JP4669291B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus configured to remove a developer image on an image carrier formed by using, for example, an electrophotographic method, with a cleaning member.

  A conventional electrophotographic image forming apparatus P2 using, for example, a non-magnetic one-component non-contact developing method will be described with reference to FIG.

  An electrophotographic photosensitive member (hereinafter referred to as “photosensitive drum”) 50 which is a normal drum as an image carrier is uniformly charged by a primary charger 51. Next, light exposure is performed on the photosensitive drum 50 from the exposure device 52 in accordance with image information input from an external device, thereby forming an electrostatic latent image.

  The electrostatic latent image on the photosensitive drum 50 is developed by a developing device 60 with a developer T (hereinafter referred to as “toner”) having a frictional charging polarity having the same polarity as the voltage applied to the primary charger 51. An image (toner image). This toner image is transferred to the transfer material Q by the transfer charger 53. The transfer material Q is separated from the photoconductor 50 and is subsequently conveyed to the fixing device 55 to form a permanent image after fixing.

  Further, the developer T on the photosensitive drum 50 remaining without being transferred by the transfer charger 53 is removed by the cleaning device 54, and the photosensitive drum 50 is subjected to the next image forming process.

  The developing device 60 will be further described. In the developing device 60, toner is stored in a toner storage portion, that is, a developing container 60A. Usually, the toner T is negatively charged, and a negatively charged nonmagnetic one-component toner containing a pigment of any color such as yellow, magenta, cyan, and black is used.

  In the developing device 60, as a stirring member, a toner first stirring member 64 and a toner second stirring member 65 made of plates or screws processed into various shapes are rotated in the direction of the arrow in the drawing. The toner T in the developing container 60A is conveyed to a developing roller 61 as a developer carrying member.

  In this example, two stirring members, that is, a toner first stirring member 64 and a toner second stirring member 65 are arranged. However, the number of agitating members is not necessarily two, and the number of agitating members is arbitrary as long as the toner can be conveyed from the end of the developing container 60A to the vicinity of the developing roller 61 in accordance with various developing device configurations. .

  In the developing device 60 of this example, a developing container partition plate 66 is provided. The height of the partition plate 66 is optimized so that a constant amount of toner is always supplied onto the developer supply and stripping member (hereinafter referred to as “RS roller”) 62 in the vicinity of the developing roller 61.

  In the non-magnetic one-component development method, it is impossible to supply toner by magnetic force. Therefore, an RS roller 62 made of urethane sponge is in contact with the developing roller 61. The RS roller 62 peels off the toner on the developing roller 61 by rotating in the counter direction at the nip portion with the developing roller 61.

  The developing roller 61 is in contact with a regulating blade 63 as a toner amount regulating member, regulates the toner on the developing roller 61 to form a thin toner layer, and is conveyed to the developing area (drum facing position). The amount is prescribed. The amount of toner conveyed to the development area is determined by the contact pressure and contact length of the regulating blade 63 that contacts the developing roller 61.

  The regulating blade 63 is a chip blade adhered or welded on a thin metal plate such as phosphor bronze or stainless steel having a thickness of several hundred μm, and is in contact with the developing roller 61 uniformly by the elasticity of the thin metal plate. At this time, the contact condition of the regulating blade 63 is determined by the material, thickness, penetration amount, and set angle of the metal thin plate.

  The developing roller 61 is opposed to the surface of the photosensitive drum at a predetermined interval (hereinafter referred to as “SD gap”) in the developing region, and an AC electric field is formed by applying a bias.

  In the above configuration, the toner adheres to the surface of the developing roller with a desired charge amount and a desired layer thickness and is conveyed to the developing area. The toner visualizes the electrostatic latent image formed on the surface of the photosensitive drum as the toner T attached to the surface of the developing roller reciprocates between the developing roller 61 and the photosensitive drum 63 by an alternating electric field.

  By the way, generally, an elastic body such as urethane rubber is used for the cleaning blade 56 as a cleaning member of the cleaning device 54. Further, many blades 56 press the edge 56 a of the blade 56 in a direction opposite to the rotation direction of the photosensitive drum 50, and a large friction is generated between the blade edge 56 a and the photosensitive drum 50. In particular, in a new image forming apparatus that the user starts using, there is nothing between the cleaning blade 56 and the photosensitive drum 50 that acts as a lubricant such as a transfer residual developer. Therefore, a large frictional force is generated between the blade edge 56a and the photosensitive drum 50, and problems such as blade turning and chatter are likely to occur. Therefore, many blade edges 56a are initially coated with a powdery lubricant to prevent blade turning (see Patent Document 1).

