JP2015176097A - Imaging device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device that can prevent abnormal images resulting from a difference in surface potential of an image carrier, and prevent breakage of driving means of the image carrier.SOLUTION: There is provided an imaging device 100 that includes an image carrier 1, and control means that controls the image carrier 1 to rotate while the image carrier 1 is in an imaging standby state, the imaging device 100 further including driving means for driving the image carrier 1 and abnormality detection means for detecting abnormality of the operation of the driving means, where the control means controls to rotate the image carrier 1 so as to satisfy at least the amount of activation or the start-up time for the abnormality detection means to detect abnormality while the imaging device 100 is in an imaging standby state.

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile, and more particularly to an image forming apparatus including an image carrier and developing means.

  This type of image forming apparatus includes an image carrier and control means for controlling the image forming apparatus. For example, an image forming apparatus disclosed in Patent Document 1 is known as an image forming apparatus including such an image forming apparatus.

  This image forming apparatus includes a photosensitive drum as an image carrier, and each processing unit is disposed around the photosensitive drum for image formation. Among the processing units, the developing unit as the developing unit and the cleaning unit as the cleaning unit are configured as a substantially closed space to prevent scattering of toner during processing, and face the surface of the photosensitive member of the photosensitive drum. It has an opening surface at the position. The image forming apparatus also includes a detection unit that detects the humidity of the atmosphere around the photoconductor, and a control unit that rotates the photoconductor drum in accordance with the humidity detected by the detection unit.

  The atmosphere in the vicinity of the photoconductor becomes high temperature and low humidity due to the image forming operation, and returns to the same as the external environmental temperature and humidity as the image forming standby state continues. At this time, the developing unit and the cleaning unit configured in the closed space are not easily affected by the external environmental temperature and humidity, and can easily maintain the temperature and humidity during the image forming operation even if the image forming standby state continues. Therefore, a temperature / humidity difference occurs between the surface of the photoreceptor surface facing the developing unit and the cleaning unit at the time of standby for image formation and the other surface.

Generally, the exposure sensitivity of an image carrier such as a photoconductor varies depending on the temperature and humidity of the atmosphere near the photoconductor. Normally, since the photosensitive drum rotates during the image forming operation of the image forming device, there is almost no variation in exposure sensitivity due to the temperature and humidity of the atmosphere, but in the image forming standby state after the image forming operation, A difference in height occurs in the partial atmospheric humidity in the vicinity of the photoconductor, and the exposure sensitivity of the photoconductor partially fluctuates.
Due to the partial fluctuation of the exposure sensitivity, the surface potential of the image carrier after the exposure partially fluctuates, and when the image forming operation is resumed, an image abnormality such as an image density unevenness occurs.

In the image forming apparatus disclosed in Patent Document 1, when the detection unit detects that the atmospheric humidity around the photosensitive drum is equal to or lower than a predetermined humidity during the image forming standby state, each of the developing unit and the cleaning unit is controlled by the control unit. The photoconductive drum is rotated so that the humidity of the surface of the photoconductor facing the same is the same as the humidity of the open photoconductor surface.
The amount of rotation of the photosensitive drum at this time is controlled to be a width corresponding to the longer one by comparing the width of the photosensitive member surface facing the developing device with the width facing the cleaning unit.
This eliminates the non-uniformity of the humidity on the surface of the photoconductor drum by exposing the surface of the photoconductor facing each of the developing unit and the cleaning unit to the same humidity as the surface of the opened photoconductor. Thus, occurrence of uneven image density can be prevented.

  Abnormalities such as motor lock can occur in the driving means for driving the image carrier. This is due to a load of a cleaning blade that is provided in the cleaning unit and cleans the surface of the image carrier by rubbing as the image carrier rotates. For this reason, the image forming apparatus includes an abnormality detection unit for detecting an operation abnormality of the drive unit.

However, the image forming apparatus disclosed in Patent Document 1 does not describe an operation abnormality of the drive unit and an abnormality detection unit for detecting this.
Furthermore, since the image forming apparatus of Patent Document 1 has a small amount of rotation of the photosensitive drum during the image forming standby state, the start-up time of the driving motor for the photosensitive drum is shorter than that during normal image forming operation. For this reason, the rotation amount of the photosensitive drum during the image forming standby state may be less than the activation amount (rotation amount) or the activation time (rotation time) for the abnormality detection means to detect an operation abnormality.
Accordingly, there is a problem that the drive motor cannot be detected during the image forming standby state and the drive motor is destroyed.

