JPH0876591A - Electrostatic latent image developing device - Google Patents

Abstract

PURPOSE: To provide an electrostatic latent image developing device provided with a supporting means capable of maintaining the surface accuracy of the blade consisting of the rigid member comprising a developer regulating means at a comparatively low cost. CONSTITUTION: The electrostatic latent image developing device 6 is provided with the developer applying means 16 for holding the developer on the surface in the developer holding area 30, transporting the holding developer to the developing area 34 and applying to the electrostatic latent image, and the regulating means 22 for regulating the developer amount held on the surface of the developer applying means 16 in the developer regulating area 32 located between the developer holding area and the developing area. The regulating means 22 is provided with the blade 46 consisting of the rigid member held in press contact with the surface of the developer applying means 16, the blade supporting means 48 for movably supporting the one side of the blade in the direction brought into press contact with the surface of the developer applying means 16, and elastic pressing means 50 for pressing the one side of the blade disposed on the other side of the blade in the direction brought into press contact with the surface of the developer applying means 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic latent image developing device used for developing an electrostatic latent image into a toner image in an image forming machine such as an electrostatic copying machine or a laser printer. The present invention relates to an electrostatic latent image developing apparatus having a developer application unit that holds a developer on the surface and conveys the developer to a development area, and a regulation unit that regulates the amount of the developer retained on the surface of the developer application unit. .

[0002]

2. Description of the Related Art As is well known, in order to develop an electrostatic latent image into a toner image in an image forming machine, a developer applying means comprising a roller or an endless belt which is rotationally driven in a predetermined direction is provided. The electrostatic latent image developing device has been widely put into practical use. The developer applying unit is driven to rotate in a predetermined direction, thereby sequentially moving the developer holding region, the developer amount regulating region, and the developing region. In the developer holding area, the developer supplied by an appropriate mode is held on the surface of the developer applying means. In the developer amount regulation area, the regulation device acts on the developer retained on the surface of the developer applying unit to regulate the developer retained on the surface of the developer applying unit to a required amount. In the developing area, a developer is applied to the surface of an electrostatic latent image bearing member such as a rotating drum having an electrostatic photoconductor on the peripheral surface, and the electrostatic latent image formed on the surface of the electrostatic latent image bearing member is developed. The latent image is developed into a toner image. In order to achieve good development, the amount of developer retained on the surface of the developer applying unit is appropriately regulated by the regulating unit so that the amount of developer retained on the surface of the developer applying unit is a required amount. In addition, it is important to make it sufficiently uniform in the width direction.

Japanese Patent Publication No. 63-16736 discloses an electrostatic latent image developing device having a regulating means having a blade made of a rubber elastic body made of synthetic rubber such as urethane rubber and silicon rubber. The rubber elastic body constituting the developer regulating means has one side or the leading edge thereof pressed against the surface of the developer applying means, and regulates the amount of the developer held on the surface of the developer applying means to a considerably small amount to develop. A thin layer of developer is formed on the surface of the agent applying means. Further, a blade of the developer regulating means is constituted by a stainless steel thin plate for spring having a thickness of 0.1 to 0.2 mm, which has been put into practical use.

[0004]

However, in the developer regulating means using the elastic blade such as the rubber elastic body or the stainless thin plate, the both ends of the elastic blade have low rigidity and the regulating force is inferior to the central portion. Therefore, the toner layer formed on the surface of the developer applying means becomes thicker at both ends than at the center,
According to experiments conducted by the present inventors, when a urethane blade is used, the toner layers at both ends are 3.5 to 7.0 μm from the center.
It turns out that it will become thicker. As described above, when the elastic blade is used, it is difficult to make the toner layer formed on the surface of the developer applying unit have a uniform thickness in the entire width direction,
Therefore, there is a problem in that it is difficult to obtain a uniform image, and the elastic blade is not always satisfactory in terms of low wear resistance and long life.

