JPH08320643A - Image forming device - Google Patents

Abstract

PURPOSE: To provide an image forming device constituted so that the surface of a photoreceptor drum is always coated with the proper quantity of lubricant. CONSTITUTION: The image forming device is constituted so that the surface of the photoreceptor drum 10 is coated with the lubricant by a lubricant coating roller 11. By a clutch 16 actuated by the control action of a CPU1, the roller 11 is faced and brought into contact with the surface of the drum 10 with a timing synchronous with the carrying action of a transfer paper. The roller 11 is rotated at a rotational speed set by a rotational speed set unit 15 in an identical direction to the drum 10 by a photoreceptor driving motor 14. Then, the circumferential surface of the drum 10 is coated with the lubricant 12 pressed to the circumferential surface of the roller 11 by a spring 13 on the condition of an optimum quantity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus provided with a coating means for coating a lubricant on the surface of an image bearing member or an intermediate transfer member.

[0002]

2. Description of the Related Art In a conventional image forming apparatus, an image carrier is uniformly charged by a charging charger, an electrostatic latent image is formed on the image carrier by an exposure optical system, and an image is transferred between transfer sheets by an eraser. The unnecessary charges in the area and the non-image area at both ends of the transfer paper are removed. Next, the developing device supplies toner to the electrostatic latent image to form a toner image on the image carrier, and when an intermediate transfer member is used, the toner image on the image carrier is transferred to the intermediate transfer member. .

The toner image on the intermediate transfer member, or the toner image on the image bearing member when the intermediate transfer member is not used,
The transfer paper is transferred to the charged transfer paper by corona discharge, and the transfer paper electrostatically adsorbed on the image carrier is separated by removing the charge from the transfer paper by the corona discharge of the separation charger. Then, it is conveyed to a fixing device and subjected to a fixing process by being heated and pressed.

In this case, when an image carrier that has not been transferred in the transfer step and an intermediate transfer member are used, the residual toner on the intermediate transfer member is further cleaned by a cleaning device to remove the toner. The image carrier, after the corona discharge by the charge removal charger, and electrostatically initialized by light irradiation by the charge removal lamp, the exposure step described above,
The developing process and the fixing process are repeated.

In such an image forming apparatus, it has been proposed to apply a lubricant such as zinc stearate to the surface of the image bearing member or the intermediate transfer member, and by applying the lubricant, (1) The surface friction coefficient of the image bearing member or the intermediate transfer member decreases, and (2) the surface of the image bearing member is constantly refreshed by repeating the coating and scraping operation of the lubricant, and (3) the lubricant adheres to the toner. The fluidity of the recovered toner is maintained.

(1) When the surface friction coefficient of the image bearing member or the intermediate transfer member is lowered, the progress of wear of the surface of the image bearing member or the edge portion of the cleaning blade is suppressed, and the deterioration of the cleaning performance is prevented. Further, the attraction force with the toner is reduced, the amount of non-adhered toner in the non-image area is reduced, and the transfer paper is prevented from being contaminated with toner. Further, the toner easily migrates to the transfer paper, the insect-eating transfer white spots that tend to occur in line images are reduced, the transfer electric field is reduced, and the toner image carrier due to the separation discharge at the time of separation of the transfer paper. Reattachment is prevented.

(2) If the surface of the image carrier is constantly refreshed by repeating the coating and scraping operation of the lubricant, non-adhesion of the fine powder additive in the toner to the surface of the image carrier is prevented, and the fine powder additive is prevented. It is prevented that the resin as the main component of the toner grows into spindle-shaped spots by using as a core, and is developed without being removed by the charge removal in the exposure step to deteriorate the image quality and damage the cleaning blade edge.

(3) If the lubricant adheres to the toner and the fluidity of the recovered toner is maintained, the fluidity is lowered and the toner is adhered to the toner to damage the transport path or the cleaning unit. To be prevented.

