JP2005024899A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus that can complete in a short time a warm-up operation for raising the surface temperature of a fixing body of a fixing means up to fixation temperature without spoiling usability. <P>SOLUTION: Once the power source is turned on, it is decided whether the temperature T1 of a fixing device 32 (the surface temperature of the fixing roller) is lower than the previously set reference temperature A (e.g. 323K) based on the output of a temperature detection sensor 409 (step S2011). Here, when the temperature T1 of the fixing device 32 is lower than the reference temperature, the warm-up operation is started to raise the electric power distribution of the fixing device 32 and switch a DF 12 to a low-speed mode (steps S2021 to S2041). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine including an automatic document reading unit having a plurality of operation modes including a low power operation mode.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, when the power is turned on, power is first supplied to the fixing device, and a warm-up operation for warming the fixing device to a predetermined temperature is started. The time required for this warm-up becomes longer as the speed increases. This is because the heat capacity of the fixing device increases as the speed increases, and it takes a long time for the fixing device to reach a predetermined temperature. In particular, in an image forming apparatus set in an office environment, when the power is turned on in the morning, the temperature of the fixing device is low, so that the waiting time until the fixing device warms up is increased. For example, in the case of a medium speed machine, the time required for warm-up is about 1 to 2 minutes, but in the case of a high speed machine, it takes about 5 minutes.
[0003]
Usually, various initialization operations are performed during warm-up. In the fixing device, the fixing roller is rotated so that the surface temperature of the fixing roller is uniform. Further, in order to confirm whether or not the sheet is retained between the sensors on the conveyance path, a conveyance motor for conveying the sheet is driven. The other motors are also driven to check whether there is any abnormality that hinders rotation / operation, such as a locked state.
[0004]
When post-processing means such as a finisher or a sorter is connected, the post-processing means starts an operation of returning the tray position to the initial position when the power is turned on. These operations are completed faster than the warm-up when the fixing device temperature is very low.
[0005]
Also, the document feeder (hereinafter referred to as DF), which is an original reading device or automatic document reading means, starts to be initialized when the power is turned on so that an output can be obtained immediately after the warm-up is completed. The document reading device or DF can operate after the initialization is completed, and an image read after the initialization operation is completed is accumulated in an image storage unit such as a hard disk until the warm-up is completed.
[0006]
In recent years, from the viewpoint of energy saving, some copiers and the like are equipped with functions such as a power saving mode and a sleep mode that automatically turn off the power when not used for a certain period of time. Such a function is very effective from the viewpoint of energy saving, but when used from a state where the power is turned off by this function, there is a problem that it takes a long time to warm up and the usability is poor. For example, even in the case of an apparatus having a specification of 4 seconds for the first copy, it takes 5 minutes for the apparatus to start up from a state where the power is automatically turned off, so that it is very inconvenient.
[0007]
In order to solve this problem, the warm-up time is shortened to about 1 minute in a high-speed machine by reducing the heat capacity of the fixing device and adopting a low melting point toner, thereby shortening the warm-up time. It's getting on.
[0008]
Further, as disclosed in, for example, Japanese Patent Application Laid-Open No. 09-368899, there is known a means for detecting whether or not each optional device is installed and used to suppress an increase in power of the entire device. ing. In the technique described in Japanese Patent Application Laid-Open No. 09-368899, when each optional device (for example, an automatic output paper classifier or an automatic document feeder) is used, a monitor signal is output to thereby reduce the total power consumption. A combination of optional devices that deviate from the standard is determined, and when using an optional device with excess power, on / off control of the fixing heater is performed according to a use state signal output from the optional device.
[0009]
[Patent Document 1]
JP 09-368899 A
[0010]
[Problems to be solved by the invention]
However, in order to further reduce the warm-up time by reducing the heat capacity of the fixing device and adopting a low-melting-point toner as described above, the fixing device will start up rapidly when the power is turned on. However, in Japan, it is necessary to suppress the input power amount to 1500 W or less, which is a permissible value for general wiring. Therefore, the input power amount cannot be increased without limit. In addition, there is a limit to the reduction in the heat capacity of the fixing device due to the restriction of the input power amount. As a result, it is difficult to further shorten the warm-up time.
[0011]
Further, in the configuration disclosed in Japanese Patent Application Laid-Open No. 09-368899, when there is no optional device, the amount of power to the heater is not restricted, and the waiting time until the warm-up is completed is shortened. However, when there is an optional device, the waiting time until the warm-up is completed is not shortened. Therefore, the above technique cannot be a solution for shortening the warm-up time.
[0012]
An object of the present invention is to provide an image forming apparatus capable of completing a warm-up operation in a short time until the surface temperature of a fixing member of a fixing unit is raised to a fixing temperature without impairing usability.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the present invention detects a surface temperature of the fixing body, a power switch for turning on the power of the apparatus, a fixing means having a fixing body and a heating element for heating the fixing body. A fixing temperature detecting unit, an automatic document reading unit having a plurality of operation modes including a low power operation mode, and variably supplying electric power to the heating unit of the fixing unit so that the surface temperature of the fixing unit reaches the fixing temperature. When the surface temperature of the fixing body detected by the fixing temperature detection means is lower than a reference surface temperature when the apparatus power is turned on by the power supply means and the power switch, the power supply means Until the surface temperature of the fixing body reaches the fixing temperature, the automatic document reading unit is controlled to operate in the low power operation mode until the amount of power supplied to the heating element is increased. And a controlling means for.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
(First embodiment)
FIG. 1 is a longitudinal sectional view showing an internal configuration of the image forming apparatus according to the first embodiment of the present invention.
