JPS62175767A - Image carrier unit in image forming device - Google Patents

Abstract

PURPOSE:To reduce the size of a toner storage part by setting the capacity of the toner storage part so that the time to fill the toner storage part with toner in a standard use state is shorter than the life of an image carrier. CONSTITUTION:The time that it takes to fill the toner storage part 15 with toner in the standard use state of a printer is set shorter than the life of the photosensitive body 4. Namely, when the toner storage part 15 is filled with toner and the fullness is displayed on a display part, an operator detaches a unit 16 from a printer body 10 and its internal toner is thrown away. Thus, the case 16 is emptied and then the unit 16 is mounted on the printer body 10 again. This operation is performed at least one throughout the lifetime of the photosensitive body 4 and the whole of the unit 16 is thrown away when the lifetime of the photosensitive body 4 expires. Consequently, the capacity of the toner storage part of the case 19 is made small even when a long-life photosensitive body 4 is used.

Description

[Detailed Description of the Invention] U-Presentation The present invention integrally comprises an image bearing member on which a toner image is formed and a toner storage portion that stores the toner removed from the image bearing member after the toner image has been transferred. , relates to an image carrier unit in an image forming apparatus.

It has long been known to use an image carrier unit of the above type in an image forming apparatus such as a copying machine, printer, or facsimile machine. The advantage is that it can be attached to and detached from the main body of the device.

In addition, for this type of unit, 1-The time it takes for the toner storage section to become full (that is, the lifespan of the toner case that partitions the toner storage section) and the lifespan of the image carrier are set to be equal, and when the lifespan of the image carrier reaches its end, A carrier unit has been proposed in which the entire unit is replaced with a new unit. In the unit according to this proposal, the toner case and the image carrier reach the end of their lifespans at approximately the same time, so that they can be used up without waste and disposed of at the same time. However, the lifespan of image carriers (for example, photoreceptors) has increased significantly in recent years, and therefore, if the lifespan of the 1-ner case and the image carrier are set to be the same, the capacity of the 1-ner storage section must be adjusted to match the lifespan of the image carrier. It has to be significantly larger. Therefore, the overall size of the unit, and ultimately the li! The disadvantage is that the overall size of the lie forming apparatus becomes large.

Furthermore, since the lifespan of the image carrier has been extended, even when it is not considered to match the lifespan of one image carrier and the case, if the capacity of the toner storage section is not increased, the expensive image carrier will not be able to be used. Regardless of the situation, the unit must be replaced, which is very uneconomical.

(2) An object of the present invention is to provide an image carrier unit of the type described at the beginning, which eliminates the above-mentioned drawbacks of the conventional art and can reduce the size of the toner storage section.

In order to achieve the above object, the present invention sets the capacity of the toner accommodating portion so that the time required for the toner accommodating portion to become full of toner under standard usage conditions is shorter than the life of the image carrier. Suggest a configuration.

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

FIG. 1 shows a laser printer as an example of an image forming apparatus, in which recording paper 2 is fed in the direction of the arrow from a paper feeder 1 and is timed by a pair of registration rollers 3 to form a drum-shaped photoreceptor 4. The image carrier is transported to the image carrier.

The photoconductor 4 is rotated clockwise, and at this time, the surface is charged by the charger 5! The electrostatic latent image is formed on the photoreceptor by being irradiated with laser light from the laser optical system 6. When this latent image passes through the developing roller 22 of the second developing unit 17, it is converted into a one-henner image by toner, and this toner image is transferred to the recording paper conveyed to the photoreceptor 4 by the transfer charger 8, and then The toner image is fixed by a fixing device 9. The recording paper that has left the fixing device 9 is discharged, as shown by arrow B, to a stray paper section 11 formed by the upper wall surface of the printer main body 10.

On the other hand, the cleaning blade 12 removes residual toner from the photoreceptor portion after the visible image has been transferred.

The static eliminating brush 13 receives a static eliminating action. The toner removed from the photoreceptor 4 is collected in the toner storage section 15 and stored there.

The above-mentioned photoreceptor 4 and toner storage section 15 constitute one image carrier unit 16 that is integrally constructed, and in the illustrated example, the above-mentioned charger 5, cleaning blade 12, static elimination brush 13, etc. are also included in this unit 16. It is integrally assembled into. The details are as follows.

