JPH0631476Y2 - Image forming device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an electronic copying machine,
The present invention relates to an image forming apparatus such as an electronic printer, and more particularly, to an image forming apparatus having an improved positioning structure of a corona discharger that charges an image carrier.

[0002]

2. Description of the Related Art Generally, in a copying machine in which a photosensitive member made of selenium or a CdS drum is used as an image bearing member, a charging device, a transfer device, a paper stripping device, and a static eliminator are provided at positions close to the photosensitive member. A charging means consisting of a corona discharger is arranged.

On the other hand, in recent years, in order to facilitate the paper jam removing work around the photoconductor,
Many copying machines have been put into practical use in which any one of these corona dischargers can be detached and returned to a predetermined position after the work is completed. As one of them, the copying machine is divided into upper and lower parts with the paper conveyance path as a boundary, the photoconductor is arranged on the upper unit side, the transfer unit is arranged on the lower unit side, and the corona discharger is arranged as the peeling unit. In some cases, the upper unit is pivotally displaced to widen the distance between the photoconductor and the corona discharger.

However, conventionally, the positioning of the photoconductor and the corona discharger is performed by abutting the frames of the respective units to which they are attached. Therefore, the relative position accuracy between the photoconductor and the corona discharger may fluctuate due to variations in manufacturing and assembly, and the relative position of the corona discharger with respect to the photoconductor may change due to repeated opening and closing of the upper unit. Therefore, stable corona discharge cannot be performed, and there is a problem that transfer failure and peeling failure occur.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. The purpose of the present invention is to divide a sheet conveying path into two parts, an upper unit and a lower unit. In an image forming apparatus in which an image carrier having the carrier support shaft as a rotation center is provided, and the corona discharger is arranged in the other unit, the image carrier and the corona discharger are relatively simple in structure. An object of the present invention is to provide an image forming apparatus which can always maintain a predetermined value without damaging the image carrier and can always perform stable charging operation.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a first unit, a conveying unit provided in the first unit for conveying a sheet, and a sheet conveying by the conveying unit. A second unit that is openable and closable with respect to the first unit across a road, and an opening / closing operation of the second unit integrally attached to the second unit with respect to the first unit. And an image carrier that moves along with the first unit, and the second unit is provided on the first unit side and faces the image carrier when the second unit is closed with respect to the first unit. A charger provided at a position exposed to the outside when opened to the first unit, and the second unit provided to the first unit side and opened to the first unit Has been done , The charger is removably supported from the direction in which the image carrier moves in a space formed by the second unit and the first unit, and the charger is movably guided. Supporting means, an urging member provided on the first unit side for movably urging the charging device so as to move toward and away from the image carrier, and provided on the second unit side. And fixedly supporting the image carrier, and when the second unit is closed with respect to the first unit,
A first restricting member that restricts the position of the charger so that the distance between the charger and the image carrier becomes constant by abutting on a part of the charger; and the first unit side. And a second restricting member that is provided in the second unit and is supported by the supporting unit and is biased by the biasing member when the second unit is opened with respect to the first unit. And is configured to include.

[0007]

According to the above-mentioned means of the present invention, when the second unit is closed with respect to the first unit, the distance between the charger and the image carrier is automatically made constant, and the charging is always stable. As a result, it becomes possible to form an excellent image.

Further, the second unit to which the image bearing member is attached is opened to the first unit with the sheet conveyance path as a boundary, so that the charger provided on the first unit side becomes the first unit. Since it is exposed to the space formed between the second unit and the first unit, the charger can be inserted and removed using the space. Therefore, it is not necessary to secure a dedicated space for inserting and removing the charging device in advance, and a drawing mechanism or the like for exposing the charging device to the outside is not required, and the structure is simple and inexpensive.

Further, since the moving direction of the image carrier when the second unit is opened with respect to the first unit is the same as the inserting / removing direction of the charger, the inserting / removing operation of the charger is performed. Can be done easily.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows the configuration of an electronic copying machine as an image forming apparatus, and reference numeral 1 in the drawing is the main body of the copying machine. A manuscript table 2 is installed on the upper surface of the main body 1 so that it can reciprocate in the direction of arrow X as necessary.
A detachable tray 3 is provided on the left side of the main body 1, and a cassette 4 containing a copy sheet P and a manual feed guide 5 are provided on the right side.