In order to solve the above problems of the elastic blade, the applicant of the present invention has proposed an invention in which the blade constituting the developer regulating means is formed of a rigid member such as glass.
-Proposed as No. 96046. By forming the blade with plate glass, the amount of developer retained on the surface of the developer applying means can be uniformly regulated in the width direction, and abrasion resistance is improved and long life is also satisfied. It became possible. However, it has been found that the precision of the supporting means for supporting the blade formed by the plate glass affects the developer amount regulation performance. That is, as a general method of supporting the plate glass, a method of adhering the plate glass to a metal supporting member can be considered. However, the plane accuracy of the adhesive surface of the support member becomes quite important, and if the adhesive surface of the support member is distorted, the plate glass is also attached along the adhesive surface of the support member, resulting in impaired flatness of the blade. Will end up. It is easy to set the flatness of the plate glass itself to, for example, 0.01 or less, but in order to process the surface of the metal supporting member with high accuracy, the processing cost increases and the cost increases.

When the developer regulating means is made of a rigid member such as glass, it is an important factor to set the hardness of the drum or roller constituting the developer applying means to an appropriate value. It became clear by experiments such as. According to experiments, the lower the hardness of the roller that constitutes the developer applying means, the thinner the toner layer formed on the surface of the roller, and the higher the hardness of the roller, the toner layer formed on the surface of the roller. Becomes thicker. Further, the thickness of the toner layer formed on the surface of the roller forming the developer applying means changes depending on the pressure contact force of the developer regulating means acting on the surface of the roller. The thicker the toner layer formed and the larger the pressure contact force, the thinner the toner layer formed on the surface of the roller. It was also found that a uniform toner layer cannot be stably obtained if the pressure contact force is too small or too large. It is also known that the image quality greatly changes depending on the thickness of the toner layer formed on the surface of the roller that constitutes the developer applying unit. When the thickness of the toner layer is, for example, 20 μm or less, the image density becomes low and it is difficult to see as a copy. Occurs. On the other hand, when the roller forming the developer applying means is formed of a synthetic rubber material, if the hardness thereof is 65 or less in Asuka C hardness, the production yield is low and it is difficult to maintain stable quality. Therefore, when setting the hardness of the roller, it is necessary to consider the practical pressure contact force of the developer regulating means which acts on the surface of the roller, the stable quality of the roller in terms of manufacturing, and the like.

The present invention has been made in view of the above facts, and its main technical problem is to provide a relatively inexpensive support capable of maintaining the surface accuracy of a blade made of a rigid member constituting a developer regulating means. It is to provide an electrostatic latent image developing device provided with the means.

Another technical problem of the present invention is that the developer regulating means is constituted by a rigid member and the hardness of the roller constituting the developer applying means is regulated to a predetermined value so that a predetermined image density can be obtained. As you can get
It is an object of the present invention to provide an electrostatic latent image developing device which has a good yield in manufacturing and can maintain stable quality.

[0009]

In order to solve the above-mentioned main technical problems, according to the present invention, a developing housing,
A developer applying means for arranging the developer on the surface in the developer holding area provided in the developing housing, and carrying the held developer to the developing area to apply the developer to the electrostatic latent image, and the developer holding means. In the electrostatic latent image developing device, a regulating means for regulating the amount of the developer held on the surface of the developer applying means in a developer regulating area located between the developing area and the developing area is provided. Is a blade made of a rigid member that is pressed against the surface of the developer applying means, a blade supporting means for movably supporting one surface of the blade in a direction of pressing against the surface of the developer applying means, and a blade of the blade. An electrostatic latent image developing device is provided, which is provided on the other surface side and has elastic biasing means for pressing one surface of the blade in a direction in which it is pressed against the surface of the developer applying means.

In order to solve the above-mentioned other technical problems, according to the present invention, a developing housing, a developer held on the surface in a developer holding region disposed in the developing housing, and the held developer. To the surface of the developer applying means in the developer regulating area located between the developer holding area and the developing area. In the electrostatic latent image developing device, the regulating means is composed of a rigid member that is brought into pressure contact with the surface of the developer applying means. Asuka C hardness is 67 to 85
An electrostatic latent image developing device is provided which is composed of a solid synthetic rubber roller.

