JPH07160102A - Development device - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] To provide a developing device capable of exhibiting stable developing performance in response to environmental changes. [Structure] The slitter 7 of the toner supply portion is formed of a shape memory alloy. As a result, in the high temperature state, the slitter 7 is deformed from the shape shown in (a) to the shape shown in (b), and the toner supply hole 7a of the slitter is changed to the toner supply roller 4.
From the position in contact with the outer circumference of the roller 4 to the upstream side in the rotation direction of the roller 4. As a result, the toner replenishment amount increases, and the required toner replenishment amount is secured even if the fluidity of the toner decreases under high temperature and high humidity conditions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for an image forming apparatus such as a copying machine, a printer and a facsimile, and more particularly to a developing device for developing an electrostatic latent image recorded by an electrostatic recording method. Is.

[0002]

2. Description of the Related Art Electrostatic recording type image forming apparatuses, particularly electrophotographic type image forming apparatuses are widely used as image forming apparatuses such as copying machines, facsimiles and printers. Since this method basically forms an image by using static electricity, it has the property of being sensitive to environmental changes. That is, when the temperature and humidity around the apparatus fluctuate, the fluidity and charging ability of the developer (toner and carrier) in the developing apparatus also change. That is, when the temperature is high and the humidity is high, the fluidity and the charging ability of the developer are lowered, and conversely, when the temperature is low and the humidity is low, the fluidity and the charging ability are increased.

[0003]

However, the conventional developing device is not configured to change the fluidity and the charging ability of the developer in response to the environmental change, and the environmental change around the device is large. If this happens, stable toner density and charging characteristics cannot be maintained, and there is the problem that abnormal images occur.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems in the conventional developing device and to provide a developing device capable of exhibiting stable developing performance in response to changes in the environment.

[0005]

According to the present invention, the above-mentioned problems can be solved by forming a main component from a material which is repeatedly deformed and recovered into a predetermined shape by an external factor.

In order to solve the above-mentioned problems, the present invention proposes that the main constituent component is a toner replenishing member of a toner replenishing section.

Further, in order to solve the above-mentioned problems, the present invention proposes that the main constituent component is a toner stirring / supplying member of a toner replenishing section.

Furthermore, the present invention proposes that the main component is a stirring member in order to solve the above-mentioned problems.

Furthermore, the present invention proposes that the main constituent component is a separator in order to solve the above-mentioned problems.

[0010]

The main constituent parts of the developing device are made of a material which is deformed and recovered into a predetermined shape by an external factor. As a result, when external factors such as temperature change, the components are deformed so as to maintain the fluidity and the charging ability of the developer.

Other functions will be apparent from the description of the embodiments below.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view showing the configuration of an embodiment of a developing device to which the present invention is applied, mounted on an electrophotographic copying machine. Since the structure of the electrophotographic copying machine itself is the same as that conventionally known, the description thereof will be omitted and only the developing device will be described.

In this figure, a dry two-component developing device 1
However, it is arranged close to the photosensitive drum 11 of the electrophotographic copying machine. In the developing device 1, the toner contained in the toner hopper 5 is agitated by the agitator (agitation / supply member) 6 and supplied to the toner supply unit 10. From the toner supply unit 10, toner is supplied by the toner replenishing roller 4 toward the stirring roller 3 through a toner supply hole of the slitter 7 which will be described later, and the stirring roller 3 mixes the toner with the carrier to stir and charge the carrier. In the developing device 1 of this embodiment, the stirring roller 3 is set to 2 in order to improve the stirring ability.
Books (3 ₁ , 3 ₂ ) are provided. Stir with the stirring roller 3.
The charged toner is magnetized on the developing roller 2, and
The electrostatic latent image formed on the photosensitive drum is developed. By the way, when the toner is magnetized by the developing roller 2, the doctor blade 9 regulates the toner to a certain amount, and the remaining toner and carrier are returned to the stirring roller 3 by the separator 8.

The developing device 1 is driven through an electromagnetic clutch (not shown), and the driving force is transmitted to each part by gears. The developing device 1 is driven only during latent image development to shorten the driving time and to develop the image. We are trying to extend the life of the agent. Also,
The toner concentration in the apparatus is detected by a toner concentration detecting means (sensor) not shown. When the toner concentration decreases, the toner replenishing clutch operates and the toner replenishing roller 4 rotates, so that the toner in the toner hopper 5 is supplied.

FIG. 2 is an enlarged side view showing the slitter (toner replenishing member) 7 and the toner replenishing roller 4 of the developing device of this embodiment. As shown in this figure, the toner replenishing roller 4 is installed in contact with the slitter 7. A toner supply hole 7a for supplying toner is formed in the slitter 7, and the toner on the outer peripheral portion of the toner replenishing roller 4 which rotates counterclockwise in the drawing is formed in this hole 7a.
Then, it is supplied to the stirring roller 3 (shown in FIG. 1).

