JP2017090644A - Image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation device capable of predicting more accurately a degradation degree of a plurality of halogen lamp heaters.SOLUTION: An image formation device includes a plurality of halogen lamp heaters 186, 187 for heating a fixing member of an image fixing part 18, an AC power source 1811 for outputting an AC voltage, temperature detection means 185 for detecting temperature of the fixing member, and control means 10 which calculates an application pattern of the plurality of halogen lamp heaters 186, 187 on the basis of the output of the temperature detection means 185, and applies an AC voltage to the plurality of halogen lamp heaters 186, 187 from the AC power source 1811 by appropriately selecting a half wave of an AC waveform of the AC power source on the basis of the application pattern. The control means 10 calculates degradation degree of each of the plurality of halogen lamp heaters 186, 187 on the basis of the application pattern and a supply time.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an image forming apparatus.

  Conventionally, in fixing control of image forming devices, multiple halogen lamp heaters are used as the fixing heater, the life of the fixing heater is predicted based on the number of times the fixing heater is turned on, and the number of times that the plurality of fixing heaters are turned on is averaged. A fixing heater control device that extends the life of the fixing heater by controlling so as to achieve the above is disclosed (see Patent Document 1).

  There is also a control method in which a half wave of an AC waveform supplied to the heater is appropriately selected and supplied to the heater as drive power (see Patent Document 2). In such a control method, when a halogen lamp heater is used as the heater, the effective value of the AC voltage supplied to the halogen lamp heater according to the number of half-waves (duty ratio) of the AC waveform selected in a predetermined cycle. Changes.

  On the other hand, the halogen lamp heater has a reference voltage at which the so-called halogen cycle is most efficiently performed. When the effective value of the supplied AC voltage is lower than the reference voltage, the filament (tungsten) of the halogen lamp heater is eroded. On the contrary, when the effective value of the supplied AC voltage is higher than the reference voltage, the sublimated tungsten becomes black powder, and blackening occurs on the inner surface of the halogen lamp heater.

  Therefore, when a halogen lamp heater is used as the heater, it is important to predict the degree of deterioration of the halogen lamp heater (hereinafter referred to as deterioration degree) in consideration of such a deterioration phenomenon. In particular, erosion of the filament of the halogen lamp heater rapidly shortens the life of the halogen lamp heater as compared with blackening. Therefore, when using the control method in Patent Document 2, a reference voltage lower than the rated voltage is set. Therefore, it is necessary to avoid the occurrence of erosion of the filament of the halogen lamp heater.

JP 2000-235327 A JP 2013-2222097 A

  However, when a reference voltage lower than the rated voltage is set and an effective value of AC voltage higher than the reference voltage is supplied to the halogen lamp heater, even if the effective value of the AC voltage is higher than the reference voltage, the AC voltage The higher the value, the more easily the deterioration of the halogen lamp heater due to blackening, and there is a problem that the degree of deterioration of the halogen lamp heater cannot be simply predicted by the lighting time and the number of lighting.

  For example, even if the effective value of the AC voltage is equal to or higher than the reference voltage, the higher the effective value of the AC voltage, the more likely the deterioration due to blackening of the halogen lamp heater proceeds. Therefore, it is impossible to predict the deterioration degree of the halogen lamp heater.

  Further, in an image forming apparatus having a plurality of halogen lamp heaters, the power, light distribution, and reference voltage are different for each halogen lamp heater, and the effective value of the AC voltage differs depending on the type and environment of the recording medium used. There is a need to predict the degree of degradation for each heater.

  An object of the present invention is to provide an image forming apparatus capable of more accurately predicting the degree of deterioration of a plurality of halogen lamp heaters.

In order to achieve the above object, an image forming apparatus according to claim 1 is provided.
A plurality of halogen lamp heaters for heating the fixing member of the image fixing unit;
An AC power supply that outputs AC voltage;
Temperature detecting means for detecting the temperature of the fixing member;
An application pattern of the plurality of halogen lamp heaters is calculated based on the output of the temperature detection means, and a half wave of the AC waveform of the AC power supply is appropriately selected based on the application pattern, and the plurality of halogens from the AC power supply. Control means for applying an AC voltage to the lamp heater;
With
The control means calculates a deterioration degree of each of the plurality of halogen lamp heaters based on the application pattern and supply time.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect,
The control means is characterized in that the deterioration degree is calculated by multiplying the supply time by a coefficient set for each of the application patterns and summing them up.

According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect,
A display means,
The control means displays the degree of deterioration on the display means.

The invention according to claim 4 is the image forming apparatus according to claim 1 or 2,
A display means,
The control means calculates the replacement time of the plurality of halogen lamp heaters based on the degree of deterioration and displays the replacement time on the display means.

According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects,
The control means calculates the degree of deterioration after the job is completed.

According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first to fifth aspects,
The control means calculates an application pattern of the plurality of halogen lamp heaters so as to average the deterioration degree.

According to a seventh aspect of the present invention, in the image forming apparatus according to the sixth aspect,
The control means is characterized in that the application pattern is calculated so as to advance the deterioration degree of the halogen lamp heater having a small deterioration degree by comparing the deterioration degrees.

The invention according to claim 8 is the image forming apparatus according to any one of claims 1 to 5,
The plurality of halogen lamp heaters include a global light distribution halogen lamp heater that heats the entire fixing member and a partial light distribution halogen lamp heater that heats a part of the fixing member;
When the width of the recording medium is wider than the first predetermined width, the control means selects the halogen lamp heater of the whole area light distribution,
When the width of the recording medium is narrower than a second predetermined width that is narrower than the first predetermined width, a halogen lamp heater for the partial light distribution is selected,
When the width of the recording medium is narrower than the first predetermined width and wider than the second predetermined width, the application patterns of the plurality of halogen lamp heaters are calculated so as to average the deterioration degree.

The invention according to claim 9 is the image forming apparatus according to any one of claims 1 to 5,
The plurality of halogen lamp heaters include a global light distribution halogen lamp heater that heats the entire fixing member and a partial light distribution halogen lamp heater that heats a part of the fixing member;
The control means includes a recording medium that is continuously conveyed, wherein the width of the preceding recording medium is narrower than a second predetermined width that is smaller than the first predetermined width, and the width of the subsequent recording medium is smaller than the first predetermined width. If it is wide, select a halogen lamp heater for the partial distribution light,
When the width of the previous recording medium is wider than the first predetermined width and the width of the subsequent recording medium is narrower than the second predetermined width, a halogen lamp heater having a full-area light distribution is selected,
When the width of the previous recording medium is narrower than the first predetermined width and wider than the second predetermined width and the width of the subsequent recording medium is wider than the first predetermined width, a halogen lamp heater for partial distribution light is provided. Use preferentially, calculate the applied pattern so that the degree of deterioration is averaged,
When the width of the preceding recording medium is narrower than the first predetermined width and wider than the second predetermined width, and the width of the subsequent recording medium is narrower than the second predetermined width, a halogen lamp heater having a full-area light distribution is provided. Use preferentially, calculate the applied pattern so that the degree of deterioration is averaged,
When the widths of the preceding recording medium and the subsequent recording medium are narrower than the first predetermined width and wider than the second predetermined width, the application patterns of the plurality of halogen lamp heaters are set so as to average the degree of deterioration. It is characterized by calculating.

  According to the present invention, the degree of deterioration of a plurality of halogen lamp heaters can be predicted.

1 is a diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment to which the present invention is applied. 2 is a block diagram illustrating a main functional configuration of the image forming apparatus. FIG. FIG. 3 is a schematic diagram illustrating a configuration of an image fixing unit. FIG. 2 is a schematic diagram illustrating an internal configuration of a fixing roller. FIG. 3 is a control circuit diagram of an image fixing unit. It is explanatory drawing which shows an example of selection operation | movement of the half wave of an alternating current waveform. It is a flowchart explaining an example of operation | movement of a control part. It is a flowchart explaining another example of operation | movement of a control part. It is a flowchart explaining another example of operation | movement of a control part. It is explanatory drawing which shows an example of the display screen in a display part. 10 is a flowchart for explaining an example of the operation of a control unit in Modification 1. 10 is a flowchart for explaining an example of the operation of a control unit in Modification 2.

(Embodiment)
[1. Description of configuration]
Hereinafter, an embodiment of the image forming apparatus of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of an image forming apparatus 1 according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating a main functional configuration of the image forming apparatus 1.

  The image forming apparatus 1 includes a control unit 10 having a CPU 101 (Central Processing Unit), a RAM 102 (Random Access Memory), and a ROM 103 (Read Only Memory), a storage unit 11, an operation unit 12, a display unit 13, an interface 14, a scanner 15, An image processing unit 16, an image forming unit 17, an image fixing unit 18, a transport unit 19, and the like are provided. The control unit 10 is connected to a storage unit 11, an operation unit 12, a display unit 13, an interface 14, a scanner 15, an image processing unit 16, an image forming unit 17, an image fixing unit 18, and a conveyance unit 19 via a bus 21. Yes.

  The CPU 101 reads out and executes a control program stored in the ROM 103 or the storage unit 11 and performs various arithmetic processes.

  The RAM 102 provides a working memory space to the CPU 101 and stores temporary data.

  The ROM 103 stores various control programs executed by the CPU 101, setting data, and the like. Instead of the ROM 103, a rewritable nonvolatile memory such as an EEPROM (Electrically Erasable Programmable Read Only Memory) or a flash memory may be used.

  The control unit 10 including the CPU 101, the RAM 102, and the ROM 103 performs overall control of each unit of the image forming apparatus 1 according to the various control programs described above. For example, the control unit 10 causes the image processing unit 16 to perform predetermined image processing on the image data and store the image data in the storage unit 11. In addition, the control unit 10 causes the conveyance unit 19 to convey the sheet, and causes the image forming unit 17 to form an image on the sheet based on the image data stored in the storage unit 11.

  The storage unit 11 includes storage means such as a DRAM (Dynamic Random Access Memory) or HDD (Hard Disk Drive), which is a semiconductor memory, and is input from the outside through image data acquired by the scanner 15 or the interface 14. Stored image data and the like. These image data and the like may be stored in the RAM 102.

  The operation unit 12 includes an input device such as an operation key or a touch panel arranged on the screen of the display unit 13. The operation unit 12 converts an input operation on these input devices into an operation signal and outputs the operation signal to the control unit 10.

  The display unit 13 includes a display device such as an LCD (Liquid crystal display), and displays an operation screen and the like indicating the state of the image forming apparatus 1 and the content of an input operation to the touch panel.

  The interface 14 is a unit that transmits and receives data to and from an external computer, another image forming apparatus, and the like, and includes, for example, any of various serial interfaces.

  The scanner 15 reads an image formed on a sheet, generates image data including single-color image data for each of R (red), G (green), and B (blue) color components, and stores the image data in the storage unit 11.

  The image processing unit 16 includes, for example, a rasterization processing unit, a color conversion unit, a gradation correction unit, and a halftone processing unit. The image processing unit 16 performs various types of image processing on the image data stored in the storage unit 11 and stores the image data in the storage unit 11. .

  The image forming unit 17 forms an image on a sheet based on the image data stored in the storage unit 11. The image forming unit 17 includes four exposure units 171, a photoconductor 172, and a developing unit 173 that respectively correspond to color components of C (cyan), M (magenta), Y (yellow), and K (black). . Further, the image forming unit 17 includes a transfer body 174 and a secondary transfer roller 175.

The exposure unit 171 includes an LD (Laser Diode) as a light emitting element. Exposure unit 171
Drives the LD based on the image data, and irradiates and exposes the photosensitive member 172 to be charged with laser light to form an electrostatic latent image on the photosensitive member 172. The developing unit 173 supplies toner (coloring material) of a predetermined color (any of C, M, Y, and K) by a developing roller that is charged on the exposed photoconductor 172, and is formed on the photoconductor 172. The developed electrostatic latent image is developed.
Images (monochromatic images) formed with C, M, Y, and K toners on four photoconductors 172 corresponding to C, M, Y, and K are sequentially superimposed on the transfer member 174 from each photoconductor 172. To be transcribed. As a result, a color image having C, M, Y, and K as color components is formed on the transfer body 174. The transfer body 174 is an endless belt wound around a plurality of transfer body transport rollers, and rotates according to the rotation of each transfer body transport roller.
The secondary transfer roller 175 transfers the color image on the transfer body 174 onto a sheet fed from the sheet feeding tray 22 or a sheet feeding device provided outside. More specifically, when a predetermined transfer voltage is applied to the secondary transfer roller 175 that sandwiches the paper and the transfer body 174, the toner forming the color image on the transfer body 174 is attracted to the paper side and applied to the paper. Transcribed.

  The image fixing unit 18 performs a fixing process for fixing the toner onto the paper by heating and pressurizing the paper on which the toner has been transferred.

  FIG. 3 is a schematic diagram showing the configuration of the image fixing unit 18. The image fixing unit 18 includes a fixing roller 183, a pressure roller 184, a temperature detection unit 185, and the like. The image fixing unit 18 and the control unit 10 constitute a fixing device.

  The fixing roller 183 includes halogen lamp heaters 186 to 187 that are fixing lamps (or fixing heaters) extending in the rotation axis direction. The halogen lamp heaters 186 to 187 generate heat when energized under the control of the control unit 10. The fixing roller 183 is driven to rotate by a rotation driving unit such as a motor (not shown) under the control of the control unit 10. The fixing roller 183 is provided with a temperature detection unit 185 that detects the temperature of the fixing roller 183. One temperature detection unit 185 or a plurality of temperature detection units 185 may be provided as long as the temperature of the fixing roller 183 can be detected.

FIG. 4 is a schematic diagram illustrating an internal configuration of the fixing roller 183.
The halogen lamp heaters 186 to 187 include tungsten filaments 186b to 187b in the cylindrical portions 186a to 187a, respectively, and halogen gases having a predetermined concentration are sealed in the cylindrical portions 186a to 187a, respectively. A reference voltage for each of the halogen lamp heaters 186 to 187 is set based on the concentration of the halogen gas sealed in the tube portions 186a to 187a.

  Further, the filament 186b of the halogen lamp heater 186 is configured to heat only the central portion in the axial direction of the fixing roller 183 (partial distribution light), and the filament 187b of the halogen lamp heater 187 extends over the entire axial direction of the fixing roller 183. It is configured to heat (entire light distribution).

As shown in FIG. 3, the pressure roller 184 is urged in a direction approaching the fixing roller 183 by an elastic member (not shown) and pressed against the fixing roller 183, thereby forming a fixing nip with the fixing roller 183. However, it rotates as the fixing roller 183 rotates.
The pressure roller 184 may be driven and rotated by a rotation driving unit such as a motor (not shown) under the control of the control unit 10.

  The fixing roller 183 and the pressure roller 184 heat and press the sheet P while sandwiching the sheet P as a recording medium at the fixing nip and transporting the sheet P in the transport direction R indicated by an arrow in FIG. As a result, the fixing roller 183 and the pressure roller 184 melt and fix the toner on the paper P. The temperature of the fixing roller 183 when coming into contact with the paper P is, for example, in a range of 180 ° C. or higher and 200 ° C. or lower. Accordingly, the halogen lamp heaters 186 to 187 heat the fixing roller 183 so that the fixing roller 183 reaches this temperature.

  As shown in FIG. 1, the transport unit 19 includes a plurality of paper transport rollers that transport paper by rotating while sandwiching the paper, and transports the paper through a predetermined transport path. The transport unit 19 includes a reversing mechanism 191 that reverses the front and back of the paper on which the fixing process has been performed by the image fixing unit 18 and transports the paper to the secondary transfer roller 175. In the image forming apparatus 1, when images are formed on both sides of a sheet, the reversing mechanism 191 reverses the front and back of the sheet to form images on both sides, and then the sheet is discharged to the discharge tray 23. When an image is formed only on one side of the paper, the paper on which the image is formed on one side is discharged to the paper discharge tray 23 without reversing the front and back of the paper by the reversing mechanism 191.

[2. Explanation of control circuit of image fixing unit]
In FIG. 5, an AC power supply 1811 outputs general AC power (for example, 100 V, 200 V, 50 Hz, or 60 Hz).

  The switching element 1812 and the switching element 1813 are elements such as a thyristor and a bidirectional thyristor (triac), and are turned ON when a trigger signal is applied to the gate as a control terminal. The output of AC power supply 1811 is connected to the input terminals of switching element 1812 and switching element 1813, respectively, and the output terminals of switching element 1812 and switching element 1813 are connected to the input terminals of halogen lamp heater 186 and halogen lamp heater 187, respectively. .

  The control unit 10 controls the temperature of the halogen lamp heater 186 and the halogen lamp heater 187. Specifically, the control unit 10 functions as a power control unit together with the switching element 1812 and the switching element 1813, controls the switching element 1812 and the switching element 1813 with a control signal (CS181, CS182), and outputs from the AC power supply 1811. The half wave of the alternating current waveform is selected and supplied to the halogen lamp heater 186 and the halogen lamp heater 187.

  The temperature detection unit 185 is a temperature detection element such as a temperature sensor, is provided in the vicinity of the fixing roller 183, detects the temperature of the fixing roller 183, and outputs it to the control unit 10.

  The zero cross detection unit 1814 takes in the output of the AC power supply 1811, generates a zero cross signal ZC 181, and outputs it to the control unit 10.

[3. Explanation of selection of half wave of AC waveform]
Here, a method of selecting a half wave of the AC waveform output from the AC power supply 1811 by the switching element 1812 and the switching element 1813 and supplying the half wave to the halogen lamp heater 186 and the halogen lamp heater 187 will be described with reference to FIG. .

  As shown in FIG. 6B, the zero-cross detection unit 1814 detects a point where the AC waveform output from the AC power supply 1811 passes ± 0 V, and generates a zero-cross signal ZC181 in which the output value is switched at the time of detection. And output to the control unit 10.

  As shown in FIG. 6C, the control unit 10 generates a control signal CS181 (control signal CS182) synchronized with the input zero-cross signal ZC181 and applies it to the control terminal of the switching element 1812 (switching element 1813). To do.

  That is, as shown in FIG. 6, the switching element 1812 (switching element 1813) is turned “ON” in the period T1, the period T2, and the period T4 when the control signal CS181 (control signal CS182) is applied from the control unit 10. A half wave of the AC waveform output from the AC power supply 1811 is selected and supplied to the halogen lamp heater 186 (halogen lamp heater 187).

  On the other hand, in the period T3 in which the control signal CS181 (control signal CS182) is not applied from the control unit 10, the switching element 1812 (switching element 1813) remains “OFF” and is non-conductive, and thus is output from the AC power supply 1811. The half wave of the alternating waveform is not selected.

  In addition, the switching element 1812 (switching element 1813) is maintained in a conductive state once a trigger signal (control signal) is applied to the gate, but returns to a non-conductive state when the voltage becomes 0 V as in an AC waveform. Therefore, even if it conducts in the cycle T2, it automatically returns to non-conduction in the cycle T3.

[4. Description of operation of image forming apparatus]
Here, the operation of the image forming apparatus 1 will be described with reference to the flowchart of FIG.

[4-1. Explanation of overall operation]
The control unit 10 obtains the application pattern by executing an “application pattern calculation loop” (described later) for calculating the application pattern from the difference between the temperature of the fixing roller 183 detected by the temperature detection unit 185 and the target temperature (described later). Step S71).

  Here, the applied pattern is obtained by selecting a half wave of an alternating waveform having a predetermined period based on the duty ratio.

  Thereafter, the control unit 10 appropriately selects a half wave of the AC waveform of the AC power supply 1811 based on the applied pattern, and applies an AC voltage as drive power to the halogen lamp heater 186 and the halogen lamp heater 187 to thereby form an image fixing unit. 18 is operated (step S72).

  In addition, the control unit 10 stores the application time of the halogen lamp heater 186 and the halogen lamp heater 187 in the storage unit 11, and the print time and the number of prints during the job, the accumulated power of the halogen lamp heater 186 and the halogen lamp heater 187. Are also stored in the storage unit 11 (step S73).

  The control unit 10 then outputs at least one value (time, number of sheets, accumulated power) of the print time and number of prints in the job stored in the storage unit 11 and the accumulated power of the halogen lamp heater 186 and the halogen lamp heater 187. ) Exceeds a predetermined value (step S74). If it is determined that the predetermined value is not exceeded (step S74: No), the process proceeds to step S77.

  On the other hand, when the control unit 10 determines that the predetermined value is exceeded (step S74: Yes), the deterioration degree of the halogen lamp heater 186 and the halogen lamp heater 187 is calculated and stored in the storage unit 11. The print time and number of prints during the job, and the accumulated power of the halogen lamp heater 186 and the halogen lamp heater 187 are cleared (step S75).

  Here, the deterioration degree is a value obtained by multiplying a coefficient set for each duty ratio of the application pattern supplied to the halogen lamp heater by multiplying the supply time of the corresponding application pattern.

For example, the duty ratio of the applied pattern is 40%, 70%, and 100%, and the coefficients per time are “a”, “1.2a”, and “2.3a” (a is a predetermined constant). When the image fixing unit 18 is operated during a certain job for a supply time of 0.3 hours at a duty ratio of 40%, 0.4 hours at a duty ratio of 70%, and 0.5 hours at a duty ratio of 100%. Deterioration level L is
L = 0.3 × a + 0.4 × 1.2a + 0.5 × 2.3a
= 1.93a (1)
It becomes.
The coefficient set for each duty ratio of the applied pattern is exemplified as a proportional relationship. However, depending on the halogen gas concentration of the halogen lamp heater, usage conditions, etc., the coefficient is a value represented by an n-order function. There may be.

  Furthermore, the control unit 10 executes a “replacement display loop” (described later) that predicts the replacement timing of the halogen lamp heater and the number of outputtable sheets based on the calculated degree of deterioration and causes the display unit 13 to display it (step S76). The process proceeds to step S77.

  Finally, the control unit 10 determines whether or not the job has been completed (step S77), and when determining that the job has not been completed (step S77: No), the control unit 10 returns to step S71. On the other hand, when the control unit 10 determines that the job has been completed (step S77: Yes), it calculates the deterioration degree of the halogen lamp heater 186 and the halogen lamp heater 187, and prints in the job stored in the storage unit 11 The time, the number of prints, the accumulated power of the halogen lamp heater 186 and the halogen lamp heater 187 are cleared (step S78), and the “exchange display loop” (described later) is executed (step S79).

[4-2. Explanation of operation of applied pattern calculation loop]
Here, the operation of the “application pattern calculation loop” executed in step S71 of the flowchart of FIG. 7 will be described using the flowchart shown in FIG.

  The control unit 10 calculates the electric power supplied to the halogen lamp heater 186 and the halogen lamp heater 187 from the difference between the temperature of the fixing roller 183 detected by the temperature detection unit 185 and the target temperature (step S81), and the two halogen lamp heaters An application pattern that satisfies a power within a predetermined value with respect to the total power is searched (step S82).

  Specifically, the so-called PID control (Proportional-Integral-Derivative Controller) is used to determine the power to be supplied, the deviation between the detected temperature of the fixing roller 183 and the target temperature, its integration, and differentiation. Calculated by

  Then, the control unit 10 compares the deterioration degree L1 of the halogen lamp heater 186 and the deterioration degree L2 of the halogen lamp heater 187, and determines whether or not the difference in deterioration degree is equal to or less than a predetermined value (step S83). That is, it is determined whether the deterioration levels of the two halogen lamp heaters 186 and 187 are substantially the same.

  When the control unit 10 determines that the difference between the deterioration levels is equal to or less than the predetermined value (step S83: Yes), is there an application pattern in which the progress degrees of the deterioration levels of the two halogen lamp heaters 186 and 187 are equal? It is determined whether or not (step S84).

  When the control unit 10 determines that there is an application pattern in which the degree of deterioration progress of the two halogen lamp heaters 186 and 187 is equal (step S84: Yes), the degree of deterioration progress is equal and the total The application pattern closest to the power is selected (step S85). In addition, when the control unit 10 determines that there is no application pattern in which the degree of deterioration of the two halogen lamp heaters 186 and 187 is equal (No in step S84), the application pattern closest to the total power is selected. (Step S86).

  On the other hand, when the control unit 10 determines that the difference in deterioration level is not less than the predetermined value (step S83: No), whether or not the deterioration level L1 of the halogen lamp heater 186 is greater than the deterioration level L2 of the halogen lamp heater 187. Is determined (step S87).

  When the controller 10 determines that the deterioration level L1 of the halogen lamp heater 186 is larger than the deterioration level L2 of the halogen lamp heater 187 (step S87: Yes), the degree of progress of the deterioration level of the halogen lamp heater 186 An application pattern is selected in which the degree of progress of the deterioration degree of the halogen lamp heater 187 is large and the difference between the degree of progress of the degree of deterioration is the largest (step S88).

  Further, when the control unit 10 determines that the deterioration degree L1 of the halogen lamp heater 186 is not greater than the deterioration degree L2 of the halogen lamp heater 187 (step S87: No), the degree of deterioration degree progression of the halogen lamp heater 187 is determined. Then, an application pattern having a large degree of progress of the deterioration degree of the halogen lamp heater 186 and a difference of the degree of progress of the degree of deterioration of both is selected (step S89).

  That is, when there is a difference of a predetermined value or more between the deterioration degrees of the two halogen lamp heaters 186 and 187, the control unit 10 deteriorates so that the deterioration degree of one halogen lamp heater does not advance excessively. Degradation is averaged by preferentially using halogen lamp heaters that have not progressed.

  For example, if two halogen lamp heaters have the same power and the same reference voltage, if there is a difference in the degree of deterioration between them, priority is given to a halogen lamp heater with a low degree of deterioration in the next job. By using it periodically, the degree of deterioration is averaged.

Specifically, two halogen lamp heaters (referred to as lamp 1 and lamp 2 for convenience) each have a power of 1000 W and a reference voltage of 80 V (duty ratio 40%).
Lamp 1: 0.3 hours at a duty ratio of 40%
0.4 hour at 70% duty ratio
0.5 hour at 100% duty ratio
Lamp 2: Duty ratio 40%, 0.7 hours
0.2 hour at 70% duty ratio
It was operated with a duty ratio of 100% and a supply time of 0.1 hour.

Then, the duty factor of the applied pattern is 40%, 70%, and 100%, and the coefficients per time are set as “b”, “1.56b”, and “4.72b” (b is a predetermined constant). The deterioration degree L1 of the lamp 1 and the deterioration degree L2 of the lamp 2 are respectively
L1 = 0.3 × b + 0.4 × 1.56b + 0.5 × 4.72b
= 3.284b (2)
L2 = 0.7 × b + 0.2 × 1.56b + 0.1 × 4.72b
= 1.484b (3)
Since “L1> L2” is satisfied, the deterioration degree is averaged by preferentially using the lamp 2 with a low deterioration degree in the next job.

  Also, for example, when the power and reference voltage of two halogen lamp heaters are different from each other, if there is a difference in the degree of deterioration between the two, a halogen lamp heater with a low degree of deterioration is given priority in the next job. By using it, the degree of deterioration is averaged.

Specifically, the lamp 1 is 1000 W, the reference voltage is 80 V (duty ratio 40%), the lamp 2 is 800 W, and the reference voltage is 100 V (duty ratio 50%).
Lamp 1: 0.7 hours at a duty ratio of 40%
0.2 hour at 70% duty ratio
0.1 hour at 100% duty ratio
Lamp 2: 0.3 hours at a duty ratio of 40%
0.4 hour at 70% duty ratio
It was operated with a supply time of 0.5 hours at a duty ratio of 100%.

The coefficients of the lamp 1 per hour when the duty ratio of the applied pattern is 40%, 70%, and 100% are “c”, “1.56c”, “4.72c”, and the coefficients of the lamp 2 are “ 1.2c "," 2.31c "," 7.22c "(c is a predetermined constant), the deterioration degree L1 of the lamp 1 and the deterioration degree L2 of the lamp 2 are respectively
L1 = 0.7 × c + 0.2 × 1.56c + 0.1 × 4.72c
= 1.484c (4)
L2 = 0.3 × 1.2c + 0.4 × 2.31c + 0.5 × 7.22c
= 9.004c (5)
Since “L1 <L2” is satisfied, the deterioration degree is averaged by preferentially using the lamp 1 having a low deterioration degree in the next job.

  However, in this case, since the power and reference voltage of the two halogen lamp heaters are different from each other, as shown in step S88 and step S89 in FIG. In addition, by selecting an application pattern that has the largest difference in the degree of progress of the degree of deterioration between them, the speed of averaging the degree of deterioration can be increased.

  Specifically, the relationship of Formula (4) and Formula (5) is established, the required total power is 1000 W (allowable range: 960 W to 1040 W), and the application pattern satisfying the conditions is shown in Table 1. In the case of two candidates, it is possible to increase the speed of averaging the degree of deterioration by selecting not the application pattern B but the application pattern A having the greatest difference in the degree of progress of the degree of deterioration.

  In this way, by averaging the degree of deterioration of a plurality of halogen lamp heaters, it is possible to prevent the deterioration degree of one halogen lamp heater from being excessively advanced and requiring replacement. Since replacement is possible at the same time, maintenance costs can be reduced.

[4-3. Explanation of operation of exchange display loop]
Next, the operation of the “exchange display loop” executed in step S76 and step S79 in the flowchart of FIG. 7 will be described with reference to the flowchart shown in FIG.

  The control unit 10 predicts the replacement timing (practicable time) of the halogen lamp heaters and the number of sheets that can be output from now based on the deterioration levels of the two halogen lamp heaters (step S91).

For example, the degree of deterioration that requires replacement of the halogen lamp heater is “100”, and a predetermined period (for example, 100 hours), 300,000 jobs are executed for 60 hours, and the halogen lamp heater that is most deteriorated Is increased by “10” and the current deterioration level is “80 (remaining 20)”, the feasible time (remaining time until replacement) T1 and the output possible number of sheets C1 are:
T1 = 20 (deterioration degree) × 60 (hours) / 10 (increase) = 120 hours
C1 = 20 (deterioration degree) × 300,000 (number of sheets) / 10 (increase) = 600,000 sheets.

  Then, the control unit 10 determines whether or not at least one of the feasible time (remaining time until replacement) T1 and the outputtable number of sheets C1 is equal to or less than a predetermined value (step S92), and the feasible time (remaining until replacement). When it is determined that the time T1 and the outputtable number C1 are not less than or equal to the predetermined values (step S92: No), the process is terminated.

  On the other hand, when the control unit 10 determines that at least one of the feasible time (remaining time until replacement) T1 and the outputable number of sheets C1 is equal to or less than a predetermined value (step S92: Yes), the feasible time together with the replacement instruction ( The display unit 13 displays the values of the remaining time (T1 until replacement) T1 and the outputtable number C1 (step S93), and updates the possible time (remaining time until replacement) T1 and the value of the outputable number C1 (step S94).

  For example, as shown in FIG. 10, on the display screen of the display unit 13, two halogen lamp heaters 186 and halogen lamp heaters 187 (represented as heater 1 and heater 2 in the display example) can be performed (remaining time until replacement). "Remaining time 50h" and "Remaining time 75h" are displayed, and at the same time, the recommended replacement time "after one week", the output possible number of sheets "24 sheets of plain paper A4", and the like are displayed.

  In this way, by displaying the deterioration degree of the halogen lamp heater, the feasible time (remaining time until replacement), the replacement time, the number of sheets that can be output, etc. on the display screen of the display unit 13, a user, a maintenance worker, etc. In addition, the deterioration degree of the halogen lamp heater can be easily grasped.

  As described above, according to the image forming apparatus 1 of the present embodiment, an AC voltage is applied to the plurality of halogen lamp heaters 186 and 187 that heat the fixing member of the image fixing unit 18 and the plurality of halogen lamp heaters 186 and 187. The AC power supply 1811 that performs the operation, the temperature detection unit 185 that detects the temperature of the fixing member, and the drive power application pattern of the plurality of halogen lamp heaters 186 and 187 are calculated based on the output of the temperature detection unit 185, and based on the application pattern A control unit 10 that appropriately selects a half-wave of the AC waveform of the AC power supply 1811 and applies an AC voltage as drive power from the AC power supply 1811 to the plurality of halogen lamp heaters 186 and 187. By calculating the deterioration degree of the plurality of halogen lamp heaters 186 and 187 based on the pattern and the supply time, It is possible to predict the degree of deterioration of the number of the halogen lamp heater 186, 187.

  Further, the control unit 10 can prevent the deterioration degree of one of the halogen lamp heaters from being excessively advanced and requiring replacement by averaging the deterioration degrees of the plurality of halogen lamp heaters 186 and 187, Since multiple halogen lamp heaters can be replaced at the same time, maintenance costs can be reduced.

  In addition, the control unit 10 displays on the display screen of the display unit 13 the degree of deterioration of the halogen lamp heaters 186 and 187, the possible time (remaining time until replacement), the replacement time, the number of sheets that can be output, and the like. And maintenance workers can easily grasp the deterioration of the halogen lamp heaters 186 and 187.

(Modification 1)
In the description of the embodiment, the size of the paper P used for the job is not mentioned, but only the central portion in the axial direction of the fixing roller 183 is heated (partially distributed light) as shown in FIGS. When the halogen lamp heater 186 or the halogen lamp heater 187 that heats the entire axial direction of the fixing roller 183 (entire light distribution) is used, the size of the paper P used in the job may be taken into consideration.

  Here, as the size of the paper P, for example, “normal size” such as A4 size, “large size” substantially the same size as the filament 187 b of the halogen lamp heater 187 of the whole area light distribution, partial distribution light (central light distribution) The “small size”, which is smaller than the filament 186b of the halogen lamp heater 186 of FIG.

  More specifically, when a predetermined width having a size relationship of “first predetermined width> second predetermined width” is set and the width of the sheet P perpendicular to the transport direction is wider than the first predetermined width, “large” When a halogen lamp heater 187 with a light distribution in the entire area is used as the “size” and the width of the paper P perpendicular to the transport direction is narrower than the second predetermined width, the partial distribution light (center light distribution) is set as “small size”. A halogen lamp heater 186 is used.

  When the width of the sheet P perpendicular to the transport direction is narrower than the first predetermined width and wider than the second predetermined width, “normal size” is set as the halogen lamp heater 186 for partial distribution light (center light distribution). In combination with a halogen lamp heater 187 of the whole area light distribution.

  In other words, using a halogen lamp heater 187 with light distribution over the entire area of the “small size” paper P heats an unnecessary portion of the fixing roller 183, which wastes power to be supplied. On the other hand, using a halogen lamp heater 186 with partial distribution light (center light distribution) for “large size” paper P is because of the heating capability of the halogen lamp heater 186 with partial distribution light (center light distribution). Since it takes a lot of time to heat the entire fixing roller 183 in the axial direction, it is necessary to avoid using such a halogen lamp heater.

  For the “normal size” paper P, the halogen lamp heater 186 for partial light distribution (central light distribution) and the halogen lamp heater 187 for light distribution over the entire area are used in combination. Must be averaged.

  Therefore, the control unit 10 determines whether or not the currently printed paper P is “normal size” as shown in the flowchart of FIG. 11 (step S111). That is, it is determined whether or not the width orthogonal to the conveyance direction of the paper P is narrower than one predetermined width and wider than the second predetermined width.

  When the control unit 10 determines that the currently printed paper P is “normal size” (step S111: Yes), the control unit 10 executes the “application pattern calculation loop” shown in the flowchart of FIG. Obtained (step S112).

  That is, if “normal size”, an “applied pattern calculation loop” that averages the degree of deterioration is executed, so that temperature control according to the size of the paper P can be performed, and the degree of deterioration of the halogen lamp heaters 186 and 187 is set. Can be averaged.

  Further, when the control unit 10 determines that the currently printed paper P is not “normal size” (step S111: No), the control unit 10 performs temperature control according to the size of the paper P (step S113).

  That is, if the “large size” is used, the halogen lamp heater 187 of the entire area light distribution is used, and if the “small size” is used, the halogen lamp heater 186 of the partial distribution light (center light distribution) is used. By calculating the applied pattern and controlling the temperature, the temperature can be controlled using a halogen lamp heater suitable for the size of the paper P.

  As described above, according to the first modification, the temperature control according to the size of the paper P can be performed according to the size of the paper P used for the job, and the deterioration degree of the halogen lamp heaters 186 and 187 is averaged. be able to.

(Modification 2)
In the description of the first modification, the degree of deterioration of the halogen lamp heaters 186 and 187 is averaged based on the size of the paper P currently printed, but the size of the paper P used in the next printing is also included. May be considered.

  That is, for example, when a “normal size” paper P is currently printed and a “large size” paper P is printed in the next print, in the first modification, a “normal size” paper P is printed. Uses a partial distribution light (center light distribution) halogen lamp heater 186 in combination with a whole area light distribution halogen lamp heater 187. For “large size” paper P, a whole area light distribution halogen lamp is used. Only the heater 187 is used, and the halogen lamp heater 187 with the entire area light distribution is continuously used, and the degree of deterioration proceeds.

  For this reason, the control unit 10 determines whether or not the next paper P to be printed is “large size” as shown in the flowchart of FIG. 12 (step S121). That is, it is determined whether the width orthogonal to the transport direction of the paper P is wider than the first predetermined width.

  When it is determined that the paper P to be printed next is “large size” (step S121: Yes), the control unit 10 determines whether or not the paper P currently printed is “normal size”. (Step S122).

  When the control unit 10 determines that the currently printed paper P is “normal size” (step S122: Yes), priority is given to the use of the halogen lamp heater 186 for partial distribution light (center light distribution). Then, the “application pattern calculation loop” shown in the flowchart of FIG. 8 is executed to obtain the application pattern (step S123).

  Specifically, in order to give priority to the use of the halogen lamp heater 186 for partial distribution light (center light distribution), the flowchart of FIG. 8 is executed after temporarily setting the deterioration degree as “L1 <L2”. Let Alternatively, the process jumps directly to step S89 in the flowchart of FIG.

  On the other hand, when it is determined that the paper P to be printed next is not “large size” (step S121: No), the control unit 10 determines whether or not the paper P to be printed next is “small size”. (Step S124). That is, it is determined whether or not the width orthogonal to the conveyance direction of the paper P is smaller than the second predetermined width.

  When it is determined that the paper P to be printed next is “small size” (step S124: Yes), the control unit 10 determines whether or not the paper P currently printed is “normal size”. (Step S125).

  Then, when the control unit 10 determines that the currently printed paper P is “normal size” (step S125: Yes), the control unit 10 prioritizes the use of the halogen lamp heater 187 with the entire area light distribution, and FIG. The application pattern is obtained by executing the “application pattern calculation loop” shown in the flowchart (step S126).

  Specifically, in order to prioritize the use of the halogen lamp heater 187 with the entire area light distribution, the deterioration degree is temporarily set as “L1> L2”, and the flowchart of FIG. 8 is executed. Alternatively, the process jumps directly to step S88 in the flowchart of FIG.

  If the control unit 10 determines that the next paper P to be printed is not “small size” (step S124: No), it determines whether or not the paper P currently printed is “normal size”. Judgment is made (step S127).

  When the control unit 10 determines that the currently printed paper P is “normal size” (step S127: Yes), the control unit 10 normally executes the “application pattern calculation loop” shown in the flowchart of FIG. Thus, an application pattern is obtained (step S128).

  Finally, when it is determined that the currently printed paper P is not “normal size” (steps S122, S125, S127: No), the control unit 10 performs temperature control according to the size of the paper P (step S122). S129). That is, the paper P currently printed is “large size” or “small size”.

  For this reason, if the “large size” is used, a halogen lamp heater 187 with a total light distribution is used, and if the “small size” is used, a partial lamp (center light distribution) halogen lamp heater 186 is used. The applied pattern is calculated and temperature control is performed.

  That is, for example, when a “normal size” paper P is currently printed and a “large size” paper P is printed in the next print, Prioritizing the use of the halogen lamp heater 186 for the distribution light (center light distribution), the application pattern is obtained by executing the “application pattern calculation loop” shown in the flowchart of FIG. For this reason, it is possible to prevent only the halogen lamp heater 187 of the entire area light distribution from being used continuously, and the deterioration degree of one halogen lamp heater from proceeding.

  At the same time, if the paper P currently printed is “large size”, the halogen lamp heater 187 of the entire area light distribution is used, and if it is “small size”, the halogen of partial distribution light (center light distribution) is used. By calculating the required application pattern using the lamp heater 186 and performing temperature control, the temperature can be controlled using a halogen lamp heater suitable for the size of the paper P. In addition, since the “applied pattern calculation loop” that averages the degree of deterioration is executed for “normal size”, temperature control according to the size of the paper P can be performed, and the degree of deterioration of the halogen lamp heaters 186 and 187 can be controlled. Can be averaged.

  As described above, according to the second modification, the temperature can be controlled according to the size of the paper P according to the size of the paper P used for the current job, and the size of the paper P used for the current and next jobs. Depending on the combination, the use of either one of the halogen lamp heaters is prioritized and the degree of deterioration is averaged. Therefore, the degree of deterioration of the halogen lamp heaters 186 and 187 can be averaged more efficiently. it can.

  In the description of the embodiment, the fixing roller 183 includes a partial distribution light (center light distribution) halogen lamp heater 186 extending in the rotation axis direction and a whole area light distribution halogen lamp heater 187. Of course, in addition to the halogen lamp heater 186 for partial light distribution (center light distribution) and the halogen lamp heater 187 for total light distribution, a halogen lamp heater for partial light distribution (end light distribution) may be provided. Good. Further, the fixing roller 183 may be configured to include a halogen lamp heater 187 for light distribution in the entire area and a halogen lamp heater for partial distribution light (end light distribution).

  In the description of the embodiment, the image fixing unit 18 configures a nip unit that sandwiches and conveys the paper P while the fixing roller 183 and the pressure roller 184 include a heating roller that is a heating member, A fixing belt, and the fixing belt is stretched between a heating roller and a fixing roller 183, and the fixing roller 183 and the pressure roller 184b sandwich and convey the paper P via the fixing belt. You may make it comprise.

  In the description of the embodiment, for example, a unit for image formation is provided for each color such as Y (yellow), M (magenta), C (cyan), K (black), and a color image is formed on the paper P. The image forming apparatus 1 to be formed has been illustrated, but is not limited to this example, and may be an image forming apparatus that forms a monochrome image, for example.

  In the description of the embodiment, the fixing roller and the pressure roller are described separately, but may be considered as a pair of fixing members.

  In the description of the embodiment, paper is exemplified as the recording medium. However, the recording medium is not limited to paper, and may be any sheet that can form and fix a toner image. , Non-woven fabric, plastic film, leather, etc.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 10 Control part (control means)
18 Image fixing unit 183 Fixing roller 184 Pressure roller 185 Temperature detection unit (temperature detection means)
186, 187 Halogen lamp heater 1811 AC power supply 1812, 1813 Switching element 1814 Zero cross detector P Paper (recording medium)
CS181, CS182 Control signal ZC181 Zero cross signal

Claims (9)

A plurality of halogen lamp heaters for heating the fixing member of the image fixing unit;
An AC power supply that outputs AC voltage;
Temperature detecting means for detecting the temperature of the fixing member;
An application pattern of the plurality of halogen lamp heaters is calculated based on the output of the temperature detection means, and a half wave of the AC waveform of the AC power supply is appropriately selected based on the application pattern, and the plurality of halogens from the AC power supply. Control means for applying an AC voltage to the lamp heater;
With
The image forming apparatus, wherein the control unit calculates a degree of deterioration of each of the plurality of halogen lamp heaters based on the application pattern and a supply time.   The image forming apparatus according to claim 1, wherein the control unit calculates the degree of deterioration by multiplying the supply time by a coefficient set for each application pattern. A display means,
The image forming apparatus according to claim 1, wherein the control unit causes the display unit to display the degree of deterioration. A display means,
3. The image forming apparatus according to claim 1, wherein the control unit calculates a replacement time of the plurality of halogen lamp heaters based on the degree of deterioration and displays the replacement time on the display unit.   The image forming apparatus according to claim 1, wherein the control unit calculates the degree of deterioration after a job is finished.   The image forming apparatus according to claim 1, wherein the control unit calculates an application pattern of the plurality of halogen lamp heaters so as to average the degree of deterioration.   The image forming apparatus according to claim 6, wherein the control unit calculates the application pattern so that the deterioration degree of the halogen lamp heater having a small deterioration degree is advanced by comparing the deterioration degrees. The plurality of halogen lamp heaters include a global light distribution halogen lamp heater that heats the entire fixing member and a partial light distribution halogen lamp heater that heats a part of the fixing member;
When the width of the recording medium is wider than the first predetermined width, the control means selects the halogen lamp heater of the whole area light distribution,
When the width of the recording medium is narrower than a second predetermined width that is narrower than the first predetermined width, a halogen lamp heater for the partial light distribution is selected,
The application pattern of the plurality of halogen lamp heaters is calculated so that the deterioration degree is averaged when the width of the recording medium is narrower than the first predetermined width and wider than the second predetermined width. The image forming apparatus according to any one of 1 to 5. The plurality of halogen lamp heaters include a global light distribution halogen lamp heater that heats the entire fixing member and a partial light distribution halogen lamp heater that heats a part of the fixing member;
The control means includes a recording medium that is continuously conveyed, wherein the width of the preceding recording medium is narrower than a second predetermined width that is smaller than the first predetermined width, and the width of the subsequent recording medium is smaller than the first predetermined width. If it is wide, select a halogen lamp heater for the partial distribution light,
When the width of the previous recording medium is wider than the first predetermined width and the width of the subsequent recording medium is narrower than the second predetermined width, a halogen lamp heater having a full-area light distribution is selected,
When the width of the previous recording medium is narrower than the first predetermined width and wider than the second predetermined width and the width of the subsequent recording medium is wider than the first predetermined width, a halogen lamp heater for partial distribution light is provided. Use preferentially, calculate the applied pattern so that the degree of deterioration is averaged,
When the width of the preceding recording medium is narrower than the first predetermined width and wider than the second predetermined width, and the width of the subsequent recording medium is narrower than the second predetermined width, a halogen lamp heater having a full-area light distribution is provided. Use preferentially, calculate the applied pattern so that the degree of deterioration is averaged,
When the widths of the preceding recording medium and the subsequent recording medium are narrower than the first predetermined width and wider than the second predetermined width, the application patterns of the plurality of halogen lamp heaters are set so as to average the degree of deterioration. The image forming apparatus according to claim 1, wherein the image forming apparatus is calculated.

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