JPH07311531A - Electrophotographic recorder - Google Patents

Abstract

PURPOSE:To prevent variance such as the increase and decrease of a lubricant on an image carrier, in an electrophotographic recorder for preventing the formation of a filming layer by coating the surface of the image carrier with the lubricant. CONSTITUTION:The electrophotographic recorder is provided with a lubricant coating means 44 coating the image carrier such as a transfer belt 23 with the lubricant 48, a detecting means 45 detecting the quantity of the lubricant on the image carrier and a control, means 46 controlling the lubricant coating means 44 based on the result of the detection of the detecting means 45. When the image carrier is coated with the lubricant 48, the lubricant coating means 44 is controlled by the control means 46 and a coating action is repeated until the result of the detection of the detecting means 45 reaches a reference value of the quantity of the lubricant on the image carrier.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic recording apparatus such as a laser copying machine, a laser printer or a laser facsimile which records on paper by an electrophotographic method. More specifically, the present invention relates to an electrophotographic recording apparatus that forms an image using toner on the surface of an image bearing member such as a photoconductor or a transfer belt.

[0002]

2. Description of the Related Art In a laser copying machine, for example, a filming layer of toner or a toner additive may be formed on the surface of an image bearing member such as a photosensitive member or an intermediate transfer member as it is used. This filming layer causes a decrease in transfer efficiency and eventually a deterioration in image quality. Therefore, it is necessary to apply a lubricant to the surface of the image carrier in order to prevent the formation of the filming layer.

Therefore, conventionally, in a laser copying machine, as shown in FIG. 15, for example, a solid lubricant 1 is used as a lubricant applying means for applying a lubricant onto an image carrier such as a photoconductor. There is a configuration in which a rotating brush 3 for scraping off the lubricant 1 little by little and applying it on the image carrier 2 and a holder 4 for holding the lubricant 1 and the rotating brush 3 are provided (Japanese Patent Application Laid-Open No. 56-56). (See Japanese Patent Publication No. 154778).

When the lubricant 1 is applied on the image carrier 2, the rotary brush 3 is rotated, and the lubricant 1 is gradually scraped by the rotary brush 3 and applied on the surface of the image carrier 2. .

[0005]

However, in such a conventional lubricant applying means, for example, the rotating brush 3 is used.
The application amount of the lubricant 1 changes due to variations in the application conditions such as, but it cannot be determined, so the image carrier 2
There was a problem that the amount of lubricant above increased or decreased.

When the amount of the lubricant on the image carrier 2 is large, the releasability between the toner and the image carrier 2 becomes too high, and the toner easily moves. The magnetic brush scrapes off the toner image and deteriorates the image, and in the transfer belt of the intermediate transfer system, retransfer of the once-transferred toner is likely to occur. On the other hand, when the amount of the lubricant on the image carrier 2 is small, the effect of preventing the filming layer formation is reduced.

Therefore, an object of the present invention is to increase or decrease the amount of the lubricant on the image carrier in an electrophotographic apparatus in which a lubricant is applied to the surface of the image carrier to prevent the formation of a filming layer. It is to prevent variation.

[0008]

Therefore, the present invention provides
For example, as shown in the illustrated embodiment below, a lubricant applying means 44 for applying a lubricant 48 onto an image carrier such as the photoconductor 20 or the transfer belt 23, and the amount of lubricant on the image carrier are detected. It is characterized by comprising a detection means 45 and a control means 46 for controlling the lubricant application means 44 based on the detection result of the detection means 45.

According to a second aspect of the present invention, for example, as shown in the following illustrated embodiment, in the electrophotographic recording apparatus according to the first aspect, the lubricant applying means 44 includes a solid lubricant 48 and a solid lubricant 48. A rotating brush 51 for scraping off the lubricant 48 little by little and applying it on the image carrier, and the lubricant 48
And a holder 47 for holding the rotary brush 51, a biasing member 54 for biasing the holder 47 to move the rotary brush 51 to the retracted position, and a drive for the holder 47 against the biasing member 54. Then, a driving means 55 for moving the rotating brush 51 to the coating position is provided.

