JP7075623B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus.

Conventionally, there is known an image forming apparatus that executes a refreshing step of forming a latent image for refreshing on a latent image carrier and developing the latent image with a developing apparatus.
For example, the image forming apparatus described in Patent Document 1 includes a proximity member such as a separation claw arranged close to a region through which a refresh toner image obtained by developing a latent image for refreshing with a developing apparatus passes. Then, as a refreshing latent image, a refreshing latent image composed of a non-proximity region not facing the proximity member is formed, and a refreshing latent image termination portion including a region facing the proximity member is formed at the terminal portion of the latent image. Form. It is described that this makes it possible to discharge the deteriorated toner without adhering the toner to the neighboring member during the refresh process, eliminate the uneven charging on the toner carrier caused by the refresh process, and form a clear image. There is.

The refreshing step is performed for various purposes such as refreshing the developing device and refreshing the surface of the latent image carrier. There is a possibility that a clear image cannot be formed only by using the refreshing latent image described in Patent Document 1.

In order to solve the above-mentioned problems, the present invention presents a proximity member on a refresh toner image passage path in an image forming apparatus that executes a refreshing step of forming a latent image for refreshing on a latent image carrier and developing the latent image in the developing apparatus. The refreshing latent image used in the refreshing step between the first refreshing latent image including the portion facing the toner in the toner adhesion region and the second refreshing latent image not including the facing portion in the toner adhesion region. It is characterized by being able to select a latent image.

According to the present invention, it is possible to form a clearer image than before.

Schematic block diagram of a monochrome electrophotographic apparatus. Enlarged schematic configuration diagram of a part of the device. Enlarged perspective view of a part of the device. A block diagram showing a part of an electric circuit. Explanatory drawing of toner refresh control pattern. Explanatory diagram of control. A flowchart showing an example of control. A flowchart showing another example of control.

Hereinafter, embodiments in which the present invention is applied to a monochrome electrophotographic apparatus which is an image forming apparatus will be described.
FIG. 1 is a schematic configuration diagram of a central cross section of a monochrome electrophotographic apparatus. In the monochrome electrophotographic apparatus 1, a process cartridge 2 as an image forming unit that can be attached to and detached from the apparatus main body is arranged in a substantially central portion of the machine frame. An optical writing device 4 for forming a latent image on the photoconductor 3 is arranged in a device main body located above the drum-shaped photoconductor 3 which is a latent image carrier inside the process cartridge 2. The transfer device 5 is installed in the main body of the device located below the photoconductor 3.

A paper feed transfer device 6 is arranged in the device main body below the process cartridge 2. The paper fed by the paper feed roller 8 from the paper feed cassette 7 for loading and accommodating the paper (sheet) which is the recording material or the recording medium of the paper feed transfer device 6 is the photoconductor 3 with the resist roller pair 9. It is conveyed at the same timing as the toner image carried on it, and is passed between the transfer device 5 and the photoconductor 3. During this passage, the toner image formed on the surface of the photoconductor 3 is transferred to the paper by the transfer electric field of the transfer device 5. The paper on which the toner image is transferred is guided to the fixing device 10 to melt and fix the toner image on the recording material by heat and pressure. Paper is discharged to the paper ejection tray 12 on the upper surface of the monochrome electrophotographic apparatus 1 by the paper ejection roller 11.

When printing on both sides of the paper, the paper having the toner image fixed on one side of the paper is switched back by reversing the paper ejection roller 11 and sent to the paper reversing unit 13, the front and back sides of the paper are reversed, and then the resist roller vs. 9 Refeed to. The toner image is transferred from the photoconductor 3 to the back surface of the re-fed paper, and the image on the back surface is fixed by the fixing device 10, so that the paper carrying the image on both the front and back surfaces is ejected to the output tray 12. , Double-sided printing is completed.

