Image forming device

Abstract

To suppress reduction of the detection accuracy of a temperature sensor.SOLUTION: An image formation device includes: a fixation member for heating a medium to carry along a transport path and fixing a developer to the medium; a temperature sensor facing the fixation member, the temperature sensor detecting the temperature of the fixation member; and a holding unit for holding the temperature sensor, the holding unit having an opening in a fixation member side of the temperature sensor. The image formation device has a protruding unit in a side facing the transport path of the holding unit and in a position in an outer side than the opening in the width direction of the medium.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] FIELD The present disclosure relates to an image forming apparatus that forms an image on a medium. [Background technology]

[0002] An image forming apparatus using an electrophotographic process has a fixing member that heats a developer image transferred onto a medium and fixes it to the medium. A non-contact temperature sensor is disposed opposite the fixing member to detect the temperature of the fixing member (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-24330 (see, for example, the Abstract) Summary of the Invention [Problem to be solved by the invention]

[0004] If a medium jams inside the image forming device and comes into contact with components around the temperature sensor when the medium is removed, unfixed developer may scatter and adhere to the temperature sensor, which can lead to a decrease in detection accuracy.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to suppress a decrease in detection accuracy by a temperature sensor. [Means for solving the problem]

[0006] The image forming apparatus of the present disclosure heats a medium transported along a transport path. The aforementioned a fixing member for fixing the developer image to the medium; The aforementioned The fixing member is disposed opposite the fixing member. The aforementioned a temperature sensor for detecting the temperature of the fixing member; The aforementioned A holder for holding the temperature sensor, The aforementionedTemperature Sensor The aforementioned A holding portion having an opening on the fixing member side death, The aforementioned The temperature sensor and the holding unit are disposed upstream of the fixing member in the transport direction of the medium, and the holding unit includes: of the holding part The aforementioned Side facing the transport path , and the longitudinal direction of the fixing member In The aforementioned A protrusion is provided outside the opening. The image forming apparatus of the present disclosure also includes a fixing member that heats a medium transported along a transport path to fix a developer image to the medium, a temperature sensor that is arranged opposite the fixing member and detects the temperature of the fixing member, and a holding portion that holds the temperature sensor and has an opening on the fixing member side of the temperature sensor, the temperature sensor and the holding portion being arranged upstream of the fixing member in the transport direction of the medium, and the holding portion having a convex portion that protrudes from the holding portion in a direction toward the fixing member, outside the opening in the longitudinal direction of the fixing member. The image forming apparatus of the present disclosure also includes a fixing member that heats a medium transported along a transport path to fix a developer image to the medium, a temperature sensor that is arranged opposite the fixing member and detects the temperature of the fixing member, and a holding portion that holds the temperature sensor and has an opening on the fixing member side of the temperature sensor, wherein the holding portion is provided with a rib that extends in the transport direction of the medium, outside the opening in the longitudinal direction of the fixing member, and the rib is formed with a first protrusion that protrudes toward the transport path and a second protrusion that protrudes toward the fixing member. [Effects of the Invention]

[0007] According to the present disclosure, when removing a medium from the transport path, the medium comes into contact with the protrusion. Because the contact area between the medium and the holder is limited to a narrow area, the amount of scattered developer is reduced and the scattered developer is less likely to reach the opening. As a result, adhesion of developer to the temperature sensor is suppressed, and a decrease in temperature detection accuracy is suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 illustrates a configuration of an image forming apparatus according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view illustrating a configuration of a fixing unit according to the first embodiment. [Figure 3] FIG. 2 is a perspective view showing the appearance of the fixing unit according to the first embodiment. [Figure 4] FIG. 2 is a perspective view showing the appearance of the fixing unit according to the first embodiment. [Figure 5] FIG. 2 is a perspective view showing a fixing unit and a sensor unit according to the first embodiment. [Figure 6] FIG. 2 is a schematic diagram illustrating the internal structure of the sensor unit according to the first embodiment. [Figure 7] FIG. 1 is a perspective view showing a temperature sensor according to a first embodiment. [Figure 8] 2 is a front view showing an opening of the sensor unit and its surroundings according to the first embodiment. FIG. [Figure 9] FIG. 3 is a diagram illustrating a fixing unit and a sensor unit during a printing operation according to the first embodiment. [Figure 10]FIG. 10 is a diagram illustrating the sensor unit when a jam is cleared according to the first embodiment. [Figure 11] 3 is a diagram showing the surface of a medium removed from the image forming apparatus according to the first embodiment; FIG. [Figure 12] FIG. 10 is a diagram illustrating a fixing unit and a sensor unit of a comparative example. [Figure 13] 10A and 10B are diagrams showing the sensor unit of the comparative example when a jam is cleared. [Figure 14] FIG. 10 is a diagram showing the surface of a medium removed from an image forming apparatus of a comparative example. [Figure 15] FIG. 10 is a perspective view showing a fixing unit and a sensor unit according to a second embodiment. [Figure 16] FIG. 10 is a front view showing an opening of a sensor unit and its surroundings according to a second embodiment. [Figure 17] FIG. 10 is a diagram illustrating a fixing unit and a sensor unit during a printing operation according to a second embodiment. [Figure 18] FIG. 10 is a diagram illustrating the sensor unit when a jam is cleared according to the second embodiment. [Figure 19] FIG. 10 is a diagram illustrating the surface of a medium removed from an image forming apparatus according to a second embodiment. [Figure 20] 10A and 10B are diagrams illustrating the relationship between the distance between two convex portions and the amount of protrusion in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] First embodiment. <Image forming device> First, a description will be given of an image forming apparatus 1 according to a first embodiment. Fig. 1 is a diagram showing the image forming apparatus 1. The image forming apparatus 1 is a printer that forms an image using an electrophotographic process.

[0010] The image forming device 1 includes a medium supply section 6 that supplies a medium P such as printing paper, an image forming unit 5 that forms an image on the medium P, a fixing unit 2 that fixes the image on the medium P, a medium discharge section 7 that discharges the medium P, and a housing 1A that houses these components.

[0011] The medium supply unit 6 includes a medium cassette 60 , a pickup roller 61 , a feed roller 62 , a retard roller 63 , a registration roller 65 , and a transport roller 66 .

