JPH08123199A - Developing device - Google Patents

Abstract

PURPOSE: To provide a developing device capable of miniaturizing the developing means constituted to be opposite to a latent image carrier, making the constitution simple, improving the operability at the time of the maintenance, and eliminating the jamming of the developer or the toner in a feeding pipe. CONSTITUTION: The developing device is provided with the developing means for applying the developer of mixing the toner with the carrier to the photoreceptor drum 1, the developer optimizing means 1000 arrange as a detached body in the place different from the developing means for optimizing the developer, and the developer transfer-circulation means 200 for transferring the developer to the developing means and the developer optimizing means 1000, and then the developer transfer-circulation means 200 is provided with the screw pump for feeding the gaseous mixture of the developer and the air, the air pump 207 for feeding the air to the screw pump, and moreover the device is controlled by the control means so that only the air pump 207 is operated for a specified duration at the drive beginning time of the developing device, and thereafter, the screw pump and the air pump 207 are simultaneously operated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus, and more particularly to a developing apparatus using a two-component developer, such as a printer, a facsimile, or a copying machine.

[0002]

2. Description of the Related Art Conventionally, a latent image carrier (photoreceptor drum) is disposed so as to face the latent image carrier by applying a two-component developer containing a mixture of toner and carrier to the latent image carrier. The following technology is known as a technology relating to a developing device equipped with a developing means for developing (developing) an electrostatic latent image formed on a holding body.

(1) A developing device using a two-component developer, which has a developer stirring means inside the photosensitive drum,
The stirring means and the developing device are connected by a pipe to circulate the developer (the "developing device" described in Japanese Utility Model Laid-Open No. 1-97355).

(2) The developer or carrier is supplied to the developing container, and at the same time, the developer of a colleague and the developer are discharged, and the toner consumed by the development is detected by the volume detecting means to supply the toner, and the development is easily performed. The developer concentration in the container is always kept constant ("Development device" described in JP-A-53-22747).

(3) The density of the developer is detected by the change in volume ("Method for detecting density of electrophotographic developer and density adjusting method" described in JP-A No. 50-19459).

(4) A developing section, a means for supplying a fixed amount of carrier to the developing section according to a predetermined developing time or a predetermined copying amount, and detection of a signal by detecting a change in the ratio of carrier to toner in the developer. And a means for supplying the toner to the developing portion in response to the signal, and a means for discharging a predetermined amount or more of the developer in the developing portion ("Electrophotographic developing device" described in JP-A-51-13249). .

(5) The life of the developer is extended by supplying the additional developer containing the toner and the carrier to the developer in the developing device ("Developing device" described in JP-A-4-353881).

[0008]

By the way, in the conventional developing device, the developer is stored in order to supply the developer to the developing sleeve provided facing the photosensitive drum as the latent image carrier. The storage part and the tank for replenishing toner are
Since the developing means is integrally formed with the developing means in the vicinity of the developing sleeve as a unit accommodating the developing sleeve, the constituent portion becomes large, the apparatus configuration becomes complicated, and the operation at the time of apparatus maintenance is performed. There was a problem that it deteriorated.

Therefore, as a method of solving this problem, the applicant of the present invention has proposed to utilize a powder pump unit (screw pump), which is commonly called a mono pump, as a developer transfer means. However, according to this method, various troubles may occur due to clogging of the developer in the supply pipe when the apparatus is stopped.

The present invention has been made in view of the above-mentioned points, and an object thereof is to reduce the size of a developing means arranged to face a latent image carrier, simplify the structure, and perform maintenance. It is an object of the present invention to provide a developing device capable of improving the operability at the time and eliminating clogging in the supply facility of the current tailing agent or toner.

[0011]

In order to solve the above-mentioned problems, the present invention provides, in claim 1, a developing device for visualizing an electrostatic latent image formed on a latent image carrier. And a developer proper disposed separately from the developing means for applying a developer containing a mixture of toner and carrier to the latent image carrier and the developing means for optimizing the developer. Means of conversion,
In a developing device having a developer transfer / circulation means for transferring the developer to the developing means and the developer optimizing means, the developer transfer / circulation means supplies a mixture of the developer and air. Of the screw pump, an air supplier for supplying air to the screw pump, and a control means for controlling the operation of the screw pump and the air supplier, by the control means, at the start of operation of the developing device, The screw pump and the air supply device are controlled so that the screw pump and the air supply device are simultaneously operated after operating only the air supply device for a certain period of time.

