JPH02199471A - Image forming device - Google Patents

Abstract

PURPOSE:To reduce oscillation transmitted from the upper main body to an image forming part by fixing the image forming part with the aid of the supporting parts and to locking levers of the lower main body and providing an adjacent part facing to the image forming part across a gap. CONSTITUTION:The upper cover 3 of the lower main body of the image forming device is provided with a paper feeding route 8, on which a basket 19 constituted of an image carrier unit 21 and a developing unit 22 is provided. Besides, projecting and engaging parts 35 and 51 provided on both sides of the unit 21 are abutted from downward by the supporting parts 40 and 42, respectively which are provided on the frame 39 of the main body 1. The supporting parts are depressed by the locking levers 45 and 47 to be freely turnably. Moreover, the adjacent part 61 facing to the supporting body 23 of the unit 21 is formed across a prescribed gap the under surface of the housing of an optical part 33 fitted at the inside of a top cover 4.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image forming apparatus that forms an image on an image carrier based on electrophotography.

2. Description of the Related Art Conventionally, an image carrier in an image forming apparatus is detachably supported for jam removal, maintenance, replacement of the image carrier, or the like. As for this supporting method, first, the upper main body is attached to the lower main body to which the paper conveyance path and the transfer section are attached, and the image carrier is removed from the upper main body in the axial direction so that it can be removed toward the front side. There is a way to install it. Second, a support section is provided to removably support the image carrier unit having the image carrier together with the developing unit in the lower body of the upper opening in which the paper conveyance path and the transfer section are built-in, and the pressure member provided on the upper body There is a method in which the image carrier unit and the developing unit are elastically pressed downward.

Problems to be Solved by the Invention In general, a lower body has a large number of parts to be mounted, and the total weight of the parts to be mounted is also large, which requires the lower body to be rigid. Since it is placed on a desk, there is less vibration, but on the other hand, there are few parts attached to the upper body, and the weight of the parts is small.
The upper body is lightweight in order to open and close. Therefore, the upper body is more likely to vibrate than the lower body. In the first method described above, the image carrier is pulled out in the axial direction, so a large work space is required for attachment and detachment.Also, since the image carrier is supported in a cantilevered state, there is concern about the supporting state after long-term use. be. Furthermore, a lock lever is provided on the front side to fix the axial movement of the image carrier, but due to variations in the mounting position of the lock lever and the length of the image carrier, It is not possible to fix even the smallest movements of

For this purpose, there is a means of pressing the other end of the image carrier with a pressing member facing the lock lever, but if the pressing force of this pressing member is small, the effect is small, and if the pressing force is strong, the lock lever will not rotate. The operation requires a lot of effort and the pressing member itself becomes fatigued quickly. Furthermore, vibrations of the upper body are easily transmitted to the image carrier through the pressing member. Furthermore, since the image carrier is held in the upper main body and the transfer section etc. is held in the lower main body,
There is a risk that the gap between the image carrier and the transfer section, which requires relative positional accuracy, may change due to variations in the relative positions of the upper main body and the lower main body. In the second method, vibrations of the upper body are transmitted to the image carrier unit and the developing unit via the pressing member, which greatly affects image formation.

Means for Solving the Problem An image carrier unit has an image carrier, the upper body is openably and closably connected to the upper part of the lower body in which a paper conveyance path and a transfer section disposed in the paper conveyance path are built-in. A plurality of locking protrusions are provided on both sides of the image forming section consisting of the and the developing unit,
Support parts are formed on both sides of the lower main body that abut from below a part of the image forming section including the locking protrusion, and a downward pressing surface that contacts the locking protrusion and one end of this pressing surface are formed. a lock lever having an upward slope bent upward is biased in one direction and is rotatably provided on the lower body, and a proximal part facing the image forming section on the upper body with a predetermined gap therebetween; has been established.

Function When attaching the image forming section to the lower body, the locking protrusion is supported by the slope of the upper surface of the lock lever, and when the upper body is closed and the image forming section is pushed down with the proximal part, the locking protrusion and the upward The lock lever is retracted by the component force generated by the contact with the slope, and the locking protrusion is lowered toward the suppressing surface, and the locking protrusion is pressed by the suppressing surface to move the image forming section to the lower body where vibrations are difficult to be transmitted. It can be fixed to the support section, and in this state, a predetermined gap is formed between the image forming section and the adjacent section on the upper main body side, and therefore vibrations transmitted from the upper main body to the image forming section can be reduced. Furthermore, by mounting the image forming section and the transfer section on a common lower body, the relative positions of both can be determined accurately. Since it can be attached and detached from above, the work space can be reduced.