[0012] The medium cassette 60 stores media P such as printing paper. The pickup roller 61 pulls out the media P from the media cassette 60 one by one. The feed roller 62 and the retard roller 63 separate the pulled out media P one by one and send them to the conveying path A1. The registration roller 65 corrects the skew of the media P sent out to the conveying path A1 and conveys them further. The conveying roller 66 conveys the media P to the image forming unit 5.

[0013] The image forming unit 5 has a photosensitive drum 51 as an image carrier, a charging roller 52 as a charging member, a developing roller 54 as a developer carrier, a supply roller 55 as a supply member, and a toner cartridge 56 as a developer container.

[0014] The photosensitive drum 51 is a cylindrical member having a photosensitive layer formed on the surface of a conductive support. The photosensitive layer is a laminate of a charge generating layer and a charge transport layer. The photosensitive drum 51 rotates clockwise in the figure.

[0015] An exposure head 53 serving as an exposure device is disposed opposite the photosensitive drum 51. The exposure head 53 has an LED array in which LEDs (light emitting diodes) serving as light emitting elements are arranged, and a lens array, and irradiates the surface of the photosensitive drum 51 with light to form an electrostatic latent image. The exposure head 53 is suspended and supported by a top cover 1B that covers the top of the housing 1A.

[0016] The charging roller 52 is disposed so as to come into contact with the surface of the photosensitive drum 51, and rotates following the rotation of the photosensitive drum 51. A charging voltage is applied to the charging roller 52, and the surface of the photosensitive drum 51 is uniformly charged.

[0017] The developing roller 54 is disposed so as to contact the surface of the photosensitive drum 51, and rotates in the opposite direction to the photosensitive drum 51 (the direction in which the surface moves at the contact point is the forward direction). A developing voltage is applied to the developing roller 54, and the electrostatic latent image on the surface of the photosensitive drum 51 is developed with toner.

[0018] The supply roller 55 is disposed so as to contact the surface of the developing roller 54, and rotates in the same direction as the developing roller 54 (the direction in which the surface moves in the contact area is opposite to that of the developing roller 54). A supply voltage is applied to the supply roller 55, and the supply roller 55 supplies toner to the developing roller 54.

[0019] The toner cartridge 56 is a removable container that contains toner as a developer. The toner cartridge 56 supplies toner to the developing roller 54 and the supply roller 55. The toner is, for example, black toner, but is not limited to this.

[0020] A transfer roller 57 serving as a transfer unit is disposed so as to contact the surface of the photosensitive drum 51. A transfer voltage is applied to the transfer roller 57, and the toner image on the surface of the photosensitive drum 51 is transferred to the medium P passing between the photosensitive drum 51 and the transfer roller 57.

[0021] The image forming apparatus 1 is configured to form a monochrome image using the image forming unit 5, but is not limited to this configuration. For example, it may be configured to form a color image by arranging multiple image forming units for yellow, magenta, cyan, black, etc. in the transport direction of the medium P.

[0022] The fixing unit 2 is disposed downstream of the image forming unit 5 in the transport direction of the medium P. The medium P onto which the toner image has been transferred is transported to the fixing unit 2 by the rotation of the photosensitive drum 51. The transport path of the medium P from the image forming unit 5 to the fixing unit 2 is referred to as transport path A2.

[0023] The fixing unit 2 has a fixing roller 21, a pressure roller 22, and a housing 20 that houses these, and is detachably attached to the housing 1A of the image forming apparatus 1. The fixing roller 21 has a built-in heater 23 such as a halogen lamp, and the pressure roller 22 is pressed against the fixing roller 21. The fixing roller 21 and the pressure roller 22 heat and pressurize the medium P to fix the toner image to the medium P. The configuration of the fixing unit 2 will be described later.

[0024] The medium discharge section 7 has discharge rollers 71 and 72 that transport the medium P that has passed through the fixing unit 2 along the transport path A3 and discharge it from a discharge opening 74. A stacker section 73 on which the discharged medium P is placed is formed in the top cover 1B.

[0025] Media sensors 91, 92, and 93 that detect the passage of media P are disposed on the above-mentioned conveying paths A1 and A3. Media sensors 91 and 92 are disposed upstream and downstream of conveying roller 66, respectively. Media sensor 93 is disposed downstream of fixing unit 2.

[0026] The detection signal of the media sensor 91 is used to determine the rotation start timing of the transport roller 66. The detection signal of the media sensor 92 is used to determine the exposure start timing of the exposure head 53. The detection signal of the media sensor 93 is used to detect a jam of the media P in the fixing unit 2.

[0027] In Figure 1, the axial direction of the photosensitive drum 51 is the X direction. The X direction is the axial direction of each roller in the image forming apparatus 1 and is also the width direction of the medium P being transported. The direction of movement of the medium P as it passes through the image forming unit 5 is the Y direction. The direction perpendicular to the X direction and the Y direction is the Z direction. Here, the Z direction is the up-down direction.

[0028] Regarding the Y direction, the transport direction when the medium P passes through the image forming unit 5 is the +Y direction, and the opposite direction is the -Y direction. Regarding the X direction, the right-hand direction when facing the +Y direction is the +X direction, and the left-hand direction is the -X direction. Regarding the Z direction, the upward direction in FIG. 1 is the +Z direction, and the downward direction is the -Z direction. Note that these directions do not limit the orientation of the image forming apparatus 1.

[0029] <Fusing unit> Next, we will explain the configuration of the fixing unit 2. Fig. 2 is a cross-sectional view showing the configuration of the fixing unit 2. Fig. 3 is a perspective view of the fixing unit 2 seen from the -Y direction, and Fig. 4 is a perspective view of the fixing unit 2 seen from the +Y direction.

[0030] 2, the fixing unit 2 has a fixing roller 21 as a fixing member, a pressure roller 22 as a pressure member, and a housing 20 that houses these. The longitudinal direction of both the fixing roller 21 and the pressure roller 22 is the X direction.

[0031] As shown in Figures 3 and 4, the housing 20 has a front cover 20a at the front (-Y direction), a rear cover 20b at the rear (+Y direction), side covers 20c and 20d on both the left and right sides (-X direction and +X direction), a lower cover 20e at the bottom (-Z direction), and a top cover 20f at the top (+Z direction).

[0032] The components of the fixing unit 2, such as the fixing roller 21 and the pressure roller 22, are arranged in the space surrounded by these covers 20a to 20f. An inlet 25 (FIG. 3) is formed in the front cover 20a, and an outlet 26 (FIG. 4) is formed in the rear cover 20b. A handle 29 is formed on the top cover 20f, which the user grips when attaching or detaching the fixing unit 2.