According to a second aspect of the present invention, there is provided a developing device for visualizing an electrostatic latent image formed on a latent image carrier, wherein a developer in which toner and carrier are mixed is used as the latent image carrier. To the developing means, the developing means for optimizing the developing agent, the developing means for separately optimizing the developing means, and the developing agent for transferring the developing agent to the developing means and the developing agent optimizing means. In a developing device equipped with a developer transfer / circulation means, the developer transfer / circulation means is a screw pump for supplying a mixture of developer and air, and an air supply for supplying air to the screw pump. And a control means for controlling the operation of the screw pump and the air supply device, and when the operation of the developing device is stopped by the control means, only the screw pump is stopped first, and only the air supply device is provided. Operated for a certain time The air supply unit to stop, a configuration for controlling the screw pump and the air supply to the.

According to a third aspect of the present invention, there is provided a developing device for visualizing an electrostatic latent image formed on a latent image carrier, comprising developing means for applying a developer to the latent image carrier. A toner storage unit provided separately from the developing unit, a toner supply unit that agitates and conveys the toner supplied to the toner storage unit, and a toner supply unit transfers the toner to the developing unit. And a screw pump for supplying a mixture of a developer and air, an air supplier for supplying air to the screw pump, and the screw. A pump and a control means for controlling the operation of the air supply device are provided, and when the operation of the developing device is started by the control means, only the air supply device is operated for a predetermined time, and then the screw pump and the air supply DOO simultaneously to actuate, a configuration for controlling the screw pump and the air supply unit.

According to a fourth aspect of the present invention, there is provided a developing device for visualizing an electrostatic latent image formed on a latent image carrier, comprising a developing means for applying a developer to the latent image carrier. A toner storage unit provided separately from the developing unit, a toner supply unit that agitates and conveys the toner supplied to the toner storage unit, and a toner supply unit transfers the toner to the developing unit. And a screw pump for supplying a mixture of a developer and air, an air supplier for supplying air to the screw pump, and the screw. A pump and control means for controlling the operation of the air supply device are provided, and when the operation of the developing device is stopped by the control means, only the screw pump is stopped first and only the air supply device is operated for a certain period of time. After the so as to stop the air supply was, a configuration for controlling the screw pump and the air supply unit.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 and 2, the structure of the developing device of the present invention that transfers and circulates the developer between the developing means and the developer optimizing means separately disposed at a position different from the developing means. Is shown together with a sectional view and a perspective view of the developing means.

In FIG. 1, a developer optimization means 1000
Has a function of optimizing the developer, and the circulation of the developer is performed by a developer transfer / circulation means (a powder pump unit 200 described later). Here, a two-component developer composed of toner and carrier is used as the developer. Further, to optimize the developer means to adjust the mixture ratio of the toner and the carrier of the developer to optimize the developer concentration and the charge amount of the developer, and to adjust the amount of paper dust mixed in the developer. It is to remove foreign matter.

In FIG. 1, reference numeral 1 indicates a photosensitive drum in which the latent image carrier is drum-shaped. The latent image carrier may be a photoreceptor belt having a belt-shaped photoreceptor, in addition to the photoreceptor drum 1 described above.

An electrostatic latent image is formed on the photosensitive drum 1 by charging and exposure by a conventionally known electrophotographic image forming process. This electrostatic latent image is visualized (developed) by the developer supplied by the developing means 10 which adopts the magnetic brush developing method in the well-known dry two-component developing method. Here, the developing means 10 includes a developing sleeve 100, which is a direct means for supplying a developer onto the photosensitive drum 1, a developer supplying member 110 provided around the developing sleeve 100, and a developing device. A unit that includes the agent discharge member 120, the developer layer restriction member 130, the passage means, and the case 150 that accommodates and holds these various members.

The developing means 10 is, around the photosensitive drum 1 rotating in the direction of the arrow in FIG. 1, an exposure device for irradiating the optical image P to form a latent image, and toner for visualizing the latent image. It is provided at a developing position between a transfer position where a transfer charger Q for transferring an image to a transfer material (transfer paper) is provided, and is rotated in the same direction as the photoconductor drum 1 at a portion close to and facing the transfer position.

