JPH05323693A - Process cartridge and image forming device - Google Patents

Abstract

PURPOSE:To measure a gap between an image carrier and a developer carrier as the appearance of a product without detaching a cartridge container or attaching a transparent member in the cartridge container and to lower cost by reducing the number of parts and assembling man-hours. CONSTITUTION:As for a process cartridge 100 which is constituted by at least including a photosensitive drum (image carrier) 10, a developing device 20, and a cleaning device 30; an aperture part 30a for measuring the gap K between the drum 10 and a developing sleeve(developer carrier) 24 is provided in the cleaning device 30. In more detail, the aperture part 30a is formed on a normal drawn at the position of the gap K on a line M connecting the center of the drum 10 and the center of the sleeve 24. For example, a laser beam for inspection R is allowed to enter from the aperture part 30a so as to directly measure the gap K.

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 copying machine or a laser beam printer adopting an electrophotographic method and a process cartridge detachably mountable to an image forming apparatus main body.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, a process cartridge is detachably disposed in the main body of the apparatus to facilitate maintenance of the apparatus.

An example of such a process cartridge is shown in FIG.
It will be explained based on. Photosensitive drum 110 that is an image carrier
Around the cleaning device 130, the primary charger 11
2 and the developing device 120 are provided, and these are integrally incorporated in the cartridge container 100a to form the process cartridge 100. In the process cartridge 100, since the photosensitive drum 110 and the developing sleeve 124 of the developing device 120 need to be closely arranged with a certain gap therebetween, spacers are provided at both ends in the axial direction of the developing sleeve 124. The member 127 is attached concentrically with the developing sleeve 124, and the spacer member 127 is pressed against the outer surface of the photosensitive drum 110 to keep the gap between the photosensitive drum 110 and the developing sleeve 124 constant.

The spacer member 127 (developing sleeve 124) is pressed against the photosensitive drum 110 by the structure shown in FIG. That is, the developing device 120 is supported on the photosensitive drum 110 side so as to be rotatable about the fulcrum 101, and a spring member 102 is interposed between the photosensitive drum 110 and the developing device 120, and the developing device 120 is supported by the spring member 102. The spacer member 127 (developing sleeve 124) of the developing device 120 is pressed against the outer surface of the photosensitive drum 110 by urging the photosensitive drum 110.

Thus, the photosensitive drum 110 rotates in a fixed direction to sequentially form a latent image on the outer peripheral surface thereof, and the developing sleeve 124 of the developing device 120 also rotates in a fixed direction to form a latent image on the photosensitive drum 110. Since it is necessary to supply the developer (toner) to the latent image, the spacer members 127 attached to both ends of the developing sleeve 124 are also the developing sleeve 127.
Will rotate with it. Therefore, the spacer member 1
If the thickness of 27 is not uniform in the circumferential direction, the gap between the photosensitive drum 110 and the developing sleeve 124 cannot be kept constant, and the image on the photosensitive drum 110 becomes thin depending on the rotation cycle of the developing sleeve 124. The problem that it becomes dark occurs.

Therefore, the process cartridge 100 in which the cleaning device 130 and the primary charger 112 are arranged on one side of the photosensitive drum 110, and the developing device 120 is arranged on the other side.
7, the cleaning device 130, the primary charger 112, the developing device 120, and the like are supported around the photosensitive drum 110, the cartridge container 100a is made removable as shown in FIG. 7, and the process cartridge from which the cartridge container 100a has been removed. The laser light emitter 60 is disposed on one side of the laser light source 100, and the laser sensor 61 is disposed on the opposite side of the gap between the photosensitive drum 110 and the developing sleeve 124 of the laser light emitter 60 from the developing sleeve 124. When the laser light R from the laser light emitter 60 is caught by the laser sensor 61 through the gap and the change in the gap is checked, and the gap changes beyond the allowable value, the spacer member 127 is replaced. And so on.

However, as described above, the photosensitive drum 110
Large process cartridge 100 having a planar shape in which a developing device 120, a cleaning device 130, etc. are provided on both sides of the process cartridge 100.
In this case, the degree of freedom in designing for attachment / detachment to / from the image forming apparatus main body is naturally limited.
There is a problem that 00 itself also becomes large and cannot meet the demand for downsizing.

