JP2003098783A - Electrophotographic image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discriminate whether a unit to be attached/detached is the new one or the used one by utilizing a sensor and a decision flag used for another purpose without providing a new decision device in an electrophotographic image forming apparatus. SOLUTION: Whether the unit is the new one or the used one is discriminated by separately setting the operation time of the sensor provided in the electrophotographic image forming apparatus and sensing that the attachment of the unit is completed and the unit is ready to work and the decision flag consisting of the combination of a cam and link and provided in the unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus (hereinafter also referred to as an image forming apparatus) such as an electrophotographic type and an electrostatic recording type.

Further, as the electrophotographic image forming apparatus, for example, an electrophotographic copying machine or an electrophotographic printer (for example, L
ED printers, laser beam printers, etc.), electrophotographic facsimiles, electrophotographic word processors, etc.

[0003]

2. Description of the Related Art Conventionally, in an image forming apparatus, when detecting whether an image forming unit detachable from an image forming apparatus main body or a consumable item is a new article, a fixing device is disclosed in Japanese Patent Laid-Open No. 9-185288. Etc., the thermal fuse is blown out, or
As shown in Japanese Patent No. 288191, a method of providing a sensor for detecting a new article is adopted.

[0004]

SUMMARY OF THE INVENTION In the prior art,
Although it functions only once when detecting whether or not it is a new product, it is necessary to provide a dedicated sensor or a dedicated circuit, which causes a cost increase.

Therefore, in the present invention, a sensor that is normally used, for example, a judgment flag when changing from a loaded state to an operable state, is used without providing a dedicated sensor for detecting a new product,
An electrophotographic image forming apparatus capable of reducing the number of parts with a simple mechanism and drastically reducing the cost by changing the phase of the cam and setting the timing of the determination flag different between a new state and a used state. The purpose is to

[0006]

The image forming apparatus of the present invention is characterized by the following constitution in order to solve the above problems.

The present invention is as follows if the same numbers as the claims are attached.

According to a first aspect of the present application, when a unit detachably mountable to the electrophotographic image forming apparatus main body is loaded in the electrophotographic image forming apparatus main body, the exchangeable unit can be replaced when detecting the presence or absence of the unit. These units have an inoperable state and an operable state when loaded in the main body of the image forming apparatus. The time from the ready state to the ready state is _Tnew, and when the removable unit that is used once or more is loaded, the time from the unavailable state to the ready state is set. It was a T _old, an electrophotographic image forming apparatus according to T _new ≠ T _old.

A second invention according to the present application is characterized in that the detachable and replaceable unit uses a cam mechanism to change from the inoperable state to the operable state. The electrophotographic image forming apparatus described in 1.

According to a third aspect of the present invention, the cam of the cam mechanism has at least three phases, that is, the detachable and replaceable unit has an unused state phase, an inoperable state phase, and an operable state phase. The electrophotographic image forming apparatus according to the second aspect of the invention.

A fourth aspect of the present invention is characterized in that once the cam of the cam mechanism is out of the phase of the initial state among the three phases, it is impossible to stay in that state again. An electrophotographic image forming apparatus according to a third aspect of the invention.

A fifth aspect of the present invention is a fixing device, wherein the removable unit is provided with a roller pair that is pressed against each other, a cam that controls the pressing force, and a sensor that determines the control state. In the fixing device, the sensor for performing pressure control of the roller pair also serves as a sensor for determining whether the fixing device is new or used, according to any one of the first to fourth inventions. Is an electrophotographic image forming apparatus.

According to a sixth aspect of the present application, a sensor detects the presence or absence of the removable unit, and the detection of the time for changing from the inoperable state to the operable state, and this sensor is used as an apparatus. The electrophotographic image forming apparatus according to any one of the first to fifth inventions, which is housed in the main body.

A seventh invention according to the present application is characterized in that the time count or the cumulative number of printed sheets is counted after it is detected that the removable unit is unused. The electrophotographic image forming apparatus according to any one of the present inventions.

An eighth invention according to the present application counts the operating time of the removable unit and the cumulative number of prints, and can notify the user of the remaining life time or the number of printable pages until the end of life. The electrophotographic image forming apparatus according to any one of the first to fifth aspects of the invention.

According to a ninth aspect of the present application, when the operating time of the removable unit is counted or the cumulative number of printed sheets is counted, the unit is replaced with the unused removable unit at this time. At this time, in the electrophotographic image forming apparatus according to the eighth invention, the operating time or the cumulative number of printed sheets is changed to the initial state.

In a tenth aspect of the present invention, the remaining service life of the removable unit or the number of printable pages up to the service life can be periodically notified to a service center or a host computer by using a network line. The electrophotographic image forming apparatus according to any one of the first to fifth inventions.

