JP2536108Y2 - Developing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a developing device, and more particularly, to a developer recovery structure of a developing device using a one-component non-magnetic developer.

(Prior Art) As shown in FIG. 2, a structure for processing an electrostatic latent image formed on a photoreceptor with a developer containing toner as a main component, such as a copying machine or a printer, is shown in FIG. There is a developing device using a non-magnetic developer carrying roller.

The developing device shown in FIG. 2 includes a developing roller B disposed in the vicinity of an outer peripheral portion of a photosensitive member A, and a one-component non-magnetic developer from a developer supply tank (not shown) proximate to the developing roller B. Abuts on the peripheral surface of the developing roller A on the downstream side of the developer replenishing roller C in the rotation direction of the developing roller B (in the direction of the arrow in the figure) to regulate the thickness of the developer on the developing roller to maintain a uniform state. A developer scraping member F that comes into contact with the peripheral surface of the set thinning regulating roller D that has passed through the developing roller A to remove the developer on the regulating roller, and a photosensitive member A of the developing roller B And a cleaning member G that contacts the peripheral surface after passing through to remove residual developer from the peripheral surface of the developing roller B.

In the developing device having such a configuration, the one-component non-magnetic developer charged into the developer replenishing roller C is carried and supplied to the developing roller B. The layer thickness is made uniform by the roller D, and the developer is attracted to the latent image portion by the electric attraction force of the electrostatic latent image formed on the photoreceptor A.

In the structure of this developing device, the following problem arises because the thinning regulating roller for keeping the thickness of the developer on the developing roller constant rotates.

Because the regulating roller rotates while abutting on the developing roller, the developer removed from the developing roller scatters due to the centrifugal force of the regulating roller and floats around the regulating roller. The developer may fall off and scatter around the regulating roller, and such a developer adheres to the regulating roller again due to its own electrostatic force and is in a reference state for setting the layer thickness. This will change the state of the peripheral surface of the regulating member.

Therefore, the developer adhering to the regulating roller changes the fixed thickness of the developer set on the developing roller, and also changes the supply state of the developer on the photoreceptor, thereby changing the image. This may cause background contamination and formation of an abnormal image.

Therefore, conventionally, it has been proposed to provide a receiving portion for collecting the developer spilled from the regulating roller in the vicinity of the regulating roller (for example, Japanese Utility Model Laid-Open No. 61-65553).
JP-A-62-146154).

(Problems to be Solved by the Invention) However, the above-described collecting structure of the developer merely stops collecting the developer in the developing device, and the collected developer accumulates in the collecting portion. In such a case, the collecting portion cannot be taken out to the outside, and as a result, the developer overflowing from the collecting portion may float and adversely affect the above-described regulating member.

Further, if the collecting section can be taken out of the developing device, if the collecting section is inclined when the collecting section is attached or detached, the collected developer may flow out. As a result, the spilled developer floats in the vicinity of the regulating roller and adversely affects the same member as in the case described above, so that there is a drawback that sufficient care must be taken when handling the developer.

Accordingly, an object of the present invention is to re-attach the developer to a thinning regulation roller used to stabilize the layer thickness of the developer on the developing roller in view of the above-described problems in the conventional developing device. It is another object of the present invention to obtain a developing device having a structure capable of setting a good developer layer thickness by preventing the above problem.

(Means for Solving the Problems) In order to solve this object, the present invention supplies a one-component non-magnetic developer to the electrostatic latent image formed on the surface of the photoreceptor and rotates the electrostatic latent image in a direction opposite to the photoreceptor. And a thinning regulating roller for uniformly regulating the thickness of the developer layer adhered on the developer carrying body, wherein the thinning regulating roller is attached to the developer carrying body. In the developing device pressed against the lower portion of the developing device, a voltage is applied to the thinning regulating roller, and the developer carrier and the thinning regulating roller are rotated in the rotation direction of the developer carrier. Downstream of the facing portion, and below the developer carrying member upstream of the facing portion between the developer carrying member and the photoconductor, a developer collecting portion detachable from the developing device was formed. A conductive developer collecting member is disposed, and one end of the developer collecting member is located on the upper side. It has a scraper that is in contact with the peripheral surface of the thinning regulation roller,
The other end of the developer collection member is for preventing the developer from flowing out when removing the developer collection member,
It is proposed to detachably couple to a backflow prevention member arranged at a position close to the photoconductor.

