JP3250420B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming a toner image on a sheet, such as a printer, a copying machine, and a facsimile. More specifically, the present invention relates to an image forming apparatus capable of reducing an occupied area during use, and mainly relates to a structure of a developing chamber.

[0002]

2. Description of the Related Art Generally, an image forming apparatus for forming a toner image on a sheet has a drawback that the sheet occupies a large area because the sheet is conveyed in a horizontal state.

On the other hand, a conventional image forming apparatus for reducing the occupied area is disclosed in JP-A-6-2.
One described in Japanese Patent Publication No. 02390 is known.

FIG. 7 is a perspective view showing the arrangement of members inside the image forming apparatus described in the publication, and FIG. 8 is a top view of the image forming apparatus.

As shown in these figures, the apparatus has a sheet storage unit 1, a sheet feeding roller 2, a sheet conveying path 3, an image forming unit 4, a fixing unit 5, a pair of sheet discharging rollers 6, and the like, which are substantially upright. With such a configuration, the sheet S is configured to be conveyed while being substantially upright.

[0006] According to such a configuration, the apparatus can be in a vertically long state, and the installation area can be reduced.

[0007]

SUMMARY OF THE INVENTION The above-mentioned JP-A-6-2
No. 02390 does not disclose a structure around the developing chamber in the image forming unit 4.

On the other hand, the structure of a generally known developing device is such that, as shown in FIG. 9, for example, a predetermined amount of toner T stored in a case 10 is supplied onto a developing roller 12 by a supply roller 11, The developing roller 12 supplies toner to the surface of a photoconductor (photosensitive drum in the drawing) 13 and develops a latent image on the photoconductor surface to form a toner image. Note that the toner image formed on the surface of the photoconductor 13 is transferred to a sheet S conveyed in a horizontal state. 1
4 is an agitator for stirring the toner in the case, 15
Is a blade for regulating the amount of toner on the developing roller 12.

However, in order to apply such a structure of the developing device to the above-described image forming apparatus described in Japanese Patent Application Laid-Open No. 6-202390, an upright state, that is, a rotation axis of the developing roller 12 and the like is in a vertical direction. In such a case, the toner T in the case 10 is shifted to the bottom, so that the toner is not supplied to the upper portion of the developing roller 12 and the toner image cannot be formed on the upper portion of the photoconductor 13.

That is, in the prior art, if the image forming apparatus is arranged so that the rotation axis of the developing roller is in the vertical direction, there is a problem that an appropriate image cannot be formed.

An object of the present invention is to solve the above-mentioned problems and to provide an image forming apparatus which can reduce an occupied area and form an appropriate image at the same time.

[0012]

According to another aspect of the present invention, there is provided an image forming apparatus, wherein toner is supplied to a surface of a photoreceptor, and a latent image on the surface of the photoreceptor is developed to form a toner image. An image forming apparatus, comprising: a developing roller having a rotation axis of the developing roller disposed in a vertical direction or a direction inclined from the vertical direction, wherein the rotation axis is disposed in a direction inclined from the vertical direction or the vertical direction. on the upper end side of the developing roller has a supply port of the toner, a developing chamber for supplying toner to the surface of the developing roller developing roller while flowing down the toner toward the lower side from the supply port, apply in this developing chamber
Supply toner to the supply port to fill the developing chamber with toner.
And a toner conveying means .

[0013] The image forming apparatus according to the second aspect is the first aspect.
In the image forming apparatus described above, the developing chamber has a discharge port at a lower end side of the developing roller for discharging a part of surplus toner that has not been subjected to development, and the conveying unit discharges the developing chamber. It is a conveying means for conveying surplus toner discharged from an outlet toward the supply port.

According to a third aspect of the present invention, there is provided the image forming apparatus according to the second aspect.
In the image forming apparatus described above, the transporting unit is disposed adjacent to the developing chamber, and is disposed inside a toner replenishing chamber containing new toner to be supplied from the supply port. It is characterized in that the new toner contained in the supply chamber and the surplus toner discharged from the discharge port are transported toward the supply port.

The image forming apparatus according to claim 4, wherein the請 Motomeko 1, 2 or 3 in the image forming apparatus described, on the side opposite to the supply port in the axial direction of the developing roller from the supply port side And a toner replenishing means for replenishing the toner into the developing chamber while conveying the toner toward the developing chamber.

