JPH02199469A - Image forming device - Google Patents

Abstract

PURPOSE:To reduce oscillation transmitted from an upper main body to an image forming part and to make relative position between the image forming part and a transfer part accurate by providing supporting parts which abut on the image forming part and an engaging means which engages with the image forming part on the lower main body. CONSTITUTION:A frame 39 is fixed on the upper cover 3 of the lower main body 1 of an electrophotographic printer and the frame 39 is formed of a supporting part 40 which supports the bearing 35 of an image carrier 24 and a supporting point part 41 which keeps the supporting shaft 37 of a toner container 30. Besides, the frame 39 is provided with the engaging means 43 which engages with an image carrier unit 21 and constituted of an engaging lever 45 and an engaging lever 47 turning around a supporting shaft 44 and a supporting shaft 46, respectively. These levers 45 and 47 are energized by the energizing force of a spring 48 in opposite directions. By this means 43, the unit 21 is brought into press-contact against the supporting parts 40 and 42 of the main body 1 and then the relative position between this means and the transfer part is made accurate.

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 body is attached to the lower body on which the paper conveyance path and the transfer section are attached, and the image carrier is attached to the upper body so that it can be removed toward the front side along the axial direction of the upper body. 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, is there a means to press the other end of the image carrier with a pressing member facing the lock lever?If the pressing force of this pressing member is small, the effect will be small, and if the pressing force is strong, the lock lever will rotate. It takes a lot of effort to operate, and the suppressing member itself becomes fatigued quickly. Furthermore, vibrations of the upper body are easily transmitted to the image carrier through the pressing portion. 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. and a developing unit, and the lower main body is provided with a support portion that abuts the image forming portion and a locking means that engages with the image forming portion.

The image forming section consisting of the image bearing unit and the developing unit is supported by the support section of the lower main body to which vibrations are not easily transmitted and is fixed by the locking means, so that the suppressing section that presses the image forming section against the upper main body is Therefore, vibration 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. Because it can be attached and detached from Niga,
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. This lower body 1 connects a base cover 2 and an 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 (2) so as to be movable up and down. 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 toward 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 1, which is on the extension surface of the paper ejection path 10 or the paper conveyance 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 unit 15 that transfers a developed image of an image carrier 24 (to be described later) onto a sheet of paper, a peeling unit 16 that peels the paper from the image carrier 24, and a high-voltage power supply. 17, and a fixing section 18 that holds the paper that has passed through the transfer section 15 and fixes the transferred image on the paper, which are arranged sequentially 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
The blade 2 scrapes off the waste toner adhering to the image carrier 24 onto the waste toner container 27.
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 vertical 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 l and the basket 19, and FIG. 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 that vertically guides a bearing 35 that protrudes from the outside and supports the image carrier 24; and a guide groove 38 that vertically guides a support shaft 37 that protrudes 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 waste toner container 2 of the image carrier unit 21 is formed.
A support portion 42 is provided upright below the portion 7 and comes into contact with the end. These support portions 40 and fulcrum portions 41 have a four-part shape with an upper opening and a shape that expands toward the top.

Furthermore, the image carrier unit 21 is attached to the frame 39.
A locking means 43 is provided which resiliently engages. This 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.

The upper part of the lock lever 45 has a downward slope 49 for pressing the bearing 35 against the support part 40, and a downward slope 49 for pressing the bearing 35 against the support part 40.
The other lock lever 47 has a bottle-shaped engagement integrally formed on the outer surface of the support 23 of the image carrier unit 21. A downward slope 52 that presses the stop protrusion 51 and an upward slope 53 that bends in the opposite direction from the two ends of the downward slope 52 are formed.

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 outer sides of the toner container 30. . 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. Moreover, these handles 54 and 56 have upwardly facing suppressing 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 bead edge of the cylindrical member 61, which faces the bead 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 above the developing roller 31 . Furthermore, the developing unit 2
2, a motor 58 for driving the developing roller 31 and the stirring blade 32 is fixed, and a power input terminal 59 connected to the motor 58 is provided to protrude downward. A knife-shaped connector 60 for elastically holding the frame 39 is fixed to the inner surface of the frame 39. This connector 60 is connected to a power source. The motor 58 is positioned in a direction away from the image carrier 24 with respect to the fulcrum portion 41 .

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 two sides of the upper cover 3, and in this state, the handle 34 is grasped and the basket 19 is attached to the image carrier unit. 21 and the developing unit 22, the paper conveyance path 8 is opened. Alternatively, the finger rests of the handles 54 and 56 are located at the portions 55a and 57a.
It is also possible to remove the image carrier unit 21 and the developing unit 22 individually with the basket 19 positioned inside the upper cover 3 by hooking a finger on the upper cover 3 and pulling it up.

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 I9 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 40, 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. Although the basket 19 is supported, the pressing portion 55 of the handle 54 can be pressed with a finger that is idle while gripping the handle 34 of the basket 19. 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. . Similarly, the locking protrusion 51 is also supported by the upward slope 53 of the lock lever 47, and by pushing down the pressing part 55 of the handle 54, the component force generated by the contact between the locking protrusion 51 and the upward slope 53 Lock lever 47
rotates clockwise against the force of the spring 48, allowing the locking protrusion 51 to move downward. The lock lever 45, which has returned to its original state due to the return force of the spring 48, presses the bearing 35 against the bottom of the support portion 40 with its downward slope 49, and similarly, the lock lever 47 is locked with its downward slope 52. The protrusion 51 is pressed downward, and the lower edges of both sides of the support body 23 are pressed against 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 located above the developing roller 31 and 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,
In this process, the bearing 35 presses the downward slope 49 of the lock lever 45, and the lock lever 45 resists the force of the spring 48 due to the force generated by the contact between the two. The locking protrusion 51 presses the downward slope 52 of the locking lever 47, and the locking protrusion 51 presses the downward slope 52 of the locking lever 47, causing the locking protrusion 51 to press the downward slope 52 of the locking lever 47. The force causes the lock lever 47 to release the spring 48.
The locking protrusion 51 is rotated clockwise against the force of the locking protrusion 51, allowing upward movement of the locking protrusion 51.

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 therebetween, the opposing portion 62 prevents vibrations caused by applying an external force to the top cover +5-4 from being transmitted to the developing unit 22. be able to. The proximal portion 61 presses the support 23 when the top cover 4 is closed even if the support 23 is not fully attached, but when the support 23 is fixed in place, the proximal portion 61 and the support 23 A small gap is formed between them. therefore,
No vibration is transmitted from the top cover 4 to the support body 23.

The lower main body l 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.

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 accuracy. 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.

Effects of the Invention Since the present invention is constructed as described above, the image forming section consisting of the image carrier unit and the developing unit is supported by the supporting section of the lower main body to which vibrations are not easily transmitted and is fixed by the locking means. There is no need for a suppression member that presses the image forming section on the main body, and therefore vibrations transmitted from the upper main body to the image forming section can be reduced. By attaching the image forming unit to the lower body, the relative position of the two can be determined accurately.Furthermore, the image forming unit can be attached and detached from above the lower body, which is perpendicular to the axial direction of the image carrier, reducing the work space. It has effects such as being able to.

The plan view, FIGS. 6 and 7 are partial front views showing the state in which the developing unit is attached, with the frame in section.

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. An image forming apparatus characterized in that a forming section is provided, a support section that abuts the image forming section is formed in the lower main body, and a locking means that engages with the image forming section is provided.