JP7705598B2 - Rotation detection mechanism, heating device, fixing device, image forming apparatus - Google Patents

Description

The present invention relates to a rotation detection mechanism, a heating device, a fixing device, and an image forming device.

In recent years, in order to save energy and increase the speed of fixing devices, low-heat-capacity fixing devices equipped with a fixing sleeve made of a thin film have become known. The fixing device uses a heating member to heat the rotating fixing sleeve to the fixing temperature.

In such a fixing device, if the rotation of the fixing sleeve stops due to an abnormality in the device, heating occurs intensively in only one part of the circumference of the fixing sleeve, causing the fixing sleeve to abnormally rise in temperature. To prevent this, a rotation detection mechanism is provided that detects the rotation of the fixing sleeve. When the rotation detection mechanism detects that the fixing sleeve has stopped rotating, control is performed to stop heating by the heating member.

For example, in Patent Document 1 (Patent Publication No. 6428700), a pulse plate is provided on a rotating shaft that rotates in response to the rotation of the fixing sleeve. As the pulse plate rotates, the light-shielding portion of the pulse plate passes the rotation detection sensor in sequence, switching the detection state and non-detection state of the rotation detection sensor, and detecting the rotation of the fixing sleeve.

The rotation detection mechanism equipped with this pulse plate etc. is provided on both ends of the fixing sleeve. This allows one of the rotation detection mechanisms to detect that the other side of the fixing sleeve is not rotating, even if the fixing sleeve breaks in the middle and only one side rotates.

The objective is to provide a rotation detection mechanism that can detect the presence or absence of rotation on both sides of a rotating body with a simple configuration.

To solve the above problems, the present invention provides a rotation detection mechanism comprising a driven rotor and a detection member for detecting the rotation of the driven rotor, the driven rotor comprising a first transmitted part provided on one side in the axial direction thereof to which a driving force is transmitted from the rotor, and a second transmitted part provided on the other side in the axial direction thereof to which a driving force is transmitted from the rotor, the first transmitted part and the second transmitted part being transmitted in different phases by the rotation of the rotor, and the driven rotor is rotated.

The rotation detection mechanism of the present invention can detect the presence or absence of rotation on both sides of a rotating body with a simple configuration.

FIG. 1 is a schematic diagram of an image forming apparatus. FIG. 2 is a side cross-sectional view of the fixing device. FIG. 2 is a schematic configuration diagram showing a rotation detection mechanism according to an embodiment of the present invention. 1A and 1B are diagrams showing meshing between an idler gear and a driven gear, in which FIG. 1A shows a first driven gear, and FIG. 1B shows a second driven gear. 5A and 5B are diagrams showing meshing between an idler gear and a driven gear in phases different from those in FIG. 4, where FIG. 5A shows a first driven gear and FIG. 5B shows a second driven gear. 11A and 11B are schematic configuration diagrams showing a rotation detection mechanism according to a different embodiment. 6A and 6B are diagrams showing an example of a first driven gear and a second driven gear having different tooth ranges from those of the embodiment of FIGS. 4 and 5, in which FIG. 6A shows the first driven gear and FIG. 6B shows the second driven gear. 8A and 8B are diagrams showing an example of a first driven gear and a second driven gear having different tooth ranges from those of the embodiments of FIGS. 4, 5, and 7, in which FIG. 8A shows the first driven gear and FIG. 8B shows the second driven gear. 13 is a schematic diagram showing a rotation detection mechanism in which a driven gear provided on a rotating shaft meshes with a fixing gear without an idler gear. FIG.

The following describes an embodiment of the present invention with reference to the drawings. In each drawing, the same or corresponding parts are given the same reference numerals, and duplicated explanations will be appropriately simplified or omitted. In the following description, a fixing device serving as a heating device that fixes a toner image onto a paper surface will be described as an example of a device equipped with a rotation detection mechanism.