A drum-shaped photosensitive member 6 serving as an image carrier is provided at a substantially central portion of the main body 1, and a charger 7, an exposure device 8, a developing device 9 and a transfer device 10 are provided around the drum-shaped photosensitive member 6. ,
A peeler 11, a static eliminator 12, a cleaning device 13, and an afterimage erasing device 14 are sequentially arranged along the rotation direction. The exposure device 8 has an illumination system 8a for illuminating a document (not shown) placed on the document table 2 and a converging light transmission body 8b for guiding the reflected light from the document to the photoconductor 6. .

On the right side of the main body 1, the paper feeding mechanisms 15, 1
6 is provided so that the copy sheet P in the cassette 4 and the copy sheet manually inserted through the manual feed guide 5 are fed into the sheet conveyance path 17. The paper transport path 17 includes a transport roller pair 18 and a transport belt 1.
9 and a conveying means including a pair of discharge rollers 20 and a guide plate 21 ... Arranged appropriately between them, and an intermediate portion thereof passes through a transfer portion between the photoconductor 6 and the transfer device 10. It is like this. Further, a fixing roller pair 22 is arranged on the trailing end side of the paper transport path 17.

The document table 2 is provided on the upper right side of the main body 1.
Of the motor and the motor 23 as a rotation drive source of the photoconductor 6
Further, a cooling device 24 for preventing an abnormal temperature rise of the heat generating portion in the main body 1 is provided in the upper left part of the main body 1. Reference numeral 25 denotes a paper discharge detection switch provided near the paper discharge roller pair 20 of the paper transport path 17.

When a copy button (not shown) is pressed, the photoconductor 6 starts to rotate clockwise in the figure, and the document table 2 is moved forward in synchronization with this movement and the photoconductor 6 is moved.
Charger 7, exposure device 8, and developing device 9 arranged around
Along with this operation, a developer image corresponding to the document table is formed on the photoconductor 6.

Further, the copy sheet P is sent to the transfer portion in synchronization with the operation of forming the developer image, the developer image is transferred to the copy sheet P by the action of the transfer device 10, and then the peeling device 11 is operated. Due to the action, the copy paper P becomes the photoconductor 6
And is conveyed to the tray 3 side via the sheet conveyance path 17. Then, during the conveyance, the fixing roller pair 22 fixes the developer image.

On the other hand, the photoreceptor 6 after the developer image is transferred
The surface of is brought into a clean state by sequentially facing the static eliminator 12, the cleaning device 13, and the afterimage erasing device 14, and again faces the charger 7.

Further, during this time, the original table 2 moves forward to return to the original position, and one copy operation is completed.

The copying machine constructed as described above is divided into two parts at the upper and lower sides of a line L which is substantially along the sheet conveying path 17, and if necessary, the upper unit 26 which is the second unit is set at an angle θ.
The upper unit is pivotally displaced upward to be separated from the lower unit 28 which is the first unit. Then, for some reason, the copy paper P is fed into the paper transport path 1
When paper 7 is jammed, most of the paper transport path 17 can be opened, and the jammed copy paper P can be easily removed.

The photoconductor 6 is provided on the frames 27, 27 on the upper unit 26 side, and the transfer unit 10 and the peeling unit 11 are provided on the frames 29, 29 on the lower unit 28 side, respectively. As a result, the relative positions of the photoconductor 6 and the transfer device 10 and the peeling device 11 change. However, in the present invention, the transfer unit 10 and the peeling unit 11 are formed by the first and second corona discharge parts of the corona discharge device 30, which is a charger, which will be described later.
When 6 is superposed on the lower unit 28, the distance between the photoconductor 6 and the transfer unit 10 and the peeling unit 11 is always kept at a predetermined value.

Next, the corona discharge device 30 will be described with reference to FIGS. 2 and 3. In the figure, 31 is the main body of the discharger,
This discharger body 31 has two shield cases 32, 3
2 are installed side by side and these shield cases 3
Discharge wires 33 and 33 are stretched inside the strips 2 and 32, and the first corona discharge portion as the transfer device 10 and the peeling device 1 are provided.
Corona discharger 3 having a second corona discharge part 1
Make up 4.

