JPH028306B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention utilizes conventionally known appropriate principles and processes such as electrophotography, electrostatic recording, and magnetic recording to form a latent image on a latent image carrier such as a photoreceptor, dielectric material, or magnetic material. 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. It is an object of the present invention to strictly prevent the wrong order of supplying 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. 151028-1981).

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 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 attraction layer. Non-magnetic developer 2
4 is a first contact with the sleeve 12 by being put into the container 14 after the magnetic particles 20 are put therein.
A large amount of magnetic particles are stored outside the magnetic adsorption layer.

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 is a magnetic particle restraining part.
Even when the sleeve 12 is rotated in the direction of the arrow b, the magnetic particle magnetic adsorption layer near the tip of the sleeve 12 has a restraining force based on the effects of gravity, magnetic force, and the presence of the magnetic blade 23, and the magnetic particle magnetic adsorption layer in the direction of movement of the sleeve 12. Point 19 on the surface of the sleeve 12 due to balance with the conveying force of
A stationary layer 20b is formed which is restrained in position and can move to some extent, but is almost immobile. In addition, the sleeve 12 is indicated by 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 the arrow c in the vicinity of the magnetic pole 17, forming a circulating layer 20c. form. 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. 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.
3. Without climbing up, it falls due to gravity 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. 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 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 binding force based on the effects of gravity, magnetic force, and the presence of the magnetic blade 23 as described above, and The coating of the non-magnetic developer is formed on the surface of the sleeve 12 without passing 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 magnetic blade 23. As the sleeve 12 rotates, only the thin 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 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 allows stable circulation of the magnetic particles and prevents blocking of the developer, fusion of the developer, leakage of the magnetic particles, etc. at the magnetic particle restraining member. 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 this happens, not only will it be impossible in principle to form a uniform thin layer of non-magnetic developer on each part of the surface of the developing sleeve 12, but also the developer will not be able to form a uniform thin layer between the developing sleeve 12 and the magnetic blade 23. 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.

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 developer component and a storage chamber 42 for a second developer component.
The non-magnetic developer 2 (only the magnetic particles or a mixture of magnetic particles and non-magnetic developer) is stored in the second storage chamber 42.
4 (the developer only, or a small amount of magnetic particles in it,
This is a magnetic particle/developer storage container (hereinafter abbreviated as storage container) in which a magnetic particle/developer storage container (hereinafter abbreviated as storage container) contains and contains externally added flow aids, abrasives, etc.).

A flange 43 is provided around the lower part of the storage container 40, and a flange 43 is provided on 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 overlapping both flanges 43 and 14c 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.

First and second elongated openings 46 and 47 are formed in the bottom plate 45 of the storage container 40 in both parts corresponding to the first storage chamber 41 and the second storage chamber 42 in the longitudinal direction of the chamber, 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.

FIGS. 5 and 6 show the first and second openings 4, respectively.
FIG. 6 is an exploded perspective view of the bottom plate 45 viewed from below, showing how to apply the seal members 48, 49 to the seals 6, 47, and an exploded perspective view showing the state of the seal members 48, 49 while the seals are being opened. That is, the first opening 4
6 applies a sealing member length portion corresponding to the length of the first opening 46 from one end side of the first tape-shaped sealing member 48 to the entire opening length region, and The edge portion is pasted to the lower surface of the bottom plate around the opening 46 by means such as heat sealing to create a sealed state, and the remaining sealing member length portion 48a is folded back toward the tip side of the pasted sealing member 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. Folded seal member 48
The free ends 48c, 49c of a, 49a are bonded to the handle 50 at the shaded areas. Here, the remaining portion 49a of the second sealing member bent at 49b has a length l longer than the folded portion 48a of the first sealing member.
It is glued to the handle 50 with a slack 49d in the middle so that it becomes longer.

After sealing as described above, the storage container 40
Incorporate into the developing device. The seal member is opened by pulling the handle 50 by the user. FIG. 6 shows the state of this seal member in the middle of being unsealed. When the handle 50 is pulled, the first seal member 48 opens the opening 46 sequentially from the folded portion 48b. At this time, since the second seal member 49 has a slack of length l in the folded portion, the opening 47 begins to be opened from the folded portion 49b only after the handle 50 is pulled by the length l. Then, the first and second seal members are pulled to the end with the unsealing positions shifted by a length l. Therefore, the magnetic particles 20 always fall onto the sleeve 12 earlier than the non-magnetic developer 24.
In this way, as shown in FIG. 4, the magnetic particles are first supplied onto the sleeve 12, and then the non-magnetic developer is further supplied on top of that, so that the non-magnetic developer does not leak out of the developer container and scatter. .

Note that the difference l between the lengths of the seal members 48 and 49 is
It is necessary to make an appropriate selection depending on the spread of these particles when magnetic particles and non-magnetic developer are introduced. In other words, when non-magnetic developer is dropped, if the developer has good fluidity, it will spread in the axial direction of the sleeve. It is necessary to determine l.

As described above, according to the present invention, by changing the length from the folded part of the first and second seal members to the handle part, it is possible to avoid putting the developer in the wrong order and putting in the non-magnetic developer first. It is possible to reliably prevent accidents that would otherwise occur. Furthermore, the first and second seal members can be opened in one operation, thereby providing a developing device with excellent operability.

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. FIG. 4 is a side view of the developing device after loading, and FIGS. 5 and 6 are exploded perspective views of the bottom plate of the storage container and the sealing 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 is a first sealing member, and 49 is a first sealing member. No. 2 sealing member.

Claims (1)

[Claims] 1. 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; first and second seal members that cover each opening of the first and second storage portions; and an end portion of the first seal member and a second seal member. one handle member having a fixed end, and the first and second seal members have different lengths so that the second opening is opened later than the first opening. A developing device characterized in that the first developer is supplied into the developer supply container before the second developer.