Such problems such as blade turning are particularly likely to occur in a high-temperature environment where the urethane rubber, which is a blade material, has a low viscoelasticity tan δ value and high followability to the photosensitive drum 50.
JP-A-62-262885

  However, when the image forming apparatus is in a low temperature environment, particularly 5 ° C. or less, cleaning failure may occur due to the influence of the lubricant applied to the blade edge 56a.

  This is because, as a characteristic of the rubber used for the blade, the viscoelastic modulus tan δ is high at low temperatures, the followability to the photosensitive drum is low, and the scraping property of the transfer residual developer is lowered, so that the cleaning property is deteriorated. .

  Furthermore, in a new image forming apparatus that the user starts to use, since the lubricant is applied to the cleaning blade, there is a lot of lubricant between the blade and the photosensitive drum, and further the follow-up to the photosensitive drum. Therefore, the scraping property of the transfer residual developer is deteriorated and cleaning failure is likely to occur.

  When cleaning failure occurs, not only image defects such as black streaks occur on the image, but also waste developer may leak into the image forming apparatus, which leads to failure of the image forming apparatus. There is a fear.

  Accordingly, an object of the present invention is to prevent a cleaning failure caused by the lubricant applied to the cleaning member in a low-temperature environment, and to prevent the cleaning member from being turned up or squealed. It is an object of the present invention to provide an image forming apparatus capable of forming the image.

The above object is achieved by the image forming apparatus according to the present invention. That is, the present invention relates to an image carrier on which an electrostatic latent image is formed, a developing device for developing the electrostatic latent image with a developer to obtain a developer image, and the developer from the image carrier. An image forming apparatus capable of detachably mounting a process cartridge having a cleaning member for removing the toner, and having a cleaning member coated with a lubricant on a portion in contact with the image carrier in a new state.
The cleaning member is a cleaning blade disposed in a counter direction with respect to a moving direction of the image carrier;
Temperature detecting means for detecting the temperature in the image forming apparatus;
New article detecting means for detecting that the image carrier and the cleaning member are in a new state;
Drive control means for controlling the drive of the image carrier, wherein the temperature detection means detects a predetermined temperature or lower, and the image detection body and the cleaning member are in a new state by the new article detection means. Drive control means for extending the time for driving the image carrier before starting image formation when it is detected, compared to cases other than the above,
An image forming apparatus comprising:

According to one embodiment of the present invention, when the drive time of the image carrier is extended by the drive control means , the image carrier is operated at least once in the direction opposite to the time of image formation , Alternatively, when the drive time of the image carrier is extended by the drive control means , the drive operation of the image carrier can be stopped and started at least once.

According to another aspect of the present invention, in an image forming apparatus for forming an image on a transfer material,
Device A capable mounted process cartridge removably to the main body of the image forming apparatus,
An image carrier on which an electrostatic latent image is formed, a developing device for developing the electrostatic latent image with a developer to form a developer image, and for removing the developer from the image carrier, A cleaning blade disposed in a counter direction with respect to the moving direction of the image carrier, wherein a cleaning member is applied to a portion in contact with the image carrier in a new state and a contact with the image carrier. An elastic sheet-like scraping member that can be contacted and separated; a scraping member that removes the lubricant from the image carrier when contacting the image carrier; and
A process cartridge having
Temperature detecting means for detecting the temperature in the image forming apparatus;
New article detecting means for detecting that the image carrier and the cleaning member are in a new state;
When the temperature detecting means detects that the temperature is higher than a predetermined temperature and the new article detecting means detects that the image carrier and the cleaning member are new, the scraping member is separated from the image carrier. Let the initial rotation for a predetermined period,
Detects less than a predetermined temperature by the temperature detecting means, and, when the image bearing member and the cleaning member by the new-product detection means detects that a new state, the extended initial rotation and extended and control means for controlling the Ru is brought into contact with the scraping member to the image bearing member in a period,
An image forming apparatus is provided.
According to an embodiment of the present invention, the scraping member is in contact with the moving direction of the image carrier in the counter direction.

  According to the present invention, it is possible to effectively prevent a cleaning failure that is likely to occur when the image bearing member and the cleaning member are new at a specific temperature or lower. Accordingly, no cleaning failure caused by the lubricant applied to the cleaning member in a low-temperature environment occurs, and the cleaning member does not turn over or squeal, and a high-quality image can always be formed. .

  The image forming apparatus according to the present invention will be described below in more detail with reference to the drawings.

Example 1
FIG. 1 shows an embodiment of an image forming apparatus of the present invention. In this embodiment, the image forming apparatus has a drum-shaped electrophotographic photosensitive member, that is, a photosensitive drum 1 as an image carrier. The photosensitive drum 1 is rotatably supported and is driven to rotate in the arrow R1 direction.

