JPH028304B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a technique for forming a latent image on the surface of a photoreceptor, dielectric, magnetic material, etc. using appropriate conventionally known principles and processes such as electrophotography, electrostatic recording, and magnetic recording. The present invention relates to a developing device that visualizes a latent image such as an electrostatic latent image or a magnetic latent image using a dry developer (toner).

More specifically, when the device is first used, first the first developer component and then the second developer component are sequentially introduced into the developer supply container to bring it into operation. The object of the present invention is to strictly prevent the wrong order of adding the first and second developer components.

The present applicant has previously developed a developing device of the above type, in which magnetic particles are first introduced into a developer supply container as the first developer component, and the developer of the developer holding member is rotated or rotated. The magnetic particles are adsorbed and retained as a magnetic adsorption layer (first layer) on the inner surface of the supply container, and then a non-magnetic developer is introduced as a second developer component and stored on the outside of the magnetic adsorption layer ( 2nd layer) A thin layer of non-magnetic developer is coated on the surface of the developer holding member, and a latent image is developed by applying the thin coating layer of non-magnetic developer to the surface of the latent image holding member. (Patent Application No. 151028-1982).

For convenience, this developing device will be explained below as an example.
FIG. 1 is an explanatory diagram of the structure of this type developing device. In the figure, 14 is a developer supply container, and 12 is a developing sleeve as a developer holding member.

The developing sleeve 12 is a non-magnetic sleeve made of aluminum or the like, and has a horizontal opening formed in the lower part of the left side wall of the developer supply container 14 in the longitudinal direction of the container.
The right half-circumferential surface protrudes into the container 14, and the left half-circumferential surface is exposed to the outside of the container, and is horizontally installed with a freely rotatable bearing, and is driven to rotate in the counterclockwise direction b as shown by the arrow. The developer holding member 12 is not limited to the above-mentioned cylindrical body (sleeve), but may be in the form of an endless belt that is rotationally driven. The surface of the developing sleeve 12 exposed outside the container faces the surface of a latent image holder 11, such as a photoreceptor, which is driven to move in the direction of arrow a, with a small gap therebetween.

Reference numeral 13 denotes a fixed permanent magnet (magnet) as a fixed magnetic field generating means inserted into the developing sleeve 12 and held at the position and orientation shown in the figure.Even when the developing sleeve 12 is rotationally driven, this magnet 13
is maintained at the position and posture shown in the figure. This magnet 13 has a north pole 17 and a south pole 18 .
The magnet 13 may be an electromagnet instead of a permanent magnet.

23 has a base fixed to the side wall of the container on the upper edge side of the opening of the developer supply container in which the developing sleeve 12 is disposed;
The tip side is a magnetic blade as a magnetic particle restraining member that is inserted into the container 14 from the position of the upper edge of the opening and arranged along the length of the upper edge of the opening. It is processed.

FIG. 2 is a diagram showing the attitude and angle relationship of the magnetic blade 23 with respect to the developing sleeve 12. 19 is a point on the sleeve that is located downstream of the magnetic pole 12 in the rotational direction of the sleeve and upstream in the rotational direction of the sleeve from the upper edge position of the container opening where the sleeve 12 is placed, l is the center line of the blade, and n is the normal to the sleeve 12 at the point 19. The magnetic blade 23 has its distal end located at the point 19 position with respect to the sleeve 12 with a gap d between the surface of the sleeve 12 and the sleeve 1 at the point 19.
The sleeve is disposed toward the downstream side in the direction of movement of the sleeve, with an angle δ formed between the normal n of the blade and the center line l of the blade. θ is the angle between the vertical line m passing through the rotation center of the sleeve 12 and the normal line n, p is the line connecting the rotation center of the sleeve 12 and the center of the magnetic pole 17, and π is the angle between the line P and the vertical line m. (position angle of the magnetic pole 17).