The image forming apparatus according to claim 5, wherein, in the image forming apparatus 請 Motomeko 1, 2, 3 or 4, wherein, arranged adjacent through the partition wall to the developing chamber, is supplied to the developing chamber A toner supply chamber accommodating new toner to be provided, and the partition wall is configured to be openable and closable.

[0017] The image forming apparatus according to the sixth aspect is characterized in that :
The image forming apparatus according to 3, 4, or 5, wherein the transporting unit includes a transport path formed by a cylindrical body, and a screw disposed in the transport path. Part of the cylindrical body partitions the developing chamber and the toner supply chamber,
And it is characterized by being formed by a partition wall configured to be openable and closable .

[0018]

According to the image forming apparatus of the first aspect, the rotation axis of the developing roller for supplying toner to the surface of the photoreceptor and developing the latent image on the surface of the photoreceptor to form a toner image has a vertical direction or a vertical direction. Since the sheet is arranged in a direction inclined from the direction, the sheet on which the image is formed can be conveyed in the vertical direction or in a state inclined from the vertical direction, so that the occupied area can be reduced.

The developing chamber is supplied with toner from a supply port located at the upper end side of the developing roller to a developing roller whose rotation axis is disposed in a vertical direction or a direction inclined from the vertical direction. Is supplied to the surface of the developing roller while flowing down toward the lower end of the developing roller, so that the toner is supplied from the upper end to the lower end of the developing roller. Moreover, this
The image forming apparatus supplies toner to the supply port in the developing chamber.
Supply means for supplying toner to fill the developing chamber with toner
The developer chamber is filled with toner.
You.

Therefore, it is possible to prevent a toner image from being formed on the upper portion of the photosensitive member, and to form a proper image.

That is, according to the image forming apparatus of the first aspect, the occupied area can be reduced, and at the same time,
An appropriate image can be formed.

According to the image forming apparatus of the present invention, in the image forming apparatus of the first aspect, the developing chamber is provided with a discharge port for discharging a part of surplus toner not used for the development by the developing roller. Since the excess toner discharged from the discharge port of the developing chamber is conveyed toward the supply port by the conveying unit, the surplus toner is reused, and the toner is efficiently consumed. can do.

According to the image forming apparatus of the third aspect, in the image forming apparatus of the second aspect, the transporting means includes:
The surplus toner discharged from the discharge port of the developing chamber and the new toner contained in the toner supply chamber containing the new toner to be supplied from the supply port are transported toward the supply port. The reuse of the toner and the replenishment of the new toner to the developing chamber can be performed by the conveying means. Therefore, for example, the structure can be simplified as compared with a case where a conveying unit for reusing the excess toner and a conveying unit for replenishing the developing chamber with new toner are provided.

Further, the toner replenishing chamber is disposed adjacent to the developing chamber, and the transport means is disposed inside the toner replenishing chamber, so that the apparatus can be made compact.

According to a fourth aspect of the present invention, there is provided the image forming apparatus according to the first, second, or third aspect, further comprising a toner replenishing unit. Since the developer is supplied into the developing chamber while being conveyed toward the opposite side of the supply port along the axial direction of the developing roller, the image forming apparatus is placed sideways so that the rotation axis of the developing roller is substantially horizontal. , The toner is supplied over the entire length of the developing roller, and an appropriate image is formed.

As described above, when the image forming apparatus having such a toner replenishing means is placed in a so-called vertical state so that the rotation axis of the developing roller is directed in the vertical direction or in a direction inclined from the vertical direction. The toner supplied from the supply port located at the upper end of the developing roller flows down toward the lower end of the developing roller and is transported by the toner replenishing means.

According to the image forming apparatus of the fifth aspect, in the image forming apparatus of the first, second, third or fourth aspect, the toner replenishing chamber containing new toner to be supplied to the developing chamber is provided. Since it is arranged adjacent to the developing chamber via a partition wall and the partition wall is configured to be openable and closable, the following operation is obtained.

That is, when the image forming apparatus is placed vertically, the partition wall is closed,
The operation described above is obtained.

On the other hand, when the image forming apparatus is placed in the horizontal state, the partition wall is opened, so that the new toner in the toner supply chamber flows into the developing chamber and the toner flows over the entire length of the developing roller. Thus, an appropriate image is formed.