  The rotationally driven photosensitive drum 1 is uniformly charged by a primary charger 2. Next, in response to the image information input from the external device, the exposure device 3 irradiates the photosensitive drum 1 with light to form an electrostatic latent image.

  The electrostatic latent image on the photosensitive drum 1 is developed with the toner T having the same triboelectric charging polarity as the voltage applied to the primary charger 2 in the developing device 10 to be a developer image, that is, a toner image. .

  The toner image is transferred to a transfer material Q supplied from a paper feed cassette S by a transfer charger 4 as transfer means. The transfer material Q is separated from the photosensitive drum 1 and subsequently conveyed to the fixing device 6 to become a permanent image after fixing.

  Further, the developer T on the photosensitive drum 1 remaining without being transferred by the transfer charger 4 is removed by the cleaning device 5 in contact with the photosensitive drum 1, and the photosensitive drum 1 is subjected to the next image forming process. Is done.

  In this embodiment, a plurality of image processing means, that is, the photosensitive drum 1, the primary charger 2, the developing device 10, and the cleaning device 5 are integrated into a process cartridge 20. The process cartridge 20 is detachably mounted on the image forming apparatus main body P.

  Next, the cleaning device 5 will be described.

  The cleaning device 5 includes a cleaning blade 7 (hereinafter referred to as “blade 7”) as a cleaning member. As shown in FIG. 1, the blade 7 is in contact with the rotation direction R <b> 1 of the photosensitive drum 1 in the counter direction.

  Further, the blade 7 is coated with a powder lubricant on a portion 7 a that contacts the photosensitive drum 1 when it is new (or in a new state). In this example, spherical silicon particles having a particle size of about 1 μm were used as the lubricant. In this specification, “new” or “new state” means that the image forming apparatus is shipped from the factory, and the user first attaches the process cartridge 20 to the image forming apparatus main body P and starts using it. It means “unused state”.

  Next, the developing device 10 will be described.

  In this embodiment, the developing device 10 is a developing device of a non-magnetic one-component non-contact developing method.

  The developing device 10 includes a developing container 10A that contains toner T that is an insulating nonmagnetic one-component developer. In the developing container 10A, a developing roller 11 as a developer carrying member that rotates in the direction of arrow R2 facing the photosensitive drum 1, and an RS roller as a developer supply and peeling member that rotates in the direction of arrow R3. 12, a regulating blade 13 as a toner amount regulating member, and a plate-like toner stirring member 14 that rotates in the direction of arrow R4 are provided.

  In this embodiment, the photosensitive drum 1 is a member formed by applying a photosensitive material such as OPC to the peripheral surface of an aluminum base tube having a diameter of 30 mm. Further, as the developing roller 11, a member obtained by spray-coating a phenol resin solution in which carbon and graphite are dispersed on the peripheral surface of an aluminum base tube having a diameter of 16 mm was used.

  SD rollers (not shown) that set the gap between the photosensitive drum 1 and the developing roller 11 to a predetermined distance are installed at both ends of the developing roller 11, and the SD gap is maintained by abutting against the surface of the photosensitive drum. The SD gap was 300 μm.

  As the RS roller 12, a member having a metal core having a diameter of 5 mm and a urethane foam having a thickness of 4.5 mm formed on the outer periphery thereof was used. As the regulating blade 13, a phosphor bronze plate having a thickness of 0.1 mm was used.

  The operation of the developing device 10 having the above configuration will be described.

  In this embodiment, the toner T is a negatively chargeable non-magnetic one-component toner that is negatively charged and contains a pigment of any one of yellow, magenta, cyan, and black.

  As described above, the toner stirring member 14 rotates in the direction of the arrow R4 in the drawing, and conveys the toner T in the toner storage portion, that is, the developing container 10A, to the developing roller 11. A developing container partition plate 15 is disposed in the developing container 10A. The height of the partition plate 15 is optimized so that a constant amount of toner is always supplied onto the RS roller 12 near the developing roller 11.

  The RS roller 12 is in contact with the developing roller 11 and rotates in the counter direction at the nip portion. The RS roller 12 supplies the toner T onto the developing roller 11 and, at the same time, strips off the toner on the developing roller 11 that has not been developed even when passing through the position facing the photosensitive drum 1.

  As described above, the developing blade 11 is in contact with the regulating blade 13 as a toner amount regulating member, and regulates the toner on the developing roller 11 to form a thin toner layer. The regulating blade 13 regulates the amount of toner conveyed to the development area and at the same time charges the toner.

