JPH07261589A - Fixing device for electrophotographic recording device - Google Patents

Abstract

PURPOSE:To provide a maintenance-free fixing device capable of preventing the local abrasion of a fixing roller and service-replacing separating claws. CONSTITUTION:A separating claw stanchion 17 fixed with four separating claws 16 and a slide shaft 18 to be kept in contact with the separating claws 16 are arranged in parallel on the rotary shaft of a fixing roller 13. One end of the slide shaft 18 is kept in contact with the cam-shaped fourth gear 24, and the slide shaft 18 is slid in the axial direction when the fourth gear 24 is rotated. Projections are provided at two positions on the slide shaft 18, and both side faces of the projections are made taper faces. Two separating claws 16 correspond to each of the projections. When the slide shaft 18 is slid, one separating claw 16 rides the taper face and is positioned on the projection, and it is separated from the surface of the fixing roller 13. The other separating claw 16 is moved on the slide shaft 18 into contact with the surface of the fixing roller 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device for an electrophotographic recording apparatus applicable to facsimiles, copying machines, printers and the like.

[0002]

2. Description of the Related Art A separating claw method is one of recording paper separating methods in an electrophotographic recording type fixing device. This separation claw method has been widely adopted from the past because it can be configured easily and at low cost.

A technique of this kind is disclosed in Japanese Patent Laid-Open No. 4-291384.
Japanese Patent Laid-Open No. 5-8574 and Japanese Patent Laid-Open No. 4-316076.

In the technique disclosed in Japanese Patent Laid-Open No. 4-291384, the separation claw is brought into contact with the heating roller in association with the entrance of the recording paper, so that the separation claw wears the peripheral surface of the heating roller and shortens the service life. Is to prevent.

The technique disclosed in Japanese Utility Model Laid-Open No. 5-8574 aims at extending the life of the fixing roller by moving the separating claw in the axial direction from the fixing roller to suppress partial wear of the fixing roller.

According to the technique disclosed in Japanese Patent Laid-Open No. 4-316076, a separating claw is installed on the fixing cover side, and a notch portion is positioned with high precision when abutting against the fixing roller. It prevents scratching.

[0007]

However, according to the above-mentioned conventional separating claw method, since the separating claw is always in contact with the fixing roller, the Teflon coating on the surface of the fixing roller is gradually scraped off, and finally, The bare tube may be exposed. Further, since toner easily enters the exposed portion, an abnormal image (fixing offset) may occur.

Further, according to the above-mentioned Japanese Patent Application Laid-Open No. 4-291384, the separation claw eventually comes into contact with the same position, so that the effect of preventing wear cannot be so desired. Further, according to Japanese Utility Model Laid-Open No. 5-8574, even though the fixing roller has a long life, the same separating claw is used, so that the separating claw needs to be replaced and the maintenance is not free. In addition, since the separation claws drag on the fixing roller during movement, abrasion may occur in the axial direction. Furthermore, according to JP-A-4-316076,
By accurately applying the separating claw, there is no difference in the installation condition depending on how the cover of the separating claw is closed, but it is only possible to prevent the fixing roller from being damaged when the cover is closed, and it is not possible to expect a long service life of the fixing roller.

The present invention provides a fixing device for a maintenance-free electrophotographic recording device, which can prevent local wear of the fixing roller and eliminate service replacement of the separating claw by solving the above problems. The purpose is to

[0010]

In order to achieve the above object, the present invention fixes a recording paper carrying an unfixed image by sandwiching it between a fixing roller and a pressure roller which are arranged so as to face each other. In the fixing device of the electrophotographic recording apparatus, which carries out the steps, separates and discharges the recording paper after fixing by the separation claw arranged so as to come into contact with the surface of the fixing roller. A paper sensor, a separation claw support member that rotatably supports a plurality of separation claws, and at least one of the separation claws abuts the fixing roller, and the other separation claws are rotated to fix the fixing roller. An actuating member having a protrusion that separates the actuating member from each other, a cam member that moves the actuating member to replace the separation claw that is brought into contact with the fixing roller by the protrusion, and the image forming operation of the electrophotographic recording unit is completed and the ejecting member is discharged. Paper detected Transmits power to the cam member can be characterized in that a drive system for moving the actuating member.

Further, in the fixing device of the electrophotographic recording apparatus, a paper ejection sensor for detecting paper ejection of the recording paper, a counter for counting detection signals of the paper ejection sensor, and a plurality of separation claws are respectively rotated. A separation claw support member that is movably supported, an actuating member having a protrusion that abuts at least one of the separation claws on the fixing roller, and rotates the other separation claws to separate from the fixing roller; A cam member that moves the member and replaces the separation claw that is brought into contact with the fixing roller by the protrusion, and a drive that moves power by transmitting power to the cam member when the counter counts a predetermined number of sheets. It is characterized by having a system.

Further, in the fixing device of the electrophotographic recording apparatus, a paper discharge sensor for detecting the discharge of the recording paper, a time counter for counting the time after the paper discharge, and a plurality of separation claws can be respectively rotated. A separation claw support member supported on
At least one of the separating claws is brought into contact with the fixing roller, and an operating member having a protrusion for rotating the other separating claw to separate from the fixing roller, and the operating member is moved for fixing by the protruding portion. A cam member for changing over the separation claws to be brought into contact with the roller; and a drive system for moving the actuating member by transmitting power to the cam member when the time counter counts a predetermined time. To do.

