JP2010078779A - Cleaner for electrifying member, electrifier, cartridge, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaner for an electrifying member to stably remove unwanted substance sticking to an electrifying member and to provide an electrifier, a cartridge and an image forming apparatus. <P>SOLUTION: The cleaner for the electrifying member includes: a cleaning member which comes into contact with the surface of the electrifying member applying a charge to the surface of a body to be electrified, while being rotated in contact with the body to be electrified, to clean the surface of the electrifying member; a measuring part which measures the temperature of environment where the electrifying member and the cleaning member exist; and a pressing part which presses the cleaning member against the electrifying member more strongly as the temperature measured by the measuring part is higher. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a charging member cleaner, a charging device, a cartridge, and an image forming apparatus.

A proposal has been made to remove unnecessary materials that have moved from the photosensitive drum to the charging roller by bringing a cleaning roller made of a sponge material into contact with the charging roller (see, for example, Patent Document 1).
JP 2006-276404 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a charging member cleaner, a charging device, a cartridge, and an image forming apparatus that can stably remove unnecessary materials adhering to the charging member even when the environmental temperature changes.

The charging member cleaner according to claim 1 is:
A cleaning member that cleans the surface of the charging member by contacting the surface of the charging member while rotating in contact with the charging member;
A measuring unit that measures the temperature of the environment in which the charging member and the cleaning member exist;
And a pressing unit that presses the cleaning member against the charging member as the temperature measured by the measuring unit increases.

The charging member cleaner according to claim 2 is:
The cleaning member is rotated in contact with the surface of the charging member, at least the surface portion is made of a foam,
The pressing portion is configured to press the cleaning member against the charging member by moving the rotation center of the cleaning member.

The charging member cleaner according to claim 3 is:
The cleaning member includes a member main body that contacts the charging member, and a rotating shaft that protrudes from the member main body along the rotation center.
The pressing portion is configured to move the rotating shaft by a cam mechanism and press the cleaning member against the charging member.

The charging device according to claim 4 is:
A charging member that imparts a charge to the surface of the charged body while rotating in contact with the charged body;
A cleaning member for cleaning the surface of the charging member by contacting the surface of the charging member;
A measuring unit that measures the temperature of the environment in which the charging member and the cleaning member exist;
And a pressing unit that presses the cleaning member against the charging member as the temperature measured by the measuring unit increases.

The cartridge according to claim 5 is:
An image carrier for holding an image on the surface;
A charging member that imparts a charge to the surface of the image carrier while rotating in contact with the image carrier;
A cleaning member for cleaning the surface of the charging member by contacting the surface of the charging member;
A measuring unit that measures the temperature of the environment in which the charging member and the cleaning member exist;
And a pressing unit that presses the cleaning member against the charging member as the temperature measured by the measuring unit increases.

An image forming apparatus according to claim 6
An image carrier for holding an image on the surface;
A charging member that applies a charge to the surface of the object to be charged while rotating in contact with the image carrier, a cleaning member that cleans the surface of the charging member by contacting the surface of the charging member, and the charging member A charging device comprising: a measuring unit that measures the temperature of the member and the environment in which the cleaning member exists; and a pressing unit that presses the cleaning member against the charging member as the measurement temperature by the measuring unit increases. An image forming unit that forms an electrostatic latent image on the image carrier charged by the apparatus and develops the electrostatic latent image to form a developed image;
It is provided with.

  According to the charging member cleaner according to the first aspect, even if the environmental temperature changes, it is possible to stably remove unnecessary substances attached to the charging member.

  According to the charging member cleaner according to the second aspect, it is possible to easily adjust the removal force of unnecessary objects as compared with the case where this configuration is not provided.

  According to the charging member cleaner according to the third aspect, it is possible to adjust the removal force of unnecessary objects with a simple configuration.

  According to the charging device of the fourth aspect, stable charging can be realized even when the environmental temperature changes.

  According to the cartridge of the fifth aspect, stable charging can be realized even when the environmental temperature changes.

  According to the image forming apparatus of the sixth aspect, stable image formation can be realized even when the environmental temperature changes.

  Hereinafter, embodiments of the present invention will be described.

