JPS62208072A - Developing device - Google Patents

Abstract

PURPOSE:To surely prevent a developer from leaking by a simple method by bringing a developer sealing member into contact with the surface of a developing roller after the roller passes through a development area and providing an end-part sealing member at both ends of the seal member. CONSTITUTION:A holding part 22 for the sealing member 21 provided below a developing roller 15 is fixed to an end part of the bottom plate 12 of a developing device and an elastic sheet 23 is brought into contact with the roller 15 to seal the surface of the roller after the roller passes through the development area. The end seal member 25 is provided between both end parts of the member 21 and the side plate of the developing device 10, its U-shaped recess part is brought into contact with both ends of the roller 15, and the lower curved part 28 is brought into contact with the sheet 23. Consequently, the leakage of a developer from the contacting parts between the side plate of the developing device and the rollers 15 and 23 is surely eliminated by the simple method.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides a method for forming a monocomponent developer supplied onto a developer carrier into a thin developer layer of a predetermined thickness using a developer layer forming member;
Regarding the developing device that conveys this thin layer of developer to an electrostatic latent image holder and develops it into a visible image, a new developer seal that prevents the developer from spilling or scattering to the outside of the developing device is particularly useful. The film is transferred to a developing device equipped with a mechanism.

(Prior Art) As developing devices for conventional electrophotographic copying machines and the like, developing devices employing a cascade development method, a magnetic brush development method, a liquid development method, etc. are widely known. Developing devices that use these developing methods include toner made of powder, magnetic powder,
A so-called two-component developer is used which is mixed with a carrier consisting of fine powder or fine particles such as sand or glass peas.

However, in the case of two-component developers, the toner is charged by friction with the carrier, but these charging characteristics are
When used for a long time, the carrier gradually deteriorates and causes fogging in the background of the copied image, so the carrier must be periodically replaced with a new one.

In addition, it is necessary to maintain the mixing ratio of toner and carrier, that is, the toner concentration, within a certain range, and maintenance inspections are frequently performed, which requires a lot of work time and labor. .

In recent years, a one-component developing method that does not include a carrier has come into widespread use as a developing method for the purpose of reducing the frequency of developer replacement and downsizing the apparatus. Among them, non-magnetic developers are used because of their high transparency and are applied to color development, resulting in good curvature.

This non-magnetic component development method is described in US Pat. No. 2895
A "touchdown development method" as disclosed in No. 847 is generally known. Although this developing method requires a large device, it also uses a corotron discharge action as a means to charge the developer.
It also had many drawbacks in terms of workability and copy image quality, such as the need to periodically clean the corotron wire.

However, even with this configuration, in order to obtain a higher quality copy image, it is necessary to form a uniform and thin layer of toner on the pressure development surface and apply an appropriate charge to the toner. It remained unresolved.

To solve these problems, non-contact transfer development has been proposed, but in order to develop by flying the toner across the gap between the electrostatic latent image holder and the donor, it is necessary to
It is necessary to control the spacing below, which is extremely difficult in terms of mechanical precision of the electrostatic latent image carrier and the donor.

To solve this problem, U.S. Patent No. 3,866,574
A method is used in which an alternating electric field is applied between an electrostatic latent image carrier and a donor, as shown in Japanese Patent No. 3,890,929, and No. 3,893,574.

Since the developer used in these -component developing devices is composed of non-magnetic material, the technology for forming a uniform thin layer of developer on the developer carrier is not sufficient, and the The toner must retain sufficient electrostatic charge before being conveyed to the electrostatic latent image carrier.
As disclosed in Japanese Patent No. 92, Japanese Patent Application No. 60-155093, good results have been obtained by using a developer carrier and a single layer toner forming member.

(Problems to be Solved by the Invention) However, in conventional non-magnetic component developing devices, the developer retention of the developer holder is unstable, and the dimensional accuracy of each mechanism of the developing device is unstable. There still remains the problem that the developer spills or scatters outside the developing device due to variations.

On the other hand, when a magnetic developer is used to form a thin layer of developer using the magnetic force generated by a magnetic field generating means provided inside the developer carrier, both -component developer and two-component developer are more stable. A developer wJ layer is obtained, but when the developer carrier is rotated at a higher speed, the developer inevitably scatters and spills from the edges.

For example, according to Japanese Patent Application Laid-Open No. 52-127242@, a developing sleeve having a cylindrical magnet inside is used to convey magnetic material powder containing toner to an electrostatic latent image holder, and the toner is transferred to the electrostatic latent image holder. The electrostatic latent image on the electrostatic 7!4 latent image carrier is developed into a visible image using toner by the relative movement of the electrostatic latent image carrier and the developing sleeve.

