JPS59189372A - Developing device - Google Patents

Abstract

PURPOSE:To perform development of high quality with good uniformity stably by producing electric fields which vary with time among plural electrodes of a developer carrier which are arranged facing an electrostatic latent image. CONSTITUTION:Linear electrodes 241-2412 on the surface of a developer carrying plate 19 which face a drum 1 are applied with polyphase AC voltages which differ in phase each other by AC power sources 25-27 to produce progressive wave type AC electric fields which progress with time form a long slanting plate part 23 to a horizontal plate part 21 and then to a shoft slanting plate part 22. Toner 11 on the surface of the lower side of the slanting plate part 23 is charged electrostatically negative by friction with the surface of the carrying plate 19, and when the progressive wave type AC electric fields are produced, the toner 11 while oscillating, flying, and turning into smoke is further charged by a corona discharger 13 in the middle of conveyance to reach the development area of the horizontal plate part 21 and then supplied to the drum 1 through an opening part 16 to develop the electrostatic latent image. Toner 11 which does not contribute to the development returns to the lower end side of the long slanting plate part 23.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electrostatic latent image developing device used, for example, in electrophotographic machines, electrostatic recording devices, and the like.

[Technical background of the invention and its problems]

Recently, an image device consists of a power source that generates alternating voltages with different phases, a carrier that supplies developer to an electrostatic latent image, and a surface of this carrier. Alternatively, a means for providing a small number of (three or more) electrodes inside, electrically connecting the power source and the electrodes, and generating an alternating electric field in the form of a traveling wave on the surface of the carrier, and a means for generating an alternating electric field in the form of a traveling wave on the surface of the carrier; means for placing a developer; and means for sending the developer to a holder having an electrostatic latent image on its surface by jumping and moving the developer using the alternating electric field and forming a developer image on the electrostatic latent image. It has been proposed that the system is equipped with
03037 and Japanese Patent Application No. 57-117233), according to this developing device, (1) the large alternating electric field on the surface of the carrier can cause the developer to jump over a long distance; It becomes possible to make it thicker.

■ There is no need to mechanically move the carrier to move the developer.

Therefore, there is no need for mechanical vibration of the carrier or means for keeping the gap between the carrier and the holder constant.

(2) Efficient development is possible because the developer does not move back and forth between the holder and carrier.

■ There is no fogging because only the charged developer adheres to the electrostatic latent image on the holder.

■ Since the primary particles in which the developer is dispersed adhere to the electrostatic latent image in a two-dimensional state, not only can detailed images be obtained, but also the gradation and fine line density are good, and the etch effect is effective. Get sharp images.

■ The holding body will not be destroyed by electric discharge.

■ Since non-contact development is possible, there is no mechanical damage to the holder, and there is no possibility that the developer will aggregate on the surface of the holder. Because post-development can be performed without disturbing the developer image,
Easy to install into color copying machines.

However, the above device has the following problems.

That is, the developer acquires an electric charge through frictional charging with the surface of the carrier, vibrates and floats due to the alternating current electric field between the electrodes, and
This vibration further promotes triboelectric charging, but when the developer particles spread on the surface of the carrier start vibrating,
Particles that have not acquired sufficient charge in advance are unable to initiate vibrational motion and remain on the surface of the carrier.

In addition, in order to solve the above problems, we have added a special developer different from the developer used in conventional two-component development methods, that is, a special charge control agent, and made it spherical to improve fluidity. In the past, it was necessary to use products that had undergone treatments such as reducing specific gravity.

Furthermore, it is necessary to increase the electric field between the electrodes by reducing the distance between the electrodes so that vibrational motion can be activated even when the amount of charge on the developer is small, and therefore a fine electrode pattern must be formed. However, since the manufacturing cost of the electrodes increases and it is unnecessary to apply a high voltage to each electrode, the electrodes and the carrier may be damaged due to discharge breakdown between the electrodes.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and its purpose is to ensure that the vibrational movement of the developer is stable and uniform even when a general developer without special treatment is used. As a result, it is possible to stably obtain a developed image with good uniformity and high quality.Furthermore, there is no need to make a fine electrode pattern on the surface of the carrier, which reduces manufacturing costs and improves the quality of the carrier. It is an object of the present invention to provide a developing device that does not require the application of high voltage to electrodes on the body surface and is free from damage caused by discharge breakdown.

