JPH06348163A - Heat-fixing device and printer, and surface potential control means of elastic rotating body - Google Patents

Abstract

PURPOSE:To provide a heat-fixing device capable of obtaining an even temperature distribution of a fixing roller in the longitudinal direction and preventing the temperature rise of a non-sheet passing part. CONSTITUTION:A heater 3 of which the initial rise speed is low and a heater 4 of which the initial rise speed is high are arranged in a fixing roller 1, and these are connected in series to an ACDriver 8. The heater 3 is arranged at a position corresponding to a non-sheet passing area the passing of small-sized record material, and the heater 4 is arranged at a position where a sheet is always passed. When the small-sized record material is passed, a continuous current passing time to the heaters is limited, and the heater 3 only is used in the course of rise to suppress heat supply to the non-sheet passing area. When a sheet of ordinary size is passed, current passing time is not limited and both heaters are used after completion of rise to supply heat to the entire area of the roller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat fixing device used in electrophotographic printers, copying machines, electrostatic recording devices and the like.

The present invention also relates to an electrophotographic printer which is connected to a host computer such as a personal computer, an office computer or a mini computer, and which prints an image according to image information and instructions from the host computer.

Further, the present invention relates to a means for controlling the surface potential of the elastic rotating body by passing an electric current through a member contacting the surface of the elastic rotating body, or applying an electric charge or an electrostatic force to a charged substance. . This means is used in roller-type latent image forming devices, developing devices, roller-type transfer devices, and roller-type fixing devices in image forming apparatuses such as electrophotographic copying machines, printers, and fax machines. It is an effective means for controlling the surface potential of the elastic rotating body, which is required to have a roundness and an axial shape with accuracy.

[0004]

2. Description of the Related Art FIG. 20 shows a conventional example. Figure 2
In 0, 1 is a fixing roller, and the fixing roller 1 is a PFA as a release layer on a core metal 1A such as aluminum.
Is coated. Reference numeral 2 is a pressure roller, and an elastic layer 2B made of silicone rubber is provided on a core metal 2A such as SUS. These pair of rollers form a nip by a pressing means (not shown) and can rotate via the bearing 10 and the bearing 9. A halogen heater 14 having a predetermined light distribution is arranged in the fixing roller 1, and these are provided with an AC power source (AC
Driver) 8 is electrically connected in series.
Further, the temperature detector 5 is in contact with the surface of the fixing roller 1, and the temperature information is taken into the CPU 7 via the A / D converter 6 and the AC driver 8 is driven by the CPU 7 so that a predetermined temperature is obtained. It is configured to control the temperature. Then, the recording material carrying the unfixed image passes by the image forming means (not shown) to the nip of the pair of heat rollers kept at a predetermined temperature, so that the heat fixing is performed. In this prior art example, the center reference is used in which the recording material is passed with the center of the fixing roller 1 as the reference.

Next, another conventional example will be described. Many conventional electrophotographic copying machines, printers and the like use a heat fixing type fixing device as shown in FIG. 36 as a fixing means. The apparatus shown in FIG. 36 includes a fixing roller 60 in which the surface of a metal core of aluminum or iron is coated with a heat-resistant release layer,
A pressure roller 61 having a heat-resistant elastic layer formed around a cored bar of stainless steel or the like is provided, and the fixing roller 60 is heated by a heater 52 provided in the cored bar of the fixing roller 60. . The pressure roller 61 is pressed against the fixing roller 60 by a spring to form a nip, and the unfixed toner image 62 is heated and pressed in the nip portion of the fixing device to be fixed on the recording material 63. .

The fixability of an image obtained by such a heat-fixing type fixing device varies greatly depending on the amount of heat applied to the toner image 62 on the recording material. The amount of heat applied to this toner is the heating temperature of the fixing device. When the (fixing temperature) is constant, it greatly changes depending on the type of recording material and the environment in which the printer is used.

Therefore, in the conventional printer, the printer main body is provided with an environmental condition detecting device such as a temperature sensor and a humidity sensor and a use condition detecting device such as a recording material size, and the fixing temperature and the pressing force at the time of fixing are detected depending on the detected condition. There are some which change fixing conditions such as fixing time. Further, there are printers that have various condition input switches and operate the switches to change fixing conditions such as fixing temperature, pressure applied during fixing, and fixing time.

Next, another conventional example will be described. Some conventional fixing devices use an elastic rotating body, but in order to lower the hardness of the elastic rotating body and control the surface potential, a low hardness layer for lowering the hardness and a charge distribution near the surface are used. It is an effective configuration to combine a conductive layer for changing.

As a conventional representative means for controlling the surface potential of an elastic rotating body having such a layer structure, conductivity is imparted to a low hardness elastic layer interposed between a cored bar and a conductive elastic layer. To control the electric potential of the core metal, or as another means, extend the conductive elastic layer to the end face of the rotating body to directly contact the core metal without interposing the elastic layer for electrical conduction. Has been.

For example, there is a pressure roller in a roller fixing device as an example of using the former conduction means. Figure 43
FIG. 3 is a schematic diagram illustrating the structure of the pressure roller 50.
In No. 0, foamed silicone rubber is used as the low hardness layer 502, and carbon is dispersed in order to impart conductivity to the low hardness layer itself so that the volume resistivity is 10 ⁵ Ωcm or less. Further, 504 is a fluororesin coating layer for improving the releasability of the pressure roller 500. Electric charges on the surface of the pressure roller 500, which are generated by friction with the fixing roller or the recording material, are released to the core metal 501 through the elastic layer 502,
The surface potential of the pressure roller 500 is kept near the ground potential. With this configuration, the electrostatic force acting on the toner is suppressed and the offset is suppressed.

Further, as shown in FIG. 44, a conductive rotating body is used as a charging roller in an image forming apparatus, and the latter means is used as means for controlling the surface potential.

Reference numeral 202 denotes an elastic layer made of foamed EPDM, which is an insulating layer having a volume resistivity of 10 ¹⁴ Ωcm or more, and mainly serves to lower the hardness of the charging roller 200. 203
Is a conductive elastic layer having a volume resistivity of 10 ⁵ Ωcm or less for applying an electric charge to the surface of a photosensitive drum (not shown), and is adhered to the cored bar 201 by a conductive primer at the end of the roller. The cored bar 201 is held by a conductive sliding bearing (not shown) in which carbon is dispersed, and a voltage is supplied from the main body.

[0013]

However, the above-mentioned conventional example has the following problems. First,
In the conventional example shown in FIG. 20, it is necessary to adjust the temperature distribution on the surface of the fixing roller by a single halogen heater having a uniform light distribution. Especially, when small size paper such as an envelope is continuously fed. It was difficult to suppress the temperature rise in the non-sheet passing area. It is necessary to apply heat to the entire length direction of the fixing roller in order to make the temperature distribution in the length direction uniform on the fixing roller during the passage of the maximum size paper. Since it is necessary to apply no heat to the non-sheet passing portion, it is inconsistent to try to satisfy these at the same time, and therefore, there is no choice but to design in which one of the points is compromised.

Therefore, as a means for solving this contradiction,
As shown in FIG. 21, a method has been proposed which has two halogen heaters and lights each heater independently. 21, the same parts as those in FIG. 20 are designated by the same reference numerals. In this conventional example, the halogen heater 16 that mainly heats the central portion and the halogen heater 17 that heats both end portions.
Are installed in the fixing roller 1, and each is an ACDriver.
It is connected to 15 and 8. And each AC Driver is C
Control is performed by the PU 7, and each heater can be controlled independently. Then, each heater is independently controlled so that an optimum temperature distribution can be obtained according to the type of paper to be passed.