  FIG. 1 is a schematic configuration diagram of a printer.

  A printer 1 shown in FIG. 1 includes a photoconductor 10, a charger 11 that applies a charge to the surface of the photoconductor 10, an exposure device 12 that generates exposure light based on image data transmitted from the outside, and the like. A developing device 13 that stores a developer containing toner, a paper cassette 16 that stores recording paper, a paper transport device 17 that pulls out and transports recording paper from the paper cassette 16, and toner that is held on the surface of the photoreceptor 10. A transfer roll 14 for transferring the image onto the recording paper conveyed in the direction of arrow B; a fixing device 15 for fixing the toner image on the recording paper by heating and pressurizing the toner image on the recording paper; And a cleaner 18 for cleaning the surface of the photoconductor 10.

  Further, the charger 11 of the printer 1 shown in FIG. 1 includes a charging roll 111 that rotates in contact with the photoreceptor 10, and a foam roll 112 that contacts the charging roll 111 and cleans the surface of the charging roll 111. It has. The photoconductor 10 is an example of an image carrier referred to in the present invention that holds an image on the surface.

  Here, the flow of image formation in the printer 1 will be briefly described.

  In the printer 1 shown in FIG. 1, charge is applied to the surface of the photoconductor 10 rotating in the direction of arrow A by the charger 11, and image data transmitted from the outside to the surface of the photoconductor 10 to which the charge is applied. By exposing the exposure light based on the above to the exposure device 12, an electrostatic latent image is formed on this surface. The developer accommodated in the developing unit 13 is supplied to the surface of the developing roll 131 and is carried to a region between the developing roll 131 and the photoreceptor 10, and the toner in the carried developer causes the toner on the photoreceptor 10. The electrostatic latent image on the surface is developed. The toner image obtained by this development is transferred by the transfer roll 14 onto the recording paper conveyed in the arrow B direction. Thereafter, the toner image on the recording paper is melted and fixed on the recording paper by a fixing device 15 that heats and pressurizes the toner image. Thereafter, the residue remaining on the portion of the photoconductor 10 where the transfer of the toner image is completed is downstream of the transfer roll 14 in the direction of arrow A and upstream of the charger 11 and of the photoconductor 10. It is removed by the cleaner 18 whose tip contacts over the entire width along the center of rotation. The printer 1 is an embodiment of the image forming apparatus of the present invention, and the charger 11 is the first embodiment of the charging apparatus of the present invention. The printer 1 is a monochrome image dedicated machine, but the present invention may be applied to a color image machine.

  2 and 3 are diagrams showing a case where the charger is viewed from the side surface side and the exposure device side.

  The charger 11 shown in FIGS. 2 and 3 includes, in addition to the above-described charging roll 111 and foam roll 112, a pressing portion 113 for pressing the foam roll 112 against the charging roll 111, and these foam rolls. 112 and an environmental sensor 114 (see FIG. 3) for detecting the temperature and humidity around the charging roll 111. A combination of the foam roll 112, the pressing portion 113, and the environmental sensor 114 is the first embodiment of the charging member cleaner of the present invention. Further, in the printer 1, the photoconductor 10 and the charger 11 are formed into a cartridge, and the cartridge 20 (see FIG. 1) is loaded so that it can be pulled out from the inside of the printer 1. When an image defect due to the photoconductor 10 or the charger 11 occurs, the photoconductor 10 and the charger 11 are replaced with the cartridge 20 by the user's hand. This cartridge 20 is an embodiment of the cartridge of the present invention. Further, the charging roll 111 is an example of a charging member according to the present invention that imparts a charge to the surface of the charged body while rotating in contact with the charged body. The foam roll 112 is a surface of the charging member. This is an example of the cleaning member according to the present invention, which cleans the surface of the charging member by contacting the surface. Furthermore, the environment sensor 114 is an example of a measurement unit according to the present invention that measures the temperature of the environment where the charging member and the cleaning member exist, and the pressing unit 113 uses the cleaning member as the charging member and the temperature measured by the measurement unit. It is an example of the pressing part said to this invention which presses strongly, so that is high. The photoconductor 10 is also an example of a member to be charged according to the present invention.