[0011]

In the electrostatic latent image developing device of the present invention, the blade made of a rigid member that constitutes the regulating means is pressed and urged by the elastic urging means, and one surface of the blade is pressed against the surface of the developer applying means. The amount of developer retained on the surface of the developer applying unit is appropriately regulated, and a required developer layer is formed on the surface of the developer applying unit.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in more detail with reference to the accompanying drawings which show preferred embodiments of an electrostatic latent image developing device constructed according to the present invention.

FIG. 1 shows an image generator equipped with an electrostatic latent image developing device constructed according to the present invention. The illustrated image generator includes a rotary drum 1 as an image carrier having a photosensitive layer on its peripheral surface. The rotary drum 1 is rotatably mounted in a machine body housing (not shown) by a rotary shaft 2. Around the rotating drum 1 which is rotated in the direction indicated by the arrow 3, a charging corona discharger 4 for sequentially charging the photosensitive layer of the rotating drum 1 to a specific polarity in the direction of rotation, and the charging corona discharger. A laser optical section 5 as an exposing means for forming an electrostatic latent image on the photosensitive layer of the rotary drum 1 which is charged with a specific polarity by an electrostatic latent image formed by the laser beam emitted from the optical section 5. An electrostatic latent image developing device 6 for developing a toner image, a transfer corona discharger 7, a peeling corona discharger 8, a cleaning device 9, and a charge eliminating lamp 10 are provided.

The developing device 6 is provided with a developing housing 12 which can be formed of synthetic resin. Inside the developing housing 12, a developer applying means 16, a supplying means 18, a stirring means 20 and a regulating means 22 are provided. It is arranged. Further, although not shown, a toner cartridge containing toner is mounted on the developing housing 12.

The developer applying means 16 is a rotary shaft 24 rotatably mounted between both side walls of the developing housing 12.
And a roller 26 fixed to the rotating shaft 24. The rotating shaft 24 can be formed of a suitable metal material such as stainless steel. The roller 26 is made of a relatively soft and conductive material, for example, a conductive solid rubber such as urethane rubber. In the illustrated embodiment, the hardness of the roller 26 is set to about 67 to 85 in terms of Asker C hardness, and the volume resistance of the roller 26 is preferably about 10 ^{6 to} 10 ⁹ Ω · cm. The roller 26 of the developer applying means 16 is exposed through an opening formed in the developing housing 12 and faces the rotary drum 1, and its peripheral surface is pressed against the peripheral surface of the rotary drum 1 in the press contact area. The peripheral surface of the roller 26 is slightly elastically compressed. The rotary shaft 24 of the developer applying unit 16 is continuously driven to rotate in a direction indicated by an arrow 28 in FIG. 1 by a driving unit (not shown). By the above rotation of the rotary shaft 24, the roller 2
6 is also continuously driven to rotate in the direction indicated by the arrow 28, and the peripheral surface of the roller 26 has a developer holding region 30 and a developer regulating region 3
2 and the developing area 34 are sequentially conveyed.

The supply means 18 includes a rotating shaft 36 rotatably mounted between both side walls of the developing housing 12.
An auxiliary roller 38 fixed to the rotating shaft 36 is included. The auxiliary roller 38 is preferably made of foam such as foam silicon or foam urethane. The auxiliary roller 38 is pressed against the roller 26 of the developer applying unit 16. The hardness of the foam forming the auxiliary roller 38 is considerably smaller than the hardness of the roller 26 (for example, the Asker C hardness is about 35), and the auxiliary roller 38 is replaced by the roller 26.
It is desirable that the auxiliary roller 38 be elastically compressed by about 0.15 to 0.25 mm in the pressure contact region by being pressed against. This auxiliary roller 38 is continuously driven to rotate in the direction indicated by arrow 39 in FIG. The stirring means 20 includes a rotating shaft 40 rotatably mounted between both side walls of the developing housing 12, and a stirring member 4 fixed to the rotating shaft 40.
2 is included and continuously driven to rotate in a direction indicated by an arrow 44 in FIG.