The gap distance d between the tip of the magnetic blade 23 and the surface of the developing sleeve 12 at the point 19 is 100.
~1000μ, preferably 200-500μ, in this example 300μ. If the distance d is smaller than 100μ, there is a drawback that magnetic particles, which will be described later, become clogged and are pushed out of the blade. If it is larger than 1000μ, a large amount of non-magnetic developer (described later) will leak out due to vibration, making it impossible to form a thin layer.

Reference numeral 27 denotes a magnetic particle circulation area limiting member whose lower surface is in contact with the upper surface side of the magnetic blade 23 and whose front end surface 27a is an undercut surface.

Reference numerals 20 and 24 designate magnetic particles as a first developer component and non-magnetic developer as a second developer component, which are sequentially charged and housed in the developer supply container 14.

The bottom plate of the developer supply container 14 is extended below the developing sleeve 12, which is a developer holding member, to prevent the developer from leaking to the outside. Further, in order to further ensure prevention of leakage of the developer to the outside, a leaked developer collecting member 14d receives and restrains the leaked developer on the upper surface of the extended bottom plate 14b.
A developer scattering prevention member 21 is disposed along the length of the leading edge of the extended bottom plate 14b. This member 21
A voltage of the same polarity as the developer is applied to.

The magnetic particles 20 have a particle size of 30 to 200μ, preferably
It is 70-150μ. Each magnetic particle may be made of only a magnetic material, a combination of a magnetic material and a non-magnetic material, or a mixture of two or more types of magnetic particles. By first putting the magnetic particles 20 into the developer supply container 14, the magnetic particles 20 are exposed to the sleeve surface area facing into the container 14, that is, the lower edge of the opening of the container made of magnetic material on which the sleeve 12 is disposed. Each part of the sleeve surface area from the part 14a to the tip of the magnetic blade 23 serving as a magnetic particle restraining member is attracted and held by the magnetic field of the magnet 13 in the sleeve 12, and the sleeve surface area is completely covered as a magnetic adsorption layer. Become. The non-magnetic developer 24 is put into the container 14 after the magnetic particles 20 are put therein, and a large amount of the non-magnetic developer 24 is stored on the outside of the magnetic particle magnetic adsorption layer as the first layer for the sleeve 12.

The first magnetic particles 20 preferably contain non-magnetic developer in an amount of about 2 to 70% (by weight) based on the magnetic particles, but may only contain magnetic particles. Furthermore, once the magnetic particles 20 are adsorbed and held on the sleeve surface area as a magnetic adsorption layer, they will not substantially shift to one side even if the device is vibrated or the device is tilted considerably, and the sleeve surface area will be completely covered. The covered state is maintained.

The magnetic particles 20 are placed inside the container 14 as described above.
and non-magnetic developer 24 are sequentially charged and stored, the magnetic particle magnetic adsorption layer portion near the sleeve surface corresponding to the magnetic pole 17 position of the magnet 13 has a magnetic pole 1.
A magnetic brush 20a of magnetic particles is formed by a strong magnetic field of 7.

In addition, even when the sleeve 12 is rotated in the direction of arrow b, the magnetic particle magnetic adsorption layer near the tip of the magnetic blade 23, which is a magnetic particle restraining member, is restrained due to the effects of gravity, magnetic force, and the presence of the magnetic blade 23. Due to the balance between the force and the conveyance force in the moving direction of the sleeve 12, the sleeve 12 is restrained at the point 19 on the surface thereof, forming a stationary layer 20b that can move to some extent but is almost immobile.