  The foam roll 112 is a roll member that is rotated by a charging roll 111 that rotates in the direction of arrow A, and whose surface layer is made of foamed polystyrene. Both ends of a shaft 1121 that is the center of rotation are guide chassis 1133 described later. The long hole 1133a and the long hole 1131a of the guide cam 1131 are penetrated.

  The pressing portion 113 includes a guide chassis 1133 having a long hole 1133a, a guide cam 1131 having a long hole 1131a, a rack 1132 fixed to the guide cam 1131, a pinion gear 1134 that meshes with the rack 1132, and the pinion gear 1134. And an attached stepping motor 1135 (see FIG. 3), and a motor controller 1130 (see FIG. 3) that issues a rotation instruction to the stepping motor 1135. In FIG. 2, the stepping motor 1135 and the motor controller 1130 are not shown in order to prevent the illustration from being complicated.

  As will be described in detail later, the motor controller 1130 simultaneously transmits a rotation instruction according to the detection result of the environment sensor 114 to the two stepping motors 1135. When the stepping motor 1135 rotates, the pinion gear 1134 engaged with the rack 1132 rotates, and accordingly, the guide cam 1131 moves in the left-right direction in FIG. In practice, a guide means for stably moving the guide cam 1131 in the left-right direction in FIG. 2 is provided, but illustration thereof is omitted.

  FIG. 4 is a diagram showing the mutual relationship between the guide chassis, the guide cam, and the axis of the foam roll.

  The shaft 1121 of the foam roll 112 passes through both the long hole 1133a of the guide chassis 1133 and the long hole 1131a of the guide cam 1131 as shown in FIG. Further, the long hole 1133a of the guide chassis 1133 is provided along the vertical direction in FIG. 4, whereas the long hole 1131a of the guide cam 1131 is provided along the oblique direction in FIG. For this reason, when the guide cam 1131 moves to the left from the reference position shown in FIG. 4, the shaft 1121 of the foam roll 112 is caused to cooperate by the long hole 1133a of the guide chassis 1133 and the long hole 1131a of the guide cam 1131. To rise. On the other hand, when the guide cam 1131 moves to the right from the reference position shown in FIG. 4, the shaft 1121 of the foam roll 112 descends due to the cooperation of the long hole 1133a of the guide chassis 1133 and the long hole 1131a of the guide cam 1131. To do. Accordingly, the shaft 1121 of the foam roll 112 approaches or separates from the shaft 1111 of the charging roll 111 according to the stop position of the guide cam 1131, thereby causing contact between the foam roll 112 and the charging roll 111. The pressure changes.

  In the printer 1, the photosensitive member 10 is rotated for confirmation of the operation of each operation unit before image formation is started, and charging is performed by rotating the photosensitive member 10 while the idle rotation is performed. The contact pressure between roll 111 and foam roll 112 is adjusted as described below.

  In this adjustment, first, the guide cam 1131 is moved to the reference position shown in FIG. 4, and the distance between the shaft 1111 of the charging roll 111 and the shaft 1121 of the foam roll 112 is set to the actual size of the radius of the charging roll 111. The charging roll 111 is bitten into the foam roll 112 by 0.5 mm less than the value obtained by adding the actual size of the radius of the roll 112 (hereinafter, this biting amount of 0.5 mm is referred to as a reference biting amount). .) And the current temperature and humidity are detected by the environmental sensor 114. Here, with respect to the charger 11, in order to stabilize the removability of the deposits attached to the charging roll 111 by the foam roll 112 at a constant level regardless of changes in temperature and humidity, the temperature and humidity Accordingly, an adjustment amount for the reference biting amount of 0.5 mm is determined in advance, and rotation angle information for realizing the adjustment corresponding to the adjustment amount is written in a memory (not shown) of the charger 11. Yes. Therefore, in the charger 11, rotation angle information set in advance corresponding to the current temperature and humidity detected by the environment sensor 114 is read and transmitted to the motor controller 1130. The stepping motor 1135 rotates in accordance with an instruction from the motor controller 1130, and the guide cam 1131 moves from the reference position in accordance with the rotation, so that the bite for the reference bite amount of 0.5 mm corresponding to the temperature and humidity is achieved. The amount can be adjusted.

