JPH1152701A - Image forming device - Google Patents

Abstract

(57) [Problem] To provide an image forming apparatus capable of continuing image formation for a while even when toner in a toner bottle becomes empty. The image forming apparatus includes a toner recycle unit that recycles used toner and a toner end detection unit that detects a toner end state in which toner supply has been completed.
The ratio of the recycled toner supplied from the toner recycling unit to the newly added toner is increased immediately before the toner end state is detected or after the toner end state is detected until the toner end state is reset.
By reusing the used toner in this manner, image formation can be continued for a while even when the toner in the toner bottle becomes empty.

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 such as a facsimile, a printer, a copying machine, etc., which can perform toner recycling and can form an image on a sheet using toner.

[0002]

2. Description of the Related Art An image forming apparatus using a toner includes:
Some form images by dry development. by the way,
For the purpose of protecting the environment, reducing running costs, and the like, this type of image forming apparatus employs a so-called toner recycling system in which recycled toner (used toner) is returned to a developing device without being discarded. .

[0003] However, when a toner having an additive such as silica added to the surface is used, since the silica is buried in the toner after development, the fluidity of the recycled toner is significantly higher than that of a new toner. Will drop. For this reason, when the ratio of recycled toner / new toner is increased, toner aggregates are likely to be formed, and white dropouts occur on the image, and the toner charging rises poorly, causing background smearing and transfer unevenness. Since uneven density occurs on the solid and the fluidity of the developer deteriorates, problems such as blurred horizontal lines occur.

[0004]

Problems to be Solved by the Invention
9 and JP-A-6-19312 perform control such that the ratio of new toner to collected toner falls within a certain range. However, the ratio cannot be changed after toner end (end of toner supply).

Japanese Patent Application Laid-Open No. Hei 7-181791 allows an operator to change the ratio between new toner and collected toner. The collected toner is not always usable until the empty toner bottle is replaced with a new toner bottle after the end.

As described above, the copier cannot be used until the empty toner bottle is replaced with a new toner bottle after the normal toner end (end of toner supply) occurs.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus which can solve the above-mentioned problems and can continue the image forming operation for a while even when the toner in the toner bottle becomes empty.

[0008]

According to a first aspect of the present invention, there is provided an image forming apparatus comprising: a toner recycling unit for recycling used toner; and a toner end detecting unit for detecting a toner end state in which toner supply has been completed. The toner end detecting means detects the toner end state, or after the toner end, and before resetting the toner end state, the recycle toner supplied from the toner recycle means for the newly added toner. It is characterized by increasing the ratio.

According to the first aspect of the present invention, the ratio of recycled toner to new toner is increased after the toner end or during the period from near the end of the toner until the toner end is reset. By using recycled toner while minimizing deterioration, downtime (unusable time) of the image forming apparatus from replacement of an empty toner bottle to replacement of a new toner bottle can be reduced.

According to a second aspect of the present invention, there is provided a classifying device for classifying a recycled toner, wherein the toner removed by the classification from near the end of the toner or after the end of the toner until resetting the toner end state. Is used.

According to the second aspect of the present invention, a recycled toner (hereinafter referred to as "waste toner") which has not passed through the sieve after the classification, from the end of the toner, or from the time near the toner end to the reset of the toner end, is used. Therefore, it is possible to minimize the image deterioration due to the use of the recycled toner and to reduce the downtime (unusable time) of the image forming apparatus from the replacement of the empty toner bottle to the replacement of the new toner bottle.

According to a third aspect of the present invention, when the toner end state is restored, the recycled toner is consumed.

According to the third aspect of the present invention, the toner in the developer in which the ratio of the recycled toner or the waste toner after the classification is increased is used for consumption to some extent and new toner is supplied. After replacement with the toner bottle), the image can be returned promptly to obtain an image without any deterioration from the first sheet.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the image forming apparatus of the present invention, and FIG. 2 is a plan view showing the image forming apparatus.

This image forming apparatus is, for example, a copying machine for dry-copying the contents of a document onto transfer paper, and can use recycled toner. The photoconductor drum 1 rotates in the R direction, but in the vicinity of the photoconductor drum 1, the charging charger 3, the grid 5, the cleaning blade 7 of the cleaning unit 23, the transfer charger 9, the separation charger 11, the developing roller 13, Lamp 15, eraser 1
7, a developing unit 25 and the like are arranged. The photosensitive drum 1 can be exposed from an exposure lamp (not shown) as indicated by an arrow t.

