JPH0943975A - Electrostatic latent image developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a developing roller from being damaged by a blade, by adapting a developing restricting means so that, when it is assembled, pressing force by a compression spring may act on the blade after the assembly is done. SOLUTION: A restricting means 22 is equipped with a supporting holder 46, a blade 48 comprizing a rigid member which is supported by the supporting holder 46 and one side face of which is brought into press contact with a surface of a developing roller 16, an elastically energizing means 52 which is disposed in the supporting holder 46 and presses against the one side face of the blade 48 toward the direction that makes press contact with the surface of the developing roller 16, and a pressure releasing means 54 which acts on the elastically energizing means 52 so as to release pressing force of the elastically energizing means acting on the other side face of the blade 48. The restricting means 22 is assembled in a state that the pressing force acting on the other side face of the blade 48 is released. Therefore a circumferential surface of the developing roller 16 is not damaged by the blade 48 when they are built into a development housing. Furthermore, perforating and stoppage plates becoming unnecessary, manufacturing costs can be reduced.

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 apparatus 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, and more specifically, An electrostatic device having a developing roller that holds the developer on the surface and conveys it to the developing area, and a regulating member that includes a rigid member that acts on the surface of the developing roller and regulates the amount of the developer retained on the surface. The present invention relates to a latent image developing device.

[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 generator, an electrostatic latent image developing device having a developing roller that is rotationally driven in a predetermined direction is widely used. Have been served. When the developing roller is driven to rotate in a predetermined direction, the developer holding area, the developer amount regulating area, and the developing area can be sequentially moved. In the developer holding region, toner as a developer supplied by an appropriate mode is held on the surface of the developing roller. In the developer amount regulation area, the regulation means acts on the toner as the developer retained on the surface of the developing roller to regulate the toner retained on the surface of the developing roller to a required amount. In the developing area, toner as a developer is applied to the surface of an electrostatic latent image bearing member such as a rotating drum having an electrophotographic photosensitive layer on the peripheral surface to form a toner on the surface of the electrostatic latent image bearing member. The electrostatic latent image is developed into a toner image. In order to achieve good development, the amount of toner retained on the surface of the developing roller is appropriately regulated by the regulating means so that the toner layer retained on the surface of the developing roller has a predetermined thickness and an axial direction. It is important to form the film sufficiently uniformly.

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 surface or the leading edge thereof pressed against the surface of the developing roller to regulate the amount of toner held on the surface of the developing roller to a considerably small amount, and the toner on the surface of the developing roller. To form a thin layer of. 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. However, in the developer regulating means using an elastic blade such as a rubber elastic body or a stainless thin plate, both ends of the elastic blade are low in rigidity and inferior in regulation force to the central portion, so that they are formed on the surface of the developing roller. The toner layer at both ends is thicker at both ends than the center portion. According to the experiments by the present inventors, when the urethane blade is used, the toner layer at both ends is 3.5 times thicker than the center portion.
It was found that the thickness was about 7.0 μm. As described above, when the elastic blade is used, it is difficult to form the toner layer formed on the surface of the developing roller to have a uniform thickness in the entire axial direction, and thus it is difficult to obtain a uniform image. In addition, the elastic blade has low wear resistance and is not always satisfactory in terms of prolonging its service 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. 36277. By forming the blade from plate glass, the layer thickness of the toner layer formed on the surface of the developing roller can be uniformly controlled in the width direction, and abrasion resistance is also improved, which is also satisfactory in terms of long life. 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 flat glass is also attached along the adhesive surface of the support member, resulting in impaired flatness of the blade. . 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.

Therefore, the applicant of the present invention has arranged a blade made of a rigid member, a blade supporting means for movably supporting one surface of the blade in a direction of being pressed against the surface of the developing roller, and the other surface of the blade. Patent application 7:
-160227.

[0006]

When assembling the developer regulating means, if the blade is set in a predetermined positional relationship with respect to the developing roller after the compression spring is assembled, the compression spring is compressed by the blade. However, the developing roller must be set while causing the blade to be damaged. To solve such problems,
After setting the blade in a predetermined positional relationship with respect to the developing roller, it is necessary to install a compression spring as an elastic biasing means. For this purpose, it is necessary to provide a mounting plate that supports the compression spring with a hole for inserting a spring, insert the compression spring through the hole, and then attach a closing plate that closes the hole. However, the accuracy of the pressing force of the compression spring is reduced due to the above-mentioned closing plate and its mounting accuracy, the machining cost is increased by processing the hole provided in the mounting plate, and the mounting plate provided with the hole is deformed due to the decrease in strength. There are problems such as occurrence.