[0016]
The image forming apparatus in the present embodiment is a digital copying machine, and as shown in FIG. 1, an automatic document feeder (hereinafter referred to as DF) 12 and a main body for reading an image on a document fed from the DF 12 The image input unit 11, the main body image output unit 10 that forms an image read by the main body image input unit 11 on the recording paper, and the recording paper discharged from the main body image output unit 10 are sorted into a plurality of bins and discharged. And a sorter 13 for the purpose.
[0017]
The main body image input unit 11 has a light source 21 for irradiating light to a document fed from the DF 12, and the light source 21 obtains a driving force from an optical system motor (not shown), and the horizontal direction in FIG. Reciprocate. The light emitted from the light source 21 to the original is reflected by the original, and the reflected light forms an image on a CCD (Charged Coupled Device) 26 via the mirrors 22, 23, 24 and the lens 25. Here, the mirrors 22, 23, and 24 are driven integrally with the light source 21. The CCD 26 converts the formed optical image into an electric signal, and this electric signal is converted into a digital signal (image data). The image data is subjected to various correction processes and image processes desired by the user, and the processed image data is stored in an image memory (not shown).
[0018]
The main body image output unit 10 reads out the image data stored in the image memory and reconverts the image data into an analog signal. The analog signal is further amplified to an appropriate output value by an exposure control unit (not shown), and then converted into an optical signal by the optical irradiation unit 27. The optical signal is irradiated onto the photosensitive drum 31 through the lens 29 and the mirror 30 while being swung left and right by the polygon mirror 28. Thereby, an electrostatic latent image is formed on the photosensitive drum 31. The electrostatic latent image is visualized as a toner image by toner, and the toner image is formed on a recording sheet fed from any of the paper feed cassettes 34, 35, the paper feed deck 26, or the manual feed tray 37. Transcribed. The recording paper on which the toner image is transferred is sent to the fixing device 32. In the fixing device 32, the toner image transferred onto the recording paper is heat-pressed and fixed on the recording paper. The recording paper on which the toner image is fixed is sent to the sorter 13 via the paper discharge roller 40.
[0019]
The sorter 13 performs a process of sorting the recording sheets discharged from the main body image output unit 10 to the discharge tray 33 and discharging the recording sheets. The sorter 13 is controlled by a control unit (not shown) provided in the main body image output unit 10, and the recording paper output from the sorter 13 is discharged to a paper discharge tray 33 instructed by the control unit.
[0020]
The respective recording sheets in the sheet feeding trays 34 and 35 are fed toward the photosensitive drum 31 through the sheet feeding rollers 38, 42 and 41. The paper feed deck 36 can accommodate a large amount of recording paper, and the recording paper on the paper feed deck 36 is fed toward the photosensitive drum 31 through the paper feed rollers 36 a and 41. The manual feed tray 37 can manually feed any type of recording paper such as an OHP sheet, thick paper, or postcard size paper. The recording paper in the manual feed tray 37 is fed by a paper feed roller 37a. The paper is fed toward the photosensitive drum 31.
[0021]
In the image forming apparatus according to the present embodiment, double-sided copying is possible. When performing double-sided copying, the recording paper discharged from the fixing device 32 is fed to the refeed rollers 39a and 39b and the paper feeds. The sheet is fed again toward the photosensitive drum 31 through the rollers 38 and 41.
[0022]
Here, each of the paper feed rollers 36a, 37a, 38, 39, 40, 41, and 42 is connected to a stepping motor via a transmission device such as a gear and is driven independently. A DC brushless motor is used for rotationally driving the photosensitive drum 31 and the fixing roller (see FIG. 2) of the fixing device 32. The rotational speeds of the photosensitive drum 31 and the fixing roller are called process speeds, and are speeds specific to the image forming apparatus that are greatly influenced by the shape of the toner, the fixing characteristics, the light emission characteristics of the laser, and the like. It is. Therefore, as the DC brushless motor used for the rotation drive, a motor capable of outputting a torque sufficient for transporting cardboard is selected. On the other hand, a stepping motor, which is a drive source such as the paper feed roller, is used only to feed and transport the recording paper, and the recording paper is sandwiched between either the fixing roller or the photosensitive drum. If not, control is performed to drive the paper feed roller as fast as possible in order to enable high-speed conveyance, high-speed paper feed, etc., and to shorten the distance between the recording papers as much as possible. As a result, the productivity of the image forming apparatus can be improved.
[0023]
Next, the fixing device 32 will be described. Examples of the fixing device 32 include an induction heating type fixing device and a fixing device using a halogen heater. In the present embodiment, any fixing device can be used.
[0024]
First, the configuration of the main part of the induction heating type fixing device 32 will be described with reference to FIG. FIG. 2 is a longitudinal sectional view showing the configuration of the main part of the fixing device 32 of FIG.
[0025]
As shown in FIG. 2, the induction heating type fixing device 32 includes a fixing roller 401 driven by a DC brushless motor, and a predetermined pressing unit so that the fixing roller 401 can be driven to rotate by a pressure mechanism (not shown). A pressure roller 402 pressed by pressure is formed, and a nip portion is formed between the fixing roller 401 and the pressure roller 402 for nipping and conveying the recording paper 410 in the direction indicated by the arrow c in the figure. Is done.
[0026]
The fixing roller 401 has an electromagnetic induction heat generation property, and is made of, for example, an iron core bar cylinder having an outer diameter of 32 mm and a thickness of 0.5 mm. The cored bar cylinder may be made of a material having a relatively high magnetic permeability μ and an appropriate resistivity ρ, such as a magnetic material (magnetic metal) such as magnetic stainless steel, instead of iron. . In order to improve the releasability on the surface of the fixing roller, a core metal cylinder having a release layer having a thickness of 10 to 50 μm made of a fluorine-based resin such as PTFE or PFA is used on its outer peripheral surface. Is preferred. Further, a desired functional layer between the cored bar cylinder and the release layer, for example, a heat-resistant and elastic rubber material or resin material having a thickness of several hundreds of micrometers in order to improve the adhesion between the recording material and the fixing roller surface An elastic layer or the like may be provided.