However, in the above-mentioned conventional example, since the two heaters are controlled independently, A for each heater is controlled.
CDriver is required, which not only causes high cost, but also
Also on the CPU side, it is necessary to control the two heaters, which tends to increase the load.

Further, in the conventional example shown in FIG. 36, it is necessary to install a sensor and a detection device in the printer, and a certain space is required for highly accurate detection, so that the size of the device is small. There was an obstacle to the conversion. Further, the thickness of the recording material has a great influence on the amount of heat given to the toner, but in order to perform control in consideration of the thickness of the recording material, it is necessary to judge a difference of about 10 μm by a detection element or a sensor. , Technically very difficult. In addition to these, there are many factors that affect the fixability, such as the type of recording material and the environment in which the printer is used, and control that takes into account multiple factors requires multiple detection elements and sensors, which increases costs. I will end up.

On the other hand, in the case where a switch is provided,
Although the problems such as cost, space, and detection accuracy described above are alleviated somewhat, it is necessary to go to the installation location of the printer and set the conditions, so when the printer is connected to the network, it is close to the host device. If it does not exist, it is troublesome to perform the operation, and the user may actually operate the printer without performing the above setting.

Further, according to the conventional example shown in FIG. 43, means for imparting conductivity to the low hardness elastic layer interposed between the cored bar and the conductive elastic layer so as to establish conduction with the conductive elastic layer. In, it is necessary to disperse carbon or metal oxide for imparting conductivity to the elastic layer, and the characteristics originally possessed by the elastic material,
For example, they tended to lose flexibility. In particular, in the elastic foam layer, there is a problem that foaming is hindered and hardness increases.

Further, in the means shown in FIG. 44 in which the conductive elastic layer is wound around the end face of the rotating body and brought into contact with the core metal, the vulcanization conditions are set because the thickness of the elastic layer at the end is different. It becomes difficult, or the shape of the shoulder is raised or the end is raised, which is an obstacle in obtaining the shape accuracy of the rotating body.

As the simplest conducting method, it may be considered that the sliding electrode is directly brought into contact with the side surface of the conductive elastic layer. However, since the elastic material is usually poor in sliding property, the sliding electrode is formed in such a structure. Damages the elastic material.

The first object of the present invention is to solve the above problems, to realize a uniform temperature distribution in the longitudinal direction of the fixing roller and to raise the non-sheet passing portion without increasing the cost and complicating the control. An object of the present invention is to provide a heat fixing device capable of preventing temperature.

A second object of the present invention is to provide a printer capable of setting proper fixing conditions according to the installation environment of the device without providing the printer itself with a sensor and a detection device. .

Further, a third object of the present invention is to provide a surface potential control means for an elastic rotating member which can impart conductivity without impairing the shape accuracy and low hardness of the elastic rotating member. is there.

[0024]

According to the first invention of the present application,
The first object is to provide a heating roller and a pressure roller arranged so as to be in pressure contact with each other, a heating source arranged inside the heating roller, and a temperature detecting means for detecting the surface temperature of the heating roller, In a heat fixing device having a control means for maintaining the surface temperature at a predetermined temperature based on temperature information obtained from the temperature detecting means, the heating source is composed of at least two kinds of heat generating parts having different rising characteristics. It is achieved by

According to the second invention of the present application, in an electrophotographic printer which receives an instruction and an image signal from the host device and prints an image, the host device prints the temperature condition, the humidity condition of the installation place, and the like. This is achieved by receiving at least one of the thickness of the paper, the type of paper, pattern information of the image to be printed, and the like, and changing the fixing condition accordingly.

Further, according to the third invention of the present application, there is provided an elastic rotating body in which a low hardness elastic layer is provided on the outer periphery of a rigid cored bar, and a conductive elastic layer is further provided on the outer periphery thereof, the elastic rotating body facing each other. A nip is formed with one or more other rotating bodies, and a conducting plate having a contact area or contact pressure with respect to the side surface of the conductive elastic layer near the nip is increased, and the potential of the conducting plate is controlled. Achieved by

[0027]

According to the first invention of the present application, a filament material of a halogen heater having a slow initial rising characteristic is provided at a position corresponding to a non-sheet passing area portion when a small-sized recording material is passed,
Halogen heater filament materials with fast initial rise characteristics are placed at positions where the paper always passes, and when passing small-sized recording materials, the continuous energization time to the heater is limited, and only filaments with slow rise characteristics By using during the start-up, heat supply to the non-sheet passing area is suppressed. On the other hand, when a normal-sized recording material is passed, the energization time is not limited, and heat is supplied to the entire area of the roller by using both filaments in a raised state. Thus,
The optimum temperature distribution on the fixing roller is realized for any paper size, and it is performed by only one AC driver.

According to the second aspect of the present invention, when the user sends information such as external conditions and usage status from the host device to the printer in accordance with the usage status, the printer fixes the fixing temperature and the pressure applied during fixing. The optimum image is output by changing the fixing conditions such as the fixing time.

Further, according to the third invention of the present application, there is provided an elastic rotating body in which a low hardness elastic layer is provided on the outer periphery of a rigid cored bar, and a conductive elastic layer is further provided on the outer periphery thereof, the elastic rotating body being opposed to each other. A nip is formed with one or more other rotating bodies, and a conducting plate having a contact area or a contact pressure with respect to the side surface of the conductive elastic layer near the nip is increased, and the potential of the conducting plate is controlled. By this, the contact surface between the conductive elastic layer and the conductive plate is appropriately refreshed without hindering the flexibility and shape of the elastic rotating body, so that reliable conduction can be maintained, and the surface of the elastic rotating body can be maintained. Control the potential over time.

[0030]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

<First Embodiment> First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a view best showing the characteristics of the first embodiment of the present invention. In FIG. 1, 1 is a fixing roller, and the fixing roller 1 has a core metal 1A such as aluminum coated with PFA as a releasing layer. Reference numeral 2 is a pressure roller, and an elastic layer 2B made of silicone rubber is provided on a core metal 2A such as SUS. These pair of rollers form a nip by a pressing means (not shown) and can rotate via the bearing 10 and the bearing 9. In the fixing roller 1,
Halogen heaters 3 and 4 each having a filament whose initial startup is different in speed are arranged.
The C power source (AC Driver) 8 is electrically connected in series. Further, the temperature detector 5 is in contact with the surface of the fixing roller 1, and the temperature detector 5 contacts the C through the A / D converter 6.
The temperature information is taken into PU7, and CPU7
By driving the CDriver 8, the temperature is adjusted to a predetermined temperature. Then, the recording material carrying the unfixed image formed by the image forming means (not shown) passes through the nip of the pair of heat rollers maintained at the predetermined temperature, whereby the heat fixing is performed. In this embodiment, a center reference is used that allows the recording material to pass through with the center of the fixing roller as the reference.

Here, the initial rising characteristics of the halogen heater will be described. Generally, the halogen heater has a property that the luminous flux emitted from the filament portion does not reach the original 100% output until a certain period of time elapses immediately after the start of energization.

The present invention utilizes the characteristic that the heat capacity of the filament material produces a rising characteristic because the halogen heater self-heats by Joule heat due to electric current. By stopping the energization while the halogen heater is completely up,
It is used with an output below the rating. As a result, a heater having a slow rising characteristic is arranged on the non-sheet passing area side when a small-sized recording material is passed and the energization time is limited, so that the temperature rise of the non-sheet passing portion can be prevented.