Here, since an image is formed in the direction perpendicular to the paper surface of the photosensitive drum 1 (axial direction), the developing sleeve 100 needs to supply the developer to the entire area in the axial direction. Development sleeve 1 according to body drum 1
00 is defined in the axial direction. Therefore, the developer supply member 110 and the developer discharge member 120 described above are configured to cover at least the entire area of the developing sleeve 100 in the axial direction.

Further, the developer supply member 110 and the developer discharge member 120 are both constituted by a transfer means using a screw, and the drive means (not shown) causes the developer supply member 110 to move to a developer described later. So that the developer is sent out from the inlet 111a toward the side surface on the opposite side to the inlet 111a, and the developer discharging member 120 has an outlet 121 which will be described later.
It is rotated so as to send out the developer to a.

On the other hand, the developer layer regulating member 130 scrapes off the excess developer on the developing sleeve 1100 to regulate the layer thickness of the developer and collects the scraped excess developer. Excessive developer at the time of this development is rotated together with the developing sleeve 100 in the direction of the arrow, which is the direction of rotation, is scraped off by the developer layer regulating member 130, and then passes through the path R to the developer discharging member. Reach 120.

A developer inlet 111a and a developer outlet 121a
a is a case 150 of the developing means 10 as shown in FIG.
Are provided on the side plates 101, respectively. In FIG. 2, the inlet 111 a is connected to the developer discharge port 206 of the developer optimizing means 1000 by a supply pipe 111 and receives the developer optimized by the developer optimizing means 1000. On the other hand, the outlet 121 a is connected to the developer inlet 225 of the developer optimizing means 1000 with respect to the discharge pipe 1.
It is connected by 21 and the excess developer used for development by the developing means 10 is discharged to the developer optimizing means 1000.

Further, reference numeral 170 in FIG. 2 is an air filter as a pressure reducing means, and the air filter 170 is a mixture of the developer and air sent from the developer optimizing means 1000 by the developer transferring means. Only air is discharged from the developing means 10.

With the structure shown in FIGS. 1 and 2, the developing means 1 is connected from the developer optimizing means 1000 to the supply pipe 111.
The developer transferred to 0 is further transferred to the developer supply member 110.
Is transferred in parallel with the developing sleeve 100, and is sent to the entire surface of the developing sleeve 100 by a notch provided in a part of the case member 141. Then, this developer is molded into an optimum developing layer thickness by the developer layer regulating member 130,
Used for development. Further, the excess developer scraped off by the developer layer regulating member 130 is the developer guide member 140.
It is guided to the developer discharging member 120 through the upper passage R, is sent to the developer optimizing means 1000 through the outlet 121a and the discharging pipe 121.

According to the developing device constructed as described above, the developer optimizing means capable of optimizing the developer and providing the toner replenishing unit can be installed at a position different from the developing means. As a result, the structure of the developing means can be extremely simplified, the size of the developing means can be reduced, the internal structure of the complicated image forming apparatus can be simplified, and a layout margin can be created to facilitate maintenance.

Next, the developer optimization means 1000, and
Powder pump unit 20 as developer transfer / circulation means
A specific example of the No. 0 pump and the like will be described with reference to FIG. In FIG. 3, the developer discharged from the developing means 10 is guided to the developer optimizing means 1000 via the discharge pipe 121.

Further, in FIG. 3, reference numeral 220 indicates a developer stirring unit, and this developer stirring unit 2
Reference numeral 20 denotes an agent storage container 223 having a cylindrical lower portion and an funnel upper portion, and a stirring screw 22 rotated by a drive motor 222 inside the agent storage container 223.
1 and 1. Here, the stirring screw 221
Has its winding direction and rotation direction of the drive motor 222 set so as to send the developer upward.
The toner concentration in the developer is made uniform, and the toner charge amount is effectively optimized by utilizing the deviation force between the developer being fed upward and falling by gravity, and the powder pump unit 200. Fluidization of the developer before entering can be promoted.

An outlet of the toner replenishing unit 230 and a developer inflow port 225 are opened in the upper part of the agent storage container 223. The toner replenishing unit 230 has an upper lid 230.
By opening a, new toner 231 can be appropriately supplied, and a toner supply member 232 is provided below the lower part to close the lower part. The toner supply member 232 has a large number of notches formed along the rotation axis direction on the peripheral surface of a cylindrical portion that is driven to rotate, and the toner in the notches is rotated to rotate the agent storage container. 223 has a function of supplying it.