The present invention has been made in view of the above facts, and its main technical problem is that the pressing force of the compression spring does not act on the blade when the developer regulating means is assembled, and the compression spring is attached to the blade after the assembly. It is an object of the present invention to provide an electrostatic latent image developing device capable of eliminating the above-mentioned inconvenience by being configured so that the pressing force by the action acts.

[0008]

In order to solve the above-mentioned main technical problems, according to the present invention, a developing housing,
A developing roller for holding the developer on the surface in the developer holding area and conveying the held developer to the developing area and applying it to the electrostatic latent image; and the developer holding area. In an electrostatic latent image developing device, the electrostatic latent image developing device is provided with a regulating means that acts on a surface of the developing roller in a developer regulating area located between the developing area and the developer and is retained on the surface. The means includes a support holder, a blade made of a rigid member supported by the support holder and one surface of which is pressed against the surface of the developing roller, and a blade disposed in the support holder with one surface of the blade being the surface of the developing roller. An elastic urging means for pressing in the direction of pressure contact and a pressure releasing means for releasing the pressing force of the elastic urging member acting on the elastic urging means and acting on the other surface of the blade. Electrostatic latent image developing device That.

Further, according to the present invention, the elastic urging means forms a guide support portion having a length corresponding to the length of the support holder in the width direction, and a predetermined interval in the width direction of the guide support portion. A pressing member including a plurality of fitting portions that are placed and project forward and a pressing portion that closes the front ends of the plurality of fitting portions, and one end portion is fitted to the fitting portion of the pressing member. Provided is an electrostatic latent image developing device configured by a combined elastic biasing member.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an electrostatic latent image developing device constituted according to the present invention will be described below in more detail with reference to the accompanying drawings.

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 device 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 light emitted from the optical device 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 made of synthetic resin. Inside the developing housing 12, a developing roller 16, a supplying means 18, an agitating means 20 and a regulating means 22 are arranged. It is set up. Further, although not shown, a toner cartridge containing toner is mounted on the developing housing 12.

The developing roller 16 is the developing housing 1 described above.
It includes a rotary shaft 24 rotatably mounted between the two side walls and a roller 26 fixed to the rotary 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. The roller 26 has an Asker C hardness of 60 to 85 in the illustrated embodiment.
The volume resistance of the roller 26 is set to about 10 ^{6 to} 10 ⁹ Ω · cm. The roller 26 of the developing roller 16 configured as described above is exposed through an opening formed in the developing housing 12 and is positioned to face the rotary drum 1. The peripheral surface of the roller 26 that constitutes the developing roller 16 is
It is pressed against the peripheral surface of the rotary drum 1, and the peripheral surface of the roller 26 is slightly elastically compressed in the pressed region. The rotating shaft 24 of the developing roller 16 is continuously driven to rotate in a direction indicated by an arrow 28 in FIG. By the above rotation of the rotary shaft 24, the roller 26 is also continuously driven to rotate in the direction indicated by the arrow 28, and the peripheral surface of the roller 26 is sequentially conveyed through the developer holding area 30, the developer regulating area 32 and the developing area 34. It

The supply means 18 includes a rotary 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 made of a foam material such as foam silicon or foam urethane. The auxiliary roller 38 is pressed against the roller 26 of the developing roller 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 pressed against the roller 26, so that the auxiliary roller 38 becomes 0 It is desirable to be elastically compressed by about 0.15 to 0.25 mm. This auxiliary roller 38 is continuously driven to rotate in the direction indicated by arrow 39 in FIG. The stirring means 20 is the developing housing 12
1 includes a rotating shaft 40 rotatably mounted between both side walls (not shown) and an agitating member 42 fixed to the rotating shaft 40.
It is driven to rotate continuously in the direction indicated by 4.

Next, the regulating means 22 will be described with reference to FIGS. 2 and 3. The restricting means 22 includes a support holder 46, a blade 48 made of a rigid member supported by the support holder 46 and pressed against the peripheral surface of the roller 26 of the developing roller 16, a support member 50 for the blade 48, and the blade 48. An elastic urging means 52 for pressing one surface of the roller 48 in a direction of being pressed against the peripheral surface of the roller 26, and a pressure releasing means 54 for releasing the pressing force acting on the elastic urging means 52 and acting on the other surface of the blade 48. It has and.