Support projections 3 as support means are provided on the lower surfaces of both end portions of the discharger body 31 of the corona discharger 34.
5, 35 are formed, and are inserted into the recesses of the support members 36, 36 as fixing portions screwed to the frames 29, 29 of the lower unit 28, and the biasing force is inserted into these recesses. It is elastically supported by coil springs (elastic support members) 37, 37 as means. The corona discharger 34 is swingable in the direction in which it comes in and out of contact with the photoconductor 6 and is always biased toward the photoconductor 6.

Further, supporting arms 38 ... Are projectingly provided at four corners on both upper surfaces of the discharger main body 31, respectively. Guide rollers (first positioning portions) are provided on the upper end surfaces of the support arms 38.
39 ... are rotatably supported. When the upper unit 26 is superposed on the lower unit 28, the photoconductors 6 mounted on the frames 27, 27 of the upper unit 26
Both end portions of the non-image forming portions (second positioning portions) 6a, 6a and the guide rollers 39 ...
The corona discharger 34 having the first and second corona discharge parts 1 is positioned.

However, if the mounting positions of the guide rollers 39 with respect to the main body 31 of the discharge device are set to predetermined values, the surface of the photoreceptor 6 and the first and second transfer devices 10 and the peeling device 11 will be described.
The distance between the discharge wires 33, 33 of the second corona discharge part is always kept constant, and extremely stable corona discharge performance can be obtained.

The guide rollers 39 ...
In accordance with the rotation of No. 2, a high voltage is applied to the discharge wires 33, 33 at a proper time from a high-voltage power supply unit (not shown) through a flexible power supply line.

Further, the present invention is not limited to the above-mentioned embodiment, but is shown in FIG.
Various modifications are possible as shown in FIG.

That is, as shown in FIG. 4, by incorporating the micrometer mechanism 40 in each of the supporting arms 38 ...
The distance between the discharge wire 33 and the photoconductor 6 at the positions of 9 ... Can be arbitrarily adjusted, and the corona discharge may be adjusted very easily. The same purpose can be achieved even if the screw mechanism is simpler than the micrometer mechanism 40.

Further, as shown in FIG. 5, the corona discharger 34
The positioning may be performed not by the surface of the photoconductor 6 but by the photoconductor support shaft (support portion) 41. With this configuration, the guide rollers 39 ... Are unnecessary and the surface of the photoconductor 6 is not damaged.

Further, the photosensitive member supporting shaft (contact portion) 41
It is desirable that the shaft contacting portions (positioning portions) 42a, 42a of the supporting pieces 42, 42 contacting the above are made of self-lubricating resin or the like. Further, the shaft contact portions 42a, 42a
Each of them is formed with a sloped portion 43 along the shaft insertion direction so that the shaft 41 can be smoothly inserted even if the shaft 41 is slidably inserted during mounting.

Further, the supporting members 44, 44 of the floating corona discharger 34 are mounted by hooking the hooking portions 44a, 44a on the frames 29, 29 integrated with the lower surface base 45 of the copying machine main body 1. May be.

Further, as shown in FIG. 6, the support pieces (positioning portions) 46, 46 are brought into contact with the frames (contact portions) 27, 27 of the upper unit 26 to which the photoconductor 6 is attached so as to be positioned. May be.

A coil spring 3 as an elastic support member
One of the terminals 7 and 37 is made of a conductive material, and one end thereof is coupled to one terminal 48 for applying a voltage to the discharge wire 33 stretched through the terminals 47 and 48, and the other end is a high-voltage power source. It is also possible to apply a voltage to the discharge wire 33 by pressing it into contact with the power supply portion 49a of 49. In this case, there is no early damage due to repeated bending of the power supply line which would occur when the discharge wire 33 and the power source 49 are connected via a flexible power supply line, which is preferable and the number of parts can be reduced.

A coil spring 3 as an elastic support member
Engagement recesses 5 are formed on both side surfaces of the discharger main body 31 of the corona discharger 34 which is constantly urged toward the photoconductor 6 by 7, 7.
0 and 50 are formed, and the locking claws 51a of the locking arms 51 and 51 extending from the power source 49 and the support member 44,
The movement amount of the corona discharger 34 may be restricted by engaging 51a to prevent the corona discharger 34 from falling off.

