JPH0744008A - Developing device, developing method and image forming device - Google Patents

Abstract

PURPOSE:To provide a developing device, a developing method, and an image forming device by which a stable image without irregularities in an image is obtained without producing dust, etc., in a state where the developing device is arranged below a photoreceptor drum being an image carrier. CONSTITUTION:When the contact position of a toner supply roller 34 with a developing roller 33 and the regulate position of a toner thin layer forming blade 35 are perpendicularly downward, and the rotating directions of the rollers 33 and 34 are reverse in a contact part, at least the base part of a developer container 32 opposed to the disposed position of the roller 34 is constituted of a flexible member 100, and the capacity of the moving area of toner T in this part is made variable and the fluctuation of toner pressure is absorbed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for visualizing an electrostatic latent image in an electrophotographic device or an electrostatic recording device, a developing method, and an image forming apparatus equipped with the developing device.
Particularly, the present invention relates to a developing device, a developing method, and an image forming apparatus capable of obtaining a high-quality image by using a one-component developer.

[0002]

2. Description of the Related Art In recent years, a one-component developing system does not require mixing with a carrier, agitation and control of toner concentration, so that it is not only small in size and low in cost, but also requires replacement work of a developer. Since printers are no longer used, the percentage of printers that are required to be maintenance-free is increasing year by year.

Conventionally, developing devices using a one-component developer include those in which toner is magnetic and those in which it is non-magnetic, but in any case, a toner layer regulating member is used to develop a developing roller (developing sleeve). ), A thin uniform toner layer is formed thereon, and the toner thin layer is brought into contact with or brought close to the image carrier to visualize the electrostatic latent image formed on the image carrier.

When a magnetic toner is used, the toner particles are conveyed by a magnetic binding force, and the toner is charged by friction between the developing roller, the toner layer regulating member, or the toner. Generally, since the magnetizing force is smaller than that of a two-component developer, the toner layer regulating member is brought into contact with the developing roller or the gap between the toner layer regulating member and the toner layer regulating member is narrowed to thin the toner on the developing roller. There is.

In the case of non-magnetic toner, since magnetic force cannot be used, a toner thin layer forming member such as a blade is brought into contact with the developing roller, so that the electric charge (image force) of the toner and the Coulomb force due to frictional charging are exerted. It is used to supply and convey toner.

Conventionally, in an image forming apparatus equipped with this type of developing device, a paper conveying path is provided below a process unit as an image forming means including a photosensitive drum as an image carrier and a developing device. It is configured to be installed together with.

Further, an optical system unit as an exposing means is necessarily arranged above the process unit in view of the layout of the electrophotographic process and practical space.

However, with such a device configuration,
There are the following defects.

1) The toner scattering and toner spill from the developing device may contaminate the transfer device and the recording paper.

2) Since the process unit is removed or the front cover attached to the process unit is lifted at the time of jam handling, not only is it difficult to design a space-saving electrical system and noise countermeasures, but also annoy the user. It will be.

3) Since the heavy optical system unit is located above the apparatus, it is easy to pick up vibration of the apparatus and stable exposure becomes difficult.

Therefore, as a solution to these problems, development of an image forming apparatus in which a sheet conveying path is arranged together with a transfer device above a process unit including a photosensitive drum, a developing device and the like is being developed.

[0013]

However, in such a case, the developing device must be arranged below the photosensitive drum, and the top and bottom are reversed in that structure.

Therefore, the contact position between the developing roller and the toner supply roller and the contact position between the developing roller and the toner thin layer forming member (toner thin layer regulation position) are the contact position between the photosensitive drum and the developing roller ( It is located vertically below the developing position).

Thus, the line from the contact position between the developing roller and the toner supply roller to the contact position between the developing roller and the toner thin layer forming member and the contact position between the developing roller and the toner thin layer forming member The tangent line drawn on the supply roller,
A triangular area formed by connecting a line from the intersection of the tangent line with the toner supply roller to the contact position between the developing roller and the toner supply roller, that is, the rotation direction of the developing roller from the contact point of the toner thin layer forming member. The area formed on the upstream side moves to the bottom of the developing device.

In the upside-down structure, gravity is not applied to the area, an appropriate toner pressure cannot be obtained, toner supply failure occurs, and it is not practically used at present.

The present invention has been made in view of the above problems, and in the state where the developing device is disposed under the image carrier, it is possible to obtain a stable image without image roughness without causing dust and the like. It is an object of the present invention to provide a developing device, a developing method, and an image forming apparatus.

