JP3721884B2 - Fixing apparatus and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a belt-type fixing device of an electrophotographic image forming apparatus.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a fixing device used in an electrophotographic image forming apparatus has an unfixed toner by a heating roller maintained at a predetermined temperature and a pressure roller having an elastic layer and being in pressure contact with the heating roller. A heat roller fixing system in which a recording material on which an image is formed is nipped and conveyed while being heated is frequently used.
[0003]
However, in this type of apparatus, the heat capacity of the heating roller is increased, the warm-up time is increased, the temperature inside the elastic layer is increased, and the life of the roller is shortened.
[0004]
Further, many color images have a large solid area, and there are many solid images other than black, and uneven gloss is conspicuous. In the case where a hard roller is used as the heating and pressure roller, there is a problem in that the unevenness of the gloss according to the unevenness of the paper or the toner layer occurs, so that the image quality is deteriorated.
[0005]
[Problems to be solved by the invention]
In order to solve the above problems, a fixing method using a rubber roller or a rubber belt has been proposed.
[0006]
Good image quality can be obtained by using a rubber roller, but there are problems such as warming up time and short roller life. This problem becomes more prominent as the speed of copiers and printers increases. It has become to.
[0007]
The fixing device using the fixing belt has the following problems.
[0008]
(1) In a system in which tension is applied using a rubber belt for fixing, the force that the belt tries to offset is large, and the cost of the unit is high and the reliability is not necessarily high for this measure.
[0009]
(2) In a fixing device in which a fixing belt suspended on a plurality of support rollers is heated and fixed by a heating means, heat escapes from the heated heating roller to the contact surface with the support roller, thereby extending the warm-up time. .
[0010]
(3) If protrusions parallel to the rotation shaft are formed on the surface of the support roller in order to reduce the contact area between the support roller and the fixing belt, noise is generated due to intermittent contact between the support roller and the fixing belt.
[0011]
(4) In a fixing device using a fixing belt, it is necessary to detect the temperature of the fixing belt in the image area and control the temperature. However, if a temperature sensor is installed on the outer peripheral surface of the fixing belt, it is generated on the surface of the fixing belt. Since a minute scratch causes an image defect, it is necessary to install a temperature sensor in a non-image area. The non-image area is not deprived of heat by the transfer material, and the temperature is different from that of the image area deprived of heat by the transfer material. Therefore, it has been difficult to control the temperature to an optimum temperature for fixing.
[0012]
(5) When a temperature sensor is installed on the outer peripheral surface of the fixing belt, toner or paper dust attached to the surface of the fixing belt causes a temperature detection failure.
[0013]
(6) If the heating means for heating the fixing belt is installed opposite to the outer peripheral surface of the fixing belt, the heating means is exposed, which is not preferable from the viewpoint of safe operation, and further close to the transfer material carried into the pressure roller. Then, there is a risk of overheating.
[0014]
The object of the present invention is to solve the above-mentioned problems, shorten the warm-up time, improve the temperature detection accuracy of the fixing belt, fast fixing and high-quality fixing, and make the fixing device safe and quiet and have a long life and the fixing An object of the present invention is to propose an image forming apparatus provided with the apparatus.
[0015]
[Means for Solving the Problems]
[0016]
The fixing device of the present invention is a fixing device that fixes a transfer material carrying a toner image by heating and pressurizing. The fixing belt is wound around at least two support rollers and is rotatable, and the fixing belt is heated. A heating unit; and at least two pressure rollers that fix the transfer material carrying the toner image by sandwiching and conveying the fixing belt and the transfer material to be fixed and heating and pressurizing. The support roller inscribed in the fixing belt is surrounded by a hollow cylindrical bag body sealed with a gas layer, and the internal pressure of the bag body is made higher than the atmospheric pressure. (Claim 1 ).
[0018]
The image forming apparatus of the present invention, which is characterized Fixing belt according to any one of the claims 1-5, heating means, pressure roller, by comprising a fixing device comprising a temperature sensor (Claim 6 ).
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a fixing device of the present invention and an image forming apparatus equipped with the fixing device will be described with reference to the drawings.
[0020]
FIG. 1 is a sectional view showing a color printer which is an image forming apparatus equipped with a fixing device of the present invention.
