JP2000221864A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of transmitting driving in a device main body to a photoreceptor drum without backlash only by operation for fixing a unit at the specified position of the device main body. SOLUTION: In order to make a unit 50 slide and move in the image forming device 1, the unit 50 is placed so that a recessed part 22 may be engaged with a boss 23. A knob 26 is rotated to move an edge part 29, and the almost center of the side plate 21a of the unit 50 is pressed to make the unit 50 slide and move from a 1st position to a 2nd position. By such movement, a tapered part 18 is fit in the receiving part 20 of the photoreceptor drum 2. Then, the unit 50 is coupled in a state where the driving from a driving source is transmitted to the drum 2 without the backlash when the unit 50 is positioned at the 2nd position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic copying machine,
The present invention relates to an image forming apparatus such as a printer, and more particularly, to an image forming apparatus capable of reliably transmitting a drive in an apparatus main body to a photosensitive drum in a unit without a backlash when the unit is mounted.

[0002]

2. Description of the Related Art In an image forming apparatus, a unit is used in which a charging device, a developing device, a cleaning device, and the like, which cooperate integrally, mainly around a photosensitive drum. By making this unit detachable from the device body,
For example, maintenance such as replacing a defective unit with a new one can be easily performed.

In attaching and detaching units, it is necessary to position the units with respect to the apparatus main body with high precision.
In particular, it is necessary to connect the drive shaft provided on the apparatus main body side and the rotation shaft of the photosensitive drum without play. If looseness occurs between the drive shaft and the rotating shaft of the photosensitive drum, the photosensitive drum has uneven rotation, which affects image formation.

[0004]

Conventionally, for example, in an image forming apparatus having an upper lid, the above-mentioned unit is positioned at a predetermined position in the apparatus main body with the lid opened, and then the drive shaft and The rotating shaft of the drum is connected with a joint or the like, which complicates the mounting work of the unit. Alternatively, when the unit is positioned at a predetermined position in the apparatus main body, the gear of the unit and the drive gear are engaged to transmit the drive. However, when the gears mesh with each other, uneven rotation of the photosensitive drum is likely to occur due to backlash.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and transmits the driving inside the apparatus main body without the play of the photosensitive drum only by the operation of fixing the unit at a predetermined position of the apparatus main body. It is an object of the present invention to provide an image forming apparatus capable of performing the following.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a photosensitive drum and a unit having at least one of a charging device, a developing device and a cleaning device disposed around the photosensitive drum along the axis of the photosensitive drum. Guide means is provided for enabling sliding movement from a first position to a second position in the apparatus main body in a substantially parallel direction, and fixing means presses one end of the unit to move the unit along the guide means. The unit is moved from the first position to the second position and fixed at the position, and the movement of the unit causes the receiving portion provided at the end of the photosensitive drum to be moved from a driving source in the device main body provided in the device main body. A transmission means having a tapered portion for transmitting the driving of the photosensitive drum to the photosensitive drum.
Wherein the receiving portion and the tapered portion are connected in a state where there is no play when located at the position.

The transmitting means further has a shaft projecting in the axial direction from the tapered portion, and the receiving portion further has a hole at the center of rotation of the photosensitive drum fitted with the shaft. The shaft is fitted in the hole before the receiving portion is fitted and connected to the tapered portion.

Further, the guide means has a boss provided on the apparatus main body and a portion provided on a side surface of the unit and engaging with the boss, wherein the unit is moved from a first position to a second position. Is provided so as to be slidable.

Still further, a detecting means for detecting that the unit is located at the second position is provided, and the detecting means is such that the fixing means connects the unit to the second position. A lid that exposes the unit or a part of the cover that covers the fixing means when it is not fixed in position is provided so as to abut against the fixing means and cannot be closed.