FIG. 2 is a schematic diagram of a process cartridge 2 (charging, developing, cleaning), an optical writing device 4, a transfer device 5, and a fixing device 10. The photoconductor 3 of the process cartridge 2 is rotationally driven in the counterclockwise direction in the figure by a driving means (not shown). The surface of the photoconductor 3 is uniformly charged to a predetermined polarity (usually negative electrode property) by the charging roller 20a of the charging device 20. The surface of the charged photoconductor is irradiated with laser light from the optical writing device 4, whereby a desired electrostatic latent image is formed on the surface of the photoconductor 3. Black toner is applied to the electrostatic latent image thus formed from the developing roller 21a, which is the toner carrier (developer carrier) of the developing apparatus 21, and is visualized as a toner image. A development bias voltage having the same polarity as the charging polarity of the toner (negative electrode property if the charging property is negative electrode property) is applied to the developing roller 21a, and so-called reverse development is performed. In the illustrated example, one component toner is used, the toner is supplied to the developing roller 21a by the supply roller 21b, and the toner is thinned by the regulation blade 21c and used for development.

Further, the transfer roller 5a of the transfer device 5 is driven to travel clockwise in the drawing, and the toner image is transferred from the photoconductor 3 when the paper P passes through the transfer roller 5a. The bias applied to the transfer roller 5a at this time has the opposite polarity to that of the toner (if the toner is negative, the transfer voltage is positive). The residual toner adhering to the surface of the photoconductor 3 after the toner image is transferred is removed from the surface of the photoconductor drum by the cleaning blade 22a of the cleaning device 22 to prepare for the next image formation.

A separation claw 23 whose tip lightly contacts the surface of the photoconductor is provided upstream of the cleaning device 22. The separation claw 23 is located on the photoconductor surface movement path from development to cleaning, which is a pass path of the refresh pattern, which is a refresh toner image described later. Further, a static elimination needle unit 24 is provided so as to correspond to the lower surface of the paper immediately after passing through the transfer roller 5a. The static elimination needle unit 24 has a partition rib 24a and a static elimination needle holder 24b between the plurality of static elimination needles. The separation claw 23 and the static elimination needle unit 24 are for assisting the function of separating the paper between the transfer roller 5a and the photoconductor 3. In particular, it is useful in a system in which paper is conveyed and directly transferred without intermediate transfer.

FIG. 3 is an enlarged perspective view of the periphery of the static elimination needle unit 24. In this figure, the static elimination needle 24c between the plurality of ribs 24a also appears. A lower guide plate 25 for guiding the paper on which the toner image is transferred to the fixing device 10 is provided downstream of the static elimination needle unit 24. A plurality of transport ribs 25a1, 25a2 ... 25n extending in the transport direction are formed on the surface of the lower guide plate 25.

Returning to FIG. 2, upper and lower paper guide members 26a and 26b are also provided at the entrance of the fixing device 10. Then, the heating roller 10a and the pressure roller 10b of the fixing device 10 are arranged so as to be curved so as to press the paper P sent from the transfer device 5 against the lower guide plate 25. Due to such an arrangement, the rear end Pa of the paper P that has received the transfer nip in which the photoconductor 3 and the transfer roller 5a come into contact is particularly the upper end portion 27 of the static elimination needle holder 24b of the static elimination needle unit 24. (See FIG. 4) and the lower guide plate 25 is guided by being pressed against the rib 25a.

FIG. 4 is a block diagram showing a part of the electric circuit of the printer according to the embodiment. A writing control unit 31, an optical writing device 4, a developing device 21, a transfer device 5, a process motor 3a, and an electrical component unit of a paper feed transfer device 6 are connected to the main control unit 30. The operation unit 32, the communication control device 33, and the chip reading circuit 34 are also connected. The chip reading circuit 34 is for reading the information of the IC chip 35 provided in the process cartridge 2.

Next, toner refresh control will be described.
The refresh control for periodically refreshing the toner in the developing device to keep the toner fresh is performed without the paper P. A laser beam is irradiated by the optical writing device 106 with a width and time corresponding to a predetermined refresh amount, and an electrostatic latent image is formed on the surface of the photoconductor 3. Since the toner is developed from the developing roller 21a on the electrostatic latent image, the toner can be refreshed from the developing device. During the refresh control (refresh step), a transfer voltage having the same polarity as the toner charging polarity of the toner image on the surface of the photoconductor 3 is applied to the transfer roller 5a, whereby the toner image on the surface of the photoconductor drum stains the transfer roller. Instead, it is removed from the photoconductor drum by the cleaning blade 22a, becomes waste toner, and is stored in the waste toner accommodating portion.