The monochrome image forming apparatus 1 shown in FIG. 1 is provided with a photosensitive drum 10. The photosensitive drum 10 can carry toner as a developer on its surface. The photosensitive drum 10 is a drum-shaped rotating body that can rotate in the direction of the arrow in the figure. Around the photosensitive drum 10, a charging roller 11, a developing device 12 including a developing roller 7, etc., and a cleaning blade 13, etc. are provided. The charging roller 11 uniformly charges the surface of the photosensitive drum 10. The developing roller 7 supplies toner to the surface of the photosensitive drum 10. The cleaning blade 13 cleans the surface of the photosensitive drum 10.

The exposure unit 3 is disposed above the process unit 2. The exposure unit 3 emits laser light Lb based on image data. This laser light Lb is irradiated onto the surface of the photoconductor drum 10 via the mirror 14.

Transfer means 15 is disposed opposite the photoconductor drum 10. The transfer means 15 includes a transfer charger and transfers the image on the surface of the photoconductor drum 10 onto the paper P.

The photosensitive drum 10, charging roller 11, process unit 2, transfer means 15, etc. constitute the image forming means for forming an image on paper.

The paper feed unit 4 is located at the bottom of the image forming device 1. The paper feed unit 4 is composed of a paper feed cassette 16, a paper feed roller 17, etc. A registration roller 18 is disposed downstream of the paper feed roller 17 in the transport direction. The paper feed cassette 16 stores paper P as a recording medium. The paper feed roller 17 conveys paper P from the paper feed cassette 16 to the transport path 5.

The fixing device 9 includes a fixing sleeve 20, a pressure roller 21, etc. The fixing sleeve 20 is heated by a heater, which will be described later, as a heating member. The pressure roller 21 applies pressure to the fixing sleeve 20.

The basic operation of the image forming device 1 will be described below with reference to FIG. 1.

When the image forming operation starts, the charging roller 11 first charges the surface of the photoconductor drum 10. Then, based on image data, the exposure unit 3 irradiates the photoconductor drum 10 with a laser beam Lb. This reduces the potential of the irradiated portion of the photoconductor drum 10, and an electrostatic latent image is formed in that portion. Toner is supplied from the developing device 12 to the surface portion of the photoconductor drum 10 on which the electrostatic latent image has been formed, and the electrostatic latent image is visualized as a toner image (developer image). Then, the toner remaining on the photoconductor drum 10 after transfer is removed from the surface of the photoconductor drum 10 by the cleaning blade 13.

When the image forming operation is started, the paper feed roller 17 of the paper feed section 4 rotates at the bottom of the image forming device 1, and the paper P stored in the paper feed cassette 16 is sent to the transport path 5.

The paper P sent to the transport path 5 is timed by the registration rollers 18 and transported to the transfer section at a timing that faces the toner image on the surface of the photosensitive drum 10. This transfer section is the opposing portion between the transfer means 15 and the photosensitive drum 10. The toner image is transferred to the surface of the paper P transported to the transfer section by the application of a transfer bias by the transfer means 15.

The paper P with the transferred toner image is transported to the fixing device 9. The paper P is heated and pressurized by the heated fixing sleeve 20 and pressure roller 21, fixing the toner image to the surface of the paper P. The paper P with the fixed toner image is then separated from the fixing sleeve 20, transported by a pair of transport rollers provided downstream of the fixing device 9, and discharged to a paper output tray. The paper output tray is provided outside the device.

Next, we will explain the configuration of the fixing device in more detail.

As shown in FIG. 2, the fixing device 9 according to this embodiment includes an endless fixing sleeve 20, a pressure roller 21 as an opposing member or pressure member, a heater 22 as a heating member, a heater holder 23 as a holding member, a stay 24 as a support member, and a thermistor 25 as a temperature detection means. The pressure roller 21 contacts the outer peripheral surface of the fixing sleeve 20 to form a fixing nip N as a nip portion. The heater 22 heats the fixing sleeve 20. The heater holder 23 holds the heater 22. The stay 24 supports the heater holder 23 from its rear side. The fixing sleeve 20, the pressure roller 21, the heater 22, the heater holder 23, and the stay 24 extend in a direction perpendicular to the plane of FIG. 2, and hereinafter this direction is referred to as the longitudinal direction of each member, or simply the longitudinal direction. This longitudinal direction is also the axial direction of the virtual rotation axis of the fixing sleeve 20, and is also the width direction of the paper P passed through the fixing device 9. As one aspect of the rotating body provided in the rotation detection mechanism of the present invention, the fixing member provided in the fixing device can be used as this rotating body. In the fixing device 9 of this embodiment, a fixing sleeve 20, which is a specific example of this fixing member, is provided as the above-mentioned rotating body.

