JPH04338777A - Transporting method for developer and developing device - Google Patents

Abstract

PURPOSE:To provide the transporting method for a developer which efficiently transports the developer upward even on a planar surface and the developing device. CONSTITUTION:An acoustic wave propagating member 21 having an acoustic wave exciting means 8 and a transmitting means 41 is disposed to face the wall surface of a hopper 1 apart a prescribed spacing and the developer is transported upward.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device that performs development using a dry developer and a method of transporting the developer within the dry developing device.

0002

2. Description of the Related Art Conventionally, a screw, a bucket, or the like has been used to transport a developer in a developing device that performs development using a dry developer.

However, in many cases, the inner wall of the developer container behind the developer carrier in a dry developing device is plate-shaped and slopes diagonally upward, and in this case, the developer transport method using the above-mentioned screw etc. This caused various problems.

For example, to explain a developing device using a one-component thin layer developing method as an example, in this type of developing device,
A so-called "ghost image", which causes a difference in image density due to a difference in image history, may occur.

As a method for preventing this ghost image, as shown in FIG. 15, an elastic roller 7 is provided as a developer stripping means on the surface of the developing sleeve 3 as a developer carrying member at a location past the development position. Rub and rub the developing sleeve 3
It has been conventional practice to strip off the remaining developer on the surface.

Furthermore, as shown in FIG. 16, an elastic roller 7
Instead, there is also a method of using an electrode roller 70 to strip off the remaining developer on the developing sleeve 3.

[0007] Using a one-component developer as described above, the residual developer on the developing sleeve 3 after passing through the developing position is once stripped off by the elastic roller 7 or the electrode roller 70, and the regulating blade 5 is used to carry out the development to the developing position. The amount of ingress of the agent is regulated and electrostatic attraction is used to transfer the agent from the developing sleeve 3 to the non-contact photosensitive drum 6.
The method of developing by moving the developer to the developer is free from ghost images and is extremely excellent in terms of development performance, image reproducibility, developer life, etc.

[0008]

[Problems to be Solved by the Invention] However, in the conventional developing method as described above, when the developer on the developing sleeve 3 is stripped off using the elastic roller 7 or the like, the stripped off developer is disposed in the lower part of the strip. As a result, the developer may become clogged or spilled. To prevent this, the developer below the stripping area can be transported into the developer container 1, but the inner wall of the developer container 1 behind the developing sleeve 3 is usually plate-shaped and slopes diagonally upward. Therefore, it is necessary to devise ways to transport the developer on a wide plate-like surface against gravity.

If a screw is used as a conveyance means in such a case, there is a problem that the conveyance efficiency decreases if the gap between the screw and the inner wall of the developer container is large; If the value is small, the conveyance efficiency increases, but the rotational torque of the screw increases due to the friction between the screw and the inner wall of the developer container, and this friction causes the developer to deteriorate, break, or melt due to frictional heat. was there. Further, since the developer is generally easily charged, the developer is often charged during transportation and adheres to the screw, and in severe cases, there is a problem in that image quality is impaired or transportation failure occurs.

Furthermore, depending on the depth of the developer container, a large number of screws may be required, resulting in problems such as a complicated device configuration, high costs, and an increase in the size of the device. Furthermore, failures were likely to occur due to wear and vibration load fluctuations in the mechanical drive section of the screw.

The present invention has been made in view of the above circumstances, and has (1) a simple structure, and (2) directs the developer upward even on a plate-like surface.
■Efficient and stable transport; ■No deterioration of developer; ■Stably maintains image quality; ■No developer clogging or spillage; ■Quiet; ■Failure due to mechanical drive. The object of the present invention is to provide a developer conveying method and a developing device that have a low probability of occurrence.

Furthermore, in order to prevent ghost images in a one-component thin layer development method, the present invention can be applied to a developer conveying method in a dry type developing device that is provided with a stripping means for stripping off residual developer on a developing sleeve. To provide a developing device that has a simple configuration, has no image fog, no ghost, has high image density, and does not cause developer clogging or spillage, and can stably obtain high-quality images.

[0013]

According to the present invention, the developer in the dry developing device is transported upward along the plate-like surface by the developer transport means, so that the developer does not stagnate. Therefore, deterioration of the developer is prevented and image quality is stably maintained. Further, clogging and spillage of developer will not occur. Furthermore, by applying the present invention to a method for transporting developer in a dry developing device, ghost images, developer clogging, and spillage can be prevented, and high-quality images can be stably provided.

[0014]

Embodiments First to seventh embodiments of the present invention will be explained based on the drawings.

First Embodiment First, a first embodiment of the present invention will be described with reference to FIGS. 1 to 3.

FIG. 1 is a sectional view showing a first embodiment of the developing device of the present invention, which is applied to a copying machine equipped with a drum-shaped photosensitive drum 6 as a latent image carrier. Although not shown in the figure, the photosensitive drum 6, which is rotatably supported in the direction of the arrow A in the figure, is surrounded by a charging mechanism, an image exposure mechanism, a transfer mechanism, and a cleaning mechanism used in the electrophotographic process, as is well known. mechanism, static elimination mechanism, etc. are installed. In order to develop the latent image on the photosensitive drum 6, a developing mechanism as described below is disposed at a position facing the photosensitive drum 6.