(Operation) According to the present invention, it is possible to collect the developer scattered from the thinning regulating member or the developer carrying member and prevent re-adhesion to the thinning regulating member. According to the present invention,
When the developer collecting member is attached or detached, scattering of the developer when the collecting portion is inclined is prevented by the backflow prevention portion.

(Embodiment) Hereinafter, the embodiment of the present invention will be described in detail with reference to FIG.

The developing device 1 uses a one-component non-magnetic developer. Inside the developing device 1, a developer carrier 3 is provided at a position facing the photoreceptor 2 and includes a roller rotatable in the direction of an arrow. Is arranged.

For example, the developer carrier 3 has a rubber hardness of 30 to 50 degrees (JI
SA) made of an elastic body composed of an NBR-based or urethane-based rubber roller, and rotated in the same direction as the photosensitive member 2 at the position of contact with the photosensitive member 2 and fed from the developer supply member 4. The developer is carried on the surface and transferred to the photoconductor 2.

The developer replenishing member 4 is located in the vicinity of the developer carrier 3 and, for example, a roller formed of a foamed polyurethane subjected to a conductive treatment is used. The roller rubs the developer against the developer carrier. Can be To carry the triboelectrically charged developer on the developer carrier, for example, -40
A voltage of 0 V is applied.

On the upstream side of the position where the developer carrier 3 faces the photoconductor 2 in the rotation direction, a thinning regulating roller 6 for stabilizing the layer thickness of the developer on the developer carrier 3 is provided. Have been.

The thinning regulating roller 6 is, for example, a doctor member composed of a hard metal roller such as stainless steel, and its peripheral surface is pressurized by an urging means such as a spring 6A. It is in pressure contact with the peripheral surface of the portion facing the developer carrier 3.

The biasing means only needs to be elastically deformable, and in the case of the present embodiment, a compression coil spring of 600 gf on one side is used. Further, the spring compression coil spring is not limited to this, but can be changed according to the required image density, the rotational torque of the developer carrier 3 and the like.

The thinning regulating roller 6 rotates in the same direction as the developer carrier 3, and is supplied with a voltage of −700 V, which is a voltage, in order to inject a sufficient charge for performing development. Of the developer transferred while being carried on the surface of No. 3, excess developer corresponding to a specified layer thickness or more is scraped off.

At the upstream and downstream positions facing the developer carrier 3 in the rotation direction of the thinning regulating roller 6, a first end for contacting the peripheral surface of the thinning regulating roller 6 is used for scraping off the developer. First and second scrapers 7 and 8 are arranged.

Among the scrapers, a first scraper 7 located on the upstream side of the position facing the developer carrier 3 is formed of an insulating material such as a polyester film. An electrical short circuit with the body 3 is prevented from occurring.

Among the scrapers, a second scraper 8 located downstream of a position facing the developer carrier 3 is formed of a metal material such as stainless steel, and the other end is located at the developer supply member 4 side. It is attached to a support (not shown).

The developer collecting member 9 is located on the downstream side of the facing portion between the developer carrier 3 and the thinning regulating roller 6 in the rotation direction of the developer carrier 3 and between the developer carrier 3 and the photosensitive member 2. A concave space which is disposed below the developer carrier 3 on the upstream side of the facing portion and which can collect the developer scattered on the peripheral surfaces of the developer carrier 3 and the thinning regulating roller 6, that is, a developer collecting section. 9A
Is formed.

The developer collecting member 9 has a first scraper 7 at one end, and the other end on the photoconductor 2 side other than the end having the first scraper 7 is connected to the backflow preventing member 10. It is connected and made of a metal material such as aluminum to have conductivity. The setting of the conductivity in the developer collecting member 9 is for eliminating the charge of the developer dropped on the developer collecting section 9A.

The backflow prevention member 10 sets a gap that allows the developer of a layer thickness regulated on the developer carrying member 3 to pass through, and protrudes to close the other gaps. And a backflow prevention portion for preventing the developer from flowing out of the minimum necessary amount.

Therefore, the developer that has fallen from the peripheral surface of the developer carrier 3 or the peripheral surface of the thinning regulating roller 6 may be scattered except for the one transported by the developer carrier 3. Is dropped into the collection unit 9A and collected.