The support holder 46 is formed by extruding an aluminum alloy, for example. The support holder 46 has a length in the width direction corresponding to both side walls of the developing housing 12, and is provided with a support recess 461a that fits the upper end of the support member 50 and abuts the upper end thereof. It comprises a wall 461, a lower wall 462 having a support portion 462a that supports the lower end of the blade 48, and an intermediate wall 463 that connects the upper wall 461 and the lower wall 462.
A guide rail 46 is formed at an intermediate portion of the upper wall 461 and the lower wall 462 so as to project inward at a position facing each other.
1b and 462b are provided. Further, screw holes 461c and 462c are formed at both ends of the upper wall 461 and the lower wall 462 which form the support holder 46, and the support holder 46 thus configured has both sides of the developing housing 12. Tightening bolts (not shown) which are arranged between the walls at predetermined positions shown in the figure and which are fitted through both side walls of the developing housing 12 are fitted to the developing housing 12 by being screwed into the screw holes 461c and 462c. It

At least one surface (that is, the surface pressed against the peripheral surface of the roller 26) of the blade 48 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 the region of one side of the blade 48 which is pressed against the peripheral surface of the roller 26 is sufficiently small, and the center line average roughness Ra defined by 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 surface of the blade 48 becomes excessively large, the surface of the toner layer formed on the peripheral surface of the roller 26 constituting the developing roller 16 is not sufficiently flattened and tends to be uneven. There is. Therefore, as a suitable rigid material having a sufficiently small surface roughness and high hardness and abrasion resistance even though the blade 48 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. The blade 4 is used to control the charging characteristics of the toner.
If it is desired to apply the required voltage to No. 8, 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 48 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 side of the metal plate constituting the blade 48, one side of the metal plate can be subjected to an appropriate surface treatment, if necessary. If desired, the blade 48 may be formed of a laminated body of plate glass and a metal plate, and one surface of the developing roller 16 that is pressed against the roller 26 may be defined by the exposed surface of the plate glass. The blade 48 thus configured has a lower end that supports the support portion 46 of the lower wall 462 that constitutes the support holder 46.
The roller 26 is placed on the roller a and one side thereof is brought into contact with the peripheral surface of the roller 26.

The support member 50 is formed of a thin steel plate in the illustrated embodiment. The supporting member 50 has a length substantially corresponding to the widthwise length of the blade 48, and is fixed to the upper end of one side of the blade 48 by a fixing means such as an adhesive. When it is desired to apply a required voltage to the blade 48 in order to control the charging characteristics of the toner, a conductive adhesive is used as the fixing means so that the blade 48 can be applied to the blade 48 via the supporting member 50. A voltage can be applied. In this way, the support member 5 fixed to the upper end of one side of the blade 48
0 is projected from the upper end of the blade 48, the upper end of which is fitted into the support recess 491a formed in the upper wall 461 of the support holder 46, and the upper end thereof is the upper surface 491d.
It comes into contact with. As described above, since the support member 50 shown in FIGS. 1 and 2 is made of the thin steel plate, the area of the upper end surface thereof is extremely small. Therefore, the support recess 461a formed in the upper wall 461 of the support holder 46 is formed. Since it comes into contact with the upper surface 461d in a substantially line contact manner, the frictional force due to the contact with the support holder 49 can be reduced.

The elastic biasing means 52 has a pressing member 521 that abuts against the other surface of the blade 48, and an elastic biasing member that presses one surface of the blade 48 in a direction of pressing the peripheral surface of the roller 26 through the pressing member 521. A plurality of compression coil springs 522 are provided as a biasing member. Pressing member 5
21 is a guide support portion 521a and a spring fitting portion 521b.
And a pressing portion 521c, which are integrally formed of, for example, a synthetic resin material. The guide support portion 521 a that constitutes the pressing member 521 has a length corresponding to the widthwise length of the support holder 46 and the blade 48, and the height dimension thereof is the upper wall 46 that constitutes the support holder 46.
1 and the guide rails 461b and 462b provided on the lower wall 462 are larger than the distance between the inner ends thereof. The spring fitting portions 521b are formed so as to project to the front side at predetermined intervals in the width direction of the guide support portion 521a, and eight spring fitting portions 521b are provided in the illustrated embodiment. The height of the spring fitting portion 521b in the height direction is smaller than the distance between the inner ends of the guide rails 461b and 462b provided on the upper wall 461 and the lower wall 462 of the support holder 46. The pressing portion 521c is the spring fitting portion 521b.
Formed by closing the front end of the blade 4
8 functions as a pressing surface that abuts the other surface. The plurality of (eight in the illustrated embodiment) compression coil springs 5
22 has one end fitted to the spring fitting portion 521b of the pressing member 521 and the other end abutted against the front surface of the intermediate wall 463 forming the holder 46. The pressure contact force of the blade 48 against the peripheral surface of the roller 26 of the developing roller 16 can be appropriately set according to the thickness of the toner 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, if 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 toner layer formed on the peripheral surface of the roller 26 is usually about 20 to 30 μm, and in order to properly form the developer layer having such a thickness. The elastic biasing means 52 may be set to a value that presses the blade 48 against the circumferential surface of the roller 26 at a linear pressure (pressure per unit length in the width direction) of 30 to 90 g / cm. .