In the present embodiment, the slitter 7 is formed of a shape memory alloy (for example, Ni-Ti alloy), and in a normal temperature state, as shown in FIG. 2A, the slitter hole 7a has a toner replenishing roller 4. The position is in contact with the outer circumference of. Then, when in a high temperature state, it is transformed into the shape shown in FIG. At this time, the toner supply hole 7a moves from the position in contact with the outer periphery of the toner supply roller 4 to the upstream side in the rotation direction of the roller 4.

By the way, since the toner has good fluidity under normal temperature and humidity conditions, the slitter hole 7a is shown in FIG.
Although an appropriate amount of toner is supplied at the position shown in, the toner fluidity deteriorates in high temperature and high humidity conditions (usually, the higher the temperature, the higher the humidity). It has been known from past cases that the supply amount cannot be secured. However, in this embodiment, when the temperature is high, the slitter hole 7a changes from the position shown in FIG. 2A to the position shown in FIG. 2B, so that the toner supply amount increases. As a result, the required toner replenishment amount can be secured even if the fluidity of the toner deteriorates under high temperature and high humidity conditions. If the temperature returns to the normal value, the slitter 7 will move to the position shown in FIG.
It goes without saying that the shape shown in FIG. 2A is restored from FIG. 2B, and the hole 7a of the slitter is also returned to the position shown in FIG. 2A from FIG. 2B. Therefore, it is possible to always stably supply the toner even if the environment changes.

FIG. 3 is a side view of the toner supply portion of the developing device of this embodiment. As shown in this figure, the tip of the agitator 6 is in contact with the inner wall of the toner hopper 5, and is conveyed to the toner replenishing section 10 by the agitator 6 which rotates counterclockwise in the figure. Then, the toner supply roller 4 supplies the toner from the hole of the slitter 7 toward the stirring roller 3 (shown in FIG. 1).

In this embodiment, the agitator 6 is made of a shape memory alloy (for example, Ni-Ti alloy),
In a normal temperature state, the shape is as shown in FIG. 3A, and in the high temperature state, the shape is changed to the shape as shown in FIG. 3B. When the shape of the agitator 6 is deformed as shown in FIG. 3B, the toner conveyance amount increases and the toner supply amount increases. Therefore, even if the fluidity of the toner deteriorates under high temperature and high humidity conditions, the required toner supply amount can be secured. Needless to say, when the temperature returns to the normal value, the agitator 6 returns to the shape shown in FIG. 3 (b) from FIG. 3 (a). Therefore, it is possible to always stably supply the toner even if the environment changes.

[0021] FIG. 4 is a side view showing a first stirring roller 3 ₁ of the developing device of the present embodiment. Stirring roller 3 ₁ in this embodiment is formed of a shape memory alloy (e.g., Ni-Ti alloy), in the normal temperature state has a shape as shown in Figure 4 (a). That is, the stirring roller 3 ₁
The tip end of the roller is bent in the rotating direction (clockwise in the figure) to improve the stirring property when the rotation of the roller rises.
By the way, in a low temperature / low humidity state (usually, humidity decreases as temperature decreases), the fluidity of the developer improves, and the toner is charged more than necessary. If the toner is excessively charged, the magnetized amount of the toner on the developing roller 2 may become abnormal. Therefore, in the low temperature state, the stirring roller 3 ₁ is deformed into the shape shown in FIG. When the shape of the stirring roller 3 ₁ is deformed as shown in FIG. 4B, the stirring performance is lowered and the toner charge amount is lowered. Therefore, the toner charge amount does not become excessive even if the fluidity of the toner is improved in the low temperature and low humidity state. If the temperature returns to the normal value,
It goes without saying that the stirring roller 3 ₁ returns to the shape shown in FIG. 4 (b) from FIG. 4 (a). Therefore, it is possible to always stably charge the toner even if environmental changes occur.

FIG. 5 is a side view showing the vicinity of the separator 8 of the developing device of this embodiment. As described above, when the developer carried from the stirring roller 3 (see FIG. 1) is magnetized by the developing roller 2 and regulated to a certain amount by the doctor blade 9, a gap between the developing roller 2 and the separator 8 is formed. The toner is triboelectrically charged by being forcibly sent to. This charging serves to supplement the frictional charging by the stirring roller 3.