Blade members for preventing developer from adhering are disposed at both ends of the developing sleeve to prevent developer from falling from both sides of the developing sleeve.

Further, a substantially similar configuration is disclosed in Japanese Utility Model Application Publication No. 53-125551. In general, Japanese Patent Application Laid-Open No. 60-51850 discloses an invention related to a developer sealing technology including a -component developing device, but according to this invention, the structure of the developing device is complicated, and the developer sealing technology includes a component developing device. There were problems such as insufficient sealing.

(Object of the Invention) The present invention solves the drawbacks of the conventionally used four-component developing device as described above. It is an object of the present invention to provide a developing device that can prevent this.

(Means and effects for solving the problems) The developing device of the present invention forms a layer of developer on the developing roller and supplies the developer to the latent image formed on the surface of the recording medium. A developer seal whose pressing force is set to a pressure that allows the developer layer to pass through the developer layer after passing through the development area and before the developer supply roller and the development roller come into contact. In this device, roller end sealing members are provided at both ends of the developer sealing member, and the roller end sealing members are integrated with the developer end sealing member.

This end sealing member is formed by making a slit in the middle of one sheet-like member, and one end is inserted as a sealing member between the inside of the U-shaped groove of the side plate of the developer and the end of the developing roller. The other end of the developer sealing member is placed in contact with the end of the developing roller, and the developer sealing member is disposed along the inner side of the end of the developer sealing member.

Therefore, in the developing device of the present invention, the upper F and left and right parts of the developing roller are completely sealed.
In particular, since the developer seal member that contacts the developer side plate and the roller end seal member that contacts the developer roller end are integrally configured, the developer seal member ends It is possible to reliably prevent developer from leaking from the area.

(Example) The configuration of the development IT of the present invention will be explained according to the illustrated example.

The embodiment shown in FIG. 1 is a developing device that uses non-magnetic component toner as a developer, and the developer "a10" has a hopper 11 in its upper part that stores the developer 2, and a tip end thereof. A developing row 515 is provided so as to close the opening.

A developer supply roller 17 is located behind the developing roller 15.
are provided, and both rollers 15 and 17 are rotated in opposite directions and come into contact at the contact portion of both rollers when they are moved together from the bottom to the top, and the rollers 15 and 17 contact each other when they are moved together from the bottom to the top, and the rollers 15 and 17 contact each other when they are moved together from the bottom to the top. The developing device is being relocated.

The developer 2 housed in the hopper 11 is fed downward from the rear side by the rotation of the developer supply row 517, and is transferred from the surface of the developer supply roller 17 to the developing roller 15.

Further, the developer 2 adhering to the surface of the developing roller 15 is formed into a layer with a constant thickness by a layer forming member 20 provided on the upper part of the blo of the developing device 10, and is developed into a thin layer. ! 1101000 is continuously delivered to the development area.

Then, the developing roller 15 exposed from the opening of the developing device 10 moves to the developing area, approaches the recording medium, and at the lζ position, the developer is flown from the developing roller 15 by the developing electric field, and the developing roller 15 approaches the recording medium 1. A developer is applied to the latent image formed on the surface and developed as a toner image.

Furthermore, in the developing device 10 of the present invention, a developer sealing member 21 is provided at the end where the above-described developing area ends. This developer sealing member 21 can be provided at any position between the end of the developing area and the area where the developing roller 15 and the developer supply roller 17 contact each other, and in reality, can be determined by the structure of the copying machine or the structure of the developing device.

As shown in FIGS. 1 and 2, this developer sealing member 21 includes a seal holding member 22 fixed to the end of the developer bottom plate 12 of the developer 10, and a seal holding member 22 extending at a predetermined length at the tip thereof. The end portion of the elastic sheet 23 is brought into contact with the developing roller 15 over its entire width.

The elastic sheet 23 has a thickness of, for example, 0.02 to 0.02 mm.
15am polyethylene terephthalate film (PE
T), or plate spring material with a thickness of 0.06~o, 1ai (
5O3304 plate, phosphor bronze plate, silicon steel plate W) are used.

In addition, instead of using the above-mentioned members alone, a soft elastic body such as silicone rubber, chloroprene rubber, or ethylene with a thickness of about 0.5 to 1 shoe can be used as the leaf spring material.

A member is used in which propylene rubber, fluororubber, urethane rubber, acrylic rubber, isoprene rubber, butadiene rubber, ethylene-vinyl acetate copolymer, or the like is adhered to the entire surface or the tip surface. Further, as the leaf spring material, in addition to the metal plate material, a synthetic resin member such as the above-mentioned PET may be used.

The contact pressure when the developer sealing member 21 of the present invention contacts the surface of the developing roller is usually 40Q/am or less, preferably 20q/α or less.