When the roller 26 is rotated in the direction indicated by the arrow 28 with one side of the blade 46 pressed against the peripheral surface of the roller 26 of the developing roller 16 by the elastic biasing means 50 as described above, the blade 48 is rotated by The upper end of the support member 50 mounted on the upper end of the blade 48 is pressed against the upper surface 461c of the support recess 461a formed in the upper wall 461 of the support holder 46 by being pressed by the force (F) in the arrow direction by the frictional force. Be touched. In this way, the support member 50
In a state where the upper end of the blade 48 is brought into contact with the support holder 46, the lower end portion of the blade 48 exceeds the pressure contact portion between the roller 26 and the blade 48, and protrudes somewhat to the upstream side when viewed in the moving direction of the roller 26. It is desirable that they are strict. The protruding length of the lower end of the blade 48 (that is, the length from the contact center between the roller 26 and the blade 48 to the lower end of the blade 48) 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 protrusion length is excessively short and becomes substantially zero, the regulating action of the blade 48 becomes excessive and it tends to be difficult to form a good developer layer, and if the protrusion 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.

The pressure releasing means 54 will be described. The pressure releasing means 54 is provided with three stopper pins 541 in the illustrated embodiment. When the regulating means 22 is assembled, the three stopper pins 541 have three holes formed between the guide rail 461b and the intermediate wall 463 in the upper wall 461 which constitutes the support holder 46 as shown in FIG. 461e respectively inserted into the pressing member 5
The pressing force of the elastic biasing means 52 that acts on the other surface of the blade 48 by acting on the front surface of the guide support portion 521a that constitutes the blade 21 is released. Then, after the regulating means 22 is assembled to a predetermined portion of the developing device 6, the above three stopper pins 54 are provided.
1 is pulled out from the hole 461e, the pressing force of the elastic biasing means 52 is increased by the blade 4 as shown in FIG.
It is supposed to be able to act on the other side of 8.