[Summary of the invention]

The present invention provides a developer carrier disposed opposite to an electrostatic latent image;
By forming a temporally varying electric field between a plurality of electrodes disposed on the developer carrier and these electrodes, the developer carried on the developer carrier is smoked and the electrostatic The present invention is characterized in that it includes an electric field forming means for supplying the electric field to the bulk holder, and a charger for charging the developer carried on the developer carrier.

[Embodiments of the invention]

A first embodiment of the present invention will be described below with reference to FIG. In the figure, l is an aluminum drum as an electrostatic latent image holder having a 5e-Te based photosensitive layer 2;
is grounded and, for example, D ? in the direction of the arrow under the condition of 89w/see. r<.

Further, the photosensitive layer 2 on the surface of the drum 1 has, for example, a +30
Electrostatic latent image 3 charged with positive polarity of 0 to +800■...
is formed. The electrostatic latent image 3 is formed by, for example, uniformly charging the photosensitive layer 2 on the surface of the drum 1 with a well-known corona discharger or Rho 2 charger, and then performing imagewise exposure. .

In addition to this, a pattern corresponding to the image to be formed may be formed using a cathode ray tube or laser light, or a dot pattern of electrostatic charge may be formed using a needle electrode, a light emitting diode, etc. (10 Reference numeral 4 denotes a cylindrical roller serving as a developer carrier, which is disposed opposite to the drum 1 and rotates in the direction of the arrow. The end face is coated with a polyimide resin thin film.In addition, the cylindrical opening = 2
A plurality of copper wire electrodes 51 to 5, 6 electrically insulated from each other are disposed on the surface of the electrode 4 in the width direction and parallel to each other. These copper wire electrodes 5° to 5□6 are formed by, for example, depositing a copper thin film on a polyimide resin thin film on the outer surface of the cylindrical roller 4 by vacuum evaporation method or the like, and selectively etching this. Width is 0.
5 mvn, the thickness is 5 μm, and the distance between the electrodes is Q, 2
mm.

Furthermore, brushes (not shown) are attached to the ends of these linear electrodes 51-516.

In addition, in the area within the cylindrical row 24 facing the drum 1, there are a plurality of curved power supply electrodes 7, -7. are fixed to the circumferential surface of the cylindrical roller 4 at regular intervals, and these power supply electrodes 7□ to 7. These electrodes 7
□～7. The linear electrodes 71 to 7. have moved to the area.
The conductors 6□~ et al. are connected to 5IC. In addition, the power feeding electrodes 71 to 7. 5th, power supply electrode 71v
7m+76 is connected to the AC power supply 8, and 72.74 is connected to the DC power supply 9.

Further, 10 is a hopper, and the toner 11 as a developer supplied from this hopper 10 is insulating, and its components are styrene resin, acrylic resin, epoxy resin, polyester resin, mylene resin, or a copolymer thereof. It is a general particulate material in which carbon black, a coloring agent such as a pigment, and a charge control agent such as a dye are blended in a resin such as the following in a desired ratio. In addition, the cylindrical opening-2 of the hopper 1°
An elastic blade 12 for charging the toner 11 to, for example, a negative polarity and regulating the layer thickness of the toner 11 is provided at a later stage in the rotational direction of the toner 11 .

Further, a corona charger 13 is closely opposed to the cylindrical opening 24, and a corona wire 15 is connected to the DC power source 14.
By applying a negative voltage to the toner 11, which is supplied from the hopper 10 to the cylindrical opening 24 and carried
is charged before facing the drum 1.

With this configuration, when the cylindrical row 24 is rotated in the direction of the arrow, the toner 26 is transferred from the hopper 10 to the cylindrical row 24.
It is supplied to the surface and is thinned by the regulating action of the elastic blade 12. By applying a negative voltage (for example, -6 KV) to the corona wire 15 by the DC power supply 14 while rotating the cylindrical row 40 times,
The toner 11 that has reached the lower part of the corona charger 13 that generates negative ions is uniformly charged to a negative polarity by adsorption of the generated negative ions. Further, among the linear electrodes 5I to 516 on the surface of the cylindrical roller 4, for example, the linear electrodes 51 to 5. In addition, the non-rotating power supply electrodes 7□ to 7. via an alternating voltage (e.g. tooVp-p, tI(I-
1z) and DC IE pressure (for example, OV) are applied to every other electrode, an AC electric field is generated between the adjacent linear electrodes 5□ to 53, and a sufficient charge is acquired in advance by the corona charger I3. The toner 1 starts to vibrate under the action of the alternating current electric field, and becomes floating near the surface of the cylindrical roller 4. In this state, as the drum 1 rotates, a static current of positive polarity is applied to the cylindrical roller 24. When the latent image approaches, the floating toner IZ is attracted to the latent image and development is performed.