The surface of the developing roller 15 of the present invention is coated with side seal members 16 on both sides thereof. As described above, this side seal member 16 is provided in a portion located outside the toner image forming area, in which both ends of the developing roller 15 come into contact with the U-shaped groove 14 formed on the side plate 13 of the developing device. It is formed with a rib to act as a seal against the U-shaped filler 14.

Further, the elastic sheet 23 of the developer sealing member 21 described above
If a metal plate spring material is used alone, the developer may stick to the contact area between the surface of the developing row 515 and the elastic sheet 23, and the sealing performance of the developer may be impaired. As described above, it is desirable to use an elastic sheet such as PET or a plate spring material to which an elastic body is bonded.

Furthermore, the elastic sheet 23 preferably has a distal end surface,
It is better to use a slightly longer material that contacts the developer layer at the side surface.In addition, by using a member whose surface is conductive and applying a voltage to it, the charge m of the developing device can be electrically controlled. It is also possible to control floating toner, and also to suck up floating toner.

In addition, charge-up of the developer can be prevented by using a charging member having the same polarity as the developer as the elastic sheet of the present invention. In this case, even if the elastic sheet slides against the surface of the recording material in a state in which the developer has run out after development and frictional charging occurs, it prevents the potential of the recording material from increasing and prevents the occurrence of the hysteresis phenomenon. It will be possible to prevent this.

Therefore, when the developer seal member 21 of the present invention is used, as shown in FIG. 3, after the side surface of the elastic sheet 23 contacts the surface of the developing roller 15 and passes through the developing area, The layer of developer remaining on the surface of the developing roller 15 can be passed through, and the developer can be accommodated in the F section of the developing device 10 without being brushed off by the elastic sheet 23.

In addition to the members for sealing the opening of the current flH 110 above and below, the present invention uses an end sealing member 25 as shown in FIG. 4. This end sealing member 25 has protrusions at diagonal positions on the upper and lower sides as shown in FIG.
The other end is configured as a developer end seal member 28.

When the end sealing member 25 is attached to the developing device, each part is bent separately in the state shown in FIG. 4A, and the developing device 10 is attached in the state shown in FIG. 5. mounted on. In other words, the roller end seal member 2
7 is curved into a substantially U-shape corresponding to the U-shape 14 of the developer side plate 13, and is integrally connected to the roller end seal member 27 at the other developer end seal member 28. The portion is such that the portion in contact with the current I&0-515 is curved together with the O-La end sealing member 27, and the lower portion separated through the slit 26 is curved downward along the elastic sheet 23. Become.

In the developing device 10 of the present invention, the developing roller 1
5 and both sides of the developer side plate 13, the end sealing members 25 having the above-mentioned shape are installed, thereby sealing the contact area between the developer side plate 13 and the developer roller and the both sides of the elastic sheet 23. It is constructed in such a way that it can reliably prevent developer from leaking out.

The installed state of the end seal member 25 shown in FIG.
Although one end of the developing device 10 is shown, the end sealing member attached to the other end has a shape symmetrical to that shown in FIG. 4.

The end sealing member 25 of the present invention is an elastic member, for example, a fluororesin cloth having a thickness of 0.1 to 5IllIII;
Members such as sponge-like sheets, urethane sheets, and rubber materials are used. Therefore, by using the above-mentioned material as an end sealing member, it becomes possible to reliably seal the part to be wrapped.

FIG. 6 is a front view of the frontage of the developing device 10 of the present invention, with the recording medium 1 removed. As shown in this figure, in the developing device 10 of the present invention, the upper and lower sides of the exposed portion of the developing row 515 corresponding to the developing area are sealed by the layer forming member 20 and the developer sealing member 21. The end seal member 25 is sealed in contact with a portion corresponding to the side seal member 16.

FIG. 7 is an explanatory diagram showing the arrangement of the seal members shown in FIG. Further, the end of the elastic sheet 23 is integrally curved with the roller end sealing member 27, which seals the end of the developer side plate 13 on the developer side. Therefore, no gap will be created in that area.

The above explanation has been made regarding an example in which a non-magnetic component toner is used as the developer, but as shown in FIG. It is also possible to apply the present invention to a case where a non-magnetic sleeve 31 is provided and the developing roller 15a is used to convey the developer with the developer adhered to the surface of the sleeve 31.

In this type of developing device, magnetic component toner 2a is used, and the layer forming member 20 and developer sealing member 21 are the same as in the other developing devices described above. There is.

Furthermore, the developing device of the present invention can also be applied to developing devices configured as shown in FIGS. 9 to 11.

