JPH06130847A - Thermal roll fixing device - Google Patents

Abstract

PURPOSE:To satisfy temperature control and fixing ability in the case two kinds of lamps are arranged for a heating roll so as to comply with conditions that rated voltage is different. CONSTITUTION:A thermal roll fixing device 1 is constituted by combining the heating roll 2 and a pressure roll 3, and two lamps 5 and 6 are arranged inside the heating roll 2 corresponding to the condition that the rated voltage is different. Relation between a position where a temperature detecting sensor 8 and the position of fixing nip with respect to the heating roll 2 is set to a=b and c=d. Whatever lamp is used, the temperature control by the temperature detecting sensor is excellently performed and the difference of the fixing ability is not made. Even when an image forming device is used in a region where the rated voltage is different, fixing temperature is easily controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat roll fixing device for use in an image forming apparatus such as an electrophotographic copying machine, and more particularly to a heat roll in which two lamps having different rated voltages are arranged as heating sources. The present invention relates to a fixing device having a mechanism for performing a fixing action by using one of the lamps according to the above.

[0002]

2. Description of the Related Art In an image forming apparatus for making a copy by using an electrophotographic system such as an electrophotographic copying machine, a toner image formed on a photosensitive drum or the like is transferred onto a sheet, and the sheet carrying the toner image is transferred. The means for fixing and fixing a copy through a fixing device is used. As the fixing device, a heat roll fixing device is often used because of its simple structure and its small size. The heat roll fixing devices are arranged so as to face each other and constitute a mechanism for nipping the paper at a predetermined pressure and applying a heating and pressurizing action. One of the two rolls or both rolls are provided. On the other hand, one having a built-in heat source such as a halogen lamp is used. Then, by turning on the lamp, the roll member is heated,
When the paper carrying the toner image is passed through, the toner is melted by heat and pressed against the paper to be fixed.

Generally, only one heating source such as a lamp provided on the heating roll of the above heat roll fixing device is arranged.
As shown in Japanese Patent No. 6988, a lamp having two built-in lamps is also used. In the heating roll of the conventional example, in an electrophotographic copying machine or the like which uses a lot of small-sized paper, a lamp having a narrow heating range is provided corresponding to the width of the small-sized paper. When the paper is continuously fixed, it is possible to prevent the temperature from locally decreasing.

In addition to the above-mentioned conventional example, even if the voltage to be used varies from country to country, it is possible to easily adapt by switching the energizing circuit of the lamp without replacing the lamp. In some cases, two lamps having different rated currents may be arranged on the heating roll. For example,
In an example as shown in Japanese Patent Laid-Open No. 62-289878, two lamps are arranged on the heating roll corresponding to two kinds of power sources of 220V and 240V, and the location where the copying machine is used is set. A predetermined lamp can be used according to the voltage.

As described above, the fixing device compatible with two kinds of power sources is constructed as shown in FIG.
For the heating roll 2 that constitutes the thermal roll fixing device 1,
A mechanism that presses the pressure roller 3 is configured so that heat and pressure are applied to the sheet that passes through the fixing nip portion between the both rollers to exert a fixing action. Further, inside the heating roll 2, two lamps 5 and 6 are arranged, and these lamps are made to correspond to two kinds of power sources of 115V and 220V, and the voltage of the installation place of the electrophotographic copying machine is set. Depending on the one lamp can be used. Therefore, in the fixing device that can handle two types of power sources as described above, it is possible to exhibit the advantage that it is not necessary to replace the lamp depending on the place of use.

[0006]

However, when the means for arranging the two lamps 5 and 6 at appropriate positions inside the heating roll 2 is used as shown in FIG. Lamps such as sensors and sensors as temperature detection means,
At present, the relationship with the fixing nip position is not taken into consideration. Therefore, when one of the lamps arranged on the heating roll is used, the time for warming up the fixing device may change with respect to the set value, which may hinder the control of the device. is there. Further, since the distance between the lamp and the fixing nip position is different between the two lamps, the fixing property may be different when the two lamps are used.