  In the above configuration, the toner adheres to the peripheral surface of the developing roller with a desired charge amount and a desired layer thickness, and is conveyed to the developing region. The toner adheres to the peripheral surface of the developing roller by a developing bias in which an AC bias and a DC bias applied from the developing bias power source 18 are superimposed, and reciprocates between the developing roller 11 and the photosensitive drum 1. As a result, the electrostatic latent image formed on the surface of the photosensitive drum is visualized.

  In this embodiment, the image forming apparatus includes a drive control unit 40 that controls the driving of the photosensitive drum 1. When the temperature detecting means 19 detects a temperature below a predetermined temperature in the image forming apparatus and the new article detecting means 30 detects a new condition of the process cartridge (hereinafter referred to as “cartridge”) 20, The drive control means 40 extends the drive time of the photosensitive drum 1.

  New detection of the photosensitive drum 1 and the blade 7 is performed by the new product detection means 30 by determining whether or not it is a new product using an identification member such as a fuse (not shown) provided in the cartridge 20.

  That is, when the new article detection means 30 detects that the fuse is not blown, it is determined that the cartridge 20 is new. Then, the fuse is blown so as not to identify that the cartridge 20 is new. The new article detection operation of the cartridge 20 is performed when the main body is turned on or when the main body door is opened and closed.

  The identification member may be a memory (not shown) that can store information provided in the cartridge 20. That is, when the cartridge 20 is new, the memory stores new information. Then, when the cartridge 20 is mounted on the apparatus main body, the memory information is read by a main body electrical contact (not shown) provided on the main body. When the information in the memory is new, the cartridge 20 is determined to be new. Thereafter, the information in the memory is rewritten to information that is not new. The operation of reading the information in the memory is performed when the main body is turned on or when the main body door is opened or closed.

  FIG. 2 is a flowchart showing the flow of control at the initial rotation of this embodiment.

  After the power is turned on or the door is opened / closed (S11), the new article detecting means 30 detects whether the cartridge 20 is new (S12). If the process cartridge is not new (No in S12), normal initial rotation is performed (S14), and a standby state is entered (S16).

  On the other hand, if the cartridge 20 is new (Yes in S12), it is determined by the temperature detection means 19 whether the image forming apparatus is less than 10 ° C. (S13).

  When the temperature detection means 19 detects that the image forming apparatus is less than 10 ° C. (Yes in S13), the photosensitive drum driving time is extended during the initial rotation (S15), and the standby state is set (S16). When the temperature detection unit 19 detects that the image forming apparatus detects 10 ° C. or higher (No in S13), normal initial rotation is performed (S14), and a standby state is set (S16).

  Here, the “initial rotation” is a sequence for preparing and adjusting various operations for shifting to the printable standby state (S16), and is performed after the power is turned on and the door is opened and closed.

  A photosensitive drum driving time extension sequence during initial rotation will be described with reference to FIG.

  With normal initial rotation, the photosensitive drum 1 is driven for several tens of seconds for the initial operation check and the photosensitive drum cleaning. However, when a new process cartridge and a predetermined temperature are detected, the photosensitive drum driving time is extended in the initial rotation as described above.

  Here, the extension time of the photosensitive drum drive in the initial rotation and the predetermined temperature will be described.

  Table 1 shows the results of studying the cleaning performance with respect to the extended time at 5 ° C. In the cleaning results, “◯” indicates no cleaning failure, “△” indicates minor cleaning failure with no more than 2 vertical black streaks on the image, and “×” indicates that cleaning failure occurs on the image. The image contains three or more vertical black stripes.

  As shown in Table 1, a cleaning failure occurred when the extension time was 90 seconds or less.

  Moreover, when the same examination was performed at 0 ° C., the same result as at 5 ° C. was obtained. Furthermore, the same examination was performed at 10 ° C. and 15 ° C., respectively. At 10 ° C., cleaning failure occurred with an extension time of 30 seconds or less (Table 2), and at 15 ° C., no cleaning failure occurred in all cases (Table 3).

  The results of these studies indicate that the lower the temperature, the worse the cleaning performance is because the rubber used for the blade has a higher viscoelastic modulus tanδ at lower temperatures, lower followability to the photosensitive drum, and scraping off the residual transfer toner. This is because the property decreases.

  From the above results, in this embodiment, the predetermined temperature is 10 ° C. and the photosensitive drum drive extension time is 120 seconds.

  As described above, when the predetermined temperature in the image forming apparatus is detected by the temperature detecting means 19 and the new state of the cartridge 20 is detected by the new article detecting means 30, the drive control means 40 performs photosensitivity. Extend drum drive time. As a result, the lubricant interposed between the photosensitive drum 1 and the blade 7 is gradually scraped off and reduced by the blade 7. Further, when the photosensitive drum is driven, the blade edge 7a comes into direct contact with the photosensitive drum 1, so that the transfer residual developer can be scraped off.