On the other hand, a developer discharge port 206 is located below the developer optimizing means 1000.
6, a developer concentration detecting member 240 is provided in the middle of the developer passage 270, and a conventionally known developer concentration detecting control (not shown) issued based on the detection signal of the developer concentration detecting member 240. The toner supply signal from the circuit rotates the toner supply member 232 to supply the toner in the toner supply unit 230 into the agent container 223.

As described above, the new toner that is replenished while being controlled by the toner replenishing unit 230 is added to the developer discharged from the developing means 10, and the developer agitating unit 22.
At 0, the optimization process of the developer is performed so that the concentration and the charge amount of the developer satisfy the optimum conditions for the development.
Further, the developer, which has been subjected to the optimization process as described above, is sent to the developer transfer / circulation means (powder pump unit) 200 located below the developer stirring unit 220.

The powder pump unit 20 in this embodiment
0 is constituted by a screw pump commonly called a MONO pump (known in the related art), and is vertically arranged so as to feed the developer downward. The powder pump unit 200 includes a rotor 201 connected to the drive motor 222 via the stirring screw 221, and a stator 202 made of an elastic material such as a rubber material and arranged so as to surround the rotor 201. , This stator 20
It is provided with an upper pump holder 203u for holding 2 and a lower pump holder 203d.

Here, the upper pump holder 203u also has a function as a connecting member for connecting the powder pump unit 200 and the developer stirring unit 220.
In addition, the side surface of the stator 202 and the lower pump holder 20
A gap of about 1 mm is provided between the inner side surface of 3d and this gap communicates with the developer passage 270. Then, the air supply port 205 is provided at a position of about 5 mm above the lower end of the stator 202 of the lower pump holder 203d so as to be blown into the developer passage 270 through this gap.
Is provided. The air supply port 205 communicates with the developer passage 270, and the outside thereof communicates with an air discharge port 208 provided in the air pump 207 via a pipe.

In FIG. 3, when the air pump 207 operates, the developer passage 27 passes through the air supply port 205.
Air is blown into the developer within 0 at a flow rate of about 1 to 3 liters per minute. As a result, fluidization of the developer discharged from the screw pump is promoted, and together with the rotation of the stirring screw 221 described above, the powder pump unit 200
The transfer of the developer in is more reliable. The supply air blown into the developer contributes to the transfer of the developer and then the air filter 170 provided in the developing unit 10.
Is released to the outside through.

As described above, the powder pump unit 20
The developer that has passed 0 is discharged from the developer discharge port 206 after the developer concentration is detected by the developer concentration detecting member 240, and is sent to the developing unit 10 through the supply pipe 111.

Next, a method of controlling the operation of the drive motor 222 of the powder pump unit 200 and the air pump 207 at the start and stop of the operation of the developing device of this embodiment will be described with reference to FIG.

Drive motor 222 and air pump 207
The respective power cords 22 shown in FIG. 3 are controlled by a control circuit (not shown) of a control means for controlling the driving of the power cords 22.
Power supply (ON / OFF) is controlled via 6, 209.

That is, the drive motor 222 and the air pump 207 of the developing device in this embodiment are shown in FIG.
As shown in (1), at the start A of the developing device, first, the power of only the air pump 207 is turned on, and then, the power of the drive motor 222 is turned on at a time B when several seconds have passed. On the other hand, as shown in FIG. 4B, when the developing device is stopped C, first, the power source of only the drive motor 222 is turned off, and then only the air pump 207 is continuously operated for a predetermined period of time. At time D when the operation time has elapsed, the air pump is controlled to be turned off.

Drive motor 2 of the developing device in this embodiment
The following effects can be obtained by controlling the operations of the air conditioner 22 and the air pump 207 as described above. That is,
In this developing device, while the powder pump unit 200 is operating, as shown in FIG.
An air-fuel mixture that is almost uniformly mixed with the air supplied from the air pump 207 fills substantially the entire area of the supply pipe 111. However, in this state, when the entire developing device is stopped at once, that is, when the drive motor 222 of the powder pump unit 200 and the air pump 207 are stopped at the same time, as shown in FIGS. 5B to 5C. , Supply pipe 1
Only air is discharged from the developer in the air-fuel mixture in the air-fuel mixture into the developing means 10, and only the developer is precipitated downward due to its own weight.
The bulk density of the developer inside is increased.

