JPH06138788A - Fixing device, image forming device and electrophotographic film - Google Patents

Abstract

PURPOSE:To properly measure the temperature of a fixing roller without damaging its surface by providing the groove of a prescribed depth on the inner surface of the fixing roller and disposing a temperature-sensitive element so as to abut on the part of the groove. CONSTITUTION:As a heater 2, a halogen heater is used and has a capacity for sufficiently rising the temperature of the fixing roller 1. The groove D is worked to obtain a depth of 22mm from the inner surface of the fixing roller at a position in the axial direction of the paper passing width end part of a minimum size paper and the surface of the groove D is ground to secure slidability. On the fixing roller 1, a driving gear is provided on the end part of the side opposite to a side provided with the groove D and driven, to protect the part of the groove D of the fixing roller 1 whose strength is lowered. Then, the temperature-sensitive element 6 is sealed in the glass bead whose diameter is 1mm, held by an alumina holding member 601 and abutted on the bottom part of the groove D.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a radiant heating element such as a halogen heater inside a fixing roller, and transfers radiant heat energy absorbed by the inner surface of the fixing roller to the surface of the fixing roller by heat conduction of the fixing roller itself. A heat generating layer is provided on the surface of a fixing device having a method of applying this heat energy to a recording material or a fixing roller having a hollow core, and the heat energy from the heat generating layer is directly applied to the recording material via a release layer. The present invention relates to a fixing device of a giving type.

The present invention also relates to an electrophotographic copying machine,
The present invention relates to an electrophotographic film used in a printer or the like.

Further, the present invention relates to a pressure roller of the above fixing device.

The present invention also relates to a fixing device for an electrophotographic apparatus such as a printer which carries out fixing using a light beam.

[0005]

2. Description of the Related Art This apparatus is an image heat fixing apparatus in an image forming apparatus such as an electrophotographic copying machine, a printer or a fax machine, that is, it is heated and melted by an appropriate image forming process means such as electrophotography, electrostatic recording or magnetic recording. Unfixed corresponding to the target image, which is formed directly or indirectly (transfer) on the surface of the recording material (electrofax sheet, electrostatic recording sheet, transfer sheet, printing paper, etc.) using the toner made of the above resin etc. Is a device for heating and fixing the toner image as a permanent fixed image on the recording surface carrying the image.

FIG. 7 shows a vertical sectional view of a specific example of the fixing device. In FIG. 7, the fixing roller 1 on the upper side is a hollow cored bar made of aluminum, iron or the like, and a heater 2 such as a halogen lamp is placed inside the hollow cored bar, and the heater 2 heats the fixing roller 1. . Reference numeral 101 denotes a release layer for improving the surface property of the fixing roller 1, and a fluororesin coating or a tube is preferably used. The lower pressure roller 3 has a cored bar 304 made of iron, stainless steel or the like, and an outer periphery of the cored bar 304 covered with an elastic body 305 having releasability such as silicone rubber. The fixing roller 1 and the pressure roller 3 are brought into contact with each other with a predetermined pressure by an urging means such as a spring (not shown), and are rotationally driven in the arrow direction.

Reference numeral 6 denotes a temperature sensitive element such as a thermistor which is in contact with the surface of the fixing roller 1, and detects the surface temperature of the fixing roller 1. The temperature control circuit controls the energization of the heater 2 according to the temperature detected by the temperature sensitive element 6, and the surface temperature of the fixing roller 1 is automatically controlled to a predetermined thermal fixing temperature. Denoted at 7 is a separation claw for separating the recording material P from the surface of the fixing roller 1, and the tip edge portion is arranged so as to be in contact with the surface of the fixing roller 1 with an appropriate pressing force. Reference numeral 8 denotes a cleaner such as felt which is brought into pressure contact with the surface of the fixing roller 1 and wipes and removes toner tc, paper dust and the like adhering to the surface of the fixing roller 1. Reference numeral 9 denotes a bottom plate made of a metal material of the fixing device, and 10 and 11 denote recording material inlet guides and outlet guides, which are attached to and supported by the bent entire surface wall of the bottom plate 9 upward.

The recording material P, which has entered the fixing device through the entrance guide 10, enters the nip portion between the fixing roller 1 and the pressure roller 3 which are rotationally driven in pressure contact with each other, and both rollers 1, 1. It goes through the nip part of 3. During this passing process, the unfixed toner image ta on the recording material P is fixed as a permanently fixed image by heat and pressure.

The recording material P, which has passed through the nip portion of the rollers 1 and 3 and has undergone image fixing, has its leading end separated from the surface of the fixing roller 1 by the separating claw 7, and is discharged to the outside of the fixing device through the exit guide 11. .

Next, FIG. 21 shows an example of another heat fixing device used in the electrophotographic apparatus. FIG. 21 is a longitudinal sectional view of the fixing device. The fixing roller 209 has a cored bar coated with a fluororesin such as PFA or PTFE, and the pressure roller 210 has an elastic layer on the cored bar and a PFA tube on the surface layer. These pair of rollers are pressed to a predetermined pressure by a pressure spring (not shown). The fixing roller has a halogen heater 211 as a heat source in its core metal, and the halogen heater 211 is controlled to be lit while detecting the temperature by a thermistor 213, which is a temperature sensitive element in contact with the surface of the fixing roller.
The temperature is controlled. Between the halogen heater 211 and the AC power supply 214, a thermo switch 212 as an excessive temperature rise prevention device is provided.

By the way, as the performance required for a recent fixing device, long life and maintenance-free are mentioned. To achieve these, a fluorine resin layer is provided on the surface layer of the fixing roller and the pressure roller, and Prevent dirt,
In addition, in order to prevent the damage on the image due to the scratches caused by the contact of the thermistor and the thermoswitch, the contact with the non-image area is performed. In the conventional example of FIG. 21, Lpic
The range of true is the image area, and the range of Lmax represents the maximum size paper width that can be passed by this machine.
The thermistor 213 is in contact with the non-paper passing area, and the thermo switch 212 is in contact with the non-image area in the paper passing area.
When the temperature control is disabled and the heater continues to light up, the thermo switch detects it as soon as possible,
The energization is required to be stopped, and therefore the abutting place must be set at a place where the temperature rise is as high as possible.

Generally, the rate of temperature rise increases toward the center of the roller. Therefore, the contact position of the thermoswitch in this conventional example has been determined as a place where the temperature rise rate is the highest where roller scratches due to durability do not affect the image.

Next, FIGS. 27 and 28 show another conventional apparatus. In this conventional fixing device, as shown in FIG. 27, a fixing roller 404 in which the surface of a core metal of aluminum or iron is coated with a heat-resistant release layer, and a heat-resistant elastic layer is formed around a core metal of stainless steel or the like. It is composed of a pressure roller 405. A heater (not shown) is provided in the core metal of the fixing roller 404.
Is included, and it is designed to be heated. The pressure roller 405 is pressed against the fixing roller 404 by a spring to form a nip, and the unfixed toner image 406 is heated and pressed at the nip portion of the fixing device to be fixed on the recording material 407.

An electrophotographic film may be used as the recording material 407, and its structure is shown in FIG. An electrophotographic film used in an electrophotographic copying machine, a printer or the like has a surface of a plastic film 401 having a thickness of 100 to 120 μm and a heat resistant temperature of 100 ° C. or higher, as disclosed in JP-A-51-34734. A coating layer 402 made of a resin soluble in an organic solvent containing a matting agent and a surfactant is applied thereon in an amount of 1 to 10 μm.

As the plastic film having a heat resistant temperature of 100 ° C. or higher, a polyester film, a polycarbonate film, a triacetyl cellulose film or the like is used.

The matting agent is added to reduce the coefficient of friction on the film surface and prevent double feeding, and inorganic fine particles such as silicon dioxide and alumina and plastic powders such as polyethylene, polypropylene and polyacrylonitrile are used.

The surfactant is added to reduce the surface resistance of the plastic film, prevent the toner from scattering when the toner image is transferred onto the recording material, and at the same time, prevent the frictional electrification between the films. , Sodium dodecyl phosphate, sodium dioctyl phosphate, etc. are used.

A resin soluble in an organic solvent is added in order to improve the fixing property of the toner, and as the resin material, polyester resin, acrylic ester resin, methacrylic ester resin, or styrene and acrylic ester, styrene are used. A methacrylic acid ester copolymer or the like is used.

As the solvent for dissolving the resin, one kind or a mixed solvent of two or more kinds of alcohols, ketones methylene chloride and chlorinated hydrocarbons is used.

The general surface resistivity of this electrophotographic film is 1 × 10 ¹¹ to 1 × 10 ¹² Ω.

Next, FIG. 38 shows another conventional apparatus. FIG. 38 is a schematic sectional view of the heating roller fixing device. Examples of the bearing material used for such a fixing roller include polyamideimide (softening temperature 274 ° C.), glass fiber-containing polyether sulfone (softening temperature 216 ° C.), glass fiber-containing polyethylene terephthalate (softening temperature 23.
5 ° C, glass fiber-containing polyamide (softening temperature 228
Heat resistant resin such as (℃) is used. In addition to this, a bearing or the like via a heat insulating bush may be used.

In this type of heat fixing device, it is possible to prevent the surface temperature of the fixing roller from rising excessively when the electric power supply to the heater such as a halogen heater becomes uncontrollable due to some abnormality. For this reason, an excessive temperature rise prevention element such as a thermo switch is provided in the heater and the series so that the power supply to the heater is shut off when the surface temperature of the fixing roller becomes abnormally high.

Next, another conventional example will be described. In recent years, images of electrophotographic printers and the like have been miniaturized year by year, and as a result, the heat fixing device has also become smaller and the heat capacity of the fixing roller has also become smaller. As a result, the temperature of the fixing roller surface rises quickly, and therefore an excessive temperature rise prevention element is also required to have a fast response in order to improve safety. In many cases, the thermoswitch is brought into contact with the fixing roller surface. It is a method. In this case, the concave contact surface of the thermoswitch is brought into contact with the fixing roller surface, or the center of the flat contact surface is brought into contact with the fixing roller surface.

Next, another conventional example will be described. As described above, the heat roller fixing device is used for the fixing device of the electrophotographic apparatus, but various improvements have been conventionally made to prevent offset, paper wrinkles, and power consumption during standby. For example, JP-A-59-9556
In the fixing device described in Japanese Patent Laid-Open No. 4 publication, the laser beam light irradiation heat energy is used as the energy for thermally fixing the toner. In this apparatus, as shown in FIG. 50, a laser beam emitted from a laser light source is repeatedly scanned in a direction perpendicular to the recording material conveyance direction, and the recording material moves in the conveyance direction, so that the entire surface of the recording material is illuminated. Irradiation energy is applied, and the thermal energy fixes the toner on the recording material. As described above, by using the radiant energy of the light irradiation of the laser beam as the energy of the thermal fixing, a non-contact fixing device having a substantially zero warm-up time is provided.

Next, another conventional example will be described. In the conventional heat fixing device, since the image forming apparatus cannot be used during the time until the heating roller reaches a predetermined surface temperature after the power is turned on, this waiting time (so-called wait time) is provided for the convenience of the user. ) Has been made various attempts have been made.

For example, by reducing the heat capacity of the heating roller,
A method of increasing the amount of heat generated by a heater provided inside the heating roller has been proposed. Further, as disclosed in Japanese Utility Model Publication No. 55-31549, the temperature is lower than the fixing temperature so that the heating roller reaches a fixing temperature when the recording material actually reaches the heating roller fixing device. A technique is known in which an image forming operation is started and the wait time is shortened as much as possible.

Regarding the standard for passing the recording material, it is known that the central portion of the fixing device or the end portion of the fixing device has its own merits.

[0028]

However, according to each of the above conventional examples, there are the following problems. First, according to the conventional example shown in FIG. 7, when a temperature sensitive element is provided on the surface of the fixing roller at the sheet passing portion, the surface of the fixing roller is damaged at the contact portion, and an offset due to a decrease in releasability occurs. I will end up. Further, in the case of contacting with the surface of the non-sheet passing portion, even if the temperature of the sheet passing portion of the fixing roller is changed by passing the sheet, it may be difficult to detect the change by the temperature sensing element.

On the other hand, when the temperature sensitive element is brought into contact with the inner surface of the fixing roller, there is a problem that the temperature sensitive element is heated by the direct radiation from the radiant heating element and the temperature of the roller cannot be accurately measured.

If the fixing roller is thick,
A large thermal gradient occurs between the surface and the inner surface, and the temperature detected on the inner surface may not necessarily reflect the temperature of the surface. In such a case, problems such as improper fixing occur.

Further, according to the conventional apparatus shown in FIG. 7, since the temperature sensitive element or the holding member which holds the temperature sensitive element and is in contact with the fixing roller is installed in the sheet passing area, The offset prevention layer on the surface of the fixing roller is damaged to reduce the releasability, causing offset, and the temperature responsiveness of the temperature sensing element is reduced by toner or paper dust adhering to the temperature sensing element. There is a risk that the temperature and the energization interruption temperature at the time of abnormal temperature rise may be increased. Further, the toner adhering to the temperature-sensitive element slipped through the sheet immediately after it was started up from room temperature and was fixed on the sheet, causing image stains.

Further, according to the conventional example shown in FIG. 21, stains due to toner or paper dust accumulate on the surface of the thermoswitch at the contact position of the thermoswitch, and when it reaches a certain amount, it slips or spills, and non-image There was a problem that black sewage appeared in the area. Here, toner stains are accumulated on the surface of the thermoswitch regardless of the non-image area because the fog toner on the recording material exists in the non-image area, and this is not fixed on the recording material but the fixing roller. This is because it is offset upward and caught on the sliding surface with the thermoswitch. Therefore, it is possible to move all the contact surfaces of the thermoswitch to the non-sheet passing area.
In the recent miniaturized fixing devices, the space between the paper non-passage area and the bearing is very small, and even if there is a contacting space, the amount of heat escaped is large near the bearing. , The temperature rise rate at the time of runaway is low, and the effect as a thermoswitch is greatly reduced.