With this configuration, the unit can be slid by the guide means in the apparatus main body, and the unit is slid from the first position to the second position by pressing the end of the unit by the fixing means. . Due to this movement, the receiving portion provided at the end of the photosensitive drum fits the tapered portion of the transmitting means, and when the unit is located at the second position, the receiving portion provided on the photosensitive drum and the tapered portion of the transmitting means are displaced. It is connected in the state without.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view of an image forming unit including a unit in the image forming apparatus. The image forming unit 1
The photosensitive drum 2 is provided at the center. A corona charger 3 (or a charging roller) for uniformly charging the surface of the photosensitive drum 2 around the photosensitive drum 2, and projecting the first document data read by a scanner or the like with an LED or the like to project the photosensitive drum 2 An image projection device 4 for forming a latent image thereon, a developing device 5 for supplying a charged toner to the latent image to form a toner image, and a surface of a transfer material sent from a paper supply unit (not shown) Transfer corona discharger 6 for transferring the toner image on the photosensitive drum 2 to the photosensitive drum 2, a separating corona discharger 7 for separating the transfer material from the photosensitive drum 2, and cleaning for removing the toner remaining on the surface of the photosensitive drum 2 after the transfer. It has an apparatus 8 and an eraser lamp 9 for uniformly removing the charge on the surface of the photosensitive drum 2. These are arranged so as to act on the photosensitive drum 2 in order, and an image is formed as is well known. In the drawing, a portion surrounded by a wavy line indicates the unit 50.

FIG. 2 is a schematic side view of the unit 50.
FIG. 3 is a schematic top view of the image forming apparatus in which the unit 50 is located at a predetermined position in the apparatus main body and viewed from the direction of arrow A in FIG. The unit 50 supports the photosensitive drum 2 and the developing device 5 around the photosensitive drum 2 by a first side plate, which will be described later.
It is constituted as. In the case of using polymerized toner, the cleaning device 8 may be omitted, or a photosensitive belt may be used instead of the photosensitive drum.

The developing device 5 includes a casing 10 that stores toner, a developing roller 11 that is in proximity to the surface of the photosensitive drum 2 and forms a toner layer, and a supply that supplies the toner consumed by image formation to the developing roller 11. Roller 12 and blade 13 for regulating the thickness of the toner layer of developing roller 11
And develops according to the electrostatic latent image formed on the photosensitive drum 2.

The unit 50 is detachably provided on the main body of the image forming apparatus 1. For example, as shown in FIG. 4, the image forming apparatus 1 has a lid 15 that can be opened and closed about a pivot 14 at an upper portion thereof, and the image projection device 4
Is provided. The lid 15 is opened together with the image projecting device 4 to expose the inside of the image forming apparatus 1, and the unit 50 having the photosensitive drum 2 is detachable from above the apparatus main body along the wavy line.

The image forming apparatus further includes a unit 50 in the image forming apparatus 1 as shown in FIGS.
Guide means 16 for allowing sliding movement in a direction substantially parallel to the axis of the image forming apparatus; fixing means 17 for fixing the unit 50 to a second position, which will be described later, of the main body of the image forming apparatus 1; A transmission unit 19 having a tapered portion 18 for transmitting the drive to the photosensitive drum 2 is provided.

The guide means 16 is provided on both side plates 2 of the unit 50.
1a (21b), and a boss 23 provided on the apparatus body 1 side. In the embodiment, the bosses 23 are fixed to four parts, such as the housing of the main body of the image forming apparatus 1, in a direction substantially parallel to the axis of the photosensitive drum 2.
When the unit 50 is mounted, the side plate 21 is attached to each boss 23.
The height of the unit 50 in the image forming apparatus 1 is determined by engaging the four concave portions 22 provided at a (21b).

The position of the unit 50 placed in the image forming apparatus 1 is defined as a first position, and the operation of the fixing means 17 causes the unit 50 to move in a direction substantially parallel to the axis of the photosensitive drum 2 along the guide means 16. Is slid, and the position where the tapered portion 18 of the transmission means 19 on the main body side of the image forming apparatus 1 and the receiving portion 20 provided on the photosensitive drum 2 are connected without play is defined as a second position.