The present invention can provide some effects without intentionally limiting the energizing time. This is because the heater is turned on for a relatively short time of about 1 second in a general use state.

FIG. 2 is a diagram showing the relationship between the halogen heater rated current and the luminous flux rise time (τ). In this figure, the characteristic curves of the two types of heaters used in this embodiment are shown. . Halogen heater 3 shown in FIG.
Has a thick filament wire and a large heat capacity. The halogen heater 4 has a thin filament wire and a small heat capacity. In general, the thinner the filament, the higher the resistance value (R), and the higher the color temperature (K), the higher the efficiency (lm / W) of the heater. So, adjust it according to the number and arrangement of the outer filaments
e, set the light distribution. As shown in FIG. 2, the current flowing from the AC driver 8 in the present embodiment to the heater is 5
When (A), the efficiency of the heater 3 is 16 (lm / W)
Then, the luminous flux rise time τ ₃ is 320 (msec). On the other hand, when the efficiency of the heater 4 is 24 (lm / W), the luminous flux rise time τ ₄ is 240 (msec). Therefore, it can be seen that the heater 3 having a larger heat capacity has a slower rising characteristic. It should be noted that what is enclosed in a square in FIG. 2 is the definition of τ, which is the time from when the heater is energized until the luminous flux of the heater reaches 90% of the rated amount. Refers to.

FIGS. 3 and 4 are diagrams showing the luminous flux rising characteristics of the heater 3 and the heater 4, respectively. From FIGS. 3 and 4, assuming that the limit of the continuous energization time to the heater in this embodiment is set to 240 (msec),
The luminous flux rising rate of each heater at that time is about 90 (%) in the heater 4 located in the central portion which is the paper passing area, and is 1%.
Although it is only 0% reduction, the heaters 3 located in the non-sheet passing area at both ends can obtain a reduction of 45% (55%).

Next, what kind of control is specifically performed by using the heater having such a property will be described with reference to the flowchart of FIG.

The control shown in FIG. 5 is control at the time of printing after the fixing device temperature is already in the RDY (standby) state. Note that the heater is energized up to RDY by a method that does not limit the usual continuous energization time.

In FIG. 5, after entering the RDY state,
The printer automatically determines the type of paper to be printed,
Alternatively, the judgment is made by the user's direct instruction to the printer. When it is determined that the paper type is an envelope, first, the continuous energization time to the heater (hereinafter, referred to as th) is th
The regulation value is stored in the printer CPU so that ≦ 240 (msec). Next, temperature detection is performed by the thermistor (measurement value at that time is Tt), and it is determined whether Tt is equal to or lower than a predetermined print temperature control temperature T _0.
If ≤T ₀ , the heater is turned on, and at the same timing, the timer for th is started and the time is counted. The temperature of the thermistor is continuously monitored until th reaches 240 (msec), the heater is turned on, and when 240 (msec) is exceeded, the heater is turned off, the counter of th is reset, and then the thermistor is used again. Detects temperature. In the control for limiting the energization time, the heater is not turned on for at least 300 msec after the heater is turned off in order to cool the filament material.

On the other hand, if Tt> T ₀ , the heater is turned off.
Then, the counter of th is reset, and the temperature is detected again by the thermistor.

Further, when the paper type is other than envelope, there is no limitation on the continuous energization time th to the heater, and the usual normal temperature control is performed.

Next, a comparison will be made between the present embodiment and the conventional example.
First, in this embodiment, the total Wattage of the fixing device is 5
00W, of which heater 3 (16lm / W) is 38
The heater 4 (24 lm / W) is 120 W. At that time, the total luminous flux of the heater 3 is 3040 (lm), and the total luminous flux of the heater 4 is 2880 (lm).
If control is performed using the above-described flowchart, the heater is turned on as shown in FIGS. 6 to 9.

FIGS. 6 and 7 show the behavior of the heater 3. FIG. 6 shows the case where normal size paper is passed (no continuous energization time limit), and FIG. 7 is the case where envelope is passed ( The continuous energization time is 240 msec or less). On the other hand, FIGS. 8 and 9 show the behavior of the heater 4, FIG. 8 shows the case of normal size paper, and FIG. 9 shows the case of envelope paper passage.

From these figures, in the case of normal size paper (without continuous energization time limit), temperature control can be performed with both heaters sufficiently raised, so that the output of both heaters is at maximum. Can be used. On the other hand, in the case of passing envelopes (continuous energization time of 240 msec or less), the heater 4 reaches 90% of the rise, while the heater 3 ends at about 45% of the rise. This causes a difference in output as a heater.

In this way, in the case of envelope paper passage, the amount of heat given to the paper passage area and the non-paper passage area is changed.

FIG. 10 shows a light distribution distribution by adjusting the filament arrangement of these heaters so that both ends are 150% with respect to the central part when the heaters 3 and 4 are continuously energized by simultaneous lighting. Shows. FIG. 11 shows the light distribution when the continuous energization time is 240 (msec).

On the other hand, in the conventional example, it is assumed that only a single heater having a power output of 500 W and showing a light distribution similar to that shown in FIG. 10 is used.

Then, these heaters were compared under the fixing conditions described below.

Fixing roller: aluminum core, wall thickness t
2.5 mm, outer diameter 30 mm, total length 270 mm Pressure roller: outer diameter 25 mm, silicone solid rubber single layer, rubber thickness t7.0 Process speed: 70 mm / sec Temperature control temperature: 185 ° C (temperature control temperature on temperature detection element ) Evaluation mode: LTR size [Xerox4024
(75 g / m ² )] 100 sheets continuous paper feed COM10 size envelope 100 sheets continuous paper feed FIG. 12 is a diagram showing the temperature distribution in the longitudinal direction on the fixing roller when 100 LTR size paper sheets are continuously fed. . From the figure, the same temperature distribution is shown in both the present example and the conventional example.

On the other hand, FIG. 13 is a diagram showing the temperature distribution on the fixing roller when 100 sheets of COM10 size envelopes are continuously passed. In the conventional example, the temperature rises in the non-sheet passing portion,
Although the temperature of the peak portion reaches about 230 ° C., in this embodiment, the temperature rise in the non-sheet passing portion is drastically reduced, and the peak portion can be suppressed to about 195 ° C.

As described above, according to the present embodiment, the heaters having different initial rising characteristics are connected in series and the continuous energizing time for the heaters is limited to increase the temperature of the non-sheet-passing portion during the passage of the envelope. Can be suppressed.

<Embodiment 2> Next, Embodiment 2 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 feature of this embodiment is that filaments having different initial rising characteristics are provided in the same glass tube to form one halogen heater.

FIG. 14 is a diagram showing the characteristics of the second embodiment of the present invention. In this embodiment, the halogen heater configuration is different from that of the first embodiment. 11A and 11B in the drawing are filament materials having different initial rising characteristics, and each is electrically connected. 11A is the filament material of τ = 320 msec used for the heater 3 described in Example 1, and 11B is used for the heater 4.
It is assumed that τ = 240 msec is used.

As a result, by combining filament materials having different initial characteristics in the heater, the same effect as that of the first embodiment can be achieved with a single heater, so that the device can be downsized. Become.

<Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIGS. In addition, Example 1
The same parts as in FIG.