Next, a procedure for assembling the regulating means 22 and assembling the regulating means 22 to the developing housing 12 will be described. In assembling the regulating means 22, first, the compression coil spring 5 is attached to the spring fitting portion 521b of the pressing member 521.
One end of 22 is fitted, and the compression coil spring 522 is compressed and inserted from one end of the support holder 46 toward the other end of the holder 46. At this time, the spring fitting portion 521b is positioned between the guide rails 461b and 462b, and the guide supporting portion 52 is
1a to the intermediate wall 463 and the guide rails 461b and 4
The elastic biasing means 52 can be inserted into a predetermined position of the support holder 46 by positioning between the 62b. In this way, when the elastic biasing means 52 is attached to the support holder 46, the front end of the spring fitting portion 521b positioned corresponding to the hole 461e formed in the upper wall 461 forming the support holder 46. The pressing portion 521c that closes the intermediate wall 4 against the force of the compression coil spring 522.
63 side, and along with this, the guide support portion 521a causes the hole 46
The hole 4 is moved from 1e toward the intermediate wall 463 side.
By inserting the stopper pin 541 into 61e,
The stopper pin 541 acts on the front surface of the guide support portion 521a constituting the pressing member 521 to regulate the forward movement of the pressing member 521, and the pressing force of the elastic biasing means 52 acting on the other surface of the blade 48. To cancel. With the pressing force of the elastic biasing means 52 being released, the supporting member 5
The upper end of the support holder 46 is fitted into the support recess 491a formed in the upper wall 461 of the support holder 46, and the blade 48 is placed on the support portion 462a of the lower wall 462 of the support holder 46. In this way, the regulating means 22 assembled in a state where the pressing force acting on the other surface of the blade 48 is released is disposed between the both side walls of the developing housing 12 at the predetermined position shown in FIG. The developing housing 12 is mounted by screwing fastening bolts (not shown) which penetrate through both side walls of the screw 12 into screw holes 461c and 462c formed in the holder 46. When the regulating means 22 is mounted at a predetermined position of the developing housing 12, the stopper pin 541 is attached to the hole 461e.
When the pressing member 521 is removed from the pressing member 521, the pressing member 521 is allowed to move forward, and the pressing portion 521 is pressed by the compression coil spring 522.
c is pressed against the other surface of the blade 48. As described above, since the regulating means 22 according to the illustrated embodiment is assembled in a state in which the pressing force acting on the other surface of the blade 48 is released, the blade 48 of the developing roller 16 is assembled by the blade 48 when assembled to the developing housing 12. It does not damage the peripheral surface. Further, according to the illustrated embodiment, the compression coil spring 522 that constitutes the elastic biasing means 52.
It is not necessary to provide a hole for inserting the compression coil spring in the support holder 46 in order to mount it, and it is not necessary to install a closing plate for closing this hole after inserting the compression coil spring. For this reason, it is possible to reduce the manufacturing cost because holes are not required and a closing plate is not required, and the accuracy of the pressing force by the compression coil spring does not decrease due to the closing plate and its mounting accuracy. In addition, according to the illustrated embodiment, the pressing member 521 includes a plurality of spring fitting portions 521b that are formed to project to the front side at predetermined intervals in the width direction of the guide support portion 521a. Since one end portion of the compression coil spring 522 as an elastic biasing member is fitted to the 521b, the compression coil spring 522 is reliably positioned, and the elastic biasing means 52 is attached to the support holder 46. Easy to put on.

The electrostatic latent image developing device according to the embodiment shown in FIGS. 1 to 3 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 developing roller 16, the auxiliary roller 38 of the supply means 18, and the stirring means 20 are rotationally driven in the directions indicated by arrows by driving means not shown. The roller 26 of the developing roller 16 is continuously driven to rotate in the direction indicated by the arrow 28, and the supplying means 18 is provided in the developer holding area 30.
Acts on the roller 26 to separate the toner held on the peripheral surface of the roller 26 until then from the roller 26, and the toner is newly supplied to the peripheral surface of the roller 26. In the developer regulation area 32, the blade 48 of the regulation means 22 acts on the developer retained on the peripheral surface of the roller 26 to regulate the toner retained on the peripheral surface of the roller 26 to a required amount and reduce the amount of toner. Form in layers. The roller 2
In order to make the thickness of the toner layer formed on the peripheral surface of No. 6 a predetermined amount, it is important that the pressing force of the blade 48 against the peripheral surface of the roller 26 by the elastic biasing means 52 is stable. However, in the illustrated embodiment, the roller 26 is pressed with one side of the blade 48 pressed against the peripheral surface of the roller 26 of the developing roller 16 by the elastic biasing means 52.
The blade 48 is pressed by the force (F) in the direction of the arrow by the frictional force caused by the rotation of the blade in the direction indicated by the arrow 28, and the upper end of the support member 50 mounted on the upper end of the blade 48 is the upper wall of the holder 46. Support recess 461a formed in 461
The support member 5 is abutted against the upper surface 461c of the
Since 0 abuts on the roller 48 of the blade 48 by the elastic urging means 52, the frictional force is small because the 0 abuts in a substantially line contact manner.
The pressure contact force to the peripheral surface can be stabilized. Therefore,
The thickness of the toner layer formed on the peripheral surface of the roller 26 can be made uniform. 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, the electrostatic latent image has a non-image area charged to about + 700V and an image area charged to about + 120V, and toner is attached to the image area (so-called reversal development). The rotary drum 1 is continuously driven to rotate in a direction indicated by an arrow 3 in FIG.
4, the peripheral surface of the rotary drum 1 and the peripheral surface of the roller 26 of the developing roller 16 are moved in the same direction. The moving speed V2 of the peripheral surface of the roller 26 is set to be slightly higher than the moving speed V1 of the peripheral surface of the rotating drum 1.
It is preferable that 1.2V1 ≦ V2 ≦ 2.2V1.
In this case, sufficient toner is conveyed to the developing area 34 by the roller 26, and the toner is once attached to the non-image portion of the electrostatic latent image by the sliding action of the peripheral surface of the roller 26 against the peripheral surface of the rotary drum 1. The toner is properly peeled off, and thus a good toner image having an appropriate development density and no fog can be obtained. As the developer, the volume average particle size (Vol. 50%: the toner having the volume average particle size or less and the toner having the volume average particle size or more have the same volume) is 8.
0 to 12.0 μm and volume resistance of 10 ⁸ Ω · c
A developer consisting of only toner having a size of m or more is preferably used.