In the above example, the case where the developing device and the cleaning device are provided has been described. However, the present invention is not limited to this, and a difference in temperature and humidity is generated by comparing the atmosphere in the vicinity of the photoconductor during the image forming operation and the image forming standby state. A similar problem can occur when the device is provided opposite the photoreceptor surface.
In Patent Document 1, the rotation amount of the photosensitive drum during the image forming standby state corresponds to the longer one of the width of the photosensitive member surface facing the developing device and the width facing the cleaning unit. The amount of rotation is such that the width is reached. If the surface position of the photoconductor is not limited to this rotation amount, the temperature / humidity difference on the surface of the photoconductor can be reduced as compared with the case where the surface position is not shifted.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an image forming apparatus capable of preventing an image abnormality due to a surface potential difference of an image carrier and preventing a driving unit of the image carrier from being destroyed. It is to be.

In order to achieve the above object, the present invention comprises an image carrier and control means, and the control means controls the image carrier to rotate during the image formation standby state of the image carrier. In the device
A drive unit that drives the image carrier; and an abnormality detection unit that detects an abnormal operation of the drive unit; and the control unit includes at least the abnormality detection unit during an image forming standby state of the image carrier. Control is performed so that the image carrier is rotated so as to satisfy an activation amount or an activation time for detecting an abnormality.

  According to the present invention, it is possible to prevent image abnormality due to the surface potential difference of the image carrier and to prevent the driving means of the image carrier from being destroyed.

1 is a schematic diagram illustrating a configuration of an image forming apparatus of an image forming apparatus according to an embodiment. It is a block diagram which shows the structure of the control system of the image forming apparatus in the image forming apparatus. It is a graph which shows the relationship between the photoreceptor surface potential after exposure in the conventional image forming apparatus, and the surface position of a photoreceptor. It is a schematic diagram which shows the state in which the abnormal image has generate | occur | produced in the imaging device of FIG. 3 is a graph showing a relationship of an image density difference with respect to a photosensitive member rotation period in Example 1. 10 is a timing chart illustrating an example of the operation of the image forming apparatus according to the second embodiment. 6 is a flowchart illustrating the operation of a photoconductor in Example 3. 10 is a flowchart illustrating a modified example of the operation of the photosensitive member according to the third exemplary embodiment. 6 is a flowchart illustrating the operation of a photoconductor in Example 4.

Hereinafter, an embodiment in which the present invention is applied to a printer as an image forming apparatus will be described.
FIG. 1 is a schematic diagram illustrating a configuration in the vicinity of an image forming apparatus 100 of a printer according to the present embodiment.
FIG. 2 is a block diagram illustrating a configuration of a control system of the image forming apparatus 100.
In addition to the image forming apparatus 100, the printer includes a paper stacking unit that stores paper as a transfer material, a transport device that transports the paper from the paper stacking unit, and a sheet on which an image is printed is discharged to the outside of the image forming apparatus. Equipped with a discharging device. (Neither shown)

  As shown in FIG. 1, the image forming apparatus 100 includes a photosensitive member 1 as an image carrier, a charger 2 as a charging unit, an exposure device 3, a developing device 4 as a developing unit, a transfer unit 5, and a cleaning unit. A cleaning device 6, a lubricant application device 7 as a lubricant application means, and a fixing device 8 are provided. Further, the image forming apparatus 100 is connected to a controller 110 that is a control unit, and is driven and controlled.

The photosensitive member 1 as an image carrier in the present embodiment is a drum-shaped photosensitive drum, but is not limited thereto, and can be applied to, for example, a belt-shaped photosensitive belt. In response to the image forming operation start signal from the controller 110, the photoconductor 1 rotates at a speed corresponding to the printing speed (process linear speed) of the image forming apparatus.
The charger 2 is a corona discharge method using a corotron. When the photosensitive member 1 starts rotating, a high voltage is applied by a high voltage power source (not shown) to uniformly charge the surface of the photosensitive member 1. In the present embodiment, the surface of the photoreceptor 1 is uniformly charged with a negative charge. In the present embodiment, the charger 2 employs a corona discharge method using a corotron, but is not limited thereto, and a corona discharge method using a scorotron provided with a grid, a contact type using a roller, or a non-contact type roller charging method. Can be adopted.

The cleaning device 6 includes a cleaning blade 6a, a cleaning brush 6b, and a recovery conveyance roller 6c. The cleaning blade 6 a is installed in contact with the surface of the photoreceptor 1, and the cleaning brush 6 b is installed in contact with the surface of the photoreceptor 1. During the image forming operation, residual toner on the photosensitive member 1 is cleaned by the cleaning blade 6a and the cleaning brush 6b, and is transported to a recovery unit (not shown) by the recovery transport roller 6c.
The fixing device 8 is formed by a pair of fixing rolls 8a and 8b, at least one of which is a heating roll, and heats and presses a sheet having a toner image adsorbed on the surface at the nip portion of the fixing rolls 8a and 8b. The toner image is melted and fixed on the surface of the paper 101.