[0027]
The pressure roller 402 is pressed against the fixing roller 401 with a weight of about 30 kg. In this case, the nip width of the nip portion formed between the pressure roller 402 and the fixing roller 401 is about 4 mm. The nip width can be changed according to the magnitude of the applied pressure.
[0028]
The fixing roller 401 incorporates an exciting coil-magnetic core unit 403 as magnetic flux generating means and a shielding plate 408 that blocks magnetic flux interlinking with the fixing roller 401. The exciting coil-magnetic core unit 403 includes an exciting coil 404, a magnetic core 405, an aluminum holding holder 406, an insulating heat-shrinkable tube jacket 407, and the like. As the coil wire of the exciting coil 404, 20 to 150 litz insulation-coated conductors having an outer diameter of 0.15 to 0.50 mm are used. More specifically, for example, litz wire having an outer diameter of 0.2 mm, 84 wires, and a total outer diameter of 3 mm is used as the coil wire. In consideration of the case where the exciting coil 404 is heated, a heat resistant material is used for the insulation coating.
[0029]
In order to increase the electromagnetic induction heat generation of the fixing roller 401, the current amplitude of the alternating current applied to the exciting coil 404 can be increased, and the number of turns of the coil wire of the exciting coil 404 can be reduced. Since heat generation due to the electric resistance of the exciting coil 404 also increases, in this embodiment, the number of turns of the coil wire of the exciting coil 404 is eight.
[0030]
The magnetic core 405 is a horizontally long member having a substantially semicircular cross section having a length dimension substantially corresponding to the longitudinal dimension of the fixing roller 401, and its semicircular arc surface is processed into a shape along the inner curved surface of the fixing roller. ing. The magnetic core 405 is made of a material having high magnetic permeability and low loss, and is used for increasing the efficiency of the magnetic circuit and for magnetic shielding.
[0031]
The holding holder 406 has a length dimension that is longer than the longitudinal dimension of the fixing roller 401 and a width dimension that substantially corresponds to the width dimension of the back plane portion of the magnetic core 405 having a substantially semicircular cross section. It consists of a horizontally long plate-like member with a certain thickness and rigidity.
[0032]
An insulating heat-shrinkable tube 407 is placed on the outside of each of the exciting coil 404, the magnetic core 405, and the holding holder 406, and the tube is sufficiently heat-shrinked. The insulating heat-shrinkable tube 407 is, for example, a silicon resin-based or fluororesin-based tube, and in this example, before heat shrinking, an outer diameter of 40 mm and a thickness of 0.3 mm are used. A heat-shrinkable tube having a thickness of 0.4 mm when heat-shrinked to 30 mm is used.
[0033]
By sufficiently heat-shrinking the heat-shrinkable tube 407, the flat spiral excitation coil 404 is formed along the semicircular arc surface portion of the magnetic core 405. That is, it is formed into a shape along the inner surface of the fixing roller. Further, the exciting coil 404, the magnetic core 405, and the holding holder 406 are integrally fixed to constitute an exciting coil-magnetic core unit 403.
[0034]
Further, in the exciting coil-magnetic core unit 403, the surface of the exciting coil 404 facing the inner curved surface of the fixing roller is covered with an insulating heat-shrinkable tube 407, so that the tube 407 is connected to the exciting coil 404 and the fixing roller. It also serves to electrically insulate the inner curved surface, improving electrical safety.
[0035]
The exciting coil-magnetic core unit 403 is inserted into a hollow portion of the fixing roller 401, and a surface portion of the exciting coil 404 formed in a shape along the inner surface of the fixing roller is close to the inner surface of the fixing roller. Adjusted to position and angle orientation. The exciting coil-magnetic core unit 403 is fixed by screwing both ends of the holding holder 406 to a support portion (not shown) on the apparatus main body side.
[0036]
In the present embodiment, the exciting coil-magnetic core unit 403 is fixed at the center of the exciting coil 404 from the nip formed between the fixing roller 401 and the pressure roller 402 in the cross section of the fixing roller 401. The rollers 401 are arranged in a tilted angular posture so as to be shifted to the upstream side in the rotation direction of the rollers 401. This is because the conductive layer of the fixing roller 401 opposed to the exciting coil 404 generates heat locally, so that the heat generating portion is located immediately before the nip portion, so that the recording paper 410 can be efficiently used at the nip portion. It is for heating.
[0037]
The shielding plate 408 is disposed between the fixing roller 401 and the exciting coil-magnetic material core unit 403. Both ends of the shielding plate 408 are rotatably supported by bearing members (not shown), and are driven to rotate in the direction of arrow a by a motor (not shown) such as a DC motor or a pulse motor.
[0038]
Further, a temperature detection sensor 409 disposed in the vicinity of the fixing roller 401 is used for managing the surface temperature of the fixing roller 401.
[0039]
Next, the operation state of the shielding plate 408 will be described with reference to FIG. FIG. 3 shows the positional relationship between the region where the magnetic flux generated by the exciting coil-magnetic core unit 403 in the fixing roller 401 in FIG. 2 is linked to the fixing roller 401 and the shielding plate 408 in the circumferential direction of the fixing roller 401. FIG. 6A is a diagram showing a positional relationship when fixing a recording sheet (for example, A4, A3, etc.) long in the fixing roller axial direction, and FIG. FIG. 8C is a diagram showing a positional relationship when fixing a recording paper having a short direction (eg, A4R size). FIG. 10C is a positional relationship after a predetermined process when the surface temperature of the fixing roller 401 rises abnormally. FIG.