Also, when the sleeve 12 is rotated in the direction of arrow b,
By appropriately selecting the arrangement position of the magnetic pole 17 and the fluidity and magnetic properties of the magnetic particles 20, the magnetic brush 20a circulates in the direction of arrow c near the magnetic pole 17, forming a circulating layer 20c. In the circulation layer 20c, as the sleeve 12 rotates, the magnetic particles relatively close to the sleeve 12 rise from the vicinity of the magnetic pole 17 onto the stationary layer 20b on the downstream side of the rotation of the sleeve. In other words, it receives a force that pushes it upward. Since the upper limit of the circulation area of the pushed-up magnetic particles is determined by the magnetic particle circulation area limiting member 27 provided on the upper part of the magnetic blade 23, the magnetic particles do not climb onto the magnetic blade 23 and are subject to gravity. It then falls and returns to the vicinity of the magnetic pole 17 again. In this case, magnetic particles that are located far from the sleeve surface and receive a small push-up force may fall before reaching the magnetic particle circulation area limiting member 27. In other words, in the circulation layer 20c, the magnetic brush 20a of magnetic particles is circulated as shown by the arrow c due to the magnetic force and frictional force caused by gravity and magnetic poles, and the fluidity (viscosity) of the magnetic particles, and during this circulation, the magnetic brush 20a is made of magnetic particles. Then, the non-magnetic developer 24 is sequentially taken in from the developer layer above the magnetic particle layer and returned to the lower part of the developer supply container 14, and this cycle is repeated as the sleeve 12 is rotated. magnetic blade 2
3 is not directly involved in this cycle.

The non-magnetic developer that is successively taken in and mixed into the magnetic particle magnetic adsorption layer on the surface of the sleeve 12 is charged by friction with the magnetic particles due to the flow of the magnetic particles, friction with the surface of the developing sleeve, etc. In this case, it is preferable to apply an insulating treatment such as an oxide film or a resin at the same electrostatic level as the non-magnetic developer to the surface of the magnetic particles to reduce the triboelectric charge from the magnetic particles and transfer the necessary charge to the developing sleeve 12. By applying the developer to the developing sleeve 12, it is possible to prevent the influence of deterioration of the magnetic particles and to stabilize the application of the developer to the developing sleeve 12. Since the charged developer is non-magnetic, it is not restrained by the magnetic field of the magnetic pole 17, and while the sleeve surface rotates from the lower edge 14a of the container opening where the sleeve 12 is disposed to the tip of the magnetic blade 23. Then, due to the mirroring force, each part of the sleeve surface is coated uniformly and thinly.

Even when the sleeve 12 is rotating, the magnetic particles in the magnetic particle stationary layer 20b near the tip of the magnetic blade 23 are affected by the restraining force based on the effects of gravity, magnetic force, and the presence of the magnetic blade 23, as described above, and the sleeve 12. The thin coating of the non-magnetic developer formed on the surface of the sleeve 12 does not pass through the gap d between the tip of the magnetic blade 23 and the sleeve 12 due to the balance with the conveying force in the moving direction of the developer. As the sleeve 12 rotates, only the layer passes through the gap d, rotates toward the latent image carrier 11, and approaches the surface of the latent image carrier 11. 24a indicates a thin coating layer of non-magnetic developer formed on the surface of the developing sleeve 12. Further, a portion where the developing sleeve 12 on which the thin layer of the non-magnetic developer is formed and the latent image holder 11 come close to each other is referred to as a developing section 30.

In the developing section 30, the non-magnetic developer layer 24a on the surface side of the developing sleeve 12 is heated by the electric field of the developing bias applied between the latent image retaining body 11 and the developing sleeve 12 by the bias power supply 25. The latent images are selectively transferred and adhered to the 11th surface in accordance with the latent image pattern, and the latent images are sequentially developed 24b (for this developing method, see, for example, Japanese Patent Publication No. 32375/1983). The bias power source 25 may be an alternating current or a direct current, but it is preferably one in which alternating current and direct current are superimposed.

The surface of the developing sleeve that has passed through the developing section 30 and been consumed by selective development of the developer layer returns to the developer supply container 14 by the subsequent rotational drive of the sleeve, where it is once again formed into a magnetic particle magnetic adsorption layer. The cycle of contacting and being coated with the non-magnetic developer contained in the layer is repeated, and the surface of the latent image carrier 11 is continuously developed. As described above, the magnetic particle magnetic adsorption layer is provided with the magnetic particle circulation layer 2.
Non-magnetic developer 24 existing outside of 0c
Developer is taken in sequentially from the reservoir layer and is naturally replenished. In order to prevent the so-called ghost image phenomenon of the developing sleeve, the developer layer that has not been subjected to development is scraped off from the surface of the developing sleeve that has been rotated back into the container 14 using a scraper means (not shown). It is also preferable to bring the surface of the layer scraping sleeve into contact with the magnetic particle magnetic adsorption layer to coat the developer.