As shown in FIG. 2, these image forming apparatuses 100 are connected to a controller 110 as control means, and each drive control is controlled. For example, the photoconductor 1 is driven and controlled by the controller 110 via a drive circuit 1 a that rotates the photoconductor 1.
The controller 110 is configured by a microcomputer including a CPU, a ROM, a RAM, and the like, and is realized by executing software. Further, a counter, a timer and the like are operable even when the main power is cut off by a backup power supply device (not shown).

An image forming operation in the present embodiment will be described.
The photoconductor 1 starts rotating upon receiving an image forming operation start signal from the controller 110, and the surface of the photoconductor 1 is uniformly charged with a negative charge by the charger 2. The rotation of the photosensitive member 1 is continuously performed until the image forming operation is completed.
When character data or graphic data is input from an external device (not shown), it is converted into a dot image and sent to the printer as an on / off signal of the exposure device 3 via the controller 110. The exposure device 3 receives this on / off signal from the printer, and partially irradiates the photoreceptor 1 with laser light or the like to partially eliminate the charge on the surface of the photoreceptor 1 to form an electrostatic latent image.

When the point where the charge on the surface of the photoconductor 1 disappears reaches a position facing the developing device 4, the negatively charged toner is attracted to the surface of the photoconductor 1 by static electricity, and a toner image is formed on the surface of the photoconductor 1. Form. As the developing device 4, any one of a so-called one-component developing method and two-component developing method can be applied.
At this time, the sheet 101 is conveyed to a nip portion between the photosensitive member 1 and the transfer unit 5 by a conveyance unit (not shown), and the transfer unit 5 applies a charge having a polarity opposite to that of the toner image to the lower surface in the drawing. When the portion where the toner image is formed on the surface of the photosensitive member 1 faces the transfer device 5, the paper 101 having a charge opposite in polarity to the toner image sucks the toner image.

The surface of the photosensitive member 1 that has passed through the transfer device 5 has residual toner attached thereto, and is cleaned by passing through the cleaning device 6. The lubricant application device 7 improves the cleaning capability of the cleaning device 6 and the photosensitive member 1. Lubricant is applied for protection.
On the other hand, the sheet 101 on which the toner image is adsorbed is conveyed to the fixing device 8, where the toner image is melted and fixed at the nip portions of the fixing rolls 8a and 8b, and then discharged from the discharge unit (not shown) to the outside of the printer.

  In this embodiment, the printer as the image forming apparatus uses a single color image forming apparatus having one image carrier. However, the printer can also be applied to, for example, a multicolor image forming apparatus having a plurality of image carriers. .

Hereinafter, the rotation of the photosensitive member 1 during the image forming standby state in the present embodiment will be described.
First, the drive motor abnormality detection means in this embodiment will be described.
In the present embodiment, a drive motor (not shown) that drives the photosensitive member 1 has a torque performance that matches the process linear velocity. For example, when a torque value higher than a predetermined value is applied to the drive motor due to the turning of the cleaning blade 6a, the rotation of the drive motor is locked by this torque performance.
Further, the drive motor in the present embodiment has a lock detection means 1b which is an abnormality detection means for detecting the lock state. The lock detection unit 1 b is connected to the controller 110 and transmits a detected signal to the controller 110. In order to operate this lock detecting means 1b stably, it is necessary to operate the drive motor for a predetermined start amount or a predetermined start time for detecting an abnormality.

  In this embodiment, the detection method of the lock detection means 1b is to detect the rotation speed of the drive motor based on the transmission interval of the pulse signal transmitted in accordance with the rotation of the drive motor, and determine the lock state of the drive motor from this rotation speed. Detected. Further, in the present embodiment, it is necessary to operate the drive motor for 500 msec or more as a startup amount necessary for the lock detection unit 1b to detect an abnormality of the drive motor.

  The amount of rotation of the photosensitive member 1 can be obtained by the equation “the amount of rotation of the rotating member ≧ the process linear speed × the driving amount of the driving unit”.

  In this embodiment, the process linear velocity (photosensitive member peripheral speed) of the image forming device is 540 mm / sec, and the diameter of the photosensitive member 1 is 100 mm. Therefore, the rotation amount of the photoconductor 1 when the drive motor is activated for 500 msec or more is controlled via the controller 110 so that the surface position of the photoconductor 1 moves by 270 mm or more. As a result, since the lock detection unit 1b satisfies the startup amount necessary for detecting an abnormality of the drive motor, it is possible to prevent the drive motor that is the drive unit of the photoreceptor 1 from being destroyed.