According to the image forming apparatus of the sixth aspect, the contract
In the image forming apparatus according to claim 3, 4, or 5,
The conveying means includes a conveying path formed by a cylindrical body, and a screw disposed in the conveying path, and a part of the cylindrical body partitions the developing chamber and the toner supply chamber.
Further, since the partition wall is formed to be openable and closable, the apparatus can be made more compact as compared with a case where the transport path and the partition wall are separately configured.

Further, the new toner in the toner supply chamber flows into the developing chamber so as to cross the screw. Therefore, by appropriately controlling the rotation of the screw, the toner can smoothly flow. Obtainable.

[0032]

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

<First Embodiment> FIG. 1 is a plan sectional view showing an image forming unit which is a main part of an image forming apparatus according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II of FIG. FIG.

The image forming unit U can be applied to, for example, the image forming unit 4 in the image forming apparatus shown in FIG.

As shown in FIG. 1, the image forming unit U
Denotes a photosensitive drum 101 as a photosensitive member and a charging roller 10
2, a developing device 200 which is a characteristic part of this embodiment;
By incorporating the cleaning blade 103 into the case 110, the cleaning blade 103 is configured as a single unit. The axes of the rotating bodies in the image forming unit U are all directed vertically. That is, as shown in FIG. 2, the image forming unit U is in a vertically placed state.

First, the entire unit will be described.
Next, the developing device 200 as a characteristic portion will be described in detail.

The photosensitive drum 101 is formed by forming a photosensitive layer made of an organic photosensitive body on a conductive base made of an aluminum drum, and is rotatably supported by a case 110.
It is rotationally driven in the direction of arrow a by a drive mechanism (not shown). The photosensitive member may be constituted by a photosensitive belt or the like in addition to the photosensitive drum.

The charging roller 102 is pressed against the photosensitive drum 101 by a pressing mechanism (not shown), and charges the photosensitive drum 101 while following the photosensitive drum 101. A bias voltage is applied to the charging roller 102.

The charged photosensitive drum 101 is scanned by a laser beam LB emitted from an optical unit (not shown), whereby a latent image is formed on the surface of the photosensitive drum 101.

The case 110 includes an upper wall 111 and a bottom wall 11.
2 and a peripheral wall 113, and a slit 114 for beam scanning is formed in the peripheral wall 113.

The developing device 200 includes a case 110
A developing chamber 201 formed to be long in the vertical direction, a supply roller 210 rotatably provided in the developing chamber 201, and a developing roller 22 also rotatably provided in the developing chamber 201.
0, and a regulating blade 230 in contact with the peripheral surface of the developing roller 220. The supply roller 210 and the developing roller 220 are each driven to rotate in the direction of the arrow in FIG. 1 by a drive mechanism interlocked with the drive mechanism of the photosensitive drum 101. The regulating blade 230 is made of an elastic body such as a stainless steel plate, and is attached to the case 110 by the attaching member 231.

The supply roller 210 rotates while stirring the toner T1 existing in the developing chamber 201, and coats the surface of the developing roller 220 with the toner. The toner coated on the surface of the developing roller 220 is slidably contacted with the regulating blade 230 to be thinned and triboelectrically charged. A bias voltage is applied to the developing roller 220, and the thinned toner is conveyed to the photosensitive drum 101, and the developing roller 220 and the photosensitive drum 1
The latent image on the photosensitive drum 101 is reversal-developed in a nip portion formed by a pressure contact portion with the photosensitive drum 101. Thus, the latent image on the surface of the photosensitive drum 101 is developed to form a toner image.

The toner image formed on the surface of the photosensitive drum 101 is transferred to a sheet S which is conveyed by being sandwiched between the transfer roller 106 to which a bias voltage having a polarity opposite to that of the toner image is applied and the photosensitive drum 101. You.

The cleaning blade 103 includes the mounting member 1
03a is attached to the case 110. One edge 103b of the cleaning blade 103 is in contact with the peripheral surface of the photosensitive drum 101, and the toner image is
After being transferred to the photosensitive drum 101, the residual toner attached to the surface of the photosensitive drum 101 is scraped off.

The photosensitive drum 101, which has been cleaned by scraping off the residual toner, returns to the above-described image forming process.

In FIG. 1, reference numeral 107 denotes a film seal that is in sliding contact with the photosensitive drum 101, and reference numeral 108 denotes a film seal that is in sliding contact with the developing roller 220.

Next, FIG. 1 and FIG.
This will be described in detail with reference to FIG.