The non-magnetic developer 24 may be externally supplemented with silica particles to improve fluidity or abrasive particles to polish the surface of the photoreceptor, which is the latent image carrier 11, in a transfer image forming system. Good too. Alternatively, a non-magnetic developer 24 containing a small amount of magnetic particles may be used.

Thus, the developing device of the above example can stably coat the surface of the developer holding member with a non-magnetic developer over a long period of time as a uniform thin layer with a sufficient amount of charge on each part.
Therefore, this thin developer layer allows the latent image on the surface of the latent image carrier to be developed clearly and with good resolution.

Furthermore, since magnetic developers can produce vivid colors, high-quality color copies (single color, multicolor, natural color) with excellent color reproducibility can be obtained. In addition, since the magnetic particle restraining member is tilted toward the downstream side in the moving direction of the developer holding member, the magnetic field in the tangential direction can be stronger than the magnetic field in the normal direction on the developer holding member, and the magnetic particle circulation area limiting member This allows for stable circulation of the magnetic particles and prevents blocking of the developer at the magnetic particle restraining member, fusion of the developer, and leakage of the magnetic particles. Therefore, a pressure fixing toner can also be used as the developer.

By the way, in an apparatus such as the above example in which there is an order in which the developer components are introduced into the developer supply container, if the order of introduction is incorrect, it is not possible to obtain a good developing effect. Regarding the above-mentioned example device, if the non-magnetic developer 24 is placed first in the developer supply container 14 and then the magnetic particles 20 are placed in the developer supply container 14 in the wrong order, in principle, each portion of the non-magnetic developer is Not only will it be impossible to form a uniform thin layer, but the developer will also leak into the gap between the developing sleeve 12 and the magnetic blade 23.
A large amount of it leaks out of the container from the gap between the developing sleeve 12 and the lower edge 14a of the container opening and scatters.

The present invention has been devised to strictly prevent such mistakes in the order of loading.

FIGS. 3 to 5 show the configuration of an embodiment of the apparatus. Components common to those in the device shown in FIG. 1 are given the same reference numerals and repeated explanations will be omitted. In FIG. 3, reference numeral 40 denotes a first storage chamber 4 for storing developer components.
The first storage room 42 is divided into two compartments, the first storage room 42 and the second storage room 42.
The magnetic particles 20 (magnetic particles only, or a mixture of magnetic particles and non-magnetic developer) are placed in the storage chamber 41 in the second
A non-magnetic developer 24 (only this developer,
Alternatively, it is a magnetic particle/developer storage container (hereinafter abbreviated as storage container) in which a small amount of magnetic particles, other flow aids, abrasives, etc. are externally added).

A flange 43 extending outward around the lower part of the storage container 40 is superimposed on a flange 14d extending outward from the outer periphery of the upper opening of the developer supply container 14 of the developing device. The storage container 40 is integrally mounted on the developer supply container 14 by fixing the flanges 43 and 14d with screws 44 or the like.

In the storage container 40, a first storage chamber 41 containing the magnetic particles 20 is defined at the left side of the container 40, and is smaller than a second storage chamber 42 containing the non-magnetic developer 24. . However, there is enough capacity to accommodate the required amount of magnetic particles 20. When the storage container 40 is attached to the upper surface opening of the developer supply container 14 as described above, the first storage chamber 41 containing the magnetic particles 20 is connected to the magnetic particle circulation area limiting member 27 in the developer supply container 14 . The relationship is such that it is located almost directly above the .

The bottom plate 45 of the storage container 40 has first and second elongated openings 46 and 47 formed in the longitudinal direction of the chamber in the surface portions corresponding to the first storage chamber 41 and the second storage chamber 42, respectively. It is always sealed with a seal member 48.

The width of the sealing member 48 is the width of the first and second openings 4.
It is larger than the width in the longitudinal direction of 6,47, and the length is more than twice the combined width of each opening, has strong tensile strength, and is flexible. thing).