Next, the temperature and humidity of the atmosphere around the photoreceptor 1 in the image forming standby state after the image forming operation is completed will be described.
As shown in FIG. 1, the developing device 4 and the cleaning device 6 are each configured in a closed space to prevent toner scattering, and have openings A and B on the surface facing the photoreceptor 1. ing.
The temperature of the developing device 4 is the highest in the vicinity of the photoconductor 1 in the image forming standby state after the image forming operation is completed. Further, the developing device 4 has a high humidity due to moisture contained in the toner accommodated in the developing device 4, and is located at a location facing the opening surface A of the developing device 4 on the surface of the photoreceptor 1. A difference in temperature and humidity occurs in the atmosphere as compared to the atmosphere other than the relevant portion on the surface of the photoreceptor 1.
Also, in the cleaning device 6 in the image forming standby state, the humidity is high due to residual toner after cleaning and moisture of the lubricant, and the portion facing the opening surface B of the cleaning device 6 on the surface of the photoreceptor 1 is as follows. A humidity difference is generated as compared with the atmosphere other than the portion on the surface of the photoreceptor 1.

  The sensitivity of the charge generation layer on the surface of the photoreceptor 1 is easily affected by humidity. For this reason, the exposure sensitivity is partially affected by a partial humidity difference generated between the surface of the photosensitive member 1 facing the opening surface of the developing device 4 and the cleaning device 6 after the image forming operation is completed and the other surface of the photosensitive member 1. There is a big difference.

FIG. 3 is a graph showing the relationship between the photoreceptor surface potential after exposure and the surface position of the photoreceptor in a conventional image forming apparatus. FIG. 4 is a schematic diagram showing a state in which an abnormal image is generated in the image forming apparatus of FIG.
In the conventional image forming apparatus, the exposure potential of the photoconductor in the low temperature and low humidity environment (10 ° C. and 15% environment) is as shown in FIG. 3 when the photoconductor is not rotated after the image forming operation. A difference occurs in the cycle of the position X facing the developing unit and the position Y facing the cleaning unit.
Table 1 shows the level of density unevenness with the elapsed time in the image forming standby state in which the photoconductor after the image forming operation of the image forming apparatus is not rotated.

In Table 1, the case where there is no density unevenness is indicated by “◯”, the case where the density unevenness is minute is indicated by “Δ”, and the case where the density unevenness is remarkable is indicated by “X”. As shown in Table 1, the level of density unevenness deteriorates with the elapsed time after the image forming operation, and when about 20 minutes have passed after entering the image forming standby state, the exposure potential difference becomes 20 V or more, and the density unevenness occurs. Become prominent. At this time, for example, when a halftone image is printed, as shown in FIG. 4, the image density such as the position X facing the position of the developing means on the surface of the photoreceptor 1 and the position Y facing the cleaning means is remarkably high. As a result, density unevenness occurs. A similar trend was seen in the 15 degree 30 percent environment.

  In the present embodiment, control is performed so that arbitrary points on the surface of the photoreceptor 1 do not take the same position in the rotation direction before and after the rotation of the photoreceptor 1 during the image forming standby state. As a result, the surface position of the photosensitive member 1 facing the opening surface A of the developing device 4 and the opening surface B of the cleaning device 6 does not stay at a fixed position for a long time, and image abnormalities such as density unevenness due to the surface potential difference of the photosensitive member 1 occur. Can be prevented.

<Example 1>
An example of the controller 110 in the present embodiment (hereinafter referred to as Example 1) will be described.
In the first embodiment, the photosensitive member 1 is rotated by a predetermined amount in the image forming standby state after the image forming operation. The predetermined amount is a rotation amount or a rotation time that sufficiently satisfies the activation time necessary for detecting the lock of the drive motor.
In the first embodiment, after the surface position of the photoconductor 1 is moved 360 degrees by the rotation of the photoconductor 1 during the image forming standby state, an opening surface A with the developing device 4 is formed on the surface of the photoconductor 1. The rotation of the photosensitive member 1 is stopped so that the angle α and the opening surface B of the cleaning device 6 are moved by half the larger angle of the angle β formed on the surface of the photosensitive member 1. Control by the controller 110.

  As described above, by rotating the photosensitive member 1 by one turn or more, it is possible to sufficiently satisfy the start-up time necessary for detecting the lock of the drive motor, so that an abnormality of the drive motor such as a motor lock can be detected. .