Therefore, in order to restart the developing device in the state shown in FIG. 5C, its drive motor 222 is operated.
Is started, the transfer of the developer sent toward the supply pipe 111 by the powder pump unit 200 is
Since the developer is blocked by the residual developer precipitated in the supply pipe 111 when the apparatus is stopped, the developer may be clogged in the supply pipe 111, and as a result, the operation of the powder pump unit 200 may be stopped. Locking or baking may occur (excessive temperature rise causes toner being developed to adhere to the rotor 201, and the adhered toner scrapes the stator 202).

Therefore, at the time of starting the operation of this developing device, as shown in FIG.
Drive only first, and after a certain period of time, drive motor 22
By operating No. 2, prior to the transfer of the developer into the supply pipe 111, the residual developer in the supply pipe 111 is discharged into the developing means 10 only by the air supplied from the air pump 207. be able to. Further, when the operation of the developing device is stopped, as shown in FIG. 4B, the operation of only the drive motor 222 is stopped first, and the operation of the air pump 207 is stopped after a certain period of time. Before the precipitation of the developer in the supply pipe 111 occurs, the developer in the supply pipe 111 is previously discharged into the developing unit 10 only by the air supplied from the air pump 207, and the supply is performed. The inside of the tube 111 can be made almost empty.

Therefore, according to the developing device of the present embodiment, the occurrence of the agent clogging due to the residual developer in the supply pipe 111 as described above is eliminated, and the transfer of the developer is made more reliable. You can

By the way, in this embodiment, as shown in FIGS.
Since it is located below 0, the developer optimization means 10
The force of the pump is required to transfer the developer from 00 to the developing means 10, but from the developing means 10 to the developer optimizing means 1
The transfer of the developer to 000 can be performed by the gravity of the developer without using a transfer means such as a pump. Incidentally, these developing means 10 and developer optimization means 1000
In the case where the positional relationship between and is opposite to that in the above-mentioned embodiment, and when they are arranged at substantially the same height, etc., in order to obtain the transfer force of the developer, the developer is appropriately circulated in the circulation path. Deploy a pump.

Further, the developing means 10 and the developer optimizing means 1
000, for example, in the middle of the discharge pipe 121 or the middle of the supply pipe 111, it is not possible to provide a foreign matter removing unit for removing foreign matter (such as paper dust) mixed in the developer. It is effective in improving the development quality. As the foreign matter removing means, a means such as a filter, an electrostatic adsorption device, a centrifugal separator, etc. is appropriately selected and adopted.

The known screw pump called a MONO pump used in this embodiment is of a rotary positive displacement type and is of a pressure-transfer type, which enables high quantitativeness and high-precision control of continuous transfer. . In addition, this screw pump uses a small amount of air in order to fluidize the powder and maintain a uniform fluidized state over the entire length of the transfer line.

Since this screw pump is a low-speed, high-concentration transfer, there is no crushing of powder and a small diameter pipe is sufficient.
In addition, the transfer pipe has no trouble of wear, it produces little noise, has a simple structure, and has excellent economical efficiency, reliability, and maintainability.

Conventional powder transfer means (here,
As the developer / toner conveying means), most of the constitution is such that the powder is transferred through a screw to the entire conveying path, and there is also one that transfers the powder only by the force of air. As described above, there is no known one that employs a transfer means (Mono pump) that is a combination of a screw pump and air.

Therefore, according to the present embodiment, (1) as the developer conveying path, it is necessary to dispose a transfer means such as a screw in the conveying path in the conventional example.
In the present embodiment, any transfer means is not necessary and only a tube is required, so that the route can be freely set, and
This path can be constructed with a small diameter tube. (2) By using air, the developer (toner
The carrier) can be pumped up (lifted upward) by a simple means. (3) By combining the screw pump and air, the amount of air supplied is smaller than that in the case where the developer is transferred only by air, so that the air pump can be downsized and the air supply is accompanied. It is possible to avoid toner scattering and complication of the air venting structure. (4) Since it is a rotary volume type, compared to a normal screw, the hazard given to the developer is less and the accuracy of the transfer amount is improved. There are various advantages such as.

In the developing device, when the carrier of the developer deteriorates due to long-term use, it is necessary to remove all the developer from the developing device. In such a case, in this embodiment, each unit is removed. In order to empty the developer, the discharge pipe 121 is removed from the developer optimizing means 1000, the tip of the discharge pipe 121 is connected to the recovery container, and the drive motor 222 is driven. As a result, all the developer containing the deteriorated carrier is collected in the above-mentioned collection container.
Incidentally, the developer contained in the above-mentioned recovery container can be appropriately treated such as discarded or reused.