First, a hopper 1 serving as a developer container is provided as a means for storing monocomponent non-magnetic toner (hereinafter referred to as toner) 2 as a developer. At the opening of the hopper 1, a non-magnetic developing sleeve 3, which is a developer carrier, is arranged to face the circumferential surface of the photosensitive drum 6 with a predetermined distance therebetween. Further, the hopper 1 is provided with an elastic blade 5 serving as a developer layer thickness regulating member for regulating the developer on the surface of the developing sleeve 3 to a required thickness of the coating layer. Other components include an elastic roller 7 as a developer supplying means and a developer stripping means that is in contact with the surface of the developing sleeve 3 and rotatably supported within the hopper 1, and a hopper 1 behind the elastic roller 7. A sound wave propagation member 21 provided substantially parallel to the inner wall, an ultrasonic excitation means 8 for vibrating the sound wave propagation member 21, and a mechanical-electric conversion means 9;
A toner feeding member 12 is provided as a developer stirring and conveying means for supplying the developer in the rear chamber S2 to the hopper front chamber S1 in which the developing sleeve 3, the elastic roller 7, etc. are disposed.

The opening of the hopper 1 is formed to extend in the longitudinal direction of the developing device (perpendicular to the plane of the paper), and the developing sleeve 3 disposed in the opening is made of aluminum, stainless steel, or the like. Made of non-magnetic material. The developing sleeve 3 is rotatably supported and rotationally driven in the direction of arrow B by a drive source (not shown). The surface of the developing sleeve 3 has a thickness of 0.5 to 5 μm to ensure toner retention.
Concavities and convexities with a pitch of m are formed.

The elastic roller 7 disposed behind the developing sleeve 3 rotates in sliding contact with the developing sleeve 3, and rotates in the same direction as the developing sleeve 3 to transfer the developer to the developing sleeve. The developing sleeve 3 is supplied to the sleeve 3 and is brought into elastic contact with the developing sleeve 3.
Peel off the top toner.

Further, the elastic blade 5 is located downstream of the sliding contact portion between the elastic roller 7 and the developing sleeve 3 in the rotational direction of the developing sleeve 3, and the free end of the elastic blade 5 is connected to the developing sleeve 3. 3 and restricts the passage of the developer on the developing sleeve 3 at this abutting portion.

The elastic blade 5 is preferably made of a triboelectrification material suitable for charging the toner to a desired polarity. For example, in order to positively charge a toner containing polystyrene, carbon, etc., ethylene propylene rubber, fluorine rubber, natural rubber, polychlorobutadiene, polyisoben, N. B. R and the like are preferred, and in order to negatively charge the toner, silicone rubber, polyurethane, styrene butadiene, etc. may be used. By using the above-mentioned materials, it is possible to further increase the frictional charging efficiency of the toner. In addition, when a suitably selected conductive rubber is used in the triboelectrification array as described above, it is possible to prevent the toner from being excessively triboelectrified, thus preventing or loosening the electrostatic agglomeration or solidification of the toner. effective. In addition to the materials mentioned above,
Metal sheets such as phosphor bronze and stainless steel can also be used.

The elastic roller 7 has an elastic layer 72 provided around the outer periphery of a shaft 71 made of a rigid body such as iron or stainless steel. These elastic materials can be used alone or in appropriate combinations. For example, the elastic layer may have a two-layer structure, with the lower layer made of silicone sponge rubber and the upper layer made of urethane rubber. With such a configuration, dimensional accuracy of the outer periphery of the elastic layer can be obtained.

Further, the contact portion between the elastic blade 5 and the developing sleeve 3 is located closer to the elastic roller 7 than the vertical line passing through the center of the developing sleeve 3 and above the elastic roller 7, and is located above the elastic roller 7. The sliding contact portion between the roller 7 and the developing sleeve 3 and the contact portion have a positional relationship with each other such that the toner separated at the contact portion can fall onto the elastic roller 7. In this way, a smooth circulating flow of toner is formed in the space between the abutting portion and the sliding contact portion.

As described above, behind the elastic roller 7, a sound wave propagation member 21 and an ultrasonic excitation means 8 for vibrating the sound wave propagation member 21 by ultrasonic waves are arranged substantially parallel to the inner wall of the hopper 1. There is.

Next, a method of transporting toner using ultrasonic excitation will be described with reference to FIG.

In FIG. 2, reference numerals 21 and 23 indicate flat sound wave propagation members, and both members are disposed close to each other and facing each other. 8 is an ultrasonic excitation means, which includes a piezoelectric vibration element 81
It is composed of a high frequency power source 82 and a horn 83 that drive this. Reference numeral 41 denotes a transmission means for transmitting vibrations generated by the ultrasonic excitation means 8 to one end of the plate-shaped sound wave propagation member 21 uniformly in the width direction of the sound wave propagation member 21. 4
2 is a long and narrow hole. These elongated holes 42 are provided with holes of different shapes at the positions of the transmission means 41 corresponding to the central part and the ends thereof in the width direction of the sound wave propagation member 21, so that the vibrations caused by the ultrasonic excitation means 8 can be prevented. The sound waves are designed to be uniformly transmitted to the plate-shaped sound wave propagation member 21 in the width direction of the sound wave propagation member 21. Reference numeral 43 denotes an additional vibrating body, and the additional vibrating body 43 is located behind the transmitting means 41 as shown in FIG. It is installed to perform vibration adjustment.

Reference numeral 9 denotes a mechanical-electrical conversion means for converting mechanical vibration into electrical energy. One side of the sound wave propagation member 21 opposite to the above (in FIG. 2, the sound wave propagation member 21
(on the right side of the
3, and this electromechanical conversion means 9 is provided behind the transmission means 41. 93 is a horn similar to 83. 91 is a piezoelectric element. Reference numeral 92 denotes an electrical resistance load, which converts mechanical vibration into electrical energy by the piezoelectric element 91 and converts it into thermal energy, thereby absorbing the energy from the mechanical vibration. The electromechanical conversion means 9 includes this horn 93 and the piezoelectric element 91
and an electrical resistance load 92. The purpose of these is to allow the transmission means 41 to receive the mechanical vibrations propagated through the sound wave propagation member 21, and to further absorb the energy of the mechanical vibrations by the electromechanical conversion means 9.