According to a third aspect of the present invention, for example, as shown in the following illustrated embodiment, in the electrophotographic recording apparatus according to the second aspect, the lubricant 4 is applied to the lubricant applying means 44.
It is characterized in that it comprises a detection means 62 for detecting the remaining amount of No.

According to a fourth aspect of the present invention, for example, as shown in the following illustrated embodiment, in the electrophotographic recording apparatus according to the first aspect, when the lubricant 48 is applied onto the image carrier, the control is performed. The means 46 controls the lubricant applying means 44, and the applying operation is repeated until the detection result of the detecting means 45 reaches a reference value.

According to a fifth aspect of the present invention, for example, as shown in the following illustrated embodiment, in the electrophotographic recording apparatus according to the first aspect, when the lubricant 48 is applied onto the image carrier, the control is performed. The means 46 controls the lubricant applying means 44 to operate for a certain period of time. During operation, the application amount is increased until the detection result of the detection means 45 reaches a reference value, and after that, the application amount is decreased. It is characterized by

According to a sixth aspect of the present invention, the electrophotographic recording apparatus according to the first aspect of the present invention, for example, as shown in the following embodiments, the detection means 45 causes the image bearing member to be used when the recording operation is completed. When the above lubricant amount is detected and the detection result does not reach the reference value, the coating operation is repeated until the detection result of the detection means 45 reaches the reference value.

According to a seventh aspect of the present invention, for example, as shown in the following illustrated embodiment, in the electrophotographic recording apparatus according to the fourth aspect, the control is performed when the coating operation is repeated a predetermined number of times or a predetermined time. The means 46 activates the display means to give a warning.

[0015]

In the present invention, the amount of lubricant on the image bearing member is detected by the detecting unit 45, and the lubricant applying unit 44 is controlled by the control unit 46 based on the detection result, thereby lubricating the image bearing member. Apply the agent.

According to the second aspect of the present invention, when the lubricant 48 is applied on the image bearing member, the holder 47 is driven by the driving means 55 against the biasing member 54 to move the rotary brush 51 to the applying position. While moving, the rotating brush 51 is rotated to scrape off the solid lubricant 48 little by little and apply it to the image carrier. After the application, the rotation of the rotary brush 51 is stopped, the operation of the driving means 55 is stopped, and the holder 47 is moved by the urging member 54 to return the rotary brush 51 to the retracted position.

In the third aspect, the detecting means 62 detects the remaining amount of the lubricant 48.

According to the fourth aspect, when the lubricant 48 is applied onto the image carrier, the control means 46 controls the lubricant applying means 44 until the detection result of the detecting means 45 reaches the reference value. Repeat the coating operation.

According to the fifth aspect of the present invention, when the lubricant 48 is applied onto the image bearing member, the control means 46 controls the lubricant applying means 44 to operate for a certain period of time, and the detection result of the detecting means 45 is The coating amount is increased until the reference value is reached, and thereafter the coating amount is decreased.

According to the sixth aspect of the present invention, when the recording operation is completed, the detection means 45 detects the amount of the lubricant on the image carrier, and when the detection result does not reach the reference value, the control means 46. The lubricant applying means 44 is controlled by the detecting means 45.
The coating operation is repeated until the detection result of 1 reaches the reference value.

According to a seventh aspect, in the electrophotographic recording apparatus according to the fourth aspect, when the coating operation is repeated a predetermined number of times or a predetermined time, the control means 46 drives the display means to warn. .

[0022]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 14 shows a schematic structure of a color laser copying machine which is an embodiment of the present invention.

This color laser copying machine is designated by reference numeral 10 in the drawing.
The copying machine main body 11 is placed on the paper storage stand indicated by, and the color scanner 12 is placed thereon.

The paper storage stand 10 has paper feed cassettes 13 and 14 provided therein. The color scanner 12 is provided with a contact glass 15 on which an original G is set,
A light source 16, mirrors 17a, 17b and 17c, an imaging lens 18, a color sensor 19 and the like are provided inside.