The developing chamber 201 is defined by a case 110, a developing roller 220, a film seal 108, a regulating blade 230, a sealing material 240, and a partition wall 250.

The partition wall 250 is formed integrally with the case 110, and has a toner supply port 251 formed at the upper end thereof. A discharge port 252 is formed at the lower end.

Reference numeral 202 denotes a toner replenishing chamber adjacent to the developing chamber 201, in which new toner T3 is stored.

Reference numeral 260 denotes a conveying means, which is disposed inside the toner supply chamber 202 adjacent to the developing chamber 201.
The conveying means 260 includes a conveying path 262 formed by the cylindrical body 261 and a screw 2 disposed in the conveying path.
63.

The cylindrical body 261 is formed of a part (substantially central portion) 253 of the partition wall 250 and the guide wall 2 having a substantially U-shaped cross section formed integrally and suspended from the upper wall 111 of the case 110.
64 are formed. An opening 264 communicating with the discharge port 252 is formed at the lower end of the cylindrical body 261, and the bottom surface 202 a of the toner supply chamber 202 is inclined toward the opening 264.

The screw 263 is connected to the upper wall 111 of the case.
And the bottom wall 112 so as to be rotatable, and is driven to rotate in a direction indicated by an arrow in FIG. 1 by a drive mechanism (not shown).

At the bottom of the screw 263, the developing chamber 20
1 outlet 252 and toner supply chamber 202 opening 2
64 faces, so that the toner from the developing chamber 201 and the toner from the toner replenishing chamber 202 can flow into the bottom of the screw 263. Therefore, when the screw 263 rotates, the toner at the bottom thereof is conveyed upward, and supplied from the supply port 251 to the developing chamber 20.
1 will be supplied. When the developing chamber 201 is filled with the toner, the flow of the toner from the toner supply chamber 202 to the lower end of the screw is stopped, and when the toner in the developing chamber 201 is consumed, the new toner T3 flows to the lower end of the screw. Thus, the developer is supplied into the developing chamber 201. That is, when the toner in the developing chamber 201 is not consumed, the developing chamber 201 is in a state of being filled with the toner, and when the toner in the developing chamber 201 is consumed, the new toner T3 is replenished accordingly. ing.

When the new toner T3 is gradually consumed and the new toner in the toner supply chamber 202 runs out, the developing chamber 20
1 gradually disappears from above. Developing room 20
If no toner is left in the upper portion of the developing roller 1, no toner is supplied to the upper portion 221 of the developing roller 220, so that an image to be formed on the upper portion of the sheet is not properly formed. For this reason, when the toner runs out in the upper part of the developing chamber 201, the operation of the image forming apparatus must be stopped irrespective of the available toner in the lower part of the developing chamber 201.

Therefore, if the toner volume of the developing chamber 201 (the volume of the portion in which the toner is stored) is large, the amount of toner remaining in the lower portion becomes large, which may be wasted. It is desirable that the toner volume of the developing chamber 201 is small, that is, the shape of the portion in which the toner is stored is vertically elongated.

However, if the toner volume in the developing chamber 201 is too small, when the consumption of toner increases, for example, when a black toner image is formed on the entire printable area of the sheet, the developing chamber 201 There is a possibility that the supply of the toner from the supply port 251 cannot keep up with the consumption of the toner inside the printer, so that an appropriate image cannot be formed.

Therefore, in this embodiment, the toner volume of the developing chamber 201 is set as small as possible within a range where the supply of the toner from the supply port 251 can catch up with the consumption of the toner in the developing chamber 201.

The above-described developing device 200 operates as follows.

(I) In the standby state, the developing chamber 201
Inside the toner T1 is the upper end 221 of the developing roller 220.
It is in a state of being filled up.

(Ii) When the apparatus operates, the photosensitive drum 1
01, the supply roller 210, and the developing roller 220 are rotated almost simultaneously with or before the screw 263 is rotated. When the screw 263 rotates, the toner flows in FIG. 2 as indicated by arrows T ′, T1 ′, T2 ′.
As shown by, the upper end of the screw enters the developing chamber 201 via the supply port 251, flows down the developing chamber 201, reaches the lower end of the screw 263 via the outlet 252, is conveyed by the screw 263, and again from the upper end of the screw. It circulates along a path of entering the developing chamber 201 through the supply port 251.

