JPH02284174A - Image forming device - Google Patents

Abstract

PURPOSE:To facilitate cleaning of a light emitting element without damaging the light emitting element or a photosensitive body by providing a means to retreat a photoirradiation means from the photosensitive body synchronized with the loading/unloading of a processing unit and to clean the photoirradiation means. CONSTITUTION:When the processing unit is pulled out, a protruding part 101d of an LED alley 101 is simultaneously ridden up to a tapered part of an opening 102e of a frame body, placed on the opening part, and the LED alley 101 is drawn away from the drum 11 against the power of pressuring springs. Further, at the time of loading/unloading, the LED alley 101 is lifted up towards the direction of an arrow B against the pressure springs 204 and 204', and with this lifting, the cleaning member 205 which is adhered to a stand part 102c of a backside plate of the frame body by double coated adhesive tapes, etc., is made to contact the light emitting surface of the LED alley 101 with just the appropriate pressure at the time of loading/unloading. Thus cleaning of the light emitting element can be facilitated without damaging the light emitting element or the drum.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to an image forming apparatus that uses an electrostatic process such as an electrostatic copying machine or an electrostatic printer, and particularly relates to an image forming apparatus that uses an electrostatic process such as an electrostatic copying machine or an electrostatic printer, and particularly relates to an image forming apparatus that uses an electrostatic process such as an electrostatic copying machine or an electrostatic printer. This invention relates to an exposure means for removing.

[Prior Art] Conventionally, in an image forming apparatus using an electrostatic process, there is a gap between a charging device that applies a constant charge to a photoreceptor and a developing device that develops an electrostatic latent image corresponding to an image. Light irradiation means is provided for removing unnecessary charges from unnecessary areas of charges applied to the photoreceptor. As this light irradiation means, there are methods using laser light, fuse lamps, fluorescent lamps, etc. However, due to cost and accuracy, LED arrays etc. in which point light emitting elements such as LEDs are arranged are used. Very often used. and many L
In order to maintain stable accuracy, the ED array is placed in a position not in contact with the photosensitive drum but very close to it, with a gap of about 1 mm in practice.

In addition, due to the recent trend toward downsizing of image forming apparatuses and the accompanying downsizing of each component within the apparatus and ease of periodic maintenance and replacement by service personnel or users, the photoreceptor drum and its surroundings have been Very often, a process unit format is used in which process means such as a primary charger, a cleaning device, etc. are housed in the same frame and can be integrally attached to and detached from the main body of the image forming apparatus.

[Problems to be Solved by the Invention] However, an image forming apparatus configured by combining an exposure means close to the drum and a process unit in which the process means are arranged in the same frame and can be integrally attached to and detached from the main body of the apparatus. When service personnel and users regularly check the process unit, the distance between the LED and the drum is only about 1/2 inch, so when installing or removing the process unit, the drum is brought into contact with the LED array, and the LED elements are There are many cases where the drum is damaged or even damaged. When attaching or detaching a process unit, the unit is attached or detached along the rail, but if the unit is attached or detached diagonally by the amount of play within the rail, this possibility becomes very high.

As a result, in the former case, it becomes impossible to remove the charge applied to the drum at the damaged part and the image is developed by the developing means, so the part where a white image is desired becomes a colored image such as black. In the latter case, the scratches can cause image defects such as image scratches and poor cleaning, which can seriously impede copywork.

Further, this type of image forming apparatus generally uses powdered toner as a developer in a developing means. However, since this toner is very small, about 10 ILm in size, it cannot be avoided that it scatters and floats in the main body of the apparatus. This foreign matter, such as toner, often contaminates the exposure means. In particular, if the light-emitting surface of the LED facing the drum becomes dirty, it becomes impossible to remove the charge applied to the drum, just as if it were damaged.

The part where a white image is desired becomes a colored image, causing a serious problem.For this reason, service personnel and users must periodically clean the light emitting surface, but in order to do this, the process unit must first be cleaned At this time, problems such as damage or scratches as described above may occur. In addition, when actually cleaning, it is necessary to reach deep into the main body of the device, so uneven cleaning is inevitable due to the difficulty of cleaning.Furthermore, the scattered toner can damage your hands and even your clothes. This has had the disadvantage that it can become dirty and cause extreme discomfort. There are also devices in which the exposure means is removable, but a means for that purpose must be provided, leading to an increase in cost. Alternatively, when a service person or user who is not a professional assembler reinstalls the exposure means into the device, the assembly is often defective, resulting in no light emitting or damage. .