  FIG. 5 is a diagram illustrating adjustment amounts that are determined in advance according to temperature and humidity.

  In FIG. 5, temperature (0 ° C. to 30 ° C.) and humidity (0% to 100%) are divided into three categories, respectively, and a total of nine environmental areas (low temperature) combining each temperature category and humidity category. Low-humidity, low-temperature medium-humidity, low-temperature high-humidity, medium-temperature low-humidity, medium-temperature medium-humidity, medium-temperature high-humidity, high-temperature low-humidity, high-temperature medium-humidity, high-temperature-high-humidity).

  The adjustment amount determined for each of these nine environmental areas (low temperature, low humidity to high temperature, high humidity) increases as the temperature increases, that is, the amount of biting of the charging roll 111 relative to the foam roll 112 increases as the temperature increases. . For example, for low-temperature and low-humidity areas, high-temperature and low-humidity areas with common humidity, the adjustment amount is 0 mm for low-temperature and low-humidity areas, while +0.1 mm for medium-temperature and low-humidity areas. +0.2 mm.

  Here, the adjustment amount shown in FIG. 5 is set as described below.

  First, the surface resistance value (log Ω) of the unused charging roll 111 of the printer 1 is measured. Next, the cleaner 18 for cleaning the surface of the photoconductor 10 is removed, and in the printer 1 in which the foam roll 112 is not in contact with the charging roll 111, the environment is low temperature and low humidity (temperature 10 ° C., humidity 15%). Below, 3000 images with an image density of 10% are printed. Thereafter, while the cleaning device 18 for cleaning the surface of the photoconductor 10 is removed, the biting amount of the charging roll 111 with respect to the foam roll 112 is set to 0.3 mm, and the photoconductor 10 is empty until the charging roll 111 rotates 1600 times. After turning, the surface resistance value (log Ω) of the charging roll 111 is measured, and the difference from the surface resistance value of the unused charging roll 111 is obtained. Note that the surface resistance value increases as the amount of deposits attached to the charging roll 111 increases. Therefore, the smaller the difference is, the more the adhered matter that has adhered to the charging roll 111 is removed by the foam roll 112. In addition, here, first, the case where the amount of biting of the charging roll 111 with respect to the foam roll 112 is set to 0.3 mm will be described, but when the amount of biting is set to 0.5 mm, it is set to 0.7 mm A similar experiment will be conducted separately.

  FIG. 6 is a diagram illustrating evaluation results of differences in surface resistance values.

  The smaller the difference, the better the evaluation of the difference in the surface resistance value. When the difference is less than 0.4 (log Ω), “◎”, when it is 0.4 or more and less than 0.5, “◯”, 0. In the case of 5 or more and less than 0.6, “△” is set.

  In the upper left column of FIG. 6, the surface obtained when the biting amount of the charging roll 111 with respect to the foam roll 112 is set to 0.3 mm in a low temperature and low humidity (temperature 10 ° C., humidity 15%) environment. It is shown that the evaluation result of the difference in resistance value is “Δ”.

  Further, in the upper part of FIG. 6, the amount of biting of the charging roll 111 with respect to the foam roll 112 is set to 0.5 mm or 0.7 mm in addition to 0.3 mm, with respect to the difference in surface resistance value obtained respectively. The evaluation results are also shown. As the amount of bite increases, the speed difference between the contact portion and the non-contact portion of the foam roll 112 with the charging roll 111 increases, and the degree of undulation on the surface of the foam roll 112 also increases. If the degree of the undulation is large, the force for removing the adhering matter adhering to the surface of the charging roll 111 is also increased. Therefore, the upper part of FIG. 6 shows that, in a low-temperature and low-humidity environment (temperature of 10 ° C. and humidity of 15%), the greater the amount of bite, the higher the removability of deposits attached to the charging roll 111. Yes. In addition, not only in a low-temperature and low-humidity environment, but in any environment, the deposit removal property increases as the amount of biting increases. In addition, in the charging machine 11, the foam roll 112 is damaged because the reference biting amount of the charging roll 111 with respect to the foam roll 112 is 0.5 mm instead of 0.7 mm, which has high removability of deposits. This is because it becomes easier and must be replaced frequently.