Further, in the fixing device of the electrophotographic recording apparatus capable of transmitting and receiving, a paper ejection sensor for detecting the ejection of recording paper, and a separation claw support member for rotatably supporting the plurality of separation claws, respectively. At least one of the separating claws is brought into contact with the fixing roller, and an operating member having a protrusion for rotating the other separating claw to separate from the fixing roller, and the operating member is moved for fixing by the protruding portion. A cam member that replaces the separation claw that abuts against the roller, and a power is transmitted to the cam member when the image forming operation at the time of the incoming data output operation is completed and paper discharge is detected to move the operating member. And a drive system.

Further, in the fixing device of the electrophotographic recording apparatus, a paper ejection sensor for detecting the ejection of recording paper, a separation claw support member rotatably supporting the plurality of separation claws, and the separation claw. At least one of which is brought into contact with the fixing roller, and the other separating claw is rotated to separate the operating member from the fixing roller, and the operating member is moved to contact the fixing roller by the protruding portion. A cam member for replacing the separation claws to be brought into contact with each other, a flexible scraper installed so as to abut the tip parts of the respective separation claws, and further to rub the tip parts when the separation claws rotate, And a drive system for transmitting the power to the cam member to move the actuating member when the image forming operation of the recording unit is completed and the paper discharge is detected.

Further, in the fixing device of the electrophotographic recording apparatus, a paper discharge sensor for detecting the discharge of the recording paper, a counter for counting the detection signal of the paper discharge sensor, and a plurality of separating claws are respectively rotated. A separation claw support member that is movably supported, an actuating member having a protrusion that abuts at least one of the separation claws on the fixing roller, and rotates the other separation claws to separate from the fixing roller; A cam member that moves the member and replaces the separation claws that abut on the fixing roller by the protrusions, and abuts on the tip ends of the separation claws, and rubs the tip parts when the separation claws rotate. And a drive system for moving the actuating member by transmitting power to the cam member when the counter counts a predetermined number of sheets. To.

Further, in the fixing device of the electrophotographic recording apparatus, a paper discharge sensor for detecting the discharge of the recording paper, a time counter for counting the time after the paper discharge, and a plurality of separation claws can be respectively rotated. A separation claw support member supported on
At least one of the separating claws is brought into contact with the fixing roller, and an operating member having a protrusion for rotating the other separating claw to separate from the fixing roller, and the operating member is moved for fixing by the protruding portion. A cam member for replacing the separation claws to be brought into contact with the rollers, and a flexible scraper arranged to abut the tip parts of the separation claws and to rub the tip parts when the separation claws rotate. And a drive system for moving the actuating member by transmitting power to the cam member when the time counter counts a predetermined time.

Further, in the fixing device of the electrophotographic recording apparatus capable of transmitting and receiving, a paper ejection sensor for detecting the ejection of recording paper, and a separation claw support member for rotatably supporting the plurality of separation claws, respectively. At least one of the separating claws is brought into contact with the fixing roller, and an operating member having a protrusion for rotating the other separating claw to separate from the fixing roller, and the operating member is moved for fixing by the protruding portion. A cam member for replacing the separation claws to be brought into contact with the rollers, and a flexible scraper arranged to abut the tip parts of the separation claws and to rub the tip parts when the separation claws rotate. And a drive system for moving the actuating member by transmitting power to the cam member.

Further, in the above-mentioned structure, the operating member is
It comprises a slide shaft that moves parallel to the rotation axis of the fixing roller and a protrusion provided on the slide shaft, and the protrusion is a cylindrical body that is coaxial with the slide shaft and has a large diameter. It is characterized in that the cylindrical body is formed with tapered portions on both side surfaces.

[0019]

By means of the above-mentioned means, in a device such as a printer, a copying machine or a facsimile, which adopts the electrophotographic recording system,
The operating member is moved each time the recording paper after the image fixing is discharged, or each time a predetermined number of papers are discharged, and further after a predetermined time elapses. As a result, the separation claw is moved over the protrusion to be separated from the fixing roller, and the separation claw on the protrusion is brought into contact with the fixing roller to replace the separation claw that comes into contact with the fixing roller and to change the contact position. Changes are made.

Further, since the flexible scraper is brought into contact with the separation claw, when the separation claw moves onto the protrusion, the flexible scraper adheres to the tip of the separation claw and foreign matter such as unfixed toner. Scrape off.

Further, since the protrusion has a shape in which the tapered portions are formed on both side surfaces of the cylindrical body, the separating claw slides on the tapered portion and moves up and down the protrusion.

[0022]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram of a plain paper copying machine (PPC) adopting an electrophotographic recording system.
Is a charging device, 3 is an exposure unit, 4 is a developing device, 5 is a paper feeding cassette, 6 is a recording paper, 7 is a transfer device, 8 is a fixing device, 9 is a waste toner cartridge, 10 is a static eliminator, and 11 is a paper discharge. Roller 12 is a discharge sensor.

After the photoconductor belt 1 is precharged by the charger 2, the exposure section 3 performs optical writing to form an electrostatic latent image. The electrostatic latent image is developed by applying toner to the developing device 4. Then, the transfer device 7 transfers the toner image onto the recording paper 6 conveyed from the inside of the paper feed cassette 5, and the fixing device 8 thermally fixes the toner image onto the recording paper 6. The heat-fixed recording paper 6 is ejected to the outside from the paper ejection roller 11. Further, when the recording paper 6 passes through the paper ejection roller 11, the paper ejection sensor 12
Detects the passage of the recording paper 6. On the other hand, the toner remaining on the photoconductor belt 1 is scraped off and collected by the waste toner cartridge 9, and the residual charge is removed by irradiating the static eliminator 10 with light.