Next, the regulating means 22 will be described with reference to FIG. The regulating means 22 supports a blade 46 made of a rigid member which is pressed against the peripheral surface of the roller 26 of the developer applying means 16, and one side of the blade 46 is movably supported in a direction of pressing against the peripheral surface of the roller 26. The blade support means 48 and the elastic biasing means 50 for pressing the surface of the blade 46 in the direction of pressing against the peripheral surface of the roller 26 are provided.

At least one surface (that is, the surface pressed against the peripheral surface of the roller 26) of the blade 46 made of the rigid member is along the peripheral surface of the roller 26 in the width direction (direction perpendicular to the paper surface in FIG. 1). It is composed of a plate-like member that is a flat surface that extends. The surface roughness of at least a region of the one side of the blade 46 which is pressed against the peripheral surface of the roller 26 is sufficiently small, and the center line average roughness Ra defined in JIS B 0601 is 6.00 or less, particularly 0.2.
It is preferably 0 or less, and particularly preferably 0.02 or less. If the surface roughness of the one side of the blade 46 becomes excessive, the thin layer surface of the developer formed on the peripheral surface of the roller 26 of the developer applying means 16 is not sufficiently flattened and becomes uneven. Tend to end up. Therefore, as a suitable rigid material having a sufficiently small surface roughness and high hardness and abrasion resistance even though the blade 46 can be formed at a relatively low cost, a commercially available plate glass is used. Can be mentioned. The plate glass may have a thickness of about 3 mm.
If it is desired to apply the required voltage to the blade 46 to control the charging characteristics of the toner, a conductive coating can be applied to one side of the sheet glass. As the plate glass having a conductive coating on one surface, a plate glass commercially available under the trade name "Nesa glass" can be conveniently used. Instead of the plate glass, the blade 46 may be made of a rigid member made of an appropriate metal plate such as stainless steel.
In order to sufficiently reduce the surface roughness of one surface of the metal plate that constitutes the blade 46, one surface of the metal plate may be subjected to an appropriate surface treatment, if necessary. If desired, the blade 46 may be formed of a laminated body of a plate glass and a metal plate, and one surface of the blade 46 that is brought into pressure contact with the roller 26 of the developer applying unit 16 may be defined by the exposed surface of the plate glass.

The blade supporting means 48 is the blade 4
6, a pair of lower support members 52, 52 supporting both lower ends of
And an upper support member 54 that supports the upper edge of the blade 46.
Is provided. The lower support members 52, 52 are provided with notches 520, 520 forming bottom surfaces 521, 521 and side surfaces 522, 522, respectively, and mounting holes 523, 523 that are long in the vertical direction are provided. The lower support members 52, 52 are arranged in the width direction at a predetermined interval, and the screws 5 are inserted into the mounting holes 523, 523 in the mounting portion 120 formed integrally with the developing housing 12.
It is fixed by 6,56. The lower support members 52, 52 fixed to the mounting portion 120 have cutout portions 520 and 52.
The distance between the side surfaces 522 and 522 forming 0 is the blade 4
The bottom surfaces 521 and 52 that are attached so as to have substantially the same length as the widthwise dimension of 6 and form the cutouts 520 and 520.
The lower end surfaces of both ends of the blade 46 are placed and supported on the blade 1. The upper support member 54 is disposed above the lower support members 52, 52 with a predetermined space therebetween, and the developing housing 1
It is fixed to the second mounting portion 120 by a plurality of screws 58. The upper support member 54 has substantially the same length as the widthwise dimension of the blade 46 and has a fitting groove 540 slightly wider than the plate thickness of the blade 46. The upper edge of the blade 46 is fitted in the fitting groove 540. Fit the parts. The fitting groove 540
As shown in FIG. 1, a plurality of recesses 541 are formed on the bottom surface of the compression coil spring 6 in the longitudinal direction.
0 are arranged respectively, and the compression coil spring 60 is fitted in the fitting groove 54.
It acts on the upper end surface of the blade 46 fitted to 0 and urges it downward.