  As a result, the cleaning property is improved, and it is possible to prevent the cleaning failure that is likely to occur when the photosensitive drum 1 and the blade 7 are in a new state or less at a specific temperature.

  Further, since the driving time is not extended above a specific temperature, it is possible to prevent the occurrence of blade turning or squealing that tends to occur in a high temperature environment. In addition, since the waiting time until the start of printing does not increase, the time required until the user finishes printing does not increase.

  The present invention is not limited to the image forming apparatus having the above-described configuration. Four developing devices 10 described in this embodiment are arranged around one photosensitive drum, and each developing device 10 has a yellow color. A color image forming apparatus configured to include toners of color, magenta, cyan, and black may be used. Also in the present embodiment, a color image forming apparatus configured by arranging four cartridges 20 having the above-described configuration and including each toner of yellow color, magenta color, cyan color, and black color in each developing device 10. Similar effects can be achieved by performing the control as described above.

  In the above embodiment, the image forming apparatus is described as having a configuration in which the developer image on the photosensitive drum 1 is directly transferred to the transfer material Q. However, the developer on the photosensitive drum 1 is temporarily transferred to the intermediate transfer member. An intermediate transfer type image forming apparatus having a configuration in which the image is transferred onto the transfer material and then transferred onto a transfer material can be obtained.

Example 2
Next, a second embodiment of the image forming apparatus according to the present invention will be described.

  Since the configuration of the image forming apparatus shown in the present embodiment is the same as that shown in FIG. 1, the description of the configuration of the image forming apparatus is referred to the description of the first embodiment, and the description thereof is omitted here.

  In the first embodiment, when the temperature detection unit 19 detects a temperature below a predetermined temperature in the image forming apparatus and the new product detection unit 30 detects the new state of the cartridge 20, the drive control unit 40 detects the photosensitive drum 1. The drive is extended. However, in the second exemplary embodiment, the photosensitive drum driving operation direction is operated in the direction opposite to the forward direction at least once (hereinafter referred to as “photosensitive drum reverse rotation”) during the photosensitive drum driving extension. .

  The flow of control at the initial rotation of the present embodiment is the flowchart of FIG. 2 used in the description of the first embodiment. In step S15, “photosensitive drum rotation time extension at initial rotation” is changed to “photosensitive drum reverse rotation at initial rotation”. It is the same as that replaced with "."

  The photosensitive drum reverse rotation sequence at the time of initial rotation in this embodiment will be described with reference to FIG.

  With normal initial rotation, the photosensitive drum 1 rotates for several tens of seconds for initial operation check and photosensitive drum cleaning. However, when a new process cartridge and a predetermined temperature are detected, the driving of the photosensitive drum 1 is extended as described above, and the photosensitive drum is reversely rotated in the initial rotation.

  Here, the number of reverse rotations of the photosensitive drum in the initial rotation and the predetermined temperature will be described.

  Table 4 shows the results of studying the cleaning performance with respect to the number of reverse rotations at 5 ° C. In the cleaning results, “◯” indicates no cleaning failure, “△” indicates minor cleaning failure with no more than 2 vertical black streaks on the image, and “×” indicates that cleaning failure occurs on the image. The image contains three or more vertical black stripes.

  As shown in Table 4, a cleaning failure occurred when the number of reverse rotations was 3 or less.

  Furthermore, the same examination was performed at 10 ° C. and 15 ° C., respectively. At 10 ° C., the number of reverse rotations of the photosensitive drum was 1 or less, and cleaning failure occurred (Table 5). At 15 ° C., no cleaning failure occurred in all cases (Table 6).

  From the above results, in this embodiment, the predetermined temperature is 10 ° C., and the number of reverse rotations of the photosensitive drum is four.

  According to the present embodiment, the photosensitive drum driving operation direction is moved in the direction opposite to the forward direction during the photosensitive drum driving extension, so that the blade 7 is moved more than when operating only in the forward direction as in the first embodiment. The effect of peeling off the adhering lubricant is increased.

  Therefore, the blade edge 7a comes into direct contact with the photosensitive drum 1 when the photosensitive drum is driven. Further, the cleaning performance is improved by increasing the scraping property of the transfer residual developer of the blade 7, and the cleaning failure due to the lubricant which is likely to occur when the photosensitive drum 1 and the blade 7 are in a new state is less than a specific temperature. Can be prevented.