(Iii) When the sheet is fed to the image forming apparatus and the photosensitive drum 101, the supply roller 210, and the developing roller 220 rotate at a predetermined timing with respect to the conveyed sheet, as described above, The toner T1 in the developing chamber 201 is supplied to the surface of the developing roller 220 by the supply roller 210, and the latent image on the photosensitive drum 101 is reversely developed. The toner image formed on the surface of the photosensitive drum 101 is transferred to the sheet S, and then is fixed to the sheet S by passing through a fixing device (not shown).

A part of the toner (excess toner) in the developing chamber 201 that has not been subjected to the development (see the arrow T2 ′ in FIG. 2) flows into the lower end of the screw 263 through the discharge port 252 to supply the toner. It is conveyed to the supply port 251 while being stirred and mixed with the new toner T3 from the chamber 202.

When the toner T1 is supplied to the surface of the developing roller 220, even if the toner T1 in the developing chamber 201 is consumed, the toner T1 rotates as described above unless the new toner T3 in the toner replenishing chamber 202 runs out. Since the toner is supplied into the developing chamber 201 from the upper end of the screw 263 via the supply port 251 as needed, the situation where the toner is not supplied to the upper portion 221 of the developing roller 220 does not occur.

The above operations (i) to (iii) are performed when the axis of the rotating body in the unit U is oriented in a direction V1 inclined at an angle θ from a vertical direction V as shown in FIG. But you can get it.

According to the image forming apparatus provided with the unit U as described above, the following effects can be obtained.

(A) The toner is supplied to the surface of the photoreceptor 101, and the rotation axis of the developing roller 220 for developing the latent image on the surface of the photoreceptor to form a toner image is arranged in the vertical direction. The sheet S to be conveyed can be conveyed in a state of standing in the vertical direction, so that the occupied area can be reduced.

For the developing roller 220 whose rotation axis is arranged in the vertical direction, the developing chamber 201
Supply port 25 located on upper end 221 side of developing roller 220
1 is supplied from the developing roller 22 to the developing roller 22.
0 while flowing down toward the lower end 222 side of the developing roller 22.
0, so that the developing roller 22
The toner is supplied from the upper end side to the lower end side of 0.

Accordingly, it is possible to prevent the toner image from being formed on the upper portion of the photosensitive member 101, and to form an appropriate image.

That is, an occupied area can be reduced, and at the same time, an appropriate image can be formed.

In this embodiment, the toner supply chamber 202 is provided on the side of the development chamber 201. For example, the toner supply chamber is disposed above the development chamber 201, 2 Supply port 115 as shown by a virtual line
The same effect can be obtained even if the toner is caused to flow down by providing

(B) The developing chamber 201 has a discharge port 252 on the lower end 222 side of the developing roller 220 for discharging a part of the surplus toner not subjected to the development. Excess toner discharged is screw 2
Since the toner is conveyed toward the supply port 251 by the 63, the surplus toner is reused, and the toner can be efficiently consumed.

(C) The screw 263 is connected to the surplus toner discharged from the discharge port 252 of the developing chamber and the toner replenishing chamber 2
02 and the new toner T3 stored in the supply port 251.
, The reuse of surplus toner and the replenishment of new toner to the developing chamber can be performed by one screw 263. Therefore, for example, the structure can be simplified as compared with a case where a transport unit for reusing the excess toner and a transport unit for replenishing the developing chamber with new toner are separately provided.

In addition, the toner supply chamber 202 is
1, the toner supply chamber 202
Since the transfer means 260 is disposed inside the device, the size of the apparatus can be reduced.

The effects of the above (a) to (c) are as follows. The axis of the rotating body in the unit U is, for example, as shown in FIG.
Even if it is suitable for 1.

<Second Embodiment> FIG. 3 is a partially omitted plan sectional view showing an image forming unit which is a main part of an image forming apparatus according to a second embodiment of the present invention, and FIG. 4 is a partially omitted IV in FIG.
It is a IV sectional view.

In these figures, the same parts as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted.

This embodiment is different from the above-described first embodiment in that a screw 270 is provided as a toner replenishing means in the developing chamber 201, and there is no other difference.

The screw 270 is connected to the upper wall 111 of the case.
And the bottom wall 112, and is rotatably driven in a direction indicated by an arrow in FIG. 3 by a driving mechanism (not shown). The screw 270 is connected to the developing roller 22 from the supply port 251 side.
The toner is replenished into the developing chamber 201 while the toner is conveyed toward the discharge port 252 along the 0 axis direction.