According to an eleventh aspect of the present invention, when a unit detachably mountable from the main body of the electrophotographic image forming apparatus is loaded in the main body of the electrophotographic image forming apparatus, the presence of the unit is detected by a detection means provided in the electrophotographic image forming apparatus. In detecting the presence / absence of the presence / absence, the replaceable unit has an inoperable state and an operable state when loaded in the main body of the electrophotographic image forming apparatus, and the detachable unit which is in an unused state. When a replaceable unit is loaded, the number of times the detection means is activated when the operation-disabled state is changed to the operation-enabled state is set to 2, and the detachable exchange is used once or more. When an enabling unit is loaded, the number of times the detection means is operated when the operation-disabled state is changed to the operation-enabled state is set to once, and the electrophotographic image formation is performed. It is the location.

A twelfth aspect of the present invention is characterized in that the detachable and replaceable unit uses a cam mechanism to change from the inoperable state to the operable state. The electrophotographic image forming apparatus described in 1.

According to a thirteenth invention of the present application, the cam of the cam mechanism has at least three phases, namely, a phase of an unused state, a phase of an inoperable state, and a phase of an operable state of the removable unit. First characterized by being
2 is an electrophotographic image forming apparatus according to the invention.

A fourteenth aspect of the present invention is characterized in that, of the three phases, once the cam of the cam mechanism comes out of the phase in the initial state, it is impossible to stay in that state again. An electrophotographic image forming apparatus according to the thirteenth invention.

A fifteenth invention of the present application is the fixing device, wherein the removable unit is equipped with a pair of rollers that are pressed against each other, a cam that controls the pressing force, and a sensor that determines the control state. In the fixing device, the sensor that controls the pressure of the roller pair also functions as a sensor that determines whether the fixing device is new or used. 15. The fixing device according to any one of the eleventh to fourteenth inventions. Is an electrophotographic image forming apparatus.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] (Overall Structure of Image Forming Apparatus) FIG. 1 shows a cross section of a color image forming apparatus according to the first embodiment, and the structure thereof will be described below in the order of image formation. To do.

First, the laser scanner unit 1Y corresponding to each color of yellow, magenta, cyan, and black,
Laser light 2Y, 2M, 2C, 2K is emitted from 1M, 1C, 1K in accordance with image data of each color, and charging roller 3
A latent image corresponding to image data of each color is drawn on the photosensitive drums 4Y, 4M, 4C, 4K of each color whose surface is uniformly charged by Y, 3M, 3C, 3K. Further, the developing sleeves 6Y, 6 of the respective colors are provided by the toners of the respective colors (not shown) contained in the developing devices 5Y, 5M, 5C, 5K corresponding to the respective colors.
The latent image is sequentially developed in the order of yellow, magenta, cyan, and black through M, 6C, and 6K. At this time,
At the same time, those four color photosensitive drums 4Y, 4M, 4C, 4
The intermediate transfer belt 8 is held so that its upper surface is in horizontal and uniform contact with K, and is rotationally driven in the clockwise direction (arrow direction) by belt drive rollers 7a, 7b, 7c.
To the toner images on the photosensitive drums 4Y, 4M, 4C, and 4K so that the images of four colors of yellow, magenta, cyan, and black are superposed in this order.
K at the primary transfer points T1Y, T1M, T1C, and T1K for each color, which are contact points between the intermediate transfer belt 8 and the photosensitive drums 4Y, 4M, 4C, and 4 from the inside.
Backup rollers 9Y and 9 urged toward K
By the primary transfer in sequence by M, 9C, and 9K, the toner in which the four color images are superposed forms an image on the intermediate transfer belt 8.

On the other hand, the paper feeding roller 11 from the paper feeding cassette 9
On the recording paper S fed by
a, 12b and 13a, 13b and 14a, 14b
After being conveyed in the direction of the arrow by the secondary transfer point T2
, The toner image formed on the intermediate transfer belt 8 is collectively transferred by being nipped and conveyed by the transfer roller 15 in which a foam is wound around a metal shaft and the belt drive roller 7b via the intermediate transfer belt 8 (two Next transcription).
At this time, the toner remaining on the surface of the intermediate transfer belt 8 without being completely transferred is cleaned by the cleaning blade 16 arranged in contact with the intermediate transfer belt 8.
7, the toner is passed through the removed toner transport path 100, and finally collected in the removed toner recovery container 102 via the removed toner recovery container connecting portion 101. After the second transfer,
The recording paper S on which the image has been transferred is placed in a fixing device 21 having a fixing roller 19 including a halogen heater 18 and a pressure roller 20 which rotates while being pressed against the fixing roller 19 at a predetermined pressure. The toner image transferred by heat and pressure is fixed on the recording paper S by passing through the nip N which is the contact point, and then the paper discharge tray 50.
Discharged on top.