[0033] 2 and 3, an opening 24 is formed in the front cover 20a above (in the +Z direction) the inlet 25. The opening 24 is provided for detecting the temperature of the fixing roller 21 by a non-contact temperature sensor 11, which will be described later.

[0034] 2, a nip is formed between the fixing roller 21 and the pressure roller 22, and the medium P introduced into the housing 20 from the inlet 25 passes through the nip. The toner image on the medium P is attached to the medium P by weak electrostatic force, but is melted by the heat of the fixing roller 21 and fixed to the medium P by the pressure of the pressure roller 22.

[0035] The fixing roller 21 has a substantially cylindrical base material 21a, an elastic layer 21b covering the surface of the base material 21a, and a surface layer 21c covering the surface of the elastic layer 21b. The base material 21a is made of a metal such as aluminum or stainless steel. The elastic layer 21b is made of a resin such as silicone rubber. The surface layer 21c is made of a fluororesin such as PTFE (polytetrafluoroethylene) or PFA (perfluoroalkoxyalkane).

[0036] Shafts are formed on both ends in the X direction of the fixing roller 21. Both shafts of the fixing roller 21 are rotatably supported by bearings attached to side covers 20c and 20d of the housing 20 (FIGS. 3 and 4).

[0037] The fixing roller 21 has a hollow structure, and a heater 23 is disposed inside the fixing roller 21. The heater 23 is, for example, a halogen heater. The heater 23 is long in the X direction and extends over almost the entire area of ​​the fixing roller 21 in the longitudinal direction (X direction).

[0038] However, the heater 23 is not limited to a halogen heater, and may be another type of heater, for example, a planar heater, etc. Also, here, two heaters 23 are arranged side by side in the Y direction, but the fixing roller 21 may have only one heater.

[0039] The pressure roller 22 has a substantially cylindrical base material 22a and an elastic layer 22b formed on the surface of the base material 22a. The base material 22a is made of a metal such as aluminum or stainless steel. The elastic layer 22b is made of a resin such as foamed silicone rubber or silicone rubber. The surface of the elastic layer 22b may be covered with a surface layer made of PFA, PTFE, or the like.

[0040] Shafts are formed on both ends of the pressure roller 22 in the X direction. Both shafts of the pressure roller 22 are attached to a swing frame 201. The swing frame 201 is supported so as to be swingable around a support shaft provided inside the housing 20, and is biased by a spring member (not shown) in a direction in which the pressure roller 22 is pressed against the fixing roller 21.

[0041] A front guide 27 is disposed on the -Y side of the fixing roller 21 and the pressure roller 22. A rear guide 28 is disposed on the +Y side of the fixing roller 21 and the pressure roller 22. The front guide 27 guides the medium P from the inlet 25 to the nip portion. The rear guide 28 guides the medium P that has passed through the nip portion to the outlet 26.

[0042] A release cam 202 is provided within the housing 20 to bring the fixing roller 21 and the pressure roller 22 into contact with and separate from each other. The release cam 202 is an eccentric cam that is rotated by a cam motor (not shown). When the release cam 202 rotates, a swing frame 201 that holds the pressure roller 22 swings, opening and closing the nip between the fixing roller 21 and the pressure roller 22.

[0043] It is also possible to maintain the fixing roller 21 and the pressure roller 22 in a constant state of pressure contact without providing the release cam 202.

[0044] As shown in FIG. 1, a lower guide 40 is disposed between the image forming unit 5 and the fixing unit 2 to guide the medium P from the image forming unit 5 to the fixing unit 2. The lower guide 40 has a guide rib 41 (FIG. 5) that extends in the Y direction. Multiple guide ribs 41 are disposed in the X direction and contact the underside of the medium P. The lower guide 40 defines the lower end of the transport path A2 for the medium P from the image forming unit 5 to the fixing unit 2.

[0045] <Sensor unit> A sensor unit 10 including a temperature sensor 11 is disposed between the image forming unit 5 and the fixing unit 2. The temperature sensor 11 is a non-contact sensor, a thermopile in this case, that measures the surface temperature of the fixing roller 21. The thermopile receives infrared rays emitted from the surface of the fixing roller 21 and converts them into an electrical signal representing the temperature.

[0046] Fig. 5 is a perspective view showing the fixing unit 2 and the sensor unit 10. Fig. 6 is a schematic diagram showing the internal structure of the sensor unit 10 shown in Fig. 5. In Figs. 5 and 6, the housing 20 of the fixing unit 2 and the like are omitted.

[0047] The sensor unit 10 has a sensor housing 12 as a holder that houses the temperature sensor 11. The sensor housing 12 is formed, for example, from sheet metal, and is fixed to the housing 1A (FIG. 1) of the image forming apparatus 1. The sensor housing 12 is disposed in the -Y direction of the fixing roller 21 (upstream in the transport direction of the medium P) and faces the surface of the fixing roller 21.

[0048] Sensor housing 12 has wall 12a facing fuser roller 21, wall 12b (FIG. 6) facing image forming unit 5 (FIG. 1), and bottom 12c facing lower guide 40. A transport path A2 for medium P is defined between bottom 12c of sensor housing 12 and guide rib 41 of lower guide 40.

[0049] A guide portion 12e that protrudes in the -Z direction (i.e., toward the lower guide 40) is formed at the end in the +Y direction of the bottom portion 12c of the sensor housing 12. The guide portion 12e has the function of contacting the medium P that has risen in the +Z direction in the transport path A2 and guiding it toward the inlet 25 of the fixing unit 2.

[0050] The guide portion 12e has a configuration in which a plurality of rotatable rollers (not shown) are arranged in the X direction so as to minimize friction with the medium P. However, the configuration is not limited to this.

[0051] 7 is a perspective view showing temperature sensor 11. Temperature sensor 11 has a thermopile element 11a mounted on a substrate 11d and a substantially cylindrical case 11b that surrounds thermopile element 11a. Thermopile element 11a is a detection element that receives infrared rays and converts them into an electrical signal.

[0052] An opening is formed at the tip of case 11b, and lens 11c that transmits infrared light and focuses it on thermopile element 11a is attached to this opening. Connector 16 that outputs an electrical signal from thermopile element 11a to the outside is attached to substrate 11d.