[0040]
When fixing recording paper (eg, A4, A3, etc.) long in the fixing roller axial direction, the magnetic flux generated by the exciting coil-magnetic core unit 403 is applied to the fixing roller 401 as shown in FIG. The interlinking region is not blocked by the shielding plate 408.
[0041]
When fixing a short recording sheet (for example, A4R size) in the fixing roller axial direction, the magnetic flux generated by the exciting coil-magnetic core unit 403 is linked to the fixing roller 401 as shown in FIG. Both ends of the area to be shielded by the shielding plate 408. Accordingly, it is possible to prevent a temperature rise at both ends of the fixing roller 401 when fixing a short recording sheet in the fixing roller axial direction.
[0042]
When the surface temperature of the fixing roller 401 rises abnormally, the entire region where the magnetic flux generated by the exciting coil-magnetic core unit 403 is linked to the fixing roller 401 is shielded as shown in FIG. The plate 408 is blocked. In this state, the temperature of the fixing roller 401 does not increase.
[0043]
Next, a temperature control device for the induction heating type fixing device 32 will be described with reference to FIG. FIG. 4 is a block diagram showing the configuration of the temperature control device of the fixing device 32 of FIG.
[0044]
As shown in FIG. 4, the temperature control device of the fixing device 32 includes diodes D1 to D4 for rectifying input AC power, a noise filter NF, a bypass capacitor C1, a resonance capacitor C2, and a switching element Q1. , Q2 and a flywheel diode D5, and in order to excite the induction heating coil L1 in the fixing device 32, an induction heating coil drive circuit for turning on / off the power supply to the induction heating coil L1 is configured. Is done.
[0045]
The power feeding operation of the drive coil circuit is controlled by a control circuit. This control circuit includes a temperature detection circuit 501 that detects the surface temperature of the fixing roller based on the output of the temperature detection sensor 409 of the fixing device 32, the surface temperature of the fixing roller detected by the temperature detection circuit 501, and the input set temperature. Based on the output from the flywheel diode D5, the applied power control circuit 503 that generates the power control signal based on the temperature control signal from the temperature control circuit 502 that generates the temperature control signal based on the temperature control circuit 502 The resonance output control circuit 504 drives the switching elements Q1 and Q2 based on the power control signal from the applied power control circuit 503 while detecting the phase and monitoring the detected phase. By the control of this control circuit, the electric power supplied to the induction heating coil L1 is variably controlled linearly.
[0046]
Next, the main configuration of the fixing device 32 using a halogen heater will be described with reference to FIG. FIG. 5 is a longitudinal sectional view showing a main part configuration of the fixing device 32 of FIG.
[0047]
As shown in FIG. 5, the fixing device 32 is a fixing device using three halogen heaters 370, 380, and 390, and each halogen heater is built in the fixing roller 601. The fixing roller 601 is pressed by a pressing mechanism (not shown) with a predetermined pressing force so that the pressing roller 602 can be driven to rotate by the fixing roller 601. A nip portion for nipping and conveying the recording paper is formed between the fixing roller 601 and the pressure roller 602, and the nip width can be changed according to the magnitude of the pressing force.
[0048]
As the fixing roller 601, it is preferable to use a roller having a release layer having a thickness of 10 to 50 μm made of a fluorine-based resin such as PTFE or PFA on the outer peripheral surface thereof. Further, for example, a rubber material having heat resistance and elasticity or an elastic layer having a thickness of several hundreds μm may be provided in order to improve the adhesion between the recording paper and the surface of the fixing roller.
[0049]
In the fixing device 32, since three halogen heaters are provided, a combination of a plurality of electric powers can be realized. For example, if the three halogen heaters 370, 380, and 390 are combined into 200W, 400W, and 600W, the output power is 1200W, 1000W, 800W,..., 200W, and the power can be increased or decreased in units of 200W. . The combination of the halogen heaters 370, 380, and 390 is controlled by the control device 603.
[0050]
In the case of a fixing device using only one halogen heater, the power can be increased or decreased by a predetermined unit by performing variable control of the power increase or decrease using constant voltage control or the like.
[0051]
The constant voltage control of the fixing device using only one halogen heater will be described with reference to FIG. FIG. 6 is a block diagram showing the configuration of a drive circuit that performs constant voltage control of a fixing device incorporating one halogen heater.
[0052]
In a driving circuit that performs constant voltage control of a fixing device including one halogen heater, as shown in FIG. 6, diodes D1 to D4 for rectifying input AC power, a noise filter NF, The bypass capacitor C1, the resonance coil L3, the diode D5, and the FET Q3 are driven by a PWM (Plus Width Modulation) signal from the DC controller 701 via the photodiode PH1. The DC controller 701 generates the PWM signal based on the fixing roller surface temperature detected by the temperature detection temperature detection circuit 501 based on the output of the temperature detection sensor 409 of the fixing device 32 and the input voltage detection signal, Output.
[0053]
In this drive circuit, the input AC power is rectified and smoothed by the diodes D1 to D4, the noise filter NF, the bypass capacitor C1, and the like to be converted into a DC voltage, and this DC voltage is supplied to the halogen heater H1. . Here, the DC voltage supplied to the heater H1 is controlled by the operation of the FET Q3 in accordance with the PWM signal from the DC controller 701. By this control, a voltage according to the following equation (1) is applied to the heater H1. Will be.
[0054]
F1 (W) / F2 (W) = (V1 (V) / V2 (V))^1.54        ... (1)
Here, F1 (W) is the amount of power consumed by the heater H1 (heat generation amount), F2 (W) is the rated power of the heater H1, V1 (V) is the voltage applied to the heater H1, and V2 (V) is the heater. This is the rated input voltage of H1.