Therefore, a compact process cartridge shown in FIG. 8 has been proposed. That is, in the illustrated process cartridge 100, the developing device 120, the cleaning device 130, and the like are arranged above and below the image light L to the photosensitive drum 110 as boundaries, and the cross section thereof is formed into a substantially rectangular shape to make it compact. Is intended.

In the process cartridge 100, in order to measure the gap between the photosensitive drum 110 and the developing sleeve 124, the cover 132a and the bottom 132b of the waste toner container 132 of the cleaning device 130 are partially transparent. The first window 50 and the second window 51 made of the transparent member are provided respectively so that the gap K between the developing sleeve 124 and the photosensitive drum 110 can be seen from the outside through the windows 50 and 51. The inspection of the size of is made possible from the outside. That is, the process cartridge 10 includes the laser light emitter 60 that emits the inspection laser light R and the laser sensor 61 that detects the light width of the inspection laser R.
0 is sandwiched, and the inspection laser light R from the laser light emitter 60 is passed through the first window 50, the second window 51 and the gap K between the developing sleeve 124 and the photosensitive drum 110 to the laser sensor 61. The gap K between the developing sleeve 124 and the photosensitive drum 110 is detected by the thick and thin width of the light transmitted to the laser sensor 61 while enabling the catch and rotating the developing sleeve 124 and the photosensitive drum 110.

If the width of the light transmitted to the laser sensor 61 is out of the allowable value, the spacer member 127 is replaced because the variation in the value of the gap K is too large. In this way, the developing sleeve 124 and the photosensitive drum 1 are replaced.
The gap K between 10 is kept constant so that proper image formation can be performed.

As described above, conventionally, in order to inspect the gap K between the developing sleeve 124 and the photosensitive drum 110, the cartridge container 100a can be detached or a transparent member having a light-transmitting property is provided in a part of the cartridge 100. Windows 50 and 51 consisting of
Was being measured. The first window 50 and the second window 5
It is not necessary to provide 1 continuously along the axial direction of the developing sleeve 124, but it is sufficient to provide 1 at at least two positions on both end sides of the developing sleeve 124.

[0012]

However, in the conventional method shown in FIG. 7, the gap is measured with a part of the process cartridge 100 (cartridge container 100a) removed, and the process cartridge 1
However, it is impossible to measure the gap between the developing sleeve 124 and the photosensitive drum 110 in a state in which all the parts 00 are assembled, and the value of the gap K in the final state of the assembled process cartridge 100 cannot be obtained. there were.

Further, when the gap K is measured by the method shown in FIG. 8, the cartridge container 10 is used to prevent the toner from scattering.
It is necessary to attach the windows 50 and 51 made of a transparent member to 0a, which causes an increase in cost due to an increase in the number of parts and the number of assembling steps, and when the windows 50 and 51 are scratched or dust, dust or the like is attached, There is a problem that the gap K cannot be measured. Further, even if the process cartridge 100 is used even once, waste toner adheres to the windows 50 and 51, and the gap K cannot be measured.

The present invention has been made in view of the above problems, and an object thereof is to remove the cartridge container and to attach a transparent member to the cartridge container, and to obtain an image carrier and a developer carrier as a product form. An object of the present invention is to provide a process cartridge capable of measuring a gap between them and capable of achieving cost reduction by reducing the number of parts and the number of assembling steps, and an image forming apparatus in which the process cartridge is detachably mounted.

[0015]

In order to achieve the above object, the present invention provides a process cartridge which includes at least an image carrier and a developing means, and which is detachable from the main body of the image forming apparatus. And an opening for measuring a gap between the developer carrying member of the developing means and the developer carrying member. The opening is formed on a normal line drawn at the position of the gap between the image carrier and the developer carrier on a straight line connecting the center of the image carrier and the center of the developer carrier.

Further, the present invention is characterized in that the image forming apparatus is configured to include a mounting means for mounting the above process cartridge in the apparatus main body and a conveying means for conveying the transfer medium.

