JPH0321968A - Single component developing device - Google Patents

Abstract

PURPOSE:To easily realize the desired contact pressure and to obtain a stable uniform toner thin layer by forming toner quantity control member by a supporting body which is constituted of a specific rigid body and a soft elastic body which is installed on the tip part of the supporting body. CONSTITUTION:The toner quantity control member 7 is constituted of the supporting body 7a, which is composed of the rigid body having the tensile strength of 10kg f/mm<2> or above and the soft elastic body 7b installed on the tip part of the supporting body, and the soft elastic body 7b is arranged between the supporting body 7a and the developer carrier 6 and the soft elastic body 7b is allowed to press-contact with the developer carrier 6. The supporting body 7a possesses a rotation center 7c and the toner quantity control member 7 is allowed to press-contact with the developer carrier 6 by loading moment on the supporting body. Thus, even when the contact pressure of the toner quantity control member 7 to the developer carrier 6 is changed in wide range, the uniform stable toner layer is formed on the developer carrier 6 and highly reliable development is performed for the long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a one-shot developing device for developing an electrostatic latent image using one-shot toner.

[Conventional technology]

The electrophotographic method disclosed in U.S. Pat. No. 2,297,791 to Carlson consists of ``uniformly charging a photoreceptor having a photoconductive insulating layer, forming an electrostatic latent image by imagewise exposure; For example, this is made into a visible image, that is, developed, with a substance such as electrostatic pine, and then transferred and fixed onto paper. As methods for developing this electrostatic latent image, cascade development, magnetic brush development, and liquid development are well known.

On the other hand, another important development method is U.S. Patent No. 2.895,8
There is a transfer development method using a toner carrying member called a donor, which is disclosed in No. 47. The transfer development described in this patent is as follows: (1) When the toner layer and the photoreceptor are not in contact and the toner jumps across this gap; (2) When the toner layer is in rotational contact with the photoreceptor; (2) When the toner layer is in contact with the photoreceptor. This is a general term for cases in which the image area slides in contact with the body, and is also well known as the touchdown development method. A representative prior art is JP-A-54-51g.
No. 48, Utility Model Application No. 58-146249, and U.S. Patent No. 3
, 372, (I75, 3, 426, and 730). In addition, the present inventors have previously filed an application for a one-component developing device in which a soft elastic body is attached by protruding from the tip of a support. (Japanese Patent Application No. 63-190043). Fig. 8 is a schematic diagram of this magnetic one-command developing device, and Fig. 9 is a diagram showing the state of pressure contact between the toner amount regulating member and the developer carrier. Figure a) is a side view thereof, and Figure 9(b) is a perspective view thereof.

In the figure, l is an electrostatic latent image holder consisting of a photoconductive drum capable of holding an electrostatic latent image 2, and a developing device is a photoconductive drum 1.
It is placed close to the position facing the. This developing device consists of a hopper 3 for storing a single magnetic toner, a magnet roll 5 in which a plurality of magnetic poles fixed so as not to rotate are arranged alternately, and a magnet roll 5 that rotates around the magnet roll 5. A developer carrier consisting of a freely supported non-magnetic cylindrical sleeve 6, and a toner amount regulating member consisting of a spring member placed in pressure contact with the sleeve 6 to regulate the amount of magnetic toner adhering to the sleeve 6. It is composed of a member 7. The sleeve 6 and the toner amount regulating member 7 are disposed within the flopper 3, and the sleeve 6 is disposed in the developing area A in close proximity to the photoconductive drum 1. In the developing device arranged in this manner, the monomer magnetic toner stored in the hopper 3 is held on the sleeve 6 surface of the developer carrier by the magnetic force of the magnet roll 5, and the sleeve 6 is held on the surface of the sleeve 6 on the developer carrier. By rotating the sleeve, the toner amount regulating member 7 made of a spring member controls the amount of toner adhering to the sleeve from 0.5 to 2.0.
(2) The photoconductive drum 1 and the sleeve 6 are fed into the developing area A facing each other. A DC superimposed AC voltage is applied to the sleeve 6 by an AC high-voltage power supply 8 and a DC power supply a9, and the photoconductive drum l is applied in the developing area A.
The upper electrostatic latent image 2 is developed with magnetic toner.