FIG. 2 is a block diagram of the fixing device 8. 13 is a fixing roller, 14 is a pressure roller whose surface is coated with heat resistant rubber, 15 is a heater arranged inside the fixing roller 13, and 16 is a heater. Shows a separate nail. As shown in FIG. 2, the fixing roller 13 and the pressure roller 14 are in pressure contact with each other, and the tip of the separation claw 16 is in contact with the surface of the fixing roller 13.

The recording paper 6 sandwiched and fixed through the nip portion between the fixing roller 13 and the pressure roller 14 is separated from the fixing roller 13 by coming into contact with the separation claw 16. The peeled recording paper 6 is sandwiched between the paper discharge rollers 11 to remove the curl at the time of heat fixing and is discharged to the outside of the apparatus. The presence or absence of ejection is detected by the paper ejection sensor 12.

FIG. 3 is a structural view showing a mechanism for separating and abutting the separating claw from the fixing roller in the first embodiment of the present invention. 17 is a separating claw support for supporting the separating claw 16 and 18 is a separating claw support. 6 shows a slide shaft that can slide in the direction of the rotation axis of the fixing roller 13. The middle portion of the slide shaft 18 is formed in a U shape, and the axial direction at both ends of the slide shaft 18 is parallel to the axial direction of the U shape.

19 is coaxial with the rotation axis of the fixing roller 13,
A first gear 20 installed at one end, a second gear 20 meshed with the first gear 19 and a one-way clutch 22 press-fitted in the center thereof, and a third gear 21 provided coaxially with the second gear 20. A gear, 22 is a one-way clutch, and 23 is a rotating shaft that coaxially supports the second and third gears 20 and 21. In FIG. 3, when the second gear 20 rotates in the D direction, only the second gear 20 is rotated by the one-way clutch 22, and when the second gear 20 rotates in the C direction, the third gear 21.
Rotates in conjunction with the second gear 20. 24 is a fourth gear that meshes with the third gear 21 and one end of the slide shaft 18 abuts on the surface.
Shows gears. The fourth gear 24 has a cam shape having a thick portion and a thin portion as shown in FIG. 3, and presses the slide shaft 18 by rotation.

Further, reference numeral 25 denotes a compression coil spring for constantly urging the other end of the slide shaft 18 in a direction of pushing it. Further, the separation claw support 17 is provided with four separation claws 16, 16, 16, 16 and these four separation claws 16, 16, 16, 16 are provided at both ends of the fixing roller 13. They are arranged one by one. Hereinafter, with respect to the separation claws 16, 16, 16, 16, the separation claws 16a, 16b, 16 are sequentially arranged in the direction from one end to the other end of the fixing roller 13.
We will call them c and 16d. The separation claw support 17 is arranged parallel to the rotation axis of the fixing roller 13.

FIG. 4 is a block diagram of the slide shaft 18,
Indicates a protrusion of a columnar body coaxial with the slide shaft 18 and having a diameter longer than the shaft diameter of the slide shaft 18.
Tapered portions 26a and 26b are formed on both side surfaces of 26. Two protrusions 26 are formed on the slide shaft 18. Further, as shown in FIG. 3, the slide shaft 18 is arranged in parallel to the rotation shaft of the fixing roller 13, and the slide shaft 18 is provided on one protrusion 26 in accordance with the sliding operation of the slide shaft 18.
The separation claws 16b (16d) and the separation claws 16a (16c) ride up alternately.

In the case of FIG. 3, since one end of the slide shaft 18 is in contact with the position of the thick portion of the fourth gear 24, the slide shaft 18 moves most in the G direction in the figure. At this time, the separation claws 16b and 16d ride on the centers of the protrusions 26 and 26, while the separation claws 16a and 16c are positioned on the slide shaft 18 on the taper portion 26a side as shown in FIG. 5 (a). However, it is in contact with the surface of the fixing roller 13. The separation claw 16 is constantly urged toward the fixing roller 13 by the spiral spring 27. Further, when the fourth gear 24 is rotated a half turn, the slide shaft
One end of 18 abuts on the position of the thin portion of the fourth gear 24, and the compression coil spring 25 presses the other end of the slide shaft 18,
The slide shaft 18 moves most in the H direction in the figure. At this time, the separation claws 16b and 16d slide on the taper portion 26b, are positioned on the slide shaft 18, and contact the surface of the fixing roller 13.
On the other hand, the separation claws 16a and 16c slide on the tapered portion 26a,
As shown in FIG. 5 (b), ride on the center of the protrusions 26, 26,
At the same time, it is separated from the surface of the fixing roller 13.

FIG. 6 is a flow chart showing the operation of the first embodiment of the present invention, and the operation of the first embodiment will be described below with reference to FIGS. 3 and 6.

When the image recording operation is started (S1-1), the fixing roller 13 starts rotating together with the pressure roller 14. The fixing roller 13 rotates in the A direction during a normal image recording operation. When the fixing roller 13 rotates in the A direction, the rotation is transmitted to the second gear 20 and the second gear 20 rotates, but the rotation of the second gear 20 is transmitted to the rotary shaft 23 by the one-way clutch 22 which is press-fitted. No, the third gear 21 does not rotate. Therefore, the fourth gear
Since the rotation is not transmitted to 24 as well, the slide shaft 18 is not pressed by the fourth gear 24. On the other hand, the fixing roller 13 rotates together with the pressure roller 14, and the recording paper 6 is nipped and pressed in the nip portion of the fixing roller 13 to heat-fix the toner image.
The recording paper 6 is separated by the separating claw 16 and discharged to the outside.