[0018]

As a developing device for solving the above problems, the present invention is a developing device holding means which is arranged so as to be close to an image carrier and which is capable of rotating and supplying a developing agent, and a developing device A developer supplying means for supplying the developer to the developer holding means by rotating so that the rotation direction of the developer supplying means is opposite to that of the developer supplying means while being in contact with the developer holding means in the vertical direction; A developer thin layer forming means for forming a developer thin layer of the developer supplied by the developer supplying means on the surface of the developer holding means, the developer thin layer forming means being in contact with the surface of the developer holding means and vertically downward; A developer holding means, a developer supplying means, and a developer thin layer forming means are housed inside, and a developer housing portion is housed for housing the developer, and at least opposed to an arrangement position of the developer supplying means. You It is obtained by the formed by and a developing device main body that constitutes the bottom portion of a flexible member configured.

As a developing method for solving the above problems, toner is supplied to a rotatable developing roller via a toner supply roller and a toner thin layer forming blade forms a toner thin layer on the surface of the developing roller. And by bringing the toner thin layer close to the image carrier,
In a developing method for visualizing an electrostatic latent image formed on the image carrier, a contact position of the toner supply roller with the developing roller and a regulation position of the toner thin layer forming blade are set vertically downward, and the developing The rotation direction of the roller and the toner supply roller is opposite to each other at the contact portion, and at least the capacity of the toner moving area facing the toner supply roller is made variable so as to develop while supplying toner to the developing roller. It is the one.

As an image forming apparatus for solving the above problems, an electrostatic latent image forming means for forming an electrostatic latent image on an image carrier, and an electrostatic latent image forming means for forming an electrostatic latent image on the image carrier. Developing means for visualizing the electrostatic latent image by supplying a one-component developer to the electrostatic latent image, and electrostatically transferring the developer image formed on the image carrier to a transfer material. An image forming apparatus comprising: a transfer unit, the developer holding unit being arranged close to the image carrier and capable of supplying the developer, and a vertically downward direction of the developer holding unit. And a surface of the developer holding means for supplying the developer to the developer holding means by rotating so that the direction of rotation of the developer supplying means is opposite to that of the developer supplying means. And it is provided in the state of contacting vertically downward Developer thin layer forming means for forming a developer thin layer by the developer supplied by the developer supplying means on the surface of the developer holding means, developer holding means, developer supplying means, and developer thin layer forming means And a developer accommodating portion for accommodating the developer, and at least a bottom surface portion of the developing device main body facing a disposition position of the developer supplying means is formed of a flexible member. It is configured as follows.

[0021]

In the developing device, the developing method and the image forming apparatus of the present invention, the contact position of the developer supplying means with respect to the developer holding means and the regulating position of the toner thin layer forming means are vertically below, and When the rotation directions of the developer holding means and the developer supplying means are opposite to each other at the contact portion, the developer holding means, the developer supplying means, and the developer thin layer forming means are housed inside and At least the bottom portion of the developing device main body having the developer accommodating portion for accommodating the developer, which is opposed to the arrangement position of the developer supplying means, is formed of a flexible member, and the developer (toner) moving region of this portion is formed. Since it is made possible to absorb the fluctuation of the toner pressure by changing the capacity of the toner, the image can be generated without dust in any one-component developing method having a toner regulating member such as a toner thin layer forming means. It can be provided not stable image of rough and composed.

Further, the transfer means and the transfer path of the material to be transferred can be arranged above the image carrier, the developing device and the like, so that the adverse effect due to the scattering of the developer from the developing device can be prevented and the jam can be prevented. The processing is easy and the user operation is simple, and moreover, the space-saving design which is advantageous for the optical and electrical equipment design is possible.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure of a laser printer 1 which is an image forming apparatus.

In FIG. 1, a photoconductor drum as an image carrier having a diameter such that the peripheral surface length is smaller than the length of an image to be recorded is provided at a substantially central portion of a printer main body 2 as an image forming apparatus main body. 3 is provided rotatably in the direction of arrow A. The photoconductor drum 3 is made of an organic photoconductor (OPC) photoconductive material.