[Means for Solving the Problems] Therefore, in order to eliminate the above-mentioned disadvantages, the present invention retracts the light irradiation means from the photoreceptor in conjunction with the attachment and detachment of the process unit, and in conjunction with the attachment and detachment of the process unit, the light irradiation means is removed. A means for cleaning the means is provided. As a result, since service personnel and users regularly check the drum unit, the light emitting element or photoreceptor is not damaged when the process unit is attached or removed, and the light emitting element can be easily cleaned.

Hereinafter, the present invention will be explained in detail based on Examples.

[Embodiment] First, FIG. 8 shows a sectional view of a copying apparatus capable of double-sided copying and multiple copying in different colors as an embodiment of an image forming apparatus to which the present invention is applied. The original 2 placed on the original a placement rack l is illuminated by a lamp 3, and its light image is captured by an optical system consisting of reflective mirrors 4, 5, 6, 7, 8.9 and a zoom lens 10. It is guided onto the photosensitive drum 11. The lamp 3, the mirror 4, and the mirror 5.6 each move at a predetermined speed in the direction of the arrow to scan the original 2. On the other hand, since the photosensitive drum 11 is also rotated in the direction of the arrow after its surface is uniformly charged by the primary charger 12, electrostatic latent images corresponding to the original image are sequentially formed on the surface of the photosensitive drum 11. Ru. lot is an LED array as an erasing means in which point light emitting elements such as LEDs are arranged along the axial direction of the photosensitive drum 11, and is arranged with a gap of about lam from the photosensitive drum. ON at any position and timing.

It is configured to be able to be controlled to turn off freely, and illuminates the top of the photosensitive tram 11 to erase charges in unnecessary areas. A color developer 13 containing color toner (for example, red, blue, etc.) and a black developer 14 containing black toner are arranged around the photosensitive drum 11. These developing devices 13°14
are movable in the directions of the arrows, and are moved close to the photosensitive drum 11 according to the desired color image.
In the case of the above figure, color developer 1 is used to visualize the electrostatic latent image.
3 is far away and the black developing device 14 is close, so a black image is formed on the photosensitive tram 11. This image is transferred by a transfer charger 15 onto a transfer paper 17 as a transfer material. Thereafter, the photosensitive tram 11 reaches a cleaner 16, where residual toner on the drum surface is removed, and the process returns to the next copying process. The photosensitive drum 11, primary charger 12, and cleaning device 16 are integrally housed in the same frame 102 to constitute a process unit, and can be attached to and detached from the main body of the apparatus.

The transfer paper 17 is fed as follows, and the original image is copied.

There are the following three methods for feeding the transfer paper 17 into the copying apparatus. In the first method, sheets are loaded in a cassette 18 and fed to a pair of rollers 20 by a feed roller 19. When multiple sheets of transfer paper 17 are fed into the roller pair 20 in an overlapping manner,
Only the top paper is separated and fed into the apparatus, and after passing through the pair of rollers 20, the transfer paper 17 reaches the registration rollers 23 via guide plates 21 and 22. Second
In this method, the sheets are loaded in a cassette 24 and sent to a pair of rollers 26 by a feed roller 25. The roller pair 26 has the same function as the previous roller pair 20, and after passing through the roller pair 26, the transfer paper 17 reaches the registration roller 23 via guide plates 27 and 28. The third method is a so-called manual paper feeding method, and in this case, when the single manual feed tray 29 is rotated in the direction of the arrow, the manual feed intermediate plate 30 slides under the paper feed roller 25 in conjunction with this movement.