Paper edge stains may occur due to this refresh control. Since the separation claw 124 is located upstream of the cleaning device 22 as shown in FIG. 2, the refresh toner image passes through the transfer nip during the refresh operation and then comes into contact with the separation claw 124. Then, the toner scatters and accumulates in the transport path.

For users who use high-resistance paper or paper with strong paper stiffness such as thick paper under control conditions such as setting a large amount of refresh toner, the scattered toner stains the edge surface of the paper. Occur. In recent years, there has been an increasing demand for miniaturization of printers, and each unit and transport path are also designed to be miniaturized. If the main body is miniaturized, it tends to become a system in which such problems are likely to become apparent.

Also in this embodiment, the separation claw 23 is provided on the outlet side of the paper with respect to the small diameter photoconductor drum (diameter 30 mm) to prevent the paper from being caught. Further, below the separation claw 23, an auxiliary member (rib 25a) for transporting paper and a static elimination needle holder 24b are arranged close to the separation claw. For this reason, the toner scattered by the separation claws stains the adjacent ribs 25a and the static elimination needle holder 24b, and then stains the end surface of the paper that has passed through, resulting in edge surface contamination. The region indicated by X in FIG. 3 indicates a region directly below the separation claw 23. The rib 25a1 closest to this is more dirty than the other ribs 25a. Even within the upper end portion 27 of the static elimination needle holder 24b extending in the width direction, there is a lot of dirt in the region X. The dirt on the end face of the paper rubbed in the portion of the upper end portion of the rib 25a1 and the static eliminator holder 24b in the region X becomes conspicuous.

FIG. 5 is a diagram illustrating a pattern of toner refresh control carried out in the present invention. The refresh pattern 1 (Pa) shown in FIG. 5 (a) is a solid pattern that has been generally performed as a toner refresh. Regarding the width W of the toner refresh pattern 1, it is common to draw an image pattern that is a toner adhesion region in the entire region of the latent image writing width and the charging width in the photoconductor drum axis direction. The toner refresh length L, which is the length in the sub-scanning direction, is set to an integral multiple of the circumference of the developing roller 21a, but it can be changed according to the toner refresh application. It is common to do. In this embodiment, the width is 300 mm, which is the entire writing width, and the length is variable depending on how it is used.

The refresh pattern 2 shown in FIG. 5B is a pattern (Pb1, Pb2, Pb3) consisting of non-proximity regions masking the pattern of the region in the main scanning direction facing the proximity member close to the photoconductor 3. The pattern consisting of the non-proximity regions is a second refresh latent image that does not include the facing region portion in the toner adhesion region. On the other hand, the refresh pattern 1 described above is a first refresh latent image including the facing region portion in the toner adhesion region.

In this embodiment, in the refresh pattern 2, the pattern of the positions of the separated claws is masked with respect to the photoconductor unit provided with the separated claws at two places. The mask width G of the pattern is set to 10 mm, and if this masking width is set narrower than the position accuracy of the separation claws and writing, the refresh pattern may pass through the separation claw position and stains on the paper edge surface occur. Resulting in. In particular, when the distance between the separation claw and the rib of the lower guide plate or the upper part of the static elimination needle holder is as small as about 7 mm, dirt is likely to occur. As the distance becomes narrower, such as 20 mm or less, particularly 10 mm or less, and further 5 mm or less, stains are likely to occur, and the present invention is particularly useful for devices having such a distance.

If the width is too wide, the toner input to the cleaning blade 22a will not be input in many portions in the photoconductor axis direction, and the problem of the photoconductor medaka, which will be described later, is likely to occur. If the width is as short as about 10 mm, problems are less likely to occur in the portion where the toner is not input by the cleaning blade 22a because the toner in the surrounding portion where the toner is input wraps around.

The present embodiment is characterized in that the above two patterns can be switched and used. When the pattern writing at the separation claw position close to the photoconductor drum is masked with respect to the main scanning direction of the toner refresh pattern, the toner scattering that occurs when the toner refresh pattern passes through the separation claw is suppressed, and the end face of the paper ( Edge surface) It is possible to prevent stains. On the other hand, when the pattern is masked, side effects such as medaka of the photoconductor may occur. In order to suppress the occurrence of problems (photoreceptor medaka, etc.) caused by masking the refresh pattern, the refresh pattern to be used can be switched to the conventional unmasked full-face refresh pattern.