[0053] 6, the sensor unit 10 has a sensor holder 13 into which the temperature sensor 11 is inserted, and a lid member 14 that secures the temperature sensor 11 so that it does not fall out of the sensor holder 13. The lid member 14 is omitted from other figures. The sensor holder 13 is secured to a wall 12a of the sensor housing 12.

[0054] An opening 12d serving as a window is formed in the wall 12a of the sensor housing 12 at a position corresponding to the lens 11c of the temperature sensor 11. The opening 12d in the wall 12a is circular here, but is not limited to a circular shape. The temperature sensor 11 faces the surface of the fixing roller 21 via the opening 24 (FIGS. 2 and 3) in the fixing unit 2 and the opening 12d in the sensor housing 12.

[0055] 5, two ribs 3 are provided on the sensor housing 12 closer to the transport path A2 (-Z direction) than the opening 12d. The ribs 3 are located on both sides of the opening 12d in the X direction. The ribs 3 protrude from the sensor housing 12 in the -Z direction and also in the +Y direction, as shown in FIG. 9, which will be described later.

[0056] 8 is a view of the sensor housing 12 as seen from the +Y direction (i.e., the fixing unit 2 side). The length of the opening 12d in the X direction (here, the outer diameter of the opening 12d) is D. Each rib 3 is disposed at a distance E from the opening 12d in the X direction. The distance between two ribs 3 in the X direction is W.

[0057] The relationship between the gap W, the distance E, and the length D is W=D+2E. Since the distance E is greater than 0 (E>0), W>D. That is, an area whose ends are defined by the two ribs 3 is formed on the conveying path A2 side of the opening 12d.

[0058] Each rib 3 has a width T1 in the X direction. The width T1 is preferably as thin as possible so that the medium P that comes into contact with the rib 3 does not tear when a jam is cleared, as will be described later. Here, the width T1 is set to 2 mm.

[0059] A plate-shaped reinforcing portion 36 is provided at the end of each rib 3 in the +Z direction. In addition, an attachment portion 37 is provided between two ribs 3 to attach the ribs 3 to the sensor housing 12. However, these reinforcing portions 36 and attachment portion 37 do not necessarily have to be provided.

[0060] 9 is a diagram showing the fixing unit 2 and sensor unit 10 during printing. As described above, the rib 3 protrudes from the sensor housing 12 in the -Z direction and also in the +Y direction. That is, the rib 3 has a protruding portion 31 that protrudes in the -Z direction and a protruding portion 32 that protrudes in the +Y direction. The protruding portion 31 is also referred to as the first protruding portion, and the protruding portion 32 is also referred to as the second protruding portion. Between the protruding portions 31 and 32, an inclined portion 33 is formed that is displaced in the +Z direction as it progresses in the +Y direction.

[0061] On the -Y side (image forming unit 5 side) of protrusion 31, there is formed opposing portion 35 that extends parallel to guide rib 41 of lower guide 40. Between protrusion 31 and opposing portion 35, there is formed inclined portion 34 that is displaced in the +Z direction as it advances in the -Y direction.

[0062] <Printing operation of image forming device> Next, the printing operation of the image forming apparatus 1 will be described with reference to Fig. 1. When the control unit of the image forming apparatus 1 receives a print command and print data from a host device, it starts the printing operation (image forming operation).

[0063] When the printing operation starts, the pickup roller 61 and feed roller 62 of the medium supply unit 6 rotate to send the media P from the medium cassette 60 one by one to the conveying path A1. Then, the registration roller 65 and the conveying roller 66 convey the media P along the conveying path A1 to the image forming unit 5.

[0064] In the image forming unit 5, a charging voltage, a developing voltage, and a supply voltage are applied to the charging roller 52, the developing roller 54, and the supply roller 55, respectively. Furthermore, the photosensitive drum 51 rotates, and accordingly the charging roller 52, the developing roller 54, and the supply roller 55 also rotate. The charging roller 52 uniformly charges the surface of the photosensitive drum 51. The exposure head 53 exposes the uniformly charged surface of the photosensitive drum 51 to light to form an electrostatic latent image.

[0065] The electrostatic latent image formed on the surface of the photosensitive drum 51 is developed by the toner attached to the developing roller 54, and a toner image is formed on the surface of the photosensitive drum 51. When the toner image approaches the surface of the transfer roller 57 due to the rotation of the photosensitive drum 51, a transfer voltage is applied to the transfer roller 57.

[0066] As a result, the toner image formed on the photosensitive drum 51 is transferred to the medium P passing between the photosensitive drum 51 and the transfer roller 57. The medium P onto which the toner image has been transferred is transported toward the fixing unit 2 by the rotation of the photosensitive drum 51.

[0067] In the fixing unit 2, the fixing roller 21 and the pressure roller 22 rotate with a nip formed therebetween, and the heater 23 is heated to a predetermined fixing temperature. The surface temperature of the fixing roller 21 is detected by the temperature sensor 11 through the opening 24 (FIGS. 2 and 3) of the fixing unit 2 and the opening 12d (FIG. 5) of the sensor housing 12. The power supply to the heater 23 is controlled by the fixing control unit of the image forming apparatus 1 based on the temperature detected by the temperature sensor 11.

[0068] The medium P that has passed through the image forming unit 5 passes through the conveying path A2 defined between the guide rib 41 of the lower guide 40 and the opposing portion 35 of the rib 3 (Figure 9), and reaches the inlet 25 of the fixing unit 2 (Figure 2).

[0069] 2, the medium P introduced into the fixing unit 2 through the inlet 25 is guided by the front guide 27 to the nip between the fixing roller 21 and the pressure roller 22. In the nip, heat and pressure are applied to the unfixed toner on the medium P, and the toner image is fixed to the medium P.

[0070] The medium P with the fixed toner image is discharged from the discharge port 26 via the rear guide 28 and heads toward the medium discharge unit 7 shown in FIG. 1. The medium P is then discharged by discharge rollers 71 and 72 of the medium discharge unit 7 and stacked on the stacker unit 73. This completes image formation on the medium P.

[0071] <effect> If a jam of medium P occurs inside image forming apparatus 1 during the above printing operation, the control unit of image forming apparatus 1 detects this based on the detection signal from medium sensor 93 and stops the printing operation. In this state, medium P with an unfixed toner image remains between image forming unit 5 and fixing unit 2. The user opens top cover 1B of image forming apparatus 1, removes fixing unit 2 from housing 1A, and removes medium P. This operation is called jam clearance.