As shown in FIGS. 1 and 2, a toner recycling mechanism 100 and a toner end detecting mechanism 110 are arranged near the photosensitive drum 1. The toner recycle unit 100 is a recycle toner (collected toner)
And a transport screw 19 and the like. The recycled toner transport screw 19 can be rotated by a motor 21.
The motor 21 is connected to a motor driver 55 and is driven by a command from the CPU 45.

The recycled toner conveying screw 19 is
The partial screw 19a and the partial screw 19 shown in FIG.
b, the partial screw 19a is arranged along the cleaning unit 23, and the partial screw 19b is
As shown in FIG. 2, the toner reaches the toner hopper 27 side from the cleaning unit 23,
It is inclined so that the side is higher.

As shown in FIGS. 1 and 2, the toner hopper 27 is arranged in parallel with the developing unit 25, and the toner hopper 27 is provided with a toner conveying screw 29. As shown in FIG. 2, a toner bottle 31 is exchangeably connected to the toner hopper 27, and a waste toner hopper 33 is arranged in parallel with the toner hopper 27. A waste toner conveying screw 35 is disposed in the waste toner hopper 33, and a waste toner bottle 37 is disposed at an end of the screw 35.

A toner replenishing roller 47 is arranged at a connection portion between the toner hopper 27 and the developing unit 25 shown in FIG. 1, and the developing roller 13 and a paddle 49 are arranged inside the developing unit 25.

As shown in FIG. 1, a toner end sensor 41 of a toner end detecting mechanism 110 is arranged at a portion near the bottom of the toner hopper 27. The toner end detecting mechanism 110 includes a toner end sensor 41, an A / D (analog / digital) converter 43, and a CPU (central processing unit) 45. The toner end sensor 41 is a sensor for detecting the end of toner supply (toner end), and uses, for example, a piezoelectric element. The toner end detection signal of the toner end sensor 41 is converted into a digital signal by the A / D converter 43 and provided to the CPU 45.

The toner supply roller 47 shown in FIG. 1 can be rotated by a motor 51. The motor 51 is connected to a motor driver 53 and driven by a command from the CPU 45. The CPU 45 has a ROM 57 and a RAM 59. The ROM 57 stores instructions and the like used by the CPU, and the RAM 59 is a work area used by the CPU.

By the charging charger 3 and the grid 5,
The photoconductor drum 1 is uniformly charged to, for example, -850V. A latent image is formed on the photosensitive drum 1 by irradiating the contents of the original placed on the contact glass (not shown) with light from an exposure lamp and exposing the reflected light. The developer in the developing unit 25 is transported to the developing roller 13 by the paddle 49, and the latent image on the photosensitive drum 1 is developed.

The toner image on the photosensitive drum 1 is transferred to the transfer paper by the charge applied to the back surface of the transfer paper by the transfer charger 9 and the electrostatic charge of the photosensitive drum 1. The toner remaining after the transfer is scraped off by the cleaning blade 7 and is conveyed to the toner hopper 27 by the rotation of the conveying screw 9 as collected toner (recycled toner).

The recovered toner is new toner (new toner) supplied from the toner bottle 31 shown in FIG.
While being agitated, it is conveyed to the inner side of the machine by the screw 29 as shown in FIG.

The screw 29 is provided with a filler 61 as shown in FIG. 3, and the filler 61 can scrape off the toner T attached to the surface of the toner end sensor 41 every one rotation. The toner end sensor 41 detects the end of the toner once each time the filler 61 scrapes off the toner T. For example, when it detects that there is no toner three or five times in a row, the operation shown in FIG. The unit 63 can display “toner end” by turning on a lamp, for example.

Next, the operation of the image forming apparatus will be described with reference to FIGS. In step S1 of FIG. 4, when the door is opened and closed, a switch (not shown) is pressed,
Opening and closing of the door is detected. At this time, if "" toner end "is not displayed on the operation unit 63 in step S2, the process ends without doing anything.

In step S2, "toner end"
When the display is displayed, the toner bottle rotation motor (not shown) and the toner conveying screw 29 are driven to rotate in steps S3 and S4.