The fixing sleeve 20 has a cylindrical base made of polyimide (PI) with an outer diameter of 25 mm and a thickness of 40 to 120 μm. A release layer made of fluororesin such as PFA or PTFE with a thickness of 5 to 50 μm is formed on the outermost surface of the fixing sleeve 20 to enhance durability and ensure releasability. An elastic layer made of rubber or the like with a thickness of 50 to 500 μm may be provided between the base and the release layer. The base of the fixing sleeve 20 is not limited to polyimide, and may be a heat-resistant resin such as PEEK or a metal base such as nickel (Ni) or SUS. The inner surface of the fixing sleeve 20 may be coated with polyimide, PTFE, or the like as a sliding layer. The fixing sleeve 20 is a heated member that is heated by the heater 22.

The pressure roller 21 has an outer diameter of, for example, 25 mm. The pressure roller 21 is composed of a solid iron core 21a, an elastic layer 21b, and a release layer 21c. The elastic layer 21b is formed on the surface of the core 21a. The elastic layer 21b is made of silicone rubber and has a thickness of, for example, 3.5 mm. The release layer 21c is formed on the outside of the elastic layer 21b. In order to increase the release properties of the surface of the pressure roller 21, it is desirable for the release layer 21c to be a fluororesin layer having a thickness of, for example, about 40 μm.

The pressure roller 21 is biased toward the fixing sleeve 20 by the biasing means, and is pressed against the heater 22 via the fixing sleeve 20. This forms a fixing nip N between the fixing sleeve 20 and the pressure roller 21. The pressure roller 21 is also configured to be driven to rotate by the drive means. When the pressure roller 21 rotates in the direction of the arrow in FIG. 2, the fixing sleeve 20 is rotated accordingly.

The heater 22 is a planar heating element arranged in the longitudinal direction.

The heater 22 is composed of a plate-shaped base material 26, a resistance heating element (heating portion) 27, an insulating layer 28, and the like. The resistance heating element 27 is provided on the base material 26. The insulating layer 28 covers conductors such as the resistance heating element 27. The heater 22 is in contact with the inner circumferential surface of the fixing sleeve 20 on the insulating layer 28 side, and the heat generated by the resistance heating element 27 is transferred to the fixing sleeve 20 via the insulating layer 28.

The heater holder 23 and the stay 24 are disposed on the inner periphery of the fixing sleeve 20. The stay 24 is made of a metal channel material, and both ends are supported by both side plates of the fixing device 9. The stay 24 supports the heater holder 23 and the heater 22 held by the heater holder 23. As a result, when the pressure roller 21 is pressed against the fixing sleeve 20, the heater 22 reliably receives the pressing force of the pressure roller 21, and a fixing nip N is stably formed between the fixing sleeve 20 and the pressure roller 21.

The heater holder 23 is desirably made of a heat-resistant material because it is prone to becoming hot due to the heat of the heater 22. For example, if the heater holder 23 is made of a heat-resistant resin with low thermal conductivity such as LCP, the transfer of heat from the heater 22 to the heater holder 23 is suppressed, and the heater 22 can efficiently heat the fixing sleeve 20.

As shown in FIG. 2, when the fixing device 9 according to this embodiment starts a printing operation, the pressure roller 21 is driven to rotate, and the fixing sleeve 20 starts to rotate in response. In addition, the fixing sleeve 20 is heated by supplying power to the resistance heating element 27 of the heater 22. Then, when the temperature of the fixing sleeve 20 reaches a predetermined target temperature (fixing temperature), the paper P carrying the unfixed toner image is transported between the fixing sleeve 20 and the pressure roller 21 (fixing nip N). As a result, the unfixed toner image is heated and pressurized to be fixed to the paper P.