(Fixing Device) The fixing device 21 will now be described. As shown in FIG. 2, the fixing roller 19 of the fixing device 21 has both ends thereof rotatably supported by the frame 21a. The pressure roller 20 is supported by a bearing (not shown) guided by a guide (not shown) parallel to a line connecting the respective axes of the fixing roller 19 and the pressure roller 20. In FIG. 2, the fixing device 21 includes a halogen heater 18, and the fixing roller 19 in which the shaft of the fixing roller 19 is supported and fixed by a positioning plate 19a of the fixing roller 19, and a pressure spring D to the fixing roller 19. The pressure roller 20 is rotated by the drive source M configured outside the fixing device via the drive transmission means A1 while being pressed with a predetermined pressure. Here, the pressure spring D is a compression coil spring. The positioning plate 19a is integrated with the frame 21a of the fixing device 21. The drive transmission means A1 is a shaft coupling or a gear fixed to the roller shaft 20a, a gear meshing with the gear, and the like. The fixing device 21 includes a fixing roller 19 and a pressure release mechanism 24 for preventing the deformation and deterioration of the rubber due to the pressure roller 20 being left pressurized while not in operation. In the fixing device 21, the fixing roller 19, the pressure roller 20, the damper C, the pressure spring D, the pressure releasing mechanism 24, and the like can be attached to and detached from the image forming apparatus main body as an integral unit by the frame 21a. Therefore, for example, a guide portion (not shown) is provided in the longitudinal direction of the frame body 21a and is inserted in the guide rail (not shown) of the image forming apparatus main body in the longitudinal direction. Here, the longitudinal direction is a direction parallel to the fixing roller 19.

FIG. 3 is an enlarged view of the pressure release mechanism 24. The pressure release mechanism 24 can be rotated clockwise by the drive source M via the drive transmission means A2.
And the pressure release cam 2 that rotates using the cam shaft 28 as a synchronous shaft.
3, a pressure release plate 24b supported and fixed around the pressure release shaft 27 as a rotation center, and rotatably linked to the pressure release plate 24b at a fulcrum 31 on the pressure release plate 24b. Pressure release arm 26 and pressure release control shaft 29,
It is composed by. Both ends of the cam shaft 28 in the longitudinal direction (the same direction as the longitudinal direction of the fixing roller 19) are rotatably supported by the frame 21a of the fixing device 21. This camshaft 2
The pressure release cam 23 is fixed to the position 8. Pressure release shaft 2
7 is fixed to the frame 21a of the fixing device 21. A pressure release plate 24b is swingably supported on the pressure release shaft 27. A pressure release control shaft 29 is attached to the pressure release shaft 27. One end of the determination flag 22 is rotatably supported on the pressure release control shaft 29.

As shown in FIG. 3, the pressure spring D includes a frame 21a.
And the left end of the pressure release plate 24b.
Both ends of the damper C are connected to the left ends of the frame body 21a and the pressure release plate 24b, respectively. The drive source M is, for example, a combination of a motor and a speed reducer.

The pressure release cam 23 is used to rotate clockwise in one direction in FIG. 3, and has a cam surface 23a and a recess 23c capable of holding the pressure release control shaft 29 at the positions shown in FIG. 4, respectively. Further, it has a cam surface 23b that comes into contact with the pressure release control shaft 29a and pushes up the shaft 29 when the pressure release cam 23 rotates. A timer portion 23d having a linear cam surface is provided on the left side of the concave portion 23c so that the pressure release control shaft 29 does not immediately descend and the determination flag 22 does not operate when the pressure applying / removing cam 23 rotates. ing.

The pressure release arm 26 holds the roller shaft 20a of the pressure roller 20. When the pressure release control shaft 29 is not regulated by the pressure release cam 23 with the pressure release shaft 27 as the center of rotation, the pressure roller 20 moves at a predetermined speed by the pressure spring D and the damper C. The pressure release plate 24b rotates clockwise until it hits the fixing roller 19. As a result, the fixing device 21 is set and the image forming apparatus is ready for operation. The image forming apparatus starts operating when the apparatus body is switched on. On the contrary, when the pressure release control shaft 29 is pushed upward by the pressure release cam 23, the pressure release plate 24b rotates counterclockwise, and the pressure release arm 26 moves The roller shaft 20a of the roller 20 is pushed downward, so that the fixing roller 19 and the pressure roller 20 are separated from each other. The image forming apparatus becomes inoperable. The fixing device 21 may be detached and replaced.

This is shown in FIGS. 6 (a), 6 (b) and 7
This will be described with reference to (a) and FIG. 7 (b). In FIG. 6B, the pressure release cam 23, which rotates clockwise about the cam shaft 28, pushes up the pressure release control shaft 29 fixed on the pressure release plate 24b. On the other hand, the pressure release arm 26 linked with the fulcrum 31 of the pressure release plate 24b is pushed down to separate the fixing roller 19 and the pressure roller 20 from each other as shown in FIG. 6A. In FIG. 7B, when the pressure release control shaft 29 is opened from the pressure release cam 23, the fixing roller 19 and the pressure roller 20 are brought into pressure contact with each other as shown in FIG. 7A. Here, a determination flag 22 is provided on the pressure release control shaft 29, and the determination flag 22 determines the operating state of the pressure release plate 24b outside the main body of the fixing device 21. It is possible to detect whether or not the fixing device 21 exists and whether or not the fixing device 21 can be operated by detecting the pressure applied by the sensor 25.