  Furthermore, since the photosensitive drum rotation time can be shortened compared to the operation in the forward direction of the first embodiment, damage to the photosensitive drum 1 can be reduced.

  In addition, as the number of times of operation in the reverse direction is increased, the effect of removing the lubricant is further enhanced. Further, since the driving time is not extended above a specific temperature, it is possible to prevent the occurrence of blade turning or squealing that tends to occur in a high temperature environment.

  In addition, since the waiting time until the start of printing does not increase, the time required until the user finishes printing does not increase.

The present invention is not limited to the image forming apparatus having the above-described configuration. Four developing devices 10 described in this embodiment are arranged around one photosensitive drum, and each developing device 10 has a yellow color. A color image forming apparatus configured to include toners of color , magenta, cyan, and black may be used. Also in the present embodiment, a color image forming apparatus configured by arranging four cartridges 20 having the above-described configuration and including each toner of yellow color, magenta color, cyan color, and black color in each developing device 10. Similar effects can be achieved by performing the control as described above.

  In the above embodiment, the image forming apparatus has been described as having a configuration in which the developer image on the photosensitive drum 1 is directly transferred to the transfer material Q. However, an intermediate transfer type image forming apparatus in which the developer on the photosensitive drum 1 is temporarily transferred onto an intermediate transfer member and then transferred onto a transfer material can be obtained.

Example 3
Next, a third embodiment of the image forming apparatus according to the present invention will be described.

  Since the configuration of the image forming apparatus shown in the present embodiment is the same as that shown in FIG. 1, the description of the configuration of the image forming apparatus is referred to the description of the first embodiment, and the description thereof is omitted here.

  In the first embodiment, when the temperature detection unit 19 detects a temperature below a predetermined temperature in the image forming apparatus and the new product detection unit 30 detects the new state of the cartridge 20, the drive control unit 40 detects the photosensitive drum 1. The drive was extended. However, in the third embodiment, the photosensitive drum driving is repeatedly stopped and started while the photosensitive drum driving is extended.

The flow of control at the initial rotation of the present embodiment is the flowchart of FIG. 2 used in the description of the first embodiment. In step S15, “photosensitive drum rotation time extension at initial rotation” is changed to “photosensitive drum drive stop at initial rotation”.・ Same as the replacement of “Starting operation”.
The photosensitive drum drive stop / start sequence at the time of initial rotation in this embodiment will be described with reference to FIG.

  With normal initial rotation, the photosensitive drum rotates for several tens of seconds for initial operation check and photosensitive drum cleaning. However, when a new process cartridge and a predetermined temperature are detected, the driving of the photosensitive drum 1 is extended and the photosensitive drum driving is stopped and started in the initial rotation as described above.

  Here, the number of photosensitive drum stop / start operations in the initial rotation and the predetermined temperature will be described.

  Table 7 shows the results of studying the cleaning performance with respect to the number of reverse rotations at 5 ° C. In the cleaning results, “◯” indicates no cleaning failure, “△” indicates minor cleaning failure with no more than 2 vertical black streaks on the image, and “×” indicates that cleaning failure occurs on the image. The image contains three or more vertical black stripes.

  As shown in Table 7, a cleaning failure occurred when the number of stop / start operations was 3 or less.

  Furthermore, the same examination was performed at 10 ° C. and 15 ° C., respectively. At 10 ° C., the photosensitive drum was stopped and started once or less, and cleaning failure occurred (Table 8). At 15 ° C., no cleaning failure occurred in all cases (Table 9).

  From the above results, in this embodiment, the predetermined temperature is 10 ° C., and the photosensitive drum stop / start operation count is four.

  According to this embodiment, when the photosensitive drum is stopped and started, the contact state of the blade with the image carrier changes. Therefore, the effect of peeling off the lubricant adhering to the blade is higher than when the photosensitive drum is only driven as in the first embodiment.

  As a result, the blade edge directly contacts the image carrier when the image carrier is driven. Further, the scraping property of the transfer residual developer on the blade is increased, so that the cleaning property is improved, and it is possible to prevent the poor cleaning due to the lubricant that is likely to occur when the image carrier and the blade are in a new state at a specific temperature or lower. .

  Furthermore, since the photosensitive drum rotation time can be shortened compared to the operation in the forward direction of the first embodiment, damage to the photosensitive drum can be reduced.

  Further, since the driving time is not extended above a specific temperature, it is possible to prevent the occurrence of blade turning or squealing that tends to occur in a high temperature environment.

  In addition, since the waiting time until the start of printing does not increase, the time required until the user finishes printing does not increase.