In this embodiment, the separator 8 is made of a shape memory alloy (for example, Ni-Ti alloy),
In the normal temperature state, the shape is as shown in FIG. 5A, and in the high temperature state, the shape is changed to the shape as shown in FIG. 5B. When the shape of the separator 8 is deformed as shown in FIG. 5B, the gap between the developing roller 2 and the separator 8 is narrowed, and the triboelectric charge amount of the toner is increased. Therefore, even if the fluidity of the toner deteriorates under high temperature and high humidity conditions, the required toner charge amount can be secured. Needless to say, when the temperature returns to the normal value, the separator 8 returns to the shape shown in FIG. 5 (b) from FIG. 5 (a). Therefore, it is possible to always stably charge the toner even if environmental changes occur.

As described above, the developing device 10 of this embodiment is
The slitter 7, the agitator 6, the first stirring roller 3 ₁
Since the separator 8 and the separator 8 are formed of a shape memory alloy, even when the slitter 7, the agitator 6 and the separator 8 are deformed into a predetermined shape in a high temperature state, even if the toner fluidity deteriorates in a high temperature and high humidity state. The required toner supply amount and toner charge amount are secured. Further, when the low temperature state is prevented that the first stirring roller 3 ₁ is deformed into a predetermined shape, the toner charge amount even if the fluidity of the toner becomes good at low temperature and low humidity condition excessive . And
When the temperature / humidity returns to normal, each member returns to its initial shape, so that stable developing performance can be exhibited even when environmental changes occur.

[0025] The present invention is not limited to this embodiment, the slitter 7 of the developing device, an agitator 6, without any of the first stirring roller 3 ₁ and the separator 8 is formed of a shape memory alloy, Only the necessary one of the parts may be formed of the shape memory alloy according to the characteristics of the device. In addition, in the present embodiment, the above-mentioned components are made of Ni-Ti alloy,
It may be formed of another shape memory alloy, a resin having the same shape memory effect, or ceramics.

[0026]

As described above, according to the developing device of the present invention, the main constituent parts relating to toner replenishment and charging are formed of a material which is repeatedly deformed and recovered into a predetermined shape due to an external factor. Therefore, if the toner's fluidity deteriorates at high temperature and high humidity, or if the toner's fluidity becomes good at low temperature and low humidity, each part will be deformed into the prescribed shape and required. The toner supply amount and the toner charge amount are secured, and the toner is prevented from being overcharged. Therefore,
It is possible to exhibit stable developing performance even when environmental changes occur.

According to the second aspect of the invention, since the toner replenishing member (slitter) of the toner replenishing section is made of the above material, it is possible to keep the replenishing amount of the toner, which changes due to environmental changes, at an appropriate amount.

According to the third aspect of the present invention, since the agitating / supplying member (agitator) of the toner replenishing section is made of the above material, the toner that changes due to environmental changes is stably conveyed to the toner replenishing section, and the necessary toner is supplied. A supply amount can be secured.

According to the structure of claim 4, since the stirring member (stirring roller) is formed of the above-mentioned material, the state of the developer which changes due to environmental changes can be stably stirred, and the toner can be prevented from being overcharged. it can.

According to the fifth aspect of the invention, since the separator is made of the above material, it is possible to keep the charge of the developer, which changes due to environmental changes, stable.

[Brief description of drawings]

FIG. 1 is a side configuration diagram showing a state in which an embodiment of a developing device to which the present invention is applied is mounted on an electrophotographic copying machine.

FIG. 2 is an enlarged side view showing a slitter of the developing device shown in FIG. 1, (a) showing a normal temperature state;
(B) is a high temperature state.

FIG. 3 is a side view showing a toner supply portion of the developing device, in which (a) is a normal temperature state and (b) is a high temperature state.

FIG. 4 is a side view showing a first stirring roller of the developing device, in which (a) is a normal temperature state and (b) is a low temperature state.

FIG. 5 is a side view showing the vicinity of a separator of the developing device, in which (a) is a normal temperature state and (b) is a high temperature state.

[Explanation of symbols]

 1 developing device 2 developing roller 3 stirring roller 4 toner replenishing roller 5 toner hopper 6 agitator 7 slitter 7a toner supply hole 8 separator 9 doctor blade 10 toner replenishing section 11 photoconductor drum

Claims (5)

[Claims] 1. A developing device, wherein main components are formed of a material that is repeatedly deformed and recovered into a predetermined shape due to an external factor. 2. The developing device according to claim 1, wherein the main component is a toner replenishing member of a toner replenishing section. 3. The developing device according to claim 1, wherein the main component is a toner stirring / supplying member of a toner replenishing section. 4. The developing device according to claim 1, wherein the main component is a stirring member. 5. The developing device according to claim 1, wherein the main component is a separator.