[0017]

According to the present invention, the gap between the image bearing member and the developer bearing member can be directly measured by, for example, entering a laser beam for inspection through the opening provided in the frame member, so that the gap is reduced. No need to remove the cartridge container for inspection,
Further, since it is not necessary to attach a transparent member to the cartridge container, the number of parts and the number of assembling steps can be reduced, and the cost can be reduced. Since no transparent member is used, it is not possible to measure the gap due to scratches, dust, or dust adhering to the transparent member, and the gap can be measured even with a process cartridge that has been used once. can do.

[0018]

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

FIG. 1 is a vertical sectional view of a process cartridge according to the present invention, FIGS. 2 and 3 are plan views of the same process cartridge, and FIG. 4 is a vertical sectional view of a laser beam printer as an image forming apparatus equipped with the same process cartridge. , Fig. 9
FIG. 10 is an external perspective view of the process cartridge, and FIG. 10 is a side view showing the structure of the cartridge loading section of the printer body.

First, the schematic configuration of the laser beam printer 1 will be described with reference to FIG. The laser beam printer 1
2, a large number of transfer sheets P are stacked on the paper feed tray 53, and each transfer sheet P is conveyed to the process cartridge 100 and the transfer portion of the transfer charger 2 by the paper feed roller 54 and the conveyance roller 55. After receiving the transfer of the image (toner image) by (3), the image is fixed by being guided to the fixing device 57, discharged by the discharge roller 58 to the outside of the machine, and stacked on the discharge tray 59. In FIG. 4, 41
Is a polygon mirror, 42 and 43 are imaging lenses, and L is a laser beam.

By the way, the above process cartridge 10
Reference numeral 0 is removable from the printer body 1A, and the structure for attaching to and detaching from the printer body 1A will be described with reference to FIG.

That is, a loading section 11 for receiving the process cartridge 100 is formed on the printer body 1A side. The loading section 11 is used for the process cartridge 10
The guide groove 12 is formed along the attachment / detachment direction of 0 (the arrow Y direction in FIG. 10) and the arc-shaped positioning groove 13 that is continuous with the guide groove 12. Is formed with an arc-shaped recess 12a. The loading sections 11 are symmetrically provided on both sides of the printer body 1A.

When the process cartridge 100 is loaded in the printer body 1A, the process cartridge 100 is moved from the state shown in FIG. 10 to the printer body 1A side in the direction of the arrow Y, and the rib of the process cartridge 100 is moved. It suffices to push the process cartridge 100 into the printer body 1A side as it is while the 105 is fitted in the guide groove 12 on the printer body 1A side.

Then, the process cartridge 100 moves while being guided by the guide groove 12 provided on the printer body 1A side, and the ring-shaped rib 106 thereof is moved to the printer body 1A.
The movement is stopped when it is fitted into the positioning groove 13 on the side,
At this time, at the same time, the guide portion 105a of the rib 105 is fitted into the concave portion 12a provided in the guide groove 12 to give the operator a click feeling.

Thus, the loading of the process cartridge 100 into the printer body 1A is completed.

Details of the structure of the process cartridge 100 will be described with reference to FIGS. 1 to 3 and 9.

That is, reference numeral 10 in FIG. 1 denotes a photosensitive drum as an image bearing member which rotates in the direction of the arrow shown in the figure. Around the photosensitive drum 10, a developing device 20 and a cleaning device 3 are provided.
0 and the charging roller 40 are provided, and these are incorporated into the cartridge container 100 a to form the process cartridge 100. In FIG. 1, reference numeral 100c denotes a drum shutter rotatable about a shaft 100d, which automatically opens when the process cartridge 100 is loaded in the printer body 1A, and the process cartridge 100 is removed from the printer body. When it is closed, it is closed to cover the photosensitive drum 10 to protect it.

Thus, when the process life of each process device such as the photosensitive drum 10 and the developing device 20 in the cartridge container 100a has expired, the process cartridge 10
Replacing the entire 0 with a new one facilitates maintenance.

The developing device 20 comprises a toner container portion 21 and a developing portion 22 adjacent to the toner container portion 21 via a partition wall 25. Inside the toner container portion 21, the toner t and the rotary blade are provided. 21 a is accommodated, and the developing unit 22 is provided with a developing sleeve 24 as a developer carrying member that rotates in the direction of the arrow in the figure. The rotary blade 21a conveys the toner t toward the developing sleeve 24.

