JPH028307B2 - - 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 electrical latent images such as electrostatic latent images and magnetic latent images using dry developer (toner).

More specifically, regarding the system in which the first developer component and then the second developer component are sequentially introduced into the developer supply container at the beginning of use, the system is put 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 a first developer component, and a developer holding member that is rotated or rotationally driven is used for development. The magnetic particles are adsorbed and retained as a magnetic adsorption layer (first layer) on the inner surface of the developer supply container, and then a non-magnetic developer is introduced as a second developer component and stored outside the magnetic adsorption layer. (Second layer) A thin layer of non-magnetic developer is coated on the surface of the developer holding member, and the thin coating layer of non-magnetic developer is applied to the surface of the latent image holding member to develop the latent image. (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, for example, a non-magnetic sleeve made of aluminum or the like, and its right half-circumferential surface extends into the container 14 into a horizontally elongated opening formed in the lower part of the left side wall of the developer supply container 14 in the longitudinal direction of the container, and its left substantially half-circumferential surface extends into the container 14. It is installed horizontally with the surface exposed outside the container and supported to rotate freely.
It is rotationally driven in the counterclockwise direction b indicated by the arrow. The developer holding member 12 is not limited to the above-mentioned cylindrical body (sleeve).
It may also 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. This is what I did.

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 of the upper edge of the container opening in which the sleeve 12 is installed in the rotational direction of the sleeve, l is the center line of the blade, and n is the normal to the sleeve 12 at the point 19 position. 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 center of rotation of the sleeve 12 and the normal line n, P is the line connecting the center of rotation 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 to 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.

In FIG. 1, reference numeral 27 denotes a magnetic particle circulation area limiting member whose lower surface is in contact with the upper surface 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, which is 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. . 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 a 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. When the magnetic particles 20 and the non-magnetic developer 24 are sequentially charged and housed in the container 14 as described above, the magnetic particle magnetic adsorption layer portion near the sleeve surface corresponding to the magnetic pole 17 position of the magnet 13 is The strong magnetic field of the magnetic pole 17 forms a magnetic brush 20a of magnetic particles. Also, a magnetic blade 23 serving as a magnetic particle restraining member
Even when the sleeve 12 is rotated in the direction of the arrow b, the magnetic particle magnetic adsorption portion near the tip of the sleeve 12 receives a restraining force based on gravity, magnetic force, and the effect of the presence of the magnetic blade 23, and a restraining force in the direction of movement of the sleeve 12. It is restrained at the point 19 on the surface of the sleeve 12 due to balance with the conveying force, forming a stationary layer 20b that can move to some extent but is almost immobile. 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 rotates in the direction of arrow c near the magnetic pole 17. The water is circulated to form a circulation 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, the magnetic particles that receive a small push-up force due to being located far from the sleeve surface are removed by the magnetic particle circulation area limiting member 27.
In some cases, the object may fall before reaching the point. That is, 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 due to 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 circulation is repeated as the sleeve 12 is rotated. The magnetic blade 23 does not directly participate in this circulation.

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. If the developing sleeve 1 is exposed to
The developer application to 2 becomes stable. Since the charged developer is non-magnetic, it is not restrained by the magnetic field of the magnetic pole 17, and the sleeve surface extends from the lower edge 14a of the container opening where the sleeve 12 is disposed to the magnetic blade 23.
During rotational movement to the tip of the sleeve, the surface of the sleeve is uniformly and thinly coated on each part due to mirroring force. 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 binding force based on the effects of gravity, magnetic force, and the presence of the magnetic blade 23 as described above, and 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 conveyance force in the moving direction of the magnetic blade 23 . As the sleeve 12 rotates, only the thin coating layer passes through the gap d and rotates toward the latent image carrier 11 to come close to and face the surface of the latent image carrier. 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 side of the surface of the developing sleeve 12 is heated by the electric field of the developing bias applied between the latent image holder 11 and the developing sleeve 12 by the bias power supply 25. The latent images are selectively transferred and adhered to each other 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-type image forming apparatus, for example. good. 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 also provides 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 the developer components are added to the developer supply container in a specific order, if the order of injection is incorrect, a good developing effect cannot be obtained. Regarding the above-mentioned example device, the non-magnetic developer 24 was first placed in the developer supply container 14, and then the magnetic particles 20 were placed in the developer supply container 14 in the wrong order.
If the non-magnetic developer is injected into the developing sleeve 12, in principle it will not be possible to form a uniform thin layer of non-magnetic developer on each part of the surface of the developing sleeve 12. A large amount of it leaks out of the container from the gap or 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 and 4 show the configuration of an apparatus according to an embodiment of the present invention. 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 has two compartments, a storage chamber 41 for a first developer component and a storage chamber 42 for a second developer component, and the first storage chamber 41 has magnetic particles 20 (only for the magnetic particles). , or a mixture of magnetic particles and a non-magnetic developer) is stored in the second storage chamber 42, and the non-magnetic developer 24 (the developer alone, or a small amount of magnetic particles, other flow aids and abrasives) is stored in the second storage chamber 42. This is a magnetic particle/developer storage container (hereinafter abbreviated as storage container) in which magnetic particles and developer are contained.

A flange 43 extending outwardly around the lower part of the storage container 40 is stacked on a flange 14c extending outwardly 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 screwing the flanges 43 and 14c together with screws 44 or the like.

In the storage container 40, a first storage chamber 41 containing the magnetic particles 20 is defined on 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 opening of the developer supply container 14 as described above, the first storage chamber 41 containing the magnetic particles 20 is located inside the magnetic particle circulation area limiting member 27 in the developer supply container 14 . The relationship is such that they are located almost directly above each other.