The copying machine main body 11 is provided with a recording section R in the substantially center thereof. The recording unit R includes a drum-shaped photoconductor 20. Around the photoconductor 20, a charging device 21, a developing device 22, a transfer belt 23, a photoconductor cleaning device 24, and a charge eliminator 25 are sequentially provided in the driving direction shown by the arrow. Also,
An optical writing device 26 is provided on the photoconductor cleaning device 24, and a transfer belt cleaning device 27 is provided on the developing device 22 side of the transfer belt 23. Further, a conveyer 28 is provided below the developing device 22, a transfer roller 29 is provided on the right side of the conveyer 28 in the figure so as to be able to come into contact with and separate from the transfer belt 23, and a fixing device 30 is provided on the left side.

Further, the copying machine main body 11 is provided with a paper feed cassette 31 on the inner bottom thereof, while the paper feed cassette 3 is provided on the outer right side in the drawing.
2 and the manual feed tray 33 are provided at the top and bottom. Then, sheets of various sizes are stored in the sheet feeding cassettes 31 and 32 and the sheet feeding cassettes 13 and 14 described above, respectively.

By the way, more specifically, the recording section R is constructed as shown in FIG. The developing device 22 is
Black from the top in the driving direction of the photoconductor 20 (Black)
-Yellow, red (Magenta), and blue (Cyan) developing units 22a, 22b, 22c, 22
d is arranged.

The transfer belt 23 is a driving roller 23.
a, bias roller 23b, backup roller 23
c, and a plurality of other driven rollers. Then, the driving force transmitted from a driving motor (not shown) can be driven at the same speed as the photoconductor 20.

The photoconductor cleaning device 24 includes a photoconductor cleaning blade 24a. The photoconductor cleaning blade 24a is made of rubber, is supported by a blade holder 24b, and has a tip protruding from the blade holder 24b and pressed against the surface of the photoconductor 20.

The transfer belt cleaning device 27 includes a transfer belt cleaning blade 27a. The transfer belt cleaning blade 27a is made of the same rubber as the photosensitive member cleaning blade 24a, is supported by the blade holder 27b, and has its tip protruding from the blade holder 27b and pressed against the surface of the transfer belt 23. Then, the transfer belt cleaning device 27 is provided rotatably around the support shaft 27c, and the transfer belt cleaning blade 27a can be brought into contact with and separated from the transfer belt 23 according to the rotation.

When a copy of the original G is made by the color laser copying machine as described above, the original G is placed on the contact glass 15 and set as shown in FIG. 14, and the switch is pressed.

Then, the color scanner 12 reads, for example, a black image (first color image) on the original G and converts it into an electrical image signal. Then, the image signal is subjected to color conversion processing in the image processing unit to obtain color image data.

On the other hand, the photoconductor 20 is driven in the counterclockwise direction indicated by the arrow, and at that time, the surface thereof is uniformly charged by the charger 21.
An optical writer 2 on the surface thereof based on the color image data.
At 6, a laser beam is irradiated to form an electrostatic latent image. Then
When passing through the position of the black developing device 22a, the electrostatic latent image is visualized by black toner. Then, a predetermined bias voltage is applied to the bias roller 23b to transfer the black toner image onto the transfer belt 23. After transfer, photoconductor 20
The surface of is cleaned with the photoconductor cleaning blade 24a.

By repeating the same operation as described above, blue, yellow and red toner images are sequentially formed on the photoconductor 20, and the blue, yellow and red toner images are sequentially and accurately recorded on the transfer belt 23. To be transferred to the transfer belt 23 to form a color image of four-color overlapping.

Then, the paper P is sent out from the paper feed cassette 32 in the direction of arrow A, and the paper P is conveyed to the lower side of the transfer belt 23 by the registration roller 37 at a timing.

Then, a predetermined bias voltage is applied to the transfer roller 29, the transfer roller 29 is brought into contact with the transfer belt 23, and the color image is transferred onto the paper P at once.
After the transfer, the sheet P is conveyed to the fixing device 30 by the conveying device 28 and fixed there, and after the fixing, the sheet P is discharged.
At 9, the sheet is discharged onto the discharge tray 40.