The elastic biasing means 50 is used for the blade 4
A plurality of (three in the illustrated embodiment) compression coil springs 60 are provided between the lower support members 52, 52 and the upper support member 54 on the other surface side of the reference numeral 6. The compression coil springs 62 are formed in the mounting portion 120 of the developing housing 12 so as to face the other surface of the blade 46 and have through holes 121 formed at predetermined intervals in the width direction.
(3 in the illustrated embodiment).
A closing plate 64 that closes one side of the through hole 121 is attached to the back surface of the attaching portion 120 with screws 66. By attaching the closing plate 64, the compression coil spring 62 acts on the other surface of the blade 46, and one surface of the blade 46 constitutes the developer applying means 16 for the roller 2.
It is pressed against the peripheral surface of 6.

The pressing force of the blade 46 against the peripheral surface of the roller 26 of the developer applying means 16 can be appropriately set according to the thickness of the developer layer to be formed on the peripheral surface of the roller 26. When the pressure contact force increases, the thickness of the developer layer formed on the peripheral surface of the roller 26 decreases. On the other hand,
When the pressure contact force becomes excessively large, smooth rotation of the roller 26 tends to be impeded. In the developing mode in the illustrated embodiment, the thickness of the developer layer formed on the peripheral surface of the roller 26 is usually 15 to 40 μm, particularly 20 μm.
It is preferably about 2 to 27 μm. In order to properly form the developer layer having such a thickness, the blade 46 is pressed against the circumferential surface of the roller 26 at a linear pressure (pressure per unit length in the width direction) of 10 to 90 g / cm. It suffices to set it to 40 to 90 g / cm in the illustrated embodiment.

It is desirable that the lower end of the blade 46 is projected to some extent upstream of the pressure contact portion between the roller 26 and the blade 46, as viewed in the moving direction of the roller 26. The protruding length of the lower end portion of the blade 46 (that is, the length from the contact center between the roller 26 and the blade 46 to the lower end of the blade 46) is generally 0.5 to 4.0 mm,
Especially 0.8 to 3.5 mm, especially 1.0 to 2.0 mm
It is preferred that If the protruding length is excessively short and becomes substantially zero, the restricting action of the blade 46 becomes excessive and it tends to be difficult to form a good developer layer, and if the protruding length becomes excessively long. The thickness of the formed developer layer tends to be too large, and the charge amount of the toner tends to be too small. As described above, the positional relationship between the lower end of the blade 46 and the roller 26 needs to maintain high accuracy. In the illustrated embodiment, the blade 4 is
The lower end surface of 6 is placed on the bottom surfaces 521 and 521 of the cutouts 520 and 520 provided in the lower support members 52 and 52, so that the blade 46 is pressed against the roller 26 of the developer applying means 16. Since the dimension control of the amount of protrusion from the position is performed, the assembling workability is dramatically improved. Moreover, in the illustrated embodiment, the lower support members 52, 52 constituting the blade support means 48 are adjustable along the mounting holes 523, 523 that are long in the vertical direction, and the amount of protrusion of the blade is adjusted. can do.