In the first embodiment, the rotation operation is controlled to operate at a predetermined time interval.
FIG. 5 is a graph showing the relationship between the image density difference and the photosensitive member rotation period in the image forming standby state according to the first embodiment.
As shown in Table 1, the difference in image density during the image forming standby state starts to become noticeable after 10 minutes have passed since the image forming operation. Therefore, the surface position of the photoconductor 1 is moved when the image forming standby state of the photoconductor 1 continues for a predetermined time or more. Then, as shown in FIG. 5, when the photosensitive member rotation period in the image forming standby state has passed 40 minutes, the developing device 4 and the cleaning device 6 on the surface of the photosensitive member face each other, and other than the corresponding portion on the photosensitive member surface. The difference in image density from this part becomes smaller with time.
Therefore, in the first exemplary embodiment, for example, a period in which the temperature of the developing device 4 and the temperature of the cleaning device 6 are in equilibrium with the environmental temperature around the photosensitive member 1 after the rotation operation of the photosensitive member is performed. The repetitive operation is stopped when 60 minutes have elapsed from the start of the image forming standby state, and the photosensitive member 1 is made to wait until the next image forming operation starts.

  As described above, the rotation operation of the photosensitive member 1 is repeated in a certain period, for example, a period of 10 minutes when the image density difference starts to become noticeable during the image standby state, so that the opening surface A of the developing device 4 or the cleaning device 6 is changed. It is possible to prevent a partial humidity difference from occurring on the surface of the photoconductor 1 without causing the surface position of the photoconductor 1 facing B to remain constant for a long time. In addition, when a predetermined time has passed such that the image density difference becomes minute, the rotation of the photosensitive member 1 is stopped to reduce power consumption and wear of components in the image forming apparatus 100. Can do.

<Example 2>
Another example (hereinafter referred to as Example 2) of the controller 110 in the present embodiment will be described.
FIG. 6 is a timing chart illustrating an example of the operation of the image forming apparatus according to the second embodiment.
In the second embodiment, the control means controls the controller 110 so that the image forming apparatus 100 is driven in an image forming standby state and intermittently drives the developing device 4 when the photosensitive member 1 rotates as shown in FIG. ing.

By rotating the developing device 4, a minute amount of toner can be positively adhered to the surface of the photoreceptor 1 by van der Waals force without applying a developing bias. This adhesion can cause better adhesion in an apparatus using contact development in both the one-component development method and the two-component development method.
In this way, a small amount of toner adhering to the surface of the photosensitive member 1 is input to the cleaning blade 6a of the cleaning device 6 to serve as a lubricant. In the image forming standby state, it is possible to prevent the cleaning blade from being swollen, which is likely to occur by repeatedly rotating and stopping the photosensitive member 1 in a state where no toner is input. Therefore, as compared with the first embodiment, the effect of preventing the cleaning blade 6a of the cleaning device 6 from wobbling can be further improved. A developing bias may be applied while the developing device 4 is being driven.

<Example 3>
Still another example (hereinafter referred to as Example 3) of the controller 110 in the present embodiment will be described.
FIG. 7 is a flowchart showing the operation of the photoreceptor 1 in the third embodiment.
The image forming apparatus 100 according to the third embodiment includes a humidity sensor (not shown) for detecting the environmental humidity of the image forming apparatus 100.
As shown in FIG. 7, the controller 110 controls the rotation / stop operation of the photoconductor 1 according to the environmental humidity of the image forming apparatus 100 in the image forming standby state. An abnormal image such as density unevenness is likely to occur when the environmental humidity of the image forming apparatus 100 is a low temperature and low humidity environment. For example, when the relative humidity is 30% or less, the photosensitive member 1 is rotated and stopped at a predetermined rotation amount. The rotation / stop operation is repeated at a predetermined time period.

  In the third embodiment, as the predetermined rotation amount, an angle α formed by the opening surface A with the developing device 4 on the surface of the photosensitive member 1 and an angle β formed by the opening surface B of the cleaning device 6 on the surface of the photosensitive member 1. The rotation is stopped after rotating to a position obtained by adding 360 degrees to the half of the larger angle α. Further, this rotation / stop operation is repeated at a cycle of 10 minutes, and when 1 hour has passed since the start of the image formation standby state, the operation is stopped and waits until the next image formation start.