After the image is transferred to the paper P, the surface of the transfer belt 23 is cleaned by the transfer belt cleaning blade 27a.

By the way, in this color laser copying machine,
As shown in FIG. 1, a lubricant application mechanism 43 is provided near the transfer belt 23. The lubricant applying mechanism 43 is
As shown in the figure, it comprises a lubricant application means 44, a detection means 45 and a control means 46.

The lubricant applying means 44 comprises a holder 47. The holder 47 is formed in a horizontally long box shape that is long in the direction orthogonal to the plane of the drawing, and a window hole 47a is opened in the left side surface in the drawing, and an arm 47b is provided by bending the edge upward from the edge of the window hole 47a and locking it to the lower surface. The portion 47c is provided so as to project downward. Inside the holder 47, the lubricant 4
8 is provided. As the lubricant 48, a lubricant containing zinc stearate as a main component is melted, then cooled and solidified to form a horizontally long plate shape. Both ends are appropriately supported between side plates of the holder 47, and the plate surface is the window. It is provided toward the hole 47a. Further, inside the holder 47, the rotary shaft 4 is provided near the window hole 47a.
9 is provided. The rotating shaft 49 is provided between the side plates of the holder 47 in parallel with the lubricant 48, and the rotating brush 51 is fixed on the shaft. The rotating brush 51 is provided so that the surface of the lubricant 48 can be rubbed, and a part of the rotating brush 51 projects from the window hole 47a. Also,
On the rotary shaft 49, rollers 5 are provided on both ends of the rotary brush 51.
2 is rotatably attached. The roller 52 has a diameter slightly smaller than that of the rotating brush 51, is rotatably provided at both ends thereof, and is provided so as to partially project from the window hole 47a.

Then, as shown in the figure, the arm 4
The tip end of 7b is attached to the support shaft 53, the holder 47 is provided rotatably around the support shaft 53, and one end of the biasing member 54 is hooked on the end of the locking portion 47c. The urging member 54 has the other end hooked appropriately on the member. Then, the holder 4 is urged by the urging force of the urging member 54.
7 is rotated counterclockwise to hold the rotating brush 51 at the retracted position where it is separated from the transfer belt 23. Further, on the right side of the holder 47 in the drawing, a driving means 55 for driving the holder 47 against the biasing member 54 is provided. The driving means 55 uses a solenoid, and the tip of the moving rod is in contact with the holder 47.

As shown in FIG. 2, the detecting means 45 uses, for example, a reflection type photo sensor, and the light projecting element 45 is used.
a and the light receiving element 45b are provided close to the transfer belt 23.

The control means 46 comprises a CPU 57. The CPU 57 is electrically connected to the detection means 45 via an A / D converter 58, and is electrically connected to the drive means 55 via a driver 59. Further, the CPU 57 is electrically connected to the ROM 60.

Then, the lubricant 4 is applied to the transfer belt 23.
8 is applied, the CPU 57 controls the driving means 55 to drive the lubricant applying mechanism 43 as shown in FIG. Then, the holder 47 is rotated clockwise around the support shaft 53 by the driving means 55 against the biasing member 54 shown in FIG. 1, and the rotary brush 51 is moved to the coating position as shown in FIG. It moves and contacts the transfer belt 23. At that time, the rotating brush 51 bites into the transfer belt 23 until the roller 52 contacts the surface of the transfer belt 23 on the driven roller. Then, the rotary brush 51 is rotated in association with the contact with the transfer belt 23, and the solid lubricant 48 is scraped off little by little with the rotary brush 51 and applied to the transfer belt 23.

Then, the amount of the lubricant applied on the transfer belt 23 is detected by the detecting means 45, and the signal is detected by the A
It is sent to the CPU 57 via the / D converter 58. Then, the CPU 57 outputs the output signal from the detection means 45 processed by the A / D converter 58 to the ROM.
The coating condition is controlled by comparing with a reference value stored in advance in 60. Then, for example, as shown in FIG. 5, when the reference value of the detection output of the detection means 45 is a, the detection output of the detection means 45 is b when the lubricant amount is a, and b> a When it is determined that the amount of lubricant on the belt 23 is small, the coating operation by the lubricant coating means 44 is repeated as shown in FIG. On the other hand, as shown in FIG. 5, when the amount of lubricant is B, the detection output of the detection unit 45 is c, and c
Since <a, it is determined that the amount of lubricant on the transfer belt 23 is large, and as shown in FIG.
Stop the coating operation. Then, the biasing member 54 moves the holder 47 to return the rotating brush 51 to the retracted position shown in FIG.

