JPH02293769A - Toner supply device in developing device - Google Patents

Abstract

PURPOSE:To most suitably control toner quantity in an axial direction by providing plural toner supply tubes in the direction in which the shaft of a toner carrier turns and allowing the toner supply tubes to supply toner independently. CONSTITUTION:A developing unit is provided with hoppers 601 to 619, detecting sensors 501 to 519, piezoelectric vibrators 181 to 195 and diaphragms 201 to 219. When toner quantity in some part F5 falls to a regulated value or below, a detecting sensor 505 operates. Its detection signal arrives at a control circuit 9, and an oscillator 16 as a supply signal oscillates the piezoelectric vibrator 195 of corresponding hopper 605. The vibration of a vibrator 195 vertically vibrates the diaphragm 205 and the hopper 605. Consequently, inside toner is rocked to be loosened and has fluidization to drop from the corresponding toner tube of small tube diameter. Thus, a required amount of toner is always secured in the axial direction, and a uniform image free of development irregularity can be obtained all the time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a toner replenishing device in a developing device used in an electrophotographic device, an electrostatic recording device, or the like.

``Prior Art'' A conventional toner replenishing device of this type has a configuration as shown in FIG. 4, for example.

In FIG. 4, 1 is an image carrier (photosensitive 1-ram), 2 is a developing device, 3 is a developing roller, 4 is a developing container, 5 is a detection sensor, 6 is a hopper, 7 is a supply roller, and 8 is a dryer. 9 is a control circuit, 10 is a concave portion of the supply roller 7, and T is a toner.

That is, when the developing device 2 is composed of the developing container 4 and the hopper 6, the sensor 5 detects the remaining amount of toner T in the developing container 4 (in the case of two components, the toner concentration, the mixture ratio of L-toner and carrier) , and serves as a developer concentration detection sensor.

) and if it is detected that replenishment is required,
The signal is sent to the control circuit 9, the signal is transmitted to the motor 8, and the motor 8 rotates. As the motor 8 rotates, the supply roller 7 rotates, and the concave portion 10 of the supply roller 7 rotates.
As the toner T staying in the developing container 4 rotates, it falls into the developing container 4 and is replenished. The toner T in the recess 10 of the replenishment roller 7 falls one after another, and when toner replenishment is sufficiently achieved, the motor 8 is stopped by the detection sensor 5 via the control circuit 9.

In addition, in the case of the batch replenishment method, there is a toner remaining amount detection element in the developing device, and when the amount of toner is low, a detection signal indicates toner replenishment, and the user can transfer toner from a separate container to the developing device inside the machine. Supply in bulk. In this case, one component 1-
limited to ners.

[Problems to be Solved by the Invention]However, regardless of whether toner is replenished by the above-mentioned replenishment roller ruff or in the case of bulk replenishment, the amount of 1.toner in the entire developer container is detected; It does not detect each toner in the axial direction. On the other hand, on the replenishing side, both the replenishment roller and batch replenishment replenish evenly in the axial direction iJ.

However, when an actual copying operation is performed and the toner T is consumed, it is not always consumed uniformly in the axial direction. That is, the amount of toner consumed in the axial direction differs depending on the size of the transfer material, and the amount of toner consumed in the axial direction also differs depending on the proportion of the character portion and the black portion in the document. Despite this, conventionally, replenishment toner is uniformly replenished in the axial direction, so some parts in the axial direction may not be supplied with enough toner.
In other areas, there may be too much toner. For this reason, since the amount of toner consumed in the axial direction is different, uneven development occurs, making it impossible to obtain a uniform image, and toner aggregates in areas with excessive toner, resulting in insufficient toner coating on the developing roller 3. When it becomes sufficient, development occurs where the image becomes thinner,
Further, since a certain portion in the axial direction is replenished even though the amount of toner is sufficient, there is a problem in that the toner overflows in that portion and stains the area around the developing device.

The present invention aims to solve the above problems. That is, an object of the present invention is to provide a toner replenishing device for a developing device that can optimally control the amount of toner to be replenished in each direction.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a developing device that turns an electrostatic latent image on an image carrier into a visible image, and which carries toner on the surface, Supplying toner to image bearing member 1. In a developing device comprising a developing container including a toner bearing member and a toner replenishing device that intermittently replenishes toner to the developing container in accordance with commands of various signals, the toner replenishing device comprises: ,
A plurality of toner supply pipes for replenishing toner to the developer container are provided in the axial direction of rotation of the toner carrier, and each toner supply pipe is provided so that toner can be replenished independently. did.

[Function] According to the present invention, the toner supply device has a plurality of toner supply pipes for supplying toner to the developer container in the axial direction of rotation of the toner carrier, and each toner supply pipe independently supplies toner. Since it is possible to replenish the toner, an optimal amount of toner is replenished via each of the plurality of toner supply pipes provided in the axial direction.

[Embodiment] FIGS. 1 and 2 show a first embodiment of the present invention.