In the fixing device 9 described above, a rotation detection mechanism is provided for detecting the rotational movement of the fixing sleeve 20. This rotation detection mechanism will be described with reference to FIG. 3. In the following description, the left-right direction C in FIG. 3 will be referred to as the axial direction of the fixing sleeve 20 and the rotating shaft 41.

As shown in FIG. 3, the pressure roller 21 receives a driving force from a motor 51 via a gear or the like provided on the shaft of the pressure roller 21. The pressure roller 21 is rotated by the driving force of the motor 51, and the fixing sleeve 20 is rotated accordingly.

Fixing gears 52A and 52B are provided on both axial sides of the fixing sleeve 20 as rotating gears. Fixing gears 52A and 52B mesh with idler gears 53A and 53B, respectively.

The rotation detection mechanism 40 includes a rotating shaft 41 as a driven rotating body, a first driven gear 42A as a first transmitted part, a second driven gear 42B as a second transmitted part, a light blocking member 43, and an optical sensor 44 as a detection member. The driven gears 42A and 42B are driven rotating body gears.

Here, the "driven rotor" in this embodiment is a member provided in the rotation detection mechanism, rotates in response to the rotor, and has its rotation detected by the detection member. The "rotor" in this embodiment is a member that directly or indirectly rotates this driven rotor, and is a member that is the subject of judgment as to whether or not both sides in the axial direction are rotating normally, depending on whether or not the driven rotor is rotating. Note that the "driven rotor" is rotated in response to the rotation of the "rotor", but this "rotor" may also be configured to rotate in response to the rotation of another member. The fixing sleeve 20, which is the "rotor" in this embodiment, is a member that is rotated in response to the rotation of the pressure roller 21.

The light-shielding member 43 is provided midway along the axial direction of the rotating shaft 41. The light-shielding member 43 has a plurality of light-shielding plates 43a in its circumferential direction. In other words, the light-shielding member 43 is configured such that light-shielding sections provided with the light-shielding plates 43a and slit sections are alternately provided along its circumferential direction.

An optical sensor 44 is provided opposite the light blocking member 43. When the light blocking plate 43a is placed at position B in FIG. 3, which is a position on the optical path of the optical sensor 44, the optical sensor 44 goes from a detection state to a non-detection state.

The detection result of the optical sensor 44 is input to a control unit 90 provided in the image forming device 1. However, the control unit 90 may be provided in the fixing device 9 or in the rotation detection mechanism 40.

A first driven gear 42A is provided on one axial side of the rotating shaft 41, and a second driven gear 42B is provided on the other axial side.

The driven gears 42A and 42B mesh with idler gears 53A and 53B on one and the other axial sides, respectively.

As shown in FIG. 4(a), the first driven gear 42A has a first tooth portion 42a in a 180-degree circumferential range, and no tooth portions are provided in the other half of the 180-degree range. As shown in FIG. 4(b), the second driven gear 42B has a second tooth portion 42b in one half of the circumferential range, and no tooth portions are provided in the other half of the 180-degree range. The first tooth portion 42a and the second tooth portion 42b are out of phase with each other by 180 degrees, and do not overlap in phase.

As shown in FIG. 3, when the motor 51 rotates, the driving force is transmitted to the idler gears 53A and 53B via the fixing gears 52A and 52B, and the idler gears 53A and 53B rotate. At this time, as shown in FIG. 4(a) and FIG. 4(b), in the phase in which the first driven gear 42A is meshed with one of the idler gears 53A, the driving force is transmitted from one of the idler gears 53A and the rotating shaft 41 rotates. On the other hand, as shown in FIG. 5(a) and FIG. 5(b), in the phase in which the second driven gear 42B is meshed with the other idler gear 53B, the driving force is transmitted from the other idler gear 53B and the rotating shaft 41 rotates.

As shown in FIG. 3, when the rotating shaft 41 rotates, the light blocking member 43 rotates accordingly. When the light blocking member 43 rotates, the light blocking plate 43a intermittently passes through position B. This causes the optical sensor 44 to alternate between a detection state and a non-detection state.