In the present invention, the judgment flag 22 is used to detect whether the product is new or not by the following method.

5 (a) and 5 (b) show the fixing device 21 which is new and unused. The fixing device 21 is shown in a state where it is used once or more. 6A and 6B, the position of the pressure release control shaft 29 is different. That is, the pressure release control shaft 29 is in contact with the cam surface 23a in FIG. 5, and is fitted into the recess 23c in FIG.
Held in different positions.

FIG. 4 shows a detailed view of the pressure release cam 23.
In FIG. 4, the pressure release control shaft 29 is in a new state when the pressure release control shaft 29 is at the position 29n when it cannot be operated, and the pressure release control shaft 29 is located at the position 29n at the time of factory shipment. The pressure roller 20 is separated from the fixing roller 19. When it is in the position of 29o, it means that it has been used more than once.

In FIG. 4, when the fixing device 21 is new,
The pressure release control shaft 29 is located at the initial position 29n, and the cam surface 23a of the pressure release cam 23 prevents the movement of the pressure release cam D in the direction of arrow A shown in the drawing. At the position 23n when the pressure release cam 23 rotates about the cam shaft 28 by θ1, the pressure release control shaft 29 follows the cam surface 23a of the pressure release cam 23 by the force of the pressure spring D. Since the pressure release control shaft 29 moves in contact with the cam surface, the pressure release control shaft 29 moves from the initial position 29n in the direction of arrow a and is present at the position 29n1.

Since the pressure release control shaft 29 moves on a circular arc locus 32 around the pressure release shaft 27,
Phase θ1 is in a state in which the pressure release control shaft 29 reaches the position 29n1, leaves the constraint of the cam surface 23a of the pressure release cam 23, and the spring force of the pressure spring D is not carried by the pressure release cam 23. It is the moment when it became. Thereafter, the pressure release control shaft 29 passes the position 29n1 and further moves on the locus 32, and stops when the fixing roller 19 and the pressure roller 20 contact each other.

When the fixing device 21 is taken out from the main body of the apparatus, the cam shaft 28 is rotated clockwise to fix the fixing roller 19
When the pressure roller 20 is separated from the pressure roller 20, the pressure release control shaft 29, which is in contact with the outer peripheral surface of the pressure release cam 23, moves while being pressed against the cam surface 23b by the force of the pressure spring D. It reaches 29o. At the position 29o, the cam surface is provided with a recess 23c, and the pressure release control shaft 29 is fitted into the recess 23c. This position 29o is the initial position 29n
Is a different position from.

The function of the pressure release mechanism 24 incorporated in the fixing device 21 and the sensor-on timing of the transmissive photosensor 25 will be described with reference to FIGS. 14 and 8. The graphs in the upper part of each figure show the relationship between the sensor-on and sensor-off states of the transmissive photosensor 25 and the time elapsed from the start of rotation of the cam shaft 28. The respective states of the pressure release mechanism 24 at the elapsed times t1 and t2 are shown in the respective frames drawn below the graph. Here, the time elapsed when the pressure release cam 23 rotates by θ1 degrees about the cam shaft 28 is t1, and the time elapsed when the pressure release cam 23 rotates by θ2 degrees is t2. . FIG. 14 shows an operation process of the pressure release mechanism 24 when the fixing device 21 is in a new state, and FIG. 8 shows an operation process of the pressure release mechanism 24 when the fixing device 21 is used once or more. The process was shown.

In FIGS. 4 and 14, the relationship between the phase angle of the pressure release cam 23 and the pressure release control shaft 29 is that the pressure release cam 23 is in the phase of θ1 when the product is new, and the pressure release control is performed. The shaft 29 is in a free state, the pressure release plate 24b is rotated clockwise around the pressure release shaft 27 at a predetermined speed, and the determination flag 22 is set to the transmission type photo center 2.
5, the sensor is turned on after a time t1 from the start of driving.

In FIG. 4, when the fixing device 21 is used more than once, the pressure release control shaft 29 exists at the position 29o, and the position when the pressure release cam 23 rotates about the cam shaft 28 by θ1 degree. 23n, the pressure release control shaft 29 is forced by the compression coil spring D by the force release cam 2
3, the pressure release control shaft 29 moves from the position 29o in the direction of arrow B to move to the position 2
It exists in 9o1. At the position 23o when the pressure release cam 23 further rotates by (θ2-θ1) degrees about the cam shaft 28, that is, when the pressure release cam 23 rotates by θ2 degree from the initial state, the pressure release control shaft 29 has the compression coil spring D. The pressure release control shaft 29 moves from the position 29o1 in the direction of the arrow C and is present at the position 29o2 because it moves in contact with the outer peripheral surface of the pressure release cam 23 by the force. Here, since the pressure release control shaft 29 moves on the locus 32 of an arc centered on the pressure release shaft 27, the phase θ2 is reached when the pressure release control shaft 29 reaches the position 29o2. Release cam 23
It is the moment the free state is released after the restraint on the outer peripheral surface of the.