In FIG. 1, 1 to 6 are the same as those shown in FIG.

That is, numeral 1 is an image carrier that carries an electrostatic latent image or a visible image, and is also called a photosensitive drum. 2 is a developing device that develops the electrostatic image on the image carrier 1; 3 is a developing roller that rotates while carrying the toner T (in the case of using a two-component developer or a one-component magnetic toner, a magnetic field is installed inside); 4 is a developer container that stores the toner T to the developer roller 3, 5 is a detection sensor that detects the amount of toner in the developer container 4, and 6 is a hopper that stores the toner T. It is. A control circuit 9 receives signals from the detection sensor 5 and outputs operating signals for other operating members.

Further, 11 is a latent image forming section that forms an electrostatic latent image on the image carrier 1, 12 is a transfer section that transfers the visible image on the image carrier 1 onto a transfer material, and 13 is a transfer section that is on the image carrier 1. 14 is a conveyance section that conveys the transfer material carrying the visible image to the fixing section; 15 is a fixing section that fixes the visible image formed with the toner on the transfer material; 16
17 is an oscillator that vibrates the piezoelectric vibrating body; 17 is a support member that includes a toner supply device and supports the diaphragm; 18 is a toner supply pipe that supplies toner T from the hopper 6 into the developer container 4; and 19 is a diaphragm support member. Piezoelectric vibrating body that vibrates and oscillates, 2
0 is a vibration plate that swings the entire hopper up and down, and 21 is a neck portion that connects the hopper 6 to the toner supply pipe 18.

In the developing device configured as shown in FIG. 1, the image carrier 1 on which the electrostatic latent image has been formed in the latent image forming section 11 is converted into a visible image by the toner T carried on the developing roller 3, that is, A toner image is formed. The toner image on the image carrier 1 is transferred to a transfer material in a transfer section 12. The transfer material carrying the toner image is conveyed on a conveyor 14 and sent to a fixing section 15, where the toner on the transfer material is fixed and discharged outside the machine. On the other hand, residual toner on the image carrier 1 is cleaned by a cleaning section 13.

Next, toner replenishment to the developer container 4 will be explained with reference to FIG.

FIG. 2 depicts the developer container 4 from above.

In Figure 2, R indicates the right side, F indicates the left side, and 1
8l,...l89,...191,...195 are piezoelectric vibrators, 20l,...205,...2l1.・・・
・219 is a diaphragm, 501, 502, 503, 504,
505,...511,512,513,514,51
5,518,517,518.519 is a detection sensor, 6
01,fi02,603,604,605,...61
1,612,613,614,615,616,617
, 618, 819 are hoppers.

That is, as the electrostatic latent image on the image carrier 1 is visualized, the toner T in the developing device 4 gradually decreases. Also, the method of reduction varies depending on the type of original, the size of the transfer material, etc. in the axial direction.

Using FIG. 2 as an example, when the amount of toner in a portion F5 in a certain partial developer container reaches a specified value or less, a detection sensor 505 that detects the amount of toner in that portion is activated. At this time, when the toner is one-component, the remaining amount sensor is used, and when the toner is two-component, the mixing ratio of toner and carrier is detected. The detection signal reaches the control circuit 9, from which the oscillator 16 is activated as a replenishment signal.
A signal is sent to the piezoelectric vibrating body 195 so that it will be replenished from the hopper 805 corresponding to 5 parts. The oscillator 16 applies a frequency of about 400 Hz to the piezoelectric vibrating body 195 to cause it to vibrate. The vibration of this piezoelectric vibrating body 195 causes vibration of a vibrating plate 205 such as a stainless steel plate.
is transmitted and starts to vibrate. The vibration of the diaphragm 205 becomes a vertical vibration, and the hopper 605 also becomes a vertical swing. As the hopper 605 swings, the toner T inside is also rocked and loosened, and the toner T becomes fluid and falls into the developer container 4 from the corresponding toner supply pipe.

At this time, the toner supply pipe is a pipe with a diameter of 1.0 to 5.0 mm, and because of its small diameter, the toner T does not fall when the vibration is stopped. Although the F5 portion has been described, similar operations are performed for other portions as well. If the detection sensor 505 detects that there is enough toner, the signal is transmitted to the control circuit 9, which outputs a stop signal to the oscillator 16,
The vibrations will stop, and toner replenishment will also stop. Also hopper 60
5 improves the fluidity by vertically swinging the toner T, even if the fluidity deteriorates due to moisture absorption and temperature rise of the toner T, it is loosened by vibration, the fluidity becomes good, and reliable replenishment is always performed. A small amount of replenishment is possible.

In this way, since the necessary amount of toner is always maintained in the axial direction, an even and uniform developed image can be obtained at all times.

Furthermore, since a small amount of toner is replenished, the amount of toner is constant not only in the axial direction but also over time, so that there is no density change and a good image can be obtained.