Therefore, even when using a general toner 11 that has not undergone any special processing, the vibration movement of the toner 11 is activated stably and uniformly, thereby stably producing a high-quality developed image with good uniformity. Obtainable. Moreover, the cylindrical row 2
There is no need to make the electrode pattern on the surface of the cylindrical row 24 minute, which reduces manufacturing costs, and there is no need to apply high voltage to the electrodes 51 to 5. does not occur.

Next, an experimental example in this embodiment will be explained.

First, the distance between the corona wire 15 and the surface of the cylindrical opening 24 is 20711 m, the voltage applied to the corona wire 15 is -6 KV, and the distance between the wire primary electrodes 5□ to 510 is 0.
．． 2 n+m, AC voltage tooV, .

Under the conditions of IKl(z, DC voltage 0), no toner vibration or floating was observed when corona charging was not performed. When corona charging was performed under the same conditions, toner 11 present in the AC electric field The toner 11 started to vibrate explosively and violently reciprocated between the electrodes, resulting in smoke. Such vibrations destroyed the aggregation of the toner 11, and the toner II became primary particles and adhered to the surface of the drum 10. The obtained developer image was extremely dense with excellent fine line reproducibility and gradation reproducibility.

Moreover, the linear electrode 5. If the distance between the linear electrodes 51 to 5 is Q and 5 mm, then these linear electrodes 51 to 5. , it was not possible to start the vibration of Toner II no matter what voltage was applied to , but when Toner 1) was corona charged under the above conditions,
AC voltage 400■p, -p.

At 1Kt-1z and a DC voltage of 0, the toner began to vibrate violently.

Furthermore, if the toner 11 is not corona charged, the polarity of the toner 1 must be sufficiently controlled using a dye or the like, and the fluidity of the toner 11 must be improved by making the toner 11 spherical. Tonano 1 barely started vibrating under any conditions. but,
When corona charging is performed, even when using general toner 11 used in the conventional two-component development method, toner 1
No began to vibrate explosively.

Next, a second embodiment of the present invention will be described with reference to FIGS. 2 and 3. Note that in FIG. 2, the same components as those in FIG. Inside this container 18 are a toner 1, a carrier plate 19 as a developer carrier fixed to face the drum 1 with a predetermined gap therebetween, and a toner 11 carried on the carrier plate 19. A corona discharger 13 for charging and a stirrer 20 for stirring the toner 1 are arranged. As shown in FIG. 3, the supporting plate 19 is made of an insulator having a short inclined plate part 22 and a long inclined plate part 23 extending obliquely downward and outward from both ends of the horizontal plate part 21. The lower end of the long inclined plate part 23 is immersed in the toner 11 on the lower inclined end side of the inclined bottom surface 17, and the lower end of the short inclined plate part 22 is located on the upper inclined end side thereof in a state that it is not immersed in the toner 11. There is.

Further, on the surface of the support plate 19, linear electrodes 241 to 24.2 are provided.
are arranged in the width direction and parallel to each other. These electrodes 24. ~2412 has AC power supply 25.26
．． 27, multiphase AC voltages having mutually different phases are applied. In other words, these AC power sources are 25.26.

27 is a three-phase AC power source whose phase differs by 120 degrees, for example, and the power source 25 connects linear electrodes 241, 24, . 247
, 24, o, a power source 26 is connected to the linear electrode 24°.

24, , 248.24. , the power supply 27 connects the linear electrode 2
4s.

246.24. ．． 2412, respectively.

Then, when an AC voltage is applied, the surface of the support plate 19 is moved from the long inclined plate part 23 to the horizontal plate part 21° and the short inclined plate part 22.
A traveling wave type alternating current electric field is generated that progresses over time.