Alternatively, as shown in FIG. 22, a method of making the thermoswitch non-contact has also been proposed. FIG. 22
In Fig. 21, the same components as those in Fig. 21 are indicated by the same numbers. The thermoswitch 216 here is fixed in the holder member 215, and the holder 215 is abutted against the roller surface in the non-image area so that the thermoswitch surface and the fixing roller surface maintain a predetermined gap. It has a simple structure.

However, in the above-mentioned non-contact thermoswitch system, in order to obtain a response similar to that of the contact type, the gap must be kept to about 0.1 mm, but the accuracy of the holder, thermal deformation, etc. are taken into consideration. However, there is a problem in that it is very difficult to keep this distance, and the holder structure becomes complicated and large-scale.

Further, in the conventional example shown in FIGS. 27 and 28, since the coating layer 402 contains a surfactant for lowering the resistance of the surface of the electrophotographic film,
The film surface is in a state where charges can move freely in the surface direction.

Then, the unfixed toner image 406 transferred onto the film is, as shown in FIG. 29, an electric charge having a polarity opposite to that of the toner existing on the back surface of the film (in the figure, a case where a negative toner is used is shown. Attracted by
Is held.

Therefore, when the charge can freely move on the surface of the film as in the conventional example, when the charge on the back surface of the film attracting the toner onto the film passes through the fixing device as shown in FIG. In some cases, the back surface of the film may leak to the fixing roller side through the left and right edges of the film.

When the back surface of the film leaks, the force with which the film retains the toner decreases, and conversely an electric field that attracts the toner to the fixing roller side is generated. There is a problem in that the force of the electric field attracts the surface of the fixing roller to cause electrostatic offset.

Further, in the conventional example shown in FIG. 38, when the temperature of the fixing device rises abnormally from room temperature, the resin-made fixing roller bearing is softened before the thermoswitch operates, and the fixing roller bearing shown in FIG. As shown, the pressure from the pressure roller pressed by the spring displaces the position of the fixing roller and changes the contact state of the thermistor. As a result, the operating temperature of the thermoswitch is the operation when the fixing roller does not displace. 40 to 50 ℃ higher than the temperature, smoke,
There is a risk of ignition. As a means to improve this, there is a method in which the thermo-switch is brought into contact with the fixing roller in consideration of the movement amount of the fixing roller at the time of abnormal temperature rise, and is brought into contact with the proper position at the time of abnormal temperature rise. However, it is necessary to use a resin that is always softened before the thermoswitch operates, and the amount of movement of the fixing roller is not constant, which is insufficient to solve the problem.

Further, in the above-mentioned conventional example, since the surface of the pressure roller is covered with the fluororesin layer and the releasability is imparted to the fluororesin layer, the releasability does not deteriorate due to the durability. However, the unreacted low molecular weight component of the rubber inside the silicone rubber elastic layer and the low molecular weight component that is generated by the thermal decomposition of the rubber while the number of prints are piled up become vapor from the rollers, and from both ends of the roller. There is a phenomenon of running away. The low-molecular component cannot escape from the paper-passing surface covered with fluororesin, so it escapes from both ends. This phenomenon becomes a particular problem in recent miniaturized fixing devices. In other words, when the diameter of the pressure roller or the fixing roller is reduced, it is desirable that the hardness of the silicone rubber elastic layer is low in order to secure the necessary nip width when the diameter is reduced. This is because the weight loss due to heating increases.

In such a pressure roller, the volume at both ends is reduced by the amount of the low-molecular weight component having escaped from the center, and the pressure roller has a crown shape. When paper is passed in this state, the driving force at the center is stronger than the driving force at the edges, so the force to move to the center of the paper works, causing wrinkles and uneven fixability, which causes uneven gloss. However, there is a problem in that the image becomes wavy, and the toner that is offset by contacting the fixing roller before the nip adheres to the paper again at the time of fixing, causing an image shift.

Further, in the conventional apparatus using the above light energy, since the heat energy is applied to the entire surface of the recording material, the unfixed toner (fog) and the scattering (Blur) at the positions other than the image area of the recording material. However, there is a problem that the image quality is deteriorated because even the toner) is fixed.

Further, in the conventional fixing device in which the wait time is shortened, regardless of the position of the recording material passing reference,
There is a problem in that the wait time setting is the same for all recording materials. For example, if you want to print immediately after turning on the power in the morning, in a device where the paper passing standard is the center of the fixing device, a heating roller is used for a certain recording material size, that is, a recording material with a size smaller than the maximum paper passing width. Since the surface temperature is considerably higher in the center than at the roller end portion, there is a problem that the image forming apparatus does not become Ready although sufficient fixing property can be secured.

A first object of the present invention is to solve the above problems and to provide a fixing device capable of appropriately measuring the temperature of the fixing roller without damaging the surface of the fixing roller.

A second object of the present invention is to cause an offset due to the breakage of the offset prevention layer of the fixing roller, to raise the cutoff temperature due to the adhesion of toner or the like to the temperature sensitive element, or to adhere to the temperature sensitive element. An object of the present invention is to provide a fixing device that does not cause image contamination due to toner slipping through.

A third object of the present invention is to provide a fixing device capable of preventing generation of toner stains from the thermoswitch and obtaining sufficient responsiveness of the thermoswitch without increasing the size of the device. Especially.

A fourth object of the present invention is to provide an electrophotographic film which does not cause charge leakage and offset when passing through a fixing device.

A fifth object of the present invention is to solve the above problems and provide a heating and fixing device which can stabilize the contact state of the thermoswitch even when the fixing device has an abnormal temperature rise. It is in.

A sixth object of the present invention is to provide a pressure roller which is free from wrinkles and uneven gloss of the recording material even when the outer diameter of the pressure roller changes due to a decrease in low molecular weight components. It is to provide a fixing device.

A seventh object of the present invention is to provide a fixing device which uses optical energy without causing deterioration of image quality due to fixing unfixed toner at a position other than the image portion of the recording material. To do.

An eighth object of the present invention is to solve the above problems and to reduce the heat capacity of the heating roller, and
An object of the present invention is to provide an image forming apparatus capable of shortening the wait time according to the recording material size without increasing the heat generation amount of the heater and without impairing the fixing property.

[0052]

According to the first invention of the present application,
The first object is a fixing device having a hollow fixing roller and a temperature sensitive element for detecting the temperature of the fixing roller, wherein a groove having a predetermined depth is provided on the inner surface of the fixing roller. This is achieved by the fact that the temperature sensitive element is arranged so as to come into contact with the groove portion.

According to the second invention of the present application, the second object is to provide a hollow fixing roller, a heating element contained in the fixing roller, and a temperature sensitive element for detecting the temperature of the fixing roller. In the fixing device having the above, the fixing roller has a paper-passing portion having an offset prevention layer on the surface of the heat-conducting core and a non-sheet-passing portion where the heat-conducting core is exposed. The holding member holding the element is achieved by being arranged in the non-sheet passing portion of the fixing roller.

Further, according to the third invention of the present application, the third object is to provide a fixing device having a heating roller provided with a heating element and an excessive temperature rise preventing device arranged so as to be in sliding contact with the heating roller. In the apparatus, in the heating roller or the excessive temperature rise prevention device, a part of the heat-sensitive surface of the excessive temperature rise prevention device is in contact with a recording material non-passage area on the surface of the heating roller, and the other portion is in the paper passage area. On the other hand, it is achieved by having a step shape so as to maintain a predetermined gap.

According to the fourth invention of the present application, the fourth object is to carry an unfixed developer image on a surface and convey the unfixed developer image to the fixing device, and heat and pressurize by the fixing device. In the electrophotographic film on which the developer image is fixed,
At least one of the front and back surfaces of the film is achieved by setting the surface resistance of the left and right non-image portions to be higher than the surface resistance of the other portions.

Further, according to the fifth invention of the present application, the heating roller having the heating source therein, the heat-resistant heat insulating resin bearing member provided between the heating roller and the frame, and the heating roller are pressed against each other. In a fixing device provided with a pressure roller arranged and an excessive temperature rise prevention means arranged so as to come into contact with or close to the surface of the heating roller, a radial direction of the heating roller when the bearing member is softened. This is achieved by having a movement restricting member that restricts the movement of the.

According to the sixth invention of the present application, the sixth object is to provide an elastic layer of silicone rubber on the surface of the core metal,
This is achieved by having a release coating layer made of a fluororesin on its surface and sealing both ends of the elastic layer with a non-polar resin.

Further, according to the seventh invention of the present application, the seventh object is to provide a fixing device of an electrophotographic apparatus for irradiating and fixing an unfixed developer image on a recording material with a light beam. It has a control means for controlling the irradiation position and a developer collecting means arranged in front of the light beam irradiation position in the recording material conveyance direction, and the control means is the unfixed developer image position on the recording material. And the vicinity thereof is set to irradiate a light beam having a light intensity capable of fixing.

According to the eighth invention of the present application, the eighth object is to detect the heating roller having a heat source therein, temperature detecting means for detecting the surface temperature of the heating roller, and the temperature detecting means. Temperature control means for maintaining the surface temperature at a set temperature based on the temperature, recording material conveying means for conveying the recording material carrying the unfixed developer image with the central portion of the heating roller as a reference, and after the power is turned on, In an image forming apparatus provided with a recording material size detecting means for detecting the size of the recording material before the surface temperature reaches a predetermined standby temperature, the temperature control means forms an image of the surface temperature after the power is turned on. when start request signal operations is raised to a temperature T _R which emits a ready signal indicating that is acceptable, receiving the start request signal from an external device prior to reaching the temperature T _R In the case of occurrence of a print, the optimum temperature T _R is obtained based on the size detected by the recording material size detecting means from among a plurality of temperature T _R data groups set in advance corresponding to the size of the recording material to be passed. It is achieved by selecting and setting the target temperature to be increased.

[0060]

According to the first aspect of the present invention, since the temperature sensitive element is attached to the inner surface of the fixing roller, the surface layer of the fixing roller is not damaged, and the disposition position is provided on the inner surface of the fixing roller. Since it is in the groove, the temperature is accurately detected without being affected by the direct radiation from the radiant heating element and without depending on the thickness of the fixing roller. Further, since it is attached to the inner surface of the fixing roller, it can be attached to a portion corresponding to the sheet passing portion of the fixing roller, and the temperature change due to sheet passing can be accurately detected.

Further, according to the second invention of the present application, the fixing roller has a paper-passing portion in which an offset prevention layer is provided on the surface of the heat-conducting core, and a non-sheet-passing portion in which the heat-conducting core is exposed. Since the temperature sensitive element or its holding member is provided in the non-sheet passing portion, the temperature sensing is performed without damaging the offset prevention layer of the fixing roller by the temperature sensitive element or its holding member. Further, since the toner, the paper powder and the like do not adhere to the temperature sensitive element, the thermal response does not deteriorate. Further, since the temperature sensitive element and the like are arranged in the non-sheet passing portion, the image stain due to the adhered toner does not occur.

Further, according to the third invention of the present application, a part of the heat-sensitive surface of the overheat prevention device is located on the surface of the heating roller due to the step shape of the heating roller or the overheat prevention device. Since they are in contact with each other and other parts are arranged so as to maintain a predetermined gap with respect to the paper passing area, the adhered toner and paper dust generated in the paper passing area do not accumulate on the heat sensitive surface, and the response Prevents excessive temperature rise without impairing property.

According to the fourth invention of the present application, the unfixed developer image is attracted to the other surface of the film by the charge on one surface of the film, and the film is fixed in a state of carrying the unfixed developer image. It is guided to the apparatus and comes into contact with a fixing roller or the like of the fixing apparatus. Therefore, the electric charge on the surface of the film is in a state of being able to move freely on the surface, but the surface resistance of the left and right non-image areas of at least one of the front and back surfaces of the film is higher than the surface resistance of other areas. Since the charge is set, the electric charge does not leak to the fixing roller side, and the force for holding the unfixed developer image does not decrease.
Therefore, no electrostatic offset is generated.

Further, according to the fifth invention of the present application, even if the fixing device causes an abnormal temperature rise for some reason and the resin bearing member begins to soften before the excessive temperature rise preventing means operates, the heating roller is heated. Since the movement restricting member for restricting the radial movement of the heating roller is provided, the heating roller is not displaced due to the pressure from the pressure roller, and the proper contact state of the excessive temperature rise prevention means is maintained. The means reliably operates to prevent ignition and the like at the time of abnormal temperature rise.

Further, according to the pressure roller of the sixth invention of the present application, since it has the release coating layer of the fluororesin, the releasability is maintained for a long period of time, and the occurrence of offset is prevented. Further, since the silicone rubber elastic layer is provided below the release coating layer, a sufficient nip width is secured and good fixing property is maintained even when the diameter of the roller is reduced. Moreover, since both ends of the roller are sealed with a non-polar resin, the unreacted low molecular weight component inside the elastic layer and the low molecular weight component formed by thermal decomposition evaporate from the both ends. Stay inside the roller without. Therefore, there is almost no change in the outer shape of the roller, and the occurrence of paper wrinkles, uneven gloss, image shift, etc. due to deterioration of durability is suppressed.

Further, according to the seventh invention of the present application, the unfixed developer image on the recording material is irradiated with a light beam, and the irradiation position of the light beam is controlled by the control means. Only the image position and its vicinity are adjusted. Therefore, when the position is irradiated with a light beam having a predetermined light intensity, only the unfixed developer image and the developer in the vicinity thereof are fixed. After that, the recording material is conveyed forward, and the developer collecting means is provided in front of this conveying direction.
The developer left unfixed on the recording material is collected by the developer collecting means.

Further, according to the eighth aspect of the present invention, when the power is turned on, the temperature control means raises the surface temperature of the heating roller to a predetermined temperature T _R. Then, when the image forming operation start request signal is received from the external device before the surface temperature reaches the temperature T _R , the recording material size detected by the recording material size detecting means after the power is turned on is detected. Based on the size, a temperature T _R most suitable for the size is selected from a plurality of T _R data groups as a target temperature. For example, when the recording material size is the B5 size, the temperature T _R lower than that of the A4 size is selected as the temperature T _R. After that, when the surface temperature reaches the newly selected temperature T _R , a ready signal is issued to an external device. Therefore, when the recording material size is small, the wait time from power-on to output of the ready signal is shortened.