In addition, when using a non-magnetic one-part developer, as shown in FIG. The developer is supplied to the developer carrier by a supply member 13 rotating in the direction of the arrow at the same circumferential speed. A plate spring member 7a and a soft elastic member 7b are arranged on the developer carrier so as to be in contact with each other under a predetermined pressure. The developer 4 supplied to the developer carrier is turned into toner by the rotation of the developer carrier. It is transported to the position of the regulating member 7,
A predetermined uniform thin layer is formed, a desired charge is applied thereto, and the layer is sent to a position ZA facing the electrostatic latent image carrier 1 . An alternating voltage is applied to the developer carrier, and the alternating electric field generated in the gap between the electrostatic latent image carrier 1 and the developer carrier causes the developer to jump to the electrostatic latent image carrier l, and the electrostatic latent It is something that causes an image to appear.

[Problem to be solved by the invention]

Generally, in order to obtain a uniform and stable amount of toner sent to the developing area 8, that is, the amount of toner on the developer carrier, it is important to know how the soft elastic member 7b is evenly pressed against the axis and circumferential direction of the developer carrier. Determined by what you do.

In the conventional developing device as described above, a spring material is used as a support in the toner amount regulating member, and the
As shown in the figure, the amount of toner on the developer carrier changes depending on the deflection angle θ of the spring member of the toner regulating member, that is, the contact pressure on the developer carrier, and the amount of toner required for development is 0, 5 to 2.0 .mu./cJA is obtained by adjusting the contact pressure by adjusting the deflection angle.

However, if the toner amount regulating member is formed of a spring member, the amount of toner changes greatly depending on the contact pressure of the toner regulating member with the developer carrier. Therefore, it is difficult to arrange the toner amount regulating member on the developer carrier. is an important issue. For example, as shown in FIG. 11, the amount of toner is 0.6.
To obtain ~0.8■/1, the contact pressure should be 5~9g.
/cm, and for that purpose, the toner regulating member 7
When fixing the supporting member 7C with a constant deflection angle θ, the setting angle of the supporting member 7a is strictly defined within a narrow range of θ, ±0.4′ as shown in FIG. Therefore, it is difficult to set the support member 7a to the fixed portion 7C.

In addition, since the toner amount regulating member 7 is formed of a spring plate material, if copies are made over a long period of time, the spring plate material 7
The contact pressure of the toner regulating member to the developer carrying member may change due to minute deformation of a or the deformation of the soft elastic member 7b.
The position of the soft elastic member in pressure contact with the developer carrier and the width of the pressure contact portion change, and the amount of toner on the developer carrier gradually changes.
Eventually, the desired amount of toner could no longer be satisfied, resulting in a problem that copy quality deteriorated.

An object of the present invention is to improve the above-mentioned prior art, and even if the contact pressure of the toner amount regulating member to the developer carrier is varied over a wide range, uniform and stable distribution of the toner on the developer carrier can be achieved. It is an object of the present invention to provide a one-component developing device in which a toner layer is formed, a toner regulating member can be easily set, and development can be performed with high reliability over a long period of time.

[Means to solve the problem]

Therefore, in the one-component developing device of the present invention, the electrostatic latent image holding member 1
The toner amount regulating member 7 forms a thin layer of the developer 4 on the developer carrying member 6 by the toner amount regulating member 7. In a one-component developing device that applies an electric charge and makes the developer 4 on the thin layer adhere to the electrostatic latent image 2 and visualize it, the toner amount regulating member 7 is heated to a tensile strength of 10K.
It consists of a support body 7a made of a rigid body with a rigidity of gf/2 or more, and a soft elastic body 7b attached to the tip of this support body, and this soft elastic body acts as a link between the support body 7a and the developer carrier 6. A soft elastic body is placed between the developer carrier and the developer carrier. The support body 7a is formed of a rigid body having a tensile strength of 10 kgf/mu" or more and a thickness of 0.5 mm or more, and has a tensile strength of 1
If the thickness is 0 kgf/mm2 or less and the thickness is 0.5 mm or less, the support will be deflected in the axial direction, and the contact portion of the soft elastic body with the developer carrier and the toner layer that is uniform in the axial direction will be The problem is that it is not given any formality.