[0055]
For example, when a heater rated at 100V / 500W is driven at 70V,
F1 (W) / 500 (W) = (70 (V) / 100 (V))^1.54
From the relational expression, F1 = 288 (W). By controlling the voltage applied to the heater H1 in this way, it is possible to increase or decrease the amount of heat generated by the heater H1.
[0056]
Next, a power distribution method according to the present embodiment will be described with reference to FIGS. 7 is a bar graph showing power distribution to each apparatus in each state of the image forming apparatus of FIG. 1 in normal (output enabled state), power-on, and sleep mode (power saving), and FIG. 8 is a diagram of FIG. FIG. 3 is a diagram schematically illustrating initial alignment of a sorter tray when the image forming apparatus is ON.
[0057]
In the present embodiment, as shown in FIG. 7A, the upper limit of power of the image forming apparatus is 1500 W, and 300 W is supplied to each optional device of the DF 12 and the sorter 13 (Fin), and 1000 W is supplied to the fixing device. Assume that each is allocated. In this case, in order to increase the startup time of the apparatus, when the temperature of the fixing device 32 is equal to or lower than a predetermined value, the power distribution to the fixing device 32 is normally performed as shown in FIG. 7B or 7C. It is set to 1200 W, which is 200 W higher than the time (FIG. 7A). Here, the problem is when the power is turned on as shown in FIG. In this case, as shown in FIG. 8, in the sorter 13, an initial operation such as initial alignment for moving the tray 33 from the position PA to the position Pini (initial position) is performed. Of course, this initial operation is also performed in other devices. That is, extra power is consumed when the power is turned on, so if the power distribution to the fixing device is simply increased, the required power exceeds the power upper limit 1500 W of the image forming apparatus.
[0058]
Therefore, in this embodiment, when the temperature of the fixing device 32 (fixing roller surface temperature) is equal to or lower than a predetermined temperature when the power is turned on, as shown in FIG. 7B, the optional device (DF12 and sorter 13). In order to operate the (Fin)) operation mode at a lower speed than normal, the power supplied to them is controlled to 200 W, which is 100 W lower than normal. For example, the tray moving speed of the sorter 13 (Fin) is set to half the normal speed, and the reading speed of the DF 12 is suppressed to 30 rpm, which is half of the normal 60 rpm. Here, since the tray movement of the sorter 13 (Fin) is normally completed in several seconds, there is no problem even if the movement speed is halved. If the initialization operation of the post-processing device such as a sorter or finisher is sufficiently fast with respect to the time required for starting the main body depending on the model, the operation itself may be stopped instead of the low speed. Even with the DF 12, the document reading time when the power is turned on is doubled compared to the normal time. However, since the output side (printer) is still in the preparation stage (warming up), the convenience is not significantly impaired.
[0059]
By the method described above, it is possible to distribute more power to the fixing device 32 while keeping the upper limit power (1500 W) of the entire apparatus and minimizing the deterioration of the function.
[0060]
Next, the operation when the power is turned on in the present embodiment will be described with reference to FIG. FIG. 9 is a flowchart showing an operation procedure when the image forming apparatus of FIG. 1 is turned on.
[0061]
When the power is turned on, as shown in FIG. 9, first, in step S2011, based on the output of the temperature detection sensor 409, the temperature T1 of the fixing device 32 (surface temperature of the fixing roller) is set to a preset reference temperature A. A determination is made as to whether it is lower than (eg, 323K). Here, when the temperature T1 of the fixing device 32 is lower than the reference temperature A, it is determined that it is necessary to operate the DF in the low speed mode to increase the power supplied to the fixing device 32. In step S2021, the warm-up operation is performed. In step S2031, the power distribution of the fixing device 32 is increased. In step S2041, the operation mode of the DF 12 is switched to the low speed mode. Here, the normal operation mode is set as the initial setting of the operation mode of the DF 12. As described above, when the temperature T1 of the fixing device 32 is lower than the reference temperature A when the power is turned on, priority is given to quickly raising the temperature of the fixing device 32 to the fixing temperature, and the power distribution of the fixing device 32 is increased. The operation mode of the DF 12 is switched to the low speed mode. Note that steps S2021 to 2041 may be performed in any order in time series.
[0062]
Next, in step S2051, it is awaited that the warm-up is completed and the copy is ready. If the copy is ready, in step S2061, it is determined whether or not the operation mode of the DF 12 is the low speed mode. . Here, since the operation mode of the DF 12 is switched to the low speed mode, in step S2071, the supply power to the fixing device 32 is returned to the normal supply power, and the operation mode of the DF 12 is returned to the normal mode. In step S2081, a transition to the standby state is performed.
[0063]
If it is determined in step S2011 that the temperature T1 of the fixing device 32 is equal to or higher than the preset reference temperature A, it is determined that it is not necessary to increase the power distribution of the fixing device 32 and switch the DF 12 to the low speed mode. In step S2091, the warm-up operation is started. At this time, the power supplied to the fixing device 32 is normal, and the operation mode of the DF 12 is the normal mode. Then, in step S2051, it is waited for the warm-up to be completed and the copy ready state to be waited. When the copy ready state is reached, in step S2061, it is determined whether or not the operation mode of the DF 12 is the low speed mode. . Here, since the operation mode of the DF 12 is the normal mode, step S2071 is skipped, and the transition to the standby state is performed in step S2081.
[0064]
Thus, the warm-up operation until the surface temperature T1 of the fixing device 32 is raised to the fixing temperature can be completed in a short time without impairing the usability.
[0065]
(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 10 is a flowchart showing an operation procedure when the image forming apparatus according to the second embodiment of the present invention is turned on. The configuration of the present embodiment is the same as that of the first embodiment, and a description thereof is omitted.