As described above, according to this embodiment, the driven gears 42A and 42B of the rotating shaft 41 for rotating the light blocking member 43 are continuously rotated (i.e., continuously rotated for 360 degrees or more) by transmitting driving forces from the idler gears 53A and 53B at different phases. Therefore, when either or both of the idler gears 53A and 53B do not rotate, the rotation of the rotating shaft 41 also stops. In other words, when the rotation of one side or the other side of the fixing sleeve 20 stops, the rotation of the rotating shaft 41 also stops. In this case, the optical sensor 44 continues to be in either a detection normal state or a non-detection state. This allows the control unit 90 to detect that the rotating shaft 41 is not rotating, that is, that the fixing sleeve 20 is not rotating normally. When the control unit 90 detects that the rotating shaft 41 has stopped, it stops the supply of electricity to the heater 22. Therefore, when some abnormality occurs in the fixing sleeve 20 and it is not rotating, the heating of the fixing sleeve 20 by the heater can be stopped to prevent the fixing sleeve 20 from being overheated.

In this embodiment, even if only one side of the fixing sleeve 20 stops rotating, the optical sensor 44 detects the stop of rotation and the control unit 90 can stop the supply of electricity to the heater 22. Therefore, for example, even if the fixing sleeve 20 breaks in the middle of the axial direction and only one side continues to rotate, the heater 22 can be prevented from continuing to heat the stopped side and causing it to overheat. In one embodiment of the present invention, the first driven gear 42A and the second driven gear 42B transmit driving forces in different phases to rotate the rotating shaft 41, but this "different phase" refers to the range of phases in which the first driven gear 42A and the second driven gear 42B transmit driving forces directly or indirectly from the fixing sleeve 20 (rotating body) do not match, and some of them may overlap. Specifically, the circumferential range in which the member (idler gear 53A in this embodiment) that directly transmits the driving force to the first driven gear 42A meshes with the first driven gear 42A is different from the circumferential range in which the member (idler gear 53B in this embodiment) that directly transmits the driving force to the second driven gear 42B meshes with the second driven gear 42B. However, when only one of the first driven gear 42A and the second driven gear 42B transmits the driving force, the above-mentioned circumferential range in which the first tooth portion 42a of the first driven gear 42A and the second tooth portion 42b of the second driven gear 42B are provided is set so that the rotating shaft 41 does not rotate continuously more than 360 degrees. This circumferential direction is the direction along the rotation direction of the rotating body, etc., and is the direction in which the teeth such as the first tooth portion 42a are arranged side by side.

Compared to a configuration in which a detection mechanism for detecting the rotation of the fixing sleeve 20 is provided at both ends of the fixing sleeve 20, in this embodiment, the above effects can be obtained with a single optical sensor 44, which reduces the cost of the rotation detection mechanism 40. Also, compared to a configuration in which multiple detection mechanisms are used, failures are less likely to occur and the reliability of the device is improved.

The above describes an embodiment of the present invention, but the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

In the above embodiment, the heating member is a planar heater having a resistance heating element, but it may be a halogen heater, a carbon heater, or an IH (induction heating) type heater. In this case, a nip forming member that forms a fixing nip N between the pressure roller 21 and the fixing sleeve 20 can be provided. In particular, when an IH type heater is used as the heating member, the heater and thermistor 25 are placed at different positions in the circumferential direction of the fixing sleeve 20 due to the size of the coil part of the heater. Therefore, in this case, if the rotation detection mechanism cannot detect the stop of rotation of the fixing sleeve 20, the thermistor 25 in particular often cannot detect an abnormal temperature rise of the fixing sleeve 20. For this reason, it is preferable to provide the rotation detection mechanism of the present invention in such a heating device.

In the above embodiment, an optical sensor and a light-shielding member are used as an example of a combination of a rotating body that rotates integrally with the rotating shaft and a detection mechanism that detects the rotation of the rotating body, but the present invention is not limited to this. For example, the rotation detection mechanism 40 of the embodiment shown in FIG. 6 includes a magnetic member 45 and a magnetic sensor 46 as a detection member instead of an optical sensor and a light-shielding member.