  The present invention is not limited to the image forming apparatus having the above-described configuration. Four developing devices 10 described in this embodiment are arranged around one photosensitive drum, and each developing device 10 has a yellow color. A color image forming apparatus configured to include toners of color, magenta, cyan, and black may be used. Also in the present embodiment, a color image forming apparatus configured by arranging four cartridges 20 having the above-described configuration and including each toner of yellow color, magenta color, cyan color, and black color in each developing device 10. Similar effects can be achieved by performing the control as described above.

  In the above embodiment, the image forming apparatus has been described as having a configuration in which the developer image on the photosensitive drum 1 is directly transferred to the transfer material Q. However, an intermediate transfer type image forming apparatus in which the developer on the photosensitive drum 1 is temporarily transferred onto an intermediate transfer member and then transferred onto a transfer material can be obtained.

Example 4
FIG. 6 shows another embodiment of the image forming apparatus according to the present invention.

  In this embodiment, the image forming apparatus has the same configuration as that of the image forming apparatus shown in FIG. 1 used in the description of the first embodiment. The only difference is the configuration in which the scraping member 21 is added. Therefore, in the image forming apparatus of the present embodiment shown in FIG. 6, the same reference numerals are assigned to members having the same configuration and function as those of the image forming apparatus of the first embodiment, and the description of the first embodiment is incorporated. Explanation here is omitted.

  The scraping member 21 added in the present embodiment will be described. The scraping member 21 is made of an elastic sheet material, and for example, a rectangular sheet made of polyethylene terephthalate and having a thickness of 0.8 mm is used. The scraping member 21 can be brought into contact with and separated from the photosensitive drum 1. When the scraping member 21 is brought into contact with the photosensitive drum 1, the scraping member 21 is brought into contact in the counter direction with respect to the rotational movement direction. Usually, the scraping member 21 is separated from the photosensitive drum 1.

  In this embodiment, when the temperature detecting means 19 detects a temperature below a predetermined temperature in the image forming apparatus and the new article detecting means 30 detects the new state of the cartridge 20, the scraping member 21 is used as the photosensitive drum 1. It is set as the structure made to contact | abut.

  The flow of control in the initial rotation of the present embodiment is the flowchart of FIG. 2 used in the description of the first embodiment. In step S15, “Extended photosensitive drum rotation time during initial rotation” is set to “Scraping member during initial rotation”. It is the same as that replaced with “contact with the photosensitive drum”.

The photosensitive drum driving stop-start sequence during initial rotation of the present embodiment will be described with reference to FIG.

  With normal initial rotation, the photosensitive drum 1 rotates for several tens of seconds for initial operation check and photosensitive drum cleaning. However, when a new process cartridge and a predetermined temperature are detected, the drive of the photosensitive drum 1 is extended and the scraping member 21 is brought into contact with the photosensitive drum 1 in the initial rotation as described above.

  Here, the time for bringing the scraping member 21 into contact with the photosensitive drum 1 in the initial rotation and the predetermined temperature will be described.

  Table 10 shows the results of investigation on the cleaning performance with respect to the time for which the scraping member at 5 ° C. is brought into contact with the photosensitive drum. In the cleaning results, “◯” indicates no cleaning failure, “△” indicates minor cleaning failure with no more than 2 vertical black streaks on the image, and “×” indicates that cleaning failure occurs on the image. The image contains three or more vertical black stripes.

  As shown in Table 10, a cleaning failure occurred when the number of reverse rotations was 3 or less.

  Furthermore, the same examination was performed at 10 ° C. and 15 ° C., respectively. At 10 ° C., cleaning failure occurred when the scraping member contact time was 10 seconds or less (Table 11), and at 15 ° C., no cleaning failure occurred in all cases (Table 12).

  From the above results, in this embodiment, the predetermined temperature is 10 ° C., and the time for which the scraping member 21 is brought into contact with the photosensitive drum is 40 seconds.

  According to the present embodiment, the lubricant adhering to the photosensitive drum 1 can be removed by bringing the scraping member 21 into contact with the photosensitive drum 1, and lubrication interposed between the photosensitive drum 1 and the blade 7. The agent can be reduced.

  Thus, the blade edge 7a comes into direct contact with the photosensitive drum 1 when the photosensitive drum is driven. Further, the scraping property of the transfer residual developer on the blade 7 is improved, so that the cleaning property is improved, and it is possible to prevent the cleaning failure that is likely to occur when the photosensitive drum 1 and the blade 7 are in a new state at a specific temperature or lower. it can.

  In addition, since the driving time is not extended above a specific temperature, it is possible to prevent the occurrence of blade turning or squealing that tends to occur in a high temperature environment.

  In addition, since the waiting time until the start of printing does not increase, the time required until the user finishes printing does not increase.