[0066]
When the power is turned on, as shown in FIG. 10, first, in step S4021, it is determined whether or not the temperature (surface temperature) T1 of the fixing device 32 is lower than a reference temperature A (for example, 323K). If the temperature T1 of the fixing device 32 is lower than the preset reference temperature A, it is determined in step S4031 whether the output value of the environmental temperature sensor, that is, the environmental temperature T2 is lower than a predetermined temperature t1 (eg, 288K). Is done. Here, it is assumed that a relationship of t1 <A is established between the predetermined temperature t1 and the reference temperature A.
[0067]
When the environmental temperature T2 is lower than the predetermined value t1, it takes a long time to raise the temperature T1 to the predetermined fixing temperature, and it is necessary to operate the DF 12 in the low speed mode and increase the power supplied to the fixing device 32. To be judged. In this case, in step S4071, a warm-up operation is started, and in step S4081, the power distribution of the fixing device 32 is increased. In step S4091, the operation mode of the DF 12 is switched to the low speed mode. Here, the normal operation mode is set as the initial setting of the operation mode of the DF 12.
[0068]
Next, in step S4101, it is awaited that the warm-up is completed and the copy is ready. If the copy is ready, in step S4111, it is determined whether or not the operation mode of the DF 12 is the low speed mode. . Here, since the operation mode of the DF 12 is switched to the low speed mode, in step S 4121, the supply power to the fixing device 32 is returned to the normal supply power, and the operation mode of the DF 12 is returned to the normal mode. In step S4131, a transition to the standby state is performed.
[0069]
If it is determined in step S4031 that the environmental temperature T2 is equal to or higher than the predetermined value t1, a warm-up operation is started in step S4041, and in step S4051, a unit is created based on a table previously created based on experiments or the like. The rate of temperature increase per hour is calculated, and the time required to raise the current temperature T1 of the fixing device 32 to a predetermined fixing temperature is obtained from this temperature increase rate. The table describes the rate of temperature increase per unit time when the temperature T1 of the fixing device 32 is raised from the environmental temperature T2 to the predetermined fixing temperature using the environmental temperature T1 and the amount of electric power supplied to the heater as parameters.
[0070]
Next, in step S4061, it is determined whether or not the calculated rise time is within a predetermined time, that is, whether or not the current temperature T1 of the fixing device 32 can be raised to a predetermined fixing temperature within a predetermined time. . Here, the predetermined time is a time required to raise the temperature T1 of the fixing device 32 to a predetermined fixing temperature, for example, 573K, on the condition that the environmental temperature T2 is 293K and the amount of electric power supplied to the heater is a standard value. Yes, for example, 30 seconds. This time varies depending on the use of the device, and may be 20 seconds or 40 seconds.
[0071]
If it is determined in step S4061 that the current temperature T1 of the fixing device 32 cannot be raised to the predetermined fixing temperature within a predetermined time, the power distribution of the fixing device 32 is increased in step S4081, and in step S4091, The operation mode of the DF 12 is switched to the low speed mode. Then, in step S4101, the process waits for the warm-up to be completed and becomes ready for copying. When the copying becomes ready, in step S4111, it is determined whether or not the operation mode of the DF 12 is the low speed mode. . Here, since the operation mode of the DF 12 is switched to the low speed mode, in step S 4121, the supply power to the fixing device 32 is returned to the normal supply power, and the operation mode of the DF 12 is returned to the normal mode. In step S4131, a transition to the standby state is performed.
[0072]
If it is determined in step S4061 that the current temperature T1 of the fixing device 32 can be raised to the predetermined fixing temperature within a predetermined time, it is not necessary to raise the power distribution of the fixing device 32 and switch the DF 12 to the low speed mode. In step 4101, it is awaited that the warm-up is completed and the copy is ready. If the copy is ready, it is determined in step S4111 whether or not the operation mode of the DF 12 is the low speed mode. Here, since the operation mode of the DF 12 is the normal mode, step S4121 is skipped, and a transition to the standby state is performed in step S4131.
[0073]
If it is determined in step S4021 that the temperature T1 of the fixing device 32 is equal to or higher than the preset reference temperature A, it is determined that it is not necessary to increase the power distribution of the fixing device 32 and switch the DF 12 to the low speed mode. In step 4141, the warm-up operation is started, and in the subsequent step S4101, it is waited for the warm-up to be completed and the copy ready state to be entered. If the copy is ready, it is determined in step S4111 whether or not the operation mode of the DF 12 is the low speed mode. Here, since the operation mode of the DF 12 is the normal mode, step S4121 is skipped, and a transition to the standby state is performed in step S4131.
[0074]
(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 11 is a flowchart showing an operation procedure when the image forming apparatus according to the third embodiment of the present invention is turned on. The configuration of the present embodiment is the same as that of the first embodiment, and a description thereof is omitted.
[0075]
In the present embodiment, a case where the initialization operation of the sorter 13 is prohibited when the fixing device 32 is started up will be described.
[0076]
When the power is turned on, as shown in FIG. 11, first, in step S3021, it is determined whether or not the temperature (surface temperature) T1 of the fixing device 32 is lower than a preset reference temperature A (for example, 323K). Is called. If the temperature T1 of the fixing device 32 is lower than the reference temperature A, it is determined in step S3031 whether or not the output value of the environmental temperature sensor, that is, the environmental temperature T2 is lower than a predetermined temperature t1 (eg, 288K). Here, it is assumed that a relationship of t1 <A is established between the predetermined temperature t1 and the reference temperature A.
[0077]
When the environmental temperature T2 is lower than the predetermined value t1, it takes a long time to raise the temperature T1 to the predetermined fixing temperature, and it is necessary to prohibit the initialization operation of the sorter 13 in order to increase the power supplied to the fixing device 32. It is judged that there is. In this case, the warm-up operation is started in step S3071, and the initialization operation of the sorter 13 is prohibited in the subsequent step S3081. In step S3091, the power distribution of the fixing device 32 is increased.