When the paper discharge sensor 12 detects the discharge of the recording paper 6, that is, the output of the paper discharge sensor 12 is switched from on to off (Yes in S1-2), the photosensitive belt 1, the fixing roller 13 , A main motor (not shown) driving the developing roller 4a (see FIG. 1) is stopped (S1-
3). Next, rotate the main motor in the reverse direction to move the first gear 19 to B.
Rotate in the direction (S1-4). When the first gear 19 rotates in the direction B in the figure, the second gear 20 rotates in the direction C in the figure in conjunction with this, and the third gear 21 rotates together with the second gear 20, so the fourth gear 24 also Rotate in the middle F direction. This 4th gear
By the rotation of 24, the slide shaft 18 is pressed and slides in the direction of the rotation axis of the fixing roller 13, and as described above, the separation claw is
By separating and contacting 16 from the surface of the fixing roller 13,
The separation claw 16 that contacts the fixing roller 13 is replaced.

After the separation claws 16 are replaced, the main motor is stopped (S1-5), and the process stands by until the next image forming operation.
(S1-6).

According to the first embodiment thus constructed,
A pair of separation claws 16a and 16b and a separation claw every time the image forming operation is completed.
Since the pair of 16c and 16d are alternately changed by changing the contact position with the fixing roller 13, it is possible to prevent local wear of the fixing roller 13 and to eliminate service replacement of the separation claw 16.

FIG. 7 is a flow chart showing the control process of the fixing device of the second embodiment of the present invention, and the operation of the second embodiment will be described below with reference to FIGS. 3 and 7.

In the first embodiment, the contact positions of the pair of separation claws 16a and 16b and the pair of separation claws 16c and 16d with respect to the fixing roller 13 are alternately changed every time the image forming operation is completed. However, in the second embodiment, a paper discharge counter (not shown) is provided, and the separation claw 16 is replaced when a predetermined number of discharged paper is reached.

The image recording operation is started (S2-1), the recording paper 6 on which an image has been recorded through each image forming process is discharged to the outside (S2-2), and is discharged every time the recording paper 6 is discharged. The paper sensor 12 generates a detection signal. The number of detection signals generated is stored in a paper discharge counter (not shown) (S2-3), and the photosensitive belt 1,
A main motor (not shown) that drives the fixing roller 13, the developing roller 4a (see FIG. 1), etc. is stopped (S2-
Four).

Next, it is judged whether or not the number of discharged sheets reaches 500 (S2-5), and when it reaches 500 (Yes in S2-5),
The paper discharge counter is cleared (S2-6), the main motor is rotated in the reverse direction, the slide shaft 18 is slid in the direction of the rotation axis of the fixing roller 13, and the separation claw 16 is replaced in the same manner as in the first embodiment. S2-7). Then, after the separation claw 16 is separated and abutted, the main motor is stopped (S2-8) and stands by until the next image forming operation (S2-9). If it has not reached 500 sheets (No in S2-5), the process stands by until the next image forming operation (S2-9).

According to the second embodiment thus constructed,
A pair of separation claws 16a and 16b and a separation claw 16 for each predetermined number of sheets.
Since the pair of c and 16d are alternately changed by changing the contact position to the fixing roller 13, the fixing roller 13 is also changed as in the first embodiment.
It is possible to prevent the local wear of the separation claw 16 and eliminate the service replacement of the separation claw 16. Furthermore, rather than the first embodiment,
Since the number of times the main motor is stopped is reduced, the copy speed can be increased.

FIG. 8 is a flow chart showing the control process of the fixing device according to the third embodiment of the present invention. The operation of the third embodiment will be described below with reference to FIGS. 3 and 8.

In the second embodiment, the separation claw 16 is separated,
The control is performed so that the contact is performed when the number of discharged sheets reaches a predetermined number. However, in the third embodiment, a time counter (not shown) is provided to replace the separation claw 16 for a predetermined time. It's something I did when I did it.

The image recording operation is started (S3-1), the recording paper 6 on which an image is recorded through each image forming process is discharged to the outside (S3-2), and each time the recording paper 6 is discharged. The paper discharge sensor 12 generates a detection signal. When it is detected that the output of the paper discharge sensor 12 is switched from ON to OFF, a main motor (not shown) that drives the photosensitive belt 1, the fixing roller 13, the developing roller 4a (see FIG. 1), etc. Stop (S3-3), and the paper ejection sensor 12 triggers
A time counter (not shown) starts counting (S3-
Four).

Next, it is judged whether or not the time counter has clocked 24 hours (S3-5), and when it has clocked 24 hours (S3-5).
3-5 Yes), clear the time counter (S3-6), rotate the main motor in the reverse direction, and slide the slide shaft 18 to the fixing roller 13
And the separation claw 16 is replaced in the same manner as in the first embodiment (S3-7). Then, after the separation claws 16 are separated and abutted, the main motor is stopped.
(S3-8), stand by until the next image forming operation (S3-9). 24
If the time has not been measured (No in S3-5), the process stands by until the next image forming operation (S3-9).