The feature of the present embodiment is that in the fixing device configuration described in the first embodiment, the temperature information obtained from the second temperature detecting element is provided in the portion which becomes the non-sheet passing area when the envelope is passed. And the temperature information from the first temperature detecting element that is in contact with the paper passing area are compared, and when it is determined that the non-paper passing portion temperature rise occurs, the continuous energizing time to the halogen heater is limited, and The limitation of the energization time is that it has multiple stages.

FIG. 15 is a diagram showing the characteristics of the third embodiment of the present invention. The first temperature detecting element 5 is in contact with the center, and the second temperature detecting element 12 is in contact with a portion which is a non-sheet passing area when the envelope is passed, and the A / D conversion section 1 is respectively provided.
Information is fetched into the CPU 7 via 3, 6.

16 to 18 are flowcharts of the temperature control of the third embodiment. This flowchart shows the temperature adjustment control during printing after the fixing device temperature reaches the RDY state in which printing is possible. The description will be given below according to the flowchart.

Section [Normal Temperature Control] tmax = ∞ After the print command, the value of tmax is first set to ∞. This is the temperature control as usual, that is, the continuous energization time is not limited. The temperature T ₅ detected by the central thermistor 5 and the temperature T detected by the non-sheet passing area thermistor 12
_{When 12} is detected and T ₁₂ -T ₅ <20, it is determined that the temperature rise of the non-sheet passing portion does not appear, and normal temperature control is performed. But T
_{If 12} −T ₅ ≧ 20, it is determined that the temperature rise in the non-sheet passing portion appears, and the section is set as the non-sheet passing portion temperature rising countermeasure mode. When moving to the section, tmax = 270
Rewritten as msec.

Section [continuous energization limit control I] tma
while also detect T _5, T ₁₂ in x = 270msec present mode, it continues to temperature control. However, for continuous energization of the heater, 270 m
A limit of sec or less is added. And T ₅ and T
Looking at the difference of ₁₂ , if T ₁₂ -T ₅ <0, it is judged that the temperature rise in the non-sheet passing portion has recovered, and the processing returns to the section. In addition, 0 ≦ T
_In the range of _12- T ₅ <20, temperature control is continued as it is, and T
_{If 12} −T ₅ ≧ 20, it is determined that the temperature rise in the non-sheet passing area has progressed, and the process moves to the section. When moving to the section, it is rewritten as tmax = 230 msec.

Section [continuous energization limit control II] tma
x = 230 msec In this mode, control is performed in the same way as in the section. Then, while T ₁₂ -T ₅ ≧ 0, control by the section is performed, and when T ₁₂ -T ₅ <0, it is determined that the temperature rise in the non-sheet passing portion has recovered, and the process returns to the section.

FIG. 19 shows the case where the value of tmax is ∞, 270 msec, and 2 as described in this embodiment.
In the case of 30 msec, each heater light distribution is shown, and as the temperature rise in the non-sheet passing portion becomes more severe, the light distribution at both ends of the heater becomes lower.

As described above, according to the present embodiment, the second temperature detecting element determines the temperature rise of the non-sheet passing portion, and accordingly the continuous energization time to the heater is limited. , Even if you do not specify the paper size, you can automatically respond to the temperature rise in the non-sheet passing area. Since there are multiple levels of control, you can perform more effective temperature control according to the degree of temperature rise in the non-sheet passing area. Is obtained.

<Fourth Embodiment> Next, a fourth embodiment of the present invention will be described with reference to FIGS. 22 is a configuration diagram of an electrophotographic printer according to the fourth embodiment of the present invention.

In FIG. 22, reference numeral 22 is a photosensitive drum which is an electrophotographic photosensitive member, and a photosensitive material such as OPC, amorphous Se or amorphous Si is formed on a cylindrical substrate such as aluminum or nickel. The photosensitive drum 2
A charging roller 23, a developing device 24, and a cleaner 25 are disposed around the periphery of 2, and are integrated as an electrophotographic cartridge.

The surface of the photosensitive drum 22 is uniformly charged by the charging roller 23, and then a laser scanner 26 raster-scans an image signal to expose the image signal. This exposure is performed by scanning the blinking of the semiconductor laser with a polygon scanner and forming an optical spot image on the photosensitive drum 22 by the optical system and the folding mirror 27. As a result, an electrostatic latent image is formed on the photosensitive drum 22, and the electrostatic latent image is developed by the developing device 24. For the development, jumping development, two-component development, FEED image, etc. are used, and image exposure is performed by turning on the laser at the place where an image is formed to eliminate the electric charge of the latent image and reversal development in which toner is attached to the less charged one. Often used as.

The developed image is transferred to the recording material.
The recording materials are contained in a cassette 28 and are fed one by one by a paper feed roller 29. When a print signal is sent from the host device, the paper is fed by the paper feed roller 29, and the toner image is transferred onto the recording material by the transfer roller 31 in synchronization with the image signal by the timing roller 30. The transfer roller 31 is an electrically conductive elastic body having a low hardness, and electrostatically transfers by a bias electric field in a nip portion formed between the transfer roller 31 and the photosensitive drum 22. The recording material on which the image is transferred is fixed by the fixing device 32, then sent by the paper discharge roller 33, and discharged to the paper discharge tray 34. On the other hand, the untransferred toner is cleaned by the blade of the cleaner 25.

In the apparatus of this embodiment as described above, the light emission intensity and the light emission duty of the semiconductor laser of the laser scanner 26 are controlled by the exposure control section 36, and the applied bias of the charging roller 23, the applied bias to the developing device 24, The bias applied to the transfer roller 31 is the high voltage controller 3
Controlled by 7. The drive control of the main motor (not shown), the scanner motor, and the fixing device 32 is controlled by the drive control unit 38, and the pressing force, temperature and fixing speed of the fixing device 32 are controlled by the fixing control unit 39. It Further, the operations of the paper feed roller 29 and the timing roller 30 are controlled by the paper feed controller 40.

FIG. 23 shows the connection between the host device and the printer device. Reference numeral 41 is the printer device of this embodiment. Reference numeral 42 denotes a host device such as a mini computer, a workstation, a personal computer, etc., which are connected by a communication cable 43. As a result, between the host device and the printer, signals relating to the operation of the printer device, or image information, environmental information, information relating to print paper, etc. are exchanged. In FIG. 23,
Although the host device and the printer device are connected one-on-one, multiple host devices and multiple printers may be connected on the network. In this case, select any combination of host and printer on the network to operate. Let

FIG. 24 is a control panel of the printer device displayed on the host device. The control panel has information 4 such as conventional paper size, paper feed direction, number of prints, magnification, font size, etc.
4, the room temperature, humidity, the thickness of the paper to be printed, the type of paper such as envelopes, OHP paper, label paper, and cardboard,
Information 45 necessary for the user to obtain a more preferable print can be set, such as whether the image to be printed emphasizes text such as characters and symbols or emphasizes gradation such as graphics and natural images. Selected items are marked with a double circle so that they can be seen at a glance. If the information 45 is not designated, it is set to a predetermined default state.

Then, the information set on the control panel is sent to the printer through the communication cable 43.

These processing routines are supplied as a printer driver OS from a printer maker, and are used by a user, a host maker, or an application maker by incorporating them in a system OS or an application.

FIG. 25 is a block diagram of the operation control unit of the printer of this embodiment. Image data or printer control information code as shown in FIG. 24 is transmitted from the host device 42 through the communication cable 43.