[0078]
Next, in step S 3101, the process waits for the warm-up to be completed and becomes ready for copying. If the copying becomes ready, in step S 3111, it is determined whether or not the initialization operation of the sorter 13 is completed. . Here, since the sorter initialization operation has not been completed, in step S3121 the prohibition of the initialization operation of the sorter 13 is canceled, and the supply power to the fixing device 32 is returned to the normal supply power. With the cancellation of the prohibition of the initialization operation of the sorter 13, the sorter 13 performs the initialization operation. Then, in step S3131, a transition to the standby state is performed.
[0079]
If it is determined in step S3031 that the environmental temperature T2 is equal to or higher than the predetermined value t1, a warm-up operation is started in step S3041, and a table created based on experiments or the like in advance in step S3051 (second embodiment) The temperature increase rate per unit time is calculated on the basis of the same table as in the above embodiment, and the time required to raise the current temperature T1 of the fixing device 32 to the predetermined fixing temperature is obtained from this temperature increase rate.
[0080]
Next, in step S3061, it is determined whether or not the calculated rise time is within a predetermined time, that is, whether or not the current temperature T1 of the fixing device 32 can be raised to a predetermined fixing temperature within a predetermined time. .
[0081]
If it is determined in step S3061 that the current temperature T1 of the fixing device 32 cannot be raised to the predetermined fixing temperature within a predetermined time, the initialization operation of the sorter 13 is prohibited in step S3081, and the fixing device is determined in step S3091. 32 power distribution is raised. Next, in step S 3101, the process waits for the warm-up to be completed and becomes ready for copying. If the copying becomes ready, in step S 3111, it is determined whether or not the initialization operation of the sorter 13 is prohibited. . Here, since the sorter initialization operation is prohibited, in step S3121 the prohibition of the sorter 13 initialization operation is canceled and the power supplied to the fixing device 32 is returned to the normal supply power. With the cancellation of the prohibition of the initialization operation of the sorter 13, the sorter 13 performs the initialization operation. Then, in step S3131, a transition to the standby state is performed.
[0082]
If it is determined in step S3061 that the current temperature T1 of the fixing device 32 can be raised to a predetermined fixing temperature within a predetermined time, it is determined that the initialization operation of the sorter 13 need not be prohibited. Wait for the upload to be completed and to be ready for copying. If the copy is ready, a determination is made in step S3111 as to whether or not the initialization operation of the sorter 13 is prohibited. Here, the initialization operation of the sorter is not prohibited, so step S3121 is skipped, and a transition to the standby state is performed in step S3131. In this case, the sorter 13 performs an initialization operation at an arbitrary timing after the power is turned on.
[0083]
If it is determined in step S3021 that the temperature T1 of the fixing device 32 is equal to or higher than a preset reference temperature A, it is determined that it is not necessary to increase the power distribution of the fixing device 32 and prohibit the sorter initialization operation. In 3141, the warm-up operation is started, and in the subsequent step S 3101, it is waited for the warm-up to be completed and the copy ready state to be entered. If the copy is ready, a determination is made in step S3111 as to whether or not the initialization operation of the sorter 13 is prohibited. Here, the initialization operation of the sorter is not prohibited, so step S3121 is skipped, and a transition to the standby state is performed in step S3131. In this case, the sorter 13 performs an initialization operation at an arbitrary timing after the power is turned on.
[0084]
In this embodiment, an example in which the sorter 13 is mounted as a post-processing device has been shown. However, in the case where a post-processing device that performs stapling, bookbinding processing, or the like is mounted instead, the sorter 13 is mounted. It goes without saying that the same effect can be obtained by prohibiting the initialization operation.
[0085]
The embodiments of the present invention are listed below.
[0086]
[Embodiment 1] A power switch for turning on the apparatus power, a fixing means having a fixing member and a heating element for heating the fixing member, a fixing temperature detecting means for detecting the surface temperature of the fixing member, An automatic document reading means having a plurality of operation modes including a low power operation mode; a power supply means for variably supplying power to a heating element of the fixing means so that a surface temperature of the fixing body reaches a fixing temperature; If the surface temperature of the fixing body detected by the fixing temperature detecting means is lower than the surface reference temperature when the apparatus power is turned on by a power switch, the power supply means supplies power to the heating element. Control means for increasing the amount and controlling the automatic document reading means to operate in the low power operation mode until the surface temperature of the fixing body reaches the fixing temperature. Image forming apparatus characterized by obtaining.
[0087]
[Embodiment 2] When the surface temperature of the fixing body detected by the fixing temperature detection means is lower than the surface reference temperature, the control means takes time required for the surface temperature of the fixing body to reach the fixing temperature. If the estimated time is longer than a predetermined time, the amount of power supplied to the heating element by the power supply means is increased, and the automatic document is kept until the surface temperature of the fixing body reaches the fixing temperature. The image forming apparatus according to claim 1, wherein the reading unit is controlled to operate in the low power operation mode.
[0088]
[Embodiment 3] An environmental temperature detecting means for detecting an environmental temperature is provided, and the control means has a surface temperature of the fixing body detected by the fixing temperature detecting means lower than the surface reference temperature, and the environmental temperature detection. When the environmental temperature detected by the means is higher than the environmental reference temperature, the time required for the surface temperature of the fixing body to reach the fixing temperature is estimated, and when the estimated time is longer than a predetermined time, the power supply The automatic document reading means is controlled to operate in the low power operation mode until the amount of power supplied to the heating element by the means is increased and the surface temperature of the fixing body reaches the fixing temperature. The image forming apparatus according to Embodiment 1.