After that, when the fixing device 21 is taken out of the main body of the apparatus, if the cam shaft 28 is rotated clockwise, the pressure release control shaft 29 returns to the position 29o and the initial position 29n.
Never return to. Therefore, the above-mentioned initial position 29n is the position where the pressure release control shaft 29 of the new fixing device 21 exists, and the pressure release control shaft 29 is once moved to the initial position 29n.
When the pressure is released, the pressure release control shaft 29 cannot be returned to the initial position 29n, and the pressure release control shaft 29 exists at the position 29o.

In FIG. 8, the fixing device 21 is used even once.
Then, the pressure release cam 23 releases the pressure at the phase of θ2.
The control shaft 29 becomes free, and the pressurization is performed at a predetermined speed.
When the release plate 24b is rotated about the pressure release shaft 27,
It rotates clockwise and the judgment flag 22 is set to the transparent photo center.
25, the sensor is detected after time t2 from the start of driving.
It turns on. Therefore, time t 1 is T_newAnd when
Interval t 2 is T_oldBecomes

As described above, the pressure release cam 23 can be used to change the timing at which the sensor is turned on after the pressure is released, and the fixing device can be a new or used one without requiring a special sensor or circuit. It is possible to determine whether or not. In addition, the transmissive photo sensor 25 is attached to the fixing device 2.
No. 1 attached to the outside of 1, i.e., the sensor is not provided in the detachable replacement unit, the cost of the replacement unit is reduced, and the sensor is provided outside the fixing device 21, so that deterioration of the sensor due to temperature rise is minimized. It is possible to limit it.

When it is detected that the fixing device 21 is new, the time counter (not shown) housed in the main body device counts the usage time or the cumulative number of printed sheets, and the replacement time approaches. Then, the data is sent to a service center, a dealer, etc. through a network line or an operation panel (not shown). As a result, the user or service person can know the replacement time of the replacement unit in good timing, and the unit can be replaced before it is damaged. FIG. 1 is a flow chart summarizing the determination of old and new fixing devices described above.
As shown in FIG.

In the above, the operating time of the detachable fixing device or the cumulative number of printed sheets may be counted to notify the user of the remaining life time or the number of printable pages until the end of life.

Further, when counting the operating time of the detachable and replaceable fixing device or the cumulative number of printed sheets,
At this time, when the fixing device that is detachable and replaceable in the unused state is replaced, the operating time or the count of the cumulative number of printed sheets may be changed to the initial state.

Further, the remaining life time of the removable fixing device or the number of printable pages until the end of the life may be periodically notified to the service center or the host computer by using a network line. .

[Second Embodiment] The mechanical structure of the second embodiment is substantially the same as that of the first embodiment. Therefore, the pressure release mechanism 24 in the fixing device 21 and the detection of a new article will be described using the structural elements shown in the first embodiment.

FIG. 9 shows the pressure releasing mechanism 24 provided in the fixing device 21. Further, in FIG. 11, the state of the pressurizing mechanism is as shown in FIG. 11A, the fixing device 21 is in a new state and is not in operation, and FIG. 11B is the state in which the fixing device 21 is used once or more and is not in operation. (C) The fixing device 21 is in an operable state. The pressure release process will be described with reference to FIG.

In the pressure release mechanism 24 shown in FIG. 9, the pressure release plate 24b is supported and fixed about the pressure release shaft 27 as the center of rotation, and rotates clockwise around the cam shaft 28 as the center of rotation. The pressure release cam 24 allows the pressure release plate 24 to be released.
The pressure release control shaft 29 fixed on b is pushed up, while the pressure release arm 26 linked with the fulcrum 31 on the pressure release plate 24b is pushed down to fix the fixing roller 19 and the pressure roller 20. Separate.

Conversely, the pressure release control shaft 29 is released due to the constraint of the pressure release cam 23, so that the fixing roller 19 is released.
And the pressure roller 20 are pressed against each other. Embodiment 2 here
The determination flag 22 is rotatably fitted to the cam shaft 28, and the determination flag 22 detects the operating state of the pressure release plate 24b by the transmissive photosensor 25 attached to the outside of the main body of the fixing device 21. Then, under pressure, the fixing device 2
It is possible to detect the presence of 1 and the availability of operation.

In the present invention, the determination flag 22 is used to detect a new product by the following method.