According to the third embodiment thus constructed,
Similar to the first embodiment, it is possible to prevent local wear of the fixing roller 13 and eliminate service replacement of the separation claw 16. Further, the copying speed can be increased as in the second embodiment.

The fixing device of the plain paper copying machine (PPC) has been described above. However, the fixing device of the first embodiment is as follows.
It can also be used for plain paper facsimiles.

FIG. 9 is a block diagram showing the overall construction of a plain paper facsimile apparatus. In FIG. 9, the reading unit includes a reading scanning unit 30, a reading processing unit 31, a line memory 32, and a line memory control unit 33.

The image information read by the reading scanning unit 30 is temporarily stored in the line memory 32 via the reading processing unit 31. The MPU 41 compresses the image information of one line while reading the image information from the line memory 32 according to the mode of the information compression / decompression unit 36 to remove the redundancy,
The data is stored again in the RAM 37 through the data bus. This R
Using the AM37 as a transmission buffer, the communication control unit 38 is again used.
To the modem 39. The signal modulated by the modem 39 is sent out to the line through the network control unit 40.

On the contrary, the image information received from the line passes through the network control unit 40, is demodulated by the modem 39, is output to the data bus via the communication control unit 38, and is stored in the RAM 37. This RAM 37 is used as a reception buffer, and is sequentially MPU.
41 indicates a RAM 37 according to the mode of the information compression / decompression unit 36.
The image information of one line is restored while the image information is read from and is input to the temporary line memory 32 via the data bus. Then, it is called from the line memory 32 again, and is reproduced as image information by the recording scanning unit 34 via the recording processing unit 35.

The image information is simply passed through the network control unit 40 and the communication control unit 38, but the communication control information is read and understood in the communication control unit 38 to execute transmission control, error control, etc. When the journal information is processed, it is stored in the RAM having a non-volatile function when required.

A call signal for network control is processed by the network control unit 40. Further, the image information that does not require information compression and decompression is taken out from the reading processing unit 31 and the line memory 32 directly to the outside such as the RAM 37 via the data bus,
It is possible to perform image processing and image communication. Furthermore, the line memory can be directly input with the image-processed information or the image-synthesized information or can be superimposed on the image information.
It is also possible to store in 32 and record and reproduce. The line memory 32 can be used separately from the information compressing / decompressing unit 36, and at the same time, a usage mode in which compressed information is decompressed and output via the line memory 32 is conceivable regardless of reading scanning and recording scanning. The MPU 41 performs overall system control, and control of information flow, communication control, and network control.

The main processing of system control is the panel section 42.
Are control related to the man-machine interface and control related to the mechanical configuration of the reading unit and the recording unit by the mechanism control unit 43.

The panel section 42 sets the number of input terminals and the control system via the interfaces 44 and 45 according to the type and format of the panel switch and panel display. Further, the mechanism control unit 43 determines the type and quantity of the driver and the sensor based on the system and mechanical configuration of the reading unit and the recording unit, and determines the control in the same manner.

FIG. 10 is a flow chart showing the control of the separation claw replacement operation in the plain paper facsimile employing the fixing device shown in FIG. In order to facilitate the description, the configuration according to FIG. 10 will be referred to as a fourth embodiment,
The operation of the fourth embodiment will be described below with reference to FIGS. 3 and 10.

In the reception standby state (S4-1), when the transmission data is received from the other party (Yes in S4-2), the recording scanning unit 34 (see FIG. 9) outputs the data (S4-3). When data is transferred to recording paper and ejected outside the fax machine,
A main motor (not shown) that drives the photoconductor belt 1, the fixing roller 13, the developing roller 4a (see FIG. 1) and the like when it is detected that the paper discharge sensor 12 has changed from on to off. Stop (S4-4). Hereinafter, similarly to the first embodiment described with reference to the flowchart shown in FIG. 6,
The main motor is rotated in the reverse direction (S4-5), the separating claws 16 are separated and brought into contact with each other, and the main motor is stopped (S4-
6) Wait until the next image forming operation (S4-7).

According to the fourth embodiment thus constructed,
Each time the output of the incoming data is completed, the pair of separation claws 16a and 16b and the pair of separation claws 16c and 16d are alternately changed by changing the contact position to the fixing roller 13, so that the local portion of the fixing roller 13 is changed. It is possible to prevent abrasion and eliminate service replacement of the separation claw 16.

The fourth embodiment described above is the same as the first embodiment shown in FIG.
As can be seen from a comparison with FIG. 6 according to the embodiment, the processing after the discharge of the recording paper is completed (processing after step S4-3) is the same as that of the first embodiment. Further, the processing after the recording paper discharge in the fourth embodiment is completed is the same as the second and third processing.
The processing of the embodiment, that is, step S shown in FIG.
Processing after 2-3, or step S3 shown in FIG.
-Processing after -3 may be applied.

FIG. 11 is a block diagram showing a main part structure in which a cleaning function of the tip of the separating claw is added to the structure of the first embodiment shown in FIG. 3, and 50 is a scraper made of polyurethane rubber. . As shown in FIG. 11, the scraper 50 has one end fixed to the main body of the fixing device 8 and the other end in contact with the tip of the separation claw 16.

FIG. 11A shows a state in which the fixing roller 13 is rotating normally, and there is a slight distance between the tip of the scraper 50 and the separation claw 16. Further, at this time, since the tip of the separation claw 16 is in contact with the fixing roller 13, unfixed toner and the like are likely to remain at the tip of the separation claw 16.