  As described above, by using the humidity sensor, the surface position of the photoconductor 1 facing the opening surfaces A and B of the developing device 4 and the cleaning device 6 does not stay at a fixed location for a long time, but a partial surface of the photoconductor 1 surface. It is possible to prevent the humidity difference from occurring. In addition, the photosensitive member 1 can be rotated only under a predetermined condition, and power consumption and wear of components in the image forming apparatus 100 can be reduced as compared with the first or second embodiment.

FIG. 8 is a flowchart showing a modified example of the operation of the photosensitive member 1 in the third embodiment.
The atmosphere in the vicinity of the photoconductor immediately after the completion of the image forming operation is almost constant, and the density unevenness due to a partial temperature and humidity difference on the surface of the photoconductor is very small. For this reason, the rotation operation of the photosensitive member 1 during the image forming standby state may be controlled so as to start after a predetermined time has elapsed in the image forming standby state.

In this modified example, as shown in Table 1, since density unevenness does not occur until the image forming standby state has elapsed for 10 minutes, the rotation operation of the photoconductor 1 during the image forming standby state is performed. It is controlled to start after 10 minutes have passed. Further, in this modification, as shown in FIG. 7, control is performed so as to start after the image forming standby state has elapsed for 10 minutes and when the humidity sensor has a predetermined value, for example, relative humidity is 30% or less. ing.
Thereby, it is possible to reduce power consumption and wear of components in the image forming apparatus 100 as compared with other embodiments.

<Example 4>
Still another example (hereinafter referred to as Example 4) of the controller 110 in the present embodiment will be described.
FIG. 9 is a flowchart showing the operation of the photoreceptor 1 in the fourth embodiment.
The image forming apparatus 100 according to the fourth embodiment includes a temperature sensor (not shown) for detecting the environmental temperature of the image forming apparatus 100.
As shown in FIG. 9, the controller 110 controls the rotation / stop operation of the photosensitive member 1 according to the environmental temperature of the image forming apparatus 100 in the image forming standby state. For example, when the predetermined temperature is 15 degrees, when it is detected that the environmental temperature of the image forming apparatus is 15 degrees or less in the image forming standby state, the photosensitive member 1 is rotated / stopped by a predetermined rotation amount via the controller 110. The humidity sensor in FIG. 8 can be replaced with a temperature sensor. Since the subsequent operation is the same as that of the third embodiment, the description thereof is omitted.

As described above, by using the temperature sensor, the surface position of the photoconductor 1 facing the opening surfaces A and B of the developing device 4 and the cleaning device 6 does not stay at a fixed position for a long time, but a partial surface of the photoconductor 1 surface. A temperature difference can be prevented from occurring. Further, the photoconductor 1 can be rotated only under a predetermined condition, and power consumption and wear of components in the image forming apparatus 100 can be reduced as compared with the first embodiment.
In the fourth embodiment, no humidity detecting means is used. However, when the image forming apparatus 100 is in a low temperature environment, it is generally in a low humidity state, and therefore only the temperature detecting means can be used.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
An image forming apparatus including an image carrier such as the photosensitive member 1 and a control unit such as a controller 110, wherein the control unit controls the image carrier to rotate during an image formation standby state of the image carrier.
Drive means such as a drive motor for driving the image carrier, and abnormality detection means such as a lock detection means 1b for detecting an operation abnormality of the drive means, and the control means is in an image forming standby state of the image carrier. In the meantime, the image carrier is controlled to rotate so as to satisfy at least the activation amount or the activation time for the abnormality detection means to detect the abnormality.

  In this aspect, the rotation amount of the photosensitive member 1 during the image forming standby state is controlled to be equal to or more than the activation amount for the lock detection unit 1b to detect an abnormality in the drive motor. Thereby, since the lock | rock detection means 1b satisfy | fills the starting amount required in order to detect abnormality of a drive motor, destruction of the drive motor of the photoreceptor 1 can be prevented.

Further, as the rotation amount of the photosensitive member 1 during the image forming standby state, any point on the surface of the photosensitive member 1 is the same in the rotation direction before and after the rotation of the photosensitive member 1 during the image forming standby state. It is controlled not to take a position.
As a result, the position of the surface of the photoconductor 1 facing the opening surfaces A and B of the developing device 4 and the cleaning device 6 does not stay at a fixed location for a long time, and a partial humidity difference on the surface of the photoconductor 1 is prevented. Can do. Therefore, image abnormalities such as density unevenness due to the surface potential difference of the photoreceptor 1 can be prevented.