The developing sleeve 24 has a fixed magnet inside, and as the developing sleeve 24 rotates, the toner t in the developing portion 22 is magnetically attracted onto the outer surface thereof. The developing sleeve 24 is provided with a concentric spacer member 27 (only one side is shown in FIG. 1) at both ends in the axial direction. By pressing against the photosensitive drum 10, a constant gap K is formed between the developing sleeve 24 and the photosensitive drum 10.

The charging roller 40 is the photosensitive drum 1
By rotating in contact with 0, the photosensitive drum 10 is uniformly charged.

Further, the cleaning device 30 includes a cleaning blade 31 and a waste toner container portion 32. The cleaning blade 31 scrapes off the residual toner on the photosensitive drum 10 which has been transferred, and discards it. The outer surface of the photosensitive drum 10 is cleaned by collecting the toner in the toner container 32. still,
Since the function of the cleaning device 30 cannot be fulfilled when the waste toner container portion 32 is filled with the waste toner, the waste toner container portion 32 has a certain size. Thus,
When the process cartridge 100 is mounted in the main body of the laser beam printer and the image forming work is started, first,
The photosensitive drum 10 is uniformly charged by the charging roller 40. Then, when the image light L of the document is exposed on the photosensitive drum 10 through the optical path 12 provided between the developing device 20 and the cleaning device 30, an electrostatic latent image is formed on the photosensitive drum 10. The electrostatic latent image moves toward the developing sleeve 24 of the developing device 20 as the photosensitive drum 10 rotates,
Toner t is supplied by the developing sleeve 24 to be developed, and visualized as a toner image.

Here, the developing sleeve 24 and the photosensitive drum 1
The value of the gap K between 0 is important when the electrostatic latent image on the photosensitive drum 10 is developed by the developing device 20. That is, if the gap K is too large, the movement of the toner t is insufficient and a thin toner image is formed, and if the gap K is too small, the movement of the toner t is excessive and a dark toner image is formed. ..
Therefore, it is desired that the gap K is always a fixed value.

However, since both the spacer members 27 attached to the developing sleeve 24 rotate integrally with the developing sleeve 24, if there is a variation in the thickness of both spacer members 27 in the circumferential direction, the photosensitive drum 10 and the developing sleeve 24 will be.
The size of the gap K between them varies, and a high-quality image cannot be obtained.

Therefore, in this embodiment, in order to inspect the gap K between the photosensitive drum 10 and the developing sleeve 24 of the final product, the central axis of the photosensitive drum 10 and the developing sleeve 24 are inspected.
The normal line drawn at the position of the gap K between the photosensitive drum 10 and the developing sleeve 24 on the straight line M connecting the central axis of the laser light R and the laser sensor R to the laser sensor 61 is aligned with the optical path. Then, the structure is such that the cover portion 32a and the bottom portion 32b of the waste toner container portion 32 of the cleaning device 30 do not exist on this normal line, and the opening portion 30a is formed at a position on the normal line of the cover portion 32a. That is, in this embodiment, a space S is formed between the bottom portion 32b of the cleaning device 30 and the lid 21b of the toner container portion 21, and this space S is formed.
Frame body 100b of the cartridge container 100a corresponding to
The opening 32a is formed in the (cover 32a) portion.
Further, the opening 30b is formed in the frame body 100b of the cartridge container 100a corresponding to the gap K between the photosensitive drum 10 and the developing sleeve 24.

With the above structure, the laser light R from the laser light emitting body 60 is detected by the laser sensor 61, and the gap K between the photosensitive drum 10 and the developing sleeve 24 (in this embodiment, about 200 .mu.m to 600 .mu.m) is detected depending on the width of the light. ) Is measured without any obstacles.