Further, around the photosensitive drum 3, a charging device 4 as a charging means for charging the surface of the photosensitive drum 3 uniformly along the rotation direction of the photosensitive drum 3, and the surface of the photosensitive drum 3 are sequentially charged. Developing device 5 as a developing device for developing the formed electrostatic latent image with toner T which is a non-magnetic one-component developer, and a developer removing device for removing the toner remaining on the surface of photoconductor drum 3 after transfer. The drum cleaner device 6 and the static elimination lamp 7 as the static elimination means are arranged in this order. The photoconductor drum 3, the charging device 4, the developing device 5, the drum cleaner device 6 and the like are integrally incorporated into a unit, and constitute a process unit 8 which is detachable from the printer body 2.

Further, a laser exposure unit 9 as an electrostatic latent image forming means is arranged in a state where a part of the process unit 8 is extended below the position where the process unit 8 is arranged, and laser light based on image information is used. LB is the charging device 4 and the developing device 5.
The surface of the photoconductor drum 3 is irradiated with light from between. Further, a transfer device 10 as a transfer unit is arranged above the photosensitive drum 3.

Image forming means 20 is formed on the peripheral surface of the photosensitive drum 3 to form a toner image TI as a developer image.

Further, in the printer main body 2, a paper P as a material to be transferred, which is taken out from a paper feed cassette 11 attached to the lower portion of the printer main body 2, is transferred to the photosensitive drum 3 of the image forming means 20. A sheet conveying path 14 is formed which leads to a sheet discharging section 13 formed on an upper surface of one side (right side in the state of FIG. 1) of the printer main body 2 via an image transfer section 12 between the transfer device 10.

Further, the image transfer section 1 of the sheet conveying path 14
On the upstream side of 2, a transfer roller pair 1 for transferring the paper P taken out from the paper feed cassette 11 via the paper feed roller 15
6 and the aligning roller pair 17 which feeds the sheet P to the image transfer portion 12 at a timing after the leading edge alignment of the sheet P is performed. Further, a fixing device 18 for fixing the toner image TI transferred onto the paper P and a paper discharge roller pair 19 for discharging the fixed paper P to the paper discharge unit 13 are provided on the downstream side of the image transfer unit 12. ing.

Next, the image forming operation of the laser printer 1 thus constructed will be described.

Rotate the photosensitive drum 3 in the direction of arrow A,
The peripheral surface of the photoconductor drum 3 is approximately uniformly charged to −500 V by the charging device 4. Then, the laser light LB is selectively irradiated from the laser exposure unit 9 to the negative charging area according to the image information to be recorded, and as a result, the laser light LB is emitted.
The surface potential of the photosensitive drum 3 irradiated with is about −50 v and an electrostatic latent image is formed.

Then, the electrostatic latent image faces the developing device 5 as the photosensitive drum 3 rotates.

On the other hand, in the developing device 5, the developing roller 33 on which a layer of toner T as a so-called non-magnetic one-component developer having a triboelectrification property is formed is in the direction of the arrow (arrow B) with respect to the photosensitive drum 3. Direction). Further, a bias voltage of about −200 V is applied to the developing roller 33.

When the photoconductor drum 3 carrying the electrostatic latent image and the developing roller 33 come into contact with each other, the photoconductor drum 3 and the developing roller 33 adhere to the developing roller 33 due to the potential difference of about 150 v. The toner T present adheres to the laser-irradiated portion of the surface of the photosensitive drum 3 and is reversely developed.

As a result, the electrostatic latent image on the surface of the photosensitive drum 3 is visualized as a toner image TI.

The toner image TI after development is next transferred to the transfer device 1.
It is conveyed to the transfer area facing 0.

On the other hand, in the transfer area, the paper P is taken out from the paper feed cassette 11 by the rotation of the paper feed roller 15, and is synchronized with the rotation of the photosensitive drum 3 through the transfer roller pair 16 and the aligning roller pair 17 in sequence. Will be sent.

The back surface of the paper P conveyed here is charged to a positive polarity by the transfer device 10 to which a voltage of +500 to 2000 v is applied from a transfer bias power source (not shown). Therefore, the photosensitive drum 3
The toner image TI on the surface of is electrostatically attracted to the paper P and transferred.

Further, the paper P after transfer is sent to the fixing device 18, where the toner T is melted and fixed on the paper P by heat and pressure, and then, the paper discharge unit 13 via the paper discharge roller pair 19.
Is discharged to.

On the other hand, the toner remaining on the photosensitive drum 3 without being transferred onto the paper P is transferred to the drum cleaner device 6.
The toner is collected in the toner container.