[0068]

Embodiments 1 to 26 of the present invention will be described with reference to the drawings.

<Embodiment 1> First, Embodiment 1 of the present invention will be described with reference to FIGS. The apparatus of this embodiment is a fixing apparatus as an image heating fixing apparatus in an image forming apparatus (not shown), and FIG. 1 is a vertical cross-sectional view showing a main part of the fixing apparatus.
FIG. 2 is a cross-sectional view of the roller in the XY plane in the roller axis direction.

In FIG. 1, the fixing roller 1 has an offset prevention layer 1 on the surface of an aluminum core metal 101 having a thickness of 3 mm.
02 is a PFA tube coated. Further, the inner surface of the fixing roller 1 is subjected to known antireflection processing so as to easily absorb the radiation.

As the heater 2, a halogen heater is used,
It has an output of 600 W (when 115 V is input) and has the ability to sufficiently raise the temperature of the fixing roller 1. The pressure roller 3 is a metal core 301 provided with a silicone rubber layer 302 and is ASK.
The hardness by ER-C is 40 degrees or less. In this embodiment, the diameter of the fixing roller 1 and the pressure roller 3 was 30 mm, and the pressure was adjusted so that the fixing nip was 4 mm or more.

The groove D shown in FIG. 2 is machined to a depth of 22 mm from the inner surface of the fixing roller at the axial position of the width-end portion of the minimum size paper, and the surface of the groove D is subjected to polishing treatment so as to be slippery. It has been secured. The fixing roller 1 is provided with a drive gear at the end opposite to the side where the groove D is provided, thereby driving the fixing roller 1.
The groove D portion of the fixing roller 1 whose strength is lowered is protected.

The temperature sensitive element 6 is enclosed in glass beads having a diameter of 1 mm, is held by a holding member 601 made of alumina, and is in contact with the bottom of the groove D.

In the present embodiment, the temperature-sensitive element 6 enclosed in glass beads is used, but it is also possible to use a simpler Kapton tape for protection or a thermocouple element. Further, since the temperature sensitive element 6 is brought into contact with the inside of the fixing roller, the installation position in the axial direction can be freely set, and even if it is set at the sheet passing position, for example, in the center, it has no influence on the image and the temperature contributing to the fixing property. Can be directly detected. Further, even when a plurality of temperature sensitive elements are installed at different positions to monitor the temperature of the fixing roller 1, it is possible to maintain a high-quality fixed image without damaging the surface of the fixing roller 1. This is an effective feature for preventing the temperature rise in the non-sheet passing portion in images in which it is necessary to pass the transfer sheets of various sizes.

Unlike the case where the temperature sensitive element 6 of this embodiment is in contact with the surface of the fixing roller 1, it is not necessary to consider the releasability of the surface of the fixing roller, so that the protective material and the like are simple,
The thermal resistance and the thermal capacity of the temperature sensitive element 6 become extremely small, resulting in a structure having excellent thermal responsiveness. The bottom of the groove D reflects the temperature of the surface of the fixing roller 1 which directly contributes to the fixing property,
With this configuration, it is possible to detect this temperature and adjust the temperature, and there is no overshoot and sufficient fixing property can be secured.

FIG. 3 shows the fixing roller 19 in this embodiment.
Although the temperature is controlled at 0 ° C (solid line), there is almost no difference compared with the temperature controlled by contacting the surface of the conventional fixing roller (dotted line), indicating that the temperature is controlled accurately. . Further, since the thermal resistance and the thermal capacity of the temperature sensitive element 6 are small, there is almost no overshoot even when the temperature sensitive element 6 is started up from room temperature.

In this embodiment, since the temperature sensitive element 6 is brought into contact with the inner surface of the fixing roller 1, there is no fear of impairing the sheet passing clearance, and it is possible to make contact with the vicinity of the fixing nip. Therefore, it is possible to detect a temperature that is more essential in securing the fixability.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIG. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The present embodiment is a fixing device as an image heating and fixing device in an image forming device (not shown), and FIG. 4 is a longitudinal sectional view showing a main part of the fixing device.

In FIG. 4, the fixing roller 1 has an offset prevention layer 1 on the surface of an aluminum core metal 101 having a thickness of 3 mm.
No. 02 is a PTFE resin coated with 30 μm. Further, the inner surface of the fixing roller 1 is subjected to known antireflection processing so as to easily absorb the radiation.

As the heater 2, a halogen heater is used,
It has an output of 600 W (when 115 V is input) and has the ability to sufficiently raise the temperature of the fixing roller 1. The heater 2 is arranged in the nip when viewed from the center of the fixing roller core metal 101 so as to effectively utilize the radiant energy.

The pressure roller 3 has a core metal 301 provided with a silicone rubber layer 302 and has a hardness of 4 in ASKER-C.
It is 0 degrees or less.

In this embodiment, the diameter of the fixing roller 1 and the pressure roller 3 was 30 mm, and the pressure was adjusted so that the fixing nip was 4 mm or more.

Also in this embodiment, the groove D is provided, and the groove portion D is 2 m deep from the inner surface of the fixing roller 1 in the sheet passing area.
The surface of the groove D is polished to secure slipperiness.

Reference numeral 12 shown in FIG. 4 is a reflection plate made of specular stainless steel installed in the fixing roller 1. The inner surface of the fixing roller 1 spreads radiation from the heater 2 from the most downstream side of the nip to the upstream side of rotation of the fixing roller 1. At an azimuth angle of about 80 °. As a result, 50 to 60% or more of the radiant energy of the heater 2 (40% or less when the heater 2 is at the center of the fixing roller 1 and there is no reflection plate) is set to the fixing roller 1.
Can be used to raise the temperature. It is considered that this is an effect that the radiation from the fixing roller 1 can be reduced by reducing the radiation directed to a direction other than the nip direction.

On the other hand, the reflecting plate 12 also has a function of blocking radiation from the heater 2 over about 280 ° of the inner surface of the fixing roller 1 spreading from the most downstream side of the nip to the downstream side of rotation of the fixing roller 1. The present embodiment is characterized in that this radiation-shielded area is selected as the installation location of the temperature sensitive element 6. In this embodiment, the most suitable position is the location immediately after the fixing nip (groove D portion). I chose. This has a feature that the temperature of the fixing nip can be accurately measured, and in addition, the heating of the temperature sensitive element 6 due to the direct radiation from the heater 2 can be suppressed. The bottom of the groove D indicates the temperature near the surface of the fixing roller that contributes to the fixing property as described above, and by detecting this temperature, proper temperature control can be performed.

<Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 6 is a cross-sectional view showing the main part of the fixing device of the present embodiment. The same parts as those of the above embodiment are designated by the same reference numerals and the description thereof is omitted.

In FIG. 6, the fixing roller 1 is formed by coating a surface of a steel cored bar 101 having a thickness of 2 mm with a PFA resin as an offset prevention layer 102 by 30 μm. Further, the inner surface of the fixing roller 1 is antireflection processed so as to easily absorb the radiation.

A halogen heater is used as the heater 2, has an output of 600 W (when 115 V is input), and has the ability to sufficiently raise the temperature of the fixing roller 1.

The pressure roller 3 has a core metal 301 provided with a silicone rubber layer 302 and has a hardness of 4 in ASKER-C.
It is 0 degrees or less.

The fixing roller 1 and the pressure roller 3 had a diameter of 30 mm, and the pressure was adjusted so that the fixing nip was 4 mm or more.

In this embodiment, the groove D is processed by inclining the inner surface of the fixing roller in the sheet passing area as shown in FIG. As a result, direct radiation from the heater 2 is blocked at the bottom of the groove D, and heating of the temperature sensitive element 6 itself can be prevented. Further, by inserting the temperature sensitive element 6 along the opening direction of the groove D,
It is possible to reduce the bending amount of the electrical connection to the temperature sensitive element 6 and to make it easy to protect.

The temperature sensitive element 6 is held by the holding member 601 and is in contact with the bottom of the groove D. Unlike the case where the temperature-sensitive element 6 is in contact with the surface of the fixing roller 1, it is not necessary to consider the releasability of the surface of the fixing roller, so that the protective material and the like are simple and the thermal resistance and heat capacity of the temperature-sensitive element 6 are reduced. Becomes extremely small, resulting in a structure having excellent thermal response. The bottom of the groove D reflects the temperature of the surface of the fixing roller 1 that directly contributes to the fixing property. With this configuration, it is possible to detect this temperature and adjust the temperature, so there is no overshoot. It is possible to secure a good fixing property.

<Fourth Embodiment> Next, a fourth embodiment of the present invention will be described with reference to FIG. The same parts as those in the above embodiment are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 6, the fixing roller 1 has a heating layer 103 formed on the surface of an alumina core metal 101 having a thickness of 2 mm.
Further, the offset prevention layer 102 is coated with PFA resin.

The heating layer 102 is made of a carbon-dispersed conductive resin and has an output of 500 W (at 115 V input).

The pressure roller 3 has a core metal 301 and a silicone rubber layer 302 provided thereon, and has a hardness of 4 in ASKER-C.
It is 0 degrees or less.

In this embodiment, the fixing roller 1 and the pressure roller 3
The diameter of and was 25 mm, and the pressure was adjusted so that the fixing nip was 3 mm or more.

The groove D is processed to a depth of 1 mm from the inner surface of the fixing roller.

The temperature sensitive element 6 is a holding member 6 made of aluminum.
It is held by 01 and is in contact with the bottom of the groove D.

This embodiment is applied to a fixing device using a fixing roller having the surface heating element of the present invention. Generally, in this method, when the temperature sensitive element 6 is brought into contact with the surface of the fixing roller 1. However, not only the releasability of the fixing roller 1 is deteriorated, but also the surface heating layer may be damaged. Therefore, it is preferable that the fixing roller is hollow and the temperature sensitive element is in contact with the inner surface thereof. Moreover, since the heat capacity can be reduced by making the fixing roller have a hollow structure, there is also an advantage that the rise time can be shortened.

However, if the temperature sensitive element 6 is simply brought into contact with the inner surface of the fixing roller 1 as in the conventional example, there is a large difference between the surface temperature and the inner surface temperature, and therefore the temperature is adjusted by this temperature sensitive element. It was difficult. A method of making the core metal of the fixing roller 1 thin to reduce the temperature gradient is also conceivable, but if it is made too thin, the flow of the heat flow in the axial direction deteriorates and a local high temperature portion is generated, and in some cases, the fixing roller is damaged. Was sometimes reached.

This embodiment shows a preferred example in which the present invention solves such a problem.

<Fifth Embodiment> Next, a fifth embodiment of the present invention will be described with reference to FIGS. The present embodiment is a fixing device as an image heating fixing device in an image forming device (not shown). FIG. 8 is a longitudinal sectional view showing a main part of the fixing device, and FIG. 9 is a sectional view in the roller axis direction in the XY plane. In the figure, the same parts as those of the above-described conventional example are denoted by the same reference numerals.

In FIG. 8, the fixing roller 1 has an offset prevention layer 1 on the surface of an aluminum core metal 101 having a thickness of 3 mm.
As No. 02, a PFA tube having a thickness of 30 μm is covered.

As the heater 2, a halogen heater is used,
It has an output of 600 W (when 115 V is input) and has the ability to raise the temperature of the fixing roller 1 at a rate of 2 ° C./sec.

The pressure roller 3 comprises a core metal 301 and a silicone rubber layer 302 provided on the core metal 301.

In this embodiment, the fixing roller 1 and the pressure roller 3
The diameter of and was 30 mm, and the pressure was adjusted so that the fixing nip was 4 mm or more.

E shown in FIG. 9 is an abutting portion whose surface has been polished to ensure slidability, which is located outside the paper passing width of the maximum size paper, and the PFA tube 102 does not cover E.

As the temperature sensitive element 6, NT for controlling temperature is used.
The C element 601 and the abnormal temperature rise prevention element 602 (element for cutting off power supply at high temperature) are brought into pressure contact with the contact portion E.
Since the pressure contact of the temperature sensitive element 6 is performed in the non-sheet passing portion, stains such as toner do not adhere and it is possible to prevent image stains.

Unlike the case where the temperature sensitive element 6 abuts on the surface of the fixing roller sheet passing portion, it is not necessary to consider the releasability of the surface of the fixing roller. Therefore, pressure contact by pinching pressure is possible and thermal response is excellent. It will be a different configuration. Further, regarding the fixing roller 1 as well, since the contact portion E is not covered with the PFA tube 102, the thermal resistance becomes small and the temperature of the fixing roller can be sensed quickly. As a result, overshoot is low and sufficient fixing property can be secured.

Also, regarding the abnormal temperature rise prevention element 602, since the thermal response is high, the power supply cutoff temperature is optimized, and a highly safe device configuration is provided. Rated breaking temperature 20
When heating was continued from room temperature with all heaters using an element of 0 ° C., the actual cut-off temperature was 380 ° C. when pressed with a contact pressure of 100 g from above the PFA tube. The cutoff temperature at the time of press contact with a contact pressure of 500 g was 310 ° C., indicating that the temperature followability was improved.

<Sixth Embodiment> Next, a sixth embodiment of the present invention will be described with reference to FIGS. In addition, Example 5
The same parts as in FIG.

In this embodiment, a step is provided at the end of the abutting portion E, and a concave portion is provided on the surface of the fixing roller over the abutting width to provide the temperature sensitive element 6.
Used for axial positioning of. The offset prevention layer 102 on the surface of the fixing roller is covered with a PFA tube or coating so as to cover the stepped portion of the contact portion E, which is also effective for preventing separation from the coated end. As a simpler configuration, as shown in FIG. 12, it is also possible to position by making a step on only one side.

As a further effect of this embodiment, since the thickness of the fixing roller is thin at the contact portion E of the temperature sensitive element 6,
This is a point that the halogen heater contained therein reacts sensitively to the lighting, thereby enabling more accurate temperature control. Also, the contact portion E
Is provided at the end portion of the roller, and since the core metal becomes thin at this portion, the heat flow to the axial non-sheet passing portion in the core metal is obstructed here, and the heat energy applied to the fixing roller 1 is fixed to the image. There is also an advantage that it can be effectively used for.