The electrostatic latent image developing device according to the illustrated embodiment is constructed as described above, and its operation will be described below.
When the operation of the electrostatic latent image developing device is started, the roller 26 of the developer applying unit 16, the auxiliary roller 38 of the supplying unit 18, and the stirring unit 20 are rotationally driven in the directions indicated by the arrows by a driving unit (not shown). Developer applying means 16
Roller 26 is continuously driven to rotate in the direction shown by the arrow 28, and in the developer holding area 30, the supplying means 18 acts on the roller 26, and the developer held on the peripheral surface of the roller 26 until then is rolled. The developer is supplied to the peripheral surface of the roller 26 while being separated from the roller 26. In the developer regulation area 32, the blade 46 of the regulation means 22 acts on the developer retained on the peripheral surface of the roller 26 to regulate the developer retained on the peripheral surface of the roller 26 to a required amount. Form a thin layer. Further, by the action of the blade 46, the toner constituting the developer is frictionally charged to have a predetermined polarity, for example, a positive polarity. In the developer regulating action of the blade 46, the blade 46 is pressed and biased by the plurality of compression coil springs 62 arranged in the width direction, so that a uniform pressure contact force is exerted over the entire width direction. be able to. Further, the blade 46 is movable by the lower side supporting members 52, 52 and the upper side supporting member 54 constituting the blade supporting means 48 in a direction of being pressed against the peripheral surface of the roller 26 of the developer applying means 16 without being fixed. Since it is supported, its surface accuracy is not affected by the surface accuracy of the support member,
It is not necessary to process the supporting member with higher precision than necessary. Next, in the developing area 34, a developer is applied to the electrostatic latent image on the electrostatic photoconductor disposed on the peripheral surface of the rotary drum 1 to develop the electrostatic latent image into a toner image. . For example, an electrostatic latent image has a non-image area charged to about +700 V and a +
The image area is charged to about 120 V, and toner is attached to the image area (so-called reversal development).
The rotary drum 1 is continuously driven to rotate in the direction indicated by the arrow 3 in FIG. 1, so that in the developing zone 34, the peripheral surface of the rotary drum 1 and the peripheral surface of the roller 26 of the developer applying means 16 move in the same direction. Be punished. The moving speed V2 of the peripheral surface of the roller 26 is the moving speed V1 of the peripheral surface of the rotating drum 1.
Is set to be slightly larger than 1.5V1 ≦ V2 ≦
It is preferably 2.2V1. In this case, a sufficient amount of the developer is conveyed to the developing area 34 by the roller 26, and the peripheral surface of the roller 26 is rubbed against the peripheral surface of the rotating drum 1 to once adhere to the non-image portion of the electrostatic latent image. The formed toner is appropriately peeled off, and thus a good toner image having an appropriate development density and no fog can be obtained. As the developer, a volume average particle diameter (Vol.
%: Toner having a volume average particle size or less and a toner having a volume average particle size or more are the same) having a volume resistance of about 8.0 to 12.0 μm and a volume resistance of 10 ⁸ Ω · cm or more Agents are preferably used.