FIG. 11A shows the pressure release mechanism 24 inside the fixing device 21 in a new state. The fixing device 21
Is new, the determination flag 22 is rotatably attached to the cam shaft 28, and is attached in synchronization with the pressure release cam 23 by the restraint of the pressure release plate 23b. A biasing force is applied to rotate clockwise about 28.
This urging force is regulated by the pressure release plate 24b.
In FIG. 11B, this restriction is released and the pressure release cam 2 is released.
3 shows the determination flag 22 in the specified position state, which indicates that the stopper 23s has been used once. Stopper 2
3 s is a brand new product, and when the determination flag 22 is regulated by the pressure release plate 24b, it overlaps below the determination flag 22 and is biased by a spring (not shown) to project onto the surface of the pressure release cam 23. Is given (see FIG. 10A in which the relevant part of FIG. 11A is enlarged). That is, once the determination flag 22 passes over the stopper 23s, the stopper 2
3 s projects onto the surface of the pressure release cam 23 and serves as a stopper for the determination flag 22. The state shown in FIG. 10B, which is an enlarged view of the relevant portion in FIG. 11B, shows a state in which the fixing device 21 has been used once or more.

Next, with reference to FIG. 12, a state of releasing the pressure when the fixing device 21 is in a new state will be described. 12
In (a), (a) the new product is not in operation, (b) the pressure release cam 23 rotates clockwise, and the pressure release plate 24b is pushed counterclockwise. Judgment flag 22 that was urged
However, it is released and starts rotating clockwise, and the photo sensor 2
Pass 5 once. (C) The determination flag 22 that has been released from the bias is rotated synchronously with the pressure release cam 23 at the specified position by the stopper 23s, and the sensor is turned on. Then, Fig. 1
The state of pressure release when the fixing device 21 is used once or more will be described in Section 3. In FIG.
(A) Unoperated state, (b) The pressure release cam 23 rotates clockwise, and the pressure release plate 24b is pushed up counterclockwise. The determination flag 22 starts rotating clockwise in synchronization with the pressure release cam. (C) The determination flag 22 rotates in synchronization with the pressure release cam 23 to reach the operating position,
This is detected.

The function of the pressure release mechanism 24 incorporated in the fixing device 21 and the sensor-on timing of the transmissive photosensor 25 will be described with reference to FIGS. 12 and 13. The graphs in the upper part of each figure show the relationship between the sensor-on and sensor-off states of the transmissive photosensor 25 and the time elapsed from the start of rotation of the cam shaft 28. The respective states of the pressure release mechanism 24 at the transition points on the graph are shown in the respective frames drawn below the graph. FIG. 12 shows the operation process of the pressure release mechanism 24 when the fixing device 21 is in a new state, and FIG. 13 shows the operation of the pressure release mechanism 24 when the fixing device 21 is used once or more. The process was shown.

FIG. 12A shows a case where a new fixing device 21 is mounted on the main body of the device. It shows the state immediately before the pressure release plate 24b releases the constraint of the determination flag 22 by starting the rotation of the cam shaft 28 in the clockwise direction so that the fixing device 21 can be operated. The time elapsed up to this time is t3
Is. This is a state between D and E on the graph, and the transmissive photosensor 25 is in a sensor-off state.

In FIG. 12B, the pressure release plate 23 is rotated clockwise to release the restraint of the determination flag 22 by the pressure release plate 24b, and at the same time, the determination flag 22 is determined to be the torsion coil spring 30 in the clockwise direction. The state is shown immediately after the flag 22 rotates due to gravity, the leading end of the determination flag 22 reaches the transmissive photosensor 25, and after passing through the transmissive photosensor 25. The time elapsed up to this time is t4
Is. In this state, the transmission photosensor 25 changes from the sensor-off state to the sensor-on state in the state of going from E to H on the graph and then to H, and returns to the sensor-OFF state after (t4-t3) time.

In FIG. 12 (c), the determination flag 22 passes through the transmissive photosensor 25 and further rotates to stop the stopper 23s.
When the determination flag 22 is pressed against the stopper 23s by the torsion coil spring 30, the determination flag 22 operates integrally with the pressure release cam 23. On the other hand, the cam shaft 28 continues to rotate clockwise, and the pressure release cam 23 rotates away from the constraint of the pressure release control shaft 29 and rotates together with the pressure release cam 23. The state where the tip of the flag 22 reaches the transmission type photo sensor 25 again and the cam shaft 28 is stopped is shown. The time elapsed up to this point is t5. In the state in which this goes from C to C on the graph, the transmissive photosensor 25 changes from the sensor-off state to the sensor-on state.

FIG. 13A shows the case where the fixing device 21 which has been used more than once is mounted on the main body of the device. Once used, the determination flag 22 is stopped from rotating by the stopper 23s and the relative position with the pressure release cam 23 is determined. FIG. 13A shows a state from the start of rotation of the cam shaft 28 in a clockwise direction in order to make the fixing device 21 operable, until a time t3 has elapsed. This is the transmission photosensor 25 in the state between D and E on the graph.
Indicates that the sensor is off. FIG. 13B shows the elapsed time t
The state from 3 to the elapsed time t4 is shown. This is the transmission photosensor 25 in the state between E and H on the graph.
Is still in the sensor off state.