[0072] 10 is a diagram showing the sensor unit 10 when a jam is cleared. Here, with the fixing unit 2 removed from the housing 1A of the image forming apparatus 1, the user pulls the medium P in approximately the +Y direction as indicated by the arrow J. The medium P passes between the sensor unit 10 and the lower guide 40 in the +Y direction and is pulled out.

[0073] At this time, the user pulls the medium P from above the image forming apparatus 1, causing the medium P to also swing in the +Z direction. As a result, the medium P comes into contact with the rib 3 (more specifically, the protruding portion 31 of the rib 3). Since the unfixed toner T on the medium P is attached to the medium P by weak electrostatic force, it is scraped off the surface of the medium P and scattered by contact with the rib 3.

[0074] FIG. 11 is a schematic diagram showing the surface of a medium P removed from the image forming apparatus 1. Two long lines L1 are formed on the image M on the medium P in the direction in which the medium P is removed (indicated by arrow J). These lines L1 are areas of low density caused by unfixed toner scattering due to contact with the ribs 3. The width of each line L1 is the same as the width T1 of the rib 3. The distance between the two lines L1 is the same as the distance W between the two ribs 3.

[0075] Here, if the length of image M in the extraction direction is A and the width in the width direction (i.e., X direction) perpendicular to the extraction direction is B, the area of ​​image M is expressed as A × B. On the other hand, the area of ​​the two lines L1 is 2 × T1 × A.

[0076] Let η be the percentage of the area of ​​the part (line L1) where toner was scattered due to contact with the rib 3 out of the area of ​​the image M. The percentage η is calculated as η = 2 × T1 × A / (A × B), or η = 2 × T1 / B. If the width T1 of the rib 3 is 2 mm and the width B of the image M is 150 mm, the percentage η is 2.7%.

[0077] Here, a comparative example to be compared with this embodiment will be described. Fig. 12 is a diagram showing a fixing unit 2 and a sensor unit 10C of the comparative example. The sensor unit 10C has a temperature sensor 11 and a sensor housing 12 that houses the temperature sensor 11. An opening 12d is formed in a wall 12a of the sensor housing 12.

[0078] However, the sensor housing 12 of the sensor unit 10C of the comparative example does not have the ribs 3 (FIGS. 8 to 10) as in the first embodiment. During printing, air flow 19 is supplied between the sensor housing 12 and the fixing roller 21 to prevent toner from entering through the opening 12d.

[0079] 13A and 13B are diagrams showing the sensor unit 10C of the comparative example when a jam is cleared. Fig. 13A shows the case where the user pulls out the medium P in approximately the +Y direction, and Fig. 13B shows the case where the user pulls out the medium P in approximately the +Z direction. Because the printing operation is stopped when a jam is cleared, the air flow 19 shown in Fig. 12 is not supplied.

[0080] 13(A), when the user pulls out the medium P in approximately the +Y direction, the surface of the medium P comes into contact with the edge E1 between the wall 12a and the bottom 12c of the sensor housing 12. As a result, unfixed toner on the medium P is scraped off by the edge E1 and scattered across the entire width of the image.

[0081] In this case, toner scatters across the entire width of image M due to contact with edge E1, resulting in a thinner overall image M. Therefore, the ratio η of the area (A×B) of the portion where toner has scattered due to contact with edge E1 to the area (A×B) of image M is η=1.

[0082] Because a large amount of toner is scattered by contact with the edge E1, some of the scattered toner easily passes through the opening 12d and enters the interior of the sensor housing 12, and the toner easily adheres to the lens 11c of the temperature sensor 11.

[0083] 13(B), when the user pulls out the medium P in approximately the +Z direction, the surface of the medium P comes into contact with the edge E2 of the opening 12d in the wall 12a of the sensor housing 12. As a result, unfixed toner on the medium P is scraped off by the edge E2 and scattered within the range of the width (diameter D) of the opening 12d.

[0084] 14 is a schematic diagram showing the surface of medium P that has been removed by a user by pulling it out in approximately the +Z direction. In this case, a single long line L0 is formed in the image M on medium P in the direction in which medium P is pulled out (indicated by arrow J). This line L0 is a low-density area caused by toner scattering due to contact with edge E2 of opening 12d.

[0085] The width of line L0 is the same as the diameter D of opening 12d. The area of ​​line L0 is D × A. The ratio η of the area of ​​image M that is the portion (line L0) where toner was scattered due to contact with edge E2 is η = 2 × D × A / (A × B), or η = D / B. If the diameter D of opening 12d is 10 mm and the width B of image M is 150 mm, the ratio η is 6.7%.

[0086] In this case, toner scattering occurs at the edge E2 of the opening 12d, and some of the scattered toner easily passes through the opening 12d and enters the inside of the sensor housing 12. As a result, toner is likely to adhere to the lens 11c of the temperature sensor 11.

[0087] 13A or 13B, toner tends to adhere to the lens 11c of the temperature sensor 11. When toner adheres to the lens 11c of the temperature sensor 11, the toner blocks infrared rays from the fixing roller 21 from entering the temperature sensor 11, reducing the accuracy of temperature detection by the temperature sensor 11.

[0088] In contrast, in this embodiment, the portion that comes into contact with the surface of the medium P when the medium P is removed is the rib 3 (protrusion 31) with a narrow width W, so the amount of toner scattering is small. In other words, the area ratio η of the toner scattering portion in the image M is expressed as η = 2 × T1 / B, and therefore, by narrowing the width T1 of the rib 3, this ratio η can also be reduced.

[0089] For example, if the width T1 of the rib 3 is 2 mm and the width B of the image M is 150 mm as described above, the ratio η of the area of ​​the toner scattered portion to the area of ​​the image M is 2.7%, which is smaller than the ratio η (6.7%) in the comparative example.

[0090] In addition, since the rib 3 is located outside the opening 12d in the X direction and contacts the medium P at a position away from the opening 12d in the -Z direction, toner scattered by contact with the protrusion 31 is less likely to reach the opening 12d.

[0091] Therefore, it is possible to suppress adhesion of toner to the temperature sensor 11 (particularly the lens 11c), and to enable highly accurate temperature detection.