Next, the setting of the hardness of the roller 26 constituting the developer applying means 16 will be described. In FIG. 3, the roller 26 constituting the developer applying means 16 is formed of urethane rubber having various hardnesses, and the pressure contact force of the blade 46 acting on the peripheral surface of the roller 26 is changed to form the roller 26 on the peripheral surface of the roller 26. The thickness of the toner layer is measured. A glass blade was used as the blade 46. In FIG. 3, the solid line shows the linear pressure of the glass blade (pressure per unit length in the width direction) acting on the peripheral surface of the roller constituting the developer applying means of 40 g / cm, and the broken line shows the linear pressure of the glass blade of 60 g / cm. cm, the one-dot chain line is the value when the linear pressure of the glass blade is 80 g / cm, and the two-dot chain line is the value when the linear pressure of the glass blade is 90 g / cm. As can be seen from FIG. 3, the lower the hardness of the roller, the thinner the thickness of the toner layer formed on the surface of the roller, and the higher the hardness of the roller, the greater the thickness of the toner layer formed on the surface of the roller. Become. Further, the smaller the linear pressure of the glass blade acting on the peripheral surface of the roller constituting the developer applying means, the thicker the toner layer formed on the surface of the roller, and the larger the linear pressure, the more the toner layer formed on the surface of the roller. The thickness of the toner layer is reduced. As described above, when the thickness of the toner layer formed on the surface of the roller that constitutes the developer applying unit is, for example, 20 μm or less, the image density becomes low and it is difficult to see as a copy.
When the thin toner layer has a thickness of, for example, 30 μm or more, so-called image-based fog occurs in which toner adheres to a portion other than the image. Therefore, when setting the hardness of the roller that constitutes the developer applying means, the thickness of the toner layer formed on the surface of the roller is set in consideration of the variation in the setting conditions (projection length, pressing force) of the blade. It is desirable that the value is within the range of 20 to 27 μm. With reference to FIG. 3, the upper limit of the roller hardness that constitutes the developer applying means will be examined. When the linear pressure of the blade is 90 g / cm, the roller hardness is 85 asker C hardness, and the upper limit value is It can be seen that a certain toner layer of 27 μm can be obtained. Therefore, if the hardness of the roller becomes greater than 85 in Asker C hardness,
The thickness of the toner layer cannot be reduced to 27 μm or less unless the linear pressure of the blade is greater than 90 g / cm. It was also found that the pressure contact force of the blade becomes excessively large, and when the linear pressure of the blade exceeds 100 g / cm, the layer thickness of the toner layer formed on the surface of the roller becomes unstable. Further, if the linear pressure of the blade is increased, the rotational load of the roller is increased, so that the driving force must be increased. In order to increase the driving force of the roller, it is necessary to increase the capacity of the electric motor, which is the driving source, and the strength of the power transmission mechanism must be increased accordingly. Also needs to be reinforced. Therefore, in an image generator equipped with this type of developing device,
Considering the image quality, the strength of each member, and the manufacturing cost, the linear pressure of the blade is practically the upper limit of about 90 g / cm. From such a point, it is desirable that the upper limit of the roller hardness is set to about 85 as the Asker C hardness that can obtain a toner layer of 27 μm which is the upper limit when the linear pressure of the blade is 90 g / cm. On the other hand, when the roller forming the developer applying means is formed of a synthetic rubber material, if the hardness thereof is 65 or less in Asuka C hardness, the production yield is low and it is difficult to maintain stable quality. Then, in consideration of variations in manufacturing, it is desirable that the lower limit of the roller hardness is set to about 67 as Asker C hardness.

[0025]

The electrostatic latent image developing device of the present invention is composed of a rigid member for pressing the regulating means for regulating the amount of the developer held on the surface of the developer applying means against the surface of the developer applying means. A blade, a blade supporting means for movably supporting one surface of the blade in a direction in which the one surface of the blade is pressed against the surface of the developer applying means, and one surface of the blade disposed on the other surface side of the blade is the developer applying means. Since it is constituted by elastic biasing means for pressing in the direction of pressing against the surface of the blade, since the blade is supported so as to be movable in the direction of pressing against the peripheral surface of the developer applying means without being fixed to the blade supporting means, Since the surface accuracy is not affected by the surface accuracy of the supporting member, it is not necessary to process the supporting member with higher precision than necessary. Therefore, it is possible to obtain an electrostatic latent image developing device equipped with a relatively inexpensive supporting means. Further, since the blade is made of a rigid member, the amount of displacement in the width direction when the developer is regulated is extremely small, so that it is possible to form a uniform toner layer in the entire width direction and obtain a stable image. You can

Further, according to the present invention, since the blade made of a rigid member is made of sheet glass, it is possible to manufacture a blade having a sufficiently small surface roughness at a relatively low cost, and it has high hardness and abrasion resistance. Since it has abrasion resistance, a stable image can be obtained over a long period of time.

Further, according to the present invention, the blade supporting means includes a lower supporting member for mounting and supporting a lower end surface of the blade, an upper supporting member for supporting an upper edge portion of the blade, and an upper supporting member. Since it is composed of an elastic biasing member that is arranged between the upper end surface of the blade and presses the blade downward, by applying the lower end surface of the blade on the lower support member, the developer of the blade is applied. Since the size control of the amount of protrusion from the pressure contact position with the means is performed, the working effect such as the assembly workability is dramatically improved.

Further, according to the present invention, the elastic urging means arranged on the other surface side of the blade for pressing one surface of the blade in a direction in which the one surface of the blade is pressed against the surface of the developer applying means is provided in the width direction of the blade. Since the plurality of spring members arranged at intervals are provided, the pressing force of the blade to the developer applying means becomes uniform in the entire width direction, so that a uniform toner layer can be formed. , A stable image can be obtained.