At this time, the transfer paper 17 in the cassette 24 is inserted into the manual feed middle plate 30.
It is pushed down so as not to interfere with the In this state, it is placed on the manual feed middle plate 30 and the manual feed tray 29,
It is sent to the registration roller 23 in the same manner as in the second method. The registration roller 23 starts rotating at a timing such that the visible image on the photosensitive drum 11 and the transfer paper 17 coincide, and the upper transfer guide 31. The transfer paper is sent to the surface of the photosensitive drum 11 via the lower transfer guide 32. As mentioned above, the transfer charger 15 transfers the image on the surface of the photosensitive drum 11 to the transfer paper, and the separation charger 33 removes the image from the drum surface. It is separated and sent via the conveying section 34 to a fixing device 35 having a heating roller 35a and a pressure roller 35b. The image on the transfer paper is fixed as a permanent image by heating and pressure in the fixing device 35, and the transfer paper 17 is sent to the first discharge roller 36, and then reaches the second discharge roller 39 via the flapper 37 and the flapper 38. , then ejected from the copying machine 0
In the figure, the flapper 38 is shown blocking the transfer paper path, but this flapper 38 is made of a light material and is rotatable in the direction of the arrow. Since it is pushed up by the leading edge of the paper and takes a retracted position with respect to the transfer paper, there is no problem in passing the transfer paper.

Furthermore, this copying device is capable of double-sided copying and multiple copying. When the copying device is instructed to perform double-sided copying, the original image is transferred and fixed on one side of the transfer paper in the same way as the basic operation described above. Then, the transfer paper is sent to the second ejection roller 39 and ejected onto the tray (T).
0 and an optical sensor 41, and then for a certain period of time (i.e., when the trailing edge of the transfer paper reaches the flapper 3
After the elapse of the time required to pass B, the second ejection roller 39 starts to rotate in reverse and feeds the transfer paper into the transfer device again, and the transfer paper 17 is then passed through the cover plate 38 and the flapper with the rear end first. 37 and the guide plate 42, and further via the guide plates 43, 44 to the roller 45. Thereafter, the transfer paper 17 passes through the rollers 46 and reaches the horizontal registration rollers 47. At this point, the horizontal registration roller 47 has stopped, and the transfer paper is
After the rollers 45 and 46 are completely occupied, the roller pairs 45 and 46 also stop.

Then, the transfer paper waits for copying operation to the other side.

When a copy signal for the other side is issued, the horizontal registration roller 47 starts rotating and feeds the transfer paper to the registration roller 23 via the guide plates 48 and 49.
Before the transfer paper arrives at the transfer paper, the side edge of the transfer paper is detected by an optical sensor (not shown), and the horizontal registration roller 47 is moved in a direction perpendicular to the paper traveling direction so that the side edge is at the same position as the first time. That is, the lateral position of the transfer paper is corrected by moving in a direction perpendicular to the drawing. The operation after the transfer paper reaches the registration roller 23 is the same as the basic operation described above.

The transfer paper with the image copied to the other side will eventually be transferred to the second side.
The discharge roller 39 discharges the paper onto a tray (T) outside the apparatus.

On the other hand, in the first copying operation when the copying apparatus is instructed to perform a multiple copying operation, the original image is transferred and fixed onto the transfer paper as in the basic operation. In the case of multiple copying, the flapper 37 is positioned as shown by the broken line. Therefore, the transfer paper 17 is sent out by the first discharge roller 36 with the front end first, sent along the right slope of the flapper 37 to the guides 42 and 43, and further sent to the roller 45 via the guides 43 and 44.

Thereafter, the transfer paper 17 passes through the rollers 46 and reaches the horizontal registration rollers 47. The rear end of the transfer paper 17 is detected by the detection lever 40 and the optical sensor 41, and after a predetermined period of time has elapsed, the flapper 37 returns to the position indicated by the solid line. When the second copy signal is issued, the horizontal registration roller 47 starts rotating, but the movement of the transfer paper at this time is the same as in the case of double-sided copying. Then, the transfer paper 17 on which the second image has been copied on the same side is finally transferred to a tray (
T) is ejected upward. In this explanation, multiple copying is performed twice, but the movement of the transfer paper is basically the same even when multiple copying is performed more frequently. The only difference is that the flapper 37 returns from the position shown by the broken line to the position shown by the solid line before the final copying.

Further, in this embodiment, an apparatus that performs double-sided copying or multiple overlapping copying of a plurality of sheets has been described, but this apparatus may be provided with a so-called intermediate tray so that double-sided copying or multiple overlapping copying of a plurality of sheets can be performed.

The above describes the general configuration and operation of the copying apparatus to which the present invention is applied. The means for cleaning will be explained.