  Moreover, the lower part of FIG. 6 shows the case where the above-described difference evaluation is performed in an environment of high temperature and high humidity (28 ° C., 85%). In high-temperature and high-humidity environments, it is more difficult to remove deposits from the charging roll 111 than in low-temperature and low-humidity environments. In high-temperature and high-humidity environments, the amount of biting in the low-temperature and low-humidity environment is 0.2 mm higher. It can be seen that the same deposit removal performance can be obtained. When the temperature is high, even when the toner adheres to the charging roll 111, the external additive applied to the surface is buried in the toner surface, and the same number of images are printed with the same image density. The amount of toner adhering to the charging roll 111 is larger than when the temperature is low, and the amount of the entire adhering material is also larger than when the temperature is low. Similarly, in the printer 1 having the cleaning device 18 that actually cleans the surface of the photoconductor 10, the gap between the cleaning device 18 and the photoconductor 10 is larger when the temperature is higher than when the temperature is low. The amount of toner passing through increases due to the burying of the external additive, and the amount of deposits adhering to the charging roll also increases accordingly. For this reason, when the temperature is high, it is necessary to increase the amount of biting in order to obtain the same deposit removal performance as that at the low temperature. Therefore, in this printer 1, as shown in FIG. 5, the adjustment amount in the area where the temperature is low is 0.0 mm, that is, the bite amount remains at the standard bite amount of 0.5 mm, whereas However, the adjustment amount in the high temperature area is +0.2 mm, and the biting amount is 0.7 mm. Further, the amount of adjustment in the medium temperature area is set to 0.1 mm to 0.15 mm which is an intermediate value between 0.0 mm and 0.2 mm, and the amount of biting is 0.6 mm to 0.65 mm.

  As described above, in the charger 11 according to the present embodiment, even if the environmental temperature changes, unnecessary substances attached to the charging roll 111 are stably removed.

  Next, a second embodiment of the charging device of the present invention will be described.

  The charger 21 of the second embodiment is provided in the printer 1 instead of the charger 11 of the first embodiment, and members other than the charger 21 of the second embodiment are described in the first embodiment. Since this is the same as the case where the charger 11 is provided, illustration and description thereof are omitted.

  7 and 8 are views showing a case where the charger of the second embodiment is viewed from the side surface side and the exposure device side. 7 and 8, the same members as those shown in FIGS. 2 and 3 are denoted by the same reference numerals as those shown in FIGS. 2 and 3.

  The difference between the charger 2 of the second embodiment and the charger 11 of the first embodiment is that, in the first embodiment, the foam roll 112 and the charging roll are cooperated by the guide chassis 1133 and the guide cam 1131. In the second embodiment, the contact pressure between the guide chassis 1133, the spring 2134 that biases the shaft 1121 of the foam roll 112 upward, and the cam 2133 is cooperated. It is different in that it is controlled by. Hereinafter, this difference will be described.

  The charger 21 of the second embodiment includes a charging roll 111, a foam roll 112, a pressing unit 213, and an environmental sensor 114. The pressing unit 213 includes a guide chassis 1133, a compression spring 2134 (see FIG. 8), A stepping motor 1135 and a cam 2133 are provided. The compression spring 2134 biases the shaft 1121 of the foam roll 112 upward, and the cam 2133 is attached to the shaft 11351 of the stepping motor 1135.

  7 and 8 show a state in which the peripheral surface of the cam 2133 is in contact with the shaft 1121 of the foam roll 112 that has passed through the long hole 1133a of the guide chassis 1133. FIG.