Further, the vibration by the ultrasonic excitation oscillation means 8 is transmitted to one end of the sound wave propagation member 21 through the transmission means 41 to cause ultrasonic excitation, thereby giving the sound wave propagation member 21 a traveling transverse wave. In this way, by arranging the sound wave propagation member 23 in close proximity to the sound wave propagation member 21, the ultrasonic wave reflection effect of the sound wave propagation member 23 causes the sound wave propagation member 2
It is possible to increase the sound pressure of the air to be floated between 1 and 23, and it is possible to efficiently move the standing wave sound field. As a result, the developer can be transported in the direction of the arrow while floating between the sound wave propagating members 21 and 23.

For example, when charged developing particles (toner) for electrophotography (recording) in which a thermoplastic resin with an average particle diameter of 3 μm to 30 μm is used as a binder component, the sound wave propagation member 21 made of an aluminum plate is used. , 23, these charged particles could be transported at a sufficiently high speed and high density without being strongly electrostatically attached due to electrostatic mirroring force. Even under harsh environments such as low humidity, the conveyance performance remained stable and could be conveyed stably. Note that this is a case where the high frequency power source 82 is ultrasonically excited at a frequency between 20 kHz and 60 kHz. The gap length between the sound wave propagating members 21 and 23 which are arranged in close proximity is, for example, about several tens of micrometers to several mm, but it goes without saying that it also depends on the power of ultrasonic excitation. The sound wave propagation member 21 and the transmission means 41 are supported by fixedly supporting the vibration node portions of the horns 83 and 93.

FIG. 3 is a perspective view showing the main part of the toner conveying means using ultrasonic excitation in this embodiment. In FIG. 3, 21 is a sound wave propagation member on a flat plate, and the sound wave propagation member 2
1 is disposed close to and facing the hopper 1. Further, above the sound wave propagation member 21, an additional vibrating body 43, an ultrasonic excitation means 8, and a mechanical-electric conversion means 9 are connected via a transmission means 41.
is installed. The central portion of the transmission means 41 on the side of the sound wave propagation member is open and serves as a powder passage port (hereinafter referred to as a toner passage port) 42, and the vibration by the ultrasonic excitation oscillation means 8 is transmitted to the sound wave propagation member through the transmission means 41. The ultrasonic wave is transmitted to one end of the wave propagation member 21 to excite the ultrasonic wave, and a traveling transverse wave is applied to the sound wave propagation member 21. In this way, since the sound wave propagation member 21 and the hopper 1 are arranged close to each other, the sound pressure of the air to be floated between the sound wave propagation member 21 and the hopper 1 can be increased, and the standing wave can be efficiently You can move the sound field. As a result, the sound wave propagation member 21 and the hopper 1
The toner can be efficiently transported while floating the toner in between.

Reference numeral 10 denotes a toner 2 which is conveyed to the upper right direction between the sound wave propagation member 21 and the hopper 1 by the ultrasonic excitation means 8.
It is a deflecting member for deflecting the conveying direction of the toner 2 and causing the toner 2 to fall and convey onto the sound wave propagation member 21, and has a curved shape. Therefore, the toner stripped from the developing sleeve 3 by the elastic roller 7 is conveyed obliquely upward between the sound wave propagation member 21 and the hopper 1 by the traveling wave transmitted to the sound wave propagation member 21 by the ultrasonic excitation means 8. ,
It is deflected diagonally downward by the deflection member 10 fixed to the hopper 1 and falls onto the sound wave propagation member 21 . The fallen toner joins and mixes with the toner that has been conveyed from the hopper rear chamber S2 over the guide wall 13 by the toner conveying member 12, and is then transferred onto the sound wave propagating member 21 by the conveying force caused by ultrasonic excitation and the action of gravity. is conveyed diagonally downward, and further conveyed diagonally downward while passing through the toner passage port 42 which is the central opening of the transmission means 41. After that, the elastic roller 7
and further supplied to the developing sleeve 3.

Further, a sealing member 11 is provided below the developing sleeve 3 of the apparatus of this embodiment to close the gap with the hopper 1. The sealing member 11 is a flexible sheet such as Mylar (trade name manufactured by DuPont; the same applies to Mylar hereinafter).

Note that a power source 15 is disposed between the photosensitive drum 6 and the developing sleeve 3 to apply a bias. The method described above applies an alternating current in which a direct current is superimposed between the photosensitive drum 6 and the developing sleeve 3, and the thin layer of toner on the developing sleeve 3 is imagewise transferred to the electrostatic latent image on the photosensitive drum 6. Although a so-called non-contact development method can be used, a contact development method may also be used.

Next, the operation of the apparatus of this embodiment as described above will be explained.

In FIG. 1, the toner feeding member 12 rotates in the direction of the arrow to convey the toner 2 to the elastic roller 7, and the elastic roller 7 rotates in the direction of the arrow C to convey the toner 2 onto the elastic roller 7. is supplied to the sliding contact portion with the developing sleeve 3. Next, at the sliding contact portion between the developing sleeve 3 and the elastic roller 7, the toner 2 on the elastic roller 7 is transferred to the developing sleeve 3.
By coming into sliding contact with the developing sleeve 3, the developing sleeve 3 receives frictional electrification and is supplied to the developing sleeve 3.