FIG. 5 is an enlarged schematic sectional view of the fixing means 17. The fixing means 17 includes a shaft 25 having a thread groove 24.
A knob 26 fixed to the tip of the shaft 25 and manually rotating the shaft 25; a nut 27 screwed into the thread groove 24 of the shaft 25 to move the shaft 25 in the axial direction; The holder 28 has a tip end portion 29 provided at the other end of the shaft 25 for pressing the side plate 21a of the unit 50.

Reference numeral 30a denotes a side plate which is a part of the housing of the main body of the image forming apparatus 1, and has a hole 31 through which the shaft 25 is inserted. The nut 27 is fixed to the end face of the holder 28 so as to be embedded, and the holder 28 is fixed to the side plate 30a with screws or the like such that the threaded hole of the nut 27 is positioned to overlap the hole 31 of the side plate 30a. The screw groove 24 of the shaft 25 is screwed into the fixed nut 27, the tip of the shaft 25 is projected from the hole 31 of the side plate 30a, and the tip 29 made of synthetic resin is fixed with a screw or the like. By manually rotating the knob 26 in this manner, the distal end portion 29 of the shaft 25 presses the unit 50, and the unit 50 slides from the first position to the second position.

The transmission means 19 is fixed to a shaft 32 transmitted from a drive source (not shown) in the image forming apparatus 1. The shaft 32 is rotatably supported by a bearing 33, and a gear 34 fixed to the shaft 32 transmits a drive from a drive source. As shown in FIG.
And a shaft 35 protruding in the axial direction from the tip of the tapered portion 18.

FIG. 6 is an enlarged schematic cross-sectional view showing a state in which the transmission means 19 and the receiving portion 20 are connected as viewed from the direction of arrow B in FIG. The tapered portion 18 has a rectangular cross section, and as shown in FIG. 6, has a tapered surface 36 whose width gradually becomes narrower as the narrow portion approaches the tip. Furthermore, the shaft 35 at the tip of the tapered portion 18 is chamfered so as to be easily inserted into a hole 37 of a receiving portion described later.

The receiving portion 20 is provided on a flange 38 for fixing the photosensitive drum 2 at both ends, and has a groove 39 shaped to fit in the shape of the tapered portion 18 described above. In the embodiment, the groove 39 has a rectangular parallelepiped shape, and the unit 5
When 0 reaches the second position, the tapered portion 18 and the receiving portion 2
0 is linked without play. The shape of the groove 39 is
In addition, the shape may be complementary to the tapered surface 36 of the tapered portion 18.

The receiving portion 20 further has a hole 37 at the center of rotation of the photosensitive drum 2 to be fitted to the shaft 35 of the tapered portion 18. When the unit 50 is mounted, the receiving portion 20 fits the tapered portion 18. Before being connected, the shaft 35
And the center of rotation of the transmission means 19 and the center of rotation of the photosensitive drum 2 are positioned at the same position.

The fixing means 17 connects the unit 20 to the second
When the unit 50 is not fixed at the position, that is, when the fastening of the unit 50 by the fixing unit 17 is forgotten while the unit is at the first position, the cover 15 that exposes the unit 50 or the cover that covers the fixing unit 17 Of the fixing means 17 cannot be closed. For example, when the knob 26 indicated by the solid line in FIG. 7 is at the first position, the cover side wall 40 that covers the fixing means 17 cannot be closed by contacting the knob 26, and the knob 26 indicated by the wavy line is The cover can be closed only when it is located at the position 2.

The operation of the above configuration will be described. To allow the unit 50 to slide within the image forming apparatus 1, the boss 23
The unit 50 is placed so as to engage with the recess 22. By rotating the knob 26 to move the distal end 29, the center of the side plate 21a of the unit 50 is pressed to
0 is slid from the first position to the second position. Due to this movement, the receiving portion 20 of the photosensitive drum 2 fits the tapered portion 18, and when the unit 50 is located at the second position, the photosensitive drum 2 and the drive from the drive source are connected without play. You.