[0092] Note that while FIG. 10 shows an example in which medium P is removed by being pulled in approximately the +Y direction, when medium P is removed by being pulled in the +Z direction (see FIG. 18 described later), medium P comes into contact with both protrusions 31 and 32 of rib 3. Because protrusions 31 and 32 are located at the same position in the X direction, the amount of scattered toner is the same as in the example shown in FIG. 10. Furthermore, because protrusions 31 and 32 are both located outside opening 12d in the X direction and closer to conveyance path A2 than opening 12d, scattered toner is less likely to reach opening 12d. In this case as well, adhesion of toner to temperature sensor 11 can be suppressed.

[0093] 8, if the portion of sensor housing 12 in the X direction that includes opening 12d is defined as opening area 18, distance S1 from transport path A2 to protrusion 31 is shorter than distance S2 from transport path A2 to opening area 18. Therefore, even if medium P comes into contact with protrusion 31, it does not come into contact with opening area 18. Therefore, scattered toner is less likely to reach opening 12d, and adhesion of toner to temperature sensor 11 can be effectively suppressed.

[0094] Here, ribs 3 are provided on both sides of opening 12d in the X direction, but only one rib 3 may be used. However, if ribs 3 are provided on only one side of opening 12d in the X direction, there is a possibility that the medium P that comes into contact with rib 3 will tilt and come into contact with other parts of sensor housing 12. By providing ribs 3 on both sides of opening 12d in the X direction, the contact area with medium P can be limited to rib 3, and toner adhesion to temperature sensor 11 can be effectively suppressed.

[0095] Also, although an example in which a rib 3 is provided on the sensor housing 12 has been described here, it is not limited to a rib 3, and it is sufficient if a protrusion is provided on the side of the sensor housing 12 facing the conveying path A2 and further outward in the X direction than the opening 12d.

[0096] In this embodiment, the temperature sensor 11 is provided as a separate unit from the fixing unit 2, and remains in the image forming apparatus 1 even when the fixing unit 2 is replaced due to its lifespan. Therefore, the temperature sensor 11 is required to maintain high detection accuracy for a long period of time. By suppressing toner adhesion to the temperature sensor 11 as described above, it becomes possible to maintain high detection accuracy for a long period of time equivalent to the product lifespan of the image forming apparatus 1.

[0097] <Effects of the embodiment> As described above, the image forming apparatus 1 of the first embodiment includes the fixing roller 21 that heats the medium P being conveyed along the conveying path A2 to fix a toner image on the medium P, the temperature sensor 11 that is disposed opposite the fixing roller 21, and the sensor housing 12 that holds the temperature sensor 11. The sensor housing 12 has an opening 12d on the side of the temperature sensor 11 that faces the fixing roller 21. A protrusion 31 is provided on the side of the sensor housing 12 that faces the conveying path A2 and on the outer side of the opening 12d in the X direction (the width direction of the medium P).

[0098] With this configuration, when a jammed medium P is removed, the surface of the medium P comes into contact with the protrusion 31. Because the contact area between the sensor housing 12 and the medium P is limited to a narrow area, the amount of toner scattered due to the contact is small, and the scattered toner is less likely to reach the opening 12d. This prevents toner from adhering to the temperature sensor 11 and reduces the deterioration of temperature detection accuracy.

[0099] Furthermore, since the rib 3 has a protrusion 32 (second protrusion) that protrudes in the +Y direction in addition to the protrusion 31 (first protrusion), when the user pulls the medium P in the +Z direction, the medium P comes into contact with the protrusions 31 and 32. Therefore, the medium P is less likely to come into contact with the edge of the opening 12d, and since the protrusions 31 and 32 are positioned in the same position in the X direction, the amount of toner that scatters due to contact between the medium P and the protrusions 31 and 32 is small. Therefore, adhesion of toner to the temperature sensor 11 can be more effectively suppressed.

[0100] Second embodiment. Next, a second embodiment will be described. Fig. 15 is a perspective view showing a fixing unit 2 and a sensor unit 10A according to the second embodiment. The sensor unit 10A according to the second embodiment has protrusions 8 on both sides of the opening 12d of the sensor housing 12 in the X direction. The protrusions 8 protrude in the +Y direction from the wall 12a of the sensor housing 12. The configurations of the fixing unit 2 and the lower guide 40 are the same as those in the first embodiment.

[0101] The protrusions 8 protrude from the wall 12a of the sensor housing 12 in the +Y direction (i.e., downstream in the transport direction of the medium P). In other words, the protrusions 8 protrude toward the fixing roller 21. The protrusions 8 are formed by deep drawing the wall 12a made of sheet metal, but are not limited to this. The protrusions 8 may also be ribs, for example.

[0102] The protrusion 8 and the opening 12d are at approximately the same height (position in the Z direction). In other words, the position of the protrusion 8 in the Z direction at least partially overlaps with the opening 12d.

[0103] 16 is a view of the sensor housing 12 as seen from the +Y direction (i.e., the fixing unit 2 side). Each protrusion 8 has a tip 81 that protrudes most in the +Y direction. The width of the tip 81 in the X direction is T2. The distance in the X direction from the opening 12d to the tip 81 of each protrusion 8 is F. The distance in the X direction between the tip 81 of two protrusions 8 is U.

[0104] The rib 3 described in the first embodiment is formed on the -Z side of the opening 12d in the sensor housing 12. The two protrusions 8 are arranged further outward in the X direction than the two ribs 3, but are not limited to such an arrangement. For example, the position of each rib 3 in the X direction may be the same as the position of each protrusion 8 in the X direction.

[0105] 17 is a diagram showing the fixing unit 2 and sensor unit 10A during printing operation. As described above, the protrusion 8 protrudes in the +Y direction from the wall 12a of the sensor housing 12, and the protrusion amount of the protrusion 8 is H. This protrusion amount H is the distance from the surface of the wall 12a to the tip 81 of the protrusion 8.

[0106] 18 is a diagram showing the sensor unit 10A when a jam is cleared. Here, it is assumed that the user pulls the jammed medium P in approximately the +Z direction as indicated by the arrow J.

[0107] In addition, if the medium P straddles the fixing unit 2 and the image forming unit 5 when a jam occurs, when the user removes the fixing unit 2 from the image forming device 1, the medium P is pulled out along with the fixing unit 2, and the pulling direction becomes approximately the +Z direction as shown in Figure 18.