Further, the electrostatic latent image remaining on the photosensitive drum 3 is erased by the charge eliminating lamp 7, the process returns to the charging step again, and the same printing cycle is repeated. That is, one recording image can be obtained by rotating the photosensitive drum 3 in an overlapping manner and using the same in an overlapping manner.

As described above, in the laser printer 1, the photosensitive drum 3, the charging device 4, the developing device 5,
Above the process unit 8 in which the drum cleaner device 6 and the like are integrally incorporated, the paper transport path 1 which is a transport path for the paper P is provided.
4 is formed.

Therefore, there is no possibility that toner scattering and toner spill from the developing device 5 will contaminate the transfer device 10 and the paper P.

During the jam processing, the transfer device 10,
By opening the upper cover 25 of the printer main body 2 to which the upper roller 17A of the aligning roller pair 17 and the upper roller 19A of the paper discharge roller pair 19 are attached, these are integrally displaced to expose the paper transport path 14. Therefore, it is not necessary to remove the process unit or lift the cover attached to the process unit as in the conventional case, the jam processing can be easily and easily performed, and the space-saving design of the electrical system and the noise countermeasure can be facilitated.

Furthermore, the heavy laser exposure unit 9
Will be placed at the bottom of the printer body 2,
It is difficult to pick up the vibration of the device and stable exposure can be performed.

Next, the structure of the developing device 5 of the present invention will be described in detail with reference to FIGS.

The developing device 5 is provided with a developing roller 33 having conductivity and elasticity, and a thin layer of the non-magnetic toner T is formed on the surface of the developing roller 33, which is formed on the photosensitive drum 3.
The developing device does not require a developer carrier, a magnet roller, a toner concentration control device, and the like, and can be downsized and reduced in cost.

FIG. 2 is a sectional view of the developing device 5.

The developing device 5 has a developing container 32 as a main body of the developing device, which is integrally formed with a toner hopper 31 which serves as a toner accommodating portion 30 as a developer accommodating portion.

The developing container 32 is in a state in which a portion facing the photoconductor drum 3 is opened, and the nip width is elastically and deformed with respect to the photoconductor drum 3 in the vicinity of the opening. The developing roller 33 is provided as a developer holding unit that contacts with the photosensitive drum 3 and rotates in the direction of the width (direction of arrow B) with respect to the rotating direction of the photosensitive drum 3.

The photosensitive drum 3 of the developing roller 33.
A toner supply roller 34 as a developer supply means for supplying the toner T, which is a non-magnetic one-component developer, to the developing roller 33 is provided in the direction opposite to the contact position (developing position). .

A developer which is located below the developing roller 33 in the developing container 32, regulates the toner conveyance amount by the developing roller 33, and forms a thin layer of the toner T on the surface of the developing roller 33. A toner thin layer forming blade 35 as a thin layer forming means is provided.

Further, a recovery blade 37 is provided which comes into contact with the developing roller 33 at a position downstream of the developing position in the rotation direction thereof.

Further, a mixer 38 as a stirring means which rotates in the direction of arrow D is provided in the toner accommodating portion 30 so that the toner T is agitated and sent to the toner supply roller 34 side.

The non-magnetic toner T in the toner hopper 31 is sent to the toner supply roller 34 side while being agitated by the mixer 38 rotating in the direction of arrow D, and further,
The toner is supplied from the toner supply roller 34 to the developing roller 33.

The toner T supplied onto the developing roller 33 by the toner supply roller 34 is triboelectrically charged with the developing roller 33, and the toner thin layer forming blade 35 is disposed by the electrostatic force and the physical force. Is transported to.

The toner T on the developing roller 33 is charged by triboelectrification while the passing amount is regulated by the toner thin layer forming blade 35. After passing through the toner thin layer forming blade 35, the toner T is conveyed to the photosensitive drum 3 side in a state where it is sufficiently charged and is uniformly layered, and the electrostatic latent image on the photosensitive drum 3 is transferred. develop.

The undeveloped toner T'which has not been used for developing the electrostatic latent image passes through the recovery blade 37 and returns into the developing container 32.

In this embodiment, since the reversal development is performed using the negatively chargeable organic photosensitive drum 3, a negatively charged toner is used as the toner T and the toner thin layer forming blade 35 is easily negatively charged. The silicone rubber is used. Further, the developing roller 33 is about 1 to 4 times as fast as the photosensitive drum 3 rotating in the arrow A direction,
It rotates in the direction of arrow B while having a contact width (developing nip) of about 1 to 5 mm. The toner supply roller 34, like the developing roller 33, has a contact width of about 1 to 5 m.
It rotates in the direction of arrow C with m.