The color laser copying machine of the illustrated embodiment is provided with a detecting means 62 for detecting the remaining amount of the lubricant 48, as shown in FIG. The detecting means 62 is, for example, a piezoelectric element, and is appropriately supported in the holder 47 to be provided by pressing the detecting surface against the right surface of the lubricant 48 in the figure, and as shown in FIG. 7, an A / D converter. It is provided by being electrically connected to the CPU 57 via 58.

When the lubricant 48 is applied to the transfer belt 23, the lubricant 48 is scraped off little by little with the rotating brush 51 as described above. When the lubricant 48 is used, as shown in FIG. 8, the remaining amount of the lubricant is gradually reduced and the detection surface of the detection means 62 is exposed, the detection output changes as shown in FIG. Then, the CPU 57
Is the detection means 6 processed by the A / D converter 58.
The detection output from No. 2 is compared with the reference value previously stored in the ROM 60. When it is determined that the remaining amount of the lubricant 48 has reached the replacement time, an end signal is output, and based on that, a warning display indicating the replacement of the lubricant 48 is displayed on the operation panel (not shown).

In the color laser copying machine of the illustrated embodiment described above, when the lubricant 48 is applied onto the transfer belt 23, the controller 46 applies the lubricant applying means 44.
The coating operation was repeated until the detection result of the detection means 45 reached a reference value. However, as shown in FIG. 10, when the coating operation is repeated a predetermined number of times or a predetermined time, the control means 46 outputs an end signal, the display means is activated to warn, and the coating operation is ended. Good.

Further, as shown in FIG. 11, when the lubricant 48 is applied on the transfer belt 23, the control means 4 is used.
6, the lubricant applying means 44 is controlled to operate for a certain period of time, and when the amount of the lubricant 48 on the transfer belt 23 is small, the rotating brush 51 is rotated to increase the amount of application, and when it is large, the rotating brush is applied. It is also possible to lower the rotation of 51 to reduce the coating amount.

In all of the above-described embodiments, the lubricant 48 is applied onto the transfer belt 23 every predetermined number of recording sheets. However, as shown in FIG. 12, when the start key of the color laser copying machine is turned on to start the copying operation and the copying operation is finished, the detecting means 4 is subsequently operated.
5, the amount of lubricant on the transfer belt 23 may be detected, and when the amount of lubricant is small, the coating operation is repeated, and when it is large, the coating operation may be stopped.

Further, in the color laser copying machine of the illustrated embodiment, the example in which the transfer belt 23 for transferring the image onto the paper P is used as the image carrier for applying the lubricant 48 is shown. However, the photoconductor 20 that transfers an image to the transfer belt 23 may be used. In a monochrome laser copying machine, a laser printer, or a laser facsimile, a photoconductor that transfers an image onto a sheet may be used as an image carrier to which the lubricant 48 is applied. The image bearing member is not limited to the belt-shaped member, but may be a drum-shaped member.

Further, in the color laser copying machine of the illustrated embodiment, an example in which a solenoid is used as the driving means 55 of the lubricant applying means 44 has been shown. However, needless to say, other driving means may be used instead of the solenoid. Further, an example has been shown in which the holder 47 is rotated by the driving means to move the rotary brush 51 to the application position. However, it is needless to say that the structure is not limited to the rotation but may be moved by sliding.

[0052]

Therefore, according to the present invention, the amount of the lubricant on the image carrier is detected by the detecting means, and the controlling means controls the lubricant based on the detection result to apply the lubricant by the lubricant applying means. Therefore, it is possible to eliminate variations in the amount of lubricant on the image carrier.

According to the second aspect, the structure of the lubricant applying means can be simplified.