  The distance from the shaft 11351 of the stepping motor 1135 to the periphery of the cam 2133 differs depending on the location. For this reason, also in the charger 21 of the second embodiment, rotation angle information corresponding to an adjustment amount determined in advance according to the temperature and humidity detected by the environmental sensor 114 is sent to the motor controller 1130, and this rotation is performed. When the stepping motor 1135 rotates by an angle, the posture of the cam 2133 changes, and the amount of biting of the charging roll 111 with respect to the foam roll 112 is changed. A combination of the foam roll 112, the pressing portion 213, and the environment sensor 114 is a second embodiment of the charging member cleaner of the present invention. Note that the posture of the cam 2133 shown in FIG. 7 is a reference posture in which the charging roll 111 is bitten into the foam roll 112 by 0.5 mm, and when the biting amount is increased from the reference biting amount of 0.5 mm, 2133 is rotated counterclockwise from the posture shown in FIG.

  In the above embodiment, a printer is shown as an example of the image forming apparatus of the present invention. However, the image forming apparatus of the present invention may be a copying machine. Moreover, although a foam roll is shown as an example of the cleaning member as an example of the pressing portion according to the present invention, the cleaning member according to the present invention may have a sponge on the surface portion. .

1 is a schematic configuration diagram of a printer. It is a figure which shows the case where a charger is seen from the side surface side. It is a figure which shows the case where a charging device is seen from the exposure device side. It is a figure which shows the mutual relationship of a guide chassis, a guide cam, and the axis | shaft of a foam roll. It is a figure which shows the reference table in which the adjustment amount preset according to temperature and humidity was described. It is a figure which shows the evaluation result of the difference of a surface resistance value. It is a figure which shows the case where the charger of 2nd Embodiment is seen from the side surface side. It is a figure which shows the case where the charger of 2nd Embodiment is seen from the exposure device side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printer 10 Photoconductor 11, 21 Charger 111 Charging roll 112 Foam roll 113, 213 Pressing part 1130 Motor controller 1131 Guide cam 1132 Rack 1133 Guide chassis 1134 Pinion gear 1135 Stepping motor 114 Environmental sensor 12 Exposure unit 13 Developer 14 Transfer roll 15 Fixing device 16 Paper cassette 17 Paper transport device 20 Cartridge 2133 Cam 2134 Spring

Claims (6)

A cleaning member that cleans the surface of the charging member by contacting the surface of the charging member that contacts the surface of the charging member while rotating while contacting the surface of the charging member;
A measurement unit that measures the temperature of the environment in which the charging member and the cleaning member exist;
A charging member cleaner, comprising: a pressing unit that presses the cleaning member against the charging member as the temperature measured by the measuring unit increases. The cleaning member is rotated in contact with the surface of the charging member, at least the surface portion is made of a foam,
The charging member cleaner according to claim 1, wherein the pressing portion presses the cleaning member against the charging member by moving a rotation center of the cleaning member. The cleaning member includes a member main body that contacts the charging member, and a rotation shaft that protrudes from the member main body along the rotation center,
The charging member cleaner according to claim 2, wherein the pressing portion is configured to press the cleaning member against the charging member by moving the rotating shaft with a cam mechanism. A charging member that imparts a charge to the surface of the charged body while rotating in contact with the charged body;
A cleaning member for cleaning the surface of the charging member by contacting the surface of the charging member;
A measurement unit that measures the temperature of the environment in which the charging member and the cleaning member exist;
A charging device comprising: a pressing unit that presses the cleaning member against the charging member more strongly as the temperature measured by the measuring unit is higher. An image carrier for holding an image on the surface;
A charging member that applies a charge to the surface of the image carrier while rotating in contact with the image carrier;
A cleaning member for cleaning the surface of the charging member by contacting the surface of the charging member;
A measurement unit that measures the temperature of the environment in which the charging member and the cleaning member exist;
A cartridge comprising: a pressing unit that presses the cleaning member against the charging member as the temperature measured by the measuring unit increases. An image carrier for holding an image on the surface;
A charging member that applies a charge to the surface of the image carrier while rotating in contact with the image carrier; a cleaning member that cleans the surface of the charging member by contacting the surface of the charging member; A charging device comprising: a measuring unit that measures the temperature of the member and the environment in which the cleaning member exists; and a pressing unit that presses the cleaning member against the charging member as the measurement temperature by the measuring unit increases. An image forming unit that forms an electrostatic latent image on the image carrier charged by the apparatus and develops the electrostatic latent image to form a developed image;
An image forming apparatus comprising:

Images