The image data output from the host device 42 is sent to the image developing section 47 via the interface 46 and converted into raster data. Further, commands relating to printer control are sent to the printer control unit 48. The image development unit 47 and the printer control unit 48 operate while synchronizing timings and exchanging data. Further, the operations of the exposure controller 36, the high voltage controller 37, the motor controller 38, the fixing controller 39, and the paper feed controller 40 are controlled by the control of the printer controller 48.

FIG. 26 shows the printer controller 48. The operation program and data for the entire device are stored in the main ROM 56.
It is stored in. The correction program and the correction data for the change information of the external conditions are stored in the sub ROM 57.

These programs and data are stored in the CPU 5
The calculation is controlled by 5. Information 45 from the host device 42 is sent from the interface 46 of FIG.
Is input to the RAM 58, and the information 45 and the result of the correction calculation processing based on the information 45 are stored in the RAM 58. In addition,
The information and the calculation result stored in the RAM 58 are held until the information is updated or the power is reset.

The feedback information from the sensors is transmitted to the CPU 55 via the I / O port 59, and the control of each part is controlled from the CPU 55 by the I / O port 59.
Is transmitted to each control unit via.

As described above, in this embodiment, environmental information, recording material information, etc. are sent from the host device to the printer, and the fixing temperature is changed based on the information to adjust the amount of heat applied to the toner to obtain a sufficient fixing property. Can be secured and a better image can be obtained.

Next, the relationship between the environmental information and the recording material information and the fixability will be described. First, FIG. 27 shows the relationship between the recording material thickness and the fixing property.
mm, outer diameter 25 mm, wall thickness 3.0 mm, aluminum cored bar coated with PFA of 25 μm, using a fixing device that uses a roller with an outer diameter of 25 mm in which a silicone rubber is bonded to an iron cored bar as a pressure roller. However, it was measured at room temperature (23 ° C.).

Here, the fixability is defined by the reduction rate of the reflection density of the image after rubbing with a paper having a constant weight applied with a weight. The recording material thickness is defined by the basis weight.

As shown in FIG. 27, generally, as the thickness (basis weight) of the recording material increases, the amount of heat taken by the recording material increases,
On the contrary, the amount of heat given to the toner is reduced and the fixing property is deteriorated.
The reflection density decrease rate of a black image fixed at a fixing temperature of 185 ° C. using the above-described fixing device is 100 g when the basis weight of the recording material is 100 g.
/ M ² or more, the reduction rate exceeds 5% and the fixing temperature is 18
At 5 ° C, sufficient fixing properties cannot be ensured, so it is necessary to further raise the fixing temperature by 10 ° C. Conversely, the basis weight is 60g
For a recording material having a fixing temperature lower than / m ² , wrinkles are likely to occur when the fixing temperature is high, so it is better to lower the fixing temperature by 10 ° C. In the case of the fixing device used in this embodiment, when a thin recording material is used, sufficient fixing property can be secured even if the fixing temperature is 175 ° C.

Next, as shown in FIG. 28, paper having a normal thickness (basis weight: 80 g / m ² ) is used as a recording material, and the fixing temperature is 185 ° C.
The relationship between the room temperature and the fixability is shown.

As shown in FIG. 28, generally, when the ambient temperature in which the printer is used is lowered, the heat given to the toner from the fixing roller is taken to the surroundings, and the fixing property tends to be deteriorated. In the case of the fixing device used in this example, the reflection density decrease rate becomes 5% or more when the room temperature becomes 17 ° C. or less,
In order to secure the fixability, it is necessary to raise the fixing temperature by 10 ° C. Especially when the room temperature is below 10 ℃, 195 ℃
Since it is not possible to secure sufficient fixability even at the fixing temperature of, it is necessary to raise the fixing temperature by 5 ° C. to 200 ° C.

FIG. 29 shows the relationship between the fixing temperature and the fixability under a normal temperature (23 ° C.) environment when a fixing device having the same structure as the above fixing device is used. Here, the recording material is plain paper (80
g / m ² ) is used.

In this embodiment, the fixing temperature is corrected based on these data.

Next, when the above-mentioned fixing device is used,
Fixing temperature control based on information from host FIG. 30
This will be described with reference to the flowchart of. When the fixing device was used, the default fixing temperature was 185 ° C. at which the reduction ratio of reflection density was 4% at room temperature.

First, it is judged whether or not there is information from the host (S1), and if there is no information, the fixing temperature is controlled to the default value (S2). On the other hand, when there is information from the host, the type of recording material is first checked to determine the recording material thickness from that type (S3). If the recording material is thick (basis weight of 100 g / m ² or more), the fixability will be poor, so
The fixing temperature is corrected by + 10 ° C (S4). Further, without correcting in the case of the thickness of the recording material is plain (basis weight ^{60~100g / m 2) (S5)} , a thin thickness of the recording member (basis weight 60 g / m ²
In the case of (below), wrinkles are likely to occur, so the fixing temperature is -10.
C is corrected (S6). These correction values are added to the control data (S7).

Next, the room temperature is judged (S8), and if the room temperature is 10 ° C to 17 ° C, the fixing temperature is corrected by + 10 ° C (S9). When the temperature is high and normal (17 ° C. or higher), nothing is corrected (S10), and when the room temperature is 10 ° C. or lower, the fixing temperature is corrected by + 15 ° C. (S11). These correction values are added to the control data (S1).
2).

The correction temperature obtained by adding the correction value as described above is added to the default value (185 ° C.) to correct the fixing temperature (S13). The fixing temperature thus determined is sent to the fixing controller 39, and the fixing controller 39 controls the heater (S14). When the printer is not used (standby), the fixing device temperature is controlled to the default value (185 ° C. here).

As described above, according to the present invention, the fixing temperature can be determined based on the recording material information and the room temperature information from the host, sufficient fixing property can be secured, and an optimum image can be obtained.

<Fifth Embodiment> Next, a fifth embodiment of the present invention will be described with reference to FIGS. In addition, Example 4
The same parts as those in FIG.

In Example 4, the fixing temperature was changed based on the information from the host device to secure sufficient fixing property. However, for example, when it is desired to immediately pass a thick recording material after a thin recording material, according to the fourth embodiment, a time of several seconds to ten and several seconds is required until the temperature of the fixing roller reaches the corrected fixing temperature. Become.

Therefore, in the present embodiment, environmental information, recording material information, etc. from the host device are ensured so that sufficient fixing performance can always be ensured even when recording materials having different thicknesses are continuously passed. Based on this, the amount of heat applied to the recording material is changed by changing the pressure applied by the pressure roller to increase or decrease the nip width so as to ensure sufficient fixing property.

FIG. 31 shows the relationship between the pressing force and the fixability when the fixing device having the same structure as that used in Example 4 is used. A recording material with a basis weight of 80 g / m ² is used and the fixing temperature is 1
It is a value measured at 85 ° C. in a normal temperature environment (23 ° C.).

Next, the control of this embodiment for correcting the pressing force of the pressure roller based on this data will be described with reference to the flowchart of FIG. The pressing force in the flowchart is a value when a fixing device having the same structure as the fixing device shown in the fourth embodiment is used. The default value of the pressing force in this case is set to 7 kgf.

First, it is judged whether or not there is information from the host (S15), and when there is no information, the pressure is controlled to the default value (S16). On the other hand, when there is information from the host, the type of the recording material is checked to determine the thickness from the type (S17), and in the case of a thick recording material, the fixing property becomes poor, so the pressing force is corrected by + 10% ( S18). If the recording material has a normal thickness, nothing is done (S19),
When the thickness of the recording material is thin, the fixing property is good and conversely wrinkles are likely to occur, so the pressing force is corrected by -10% (S20).
These correction values are added to the control data (S)
21).

Thereafter, the room temperature is judged (S22), and if the temperature is high or normal, the fixing property is good and no correction is made (S23). Correct by + 5% (S24). These correction values are
A correction value is added to the control data (S25). A value obtained by further adding a correction value and a default value (7 kg in this embodiment)
From f), the corrected pressure is calculated (S26).

The pressing force thus calculated is controlled by the fixing controller 39 and the drive controller 38 (S27).

FIG. 33 shows an example of pressure control. The solenoid 65 for suppressing the eccentric cam 64 abutting on the core metal of the pressure roller 61 is turned off by a signal from the fixing control section. In that state, the eccentric cam 64 is rotationally driven until the desired pressure is applied, and the solenoid 65 is turned on again to fix the eccentric cam 64 and the pressure roller 61. When the printer is not used (standby), the pressure is controlled to the default value (total pressure 7 kgf here).

As described above, according to the present invention, by determining and changing the pressing force based on the recording material information and the room temperature information from the host, sufficient fixing property can be secured and an optimum image can be obtained. it can. Further, even when recording materials having different thicknesses are continuously flowed, the pressure can be changed in a few seconds to secure sufficient fixing property, and an optimum image can always be obtained.

<Sixth Embodiment> Next, a sixth embodiment of the present invention will be described with reference to FIGS. In addition, the same parts as those in the fourth embodiment will be described with the same reference numerals.

Although the fixing temperature and the pressing force at the time of fixing are changed in each of the fourth and fifth embodiments, in the present embodiment, the recording material conveying speed of the fixing device is based on the environmental information and the recording material information from the host device. (Hereinafter referred to as fixing speed) is changed to optimize the fixing time, and the amount of heat applied to the toner is changed to secure sufficient fixing property.

FIG. 34 shows the relationship between the fixing speed and the fixability when the fixing device having the same structure as the fixing device shown in the fourth embodiment is used. As the recording material, plain paper having a basis weight of 80 g / m ² was used, and the measurement was performed at a fixing temperature of 185 ° C. and under a normal temperature environment (23 ° C.).

Next, the control of this embodiment for correcting the fixing speed based on this data will be described with reference to the flowchart of FIG. The fixing speed in the flowchart is
The values are obtained when the fixing device having the same structure as that of the fourth embodiment is used. The default value of the fixing speed is 50 mm / sec.

First, it is judged whether or not there is information from the host (S28), and if there is no information, the fixing speed is controlled to the default value (S29). On the other hand, when there is information from the host, the type of recording material is checked to determine the thickness from the type (S30), and the thick recording material (100 g / m 2 basis weight) is used.
² ) or more), the fixing property will deteriorate, so the fixing speed should be
Correct by 10% (S31). When the recording material has a normal thickness (basis weight 60 to 100 g / m ² ), no correction is made (S32), and when the recording material has a thin thickness (basis weight 60 g / m ² or less), fixing is performed. Good, and conversely wrinkles easily occur,
The fixing speed is corrected by + 10% (S33). These correction values are added to the control data (S34).

After that, the room temperature is judged (S35), no correction is made in the case of high temperature or normal (17 ° C. or higher) (S36), and the fixing property deteriorates in the case of low temperature (17 ° C. or lower). The fixing speed is corrected by -5% (S37). These correction values are added to the control data (S3).
8). Further, the corrected fixing speed is calculated from the value obtained by adding the correction value and the default value (50 mm / sec in this embodiment) (S39), and the fixing speed thus calculated is controlled by the fixing control unit 39 and the drive control. It is controlled by the unit 38 (S4
0). The fixing speed is changed by, for example, providing a gear box between the main motor and the fixing roller drive gear. The fixing speed is controlled to a default value (here, 50 mm / sec) when the printer is not used (standby).

As described above, according to the present invention, the fixing temperature (recording material conveying speed of the fixing device) is determined based on the recording material information and the room temperature information from the host, and the amount of heat given to the toner is optimized by changing the fixing temperature. It is possible to obtain an optimum image while ensuring sufficient fixing property. Further, even when recording materials having different thicknesses are continuously flowed, the fixing speed can be changed in a few seconds to secure sufficient fixing property. Further, the drive for changing the recording material conveying speed of the fixing device can be made easier than the drive for changing the pressing force of the pressure roller.

<Seventh Embodiment> Next, a seventh embodiment of the present invention will be described. In addition, the same parts as those in the fourth embodiment will be described with the same reference numerals.

In the sixth embodiment, the recording material conveying speed of the fixing device is changed based on the information from the host device, and the total amount of heat given to the toner is changed to secure the fixing property.
In this embodiment, the fixing speed is optimized by changing the process speed based on the environmental information and the recording material information from the host device, and the amount of heat applied to the toner is changed to secure sufficient fixing property.

The process speed (= fixing speed) is calculated by the same method as in the sixth embodiment.

The calculated process speed is controlled by the drive control unit 38. If a variable speed motor whose rotation speed changes only by electrical control is used as the main motor,
The process speed can be changed without any special drive mechanism only by software control, and the fixing speed can be easily optimized. Therefore, it is possible to always secure sufficient fixing property and obtain the optimum image. it can.

<Eighth Embodiment> Next, an eighth embodiment of the present invention will be described with reference to FIGS. 37 and 38. This embodiment relates to a fixing device in an image forming apparatus (not shown), and FIG. 37 is a schematic sectional view showing the main part of this embodiment.
FIG. 4 is a sectional view in the roller axial direction.

The fixing roller 300 is a halogen heater 400.
And a surface of an aluminum core metal 301 is covered with a fluororesin layer 302.

The pressure roller 500 comprises a core metal 501, a low hardness silicone rubber layer 502, a low resistance silicone rubber layer 503, and a release layer 504, which are coated in this order. The conductive elastic layer 503 is made by dispersing carbon black in silicone rubber and has a higher rubber hardness than the elastic layer 502, but the roller hardness is reduced by reducing the layer thickness. By using the multi-layer structure as in this embodiment, the temperature is 5 to 10 degrees or more compared to the case where the conductive silicone rubber is used to form the single-layer structure.
r-C) hardness can be reduced.

The pressure roller 500 forms a nip together with the fixing roller 300, where heat is applied to the toner image to melt it and form a permanently fixed image on the recording material. At this time, the pressure roller 50
The surface potential of 0 has an important meaning for the offset phenomenon together with the surface potential of the fixing roller 300, and it is preferable to form the electric field in the direction of pressing the toner against the recording material. The conductive elastic layer 503 of the pressure roller 500 of this embodiment is for controlling the surface potential of the pressure roller 500.

A conductive plate 700 is formed on the conductive elastic layer 503.
The electric potential is given from. Reference numeral 600 in FIG. 38 indicates a contact point of the carbon chip, which is in good contact with the conductive plate 700 and is kept at the ground potential in this embodiment. Further, by supplying the electric potential of the conductive plate 700 to the power source, the surface potential of the pressure roller 500 can be made the toner holding potential, and a stronger offset preventing effect can be provided.

The conductive plate 700 is mainly in pressure contact with the end surface of the insulating elastic layer 502 except near the nip portion, but the pressure roller 500 near the nip portion follows the curvature of the fixing roller due to elastic deformation. The conductive plate 700 surely contacts the side surface of the conductive elastic layer 503.

As the pressure roller 500 rotates, the conductive elastic layer 503 rubs against the conductive plate 700 and both contact surfaces are refreshed appropriately, so that the contact state between them is always kept good. The surface potential of the pressure roller 500 is controlled over long-term use.

<Ninth Embodiment> Next, a ninth embodiment of the present invention will be described with reference to FIGS. 39 and 40. The same parts as those of the eighth embodiment are designated by the same reference numerals and the description thereof will be omitted.

This embodiment relates to a fixing device in an image forming apparatus (not shown). FIG. 39 is a schematic sectional view showing the main part of this embodiment, and FIG. 40 is a sectional view in the roller axial direction.

The low hardness elastic layer 502 of the pressure roller 500 is further reduced in hardness by using foamed silicone rubber, and the conductive elastic layer 503 is molded so as to cover a part of the end surface of the elastic layer 502 (2 to 5 mm). And the conduction plate 700
Is brought into contact with the recess.

The pressure roller 500 forms a nip together with the fixing roller 300, where heat is applied to the toner image to melt it and form a permanently fixed image on the recording material. At this time, the pressure roller 50
The surface potential of 0 has an important meaning for the offset phenomenon together with the surface potential of the fixing roller 300, and it is preferable to form an electric field in the direction of pressing the toner against the recording material. The conductive elastic layer 503 of the pressure roller 500 of this embodiment.
Is for controlling the surface potential of the pressure roller 500.

A conductive plate 700 is formed on the conductive elastic layer 503.
The electric potential is given from. Reference numeral 600 in FIG. 40 indicates a contact point of a carbon chip, which is in good contact with the conductive plate 700 and is kept at the ground potential in this embodiment. Further, by supplying the electric potential of the conductive plate 700 to the power source, the surface potential of the pressure roller 500 can be made the toner holding potential, and a stronger offset preventing effect can be provided.

The conductive plate 700 is mainly in contact with the end surface of the insulating elastic layer 502 except in the vicinity of the nip portion, but in the vicinity of the nip portion, the pressure roller 500 follows the curvature of the fixing roller due to elastic deformation. The plate 700 surely contacts the inner wall of the conductive elastic layer 503.

With the rotation of the pressure roller 500, the conductive elastic layer 503 rubs against the conductive plate 700 and the contact surfaces of both are appropriately refreshed, so that the contact state between the two is always kept good. The surface potential of the pressure roller 500 is maintained over long-term use. Further, in this embodiment, since the pressure applied by the pressure roller 500 to the fixing roller 300 is also applied to the conductive plate 700 as a contact pressure, there is an advantage that more reliable conductivity can be secured.

<Embodiment 10> Next, Embodiment 10 of the present invention.
Will be described with reference to FIGS. 41 and 42. The same parts as those of the eighth embodiment are designated by the same reference numerals and the description thereof will be omitted.

This embodiment relates to a latent image forming portion using a charging roller in an image forming apparatus (not shown), and FIG. 41 is a schematic sectional view showing a main portion of this embodiment, FIG.
FIG. 4 is a sectional view in the roller axial direction.

Reference numeral 100 is a photosensitive drum, and 200 is a charging roller. The charging roller 200 has an EP on the surface of the core 201.
E coated with DM foam layer 202 and further provided with conductivity
PDM rubber layer 203, protective layer 204 for adjusting electric resistance
Consists of.

The surface potential of the charging roller 200 is controlled to Vd by applying a voltage to the conductive EPDM rubber layer 203 from the outside (DC component), and charges are exchanged through the protective layer 204 to allow the photosensitive drum 100 to be exposed. Is charged to a potential of Vd. It is considered that the charging process is performed in the gap between the charging roller 200 and the photosensitive drum 100, but the normal charging roller 2 is used to facilitate the gap management.
00 is pressed against the photosensitive drum 100 to form a nip.

Further, in this embodiment, the conductive EPDM rubber layer 2 is used.
Although the charging bias of the photosensitive drum 100 is ensured by superimposing an AC bias Vpp as a voltage applied to 03, the charging roller 200 may vibrate due to this AC bias and generate a sound called a charging sound. is there. In this embodiment, by providing the EPDM foam layer 202, the hardness of the charging roller 200 is suppressed to a low level and the charging noise is reduced.

The conductive plate 700 is a metal plate made of stainless steel or the like, and is placed at a position where it is brought into contact with the side surface of the charging roller 200 with a light pressure or a minute gap is formed, and does not move to the outside in the axial direction. To limit the movement. Therefore, the charging roller 2 by pressing the conductive plate 700
It is possible to prevent mechanical deterioration such as deformation and biting of 00.

Since it is necessary to constantly supply the charge from the power source to the charging roller 200, there is a risk of electrical failure such as conduction failure in the power supply by such a light pressure contact, but in the present embodiment, the nip is formed. By using a low hardness elastic roller having a large elastic deformation amount as the charging roller 200,
As shown in FIG. 42, the end surface of the charging roller 200 is displaced outward at the nip portion, and a contact pressure is generated between the charging roller 200 and the conduction plate 700, so that conduction can be surely achieved.

[0134]

According to the first aspect of the present invention, since the heating source disposed on the heating roller is composed of at least two kinds of heat generating portions having different rising characteristics, continuous energization of the heater during small size sheet feeding. By limiting the time and using only the heat-generating part with a slow start-up during the start-up, the heat supply to the non-paper-passage area can be suppressed. By using it with the heat generating part of the stand up, it is possible to supply heat to the entire area of the roller, so that an optimum temperature distribution on the heating roller can be obtained for any paper size. , That one AC
It can be done only by the driver.

Further, according to the second invention of the present application, at least one of the temperature condition of the installation place, the humidity condition, the thickness of the printing paper, the type of the printing paper, the pattern information of the printing image, etc. is received from the host device, Accordingly, by changing the fixing conditions such as the fixing temperature, the pressing force during fixing, and the fixing time, the amount of heat given to the toner is changed to improve the fixing performance, and the user can change the fixing condition from the host device according to the usage situation. By sending information such as external conditions and the state of use to the printer, it is possible to obtain an optimum image with sufficient fixing property.

Therefore, the external condition detecting device is not required and the cost is reduced. Further, since it is not necessary to install the detection device in the printer, the space for it can be saved, and the device can be downsized. Also, regarding factors such as recording material thickness that are technically difficult to detect and have a large effect on fixability, it is possible to easily determine the recording material thickness by human judgment, improve accuracy, and achieve more optimal fixing. The printer can be controlled according to the conditions. Further, it is also possible to send information that cannot be detected by a detection device or the like, and thereby it is possible to select more optimal fixing conditions for securing sufficient fixing property.

Also, since the settings can be made while the host is present, it is not necessary to go to the printer that is placed at a remote place to set the conditions, the operation is convenient, and the settings can be neglected. There is no.

Furthermore, according to the third invention of the present application, there is provided an elastic rotating body in which a low hardness elastic layer is provided on the outer periphery of a rigid cored bar, and a conductive elastic layer is further provided on the outer periphery thereof, and the elastic rotating body is opposed to each other. A nip is formed with one or more other rotating bodies, and a conducting plate having a contact area or a contact pressure with respect to the side surface of the conductive elastic layer near the nip is increased, and the potential of the conducting plate is controlled. By this, the contact surface between the conductive elastic layer and the conductive plate is appropriately refreshed without hindering the flexibility and shape of the elastic rotating body, so that reliable conduction can be maintained, and the surface of the elastic rotating body can be maintained. The potential could be controlled over a long period of time.

