JP3425908B2 - Developing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device applied to an image forming apparatus such as a printer, a copying machine or a facsimile.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Laid-Open No. 10-33340.
As shown in Japanese Patent Publication No. 6, a first-stage storage chamber and a second-stage storage chamber, which are respectively partitioned by partition walls and arranged in parallel, are provided with a first stirring unit and a second stirring unit, and are externally supplied to the first-stage storage chamber. While stirring the formed toner by the stirring means,
By supplying the developing roller from the latter-stage transfer chamber,
There is known a developing device configured to supply toner to a developing roller in a state where the toner is uniformly charged.

[0003]

When toner is replenished on the agitating means arranged in the developing container as described above, new toner replenished from the toner hopper and the developing container Although it has the advantage that the toner charge ratio can be prevented from becoming non-uniform by thoroughly mixing the toner remaining in the inside, on the other hand, it is an initial adjustment performed when setting up the image forming apparatus or when replacing the developing apparatus. There is a problem that the time required for work becomes long.

That is, in the developing device, when the amount of toner remaining in the developing container is extremely small, the image quality is deteriorated due to the high density of the toner whose chargeability is lowered due to the deterioration of the toner. Therefore, the toner in the toner hopper is replenished into the developing container when it is detected that the amount of toner remaining in the developing container becomes equal to or less than a certain value (for example, 200 g). Therefore, when setting up the image forming apparatus having the developing device or replacing the developing device, the initial adjustment work of the image forming device is performed until the predetermined amount of toner is replenished in the empty developing container. However, there is a problem that the time required for this initial adjustment work is unavoidably long.

The present invention has been made in view of the above points, and can shorten the time required for the initial adjustment work at the time of setting up the image forming apparatus or replacing the developing device, and can be used in normal use. At the same time, it is an object of the present invention to provide a developing device capable of preventing deterioration of image quality due to an extremely small amount of toner remaining in the developing container.

[0006]

The invention according to claim 1 is
A developing container containing a developer made of a one-component toner,
A developing roller disposed in the developing container, a toner replenishing portion for replenishing the toner in the developing container as necessary, and a portion for installing the developing roller while stirring the toner replenished from the toner replenishing portion. A developing device having a stirrer for transporting the toner to the toner replenisher is provided with a toner guide for selectively guiding the toner replenished from the toner replenisher to the stirrer setting part and the developing roller setting part. is there.

According to the above construction, in the normal state, the toner guiding direction of the toner guiding portion is set to the side where the stirring means is installed, so that the toner supplied to the stirring means is stirred by the stirring means. Meanwhile, it is conveyed to the installation portion of the developing roller. On the other hand, when the image forming apparatus is set up or the developing device is replaced, the toner guiding direction of the toner guiding section is set to the developing roller installation section side, so that the toner replenished on the developing roller is set. The initial adjustment work for confirming whether or not the image is properly formed by using is quickly performed.

According to a second aspect of the present invention, in the developing device according to the first aspect, the toner guide portion swingably displaces the guide plate which is swingably supported in the developing container. And a drive unit.

According to the above construction, the guide direction of the toner by the guide plate of the toner guide section is normally set to the side where the stirring means is installed, and the image forming apparatus is set up or the developing apparatus is replaced. In this case, the guide plate of the toner guide section is pivotally displaced by the drive section, so that the guide direction of the toner by the guide plate is set to the developing roller installation section side.

[0010]

1 and 2 show an embodiment of a developing device according to the present invention. This developing device includes a developing container 1 containing a developer made of a one-component toner, a developing roller 2 arranged in the developing container 1, and a toner for replenishing the developing container 1 with toner as necessary. Supply section 3
And a stirring means 6 composed of a first stirring roller 4 and a second stirring roller 5 that conveys the toner replenished from the toner replenishing portion 3 to the installation portion of the developing roller 2 while stirring the toner. In the container 1, the toner replenished from the toner replenishing unit 3 and the developing roller 2 are provided.
A toner guide portion 7 is provided for selectively guiding the sheet to the installation portion of the toner.

The developing container 1 includes a first accommodating portion 8 in which the first stirring roller 4 is arranged, a second accommodating portion 9 in which the developing roller 2 and the second stirring roller 5 are arranged, and the first accommodating portion 9. Housing section 8
And a second accommodating part 9 for partitioning the second accommodating part 9. Above the second accommodating part 9, the thickness of the toner layer formed on the surface of the developing roller 2 is regulated and the developing roller 2 is provided.
A regulating blade 11 made of a magnetic member for frictionally charging the toner is provided between and.

