JPH02282765A - electrophotographic equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an electrophotographic apparatus.

In prior art electrophotographic devices, various corona dischargers are arranged around a photoreceptor. It is necessary to accurately determine the distance between the discharge wire of these corona dischargers and the image carrier. Conventionally, there is a structure in which an image carrier and a corona discharger are attached to separate support members with screws or the like. As another example, as shown in FIG. 6, a frame 100 is provided inside the lower body of the upper opening, and the support shaft 103 of the image carrier 102 protruding from both sides of the support 101 is connected to the frame 100.
A suppressing member 106 is provided at the lower part of an upper main body 105 that is positioned by the bottoms of grooves 104 formed on both sides of the image carrier 105 and is movable up and down. A corona discharger 107 is provided on a base 109 so as to be movable up and down, and a support member 101 holding the image carrier 102 is elastically pressed by a pressing member 106 to position the image carrier 102 at the bottom of the groove 104. By urging the corona discharger 107 upward with a spring 108 and bringing it into contact with the support 101, the distance between the outer peripheral surface of the image carrier 102 and the discharge wire of the corona discharger 107 is kept constant. There is something I did.

Further, as shown in FIG. 7, the support shaft 10 of the image carrier 102
Frame 1 formed with U-shaped groove 110 for holding 3
00 to the base 109 with screws, and this frame 100
Support pieces 110 and 111 are screwed to both sides of the corona discharger 107, and a protrusion 112 protruding from one end of the corona discharger 107 is fitted into a fitting hole 113 formed in one of the support pieces 110. The protruding piece 114 formed at the end is connected to the other supporting piece 1.
11 with screws 115 has been considered.

Problems to be Solved by the Invention When the image carrier and the corona discharger are held by separate support members, it is difficult to adjust their relative positions. In the case shown in FIG. 6, if toner, dust, or foreign matter adheres to the contact area between the support 101 and the corona discharger 107,
Support 101, image carrier 102, and corona discharger 107
There is a problem that the relative position with respect to the main body changes and the state becomes unstable.

Furthermore, the device shown in FIG. 7 uses left and right support pieces 110 and 111 to hold the corona discharger 107, so there is a problem that the number of parts increases.

Means for Solving the Problems An electrophotographic device that develops an electrostatic latent image formed on an image carrier using a developing unit, transfers this developed image onto transfer paper using a corona discharger, and fixes this transferred image using a fixing unit. A frame having holding parts for holding both ends of the image carrier is fixed to a base frame, and a frame for holding the center part of the corona discharger facing the outer periphery of the image carrier is fixed to the base frame. A mounting base is fixedly provided.

Since the mount that holds the corona discharger and the frame that holds the image carrier are fixed to a common base frame, the relative position of the corona discharger and the image carrier can be fixed and maintained in a stable state. be able to. In addition, the corona discharger can be fixed to the base frame with only one mount, thereby simplifying the support structure of the corona discharger.

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 to 5. Figure 4 is a longitudinal side view showing the overall structure.
1 is a lower main body constituting a part of the main body of an electrophotographic printer, and this lower main body 1 is formed by combining a base cover 2 and an upper cover 3, and a top cover 4 as an upper main body is mounted on the upper part of this lower main body 1. One end is attached so that it can move up and down. The base cover 2 includes a power supply 5 and a circuit board 6.
is installed. The upper cover 3 is provided with a paper transport path 8 for transporting the transfer paper in the paper feed cassette 7.
A paper discharge path 10 for discharging the transfer paper toward a paper discharge receptacle 9 formed on the top surface of the top cover 4 is connected to an end of the paper conveyance path 8. A switching unit 11 is provided for switching the path to the paper discharge path lO or the side surface of the lower main body 1 that is on the extended surface of the paper transport path 8. Further, the paper conveyance path 8 includes a paper feed roller 12 that contacts the uppermost layer of transfer paper of the paper feed cassette 7;
A start sensor 13 optically detects the transferred transfer paper, a registration roller 14 whose rotational movement is controlled by a detection signal from the start sensor 13, and a developed image on an image carrier 24 to be described later is transferred to the transfer paper. a corona discharger 15 for transferring, a corona discharger 16 for peeling the transfer paper from the image carrier 24, a high-voltage power source 17, and a corona discharger 17 for clamping the transfer paper that has passed through the corona discharger 15 and performing transfer on the transfer paper. Fixing units 18 for fixing images 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 corona discharger 25 that charges the image carrier 24, and a corona discharger 25 that exposes the image carrier 24 to its outer periphery. A static eliminator 26 that uniformizes the charge on the image carrier 24 and a waste toner container 27 are attached to the support 23, and a blade 28 that scrapes off the waste toner adhering to the image bearing member 24 and the scraped waste toner are attached to the waste toner container 27. A roller 29 that conveys the waste toner toward the back of the waste toner container 27 is attached. The developing unit 22 includes a toner container 30 containing toner, and a developing roller 31 and a stirring blade 32 for stirring the toner. Furthermore, an optical section 33 is attached to the inner surface of the top cover 4 to scan the photosensitive surface of the image carrier 24 with a beam of light.