According to such a configuration, the toner supplied from the supply port 251 is supplied to the lower end 222 of the developing roller 220.
It is conveyed by the screw 270 while flowing down toward the side.

Therefore, even when the image forming apparatus is placed in the horizontal position such that the rotation axis of the developing roller 220 is substantially horizontal, the toner is transferred from the supply port 251 to the discharge port 252 by the screw 270. Since the toner is supplied into the developing chamber 201 while being transported toward the developing roller 201, the toner is supplied over the entire length of the developing roller 220, and an appropriate image is formed.

That is, according to this embodiment, an appropriate image can be formed regardless of whether the image forming apparatus is arranged vertically or horizontally.

<Third Embodiment> FIGS. 5A and 5B are partially omitted plan sectional views each showing an image forming unit which is a main part of an image forming apparatus according to a third embodiment of the present invention.

In these figures, the same parts as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted.

The feature of this embodiment resides in that the partition wall 250 'can be opened and closed.

The partition wall 250 ′ is composed of fixed walls 254, 255 formed integrally with the case 110 and the sliding wall 2.
56. The edge of one fixed wall 255 is formed in a crank shape in a plan view, and the slide wall 256 is formed in a T-shape in a plan view, and the slide wall 256 is closed as shown in FIG. Thus, a rectangular cylindrical transport path 262 'is formed.

When the sliding wall 256 is slid in the direction of the arrow b, an opening 257 is formed to communicate the developing chamber 201 with the toner replenishing chamber 202. Through this opening 257, the new toner T3 in the toner replenishing chamber 202 is formed. Arrow T
As shown by reference numeral 4, the developer is supplied into the developing chamber 201.

According to such a configuration, when the image forming apparatus is placed vertically, the partition wall 250 'is closed as shown in FIG. The same operation and effect as the example can be obtained.

On the other hand, when the image forming apparatus is placed in the horizontal state, the partition wall 250 ′ is opened as shown in FIG. The toner flows into the developing chamber 201 as indicated by an arrow T4 and is supplied over the entire length of the developing roller 220, so that an appropriate image is formed.

That is, according to this embodiment, an appropriate image can be formed regardless of whether the image forming apparatus is arranged vertically or horizontally.

The opening and closing of the slide wall 256 may be manually performed by interlocking with an operation lever via a mechanism (not shown), or the posture of the image forming apparatus (vertical or horizontal) by a sensor (not shown). May be automatically detected by a driving device (for example, a device using a motor or a solenoid).

When the slide wall 256 is opened, the screw 263 may be stopped, or may be rotated forward and backward at a predetermined pitch. When the screw 263 is rotated forward and backward at a predetermined pitch, the toner supply chamber 202
The flow of the toner from the toner into the developing chamber 201 is smoothly performed.

<Fourth Embodiment> FIG. 6 is a partially omitted plan sectional view showing an image forming unit which is a main part of a fourth embodiment of the image forming apparatus according to the present invention.

In these figures, the same parts as those shown in FIGS. 3 and 4 are denoted by the same reference numerals, and description thereof will be omitted.

The feature of this embodiment is that a partition wall 250 '' is provided.
Is slidable in the direction of arrow c.

One end of the partition wall 250 ″ is
6 and an L plate portion 289, and are formed in an h-shape in plan view, and when closed as shown by a solid line in FIG. 6, the end portion 258a of the flat plate portion 258 and the end portion 289 of the L plate portion 289.
a comes into contact with the inner surface of the peripheral wall 113 ′ of the case 110 ′ and the flat plate portion 258, the L plate portion 289, and the peripheral wall 113 ′.
Thus, a transport path 262 ″ is formed.

Also, as shown by the imaginary line in FIG.
When 50 '' is slid in the direction of arrow c, the developing chamber 20
Opening 257 'communicating between 1' and toner supply chamber 202 '
Is formed, and the new toner T3 in the toner supply chamber 202 'is supplied into the developing chamber 201' through the opening 257 'as shown by an arrow T4'.

According to such a configuration, when the image forming apparatus is placed in the vertical position, the same operation and effect as in the second embodiment described above can be obtained by closing the partition wall 250 ''. can get.