By forming the locking arms 51, 51 from a synthetic resin or the like having elasticity, the locking arms 51 can be elastically opened and the corona discharger 34 can be inserted for easy assembly. Moreover, not only the vertical movement of the corona discharger 34 but also the horizontal movement may be restricted at the same time.

The power source 49 is a well-known method for producing a necessary high voltage power source from a DC power source.

Further, the elastic supporting member which also serves as the power feeding member is composed of a conductive coil spring, but the present invention is not limited to this. For example, as shown in FIG. 7, the power source side power feeding body 52 and the charger which are respectively conductive leaf springs. The side power receiving body 53 may be formed so that the contact portions 52a and 52b are brought into pressure contact with each other in a state where the upper unit 26 is superposed on the lower unit 28.

In addition, as shown in FIG.
The contact points 52a, 53a of the charger and the charger-side power receiver 53 are tilted so that the contact points 52a, 53a are slidably contacted with each other at the time of pressure contact, and the contact points 52a, 53a are cleaned each time the sliding contact is performed to prevent contact failure. You may do it.

Further, it may be as shown in FIG. 9 and FIG. 10 which is a sectional view taken along line XX of FIG. Ie 5
Reference numeral 4 denotes a support member that supports the corona discharger 34, and a power supply 49 is built in the support member 4, and the voltage generated by the power supply 49 is transmitted to the power supply side power supply body 52.

The support member 54 is made of elastic resin or the like and has locking arms 55 and 56 formed at both ends thereof. The locking claws 55 of the lower locking arms 55 and 55 are formed.
The supporting members 54 are fixed to the frames 47, 47 by engaging the holes a, 55a with the engaging holes 57, 57 formed in the frames 29, 29 integrated with the lower surface base 45 of the copying machine main body 1.

Further, a corona discharger 34 is provided between the upper locking arms 56, 56, and the locking claws 56a, 5 are respectively provided.
The 6a is engaged with the engagement recesses 50, 50 formed on the outer side surfaces of the support pieces 46, 46, so that the vertical and lateral movements thereof are restricted.

As shown in FIG. 10, the support members 54,
Stopper members 58, 58 are integrally formed at both end portions of 54, respectively, so as to regulate the lateral movement and whirling of the corona discharger 34 in FIG.

The portions of the lower surface of both ends of the discharger body 31 corresponding to the engaging recesses 50, 50 are sloped portions 59, 5 like the sloped portions of the locking claws 56a, 56a of the locking arms 56, 56.
9 is formed, and the discharger main body 31 can be incorporated into the support member 54 with one touch.

After the corona discharger 34 is assembled, the repulsive force at the time of contact between the power supply side power supply body 52 formed of a conductive leaf spring and the charger side power reception body 53 and the lower surface of the discharger body 31 are formed. The engaging claws 56a and 56a of the engaging arms 56 and 56 and the engaging recesses 50 and 50 that push the corona discharger 34 upward by the repulsive force generated when the elastic pieces 60 and 60 and the supporting member 54 come into contact with each other. The corona discharger 34 does not fall off due to the engagement of.

The elastic pieces 60, 60 are the discharger main body 31.
It may be formed integrally with resin with, or may be formed by a separate member and attached, and further, it may be attached on the support member 54 side instead of the discharger main body 31 side.

When the upper unit 26 is closed, the frames 27, 27 descend and come into contact with the upper surfaces of the positioning members 46, 46 of the discharger body 31 to push them down. This determines the positional relationship between the corona discharger 34 and the frames 27, 27.

Further, the relative positions of the frames 27, 27 and the photoconductor 6 are determined in advance, and the height of the discharge wire 33 is determined by the terminals 48 and 47, such as an eccentric screw (not shown) or the like. The distance between the photoconductor 6 and the discharge wire 33 is kept constant because the distance between the photoconductor 6 and the discharge wire 33 is kept constant.

Further, as shown in FIG. 11, a corona discharger 34
The discharger main body 31 and the supporting member 54 may be integrated into a unit. Then, elastic unit support members 63, 63 are formed at both ends of the discharge unit 62, and the tips of the unit support members 63, 63 are engaged with the locking holes 64, 64 formed in the frames 29, 29. 62
May be elastically supported.

The discharge unit 62 may be formed by integrally forming the discharger main body 31 and the supporting member 54, or may be formed of an optimum material and combined together.