In FIG. 11 (b), the image forming operation is completed, and the separation claw 16
This shows a state in which the separation claws 16 are rotated, and the distance between the tip of the scraper 50 and the separation claws 16 is reduced by the rotation of the separation claws 16. At this time, the tip of the separation claw 16 is brought into sliding contact with the tip of the scraper 50, so that the foreign matter adhering to the tip of the separation claw 16 is scraped off.
Toner can be prevented from accumulating on the tip, and the function of separating the recording paper 6 by the separation claw 16 can be maintained.

FIG. 12 is a structural view showing another structure of the protrusion of the slide shaft. In the other structure, the structure of the protrusion 26 shown in FIG. 4 is such that the tapered portions 26a and 26b are formed on both side surfaces of the cylindrical body, whereas the tapered portions 26c and 26d are formed in the central portion. . Even with this configuration, the protrusions shown in FIG.
Has the same effect as 26.

[0063]

According to the present invention constructed as described above, the following effects can be obtained.

According to the first, second and eleventh aspects, the pair of separation claws are alternately changed by changing the contact position with the fixing roller each time the image forming operation is performed. Wear can be prevented, and service replacement of the separating claw can be eliminated.

According to the constitutions of claims 3 and 4, the effect of the constitutions of claims 1 and 2 can be obtained, and since the number of times the main motor is stopped is reduced, the copying speed can be increased.

According to the fifth aspect of the present invention, the pair of separating claws and the pair of separating claws are alternately replaced by changing the contact position with the fixing roller each time the output of the incoming data is completed. It is possible to prevent local wear of the fixing roller and eliminate service replacement of the separating claw.

According to the structure of the sixth aspect, the pair of separation claws are alternately changed by changing the abutting position to the fixing roller each time the image forming operation is performed, so that the local wear of the fixing roller is prevented. , It is possible to eliminate the service replacement of the separation claw.
Further, it is possible to prevent the toner from accumulating on the tip of the separation claw and stabilize the recording paper separation performance for a long period of time.

According to the structure of claim 7, the pair of separation claws are alternately replaced by changing the contact position with the fixing roller every time a predetermined number of sheets are copied, so that the local wear of the fixing roller is prevented. It is possible to prevent and replace the service of the separating claw. Further, it is possible to prevent the toner from accumulating on the tip of the separation claw and stabilize the recording paper separation performance for a long period of time. Further, it is possible to provide a fixing device for an electrophotographic recording device which can increase the copying speed and has a maintenance-free structure, compared with the structure of the sixth aspect.

According to the structure of claim 8, after copying,
Each time a predetermined time elapses, the pair of separating pawls are alternately changed by changing the contact position with the fixing roller, so that local wear of the fixing roller can be prevented and service replacement of the separating pawl can be eliminated. Further, it is possible to prevent the toner from accumulating on the tip of the separation claw and stabilize the recording paper separation performance for a long period of time. Further, it is possible to provide a fixing device for an electrophotographic recording device which can increase the copying speed and has a maintenance-free structure, compared with the structure of the sixth aspect.

According to the ninth and tenth aspects of the present invention, each time the output of the incoming data is completed, the pair of separating claws are alternately replaced by changing the contact position with the fixing roller. Local wear can be prevented. Further, it is possible to eliminate the service replacement of the separation claw, prevent the toner from accumulating on the tip of the separation claw, and provide a fixing device of a maintenance-free facsimile device having stable recording paper separation performance for a long period of time.

[Brief description of drawings]

FIG. 1 A plain paper copier (P
It is a block diagram of (PC).

FIG. 2 is a configuration diagram of a fixing device.

FIG. 3 is a configuration diagram including a partial cross section showing a mechanism for separating and abutting a separation claw from a fixing roller in the first embodiment of the present invention.

FIG. 4 is a perspective view of a slide shaft and a protrusion.

FIG. 5 is an explanatory view showing the operation of the separation claw by sliding the slide shaft.

FIG. 6 is a flowchart showing the operation of the first embodiment of the present invention.

FIG. 7 is a flowchart showing a control process of the fixing device according to the second embodiment of the present invention.

FIG. 8 is a flowchart showing a control process of the fixing device according to the third embodiment of the present invention.

FIG. 9 is a block diagram showing the overall configuration of a plain paper facsimile apparatus.

10 is a flowchart showing the control of the replacement operation of the separation claws in the plain paper facsimile employing the fixing device shown in FIG.

FIG. 11 is a configuration diagram showing a main part configuration in which a cleaning function of a tip portion of a separation claw is added to the configuration of the first embodiment shown in FIG.

FIG. 12 is a perspective view showing another configuration of the protrusion of the slide shaft.

[Explanation of symbols]

1 ... Photosensitive belt, 2 ... Charger, 3 ... Exposure part, 4
... developing device, 5 ... paper feed cassette, 6 ... recording paper, 7 ...
Transfer device, 8 ... Fixing device, 9 ... Waste toner cartridge,
10 ... Static eliminator, 11 ... Paper ejection roller, 12 ... Paper ejection sensor,
13 ... Fixing roller, 14 ... Pressure roller, 15 ... Heater, 1
6, 16a, 16b, 16c, 16d ... Separation claw, 17 ... Separation claw support,
18 ... slide shaft, 19 ... first gear, 20 ... second gear,
21 ... Third gear, 22 ... One-way clutch, 23 ... Rotating shaft, 24 ... Fourth gear, 25 ... Compression coil spring, 26 ... Projection portion, 26a, 26b, 26c, 26d ... Tapered portion, 27 ... Spiral spring, 30 ... Read scanning unit, 31 ... Read processing unit,
32 ... Line memory, 33 ... Line memory control unit, 34
... recording scanning section, 35 ... recording processing section, 36 ... information compression / decompression section, 37 ... RAM, 38 ... communication control section, 39 ... modem, 40 ... network control section, 41 ... MPU, 42 ... panel section,
43 ... Mechanism control unit, 44, 45 ... Interface, 50 ...
Scraper.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G03G 21/16