FIG. 2 shows the LED array lot and the process unit 1 including the photosensitive tram 11 when viewed from the six directions of arrows in FIG.
02, a front flange 210 and a rear flange 209 are bonded to the photosensitive drum 11. In particular, the rear flange 209 is provided with a gear portion, and a gear portion (not shown) provided on the main body side is attached to the photosensitive drum 11. This drum, which is rotationally driven by a driving means, is held in the same frame by a primary charger and a cleaning device, and the gear side of the drum is
Fits into the rear side plate 102b of the frame via a bearing (not shown),
The front flange side of the drum is pivotally supported by the front side plate 102a of the frame via a bearing 207. Furthermore, a felt for cleaning the LED light emitting element made of a fine fiber material is provided on the base portion 102c of the rear side plate of the frame.

On the other hand, the LED array 101 has a support plate 101c.
is maintained. Support pins 101 are installed before and after the support sheet metal.
a and 101b are provided, and the support pin 101a is inserted into an elongated hole 202a provided on the rear side plate 202 side, and a mounting plate 206 provided with a similarly elongated hole 206a on the front side.

By fitting into this elongated hole, positioning in the left and right direction in the cross-sectional direction is performed. In addition, the LED array 101 has its support plate 10
1c is a lens stand 203 on which an optical system such as a lens 1O is arranged.
The leaf springs 204, 204' provided at the bottom of the
Pressure is applied in the direction toward the drum surface.

FIG. 4 is a schematic sectional view showing the relationship between the LED array lot and the drum unit 102.

The LED array 101 is attached to its mounting plate 101c or plate spring 2.
04 and 204', pressure is applied in the direction of the drum surface. The positioning for creating a gap of about ll■ with the drum surface is done by using a portion 101d protruding from the support sheet metal 101c,
This is achieved by abutting the bottom surface 102d of the notch opening 102e of the frame 102.

Figure 1 shows details of the positioning section. The protrusion 101d of the support metal plate 101c of the LED array is connected to the opening 1 of the frame 102.
It is fitted in 102e to 102f. When the process unit is completely set in the apparatus main body, the protrusion 101d abuts against the bottom surface 102d of the notch opening 102c under the pressure of the pressure spring 204.

This bottom surface 102d is a precisely formed part of the frame 102, and its dimensions from the position supporting the drum are very reliable. This allows the LED array to be held with a gap of about 1 mm from the drum surface.

Next, a method for retracting the LED array 101 by pulling out the process unit from the apparatus main body will be described. At the same time as the process unit is pulled out, the protrusion 101d of the LED array rides on a tapered part of the notch opening 102C of the frame and is placed on the notch indicated by the opening 2f.

As a result, the LED array is moved away from the drum against the force of the pressurized spring. Such protrusions are provided at several locations (three locations in this embodiment) in the longitudinal direction, so that they can be lifted up against the spring force. The amount of lift (that is, the amount of taper) is sufficient to prevent the LED array or drum from being damaged during attachment and detachment.

Next, in Figure 3, the L
0 Describing the cleaning of the ED array When attaching and detaching, the LED array is moved by the pressure springs 204 and 204' by the above-mentioned means.
is lifted in the direction of arrow B against the By this lifting, the cleaning member 205 adhered to the base part 102c of the rear side plate of the frame with double-sided tape etc.
Contact the light emitting surface of the array with appropriate pressure. This positional relationship is determined in advance by taking into consideration the lifting amount and the crushing amount of the cleaning member. This cleaning member has a size of 0 or more that is large enough to cover the light emitting surface of the LED array even in the lfr plane direction, so that it can be moved in the longitudinal direction in conjunction with the attachment and detachment of the process unit. The cleaning member can sufficiently clean the light emitting surface of the LED array over the entire area. Since this cleaning member is simply glued to the process unit, service personnel and users can easily replace it if it becomes heavily contaminated.

Furthermore, since the cleaning member is provided on the back side of the frame, the following effects are also achieved. As explained in the conventional example, process units are often inserted and removed along the rails. At this time, the units can be inserted and removed diagonally to compensate for the play between them and the rails (see Figure 9). This prevents damage and damage. Scratches are more likely to occur, but if there is a cleaning member on the back side, even if the LED array is inserted diagonally, the cleaning member will be the first to come into contact with the LED array. can be on the safer side when retreating.