[0108] 18, the medium P first comes into contact with the protruding portion 31 of the rib 3, then with the protruding portion 32 of the rib 3, and then with the tip 81 of the convex portion 8. Due to the contact with the protruding portions 31 and 32 of the rib 3 and the tip 81 of the convex portion 8, the unfixed toner on the medium P is scraped off and scattered.

[0109] 19 is a schematic diagram showing the surface of a medium P removed from the image forming apparatus 1. In the image M on the medium P, two long lines L1 and two long lines L2 are formed in the direction in which the medium P is removed (indicated by the arrow J).

[0110] Line L1 is a low density area caused by unfixed toner scattering when the medium P comes into contact with the protrusions 31 and 32 of the rib 3. Line L2 is a low density area caused by unfixed toner scattering when the medium P comes into contact with the tip 81 of the protrusion 8.

[0111] The width of each line L1 is the same as the width T1 of the rib 3. The distance between two lines L1 is the same as the distance W between two ribs 3. The width of each line L2 is the same as the width T2 of the tip 81 of a protrusion 8. The distance between two lines L2 is the same as the distance U between the tip 81 of two protrusions 8 (FIG. 16).

[0112] If the length of image M in the pull-out direction is A and the width in the width direction (X direction) perpendicular to the pull-out direction is B, the area of ​​image M is expressed as A × B. Meanwhile, the sum of the areas of the two lines L1 is 2 × T1 × A, and the sum of the areas of the two lines L2 is 2 × T2 × A.

[0113] The ratio η of the area of ​​the portion (lines L1, L2) where toner was scattered due to contact with the rib 3 and the protrusion 8 to the area of ​​the image M is η = 2 × (T1 + T2) × A / (A × B), or η = 2 × (T1 + T2) / B. If the width T1 of the rib 3 is 2 mm, the width T2 of the tip 81 of the protrusion 8 is 2 mm, and the width B of the image M is 150 mm, the ratio η is 5.3%.

[0114] Here, since the protrusions 8 are formed further outward in the X direction than the ribs 3, the distance F from the protrusions 8 to the openings 12d can be ensured. In other words, the distance in the X direction from the toner scattering position to the openings 12d can be ensured, making it difficult for the toner to reach the openings 12d.

[0115] The positional relationship between the protrusions 8 and the ribs 3 is not limited to the above example, and the X-direction positions of the protrusions 8 and the ribs 3 may be aligned. In this case, the lines L1 and L2 overlap, reducing the amount of scattered toner. For example, if the widths T1 and T2 are both 2 mm and the width B of the image M is 150 mm, the ratio η of the area of ​​the toner scattered portion to the area of ​​the image M is 2.7%.

[0116] Furthermore, since the convex portion 8 is at approximately the same height (Z-direction position) as the rib 3, the medium P that comes into contact with the convex portion 8 is less likely to come into contact with the edge of the opening 12d, thereby suppressing the occurrence of toner scattering near the opening 12d.

[0117] Next, a further explanation will be given of the distance U between the tip ends 81 of the two protrusions 8. As shown in FIG. 18, when the medium P is removed, the medium P may be curled.

[0118] 20(A) shows a state in which the medium P is curled so that it is convex toward the sensor unit 10. The distance from the surface of the wall 12a of the sensor housing 12 to the tip 81 of the convex portion 8 is the above-mentioned protrusion amount H. The distance between the two convex portions 8 is the above-mentioned distance U.

[0119] If the medium P is curled, the center of the medium P in the width direction approaches the opening 12d of the sensor housing 12 while the medium P is in contact with the protrusion 8. Therefore, it is desirable to prevent the curled medium P from coming into contact with the edge of the opening 12d and causing toner scattering.

[0120] 20(B) is a schematic diagram showing a state in which the medium P is in contact with the convex portions 8 and curled to a radius of curvature R. The amount of protrusion of the medium P2 from the edges of the tip portions 81 of both convex portions 8 is defined as the medium curl amount δ.

[0121] To prevent the curled medium P from reaching the opening 12d while in contact with the convex portions 8, the protrusion amount H of the convex portions 8 (FIG. 20(A)) should be greater than the medium curl amount δ (H>δ). In other words, the protrusion amount H should satisfy the following formula (1) based on the radius of curvature R and the spacing U between the convex portions 8.

number

[0122] The radius of curvature (also referred to as the curl radius) R of the medium P when it curls is set to, for example, 20 mm. This value is slightly smaller than the radius of curvature of the medium P when it curls as expected in a typical printer. If the distance m between the two convex portions 8 is 18.3 mm, then it can be seen from the above formula (1) that the protrusion amount H of the convex portions 8 should be greater than 1.796 mm. Therefore, for example, if the protrusion amount H = 1.8 mm, it is possible to prevent contact between the medium P and the edge of the opening 12d.

[0123] It should be noted that the protrusion amount H of each protrusion 8 may not only be calculated from the distance U between two protrusions 8, but also conversely, the distance U between two protrusions 8 may be calculated from the distance H of each protrusion 8.

[0124] Here, convex portions 8 are provided on both sides of opening 12d in the X direction, but it is also possible to provide only one convex portion 8. However, providing convex portions 8 on both sides of opening 12d in the X direction makes it more difficult for medium P to come into contact with the edge of opening 12d, thereby making it possible to effectively suppress toner adhesion to temperature sensor 11.

[0125] Also, although an example in which both the ribs 3 and the protrusions 8 are provided on the sensor housing 12 has been described here, it is not necessary to provide the ribs 3. In this case as well, the medium P being removed comes into contact with the protrusions 8, thereby reducing the amount of toner scattering.

[0126] As described above, in the second embodiment, the protrusion 8 protruding from the sensor housing 12 in the +Y direction (toward the fixing unit 2) is provided on the outer side of the opening 12d of the sensor housing 12 in the X direction. Therefore, when a jammed medium P is removed, the surface of the medium P comes into contact with the protrusion 8. Because the contact area between the sensor housing 12 and the medium P is limited to a narrow area, the amount of toner scattering can be kept small. In addition, because the protrusion 8 is provided on the outer side of the opening 12d in the X direction, scattered toner is less likely to enter the sensor housing 12 through the opening 12d. This prevents toner from adhering to the temperature sensor 11 and prevents a decrease in temperature detection accuracy.