In another aspect of the invention, the regulating means comprises a rigid member which is pressed against the surface of the developer applying means, and the developer applying means is a solid synthetic rubber roller having an Asuka C hardness of 67 to 85. Electrostatic latent image development that can maintain a stable quality with a good yield without increasing the manufacturing cost, while being able to obtain a toner layer thickness that provides a predetermined image density. A device can be provided.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an image generator equipped with an electrostatic latent image developing device configured according to the present invention.

FIG. 2 is a perspective view of a regulating unit that constitutes the electrostatic latent image developing device shown in FIG.

FIG. 3 is a diagram showing the relationship between the hardness of a roller forming the developer applying unit and the thickness of a toner layer formed on the peripheral surface of the roller.

[Explanation of symbols]

 1: Rotating drum 4: Corona discharge device for charging 5: Laser optical part 6: Electrostatic latent image developing device 7: Corona discharge device for transfer 8: Corona discharge device for peeling 9: Cleaning device 10: Static elimination lamp 16: Developer Application means 18: Supply means 20: Stirring means 22: Regulation means 26: Roller of developer application means 30: Developer holding area 32: Developer regulation area 34: Development area 38: Auxiliary roller of supply means 46: Blade 48: Blade support means 50: Elastic biasing means 52: Lower support member 54: Upper support member 60: Compression coil spring 62: Compression coil spring

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Masayuki Nakajima, 1-2-2 Tamatsukuri, Chuo-ku, Osaka City Mita Industrial Co., Ltd. (72) Kenichiro Kitajima 1-2-2 Tamatsukuri, Chuo-ku, Osaka City Mita Within Kogyo Co., Ltd.

Claims (7)

[Claims] 1. A developing housing, and a developer for holding a developer on a surface in a developer holding area provided in the developing housing and conveying the held developer to the developing area to apply it to an electrostatic latent image. Electrostatic comprising a developer applying means and a restricting means for restricting the amount of the developer held on the surface of the developer applying means in a developer controlling area located between the developer holding area and the developing area. In the latent image developing device, the regulating means supports a blade made of a rigid member that is brought into pressure contact with the surface of the developer applying means, and one side of the blade is supported so as to be movable in a direction of being brought into pressure contact with the surface of the developer applying means. And an elastic biasing means that is disposed on the other surface side of the blade and presses one surface of the blade in a direction in which the one surface of the blade is pressed against the surface of the developer applying means. Latent image developing device. 2. The electrostatic latent image developing device according to claim 1, wherein the blade made of the rigid member is made of plate glass. 3. The blade supporting means comprises a lower support member for placing and supporting a lower end surface of the blade, an upper support member for supporting an upper edge portion of the blade, an upper support member and an upper portion of the blade. The electrostatic latent image developing device according to claim 1, further comprising: an elastic biasing member that is disposed between the end surface and the blade and presses the blade downward. 4. The electrostatic latent image developing device according to claim 1, wherein the lower support member is configured to be vertically movable. 5. The electrostatic latent image developing device according to claim 1, wherein the lower support member comprises a pair of support members that respectively mount and support lower surfaces of both ends of the blade. 6. The elastic biasing means comprises a plurality of spring members arranged at intervals in the width direction of the blade.
The electrostatic latent image developing device according to claim 1. 7. A developing housing, and a developer for holding the developer on the surface in a developer holding area provided in the developing housing and conveying the held developer to the developing area to apply it to the electrostatic latent image. Electrostatic comprising a developer applying means and a restricting means for restricting the amount of the developer held on the surface of the developer applying means in a developer controlling area located between the developer holding area and the developing area. In the latent image developing device, the regulating means is composed of a rigid member pressed against the surface of the developer applying means, and the developer applying means is composed of a solid synthetic rubber roller having an Asuka C hardness of 67 to 85. The electrostatic latent image developing device is characterized by the following.