In addition, especially in the case of one-component magnetic toner, if there is a magnetic substance in the replenishment path, when the magnetic substance is magnetized by the magnetic roller in the developing roller 3 or magnetized by processing, the magnetic toner will not be replenished properly. It will not be fulfilled. Therefore, it is desirable that the diaphragm 20, toner supply pipe 18, and hopper 6 be made of non-magnetic materials. Hopper 6 is plastic,
Stainless steel SUS304, SUS316, etc.
1. The material of the fuel supply pipe 18 is also approximately the same as that of the hopper 6. The diaphragm 20 is made of stainless steel SUS304. SUS31
A non-magnetic material such as No. 6 is preferable. Further, the vibrating portion is provided in the neck portion 21 at the lower part of the hopper 6 because vertical vibration is most likely to occur and toner replenishment can be performed satisfactorily.

In the developing device configured as shown in FIG.
Whether you have copied several thousand copies of each text document (documents with low toner consumption), the amount of toner in the developing device 4 is
It was almost quantitative. Furthermore, the environment under high temperature and high humidity (R
Even though the copying operation was performed at T=30.0° C. and RH=90%, the amount of toner in the developer container 4 was almost constant.

FIG. 3 shows a second embodiment of the present invention, which corresponds to FIG.

In other words, the present invention detects the entire document and can replenish only the toner that is consumed even without a toner amount detection sensor. Moreover, since the image can be matched in the axial direction of the developing device, it is always uniform in the axial direction.

This will be explained in detail with reference to FIG. In FIG. 3, reference numeral 22 denotes an original table glass, 23 an original, 24 a lamp for illuminating the original, 25 a reflector, and 26 an image sensor such as a CCD. The image sensor 26 scans the original 23 while reading all the signals in the axial direction of the original 23. Therefore, if it is in front of the document 23, toner consumption at a point in the front can be detected. Therefore, it is possible to supply the same amount of toner to the opposing portions of the developing roller 3.

Next, a third embodiment of the present invention will be described. First, even for the same document, the amount of toner consumed depends on the environment. At that time, the environment is detected by an environmental sensor (temperature, humidity), and the signal is sent to the control circuit 9. The control circuit 9 calculates an appropriate operating time together with the original light amount signal, and operates the oscillator 16.

For example, even with the same original, the developability under high humidity is poor and toner consumption is low. On the other hand, under low humidity,
Toner consumption is high. Therefore, the operating time of the oscillator 16 increases in the order of high humidity, normal humidity, and low humidity. It is desirable that the operating time under low humidity be increased by 30 to 50% compared to under high humidity.

[Effects of the Invention] As explained above, according to the present invention, the toner replenishing device has a plurality of toner supply pipes for replenishing toner in the developer container or a plurality of toner supply pipes in the axial direction of rotation of the toner carrier, and each toner supply Since the tubes are capable of independently replenishing toner, an optimal amount of toner can be replenished through each of the plurality of toner supply tubes provided in the axial direction. Therefore, a uniform image can be obtained without uneven development.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view showing the first embodiment of the present invention;
The figure is an enlarged plan view of the developing container shown in Fig. 81, Fig. 3 is an enlarged plan view showing only a part of the second embodiment of the present invention, and Fig. 4 is a cross-sectional side view showing an example of the conventional technique. be. 1... Image carrier, 2... Developing device, 3...
...Developing roller, 4...Developing container, 5...
Detection sensor, 6... Hopper, 9... Control circuit, 11... Latent image forming section, 12... Transfer section, 15... Fixing section, 16... Oscillator,
18... Toner supply pipe, 19... Piezoelectric vibrating body, 20... Vibration plate.

Claims (1)

[Scope of Claims] 1. A developing device that converts an electrostatic latent image on an image carrier into a visible image, and includes a toner carrier that carries toner on its surface and supplies toner to the image carrier. In a developing device comprising a container and a toner replenishing device that replenishes toner intermittently to the developing container according to commands of various signals, the toner replenishing device has a toner supply pipe that replenishes toner to the developing container. It has multiple pieces in the direction of the axis of rotation of the body,
A toner replenishing device for a developing device, characterized in that each toner supply pipe is provided so that toner can be replenished independently. 2. The toner replenishing device has a plurality of hoppers in an upper part for storing toner, and a plurality of thin supply pipes provided in a lower part of the hoppers to supply toner to each container, and
Each of the supply pipes has a respective vibration device composed of a vibration plate and a piezoelectric vibrating body in contact with the vibration plate, and the vibration device is in contact with the supply pipe, and the toner supply device is activated by the operation of the vibration device. 2. A toner replenishing device for a developing device according to claim 1, wherein the entire body vibrates up and down, and toner is replenished into the developing device from inside the hopper through a toner supply pipe. 3. The toner replenishing device in a developing device according to claim 2, wherein the plurality of toner replenishing devices are separated into operating and non-operating depending on the size of the transfer material. 4. The toner replenishing device in a developing device according to claim 2, wherein the operation or non-operation of the corresponding toner replenishing device is controlled depending on the presence or absence of an image in the traveling direction of the document image.