According to the third aspect of the present invention, since the remaining amount of the lubricant is detected by the detecting means, the life of the lubricant and the replacement time can be accurately known, and the lubricant can be used to the end without waste. You can

According to a fourth aspect of the present invention, when the lubricant is applied after every predetermined number of recorded sheets, and when a fifth aspect of the invention is when the lubricant is applied after every predetermined number of recorded sheets for a certain period of time, the sixth aspect is described. When the lubricant is applied after each recording, the variation of the lubricant amount on the image carrier can be eliminated by a simple method.

According to the seventh aspect of the present invention, it is possible to alert the operator by warning when the lubricant is exhausted.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram illustrating a mechanism for applying a lubricant to a transfer belt of a color laser copying machine that is an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a configuration of a detection unit used in the lubricant application mechanism.

FIG. 3 is a flowchart when a lubricant is applied by the lubricant applying mechanism.

FIG. 4 is a drive state diagram of a lubricant applying unit used in the lubricant applying mechanism.

FIG. 5 is a graph showing the relationship between the amount of lubricant on the transfer belt and the detection output of the detection means in the color laser copying machine.

FIG. 6 is a schematic configuration diagram of another embodiment of the lubricant applying means.

FIG. 7 is a block diagram showing an electrical configuration for detecting the remaining amount of lubricant.

FIG. 8 is a drive state diagram of the lubricant applying means.

FIG. 9 is a graph showing the relationship between the remaining amount of lubricant in the lubricant applying means and the detection output of the remaining amount detecting means.

FIG. 10 is a flowchart showing another method of applying a lubricant.

FIG. 11 is a flowchart showing yet another way of applying a lubricant.

FIG. 12 is a flowchart showing yet another way of applying a lubricant.

FIG. 13 is an enlarged schematic configuration diagram of a recording unit in the color laser copying machine.

FIG. 14 is an overall schematic configuration diagram of the color laser copying machine.

FIG. 15 is a schematic configuration diagram of a lubricant applying unit in a conventional laser copying machine.

[Explanation of symbols]

 20 Photoreceptor (Image Carrier) 23 Transfer Belt (Image Carrier) 44 Lubricant Applying Means 45 Detecting Means 46 Control Means 47 Holder 48 Lubricant 51 Rotating Brush 54 Biasing Member 55 Driving Means 62 Detecting Means

Claims (7)

[Claims] 1. A lubricant applying means for applying a lubricant onto an image carrier, a detecting means for detecting an amount of lubricant on the image carrying body, and the lubricant applying means based on a detection result of the detecting means. An electrophotographic recording apparatus comprising: a control unit that controls the electrophotographic recording apparatus. 2. The lubricant applying means includes a solid lubricant, a rotary brush that scrapes the lubricant little by little and applies the lubricant onto the image carrier, and a holder that holds the lubricant and the rotary brush. An urging member that urges the holder to move the rotating brush to the retracted position, and a driving unit that drives the holder against the urging member to move the rotating brush to the coating position. The electrophotographic recording apparatus according to claim 1, which is provided. 3. The electrophotographic recording apparatus according to claim 2, wherein the lubricant applying means includes a detecting means for detecting the remaining amount of the lubricant. 4. When applying a lubricant on the image carrier, the control means controls the lubricant applying means to repeat the applying operation until the detection result of the detecting means reaches a reference value. The electrophotographic recording apparatus according to claim 1. 5. When applying a lubricant to the image carrier, the control means controls the lubricant applying means to operate for a certain period of time until the detection result of the detecting means reaches a reference value during operation. The electrophotographic recording apparatus according to claim 1, wherein the coating amount is increased, and after the coating amount is reached, the coating amount is decreased. 6. When the recording operation is completed, the detection means detects the amount of lubricant on the image carrier, and when the detection result does not reach a reference value, the detection result of the detection means is a reference value. The electrophotographic recording apparatus according to claim 1, wherein the coating operation is repeated until the temperature reaches the value. 7. The electrophotographic recording apparatus according to claim 4, wherein when the coating operation is repeated a predetermined number of times or a predetermined time, the control means operates the display means to warn.