(Aspect B)
In aspect A, the image forming apparatus includes a developing unit such as a developing machine 4 that develops the developer by attaching a developer to the electrostatic latent image formed on the image carrier such as the photoconductor 1, and the control unit such as the controller 110 includes: The rotation of the image carrier is controlled so that an arbitrary surface position of the image carrier is moved at least one turn of the image carrier during an image forming standby state of the image carrier such as the photoreceptor 1. It is characterized by that.
In this embodiment, since the photosensitive member 1 is rotated by one turn or more, the start-up time necessary for detecting the lock of the drive motor can be sufficiently satisfied, so that an abnormality of the drive motor such as a motor lock can be detected. it can. Therefore, it is possible to prevent the drive motor that is the drive means of the photosensitive member 1 from being destroyed.

(Aspect C)
In the aspect A or B, the developing means such as the developing device 4 that develops the developer by attaching the developer to the electrostatic latent image formed on the image carrier such as the photosensitive member 1 and the surface of the image carrier. Cleaning means such as a cleaning device 6 for removing the developed developer, and the control means sets the surface position of the image carrier one round of the image carrier during the image forming standby state of the image carrier. And an angle formed by the surface position of the image carrier facing the developing unit and an angle formed by the surface position of the image carrier facing the cleaning unit. Among these, the rotation of the image carrier is controlled so as to move by half the larger angle.

  As a result, the position of the surface of the photoconductor 1 facing the opening surfaces A and B of the developing device 4 and the cleaning device 6 does not stay at a fixed location for a long time, and a partial humidity difference on the surface of the photoconductor 1 is prevented. Can do. Therefore, image abnormalities such as density unevenness due to the surface potential difference of the photoreceptor 1 can be prevented. In addition, by rotating the photosensitive member 1 by one or more revolutions, it is possible to sufficiently satisfy the start-up time necessary for detecting the lock of the drive motor, so that an abnormality of the drive motor such as a motor lock can be detected. Therefore, it is possible to prevent the drive motor that is the drive means of the photosensitive member 1 from being destroyed.

(Aspect D)
In any one of the aspects A to C, the control unit such as the controller 110 moves the surface position of the image carrier when the image formation standby state of the image carrier continues for a predetermined time or more. The rotation of the image carrier is controlled.
In this aspect, control is performed so that the rotating operation of the photosensitive member 1 is started when the standby state continues until a predetermined time when the density unevenness becomes remarkable. Thereby, compared with another aspect, power consumption and wear of components in the image forming apparatus 100 can be reduced.

(Aspect E)
In any one of the aspects A to D, the control unit such as the controller 110 rotates the image carrier at a constant cycle during an image forming standby state of the image carrier such as the photoconductor 1 to make a constant After the rotation for a period of time, control is performed so that the image forming device is kept waiting until the next image forming operation.
In this embodiment, the surface position of the photosensitive member 1 facing the opening surfaces A and B of the developing device 4 and the cleaning device 6 is fixed by repeating the rotating operation of the photosensitive member 1 at a constant cycle during the image forming standby state. It is possible to prevent the occurrence of a partial humidity difference on the surface of the photosensitive member 1 without staying at this point for a long time. Further, by stopping the rotation of the photosensitive member 1 when a predetermined time has passed such that the difference in image density becomes small, the power consumption and the internal capacity of the image forming apparatus 100 can be reduced as compared with other modes. The wear of components can be reduced.

(Aspect F)
In any one of the aspects A to E, the controller 110 includes a developing unit such as a developing unit 4 that develops an electrostatic latent image formed on the image carrier such as the photosensitive member 1 by attaching a developer to the electrostatic latent image. The control device is configured to control the developing unit to be driven when the image carrier is in an image forming standby state and when the image carrier is rotationally driven.
In this embodiment, by rotating the developing device 4, a small amount of toner can be positively attached to the surface of the photoreceptor 1 by van der Waals force without applying a developing bias. Thereby, a small amount of toner adhering to the surface of the photosensitive member 1 serves as a lubricant, and compared with the other embodiments, the effect of preventing the cleaning blade 6a of the cleaning device 6 from curling can be increased, and the load on the drive motor is increased. Can be reduced.

(Aspect G)
In any one of the aspects A to F, the apparatus includes environmental humidity detection means such as a humidity sensor that detects environmental humidity of the image forming apparatus such as the image forming apparatus 100, and the control means is based on the environmental humidity detection means. Based on the detection result, the rotation operation of the image carrier is controlled during the image forming standby state of the image carrier.
In this aspect, when the relative humidity of the image forming apparatus 100 in the image forming standby state is 30% or less, the photosensitive member 1 is rotated by a predetermined rotation amount, and this rotation operation is repeated at a predetermined time period.
Thereby, the photoconductor 1 can be rotated only under a predetermined condition, and power consumption and wear of components in the image forming apparatus 100 can be reduced as compared with other modes.