[0021]
In this color printer, four sets of scorotron chargers (hereinafter referred to as chargers) 2Y, 2M are disposed around a flexible endless belt-like photoreceptor (hereinafter referred to as a photoreceptor) 1 as an image carrier. , 2C, 2K, four sets of image exposure devices (scanning optical devices) 3Y, 3M, 3C, 3K, and four sets of developing units 4Y, 4M, 4C, 4K. Are arranged. The illustrated image exposure apparatuses 3Y, 3M, 3C, and 3K use a laser beam scanning optical apparatus.
[0022]
The photosensitive member 1 is stretched around the driving roller 11, the lower roller 12, and the upper roller 13, is in a tension state by the action of the tension roller 14, and is locally in contact with the backup member 15 provided on the inner peripheral surface. It rotates clockwise as shown. The backup member 15 is in contact with the back surface of the photosensitive member 1 and develops areas and images of the developer carriers (hereinafter referred to as developing sleeves) 41Y, 41M, 41C, and 41K of the developing devices 4Y, 4M, 4C, and 4K. The photosensitive member 1 is restricted to the image forming positions of the exposure devices 3Y, 3M, 3C, and 3K.
[0023]
The toner of the two-component developer used in the color image forming apparatus is a colorant composed of pigments or dyes such as yellow, magenta, and cyan, and a black pigment such as carbon black, a binder resin, a release agent, a charge control agent, etc. Containing. As the carrier, ferromagnetic particles such as ferrite, magnetite, and iron powder are used. Preferably, the surface of the ferromagnetic particles is coated with a resin such as a fluorine-based resin or a silicone-based resin.
[0024]
At the start of image recording, a driving motor (not shown) rotates and the photosensitive member 1 rotates clockwise through the driving roller 11, and the charging device 2 </ b> Y charges the photosensitive member 1. Application of a potential is started. After the photoconductor 1 is applied with a potential, exposure by an electric signal corresponding to the first color signal, that is, the yellow (Y) image signal is started in the image exposure device 3Y, and the photoconductor 1 is rotated (sub-scanning). As a result, an electrostatic latent image corresponding to the yellow (Y) image of the developed image is formed on the photosensitive layer on the surface. The latent image is reversely developed with the developer adhered and conveyed on the developing sleeve 41Y by the developing device 4Y in a non-contact state in the developing area, and becomes a yellow (Y) toner image.
[0025]
Next, the photosensitive member 1 is further applied with a potential on the yellow (Y) toner image by the charging action of the charger 2M, and an electric signal corresponding to the second color signal of the image exposure device 3M, that is, the magenta (M) image signal. Signal exposure is performed, and a magenta (M) toner image is formed on top of the yellow (Y) toner image by non-contact reversal development by the developing device 4M.
[0026]
By the same process, a cyan (C) toner image corresponding to the third color signal is further formed by the charger 2C, the image exposure device 3C, and the developing device 4C. Further, a black (K) toner image corresponding to the fourth color signal is sequentially superimposed by the charger 2K, the image exposure device 3K, and the developing device 4K, and is formed on the peripheral surface within one rotation of the photoreceptor 1. A color toner image is formed.
[0027]
In the developing operation by the developing devices 4Y, 4M, 4C, and 4K, the developing sleeves 41Y, 41M, 41C, and 41K are each developed with a DC bias having the same polarity as the charging of the photosensitive member 1 or a developing bias obtained by adding an alternating current to the DC bias. Is applied, and non-contact reversal development is performed by the two-component developer adhered on the developing sleeve, and the toner is adhered to the electrostatic latent image forming portion on the photoreceptor 1 with the conductive layer grounded.
[0028]
Thus, the color toner image formed on the peripheral surface of the photoreceptor 1 reaches the transfer region after the potential of the adhered toner is made uniform by the charger 2F. The transfer material P fed from the paper feeding cassette 51 or the manual paper feeding tray 53 of the paper feeding device 5 by the paper feeding means 52 and 54 and conveyed to the registration roller pair 55 is photosensitized by driving the registration roller pair 55. The toner image is transferred by a transfer means 6 such as a transfer roller which is fed in synchronization with the passage of the toner image area on the body 1 and is opposed to the lower portion of the driving roller 11 for driving the photoreceptor 1.