The developer collecting section 9A is configured such that the developer collecting member 9 including the first scraper can be attached to and detached from the developing device 1 in a direction perpendicular to the paper surface, and the developer is filled in the collecting section 9A. In this case, the developer collecting member 9 is detached and the collected developer can be transferred to the outside. When removing the developer collecting member 9, the first scraper 7
Is slightly inclined within the gap of the connection between the developer recovery member 9 and the backflow prevention member 10, that is, within the range of the play of the connection portion, in order to separate the leading end of the roller from the peripheral surface of the thinning regulating roller 6. However, since the backflow preventing member 10 functions as a weir in the developer in the collection unit 9A, the developer in the collection unit 9A can be prevented from flowing out.

Further, since the developer collecting member 9 is formed of a metal material, when the developer falls to the collecting portion 9A, the developer is discharged by the charged charge of the developer, and the developer carrying member 3 or the thinned layer is charged. The re-adhesion to the regulating roller 6 is prevented.

Since the present embodiment has the above structure, the developer removed from the peripheral surface of the developer carrier 3 by the thinning regulating roller 6 for regulating the layer thickness of the developer in the developer carrier 3 is When the toner scatters in a closed space defined by the concave shape of the developer collecting portion 9A and the weir portion by the backflow preventing member 10, the developer contacts the collecting portion 9A and the backflow preventing member 10 to be neutralized and fall.

When the collecting section 9A is full of the developer, the developer can be discharged by taking out the developer collecting member 9, and the overflow phenomenon of the developer due to the inclination of the collecting section 9A at the time of taking out the developer is prevented by the backflow preventing member. Prevented by 10 damming functions.
Using the developing device of the present invention, the present inventors took out the developer collecting member 9 every 100,000 sheets using A4 size transfer paper and performed 300,000 copies while cleaning the image. In other words, a copy having good image quality, that is, free from background stain and image density variation could be obtained.

Although the above-described embodiment is directed to a structure in which the developer carrier is brought into contact with the photoconductor, a non-contact developing method in which the developer carrier is not brought into contact with the photoconductor may be adopted.

(Effects of the Invention) As described above, according to the present invention, a conductive developer recovery member having a developer recovery space is provided at a lower position of the developer carrier, and the developer recovery member is attached to and detached from the developing device. In addition, the developer collected by the developer collecting member is neutralized, and is prevented from re-adhering to the developer carrier or the thinning regulating roller to which a voltage is applied, and a standard for setting the layer thickness is used. Since the state is not changed, the state of carrying the developer on the developer carrying member is maintained uniformly, so that the layer thickness setting which causes background contamination and abnormal images does not fluctuate. In addition, the developer collected in the collection section can be discharged by a simple operation of simply taking out the developer collection member. In addition, when the developer collection member is taken out to the outside, the developer collection is often performed. Even when the member is inclined, the outflow of the developer can be prevented by the blocking function by the backflow prevention mechanism, so that re-adhesion to each member due to the scattering of the developer can be prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing the overall configuration of a developing device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing the main configuration of a conventional developing device. 1, a developing device, a photoreceptor, a developer carrier,
6 ... thinning regulation roller 9 ... developer recovery member 9A ...
... developer recovery section, 10 ... backflow prevention member.

Claims (1)

(57) [Scope of request for utility model registration] An electrostatic latent image formed on a surface of a photoreceptor; a one-component non-magnetic developer supplied to the electrostatic latent image to rotate in a direction opposite to the photoreceptor; A regulating roller for uniformly regulating the thickness of the developing material layer to be formed, and wherein the regulating roller is pressed against a lower portion of the developer carrying member. A voltage is applied to the regulating roller, and in the rotation direction of the developer carrier, the downstream side of the facing portion between the developer carrier and the thinning regulating roller, and
A conductive developer collecting member having a developer collecting portion detachable with respect to the developing device is formed below the developer carrying member on the upstream side of the opposing portion between the developer carrying member and the photoconductor. One end of the developer collecting member has a scraper in contact with a peripheral surface of the thinning regulating roller, and the other end of the developer collecting member is To prevent the developer from flowing out when removing the
A developing device, which is detachably connected to a backflow prevention member disposed at a position close to the photoconductor.