(Aspect H)
In any one of the aspects A to G, the image forming apparatus includes an environmental temperature detection unit such as a temperature sensor that detects an environmental temperature of the imaging apparatus, and the control unit is based on a detection result by the environmental temperature detection unit. The rotation operation of the image carrier is controlled during the image formation standby state of the image carrier.
In this embodiment, when the environmental temperature of the image forming apparatus 100 in the image forming standby state is 15 degrees or less, the photosensitive member 1 is rotated by a predetermined rotation amount, and this rotation operation is repeated at a predetermined time period.
Thereby, the photosensitive member 1 can be rotated only under a predetermined condition, and power consumption and wear of the apparatus in the image forming apparatus 100 can be reduced as compared with other modes.

(Aspect I)
In an image forming apparatus, comprising an image carrier such as a photosensitive member 1 and a control unit such as a controller 110, wherein the control unit controls the image carrier to rotate during an image forming standby state of the image carrier. The image forming apparatus according to any one of aspects A to H is provided.
As a result, it is possible to prevent image abnormality due to the surface potential difference of the image carrier and to prevent the driving means of the image carrier from being destroyed.

DESCRIPTION OF SYMBOLS 1 Photoconductor 1b Lock | rock detection means 2 Charging device 3 Exposure apparatus 4 Developing machine 5 Transfer device 6b Cleaning brush 6a Cleaning blade 6c Recovery conveyance roller 6 Cleaning device 7 Lubricant coating device 8a, 8b Fixing roll 8 Fixing device 100 Imaging device 101 Paper 110 Controller A, B Aperture plane X Position Y Position α Angle β Angle

Japanese Patent No. 3945423

Claims (9)

In an image forming apparatus comprising an image carrier and control means, wherein the control means controls the image carrier to rotate during an image formation standby state of the image carrier.
A drive unit that drives the image carrier; and an abnormality detection unit that detects an abnormal operation of the drive unit; and the control unit includes at least the abnormality detection unit during an image forming standby state of the image carrier. An image forming apparatus, wherein the image carrier is controlled to rotate so as to satisfy an activation amount or an activation time for detecting an abnormality.   2. The image forming apparatus according to claim 1, further comprising developing means for developing a developer on the electrostatic latent image formed on the image carrier, wherein the control means is in an image forming standby state of the image carrier. The rotation of the image carrier is controlled so that the position of the surface of the image carrier facing the opening surface of the closed space of the developing unit moves during at least one turn of the image carrier. An imaging device.   3. The image forming apparatus according to claim 1, wherein developing means for developing the electrostatic latent image formed on the image carrier by developing the developer and removing the developer attached to the surface of the image carrier. And a cleaning unit that moves the surface position of the image carrier by one turn of the image carrier during an image forming standby state of the image carrier, and further, the image carrier. Of the surface of the image carrier facing the developing unit and the angle formed by the surface position of the image carrier facing the cleaning unit An image forming apparatus, wherein the rotation of the image carrier is controlled so as to be moved by a half angle.   4. The image forming apparatus according to claim 1, wherein the control unit moves the surface position of the image carrier when the image formation standby state of the image carrier continues for a predetermined time or more. An image forming apparatus that controls rotation of a carrier.   5. The image forming apparatus according to claim 1, wherein the control unit rotates the image carrier at a constant cycle during an image forming standby state of the image carrier and rotates the image carrier for a certain period. An image forming apparatus, wherein the image forming apparatus is controlled to wait until the next image forming operation.   6. The image forming apparatus according to claim 1, further comprising developing means for developing the electrostatic latent image formed on the image carrier by attaching a developer to the electrostatic latent image, and the control device includes the image carrier. Is an image forming standby state, and controls to drive the developing means when the image carrier is driven to rotate.   The image forming apparatus according to any one of claims 1 to 6, further comprising an environmental humidity detecting unit that detects an environmental humidity of the image forming apparatus, wherein the control unit is based on a detection result by the environmental humidity detecting unit. An image forming apparatus, wherein the rotation operation of the image carrier is controlled during the image formation standby state of the image carrier.   The image forming apparatus according to any one of claims 1 to 7, further comprising an environmental temperature detecting unit that detects an environmental temperature of the image forming device, wherein the control unit is based on a detection result by the environmental temperature detecting unit. An image forming apparatus, wherein the rotation operation of the image carrier is controlled during the image formation standby state of the image carrier.   9. An image forming apparatus comprising: an image carrier and a control unit, wherein the control unit controls the image carrier to rotate during an image forming standby state of the image carrier. An image forming apparatus comprising an image forming device.