At this time, in step S5, when the toner end sensor 41 detects "no toner" three times in a row, for example, the CPU 45 in FIG. 1 determines that the toner bottle 31 shown in FIG. Since it is determined that the bottle has not been replaced, the toner bottle rotation motor is stopped in step S6, and in steps S7 and S8 the
It is driven to rotate for 0 seconds and then stopped. In step S9, the toner transport screw 29 stops thereafter. When the recycled toner conveying screw 19 is driven to rotate for 10 seconds, for example, about 10 g in the embodiment of the present invention.
Since the recycled toner is supplied to the toner hopper 27, if the document is a normal document, several hundred copies can be made even after detecting "no toner".

On the other hand, if the toner end sensor 41 does not detect "no toner" three consecutive times even if the toner bottle rotation motor is driven in step S5 after the door is opened and closed, the CPU 45 in FIG. Step S in FIG.
In steps 10 and S11, it is determined that the toner bottle 31 has been replaced with a new toner bottle, and once the toner bottle rotation motor is turned off, the rotation of the toner bottle 31 is stopped, and a solid image is formed on the photosensitive drum 1. (10 seconds). In this case, the photosensitive drum 1 is rotating,
The “no toner” display is lit, and the charger 3
Is on, the developing bias is on, and the developing unit 25
Are also rotating. Thereafter, in step S12, the rotation of the developing roller 13 and the like of the developing unit 25 is stopped, and the rotation of the photosensitive drum 1 is also stopped, thereby completing the image forming operation.

Next, in step S13 of FIG. 5, the toner bottle rotating motor is again driven for, for example, 30 seconds, and
New toner is supplied from the toner bottle to the toner hopper 27. When the toner bottle rotation motor is stopped in step S14, the "toner end" display on the operation unit 63 in FIG. 1 is turned off in step S15. Thereafter, the process proceeds to step S9 in FIG.

By forming a solid image for 10 seconds, a toner having a high ratio of collected toner (recycled toner) is consumed at a toner concentration of about 1 wt%, and new toner is supplied. After replacing the toner bottle with a new toner bottle, the image forming apparatus can immediately return to the original copy operation state.

In the above-described embodiment, the ratio of recycled toner / new toner is increased after the toner end or during the period from near the end of the toner until the toner end is reset. Therefore, image deterioration due to a high recycled toner ratio is minimized. By using recycled toner while keeping the minimum, the downtime (unusable time) of the copier from the replacement of an empty toner bottle to the replacement of a new toner bottle can be reduced. If the Toner End indicator is turned on early without using recycled toner, new toner remains in the toner bottle, so copying from an empty toner bottle to the replacement of a new toner bottle The downtime of the machine (time when it cannot be used) cannot be reduced.

Further, by using the recycled toner remaining in the recycling path of the image forming apparatus employing the toner recycling system, copying can be performed for a while even after the toner bottle becomes empty. . Further, by providing a mode (steps S10 and S11) for consuming the recycled toner at the time of the toner recovery, the recovered toner /
A state in which the image has deteriorated slightly due to an increase in the ratio of new toner can be quickly restored at the time of toner recovery.

Next, another embodiment of the image forming apparatus of the present invention will be described with reference to FIGS. The image forming apparatus shown in FIG. 6 is different from the image forming apparatus shown in FIG. 1 in that a classification device 81 shown in FIG. 7 is provided, and other components of the image forming apparatus shown in FIG. FIG.
Are substantially the same as the corresponding components of the image forming apparatus shown in FIG.

The classifier 81 is located above the replenishing roller 83 and at the end of the recycled toner conveying screw 19. Cleaning blade 7 shown in FIG.
The untransferred toner scraped off by this is transported to the classifier 81 by the recycled toner transport screw 19. The classifier 81 is made of, for example, a basket of 150 mesh (having a hole diameter φ of 0.06 mm), and rotates integrally with the recycled toner conveying screw 19. The recycled toner D passing through the mesh hole of the recycled toner shown in FIG. 7 enters the toner hopper 27, and the waste toner E not passing through the mesh hole of the recycled toner is distributed to the waste toner hopper 33. A supply roller 83 is provided between the toner hopper 27 and the waste toner hopper 33.
There is a stop during normal copying. When the CPU 45 instructs the motor driver 93, the supply roller 83 is rotated by the operation of the motor 91. The waste toner E after the classification by the classification device 81 is normally stored in a waste toner bottle 37 on the back side of the machine shown in FIG. 2 and is discarded when the waste toner E becomes full, but the recycled toner D after the classification is replaced with a new toner. Used together.