Further, the developing roller 33 is the photosensitive drum 3
The first characteristic required of the developing roller 33 is "having conductivity and elasticity" because it is contact development in which the metal as a support is used as shown in FIGS. 2 and 3. An elastic body layer 33B having conductivity and a surface conductive layer 33C applied so as to satisfy the surface smoothness are sequentially formed around the shaft 33A to form an elastic roller as a whole.

The elastic layer 33B has a rubber hardness of 2
Silicone rubber with 5 degrees, elongation of about 425% and resistance value of 5 × 10 ³ Ωcm is used, and the surface conductive layer 33C is a conductive polyurethane paint (Nippon Miractran Co., Ltd. Spalex) resistance value of about 5 × 10 ³ Ωcm. A material having an elongation of about 353% was used to form a surface layer having a thickness of about 70 μm. As a result, the rubber hardness of the formed developing roller 33 is about 30.
The resistance between the shaft 33A and the surface conductive layer 33C was about 100 KΩ / cm ² , and the surface roughness was about 3 μm.

Further, as shown in FIG. 2, the metal shaft 33A of the developing roller 33 has 100 k to 50 MΩ.
DC power supply 3 as a voltage applying means through the protection resistor 60 of
6 is connected, the surface potential of the photosensitive drum 3 (V _0); - with respect to _{500v (V H) ~50v (V} L), adapted to apply a developing bias potential (V _D) -200v ing.

The recovery blade 37 is made of a phosphor bronze thin leaf spring, and has an end fixed to the frame of the developing container 32 and the other end free so that the developing roller as a developer holding member. It is pressed over the entire length of 33. The pressing force is about 3 g / cm ² .

Further, the toner supply roller 34 has two roles of supplying the toner T to the developing roller 33 and scraping off the toner T on the developing roller 33 after development as described above. The toner supply roller 34 is
A conductive soft polyurethane foam layer [trade name: Everlight, manufactured by Bridgestone Corporation] layer 34B is provided on the outer periphery of the metal shaft 34A.

The width of contact with the developing roller 33 is
The contact depth is set to about 1 to 5 mm and the contact depth is set to about 0.2 to 1.0 mm, and the developing roller 33 rotates in the against direction (arrow C direction).

Then, the toner T is fed and supplied, and the hopper 31 is used.
It plays a role of preventing aggregation of the toner T on the inner bottom.

[0068] Further, the metal shaft 34A of the toner supply roller 34, the toner supply bias power source (variable) 39 as voltage applying means, as shown in FIG. 2, the toner supply bias voltage (V _M) -200v~-400v Is applied so that good mobility of the toner T can be obtained.

The toner thin layer forming blade 35 is held by a first blade holder 40, a spacer 41 and a second blade holder 42, as shown in FIG. The first blade holder 40 is rotatably supported via a shaft 43 and is always biased by a plurality of compression springs 44 for pressing so as to rotate in a predetermined direction.

Since the spring constant of the compression spring 44 is smaller than the spring constant of the thin leaf spring material of the toner thin layer forming blade 35, even if the contact portion of the toner thin layer forming blade 35 is worn, the pressing force changes almost. It is possible to maintain a stable layer forming ability for a long period of time. In the embodiment, the pressing force of the toner thin layer forming blade 35 against the developing roller 33 is about 80 g / cm ² .

On the back surface of the toner thin layer forming blade 35, a foam material 45 made of maltoprene or the like is attached, and the foam material 45 is attached to a baffle plate 46 attached to the first blade holder 40. It comes to abut. As a result, the vibration of the toner thin layer forming blade 35 can be suppressed, and a good toner T layer can be formed.

As shown in FIG. 4, the toner thin layer forming blade 35 has a tip 35B of a thin leaf spring material made of phosphor bronze or the like, and at least a tip 35B which is a protrusion made of a silicon rubber elastic body in the longitudinal direction. It is provided in an area larger than the image forming width, and a sealing material 35C made of urethane foam is attached to both ends thereof. The sealing material 35C is thicker than the height of the chip 35B, and reliably seals the movement of the toner T toward both ends.

The chip 35B, as shown in detail in FIG.
The first protrusion 55 has a semicircular cross-sectional surface shape on the side facing the developing roller 33, and the minute second protrusion 56 is arranged on the surface. The chip 35B is pressed against the developing roller 33 with a predetermined weight. The toner T passing therethrough is negatively triboelectrically charged with the same polarity as that of the photoconductor drum 3, and forms one to three layers of toner T.