If the above-mentioned operation of storing the developer in the collecting container is carried out during maintenance such as replacement and repair of various members of the developing device, no developer remains in the various members of the developing device. Scattering of the developer during maintenance work is eliminated, and workability during maintenance is improved. That is, by performing the developer recovery as described above, the developer recovery work that has been conventionally performed, that is, the entire developing device is detached from the machine body, the developing device is disassembled, and the developer is manually developed. Compared with the work of collecting the agent, the work efficiency can be greatly improved, and the toner scattering and the contamination of hands, clothes, etc. can be prevented during this work.

Furthermore, the developer optimizing means 100 of the present embodiment.
According to 0, the storage capacity of the developer is
This developer storage container 223 is determined by the capacity of 3
By increasing the size of the toner, it is possible to make the developer replacement interval very long due to the fatigue of the developer.

Further, the developer optimizing means 100 of the present embodiment.
Reference numeral 0 is a unit separate from the developing means 10, and the supply pipe 111 and the discharge pipe 12 are connected to the developing means 10.
Because they are only connected by 1, the restrictions on the installation location are reduced, and it is excellent in economical developer storage amount, operability of developer replacement, and productivity such as assembly and adjustment. ing.

Further, according to this embodiment, as described above,
Since the degree of freedom in layout is expanded, the toner replenishing unit 230 can also be arranged at a position where the user can easily perform the toner replenishing operation, and the same advantages as the developer optimizing unit 1000 can be obtained. it can.

Further, by using a detachable toner cartridge system conventionally used as the toner replenishing unit 230, the operability of toner replenishment can be further improved. In this case, according to the present embodiment, since the shape of the toner cartridge does not depend on the developing device 10, the operability of toner replenishment can be further improved, and standardization with other models can be easily performed. Therefore, it is possible to further improve productivity and reduce costs due to significant economic effects.

Next, another embodiment of the present invention (an embodiment corresponding to claims 3 and 4) will be described. As shown in FIG. 6, the developing device according to the present exemplary embodiment includes a toner supply unit 304 that transfers toner from a toner storage unit 303 that is provided separately from the developing unit 302 to the developing unit 302, and a toner transfer unit 305. It is mainly composed of etc.
Here, the main configurations and functions of the various members in this embodiment are the same as those in the above-described embodiment except that the configuration in the developing device is different, and therefore the description of the similar members will be omitted.

In FIG. 6, the developing means 302 includes a developing sleeve 306 for supplying the developer to the photosensitive drum 1, a toner replenishing means 307, developer agitating members 308 and 309, a developer layer regulating member 310, and an agitating / conveying member 311. , And a case 312 for accommodating and holding them. Here, the developing sleeve 306 and the developer layer restricting member 310 are the same as those in the above-mentioned embodiment, and therefore their explanations are omitted.

The toner replenishing means 307 is of a well-known structure having a screw 307a for conveying toner and a paddle 307b for ejecting toner having a groove in the direction of the mother ship on the peripheral surface of the cylindrical body. The generated toner is uniformly supplied into the developing unit 302 based on a detection signal from a toner detecting unit (not shown).

The toner replenishing member 307 is shown in FIG.
As in the case of the developing means shown in FIG. 3, a toner supply port 314 for receiving the toner transferred by the toner transfer means 305 composed of a powder pump unit is provided at the position where the side plate of the developing means 302 discharges. are doing.

In FIG. 6, the toner taken in from the toner supply port 314 is supplied to one end of the screw 307a. The toner replenishing means 307 has an air vent hole 307 above the paddle 307b of the upper plate 307c.
d is formed, and an air filter 315 is fitted in the air vent hole 307d.

The developer stirring members 308 and 309 are constituted by well-known paddles that stir the toner and carrier inside the developing means 302 and send the developer to the developing sleeve 306.

On the other hand, the excess developer scraped off by the developer layer regulating member 310 is as shown by the arrow in FIG.
It is conveyed to the upper part of the stirring and conveying member 311. The stirring and conveying member 311 includes a screw 311a and fins 311.
b, and the developer conveyed to this is distributed to each of the developer stirring members 308 and 309 and conveyed.