The developing device shown in FIG.
0 is provided at the bottom, and the developing roller 15 is provided in that area, but even if such a configuration is adopted, the area around the developing roller is completely sealed by each sealing member. Even if the developer is not blown away in the developing area and remains on the surface of the developing roller, the developer is reliably stored inside the developing device, so that the developer will not be scattered around. Prevented.

Further, as shown in FIG. 10, when a developing device configured with an opening facing upward is used at the bottom of the recording medium 1, the developer is supplied to the developing roller 15 by the developer supply row 517, The layer forming member 20 allows a layer of developer to be formed and transported to the development area.

Furthermore, in the same way, even when a developing device is provided below the recording medium 1, as shown in FIG. 11, the developing roller 15
The effects of the present invention can be fully exhibited even when the contact area between the developer and the developing row 515 is set to be very small by providing the developer row 515 with a large exposed portion on the side of the developing device 10. In this case, even without using a developer supply roller,
The developer can be reliably supplied to the developing roller.

As described above, when using the developing device configured according to the present invention, it becomes possible to arbitrarily set the arrangement of the developing device or the developing roller with respect to the recording medium, and developer leaks from around the developing roller. This will prevent it from coming out.

Example 1 In a developing device configured as shown in FIG. 1, a developing roller 15 whose surface is made of high-resistance resin is used, and a rubber layer is coated on the surface of a urethane foam layer as a developer supply row 517. Further, an end seal member 25 having a configuration as shown in FIG. 4 was provided.

As this end seal member 25, a cloth made of fluorine resin 111 with a thickness of 2.3M is used so that the developer seal member 28 can sufficiently contact the back surface of the developer seal member 21. We used a material with a suitable length that could be pressed in such a way that no gap was formed between the two members. Further, the roller end sealing member 27 is
It is adhered to the surface of the character-shaped groove 14 and is brought into contact with the side seal member 16 of the developing roller 15 with a predetermined pressure, but the pressure is set so that the developing roller 15 can rotate sufficiently. There is.

Using the developing device configured as described above, a maintenance test of a copying machine was conducted using non-magnetic component toner. 5×10
When copies were made, no toner leakage occurred, nor did toner blow out from the end of the developer sealing member. This is considered to be because the end sealing member sealed the end portion in such a manner that no gaps were formed.

(Effects of the Invention) Since the developing device of the present invention has the above-described configuration, the area around the opening of the developing device is sealed by the layer forming member and the developer sealing member, and the developing device side plate is sealed by the layer forming member and the developer sealing member. It is now possible to provide a seal so that there is no gap between the developer roller and the side plate of the developer and the developer seal member. It can reliably prevent the agent from blowing out or leaking.

In the developing area, the developer remaining on the surface of the developing roller without being blown away to the recording medium is reliably collected and stored inside the developing device, so that leaked toner can be used to make copies. Contamination of other equipment inside the machine and copies can be reliably prevented.

Further, in the developing device of the present invention, since the installation position of the developing device with respect to the recording medium is not limited, it is possible to install the developing device at any position in the space of the copying machine, and thereby, This increases the degree of freedom when designing a copying machine.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of the developing device of the present invention, FIG. 2 is a perspective view showing the structure of the developing roller and developer sealing member of the present invention, and FIG. 3 is the position of the members shown in FIG. FIG. 4 is a plan view showing the configuration of the end seal member of the present invention, FIG. 4A is a perspective view showing the state of the end seal member when installed in a developing device, and FIG. 5 is an explanatory diagram showing the relationship. An explanatory view showing the state of the end of the developing unit frontage, FIG. 6 is a front view of the opening,
FIG. 7 is an explanatory diagram showing the Ill section of each seal member,
8 to 11 are side views, each not showing the structure of another embodiment of the present invention. Reference numeral 1 in the figure: Recording body, 2: Developer, 10.
...Developer, 11...Hopper, 12...
...Developer bottom plate, 13...Developer side plate, 1
4...U-shaped groove, 15...Developing roller, 16...Nide seal member, 17...
・Developer supply roller, 20...Layer forming member, 2
DESCRIPTION OF SYMBOLS 1... Developer sealing member, 22... Seal holding member, 23... Elastic sheet, 25...
...End seal member, 26...Slit,
27... Roller end seal member, 28...
...Developer end sealing member, 30...Internal magnet, 31...Nonmagnetic sleeve.

Claims (1)

[Claims] A layer of developer is formed on the developing roller, and the developer is supplied to the latent image formed on the surface of the recording medium to perform development. a developer sealing member set at a pressure that allows the developer layer to pass through is provided at a position before the developer is contacted;
A developing device characterized in that a roller end sealing member is provided on the back side of both ends of the developer sealing member, and the roller end sealing member is configured integrally with a developer end sealing member.