Further, the support body 7a has a rotation center 7C, and is characterized in that by applying a moment to the support body, the toner amount regulating member is brought into pressure contact with the developer carrier. The rotation center 7C is preferably provided at one end of the support 7a parallel to the axial direction of the developer carrier. There are no particular restrictions on the pressurizing method and various methods can be applied, but for example, as shown in FIG. Alternatively, as shown in FIG. 3(b), a compression coil bar may be installed at the end of the support 7a opposite to the position where the soft elastic body is attached to apply pressure. Alternatively, as shown in FIG. 3(c), it may be pressed from the rear of the support 7a and brought into pressure contact with the developer carrier. Note that when pressing the soft elastic body against the developer carrier, the support may be fixed with no rotation center provided in the support, and the soft elastic body is pressed against the developer carrier with a predetermined pressure. .

The prescribed toner adhesion amount required for development is 0.5 to 2.0 mg.
/cI1, and if the amount of Cm with toner is larger than this, background blurring will occur, and if it is smaller than this, the image density will be low. Therefore, the contact pressure of the toner amount regulating member 7 against the developer carrier is set from Ig/cm to 200 g/cta. If the contact pressure is 200 g/am or more, the stress on the toner becomes high, and if copies are continued, a problem arises in that a uniform thin layer of toner cannot be formed.

Further, the soft elastic body 7b supports the support body 7a from the tip Q*
*- attached with a length e of 10 ms. The soft elastic body 7b does not have to be attached so as to protrude from the tip of the support 7a, but preferably has a length of 10 mm or less and is attached so as to protrude from the tip of the support. If the length of the protruding portion is Ion or more, if copies are made over a long period of time, the deformation of the soft elastic body will increase, causing a problem that the amount of toner adhesion will change.

Further, when the toner amount regulating member is set, the width of the soft elastic body 7b in pressure contact with the developer carrier varies depending on the attachment length e from the tip of the support body 7a, but is approximately 0.5 to 5.5 mm. Shows a constant value while ON. The shape of silicone rubber has a thickness of 1 to 61 mm.
It is recommended that the diameter be 5 to 15 mm. Further, as the soft elastic body, a soft elastic body having a rubber hardness of 30'' to 70'' can be used.

If the rubber hardness is less than 300, toner will stick to the rubber surface, and if it is more than 70°, there will be a problem that the rubber will be worn significantly and the life of the rubber will be shortened.

[Effect]

In the present invention, the toner amount regulating member is pressed against the developer carrier. When making contact, the support of the toner amount regulating member is changed from a conventional thin spring plate to a rigid body, a soft elastic body is attached to the tip of this support, and a rotation center is provided on the support, and a moment is applied using a coil spring or the like. By pressing the soft elastic body against the developer carrier under a load of The inventors have discovered that since the toner particles can be uniformly contacted in the circumferential and axial directions of the developer carrier, a uniform and stable toner layer can be formed on the developer carrier.

[Example 1] Fig. 1 is a schematic diagram of a one-shot developing device of the present invention. In the figure, 1 is a photoconductive drum (electrostatic latent image bearing member) having a surface made of a negatively charged organic photoreceptor, and is exposed after being uniformly charged over the entire surface by a charging means (not shown). Ru. 2 is an electrostatic latent image formed on the surface of the photoreceptor, the surface potential at this time is, for example, -aoov, and the potential of the background part is -12
It is 0v. Reference numeral 3 denotes a hosopar containing a magnetic toner 4, and the toner 4 contains 48% magnetic powder. 5 is a magnet roll, which has a magnetic pattern as indicated by N and S in the figure, and is fixed to a frame (not shown).

The sleeve 6, which is a developer carrier, has a specific resistance value of 5×l07
A phenolic resin with a value of Ω was formed into a cylindrical shape with a wall thickness of 1.0 m, and its surface had a JIS 10-point average roughness of Rz = 4.3.
It is made of a semi-conductive resin that has been polished in the longitudinal direction so as to have a diameter of .mu.m, and is rotatably supported around a magnet roll 5.