The magnetic member 45 is provided on the rotating shaft 41 and rotates integrally with the rotating shaft 41. The magnetic member 45 has magnetic bodies 45a as magnetic portions and non-magnetic bodies 45b as non-magnetic portions alternately in the circumferential direction.

When the rotating shaft 41 rotates, the magnetic body 45a and the non-magnetic body 45b alternately pass through position B. This causes the magnetic sensor 46 to alternate between a detection state and a non-detection state, allowing the control unit 90 to detect the rotation of the fixing sleeve 20. The configuration of this embodiment allows accurate detection even in an environment where paper dust or oil can cause erroneous detection by the optical sensor. Also, as in the above embodiment, a single magnetic sensor 46 can detect when either side of the fixing sleeve 20 has stopped rotating.

Although the optical sensor 44 shown in FIG. 3 is a transmission type sensor, it may be a reflection type optical sensor. Also, instead of the light shielding plate 43a provided on the rotating shaft 41 in FIG. 3, contact parts may be provided intermittently in the circumferential direction of the rotating shaft 41, and the detection member may be a contact type sensor. In other words, the detection member may change its detection state by switching between contact and non-contact of the contact parts with the detection member.

In the above description, the first tooth portion 42a on the first driven gear 42A and the second tooth portion 42b on the second driven gear 42B are each provided in a range of 180 degrees in the circumferential direction, but the present invention is not limited to this. In other words, the range of each tooth portion may be smaller than 180 degrees as long as the rotation of the rotating shaft 41 does not stop. On the other hand, if the range of each tooth portion is made larger than 180 degrees, and there is a phase in which the tooth portions overlap, the driving force will be transmitted to the rotating shaft 41 from two places. This may cause an increase in the rotation load and abnormal noise. On the other hand, by providing each tooth portion 42a, 42b in a range in which the phases of the respective tooth portions 42a do not overlap and the rotating shaft 41 can continue to rotate, it is possible to prevent an increase in the rotation load and the generation of abnormal noise, which is preferable.

An example in which the phases of the first tooth portion 42a provided on the first driven gear 42A and the second tooth portion 42b provided on the second driven gear 42B overlap is shown in Figure 7. In Figures 7(a) and 7(b), the first tooth portion 42a provided on the first driven gear 42A and the second tooth portion 42b provided on the second driven gear 42B are each provided in a range of 240 degrees in the circumferential direction, and the range in which the two tooth portions overlap is 120 degrees. Also, an example in which the phases of the first tooth portion 42a provided on the first driven gear 42A and the second tooth portion 42b provided on the second driven gear 42B do not overlap and the ranges of the respective tooth portions are different is shown in Figure 8. The first tooth portion 42a in FIG. 8(a) is provided over a circumferential range of 240 degrees, and the second tooth portion 42b in FIG. 8(b) is provided over a circumferential range of 120 degrees. These tooth portion ranges are examples, and the tooth portions can be provided in any range required.

In the above embodiment, as shown in FIG. 3 etc., the first driven gear 42A and the second driven gear 42B provided on the rotating shaft 41 are engaged with the fixing gears 52A and 52B of the fixing sleeve 20 via the idler gears 53A and 53B, respectively, but the present invention is not limited to this. For example, as shown in FIG. 9, the first driven gear 42A and the second driven gear 42B may be directly engaged with the fixing gears 52A and 52B, respectively.

The image forming apparatus according to the present invention is not limited to the monochrome image forming apparatus shown in FIG. 1, but may be a color image forming apparatus, a copier, a printer, a facsimile, or a combination machine of these.

Recording media include paper P (plain paper), as well as cardboard, postcards, envelopes, thin paper, coated paper (coated paper, art paper, etc.), tracing paper, overhead projector sheets, plastic film, prepreg, copper foil, etc.

The present invention is not limited to fixing devices as described in the above embodiment, but can also be applied to drying devices that dry ink applied to paper, and further to thermocompression devices such as laminators that thermocompress a film as a covering member onto the surface of a sheet such as paper, and heat sealers that thermocompress the seal portion of a packaging material. By applying the rotation detection mechanism of the present invention to such devices, the stop of rotation can be detected when the rotation of either side of the axial direction of the rotating body stops.