FIG. 13 (c) shows the state from the elapsed time t4 until the judgment flag 22 rotates integrally with the pressure release cam 23, reaches the transmission type photo sensor 25 and stops the cam shaft. There is. The elapsed time at this time is t5. In the state in which this goes from C to C on the graph, the transmissive photosensor 25 changes from the sensor-off state to the sensor-on state.

As described above, in the case of the new fixing device 21, the time t elapsed after the rotation of the cam shaft 28 is started.
At 3, t5, the transmissive photosensor 25 is turned on, but in the case of the fixing device 21 that has been used once or more,
At the elapsed time t3, the sensor is not turned on and the elapsed time t5
Only when the sensor is turned on, the transmission photosensor 25 can be distinguished by the number of times the sensor is turned on. In the above description, the sensor ON of the transmissive photosensor 25 is the H active signal, but the L active signal may be the sensor ON depending on the type of the sensor.

As described above, the number of times the determination flag 22 passes through the transmissive photosensor 25 is changed depending on whether it is a new product or a condition in which it has been used more than once, without requiring a special sensor or circuit. It is possible to discriminate between the new fixing device 21 and the used fixing device 21.

In the embodiment of the present invention, the fixing device 21 has been described as an example of the detachable and replaceable unit. However, as described in claim 1, the present invention includes a process cartridge, a toner cartridge, and an intermediate transfer member. Needless to say, the present invention can be applied to all so-called units including a cleaner, etc., which can be detached and replaced from the main body.

[0064]

As described above, it is possible to detect a new product for a unit that can be attached to and detached from the main body device without providing a special circuit or sensor, and it is possible to significantly reduce the cost. At the same time, it can be expected to provide users with replacement parts at low cost.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the outline of the internal structure of a color image forming apparatus.

FIG. 2 is a perspective view showing a positional relationship among a roll, a pressure release mechanism, and a drive unit in the fixing device.

FIG. 3 is a diagram showing a pressure release mechanism according to the first embodiment.

FIG. 4 is a diagram showing a mechanism for discriminating between a new product and a used product in the pressure release mechanism according to the first embodiment.

5A and 5B are diagrams showing a roll pressure release state (new) in which the operation of the image forming apparatus is disabled in the first embodiment.

6 (a) and 6 (b) are diagrams showing a roll pressure release state (second-hand product) in which the operation of the image forming apparatus is disabled in the first embodiment.

7A and 7B are diagrams showing a roll pressurization state in which the image forming apparatus can be operated in the first embodiment.

FIG. 8 is a timing chart showing a sensor on state of a used product according to the first embodiment.

FIG. 9 is a diagram showing a pressure release mechanism according to the second embodiment.

10 (a) and 10 (b) are views showing a mechanism for discriminating between a new product and a used product in the pressure release mechanism in the second embodiment.

11 (a), (b) and (c) are diagrams showing an operation process of the pressure release mechanism in the second embodiment.

FIG. 12 is a timing chart showing a state where a new sensor is turned on in the second embodiment.

FIG. 13 is a timing chart showing a sensor-on state of a used product according to the second embodiment.

FIG. 14 is a timing chart showing a new sensor on state according to the second embodiment.

FIG. 15 is a flowchart showing a method of discriminating between a new article and a used article in the first embodiment.

[Explanation of symbols]

1Y, 1M, 1C, 1K ... Laser scanner 2Y, 2M. 2C, 2K ... Laser light 2Y, 3M, 3C, 3K ... Charging roller 4Y. 4M, 4C, 4K ... Photosensitive drums 5Y, 5M, 5C, 5K ... Developing devices 6Y, 6M, 6C, 6K ... Developing sleeves 7a, 7b, 7c ... Driving roller 8 ... Intermediate transfer roller 9 ... Paper feeding cassettes 9Y, 9M, 9C, 9K ... Backup roller 11 ... Paper feeding rollers 12a, 12b, 13a, 13b, 14a, 14b ... Conveying roller pair 15 ... Transfer roller 16 ... Cleaning blade 17 ... Cleaner 18 ... Halogen heater 19 ... Fixing roller 19a ... Positioning plate 20 ... Pressure roller 20a ... Roller shaft 21 ... Fixing device 21a ... Frame 22 ... Judgment flag 23 ... Pressure release cam 23a ... Cam surface 23b ... Cam surface 23c ... Concave portion 23n ... Position (new article) 23o ... Position (used item) ) 23s ... Stopper 24 ... Pressure release mechanism 24a ... Pressure release plate 25 ... Sensor 26 ... Pressure release arm 27 ... Pressure Dividing shaft 28 ... cam shaft 29 ... pressure release control shaft 29n ... initial position 29N1 ...
Position 29o ... Position (second-hand goods) 29o1 Position 29o2 ... Position 30 ... Torsion coil spring 31 ... Rotation fulcrum 32 ... Trajectory 50 ... Paper discharge tray 100 ... Removed toner transport path 101 ... Removed toner recovery container connection 102 ... Removed toner recovery container A1, A2 ... Drive transmission means C ... Damper D ... Pressing spring M ... Drive source N ... Nip S ... Recording paper t ... Time t1, t2, t3, t4, t5 ... Time T1Y, T1M, T1C, T1K ... Primary transfer Point T2 ... Secondary transfer point θ1, θ2 ... Phase a, b, c ... Arrow