In a conventional image forming apparatus, as shown in FIG. 7, when a scan of an optical unit is started by turning ON a print key of the apparatus, a roller for applying a lubricant starts to operate, and an image carrier is formed. The lubricant was applied to the intermediate transfer member and the lubricant was continuously applied until the copying operation was completed.

[0010]

As described above, by applying a trace amount of lubricant to the image carrier and the intermediate transfer member,
Although the effects as described in (1) to (3) can be obtained, this can be said in the case of an appropriate amount of coating. If the coating amount is small, these effects cannot be obtained, and if the coating amount is excessive. On the contrary, there arises a problem that the toner adhering to the background portion is increased more and the electrostatic characteristics of the image carrier are changed, so that a stable image cannot be obtained.

In this case, for example, as shown in FIG. 7A, the non-sheet passing time a before and after passing the transfer sheet at the time of copying one sheet,
Since c is longer than the paper non-passing time b during continuous copying, the optimum amount of lubricant applied differs between continuous copying and copying one sheet at a time.

The present invention has been made in view of the present situation of lubricant application in the image forming apparatus as described above, and an object thereof is to provide an image forming apparatus capable of always applying an appropriate amount of lubricant. Especially.

[0013]

In order to achieve the above object, the invention according to claim 1 provides an image forming apparatus provided with a coating means for coating a lubricant on the surface of an image bearing member or an intermediate transfer member. , At the timing synchronized with the transfer paper conveyance,
It is characterized in that it has control means for causing the application means to apply the lubricant.

Similarly, in order to achieve the above-mentioned object, the invention according to claim 2 is the image forming apparatus according to claim 1, wherein the amount of lubricant applied by the applying means is changed according to the size of the transfer paper. It is characterized in that a coating amount setting means for setting is provided.

Similarly, in order to achieve the above object, the invention according to claim 3 sets the lubricant applying time of the applying means to the image forming apparatus according to claim 1 according to the size of the transfer paper. It is characterized in that a coating time setting means is provided.

[0016]

According to the present invention, in the image forming apparatus having the coating means for coating the surface of the image carrier or the intermediate transfer body with the lubricant, the image carrying means is operated by the control means by the control means. On the surface of the body or intermediate transfer body,
The lubricant is applied at the timing synchronized with the transfer sheet transfer.

According to the second aspect of the present invention, in the image forming apparatus having the coating means for coating the surface of the image carrier or the intermediate transfer body with the lubricant, the coating amount setting means is used to adjust the size of the transfer paper. , The lubricant application amount of the application device is set, and the application device operated by the control of the control device applies the set application amount to the surface of the image carrier or the intermediate transfer member at a timing synchronized with the conveyance of the transfer paper. Lubricant is applied.

According to the third aspect of the invention, in the image forming apparatus provided with the coating means for coating the surface of the image carrier or the intermediate transfer body with the lubricant, the coating time setting means is used.
The lubricant application time of the application means is set according to the size of the transfer paper, and the application of the lubricant is performed on the surface of the image carrier or the intermediate transfer body by the application means operated by the control of the control means. The coating is performed for a set coating time at the timing synchronized with the transportation.

[0019]

【Example】

[First Embodiment] A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory diagram showing the configuration of this embodiment, and FIG. 2 is a time chart showing the operation of this embodiment.

In this embodiment, as shown in FIG. 1, a CPU 1 for controlling the whole operation is provided, and this CPU 1 is
An optical unit 4 including an exposure lamp 2 and a photo sensor 3 for optically capturing an image of an original 6 on a contact glass 5, a tray selection key for selecting the size of a transfer sheet, and a ROM 8 storing an operation control program. , And a RAM 9 to which various data during operation are read and written.

On the other hand, on the peripheral surface of the photosensitive drum 10 on which the electrostatic latent image of the original 6 and the toner image corresponding to the electrostatic latent image are formed, the photosensitive drum is rotatable in the same direction as the photosensitive drum 10. A lubricant applying roller 11 which can be brought into and out of contact with the drum 10 is disposed in contact with the drum 10, and a lubricant 12 such as zinc stearate is pressed against the lubricant applying roller 11 by a spring 13.