[0024]

In the electrostatic latent image developing device according to the present invention, the regulating means that acts on the surface of the developing roller and regulates the amount of developer retained on the surface is the supporting holder, the supporting holder, and the supporting holder. A blade made of a rigid member that is supported by the one surface of the developing roller and is pressed against the surface of the developing roller; and an elastic urging means that is disposed in the support holder and presses one surface of the blade in the direction of pressing against the surface of the developing roller. And the pressure releasing means for releasing the pressing force of the elastic biasing member acting on the elastic biasing means and acting on the other surface of the blade, the regulating means acts on the other surface of the blade. It is assembled in a state in which the pressing force is released, and the blade does not damage the peripheral surface of the developing roller when it is assembled to the developing housing. Further, it is not necessary to provide a hole for inserting an elastic urging member such as a compression coil spring which constitutes the elastic urging means in the support holder in order to mount the elastic urging means, and the hole is closed after the elastic urging member is inserted. It is not necessary to attach a closing plate for doing this. For this reason, it is possible to reduce the manufacturing cost because hole processing and the closing plate are not necessary, and the accuracy of the pressing force by the elastic biasing member does not decrease due to the closing plate and its mounting accuracy.

Further, according to the present invention, the elastic urging means forms a guide support portion having a length corresponding to the length of the support holder in the width direction and a predetermined interval in the width direction of the guide support portion. A pressing member including a plurality of fitting portions that are placed and project forward and a pressing portion that closes the front ends of the plurality of fitting portions, and one end portion is fitted to the fitting portion of the pressing member. Since the elastic urging member is combined with the elastic urging member, the elastic urging member can be reliably positioned and the elastic urging means can be easily attached to the support holder.

[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 cross-sectional view showing an assembled state of a regulation unit provided in the electrostatic latent image developing device shown in FIG.

FIG. 3 is a perspective view showing a part of a regulating unit provided in the electrostatic latent image developing device shown in FIG.

[Explanation of symbols]

 1: Rotating drum 4: Corona discharger for charging 5: Laser optical part 6: Electrostatic latent image developing device 7: Corona discharger for transfer 8: Corona discharger for peeling 9: Cleaning device 10: Static elimination lamp 16: Development roller 18: Supplying Means 20: Stirring Means 22: Regulation Means 26: Developing Roller Rollers 30: Developer Retaining Region 32: Developer Regulating Region 34: Developing Region 38: Auxiliary Roller of Supplying Means 46: Support Holder 48: Blade 50: Supporting member 52: Elastic biasing means 54: Pressure releasing means 521: Pressing member 522: Compression coil spring 541: Stopper pin 521a: Guide supporting part 521b: Spring fitting part 521c: Pressing part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoyuki Ishida 1-2-2 Tamatsukuri, Chuo-ku, Osaka Mita Industrial Co., Ltd. (72) Akinobu Nakahata 1-2-2 Tamatsukuri, Chuo-ku, Osaka Mita Within Kogyo Co., Ltd.

Claims (2)

[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. A static roller including a roller, and a regulation unit that regulates the amount of the developer retained on the surface of the developing roller in the developer regulation region located between the developer retaining region and the developing region. In the electrostatic latent image developing device, the regulating means includes a support holder, a blade made of a rigid member supported by the support holder and one surface of which is in pressure contact with the surface of the developing roller, and the blade disposed in the support holder. Elastic biasing means for pressing one surface of the elastic roller against the surface of the developing roller, and pressure release for releasing the pressing force of the elastic biasing member acting on the elastic biasing means and acting on the other surface of the blade. Have means, Electrostatic latent image developing device according to. 2. The elastic urging means has a guide support portion having a length corresponding to the length of the support holder in the width direction, and protrudes to the front side at a predetermined interval in the width direction of the guide support portion. A pressing member including a plurality of formed fitting portions and a pressing portion that closes the front ends of the plurality of fitting portions, and an elastic member whose one end is fitted to the fitting portion of the pressing member. The electrostatic latent image developing device according to claim 1, wherein the electrostatic latent image developing device comprises a biasing member.