Further, when the toner 2 passes through the contact portion between the elastic blade 5 and the developing sleeve 3, it comes into sliding contact with the surface of the developing sleeve 3 by the elastic blade 5, and is further subjected to frictional electrification. In this way, the toner 2 can receive sufficient triboelectric charging. The toner 2 that has been sufficiently triboelectrically charged passes through the contact portion and is formed as a thin layer of toner on the developing sleeve 3, and is carried on the developing sleeve 3 to a developing section facing the photosensitive drum 6. In the developing section, some toner is consumed by the developing operation, and other toner is collected from the lower part of the developing sleeve 3 as the developing sleeve 3 rotates. A sealing member 11 is provided in this collection portion to allow the toner that has not been consumed in development to pass into the hopper 1 and to prevent the toner 2 in the hopper 1 from leaking from the lower part of the hopper 1. The collected toner on the developing sleeve 3 is scraped off by elastic contact at the sliding contact portion between the elastic roller 7 and the developing sleeve 3. The scraped off toner is floated and conveyed into the hopper 1 between the sound wave propagation member 21 and the hopper 1 as shown by arrow D by the action of ultrasonic excitation, and is deflected downward by the deflection member 10. At this time, it merges with the toner conveyed by the toner conveying member 12, is conveyed downward on the sound wave propagation member 21 by the conveying force caused by the ultrasonic excitation, and the action of gravity, and is again transferred to the elastic roller 7 and the developing sleeve as described above. It is transported to the sliding contact part with 3. Therefore, even with such a simple configuration, the toner stripped off from the developing sleeve by the developer stripping means can be efficiently and stably transported into the hopper, thereby preventing toner clogging and spillage. In addition, toner that was not subjected to development due to a non-image forming area (blank area) on the surface of the photosensitive drum 6 or toner that was not subjected to development due to a defective tribo is mixed with newly replenished toner. Since toner can be reused at the same time, uneven consumption of toner can be prevented.

Next, an experimental example conducted under the following conditions will be explained.

In this experimental example, a developing sleeve with a diameter of 2
The surface of an aluminum sleeve with a diameter of 0 mm was roughened with No. 600 sandpaper to form unevenness with a pitch of 1.5 μm. The elastic blade has a thickness of 2 mm,
Urethane with a width of 20 mm and a hardness of 60° rubber was used. Regarding hardness, when the dimensions and shapes are changed, 5
0° to 80° was effective.

The non-magnetic toner used at this time was a powder containing 10 parts of carbon and 90 parts of polystyrene with an average particle diameter of 7 to 15 μm, and approximately 1.0% of silica was added as an external additive. Gives fluidity to the toner. A thin Mylar seal with a thickness of 50 μm was used as a seal member to prevent the toner from scattering from the container. The contact pressure of the elastic blade against the developing sleeve is effective to be about 5 to 100 g/cm when the hardness and size and shape of the blade are changed, and it is preferable to keep the error within 5 g in the longitudinal direction of the developing sleeve. In the experimental example, it was set to about 45 g/cm. As the elastic roller, a foamed Everlight (trade name manufactured by Bridgestone Corporation. The same applies to Everlight) material with a diameter of 1 mm is wound around a stainless steel core metal with a diameter of 6 mm.
A sponge roller shaped into a roller with a diameter of 14 mm was used. In addition, the developing sleeve was rotated at 120 mm/sec and the supply roller was rotated at a relative speed of 50 to 30 mm with respect to the developing sleeve.
It was rotated at a speed of 00 mm/sec. The results below are
This is when the speed was set to 70mm/sec.

As the sound wave propagation member 21, an aluminum plate having a thickness of 2 mm was used, and the distance between the sound wave propagation member 21 and the bottom surface of the hopper 1 was 2 mm. As a sealing member, foam diameter 1
mm Everlight was used. An alternating current voltage with a peak-to-peak voltage of 100 V and a frequency of 50 kHz was applied to the ultrasonic excitation means 8.

As a result of conducting the experiment in this manner, it was found that the surface of the developing sleeve had no streaks of 30 to 100 μm.
A thin toner layer could be formed. It was also confirmed that the toner layer thickness could be changed by changing the linear pressure of the elastic blade.

In this experimental example, the thickness of the toner layer on the developing sleeve was made smaller than the length of the facing gap between the developing sleeve and the photosensitive drum, and the toner was moved from the developing sleeve to the photosensitive drum within the gap as described above. A method of developing the film (so-called non-contact development or jumping development) was used.

In this experimental example, a dark area of +60
0V, forming a latent image with 0V in bright areas, keeping the gap between the photosensitive drum and developing sleeve at about 300 μm, regulating the toner layer thickness to 50 μm, and applying a peak-to-peak voltage of 1400 V and a 1800 Hz square wave to the developing sleeve. +1 to alternating voltage
A developing bias with a DC voltage of 50 V superimposed was applied, and development was carried out using an NP1215 machine manufactured by Canon Inc. (process speed 100 mm/sec).

As a result, even under long-term use, the toner can be transported efficiently and stably, and the image density is sufficiently high without causing toner deterioration, toner clogging, or spillage, and without producing "ghost images." It was possible to maintain a stable and good image without image deterioration such as background fog or scattering. Furthermore, toner could be transported quietly without any noise, and no malfunctions occurred.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIGS. 4 and 5. The same reference numerals are given to the same parts as in the first embodiment, and the explanation thereof will be omitted.

FIG. 4 is a side cross-sectional view of the developing device according to this embodiment, and FIG. 5 is a perspective view showing the main parts of the toner conveying means using ultrasonic excitation according to this embodiment (a portion slightly before the center in the longitudinal direction). perspective view when cut at the position).

This embodiment differs from the first embodiment only in the arrangement of the ultrasonic excitation means, and the other structures are the same.

That is, the ultrasonic excitation means 8 and the transmission means 4
1. The electromechanical conversion means 9 and the like are arranged below the sound wave propagation member 21 rather than above it.