1 Image forming apparatus 9 Fixing device (heating device)
20 Fixing sleeve (rotating body)
21 Pressure belt (pressure member)
22 Heater (heating member)
40 Rotation detection mechanism 41 Rotating shaft (driven rotating body)
42A First driven gear (first transmission part or driven rotor gear)
42B Second driven gear (second transmitted part or driven rotor gear)
42a: First tooth portion 42b: Second tooth portion 43: Light blocking member 43a: Light blocking plate (light blocking portion)
44 Optical sensor (detection member)
45 Magnetic member 45a Magnetic body (magnetic part)
45b Non-magnetic material (non-magnetic part)
46 Magnetic sensor (detection member)
52A, 52B Fixing gear (rotating gear)
53A, 53B Idler gear 90 Control part C Axial direction of rotation shaft

Patent No. 6428700

Claims (10)

A driven rotor;
A rotation detection mechanism including a detection member that detects the rotation of the driven rotor,
the driven rotor includes a first transmitted part provided on one side in an axial direction thereof to which a driving force is transmitted from the rotor, and a second transmitted part provided on the other side in the axial direction thereof to which a driving force is transmitted from the rotor,
A rotation detection mechanism characterized in that, as a result of rotation of the rotating body, the first transmitted part and the second transmitted part receive driving force from the rotating body in different phases, and the driven rotating body rotates in a driven manner. The rotor has rotor gears on both axial sides thereof, the rotor gears rotating integrally with the rotor,
The driven rotor has driven rotor gears on both axial sides thereof, the driven rotor gears rotating integrally with the driven rotor,
The rotor gear meshes with the driven rotor gear via an idler gear on both axial sides,
the first transmitted portion is a first tooth portion provided in a circumferential portion of the driven rotor gear on one side in the axial direction,
the second transmitted portion is a second tooth portion provided in a partial circumferential region of the driven rotor gear on the other axial side,
2. The rotation detection mechanism according to claim 1, wherein the first tooth portion and the second tooth portion mesh with the idler gear at different phases, so that the driven rotor is rotated by a driving force transmitted from the rotor via the idler gear. The rotor has rotor gears on both axial sides thereof, the rotor gears rotating integrally with the rotor,
The driven rotor has driven rotor gears on both axial sides thereof, the driven rotor gears rotating integrally with the driven rotor,
The rotor gear meshes with the driven rotor gear on both axial sides,
the first transmitted portion is a first tooth portion provided in a circumferential portion of the driven rotor gear on one side in the axial direction,
the second transmitted portion is a second tooth portion provided in a partial circumferential region of the driven rotor gear on the other axial side,
2. The rotation detection mechanism according to claim 1, wherein the first tooth portion and the second tooth portion mesh with the rotor gear at different phases, so that the driven rotor is rotated by a driving force transmitted from the rotor. The rotation detection mechanism according to claim 2 or 3, in which the phases in which the first teeth and the second teeth are provided do not overlap. the driven rotor rotates integrally with the driven rotor and has a plurality of light-shielding portions provided in a circumferential direction of the driven rotor,
5. The rotation detection mechanism according to claim 1, wherein the detection member is an optical sensor whose detection state changes depending on whether or not the light is blocked by the light blocking portion. the driven rotor has magnetic portions and non-magnetic portions that rotate integrally with the driven rotor, the magnetic portions and non-magnetic portions being arranged alternately in a circumferential direction of the driven rotor,
5. The rotation detection mechanism according to claim 1, wherein the detection member is a magnetic sensor. The rotation detection mechanism according to any one of claims 1 to 6, wherein the rotating body is an endless fixing sleeve. A rotation detection mechanism according to any one of claims 1 to 6;
The rotating body ;
A heating device comprising a heating member. A rotation detection mechanism according to claim 7;
The rotating body ;
A heating member.
A fixing device that fixes the toner on the recording medium using heat. An image forming apparatus equipped with the fixing device according to claim 9.

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