Next, the mounting structure of the basket 19 and the image forming section 20 is shown in FIG. At both ends of the basket 19, there are a pair of handles 34 located above both ends of the image carrier 24.
are integrally formed, and these handles 34 have shaft portions 3 of the image carrier 24 that protrude from both outsides of the support body 23.
A guide groove 36 for vertically movably guiding the toner container 3 and a guide groove 38 for vertically guiding a support shaft 37 protruding from both sides of the toner container 3°. Further, a frame 39 fixed inside the upper cover 3 is formed with a holding part 40.41 for positioning and supporting the shaft part 35 and the support shaft 37, and the image carrier unit 21. A stopper 42 that comes into contact with the lower end of the support body 23 of
has been erected. These holding portions 40, 41 have a concave shape with an opening at the top and a shape that widens 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 is connected to a lever 4 that rotates around a support shaft 44.
5 and a lever 47 that rotates around a support shaft 46.

The upper portions of these levers 45 and 47 are urged in opposite directions by the urging force of a spring 48. One lever 4
5 has a downward slope 49 that presses the shaft part 35 against the bottom of the holding part 40 of the frame 39, and this slope 4.
A slope 50 whose slope direction is changed upward from 9 is formed, and the other lever 47 has a downward slope 52 that presses a pin 51 protruding from the outer surface of the support 23 of the image carrier unit 21. A slope 53 whose slope direction is changed upward from this slope 52 is formed. Further, the static eliminator 26 which is a component of the image carrier unit 21
A handle 54 is integrally formed on the housing, and handles 56 are integrally formed on both outer sides of the toner container 30. These handles 54, 56 are attached to the basket 19.
The distance to the handle 34 is so close that when the user grips the handle 34, the fingers of the same hand can be placed on the handle 34. Further, these handles 54, 56 are formed with an upward pressing portion 55, 57 and downward finger hook portions 55a, 57a for hanging fingers.

Further, the developing unit 22 includes the developing roller 3.
1 and the stirring blade 32 is fixed, and a power input terminal 59 connected to this motor 58 is provided to protrude downward, and these power input terminals 59 are elastically clamped. knife-shaped connector 60
is fixed to the inner surface of the frame 39. This connector 60 is connected to a power source. Further, the image carrier unit 2 is provided on the lower surface of the housing of the optical section 33.
A proximal portion 61 is formed on the upper edge of one support body 23 and faces each other with a predetermined gap.

Next, the support structure of the corona discharger 15 will be explained based on FIG. First, an insulating mounting base 75 is fixed to the base frame 1b fixed on the base la by a single screw 76. The corona discharger 15
Insulating blocks 63 and 64 are welded to both ends of a metal shield case 62 which is open at both ends and the upper part and whose lower center part is welded to the mounting base 75, and inside these insulating blocks 63 and 64. Terminals 65 and 66 are provided, one end of the discharge wire 68 is fixed to the - terminal 65, and the other terminal 6
A cover 6 fixes the other end of the discharge wire 68 to the cover 6 via a spring 68a to set the discharge range of the discharge wire 68.
7 is fixed to insulating blocks 63 and 64. Positioning portions 69 such as grooves for setting the position of the discharge wire 68 are formed in these insulating blocks 63 and 64.

Such a corona discharger 15 has its shield case 62.
Both ends of the image carrier 2 are supported by springs 70 and 74.
It is biased towards the 4th side. The terminal 66 is connected to the high voltage power source 17 via a spring 70, a screw 71 for fixing the lower end of the spring 70, a connecting terminal 72, and a cord 73. Further, the shield case 62 is connected to the frame 3 via the spring 74.
It is grounded to 9. Further, the base frame 1b to which the frame 39 is fixed is screwed to the base 1a that holds the high voltage power supply 17 and other functional parts.

FIG. 2 is a perspective view showing the corona discharger 15 for transfer, in which a bearing portion 78 that rotatably holds the shaft portion of a guide roller 77 that guides the transfer paper is integrally attached to one side of the insulating block 63.64. is formed.

Further, as shown in FIG. 3, the registration roller 14
A pair of upper and lower guide plates 79, 80 for guiding the transfer paper are provided between the corona discharger 15 and the corona discharger 15.

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 assembling after jam removal or maintenance, the shaft portion 35 of the image carrier unit 21 is inserted into the guide groove 36 of the basket 19 taken out from the outside of the upper cover 3, and the support shaft 37 of the developing unit 22 is inserted into the guide groove 38. The handle 34 of the basket 19 is grasped, and the basket 19 is housed in the upper cover 3 while the shaft portion 35 and the support shaft 37 are fitted into the holding portions 40 and 41 of the frame 39.