Further, the photoconductor drum 10 is connected with a photoconductor drive motor 14 for rotatably driving the photoconductor drum 10, and the photoconductor drive motor 14 is connected with a rotation speed setting device 15, which is a rotation speed setting device. A clutch 16 for connecting and disconnecting the lubricant applying roller 11 with respect to the photosensitive drum 10 is connected to the clutch 15.
1 is connected. Further, the photoconductor drive motor 14 and the clutch 16 are connected to the CPU 1.

In the present embodiment, upon detecting the activation of the optical unit 4, the CPU 1 controls the ON / OFF of the clutch 16 based on the selection signal of the tray selection key 7 at the timing synchronized with the conveyance of the transfer sheet. It has the function of

The operation of this embodiment having such a configuration will be described. In this embodiment, when the "A4 landscape" button is operated with the tray selection key 7, as shown in FIG.
In response to the command No. 1, after a predetermined time Tr has elapsed from the ON operation of the print key, the paper passing time T1 of A4 size transfer paper
Corresponding to, the clutch 16 is turned on for αT1 hour, the lubricant applying roller 11 is brought into contact with the photosensitive drum 10, and the lubricant applying roller 11 is exposed to light at the rotation speed set by the rotation speed setting device 15. The photoconductor drum 10 is rotated in the same direction as the photoconductor drum 10 in contact with the photoconductor drum 10, and a predetermined amount of lubricant specified by the rotational speed is applied to the photoconductor drum 10. 16 is turned off.

Then, according to the instruction of the CPU 1, the time T
While the clutch 16 is kept in the OFF state for 2 seconds, after the time T2 elapses, in response to the paper passing time T1 of A4 size transfer paper,
The clutch 16 is turned on for αT1 hour. Hereinafter, in the same manner, the lubricant application operation at time αT1 is repeated with the application stopped state at time T2.

When the "A3 portrait" button is operated with the tray selection key 7, as shown in FIG.
In response to a command from the CPU 1, the clutch 16 is turned on for βT3 hours, which corresponds to the sheet passing time T3 of the A3 size transfer sheet after a predetermined time Tr has passed from the ON operation of the print key.
Therefore, the lubricant applying roller 11 contacts the photosensitive drum 10, and the lubricant applying roller 11 contacts the photosensitive drum 10 at the rotation speed set by the rotation speed setting device 15.
It rotates in the same direction as the photoconductor drum 10, and a predetermined amount of lubricant specified by the rotation speed is applied to the photoconductor drum 10,
The clutch 16 is turned off after Tr + T3 hours from the ON operation of the print key.

Then, according to a command from the CPU 1, the time T
The clutch 16 is kept in the OFF state during the period of 4, and after the time T4 elapses, in response to the sheet passing time T3 of the A3 size transfer sheet,
The clutch 16 is turned on during βT3 hours.

In the same manner, the lubricant application operation at time βT3 is repeated in the same manner with the application stopped state at time T4.

Thus, according to this embodiment, the CP
In response to the command from U1, the operation of applying the lubricant to the photoconductor drum 10 is performed at the timing synchronized with the conveyance and feeding of the transfer paper. Therefore, continuous copying with a high duty and one copy with a low duty are performed. In this case, the lubricant is applied under the optimum application conditions corresponding to each case, and high-quality image formation without background stains and density reduction becomes possible.

[Second Embodiment] A second embodiment of the present invention will be described with reference to FIGS. FIG. 3 is an explanatory diagram showing the configuration of this embodiment, and FIG. 4 is a time chart showing the operation of this embodiment.

As shown in FIG. 3, this embodiment is different from the first embodiment already described with reference to FIG. 1 in that a rotation speed setting device 15 is provided between the photoconductor drive motor 14 and the clutch 16.
Instead of the above, the rotation speed conversion controller 20 is newly connected,
The rotation speed conversion controller 20 is connected to the CPU 1A.