Considering that there is a trade-off between the effect of masking the refresh pattern to prevent edge stains and the side effects (photoreceptor medaka, etc.) that may be a concern when masking, it is now possible to set the optimum refresh pattern. do. Since the conditions under which the side effects of masking the pattern are different from the dirt on the edge of the paper caused by not masking the pattern, set the optimum refresh pattern according to the customer's usage.

There are the following three types of toner refresh control.
(1) "Low image refresh"
Low image refresh that performs a refresh operation for the purpose of preventing toner deterioration in the developer due to use in low images. The lower the image area ratio of the user, the higher the frequency and the higher the area of toner refresh. For example, if images with a low image area ratio of 2 to 3% are continuously formed, it is difficult for the toner on the developing roller to be replaced, and the toner deteriorates on the developing roller. In a developing apparatus using a two-component developer, it is difficult for the toner in the developer in the developer to be replaced, and the toner in the developer in the developer is deteriorated. In order to avoid this, for example, the execution is performed every time the cumulative number of images (image formation amount) of the low image area ratio reaches 10 (execution time is every 10 images).

(2) "Refresh a certain distance"
Toner is periodically input to the cleaning blade to refresh the photoconductor for a certain distance at a certain distance to prevent killifish and cleaning defects. What is photoconductor medaka? Silica, which is an additive for toner, calcium carbonate contained in paper, etc. adheres to and immobilizes on the surface of the photoconductor 3, and at the place where these are immobilized, potential drop is unlikely to occur even by optical writing. It causes the above white spots. These adhesions and fixations have a streamlined shape extending in the sub-scanning direction, and are generated as a group of medaka fish. As a result, the white spots on the image are also called photoconductor medaka because a plurality of streamline-shaped medaka fish appear to form a group.

Since the purpose is to input toner into the photoconductor and remove the adhered portion on the surface of the photoconductor by rubbing the surface of the photoconductor with the toner by the cleaning blade 22a, the toner is refreshed at a certain distance. For example, the execution is performed in the range of 50 to 100 sheets (execution time is every 50 to 100 sheets). Since refreshing is performed at a fixed distance regardless of how it is used, it is desirable to design it so that it is performed infrequently.

(3) "Small size refresh"
Since the surface of the photoconductor is not polished by the paper at the edges where the paper does not pass when the small size paper is passed, the photoconductor medaka is likely to occur. For this reason, when using small-sized paper, small-sized refreshing (measures against edge medaka) is carried out, and the adhered portion on the surface of the photoconductor is removed by rubbing the surface of the photoconductor with toner by the cleaning blade 22a. For example, it is executed every time the cumulative number of small size sheets reaches 100 (execution time is every 100 sheets).

The issues to be dealt with are different for each. For example, low-image toner ejection is to prevent toner deterioration on the developing roller or in the developing device, so the disadvantage of masking (generation of photoconductor medaka) is small. Also, the required timing is different. For example, low image refresh is frequent for low print users, but not for high print users. Small size ejection should be performed only when printing on small size paper. And each problem and the deterioration condition of the edge surface dirt are also different. For example, edge stains are likely to occur on thick paper and high resistance paper. Thick paper has a strong waist and is easily rubbed against the rib 25a of the lower guide plate 25 and easily soiled. If the electrical resistance of the paper is high, the charged toner is electrostatically attached and easily soiled. Paper containing a large amount of additives such as calcium carbonate tends to cause killifish, but its low electrical resistance makes it difficult for edge stains to occur. From the above, by masking the refresh pattern in the optimum case, it is possible to achieve both edge stains and prevention of side effects such as killifish.

FIG. 6 is a diagram showing an example of case classification of pattern setting. Allow the user or service person to check the paper / environment used by the customer, enter settings from the main unit operation unit 32 (see FIG. 4), and switch the refresh pattern. For example, for customers who use a lot of thick paper and high resistance paper, setting 1 is selected because edge surface stains are likely to occur, but for customers with a lot of paper dust such as calcium carbonate, there is concern about photoconductor medaka. Therefore, select setting 2, which is set so as not to mask the refresh for a certain distance. The control of the writing control unit 31 (see FIG. 4) that controls the optical writing device 4 is switched according to the settings 1 and 2.