The toner amount regulating member 7 has a thickness of 1.5 mm as a support body 7a. on
+ non-magnetic stainless steel (tensile strength 53 kgf/tuna M
SUS304 is used, and silicone rubber with a rubber hardness of 60'' is vulcanized and bonded to the tip of the support as the soft elastic body 7b.The silicone rubber is shaped to have a biaxial thickness and a medium IQfl to support the developer. The tip that comes into contact with the body is the support 7a.
Vulcanize and adhere to a shape having a length e of 3 tuna from the tip.

This toner amount regulating member 7 was brought into contact with the developer carrier by the urging means shown in FIG. 3(b).

When setting the toner amount regulating member, the pressure width of the soft elastic body 7b against the developer carrier shows a value of about 2 degrees, and in this case, the contact pressure of the toner amount regulating member to the developer carrier is 50 g. /
It was set as am.

This one-component developing device includes a sleeve 6 and a photoconductive drum 1.
It is installed in the copying machine so that the gap width between the
z, peak-beak voltage 2 4 0 0 V, DC command - 200 V DC weight AC voltage semi-conductive sleeve 6
to be applied. When a copy was taken in this condition, a very clear image was obtained. Furthermore, even after making copies for a long period of time, there was no effect on the toner layer on the sleeve, and clear images were obtained. The results of comparison with the conventional developing device shown in Fig. 8 will be explained with reference to Fig. 4. FIG. 4 is a diagram showing the relationship between the contact pressure of the toner amount regulating member to the developer carrier and the amount of toner adhering to the developer carrier. In the figure, line A shows the amount of toner applied in the conventional developing device, and line B shows the amount of toner applied in the developing device of the present invention. Looking at the variation of the toner adhesion amount with respect to the contact pressure, it can be seen that the developing device of the present invention is smaller than the conventional developing device, and it is easier to set the toner amount regulating member to obtain the desired toner adhesion amount. Further, even during long-term copying, a stable toner adhesion amount can be maintained because there is little change due to fluctuations in the toner amount regulating member.

Even if the direction of the toner amount regulating member 7 is arranged in the same direction as the rotation of the developer carrier as shown in FIG. Since the developer layer is regulated at the toner outflow section, a uniform developer layer can be maintained over a long period of time, and copies of good quality can be obtained stably.

[Embodiment 2] A case will be described in which a microcapsule toner is used as the toner 4 in the developing device of the present invention shown in FIG. Note that the microcapsule toner 4 stored in the hopper 3 contains 40% magnetic powder.

The support body 7a in the toner amount regulating member 7 has a thickness of 1
．． A rigid body made of 0u non-magnetic stainless steel SOS 3 0 4 is used, and the soft elastic body 7b has a rubber hardness of 50@
, IISILm silicone rubber is used, and the support 7a is
It is vulcanized and bonded to the support 7a so that it protrudes from the tip with a width (e) of 2.0 m.

The toner amount regulating member is rotated about a rotation center 7c provided at the other end of the support body 7a, and biased to press the soft elastic member 7b against the sleeve 6. This pressure contact force is 6g/c
When I1, the amount of toner on the sleeve could be controlled to 0.70/1.

This one-component developing device includes a sleeve 6 and a photoconductive drum 1.
It is installed in the copying machine so that the gap width between the AC power source 8 and the DC T! frequency 2.1 by source 9.
A DC weight AC voltage of 4 KHz, a peak-to-peak voltage of 2400 V, and a DC component of -200 V was applied to the sleeve 6. When a copy was taken in this condition, a very clear image was obtained. Furthermore, even when copies were made over a long period of time, clear images were obtained without any effect on the toner layer on the sleeve.

The effect of using microcapsule toner as the toner in the developing device of the present invention was compared with that of the conventional developing device shown in FIG. , and the amount of toner adhering to the developer carrier will be explained with reference to FIG. As is clear from FIG. 6, the amount of toner adhesion (
B line) is the toner adhesion it (
It can be seen that compared to line A), a stable amount of I-ner can be formed on the sleeve over a wide range of contact pressure.

For example, set the toner amount to 0.7±0. When it is desired to set lw/1, it is necessary to set the contact pressure to 5 to 9 g/cm in conventional developing devices, but in the developing device of the present invention, the contact pressure is 5 to 1 g/cm.
/cm and can be set over a wide range. As a result, the setting range of the contact pressure is expanded by about three times, the toner amount regulating member can be easily attached, and a stable toner layer can be formed over a long period of time.