Even in such a configuration, the elastic roller 7
The toner peeled off from the top of the developing sleeve 3 is conveyed obliquely upward between the sound wave propagation member 21 and the hopper 1 by the traveling wave transmitted to the sound wave propagation member 21 by the ultrasonic excitation means 8, and is transported diagonally upward to the center of the transmission means 41. It is further conveyed diagonally upward while passing through the open portion, and is deflected diagonally downward by a deflection member 10 fixed to the hopper 1. At this time, the toner feeding member 12 moves the guide wall 1 from the hopper rear chamber S2.
It joins and mixes with the toner that has been conveyed in small amounts over 3. The mixed toner is conveyed obliquely downward on the sound wave propagating member 21 by the conveying force caused by ultrasonic excitation and the action of gravity, and is supplied to the elastic roller 7 and further to the developing sleeve 3.

When an image was formed using the apparatus of this embodiment in the same manner as in the first embodiment, there was little or no difference in image density due to differences in image history (so-called ghost images), there was no clogging or spillage of toner, and there was no background image. There is no image deterioration such as fogging or scattering, and a sufficiently high image density is maintained.
Stable and good images were obtained. Furthermore, toner could be transported quietly without any noise, and no malfunctions occurred.

<Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIGS. 6 and 7. The same reference numerals are given to the same parts as in the first embodiment, and the explanation thereof will be omitted.

FIG. 6 is a sectional side view of a developing device showing this embodiment, and FIG. 7 is a perspective view showing a main part of a toner conveying means using ultrasonic excitation of this embodiment.

This example is based on the sound wave propagation member 2 of the first example.
A flat plate 23 is provided above the flat plate 1, and a sound wave propagating member 24 is provided above the flat plate 23, and an ultrasonic excitation means 8' and a mechanical-electrical converting means 9' are connected to both upper ends of the sound wave propagating member 24 via transmission means 44, respectively. The deflection means 10 provided in the first embodiment is removed.

Further, the sound wave propagation member 21 and the flat plate 23 are arranged close to each other and opposed to each other, and the sound wave propagation member 2
A sealing member 22 is disposed between the hopper 1 and the hopper 1 . As the sealing member 21, a flexible adhesive tape such as Mylar tape or Sellotape, or a foam such as sponge rubber or Moltoprene was used.

To explain the conveyance of toner by ultrasonic excitation in this embodiment, the toner stripped off from the developing sleeve 3 by the elastic roller 7 serving as developer peeling means is transferred to the sound wave propagation member 21 by the ultrasonic excitation means 8. The traveling wave transmitted to
The toner discharged and conveyed to the upper right of the toner transport member 1
2, it joins and mixes with the toner that has been conveyed little by little over the guide wall 13 from the hopper rear chamber S2. The mixed toner is conveyed obliquely downward between the sound wave propagation member 24 and the flat plate 23 by a traveling wave transmitted to the sound wave propagation member 24 by the ultrasonic excitation means 8', and is then supplied to the elastic roller 7, and then developed. It is supplied to the sleeve 3.

With this configuration, the toner peeled off from the developing sleeve is stably conveyed diagonally upward as in the first embodiment, but the toner is conveyed beyond the guide wall 13 from the hopper rear chamber S2. This has the effect of more stably conveying and supplying the toner to the elastic roller 7 after merging and mixing with the incoming toner.

When an image was formed using the apparatus of this embodiment in the same manner as in the first embodiment, there was little or no difference in image density due to differences in image history (so-called ghost images), there was no toner clogging or spillage, and there was no background image. There is no image deterioration such as fogging or scattering, and a sufficiently high image density is maintained.
Stable and good images were obtained. Furthermore, toner could be transported quietly without any noise, and no malfunctions occurred.

<Fourth Embodiment> Next, a fourth embodiment of the present invention will be described with reference to FIGS. 8 to 10. The same reference numerals are given to the same parts as in the first embodiment, and the explanation thereof will be omitted.

This embodiment differs from the first embodiment only in the arrangement of the ultrasonic excitation means, and the other structures are the same.

FIG. 8 is a side sectional view of a developing device showing this embodiment, and will be described later.

FIG. 9 shows a method of applying a traveling wave to a sound wave propagation member, which is different from the method of ultrasonic excitation of the propagation member by the ultrasonic wave excitation means 8 used in the first to third embodiments. Another embodiment for transporting toner is shown. 101, 102
is a flat sound wave propagation member made of materials such as duralumin and stainless steel. 103, 104, 105, 106
is a piezoelectric vibrating element for causing the sound wave propagation members 101 and 102 to undergo ultrasonic excitation of bending vibration to provide a traveling transverse wave. These piezoelectric vibration elements 103, 104, 105
, 106 indicate the difference in polarization orientation direction in the thickness direction of the piezoelectric vibrating element. Plate-shaped piezoelectric vibration elements 103, 104, 105, 10
Electrodes are provided on both wide sides of 6, and 103 and 10
5, 104 and 106 are joined to the back surfaces of the sound wave propagation members 101 and 102 so as to face each other. The piezoelectric vibration elements 103 and 105 are elements that give sine mode vibration, and the piezoelectric vibration elements 104 and 106 are elements that give cos mode vibration. 107 is a high frequency power source for driving piezoelectric vibrating elements 103, 104, 105, and 106. 108 is a coupler, which corresponds to the antinode of vibration for the sin mode vibration of the piezoelectric vibration elements 103 and 105;
For the cos mode vibration of No. 6, four rod-shaped rods are placed at the four corners of the sound wave propagation members 101, 102 corresponding to the nodes of vibration, with piezoelectric vibration elements 103, 104, 105, 106 sandwiched therebetween. The sound wave propagation members 101 and 102 are firmly connected to each other via a coupler. The gap length between the sound wave propagation members 101 and 102 that are arranged closely together depends on the power of ultrasonic excitation, but may be set to, for example, several tens of micrometers to several millimeters. It is preferable that the resonance frequencies of piezoelectric vibrating elements 103 and 104, 105 and 106 be as close as possible, and the use of coupler 108 is effective for this purpose.