The developing roller 2 is installed so as to face the photoconductor drum 12 and is rotated by a rotation driving mechanism (not shown), and a magnet roller 14 disposed in the developing sleeve 13. And the toner layer formed on the developing sleeve 13 on the photosensitive drum 1
By causing the toner to fly close to the electrostatic image of 2,
It is configured to perform development.

The toner replenishing section 3 is provided in the developing container 1
Toner hopper 15 disposed above the first storage portion 8 of the
And a replenishment roller 16 for replenishing the replenishment toner accommodated in the toner hopper 15 into the developing container 1, and a toner amount detecting means (not shown) disposed in the second accommodating portion 9. When it is detected that the amount of toner in the developing container 1 is less than a certain value, for example, 200 g or less, the replenishing roller 16 is actuated and the toner hopper 1
The toner in 5 is replenished in the developing container 1.

The first agitating roller 4 and the second agitating roller 5 constituting the agitating means 6 each have a spiral blade for toner conveyance and are replenished onto the first agitating roller 4 from the toner replenishing section 3. The first stirring roller 4 is configured to be conveyed from one end side to the other end side while stirring the toner.

The toner conveyed to the other end by the first stirring roller 4 is transferred to the developing container 1 and the partition wall 1.
0 is introduced into the installation portion side of the second stirring roller 5 through a first gap 17 formed between the second stirring roller 5 and the second stirring roller 5, and the other end portion side of the second stirring roller 5 while being stirred by the second stirring roller 5. From the first stirring roller to the one end side, a part of which is supplied onto the developing roller 2, and the remaining part passes through the second gap 18 formed between the developing container 1 and the partition wall 10 4 is returned to the installation section side.

The toner guide portion 7 is provided with the second stirring roller 5
And a pair of guide plates 20 projectingly provided on the peripheral surface of the rotary shaft 19.
And a drive unit including an operation handle 21 for swinging and displacing the guide plate 20 by rotating the rotary shaft 19. Then, the operation handle 21
By rotating the rotary shaft 19 by means of, the direction in which the toner is guided by the guide plate 20 is set to the installation portion side of the first stirring roller 4 as shown by the phantom line in FIG. As indicated by the solid line 1 in FIG. 1, the developing roller 2 is displaced so as to be set on the side where the developing roller 2 is installed.

In the above structure, during normal operation of the developing device, the guiding direction of the toner by the guide plate 20 is
As shown by the phantom line in FIG. 1, the first stirring roller 4 is set on the side where it is installed. Then, when it is confirmed that the amount of toner in the developing container 1 is below a certain value according to the detection signal of the toner detecting means, the replenishing roller 16 is driven and the toner in the toner hopper 15 is It is replenished on the first stirring roller 4.

The toner replenished on the first stirring roller 4 is supplied to the installation side of the second stirring roller 5 while being stirred by the first stirring roller 4, and then the second stirring roller 5 is supplied. It is supplied onto the developing roller 2 while being stirred by. By this, the toner in the developing container 1
After being mixed with the toner newly replenished from the toner replenishing section 3, it is used for development.

On the other hand, when the image forming apparatus having the developing device is set up or when the developing device is replaced, the guide plate 20 is driven by the driving portion including the operation handle 21.
By oscillating and displacing the toner, the toner supply direction by the guide plate 20 is set to the installation portion side of the developing roller 2 as shown by the solid line in FIG. The toner in the toner hopper 15 is replenished on the developing roller 2. As a result, the toner required for the initial adjustment work such as the above-mentioned setup is rapidly supplied to the installation portion of the developing roller 2, and the time required for the initial adjustment work can be shortened.

That is, at the time of setting up the image forming apparatus or replacing the developing apparatus, the toner replenishing section is set in a state where the guiding direction of the toner by the guide plate 20 is set to the installation section side of the first stirring roller 4. When the toner is replenished onto the first stirring roller 4 from No. 3, the amount of toner necessary for starting the initial adjustment work, that is, about 200 g of toner is supplied to the installation portion of the developing roller 2, 10
It takes about a minute. On the other hand, as described above, with the toner guiding portion 7 guiding the toner to the installation portion side of the developing roller 2, the toner replenishing portion 3 is set.
When the toner is replenished from the developing roller 2 to the developing roller 2, the initial adjustment work can be started only by supplying about 50 g of toner to the installation portion of the developing roller 2. The time required will be reduced to about 2 to 3 minutes.