However, in the conventional fixing device equipped with two lamps having different rated voltages, it is possible to use the fixing device as it is in any area without changing the lamp corresponding to the rated voltage according to the area. It is an object. Therefore, even if there are some troubles such as the warm-up time of the fixing device and the fixing property, the above-mentioned problems occur because the device manufacturing is prioritized.

[0008]

SUMMARY OF THE INVENTION The present invention solves the problems of the conventional fixing device as described above.
Corresponding to the fixing nip position, the positional relationship between the two lamps is set, and even when fixing is performed using either one of the lamps, the heating of the device can be accurately controlled, and
It is an object of the present invention to provide a heat roll fixing device that can set the fixability well.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a heating roll having a built-in heating source and a pressure roll for pressing a sheet against the heating roll are arranged so as to face each other, and a toner image is provided between the both rolls. The present invention relates to a fixing device for fixing through a sheet carrying paper. In the fixing device of the present invention, two lamps having different rated voltages are arranged on the heating roll as a heating source, and either one of the lamps is used according to the application, and there is a difference in fixing property between the respective lamps. The lamps are arranged so that the number of lamps decreases. Further, the two lamps arranged on the heating roll of the present invention can be arranged at positions where the distances from the nip portion by the two rolls are equal to each other.

Further, in the fixing device of the present invention, temperature detecting means is arranged for the heating roll to control heating of the heating roll, and the temperature detecting sensor and the heating roll are arranged inside the heating roll. Each member can be arranged at a position where the distance between the two lamps is equal. Further, in the fixing device, a tangent line at which the temperature detection sensor is arranged and a tangent line at the fixing nip position are 20 with respect to a line connecting two lamps provided on the heating roll.
The temperature detecting sensor and the nip position can be arranged so as to intersect at an angle of within °. In addition to the above-mentioned configuration, in the present invention, the distance between the temperature detection sensor and the fixing nip position for the two lamps arranged on the heating roll is
It is possible to set equal distances to each other.

As described above, in the hot roll fixing device of the present invention, two types of lamps are arranged inside the heating roll,
By setting the distance between the lamp and the temperature detection sensor and the mutual distance between the fixing nip position, the temperature detection by the temperature detection sensor and the heating control operation are performed accurately regardless of which lamp is used. be able to. Since the effect of temperature detection by the temperature detection sensor is not affected by the position of the lamp, it is possible to accurately control the time required for warming up the fixing device, and it is possible to avoid time lag in temperature control. It can be prevented. Also, in the fixing nip portion between the heating roll and the pressure roll,
By ensuring that the heating action is constant when using either of the two lamps, it is possible to keep the quality of the copy made constant, whichever lamp is used.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The hot roll fixing device of the present invention will be described with reference to the illustrated example. The example shown in FIG. 1 shows a heat roll fixing device 1 in which a heating roll 2 and a pressure roll 3 are arranged to face each other, as in the conventional fixing device. In the heat roll fixing device 1, the heating roll 2 accommodating the two lamps 5 and 6 is arranged at a fixed position, and the pressure roll 3 is pressed toward the heating roll 2 by using a pressure means, and both rolls are pressed. The nip pressure of a predetermined value can be set during the period. Lamps 5 and 6 housed in the heating roll 2
Is configured to have specifications corresponding to two kinds of voltages of 115 V and 240 V, for example, and either one of the lamps can be used depending on the rated voltage used.

In the heat roll fixing device 1 shown in FIG. 1, two lamps 5 arranged in the heating roll 2 are provided.
6 and the fixing nip portions of both rolls are a and b are a =
They are arranged at equal distances so as to have the relationship of b. The heat roll fixing device 1 is configured so that there is no difference in fixability regardless of which lamp is used. Further, in the example shown in FIG. 2, the heating roll 2
The temperature detection sensor 8 is arranged for the above, and the heating temperature of the heating roll is controlled by the temperature detection sensor.