As in the fifth embodiment, the contact portion E is disposed outside the paper passing area to enable the pressure-sensitive contact of the temperature sensitive element 6, and since the offset prevention layer 102 is not coated, the temperature sensitive element is not provided. The thermal conductivity with respect to can be improved. In particular, in the present embodiment, since the step is provided, it is possible to prevent the escape in the axial direction when the temperature sensitive element 6 is strongly pressed, and for example, when the NTC element embedded in the sponge surface is used as a temperature control sensor. However, it is possible to prevent the sponge from being deformed in the fixing roller axial direction and obtain an appropriate contact pressure.

<Seventh Embodiment> Next, a seventh embodiment of the present invention will be described with reference to FIGS. FIG. 13 is a sectional view showing the main part of the fixing device of this embodiment, and FIG. 14 is a sectional view in the roller axis direction on the XY plane. Is omitted.

In this embodiment, the end portion of the fixing roller 1 has a diaphragm shape, and the starting position of the diaphragm portion on the side where the temperature sensitive element 6 is installed is set to be equal to the end of the paper passing area of the maximum paper size, thus preventing the offset. The layer 102 is formed by applying a PFA tube having a thickness of 50 μm to a barrel having a diameter of 60 mm. In the present embodiment, the temperature-sensitive element 6 is installed with its temperature-sensitive surface facing the end face of the squeezing portion of the fixing roller 1. Particularly, the NTC element 601 for temperature control is arranged on the fixing nip side to reduce the heat capacity of paper. It is devised to react sensitively to the temperature change of the fixing roller 1 due to the temperature. In the present embodiment, the paper edge is positioned on the same plane as the end surface of the squeeze portion, and the temperature of the squeeze portion end surface reflects the temperature of the fixing roller of the paper passing portion. The temperature sensitive element 6 such as the prevention device 602 can be installed. The end face of the diaphragm portion is not covered with the offset prevention layer 102 and does not come into contact with the image surface, so that strong pressure contact is possible and the temperature responsiveness of the temperature sensitive element 6 can be enhanced. Further, since the contact portion E is a flat surface, the temperature sensitive element 6 and the contact portion E can be reliably brought into contact with each other over a large area, so that a stable temperature measurement state can be maintained and the temperature responsiveness can be further improved. You can

Further, a part of the toner image does not adhere to the temperature-sensitive element 6, the response performance of the temperature-sensitive element 6 is maintained for a long period of time, and an image due to the toner mass slipping from the temperature-sensitive element 6 is obtained. It can prevent dirt.

This embodiment is particularly suitable for a large-diameter fixing roller, and is particularly effective in the case where a diaphragm portion is formed for a fixing roller having a diameter exceeding 50 mm.

<Embodiment 8> Next, an embodiment 8 of the present invention will be described with reference to FIGS. FIG. 15 is a longitudinal cross-sectional view of a fixing device that best shows the characteristics of the eighth embodiment of the present invention. In FIG. 15, reference numeral 201 denotes a fixing roller, and 201A has a core metal, for example, a PFA resin layer 201B as a releasing layer with a primer layer interposed therebetween. , 2020 are pressure rollers, and a silicone rubber layer 202B is provided on the core metal 202A and a PFA tube layer is provided on the surface layer. Note that L _MAX shown in the figure is the maximum size paper width for this machine. A halogen heater 203 is disposed in the fixing roller 201 to reduce heating, is a non-paper passing area on the fixing roller, and has a predetermined temperature by a temperature adjusting element 205 installed at a position closest to the paper passing area. The control is made to keep it. In the figure, the fixing roller 201
It is shown that it is in contact with the surface on the opposite side of. The fixing roller 201 and the pressure roller 202 are pressed to a predetermined pressure by a pressure spring (not shown) provided on the pressure roller bearing side, and a recording material having an unfixed toner image between the roller pair. Passes through. By the way, halogen heater 2
03 and the AC power source 206 are connected to the thermoswitch 204 as shown in the figure, so that the power supply from the AC power source 206 is stopped at the same time when the thermoswitch is turned off when the temperature rises abnormally.

The characteristics of the eighth embodiment of the present invention are as follows.
A part of the heat sensitive surface of the thermoswitch is convex, and only the convex is in contact with the non-sheet passing area on the surface of the fixing roller. FIG. 16 is a sectional view showing the thermoswitch 204 shown in FIG. 15 in detail. In the figure, a cylindrical frame 20 made of phenolic resin or ceramic
Bimetal 204F and bimetal holding plate 20 in 4B
4E, a contact release pin 204D, and a contact 204C are incorporated, and a metal cap 204G made of aluminum or stainless steel is enclosed, and the metal cap surface is covered with a polyimide tape 204H. The contact point 204C is electrically connected to a contact point provided outside the frame 204B. The operating principle of this thermoswitch is that when the metal cap, which is the heat-sensitive surface, is heated,
When the bimetal 204F of the temperature sensing part is heated and exceeds the set temperature, the warp of the bimetal is reversed and the pin 204D
Is pushed up to release the contact of the contact point 204C.

Next, the effect of this embodiment will be described while comparing with the conventional example. FIG. 17 shows the effect of performance comparison for each state of the thermoswitch.
Regarding the form, a: Thermoswitch center paper edge (conventional type) b: Thermoswitch center paper edge (zero type in this embodiment) (three heights) c: Thermoswitch entire non-sheet passing area (conventional type) d: Thermo switch center paper edge (non-contact on the entire surface) (conventional type) We saw the above four types.

For each type, one is the surface temperature of the fixing roller at the edge of the paper when the thermoswitch operates when the fixing device is out of control, and the other is the level of dirt falling from the thermoswitch. The durability evaluation and the above two items were evaluated. The runaway test here is a test in which the heater is turned on until the thermoswitch operates without performing temperature control. The runaway test conducted this time was conducted under the following conditions. Room temperature during testing: 23 ° C Fixing roller: Core metal (aluminum) diameter 2.0 mm, thickness 2.0 mm Heater Wattage: 500 W Thermoswitch setting temperature: 200 ° C (bimetal setting) Thermoswitch surface: 25 μm polyimide tape attached Thermoswitch press : 30gf

From the results shown in FIG. 17, the type a has the best responsiveness, but since it is in contact with the paper passing area, as the durability is continued, the dirt drops and appears on the recording material. Will end up. On the other hand, in the c type and the d type, although the dirt does not drop, the response becomes extremely poor.
Compared with these conventional types, the present embodiment can obtain a level that is practically no problem by setting the gap amount (Δ) in the responsiveness to an appropriate level without causing dirt drop due to its structure. You can The level at which there is no problem in practical use here means that it is essential that no ignition occurs when the paper is sandwiched between the rollers during the runaway test under the above conditions. Generally, there is a high possibility that ignition will occur in this state when the surface temperature of the fixing roller at the thermoswitch position of this embodiment reaches 400 ° C. Here, in the present embodiment, the temperature reached by the roller surface is 400
The temperature becomes 0 ° C. when the gap amount (Δ) is 1.0 mm. Therefore, the appropriate gap amount is 1.0 mm or less.

<Ninth Embodiment> Next, a ninth embodiment of the present invention will be described with reference to FIGS. The same parts as those of the eighth embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 18 is a diagram showing a thermoswitch used in Example 9 of the present invention. This thermoswitch will be used in the same configuration as described in the eighth embodiment. The present embodiment is characterized in that a resin material having a predetermined thickness is adhered to a part of the thermosensitive surface of the thermoswitch, and the resin material portion comes into contact with the non-sheet passing position on the surface of the fixing roller. In FIG. 18, reference numeral 207 is a thermoswitch, which is of a commonly used type. Further, 208 is a resin material having a predetermined thickness and is directly adhered to the metal cap surface of the thermoswitch 207.

The performance required for the material used for the resin material 208 is heat resistance, low friction coefficient, wear resistance, releasability, etc., and usable materials include, for example, PTF.
Examples thereof include fluororesins such as E and PFA, PPS, and polyimide. Then, by adding an appropriate amount of carbon or an inorganic material filler to these resins, the thermal conductivity of the resin material can be improved and the response of the thermoswitch can be made faster. Further, as the thickness of the resin material, a thickness at which the surface temperature reached by the fixing roller during the runaway test is 400 ° C. or less is used.

By the way, in this embodiment, in order to further improve the responsiveness of the thermoswitch, the surface of the thermosensitive heat-sensitive surface to which the resin material is not adhered, that is, the surface not in contact with the fixing roller is blackened. Is effective.
The method of blackening can be effective either by plating the metal cap to black beforehand (alumite treatment with a dye) or by black coating (Tetuzole (trademark) or the like).

FIG. 19 shows the result of a runaway test carried out on an actual machine for the above embodiment. The conditions in this experiment are the same as the conditions performed in Example 8. FIG. 19 shows three types of thermoswitches, e, f, and g. In this embodiment, unlike the eighth embodiment, Capto C on the surface of the thermoswitch is not used. e: PFA resin layer is adhered to the surface of the thermoswitch metal cap. Three types with thicknesses of 0.3, 0.8, and 1.3 (mm) f: PFA resin with 5% carbon added is used. Thickness 0.8 mm g: Uses a resin material thickness of 0.8. The surface of the thermoswitch is painted black with Tetuzole.

Comparing the result of FIG. 19 with the result of FIG. 17, it is possible to obtain a response of e which is substantially equal to or higher than that of the form b in which the thermoswitch cap is convex. This is because the surface temperature of the fixing roller is 300
It is considered that when the temperature exceeds ℃, the resin material suddenly softens and the thermoswitch approaches the roller surface. A suitable resin material thickness for this system e is 1.0 mm or less.

Next, regarding f and g, the thermal conductivity of the resin material is raised to about 10 K, and the cap is painted black to 5
It can be seen that K can be improved.

As described above, according to the present embodiment, a resin material having a predetermined thickness is adhered to the thermosensitive surface of the thermoswitch, and the resin material portion is brought into contact with the non-sheet passing portion on the surface of the fixing roller. The parts are not damaged, the toner does not fall from the thermoswitch part, and sufficient responsiveness can be obtained even during runaway.

<Embodiment 10> Next, Embodiment 10 of the present invention.
Will be described with reference to FIG. 20 is a longitudinal sectional view best showing the features of the tenth embodiment of the present invention. In the figure, the same numbers are given to the same configurations as those in FIG. A feature of this embodiment is that a step is provided on the fixing roller side and a part of the thermoswitch is brought into contact with the step.

In the figure, the fixing roller 201 'has a predetermined amount of step in the vicinity of the thermoswitch part, and a part of the heat-sensitive surface of the thermoswitch 208 of a commonly used type is abutted thereon. There is. At this time, polyimide tape (25 μm thick) is formed on the thermosensitive surface of the thermoswitch.
Is pasted.

The responsiveness of the thermoswitch during runaway in the present embodiment can obtain substantially the same performance if the contact area with the roller and the step amount of the non-contact portion are the same. Therefore, in the present embodiment, the appropriate step amount is 1 mm or less.

The use of this embodiment has the following advantages over the eighth and ninth embodiments. First, the cap shape of the thermoswitch is a general commercial product, which reduces costs. Secondly, if the fixing roller has no step, dirt such as toner and paper dust will move in the roller longitudinal direction even in the non-sheet passing area, and some adhesion will occur on the thermoswitch, which will result in long-term durability. However, in this embodiment, since there is a step on the fixing roller, the movement of dirt in the longitudinal direction is blocked by the step, so that dirt can adhere to the thermoswitch section. The point is that the sex can be made very low.

<Embodiment 11> Next, an embodiment 11 of the present invention.
Will be described with reference to FIGS. 23 and 24. 23 is a sectional view of Embodiment 11 of the present invention, and FIG. 24 is a plan view of Embodiment 11. The film of the present invention comprises a plastic film 401 having a heat resistant temperature of 100 ° or more and a coating layer 402 comprising a resin soluble in an organic solvent, an inorganic or plastic matting agent insoluble in the organic solvent, and a surfactant on the surface of the film. The coating is applied to the entire surface, and to the back surface of the film except the left and right non-image areas.

The surface resistivity of the coating layer 402 is generally 1 × 10 ¹¹ to 1 × 10 ¹² Ω, and the surface resistance of the plastic film is approximately 1 × 10 ¹⁶ Ω.

As an example, an ester resin, a polyacrylonitrile powder as a matting agent, and sodium dioctyl phosphate as a surfactant, methylene chloride,
In the case of an electrophotographic film in which a coating solution dissolved in a mixed solvent of phenol and tetrachloroethane is applied to both sides of a polyester film with a thickness of 100 μm, the surface resistivity of the coating part is 4 × 10 ¹² Ω, the surface of the polyester film. The specific resistance is 1.1 × 10 ¹⁵ Ω. Using this film, the relationship between the non-application area width X on the back surface of the film and the offset was measured. The results are shown in Table 1.

[0141]

[Table 1] ○… Good △… Slightly bad △… Bad

As described above, when the width of the non-application area is 3.0 mm or more from the left and right end portions of the film, offset can be prevented and a good image can be obtained.

As described above, by cutting the coating layers on the left and right ends of the back surface of the film, it is possible to cut off the charge leakage path of the fixing roller from the back surface of the film and suppress the occurrence of electrostatic offset. Further, since the portion where the coating layer is cut is the non-image area, the toner is not scattered during the transfer in the image area, and a good image can be obtained.

<Embodiment 12> Next, Embodiment 12 of the present invention.
Will be described with reference to FIG. The same parts as those of the eleventh embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 25 is a sectional view of the twelfth embodiment of the present invention. The film of this example has a resin soluble in an organic solvent on the surface of the plastic film 401 having a heat resistant temperature of 100 ° C. or higher.
A coating layer 402 composed of an inorganic or plastic matting agent insoluble in the organic solvent and a surfactant is applied to the front and back surfaces of the film except the non-image areas on the left and right ends.