As described above, there is provided a toner guide portion 7 for selectively guiding the toner replenished from the toner replenishing portion 3 to the installation portion of the agitating means 6 and the installation portion of the developing roller 2, which is normally provided. The guide direction of the toner by the toner guide portion 7 is set to the installation portion side of the stirring means 6, and the toner supplied on the stirring means 6 is stirred by the stirring means 6,
Since it is configured to be conveyed to the installation portion of the developing roller 2, a certain amount of toner accommodated in the developing container 1 and the toner newly replenished from the toner replenishing portion 3 are sufficiently mixed to form the toner The charge rate can be made uniform. Therefore, it is possible to effectively prevent the deterioration of the image quality due to the increase in the density of the toner whose chargeability is lowered due to the extremely small amount of the toner remaining in the developing container 1 and to always form a clean image. it can.

In addition, when the image forming apparatus is set up or the developing apparatus is replaced when the developing container 1 is empty, the toner guiding section 7 guides the toner to the developing roller 2. When the toner is supplied to the developing roller 2, the amount of toner necessary for the initial adjustment work for confirming whether the image is properly formed by using the toner replenished on the developing roller 2 is set on the developing roller 2 Since it can be quickly supplied to the installation portion of, the time required for this initial adjustment work can be effectively shortened.

In the above embodiment, the operating handle 2
By manually operating the drive unit consisting of 1 to swing and displace the guide plate 20, the guiding direction of the toner by this guide plate 20 is displaced from the installation portion side of the stirring means 6 to the installation portion side of the developing roller 2. Although the example configured as described above has been described, a rotating mechanism having an electric motor that rotationally drives the rotation shaft 19 of the toner guide portion 7 or a push-pull type that swings and displaces the guide plate 20 of the toner guide portion 7 is described. The structure may be such that an electric drive unit including a swing mechanism having a solenoid is provided.

By moving the installation position of the toner replenishing section 3 with respect to the developing container 1, the toner replenished from the toner replenishing section 3 is moved to the installation section of the stirring means 6 and the installation section of the developing roller 2. It may be configured such that the vehicle can be selectively guided.

[0025]

As described above, according to the present invention, the developing container for containing the developer composed of the one-component toner, the developing roller disposed in the developing container, and the developing container in the developing container as necessary. In a developing device having a toner replenishing section for replenishing the toner and a stirring means for agitating the toner replenished from the toner replenishing section and conveying it to the developing roller installation section, the toner is replenished from the toner replenishing section Since the toner guide portion that selectively guides the toner to the installation portion of the agitating means and the installation portion of the developing roller is provided, the guide direction of the toner by the toner guide portion is normally set to the installation portion side of the agitation means. By doing so, a certain amount of toner accommodated in the developing container and the toner newly replenished from the toner replenishing section can be sufficiently mixed to make the toner charge ratio uniform. In addition, at the time of setting up the image forming apparatus, by setting the guiding direction of the toner by the toner guiding portion to the developing roller installation portion side, an image is properly formed by the toner replenished on the developing roller. There is an advantage that the time required for the initial adjustment work for confirming whether or not the adjustment is performed can be effectively shortened.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of a developing device according to the present invention.

FIG. 2 is a plan sectional view showing a configuration of the developing device.

[Explanation of symbols]

1 developer container 2 developing roller 3 Toner supply section 6 stirring means 7 Toner guide 20 guide plate 21 Operation handle (drive unit)

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Yamazaki 1-2-2 Tamatsukuri, Chuo-ku, Osaka Mita Kogyo Co., Ltd. (56) References Showa 63-107455 (JP, U) Showa 63 -86654 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 15/08 112 G03G 15/08 507

Claims (2)

(57) [Claims] 1. A developing container for accommodating a developer composed of a one-component toner, a developing roller arranged in the developing container, and a toner replenishing section for replenishing the developing container with toner as necessary. In a developing device having a stirring unit that conveys the toner supplied from the toner supply unit to the installation unit of the developing roller, the toner supplied from the toner supply unit is installed in the installation unit of the stirring unit, A developing device comprising: a developing roller installation portion and a toner guide portion for selectively guiding the developing roller. 2. The toner guide portion includes a guide plate swingably supported in the developing container, and a drive portion for swingably displacing the guide plate. Development device.