Further, by providing the minute second protrusions 56, the load is concentrated on the second protrusions 56 at the contact portion of the developing roller 33, and the first protrusions 55 are deformed. This facilitates elimination of image defects such as uneven density due to defective toner layer formation.

By the way, as shown in FIG. 1, when the paper conveying path 14 is arranged together with the transfer device 10 above the process unit 8 including the photosensitive drum 3, the developing device 5, etc., the developing device 5 is As shown in FIGS. 2, 6, and 7, the photoconductor drum 3 must be disposed below the photoconductor drum 3, and the top and bottom sides of the conventional device are reversed in that structure.

Therefore, the contact position between the developing roller 33 and the toner supply roller 34 and the contact position between the developing roller 33 and the toner thin layer forming blade 35 (toner thin layer regulating position) are the same as those of the photosensitive drum 3. It is located vertically below the contact position (developing position) of the developing roller 33.

As a result, the line from the contact position between the developing roller 33 and the toner supply roller 34 to the contact position between the developing roller 33 and the toner thin layer forming blade 35, and the developing roller 33 and the toner thin layer forming blade. A tangent line drawn from the contact position with the toner supply roller 34 to the toner supply roller 34 and a line from the intersection of the tangent line with the toner supply roller 34 to the contact position between the developing roller 33 and the toner supply roller 34 are connected. A triangular area, that is, an area E formed by mesh hatching in the drawing formed on the upstream side in the rotation direction of the developing roller 33 from the contact point of the toner thin layer forming blade 35 is the developing container 32.
To the inner bottom surface 32A side.

It is clear that gravity is not applied to the area E in this upside-down structure, and in order to supply the toner T, the toner supply roller 34 and the inner bottom surface 32 of the developing container 32 are supplied.
It is necessary to narrow the space with A and increase the toner pressure per unit area.

However, the developing device 5'actually shown in FIG.
When printing was carried out by incorporating the above into the laser printer 1 shown in FIG. 1, an increase in dust and disturbance of halftone reproduction were conspicuous, and the image was remarkably deteriorated.

This is the same as the conventional developing roller 33.
And the toner supply roller 34 rotate in the same direction (B, C
Direction), that is, a phenomenon caused by the opposite direction (against direction) at the contact portion between the rollers 33 and 34.

That is, since the distance between the toner supply roller 34 and the inner bottom surface 32A of the developing container 32 is narrow, the toner carrying pressure in the area E becomes excessive, and the toner T, which has no escape, presses the toner thin layer forming blade 35. By raising the pressure, the amount of pressure applied to the developing roller 33 changes, and it becomes impossible to obtain an optimum and uniform toner charge distribution.

Therefore, in order to release the transfer pressure of the toner T to the area E, an attempt was made to widen the space between the toner supply roller 34 and the inner bottom surface 32A of the developing container 32, but the strong magnetic transfer of the two-component developer was carried out. In contrast to the one-component developer, the toner T on the inner bottom surface 32A of the developing container 32 is unsuitable for the one-component developer regardless of whether it is a magnetic toner or a non-magnetic toner.

Further, even if the rotation speed of the toner supply roller 34 is decreased, the toner conveying pressure does not decrease so much, so that the problem cannot be solved.

Therefore, as a countermeasure against the above-mentioned inconvenience, as shown in FIG. 7, a part of the inner bottom surface 32A of the developing container 32, which is the lower portion of the toner supply roller 34, is formed of a flexible member 100, and this flexible member 100 is used. We decided to conduct an experiment using the "bending" and "bending stress" obtained in the flexible member 100. In the figure, 101 is an elastic support member that supports the flexible member 100 so as not to impair the bending deformation and the like.

That is, when the toner T has a large number of insertions (accommodation amount), as shown in FIG. 8, the toner carrying pressure applied to the area E is released by the bending deformation of the flexible member 100, and the toner T is inserted. When the number of eyes is small, as shown in FIG. 9, the bending stress is brought into close contact with the toner supply roller 34 to stabilize the toner conveyance.

As the flexible member 100, an elastic film having a thickness of 10 μm to 2 mm and a bending elastic modulus of 1 × 10 ⁴ to 1 × 10 ⁶ kg / cm ² is preferable as a result of studying various materials. In this example, the thickness is 100 μm, which is excellent in mechanical strength, and the bending elastic modulus is 1 × 10 ^5.
A kg / cm ² polyethylene telefilterate film (PET film) was used.