In the eleventh embodiment described above, the non-coated area of the coating layer is provided only on the back surface of the film. However, with this structure, if the front and back surfaces of the film are mistaken, the offset prevention effect is completely lost. In addition, since the plastic film and the coating layer of the electrophotographic film itself are colorless and transparent, the front and back surfaces of the film cannot be distinguished at a glance.

According to the present embodiment, by providing the non-coated area of the coating layer on both the front and back surfaces of the film, the effect of preventing the offset is not changed even if either of the front and back surfaces of the film is used. it can.

As an example, an electrophotographic film prepared by using the same plastic film and coating solution as used in Example 11 and having non-coated areas in the non-image areas on both front and back surfaces of the film was used. The same measurement was performed. The results are shown in Table 2.

[0149]

[Table 2] ○… Good △… Slightly bad △… Bad

As described above, by providing the non-coated area of the coating layer not only on one side but also on both sides of the film, the offset can be prevented by using either the front or back surface of the film, and the non-coated area should be 2.0 mm or more. For example, it is possible to obtain an electrophotographic film which can sufficiently obtain the effect. Further, since the portion where the coating layer is cut is the non-image area, toner does not scatter during transfer in the image area.

<Embodiment 13> Next, Embodiment 13 of the present invention.
Will be described with reference to FIG. FIG. 26 shows a sectional view of Embodiment 12 of the present invention. The film of this example has a heat resistant temperature of 1
A coating layer 402 composed of a resin soluble in an organic solvent, an inorganic or plastic matting agent insoluble in the organic solvent, and a surfactant is provided on the front and back surfaces of the plastic film 401 at a temperature of 00 ° C. or higher, and the left and right edges of the film front and back are not imaged. The coating is applied to the entire area excluding the area, and the high resistance coating layer 403 made of a resin soluble in an organic solvent and a matting agent is applied to the non-coating portion of the coating layer on the film.

In Example 12, the plastic film was exposed as it was on the coating layer non-painted portions on the left and right ends of the electrophotographic film, but such a film was copied, for example, with a one-sided reference transport system. If the paper is passed through a machine or printer, the plastic film 401
Since the coefficient of friction of the surface is small, problems such as poor paper feeding and poor conveyance may occur.

However, by providing the high resistance coating layer 403 in which the surfactant is removed to increase the resistance on the left and right ends of the film as in the present embodiment, offset does not occur and feeding failure or skew feeding occurs. It is possible to obtain an electrophotographic film that does not cause the above problem.

As an example, the same coating solution as that used in Example 11 was applied to both sides of the 100 μm-thick polyester film excluding the non-image areas on the left and right sides, and the non-image area was coated with the above-mentioned coating solution to form an interface. The relationship between the high resistance coating layer width Y and the offset was measured for the electrophotographic film coated with the coating solution (ester resin, polyacrylonitrile powder organic solvent solution) from which the activator sodium dioctyl phosphate had been removed. The surface resistivity of the coating layer 402 of this electrophotographic film is 4 × 10.
¹² Ω, surface resistivity of high resistance coating layer 403 is 2
It is × 10 ¹⁶ Ω. The results are shown in Table 3.

[0155]

[Table 3] ○… good △… somewhat bad ×… bad

As shown in the measurement results, the electrophotographic film having the constitution of this example has the same effect as that of Example 12 in preventing offset. Further, since the high resistance coating layer 403 is in the non-image area, toner does not scatter during transfer in the image area. Furthermore, since the matting agent that lowers the friction coefficient of the surface is applied to the entire surface of the film, it does not cause problems such as poor paper feeding or conveyance even if it passes through a single-sided copying machine or printer. Images can be obtained.

<Embodiment 14> Next, Embodiment 14 of the present invention.
Will be described with reference to FIGS. 31 to 34. 31 is a sectional view of Embodiment 14 of the present invention, and FIG. 32 is a plan view of this Embodiment. In FIG. 31, reference numeral 504 is a fixing roller, which is a cored bar of aluminum or iron coated with a heat-resistant release layer such as PFA or PTFE. A heater (not shown) is contained in the core bar to heat the core bar. Both ends of the fixing roller 504 are rotatably held by fixing roller bearings 503 made of heat resistant resin.
A pressure roller 506 is formed by forming a heat resistant elastic layer around a core metal such as stainless steel. The pressure roller 506 is held by a bearing 510, and is pressed against the fixing roller 504 by a pressure spring 507. The surface temperature of the fixing roller 504 is controlled by a temperature detecting element (not shown) and a control circuit (not shown).
Is maintained at a predetermined temperature. Positional deviation preventing members are extended from the fixing device side plate 9 and provided on both ends of the fixing roller 504. The position of the overheat prevention element is a leaf spring (not shown)
Is held by the fixing roller 504.

A fixing roller having a length of 240 mm and an outer shape 2
A thermoswitch is shown in FIG. 34 using an aluminum cored bar having a thickness of 5 mm and a thickness of 3.0 mm coated with PFA of 25 μm.
Table 4 summarizes the thermoswitch operating temperatures when the fixing device is installed at positions (1) to (5) and the fixing device is sufficiently acclimatized to room temperature, and the power is turned on and the fixing device is forced to run out of control.

[0159]

[Table 4]

In the case of A, since the pressure from the pressure roller is not applied, there is no displacement of the fixing roller even after the bearing is softened.
At any position, the thermoswitch operated at around 350 ° C, and neither smoke nor ignition occurred. In the cases of C and D, the thermoswitch operated in the vicinity of 350 to 360 ° C. and neither smoking nor ignition occurred. In the case of E, the operating temperature of the thermoswitch was around 365 to 380 ° C, and a small amount of smoke was generated. Further, in the case of B, the operating temperature of the thermoswitch installed at the position of ~ reached up to around 400 ° C, and considerable smoke was generated. According to the experiment, if the gap L between the misregistration prevention member and the fixing roller is set to 1.0 mm or less, no smoke or ignition will occur regardless of the installation position of the thermoswitch, so L <1.0 mm is set.

By thus providing the fixing roller position deviation preventing portion, even if the fixing roller bearing is softened, the fixing roller is held by the fixing roller 1 deviation preventing member as shown in FIG. The proper contact state is maintained, and the operating temperature of the excessive temperature rise prevention element falls within 350 + 10 ° C.

<Embodiment 15> Next, Embodiment 15 of the present invention.
Will be described with reference to FIGS. 35 and 36. The same parts as those of the fourteenth embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the fourteenth embodiment, the fixing roller bearing is made of resin only, but in this embodiment, the bearing reinforcing sheet metal 511 is used.
It uses a bearing made by outsert molding a resin bearing on top. At this time, the difference R ₁ -R ₂ between the inner diameter R ₁ of the reinforcing sheet metal and the inner diameter R ₂ of the fixing roller bearing is set to 1.0 mm or less. With such a configuration, it is possible to prevent the position of the fixing roller from being displaced without the fixing roller 1 displacement preventing member provided in the fourteenth embodiment, and it is possible to prevent the bearing from being deformed due to long-term use.

<Embodiment 16> Next, Embodiment 16 of the present invention.
Will be described with reference to FIG. 37 shows a perspective view of Embodiment 16 of the present invention. Reference numeral 512 shown in the figure is a pressure roller stopper, and is provided with a member formed by processing a sheet metal member into a U-shape at both ends of the pressure roller core metal 513. The gap between this stopper and the core of the pressure roller is 1.0 m
m or less. In each of the fourteenth and fifteenth embodiments, the positional deviation is prevented by pressing the fixing roller itself, but in the present embodiment, the positional deviation of the fixing roller is restricted by regulating the displacement amount of the pressure roller in the fixing roller direction. Is to prevent. Displacement of the fixing roller when the fixing roller bearing is softened due to abnormal temperature rise is caused by the pressure from the pressure roller, but by providing the pressure roller stopper 512, it is possible to easily release the pressure immediately after the softening of the bearing starts. The fixing roller can be prevented from being displaced.

In each of the fourteenth and fifteenth embodiments, since a member for holding the fixing roller position is provided near the heat source, a material that does not soften at the fixing roller temperature during normal use must be used. In the example, since the position where the stopper is provided is relatively far from the heat source, the material can be freely selected. In addition, the drive gear around the fixing roller,
Since there are many restrictions on the installation position of the position shift prevention member because the temperature detection element, the thermoswitch, etc. are installed, it may be impossible to carry out Examples 14 and 15, but even in this case, according to this Example Positional deviation of the fixing roller can be prevented.

<Embodiment 17> Next, Embodiment 17 of the present invention.
Will be described with reference to FIG. 40 is a sectional view of Embodiment 17 of the present invention. In FIG. 40, 701 is a pressure roller, and the pressure roller 701 is configured as follows.
A core metal 702 is made of iron, stainless steel, aluminum, or the like. A silicone rubber elastic layer 70 is provided on the core metal 702.
3 is provided. As the silicone rubber elastic layer 703, one having a low hardness of 15 ° or less according to JIS-A is used. A releasable coating layer 704 made of fluororesin is formed on the surface.
Is provided. The release coating layer 704 is made of PTFE, P
Fluorine resin such as FA and FEP, film thickness is 10 ~ 80μ
m coating film or tube.

If necessary, an epoxy-based or polyimide-based primer is provided between the core metal and the elastic layer and between the elastic layer and the releasable coating layer to improve the adhesiveness.

In addition, the above silicone rubber hardness is JIS-
The reason why the angle A is 15 ° or less is to secure the nip width. That is, in recent years, there is a demand for downsizing of the fixing device in order to downsize the main body, and as a result, both the fixing roller and the pressure roller are formed to have a diameter of about 30 mm or less. Is difficult to secure. Further, in order to reduce the motor size and power consumption, there is a demand to reduce the driving torque of the fixing device, and there is a tendency to reduce the pressure applied between the fixing roller and the pressure roller, which is another factor that makes it impossible to obtain the nip width. . Therefore, in the present invention, the hardness of the roller is reduced to secure the nip width, and the hardness of the silicone rubber elastic layer 703 is set to a low hardness of 15 ° or less according to JIS-A, whereby the hardness of the entire pressure roller is 55. °
Below.

To reduce the hardness of silicone rubber,
Silicone rubber oil is added, the crosslinking reaction is not completely finished, or siloxane having a small molecular weight is used as a raw material. For this reason, when the fixing operation is performed and is repeatedly placed at a temperature of 100 ° C. to 200 ° C., silicone oil, unreacted components, and low molecular weight components decomposed by heat evaporate from both ends of the rubber layer and escape. Tend to try.

However, since both ends of the roller in the present invention are covered with the fluororesin coating layer 704,
Low molecular weight components cannot escape. Therefore, the outer diameter of the pressure roller does not change, and the initial shape can be maintained.

(Comparative Example) A roller A whose both ends were sealed and a roller B which was not sealed were actually compared by using silicone having a hardness of 13 ° (JIS-A).

The core metal has a diameter of 9 mm and the roller has an outer diameter of 20.
mm, the surface is a PFA tube with a thickness of 50 μm.

Roller A and roller B were incorporated into a fixing device as shown in FIG. 41 to carry out durability. Fixing roller 70
5 is a fluorine resin 70 on the surface of the aluminum core metal 706.
In this example, PTFE was used as the fluororesin. A halogen lamp heater 708 is provided at the center of the fixing roller 705, and the surface temperature is maintained at 190 ° C. by a temperature control circuit (not shown). Between the fixing roller 705 and the pressure roller 701,
A spring (not shown) exerts a pressure of 9 kg. The fixing roller 705 is driven by a motor (not shown) at 60 mm /
The toner image is fixed at a nip with the pressure roller by rotating at a surface speed of sec.

Before the endurance, the shape of the pressure roller is 1 for both A and B.
Shows a straight shape with an accuracy of 0 μm or less, and a fixing device incorporating each roller has a temperature of 35 ° C. and a humidity of 85%.
The fixing operation was performed in a severe environment of high temperature and high humidity, but no wrinkles occurred.

Table 5 shows the results of comparison between both rollers and durability test for 200,000 sheets.

[0176]

[Table 5]

Due to the durability, both ends of the roller B are 200 in front.
It can be seen that it is extremely thin compared to 10 μm in the central part such as μm and 220 μm in the back. As a result, the outer shape of the roller became a crown shape, and wrinkles occurred. However, since the roller A of the present invention showed almost no change in diameter and the outer shape maintained a straight shape, no wrinkles occurred.

<Embodiment 18> Next, Embodiment 18 of the present invention.
Will be described with reference to FIG. The same parts as those of the seventeenth embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 42 shows a pressure roller manufacturing apparatus of this embodiment. Reference numeral 702 denotes a core metal, which is obtained by plating nickel on the surface of iron and applying a polyimide-based primer in advance.
Reference numeral 704 denotes a releasable coating layer, which is a PFA tube having a thickness of 50 μm, and a polyimide-based primer is also applied inside. These are positioned and fixed by the cylinder 709, the lower lid 711, and the upper lid 713.

A core 71 is provided between the upper lid 713 and the core metal 702.
2. A core 710 is provided between the lower lid 711 and the core metal 702 so that the releasable coating layer 704 is squeezed and fixed.

The upper lid 713 and the core 712 are made of silicone LT.
It is removed until the liquid of V is injected, and is fixed after the injection. The apparatus after the injection is put into a heating furnace as it is and heated and vulcanized at a temperature of about 120 ° C. When the vulcanization reaction is complete, the equipment is disassembled and the furnace is removed.

The furnace is then secondarily vulcanized at a temperature of 200 ° C., and the protruding portions at both ends are molded to obtain a finished product.

As described above, since the pressure roller according to the present invention is easy to manufacture, it can be manufactured at a low cost.

Example 19 Next, Example 19 of the present invention.
Will be described with reference to FIG. FIG. 43 is a cross-sectional view of the pressure furnace of this example. In this embodiment, the end portion of the furnace is sealed with another non-polar resin 714 instead of extending the fluororesin layer 704. As the nonpolar resin, polyethylene resin, polypropylene resin, fluororesin or the like is used. Since the non-polar resin has a low air permeability, it is possible to prevent vapor in which silicone is decomposed from escaping from both ends of the furnace.