1 and 2, the unit 16 has a box-shaped case 19, and both support shafts 4a of the photoreceptor 4 are rotatably mounted on both side walls of the case 19, either directly or via bearings (not shown). Supported. Further, a hole 20 is formed in the upper wall of the case 19, through which the laser beam from the laser optical system 6 described above enters, and a space is defined to the left of the hole 20, in which a charge wire of the charger 5 is located. An elastic sheet 1-42 made of a thin synthetic resin sheet or the like is fixed below the partition wall 41 in the case 19, and this sheet 42 is pressed against the square rod 43. A support shaft 44 that fixedly supports the square rod 43 is rotatably supported on both side walls of the case 19.
It is rotated clockwise in FIG. 1 by a driving device V1 (not shown) provided outside the case. Also, this support shaft 4
4 supports a support arm 44 so as to be relatively rotatable, and is fixed on the arm 44, and the cleaning blade 12 and the static elimination brush 13 described above are fixed to a support member 45. A compression spring 46 is press-fitted between the support member 45 and the partition wall 41, and the blade 12 is pressed against the surface of the photoreceptor 4 by the action of this spring 46, and the blade 12 scrapes off the residual toner on the photoreceptor 4. In addition, the case 19 has a seal member 47.
The lower end of the case 19 is fixed, and its tip abuts against the photoreceptor 4, ensuring sealing within the case 19.

When the printer is in operation, residual toner on the photoreceptor 4 is removed by the blade 12 as described above, and this removed toner is transferred to the aforementioned toner storage section 15 divided by the outer wall of the case 19 and the partition wall 41. It is fed by a square rod 43 that rotates in the direction and a sheet 42 that swings against it. Therefore, as the usage time of the printer passes, toner accumulates in the toner storage section 15, and when the toner storage section 15 becomes full, this is detected by the fullness detection device 48.

The fullness detection device 48 shown as an example in the figure is connected to the case 19.
The operating member 49 is made of an elastic or flexible sheet such as rubber, and its periphery is fixed to the inner wall surface of the case 19, and the operating member 49 covers the opening formed in the upper part. It has a protrusion 850 that protrudes upward. In addition, the main body frame 34 of the printer has one light emitting section 3.
A photosensor 32 (which may be a microswitch) having a light receiving section 31 and a light receiving section 31 is fixedly supported.

When the toner container 15 is not yet full of toner, the actuating member 49 is lowered by its own weight to the position shown in FIG.
and the light receiving section 31. As the amount of toner in the toner storage section 15 increases, the actuating member 49 is sequentially lifted upward by the pressure of the accumulated toner. When the toner storage section 15 is full of toner, the protrusion 50 moves toward the light emitting section 30.
and the light receiving section 31 as shown by the chain line, thereby generating a full detection signal indicating that the toner is full. As a result, a display section (not shown) of the printer displays that the case 19 is full, and the operator is notified of this fact.

The image carrier unit 16 configured as described above is detachably supported by the main body of the printer. In this case, the unit 16 may be directly supported by the printer main body 10, but in the illustrated embodiment, it is supported by the frame of the main body 10 via the unit case 18 as follows.

That is, the printer main body 10 is divided into two parts, an upper main body 10a and a lower main body lOb, as clearly shown in FIGS. The unit case 18 described above is configured to be able to be opened and closed with respect to the lower part 10b of the main body.
is provided at the lower part 10b of the main body. The frame 34 supporting the photo sensor 32 mentioned above is the frame of the upper part 10a of the main body. The unit case 18 also includes a developing unit 1.
-17 is also supported, so when the main body upper part 10a is opened as shown in FIG. 3, the upper parts of both units 15 and 17 are exposed. The unit case 18 may be immovably fixed to the frame of the lower part 10b of the main body, but in the example shown in FIG.
3 are supported in notches 55, 56 formed in the frame side plates 54a, 54b of the lower body part 10b, and a pair of claws 65 constituting the locking device are inserted into locking holes 70, 70 formed in each side plate 54a, 54b. They are removably engaged. By releasing this engagement, the unit case 18 is
It can be rotated in the direction of arrow C as shown in the figure.

On the front and rear walls 18a and 18b of the unit case 18,
A pair of groove-shaped support portions 27 are formed that support the support shaft 4a of the photoreceptor 4 via bearings (not shown), and a pair of groove-shaped support portions 27 that support the support shaft 22a of the developing roller 22 via bearings (not shown). The support member 28 of the case 18
It is integrated into the . Also, the image carrier unit 16
A locking portion 19a of the case 19 is locked to a claw 35 of a collar 29 formed on the unit case 18.

As a result, the image carrier unit 16 is held at a predetermined position in the unit case 18 as shown in FIG. Open the upper part 10a of the main body as shown in Fig. 3, and press the knob 3 of the stopper 29.
7 and elastically deform it in the direction of arrow P, and then
When the engagement between the locking portion 19a and the locking portion 19a is released, the image carrier unit 16 can be lifted up one degree and removed from the printer main body. The unit 16 can be attached to the printer body by reverse mounting. When the unit 16 is attached to the upper part of the main body and the Oa is closed as shown in FIG. 1, the frame 34 of the main body presses down and holds the unit 16 through an elastic body 36 such as a sponge. When the carrier unit 16 is supported by the unit case 18, a part of the photoreceptor 4 enters the opening 6I formed in the bottom wall of the case 18, and also a gear (not shown) attached to the support shaft 4a. It enters the opening 61 and is driven by meshing with a gear (not shown) supported on the lower part 10b of the printer body.