FIG. 7 shows a concrete example of the toner storage means (toner storage unit) 303, toner supply means (toner supply unit) 304, and toner transfer means (powder pump unit) 305 in the embodiment shown in FIG. Here is an example:
In FIG. 7, the toner storage unit 303 has a funnel-shaped storage unit main body 316 having openings 303a and 303b in the upper and lower portions, and an opening 30 in the upper portion.
It is composed of an openable / closable lid 317 provided so as to close 3a. The toner 318 has an upper opening 303a.
Is appropriately supplied to the inside of the storage unit main body 316.

At the bottom of the toner storage unit 303, an opening 303b at the bottom of the storage unit main body 316 is formed.
A toner supply unit 304 is arranged so as to communicate with the. The toner supply unit 304 is mainly composed of a supply unit main body 319, a supply motor 320, a supply screw 321, and the like. Further, the powder pump unit 305 is provided at the lower end of the toner supply unit 304 so as to communicate with the supply unit main body 319.
Is connected. The configurations and operations of the toner supply unit 304 and the powder pump unit 305 are almost the same as those of the developer stirring unit 220 and the powder pump unit 200 shown in FIG.

However, since the powder to be transferred and stirred in this embodiment is the toner 318 instead of the two-component developer as in the above embodiment, the toner supply unit 304 in this embodiment is The developer stirring unit 220 in the above-described embodiment does not have the effect of making the toner and carrier concentrations uniform and making the charge amount proper, and the function thereof is mainly the fluidization of the toner 318 supplied thereto. Is promoted to cause the toner 318 to flow into the powder pump unit 305.

On the other hand, the control of the powder pump unit 305 and the air pump 328 at the time of starting and stopping the operation of the developing device in this embodiment is performed via the respective power supply cords 320a and 328a as in the case of the above embodiment. The on / off control is performed in the same manner as shown in FIG.

As a result, similarly to the case of the developer in the above-described embodiment, only the air pump 328 is operated for a certain time when the developing device is started or stopped, so that the toner 318 is blocked in the supply pipe 332. Is eliminated, and the transfer of the toner 318 can be made more reliable. In particular, when the toner is to be transferred as in the present embodiment, the fluidity of the developer is much worse when the toner is left as it is (when the developing device is stopped) than when the toner is to be transferred. The control is also effective in ensuring the fluidity of the toner at all times, and for this reason, in this embodiment, the operating time of only the air pump shown by A to B and C to D in FIG. It is desirable to set the time to be longer and control the air pump 328 to operate until the residual toner completely disappears in the supply pipe 332.

[0067]

According to the present invention, in claim 1, it is possible to reduce the size of the developing means arranged facing the latent image carrier and to simplify the structure, and to improve the operability during maintenance. Can be improved. Further, since the residual developer in the developer supply pipe when the developing device is used can be removed prior to the supply of the developer by starting the operation of the developing device, the transfer of the developer can be made more reliable. You can

According to the second aspect, it is possible to reduce the size of the developing means arranged facing the latent image carrier and simplify the structure, and it is possible to improve the operability during maintenance. Further, since the residual developer in the developer supply pipe after the use of the developing device can be removed prior to the precipitation of the developer due to the stop of the developing device, the transfer of the developer can be made more reliable. You can

According to the third aspect of the present invention, it is possible to reduce the size of the developing means arranged facing the latent image carrier and to simplify the structure, to secure an economical toner storage amount, and to replenish toner at the time of toner supply. It is possible to improve workability and operability during maintenance such as assembly and adjustment of the device. Further, since the residual developer in the developer supply pipe when the developing device is used can be removed prior to the supply of the developer by starting the operation of the developing device, the transfer of the developer can be made more reliable. You can

According to the present invention, it is possible to reduce the size of the developing means arranged facing the latent image carrier and to simplify the structure, to secure an economical toner storage amount, and to replenish toner at the time of toner supply. It is possible to improve workability and operability during maintenance such as assembly and adjustment of the device. Further, since the residual developer in the developer supply pipe after the use of the developing device can be removed prior to the precipitation of the developer due to the stop of the developing device, the transfer of the developer can be made more reliable. You can

[Brief description of drawings]

FIG. 1 is a schematic sectional view including developing means of a developing device in which the present invention is implemented.

FIG. 2 is a schematic perspective view including developing means of a developing device in which the present invention is implemented.

FIG. 3 is a cross-sectional view illustrating a developer optimizing unit and a developer transfer pump according to an embodiment of the present invention.