FIG. 10(a) is a side view showing the state between the two sound wave propagation members shown in FIG. (A) in Figure 10(a),
(B), (C), (D) are sound wave propagation members 101, 102
This figure shows a bending vibration pattern that clearly shows the bending vibration of a transverse wave. (A) and (B) are sin mode vibrations,
It shows how they vibrate relative to each other in symmetrical modes. On the other hand, (C) and (D) are cos mode vibrations, and show how they vibrate in an asymmetric mode relative to each other so as to follow each other. Furthermore, the toner 2 is shown floating and conveyed along approximately the center of the gap between the opposing sound wave propagation members 101 and 102. However, if the gap length between the sound wave propagation members 101 and 102 is 100 μm or less, it appears as if the toner 2 is conveyed along both sound wave propagation members 101 and 102 while occasionally coming into contact with each member. FIG. 10(b) shows the sound wave propagation member 101,1
2 is a diagram schematically representing the particle velocity v of air in the gap direction and the magnitude of the sound pressure p with respect to the gap length of the gap 02. FIG. In other words, when a traveling wave is applied to both sound wave propagation members, the sound pressure distribution between the two members will be lower at the center between the members, and the air particle velocity (particle velocity in the direction of the gap between the members) will be lower between the members. The center becomes larger. As a result, the toner gathered at the center between the members, and could be effectively transported by floating without electrostatically adhering due to electrostatic mirroring force or the like.

[0063] In this way, it is also possible to use a piezoelectric element as the ultrasonic excitation means.

Next, toner conveyance by ultrasonic excitation in this embodiment will be explained using FIG. 8. The toner stripped off from the developing sleeve 3 by the elastic roller 7 serving as developer stripping means is transferred to piezoelectric vibrating elements 103 and 1.
Sound wave propagation members 101, 10 by 04, 105, 106
The traveling waves applied to the sound wave propagating members 101 and 1
02, and is deflected diagonally downward by a deflection member 10 fixed to the hopper 1. At this time,
The toner is joined and mixed with the toner conveyed little by little from the hopper rear chamber S2 over the guide wall 13 by the toner feeding member 12. This mixed toner is transferred to the sound wave propagation member 101
It is conveyed obliquely downward by the action of gravity, is supplied to the elastic roller 7, and is then supplied to the developing sleeve 3.

When an image was formed using the apparatus of this embodiment in the same manner as in the first embodiment, there was little or no difference in image density due to differences in image history (so-called ghost images), there was no toner clogging or spillage, and there was no background image. There is no image deterioration such as fogging or scattering, and a sufficiently high image density is maintained.
Stable and good images were obtained. Furthermore, toner could be transported quietly without any noise, and no malfunctions occurred.

<Fifth Embodiment> Next, a fifth embodiment of the present invention will be explained using FIG. 11. The same reference numerals are given to the same parts as in the third embodiment, and the explanation thereof will be omitted.

This embodiment differs from the third embodiment in that an electrode roller 70 is used as the developer stripping means and that the type of photoreceptor is changed to perform reverse development. Other configurations are common.

In this embodiment, an electrode roller 70 is provided as a developer stripping means and an electric field generating means, and maintains a predetermined gap (approximately 300 μm) between it and the surface of the developing sleeve 3. 1 and is rotatably supported in the direction of the arrow. Note that the electrode roller 70 is grounded.

Further, a scraper blade as a developer removing means is provided on the electrode roller 70 and is attached to the hopper 1 with its cutting edge in contact with the electrode roller 70 in the forward direction relative to the moving direction of the electrode roller 70. . At this time, of course, the scraper blade may be disposed in contact with the electrode roller 70 in a direction opposite to the moving direction thereof.

Note that the outer diameter of the electrode roller 70 is 6 mm, and the peripheral speed ratio of the electrode roller 70 and the developing sleeve 3 is 20.
~150%.

The following results are obtained when the circumferential speed of the electrode roller 70 was set to 120 mm/sec, which is the same as the circumferential speed of the developing sleeve 3.

As the photosensitive drum 6, an OPC photosensitive member is used, and the dark area on the photosensitive drum is -700V and the bright area is -100V.
The gap between the photosensitive drum and the developing sleeve 3 was maintained at approximately 300 μm, the toner layer thickness was regulated at 50 μm, and a peak-to-peak voltage of 1400 V was applied to the developing sleeve.
, 1800 Hz alternating square wave voltage and a DC voltage of -550 V were applied to perform reversal development.

The distance between the photosensitive drum 6 and the developing sleeve 3 and the distance between the developing sleeve 3 and the electrode roller 70 are both 30
0 μm, which is the same. The developing potential between the photosensitive drum 6 and the developing sleeve 3 is -100-(-55
0)=450V, and the stripping potential between the electrode roller 70 and the developing sleeve 3 is 0-(-550)=550V. Therefore, the electric field during stripping is larger than the electric field during development. When calculated, in this example, the electric field during development is 1.5 x 104 V/cm, and the electric field during peeling is 1.8
It becomes 3×104V/cm.

Furthermore, in reversal development, the toner is not consumed on the developing sleeve 3 corresponding to the dark area and remains as it is, and the toner is consumed on the area corresponding to the bright area, so almost no toner remains on the developing sleeve. Or there is nothing left at all. The remaining toner on the developing sleeve 3 after development is removed by the electrode roller 70 using an electric field larger than the electric field during development, so that the toner on the developing sleeve 3 is removed uniformly in all areas, and most of the toner is removed. There are no or none left.