Therefore, the toner 11 is always present on the lower end surface of the long inclined plate portion 23 of the carrier plate 19, and this toner 11 is negatively charged due to friction with the surface of the carrier plate 19. Then, when a voltage is applied to the electrodes 24, - 24.2 and a traveling wave type alternating current electric field is generated, the toner 11 vibrates, floats, and smokes between the linear electrodes 24□ - 2412, and the toner 11 is transferred to the carrier plate 19. The long inclined printing plate section 23 is conveyed with the inclined surface facing upward, and is further charged by the corona discharger 13 during the conveyance, and reaches the development area of the horizontal plate section 2, where it reaches the opening I6.
The electrostatic latent image is supplied to the drum 1 via the drum 1, where the electrostatic latent image is developed. The toner 11 that does not contribute to development is further conveyed and falls downward on the short inclined plate part 22, falls on the inclined bottom surface 17 of the container 18, slides down by the action of gravity, and reaches the lower end side of the long inclined plate part 23 of the carrier plate 19. Return to

Even with the above configuration, not only can the same effects as in the first embodiment described above be obtained, but also a toner conveying function is added, and there is no need to use a rotating body drive device as the carrier plate 19, which simplifies the apparatus. This makes it possible to reduce the size and size of the device. Particularly in this embodiment, toner charging by the first corona charger 13 is a very effective means for transporting the toner 11 upward on the inclined surface of the carrier plate 19.

[Effects of the Invention] As explained above, according to the present invention, a developer carrier disposed opposite to an electrostatic latent image holder, a plurality of electrodes disposed on this developer carrier, and an electric field forming means for supplying the developer carried on the developer carrier to the electrostatic latent image carrier in a smoked state by forming a temporally varying electric field between the electrodes; Since it is equipped with a charger that charges the developer carried on the body, even when using a general developer that has not been specially treated, the vibration movement of the developer is activated stably and uniformly. , it is possible to stably obtain a high-quality developed image with good uniformity, and there is no need to make a fine electrode pattern on the surface of the carrier, which reduces manufacturing costs and improves the quality of the surface of the carrier. There is no need to apply a high voltage to the electrodes, and there are excellent effects such as no damage caused by discharge breakdown.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing a first embodiment of the present invention, FIG. 2 is a schematic cross-sectional view showing a second embodiment of the present invention, and FIG.
The figure is a perspective view showing the support plate of the same embodiment. DESCRIPTION OF SYMBOLS 1... Electrostatic latent image holder (drum), 4... Developer carrier (cylindrical roller), 5, ~5.6... Electrode, 8...
- AC power supply, 9... DC power supply, 11... Developer (toner), 13... Charger (corona charger), 19...
・Developer carrier (carrying plate), 24□~24□2... Electrode, 25... AC power supply, 26... AC power supply, 27.
··AC source. Applicant's representative Patent attorney Takehiko Suzue Procedural amendments Showa 4 doors 8, 1ρ, 20 [-1 Commissioner of the Patent Office Kazuo Wakasugi ■, Indication of the case Patent application No. 1983-65034 2, Title of the invention Image device 3, relationship with the case of the person making the amendment Patent applicant (307) Tokyo Shibaura Electric Co., Ltd. 4, agent 6 Specification subject to amendment 7, content of amendment (1) Specification, page 2, No. 17 In the first line, ``with mechanical vibration or a carrier'' is corrected to ``with a carrier without mechanical vibration.'' (2) In the specification, from the 20th page of the 2nd page to the 1st line of the 3rd page, "■ The developer is available." is deleted. (3) In the specification, page 3, line 2, "■Only the charged developer is on the holder" has been changed to [■ Only the charged developer flies,
"on the holder" is corrected. (4) "■" in the fourth line of page 3 of the specification is corrected to "■". (5) "■" on page 3, line 9 of the specification is corrected to "■". (6) In the specification, page 3, line 10, “■” is corrected to “0.” (7) In the specification, page 4, lines 17 to 18, “It is unnecessary to apply ” is corrected to (it is also necessary to apply).

Claims (1)

[Claims] The above-mentioned development is carried out by forming a time-varying electric field between a developer carrier disposed to face the electrostatic latent image carrier, a plurality of electrodes disposed on the developer carrier, and these electrodes. The present invention further comprises an electric field forming means for supplying the developer carried on the developer carrier to the electrostatic latent image carrier in a smoked state, and a charger for charging the developer carried on the developer carrier. A developing device characterized by: