JP5063011B2 - Fixing control device, image forming apparatus, and fixing device warm-up time control method - Google Patents

Description

The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, or a complex machine thereof. And, in preparation for such such an image forming apparatus, a fixing control unit for heating the heating member of the fixing device using the heat source to control the heat source. The present invention also relates to a warm-up time control method for controlling the warm-up time of the fixing device using such a fixing control device.

  For example, in an electrophotographic image forming apparatus, along with the rotation of a drum-shaped or belt-shaped photoconductor, charging and writing are performed on the photoconductor to form an electrostatic latent image, and then toner is applied by a developing device. By forming a visible toner image, the toner image is transferred directly or indirectly to a recording material such as paper or an OHP film via an intermediate transfer member, and the transferred image is used with a fixing device. Then, the image is recorded on the recording material by fixing.

  In a fixing device provided in such an image forming apparatus, heat and pressure are applied through a recording material between fixing nips of a heating member and a pressure member, and the toner melted by the heat is adhered to the recording material with pressure and fixed. The method of performing is widely adopted. As the heating member, a roller-like or belt-like one is used, which is incorporated in the roller-like heating member, incorporated in a roller around which the belt-like heating member is wound, or disposed around the heating member. Heating was performed by a heat source such as a heater or an IH coil.

  In this type of fixing device, all heat sources are turned off from the standpoint of energy saving during standby when image formation is not being performed. At the start of image formation, a warm-up time (start-up time) is provided and the heat source is turned on. After that, the heating member was heated to a sufficient fixing temperature so as not to cause fixing failure, and image formation was started.

  Originally, when the fixing temperature is raised, the image forming apparatus adopts a temperature priority mode that determines that fixing is possible when the temperature of the heating member reaches a set temperature, and the warm-up time is determined by the temperature priority mode. It was. However, in the temperature priority mode, since the warm-up time varies, the user is dissatisfied. Therefore, in order to keep this warm-up time constant, a time priority mode is adopted to determine that fixing is possible when a predetermined time has elapsed since the start of startup. "XX seconds".

Japanese Patent No. 3350315 JP 2005-345990 A

  By adopting the time priority mode as described above, it is possible to make the warm-up time constant and, in a normal case, variations in the fixing temperature can be made into a problem-free level. However, even in such an image forming apparatus, when the heat source becomes insufficient in power due to a decrease in input voltage, the temperature of the heating member may be significantly lower than the set temperature necessary for fixing in a certain warm-up time. If it is determined that fixing is possible, there is a problem that fixing failure occurs.

  SUMMARY OF THE INVENTION Accordingly, a first object of the present invention is to provide a fixing control device that controls a heat source and heats a heating member of the fixing device using the heat source. An object of the present invention is to prevent the occurrence of fixing failure due to the temperature of the member being lower than the set temperature.

  A second object of the present invention is to prevent the occurrence of poor fixing due to the heat source becoming insufficient in power due to a decrease in the input voltage to the heat source and the temperature of the heating member being lower than the set temperature.

  The third object of the present invention is that, for example, when the input voltage sampling time cannot be secured and the input voltage cannot be detected, the heat source is insufficient in power due to a decrease in the input voltage to the heat source. Thus, the temperature of the heating member is lower than the set temperature and the fixing failure is prevented.

  A fourth object of the present invention is to accurately detect a decrease in input voltage, which is one of the causes of fixing failure.

  A fifth object of the present invention is to make the warm-up time constant as much as possible and prevent the occurrence of fixing failure even when the input voltage is not reduced, considering the temperature of the heating member. is there.

  According to a sixth object of the present invention, when the heat source becomes insufficient in power due to a decrease in the input voltage to the heat source, the temperature gradient is also reduced. It is to prevent.

  The seventh object of the present invention is that, for example, when the temperature gradient sampling time cannot be secured and the temperature gradient cannot be detected, the heat source is insufficient in power due to a decrease in the input voltage to the heat source. Thus, the temperature of the heating member is lower than the set temperature and the fixing failure is prevented.

  An eighth object of the present invention is to reduce the cost by eliminating the need for temperature gradient storage means for storing the temperature gradient detected at the time of previous image formation.

  A ninth object of the present invention is to make the warm-up time as constant as possible and prevent the occurrence of fixing failure even when the temperature gradient exceeds a predetermined value, considering the temperature of the heating member. It is in.

  The tenth object of the present invention is that, in the color mode where the amount of heat required for fixing is larger than that in the black and white mode, the heat source becomes insufficient in power and the temperature of the heating member is lower than the set temperature required for fixing. This is to prevent occurrence of fixing failure.

  An eleventh object of the present invention is that there is no time to detect whether the image mode is black and white or color, and in the case of color, the heat source becomes insufficient in power due to a decrease in the input voltage to the heat source. The purpose is to prevent the fixing failure from occurring because the temperature is lower than the set temperature.

  A twelfth object of the present invention is to reduce the cost by eliminating the need for an image mode storage means for storing an image mode detected at the time of previous image formation.

  The thirteenth object of the present invention is to make the warm-up time as constant as possible and prevent the occurrence of fixing failure even when the monochrome mode is selected in consideration of the temperature of the heating member. is there.

  A fourteenth object of the present invention is to prevent the occurrence of poor fixing due to the heat source becoming insufficient in power due to the low room temperature and the temperature of the heating member being lower than the set temperature.

  A fifteenth object of the present invention is to make the warm-up time as constant as possible and prevent the occurrence of fixing failure even when the room temperature exceeds a predetermined value, taking into consideration the input voltage to the heat source. It is in.

  A sixteenth object of the present invention is to make the warm-up time constant as much as possible and prevent the occurrence of fixing failure even when the room temperature exceeds a predetermined value in consideration of the temperature gradient of the heating member. It is in.

  A seventeenth object of the present invention is to make the warm-up time constant as much as possible and to generate a fixing failure in consideration of whether the image mode is monochrome or color even when the room temperature exceeds a predetermined value. Is to prevent.

  An eighteenth object of the present invention is to provide an image forming apparatus that controls a heat source of a fixing device by a fixing control device and heats a heating member of the fixing device using the heat source. The purpose is to keep the up time constant and to prevent the occurrence of fixing failure due to the temperature of the heating member being lower than the set temperature.

  A nineteenth object of the present invention is to control the warm-up time of a fixing device that prevents the occurrence of defective fixing due to the heat source becoming insufficient in power due to a decrease in the input voltage to the heat source and the temperature of the heating member being lower than the set temperature. It is to provide a method.

  According to a twentieth object of the present invention, when the heat source becomes insufficient in power due to a decrease in the input voltage to the heat source, the temperature gradient is also reduced. Therefore, the occurrence of fixing failure due to the temperature of the heating member being lower than the set temperature. An object of the present invention is to provide a method for controlling the warm-up time of a fixing device to prevent.

  The twenty-first object of the present invention is that, in the color mode where the amount of heat required for fixing is larger than that in the black and white mode, the heat source becomes insufficient in power and the temperature of the heating member is lower than the set temperature required for fixing. It is an object of the present invention to provide a method for controlling the warm-up time of a fixing device that prevents the occurrence of fixing failure.

Therefore, in order to achieve the first , second , tenth and fourteenth objects, the invention described in claim 1 controls a heat source such as an IH coil of the fixing device and uses the heat source to use the belt of the fixing device. In a fixing control device for heating a heating member such as a roller shape or a roller shape,
When the fixing temperature is raised, a temperature priority mode for determining that fixing is possible when the temperature of the heating member reaches the set temperature, and a time priority mode for determining that fixing is possible when the predetermined time has elapsed since the start of the heating. Mode switching means capable of switching between
At least one of the detection result of the voltage detection means for sampling and detecting the input voltage to the heat source, for example, for a certain period of time, the image mode in the color mode or the black and white mode, or the detection result of the room temperature detection means for detecting the room temperature The mode switching means performs mode switching based on one of the above.

  In the time priority mode, when there is a possibility of causing a fixing failure or taking an unnecessary time for start-up, the mode is switched by the mode switching means to set the temperature priority mode.

The mode is switched by the mode switching means. When the detection result of the voltage detection means exceeds the predetermined value, the time priority mode is set. When the detection result is less than the predetermined value, the temperature priority mode is set. In the monochrome mode, the time priority mode is set. In the color mode, the temperature priority mode is set, and the room temperature is detected when the image forming apparatus or the like is turned on or returned from the energy saving mode. If the detected room temperature exceeds a predetermined value, heating is performed by the temperature gradient detecting means. A temperature gradient of the member is detected, and mode switching is performed by the mode switching means based on the detection result. When the detection result exceeds a predetermined value, the time priority mode is set, and when the detection result is less than the predetermined value, the temperature priority mode is set.

According to a second aspect of the present invention, there is provided the fixing control device according to the first aspect, wherein the third object is achieved.
In the fixing control device that performs mode switching by the mode switching means based on the detection result of the voltage detection means,
For example, an input voltage storage means for detecting an input voltage by a voltage detection means other than when the fixing temperature is raised and storing a detection result of the voltage detection means is provided, and detection of the voltage detection means stored in the input voltage storage means Based on the result, the mode is switched by the mode switching means.

  Then, based on the detection result of the voltage detection means stored in the input voltage storage means at the time of previous image formation, mode switching is performed by the mode switching means, and when the stored detection result exceeds a predetermined value, the time priority mode is set. In this case, the temperature priority mode is set.

According to a third aspect of the present invention, there is provided the fixing control device according to the first or second aspect , in order to achieve the fourth object described above.
In the fixing control device that performs mode switching by the mode switching means based on the detection result of the voltage detection means,
In addition to the rise of the fixing temperature, the voltage detection means detects the input voltage to the heat source.

  When the voltage detection means detects the input voltage to the heat source, the input voltage is sampled avoiding the rise of the fixing temperature.

The invention according to claim 4, in order to achieve the fifth object described above, in the fixing control device as claimed in any one of claims 1 to 3,
In the fixing control device that performs mode switching by the mode switching means based on the detection result of the voltage detection means,
When the detection result of the voltage detection means exceeds a predetermined value, the mode switching means switches between the time priority mode and the temperature priority mode based on the detected temperature of the heating member.

  When the detection result of the voltage detection means exceeds a predetermined value, the surface temperature of the heating member is detected when the image forming apparatus or the like is turned on or returned from the energy saving mode. Based on the detection result, the mode switching means When the mode is switched and the detection result exceeds the threshold value, the temperature priority mode is set, and when the detection result is equal to or lower than the threshold value, the time priority mode is set.

The invention according to claim 15, in order to achieve the first 1,6, 9 purpose of the above,
In a fixing control device that controls a heat source of a fixing device and heats a heating member of the fixing device using the heat source .
When the fixing temperature is raised, a temperature priority mode for determining that fixing is possible when the temperature of the heating member reaches the set temperature, and a time priority mode for determining that fixing is possible when the predetermined time has elapsed since the start of the heating. Mode switching means capable of switching between, and
A temperature gradient detecting means for detecting a temperature gradient of the heating member,
When the detection result of the temperature gradient detection means exceeds a predetermined value, the mode switching means performs mode switching based on the detected temperature of the heating member.

  When the detection result of the temperature gradient detection means exceeds a predetermined value, the surface temperature of the heating member is detected when the image forming apparatus or the like is turned on or returned from the energy saving mode. Based on the detection result, the mode switching means When the detection result exceeds the threshold, the temperature priority mode is selected. When the detection result is less than the threshold value, the time priority mode is selected.

According to a fifth aspect of the present invention, there is provided the fixing control device according to the first aspect, wherein the eleventh object is achieved.
A fixing control device that performs mode switching by mode switching means based on whether an image mode of color mode or black and white mode is selected,
Image mode storage means for storing the selected image mode is provided, and mode switching is performed by the mode switching means based on the monochrome or color image mode stored in the image mode storage means.

  Then, based on the image mode stored in the image mode storage unit at the time of the previous or previous image formation, the mode is switched by the mode switching unit. When the stored image mode is the monochrome mode, the time priority mode is selected. Set to priority mode.

According to a sixth aspect of the present invention, there is provided the fixing control device according to the first aspect, wherein the fifteenth object is achieved.
A fixing control device that performs mode switching by mode switching means based on whether an image mode of color mode or black and white mode is selected,
The mode is switched by mode switching means based on the monochrome or color image mode selected when the fixing temperature is raised.

  Then, when the fixing temperature is raised when starting one image formation, it is detected whether the image mode is monochrome or color.

According to a seventh aspect of the present invention, there is provided the fixing control device according to the first, fifth, or sixth aspect of the invention, in order to achieve the thirteenth object.
A fixing control device that performs mode switching by mode switching means based on whether an image mode of color mode or black and white mode is selected,
Even when the monochrome mode is selected, the temperature of the heating member is detected when the image forming apparatus or the like is turned on or returned from the energy saving mode, and the mode is switched by the mode switching means based on the detected temperature. Features.

  Based on the detected temperature of the heating member, the mode is switched by the mode switching means, and the temperature priority mode is set in the color mode, and the time priority mode is set in the monochrome mode.

According to an eighth aspect of the present invention, there is provided a fixing control device according to the first aspect , wherein the fifteenth object is achieved.
In the fixing control device that performs mode switching by the mode switching unit based on the detection result of the room temperature detection unit,
When the room temperature exceeds a predetermined value, the mode is switched by the mode switching unit based on the detection result of the voltage detection unit that detects the input voltage to the heat source.

  When the image forming apparatus or the like is turned on or returned from the energy saving mode, the room temperature is detected. If the detected room temperature exceeds a predetermined value, the voltage detection means detects the input voltage to the heat source, and the detection is performed. Based on the result, the mode is switched by the mode switching means. When the detection result exceeds a predetermined value, the time priority mode is set, and when the detection result is equal to or lower than the predetermined value, the temperature priority mode is set.

According to a ninth aspect of the present invention, in the fixing control device according to the eighth aspect, when the detection result of the voltage detecting means exceeds a predetermined value, the mode switching means switches the mode based on the temperature of the heating member. Features.
According to a tenth aspect of the present invention, in the fixing control device according to the ninth aspect, when the temperature of the heating member exceeds a predetermined temperature, the fixing temperature is raised in the temperature priority mode.
According to an eleventh aspect of the present invention, in the fixing control device according to the eighth aspect, when the heating member is a fixing belt and the detection result of the voltage detecting means is not more than a predetermined value, the fixing belt is operated in the temperature priority mode. The fixing temperature is raised by rotating the fixing belt, and the fixing belt is continuously rotated for a predetermined time from the time when the fixing temperature is reached.
According to a twelfth aspect of the present invention, in the fixing control device of the first aspect,
In the fixing control device that performs mode switching by the mode switching unit based on the detection result of the room temperature detection unit,
The heating member is a fixing belt, and when the room temperature is equal to or lower than a predetermined value, the fixing belt is rotated by rotating the fixing belt in the temperature priority mode and the fixing belt is raised for a predetermined time from the time when the set temperature is reached. Is continuously rotated.
According to a thirteenth aspect of the present invention, there is provided the fixing control device according to the fourteenth aspect , in order to achieve the sixteenth object described above.
In the fixing control device that performs mode switching by the mode switching unit based on the detection result of the room temperature detection unit,
When the room temperature exceeds a predetermined value, the mode is switched by the mode switching unit based on the detection result of the temperature gradient detecting unit that detects the temperature gradient of the heating member.

According to the thirteenth aspect of the present invention, when the image forming apparatus or the like is turned on or returned from the energy saving mode, the room temperature is detected, and when the detected room temperature exceeds a predetermined value, the temperature gradient detecting means uses the heating member. A temperature switching mode is detected, and mode switching is performed by the mode switching means based on the detection result. When the detection result exceeds a predetermined value, the time priority mode is set, and when the detection result is less than the predetermined value, the temperature priority mode is set.

According to a fourteenth aspect of the present invention, there is provided the fixing control device according to the first aspect , wherein the fifteenth object is achieved.
In the fixing control device that performs mode switching by the mode switching unit based on the detection result of the room temperature detection unit,
When the room temperature exceeds a predetermined value, the mode is switched by the mode switching unit based on which of the color mode and the monochrome mode is selected.

  When the image forming apparatus or the like is turned on or returned from the energy saving mode, the room temperature is detected. If the detected room temperature exceeds a predetermined value, the selected image mode is detected, and the mode is determined based on the detection result. The mode is switched by the switching means. When the detection result exceeds a predetermined value, the time priority mode is set. When the detection result is equal to or lower than the predetermined value, the temperature priority mode is set.

The invention according to claim 16, in order to achieve the first 18 object of the above, a copying machine, a printer, a facsimile or the image forming apparatus of such a composite of these machines, in any one of claims 1 to 15 The fixing control device described above is provided.

  The fixing control is based on the time priority mode. In the time priority mode, if there is a possibility of causing a fixing failure or taking an unnecessary time for start-up, the mode switching means may be used. Switch to temperature priority mode.

According to a seventeenth aspect of the present invention, in order to achieve the nineteenth object described above, in a warm-up time control method for a fixing device,
The voltage detection means detects the input voltage to the heat source of the fixing device,
Based on the detection result of the voltage detection means, mode switching is performed by the mode switching means,
When the temperature priority mode is selected, it is determined that fixing is possible when the temperature of the heating member of the fixing device reaches the set temperature when the fixing temperature is raised. When it reaches the predetermined time from
The heat source is controlled by a fixing control device, and the heating member is heated using the heat source.

According to an eighteenth aspect of the present invention, there is provided a warm-up time control method for a fixing device in order to achieve the twentieth object.
The temperature gradient of the heating member of the fixing device is detected by the temperature gradient detecting means,
If the detection result of the temperature gradient detection means exceeds a predetermined value , mode switching is performed by the mode switching means based on the detected temperature of the heating member ,
When the temperature priority mode is selected, it is determined that fixing is possible when the temperature of the heating member reaches the set temperature when the fixing temperature is raised. When it reaches
The heat source of the fixing device is controlled by the fixing control device, and the heating member is heated using the heat source.

According to a nineteenth aspect of the present invention, in order to achieve the twenty-first object, a warm-up time control method for a fixing device comprises:
Detect whether the image mode of color mode or black and white mode is selected,
When the mode is switched by the mode switching unit based on which image mode is selected and the temperature priority mode is set, when the temperature of the heating member of the fixing device reaches the set temperature when the fixing temperature is raised In the case of time priority mode, it is determined that fixing is possible when a predetermined time has elapsed from the start of startup.
A heat source of the fixing device is controlled by a fixing control device, and a heating member of the fixing device is heated using the heat source.
An image forming apparatus including a fixing device having a heating member heated by a heat source.
Voltage detecting means for detecting an input voltage to the heat source;
Based on the voltage value detected by the voltage detection means, a temperature priority mode for starting an image forming operation when the temperature of the heating member reaches a set temperature, and an image when a predetermined time has elapsed from the start of the fixing temperature rise. The time priority mode for starting the forming operation is switched .

  According to the first aspect of the present invention, in the fixing control device that controls the heat source and uses the heat source to heat the heating member of the fixing device, in the time priority mode, there is a possibility that a fixing failure may occur or the startup is started. When there is a possibility that an unnecessary time is excessively taken, the mode is switched by the mode switching means to set the temperature priority mode. Thus, for example, while basically fixing the warm-up time of the fixing device, when there is a possibility that the heat source will obviously become insufficient in power due to a decrease in input voltage, etc., abandon the user waiting time. By adopting a temperature priority mode in which it is determined that fixing is possible after the temperature of the heating member reaches a set temperature necessary for fixing, it is possible to prevent occurrence of fixing failure due to the temperature of the heating member falling below the set temperature. .

Further , based on the detection result of the voltage detection means, the mode is switched by the mode switching means. When the detection result exceeds a predetermined value, the time priority mode is set. When the detection result is less than the predetermined value, the temperature priority mode is set. When the heat source becomes insufficient in power due to the lowering and the temperature of the heating member may fall below the set temperature necessary for fixing, the occurrence of fixing failure can be prevented by setting the temperature priority mode.

According to the second aspect of the present invention, the mode switching unit switches the mode based on the detection result of the voltage detection unit stored in the input voltage storage unit at the time of previous image formation, and the stored detection result is a predetermined value. The time priority mode is selected when the value exceeds 1, and the temperature priority mode is selected in the following cases. In order to detect the input voltage, it is necessary to sample the input voltage for a certain period of time. For example, when the temperature of the heating member is already high, the start-up time is short and the sampling time may not be secured. . In such a case, the input voltage cannot be detected, but the mode can be switched by using the detection result of the voltage detection means that has been detected and stored in the input voltage storage means.

According to the third aspect of the invention, when the input voltage to the heat source is detected by the voltage detection means, the input voltage is sampled while avoiding the rise of the fixing temperature, so that the input voltage can be accurately detected. it can. This is because when the fixing temperature is raised, such as when the image forming apparatus is turned on or returned from the energy saving mode, the entire apparatus such as the image forming apparatus rises all at once and the voltage is not stable. In other words, not only the fixing temperature reaches the set temperature but also the input voltage is detected when the fixing temperature reaches the set temperature and is stable. If an attempt is made to detect the voltage, the input voltage may not be detected correctly, but can be detected accurately in a steady state.

According to the fourth aspect of the present invention, when the detection result of the voltage detection unit exceeds a predetermined value, the surface temperature of the heating member is detected when the image forming apparatus or the like is turned on or returned from the energy saving mode. Based on the detection result, the mode is switched by the mode switching means. When the detection result exceeds the threshold value, the temperature priority mode is set. Therefore, even when the input voltage does not decrease, the heating member temperature is taken into consideration. When the temperature of the member exceeds the threshold, the temperature priority mode is set. When the temperature of the heating member reaches the set temperature, it is determined that fixing can be performed without taking a normal time, and an unnecessary time for starting up is not excessive. Can be. When the temperature of the heating member is equal to or lower than the threshold value, the time priority mode is set, so that it is determined that fixing is possible when a predetermined time has elapsed from the start of startup as usual, and heating is performed over a normal time.

According to the fifth aspect of the present invention, mode switching is performed by the mode switching means based on the detection result of the temperature gradient detection means. When the detection result exceeds a predetermined value, the time priority mode is set. Since it is in the temperature priority mode, it is detected from the temperature gradient of the heating member that the heat source is insufficient in power due to a decrease in the input voltage, and the temperature of the heating member may be lower than the set temperature required for fixing, At that time, the occurrence of fixing failure can be prevented by setting the temperature priority mode.

According to the fifteenth aspect of the present invention, when the detection result of the temperature gradient detecting unit exceeds a predetermined value, the surface temperature of the heating member is detected when the image forming apparatus or the like is turned on or returned from the energy saving mode. Based on the detection result, the mode is switched by the mode switching means, and when the detection result exceeds the threshold, the temperature priority mode is set. Therefore, even when the temperature gradient exceeds the predetermined value, the temperature of the heating member is also taken into consideration. When the temperature of the heating member exceeds the threshold, the temperature priority mode is set, and when the temperature of the heating member reaches the set temperature, it is determined that fixing can be performed without taking a normal time, and an unnecessary time for startup is taken. You can avoid it. When the temperature of the heating member is equal to or lower than the threshold value, the time priority mode is set, so that it is determined that fixing is possible when a predetermined time has elapsed from the start of startup as usual, and heating is performed over a normal time.

According to the first aspect of the present invention, the mode is switched by the mode switching means based on whether the color mode or the monochrome mode is selected. In the monochrome mode, the time priority mode is set. In the color mode, the mode is switched. Since the temperature priority mode is used, the time priority mode is usually set based on the monochrome mode that requires less heat for fixing. In the color mode that requires a larger amount of heat for fixing than the monochrome mode, the temperature priority is used. By setting the mode, it is possible to eliminate the possibility that the heat source becomes insufficient in power and the temperature of the heating member falls below the set temperature necessary for fixing, and the occurrence of fixing failure can be prevented. This is because, under the same input voltage, room temperature, and temperature of the heating member, if the time priority mode is set, the heating member reaches the set temperature in black and white but may not reach in color.

According to the fifth aspect of the present invention, the mode is switched by the mode switching unit based on the monochrome or color image mode stored in the image mode storage unit when the previous image was formed, and the stored image mode is the monochrome mode. In this case, the time priority mode is set, and the color mode is set to the temperature priority mode. For example, when the temperature of the heating member is already high, the start-up time is short and there is no time to detect the image mode. The mode can be switched by using the image mode detected and stored in the image mode storage means.

According to the sixth aspect of the present invention, since the image mode is detected when the fixing temperature is raised when starting one image formation, the image mode for storing the image mode detected during the previous image formation is stored. The cost can be reduced by eliminating the storage means.

According to the seventh aspect of the present invention, even when the black and white mode is selected, the surface temperature of the heating member is detected when the image forming apparatus or the like is turned on or returned from the energy saving mode, and the detected temperature is set to the detected temperature. Based on this, when the mode is switched by the mode switching means and the detection result exceeds the threshold value, the temperature priority mode is set. Therefore, even when the monochrome mode is selected, the temperature of the heating member is also taken into consideration. When the temperature exceeds the threshold, the temperature priority mode is set, and when the temperature of the heating member reaches the set temperature, it is determined that fixing can be performed without taking a normal time, and an unnecessary time is not taken for startup. be able to. When the temperature of the heating member is equal to or lower than the threshold value, the time priority mode is set, so that it is determined that fixing is possible when a predetermined time has elapsed from the start of startup as usual, and heating is performed over a normal time.

According to the first aspect of the present invention, the room temperature detecting means detects the room temperature when the image forming apparatus or the like is turned on or returned from the energy saving mode, and based on the detection result of the room temperature detecting means, the mode switching means When the mode is switched and the room temperature exceeds the predetermined value, the time priority mode is selected. When the room temperature is lower than the predetermined value, the temperature priority mode is selected. Therefore, the heat source becomes insufficient due to the low room temperature, and the temperature of the heating member is fixed. When there is a possibility that the temperature will be lower than the required set temperature, it is possible to prevent occurrence of fixing failure by setting the temperature priority mode.

According to the eighth aspect of the present invention, when the room temperature exceeds a predetermined value, the voltage detection means detects the input voltage to the heat source, and based on the detection result, the mode switching means switches the mode. When the specified value is exceeded, the time priority mode is selected. When the specified value is less than the specified value, the temperature priority mode is selected. Even when the room temperature exceeds the specified value, the mode is switched by the mode switching means considering the input voltage to the heat source. When the input voltage exceeds a predetermined value, the time priority mode is set, and it is determined that fixing is possible when the predetermined time has elapsed from the start of startup as in the basic case, and the user waiting time can be made as constant as possible. On the other hand, when the input voltage is lower than the predetermined value, the temperature priority mode is set, and it is determined that the fixing is possible when the temperature of the heating member reaches the set temperature. Can do.

According to the thirteenth aspect of the invention, when the room temperature exceeds a predetermined value, the temperature gradient of the heating member is detected by the temperature gradient detecting means, and the mode is switched by the mode switching means based on the detection result. When the temperature exceeds the predetermined value, the time priority mode is set. When the temperature is lower than the predetermined value, the temperature priority mode is set. Therefore, even when the room temperature exceeds the predetermined value, the mode switching means takes into account the temperature gradient of the heating member. When the switching is performed and the input voltage exceeds a predetermined value, the time priority mode is set, and it is determined that the fixing can be performed when the predetermined time has elapsed from the start of the startup as usual, and the user waiting time can be made as constant as possible. On the other hand, when the temperature gradient of the heating member is below a predetermined value, the temperature priority mode is set, and it is determined that fixing is possible when the temperature of the heating member reaches the set temperature. Can be prevented.

According to the fourteenth aspect of the present invention, when the room temperature exceeds a predetermined value, the selected image mode is detected, the mode is switched by the mode switching means based on the detection result, and the monochrome mode is selected. If the color mode is selected, the time priority mode is selected, and the temperature priority mode is selected. Therefore, even when the room temperature exceeds a predetermined value, the mode switching means switches the mode in consideration of the image mode. In the case of the monochrome mode, the time priority mode is set, and it is determined that the fixing can be performed when the predetermined time has elapsed from the start of startup as in the basic case, and the user waiting time can be made as constant as possible. On the other hand, in the case of the color mode, the temperature priority mode is set, and it is determined that the fixing is possible when the temperature of the heating member reaches the set temperature, and it takes more time than usual, but the occurrence of fixing failure can be prevented. .

According to the sixteenth aspect of the present invention, in the image forming apparatus in which the heat source of the fixing device is controlled by the fixing control device and the heating member of the fixing device is heated using the heat source, the fixing control is based on the time priority mode. In the time priority mode, if there is a possibility that fixing failure may occur or an unnecessary time may be taken for startup, the temperature priority mode is selected by switching with the mode switching means. However, if the heat source is clearly inadequate due to a decrease in the input voltage or the like while the warm-up time of the fixing device is constant, the user waits for a constant user waiting time and the temperature of the heating member A temperature priority mode is adopted in which it is determined that fixing is possible after the set temperature required for fixing is reached. It is possible to prevent the occurrence.

  In addition, when the temperature of the heating member is high, the user waits unnecessarily even though the temperature of the heating member reaches the set temperature before a certain user waiting time and is actually fixable. Therefore, in such a case, it is possible to give up the user waiting time and adopt the temperature priority mode so as not to spend too much time for startup. .

According to the seventeenth aspect of the present invention, mode switching is performed by the mode switching means based on the detection result of the voltage detection means. When the detection result exceeds a predetermined value, the time priority mode is set. Since priority mode is selected, when the heat source becomes insufficient due to a decrease in input voltage and the temperature of the heating member may fall below the set temperature required for fixing, the occurrence of fixing failure can be prevented by using the temperature priority mode. can do.

According to the invention described in claim 18 , based on the detection result of the temperature gradient detection means, the mode is switched by the mode switching means. When the detection result exceeds a predetermined value, the time priority mode is set. Since it is in the temperature priority mode, it is detected from the temperature gradient of the heating member that the heat source is insufficient in power due to a decrease in the input voltage, and the temperature of the heating member may be lower than the set temperature required for fixing, At that time, the occurrence of fixing failure can be prevented by setting the temperature priority mode.

According to the nineteenth aspect of the present invention, mode switching is performed by the mode switching means based on whether the color or monochrome image mode is selected. In the monochrome mode, the time priority mode is selected. Since the temperature priority mode is used, the time priority mode is usually set based on the monochrome mode that requires less heat for fixing. In the color mode that requires a larger amount of heat for fixing than the monochrome mode, the temperature priority is used. By setting the mode, it is possible to eliminate the possibility that the heat source becomes insufficient in power and the temperature of the heating member falls below the set temperature necessary for fixing, and the occurrence of fixing failure can be prevented. This is because, under the same input voltage, room temperature, and temperature of the heating member, if the time priority mode is set, the heating member reaches the set temperature in black and white but may not reach in color.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 shows an overall schematic configuration of an internal mechanism in an example of an image forming apparatus such as a copying machine, a printer, a facsimile, or a complex machine thereof.

  In the figure, reference numeral 100 denotes an image forming apparatus main body, and reference numeral 200 denotes an image reading apparatus mounted on the image forming apparatus main body 100.

  In the image forming apparatus main body 100, four image forming stations 10c, 10m, 10y, and 10b of cyan, magenta, yellow, and black are arranged in a tandem manner. Each image forming station is provided with drum-shaped photoconductors 11c, 11m, 11y, and 11b, respectively, and a bias voltage is first applied by each of the charging devices 12c, 12m, 12y, and 12b in accordance with the clockwise rotation in the drawing. Charge the surface uniformly.

  Next, based on a reading signal from the image reading apparatus 200 in a copying machine, an image signal from a host in a printer, or a transmission signal sent via a telephone line in a facsimile, Writing is performed by irradiating laser beams Lc, Lm, Ly, and Lb from the writing device 13 to form electrostatic latent images on the photoreceptors 11c, 11m, 11y, and 11b. After that, toner is attached by the developing devices 14c, 14m, 14y, and 14b to visualize the electrostatic latent images, and single-color images of the respective colors are formed on the photoreceptors 11c, 11m, 11y, and 11b.

  Then, the endless belt-shaped intermediate transfer body 15 is moved counterclockwise in the drawing in contact with the photoreceptors 11c, 11m, 11y, and 11b, and the photoreceptors 11c, 11m are moved by the primary transfer devices 16c, 16m, 16y, and 16b. , 11y, and 11b, primary images are sequentially transferred onto the intermediate transfer member 15 in order from cyan, and the transferred images are superimposed to form a full-color image on the intermediate transfer member 15.

  On the other hand, one of the feeding rollers 20 is selectively rotated at an appropriate timing, the recording material P is fed out from the corresponding paper feed cassette 21 in the image forming apparatus main body 100, and conveyed through the recording material conveyance path 23 to be paired. Abutting between the registration rollers 24 is stopped. Then, the pair of registration rollers 24 are rotated in synchronization with the full color image on the intermediate transfer body 15, and the full color image is secondarily transferred to the recording material P by the secondary transfer device 25.

  After that, the recording material P after full color image transfer is conveyed upward as it is through the recording material conveyance path 23, and unfixed transfer toner is fixed to the recording material P when passing through the fixing nip of the fixing device 300, and the discharge roller 26. Are stacked on the paper discharge stack device 27 on the image forming apparatus main body 100.

  The photoreceptors 11c, 11m, 11y, and 11b after the completion of the primary transfer are cleaned by the primary cleaning devices 17c, 17m, 17y, and 17b to remove the transfer residual toner and are initialized. The intermediate transfer body 15 after the completion of the secondary transfer is cleaned by the secondary cleaning device 18 to remove the transfer residual toner and is initialized.

  Reference numerals 28c, 28m, 28y, and 28b in the figure denote toner bottles for the respective colors that supply toner to the respective color developing devices 14c, 14m, 14y, and 14b.

  When images are recorded on both the front and back surfaces of the recording material P by the illustrated image forming apparatus, the recording material P that has been recorded on one side after passing through the fixing device 300 is switched by a switching claw (not illustrated) from the image forming apparatus main body 100 to both sides. It is inserted into the unit 92, switched back by the switchback path 93, turned upside down, and then re-entered into the image forming apparatus main body 100 through the refeed path 94, re-fed to the secondary transfer position, and separately transferred to the intermediate transfer body 15. After the image formed above is transferred and the image is recorded on the back side, the image is discharged to the paper discharge stack device 27 by the discharge roller 26.

  In the above description, the case where a color image is recorded on the recording material P has been described. However, in the above-described image forming apparatus, the image forming stations 10c, 10m, and 10y are appropriately selected according to the selected single color mode or multiple color mode. By selecting and using some of 10b, a monochrome image or a color image can be arbitrarily formed.

  FIG. 2 shows a fixing device 300 provided in the image forming apparatus main body 100 shown in FIG.

  The fixing device 300 wraps an endless fixing belt 30 as a heating member between a first roller 31 and a second roller 32, and allows the other roller to be driven and rotated by rotation of one roller. Further, a heat source 33 for heating the fixing belt 30 is disposed around the first roller 31, while a pressure roller 40 is pressed against the second roller 32 via the fixing belt 30 to form a fixing nip. As the heat source 33, an IH coil is used in this example.

  When the recording material P after image transfer passes through the fixing nip, pressure is applied by pressing the pressure roller 40 against the second roller 32 via the fixing belt 30, and the fixing belt 30 is heated by the heat source 33. Then, heat is applied to fix the secondary transfer image.

  The heat source 33 of the fixing device 300 is controlled by the fixing control device 500. The fixing control device 500 is provided with an IH control unit 50 connected to the heat source 33. The IH control unit 50 includes an inverter circuit 51 and voltage detection means 52 that detects an input voltage to the heat source 33. A fixing control unit 53 is connected to the IH control unit 50. The fixing control unit 53 includes a mode switching unit 54, an input voltage storage unit 55, and the like.

  When the fixing temperature is raised, the mode switching unit 54 reaches a predetermined time from the start of the temperature priority mode for determining that the fixing is possible when the temperature of the fixing belt 30 as a heating member reaches the set temperature. At the time, the time priority mode for determining that fixing is possible can be switched. Further, the input voltage storage means 55 stores the detection result of the voltage detection means 52.

  The fixing controller 53 automatically controls the thermistor 56 for detecting the temperature of the fixing belt 30 as a heating member, the room temperature detecting means 57 for detecting the room temperature of the room where the image forming apparatus is installed, and the heat source 33 of the fixing apparatus 300. An automatic manual switching means 58 or the like for switching between performing or manually is connected.

  In the fixing control device 500 that controls the heat source 33 and heats the fixing belt 30 of the fixing device 300 using the heat source 33, the time priority mode is basically used. When there is a possibility that an unnecessary time is excessively taken for starting up, the mode is switched by the mode switching means 54 and the temperature priority mode is set.

  Thus, basically, the time priority mode is adopted to make the warm-up time of the fixing device 300 constant. On the other hand, when there is a possibility that the heat source 33 is clearly insufficient in power due to a decrease in input voltage or the like, after giving up the user waiting time constant, the temperature of the fixing belt 30 becomes a set temperature necessary for fixing. A temperature priority mode for determining that fixing is possible is employed to prevent occurrence of fixing failure due to the temperature of the fixing belt 30 being lower than the set temperature.

  Further, when the time priority mode is adopted, for example, when the time has not elapsed since the previous fixing and the temperature of the fixing belt 30 is high, the temperature of the fixing belt 30 reaches the set temperature before a certain user waiting time. However, even though it is actually possible to fix, the user will wait unnecessarily, so in this case we will give up the user waiting time and adopt the temperature priority mode Do not spend too much time starting up.

FIG. 3 shows a flow of an example of a warm-up time control method for the fixing device 300.
In the control method shown in FIG. 3, the voltage detection means 52 detects the input voltage to the heat source 33, and the mode switching means 54 performs mode switching based on the detection result. When the detection result exceeds a predetermined value A, The time priority mode is set, and when it is equal to or less than the predetermined value A, the temperature priority mode is set.

  In this case, when the heat source 33 becomes insufficient in power due to a decrease in the input voltage and there is a possibility that the temperature of the fixing belt 30 is lower than the set temperature necessary for fixing, the fixing of the fixing failure is caused by setting the temperature priority mode. Can be prevented.

  By the way, when the fixing temperature is raised such as when the image forming apparatus is turned on or returned from the energy saving mode, the entire image forming apparatus rises all at once and the voltage is not stable. In such a state, the input voltage may not be detected correctly. Therefore, when the voltage detection means 52 detects the input voltage to the heat source 33, the input voltage is sampled when the fixing temperature reaches the set temperature and is stable while avoiding the rise of the fixing temperature, and the input voltage is sampled. It is preferable to detect accurately.

  The detection result detected by the voltage detection means 52 is stored in the input voltage storage means 55, and the mode switching means 54 performs mode switching based on the stored detection result of the voltage detection means 52. As described above, when the input voltage storage unit 55 is provided, for example, when the temperature of the fixing belt 30 is already high, the start-up time is short, the sampling time cannot be secured, and the input voltage cannot be detected. However, the mode can be switched by using the detection result of the voltage detection means 52 previously detected and stored in the input voltage storage means 55.

  FIG. 4 shows a flow of an example of storing the detection result of the voltage detection unit 52 in the input voltage storage unit 55.

  First, the initial value of the stored value c is 100% (ratio of the input voltage to the reference voltage), and it is determined whether the stored value c is within the voltage range of 70 to 120%. If the stored value c is within the range, the stored value c is normal. It is determined that the value is a value, and is started up using the stored value c. On the other hand, when the stored value c is out of the voltage range, it is determined that the stored value c is an abnormal value with no reliability, and the initial value b is used for startup.

  Note that starting up using the stored value c or b means comparing with the predetermined value A using the stored value c or b as the input voltage in FIG. The initial value of the predetermined value A is 96, but the predetermined value A can be changed in the range of 85-100.

  After that, when reloading (becomes fixable), the input voltage is measured. If the measurement is successful, the stored value c is updated using the measured value e. If the measurement fails, the stored value c is not updated. Next, after the “next temperature increase start”, the operations performed after the first “start” are repeated.

FIG. 5 shows a flow of another example of the warm-up time control method of the fixing device 300.
In the control method shown in FIG. 5, first, the room temperature detecting means 57 detects the room temperature of the room in which the image forming apparatus is installed to determine whether the room temperature exceeds a predetermined value. Based on this, the mode is switched by the mode switching means 54 of the fixing controller 53. For example, when the room temperature is a predetermined value of 15 ° C. or lower, the temperature priority mode is set, and the heat source becomes insufficient due to the low room temperature even when the time is longer than the normal time, and the temperature of the fixing belt 30 is fixed. Therefore, it is possible to prevent a fixing defect from occurring due to a temperature lower than the required set temperature.

  When the room temperature exceeds the predetermined value 15 ° C., the mode is switched to the time priority mode. Next, the voltage detection means 52 detects the input voltage to the heat source 33, and whether or not the input voltage exceeds the predetermined value. Based on the detection result of the voltage detecting means 52, the mode is switched by the mode switching means 54 of the fixing control unit 53. For example, even when the room temperature exceeds 15 ° C., when the detection result is equal to or less than the predetermined value A, the temperature priority mode is set in consideration of the input voltage to the heat source 33 and the temperature of the fixing belt 30 reaches the set temperature. In this case, it is determined that fixing is possible, and it takes more time than usual, but the occurrence of fixing failure is prevented.

  On the other hand, when the input voltage exceeds the predetermined value A, the mode is further switched to the time priority mode. However, the thermistor 56 detects the temperature of the fixing belt 30 and determines whether or not the detected temperature exceeds the threshold value. Based on the detected temperature of the fixing belt 30, the mode is switched by the mode switching means 54 of the fixing controller 53. For example, even when the input voltage exceeds a predetermined value A, if the detected temperature exceeds the threshold value 50 ° C., the temperature priority mode is set, and when the temperature of the fixing belt 30 reaches the set temperature, a normal time is not taken. Judging that fixing is possible, do not spend unnecessary time for startup.

  On the other hand, when the detected temperature is equal to or lower than the threshold value of 50 ° C., the time priority mode is set, and it is determined that fixing can be performed when the predetermined time has elapsed since the start of startup as usual.

  In the method for controlling the warm-up time of the fixing device 300 shown in FIGS. 3 and 5, as described above, the heat source 33 of the fixing device 300 is controlled by the fixing control device 500 and the fixing belt 30 is heated using the heat source 33.

  FIG. 6 shows the relationship between the time t and the temperature T of the fixing belt 30 when the mode is switched in the flow shown in FIG.

  A curve h is a case where the temperature priority mode is selected when the room temperature is 15 ° C. or lower in FIG. Since temperature priority is given, heating is continued until the forced reload time (time priority setting time) is exceeded and the fixing temperature reaches the setting temperature T1. Meanwhile, the fixing belt 30 of the fixing device 300 continues to rotate. Although it may be determined that the fixing is possible when the fixing temperature reaches the set temperature T1, since the entire fixing device 300 is not always at the set temperature T1 due to the low sound environment, only a predetermined pre-rotation time is required. Continue heating and rotating. Then, after the pre-rotation time has elapsed, it is determined that fixing is possible.

  A curve i is a case where the temperature priority mode is selected when the room temperature is 15 ° C. or more and the input voltage A or less in FIG. Since it is in the temperature priority mode, heating is continued until the forced reload time (time priority setting time) is exceeded and the fixing temperature reaches the setting temperature T1. Meanwhile, the fixing belt 30 of the fixing device 300 continues to rotate. Although it may be determined that the fixing is possible when the fixing temperature reaches the set temperature T1, since the temperature drops greatly when the paper is subsequently passed due to the low voltage, the heating and the rotation are continued until the higher set temperature T2 is reached. To do. When the set temperature T2 is reached, it is determined that fixing is possible.

  A curve j is a case where the time priority mode is selected when the room temperature is 15 ° C. or higher, the input voltage A or higher, the fixing belt 30 temperature is 50 ° C. or lower in FIG. Since time priority is given, heating is continued until the forced reload time (time priority setting time) is reached even if the fixing temperature is the set temperature T1. Meanwhile, the fixing belt 30 of the fixing device 300 continues to rotate. The curve j is an example in which the fixing temperature exceeds the set temperature T1 when the forced reload time elapses. However, due to variations, the fixing temperature may be equal to or lower than the set temperature T1 when the forced reload time elapses.

  A curve k is obtained when the temperature priority mode is selected when the room temperature is 15 ° C. or higher, the input voltage A or higher, the temperature of the fixing belt 30 exceeds the threshold 50 ° C. in FIG. Heating and rotation are performed until the fixing temperature reaches the set temperature T1, and overshoot is prevented when the set temperature T1 is reached, but this is prevented. Further, it can be determined that fixing is possible much faster than the forced reload time.

  The illustrated image forming apparatus includes an automatic switching unit 58 that switches between automatic and manual operations by performing a special operation on the operation unit. The special operation of the operation unit is, for example, a well-known technique, which is performed by a service person as a maintenance operation, such as making a hidden mode after long-pressing a specific switch.

  In FIG. 2, the IH control unit 50 and the fixing control unit 53 perform serial communication. When detecting the input voltage, if detection data is serially communicated, there is a problem that it takes a long processing time for detection. Therefore, if the input voltage is detected and the mode is switched during one image forming operation, the input voltage cannot be detected and the mode cannot be switched. Therefore, under the condition of serially communicating the detection data, it is better to switch the mode using the stored value of the input voltage than to switch the mode even if the input voltage is detected during one image forming operation. .

  When the heat source 33 is of the IH induction heating type as in the illustrated example, if the voltage detection means 52 is provided in the IH control unit 50 that performs serial communication with the fixing control unit 53, the voltage detection data is temporarily stored in the IH control unit 50. Serial communication. Therefore, the detection processing time is further increased by the amount via the IH control unit 50. Therefore, since the input voltage cannot be detected at this time and the mode cannot be switched, it is better to switch the mode using the stored value of the input voltage.

  FIG. 7 shows another example of a fixing device 300 provided in the image forming apparatus main body 100 shown in FIG.

  In this example, the fixing control unit 53 includes a temperature gradient detecting unit 60 and a temperature gradient storing unit 61 instead of the voltage detecting unit 52 of the IH control unit 50 and the input voltage storage unit 55 of the fixing control unit 53.

  FIG. 8 shows a flow of still another example of the warm-up time control method for the fixing device 300 using the configuration shown in FIG.

  In the control method shown in FIG. 8, the temperature gradient of the fixing belt 30 as the heating member is detected by the temperature gradient detecting means 60 when the fixing temperature rises when starting one image forming operation, and based on the detection result. The mode is switched by the mode switching means 54. When the detection result exceeds the predetermined value B, the time priority mode is set. When the detection result is equal to or lower than the predetermined value B, the temperature priority mode is set.

  Similar to the case of switching the mode based on the detection result of the input voltage detection unit 52, the mode switching unit 54 selects the mode based on the detection result of the temperature gradient detection unit 60 stored in the temperature gradient storage unit 61 at the time of previous image formation. When switching is performed and the sampling time cannot be secured, the mode switching can also be performed using the detection result previously detected and stored.

  FIG. 9 shows the temperature change of the fixing belt 30 over time when the fixing temperature is raised.

  As shown in FIG. 9, the temperature gradient is a value of T3 / t calculated by measuring the rising temperature T3 at a certain set time t from the time when the temperature of the fixing belt 30 reaches a certain temperature when the fixing temperature is raised. In this example, the temperature rises from 40 ° C. for 20 seconds.

  As described above, when the mode switching unit 54 performs mode switching based on the detection result of the temperature gradient of the fixing belt 30, the heat source 33 becomes insufficient in power due to a decrease in input voltage due to the temperature gradient, and the fixing belt 30. It is possible to prevent the occurrence of fixing failure by detecting that there is a possibility that the temperature of the toner is lower than the set temperature necessary for fixing, and setting the temperature priority mode at that time.

  FIG. 10 shows a flow of still another example of the warm-up time control method of the fixing device 300.

  In the control method shown in FIG. 10, similarly to the case shown in FIG. 5, the room temperature detecting means 57 first detects the room temperature of the room where the image forming apparatus is installed, and determines whether the room temperature exceeds a predetermined value. Based on the detection result of the room temperature detecting means 57, the mode is switched by the mode switching means 54 of the fixing control unit 53. For example, when the room temperature is a predetermined value of 15 ° C. or less, the temperature priority mode is set, and even if it takes a time longer than the normal time, the heat source becomes insufficient due to the low room temperature, and fixing failure occurs. To prevent.

  When the room temperature exceeds a predetermined value of 15 ° C., the mode is switched to the time priority mode. Next, the temperature gradient of the fixing belt 30 is detected by the temperature gradient detecting means 60, and whether or not the temperature gradient exceeds the predetermined value. The mode is switched by the mode switching unit 54 of the fixing control unit 53 based on the detection result of the temperature gradient detecting unit 60. For example, even when the room temperature exceeds 15 ° C., if the detected temperature gradient is equal to or lower than the predetermined value B, the temperature priority mode is set, and it is determined that the fixing can be performed when the temperature of the fixing belt 30 reaches the set temperature. Although it takes time, it prevents the occurrence of fixing failure.

  On the other hand, when the detected temperature gradient exceeds the predetermined value B, the mode is further switched to the time priority mode. However, the thermistor 56 detects the temperature of the fixing belt 30 and determines whether the detected temperature exceeds the threshold value. Based on the detected temperature of the fixing belt 30, the mode is switched by the mode switching means 54 of the fixing controller 53. For example, even when the detected temperature gradient exceeds a predetermined value B, when the detected temperature of the fixing belt 30 exceeds the threshold value 50 ° C., the temperature priority mode is set, and when the temperature of the fixing belt 30 reaches the set temperature, the normal temperature is set. Judge that fixing is possible without spending time, so as not to spend too much time for startup.

  On the other hand, when the detected temperature is equal to or lower than the threshold value of 50 ° C., the time priority mode is set, and it is determined that fixing is possible when the predetermined time has elapsed from the start of startup as basic, and the user waiting time is made as constant as possible.

  In the above example, the fixing control device and the warm-up time control method used in the color image forming apparatus have been described. Of course, the fixing control device and the warm-up time control method used in the monochrome image forming apparatus are not limited to color. When applied, the fixing device is started up using the time priority mode or the temperature priority mode, and a heating member such as a fixing belt is heated by a heat source to fix the transferred image on the recording material passing through the fixing nip.

  FIG. 11 shows still another example of the fixing device 300 provided in the image forming apparatus main body 100 shown in FIG.

  In this example, the fixing control unit 53 shown in FIG. 7 includes a mode switching unit 54 and an image mode storage unit 62, and is connected to an image mode switching unit 63 that switches between a color mode and a monochrome mode.

  FIG. 12 shows a flow of still another example of the warm-up time control method of the fixing device 300 using the configuration shown in FIG.

  In the control method shown in FIG. 12, when the fixing temperature rises when one image forming operation is started, the mode is switched by the mode switching unit 54 based on the image mode selected by the image mode switching unit 63, and the black and white is changed. In the mode, the time priority mode is selected, and in the color mode, the temperature priority mode is selected.

  Similarly to the case of switching the mode based on the detection result of the input voltage detection unit 52, the mode switching unit 54 performs the mode switching based on the image mode stored in the image mode storage unit 62 at the time of previous image formation. When the time for detecting the image mode cannot be secured, the mode can be switched from the previously detected and stored image mode.

  In this way, the time-priority mode is basically set based on the black-and-white mode that normally requires less heat for fixing, and the temperature-priority mode is used for the color mode that requires a larger amount of heat for fixing than the black-and-white mode. By doing so, it is possible to eliminate the possibility that the heat source becomes insufficient in power and the temperature of the fixing belt 30 falls below the set temperature necessary for fixing, and it is possible to prevent the occurrence of fixing failure.

  FIG. 13 shows a flow of still another example of the warm-up time control method of the fixing device 300.

  In the control method shown in FIG. 13, as in the case shown in FIGS. 5 and 10, the room temperature detecting means 57 first detects the room temperature of the room where the image forming apparatus is installed, and determines whether the room temperature exceeds a predetermined value. Based on the detection result of the room temperature detector 57, the mode is switched by the mode switch 54 of the fixing controller 53. For example, when the room temperature is a predetermined value of 15 ° C. or less, the temperature priority mode is set to prevent the heat source from being insufficient due to the low room temperature even if the time is longer than the normal time, thereby preventing poor fixing. To do.

  When the room temperature exceeds a predetermined value of 15 ° C., the mode is switched to the time priority mode. Next, it is determined whether or not the mode is the monochrome mode, and the mode is switched by the mode switching means 54 of the fixing control unit 53 based on the image mode. I do. For example, even when the room temperature exceeds 15 ° C., in the color mode, the mode is switched by the mode switching means in consideration of the image mode, and the temperature priority mode is set. Prevent occurrence.

  On the other hand, in the black-and-white mode, the mode is further switched to the time priority mode. However, the temperature of the fixing belt 30 is detected by the thermistor 56, and it is determined whether or not the detected temperature exceeds a threshold value. Based on the temperature, the mode is switched by the mode switching means 54 of the fixing controller 53. For example, even in the black and white mode, when the detected temperature of the fixing belt 30 exceeds the threshold value of 50 ° C., the temperature priority mode is set so as not to spend excessive time for start-up.

  On the other hand, when the detected temperature is equal to or lower than the threshold value of 50 ° C., the time priority mode is set, and it is determined that fixing is possible when the predetermined time has elapsed from the start of startup as basic, and the user waiting time is made as constant as possible.

  In the above-described example, the fixing control device 500 of the fixing device 300 that uses the fixing belt 30 as a heating member and the control method of the warm-up time have been described. However, the heating member is not limited to the fixing belt, but a fixing roller. There may be. Further, although the case where an IH coil is used as the heat source 33 has been described, not only the induction coil but also a halogen lamp or the like may be used. Further, the present invention is not limited to the case of being provided around the heating member, and may be incorporated in a fixing roller as a heating member or incorporated in a roller around which a fixing belt as a heating member is wound.

It is a principal part schematic block diagram of the internal mechanism which is an example of an image forming apparatus. FIG. 2 is a configuration diagram of a fixing device provided in the image forming apparatus main body shown in FIG. 1 and a fixing control device thereof. 3 is a flowchart illustrating an example of a method for controlling the warm-up time of the fixing device. It is a flowchart of an example which memorize | stores the detection result of a voltage detection means in the input voltage memory | storage means. 6 is a flowchart illustrating another example of a method for controlling the warm-up time of the fixing device. FIG. 6 is a relationship diagram between a fixing belt time t and a temperature T when mode switching is performed in the flowchart shown in FIG. 5. FIG. 3 is a configuration diagram of another example of a fixing device provided in the image forming apparatus main body shown in FIG. 1 and a fixing control device thereof. 10 is a flowchart of still another example of a warm-up time control method for a fixing device using the configuration shown in FIG. 7. FIG. 6 is a diagram illustrating a temperature change of the fixing belt with time when the fixing temperature is raised. 10 is a flowchart of still another example of the method for controlling the warm-up time of the fixing device. FIG. 5 is a configuration diagram of still another example of a fixing device provided in the image forming apparatus main body shown in FIG. 1 and a fixing control device thereof. 12 is a flowchart of still another example of the method for controlling the warm-up time of the fixing device using the configuration shown in FIG. 11. 10 is a flowchart of still another example of the method for controlling the warm-up time of the fixing device.

Explanation of symbols

30 Fixing belt (heating member)
33 Heat source 40 Pressure roller 50 IH control unit 51 Inverter circuit 52 Voltage detection unit 53 Fixing control unit 54 Mode switching unit 55 Input voltage storage unit 56 Thermistor 57 Room temperature detection unit 58 Automatic manual switching unit 60 Temperature gradient detection unit 61 Temperature gradient storage Means 62 Image mode storage means 63 Image mode switching means 300 Fixing device 500 Fixing control device

Claims (20)

In the fixing control device for controlling the heat source of the fixing device and heating the heating member of the fixing device using the heat source,
When raising the fixing temperature, when the temperature of the heating member reaches the set temperature, the temperature priority mode for determining that fixing is possible, and the time priority for determining that fixing is possible when the predetermined time has elapsed from the start of startup. Provided with mode switching means capable of switching between modes,
The mode based on at least one of a detection result of a voltage detection means for detecting an input voltage to the heat source, an image mode in a color mode or a monochrome mode, or a detection result of a room temperature detection means for detecting a room temperature. A fixing control device characterized in that mode switching is performed by a switching means. The fixing control device according to claim 1,
In the fixing control device that performs mode switching by the mode switching unit based on the detection result of the voltage detection unit,
Input voltage storage means for storing the detection result of the voltage detection means is provided, and mode switching is performed by the mode switching means based on the detection result of the voltage detection means stored in the input voltage storage means. Fixing control device. In the fixing control device according to claim 1 or 2,
In the fixing control device that performs mode switching by the mode switching unit based on the detection result of the voltage detection unit,
A fixing control apparatus, wherein the voltage detecting means detects an input voltage to the heat source other than when the fixing temperature is raised. The fixing control device according to any one of claims 1 to 3,
In the fixing control device that performs mode switching by the mode switching unit based on the detection result of the voltage detection unit,
When the detection result of the voltage detection unit exceeds a predetermined value, the mode switching unit performs mode switching based on the temperature detected by the heating member. The fixing control device according to claim 1,
In the fixing control device that performs mode switching by the mode switching unit based on whether an image mode of color mode or monochrome mode is selected,
A fixing control apparatus comprising: an image mode storage unit that stores a selected image mode, and mode switching is performed by the mode switching unit based on an image mode stored in the image mode storage unit. The fixing control device according to claim 1,
In the fixing control device that performs mode switching by the mode switching unit based on whether an image mode of color mode or monochrome mode is selected,
A fixing control device characterized in that mode switching is performed by the mode switching means based on an image mode selected at the time of raising a fixing temperature. The fixing control device according to claim 1, 5 or 6.
In the fixing control device that performs mode switching by the mode switching unit based on whether an image mode of color mode or monochrome mode is selected,
A fixing control device, wherein when the monochrome mode is selected, the mode switching unit performs mode switching based on a temperature detected by the heating member. The fixing control device according to claim 1,
In the fixing control device that performs mode switching by the mode switching unit based on the detection result of the room temperature detection unit,
When the room temperature exceeds a predetermined value, the mode switching unit performs mode switching based on the detection result of the voltage detection unit.   9. The fixing control device according to claim 8, wherein when the detection result of the voltage detection unit exceeds a predetermined value, the mode switching unit performs mode switching based on the temperature of the heating member.   The fixing control device according to claim 9, wherein when the temperature of the heating member exceeds a predetermined temperature, the fixing temperature is raised in the temperature priority mode.   The heating member is a fixing belt, and when the detection result of the voltage detecting means is equal to or less than a predetermined value, the fixing belt is raised by rotating the fixing belt in the temperature priority mode, and the set temperature is reached. The fixing control device according to claim 8, wherein the fixing belt is continuously rotated for a predetermined time from the point of time reached. The fixing control device according to claim 1,
In the fixing control device that performs mode switching by the mode switching unit based on the detection result of the room temperature detection unit,
The heating member is a fixing belt, and when the room temperature is equal to or lower than a predetermined value, the fixing belt is rotated by rotating the fixing belt in the temperature priority mode, and a predetermined time is reached from the time when the set temperature is reached. The fixing control device is characterized in that the fixing belt is continuously rotated during the operation. The fixing control device according to claim 1,
In the fixing control device that performs mode switching by the mode switching unit based on the detection result of the room temperature detection unit,
When the room temperature exceeds a predetermined value, the mode switching unit performs mode switching based on the detection result of the temperature gradient detecting unit that detects the temperature gradient of the heating member. The fixing control device according to claim 1,
In the fixing control device that performs mode switching by the mode switching unit based on the detection result of the room temperature detection unit,
A fixing control apparatus, wherein when the room temperature exceeds a predetermined value, mode switching is performed by the mode switching means based on whether an image mode of a color mode or a monochrome mode is selected. In the fixing control device for controlling the heat source of the fixing device and heating the heating member of the fixing device using the heat source,
When raising the fixing temperature, when the temperature of the heating member reaches the set temperature, the temperature priority mode for determining that fixing is possible, and the time priority for determining that fixing is possible when the predetermined time has elapsed from the start of startup. Mode switching means capable of switching between modes;
Temperature gradient detecting means for detecting a temperature gradient of the heating member,
The fixing control device according to claim 1, wherein when the detection result of the temperature gradient detection unit exceeds a predetermined value, the mode switching unit performs mode switching based on the temperature detected by the heating member.   An image forming apparatus comprising the fixing control device according to claim 1. The voltage detection means detects the input voltage to the heat source of the fixing device,
Based on the detection result of the voltage detection means, mode switching is performed by the mode switching means,
When the temperature priority mode is set, it is determined that fixing is possible when the temperature of the heating member of the fixing device reaches a set temperature when the fixing temperature is raised. When it reaches a certain time from the start, it is determined that it can be fixed,
A method for controlling a warm-up time of a fixing device, comprising: controlling the heat source with a fixing control device and heating the heating member using the heat source. The temperature gradient of the heating member of the fixing device is detected by the temperature gradient detecting means,
When the detection result of the temperature gradient detection means exceeds a predetermined value, mode switching is performed by the mode switching means based on the detected temperature of the heating member,
When the temperature priority mode is set, it is determined that fixing is possible when the temperature of the heating member reaches a set temperature when the fixing temperature is raised. When it reaches the time, it is determined that it can be fixed,
A method for controlling a warm-up time of a fixing device, comprising: controlling a heat source of the fixing device with a fixing control device and heating the heating member using the heat source. Detect whether the image mode of color mode or black and white mode is selected,
Based on which image mode is selected, mode switching is performed by mode switching means,
When the temperature priority mode is selected, it is determined that fixing is possible when the temperature of the heating member of the fixing device reaches the set temperature when the fixing temperature is raised. When it reaches the predetermined time from
A method for controlling a warm-up time of a fixing device, comprising: controlling a heat source of the fixing device with a fixing control device and heating a heating member of the fixing device using the heat source. In an image forming apparatus including a fixing device having a heating member heated by a heat source,
Voltage detecting means for detecting an input voltage to the heat source;
Based on the voltage value detected by the voltage detection means, a temperature priority mode for starting an image forming operation when the temperature of the heating member reaches a set temperature, and an image when a predetermined time has elapsed from the start of the fixing temperature rise. An image forming apparatus that switches between a time priority mode for starting a forming operation.

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