When the user sets it, set 1 can be set and registered as the name of the paper type, paper size, and paper thickness used by the user so that the user can easily select either setting 1 or setting 2 when setting. Is desirable. For example, with respect to the paper thickness, a paper thickness of 106 g / m ² or more is described as thick paper, a paper of 105 g / m ² or less is described as plain paper, and the thick paper is masked as setting 1.
In addition, it is desirable to use the pattern without refresh mask of setting 2 because the possibility of killifish generation increases in the paper type in which the amount of calcium carbonate exceeds 10%. Paper containing a large amount of calcium carbonate may be referred to as "high white paper", or the brand of the paper type to be used may be registered.

Further, since the constant distance refresh is executed regardless of the conditions such as the image area ratio, it is generally set to be less frequent than the low image refresh. Therefore, the default condition may be setting 1 in which the refresh pattern is masked for a certain distance refresh, and setting 2 may be set when a problem such as occurrence of a photoconductor medaka occurs at the masked portion.

In addition, this setting can be changed so that it can be changed by remote control other than the user or the service person. In recent years, models equipped with software that can acquire log information, grasp the usage status, and change internal parameters by remote control by connecting the printer via a network have become common. Also in this embodiment, it can be set by an internal parameter. Then, check the action contents at the time of emergency replacement of the process cartridge and how to use it from the log information, and if it is necessary to change the pattern, change the setting by remote control (receive it from another device via the network). Select based on the selection instruction information) to enable countermeasures. As a result, the number of visits by service personnel can be reduced and downtime can be reduced. A communication control device 33 (see FIG. 4) is used for communication for this remote control.

FIG. 7 is a diagram explaining the flow when the usage is judged and the refresh pattern is automatically switched. First, this flow is executed at the end of the print JOB. Toner refresh is performed by a series of operations of determining the presence or absence of refresh at the JOB end and executing refresh.

First, information on the average image area ratio used so far by the user is acquired (S1), and it is determined whether the image area ratio refresh is necessary for the user with a low image (S2). If necessary, perform toner refresh with the separated claw position masked (S3). If not, then the mileage is confirmed (S4), and it is determined whether a certain distance refresh is necessary (S5).

When a certain distance refresh is required, the paper type and environmental information are then acquired (S6), and the presence or absence of a mask at the separation claw position is determined (S7). Regarding the determination of the paper type, thick paper is a condition for worsening edge stains because the paper has a strong stiffness. The thick paper 2 has a refresh pattern masked (S3), and the plain paper has a refresh pattern without a mask (S8). Of course, the pattern may be switched according to the paper type and the paper size.

Next, the environment information is judged and the refresh pattern is changed. In a high-temperature and high-humidity environment, the pattern is not masked because the photoconductor medaka is likely to be generated due to the heat inside the machine. In a low temperature and low humidity environment, the resistance of the paper becomes high and the edge surface of the paper is electrostatically soiled, so that the refresh pattern is masked (S3). As the boundary of the absolute humidity for changing the pattern, for example, the absolute humidity of 15 g / m ³ which is the absolute humidity generated by the photoconductor medaka can be mentioned. When the absolute humidity is 15 g / m ³ or less, a pattern masking the refresh pattern is selected (S3).

When neither low image toner refresh nor quantitative discharge is performed, toner refresh control is not performed (S9). From the above, it is possible to mask the separation claw position of the refresh pattern and take measures against the dirt on the edge surface. It is possible to achieve both by performing toner refresh without a mask only under conditions where the edge surface is well soiled and side effects are large. This is related information used to automatically select the refreshing latent image used by the above average image area ratio (S1), mileage (S4), paper type, and environmental information (S6).

FIG. 8 is a diagram explaining the flow when the process cartridge type and usage are determined and the refresh pattern is automatically switched.
In order to set the paper separation function of the process cartridge according to the paper size and paper type, prepare multiple types of process cartridges with different numbers and positions of separation claws. The position and number of patterns to be masked are automatically changed according to the type of this process cartridge. Especially for users who do not need the separation claws of the process cartridge, such as users who do not use thin paper, the edge surface does not get dirty even without a mask for the refresh pattern, so there are no problems caused by masking, which simplifies the flow. can.

FIG. 8 shows a flow assuming that the following two types of process cartridges are prepared as an example. The process cartridge 1 is a process cartridge in which a separation claw is arranged in the vicinity of the photoconductor drum in order to have a paper separation function. The process cartridge 2 is a process cartridge in which the separation claws are not arranged.

When the cartridge is set in the printer body, the information of the ID chip which is the IC chip 35 in the process cartridge 2 is read by the chip reading circuit 34 (see FIG. 3), and the set cartridge is the cartridge 1 or the cartridge. It is determined whether it is 2 (S10). In the case of the process cartridge 1, the same flow as in FIG. 7 (cartridge 1 subroutine) (S11) is executed, and the toner refresh pattern is automatically selected. In the case of the process cartridge 2, no pattern mask is set when the refresh pattern is created (S23, S28, S29). Here, S24, S25, S28, and S29 in FIG. 8 correspond to the floats S4, S5, S8, and S9 in FIG. 7. From the above, it is possible to set optimum conditions for stains on the edge of the paper, side effects caused by masking the pattern, and poor separation of the paper.

The above description is an example, and the present invention exerts a peculiar effect in each of the following aspects.
[First aspect]
In the first aspect, an image forming apparatus (for example, monochrome) for executing a refreshing step of forming a refreshing latent image (for example, Pa) on a latent image carrier (for example, the photoconductor 3) and developing the latent image (for example, Pa) on the latent image carrier (for example, the developing apparatus 21). In the electrophotographic apparatus 1), the first refreshing latent image (for example, Pa) including the portion of the refresh toner image passage path facing the proximity member (for example, the separation claw 23) in the toner adhesion region (for example, Pa), and the above. It is characterized in that it is possible to select a refreshing latent image to be used in the refreshing step with a second refreshing latent image (for example, Pb) whose facing portion is not included in the toner adhesion region. ..

In the invention of Patent Document 1, as a refreshing latent image, a refreshing latent image termination portion including a region facing the proximity member is continuously provided at the termination portion of the refreshing latent image composed of a non-proximity region not facing the proximity member. Since only the latent image for refreshing is used, the toner at the end is scattered by the separation claws near the photoconductor in the paper type and environment where the paper end surface (edge surface) is likely to be soiled, and the paper end surface (edge surface) is used. Dirt occurs.
On the other hand, in the first aspect, it is possible to select the refreshing latent image to be used in the refreshing step between the first refreshing latent image (for example, Pa) and the second refreshing latent image (for example, Pb). Therefore, for paper types and environments where the paper edge surface (edge surface) is likely to be stained, select the second refresh latent image to prevent the paper edge surface (edge surface) from becoming dirty, and also to prevent the paper edge surface (edge surface) from becoming dirty. It is also possible to avoid problems such as photoconductor medaka by selecting the latent image for the first refresh and using the latent image for the second refresh in a paper type or environment where stains on the (edge surface) are unlikely to occur. .. Therefore, it is possible to form a clearer image than before.

[Second aspect]
The second aspect is characterized in that, in the first aspect having an operation unit (for example), the selection is made based on the operation of the operation unit. According to this, an appropriate refreshing latent image can be selected by operation using the operation unit.

[Third aspect]
The third aspect is characterized in that, in the first aspect of being connected to a network (for example), selection is made based on selection instruction information received from another device connected to the network via the network. be. According to this, an appropriate refreshing latent image can be selected by remote control.

[Fourth aspect]
The fourth aspect is characterized in that, in the first aspect, a means for acquiring related information and a selection means for making the selection based on the acquisition information of the acquisition means are provided. This allows you to automatically select the appropriate refresh latent image.

[Fifth aspect]
A fifth aspect is characterized in that, in the fourth aspect, the related information is at least one information of the type of the sheet forming the image and the thickness of the sheet. This makes it possible to appropriately select a refreshed latent image according to the ease with which the edge surface (edge surface) of the paper is soiled, such as the strength of the waist.

[Sixth aspect]
A sixth aspect is characterized in that, in the fourth aspect, the related information is information on the type of the attached removable image forming unit (for example, the process cartridge 2). According to this, information on the position and number of proximity members such as separation claws in the image forming unit can be related information, and a latent image for second refresh corresponding to these can be formed. If there is no proximity member to be considered, only the first latent image for refreshing should be selected.