[0029]
The transfer material P onto which the toner image has been transferred is separated from the circumferential surface of the photoreceptor 1 along the curvature of the drive roller 11 and then conveyed to the fixing device 7. The toner image is melted by the fixing device 7 and fixed to the transfer material P. After the fixing process is completed, the transfer material P is transported by a pair of paper discharge rollers 81, 82, and 83, and is discharged to a paper discharge tray 84 provided at the top with the toner image surface on the transfer material as the bottom surface.
[0030]
On the other hand, the photoreceptor 1 from which the transfer material P has been separated is rubbed by the cleaning blade 91 of the cleaning device 9 to remove residual toner and be cleaned. When the toner image of the next document image is subsequently formed, the pre-charge static eliminator 92 exposes the photoconductor surface of the photoconductor 1 and the previous charge is removed.
[0031]
(First embodiment)
FIG. 2 is a sectional view showing an embodiment of the fixing device of the present invention, and FIG. 3 is a plan view of the fixing device.
[0032]
In FIG. 2, reference numerals 71 and 72 denote a pair of pressure rollers that can be moved toward and away from each other, 73 denotes an endless belt-like fixing belt, 74 and 75 denote a pair of support rollers that support and support the fixing belt 73, and 76 denotes heating. Heating means comprising a halogen heater 76A and a reflector 76B as a source, 77 a cleaning means for cleaning the outer peripheral surface of the fixing belt 73, and 78 a temperature sensor for detecting the temperature of the fixing belt 73.
[0033]
At least one of the pair of pressure rollers 71 and 72 has a movable rotational axis position. At the time of fixing, the fixing belt 73 and the transfer material P are clamped and conveyed. At the time of non-fixing, at least one roller, for example, the pressure roller 72 shown in the figure moves in the direction of the arrow against the pressure contact force, and is separated from the pressure roller 71 to form a gap.
[0034]
The fixing belt 73 is formed by, for example, laminating a silicone rubber layer and a protective layer on the surface of a base made of an endless belt-like Ni layer formed by electroforming.
[0035]
The silicone rubber layer is, for example, a belt having a thickness of 0.2 mm, a rubber hardness of 3 ° to 60 ° (JISA), and a small heat capacity. Further, the inner circumference of the fixing belt 73 is coated with an infrared ray absorbing material, and the absorption rate of irradiation light is high, and the temperature rises to a predetermined temperature (for example, 190 ° C.) in a short time by heating with the halogen heater 76A. Yes.
[0036]
The fixing belt 73 is stretched between the support roller 74 and the support roller 75 with a very weak tension of 0.5 kg / cm or less, more preferably 0.2 kg / cm or less. Alternatively, it may be in a state where the tension is zero.
[0037]
The fixing belt 73 is rotated by the rotation of the support roller at times other than the fixing process. The fixing belt 73 at the time of the fixing process is nipped and rotated by the pressure contact driving of the pressure rollers 71 and 72. The rotation speed of the fixing belt 73 is the same as the conveyance speed of the transfer material P.
[0038]
As shown in FIG. 3, the support roller 74 includes a roller portion 74A having a spiral protrusion having an inclination angle with respect to the axial direction of the rotation shaft 74B, a rotation shaft 74B driven and rotated by a drive source, and a roller portion. A flange member 74C connected to both ends of 74A and a gear 74D fixed to one shaft end of the rotating shaft 74B and connected to a drive source.
[0039]
The support roller 75 includes a roller portion 75A formed with a spiral protrusion having an inclination angle with respect to the axial direction of the rotation shaft 75B, a rotation shaft 75B, and a flange member 75C connected to both ends of the roller portion 75A.
[0040]
The roller portions 74A and 75A are made of a material having heat resistance with respect to the fixing temperature by the heating means 76 and having a low thermal conductivity, such as foamed silicone rubber.
[0041]
The roller parts 74A and 75A are formed by integrally molding silicone rubber or other heat-resistant resin on the outer circumferences of the rotating shafts 74B and 75B, or spiral string-like silicone rubber on the outer circumferential surface of a hollow cylindrical member made of metal or resin. The thing etc. which were wound in the shape and formed the protrusion are used.