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. They are normally sealed by first and second seal members 48 and 49, respectively. The first and second sealing members 48 and 49 have a width larger than the first and second openings 46 and 47, a length more than twice the length of each opening, strong tensile strength, and flexibility. It is a long and narrow tape-like material (for example, a tape-like cut material of a synthetic resin sheet). Figure 4 shows the seal member 4.
8,49 is shown in an opened state.

FIG. 5 shows how seal members 48 and 49 are applied to first and second openings 46 and 47, respectively.
It is an exploded perspective view of the bottom plate 45 looking up from below.
That is, the first opening 46 extends from one end side of the first tape-shaped sealing member 48 to the first opening 46 over the entire length of the opening.
A sealed state is achieved by applying a length of the sealing member corresponding to the length of the opening 46 and pasting the edge of the length of the sealing member to the lower surface of the bottom plate around the opening 46 by means such as heat sealing. Then, the remaining sealing member length portion 48a is folded back toward the distal end side of the pasted sealing material length portion. 48b indicates the folded portion.

On the other hand, the second opening 47 is also sealed with a second tape-shaped sealing member 49 in the same manner as the first opening 46 described above. Furthermore, the first seal member 48
The sealed end 48d of is adhered to the free end 49c of the folded portion 49a of the second sealing member. In this state, the storage container 40 is assembled into the developing device. When installed in the developing device, only the end portion 48c of the first sealing member is exposed to the outside of the device.
The first seal member 48 is first opened by the user pulling the first seal member end 48c, and the magnetic particles 20 are first introduced into the developer supply container 14. The first sealing member 48 is sequentially peeled off from the folded portion 48b and finally at the terminal end 48d.
When pulling out the second seal member, the end portion 49c of the second seal member hidden inside the developing device is simultaneously pulled out. The user can charge the non-magnetic developer into the developer supply container 14 by further pulling the second seal end 49c pulled out by the terminal end 48d of the first seal member. The seal members 48 and 49 may be integrated into one seal member. In this way, as shown in FIG. 4, first the magnetic particles are supplied onto the sleeve 12, and then the non-magnetic developer is further supplied thereon, so that the non-magnetic developer does not leak out of the developer container and scatter.

FIG. 6 is a side view of a developing device showing another embodiment of the present invention, and FIG. 7 is an exploded perspective view showing how the seal member is applied. In the figure, reference numeral 50 denotes a first sealing member that covers the first opening 46, and is made of a thin plate of synthetic resin or metal. It is inserted into the grooves 52 and 53 between them. A second sealing member 51 covers the second opening 47, is made of the same material as the first sealing member 50, and is inserted into the grooves 53 and 54 so that almost the entirety thereof is hidden inside the developing device. When the user starts using the device, the user first pulls the handle 50a to open the first seal member 50, and inserts the magnetic particles 20 into the developer supply container 1.
Insert within 4. When the first seal member 50 is pulled out, the protrusion 50b provided at the rear end engages with the protrusion 51a of the second seal member 51, and the end 51b of the second seal member 51 is removed from the developing device. Pull out. This second seal member end 51
The second seal member 51 is opened by holding b, and the non-magnetic developer 24 is poured into the container 14 from the storage chamber 42. In this way, magnetic particles and non-magnetic developer are placed in the container 14 in the same order as in the embodiment shown in FIG.
can be put into.

As described above, according to the present invention, with a simple configuration, it is possible to prevent a user from making a mistake in the order in which two types of developers are introduced. Furthermore, since the second seal can only be opened after the first seal member has been completely pulled out, non-magnetic developer can be introduced after the magnetic particles have reliably covered the developing sleeve, preventing scattering. Problems such as this can be prevented.

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 single-use type developing device has been described as an example in which the storage container 40 for magnetic particles and non-magnetic developer is integrated with the developer supply container 14, in this respect as well, the storage container is separate from the developing device. It can also be applied to replaceable supply cartridges.

[Brief explanation of drawings]

Figure 1 is a side view of the main parts of an example of a developing device, Figure 2 is an explanatory view of the orientation and angle of the developing sleeve and magnetic blade of the device, and Figure 3 is a diagram of the state before magnetic particles and non-magnetic developer are introduced. 4 is a side view of the developing device after charging, FIG. 5 is an exploded perspective view of the bottom plate of the storage container and the sealing member, and FIG. 6 is a side view of another embodiment of the present invention. FIG. 7 is an exploded perspective view of the storage container and the seal member. In the figure, 14 is a developer container, 20 is a magnetic particle, 24 is a non-magnetic developer, 41 is a storage chamber for magnetic particles, 42 is a storage chamber for non-magnetic developer, 48 and 50 are first seal members, 49 , 51 represents a second seal 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 first and second seal members that cover respective openings of the first and second storage sections that are arranged horizontally to each other. , after the opening operation of the first seal member is completed, the second seal member is opened.
In order to unseal the seal member, engaging portions that engage with each other are provided on the rear end side of the first seal member and the front end side of the second seal member, and the first and second developers are applied in this order. A developing device characterized by supplying into a supply container. 2. A first storage section that stores a first developer containing magnetic particles, and a second storage section that stores a second developer that is different from the first developer and whose main component is a non-magnetic developer. a developer storage container having two storage portions, and first and second seal members that cover respective openings of the first and second storage portions that are arranged laterally to each other, the first seal member having a first seal member; After the opening operation is completed, the second
In order to unseal the seal member, the rear end side of the first seal member and the front end side of the second seal member are connected, and the first and second developers are supplied into the developer supply container in this order. A developing device characterized by: