JP3427282B2 - Image forming device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus,
More specifically, the present invention relates to an image forming apparatus that has an image exposing unit inside a drum of an image forming unit, and the image forming unit and the image exposing unit are detachable. 2. Description of the Related Art As a method of forming a multicolor image, a single-color toner image formed on a photoconductor is provided with the same number of photoconductors, chargers and developing devices as the required number of colors. (A) to make a color image by superimposing the image on an intermediate transfer
Or a device (B) for forming a color image by repeating charging, image exposure and development for each color by rotating one photoconductor a plurality of times, or charging and image forming for each color within one rotation of one photoconductor. An apparatus (C) for forming a color image by sequentially performing exposure and development is known. However, the apparatus (A) requires a plurality of photoconductors and an intermediate transfer body, and thus has a disadvantage of increasing the volume of the apparatus. On the other hand, the apparatus (B) has a charging unit, an image exposure unit, and a photoconductor. However, there is a restriction that the size of the formed image is limited to the surface area of the photoreceptor or less, although the volume is reduced. The apparatus (C) enables high-speed image formation, but requires that a plurality of sets of a charger, an image exposing means and a developing unit be provided in one circumference of a photoreceptor, and an optical system for performing image exposure. However, there is a risk that the toner leaks from the adjacent developing device and the image quality may be impaired.To avoid this, it is necessary to increase the distance between the image exposure means and the developing device. There is a contradiction of increasing the size of the. In order to avoid the drawbacks of the above-mentioned obstacles in the apparatus (C), the base of the image forming body is formed of a transparent material, and a plurality of image exposure means are accommodated therein.
An apparatus in which an image is exposed to a photosensitive layer formed on the outer periphery of the substrate through the above-described substrate has been proposed (for example, see Japanese Patent Application Laid-Open No. HEI 5 (1993) -259).
-907907). [0006] However, the apparatus according to the above-mentioned proposal has a complicated structure because image exposure means is provided inside the image forming body and a number of chargers and developing devices are provided outside the image forming body. Attaching and detaching operations of the formed body and the image exposing means become complicated, and the handling property is deteriorated. In particular, it is difficult to stably fix the detachable image forming body and the image exposing means. SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide an image forming apparatus which facilitates the attaching and detaching operations of an image forming body and an image exposing means, and maintains a high positional accuracy. [0008] The above object is achieved by the following means. That is, a charging device, an image exposing means and a developing device are arranged on the image forming body, and charging, image exposing and developing are repeated to form a toner image on the image forming body in a superimposed manner. in the image forming apparatus that performs, the developing device in which the image forming body enclosing said image exposure means of the number of multiple of a drum-shaped image forming body Ru is fixed to the apparatus main body abuts against the outside of the drum-shaped image forming body with arranging the interference pre Kigen imager during attachment and detachment of the image forming body
An image forming apparatus characterized by a detachable integrally to at least interference portion the device body the image forming body by saving and with said image exposing means to avoid. The operation configured as described above will be described. According to the first aspect, a charger, an image exposing means, and a developing device are arranged on the image forming body, and a toner image is formed on the image forming body by repeating charging, image exposing, and developing. after the image forming apparatus for collectively transferred to a transfer material, said image forming body enclosing said image exposure means of the number of multiple of a drum-shaped image forming body Ru is fixed to the apparatus main body, the drum-shaped image forming body while disposing the developing unit abuts against the outside of the interference pre Kigen imager during attachment and detachment of the image forming body
In order to avoid this, at least the interference portion is temporarily retracted, and the image forming body and the image exposing means can be integrally attached to and detached from the apparatus main body. As a result, the image forming body requiring high positioning accuracy and the image exposing means can be easily attached and detached as a single unit, and maintenance is facilitated. [0011] is inserted along the U-shaped groove is supported by side plates provided axis of the apparatus main body for supporting the support image exposure means for image forming body, easy attachment and detachment of the image forming member and the image exposure means And the image forming body and the image exposing means can be stably fixed to the apparatus main body. [0012] a unit to the image forming member and the image exposure unit, a cleaning unit further cleaning the image forming body in units, there have includes a strip collector, when the detachable integrally to the device body, The image forming body, the image exposing means, the charger and the cleaning means can be taken out, so that they can be integrated and exchanged, and these can be easily cleaned. Also, maintainability is improved. [0013] Possible process unit taken out from the apparatus main body includes one of the developing devices even without low. Becomes easy attachment and detachment of the developing unit by withdrawing the process Yu <br/> Stevenage bets from the main body. Further, maintenance properties such as replacement of the developing device are improved. DESCRIPTION OF THE PREFERRED EMBODIMENTS Prior to the description of each embodiment of the present invention, the structure of an image forming apparatus suitable for carrying out each of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of a configuration of an image forming apparatus suitable for carrying out the present invention, FIG. 2 is a sectional view of a main portion suitable for carrying out the present invention, and FIG. 3 is a unit suitable for carrying out the present invention. FIG. 4 is an explanatory diagram of a layout. In FIG. 1, a drum-shaped image forming body 20 is a photosensitive drum and is formed of a transparent member such as an optical glass or a transparent acrylic resin. Is applied. FIG. 2 shows the opposite ends of the photosensitive drum 20 in FIG.
A flange is provided as shown by and supported by a bearing,
The drive gear meshes with the gear provided on the outer periphery of the flange,
With the power, the transparent conductive layer is rotated clockwise in FIG. 1 with the transparent conductive layer grounded. Charger 45 (45C, 45M, 45
Y, 45K) performs a charging action on the organic photoconductor layer of the photoconductor drum 20 by a grid maintained at a predetermined potential and corona discharge by a discharge wire.
To give a uniform potential. The exposure optical system 30 includes LEDs arranged in the axial direction of the photosensitive drum 20 and a self-occurring lens. Further, in the exposure optical system 30, the image signals of each color read by a separate image reading device are sequentially taken out of the memory and input to the respective exposure optical systems 30 as electric signals. Each of the exposure optical systems 30 is mounted on a prism-shaped support member 31 fixed to a substrate of the apparatus main body, and is housed inside the base of the photosensitive drum 20. Developing unit 40Y is yellow (Y), developing unit 4
0M is a magenta (M) developing device, 40C is a developing device containing cyan (C) developer, and 40K is a developing device containing black (K) developer. Further, the developing device 40 has an interval holding member, and a photosensitive drum. 20 is in contact with the peripheral surface. Further, the developing device 40
Is a developing sleeve 4 which rotates in the same direction with a predetermined gap kept by the spacing member with respect to the peripheral surface of the photosensitive drum 20.
1 is provided. Each of the developing devices is in a non-contact state by applying a developing bias voltage to the electrostatic latent image formed on the photosensitive drum 20 by the charging by the charger 45 and the image exposure by the exposure optical system 30. To reverse development. Incidentally, the toner hopper 43Y,
43M, 43C, and 43K are provided, respectively, to supply toner to the respective developing devices 40. Next, the structure of the image forming body and the image exposing means will be described in more detail with reference to FIG. 2. Both ends of the image forming body 20 are fixed to a flange 26 and a flange 27.
6 and the flange 27 are rotatable about the shaft 21 via a bearing. On the other hand, the image exposure means 30 composed of an LED and a self-focal lens is fixed to a support member 31, and the support member 31 is fixed to the shaft 21. The shaft 21 is fixed to the side plate 22 by a lock member 23 . Also, the outer periphery of the flange 26 is meshed with the gear is provided driving gear 28. The image forming body 20 is rotated by the rotation of the driving gear 28. Also <br/>, the developing sleeve 41 current image 40 by the spacing members
The distance between the image forming body 20 and the peripheral surface of the image forming body 20 can be kept constant. Next, the process of the image forming apparatus in the present apparatus will be described. In the original image, an image read by an image sensor or an image edited by a computer is once converted into an image signal for each color of Y, M, C and K by an image reading apparatus separate from the present apparatus. Stored and stored in memory. A drive gear 28 (see FIG. 2) is started by starting a photoconductor drive motor (not shown) at the start of image recording.
Rotates to rotate the photosensitive drum 20 clockwise, and at the same time, the application of a potential to the photosensitive drum 20 is started by the charging action of the charger 45Y . After the photosensitive drum 20 is applied with a potential,
Yellow photosensitive layer to the original image of the surface by rotational scanning of the drum is started exposure by electric signals corresponding to the image signal of the first color signal, namely yellow Oite the exposure optical system 3 0Y (Y) (Y), An electrostatic latent image corresponding to the image is formed. [0027] The latent image toner image of yellow corresponding to the rotation of the developing unit 4 developer on the developing sleeve More 0Y is reverse-developed by a non-contact state photosensitive drum 20 (Y) is formed. Next, the photosensitive drum 20 is further provided with a potential on the yellow (Y) toner image by the charging action of the charger 45M, and is converted into a second color signal of the exposure optical system 30M, that is, a magenta (M) image signal. exposure by corresponding electrical signal is performed, a toner image of magenta (M) by non-contact reversal development by the developing device 4 0M over the toner image of the yellow (Y) is gradually formed by sequentially superimposed . Charger 4 5C by the same process, a toner image of cyan (C) corresponding to the exposure optical system 3 0C Contact <br/> preliminary developing device 4 0C Therefore further third color signal, also charger 4 5K, black toner image (K) corresponding to the exposure optical system 3 0K Contact and developing device 4 0K Therefore fourth color signal is formed sequentially superimposed, on its peripheral surface within one rotation of the photosensitive drum 20 A color toner image is formed. The exposure of the organic photosensitive layer of the photosensitive drum 20 by each of these exposure optical systems is performed from the inside of the drum through the above-mentioned transparent substrate. Therefore, the exposure of the images corresponding to the second, third, and fourth color signals is performed without any influence from the previously formed toner image,
An electrostatic latent image equivalent to an image corresponding to the first color signal can be formed. In the developing operation of each developing device, a developing bias to which a direct current or a further alternating current is applied is applied to the developing sleeve 41, and a one-component or two-component developer accommodated in the developing device is subjected to jumping development to perform transparent development. Photoconductor drum 2 grounding conductive layer
Non-contact reversal development is performed on 0. Thus, the color toner image formed on the peripheral surface of the photosensitive drum 20 is transferred from the paper feed cassette 65 in the transfer unit 50A and transferred to the transfer paper fed synchronously by the driving of the timing roller 66. You. The transfer paper to which the toner image has been transferred is separated from the peripheral surface of the drum by the removal of the charge in the static eliminator 50B, and after the toner is fused in the fixing device 60, the toner is transferred to the upper portion of the device via the discharge roller 71. It is discharged on a tray. On the other hand, the photosensitive drum 20 from which the transfer paper is separated
The cleaning device 55 removes and cleans the residual toner to continue forming the toner image of the original image, or temporarily stops and starts forming a new toner image of the original image. Next, in FIG. 3, since the photosensitive drum 20 accommodates the exposure optical system 30 therein, even if the drum diameter is relatively small, the plurality of chargers 4 described above are provided on the outer peripheral surface thereof.
5. It is possible to arrange the developing device 40 and the like, and the volume of the apparatus can be made compact by using a small-diameter drum having an outer diameter φ of 60 mm to 660 mm. Further, a vertical line MM passing through the center of the photosensitive drum 20 is set as a symmetry axis, and two exposure optical systems 30 and two developing devices 40 are respectively provided on the left and right sides thereof, and a horizontal line N- passing through the center of the photosensitive drum 20. N transfer device 50 on one side
A, a cleaning device 55 is arranged on the other side. The exposure optical system 30 and the developing device 40 are located at positions substantially opposite to the left and right of the vertical line MM as shown in the figure, and the center of the transfer device 50A is positioned at a position lower than the vertical line MM below the horizontal line NN. The angle θ1 on the rotation upstream side of the drum 20 is 5 degrees to 4 degrees.
0 degree, while the contact portion of the cleaning device 55 is arranged at each position where the angle θ2 on the downstream side of rotation of the photosensitive drum 20 from the vertical line MM below the horizontal line NN is 20 degrees to 50 degrees, and A pair of left and right developing devices 40 further disposed at the upper and lower sides of angles θ3 and θ4 between the centers of the developing sleeves of the pair of left and right developing devices 40 and the horizontal line NN within ± 31 degrees, respectively. By setting the angles .theta.5 and .theta.6 within the range of 45.degree. To 75.degree. Respectively, the periphery of the photoreceptor can be effectively used, and a layout having a balanced external shape and a well-balanced vertical can be obtained. Note that a transfer roller or a transfer belt can be used as the transfer device 50A instead of the corona discharge device. When the developing device is disposed on the left, right, and upper sides, and comes into contact with the image forming body, a force for moving the developing device downward is generated. With such an arrangement, the image forming body 20 is stably
The shaft supporting the image exposure means 30 can be stably fixed and supported in the side grooves of both side plates provided in the apparatus main body. To fix the image forming body 20, a lock member is provided and securely fixed (see FIG. 4). <Embodiment 1> An image forming apparatus according to an embodiment will be described based on FIG. 4 and also with reference to FIGS. FIG. 4 is a cross-sectional view of the entire configuration of the image forming apparatus in a state where the units according to the embodiment are attached and detached. The same members as those in FIGS. 1, 2, and 3 are denoted by the same reference numerals, and descriptions of those members that do not change structurally or functionally are omitted. The main body 10 is provided with a side plate 22.
The developing unit 40M and the charging unit 45M are provided with an interference portion to prevent interference with the unit 92 when the unit 92 is attached and detached.
So that the can be moved to the position indicated by the left solid line in figure. Similarly, the developing device 40Y is positioned as indicated by the solid line on the left.
It can be moved to the place. Also, the developing device 40C
And the charger 45C and the charger 45K are integrated into a single unit on the right side .
The developing device 40K can be moved to the position shown by the solid line on the right in the same manner.
On the other hand, the image forming body 20 and the image exposing means 30
And, a shaft 21 is provided. To fix the unit 92, the shaft 21 enters the U-shaped groove of the apparatus main body and is pushed downward, and the shaft 2
5 can be fixed by a lock member 23 provided. Note that the lock member 23 is urged by a spring 24. <Embodiment 2> An image forming apparatus according to another embodiment will be described with reference to FIG. FIG. 5 is a cross-sectional view of the entire configuration of the image forming apparatus when the unit according to the embodiment is detached. The same members as those in FIGS. 1, 2, and 3 are denoted by the same reference numerals, and descriptions of those members that do not change structurally or functionally are omitted. FIG. 5 shows a modification of FIG. 4 in which the retractor of the developing device and the charging device is of a rotary type. The unit 92 is provided with the image forming body 20, the image exposing means 30, and the shaft 21. Further, a lock member 23 provided on the main body 10 and supported by a shaft 25 is provided on the side plate 22, and a bearing portion for supporting the shaft 21 is provided on the side plate 22. Further, when the unit 92 is attached and detached to and from the main body 10, the developing device 40M, the developing device 40Y and the charging device 45M are integrated.
Can be rotated to the position shown by the solid line . Similarly, when the developing unit 40C and the developing unit 40K, the charging unit 45C, and the charging unit 45K are integrated and the unit 92 is attached and detached, the shaft 42
Can be rotated to the position indicated by the solid line with the center as the center. Unit 92 outside the claw of the lock member 23, the developing device
When the charger and the charger are retracted to the position shown by the solid line, they can be taken out of the apparatus. As in the first embodiment, the unit 92 is stably fixed to the apparatus main body by the contact of the developing device. Here, a method of removing the unit will be described. First, each developing unit and the charger are rotated clockwise or counterclockwise as shown in the figure by a method not shown. Thereafter, the unit 92 is taken out above the apparatus main body. <Embodiment 3> An image forming apparatus according to another embodiment will be described with reference to FIGS. 1 to 3 based on FIG. [0044] Figure 6 is a preparative process unit of Example Dejo
FIG. 1 is an overall configuration cross-sectional view of an image forming apparatus showing a state . The same members as those in FIGS. 1, 2, and 3 are denoted by the same reference numerals, and descriptions of those members that do not change structurally or functionally are omitted. The side plate 22 provided on the main body 10 has a shaft 2
The lock member 23 supported provided by 5, also the shaft receiving portion you supporting the shaft 21 is provided in the side plate 22. Further, the developing device 40M, the developing device 40Y, the developing device 40
C and the developing unit 40K are movable between a solid line and a two-dot chain line . Further, the unit 93 includes the image forming body 2.
0, image exposure means 30, chargers 45M, 45Y, 45C,
45K, a cleaning device 55, and a shaft 21 are provided. [0046] Here, explaining extraction method of the unit, first, by a method not shown, the left side with respect to the apparatus main body as shown each developing device or the right to the unit 9,
Position to show the interference part with a solid line to avoid interference with 3
To retreat to. After that, the unit 93 is
And can be taken out upward. Since Kuriningu device 55 is detachably attached to the upper side, so that toner does not spill. Further, similarly to the first embodiment, the unit 93 is stably fixed to the apparatus main body by the contact of the developing device. <Embodiment 4> An image forming apparatus according to another embodiment will be described with reference to FIG. FIG. 7 shows the removal status of the process unit of the embodiment.
FIG. 2 is a perspective view of the image forming apparatus showing the state . In addition, FIG.
2 and 3 are denoted by the same reference numerals,
Descriptions of those which are not structurally and functionally unchanged will be omitted. The main body 10 is provided with a guide plate 96, and the guide plate 96 holds a process unit 95 having a drawer plate 97. The process unit 95 is a process unit including the unit 92 or 93 . The drawer plates 97 and 98 are fixed with screws 99,
It is designed to be pulled out of the apparatus body by pulling out. On the other hand, the unit 92 is provided with the image forming body 20, the image exposing means 30, and the shaft 21. Further, as another example, the unit 93 is provided with a cleaning unit and a charger in addition to the unit 92. These units 9
2 or 93 is detachable from the process unit 95. Here, a method of taking out the units 93 and 92 will be described. The process unit 95 is pulled out to the right in the figure. Further, the developing unit, the charging unit, and the cleaning device are the same as those of the first embodiment.
After retreated as the unit 92 above the apparatus main body 10
Can be taken out. Further, as an example, after the developing device is retracted in the same manner as in the first embodiment, a unit 93 in which a charger and a cleaning device are integrated is also included in the process unit 9.
It is also possible to take out than 5. <Embodiment 5> An image forming apparatus according to another embodiment will be described with reference to FIG. FIG. 8 is a perspective view of the image forming apparatus showing a detached state of the process unit of the embodiment. The same members as those in FIGS. 1, 2, and 3 are denoted by the same reference numerals, and descriptions of those members that do not change structurally or functionally are omitted. The main body 10 is provided with a guide plate 96, and the guide plate 96 holds a process unit 94. The process unit 94 is a process unit including a unit 92 or uni <br/> Tsu preparative 9 3,. The unit 92 is provided with an image forming body 20, an image exposing means 30, and a shaft 21. As another example, the unit 9
3 is provided with a cleaning means and a charger in addition to the unit 92. Although not shown, the process unit 92 can be stably fixed by the contact of the developing device as in the other embodiments. Here, a method of taking out the units 92 and 93 will be described. The process unit 94 can be Eject by pulling to the left in FIG. 8, further than the process unit 94 has been removed, similarly unit 92 as explained in FIG. 7 above the apparatus main body 10, or other examples
It has to be taken out unit 93 is. As described above, in the image forming apparatus of the type in which the image exposing means is included in the image forming body, the image forming body requiring high positioning accuracy and the image exposing means are integrated. to avoid interference when the developing unit is attached to or detached from the image forming body.
To, by Rukoto retracts the least interference portion, and an image forming member and the image exposure means it has become possible to adopt a structure to easily removable in one piece to the instrumentation Okimoto body. Also, by arranging the developing device arrangement of the image forming body upward symmetrically,
Since no unbalanced force acts on the image forming body, the image forming body can be easily fixed and easily detached from above. Further, the image forming apparatus has good maintainability while maintaining high accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration sectional view of an image forming apparatus suitable for carrying out the present invention. FIG. 2 is a sectional view of a main part suitable for carrying out the present invention. FIG. 3 is an explanatory diagram of a layout of a unit suitable for carrying out the present invention. FIG. 4 is a cross-sectional view of the entire configuration of the image forming apparatus in a state where a unit according to the embodiment is attached and detached. FIG. 5 is a cross-sectional view of the entire configuration of the image forming apparatus in a state where a unit according to the embodiment is attached and detached. Figure 6 is an overall configuration sectional view of an image forming apparatus showing the process unit removal state examples. FIG. 7 is a perspective view of the image forming apparatus showing a state in which the process unit according to the embodiment is taken out . FIG. 8 is a perspective view of the image forming apparatus showing a detached state of the process unit according to the embodiment.

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Toshihide Miura 5-14-14 Midoricho, Koganei-shi, Tokyo (56) References JP-A-5-307307 (JP, A) JP-A-7-114236 (JP, A) JP-A-4-110873 (JP, A) JP-A-2-141773 (JP, A) JP-A-5-265267 (JP, A) JP-A-3-215875 (JP, A) JP-A-6 JP-A-194924 (JP, A) JP-A-62-153965 (JP, A) JP-A-4-116669 (JP, A) JP-A-64-80973 (JP, A) JP-A-8-191381 (JP, A) (58) Fields surveyed (Int. Cl. ⁷ , DB name) G03G 15/01-15/01 117 G03G 15/04-15/04 120

Claims (1)

(57) [Claim 1] A charging device, an image exposure means and a developing device are arranged on an image forming body, and charging, image exposure and development are repeated to form a toner image on the image forming body. after forming superposed, in an image forming apparatus for collectively transferred to a transfer material, said image forming body is Ru is fixed to the apparatus main body a drum-shaped image forming body
Enclosing said image exposing means multiple, as well as disposing the developing unit abuts against the outside of the drum-shaped image forming body, the interference pre Kigen <br/> imager during attachment and detachment of the image forming body Less to avoid
Image forming apparatus characterized by saves the Kutomo interference portion is detachably mountable and said image exposing means and said image forming body integrally with respect to the apparatus main body.