<Embodiment 20> Next, Embodiment 20 of the present invention.
Will be described with reference to FIG. FIG. 44 shows a fixing device using the pressure roller of this embodiment. The fixing roller 705 and the pressure roller 701 are grounded via a diode 715, respectively, and the elastic layer 703 of the pressure roller 701 is electrically conductive with a volume resistance of 10 ¹³ Ω · cm or less. Also,
The fixing roller is biased by a diode 715 so that electric charges having the same polarity as the toner are accumulated in the fixing roller and electric charges having the opposite polarity to the toner are accumulated in the pressure roller.

When the pressure roller is made conductive as in the apparatus of this embodiment and biased as shown in FIG. 45, the effect of the accumulated charges easily reaches the surface of the roller, and the offset is prevented when the negative toner is used. Has an effect on.

However, the hardness is inevitably increased because carbon or metal oxide is added in order to impart conductivity. However, in order to secure the fixability with the small-diameter roller, as described above, JIS-A is 15 °.
Since it is necessary to make the content below, a silicone oil component is added more than usual rubber, the crosslinking reaction is stopped in the middle, and a low molecular weight siloxane is used. as a result,
The heat resistance is inferior to that of ordinary rubber, and the outer shape may change.

However, when the pressure roller of the present invention as described above is used, the outer shape of the pressure roller hardly changes even when a conductive rubber having poor heat resistance is used, and therefore wrinkles do not occur for a long period of time. It is possible to obtain a pressure roller and a fixing device that prevent offset.

<Embodiment 21> Next, Embodiment 21 of the present invention.
Will be described with reference to FIGS. 45 and 46. In FIG. 45, 805 is image information that has been bit-mapped, 806 is a line memory that holds image recording information for one scan in the main scanning direction, and 807 is data in the line memory that corresponds to the scanning speed of the optical deflector. And an image density conversion unit 813 for converting the image density, and a sensor 813 for detecting the leading edge of the paper.
4 is a sensor for detecting the scanning start timing, 80
Reference numeral 8 is a timing adjustment unit for adjusting the timing of sending the recording image information based on the signals of the sensors 813 and 814, and 809 is an LD drive unit for intensity-modulating the output of the laser diode which is the light source based on the recording image information. Reference numeral 810 denotes a laser diode as a light source, 811 denotes an optical deflector for scanning a light beam emitted from the laser diode as a light source in a direction perpendicular to the traveling direction of the recording material, and 812 condenses the light beam on the recording material. A focusing lens, 802 a recording material, 801 a photosensitive drum, 803 a transfer roller, 8
Reference numeral 15 is a toner collecting portion for collecting unfixed toner. The electrostatic latent image formed on the photosensitive drum 801 is developed by a developing device (not shown) and transferred onto a recording material by a transfer roller 803.

Since the latent image is formed on the photosensitive drum, the bit-mapped image information used is held in the line memory for each scanning in the main scanning direction. In this embodiment, a case will be described in which the developed unfixed toner image of one pixel is scanned by the fixing light beam four times. Since one pixel is scanned by the fixing light beam four times, when a rotating polyhedron having the same number of faces as the rotating polyhedron used for exposure during latent image formation is used as an optical deflector for the fixing light beam, the rotating polyhedron for exposure is used. It is necessary to rotate the rotating polyhedron for the fixing light beam at a rotation speed that is four times as high as the rotation speed. Therefore, the scanning speed of the fixing light beam in the main scanning direction is four times the scanning speed of the exposure light beam (not shown) in the main scanning direction. Therefore, when the data is read from the line memory 806 at the same clock as the image recording clock used to modulate the exposure beam and the fixing light beam is modulated, the fixing light beam can be emitted corresponding to the unfixed toner image. Can not.

Therefore, it is necessary to convert the pixel density. The pixel density conversion unit 807 does this. FIG. 46 shows an example of the pixel density conversion unit 807 in this embodiment.

Image recording information is stored in the line memory while being sequentially shifted in synchronization with the same image recording clock as during exposure. Then, the dot information of the main scanning length for one line in the sub scanning direction is stored. Next, data is read from this line memory in synchronization with a fixing image recording clock having a clock frequency which is four times as high as the clock frequency of the image recording clock at the time of exposure, and is input to the shift register 817 through the selector 816. . This shift register is
It consists of bits for the number of dots in the main scanning length for one line in the sub-scanning direction, and the output is output to the timing adjustment unit for driving the next laser diode, and also passes through the selector to the shift register entrance. I'm supposed to come back. Also, the selector counts the signals from the sensor,
The data of the line memory is input to the shift register only once every four times, and the other operations operate so that the head output of the shift register is input again from the entrance of the shift register.
Therefore, the main scanning length dot information for one line in the sub-scanning direction is output four times in synchronization with the fixing image recording clock, and the fixing light beam is positioned at the position of the unfixed toner image on the recording material. Correspondingly, it will be scanned four times.

Next, the fixing image recording signal enters the timing adjusting section. Here, the sensor is a sensor for detecting the position of the front end of the paper, and in the present embodiment, the front end of the paper is detected by utilizing the fact that the output of the sensor changes when the fixing light beam is blocked by recording. There is. The sensor detects the scanning start reference position of the fixing light beam in the main scanning direction.
The timing adjusting section delays a predetermined time based on the output from the sensor and the sensor and sends out the fixing image recording signal. Then, the output of the laser diode, which is the light source of the fixing light beam, is intensity-modulated by the LD drive section by this signal. Therefore, the fixing light beam can perform the irradiation necessary for fixing the toner only on and near the unfixed toner image. Only the image on the recording material and the toner in the vicinity thereof are fixed, and other unfixed toner (fog toner) is not fixed.

The recording material then moves to the toner collecting section. In this embodiment, Mag toner is used, and a magnet roll is used as the toner collecting unit.
The unfixed toner on the recording material moves from the recording material to the toner collecting portion in the toner collecting portion, and the unfixed toner on the recording material is cleaned.

Therefore, according to this embodiment, since the recording material is not contaminated due to the fixing offset due to the non-contact fixing, and it is advantageous against paper wrinkles, and the heat source for fixing is the irradiation heat energy of the light beam. It is possible to perform a quick start with a warm-up time of substantially zero, fix only the image portion and its vicinity, and clean fog toner and the like. Therefore, it is possible to provide a fixing device that can obtain a high-quality image.

<Embodiment 22> Next, Embodiment 22 of the present invention.
Will be described with reference to FIGS. 47 and 48. The same parts as those of the twenty-first embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 47 shows the apparatus of this embodiment. In this embodiment, instead of scanning one fixing light beam using the optical deflector, a plurality of light sources are arranged in a line in the main scanning direction.

In this embodiment, the range on the recording material irradiated by one of the plurality of light sources 820 is the recorded image.
A case corresponding to × 2 pixels will be described. FIG. 48
Shows the configuration of the image density conversion unit.

The line memory stores dot information of the main scanning length for two lines in the sub scanning direction. Data is read from this line memory at a clock having the same clock frequency as the image recording clock at the time of exposure and input to the shift register. Each shift register is composed of 2 bits. The value of this shift resist (831a, 831
b, 832a, 832b) and reads 831a, 83
If the value of any one of 1b, 832a, and 832b is 1 (that is, there is a pixel to be recorded), the output of the light source is turned on for fixing. These 831a, 831b,
The output obtained by ORing the data of 832a and 832b is then input to the gate. This gate is opened / closed by a clock obtained by dividing the image recording clock by 2 by a frequency dividing circuit. For this reason,
The data for two lines is read (2 × 2) at a time, and the OR of the respective data is output.

The timing of this output is adjusted by the timing adjusting unit, and the output of the laser diode which is the light source is intensity-modulated. The light beam emitted from the light source is a focusing lens (in this embodiment, the Selfoc lens array 819,
S. L. A. , "Selfoc lens" is a registered trademark of Nippon Sheet Glass Co., Ltd., and is condensed on the recording material, and the unfixed toner is fixed on the recording material by the irradiation heat energy of the light beam.

In this embodiment, a plurality of light sources are arranged in a line in the main scanning direction without using an optical deflector, and an S.V. L. A. Since it is used, a small fixing device can be obtained.

<Embodiment 23> Next, Embodiment 23 of the present invention.
Will be described with reference to FIG. FIG. 49 shows the device of this example. In this embodiment, two light beams emitted from two light sources are combined into one light beam and used as the light source.

A semiconductor laser is used as a light source, and its deflection surface is a PBS (deflection beam splitter) as shown in FIG.
822 is arranged so that P deflection and S deflection are performed.

Then, the P-polarized light beam passes through the PBS, and the S-polarized light beam is reflected by the PBS so that the traveling direction is 9
It is deflected by 0 ° and becomes the same as the traveling direction of the P-polarized light beam. Therefore, if the position of the light source is adjusted and arranged so that the traveling directions of the light beams after passing through the PBS match,
The two light beams after passing through the PBS will be combined into one. Then, the two light sources are intensity-modulated in synchronization with a signal from the LD drive section, so that one combined light beam irradiates the unfixed toner image and its vicinity to fix the unfixed toner image.

In this embodiment, since the light beams emitted from the two light sources are combined and used as one light beam, even if a light source with a small output is used as the light source, the light beam is used as the fixing light beam. A light beam with sufficient light intensity can be obtained.

<Embodiment 24> Next, Embodiment 24 of the present invention.
Will be described with reference to FIGS. 51 to 56. FIG. 51 shows a schematic cross-sectional view of a laser beam printer which is an image forming apparatus according to Embodiment 24 of the present invention. The laser beam printer 910 of this embodiment is connected to a host such as a personal computer or a workstation, and after receiving image data from the host, the controller expands it into bitmap data. The image information developed into the bitmap data is sent to the engine unit of the laser beam printer 910 via the video interface, and the engine unit modulates the laser beam based on the image information and raster-scans the desired image to obtain a desired image. Form. At this time, the controller and the laser beam printer 9
The engine unit 10 performs the following communication via the video interface. First, the engine unit transmits a ready signal when the recording material size can be confirmed and paper can be fed by the signal from the controller and the printer can be operated.

Incidentally, the recording material size is detected by detecting the size by providing a frame for each paper size and paper thickness in the cassette of FIG. 51, or by detecting the size specified by the host side on the engine side. There is.

Next, the controller confirms that the ready signal is transmitted from the engine unit and transmits a print signal, which is a paper feed command, to the engine unit.

Upon receiving the print signal, the engine section feeds the recording material P from the recording material storage section such as the cassette 920 by the paper feed roller 915 and conveys it to the registration roller 16. The recording material P is temporarily stopped by the registration rollers 916, the scanner and the motor (provided in the scanner 921, not shown) rise, and the photosensitive drum 9 is stopped.
After sending the vertical synchronization request signal (VSREQ) to the controller section, which notifies that the image is ready to be written after waiting for the completion of the preparatory rotation (so-called pre-rotation) for potential stabilization of 11 and so on, The controller section sends a vertical synchronizing signal (VSYNC), and after a certain period of time, sends an image signal (VIDEO) to the engine section. After receiving VSYNC in the engine section, the registration roller 91
The recording material is conveyed from 6 to the transfer portion.

Next, image formation in the laser beam printer section will be described. The photosensitive drum 911 having a photosensitive layer such as an organic photoconductor (OPC) is uniformly negatively charged by a charging unit such as a charging roller 912, and then irradiated with the laser beam 913 modulated according to the above-mentioned image signal. An electrostatic latent image is obtained. This electrostatic latent image is developed by the developing device 914 having negatively charged toner and visualized as a toner image T0. The toner image T0 is transferred to the transfer roller 91 at the transfer portion.
After being electrostatically transferred to the recording material P by a transfer means such as 7, the recording material P is conveyed to the heating roller fixing device 919,
The toner image is permanently fixed. The transfer residual toner on the photosensitive drum 911 is cleaned by the cleaner 918,
The same image process is repeated again. In the image forming unit, the developing device 914, the charging roller 912, the photosensitive drum 9
The cleaner 11 and the cleaner 918 are integrally formed into a cartridge that is detachable from the main body.

Conventionally, in the above laser beam printer, the time until the engine section transmits the ready signal is until the surface temperature T of the heating roller 901 (at the NTC position) reaches the temperature T1 shown in FIG. Was determined by the time. This temperature T1 is a temperature at which the surface temperature T of the heating roller 901 can rise to the fixable temperature T2 within the time required for the recording material to reach the heating roller fixing device, and it is set so that the fixing failure does not occur. . Incidentally, in FIG. 55, the Rea when the image forming operation start request signal is received from the host before the standby temperature T1 is reached.
The Print signal is transmitted immediately after the dy signal is transmitted.

Therefore, in order to reduce the time until the Ready signal is transmitted, the surface temperature T of the heating roller 901 is quickly raised to the temperature T1, or
It is conceivable to set the temperature T1 itself as low as possible.

However, first, in order to quickly raise the surface temperature T of the heating roller 901, it is necessary to reduce the heat capacity of the heating roller 901 or increase the heat generation amount of the heater.

When the temperature T1 itself is set low, the ready signal is transmitted quickly, but the subsequent image writing operation proceeds regardless of the surface temperature T of the heating roller 901, so that the recording material is heated by the heating roller fixing device. When the temperature reaches, the temperature is insufficient and fixing failure occurs.

In the example of FIG. 55, the surface temperature T _R of the heating roller and the standby temperature T _S at the time of sending the Ready signal are set to the same T1, but in the present embodiment, the temperature of this T _R is set as the recording material size. The wait time is shortened by setting a plurality of numbers accordingly.

FIG. 54 shows the main part of the fixing device of this embodiment.

In the figure, reference numeral 901 denotes a heating roller which has a halogen heater 902 as a heat source therein and is rotated in a fixed direction via a drive gear 903, and rotates below the heating roller 901 in pressure contact therewith. A pressure roller 904 is provided. In addition, NTC90 which is a temperature detection signal element
Reference numeral 5 is provided in the central portion which is the reference for sheet passing, and the surface temperature of the heating roller is controlled to a predetermined constant value. Further, the light distribution intensity 908 of the heater 902 is set so that the temperature of the roller surface becomes substantially the same in the longitudinal direction when continuously passing the maximum size (for example, A3 width) which can be passed as a recording material. The light distribution at both ends is larger than that in the central part.

In this embodiment, after the power is first turned on in the morning, the heating roller surface temperature detected by the NTC 905 is R.
When the image forming operation start request signal is received from the host before the temperature T _R for sending the ready signal is reached, the engine unit immediately raises the temperature to fixable temperature T2 after sending the Ready signal as shown in FIG. The distribution of the roller surface temperature in the longitudinal direction of the heating roller at this time is shown in the figure.

As shown in the figure, the surface temperature of the heating roller has a higher distribution at the center than at the ends. Here, the fixing property at the time of printing when the power is first turned on in the morning is such that the end portion of the recording material tends to be defective in comparison with the central portion of the recording material, corresponding to the above temperature distribution. Therefore, the temperature T _{R at} which the Ready signal is sent is normally set by evaluating the fixing property of the end portion of the recording material having the maximum width through which the paper can pass. That is, T _R is set from the temperature at which the fixing property of the recording material can be secured under the worst condition determined by the specifications.

Therefore, when a recording material 907 (for example, B5 size) smaller than the maximum paper passing width is designated at the time of printing when the power is first turned on in the morning, the heating roller corresponding to the end portion of the recording material is The surface temperature T _B is higher than the temperature T _A of the maximum size recording material. That is, the end portion of the recording material 906 is excessively fixed in comparison with the end portion of the recording material 906, and sufficient fixing property is secured.

Conversely, if the fixability of the small-sized recording material 7 is made equal to the fixability of the maximum-sized recording material 906, the above temperature T _B can be lowered to near T _A (actually). The difference in the NIP width at the paper passing edge and the shortening of the wait time cause a slight difference in excessive heating of the pressure roller, and it is advantageous to warm the pressure roller between small-sized paper. It is necessary to determine the value near T _A after confirming the effect on fixability).

That is, when a recording material of a smaller size than the recording material of the maximum width is designated as the print paper, the amount of time required for the heater 902 to raise the temperature of approximately T _B −T _A described above. It becomes possible to shorten the wait time. The shortened time depends on the recording material width, and the smaller the maximum width, the shorter the wait time.

To explain the above with reference to FIG. 53, the Ready temperature T _R when the recording material 907 of small size paper (for example, B5 size) is designated is the recording material 906 of the maximum width.
The temperature T1 (for example, A3 size) (T1 in FIG. 53)
= T _S ). Each wait time is WT _R
And WT ₁ , the wait time can be shortened by the difference WT ₁ −WT _R = ΔWT.

In FIG. 53, the standby temperature T _S ′ and the Ready temperature T _R = T1 when the wait time becomes the longest are the same temperature, but it is not necessary that T _S = T1.

In addition, the print temperature when the power is first turned on in the morning and the print temperature after the standby are the same temperature T in FIG.
Although it is 2, this may be set at different temperatures. The set temperature may be changed depending on the size of the recording material and the number of printers.

Further, not only the paper size but also a means for detecting the paper thickness may be provided to set the Ready temperature to a predetermined value.

The engine section control of this embodiment will be described below with reference to FIG.
A description will be given based on the flowchart. Here, the Ready temperature with the shortest wait time is set to T0. First, when the printer engine is powered on (S100), the heating roller surface temperature T is set to a lower first set temperature T0, and the process waits until the surface temperature reaches T0 (S101). Then, when the image forming operation start request signal is received from the host before reaching this temperature, the recording material size designated by the signal from the controller is confirmed (S102). Here, the target temperature is switched to the Ready temperature T _R preset for each recording material size (S103). When the surface temperature T reaches the temperature T _R , a Ready signal is transmitted (S10).
4). Therefore, at this point, Pr from the controller
The int signal is ready to be received. Here, when receiving the Print signal from the controller (S105),
Immediately after starting preparations such as paper feeding and pre-rotation, the target temperature on the surface of the heating roller is switched to the preset print temperature T _P (S106), and the recording material P is temporarily stopped by the registration roller 916. Then, if the preparatory processing to be performed before the normal writing such as the rise of the scanner and the potential stabilization of the photosensitive drum is completed (S107), VSR is set.
The EQ signal is transmitted (S108). Upon reception of the VSYNC signal (S109), the registration roller 916 is rotated to convey the recording material to the transfer section (S110). At this time, the surface temperature does not need to reach T _P. Also, T _P
When the temperature reaches, the temperature is controlled during printing. When the fixing operation is completed (S111), the surface temperature is set to T _P → T _S (S112), and the process waits for a print signal again.

FIG. 52 shows a case where a request signal for the image forming operation is received from the host after the power is turned on and before the Ready signal is transmitted. However, when it is not received, the Ready signal is sent when the surface temperature T reaches T0. Send the above surface temperature T
Is raised to the standby temperature T _S to enter the standby state (S11
3). Thereby, the wait time can be shortened.

<Example 25> Next, Example 25 of the present invention.
Will be described with reference to FIG. The same parts as those of the twenty-fourth embodiment are designated by the same reference numerals and the description thereof will be omitted.

FIG. 56 shows the main part of the fixing device of this embodiment. The difference from the twenty-fourth embodiment is that the temperature sensing element 90
5 is arranged not at the center of the heating roller 901 but at the end portion which is the non-image area.

Therefore, the light distribution intensity of the halogen heater 2 has a flat light distribution characteristic 908 so that the surface temperature of the heating roller becomes substantially the same in the longitudinal direction when the maximum size recording material is continuously fed. There is.

In such a structure, T2 shown in FIG.
The surface temperature distribution in the longitudinal direction of the heating roller at the time when the NTC temperature has reached is shown in the lower part of FIG. In the structure of this embodiment, especially when the power is turned on in the morning, the temperature distribution of the heating roller surface at the time of start-up is considerably higher in the center than in the end portions.

Therefore, when the recording material 907 having a smaller size than the recording material 906 having the maximum paper passing width is designated at the time of printing when the power is first turned on in the morning, the heater is heated to a temperature approximately equivalent to T _B -T _A. It becomes possible to shorten the wait time by the time required for 902 to rise, and NTC905
The ΔWT shown in FIG. 53 is larger than that in the case where the heating roller is arranged at the center of the heating roller, which is the sheet passing standard, and the wait time is shortened accordingly.

Description of parts common to those of the twenty-fourth embodiment will be omitted below.

Next, the process speed of the apparatus of this embodiment is set to 1
2π mm / sec, print speed is A4 size transverse feed 8 sheets / min, maximum width of recording material that can be passed is A3 size (width 297 mm), outer diameter of heating roller is 28 mm, thickness of core metal is aluminum. 2.9 mm, the heating value of the halogen heater as a heat source is 600 W (at 100 V input)
An experimental example in the case where the condition is set will be described with reference to FIG.

Here, the standby temperature T _S = 165 ° C., the print temperature T _P = 180 ° C., and the temperature T _R at the time of sending the Ready signal is T3 = A1 width T1 = 165 ° C., which is the lower limit specified in the specifications of this apparatus. When a voltage of 85 V was inputted, T _A in FIG. 56 became 167 ° C. Further, at this time, if the recording material 7 is B5 size, T _B = 192 ° C., and T _A −T _B =
It reached 25 ° C.

Therefore, if T _R = 140 ° C. when the B5 width is specified at the time of printing when the power is first turned on in the morning, the wait time difference from the A3 width is ΔT = 20 sec, and the wait time is shortened by this time. Was done. At this time, the fixing properties of the A3 and B5 size recording materials were evaluated under the same conditions and found to be almost the same.

<Example 26> Next, Example 26 of the present invention.
Will be described with reference to FIG. FIG. 57 shows the device of this embodiment. This example is an improvement of Example 25,
The same parts as those in the twenty-fifth embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the twenty-fifth embodiment, the surface temperature of the central portion of the heating roller is estimated and the set temperature is controlled by the NTC905 at the end portion. However, in the twenty-fifth embodiment, the roller temperature at the end portion of the small-sized recording material is more accurately determined. NTC9 at the end to know
Another 06 is arranged. There are two in this embodiment,
You may provide more than one.

In this case, the surface temperature of the heating roller on which the recording material 907 of a small size can be fixed is set in advance, and the NTC is set.
When the 906 detects this temperature, it sends a Ready signal to reliably prevent fixing failure.

As the place for disposing the NTC 906, the smallest end of the recording material which can pass the paper is preferable. When a small size recording material between the maximum and minimum size recording materials is designated by the host, the temperature at the end of the size can be estimated almost accurately from the temperature difference between NTC 905 and NTC 906.

<Example 27> In Example 24, a start request signal for an image forming operation was received from the host after the power was turned on, the Ready signal was transmitted, and before the heating roller surface temperature T reached the standby temperature T _S. The case will be described with reference to FIG.

Description of common points with the twenty-fourth embodiment will be omitted.

When the heating roller surface temperature T reaches T0 after the power is turned on (S100) (S101) and a ready signal is transmitted (S104) and the image forming operation start request signal is received from the host, the embodiment shown in FIG. However, since the subsequent image writing operation proceeds regardless of the heating roller surface temperature, fixing failure may occur on a recording material having a large size width.

Therefore, in this embodiment, after the Ready signal is transmitted (S120), the Print signal is received (S121).
Then, the size of the recording material is confirmed (S122), and the heating roller temperature T at this time is Ready for the recording material.
Transmission of a VSREQ signal for starting the subsequent image writing operation after waiting for the temperature T _R to be reached (S108)
Decide to do.

It should be noted that the preparation processing operation such as the pre-rotation (S12
3) is simultaneously performed while increasing toward the heating roller temperature T _R , and the heating roller surface temperature T is set to the printing temperature T _P as soon as it reaches T _R (S124) (S12).
5). The subsequent operation is similar to that of FIG.

As described above, after waiting for the heating roller temperature T to reach the Ready temperature T _R corresponding to the designated recording material size, the subsequent image forming process is performed to eliminate the above-mentioned fixing failure. It is possible to prevent it.

[0248]

As described above, according to the first invention of the present application, in the fixing device for fixing the unfixed toner image on the recording material by heating and pressurizing the recording material carrying the unfixed toner image, the hollow fixing is performed. Since the fixing roller has a roller and a temperature sensitive element for detecting the temperature of the fixing roller, a groove having a predetermined depth is provided on the inner surface of the fixing roller, and the temperature sensitive element is brought into contact with the groove portion. Even when a thick roller is used, the surface temperature can be accurately detected, the overshoot can be suppressed to a low level, thermal deterioration of the member can be prevented, and the fixing property can be improved. Further, since there is no friction between the temperature sensitive element and the surface of the fixing roller, the releasing property of the fixing roller is not deteriorated,
It was possible to prevent dirt and the like from accumulating on the abutting portion and disturbing the temperature control, and it was also possible to solve problems such as dirt slipping through.

According to the second invention of the present application, in the fixing device for fixing the unfixed toner image on the recording material by heating and pressing the recording material carrying the unfixed toner image, the hollow fixing roller and the fixing roller are provided. The fixing roller comprises a heating element enclosed in a sheet, and a temperature sensitive element for detecting the temperature of the fixing roller. And a holding member holding the temperature sensitive element are strongly pressed against the fixing roller non-sheet passing portion to form a temperature sensitive element. In addition to reducing the thermal resistance with the surface of the fixing roller, it is also possible to reduce the thermal capacity of the temperature-sensitive element itself, so that excellent thermal response can be obtained. Further, since toner, paper dust, etc. do not adhere to the temperature-sensitive element, the thermal responsiveness does not deteriorate in durability due to use, and furthermore, it is possible to prevent image smearing due to slipping of toner.

Although the contact type temperature sensitive element has been described in the description of the embodiments, even when the non-contact type temperature sensitive element is used, the temperature can be measured by facing the heat conductive core metal surface.
It was possible to improve the temperature response of the temperature sensitive element by reducing heat absorption, radiation scattering, etc. by the offset prevention layer.

Further, according to the third invention of the present application, a part of the heat-sensitive surface of the excessive temperature rise prevention device is brought into contact with the non-paper passing area on the surface of the heating roller, and the remaining surface has a predetermined gap with respect to the paper passing area. Therefore, the fixing device is not upsized, toner stains do not drop from the excessive temperature rise prevention device, and sufficient responsiveness of the excessive temperature rise prevention device can be obtained.

Further, according to the fourth invention of the present application, the surface resistance of the left and right end portions of the electrophotographic film is made higher than the surface resistance of the other portions, so that the surface charge of the film holding the unfixed developer image is Leakage can be prevented and electrostatic offset can be prevented from occurring.

Further, according to the fifth invention of the present application, even if the bearing member is softened during abnormal temperature rise, the displacement of the heating roller can be slightly suppressed by providing the movement regulating member of the heating roller. Since the optimum contact position of the excessive temperature rise prevention means can be maintained and the operating temperature range of the excessive temperature rise prevention means can be kept within a predetermined range, the heater can be turned off quickly and reliably to emit smoke. -Can prevent ignition.

According to the sixth invention of the present application, a silicone rubber elastic layer is provided on the surface of the cored bar, and a release coating layer made of fluororesin is provided on the surface, and both ends of the elastic layer are nonpolar. By sealing with a resin, the releasability does not deteriorate due to durability, and a sufficient nip can be obtained even when the roller has a small diameter. Further, since the unreacted low molecular weight component of the rubber inside the silicone rubber elastic layer and the low molecular weight component formed by thermal decomposition are suppressed by the sealing action of the nonpolar resin, the roller is deformed into a crown shape. It is possible to prevent the occurrence of paper wrinkles, uneven gloss, image shift, and the like. In addition, the manufacturing process is simple and it can be manufactured at low cost.

Further, according to the seventh invention of the present application, when fixing is performed by using the light beam, the irradiation position of the light beam is set to only the image position of the image by the unfixed developer image and its vicinity according to the output image information, and By cleaning the unfixed developer on the recording material by the unfixed developer collecting means arranged in front of the beam irradiation position in the recording material conveyance direction,
The image quality of the recording material after fixing can be improved.

According to the eighth aspect of the present invention, when the image forming operation start request signal is received from the external device before the surface temperature of the heating roller reaches the temperature T _R at which the ready signal is emitted after the power is turned on. Since the optimum temperature T _R for the recording material size to be passed is selected from the temperature T _R data group corresponding to the recording material size set in advance as the target temperature, The wait time can be shortened without increasing the amount of heat generation or reducing the heat capacity of the heating roller, while ensuring the fixability. Further, particularly when the present invention is applied to a laser beam printer connected to a host, the host can be released from the print waiting state earlier.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a main part of a device according to a first embodiment of the present invention.

FIG. 2 is an axial sectional view of a fixing roller of the apparatus shown in FIG.

FIG. 3 is a diagram showing an experimental example using the apparatus of FIG.

FIG. 4 is a vertical cross-sectional view showing a main part of a device according to a second embodiment of the present invention.

FIG. 5 is a sectional view of a fixing roller in an axial direction according to a third exemplary embodiment of the present invention.

FIG. 6 is a vertical cross-sectional view showing the main parts of a device according to a fourth embodiment of the present invention.

FIG. 7 is a diagram showing a schematic configuration of a conventional fixing device.

FIG. 8 is a sectional view showing a schematic configuration of a device of Example 5 of the present invention.

FIG. 9 is a sectional view in the roller axis direction taken along the XY plane in FIG.

FIG. 10 is a sectional view showing a schematic configuration of a device according to a sixth embodiment of the present invention.

11 is a sectional view in the roller axis direction taken along the XY plane in FIG.

FIG. 12 is a cross-sectional view of the fixing roller in the apparatus of FIG. 11 when the non-sheet passing portion has a step shape.

FIG. 13 is a cross-sectional view showing a schematic configuration of a device according to a seventh embodiment of the present invention.

14 is a sectional view in the roller axis direction taken along the XY plane in FIG.

FIG. 15 is a longitudinal sectional view showing a schematic configuration of an eighth embodiment device of the present invention.

16 is a cross-sectional view showing a schematic configuration of an excessive temperature rise prevention device of FIG.

FIG. 17 is a diagram showing an experimental result in Example 8 of the present invention.

FIG. 18 is a diagram showing a schematic configuration of an excessive temperature rise prevention device in embodiment 9 of the present invention.

FIG. 19 is a diagram showing an experimental result in Example 9 of the present invention.

FIG. 20 is a longitudinal cross-sectional view showing the schematic configuration of a device of Example 10 of the present invention.

FIG. 21 is a longitudinal sectional view showing a schematic configuration of a conventional device having a contact type excessive temperature rise prevention device.

FIG. 22 is a longitudinal cross-sectional view showing a schematic configuration of a conventional device having a non-contact type excessive temperature rise prevention device.

FIG. 23 is a sectional view showing a schematic configuration of an electrophotographic film in Example 11 of the present invention.

FIG. 24 is a plan view of the electrophotographic film shown in FIG. 23.

FIG. 25 is a sectional view showing a schematic configuration of an electrophotographic film in Example 12 of the present invention.

FIG. 26 is a sectional view showing a schematic configuration of an electrophotographic film in Example 13 of the present invention.

FIG. 27 is a cross-sectional view showing a schematic configuration of a fixing device that holds and conveys an electrophotographic film.

FIG. 28 is a cross-sectional view showing a schematic configuration of a conventional electrophotographic film.

FIG. 29 is a view for explaining a mechanism for holding an unfixed developer image on an electrophotographic film.

FIG. 30 is a diagram for explaining charge leakage in a conventional electrophotographic film.

FIG. 31 is a front view showing a schematic configuration of a device according to a fourteenth embodiment of the present invention.

32 is a cross-sectional view of the FIG. 31 device.

FIG. 33 is a diagram showing a state in which the bearing member is softened and the heating roller is in contact with the movement restricting member in the apparatus of FIG. 31.

[Fig. 34] Fig. 34 is a view showing each arrangement position of the excessive temperature rise prevention means in the experimental example of the fourteenth embodiment of the present invention.

FIG. 35 is a cross-sectional view showing a schematic configuration of a device according to a fifteenth embodiment of the present invention.

FIG. 36 is a front view showing the vicinity of the bearing member of the heating roller of the apparatus of FIG. 35.

FIG. 37 is a perspective view showing a schematic device of an Embodiment 16 device of the present invention.

FIG. 38 is a perspective view showing a schematic device of a conventional device.

FIG. 39 is a diagram showing a state in which the heating roller is displaced in the apparatus shown in FIG. 38;

FIG. 40 is a cross-sectional view showing a schematic device of a pressure roller in Example 17 of the present invention.

FIG. 41 is a sectional view showing a schematic configuration of a fixing device used in a comparative experiment in Example 17 of the present invention.

FIG. 42 is a sectional view showing a schematic configuration of a pressure roller according to Example 18 of the present invention.

FIG. 43 is a cross-sectional view showing the schematic structure of a pressure roller according to Example 19 of the present invention.

FIG. 44 is a sectional view showing a schematic configuration of a pressure roller according to Example 20 of the present invention.

FIG. 45 is a perspective view showing a schematic configuration of a device according to a twenty-first embodiment of the present invention.

46 is a diagram showing a schematic configuration of an image density conversion unit in the apparatus shown in FIG. 45.

FIG. 47 is a perspective view showing a schematic configuration of a device of Example 22 of the present invention.

48 is a diagram showing a schematic configuration of an image density conversion unit in the apparatus shown in FIG. 47.

FIG. 49 is a perspective view showing a schematic configuration of an apparatus of Example 23 of the present invention.

FIG. 50 is a perspective view showing a schematic configuration of a conventional fixing device using a light beam.

FIG. 51 is a sectional view showing a schematic configuration of a device of Example 24 of the present invention.

52 is a flowchart showing an outline of temperature control of the apparatus shown in FIG. 51.

53 is a diagram showing changes in the surface temperature of the heating roller in the apparatus shown in FIG. 51.

54 is a diagram showing the positional relationship between the heating roller and the recording material, the surface temperature of the heating roller, and the light distribution intensity of the heat source in the apparatus of FIG. 51.

FIG. 55 is a diagram showing changes in the surface temperature of the heating roller when the temperature TR at the time of sending the ready signal and the standby temperature TS are both set to the temperature T1 in the apparatus of FIG. 51.

FIG. 56 is a diagram showing the positional relationship between the heating roller and the recording material, the surface temperature of the heating roller, and the light distribution intensity of the heat source in the apparatus of Example 25 of the present invention.

FIG. 57 is a diagram showing the positional relationship between the heating roller and the recording material, the surface temperature of the heating roller, and the light distribution intensity of the heat source in the apparatus of Example 26 of the present invention.

FIG. 58 is a flowchart showing an outline of temperature control in Example 27 of the present invention.

[Explanation of symbols]

1 Fixing Roller 2 Radiant Heating Element 3 Pressurizing Roller 6 Temperature Sensing Element D Groove E Non-Paper Portion 201, 201 'Fixing Roller (Heating Roller) 203 Halogen Heater (Heating Element) 204, 207, 208 Thermo Switch (Excessive Temperature Increase) Preventing device) 401 Plastic film (film for electrophotography) 402 Coating layer (film for electrophotography) X Non-application area width (left and right non-image areas) Y High resistance coating layer width (left and right non-image areas) 501 Overheating Preventing element (excessive temperature rise preventing means) 503 Fixing roller bearing (bearing member) 504 Fixing roller (heating roller) 506 Pressure roller 508 Position deviation preventing member (movement restricting member) 511 Bearing reinforcing sheet metal (moving restricting member) 512 Addition Pressure roller stopper (movement restriction member) 701 Pressure roller 702 Core metal 703 Silicone rubber elastic layer 70 Release coating layer 802 recording medium 815 toner collecting portion (developer collecting means) 901 heating roller 902 halogen heater (heat source) 905 NTC (temperature detection means) 906 and 907 a recording medium

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuko Tanaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Tatsunori Ishiyama 3-32-3 Shimomaruko, Ota-ku, Tokyo (72) Inventor Tatsukazu Tsukita 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masahiro Goto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. In-house (72) Inventor Koichi Hiroshima 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Koichi Tanigawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. ( 72) Inventor Katsuhiko Nishimura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Toru Saito 3-30-2 Shimomaruko, Ota-ku, Tokyo In emissions Co., Ltd. (72) inventor Satoshi Tsurutani Ota-ku, Tokyo Shimomaruko Third Street No. 30 No. 2 Canon within Co., Ltd.

Claims (20)

[Claims] 1. A fixing device having a hollow fixing roller and a temperature-sensitive element for detecting the temperature of the fixing roller, wherein a groove having a predetermined depth is provided on the inner surface of the fixing roller, The fixing device is characterized in that the temperature element is arranged so as to come into contact with the groove portion. 2. A fixing device having a hollow fixing roller, a heating element contained in the fixing roller, and a temperature sensitive element for detecting the temperature of the fixing roller, wherein the fixing roller is provided on a surface of a heat conductive core metal. The temperature-sensitive element or the holding member holding the temperature-sensitive element has a paper-passing portion provided with an offset prevention layer and a non-paper-passing portion where the heat-conducting core bar is exposed. A fixing device, which is disposed in a paper section. 3. A fixing device having a heating roller provided with a heating element and an excessive temperature rise prevention device arranged so as to be in sliding contact with the heating roller, wherein the heating roller or the excessive temperature rise prevention device comprises: A part of the heat-sensitive surface of the excessive temperature rise prevention device is in contact with the recording material non-sheet passing area on the surface of the heating roller, and the other part has a step shape so as to maintain a predetermined gap with respect to the sheet passing area. The fixing device is characterized in that 4. An electrophotographic film in which an unfixed developer image is carried on a surface and conveyed to a fixing device, and the developer image is fixed on the surface by heating and pressurizing by the fixing device. An electrophotographic film, wherein at least one of the front and back surfaces is set such that the surface resistance of the left and right non-image portions is higher than the surface resistance of the other portions. 5. A heating roller having a heating source therein, a heat-resistant heat-insulating resin bearing member provided between the heating roller and a frame, and a pressure roller arranged so as to be in pressure contact with the heating roller. A movement regulating member that regulates radial movement of the heating roller when the bearing member is softened, in a fixing device provided with an excessive temperature rise prevention means arranged so as to come into contact with or come close to the surface of the heating roller. A fixing device having: 6. An elastic layer of silicone rubber is provided on the surface of a cored bar, a release coating layer made of fluororesin is provided on the surface, and both ends of the elastic layer are sealed with a nonpolar resin. A pressure roller characterized by. 7. The hardness of the silicone rubber elastic layer is JIS
The pressure roller according to claim 6, wherein the pressure roller is set to 15 ° or less in the standard of −A. 8. The silicone rubber elastic layer is electrically conductive with a volume resistance value of 10 ¹³ Ω · cm or less.
The developer supply container according to. 9. A fixing device comprising the roller pair of the pressure roller and the fixing roller according to claim 6. 10. In a fixing device of an electrophotographic apparatus for irradiating and fixing an unfixed developer image on a recording material with a light beam, a control means for controlling a light beam irradiation position, and a light beam irradiation position rather than a light beam irradiation position. And a developer collecting means arranged in the front in the recording material conveying direction, wherein the control means irradiates a light beam having a light intensity capable of fixing only the unfixed developer image position on the recording material and its vicinity. A fixing device, which is set to 11. The fixing device according to claim 10, wherein the developer collecting means includes a developer collecting member arranged on the recording surface side of the recording material without contacting the recording material. 12. The fixing device according to claim 11, wherein the developer collecting member includes a magnet roller. 13. The fixing device according to claim 10, wherein the light source of the light beam is a laser diode. 14. The control means comprises scanning means for scanning the light beam in a direction perpendicular to the recording material conveyance direction, and bitmapped image information used for forming an unfixed developer image. A detection means for detecting the recording material tip position, a detection means for detecting the light beam scanning reference,
A means for modulating the light intensity of the light beam, and a timing adjusting means for adjusting the timing of sending out the image information as a modulation signal to the light intensity modulating means based on the information from the detecting means. The fixing device according to item 10. 15. The fixing device according to claim 14, wherein the scanning unit has an optical deflector such as a rotary polygon mirror and a focusing lens such as an fθ lens. 16. The fixing device according to claim 14, wherein the scanning unit has a plurality of light sources arranged in a line in the main scanning direction and a focusing lens. 17. The scanning means is set to scan one pixel on the unfixed developer image with a light beam twice or three times or more, and a pixel density conversion means for converting the pixel density of the image information. The fixing device according to claim 14, which has the fixing device. 18. A heating roller having a heat source inside, temperature detecting means for detecting a surface temperature of the heating roller, and temperature control for maintaining the surface temperature at a set temperature based on the temperature detected by the temperature detecting means. Means, a recording material conveying means for conveying the recording material carrying an unfixed developer image with the center of the heating roller as a reference, and the recording material before the surface temperature reaches a predetermined standby temperature after power is turned on. In the image forming apparatus provided with a recording material size detecting unit for detecting the size of the image forming device, the temperature control unit is a ready signal indicating that the surface temperature after the power is turned on can be accepted by the image forming operation start request signal. when raised to a temperature T _R which emits, when receiving the start request signal from an external device prior to reaching the temperature T _R, versus the size of the recording material to be fed A plurality of temperature T set in advance in
_{From the R} data group, the optimum temperature T _R is selected based on the size detected by the recording material size detection means,
An image forming apparatus, wherein the image forming apparatus is set to have a target temperature to be increased. The surface temperature of 19. After power-on the heating roller exceeds the temperature T _R, before reaching a predetermined standby temperature, when receiving a start request signal of the image forming operation from an external device, said surface After waiting for the temperature to reach the temperature T _R , a control means is set so as to issue a signal requesting output of image data to an external device to start an image forming operation. The image forming apparatus according to claim 18. 20. A control means, when the surface temperature of the heating roller is not subjected to-start request signal of the image forming operation from the outside before it reaches the predetermined standby temperature, the surface temperature more than a temperature T _R data 19. The image forming apparatus according to claim 18, wherein a ready signal is issued at the time when the lowest temperature TR in the _group is reached, and the surface temperature is set to the standby temperature.