In this embodiment, when the CPU 1A detects the activation of the optical unit 4, it controls the ON / OFF of the clutch 16 based on the selection signal of the tray selection key 7 at the timing synchronized with the conveyance of the transfer sheet. In addition to the function for controlling the rotation speed, the rotation speed conversion controller 20 is controlled based on the selection signal of the tray selection key 7 to set the optimum rotation speed according to the transfer paper size in the lubricant application roller 11, It has the function of setting the coating amount.

The configuration of the other parts of this embodiment is the same as that of the first embodiment already described.

The operation of this embodiment having such a configuration will be described. In this embodiment, when the "A4 landscape" button is operated with the tray selection key 7, the rotation speed conversion controller 20 is in the conversion control state corresponding to the A4 landscape size by the instruction of the CPU 1A, and the lubricant application roller 11 Rotates at the rotation speed set by the rotation speed conversion controller 20.

Then, as shown in FIG.
In response to the command No. 1, after a predetermined time Tr has elapsed from the ON operation of the print key, the paper passing time T1 of A4 size transfer paper
Corresponding to, the clutch 16 is turned on for αT1 hour, and the lubricant application roller 11 is brought into contact with the photosensitive drum 10. The lubricant application roller 11 is in contact with the photoconductor drum 10 at the rotation speed set by the rotation speed conversion controller 20, rotates in the same direction as the photoconductor drum 10, and is an amount defined by the rotation speed. The lubricant is applied to the photosensitive drum 10, and the clutch 16 is turned off one hour after Tr + αT from the ON operation of the print key.

Then, in response to a command from the CPU 1, the time T
The clutch 16 is kept in the OFF state during the period of 4, and after the time T4 elapses, corresponding to the paper passing time T1 of the A4 size transfer sheet,
The clutch 16 is turned on for αT1 hour.

Thereafter, in the same manner, the lubricant application operation at time αT1 is repeated with the application stopped state at time T4.

When the "A3 portrait" button is operated with the tray selection key 7, the rotation speed conversion controller 20 is brought into the conversion control state corresponding to the A3 portrait size by the instruction of the CPU 1A, and the lubricant application roller 11 is pressed. Rotates at the rotation speed set by the rotation speed conversion controller 20.

Then, as shown in FIG.
In response to the command No. 1, after a lapse of a predetermined time Tr from the ON operation of the print key, the transfer time T3 of the A3 size transfer paper is set.
Corresponding to, the clutch 16 is turned on for βT3 hours, and the lubricant application roller 11 contacts the photosensitive drum 10. The lubricant application roller 11 is in contact with the photoconductor drum 10 at the rotation speed set by the rotation speed conversion controller 20, rotates in the same direction as the photoconductor drum 10, and is an amount defined by the rotation speed. The lubricant is applied to the photoconductor drum 10, and the clutch 16 is turned off 3 hours after Tr + βT from the ON operation of the print key.

Then, according to the instruction from the CPU 1, the time T
During time 5, the clutch 16 remains in the OFF state, and after the time T5 elapses, in response to the paper passing time T3 of A3 size transfer paper,
The clutch 16 is turned on during βT3 hours. Thereafter, in the same manner, the lubricant application operation at time βT3 is repeated with the application stopped state at time T5.

As described above, according to the present embodiment, in addition to the effect obtained in the first embodiment, the rotational speed conversion is performed by the instruction of the CPU 1 in accordance with the transfer paper size selected by the tray selection key 7. The controller 20 changes the rotation speed of the lubricant application roller 11 and sets the optimum application amount for the transfer paper size. Therefore, even when the paper width of the transfer paper changes, the application lubricant becomes insufficient or excessive. The optimum amount of lubricant is always applied without causing deterioration, and it is possible to form stable high-quality images without causing background stains and density reduction, corresponding to the use of transfer paper of various sizes.

[Third Embodiment] A third embodiment of the present invention will be described with reference to FIGS. FIG. 5 is an explanatory diagram showing the configuration of this embodiment, and FIG. 6 is a time chart showing the operation of this embodiment.