The operation of the image forming apparatus shown in FIGS. 6 and 7 is almost the same as the operation of the image forming apparatus of FIG. 1, but the operation shown in FIG. 8 is different. Step S of the operation shown in FIG.
Steps 71 and 81 are operations in place of steps S7 and S8 shown in FIG. 4. If the toner bottle is not replaced after the door is opened and closed, in step S71, the waste toner hopper and the toner hopper are switched as shown in FIG. The intermediate supply roller 83 is rotated by, for example, 10 seconds by the motor 91 shown in FIG. 6 and recycled toner (waste toner) is supplied to the toner hopper.
When the supply roller D is supplied, at step 82
3 stops.

In the present embodiment, the recycled toner D after the classification is used after the toner end or from the time near the toner end to the toner end reset, so that the image deterioration due to the use of the recycled toner D is minimized. In addition, downtime (unusable time) of the copying machine from the replacement of an empty toner bottle to the replacement of a new toner bottle can be reduced.

After the "toner end" display is turned on, the recycled toner or the waste toner after the classification is used. For example, before the toner end lighting (close to the toner end lighting), the ratio of the recycled toner to the new toner or the waste toner after the classification is used. Increasing the ratio of E gradually can be easily considered by devising the mounting position of the toner end sensor.

Although the opening / closing of the door is set at the timing of supplying the recycled toner after the toner end or the waste toner after the classification, it is easy to set a switch or the like which can be selected by the operator at the timing.

Further, in the above-described embodiment, a new toner bottle is used to supply the new toner to the toner hopper after the toner in the developer in which the ratio of the recycled toner or the waste toner after the classification is increased is consumed to some extent. After the replacement, an image without any deterioration can be obtained from the first sheet. Incidentally, the image forming apparatus of the present invention can be applied not only to a copying machine but also to a facsimile or a printer.

[0041]

According to the first aspect of the present invention, the ratio of the recycled toner to the new toner is increased after the end of the toner or between the time near the toner end and the time the toner end is reset. For this reason, image deterioration due to a high ratio of recycled toner is minimized, and by using recycled toner, the downtime of the image forming apparatus from the replacement of an empty toner bottle to the replacement of a new toner bottle is not possible. Time).

According to the second aspect of the present invention, the waste toner after the classification is used immediately before or after the toner end and before the toner end state is reset, so that the waste toner is used. Thus, downtime (unusable time) of the image forming apparatus from the replacement of an empty toner bottle to the replacement of a new toner bottle can be reduced while minimizing image deterioration due to the above.

According to the third aspect of the present invention, when recovering the toner end state, the recycled toner is consumed, so that the toner in the developer in which the ratio of the recycled toner or the waste toner after classification has increased is reduced to some extent. In order to supply new toner for consumption, the toner can be immediately restored at the time of toner recovery (after replacement with a new toner bottle) to obtain an image without any deterioration from the first sheet.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a plan view of the image forming apparatus of FIG.

FIG. 3 is a diagram illustrating an internal structure of a toner hopper and a toner end sensor of the image forming apparatus of FIG. 1;

FIG. 4 is a flowchart illustrating an operation of the image forming apparatus of FIG. 1;

FIG. 5 is a flowchart showing a part of the flowchart of FIG. 4;

FIG. 6 is a diagram showing another embodiment of the image forming apparatus of the present invention.

FIG. 7 is a diagram illustrating a classification device of the image forming apparatus of FIG. 6;

FIG. 8 is a flowchart showing an operation part of the image forming apparatus of FIG. 6 which is different from that of the image forming apparatus of FIG. 1;

[Explanation of symbols]

81 Classifier 100 Toner recycling mechanism (toner recycling means) 110 Toner end detection mechanism (toner end detection means) D Recycled toner after classification (recycled toner) E Waste toner

Claims (3)

[Claims] 1. An image forming apparatus comprising: a toner recycling unit that recycles used toner; and a toner end detection unit that detects a toner end state in which toner supply is completed, wherein the toner end detection unit is in a toner end state. An image forming apparatus which increases the ratio of the recycled toner supplied from the toner recycling unit to the newly added toner immediately before the toner is detected or after the end of the toner until the toner end state is reset. 2. A classifier for classifying the recycled toner, wherein a classifier is provided near the toner end or after the toner end.
2. The image forming apparatus according to claim 1, wherein the toner removed by the classification is used until the toner end state is reset. 3. The image forming apparatus according to claim 1, wherein recycled toner is consumed when the toner end state is recovered.