The direction B of rotation of the developing roller 33 is opposite to the direction A of rotation of the photosensitive drum 3 in which the rotational drive of the photosensitive drum 3 is smooth (the wise direction with respect to the tangent line).
The rotation speed was the same as that of the photosensitive drum 3.

Further, the rotation direction C of the toner supply roller 34
Is the same direction as the rotating direction B of the developing roller 33 (against the tangent to the roller), and the rotating speed is a relative speed with respect to the rotating peripheral speed of the developing roller 33, that is, , About twice.

In FIG. 10, a developing device 5'corresponding to a conventional device is used in which a part of the inner bottom surface 32A of the developing container 32 corresponding to the lower part of the toner supply roller 34 is a non-flexible member as it is. It is an enlarged photograph showing the situation of "dust" in the case.

In FIG. 11, a part of the inner bottom surface 32A of the developing container 32 below the toner supply roller 34 is partially covered by the flexible member 100.
6 is an enlarged photograph showing the situation of "dust" when the developing device 5 of the present invention is used.

Table 1 and FIG. 12 show the analysis results. An image analyzer (TOSPIX-I)
I) was used.

[0092]

[Table 1] From this result, if a part of the inner bottom surface 32A of the developing container 32, which is the lower portion of the toner supply roller 34, is made of a non-flexible member as in the conventional case, the toner carrying pressure in the area E becomes excessive and dust increases. Distortion of dot reproduction occurs. On the other hand, when the flexible member 100 was used, good results were shown, and it was found that there was a great effect against the above-mentioned problems.

In this embodiment, the contact type one-component developing system and the non-magnetic toner are used. However, in the case where a thin toner layer is formed on the developing roller (developing sleeve) by the toner layer regulating member, it is Transformation is also possible.
For example, even when the toner layer regulating member is not in contact with the developing roller (developing sleeve) and the magnetic toner is used, the same effect can be expected from the intention of the present invention.

In addition, it goes without saying that the present invention can be variously modified without departing from the spirit of the present invention.

[0095]

As described above, according to the developing device, the developing method and the image forming apparatus of the present invention, the contact position of the developer supplying means with respect to the developer holding means, and the toner.
When the regulating position of the thin layer forming means is vertically downward and the rotation directions of the developer holding means and the developer supplying means are opposite to each other at the contact portion, the developer holding means, the developer supplying means, Also, at least the bottom surface portion of the developing device main body which houses the developer thin layer forming means and which has the developer containing portion for containing the developer is opposed to the arrangement position of the developer supplying means. Since the capacity of the developer (toner) moving region in this portion is made variable so that the fluctuation of the toner pressure can be absorbed, any one-component developing method having a toner regulating member such as a toner thin layer forming means. Also in the above, it is possible to provide a stable image without image roughness without causing dust and the like.

Further, the transfer means and the transfer path of the material to be transferred can be arranged above the image carrier, the developing device, etc., and the adverse effect due to the scattering of the developer from the developing device can be prevented and the jam can be prevented. The processing is easy and the user's operation is simple, and moreover, the space-saving design advantageous for the optical and electrical equipment design can be achieved.

[Brief description of drawings]

FIG. 1 is a front view schematically showing an internal configuration of an image forming apparatus of the present invention.

FIG. 2 is a sectional view showing an embodiment of the developing device of the present invention.

FIG. 3 is a perspective sectional view of a developing roller which is a main part of the embodiment.

FIG. 4 is a perspective view of a blade that is a main part of the embodiment.

FIG. 5 is a sectional view of a blade tip portion of the embodiment.

FIG. 6 is a schematic view of the developing device of the embodiment when the developing container is made of a non-flexible member.

FIG. 7 is a schematic view of a case where a part of a developing container is formed of a flexible member in the developing device of the embodiment.

FIG. 8 is a schematic view of the developing device of the embodiment when an excessive toner conveying pressure is applied.

FIG. 9 is a schematic view of the developing device of the embodiment when the toner transport pressure in the area is reduced.

FIG. 10 is a view showing an image when the developing container is made of a non-flexible member.

FIG. 11 is a diagram showing an image when the developing container is made of a flexible member.

FIG. 12 is a diagram showing the effect of the present invention.