FIG. 4 is an exploded perspective view of the bottom plate 45 viewed from below, showing how the sealing member 48 is applied to the first and second openings 46 and 47, and FIG. 5 is a perspective view of the developer container section.

That is, by applying the sealing member 48 to the bottom plate 45 in a state that covers the entire area of the first opening 46 and the second opening 47, and pasting the sealing member 48 around the opening by means such as heat sealing. The remaining sealing member is folded back at the folded portion 48a, and the sealing end portion 48b is exposed at the side of the storage container 45. In this state, the storage container 45 and the developer supply container 14 are integrated.

On the other side, magnetic particles 20 and non-magnetic developer 24 are placed in the developer supply container 14.
When operating the developing device by sequentially introducing magnetic particles and non-magnetic developer, the magnetic particles and non-magnetic developer can be introduced in the correct order simply by pulling the seal end 48b protruding from the side of the developer supply container 14a. That is, when the user pulls the seal end 48b, the seal member 48 is sequentially removed from the folded part 48a,
First, the first opening 46 is opened and the magnetic particles 20
falls through the opening 46 onto the upper surface of the magnetic particle circulation area limiting member 27 in the developer supply container 14, and then flows down the inclined surface of the upper surface of the member toward the tip side of the member and is thrown into the container 14. . Then, the peripheral surface area of the developing sleeve 12 on the inner side of the developer supply container is completely covered with the charged magnetic particles.
Next, the second opening 47 is opened, and finally the sealing member 48 is pulled out of the developing device and removed. As a result, the non-magnetic developer 24 between the second storage chambers 42 is transferred to the opened second opening 47.
The magnetic particles 20 are then placed into the developer supply container 14 into which the magnetic particles 20 have already been placed. FIG. 1 shows the state after this injection is completed. Note that 49 is a packing member for cleaning the magnetic particles and non-magnetic developer attached to the sealing member 48 and at the same time preventing the developer from leaking from the opening.

Note that since it is desirable that the magnetic particles and non-magnetic developer fall evenly over the entire length of the developer holding member 12, the openings 46 and 47 are
It is desirable that the length of the holding member 12 be substantially parallel to the axial direction of the holding member 12 and substantially equal to the length of the holding member 12.

Further, in this embodiment, an example was described in which two types of developer, magnetic particles and non-magnetic developer, were used, but the present invention is not limited to the type of developer at all. In addition, although a disposable type developing device in which the storage container 40 for magnetic particles and non-magnetic developer is integrated with the developer supply container 14 has been described as an example, in this regard also, a replenishment cartridge in which the storage container can be replaced separately is used. The present invention can also be applied to

As described above, according to the present invention, the user can reliably introduce the magnetic particles first and then the non-magnetic developer into the developer supply container without making a mistake in the order by opening the seal. I can do it. Further, since the seal is opened in a direction perpendicular to the axial direction of the developer holding member, the length of pulling the seal can be shortened, and operability is improved.

[Brief explanation of drawings]

FIG. 1 is a side view of essential parts of an example of a developing device, FIG. 2 is an explanatory view of the arrangement posture and angle of the device, and FIG. 3 is a side view of the developing device in a state before magnetic particles and non-magnetic developer are introduced. FIG. 4 is an exploded perspective view of the bottom plate of the storage container and the sealing member, and FIG. 5 is a perspective view of the developer container section. In the figure, 14 represents a developer container, 20 represents magnetic particles, 24 represents a non-magnetic developer, 40 represents magnetic particles and a non-magnetic developer container, and 48 represents a sealing member.

Claims (1)

[Scope of Claims] 1. A first storage section that stores a first developer containing magnetic particles, and a second developer that is different from the first developer and whose main component is a non-magnetic developer. a developer storage container having a second storage section for storing developer; and a sealing member that covers each opening of the first and second storage sections, the opening direction of the sealing member being the first storage section. The developing device is characterized in that the first developer and the second developer are supplied in this order into the developer supply container.