[Brief description of drawings]

FIG. 1 is a sectional view showing a schematic configuration of a device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a rated current of a heater used in the apparatus of FIG. 1 and a luminous flux rise time.

FIG. 3 is a diagram showing a rising state of a heater having a slow rising characteristic used in the apparatus of FIG.

FIG. 4 is a diagram showing a rising state of a heater having a fast rising characteristic used in the apparatus of FIG.

FIG. 5 is a diagram showing a flowchart of temperature control in the device according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a normal lighting state of a heater having a slow rising characteristic used in the apparatus of FIG. 1;

7 is a diagram showing a lighting state of a heater having a slow rising characteristic used in the apparatus of FIG.

FIG. 8 is a diagram showing a normal lighting state of a heater having a fast rising characteristic used in the apparatus of FIG. 1;

FIG. 9 is a diagram showing a lighting state of a heater having a fast rising characteristic used in the apparatus of FIG.

FIG. 10 is a diagram showing a heater light distribution when the device in FIG. 1 is normally used.

FIG. 11 is a diagram showing a heater light distribution when a small-sized sheet is passed through the apparatus of FIG. 1;

FIG. 12 is a diagram showing a heating roller surface temperature distribution during normal use in the apparatus of FIG.

13 is a diagram showing a heating roller surface temperature distribution when a small-sized sheet is passed in the apparatus of FIG.

FIG. 14 is a cross-sectional view showing a schematic configuration of a second embodiment device of the present invention.

FIG. 15 is a cross-sectional view showing a schematic configuration of a device of Example 3 of the present invention.

16 is a diagram showing a flowchart of temperature control in the apparatus of FIG.

17 is a diagram showing a flowchart of temperature control in the apparatus of FIG.

18 is a diagram showing a flowchart of temperature control in the apparatus of FIG.

FIG. 19 is a diagram showing a heater light distribution with respect to an energization limit time in the apparatus of FIG. 15;

FIG. 20 is a sectional view showing a schematic configuration of a conventional device.

FIG. 21 is a cross-sectional view showing a schematic configuration of a conventional device.

FIG. 22 is a configuration diagram of an electrophotographic printer according to a fourth embodiment of the present invention.

FIG. 23 is a connection diagram of a host device and a printer device in Embodiment 4 of the present invention.

FIG. 24 is a diagram of a control panel of the printer device displayed on the host device of FIG. 23.

FIG. 25 is a block diagram of an operation control unit of the printer device of FIG. 22.

FIG. 26 is a diagram illustrating the printer control unit in FIG. 22.

FIG. 27 is a graph showing the relationship between recording material thickness and fixability used in Example 4 of the present invention.

FIG. 28 is a graph showing the relationship between room temperature and fixability used in Example 4 of the present invention.

FIG. 29 is a graph showing the relationship between fixing temperature and fixability used in Example 4 of the present invention.

FIG. 30 is a flowchart of fixing temperature control according to the fourth embodiment of the present invention.

FIG. 31 is a graph showing the relationship between the pressure applied during fixing and the fixability used in Example 5 of the present invention.

FIG. 32 is a flow chart of pressurizing force control in Embodiment 5 of the present invention.

FIG. 33 is a diagram showing an example of pressurizing force control according to the fifth embodiment of the present invention.

FIG. 34 is a graph showing the relationship between the fixing speed and the fixability used in Example 6 of the present invention.

FIG. 35 is a flowchart of fixing speed control in Embodiment 6 of the present invention.

FIG. 36 is a cross-sectional view of a conventional heat fixing device.

FIG. 37 is a schematic cross-sectional view showing the main parts of an eighth embodiment device of the present invention.

38 is an axial cross-sectional view of the device of FIG. 37.

FIG. 39 is a schematic cross-sectional view showing the main parts of the device of Example 9 of the present invention.

40 is an axial cross-sectional view of the device of FIG. 39.

FIG. 41 is a schematic sectional view showing a main part of the device according to the tenth embodiment of the present invention.

42 is an axial cross-sectional view of the device of FIG. 41. FIG.

FIG. 43 is a schematic view showing a conventional example.

FIG. 44 is a schematic view showing a conventional example.

[Explanation of symbols]

 1 Fixing Roller (Heating Roller) 2 Pressurizing Roller 3 and 4 Halogen Heater (Heating Source) 5 Temperature Detector (Temperature Detection Means) 7 CPU (Control Means) 38 Drive Control Unit 39 Fixing Control Unit 50 Fixing Device 52 Heater 60 Fixing Roller 61 Pressure roller 62 Toner image 63 Recording material 64 Eccentric cam 65 Solenoid 100 Photosensitive drum 200 Charging roller 300 Fixing roller 500 Pressure roller 700 Conductive plate

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical indication location G03G 15/00 102 G05D 23/19 A 9132-3H (72) Inventor Yuko Tanaka Shimomaruko Ota-ku, Tokyo 3-30-2 Canon Inc. (72) Inventor Tatsuichi Tsukita 3-30-2 Shimomaruko, Ota-ku, Tokyo Incorporated Canon Inc. (72) Masahiro Goto 3-chome Shimomaruko, Ota-ku, Tokyo No. 30-2 Canon Inc. (72) Inventor Tatsunori Ishiyama 3-30-2 Shimomaruko, Ota-ku, Tokyo No. 30 Canon Inc. (72) Takahiro Inoue 3-30-2 Shimomaruko, Ota-ku, Tokyo No. Canon Inc.

Claims (10)

[Claims] 1. A heating roller and a pressure roller arranged so as to be in pressure contact with each other, a heating source arranged inside the heating roller, a temperature detecting means for detecting a surface temperature of the heating roller, and the temperature. In a heat fixing device having a control means for maintaining the surface temperature at a predetermined temperature based on the temperature information obtained from the detection means, the heating source is composed of at least two kinds of heat generating parts having different rising characteristics. A heating and fixing device characterized by the above. 2. The heat fixing device according to claim 1, wherein the heat generating portion is electrically connected in series. 3. The heat fixing device according to claim 1, wherein the time during which continuous heat can be supplied to the heat generating portion is limited depending on the type of paper to be passed. 4. The temperature detecting means is provided with a means for detecting the surface temperature of the heating roller in the paper passing area and a means for detecting the surface temperature of the non-paper passing area. The heat fixing device according to claim 1 or 2, wherein the heat fixing device is limited by a difference between temperature information obtained by the two temperature detecting means. 5. The heat fixing device according to claim 1, wherein the heating source is a halogen heater. 6. An electrophotographic printer for receiving an instruction and an image signal from a host device to print an image, the host device's temperature condition, humidity condition, thickness of printing paper, type of paper, A printer characterized by receiving at least one of pattern information of an image to be printed and changing a fixing condition in accordance therewith. 7. The printer according to claim 6, wherein the fixing temperature is changed according to the information received from the host device. 8. The printer according to claim 6, wherein the pressing force at the time of fixing is changed according to the information received from the host device. 9. The printer according to claim 6, wherein the fixing time is changed according to the information received from the host device. 10. An elastic rotating body in which a low hardness elastic layer is provided on the outer periphery of a rigid cored bar, and a conductive elastic layer is further provided on the outer periphery thereof, wherein the elastic rotating body is one or more other rotating members facing each other. An elastic rotating body characterized by forming a nip with a body and comprising a conducting plate having a contact area or a contact pressure with respect to the side surface of the conductive elastic layer which is increased in the vicinity of the nip, and controlling the potential of the conducting plate. Surface potential control means.