JPH07230237A - Cleaning device of image forming device - Google Patents

Abstract

PURPOSE:To provide a cleaning device of image forming device capable of thoroughly removing residual toner irrespective of the quantity by making use of the merit and compensating for the demerit existing on the respective blade of the counter system and the trailing system. CONSTITUTION:In the device provided with fitting members 4a and 4b formed on a pivotally supported blade supporting body 2, a first blade 5a opposed to the rotary direction of a photoreceptor 1 is fitted to the fitting member 4a, a second blade 5b oriented in the same direction as the rotary direction of the photoreceptor 1 is fitted to the fitting member 4b, and an energizing spring 6 for energizing the blade supporting body 2 in the direction of pressurizing the first blade 5a to the photoreceptor 1 is disposed, then a solenoid 8 is connected with the energizing spring 7 for energizing the blade supporting body 2 in the counter direction to the energizing spring 6. The light beam after scanning the original is detected by the light quantity sensor 11 and inputted to a controller 12, and when the detection signal is larger than a set value, the energizing spring 7 is pulled by the solenoid 8 to which the voltage is impressed by the controller 12, hence the blade supporting body 2 is turned against the energizing spring 6, thus the second blade 5b is bought into press-contact with the photoreceptor 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device in an image forming apparatus such as an electrostatic photocopier, a facsimile or a printer, which uses a blade for removing residual toner on the surface of a photosensitive member such as a drum.

[0002]

2. Description of the Related Art As a cleaning device for removing residual toner on a photoconductor in an electrostatic photocopier or other image forming apparatus, the tip edge portion of a blade made of an elastic material is pressed against the surface of the photoconductor. It is known that the residual toner on the surface of the photoconductor is separated at the edge portion. In a cleaning device using this blade, a counter method is known in which the blade is fixedly arranged in the direction opposite to the traveling direction of the photoconductor, and the tip edge portion thereof is appropriately pressed against the surface of the photoconductor. The counter type cleaning device using this blade is arranged so that the edge portion of the blade abuts the surface of the photoconductor, and the residual toner on the surface of the photoconductor is peeled off at the edge portion, so that the residual toner Even when the amount of toner is large, the residual toner can be efficiently removed.

There is also known a trailing system in which a blade is fixedly arranged in the same direction as the advancing direction of a photoconductor, and its leading edge portion is appropriately pressed against the surface of the photoconductor. In this trailing method, since the direction of the blade and the advancing direction of the photoconductor are the same direction, the influence of the blade on the surface of the photoconductor is smaller than that of the counter system, but the residual toner removal efficiency is slightly low. Therefore, it is suitable for use when the amount of residual toner is relatively small.

When the blade removes the residual toner on the surface of the photoreceptor, the removed residual toner is in a state of being interposed between the surface of the photoreceptor and the blade, and between the surface of the photoreceptor and the blade. Since the residual toner intervening therein acts as a lubricant, the coefficient of friction between the surface of the photoconductor and the blade becomes small, and the photoconductor advances smoothly with respect to the blade. In this way, the residual toner serves as a lubricant, thereby preventing the blade from affecting the photosensitive film on the surface of the photosensitive member and reducing the wear of the edge portion of the blade to prolong the life of the blade.

[0005]

In the conventional cleaning device for the image forming apparatus, the counter type cleaning device has a high ability to remove the residual toner on the photoconductor and a large amount of the residual toner, as described above. Sometimes,
It is possible to sufficiently remove the residual toner. However, there is also a problem that the friction coefficient between the photoconductor and the blade tends to be large, and when there are many white parts and few characters such as characters in the document, the amount of residual toner on the photoconductor surface decreases, There is also a problem that the effect of reducing the lubrication effect of the blade due to the residual toner occurs and the abrasion of the blade is accelerated. If the friction coefficient between the photoconductor and the blade becomes larger than the set value due to the deterioration of the blade lubrication effect due to the residual toner and the progress of the blade wear, for example, as shown in FIGS. , (c), (d) in the order shown, the end of the blade A moves by friction in the advancing direction of the photoconductor,
It may also be largely bent and deformed so as to be far from the photoconductor B. As described above, when the blade A is bent and deformed, the cleaning effect is deteriorated, the use of the image forming apparatus becomes difficult, and the surface of the photoconductor is quickly damaged.