[Other Embodiments] Figures 5 to 7 show other embodiments for achieving the present invention.
The figure is a cross-sectional view of the process unit 102 completely attached to the main body of the apparatus. The LED array 101 is fitted and positioned with respect to the main body of the device by means of pins 101k. Furthermore, a torsion coil spring 301 is applied to this pin 101, and an LED is connected to the 301b side.
The 301a side of the array is hooked on the main body side, and receives force in the direction of arrow C with the pin 101 as the center of rotation. LED array is drum and 1
It is configured to maintain a gap of about 1. On the other hand, the lever 301 having the cleaning member 205 over the entire length in the potato direction has a similar configuration and receives a force in the direction of the arrow with the pin portion 301 as the rotation center. However, the part of the lever protrusion 3011 that just abuts the frame is the opening 1.
02g, and is positioned in a cross-sectional shape as shown in the figure.

FIG. 7 shows the relationship between the opening of the frame and the protrusions of the LED array and lever. The frame 102 has two openings 102.
g and 102j are provided. As mentioned above, LED
The protrusion 1 of the array 101 is in contact with the frame, but as the process unit is attached and removed in the E direction, the protrusion 10 is disposed on the frame side because the opening 102j is provided on the frame side.
11 is pushed into the interior as shown by the two-dot chain line.On the other hand, the lever 301 is not shown, but the L
It has the same configuration as the ED array, and when the process unit is installed, it fits into the opening 2j, but as the 1 is attached and removed, that opening disappears, so the frame It hits the body and becomes positioned. Figure 6 shows the state when it is attached and detached.

The protrusion 1011 of the LED array fits into the opening of the frame, and the protrusion 3011 of the old lever 3 abuts against the frame and is positioned. As a result, the LED array is retracted at a sufficient distance from the drum, and the light emitting elements of the LED array can come into contact with the cleaning member 205 provided at the tip of the lever, allowing the light emitting surface to be cleaned smoothly. As mentioned above, since the cleaning member 205 is formed over the entire length of the lever in the long direction, the light emitting surface can be cleaned uniformly. The array is retracted from the drum and the LEDs can be cleaned. In addition, in the case of this configuration, the lever 301 is placed between the LED array part and the image exposure part, which corresponds to part F in FIG.
From 3.14, the effect of blocking dirt such as scattered toner, and 1
It also has the effect of blocking light leaking to the next charger.

It goes without saying that the present invention is not limited to this embodiment, and any means may be used as long as it achieves the object of the present invention.

[Effects of the Invention] As explained above, there is provided a means for retracting the light irradiation means such as an LED array from the photoreceptor in conjunction with the attachment and detachment of the process unit, and cleaning the light irradiation means in conjunction with the attachment and detachment of the process unit. By providing this, service personnel and users regularly check the tram unit, so that the light emitting element or drum is not damaged when the process unit is attached or removed, and the light emitting element can be easily cleaned.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention. 2 and 3 are schematic side views for explaining the operation of the cleaning means of the embodiment of FIG. 1, respectively, and FIG. 4 is a schematic sectional view of the process unit of the embodiment of FIG. 1. 5 and 6 are schematic cross-sectional views showing other embodiments of the present invention, FIG. 7 is a perspective view illustrating the embodiment of FIG. 5, and FIG. 8 is a copying apparatus to which the present invention is applied. Schematic diagram. FIG. 9 is a schematic cross-sectional view illustrating the operation when the process unit is tilted and removed. In the figure, 11 is a photoreceptor, lot is a light irradiation means such as an LED array, 102 is a frame of a process unit, and 205 is a cleaning member. old

Claims (3)

[Claims] (1) A process unit in which a photoconductor and a process means acting on the photoconductor are housed in the same frame and can be integrally attached to and detached from the main body of the image forming apparatus, and a process unit that is close to the photoconductor of the process unit. In an image forming apparatus, the image forming apparatus includes a light irradiation means for removing electric charge applied to the photoreceptor, and a means for retracting the light irradiation means from the photoreceptor in conjunction with attachment and detachment of the process unit; An image forming apparatus comprising: means for cleaning the light irradiation means in conjunction with each other. (2) The image forming apparatus according to claim 1, wherein the light irradiation means is constituted by an LED element. (3) The image forming apparatus according to claim 1 or 2, wherein the means for cleaning the light irradiation means is provided in the process unit.