As shown in FIG. 5, this embodiment is different from the first embodiment already described with reference to FIG. 1 in that the CPU 1
B and the photoconductor drive motor 14 between the photoconductor drive motor 14
The motor speed controller 21 for controlling the rotation speed of is configured to be newly provided.

When detecting the activation of the optical unit 4, the CPU 1B of the present embodiment controls the ON / OFF control of the clutch 16 based on the selection signal of the tray selection key 7 at the timing synchronized with the conveyance of the transfer paper. In addition, the motor speed controller 21 controls the rotation speed of the photoconductor drive motor 14 based on the selection signal of the tray selection key 7 to set the optimum lubricant application time corresponding to the transfer paper size. It has a function.

The structure of the other parts of this embodiment is the same as that of the first embodiment already described.

The operation of this embodiment having such a configuration will be described. In this embodiment, when the "A4 landscape" button is operated with the tray selection key 7, the motor speed controller 21 causes the rotation speed of the photoconductor drive motor 14 to be the A3 size of the transfer sheet in response to a command from the CPU 1B. Accordingly, the photoconductor drum 10 is set to a preselected rotation speed, and starts rotating at the set speed.

Then, as shown in FIG. 6A, the CPU
In response to the command 1 of FIG. 1, after a predetermined time Tr has passed from the ON operation of the print key, the sheet passing time T6 of the A4 size transfer sheet is determined by the rotation speed of the photoconductor drum 10 set by the motor speed controller 21. , ΓT 6 hours, the clutch 16 is turned on. In this state, the lubricant applying roller 11 is in contact with the photosensitive drum 10 and the lubricant applying roller 1
Reference numeral 1 denotes a rotation speed set by the rotation speed setting device 15, which is in contact with the photoconductor drum 10 and rotates in the same direction as the photoconductor drum 10, and a predetermined amount of lubricant specified by the rotation speed is applied. The toner is applied to the photoconductor drum 10 for a time set by the rotation speed of the photoconductor drum 10, and the clutch 16 is turned off 6 hours after Tr + γT from the ON operation of the print key.

Then, according to the instruction from the CPU 1, the time T
While the clutch 16 is kept in the OFF state for 8 hours, after the time T8 elapses, γ corresponds to the paper passing time T6 of the A4 size transfer paper determined by the rotation speed of the photosensitive drum 10 in this case.
The clutch 16 is turned on during the time T6.

Thereafter, in the same manner, the lubricant applying operation at time γT6 is repeated with the application stopped state at time T8.

When the "A3 portrait" button is operated with the tray selection key 7, the motor speed controller 21 causes the rotation speed of the photoconductor drive motor 14 to be the A3 size of the transfer sheet in response to a command from the CPU 1B. Accordingly, the photoconductor drum 10 is set to a preselected rotation speed, and starts rotating at the set speed.

Then, as shown in FIG. 6B, the CPU
In response to the command 1 of FIG. 1, after a predetermined time Tr has elapsed from the ON operation of the print key, the sheet passing time T9 of the A3 size transfer sheet determined by the rotation speed of the photosensitive drum 10 set by the motor speed controller 21 is corresponded. , 16T is turned on for 9 hours. In this state, the lubricant applying roller 11 is in contact with the photosensitive drum 10 and the lubricant applying roller 1
Reference numeral 1 denotes a rotation speed set by the rotation speed setting device 15, which is in contact with the photoconductor drum 10 and rotates in the same direction as the photoconductor drum 10, and a predetermined amount of lubricant specified by the rotation speed is applied. The toner is applied to the photoconductor drum 10 for a time set by the rotation speed of the photoconductor drum 10, and the clutch 16 is turned off after Tr + δT9 hours from the ON operation of the print key.

Then, according to the instruction of the CPU 1, the time T
The clutch 16 remains in the OFF state for 10 hours,
After the lapse of 0, the clutch 16 is turned on for δT9 hours corresponding to the sheet passing time T9 of the A3 size transfer sheet determined by the photosensitive drum 10 in this case.