Claims (11)

[Claims] 1. A recording paper carrying an unfixed image is sandwiched between a fixing roller and a pressure roller which are arranged so as to face each other to perform a fixing process, and the recording paper is arranged so as to come into contact with the surface of the fixing roller. In a fixing device of an electrophotographic recording apparatus that separates and discharges recording paper after fixing by the separated claws, a discharge sensor for detecting the discharge of the recording paper and a plurality of the separation claws are rotatably supported. The separation claw support member, an actuating member having a protrusion that abuts at least one of the separation claws on the fixing roller, and rotates the other separation claws to separate from the fixing roller, and the actuating member is moved. An electrophotographic recording device comprising: a cam member that replaces the separation claw that is brought into contact with the fixing roller by the protruding portion; and a drive system that transmits power to the cam member to move the operating member. apparatus The fixing device. 2. A recording paper carrying an unfixed image is sandwiched between a fixing roller and a pressure roller, which are arranged to face each other, to perform a fixing process, and the recording paper is arranged to contact the surface of the fixing roller. In a fixing device of an electrophotographic recording apparatus that separates and discharges recording paper after fixing by the separated claws, a discharge sensor for detecting the discharge of the recording paper and a plurality of the separation claws are rotatably supported. The separation claw support member, an actuating member having a protrusion that abuts at least one of the separation claws on the fixing roller, and rotates the other separation claws to separate from the fixing roller, and the actuating member is moved. And a cam member that replaces the separation claw that is brought into contact with the fixing roller by the protrusion, and a power is transmitted to the cam member when the image forming operation in the electrophotographic recording unit is completed and paper discharge is detected. The operating part The fixing device of an electrophotographic recording apparatus characterized by comprising a driving system for moving. 3. A recording paper carrying an unfixed image is sandwiched between a fixing roller and a pressure roller which are arranged so as to face each other to perform a fixing process, and the recording paper is arranged so as to come into contact with the surface of the fixing roller. In a fixing device of an electrophotographic recording device that separates and ejects recording paper after fixing by the separated claws, a paper ejection sensor that detects paper ejection of the recording paper, and a counter that counts the detection signal of the paper ejection sensor. , A separation claw support member that rotatably supports the plurality of separation claws, and at least one of the separation claws is brought into contact with a fixing roller, and the other separation claws are rotated to be separated from the fixing roller. An actuating member having a protrusion, a cam member for moving the actuating member to replace a separation claw that is brought into contact with the fixing roller by the protrusion, and the cam when the counter counts a predetermined number of sheets. The fixing device of an electrophotographic recording apparatus characterized by comprising a transmits power drive system for moving the actuating member in wood. 4. A recording paper carrying an unfixed image is sandwiched between a fixing roller and a pressure roller which are arranged so as to face each other to perform a fixing process, and the recording paper is arranged so as to contact the surface of the fixing roller. In a fixing device of an electrophotographic recording device that separates and discharges recording paper after fixing by the separated claws, a discharge sensor that detects discharging of the recording paper, a time counter that counts the time after discharging, A separation claw support member that rotatably supports a plurality of separation claws, and a projection that abuts at least one of the separation claws on a fixing roller and rotates the other separation claws to separate from the fixing roller. An actuating member having a portion, a cam member for moving the actuating member and replacing the separation claw abutting against the fixing roller by the protrusion, and the cam when the time counter counts a predetermined time. The fixing device of an electrophotographic recording apparatus characterized by comprising a transmits power drive system for moving the actuating member in wood. 5. A recording paper carrying an unfixed image is sandwiched between a fixing roller and a pressure roller which are arranged so as to face each other to perform a fixing process, and the recording paper is arranged so as to come into contact with the surface of the fixing roller. In a fixing device of an electrophotographic recording apparatus that can send and receive recording paper after fixing with the separated separation claws, the discharge sensor that detects the discharge of the recording paper and the plurality of separation claws are rotated. A separation claw support member that is movably supported, an actuating member having a protrusion that abuts at least one of the separation claws on the fixing roller, and rotates the other separation claws to separate from the fixing roller; A cam member that moves the member and replaces the separation claw that is brought into contact with the fixing roller by the protrusion, and a power source that drives the cam member when the image forming operation at the time of the incoming data output operation is completed and paper ejection is detected. To It reached and fixing apparatus of the electrophotographic recording apparatus characterized by comprising a driving system for moving the actuating member. 6. A recording paper carrying an unfixed image is sandwiched between a fixing roller and a pressure roller which are arranged so as to face each other to perform a fixing process, and the recording paper is arranged so as to contact the surface of the fixing roller. In a fixing device of an electrophotographic recording apparatus that separates and discharges recording paper after fixing by the separated claws, a discharge sensor for detecting the discharge of the recording paper and a plurality of the separation claws are rotatably supported. The separation claw support member, an actuating member having a protrusion that abuts at least one of the separation claws on the fixing roller, and rotates the other separation claws to separate from the fixing roller, and the actuating member is moved. A cam member for replacing the separation claws that are brought into contact with the fixing roller by the protrusions, and the tip parts of the respective separation claws, and further rub the tip parts when the separation claws are rotated. Installed flexible space And Repa, fixing apparatus of the electrophotographic recording apparatus characterized by comprising a driving system for moving said actuating member to transmit power to the cam member. 