As shown in FIG. 2, the heating roll 2
For the two lamps 5 and 6 disposed inside, the arrangement intervals c and d of the temperature detection sensor 8 are set to have a relationship of c = d, and when the fixing device is warmed up, the time by the power supply is increased. I try not to make a difference. Therefore, as shown in FIG. 2, by adjusting the distance between the temperature detecting sensor and the two lamps, there is no difference in the warm-up time due to the difference in the voltage used.
It is not necessary to change the control program of the copying machine according to the voltage. Further, as described above, when the positions of the two lamps are set to be equidistant from the temperature detection sensor, there is no difference in the temperature detection information by the temperature detection sensor, and therefore there is a problem in fixability. Will not occur.

In the example shown in FIG. 3, when the two lamps 5 and 6 are arranged inside the heating roll, the heating roll 2
The temperature detection sensor 8 is arranged for the above, and the relationship of each member in the apparatus that constitutes the fixing nip portion by the heating roll 2 heated by the lamp and the pressure roll 3 is shown. As shown in FIG. 3, when the line connecting the centers of the two lamps 5 and 6 is L, the tangent to the heating roll of the temperature detection sensor is M, and the tangent to the heating roll 2 at the fixing nip portion is N. In addition, the angles of the tangents M and N with respect to the line L are set to ± 20 °, respectively.

In the example shown in FIG. 3, the relationship between tangents M and N is set for the line L connecting the two lamps, and
Each of the two lamps is located equidistant from the fixing nip position and the temperature detection sensor. And
When the fixing device is configured by setting such conditions, it is possible to control the temperature of heating the heating roll and the fixing action in a good state when using one lamp. become. However, in the example of FIG. 3, the distance between the temperature detection sensor and the fixing nip portion is not set to be constant for each of the two lamps, and therefore when different lamps are used due to the difference in rated voltage. , It is inevitable that there will be a difference in warm-up time between the two lamps.

In the example shown in FIG. 4, the temperature detecting sensor 8 is provided for the two lamps 5 and 6 arranged on the heating roll 2.
In this example, the intervals c and d of the arrangement positions are set to be equal, and the lamp intervals a and b are also set to be equal to each other in the fixing nip portion. In the example shown in FIG. 4, the heating roll is constructed in a state where the means shown in FIGS. 1 and 2 are combined. When the thermal roll fixing device is constructed under such conditions, an arbitrary lamp is used. However, it is possible to prevent a difference between the temperature detection operation and the fixing property.

As shown in FIGS. 1 to 4, respectively,
Two lamps arranged on the heating roll can be arranged for each of the fixing nip position and the temperature detection sensor, or for both members by setting predetermined conditions, respectively. In the invention, the arrangement relationship as shown in FIG. 5 can be set. FIG. 5
In the example shown in FIG. 2, in comparison with the example shown in FIG.
When a line L connecting the two lamps and a line connecting the temperature detection sensor 8 and the center of the heating roll are Ma and a line connecting the centers of the two rolls 2 and 3 is Na, each of the lines L, Ma and Na is The members to be arranged with respect to the heating roll are positioned so that they are at 45 °, 30 °, and 60 ° with respect to the horizontal plane.

Further, in the example shown in FIG. 5, for example, when the arrangement relationship between the two rolls is set to a condition different from the angle of the line Na, the relationship between the other two lines L and Ma is set as follows. It can be changed corresponding to the line Na. Then, in the thermal roll fixing device 1 shown in FIG. 5, the sheet carrying the toner image is guided from the direction of the arrow X toward the fixing nip position, and each roll member is rotated in the direction of the arrow. The sheet is fixed while being conveyed. Therefore, as shown in FIG. 5, the relationship between the temperature detection sensor arranged on the heating roll 2 and the two lamps, and the relationship with the fixing nip position can be set to a constant condition. Even if the rolls have different diameters, the arrangement relationship of the respective members can be set in a good state corresponding to the heating roll.