[Explanation of symbols]

1 ... Image forming device, 3 ... Photosensitive drum (image bearing member), 4
... charging device (charging means), 5 ... developing device (developing means),
6 ... Drum cleaner device (developer removing means), 7 ... Static elimination lamp (static elimination means), 8 ... Process unit, 9 ... Laser exposure unit (electrostatic latent image forming means), 10 ... Transfer device (transfer means), 14 ... Paper transport path, 30 ... Toner containing section (developer containing section), 31 ... Toner hopper, 32 ... Developing container (developing apparatus main body), 32A ... Inner bottom surface, 33 ... Developing roller (developer holding means), 34 ... Toner Supply roller (developer supply means), 35 ... Toner thin layer forming blade (developer thin layer forming means), 100 ... Flexible member, 101 ... Elastic support member, P ... Paper (transferred material), T ... Toner (Developer), TI ... Toner image (developer image).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location G03G 15/08 M 8530-2H (72) Inventor Toshiro Honda 70 Yanagicho, Saiwai-ku, Kawasaki-shi, Kanagawa Stock Company Toshiba Yanagimachi factory

Claims (4)

[Claims] 1. A rotationally drivable developer holding means which is arranged close to an image carrier and which supplies a developer, and a rotation of the developer supplying means which is in contact with the developer holding means vertically below the developer holding means. The developer supply means for supplying the developer to the developer holding means by rotating so that the directions thereof are opposite to each other at the contact portion, and the developer provided in a state of being in contact with the surface of the developer holding means and vertically downward. A developer thin layer forming means for forming a developer thin layer by the developer supplied by the developer supplying means on the surface of the developer holding means; a developer holding means, a developer supplying means, and a developer thin layer forming means. And a developing device main body having a developer containing portion for containing the developer therein, and at least a bottom surface portion facing the arrangement position of the developer supplying means is made of a flexible member. Will do Developing apparatus is characterized and. 2. A developer holding means which is arranged so as to be close to an image carrier and which is capable of rotating and supplies a developer, and a rotation of the developer supplying means which is in contact with the developer holding means vertically below the developer holding means. The developer supply means for supplying the developer to the developer holding means by rotating so that the directions thereof are opposite to each other at the contact portion, and the developer provided in a state of being in contact with the surface of the developer holding means and vertically downward. A developer thin layer forming means for forming a developer thin layer by the developer supplied by the developer supplying means on the surface of the developer holding means; a developer holding means, a developer supplying means, and a developer thin layer forming means. It has a developer accommodating portion for accommodating the developer therein and accommodating the developer, and at least the bottom surface portion facing the disposition position of the developer supply means has a thickness of 10 μm to 2 μm.
A developing device main body formed of an elastic film having a bending modulus of elasticity of 1 × 10 ⁴ to 1 × 10 ⁶ kg / cm ² and a developing device main body. 3. Toner is supplied to a rotatable developing roller through a toner supply roller, and a toner thin layer forming blade forms a toner thin layer on the surface of the developing roller, and the toner thin layer is imaged. In a developing method for visualizing an electrostatic latent image formed on the image carrier by approaching the carrier, a contact position of the toner supply roller with the developing roller, and a regulation position of the toner thin layer forming blade Is vertically downward, and the rotation direction of the developing roller and the toner supply roller are opposite to each other at the contact portion, and at least the capacity of the toner moving area facing the toner supply roller is made variable to the developing roller. A developing method comprising developing while supplying toner. 4. An electrostatic latent image forming means for forming an electrostatic latent image on an image carrier, and a one-component system developing on the electrostatic latent image formed on the image carrier by the electrostatic latent image forming means. An image including a developing unit that visualizes the electrostatic latent image by supplying a developer, and a transfer unit that electrostatically transfers the developer image formed on the image carrier to a transfer material. A forming device, which is arranged close to the image carrier and is capable of rotating and supplying the developer, and the developer supplying means while contacting vertically below the developer holding means. Provided in a state in which the developer supply means for supplying the developer to the developer holding means by rotating so as to rotate in the opposite direction to the developer holding means, and the surface of the developer holding means and vertically downward contact with each other. Developer supplied by the developer supply means The developer thin layer forming means for forming the developer thin layer on the surface of the developer holding means, the developer holding means, the developer supplying means, and the developer thin layer forming means are housed inside, and the developer is An image forming apparatus, comprising: a developer accommodating portion for accommodating the developer; and a developing device main body in which at least a bottom surface portion facing the disposition position of the developer supplying means is formed of a flexible member. Forming equipment.