In the trailing type cleaning device, the influence of abrasion on the blade and the photoconductor is smaller than that in the counter type, but the residual toner removing ability is slightly lower than that in the counter type. Become. Therefore, when the amount of residual toner on the photoconductor is relatively small, it can be sufficiently removed, but when the amount of residual toner is large, there are cases in which the entire amount cannot be removed. Therefore, there is a problem in that a toner filming phenomenon occurs in which a thin film of toner is gradually formed on the surface of the photoconductor, and a phenomenon occurs in which the base portion of the formed image is toner-developed. That is, each of the counter type cleaning device and the trailing type cleaning device has advantages and disadvantages.

The present invention has been made to solve the above-described problems, and utilizes the advantages and disadvantages of each of the counter type and trailing type cleaning devices to compensate for their respective disadvantages, thereby improving the blade and the photoreceptor. An object of the present invention is to provide a cleaning device for an image forming apparatus, which can reduce the influence of abrasion and the like and can sufficiently remove the residual toner regardless of the amount of residual toner.

[0008]

A cleaning device for an image forming apparatus according to the present invention is a cleaning device for an image forming apparatus in which a front edge portion of a blade made of an elastic material is pressed against the surface of the photosensitive member. A first blade whose tip is in pressure contact with the photoconductor in the direction opposite to the advancing direction, and a second blade whose tip is in pressure contact with the photoconductor in the same direction as the direction of travel of the photoconductor. Is attached to a blade support member rotatably arranged on the side of the blade support member, and biasing means for rotating the blade support member in a direction of pressing the first blade against the photosensitive member and separating the second blade from the photosensitive member. A drive means for the blade support, which is provided to rotate the blade support in a direction in which the second blade is pressed against the photoconductor and separates the first blade from the photoconductor, is provided to scan the document. The amount of light emission is detected light quantity sensor, when the amount is less than the amount set value determined in advance, the biasing means is rotated the blade support first
It is characterized in that the blade is brought into pressure contact with the photoconductor, and when the amount of light detected by the light amount sensor is larger than the set value, the drive means rotates the blade support to bring the second blade into press contact with the photoconductor.

The light beam detected by the light amount sensor is used to select the density at which the latent image formed on the photoconductor is developed with toner in accordance with the type of each original set in the image forming apparatus. It is optional to use a light beam obtained by pre-scanning an original document or a light beam obtained by scanning each original document only for detection by a light amount sensor. In addition, the set value of the light amount as a reference when operating the driving means based on the light amount detected by the light amount sensor is such that the total amount of residual toner generated on the surface of the photoconductor at the set light amount is sufficiently adjusted by the trailing blade. The amount of light that can be removed is set by the first blade and the second blade.
It is set according to conditions such as the material and hardness of the blade, linear pressure, and pressure contact angle. Drive means for the blade support includes a cam operated by a solenoid or a motor.

The urging means and the driving means for rotating the blade support body in mutually opposite directions are constructed so that the blade support body can be rotated by the respective means.
For example, the blade support can be rotated by the drive means against the force of the biasing means. Alternatively, a cam operated by a solenoid or a motor is connected to the urging means so as to enable the urging by the urging means and release the urging force. When the amount of light detected by the light amount sensor is larger than a set value, the urging force of the urging means can be released by the operation of the solenoid or the cam, and the blade support can be rotated by the driving means. is there. The photoconductor may be drum-shaped or belt-shaped.
The biasing means includes a spring or a weight.