The developing unit 17 is similarly detachably attached to the unit case 18, but its configuration is not directly related to the present invention, so its details will be omitted.

As is clear from FIG. 2, the developing unit 17 includes a main body case 21 containing toner T, and the aforementioned developing roller 22, which is opposed to the photoreceptor 4. It has a regulating blade 24 that regulates the layer thickness of the toner on the developing roller, and a supply roller 23 that supplies toner to the developing roller 22.A toner cartridge 25 is removably attached to the main body case 21. 1- When the remaining amount of toner becomes low, replace the previously installed cartridges 1 to 25 with new cartridges containing toner, and install 1 to 1 in the case 21.
- Can replenish energy.

When using a printer configured as described above for a period of time,
The photoreceptor deteriorates, the density of the recorded image becomes extremely high, and the background becomes noticeably stained. This means that the photoreceptor has reached the end of its life, and the photoreceptor that has reached the end of its life needs to be replaced with a new one. In this case, as explained earlier, in the configuration related to the conventional proposal, the time when the photoreceptor reaches the end of its life.

The toner accommodating portion 15 of the image carrier unit is filled with toner at approximately the same time.

The unnecessary photoconductor, which had reached the end of its life, was removed from the main body of the printer along with the case, which was also full of toner and no longer needed, and was discarded, and a new image carrier unit was installed in the main body. However, since the lifespan of the photoreceptor has been significantly extended, if the lifespan of the case and the photoreceptor are to be the same, the capacity of the toner storage portion of the case must be significantly increased.

Therefore, in the illustrated configuration according to the present invention, the time it takes for the toner storage section 15 to become full of toner in the standard usage state of the printer is set to be shorter than the life of the photoreceptor 4. That is, the toner storage section 15 becomes full of toner before the photoreceptor 4 reaches the end of its life, and the aforementioned detection device 48 generates a full signal. Further, as shown in FIG. 2, a toner discharge port 71 is formed in the case 19.

During normal use of the unit 16, the discharge lower 1 is closed by the cap 72. When the toner accommodating portion 15 of the case 19 is full of toner and the display shows that, the operator moves the unit 1-16 to the printer main body 10.
The cap 72 is removed from the case 19, and the toner inside is discharged from the discharge lower 1 and discarded. After emptying the case, the discharge lower 1 is again closed with the cap 72, and the unit 16 is again attached to the printer main body 10. This operation is performed at least once until the photoreceptor 4 reaches the end of its life, and when the life of the photoreceptor 4 comes to an end, the entire 22-16 is discarded. In this way, even if the long-life photoreceptor 4 is used, the volume of the toner storage portion of the case 19 can be reduced, and the longer life of the photoreceptor can be achieved without any problem.

The time it takes for the toner storage unit 15 to become full is approximately proportional to the progress of deterioration of the photoreceptor 4, in other words, the usage time of the printer, but it is proportional to the area of the toner image relative to the area of the recording paper. When toner images with a high ratio (image ratio) are repeatedly printed and when only toner images with a low image ratio are printed, the amount of accumulated toner in the toner storage section 15 and the state of deterioration of the photoreceptor are different. In the former case, the toner storage portion becomes full of toner earlier. The same thing can be said when printing on a large area recording paper and when printing on a small area recording paper, and the toner becomes full more quickly in the case of a large area. This is the reason for adding the condition ``under standard usage conditions of the printer.'' In other words, using standard size recording paper such as A4 size,
The volume of the toner storage section 15 is set so that when printing is performed at a standard image ratio of 5 to 7%, the toner becomes full earlier than the life of the photoreceptor 4.

It is advantageous to determine the relationship between the two so that the life of the photoreceptor 4 is an integral multiple (twice or more) of the time it takes for the toner storage section 15 to become full. In this way, the photoreceptor will theoretically reach the end of its life when the toner in the toner storage section 15 is just full, and the efficiency of use of the case 19 can be increased. If the number is not set to an integral multiple, the unit 16 must be discarded while the case 19 can still contain toner.

By the way, since the unit 16 is discarded when the photoreceptor 4 reaches the end of its life, it would be convenient if the operator could be informed that the photoreceptor 4 has reached the end of its life.