  The present invention is not limited to the image forming apparatus having the above-described configuration. Four developing devices 10 described in this embodiment are arranged around one photosensitive drum, and each developing device 10 has a yellow color. A color image forming apparatus configured to include toners of color, magenta, cyan, and black may be used. Also in the present embodiment, a color image forming apparatus configured by arranging four cartridges 20 having the above-described configuration and including each toner of yellow color, magenta color, cyan color, and black color in each developing device 10. Similar effects can be achieved by performing the control as described above.

  In the above embodiment, the image forming apparatus is described as having a configuration in which the developer image on the photosensitive drum 1 is directly transferred to the transfer material Q. However, the developer on the photosensitive drum 1 is temporarily transferred to the intermediate transfer member. An intermediate transfer type image forming apparatus having a configuration in which the image is transferred onto the transfer material and then transferred onto a transfer material can be obtained.

1 is a diagram showing a schematic configuration of an embodiment of an image forming apparatus according to the present invention. It is a flowchart figure which shows the flow of control by the initial rotation in Example 1 of this invention. It is a sequence diagram which shows initial rotation in Example 1 of this invention. It is a sequence diagram which shows initial rotation in Example 2 of this invention. It is a sequence diagram which shows initial rotation in Example 3 of this invention. FIG. 10 is a diagram illustrating a configuration of an image forming apparatus according to a fourth embodiment of the present invention. It is a sequence diagram which shows the initial rotation in Example 4 of this invention. It is a figure which shows the structure of the conventional image forming apparatus.

Explanation of symbols

1 Photosensitive drum (image carrier)
2 Primary charger)
3 Exposure device 4 Transfer charger 5 Cleaning device 7 Cleaning blade (cleaning member)
10 Developing Device 11 Developing Roller (Developer Carrier)
12 RS roller (developer supply, stripping member)
13 Regulating blade (Toner amount regulating member)
14 Toner stirring member 19 Temperature detection means 20 Process cartridge 21 Scraping member P Image forming apparatus main body

Claims (5)

An image carrier on which an electrostatic latent image is formed, a developing device for developing the electrostatic latent image with a developer to form a developer image, and a cleaning for removing the developer from the image carrier In an image forming apparatus capable of detachably mounting a process cartridge having a cleaning member in which a lubricant is applied to a portion that is a member and is in contact with the image carrier in a new state,
The cleaning member is a cleaning blade disposed in a counter direction with respect to a moving direction of the image carrier;
Temperature detecting means for detecting the temperature in the image forming apparatus;
New article detecting means for detecting that the image carrier and the cleaning member are in a new state;
Drive control means for controlling the drive of the image carrier, wherein the temperature detection means detects a predetermined temperature or lower, and the image detection body and the cleaning member are in a new state by the new article detection means. Drive control means for extending the time for driving the image carrier before starting image formation when it is detected, compared to cases other than the above,
An image forming apparatus comprising:   2. The image according to claim 1, wherein when the drive time of the image carrier is extended by the drive control unit, the image carrier is operated at least once in a direction opposite to that at the time of image formation. Forming equipment.   2. The image forming apparatus according to claim 1, wherein when the drive time of the image carrier is extended by the drive control unit, the drive operation of the image carrier is stopped and started at least once. 3. . In an image forming apparatus for forming an image on a transfer material,
Device A capable mounted process cartridge removably to the main body of the image forming apparatus,
An image carrier on which an electrostatic latent image is formed, a developing device for developing the electrostatic latent image with a developer to form a developer image, and for removing the developer from the image carrier, A cleaning blade disposed in a counter direction with respect to the moving direction of the image carrier, wherein a cleaning member is applied to a portion in contact with the image carrier in a new state and a contact with the image carrier. An elastic sheet-like scraping member that can be contacted and separated; a scraping member that removes the lubricant from the image carrier when contacting the image carrier; and
A process cartridge having
Temperature detecting means for detecting the temperature in the image forming apparatus;
New article detecting means for detecting that the image carrier and the cleaning member are in a new state;
When the temperature detecting means detects that the temperature is higher than a predetermined temperature and the new article detecting means detects that the image carrier and the cleaning member are new, the scraping member is separated from the image carrier. Let the initial rotation for a predetermined period,
Detects less than a predetermined temperature by the temperature detecting means, and, when the image bearing member and the cleaning member by the new-product detection means detects that a new state, the extended initial rotation and extended and control means for controlling the Ru is brought into contact with the scraping member to the image bearing member in a period,
An image forming apparatus comprising:   The image forming apparatus according to claim 4, wherein the scraping member abuts in a counter direction with respect to a moving direction of the image carrier.

Images