[0011]

The cleaning device for the image forming apparatus of the present invention detects a light beam obtained by scanning each document set in the image forming device, for example, a light amount sensor when prescanning the document. When the amount of light detected by this light amount sensor is smaller than the set value, in other words, there are more parts formed as other images than the white part of the document, and the toner that the developing means adheres to the surface of the photoconductor. When it is detected that the amount of residual toner increases, the first blade, which is a counter type, is pressed against the surface of the photoconductor by urging the blade support by the urging means without operating the driving means. Then, the relatively large amount of the residual toner is completely removed by the first blade having a large ability to remove the residual toner.

On the other hand, when the light amount sensor detects that the light amount obtained by scanning the document is larger than the preset value of the light amount, that is, the white part of the document is whiter than the part formed as an image on the surface of the photoconductor. However, when it is detected that the amount of toner adhered to the surface of the photoconductor by the developing means is small and the amount of residual toner becomes relatively small, the drive means is activated to rotate the blade support. Therefore, the first blade separates from the photoconductor and the second blade presses against the surface of the photoconductor, so that the relatively small amount of residual toner is removed from the second blade. In this way, the first blade or the second blade suitable for removing different amounts of residual toner corresponding to each original is selected and pressed against the surface of the photoconductor.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a cleaning device for an image forming apparatus of the present invention will be described with reference to FIG. In FIG. 1, 1
Is a photosensitive member that is drum-shaped and rotatably mounted,
Reference numeral 2 denotes a blade support disposed on a side portion of the photoconductor 1, which is rotatably supported by a support shaft 3 in a direction parallel to the rotation direction of the photoconductor 1 and has a pair at an end facing the photoconductor 1. The mounting members 4a and 4b are provided so as to project in the radial direction of the photoconductor 1 at intervals. Then, a first blade 5a formed of an elastically deformable material such as polyurethane is fixedly projected on the mounting member 4a in the direction opposite to the rotation direction of the photoconductor 1, and is in the same direction as the rotation direction of the photoconductor 1. The second blade 5b is fixedly provided on the mounting member 4b so as to project toward.

Reference numeral 6 is an urging spring for urging and rotating the blade support 2 to bring the first blade 5a into pressure contact with the surface of the photosensitive member 1 and separating the second blade 5b from the photosensitive member 1, and 7 is an urging member. An urging spring for urging and rotating the blade support body 2 against the urging force of the spring 6 in the direction opposite to the urging direction of the spring 6, and 8 is a solenoid as a driving means, and the urging force is applied to the slide rod 8a. The ends of the spring 7 are connected. Therefore, when the voltage applied to the solenoid 8 is cut off, the slide rod 8a projects therefrom and the biasing spring 7 loses its elasticity or becomes smaller. When a voltage is applied to the solenoid 8, the slide rod 8a slides therein and pulls the biasing spring 7, so that the repulsive elasticity acts on the blade support 2 and resists the elastic force of the biasing spring 6. The blade support 2 is rotated to bring the second blade 5b into pressure contact with the photoconductor 1 and separate the first blade 5a from the photoconductor 1.

Reference numeral 9 is an original, 10 is a light source such as a halogen lamp for scanning the original 9, and a light beam emitted from the light source 10 to scan the original is incident on a light quantity sensor 11, and the light quantity detected by the light quantity sensor 11 is detected. The signal is input to the controller 12. When the light quantity input from the light quantity sensor 11 is equal to or less than the set value, the control device 12 does not apply the voltage to the solenoid 8 and if the light quantity detection signal input from the light quantity sensor 11 is larger than the set value, the solenoid is operated. 8 is applied to pull the urging spring 7, and the blade support 2 is rotated against the urging force of the urging spring 6. As described above, the light amount set value of the controller 12 is the first blade in which the amount of residual toner generated on the surface of the photoconductor corresponding to the original 9 is the trailing type.
5b is the amount of light that can be sufficiently removed.

The cleaning device of the image forming apparatus is
When the document 9 is set in the image forming apparatus, the light beam scanning the document 9 is incident on the light amount sensor 11, and the light amount sensor 11 detects the light amount and inputs it to the control device 12. The light amount detection signal input from the light amount sensor 11 is smaller than the set value. That is, when it is detected that the amount of residual toner generated on the surface of the photoconductor 1 is larger than the set amount, based on the ratio of the white color and the other color portions of the original document 9, the control device 12 applies a voltage to the solenoid 8. Since no bias is applied, the biasing spring 12 rotates the blade support 2 to press the first blade 5a against the surface of the photoconductor 1 and remove the second blade 5b from the photoconductor 1 as shown by the solid line. To do.