Alternatively, the basket 19 stored in the upper cover 3
The image carrier unit 21 and the developing unit 22 are stored in the basket I9 without fitting the shaft portion 35 or the support shaft 37 into the guide groove 36.38 and the holding portion 40.41. At this time, the shaft portion 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 lever 44, and the bottle 51 is supported by the upward slope 53 of the lever 47, but the handle of the basket 19 It is possible to press the pressing portion 55 of the handle 54 with fingers that are playing with the grip 34. By this operation, the lever 45 is rotated counterclockwise against the force of the spring 48 by the force generated by the abutment between the shaft portion 35 and the slope 50, allowing the shaft portion 35 to move downward. Similarly, the bottle 51 is also supported by the slope 53 of the lever 47, and by pressing down the pressing part 55 of the handle 54,
The lever 47 rotates clockwise against the force of the spring 48 due to the force generated by the contact between the pin 51 and the slope 53, allowing the bin 51 to move downward.

Then, the lever 45 returns to its original state due to the return force of the spring 48.
presses the shaft portion 35 against the bottom of the holding portion 40 with its downward slope 49, and similarly, the lever 47 presses its downward slope 52 against the bottom of the holding portion 40.
The pin 51 is pressed downward, and the lower edges of both sides of the support body 23 are pressed against the stopper 42.

The developing unit 22 is supported by its own weight with a supporting shaft 37 positioned on the holding portion 41. By positioning the supporting shaft 37 above the developing roller 31 and closer to the image carrier 24 than the center of gravity of the developing unit 22. , developing unit 22
The developing roller 31 rotates clockwise around the support shaft 37.
Flanges provided at both ends of the image carrier 24 abut against 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 between the image carrier 24 and the developing roller 31.

Furthermore, since the mounting base 75 holding the corona discharger 15 and the frame 39 holding the image carrier 24 are fixed to the base frame 1a serving as a common reference, the corona discharger 15
By setting the relative position between the image bearing member 24 and the image carrier 24 at a constant value, it is possible to maintain the relative position between the two in a stable state regardless of whether or not toner is attached between the two. Moreover, the corona discharger 15 can be fixed to the base frame 1b with only one mounting base 75, and thereby the support structure of the corona discharger 15 can be simplified.

Furthermore, in this embodiment, a corona discharger 1 for peeling
Since the corona discharger 6 is also held by the frame 39, the relative position of the corona discharger 16 and the image carrier 24 can be determined accurately. Similarly, a corona discharger 25 for charging the image carrier 24 can be attached to the frame 39 to accurately maintain the relative position with the image carrier 24.

Furthermore, the transfer paper fed by the registration rollers 14 is guided by guide plates 79 and 80, and further by a guide roller 77 that is close to the image carrier 24 at the entrance of the corona discharger 15. The transfer paper needs to be aligned along the outer periphery of the image carrier 24 as it approaches the corona discharger 15, but it is difficult to position the guide member near the outer periphery of the image carrier 24. However, according to Honji, this guide roller 77
is held by the bearing 78 of the corona discharger 15 whose relative position with the image carrier 24 is accurately maintained.
And the position of the guide roller 77 with respect to the corona discharger 15 can be determined accurately.

Effects of the Invention Since the present invention is configured as described above, the mount that holds the corona discharger and the frame that holds the image carrier are fixed to the base frame that serves as a common reference, so that the corona discharger and the image carrier are fixed to each other. By fixing the relative position with the body, the relative position between the two can be maintained in a stable state regardless of the presence or absence of toner adhesion between the two, and the corona discharger can be attached to the base frame with just one mounting stand. This has the effect of simplifying the support structure of the corona discharger.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is a front view partially cut away, Fig. 2 is a perspective view showing a corona discharger for transfer, and Fig. 3 is an image carrier and transfer. 4 is a longitudinal side view showing the overall structure, FIG. 5 is a side view showing the locking means of the image forming section, and FIG. 6 is a partially sectional view. FIG. 7 is a front view showing a conventional mounting structure between an image carrier and a corona discharger, and FIG. 7 is a partially sectional front view showing a prior art mounting structure between an image carrier and a corona discharger. . 1b...Base frame, 15...Corona discharger,
8... Fixing section, 24... Image carrier, 39... Frame, 40... Holding section, 75... Mounting base

Claims (1)

[Claims] In an electrophotographic apparatus in which an electrostatic latent image formed on an image carrier is developed by a developing unit, this developed image is transferred to a transfer paper by a corona discharger, and this transferred image is fixed in a fixing section, the electrostatic latent image formed on the image carrier is A frame in which holding portions for holding both ends are formed is fixed to a base frame, and a mounting base for holding a center portion of the corona discharger facing the outer periphery of the image carrier is fixedly provided on the base frame. An electrophotographic device characterized by: