JPS61249061A - Image forming unit - Google Patents

Abstract

PURPOSE:To reduce the thickness of an image forming unit by arranging a toner supply device at the opposite side from a photosensitive drum about a cleaning device and supplying toner from the supply device to a developing device. CONSTITUTION:The developing device 20 and cleaning device 50 are arranged on both sides of the photosensitive drum 10 and the toner supply device 30 is arranged on the opposite side from the drum 10 about the device 50. An electrostatic charger 9 is provided above the device 10 and respective members are united in one by a frame 1. This image forming unit is attached to and detached from the front of a copying machine which is not shown in a figure; the unit is detached by being drawn out as shown by an arrow and also attached by engaging a lock lever provided to the frame 1 with part of the frame of the copying machine body. When toner is supplied, a clutch 34 is turned on and off on the basis of a signal from a toner density controller to control the rotation of a screw roller 32.

Description

[Detailed description of the invention] Elm! FIELD OF THE INVENTION The present invention relates to an image forming unit that is detachably incorporated into a copying machine or the like.

In recent years, copying machines have been manufactured with developing devices, cleaning devices, etc. arranged around the photoreceptor drum in order to simplify the assembly process and facilitate maintenance. There has been provided a copying machine which includes an image forming unit and which can be pulled out from the main body of the copying machine.

On the other hand, copying machines themselves tend to be smaller and thinner, and if a cell 7 lens array with a short focal length is used as an imaging element in the optical system, it is possible to achieve a significantly smaller and thinner profile. be.

Incidentally, it is possible to make the image forming unit smaller and thinner by reducing the diameter of the photoreceptor drum, but there are problems with toner replenishment to replenish the developing device with new toner, the capacity of the device, or its installation location. becomes. The toner replenishing device requires a certain capacity, and as is well known in the art, it is not preferable to install it above the developing device because it increases the height of the image forming unit, so it is not preferable to install it next to the developing device. However, since the developing device itself takes up a relatively large volume, it is difficult to install it in terms of space.

Means for Solving the Problems Therefore, in the image forming unit according to the present invention, the toner replenishing device is disposed on the opposite side of the cleaning device from the photosensitive drum, and the toner replenishing device accommodated in the toner replenishing device is The present invention is characterized by being provided with a conveying means for conveying the toner for use to the developing device.

That is, on the opposite side of the cleaning device from the photoreceptor drum, the fixing device is usually installed at a position slightly away from the cleaning device, so there is a relatively large amount of space. In the present invention, a toner replenishing device is disposed in this space so as not to impair the thinning of the image forming unit.

Note that when the toner replenishment device is installed on the cleaning device side, a conveying means for conveying the replenishing toner to the developing device is required, but this is also used as a recycling means for returning the toner collected by the cleaning device to the developing device. By doing so, it is possible to avoid the need to newly install a special conveyance means.

Embodiment The attached drawings show an embodiment of the image forming unit according to the present invention, and as shown in FIGS. a developing device (20) and a cleaning device (50) installed, a toner replenishing device (30) installed on the side of the cleaning device (50), that is, on the opposite side of the photoreceptor drum (10), and a photoreceptor drum. The charger (9) placed on the road of (10)
), and each member is integrated into a unit by a frame (1) (the rear part is not shown), and a developing device is installed on the front side to store replenishing toner and toner collected by the cleaning device (50). A conveying means (45) for conveying to (20) is installed.

This image forming unit can be attached to and removed from the front of the main body of the copying machine (not shown), and can be removed by pulling it out toward the front (in the direction of arrow (A)). During installation, a lock lever (2) provided on the frame (1) engages with a part of the frame of the copying machine body and is locked. The drive system of the image forming unit is connected to and disconnected from a drive system whose drive system is a main motor provided in the main body of the copying machine in conjunction with the attachment/detachment operation by a well-known clutch means.
, ) is attached with a connector pin (3) for controlling the developing device (20), etc., and when the image forming unit is attached or detached, the connector of the control system centered on the microcomputer of the copying machine body is attached or detached. ing.

The photoreceptor drum (10) is rotatably supported, and rotational force is transmitted to a gear (11) fixed to one end from a conveying coil drive gear (54) of a cleaning device (50), which will be described below, so that the photoreceptor drum (10) rotates in the direction of the arrow. It is rotated in the (,) direction.

The space (7) between the charger (9) and the developing device (20) is used for image exposure, and the open space (8) between the charger (9) and the cleaning device (50) is used for charge erase. When installed in the main body of the copying machine, the SELFOC lens array is located in the space (7), and the eraser lamp is located in the space (8).

The developing device (20) is a well-known device that includes a developing sleeve (not shown) containing a magnetic roller.

The toner replenishing device (30) includes a toner box (31) extending parallel to the photoreceptor drum (10), a screw roller (32) and a rotary blade (35) attached thereto, and a toner cartridge (40) provided above. It is something.

The screw roller (32) has a wing plate (
32b) appears to be wound in an upward spiral, and is installed at the bottom of the toner box (31), and is connected to the clutch (32b).
The drive gear (33) connected via the arrow (b)
) direction, and this rotation conveys the toner toward the front side [in the direction of arrow (B)]. Rotating blade (35)
is rotatably supported by support shafts (35a) and (35b) at both ends, and has a drive gear (36) fixed to the support shaft (35b).
is meshed with the drive gear (33)] at arrow (c)
It can be rotated in the direction q, and the toner is conveyed to the upper part of the screw roller (32) by rotation q.

Further, a toner empty detection plate (37) is rotatably installed in the toner box (31). This detection plate (37) is connected to a rotating blade (
35) engages and moves upward each time it rotates, and when the engagement disengages, it moves downward under its own weight. This lowering time is the toner box (
Toner empty is detected by turning on and off a reed switch using a magnet attached to the part (37a) which rotates together with the detection plate (37) in proportion to the amount of toner in the toner inside (31). There is.

A toner cartridge (40) is detachably attached to the top of the toner box (31) from the front side.

As shown in FIGS. 3 and 5, this toner cartridge (40) consists of a cylindrical body having an opening (41) in the longitudinal direction, and the opening (41) is sealed with a folded sealing material (44). The front end is also closed and the knob (4) is closed.
2) is provided.

Further, the rear end portion is closed with caps (45) and (46), and the caps (45) and (46) are attached after the toner cartridge (40) is filled with toner. To remove the toner, insert the toner cartridge (40) into the toner box (31) from the front side with the sealing material (44) facing upward, and pull the end (44a) toward you to peel off the sealing material (44). After that, by pinching the knob (42) and turning it half a turn, the toner box (31) is replenished through the opening (41). By the way, the bottom of the toner cartridge (40) has a cap (45), (
46) is flat to prevent the toner remaining in the toner box (31) from being scraped off when the toner cartridge (40) is inserted. Further, the rotational position of the toner cartridge (40) is determined by the protrusions (43a) and (43b).

Note that the toner cartridge (40) may have a rib (41a) provided in the opening (41), as shown in FIG. 4. This rib (4ja) is for strength reinforcement.

The toner conveying means (45) is provided with a conveying coil (47) in a conveying pipe (46), and is installed toward the developing device (20) from the toner replenishing device (30). One end of the conveying pipe (46) is connected to a toner box (31) so as to surround the protruding portion of the screw roller (32).
The opening (46a) at the other end is connected to the front of the developing device (
20) is installed so as to be located on the developer transport path (21). Toner is transported to one end of the transport pipe (46) by the rotation of the screw roller (32). Then, the blade tip portion (32) of the screw roller (32)
b') has a substantially V-shape that expands in the rotational direction [arrow (b) direction], and makes it easy for the toner to fall into the conveyance pipe (46). On the other hand, the conveyance coil (47) is installed over the entire length of the conveyance pipe (46), and is rotationally driven in the direction of arrow (d) by a helical gear (48) provided at the other end. The developer is transported in the direction (D) and replenished from the opening (46g) to the end of the developer transport path (21). Note that the helical gear (48) is the developer conveyance path (21).
The gear (23) fixed to the shaft end of the conveyance screw roller (22) provided in the
) and an idle gear (25) through a helical gear (not shown) that rotates together with the idle gear (25).

The cleaning device (50) uses a blade (51) to scrape off residual toner on the photosensitive drum (10), and the front end of the conveyance path (52) where the conveyance coil (53) is installed is It is connected to the middle of the conveyance pipe (46). The conveyance coil (53) is rotationally driven in the direction of the arrow (e>) by the drive gear (54), and this rotation causes the conveyance path (5
2) Transport the toner scraped off in the direction of arrow (E),
That is, it is fed into the conveying pipe (46). The collected toner thus sent to the conveying pipe (46) together with the toner replenished from the toner replenishing device (30) is transferred to the conveying means (46).
5), the image is transported to the developing device (20).

In the above configuration, toner replenishment is performed by turning on and off the clutch (34) based on a signal from a conventionally known toner concentration control means and controlling the rotation of the screw roller (32).

Note that the image forming unit according to the present invention is not limited to the above-mentioned embodiments, and can be variously modified within the scope of the gist thereof. For example, the toner collected by the cleaning device (50) is transferred to the toner conveying means (45) as described above.
) may be returned to the toner box (31) of the toner replenishing device (30).

Effects of the Invention As is clear from the above explanation, the present invention has a relatively large amount of space and the toner replenishing device is disposed on the side opposite to the photosensitive drum of the leaning device, so that the image forming unit 7
), it can be installed inside a copier or the like in a space-efficient manner without sacrificing its ability to be made larger or, in particular, thinner.

Moreover, if the conveying means for conveying the toner from the replenishing device to the developing device and the toner recycling means are shared as in the embodiment described above, there is no need to newly install a special conveying means, which is advantageous in terms of component configuration.

[Brief explanation of the drawing]

The drawings show an embodiment of the image forming unit according to the present invention, in which FIG. 1 is a perspective view, FIG. 2 is a perspective view with main parts cut away, and FIG.
4 is a perspective view showing a modified example of the toner cartridge, and FIG. 5 is a partial sectional view of the toner cartridge. (9)... Charger, (10)... Photosensitive drum, (20)... Developing device, (30)... Toner supply device, (32)... Screw roller, (40)...
... Toner cartridge, (45) ... Toner transport means, (46) ... Transport pipe, (47) ... Transport coil, (5o) ... Cleaning device, (53)
...Collected toner transport coil.

Claims (1)

[Claims] 1. An integrated unit including a photoreceptor drum and having a developing device and a cleaning device arranged on at least both sides thereof;
In an image forming unit that can be pulled out from the main body of the machine toward the front, a toner replenishing device is disposed on the opposite side of the cleaning device from the photosensitive drum, and the replenishing toner stored in the toner replenishing device is An image forming unit characterized by comprising a conveying means for conveying to a developing device.