[0042]
In order to reduce the contact area with the fixing belt 73 so that heat is not taken away from the fixing belt 73 as much as possible, the roller portions 74A and 75A are formed with spiral protrusions. As a result, when the fixing device 7 is warmed up, only the fixing belt 73 needs to be heated, and the amount of heat lost to the cored bar or the like is less than that of the conventional roller fixing method, so that the warming up time can be greatly shortened. It was. Further, since the protrusion is spiral, the fixing belt 73 and the roller portions 74A and 75A are in continuous contact with each other, and the operation noise of the fixing belt 73 is reduced.
[0043]
When both the support roller 74 and the support roller 75 are driven by the drive device of the image forming apparatus main body, the direction of the inclination angle of the spiral protrusion formed on the roller portion 74A of the support roller 74, and the support roller The directions of the inclination angles of the spiral protrusions formed on the 75 roller portions 75A are opposite to each other. The force that causes the fixing belt 73 to move to one side by the spiral protrusions is in the opposite direction between the roller portion 74A and the roller portion 75A, and the bias of the fixing belt 73 due to the provision of the spiral protrusions is prevented. The
[0044]
When one of the two support rollers is driven to be driven via the fixing belt 73, such as when the support roller 75 is rotated by the drive transmitted from the support roller 74 via the fixing belt 73, a spiral shape is used. By making the inclination angle directions of the protrusions in the same direction, the direction of the force that biases the fixing belt 73 is reversed, and similarly, the bias of the fixing belt 73 is prevented.
[0045]
The inclined surface of the flange member 74C provided at both ends of the roller portion 74A and the inclined surface of the flange member 75C provided at both ends of the roller portion 75A are meandered by the fixing belt 73 stretched with a very weak tension. , To prevent deviation from the roller portions 74A and 75A.
[0046]
The support roller 74 is driven and rotated in a clockwise direction indicated by an arrow by a power device of the image forming apparatus main body. As the support roller 74 rotates, the fixing belt 73 and the support roller 75 are rotated clockwise. The design value of the driving speed of the fixing belt 73 is the same as the transfer speed of the transfer material P. The peripheral speeds of the pressure rollers 71 and 72 are driven to be the same as the driving speed of the fixing belt 73.
[0047]
Inside the fixing belt 73, one or a plurality of halogen heaters 76A are provided to irradiate and heat the inside of the fixing belt 73 on the upstream side of the fixing position. A reflector 76B is provided behind the halogen heater 76A so as not to heat a member that does not need to be heated, such as the support roller 74, and to improve thermal efficiency.
[0048]
As the transfer material P holding the toner image is conveyed to the fixing region via the conveyance guide plate 56, or prior to this, the pressure roller 72 disposed outside the fixing belt 73 is raised, Pressure is applied with the transfer material P and the fixing belt 73 interposed therebetween. The toner image on the transfer material P is fixed to the transfer material P by heating by the heat of the fixing belt 73 and nipping and pressurization by the pressure rollers 71 and 72.
[0049]
A predetermined load acts on the support shaft 72A at both ends of the pressure roller 72 toward the pressure roller 71 when sandwiched by the spring member, and a constant pressure acts on the pressure-bonding portions of the pressure rollers 71 and 72. It has become.
[0050]
The strength of this pressure is adjusted to 0.2 to 2 kg / cm, preferably 0.6 to 1.0 kg / cm per unit length in the direction parallel to the axis of the pressure roller 72.
[0051]
The pressing by the pressure rollers 71 and 72 may be performed by moving both the pressure roller 71 downward and the pressure roller 72 upward. Since the peripheral speed of the pressure roller 71 or the pressure roller 72 is driven at the same speed as the moving speed of the fixing belt 73, an excessive force is not applied to the fixing belt 73 and the transfer material P. Yes. Further, after the fixing, the pressure rollers 71 and 72 are released from the pressure bonding, so that distortions and deviations caused by a minute speed difference between the fixing belt 73 and the pressure rollers 71 and 72 are eliminated, and the pressure roller 71 from the fixing belt 73 is removed. , 72 is prevented from flowing out of heat.
[0052]
The toner rubber image on the transfer material P is in contact with the silicone rubber belt of the fixing belt 73. The elasticity of the silicone rubber follows the unevenness of the transfer material P and the toner image, and is uniformly contacted and heated by the halogen heater 76A. Uniform fixing without uneven gloss is performed by the heat of the fixing belt 73 and the pressure applied by the pressure rollers 71 and 72.