7. A recording paper carrying an unfixed image is sandwiched between a fixing roller and a pressure roller which are arranged so as to face each other to perform a fixing process, and the recording paper is arranged so as to contact the surface of the fixing roller. In a fixing device of an electrophotographic recording apparatus that separates and discharges recording paper after fixing by the separated claws, a discharge sensor for detecting the discharge of the recording paper and a plurality of the separation claws are rotatably supported. The separation claw support member, an actuating member having a protrusion that abuts at least one of the separation claws on the fixing roller, and rotates the other separation claws to separate from the fixing roller, and the actuating member is moved. A cam member for replacing the separation claws that are brought into contact with the fixing roller by the protrusions, and the tip parts of the respective separation claws, and further rub the tip parts when the separation claws are rotated. Installed flexible space An electronic device including a reaper and a drive system for transmitting power to the cam member to move the actuating member when a paper discharge is detected after the image forming operation in the electrophotographic recording unit is completed. Fixing device for photo recording device. 8. A recording paper carrying an unfixed image is sandwiched between a fixing roller and a pressure roller which are arranged so as to face each other to perform a fixing process, and the recording paper is arranged so as to come into contact with the surface of the fixing roller. In a fixing device of an electrophotographic recording device that separates and ejects recording paper after fixing by the separated claws, a paper ejection sensor that detects paper ejection of the recording paper, and a counter that counts the detection signal of the paper ejection sensor. , A separation claw support member that rotatably supports the plurality of separation claws, and at least one of the separation claws is brought into contact with a fixing roller, and the other separation claws are rotated to be separated from the fixing roller. An actuating member having a protrusion, a cam member for moving the actuating member to replace the separation claw abutting against the fixing roller by the protrusion, abutting the tip of each separation claw, and further separating the claw. of A flexible scraper installed so as to rub the tip portion during movement, and a drive system for moving power by transmitting power to the cam member when the counter counts a predetermined number of sheets A fixing device for an electrophotographic recording device, which is characterized in that 9. A recording paper carrying an unfixed image is sandwiched between a fixing roller and a pressure roller which are arranged so as to face each other to perform a fixing process, and the recording paper is arranged so as to contact the surface of the fixing roller. In a fixing device of an electrophotographic recording device that separates and discharges recording paper after fixing by the separated claws, a discharge sensor that detects discharging of the recording paper, a time counter that counts the time after discharging, A separation claw support member that rotatably supports a plurality of separation claws, and a projection that abuts at least one of the separation claws on a fixing roller and rotates the other separation claws to separate the separation claw from the fixing roller. An actuating member having a portion, a cam member that moves the actuating member and replaces the separation claw that abuts against the fixing roller by the protrusion, and abuts on the tip of each separation claw. When turning A flexible scraper installed so as to rub the tip portion; and a drive system for transmitting power to the cam member to move the actuating member when the time counter counts a predetermined time. A fixing device for an electrophotographic recording device, characterized by: 10. A recording paper carrying an unfixed image is sandwiched between a fixing roller and a pressure roller which are arranged so as to face each other to perform a fixing process, and the recording paper is arranged so as to contact the surface of the fixing roller. In a fixing device of an electrophotographic recording apparatus that can send and receive recording paper after fixing with the separated separation claws, the discharge sensor that detects the discharge of the recording paper and the plurality of separation claws are rotated. A separation claw support member that is movably supported, an actuating member having a protrusion that abuts at least one of the separation claws on the fixing roller, and rotates the other separation claws to separate from the fixing roller; A cam member that moves the member and replaces the separation claws that abut on the fixing roller by the protrusions, and abuts on the tip ends of the separation claws, and rubs the tip parts when the separation claws rotate. Set to And a drive system for moving the actuating member by transmitting power to the cam member when the paper discharge is detected after completion of the image forming operation during the incoming data output operation. A fixing device for an electrophotographic recording device, characterized by: 11. A recording paper carrying an unfixed image is sandwiched between a fixing roller and a pressure roller which are arranged so as to face each other to perform a fixing process, and the recording paper is arranged so as to contact the surface of the fixing roller. In a fixing device of an electrophotographic recording apparatus that separates and discharges recording paper after fixing by the separated claws, a plurality of the separating claws are rotatably supported and arranged parallel to the axial direction of the fixing roller. The separation claw support provided, the slide shaft arranged in parallel with the axial direction of the fixing roller and sliding, the cylindrical protrusion arranged coaxially with the slide shaft, and the protrusion of the protrusion. Tapered portions formed on both side surfaces, a cam gear whose surface contacts one end of the slide shaft, a drive system that transmits rotation to this gear, and a biasing force that constantly pushes the other end of the slide shaft. And one end on the surface of the gear A pair of coil springs for contacting each other, and when one of the separating claws makes a pair, the other separating claw is positioned on the protrusion and is fixed. In the state of being separated from the roller, one separation claw moves to the projection via the taper part and the other separation claw moves down the projection and hits the fixing roller as the projection slid by the rotation of the gear moves. A fixing device for an electrophotographic recording apparatus, wherein the separation claw and the protrusion are arranged so as to be in contact with each other.