FIG. 4 is a timing chart for explaining the operation control of the drive motor and air pump of the powder pump unit in the embodiment of the present invention.

FIG. 5 is a cross-sectional view for explaining the state of the developer in the supply pipe of the developer transfer pump in the developing device according to the present invention.

FIG. 6 is a schematic cross-sectional view showing a developing device, a developer optimizing device, and a developer transferring pump according to another embodiment of the present invention.

FIG. 7 is a cross-sectional view for explaining a developer optimizing unit and a developer transfer pump according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Photoconductor drum (latent image carrier) 10,302 Development means 110 Developer supply member 111,332 Supply pipe 111a Supply pipe inlet 120 Developer discharge member 121 Discharge pipe 121a Discharge pipe outlet 170 Air filter 200 Developer Transfer / circulation means (powder pump unit) 201 Rotor 202 Stator 205 Air supply port 206 Developer discharge port 207, 328 Air pump 208 Air discharge port 209, 226, 320a, 328a Power cord 220 Developer stirring unit 221 Stirring screw 222 Drive motor 223 Agent container 225 Developer inlet 230 Toner replenishing unit 230a Toner replenishing unit lid 232 Toner replenishing member 240 Developer concentration detecting member 270 Developer passage 303 Toner accumulating means (toner accumulating unit) ) 304 toner supply means (toner supply unit) 305 toner transfer means (powder pump unit) 320 supply motor 321 supply screw

Claims (4)

[Claims] 1. A developing device for visualizing an electrostatic latent image formed on a latent image carrier, wherein a developer obtained by mixing toner and carrier is applied to the latent image carrier. A developing means, a developer optimizing means for optimizing the developer, which is separately arranged at a different position from the developing means, and a developer transfer for transferring the developer to the developing means and the developer optimizing means. In a developing device including circulation means, the developer transfer / circulation means includes a screw pump for supplying a mixture of developer and air, and an air supplier for supplying air to the screw pump. The screw pump and a control means for controlling the operation of the air supply device are provided, and when the operation of the developing device is started by the control means, only the air supply device is operated for a predetermined time, and then the screw pump and the air supply device are operated. Operate the air supply at the same time So that, a developing device and controls the screw pump and the air supply unit. 2. A developing device for visualizing an electrostatic latent image formed on a latent image carrier, wherein a developer in which toner and carrier are mixed is applied to the latent image carrier. A developing means, a developer optimizing means for optimizing the developer, which is separately arranged at a different position from the developing means, and a developer transfer for transferring the developer to the developing means and the developer optimizing means. In a developing device including circulation means, the developer transfer / circulation means includes a screw pump for supplying a mixture of developer and air, and an air supplier for supplying air to the screw pump. The screw pump and a control means for controlling the operation of the air supply device are provided, and when the operation of the developing device is stopped by the control means, only the screw pump is stopped first and only the air supply device is operated for a predetermined time. After operating the air supply Vessel and to stop the developing apparatus characterized by controlling the screw pump and the air supply unit. 3. A developing device for visualizing an electrostatic latent image formed on a latent image carrier, comprising developing means for applying a developer to the latent image carrier, and the developing device. Toner storage means separately provided at a position different from the means, toner supply means for stirring and conveying the toner supplied to the toner storage means, and toner transfer for transferring toner from the toner supply means to the developing means And a screw pump for supplying a mixture of a developer and air, an air supplier for supplying air to the screw pump, the screw pump and the air. A control means for controlling the operation of the supply device, and when the operation of the developing device is started by the control means, only the air supply device is operated for a predetermined time, and then the screw pump and the air supply device are connected. Made at the same time As to the developing apparatus characterized by controlling the screw pump and the air supply unit. 4. A developing device for visualizing an electrostatic latent image formed on a latent image carrier, the developing device applying a developer to the latent image carrier, and the developing device. Toner storage means separately provided at a position different from the means, toner supply means for stirring and conveying the toner supplied to the toner storage means, and toner transfer for transferring toner from the toner supply means to the developing means And a screw pump for supplying a mixture of a developer and air, an air supplier for supplying air to the screw pump, the screw pump and the air. A control means for controlling the operation of the feeder, and when the operation of the developing device is stopped by the control means, only the screw pump is stopped first, and only the air feeder is operated for a predetermined time. Sky The feeder to stop, developing device and controls the screw pump and the air supply unit.