Therefore, the counter type first blade
5a removes a relatively large amount of the residual toner, but since the first blade 5a has a large cleaning ability, it also sufficiently removes a relatively large amount of the residual toner.
The first blade 5a has a second friction coefficient with the photosensitive member 2
It becomes larger than the friction coefficient of the blade 5b. But first
The amount of residual toner removed by the blade 5a is always larger than the fixed amount, and this relatively large amount of residual toner acts as a lubricant to smoothly rotate the photoconductor 1 relative to the first blade 5a. It is possible to reduce the influence of abrasion and the like on the first and first blades 5a.

On the other hand, the detection signal input to the control device 12 from the light amount sensor 11 by detecting the light amount of the scanning light of the original 9 is larger than the set value, in other words, the white portion of the original 9 is large. When the controller 12 applies a voltage to the solenoid 8 when it detects that the amount of residual toner generated on the photoconductor 1 is small, the slide rod 8a slides in the solenoid 8 and pulls the biasing spring 7. Therefore, the urging spring 7 rotates the blade support 2 against the elastic force of the urging spring 6, and presses the second blade 5b against the photoconductor 1 as shown by the chain line, and the first blade 5a Are separated from the photoconductor 1.

Therefore, a relatively small amount of residual toner is
Blade 5b removes. The trailing type second blade 5b has a slightly lower cleaning ability than the first blade 5a. However, since the residual toner removed by the second blade 5b is always smaller than the fixed amount, it is possible to sufficiently remove the small amount of the residual toner. Since the trailing type second blade 5b has a smaller friction coefficient with the photoconductor 1 than the first blade 5a, even if the amount of residual toner is small,
The influence of wear on the blade 5b is reduced.

FIG. 2 shows a second embodiment. In this embodiment, a cam is used as the driving means instead of the solenoid of the first embodiment. In FIG. 2, reference numeral 13 denotes a cam arranged on the side portion of the mounting member 4b for rotating the blade support 2 to press the second blade 5b against the photoconductor 1, which is a driving means (not shown). Is configured to be rotated by the motor. The other structure is the same as that of the first embodiment, and therefore, the same reference numerals are given. In the second embodiment, when the detection signal input to the control device 12 by the light amount sensor 11 is larger than a set value, the control device 12 outputs a signal to the motor to rotate the cam 13. Therefore, the cam 13 rotates the blade support 2 via the mounting member 4b, presses the second blade 5b against the photoconductor 1, and separates the first blade 5a from the photoconductor 1.

FIG. 3 shows a third embodiment. In FIG.
Reference numeral 14 is a solenoid, and an urging spring 6 as an urging means connected to the slide rod 14a is attached to the blade support 2. When the detection signal input by the light amount sensor 11 is smaller than the set value, the control device 12 applies a voltage to the solenoid 14 to slide the slide rod 14a to pull the urging spring 6 to urge the urging spring. The elastic force of 6 acts on the blade support 2, and no voltage is applied to the solenoid 8. Therefore, the first blade 5a is pressed against the photoconductor 1 and the second blade 5b is separated from the photoconductor 1. On the other hand, when the detection signal input to the control device 12 is larger than the set value, the control device 12 is configured so that the voltage is applied to the solenoid 8 and the voltage is not applied to the solenoid 14. The other structure is the same as that of the first embodiment, and therefore, the same reference numerals are given.