On the other hand, when the image forming apparatus is placed in the horizontal state, the partition wall 250 ″ is opened as shown by the imaginary line, so that the new toner T3 in the toner supply chamber 202 ′ is removed. The toner flows into the developing chamber 201 'as shown by the arrow T4' and the toner is supplied over the entire length of the developing roller 220, so that an appropriate image is formed. In this case, the toner T3 is supplied so as to slide down the inner surface of the peripheral wall 113 ', so that the toner T3 is supplied smoothly.

The opening and closing of the partition wall 250 '' can be performed manually or automatically as in the third embodiment.

When the partition wall 250 '' is opened, the screws 263 and 270 are rotated in the directions shown by the arrows. As shown in FIG. 4, these screws convey the toner in the reverse direction, so that the toner replenishing chamber 202 ′
The flow of the toner from the developer into the developing chamber 201 'is smoothly performed.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and can be appropriately modified within the scope of the present invention.

[0103]

According to the image forming apparatus of the first, second, or third aspect, it is possible to reduce the occupied area in a vertically placed state and at the same time to form an appropriate image.

According to the image forming apparatus of the fourth, fifth, or sixth aspect, it is possible to use the image forming apparatus in any of vertical and horizontal directions, and at the same time, to form an appropriate image. In addition, in the case of the vertical position, the occupied area can be reduced.

[0105]

[Brief description of the drawings]

FIG. 1 is a plan sectional view showing an image forming unit which is a main part of a first embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a cross-sectional view taken along a line II-II in FIG.

FIG. 3 is a partially omitted plan sectional view showing an image forming unit which is a main part of a second embodiment of the image forming apparatus according to the present invention.

FIG. 4 is a sectional view taken along line IV-IV in FIG. 2;

FIGS. 5A and 5B are partially-omitted plan sectional views each showing an image forming unit which is a main part of a third embodiment of the image forming apparatus according to the present invention.

FIG. 6 is a partially omitted plan sectional view showing an image forming unit which is a main part of a fourth embodiment of the image forming apparatus according to the present invention.

FIG. 7 is an explanatory diagram of a conventional technique.

FIG. 8 is an explanatory diagram of a conventional technique.

FIG. 9 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 S sheet 101 Photosensitive drum 200 Developing device 201 Developing chamber 202 Toner replenishing chamber 220 Developing roller 250 Partition wall 251 Supply port 252 Discharge port 260 Conveying means 261 Cylindrical body 263 Screw 270 Toner replenishing means

Claims (6)

(57) [Claims] A developing roller that supplies toner to the surface of the photoconductor and develops a latent image on the surface of the photoconductor to form a toner image, wherein a rotation axis of the developing roller is vertically or inclined from the vertical direction. An image forming apparatus arranged in a direction, wherein a rotation axis is provided in a vertical direction or a direction inclined from the vertical direction at an upper end side of the developing roller, and a toner supply port is provided at the upper end side of the developing roller, A developing chamber for supplying the toner to the surface of the developing roller while causing the toner to flow down toward the lower end of the developing chamber;
An image forming apparatus comprising: a toner conveying unit that supplies the toner to the developing chamber to supply the toner to the developing chamber . 2. The developing chamber has a discharge port at a lower end side of the developing roller for discharging a part of surplus toner that has not been used for development. the image forming apparatus according to claim 1, wherein the discharged excess toner is conveying means for conveying toward the supply port. 3. The toner supply chamber is disposed adjacent to the developing chamber, and is disposed inside a toner supply chamber containing new toner to be supplied from the supply port. 3. The image forming apparatus according to claim 2, wherein the new toner contained in the image forming apparatus and the excess toner discharged from the discharge port are conveyed toward the supply port. That it includes a toner replenishing means for replenishing toner to the developing chamber while conveying the toner toward the side opposite to the 4. Before Symbol the supply port in the axial direction of the developing roller from the supply port side The image forming apparatus according to claim 1, 2, or 3, wherein 5. A are adjacently arranged via the partition wall prior Symbol developing chamber provided with a toner supply chamber accommodating the new toner to be supplied to the developing chamber, and the partition wall is configured to be opened and closed Claims 1, 2, 3, and 3
Or the image forming apparatus according to 4. 6. The transfer means includes a transfer path formed by a cylindrical body, and a screw disposed in the transfer path, and a part of the cylindrical body is connected to the developing chamber and the toner.
A supply chamber, which is formed by a partition wall configured to be openable and closable .
Or the image forming apparatus according to 5 .