[Embodiment 3] FIG. 7 is a schematic diagram of a non-magnetic one-shot developing device of the present invention.

In this non-magnetic one-component developing device, the soft elastic body 7b is made of glass fiberized polyphenylene oxide (tensile strength 1
2 kgf/+u+") and having a thickness of 2.Q am, the support body 7a was provided so as to protrude from the tip by 3**, and was rotated around the rotation free end 7c and pressed against the developer carrier. A uniform amount of toner was obtained, and when development was performed in the same manner as in Example 1, a very clear image was obtained.

〔Effect of the invention〕

In the developing device of the present invention, the support in the toner M developing member has a tensile strength of 10 kgf/*@'' or more and a thickness of 0.
By forming a support made of a rigid body of 5+m+* or more and a soft elastic body attached to the tip of this support, desired contact pressure can be achieved over a wide range of contact pressure between the toner control member and the developer carrier. It is possible to easily obtain contact pressure, and a stable and uniform thin toner layer can be obtained. Furthermore, compared to the conventional toner amount regulating member using a thin spring plate as a support, the difficulty in mounting the support is eliminated.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the magnetic one-component developing device of the present invention, and FIG.
3 is a diagram for explaining the shape of the toner amount regulating member in the present invention, FIG. 3 is a diagram for explaining the method of applying pressure to the toner amount regulating member, and FIG. A diagram for explaining the amount of toner adhesion in the developing device of the invention,
FIG. 5 is a schematic diagram of the magnetic single-portion developing device of the present invention when the direction of the toner amount regulating member is arranged in the same direction as the rotation of the developer carrier, and FIG. Figure 7 is a schematic diagram of the non-magnetic one-component developing apparatus of the present invention, and Figure 8 is a diagram for explaining the toner adhesion amount in the conventional developing device and the developing device of the present invention when used. A schematic diagram of a magnetic one-component developing device, FIG. 9 is a diagram for explaining the shape of a conventional toner amount regulating member, FIG. 10 is a schematic diagram of a conventional non-magnetic one-component developing device, and FIG. FIG. 12 is a diagram for explaining the relationship between the contact pressure of the l/toner amount regulating member to the developer carrier and the amount of toner adhering to the developer carrier in a conventional magnetic one-command developing device. FIG. 2 is a diagram for explaining the setting range of a toner amount regulating member of a conventional magnetic one-force phenomenon device. In the figure, 1 is an electrostatic latent image holder, 2 is an electrostatic latent image, 3 is a hover bar, 4 is toner, 5 is a magnet roll, 6 is a developer carrier consisting of a sleeve, and 7 is a toner amount regulating member. , 7a is a support body, 7b is a soft elastic body, 7c is a center of rotation, 8 is an AC high voltage power supply, and 9 is a DC power supply.

Claims (5)

[Claims] (1) A developer carrier that faces the electrostatic latent image carrier and a toner amount regulating member that is in pressure contact with the developer carrier, the toner amount regulating member causing a thin layer of developer on the developer carrier. In a one-component developing device that forms a layer and applies an electric charge to make the developer formed in the thin layer adhere to an electrostatic latent image and visualize it, the toner amount regulating member has a tensile strength of 10
kgf/mm^2 or more and a rigid support with a thickness of 0.5 mm or more, and a soft elastic body attached to the tip of this support, and the soft elastic body connects the support and the developer. A one-component developing device, characterized in that it is disposed between the developer carrier and the developer carrier and is in pressure contact with the developer carrier. (2) The one-component developing device according to claim 1, wherein the support has a rotation center, and the toner amount regulating member is pressed against the developer carrier by applying a moment to the support. (3) The one-component developing device according to claim 1, wherein the contact pressure of the toner amount regulating member against the developer carrier is set to 1 g/cm to 200 g/cm. (4) The soft elastic body is located at a distance of 0 mm to 10 mm from the tip of the support body.
2. The monocomponent developing device according to claim 1, wherein the one-component developing device is attached to the support body so as to protrude by a length of 0 mm. (5) The one-component developing device according to claim 1, wherein the soft elastic body is a soft elastic body having a rubber hardness of 30° to 70°.