The thermal roll fixing device of the present invention constructed by setting the above-mentioned conditions is suitable for an image forming apparatus such as an electrophotographic copying machine or a printer which makes a copy using an electrophotographic method. It is possible to apply. Further, the heating lamp can be adapted to any voltage such as using two kinds of lamps of 220V and 240V. Further, as shown in the hot roll fixing device of the present invention, the diameter of the heating roll is different by using the means for setting the relationship between the temperature detection sensor and the fixing nip position for the lamp arranged on the heating roll. A device or a device having a different lamp capacity can be easily configured. Therefore, the fixing device can be easily designed when configuring an image forming apparatus that can support two types of rated voltages.

[0021]

Since the heat roll fixing device of the present invention is constructed as described above, the heat roll fixing device is installed inside the heating roll.
By arranging different types of lamps and setting the distance between the lamp and the temperature detection sensor and the distance between the fixing nip position and each other, whichever lamp is used for the temperature detection and heating control operations by the temperature detection sensor. Even when used, it can be performed accurately. And because the action of temperature detection by the temperature detection sensor is not affected by the position of the lamp,
It is possible to accurately control the time required for warming up the fixing device, and prevent a time lag in temperature control. In addition, the fixing nip portion between the heating roll and the pressure roll was produced under any condition by allowing the heating action to be constant regardless of which of the two lamps is used. The copy quality can be kept constant. By arranging two types of lamps with different rated voltages inside the heating roll, the same product can be delivered even when shipping to countries with different voltages, which is a great advantage in manufacturing. Can be demonstrated.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a relationship between a lamp arranged on a heating roll and a fixing nip position.

FIG. 2 is an explanatory diagram showing a relationship between a lamp arranged on a heating roll and a temperature detection sensor.

FIG. 3 is an explanatory diagram showing a relationship between two lamps, a temperature detection sensor, and a fixing nip position.

FIG. 4 is an explanatory diagram showing a configuration in which two lamps are arranged at the same distance from a temperature detection sensor and a fixing nip position.

FIG. 5 is an explanatory diagram of another embodiment showing the positional relationship of each component in the fixing device of the present invention.

FIG. 6 is an explanatory diagram showing a positional relationship of lamps in a conventional fixing device.

[Explanation of symbols]

1 heat roll fixing device, 2 heat rolls, 3
Pressure roll, 5/6 lamp, 8 temperature detection sensor.

Claims (5)

[Claims] 1. A fixing device in which a heating roll having a built-in heating source and a pressure roll for pressing a sheet against the heating roll are arranged so as to face each other, and a sheet carrying a toner image is fixed between both rolls. , Two lamps having different rated voltages are arranged as heating sources on the heating roll, and either one of the lamps is used according to its application, and the difference in fixing property between the lamps is reduced. A heat roll fixing device having a lamp. 2. The thermal roll fixing device according to claim 1, wherein the two lamps arranged on the heating roll are arranged at positions where the two rolls have the same distance from the nip portion. 3. A temperature detecting means is arranged for the heating roll to control heating of the heating roll, and the distance between the temperature detecting means and two lamps arranged inside the heating roll is equalized. The thermal roll fixing device according to claim 1, wherein the respective members are arranged at positions. 4. The temperature detection is performed such that a tangent line at which the temperature detection means is arranged and a tangent line at a fixing nip position intersect with each other at an angle within 20 ° with respect to a line connecting two lamps provided on a heating roll. The thermal roll fixing device according to claim 1, wherein the means and the nip position are arranged. 5. The heat roll fixing device according to claim 1, wherein the two lamps arranged on the heating roll are set to have the same distance between the temperature detecting means and the fixing nip position. apparatus.