Example An embodiment of the present invention will be described based on the drawings.

FIG. 2 is a longitudinal side view showing the overall structure. In the figure, 1 is a lower body that constitutes a part of the main body of the electrophotographic printer, and this lower body 1 connects the base cover 2 and the upper cover 3. One end of a top cover 4 serving as an upper body is attached to the upper part of the lower body 1 so as to be vertically movable. A power source 5 and a circuit board 6 are attached to the base cover 2. The upper cover 3 is provided with a paper transport path 8 for transporting the paper in the paper feed cassette 7, and at the end of this paper transport path 8, the paper is transported to a paper ejection tray 9 formed on the top surface of the top cover 4. A paper ejection path 10 for ejecting the paper towards is connected to this connecting portion, and a switching unit 11 for switching the ejection path of the paper to the side surface of the lower main body l, which is on the extended surface of the paper ejection path 10 or the paper transport path 8 is connected to this connection part. It is provided. Further, the paper conveyance path 8 includes a paper feed roller 12 that contacts the uppermost sheet of the paper feed cassette 7, a start sensor 13 that optically detects the conveyed paper, and a detection sensor 13 that detects the paper that is being conveyed. A registration roller 14 whose rotational movement is controlled by a signal, a transfer section 15 that transfers a developed image on an image carrier 24 to a sheet of paper, which will be described later, a peeling section 16 that separates the paper from the image carrier 24, and a high-voltage power source 17. and a fixing section 18 that clamps the paper that has passed through the transfer section 15 and fixes the transferred image on the paper are sequentially arranged from upstream to downstream.

Further, a basket 19 with vertical openings located above the paper transport path 8 is attached to the upper cover 3, and an image forming unit 2 is detachably housed in the basket 19.
0 consists of an image carrier unit 21 and a developing unit 22. The image carrier unit 21 includes an image carrier 24 rotatably mounted on both sides of a support 23, a charging section 25 that charges the image carrier 24, and a charging section 25 that charges the image carrier 24 and exposes the image carrier 24 to light on its outer periphery. A static eliminator 26 that makes the charge uniform and a waste toner container 2
7 is attached to the support body 23, and a blade 2 is attached to the waste toner container 27 to scrape off the waste toner adhering to the image carrier 24.
8 and a roller 29 that conveys the scraped off waste toner toward the back of the waste toner container 27. The developing unit 22 includes a developing roller 31 and a stirring blade 32 that stirs the toner in a toner container 30 containing toner.
(See Figure 5). Furthermore, flange-shaped protrusions 31a are formed at both ends of the developing roller 31 to contact the outer circumferential surfaces of both ends of the image carrier 24. Further, the image carrier 24 is provided on the inner surface of the top cover 4.
An optical section 33 is attached to scan the light beam on the photosensitive surface of the photosensitive surface.

Next, the mounting structure of the basket 19 and the image forming section 20 is shown in FIGS. 1, 3, and 4. FIG. 1 is a longitudinal sectional side view showing the support structure for the basket 19 and the image forming section 20, FIG. 3 is an exploded perspective view showing the relationship between the lower main body 1 and the basket 19, and FIG. 4 is an exploded perspective view showing the support structure for the image forming section 20. FIG. 3 is a plan view of the basket 19. As shown in these figures, a pair of handles 34 located above both ends of the image carrier 24 are integrally formed at both ends of the basket 19 . a guide groove 36 for vertically movably guiding a bearing 35 which protrudes from the side of the toner container 30 and supports the image carrier 24; and a guide groove 38 for vertically movably guiding a support shaft 37 protruding from both sides of the toner container 30. is formed. Further, the transfer portion 15 and the peeling portion 16 are positioned on a frame 39 fixed to the upper cover 3 and fixed by screws, and the frame 39 includes a support portion 40 that positions and supports the bearing 35. A fulcrum portion 41 for positioning and rotatably holding the support shaft 37 is formed, and a support portion 42 is erected to abut the lower end of the waste toner container 27 of the image carrier unit 21. . These support portions 40 and fulcrum portions 41 have a concave shape with an upper opening and a shape that expands toward the upper side.