Continued front page    F-term (reference) 2H027 DA21 DA27 DA38 DA45 EJ15                       GB10 GB11                 2H033 AA36 BA03 BA06 BB35 CA12                       CA57                 2H071 BA02 BA13 BA22 BA29 BA33                       DA12 DA32

Claims (15)

[Claims] 1. When a unit that is removable from the electrophotographic image forming apparatus main body is loaded into the main body of the electrophotographic image forming apparatus, it is possible to detect the presence or absence of the unit. When loaded in the main body of the forming apparatus, it has an inoperable state and an operable state, and when the detachable and replaceable unit which is in an unused state is loaded, the operation is performed from the inoperable state. When the ready state is T _new, and when the removable unit that has been used more than once is loaded, the time from the inoperable state to the ready state is T _old , An electrophotographic image forming apparatus, wherein T _new ≠ T _old . 2. The electrophotographic image forming apparatus according to claim 1, wherein the detachable and replaceable unit uses a cam mechanism to change from the inoperable state to the operable state. . 3. The cam of the cam mechanism has at least three phases, namely, a phase of an unused state, a phase of an inoperable state, and a phase of an operable state of the removable exchangeable unit. Item 2. The electrophotographic image forming apparatus according to Item 2. 4. The electronic device according to claim 3, wherein once the cam of the cam mechanism is out of the phase of the initial state among the three phases, it is impossible to stay in that state again. Photo image forming apparatus. 5. A fixing device, wherein the removable unit is provided with a roller pair that is pressed against each other, a cam that controls a pressing force, and a sensor that determines a control state, and in the fixing device, the roller pair is provided. The electrophotographic image forming apparatus according to any one of claims 1 to 4, wherein the sensor for performing the pressure control of (1) also serves as a sensor for determining whether the fixing device is new or used. 6. A sensor detects the presence / absence of the detachable / replaceable unit and the time for changing from the inoperable state to the operable state, and the sensor is housed in the apparatus body. The electrophotographic image forming apparatus according to claim 1, wherein the electrophotographic image forming apparatus is an electrophotographic image forming apparatus. 7. The time count or the cumulative number of printed sheets is counted after it is detected that the removable unit is unused.
The electrophotographic image forming apparatus according to any one of 1 to 5. 8. The operating time of the removable unit, or the cumulative number of printed sheets is counted, and the remaining life time or the number of printable pages until the end of the life can be notified to the user. The electrophotographic image forming apparatus according to any one of 1 to 5. 9. When counting the operating time of the detachable and replaceable unit or the cumulative number of printed sheets,
9. The electrophotographic image according to claim 8, wherein the operating time or the count of the cumulative number of printed sheets is changed to the initial state when the unit is replaced by the detachable and replaceable unit in the unused state. Forming equipment. 10. The remaining life time of the removable unit or the number of printable pages until the end of the life can be periodically notified to a service center or a host computer by using a network line. The electrophotographic image forming apparatus according to claim 1. 11. When a unit detachably mountable to the main body of the electrophotographic image forming apparatus is loaded in the main body of the electrophotographic image forming apparatus, the presence or absence of the unit is detected by a detecting unit provided in the electrophotographic image forming apparatus. The replaceable unit has an inoperable state and an operable state when loaded in the main body of the electrophotographic image forming apparatus, and the detachable and replaceable unit in an unused state is loaded. In this case, the number of times the detection means is activated when the operation-disabled state is changed to the operation-enabled state is 2
When the detachable / replaceable unit that has been used once or more is loaded, the number of times that the detection means is operated when the operation-disabled state is changed to the operation-enabled state is once. An electrophotographic image forming apparatus characterized by: 12. The cam mechanism is used when the removable unit is changed from the inoperable state to the operable state.
1. The electrophotographic image forming apparatus described in 1. 13. The cam of the cam mechanism has at least three phases, a phase of an unused state, a phase of an inoperable state, and a phase of an operable state of the removable exchangeable unit. Item 13. The electrophotographic image forming apparatus according to Item 12. 14. The electronic device according to claim 13, wherein once the cam of the cam mechanism is out of the phase of the initial state among the three phases, it is impossible to stay in that state again. Photo image forming apparatus. 15. A fixing device, wherein the removable exchangeable unit includes a roller pair that is pressed against each other, a cam that controls a pressing force, and a sensor that determines a control state. 15. The electrophotographic image forming apparatus according to claim 11, wherein the sensor for performing the pressurization control also serves as a sensor for determining whether the fixing device is new or used.