Further, according to the present embodiment, it is not necessary to remove the cartridge container 100a in order to inspect the gap K, and it is necessary to attach a transparent member to the cartridge container 100a because there is no risk of the toner t being scattered. Therefore, the number of parts and the number of assembling steps can be reduced to reduce the cost. Since the transparent member is not used, the measurement cannot be made due to scratches, dust, dust, etc. attached to the transparent member, and the gap K between the process cartridge 100 and the process cartridge 100 used once can be measured. You can

Further, in this embodiment, since the opening 30a is formed long in the axial direction of the photosensitive drum 10, the gap K between the photosensitive drum 10 and the developing sleeve 24 can be measured in a wide range. Further, the gap K can be measured not only by using the laser light R but also by using a gap gauge.

By the way, it is not necessary to measure the gap K between the photosensitive drum 10 and the developing sleeve 24 over a wide range.
If it is sufficient to perform measurement at several points, a normal line is drawn to this straight line M at a gap K position on the straight line M connecting the center of the photosensitive drum 10 and the center of the developing sleeve 24 at the desired measurement point, and cleaning is performed on this normal line. If the cover portion 32a and the bottom portion 32b of the waste toner container portion 32 of the apparatus 30 are not provided and the opening portion 30a is partially formed on the normal line as shown in FIG. 3, the gap K is formed at a portion requiring measurement. Can be measured. Further, with such a configuration, there is an advantage that a large capacity of the waste toner container portion 32 can be secured.

The Proseca cartridge according to the present invention may have at least an image carrier and a developing means, but is not limited to this, and as in the above-described embodiment, a cleaning device, a charging device, etc. It may have a process means.

[0041]

As is apparent from the above description, according to the present invention, there is provided a process cartridge which includes at least an image carrier and a developing means, and which is detachable from the main body of the image forming apparatus. Since the opening for measuring the gap between the developer carrier of the developing means and the developing means is provided in the frame, the image carrying of the process cartridge as a product is carried out without removing the cartridge container or attaching a transparent member to the cartridge container. The gap between the body and the developer carrying body can be accurately measured, and the number of parts and the number of assembling steps can be reduced, so that the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a process cartridge according to the present invention.

FIG. 2 is a plan view of the process cartridge according to the first embodiment of the present invention.

FIG. 3 is a plan view of a process cartridge according to a second embodiment of the present invention.

FIG. 4 is a vertical sectional view of a laser beam printer according to the present invention.

FIG. 5 is a vertical sectional view of a conventional process cartridge.

FIG. 6 is a sectional view showing a gap setting structure between a photosensitive drum and a developing sleeve of a conventional process cartridge.

FIG. 7 is an exploded sectional view of a process cartridge showing a conventional method for measuring a gap between a developing sleeve and a photosensitive drum.

FIG. 8 is a vertical sectional view of a process cartridge showing a conventional method for measuring a gap between a developing sleeve and a photosensitive drum.

FIG. 9 is an external perspective view of the process cartridge according to the first embodiment of the present invention.

FIG. 10 is a side view showing the structure of the cartridge loading unit of the printer body.

[Explanation of symbols]

 10 Photosensitive Drum (Image Bearing Body) 20 Developing Device (Developing Means) 24 Developing Sleeve (Developer Bearing Body) 30 Cleaning Device 30a Opening 100 Process Cartridge 100a Cartridge Container 100b Frame K K P P Transfer Sheet (Transfer Medium)

Claims (5)

[Claims] 1. A process cartridge comprising at least an image carrier and a developing means, which is detachable from an image forming apparatus main body, and measures a gap between the image carrier and the developer carrying body of the developing means. A process cartridge characterized in that an opening portion is provided in the frame body. 2. The opening is formed on a straight line connecting the center of the image bearing member and the center of the developer bearing member on a normal line drawn at a gap position between the image bearing member and the developer bearing member. The process cartridge according to claim 1, wherein: 3. The process cartridge according to claim 1, further comprising cleaning means for cleaning the image carrier, in addition to the image carrier and the developing means. 4. A process cartridge comprising at least an image carrier and a developing means, wherein a frame body is provided with an opening for measuring a gap between the image carrier and the developer carrier of the developing means. An image forming apparatus comprising: a mounting unit that is mounted on the apparatus main body; and a conveying unit that conveys a transfer medium. 5. The image forming apparatus according to claim 4, wherein the process cartridge includes a cleaning unit that cleans the image carrier, in addition to the image carrier and the developing unit.