Thus, the corona discharger 3 is installed in the same unit.
4. The provision of the power source 49 and the unit support member 63 not only facilitates the adjustment of the unit, but also facilitates the assembly and mounting, and has the effect of greatly reducing the number of steps for assembling and adjusting the copying machine. Moreover, it is possible to eliminate a contact point through which a high voltage passes.

In the description of the other embodiment described above, the same parts as those of the above-described one embodiment and the other embodiment of the preceding stage are denoted by the reference numerals and the description thereof will be omitted.

Besides, the present invention is not limited to the above-mentioned one embodiment,
Of course, various modifications can be made without departing from the spirit of the present invention.

[0051]

As described above, according to the present invention, when the second unit is closed with respect to the first unit, the distance between the charger and the image carrier becomes constant automatically.
A stable charging action is possible and good image formation is possible.

Further, by opening the second unit, to which the image carrier is attached, to the first unit with the sheet conveying path as a boundary, the charger provided on the side of the first unit becomes the first unit. Since it is exposed to the space formed between the second unit and the first unit, the charger can be inserted and removed using the space. Therefore, it is not necessary to secure a dedicated space for inserting and removing the charging device in advance, and a drawing mechanism or the like for exposing the charging device to the outside is not required, and the structure is simple and inexpensive.

Since the moving direction of the image carrier when the second unit is opened with respect to the first unit is the same as the inserting / removing direction of the charger, the inserting / removing operation of the charger is performed. There is an effect that can be easily performed.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional front view of a copying machine in which an embodiment of the present invention is applied to a transfer device and a peeling device.

FIG. 2 is a schematic vertical cross-sectional side view of the main part of the same.

FIG. 3 is a schematic vertical sectional front view of the same.

FIG. 4 is a perspective view showing a modified example of a positioning member that can arbitrarily change the position of a guide roller.

FIG. 5 is a schematic vertical cross-sectional front view showing an example of positioning by a photoconductor shaft according to another embodiment of the present invention.

FIG. 6 is a schematic vertical cross-sectional front view showing an example of positioning by a frame to which a photoconductor is attached according to a second embodiment of the present invention.

FIG. 7 is an exploded perspective view showing a modified example of a power feeding portion.

FIG. 8 is a sectional view showing an improved contact portion of a power feeding portion.

FIG. 9 is a schematic vertical sectional front view showing an example in which a high-voltage power supply unit is incorporated in a supporting member according to a third embodiment of the present invention.

10 is a cross-sectional view taken along line XX of FIG.

FIG. 11 is a schematic vertical sectional front view showing an example in which a discharger main body and a supporting member are integrated with each other according to a fourth embodiment of the present invention.

[Explanation of symbols]

6 ... Image carrier (photoreceptor), 17 ... Paper transport path, 18, 1
9, 20 ... Transporting means, 26 ... Second unit (upper unit), 27 ... First restricting member, 28 ... First unit (lower unit), 30 (10, 11) ... Charger (corona discharge device) ), 55, 56, 58 ... Supporting means, 52, 5
3, 60 ... Energizing means, 56a ... Second restricting member.

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A first unit, a conveying unit that is provided in the first unit, and conveys a sheet, and is openable and closable with respect to the first unit with a sheet conveying path formed by the conveying unit as a boundary. A second unit provided, an image carrier that is integrally attached to the second unit and moves in accordance with the opening / closing operation of the second unit with respect to the first unit, and the first unit side And facing the image carrier when the second unit is closed with respect to the first unit, and exposed to the outside when the second unit is opened with respect to the first unit. A charger provided at a position, and the second unit and the first unit, which are provided on the side of the first unit and when the second unit is open to the first unit. By Supporting means for supporting the charger so that it can be inserted into and removed from the formed space in the direction in which the image carrier moves, and for supporting the charger so that the charger can move, and provided on the side of the first unit. An urging member that urges the charger so that the charger can move toward and away from the image carrier, and fixedly supports the image carrier provided on the second unit side. When the second unit is closed with respect to the first unit, it comes into contact with a part of the charger so that the distance between the charger and the image carrier becomes constant. A first restricting member for restricting the position of the charger, and a first restricting member provided on the side of the first unit and supported by the supporting means when the second unit is open to the first unit. And by the biasing member An image forming apparatus comprising: a second restricting member that restricts a movement of the charged charger toward the image carrier within a predetermined amount.