[0053]
In addition, an elastic layer made of silicone rubber is provided on the outer periphery of the pressure roller 72 outside the fixing belt 73 so that a large nip width is formed at the contact portion between the pressure rollers 71 and 72, thereby completely fixing. Is done.
[0054]
The fixed transfer material P is separated by the fixing belt 73 by the curvature of the support roller 75 that supports the fixing belt 73.
[0055]
The fixed transfer material P is cooled by the outside air when it comes out of the nip portion by the pressure rollers 71 and 72, so that an offset or a separation failure during separation is avoided.
[0056]
(Second Embodiment)
FIG. 4 is a front view showing a second embodiment of the fixing device of the present invention, and FIG. 5 is a sectional view. In addition, about the code | symbol used in these drawings, the same code | symbol as FIG. 2, FIG. 3 is attached | subjected to the part which has the same function as the said embodiment. Further, differences from the embodiment will be described.
[0057]
The fixing belt 73 is rotatably supported by support rollers 740 and 750. Since the support roller 740 connected to the drive source and the support roller 750 driven to rotate via the fixing belt 73 have substantially the same shape, the configuration of the support roller 740 will be described below with reference to FIG.
[0058]
The support roller 740 includes a bag 741 made of a hollow cylindrical elastic body, a rotary shaft 742 driven and rotated by a drive source, a flange member 743 connected to both ends of the bag 741, and one shaft end of the rotary shaft 742. It consists of a gear 744 that is fixed and connected to the drive source.
[0059]
The bag body 741 has heat resistance with respect to the fixing temperature by the heating means 76, has low thermal conductivity, has elasticity, resin, rubber, flexible thin film, or a laminated material thereof, or These composite materials are used.
[0060]
That is, the bag body 741 is formed of a thin film made of a resin material such as aromatic polyamide, polyimide, or polyamideimide, or a thin film made of rubber such as high hardness silicone rubber having a rubber hardness of 70 ° (JISA) or more. Yes.
[0061]
The film thickness of the bag 741 is preferably 10 to 200 μm in the case of the resin thin film and 100 to 500 μm in the case of the rubber thin film.
[0062]
The bag body 741 is formed in a balloon shape made of a hollow cylindrical elastic body sealed at both ends by flange members 743, and seals the periphery of the rotating shaft 742 of the support roller 740 via a gas layer. The internal pressure 741 is set higher than the atmospheric pressure.
[0063]
The film thickness of the bag body 741 is extremely thin and has a small heat capacity compared to a hollow cylindrical body made of metal or hard resin. Since the bag body 741 has a thin film thickness, its cross-sectional area is small, and heat conduction in a direction parallel to the rotation shaft 742 is low. Further, since the bag body 741 is thin, the amount of heat that escapes through the flange member 743 is small. For this reason, the heat taken away from the fixing belt 73 by the bag body 741 is very small.
[0064]
As a result, when the fixing device 7 is warmed up, only the fixing belt 73 needs to be heated, and the amount of heat lost to the cored bar or the like is less than that of the conventional roller fixing method, so that the warming up time can be greatly shortened. It was.
[0065]
A flange member 743 having an outer diameter larger than the outer diameter of the bag body 741 is provided in the vicinity of both ends of the bag body 741 to prevent the fixing belt 73 from being displaced.
[0066]
(Third embodiment)
FIG. 6 is a cross-sectional view showing another embodiment of the bag body 741.
[0067]
The outer peripheral surface of the bag body 741A is formed in a middle and high drum shape where the outer diameter D1 of the central portion in the axial direction of the rotating shaft 742 is larger than the outer diameter D2 of both end portions (D1> D2). As a result, displacement of the fixing belt 73 during rotation is prevented.
[0068]
(Fourth embodiment)
Next, a fourth embodiment of the fixing device of the present invention will be described with reference to FIGS.
[0069]
Inside the fixing belt 73, a halogen heater 76A is installed so as to irradiate the inner peripheral surface of the fixing belt 73. The fixing belt 73 is heated to a predetermined temperature by the halogen heater 76A.