Furthermore, the image carrier unit 21 is attached to the frame 39.
A locking means 43 is provided which resiliently engages. 20 The locking means 43 includes a lock lever 45 that rotates around a support shaft 44 and a lock lever 47 that rotates around a support shaft 46.
It becomes more. The upper portions of these lock levers 45 and 47 are urged in opposite directions by the urging force of a spring 48.

On the upper part of the one lock lever 45, there is a downward slope 49 which is a suppressing surface that presses the bearing 35, which is a locking protrusion, against the bottom of the support part 40 of the frame 39, and a downward slope 49 from the upper end of this downward slope 49. The other lock lever 47 has a bottle-shaped lock integrally formed on the outer surface of the support 23 of the image carrier unit 21. A downward slope 5 that is a pressing surface that presses the protrusion 5I
2, and an upward slope 53 that is bent upward in a dogleg shape from the upper end of the downward slope 52.

Furthermore, a handle 54 is integrally formed on the housing of the static eliminator 26, which is a component of the image carrier unit 21, and handles 56 are integrally formed on both sides of the toner container 30. There is. These handles 54 and 56 are so close to the handle 34 that when the handle 34 of the basket 19 is grasped, the fingers of the same hand can be hung thereon. These handles 54 and 56 also have upward pressing parts 55 and 5.
7 and the downward finger hook for hanging the finger is part 55a.

57a are formed.

Further, on the lower surface of the housing of the optical section 33, a first
As shown in the figure, the support body 23 of the image carrier unit 21
A proximal portion 61 is formed on the upper edge of the cylindrical portion 61, which faces each other with a predetermined gap therebetween.

The fulcrum portion 41 is located closer to the image carrier 24 than the center of gravity of the developing unit 22 and further away from the developing roller 31 . Further, a motor 58 for driving the developing roller 31 and the stirring blade 32 is fixed to the developing unit 22, and a power input terminal 59 connected to the motor 58 is provided to protrude downward, A knife-shaped connector 60 that elastically holds these power input terminals 59 is fixed to the inner surface of the frame 39. This connector 60 is connected to a power source. The motor 58 rotates the image carrier 24 with respect to the fulcrum portion 41.
It is located in the direction away from the

Furthermore, as shown in FIG. 5, a facing portion 62 is formed on the inner surface of the top cover 4 and faces a part of the toner container 30 with a predetermined gap S therebetween.

FIG. 6 is a partial front view showing a state in which the support shaft 37 of the developing unit 22 is fitted into the support portion 41 of the frame 39 with the frame 39 in cross section.

In such a configuration, when performing jam removal or maintenance, the top cover 4 is rotated upward to open the upper surface of the upper cover 3, and in this state, the handle 34 is grasped to move the basket 19 to the image carrier unit 21 and the upper cover 3. When it is pulled up together with the developing unit 22, the paper conveyance path 8 is opened. Alternatively, the image carrier unit 21 and the developing unit 22 can be moved independently with the basket 19 positioned inside the upper cover 3 by hooking the fingers on the finger hooks 55a and 57a of the handle 54 and 56 and pulling up. It can also be removed.

When disassembling a jam or assembling after maintenance, insert the bearing 35 of the image carrier unit 21 into the guide groove 36 of the basket 19 taken out from the upper cover 3, and insert the support shaft 37 of the developing unit 22 into the guide groove 38. Insert the basket 19, grasp the handle 34, and remove the bearing 35.
The basket 19 is housed in the upper cover 3 while fitting the supporting part 40 of the frame 39 and fitting the supporting shaft 37 to the supporting part 41. Or upper cover 3
The image carrier unit 21 and the developing unit 22 are stored in the basket 19 by fitting the bearing 35 or the support shaft 37 into the guide groove 36° 38, the support portion 4o, and the fulcrum portion 41 of the basket 19 stored in the basket 19. . At this time, the bearing 35 whose movement in directions other than the vertical direction is regulated by the guide groove 36 is supported by the upward slope 50 of the lock lever 44, and the locking protrusion 51 is supported by the upward slope 53 of the lock lever 47. However, when the top cover 4 is closed, the support body 23 can be pressed by the proximal portion 61.