Therefore, if the detection signal input to the control device 12 is smaller than the set value, the voltage is applied to the solenoid 14 without applying the voltage to the solenoid 8 as described above, so that the first blade 5a is exposed to light. Pressure contact with body 1. vice versa,
When the detection signal input to the control device 12 is larger than the set value, the voltage is not applied to the solenoid 14 and the solenoid 8
Since a voltage is applied to the second blade 5b, the second blade 5b is pressed against the photoconductor 1. As described above, since the urging spring 6 and the urging spring 7 are connected to the solenoids 8 and 14, respectively, the spring constants of the urging spring 6 and the urging spring 7 may be set to be the same.

In place of the solenoid 8 of the first embodiment and the solenoids 8 and 14 of the third embodiment, the cam shown in the second embodiment is used, and the urging spring 6 and the urging force are applied to the cam. It is also possible to connect each of the springs 7.

[0024]

As described above, in the cleaning device for the image forming apparatus of the present invention, a light beam obtained by scanning each document set in the image forming apparatus is incident on the light amount sensor, and the light amount detected by the light amount sensor, The control device determines the ratio of the white portion and the other-color portion of each document based on the relationship with the set value determined in advance for the light amount. When the amount of residual toner on the photoconductor that is different for each original is larger than the reference amount, the first blade, which is a counter type having a large cleaning ability, is selected and brought into pressure contact with the photoconductor. If the amount of residual toner is less than the reference amount, the cleaning ability will be slightly lower, but it is possible to select the second blade that is a trailing method that reduces the friction coefficient with the photoconductor and press it against the photoconductor. Configured to. Therefore, since each of the residual toners of the photoconductor generated corresponding to each original is removed by selecting either the first blade or the second blade, all of the residual toners are surely and efficiently performed. Can be removed by reducing the effect on.

Compared to the trailing type second blade, the counter type first blade has a slightly larger coefficient of friction with the photosensitive member. However, the first blade always removes only a relatively large amount of residual toner, and the relatively large amount of residual toner acts as a lubricant to reduce the friction coefficient between the photoconductor and the first blade. Therefore, it is possible to reduce the influence of the first blade on the photoreceptor such as wear, and increase the coefficient of friction with the photoreceptor, so that, for example, as shown in FIG. 4 (a), (b), (c) Also, in the order shown in (d), it is possible to prevent the end portion of the blade from moving in the traveling direction of the photoconductor due to friction and being largely bent and deformed away from the photoconductor. It is also possible to extend the life of the.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment.

FIG. 2 is a configuration diagram of a second embodiment.

FIG. 3 is a configuration diagram of a third embodiment.

FIG. 4 is an explanatory diagram when the tip of the blade is bent.

[Explanation of symbols]

1: photoconductor, 2: blade support, 4a, 4b: mounting material, 5a:
First blade, 5b: Second blade, 6: Energizing spring, 7:
Energizing spring, 8: solenoid, 9: document, 11: light amount sensor, 12: control device, 13: cam, 14: solenoid.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Hamakawa 1-2-2 Tamatsukuri, Chuo-ku, Osaka-shi, Osaka Mita Kogyo Co., Ltd. (72) Inventor Hitoshi Nagahama 1-2-chome Tamatsukuri, Chuo-ku, Osaka No. 28 Inside Mita Industry Co., Ltd.

Claims (1)

[Claims] 1. A cleaning device for an image forming apparatus in which a front edge portion of a blade made of an elastic material is pressed against the surface of a photoconductor, and the front end is pressed against the photoconductor in a direction opposite to the traveling direction of the photoconductor. A first blade that can be moved, and a second blade that can press the tip of the first blade in the same direction as the moving direction of the photosensitive member to press the photosensitive member on the side surface of the photosensitive member rotatably. The first blade is attached to the photoconductor and the biasing means is provided to rotate the blade support in a direction to separate the second blade from the photoconductor. 1 means for driving the blade support for rotating the blade support in a direction of separating the blade from the photoconductor,
When the light amount sensor detects the light amount of the scanned original and the light amount is smaller than a preset value of the light amount, the biasing means rotates the blade support to press the first blade against the photoconductor. A cleaning device for an image forming apparatus, wherein when the amount of light detected by the light amount sensor is larger than the set value, the driving means rotates the blade support to bring the second blade into pressure contact with the photoconductor.