By using the electrode roller 70 as described above, it is possible to reliably remove the toner on the developing sleeve 3 and to reliably prevent so-called "ghost images," which cause variations in image density due to differences in image history. can. Moreover, since the electrode roller 70 and the developing sleeve 3 are not in contact with each other, the electrode roller 70 and the developing sleeve 3, which serve as the stripping means, are not damaged and can be used stably for a long period of time.

When an image was formed using the apparatus of this embodiment in the same manner as in the first embodiment, there was little or no difference in image density due to differences in image history (so-called ghost images), there was no toner clogging or spillage, and there was no background image. There is no image deterioration such as fogging or scattering, and a sufficiently high image density is maintained.
Stable and good images were obtained. Furthermore, toner could be transported quietly without any noise, and no malfunctions occurred.

<Sixth Embodiment> Next, a sixth embodiment of the present invention will be described with reference to FIGS. 12 and 13. The same parts as in the first embodiment are given the same reference numerals, and the description thereof will be omitted.

This embodiment has the same structure as the first embodiment except for the developer conveying means. That is, while the first embodiment utilizes the action of ultrasonic excitation as a means for transporting the developer, this embodiment uses the action of an electric field.

FIG. 12 is a sectional side view of a developing device according to this embodiment, and FIG. 13 is a perspective view showing a main part of an electric field conveying means 80, which is a developer conveying means using an electric field according to this embodiment.

In FIG. 12, an insulating film is installed on the inner wall of the hopper 1 behind the elastic roller 7, which is in contact with the surface of the developing sleeve 3 and is rotatably supported in the hopper 1, as a developer supply means and a developer stripping means. Striped electrode groups 80a to 80g are provided via a sheet 84 that is a base material.

FIG. 13 is a perspective view of stripe electrode groups 80a to 80g arranged in hopper 1. In the figure, stripe electrode groups 80a to 80g are provided substantially parallel to the axial direction of the elastic roller 7 and spaced apart from each other, and thin pieces of metal such as copper, aluminum, and stainless steel are preferably used as the stripe electrodes. , even if it is linear. The stripe electrode groups 80a to 80g are, for example,
It is formed on an insulating sheet 84 by means such as printing, etching, vapor deposition, etc., and the width of the electrode is 0.1 to 1.
mm, and the electrode spacing is set to 0.1 to 1 mm. Furthermore, AC power supplies 16A, 16B, and 16C are connected to these linear electrodes 80a to 80g, so that AC voltages of three or more phases having mutually different phases can be applied.

In FIGS. 12 and 13, seven stripe electrodes 80a to 80g are used to simplify the explanation, but in reality, more electrodes are used. The AC power supplies 16A, 16B, and 16C are three-phase AC power supplies whose phases differ by 120°, and the power supply 16A is connected to the electrodes 80a,
80d, 80g..., the power supply 16B connects the electrodes 80b, 80
e..., a power source 16C is connected to the electrodes 80c, 80f..., respectively. When an alternating current voltage is applied, an alternating electric field is generated that advances in the direction of arrow D. In this embodiment, negatively charged toner is used, and the toner 2 stripped off from the developing sleeve 3 by the elastic roller 7 falls onto the stripe electrode 80a.

At this time, when a voltage is applied to the electrodes 80a to 80g, an alternating current electric field is generated in the direction of arrow D, and the toner 2
is transported inside the hopper 1 in the direction of arrow D on the hopper 1 while vibrating between the electrodes 80a to 80g, and then merges and mixes with the toner 2 transported from the hopper rear chamber S2 by the toner transport member 12. Thereafter, it is supplied to the elastic roller 7 and further supplied to the developing sleeve 3.

Next, an experimental example conducted under the following conditions will be explained.

In this experimental example, a developing sleeve with a diameter of 2
The surface of an aluminum sleeve with a diameter of 0 mm was roughened with No. 600 sandpaper to form unevenness with a pitch of 1.5 μm. The elastic blade has a thickness of 2 mm,
Urethane with a width of 20 mm and a hardness of 60° rubber was used. Regarding hardness, when the dimensions and shapes are changed, 5
0° to 80° was effective.

The non-magnetic toner used at this time was a powder containing 10 parts of carbon and 90 parts of polystyrene with an average particle size of 7 to 15 μm, and about 1.0% of silica was added as an external additive. Gives fluidity to the toner. A thin Mylar seal with a thickness of 50 μm was used as a seal member to prevent the toner from scattering from the container. The contact pressure of the elastic blade against the developing sleeve is effective to be about 5 to 100 g/cm when the hardness and size and shape of the blade are changed, and it is preferable to keep the error within 5 g in the longitudinal direction of the developing sleeve. In the experimental example, it was set to about 45 g/cm. The elastic roller is made of Everlite material with a foam diameter of 1 mm and a diameter of 6 mm.
A sponge roller having a diameter of 14 mm and wound around a stainless steel core metal having a diameter of 14 mm was used. In addition, the developing sleeve is rotated at 120 mm/sec, and the supply roller is rotated at a relative speed of 50 to 300 mm/sec with respect to the developing sleeve.
and rotated it. The following results are 70mm/sec
This is when it is set to .

The stripe electrode groups 80a to 80g were made of copper. It is effective for the electrode width of the stripe electrode group to be 0.1 to 1.0 mm and the electrode spacing to be 0.1 to 1.0 mm. In this example, the electrode width of 0.3 mm and the electrode spacing of 0.3 mm are used. there was.

As a result of conducting experiments in this manner, it was possible to form a thin toner layer of 30 to 100 μm in thickness without streaks or unevenness on the surface of the developing sleeve. It was also confirmed that the toner layer thickness could be changed by changing the linear pressure of the elastic blade. In this experimental example, the thickness of the toner layer on the developing sleeve was made smaller than the length of the facing gap between the developing sleeve and the photosensitive drum, and as described above, the toner was moved from the developing sleeve to the photosensitive drum within that gap to develop the image. (so-called non-contact development or jumping development).