By this operation, the lock lever 45 rotates counterclockwise against the force of the spring 48 due to the force generated by the contact between the bearing 35 and the upward slope 50, allowing the bearing 35 to move downward. do. Similarly, the locking protrusion 51 also locks the lock lever.
The pressing portion 55 of the handle 54 is supported by the upward slope 53 of the handle 54.
By pushing down, the locking protrusion 51 and the upward slope 53
The lock lever 47 rotates clockwise against the force of the spring 48 due to the force generated by the contact with the locking protrusion 5.
Allow downward movement of 1. And spring 48
The lock lever 45, which has returned to its original state with the restoring force, presses the bearing 35 against the bottom of the support part 40 with its downward slope 49, and similarly, the lock lever 47 presses the locking protrusion 51 with its downward slope 52. By pressing downward, the lower edges of both sides of the support body 23 are brought into pressure contact with the support part 42 .

The developing unit 22 is supported by its own weight with a support shaft 37 positioned at a fulcrum portion 41, but this fulcrum portion 41 is the center of the developing roller 31 and is positioned closer to the image carrier 24 than the center of gravity of the developing unit 22. As a result, the developing unit 22 rotates clockwise about the fulcrum portion 41, and the protrusions 31a provided at both ends of the developing roller 31 come into contact with the outer periphery of the end portion of the image carrier 24. As a result, the developing unit 22 is attached to the frame 39 in a stable state with a constant gap at the intermediate portion between the image carrier 24 and the developing roller 31.

As described above, the image carrier unit 21 and the developing unit 2
2 is stably attached to a frame 39 that positions and fixes the transfer section 15 and the peeling section 16, so the relative position of the image carrier 24 with respect to the transfer section 15 and the peeling section 16 can be determined accurately.

Also, when handling jams or maintaining the basket,
9 is pulled up, but in this process, the bearing 35 presses the downward slope 49 of the lock lever 45, and the force generated by the contact between the two causes the lock lever 45 to move against the spring 4.
The locking protrusion 51 rotates counterclockwise against the force of the lock lever 8, allowing upward movement of the bearing 35.
The lock lever 47 rotates clockwise against the force of the spring 48 due to the force generated by the contact between the two, and the locking protrusion 51 moves upward. is allowed.

Furthermore, the developing unit 22 is exposed to extreme vibrations during transportation, etc.
can be prevented from floating by the facing portion 62 of the top cover 4. In this case, by forming the facing portion 62 with a buffer member, even if it interferes with the developing unit 22, it will not be damaged. Furthermore, by facing the developing unit 22 with a predetermined gap S between the opposing portion 62 and the developing unit 22, it is possible to prevent vibrations caused by applying an external force to the top cover 4 from being transmitted to the developing unit 22. can. When the support body 23 is fixed in place, the proximal portion 61
Since a slight gap is formed between and the support body 23,
No vibration is transmitted from the top cover 4 to the support body 23. The lower main body 1 has a large number of parts mounted through the frame 39, and has high rigidity because it can hold even heavy parts.Moreover, since it is placed on a stable stand or desk, there is little vibration. There is no possibility that harmful vibrations will be transmitted from the lower main body 1 to the developing unit 22 or the image carrier unit 21.

Furthermore, when attaching the image forming section 20 to the lower main body l,
The bearing 35 and the locking projection 51 are once supported by the upward slopes 50 and 53 of the lock levers 45 and 47, and when the image forming section 20 is pushed down, the bearing 35 or the locking projection 51 and the upward slope 5
The lock lever 44,4 is activated by component force based on the contact with 0.53.
When the upper body 4 is opened and the image forming section 20 is pulled up together with the basket 19, the bearing 35 Alternatively, the locking levers 45 and 47 are rotated in the retracting direction by the component force based on the contact between the locking protrusion 51 and the downward slope 49.52, and the bearing 35 and the locking protrusion 51 are moved toward the upward slope 50
．． 53, thereby eliminating the need to manually operate the lock levers 45 and 47, improving operability.

Furthermore, by positioning the bearing 35 on the rotational axis of the image carrier 24 as a locking protrusion using the support portion 40 and fixing it with the lock lever 45, the axial center position of the image carrier 24 can be accurately set. Out.