[0070]
The temperature control of the fixing belt 73 is performed based on the temperature detected by the temperature sensor 78 installed in contact with or close to the inner peripheral surface of the fixing belt 73. For the temperature sensor 78, a thermocouple, a thermistor, or the like is used.
[0071]
The temperature sensor 78 supports the fixing belt 73 on the tension side of the fixing belt 73 on the upstream side in the conveyance direction of the fixing belt 73 from the contact position of the fixing belt 73 with the driving-side support roller 74 (or 740) that rotates. Has been placed. Note that the installation position of the temperature sensor 78 is not limited to the above position as long as a means for maintaining stable contact or proximity is provided by a mechanism for following the temperature sensor 78 to the fixing belt 73.
[0072]
Since the temperature sensor 78 is disposed in contact with or close to the inner peripheral surface of the image forming area of the fixing belt 73, the temperature sensor 78 contacts the outer peripheral surface of the fixing belt 73 that affects the image and damages the image. There is nothing to do. Accordingly, it is possible to accurately detect the temperature of the image forming area where the image is fixed.
[0073]
Further, in the fixing region, since the fixing belt 73 in contact with the transfer material P is deprived of heat only at the contact portion, the halogen heater 76A is synchronized with the timing when the contact portion reaches the heating region by the halogen heater 76A. Lights up.
[0074]
By disposing the temperature sensor 78 of the present invention, it becomes possible to detect the temperature of the fixing belt 73 in the image forming area, and high-precision temperature control is realized without affecting the image.
[0075]
【The invention's effect】
According to the present invention, with the above-described configuration, the warm-up time can be shortened, the fixing belt can be prevented from being displaced, the temperature detection accuracy of the fixing belt can be improved, high-speed fixing, and high-quality fixing can be achieved. A fixing device having a long life and an image forming apparatus including the fixing device are provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional configuration diagram showing a color printer which is an image forming apparatus equipped with a fixing device of the present invention.
FIG. 2 is a cross-sectional view showing an embodiment of a fixing device of the present invention.
FIG. 3 is a plan view of the fixing device.
FIG. 4 is a front view showing a second embodiment of the fixing device of the present invention.
FIG. 5 is a cross-sectional view of a fixing device according to a second embodiment.
FIG. 6 is a sectional view showing another embodiment of a fixing roller bag.
[Explanation of symbols]
7 Fixing devices 71, 72 Pressure roller 72A Support shaft 73 Fixing belts 74, 75, 740, 750 Support rollers 74A, 75A Roller portions 74B, 75B, 742 Rotating shafts 74C, 75C, 743 Flange members 741, 741A Bag body 76 Heating Means 76A Halogen heater (heating source)
76B Reflecting plate 77 Cleaning means 78 Temperature sensors D1, D2 Outer diameter P Transfer material

Claims (6)

In a fixing device for fixing a transfer material carrying a toner image by heating and pressing,
A fixing belt that is wound around at least two support rollers and is rotatable;
Heating means for heating the fixing belt;
And at least two pressure rollers for fixing the transfer material carrying the toner image by sandwiching and conveying the fixing belt and the transfer material to be fixed in a state of being heated and pressed.
The periphery of the rotating shaft of the support roller inscribed in the fixing belt is formed as a hollow cylindrical bag body hermetically sealed with a gas layer, and the internal pressure of the bag body is set higher than atmospheric pressure. Fixing device. The fixing device according to claim 1, wherein the bag body of the support roller is formed of any one of elastic resin, rubber, and a flexible thin film, or a laminated material thereof. The outer peripheral surface of the bag body of the support roller is formed in a middle and high drum shape in which the outer diameter of the central portion in the axial direction of the rotating shaft is larger than the outer diameters of both end portions. The fixing device described. The fixing device according to claim 1, wherein a flange member having an outer diameter larger than an outer diameter of the support roller is provided in the vicinity of both end portions of the rotation shaft of the support roller. At least one of the at least two pressure rollers is supported so as to be capable of being pressed and separated, and is in a separated state for a part of time when there is no transfer material at a transfer material sandwiching position. The fixing device according to claim 1, wherein the pressure roller holds the transfer material in a pressure contact state when passing between the pressure rollers. An image forming apparatus comprising the fixing device comprising the fixing belt according to any one of claims 1 to 5, a heating unit, a pressure roller, and a temperature sensor.

Images