In this experimental example, a dark area of +60
0V, forming a latent image with 0V in bright areas, keeping the gap between the photosensitive drum and developing sleeve at about 300 μm, regulating the toner layer thickness to 50 μm, and applying a peak-to-peak voltage of 1400 V and a 1800 Hz square wave to the developing sleeve. +1 to alternating voltage
A developing bias with a DC voltage of 50 V superimposed was applied, and development was carried out using an NP1215 machine manufactured by Canon Inc. (process speed 100 mm/sec).

When an image was formed using the apparatus of this embodiment in the same manner as in the first embodiment, there was little or no difference in image density due to differences in image history (so-called ghost images), there was no toner clogging or spillage, and there was no background image. There is no image deterioration such as fogging or scattering, and a sufficiently high image density is maintained.
Stable and good images were obtained. Furthermore, toner could be transported quietly without any noise, and no malfunctions occurred.

<Seventh Embodiment> Next, a seventh embodiment will be described using FIG. 14. The same reference numerals are given to the same parts as in the sixth embodiment, and the explanation thereof will be omitted.

This embodiment differs from the sixth embodiment only in the arrangement position of the stripe electrode group 80, and the other configurations are the same.

[0093] This stripe electrode group 80a to 80g is
An elastic roller 7 is provided on the outer wall of the hopper 1 behind the elastic roller 7 as a developer supply and developer stripping means, and on the outside thereof,
An insulating protective sheet 84 is provided.

When an image was formed using the apparatus of this embodiment in the same manner as in the first embodiment, there was little or no difference in image density due to differences in image history (so-called ghost images), there was no toner clogging or spillage, and there was no background image. There is no image deterioration such as fogging or scattering, and a sufficiently high image density is maintained.
Stable and good images were obtained. Furthermore, toner could be transported quietly without any noise, and no malfunctions occurred.

[0095]

[Effects of the Invention] As explained above, according to the present invention,
The developer conveying means transports the developer in the dry developing device upward along the plate-like surface, so that: ■ It has a simple structure, ■ It moves the developer upward even on the plate-like surface, and ■ It is efficient and stable. ■Without deterioration of the developer, ■Stably maintaining image quality, ■Without developer clogging or spillage, ■Quiet, ■Low probability of failure due to mechanical drive. , the developer can be transported stably.

Furthermore, in order to prevent ghost images in a one-component thin layer developing method, the present invention can be applied to a developer conveying method in a dry developing device provided with a stripping means for stripping off residual developer on a developing sleeve. With a simple configuration, there is no image fogging, no ghosting, high image density, no clogging or spillage of developer, and high quality images can be stably obtained.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing a schematic configuration of a first embodiment of the device of the present invention.

FIG. 2 is a diagram illustrating a powder conveyance method according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing a main part of a developer conveying means of the apparatus according to the first embodiment of the present invention.

FIG. 4 is a side sectional view showing a schematic configuration of a device according to a second embodiment of the present invention.

FIG. 5 is a perspective view showing a main part of a developer conveying means of a second embodiment of the apparatus of the present invention.

FIG. 6 is a side sectional view showing a schematic configuration of a device according to a third embodiment of the present invention.

FIG. 7 is a perspective view showing a main part of a developer conveying means of an apparatus according to a third embodiment of the present invention.

FIG. 8 is a side cross-sectional view showing a schematic configuration of a device according to a fourth embodiment of the present invention.

FIG. 9 is a perspective view showing a main part of a developer conveying means of an apparatus according to a fourth embodiment of the present invention.

FIG. 10 (a) is a cross-sectional view of the device in FIG. 9, (b) is (a)
FIG. 3 is a diagram schematically representing the magnitude of the air particle velocity v and the sound pressure p at .

FIG. 11 is a side sectional view showing a schematic configuration of a fifth embodiment of the device of the present invention.

FIG. 12 is a side sectional view showing a schematic configuration of a device according to a sixth embodiment of the present invention.

FIG. 13 is a perspective view showing a main part of a developer conveying means of an apparatus according to a sixth embodiment of the present invention.

FIG. 14 is a side sectional view showing a schematic configuration of a device according to a seventh embodiment of the present invention.

FIG. 15 is a side sectional view showing a schematic configuration of a conventional device.

FIG. 16 is a side sectional view showing a schematic configuration of another conventional device.

[Explanation of symbols]

1 Developer container (hopper) 2 Developer (toner, one-component developer) 3 Developer carrier (developing sleeve) 5 Developer regulating means (elastic blade) 7 Developer supplying means (elastic roller) 21 Sound wave propagation member

Claims (6)

[Claims] 1. A method for transporting a developer, characterized in that the developer in a dry developing device is transported upward along a plate-like surface by a developer transporting means. 2. The developer transport method according to claim 1, wherein the developer transport means transports the developer by ultrasonic excitation. 3. The developer transport method according to claim 1, wherein the developer transport means transports the developer by the force of an electric field. 4. A developer container having an opening at the front;
a developer carrier rotatably disposed in the opening for carrying and conveying a one-component developer; a supply means for supplying the developer to the developer carrier; and coating of the developer on the developer carrier. What is claimed is: 1. A developing device comprising a developer regulating means for regulating the amount of developer, the developing device comprising a developer conveying means for conveying the developer upward along the wall surface of the developer container. 5. The developer conveying means includes a sound wave propagating member provided along the wall surface of the developer container, and applying a traveling transverse wave to the sound wave propagating member to move a standing wave sound field.
5. The developing device according to claim 4, wherein the developing device is configured to transport developer. 6. The developer transporting means is provided with a group of electrodes along the wall surface of the developer container, and the developer is transported by applying a voltage that changes over time to the electrode group. 4. The developing device according to 4.