[7th aspect]
A seventh aspect is characterized in that, in the fourth aspect, the related information is environmental information. According to this, the refresh latent image can be appropriately selected according to the environment such as temperature and humidity.

[8th aspect]
The eighth aspect is characterized in that, in any one of the first to seventh aspects, there are two or more kinds of refreshing steps. According to this, an appropriate refresh latent image can be selected according to the aim and hint of each refresh process.

[9th aspect]
In the ninth aspect, in the eighth aspect, a combination used in the two or more types of refreshing steps can be selected from a plurality of combinations of the first refreshing latent image and the second refreshing latent image used in each refreshing step. It is characterized by the fact that. According to this, an appropriate refresh latent image can be selected by selecting from a plurality of predetermined combinations.

[10th aspect]
In the tenth aspect, in the eighth or ninth aspect, the two or more types of refreshing steps are a step in which an execution time is determined based on an image formation amount of an image area ratio of a predetermined value or less, and an image having a size of a predetermined size or less. It is characterized by including a step in which an execution time is determined based on the amount of formation. According to this, it is possible to select an appropriate refresh latent image that can prevent defects such as killifish of the photoconductor by forming a size smaller than a predetermined size.

1: Monochrome electrophotographic device 2: Process cartridge 3: Photoreceptor 3a: Process motor 4: Optical writing device 5: Transfer device 5a: Transfer roller 6: Paper feed transfer device 7: Paper cassette 8: Paper feed roller 9: Resist roller pair 10: Fixing device 10a: Heating roller 10b: Pressurizing roller 11: Paper ejection roller 12: Paper ejection tray 13: Paper reversing unit 20: Charging device 20a: Charging roller 21: Developing device 21a: Developing roller 21b: Supply Roller 21c: Restriction blade 22: Cleaning device 22a: Cleaning blade 23: Separation claw 24: Static elimination needle unit 24a: Rib 24b: Static elimination needle holder 24c: Static elimination needle 25: Lower guide plate 25a: Rib 25a1: Transport rib 25a2: Transport rib 26a: Paper guide member 26b: Paper guide member 27: Upper end 30: Main control unit 31: Write control unit 32: Operation unit 33: Communication control device 34: Chip reading circuit 35: IC chip 106: Optical writing device 124: Separation claw G: Mask width JOB: Printing P: Paper Pa: Rear edge X: Area

Japanese Unexamined Patent Publication No. 2008-268390

Claims (10)

In an image forming apparatus that executes a refreshing step of forming a latent image for refreshing on a latent image carrier and developing it with a developing apparatus.
Between the first refreshing latent image in which the portion of the refresh toner image passing path facing the proximity member is included in the toner adhesion region and the second refreshing latent image in which the facing portion is not included in the toner adhesion region. The image forming apparatus is characterized in that the latent image for refreshing used in the refreshing step can be selected. In the image forming apparatus of claim 1, which has an operation unit,
An image forming apparatus characterized in that the selection is made based on the operation of the operation unit. In the image forming apparatus of claim 1, which is connected to a network,
An image forming apparatus, characterized in that selection is performed based on selection instruction information received from another device connected to the network via the network. In the image forming apparatus of claim 1,
An image forming apparatus provided with a means for acquiring related information and a selection means for making the selection based on the acquisition information of the acquisition means. In the image forming apparatus of claim 4,
An image forming apparatus, wherein the related information is at least one information of a type of a sheet forming an image and a thickness of the sheet. In the image forming apparatus of claim 4,
The image forming apparatus, characterized in that the related information is information on the type of the attached removable image forming unit. In the image forming apparatus of claim 4,
The image forming apparatus, characterized in that the related information is information on the environment. In the image forming apparatus according to any one of claims 1 to 7.
An image forming apparatus characterized by having two or more types of refreshing steps. In the image forming apparatus of claim 8,
An image forming apparatus characterized in that it is possible to select a combination used in two or more types of refreshing steps from a plurality of combinations of the first refreshing latent image and the second refreshing latent image used in each refreshing step. .. In the image forming apparatus of claim 8 or 9,
The two or more types of refreshing steps include a step in which the execution time is determined based on the image formation amount of the image area ratio of the predetermined size or less, and a step in which the execution time is determined based on the image formation amount of the predetermined size or less. An image forming apparatus comprising.

Images