The unit 50 is moved from the first position to the second position.
The shaft 35 is fitted into the hole 37 before the receiving portion 20 is fitted into the tapered portion 18 and connected during the movement to the position of, so that the rotation center of the transmission means and the rotation center of the photosensitive drum 2 are at the same position. .

In the embodiment, the unit has been described with a configuration in which the developing device is arranged around the photosensitive drum. However, in the case where at least one of the charging device, the developing device, and the cleaning device is arranged in addition to the developing device. Is also good.

Also, by providing a reference mark on the shaft or the like indicating that the knob of the fixing means has reached the second position, excessive tightening of the fixing means can be prevented. In the embodiment, as the detection means, the cover is partially in contact with the knob to inform the worker. However, when the unit does not exist at the second position, the unit is detected by a position detection sensor or the like to detect the unit. You may let me know.

[0029]

According to the present invention, the unit can be arranged at the first position of the apparatus main body, and the unit can be slid to the second position by the fixing means only. , Work efficiency is improved. Also,
Even if the operation of the fixing means is forgotten so that the unit is at the second position, this can be detected.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an image forming unit.

FIG. 2 is a schematic side view showing the side of the unit.

FIG. 3 is a schematic top view of the image forming apparatus including the unit viewed from the direction of arrow A in FIG. 2;

FIG. 4 is a schematic diagram of an image forming apparatus having a lid.

FIG. 5 is an enlarged schematic sectional view of a fixing means.

FIG. 6 is a schematic enlarged cross-sectional view of a transmission unit and a receiving unit as viewed from the direction of arrow B in FIG. 3;

FIG. 7 is an enlarged schematic sectional view of a fixing means.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming part 2 Photosensitive drum 3 Corona discharger 4 Image projection device 5 Developing device 6 Transfer corona discharger 7 Separate corona discharger 8 Cleaning device 9 Eraser lamp 10 Casing 11 Developing roller 12 Supply roller 13 Blade 14 Axis 15 Lid 16 Guide means 17 Fixing means 18 Taper part 19 Transmission means 20 Receiving part 21a, b Side plate 22 Depression 23 Boss 24 Screw groove 25 Shaft 26 Knob 27 Nut 28 Holder 29 Tip part 30a, b, c Side plate 31 Hole 32 Shaft 33 Bearing 34 Gear 35 shaft 36 tapered surface 37 hole 38 flange 39 groove 40 cover side wall 50 unit

Claims (5)

[Claims] 1. A photosensitive drum and a unit around which at least one of a charging device, a developing device, and a cleaning device are disposed are arranged in a direction substantially parallel to an axis of the photosensitive drum from a first position in an apparatus main body. A guide means for allowing the slide unit to slide to a position 2; and a fixing means pressing one end of the unit to move the unit from the first position to the second position along the guide means. A transfer means fixed at a position, and a receiving portion provided at an end of the photosensitive drum by movement of the unit has a tapered portion for transmitting a drive from a drive source in the apparatus main body provided to the apparatus main body to the photosensitive drum. And the unit is the second
An image forming apparatus, wherein the receiving portion and the tapered portion are connected without any backlash when the image forming apparatus is located at the position. 2. The transmission means further has a shaft protruding in the axial direction from the tapered portion, and the receiving portion further has a hole at the center of rotation of the photosensitive drum fitted with the shaft.
The image forming apparatus according to claim 1, wherein the shaft is fitted into the hole before the receiving portion is connected by fitting the tapered portion. 3. The guide means has a boss provided on the apparatus main body, and a portion provided on a side surface of the unit and engaging with the boss, wherein the unit is moved from a first position to a second position.
3. The image forming apparatus according to claim 1, wherein the image forming apparatus is provided so as to be slidable at a position. 4. The apparatus according to claim 1, further comprising detecting means for detecting that the unit is located at the second position. 5. The detecting means includes: a cover that exposes the unit when the fixing means does not fix the unit at the second position; The image forming apparatus according to claim 1, wherein the image forming apparatus is provided so as not to be closed by contact with the image forming apparatus.