[0127] Furthermore, by providing both the ribs 3 and the protrusions 8 on the sensor housing 12, it is possible to enhance the effect of suppressing toner from entering the sensor housing 12. Furthermore, by aligning the positions of the ribs 3 and the protrusions 8 in the X direction, it is possible to further reduce the amount of toner scattering caused by contact between the medium P and the ribs 3 and the protrusions 8.

[0128] Furthermore, because the distance U between the two protrusions 8 in the X direction and the protrusion amount H of the protrusions 8 satisfy the above formula (1), contact between the medium P and the edge of the opening 12d is unlikely to occur even if the medium P curls. This increases the effect of suppressing toner adhesion to the temperature sensor 11.

[0129] While the preferred embodiments have been specifically described above, the present disclosure is not limited to the above-described embodiments, and various improvements and modifications can be made. The above-described embodiments can be combined as appropriate.

[0130] The image forming apparatuses according to the embodiments can be used as, for example, printers, copiers, facsimiles, MFPs (Multi-Function Peripherals), and the like. [Explanation of symbols]

[0131] REFERENCE SIGNS LIST 1 image forming apparatus, 2 fixing unit (fixing section), 3 rib, 5 image forming unit (image forming section), 6 media supply section, 7 media discharge section, 8 convex section, 10, 10A sensor unit, 11 temperature sensor, 11a thermopile element (detection element), 11b case, 11c lens, 11d substrate, 12 sensor housing (holding section), 12a wall section, 12c bottom section, 12d opening (window section), 12e guide section, 13 sensor holder, 18 opening area, 20 housing, 21 fixing roller (fixing member), 22 pressure roller (pressure member), 23 heater (heat source), 24 opening, 31 protrusion (first protrusion), 32 protrusion (second protrusion), 33 Inclined portion, 34 inclined portion, 35 opposing portion, 40 lower guide, 41 guide rib, 51 photosensitive drum (image carrier), 52 charging roller (charging member), 53 exposure head (exposure device), 54 developing roller (developer carrier), 55 supply roller (supply member), 56 toner cartridge (developer container), 57 transfer roller (transfer member), 81 tip surface.

Claims

1. a fixing member that heats the medium transported along the transport path to fix the developer image on the medium; a temperature sensor disposed opposite the fixing member and configured to detect a temperature of the fixing member; a holding portion for holding the temperature sensor, the holding portion having an opening on the fixing member side of the temperature sensor; and the temperature sensor and the holding unit are disposed upstream of the fixing member in a transport direction of the medium, The holding portion is provided with a protruding portion on a side of the holding portion facing the transport path and on an outer side of the opening in the longitudinal direction of the fixing member. An image forming apparatus characterized by:

2. When a portion of the holding portion that includes the opening in the longitudinal direction is defined as an opening area, The distance from the transport path to the protrusion is shorter than the distance from the transport path to the opening area.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

3. The protrusions are provided on both sides of the opening in the longitudinal direction.

3. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

4. the protrusion is a first protrusion formed on a rib extending in the conveying direction, The rib has a second protrusion formed thereon that protrudes toward the fixing member.

4. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

5. The holding portion is provided with a protrusion that protrudes from the holding portion toward the fixing member, the protrusion being located outside the opening in the longitudinal direction.

5. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

6. The distance from the opening to the protrusion in the longitudinal direction is longer than the distance from the opening to the protrusion in the longitudinal direction.

6. The image forming apparatus according to claim 5,

7. The position of the convex portion in the longitudinal direction coincides with the position of the protruding portion in the longitudinal direction.

6. The image forming apparatus according to claim 5,

8. The protrusions are at least partially overlapped with the openings in a direction perpendicular to the transport direction and the longitudinal direction.

8. The image forming apparatus according to claim 5, wherein the image forming apparatus is a recording medium.

9. The protrusions are provided on both sides of the opening in the longitudinal direction.

9. The image forming apparatus according to claim 5, wherein the image forming apparatus is a recording medium.

10. a fixing member that heats the medium transported along the transport path to fix the developer image on the medium; a temperature sensor disposed opposite the fixing member and configured to detect a temperature of the fixing member; a holding portion for holding the temperature sensor, the holding portion having an opening on the fixing member side of the temperature sensor; and the temperature sensor and the holding unit are disposed upstream of the fixing member in a transport direction of the medium, The holding portion is provided with a protrusion that protrudes from the holding portion toward the fixing member, the protrusion being located outside the opening in the longitudinal direction of the fixing member. An image forming apparatus characterized by:

11. A fixing member that heats the medium transported along the transport path to fix the developer image on the medium; a temperature sensor disposed opposite the fixing member and configured to detect a temperature of the fixing member; a holding portion for holding the temperature sensor, the holding portion having an opening on the fixing member side of the temperature sensor; and The holding portion has: a rib extending in a transport direction of the medium is provided on the fixing member outside the opening in the longitudinal direction of the fixing member; The rib has: A first protrusion protruding toward the transport path and a second protrusion protruding toward the fixing member are formed. An image forming apparatus characterized by:

12. The ribs are provided on both sides of the opening in the longitudinal direction.

12. The image forming apparatus according to claim 11.

13. The holding portion is provided with a protrusion that protrudes from the holding portion toward the fixing member, the protrusion being located outside the opening in the longitudinal direction.

13. The image forming apparatus according to claim 11 or 12.

14. The longitudinal distance from the opening to the protrusion is longer than the longitudinal distance from the opening to the rib.

14. The image forming apparatus according to claim 13.

15. The longitudinal position of the protrusion and the longitudinal position of the rib are aligned.

14. The image forming apparatus according to claim 13.

16. The position of the convex portion in a direction perpendicular to the conveying direction and the longitudinal direction at least partially overlaps with the opening.

16. The image forming apparatus according to claim 13, wherein the image forming apparatus is a recording medium.

17. The protrusions are provided on both sides of the opening in the longitudinal direction.

17. The image forming apparatus according to claim 13, wherein the image forming apparatus is a recording medium.

18. The fixing member is a part of a fixing unit that is detachable from a housing of the image forming apparatus, The temperature sensor and the holding portion are disposed outside the fixing unit.

18. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

19. a medium supply unit that supplies the medium; an image forming unit that forms an image on the medium; Furthermore, The medium is transported along the transport path from the image forming unit to a fixing unit including the fixing member.

19. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

Images