Thereafter, in the same manner, the lubricant applying operation at time δT9 is repeated with the application stopped state at time T10. As described above, the setting of the lubricant application time to be set is performed with higher accuracy than the control of the rotation speed of the lubricant application roller 11 of the second embodiment.

As described above, according to this embodiment, in addition to the effect obtained in the first embodiment, the motor speed control is executed by the command of the CPU 1 in accordance with the transfer paper size selected by the tray selection key 7. The rotation speed of the photoconductor drum 10 is controlled by the device 21, and the optimum lubricant application time according to the transfer paper size is set with high accuracy. Therefore, even if the paper width of the transfer paper changes, There is no shortage or excess, the optimum amount of lubricant is always applied, and even if the size of the transfer paper changes, the lubricant application concentration can be kept constant with higher accuracy. Corresponding to the use of transfer paper of various sizes, it becomes possible to perform stable and high-quality image formation with high accuracy without background stains and density reduction.

In each of the embodiments, the case where A4 size and A3 size are selected as the transfer paper size has been described, but the present invention is not limited to these embodiments, and transfer of various sizes is possible. It is possible to always apply the optimum amount of lubricant corresponding to the paper.

[0056]

According to the first aspect of the invention, in the image forming apparatus having the coating means for coating the surface of the image carrier or the intermediate transfer body with the lubricant, the coating means operates under the control of the control means. Since the lubricant is applied to the surface of the image carrier or the intermediate transfer body at the timing synchronized with the transfer paper conveyance, it is possible to perform continuous copying with a high duty and one copy with a low duty. By applying the lubricant under the optimum application conditions corresponding to each, stable and high-quality image formation without background stains and density reduction becomes possible.

According to the invention of claim 2, in addition to the effect obtained by the invention of claim 1, the application amount setting means sets the lubricant application amount of the application means according to the size of the transfer paper. Therefore, even if the width of the transfer paper changes, the concentration of the lubricant applied is always constant, and it is compatible with the use of transfer paper of various sizes, and stable, high-quality image formation without background stains or density reduction Will be possible.

According to the invention of claim 3, in addition to the effect obtained by the invention of claim 1, the application time setting means sets the lubricant application time of the application means according to the size of the transfer paper. Therefore, even if the width of the transfer paper changes,
The lubricant application density can always be kept constant with a higher degree of accuracy, and stable, high-quality image formation without background stains and density reduction can be performed with high accuracy, corresponding to the use of transfer paper of various sizes. Will be possible.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a time chart showing the operation of the embodiment.

FIG. 3 is an explanatory diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 4 is a time chart showing the operation of the embodiment.

FIG. 5 is an explanatory diagram showing a configuration of a third exemplary embodiment of the present invention.

FIG. 6 is a time chart showing the operation of the embodiment.

FIG. 7 is a time chart of a lubricant application operation of a conventional image forming apparatus.

[Explanation of symbols]

 1 CPU 4 Optical Unit 6 Original 7 Tray Selection Key 10 Photosensitive Drum 11 Lubricant Applying Roller 12 Lubricant 14 Photosensitive Drive Motor 15 Rotational Speed Setting Device 16 Clutch 20 Rotational Speed Controller 21 Motor Speed Controller

Claims (3)

[Claims] 1. An image forming apparatus comprising a coating means for coating a lubricant on the surface of an image carrier or an intermediate transfer body, wherein the lubricant is coated on the coating means at a timing synchronized with the transfer paper conveyance. An image forming apparatus having control means for performing the operation. 2. The image forming apparatus according to claim 1, wherein
An image forming apparatus, comprising: an application amount setting means for setting the lubricant application amount of the application means according to the size of the transfer paper. 3. The image forming apparatus according to claim 1,
An image forming apparatus, comprising: an application time setting means for setting a lubricant application time of the application means according to the size of the transfer paper.