To meet this requirement, since the approximate number of prints of recording paper when the photoreceptor reaches the end of its life is known in advance, the actual number of prints per print 1 is counted with a counter from the time the new unit 16 starts to be used, and the count value is When the number reaches the number at the end of the photoreceptor's life, the display section may display that the photoreceptor 4 has reached the end of its life and that the unit 16 should be replaced with a new one. Or, development unit 1~
The number of replacements of the toner cartridge 25 in 17 and the progress of deterioration of the photoconductor 4 are almost proportional, so for example, see FIG. 1! A counter 73, which is activated when a cartridge 25 is set, is fixedly installed in the main body of the printer or the main body case 21 of the developing unit, as shown by the arrow '1. Activate this counter 73 and run 1-
When the value reaches the number of times the photoreceptor 4 reaches the end of its life, this fact may be displayed on the display section.

Furthermore, since the number of times the toner is discharged from the case 19 and the number of times the unit 16 is attached to the printer body if the head is replaced is approximately proportional to the deterioration state of the photoreceptor, this can be used to determine the lifespan of the photoreceptor.

That is, as shown in FIG. 2, there is a detection piece 74 on the outer wall surface of the case 19 that can be bent or cut out manually by the operator.
．． 74a is provided protrudingly. The number is made equal to the number of times toner is discharged until the photoreceptor 4 reaches the end of its life. For example, the toner in the case 19 is discharged from the discharge lower 1 twice, so that when the toner storage section 15 is full of toner three times, the life of the photoreceptor 4 is reached. When set, 2 is set as shown in Figure 2.
Two detection pieces 74 and 74a are provided. After starting to use the new image carrier units 1 to 16, the toner storage section 15 of the new image carrier unit 1 to 16 is
When the unit is full of toner, the toner is discharged from the discharge lower 1 as described above, and then the empty unit]・1
6 to the printer body again, but the first detection piece 74 is bent or cut off at an appropriate time when performing this operation. If the case 19 becomes full of toner again, the same operation will be performed again, but at this time the second detection piece 7
Bend or cut 4a. In this way, 1st order
When the henna container 15 is full of toner and the unit 16 is removed from the printer body, the detection strips are either not present at all or are all bent. You can know what you have achieved.

Therefore, when the unit 16 is removed for the third time, it is discarded and a new unit is installed.

In this way, the detection strip counts the number of times the toner is discharged, and the life of the photoconductor can be determined from the count value. However, a label is used instead of the detection strip, and one label is printed every time the toner is discharged. It may be peeled off one by one or pasted on the other way, or it is also possible to know the number of times the toner has been discharged by writing a mark or the like on the case 19.

It is also possible to count the number of full detections by the full detection bag opening 18 using a counter when the unit 16 is newly started, determine the lifespan of the photoreceptor 4 from the counted value, and display this on the display section.

In the same way that the counter 73 is operated by the toner cartridge 25, the unit case 18 is operated as shown in FIG.
A counter 75 is provided (or at a suitable location on the printer body),
This counter 75 is activated every time the unit 16 is set, and the number of times the toner is discharged from the discharge lower 1 or the unit 1 is set.
It is also possible to count the number of times -16 is applied to the printer main body, determine the lifespan of the photoreceptor 4 from the counted value, and display this.

The above-mentioned various counters are provided in the new image carrier unit 1.
It goes without saying that each time the number 6 is set, it is reset by, for example, pressing a reset key provided on the operation section of the printer, and a counting operation for the photoreceptor 4 of this new unit 16 is performed.

The present invention can also be applied to image carrier units in various image forming apparatuses other than laser printers, and
It goes without saying that the present invention can be widely applied to devices that are attached and detached by sliding in a direction perpendicular to the paper plane of FIG.

According to the present invention, it is possible to reduce the capacity of the toner accommodating portion, and it is also possible to eliminate the fear of discarding a usable image carrier.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of a laser printer having an image carrier unit according to the present invention, FIG. 2 is a perspective view showing a unit case, an image carrier unit, and a developing unit, and FIG. A perspective view showing the upper part of the main unit in an open state;
FIG. 4 is a perspective view of the unit case when it is tilted. 15... Toner storage section 16... To image carrier unit 1 19... Toner container 71... Outlet

Claims (3)

[Claims] (1) In an image carrier unit in an image forming apparatus, which integrally includes an image carrier on which a toner image is formed and a toner storage section that accommodates the toner removed from the image carrier after the toner image has been transferred. . The image carrier unit, wherein the capacity of the toner accommodating portion is set so that the time it takes for the toner accommodating portion to become full with toner under standard usage conditions is shorter than the life of the image carrier. (2) The image carrier unit according to claim 1, wherein a toner discharge port is provided in the case that partitions the toner storage section. (3) After starting to use a new image carrier unit, a means is provided to count the number of times the toner accommodating unit is detected to be full, the number of times the toner is discharged from the accommodating unit, or the number of times the image carrier unit is set, and based on the count value. The image carrier unit according to claim 1 or 2, which determines the lifespan of the image carrier.