layer became non-uniform due to the toner agglomeration from 3000 sheets, causing image unevenness.

[0063]

According to the blade for forming a thin toner layer of the present invention, a uniform thin toner layer having a sufficient amount of triboelectric charge can be formed, so that high image quality can be formed and reliability can be improved. An excellent blade for forming a thin toner layer of a one-component dry developing device can be provided. Further, according to the method for manufacturing a toner thin layer forming blade of the present invention, it is possible to efficiently and inexpensively manufacture the toner thin layer forming blade.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view showing a state of development by a toner thin layer forming blade of the present invention, and FIG. 1B is a sectional view of a plate-like elastic member constituting the toner thin layer forming blade. FIG. 3 is a partially enlarged cross-sectional view showing a part.

FIG. 2 is a cross-sectional view schematically showing a state in which a toner thin layer forming blade of the present invention is close to a developing roller during development.

FIG. 3 is a perspective view schematically showing an apparatus for manufacturing a plate-like elastic member constituting the blade for forming a thin toner layer according to the present invention.

FIG. 4 is a cross-sectional view schematically showing a forming groove formed on a drum constituting the apparatus for manufacturing a plate-like elastic member shown in FIG.

FIG. 5A is a perspective view schematically illustrating a toner thin layer forming blade manufactured in an example, and FIG.
It is sectional drawing.

FIG. 6 is a cross-sectional view schematically illustrating a conventional blade for forming a thin toner layer.

FIG. 7 is a cross-sectional view schematically illustrating a conventional blade for forming a thin toner layer.

FIG. 8 is a cross-sectional view schematically illustrating a conventional blade for forming a thin toner layer.

FIG. 9 is a cross-sectional view schematically illustrating a conventional blade for forming a thin toner layer.

FIG. 10 is a cross-sectional view schematically illustrating a conventional blade for forming a thin toner layer.

FIG. 11 is a cross-sectional view schematically illustrating a conventional blade for forming a thin toner layer.

[Explanation of symbols]

 2 Developing roller 3 Toner 10, 50 Toner thin layer forming blade 11, 51 Support member 12, 52 Plate elastic member 12a, 52a Edge 12b Upper main surface 12c Lower main surface 12d Upper main surface end 20 Plate elastic Member manufacturing apparatus 22 Endless belt 27 Liquid composition 40 Rotational and continuous molding die 42 Molding groove 120 Continuous strip

Claims (5)

[Claims] 1. A plate-like elastic member having an edge portion for forming a thin toner layer on a developer carrier, and said plate-like elastic member is provided with an adhesive on an end of a main surface opposite to said edge portion. A toner thin layer forming blade including a support member adhered through the edge portion, wherein the edge portion has a radius of 0.05 to 2.0.
a thin surface layer for forming a thin toner layer, wherein an angle between two surfaces continuous with the curved surface is 90 to 110 °. 2. The blade for forming a thin toner layer according to claim 1, wherein the plate-like elastic member has a Wallace hardness of 30 to 80 °. 3. The blade for forming a thin toner layer according to claim 1, wherein the plate-like elastic member is formed of polyurethane. 4. A method for producing a blade for forming a thin toner layer according to claim 1, wherein the drum is formed with a groove over the entire outer periphery thereof, wherein the cross section of the groove is: A continuous rotation comprising a drum formed in a shape similar to a part of a cross section perpendicular to an edge portion of the plate-like elastic member, and a belt body running along a part of an outer periphery of the drum and covering the groove portion. While rotating the molding die, the liquid composition for forming the plate-like elastic member is injected into the groove portion, molding is performed, and a continuous belt-like body is produced. Then, the continuous belt-like body is cut into a predetermined length. A method for producing a blade for forming a thin toner layer, wherein a plate-like elastic member is produced. 5. A developing apparatus comprising: a developer carrier; and a toner thin layer forming blade for forming a one-component toner thin layer on the developer carrier, the developing device comprising: 4. A developing device, wherein the blade for forming a thin toner layer according to claim 1, 2 or 3 is used as a blade.