Moreover, the lock levers 45 and 47 are made of one spring 4.
However, by changing the distance from the respective support shafts 44 and 46 to the tip, the lock lever 45 is pushed down onto the bearing 35 by the pushing down force on the locking protrusion 51 by the lock lever 47. By increasing the force, the bearing 35 at the center of the image carrier 24 is
The support body 23 can be brought into contact with the support part 42 by rotating the support body 23 using the contact part as a fulcrum. That is, the axial center position of the image carrier 24 is always stabilized at a fixed position.

Therefore, the position of the image carrier 24 relative to the transfer section 15 can be determined even more accurately. Since this bearing 35 is fixed to the frame 39 by a lock lever 45,
Wear between the bearing 35 and the support portion 40 can be prevented.

Note that by making the support shaft 37 made of metal, wear of the support shaft 37 due to contact with the metal frame 39 can be prevented. Thereby, the developing unit 22 can be positioned with high precision. Of course, a method may be adopted in which the support shaft 37 is molded integrally with the toner container 30 to improve productivity. In this case, a synthetic resin chip that contacts the support shaft 37 may be attached to a part of the frame 39, or the frame 39 itself may be made of synthetic resin, and the support shaft 37 may be
7 may be prevented from wearing out. Furthermore, as shown in FIG. 7, a protrusion 37a may be formed at the end of the support shaft 37. This protrusion 37a contacts the side surface of the frame 39 and acts as a guide member when fitting the support shaft 37 to the support portion 41, and also prevents the development unit 22 from swinging in the left and right direction. Even if the width dimension of the frame 39 has expanded due to deformation, the width dimension of the frame 39 can be corrected by fitting the support shaft 37 to the fulcrum part 41.

In the embodiment described above, the downward slopes 49 and 52 were used as the pressing surfaces of the lock levers 45 and 47, but the pressing surfaces may be formed substantially horizontally.

Effects of the Invention Since the present invention is configured as described above, when the image forming section is attached to the lower body, the locking protrusion is once supported by the upward slope of the lock lever, the upper body is closed, and the proximal part is mounted. When the image forming section is pushed down, the lock lever is retracted by the component force based on the contact between the locking protrusion and the upward slope, and the locking protrusion is lowered toward the pressing surface, and the locking protrusion is moved against the pressing surface. The image forming section can be fixed to the support section of the lower main body by pressing, and in this state, a predetermined gap is formed between the image forming section and the adjacent section on the upper main body side, so that the upper It is possible to reduce vibrations transmitted from the main body to the image forming section, and
By attaching the image forming section and the transfer section to a common lower body, the relative positions of both can be determined accurately.Furthermore, the image forming section can be attached and detached from above the lower body, which is perpendicular to the axial direction of the image carrier. This has the effect of reducing the work space.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG.
The figure is a vertical side view showing the overall structure, Figure 3 is an exploded perspective view showing the relationship between the lower body and the basket, Figure 4 is a plan view of the basket housing the image forming section, and Figure 5 is a diagram of the developing unit. The longitudinal side view and FIGS. 6 and 7 are partial front views showing the mounting state of the developing unit with the frame in section. l... Lower main body, 4... Upper main body, 8... Paper transport path, 15... Transfer section, 20... Image forming section, 21
...Image carrier unit, 22...Development unit, 2
4... Image carrier, 35... Locking protrusion, 40-42.
・・Support part, 45° 47・・Lock lever 149・・
- Pressing surface, 50... upward slope, 51... locking protrusion,
52... Pressing surface, 53... Upward slope, 61... Proximity part

Claims (1)

[Claims] The upper body is openably and closably connected to the upper part of the lower body in which a paper conveyance path and a transfer section disposed in the paper conveyance path are incorporated, and an image carrier unit including an image bearing member and a developing unit are formed. A plurality of locking protrusions are provided on both sides of the forming part,
Support parts are formed on both sides of the lower main body that abut from below a part of the image forming section including the locking protrusion, and a downward pressing surface that contacts the locking protrusion and one end of this pressing surface are formed. A lock lever having an upwardly bent slope is provided on the lower main body so as to be able to rotate in one direction, and a proximal part faces the image forming section on the upper main body with a predetermined gap therebetween. An image forming apparatus characterized by being provided with.