[0089]
[Embodiment 4] The control unit is configured such that the surface temperature of the fixing body detected by the fixing temperature detecting unit is lower than the surface reference temperature, and the environmental temperature detected by the environmental temperature detecting unit is based on the environmental reference temperature. When the temperature is low, the amount of power supplied to the heating element by the power supply means is increased, and the automatic document reading means is operated in the low power operation mode until the surface temperature of the fixing body reaches the fixing temperature. The image forming apparatus according to Embodiment 3, wherein the image forming apparatus is controlled.
[0090]
[Embodiment 5] The image forming apparatus according to claim 3 or 4, wherein the surface reference temperature is lower than the reference environment temperature.
[0091]
[Embodiment 6] The control means includes an amount of power supplied to the heating element, a surface temperature of the fixing body detected by the fixing temperature detecting means, an environmental temperature detected by the environmental temperature detecting means, and the fixing temperature. 5. The image forming apparatus according to claim 3, wherein the time required for the surface temperature of the fixing body to reach the fixing temperature is estimated based on the above.
[0092]
[Embodiment 7] A power switch for turning on the apparatus power, a fixing means having a fixing member and a heating element for heating the fixing member, a fixing temperature detecting means for detecting the surface temperature of the fixing member, Post-processing means for performing an initialization operation when the apparatus power is turned on by the power switch, and power for variably supplying power to the heating element of the fixing means so that the surface temperature of the fixing body reaches the fixing temperature When the apparatus power is turned on by the supply means and the power switch, if the surface temperature of the fixing body detected by the fixing temperature detection means is lower than the surface reference temperature, the heat generation by the power supply means Control means for controlling the initialization operation by the post-processing means until the power supply amount to the body is increased and the surface temperature of the fixing body reaches the fixing temperature. An image forming apparatus, comprising.
[0093]
[Embodiment 8] When the surface temperature of the fixing body detected by the fixing temperature detecting means is lower than the surface reference temperature, the control means takes time required for the surface temperature of the fixing body to reach the fixing temperature. If the estimated time is longer than a predetermined time, the amount of power supplied to the heating element by the power supply means is increased, and the post-processing is performed until the surface temperature of the fixing body reaches the fixing temperature. 8. The image forming apparatus according to claim 7, wherein the image forming apparatus is controlled to prohibit the initialization operation by the means.
[0094]
[Embodiment 9] Environmental temperature detection means for detecting environmental temperature is provided, and the control means is such that the surface temperature of the fixing body detected by the fixing temperature detection means is lower than the surface reference temperature and the environmental temperature detection. When the environmental temperature detected by the means is higher than the environmental reference temperature, the time required for the surface temperature of the fixing body to reach the fixing temperature is estimated, and when the estimated time is longer than a predetermined time, the power supply The power supply amount to the heating element by the means is increased, and control is performed so as to prohibit the initialization operation by the post-processing means until the surface temperature of the fixing body reaches the fixing temperature. 8. The image forming apparatus according to 7.
[0095]
[Embodiment 10] The control unit is configured such that the surface temperature of the fixing body detected by the fixing temperature detecting unit is lower than the surface reference temperature, and the environmental temperature detected by the environmental temperature detecting unit is based on the environmental reference temperature. When the temperature is low, the amount of power supplied to the heating element by the power supply means is increased, and control is performed so as to prohibit the initialization operation by the post-processing means until the surface temperature of the fixing body reaches the fixing temperature. An image forming apparatus according to Embodiment 9, wherein:
[0096]
[Embodiment 11] The image forming apparatus according to claim 9 or 10, wherein the surface reference temperature is lower than the reference environment temperature.
[0097]
[Embodiment 12] The control means includes an amount of electric power supplied to the heating element, a surface temperature of the fixing body detected by the fixing temperature detecting means, an environmental temperature detected by the environmental temperature detecting means, and the fixing temperature. 12. The image forming apparatus according to embodiment 9 or 11, wherein the time required for the surface temperature of the fixing body to reach the fixing temperature is estimated based on the above.
[0098]
[Embodiment 13] A power switch for turning on the apparatus power, a fixing means having a fixing member and a heating element for heating the fixing member, a fixing temperature detecting means for detecting the surface temperature of the fixing member, An automatic document reading unit having a plurality of operation modes including a low power operation mode; and a power supply unit that variably supplies power to a heating element of the fixing unit so that a surface temperature of the fixing unit reaches a fixing temperature. An image forming apparatus control method, wherein when the apparatus power is turned on by the power switch, the surface temperature of the fixing body detected by the fixing temperature detection means is lower than a surface reference temperature. Until the surface temperature of the fixing body reaches the fixing temperature by increasing the amount of power supplied to the heating element by the power supply means, the automatic document reading means is operated in the low power operation mode. The method of in the image forming apparatus and controls to operate.
[0099]
[Embodiment 14] A power switch for turning on the apparatus power, a fixing means having a fixing member and a heating element for heating the fixing member, a fixing temperature detecting means for detecting the surface temperature of the fixing member, Post-processing means for performing an initialization operation when the apparatus power is turned on by the power switch, and power for variably supplying power to the heating element of the fixing means so that the surface temperature of the fixing body reaches the fixing temperature An image forming apparatus control method comprising: a supply unit, wherein the surface temperature of the fixing body detected by the fixing temperature detection unit is lower than a surface reference temperature when the apparatus power is turned on by the power switch. In this case, the amount of power supplied to the heating element by the power supply means is increased, and the initial processing by the post-processing means is performed until the surface temperature of the fixing body reaches the fixing temperature. Method of controlling an image forming apparatus and controls so as to prohibit the operation.
[0100]
【The invention's effect】
As described above, according to the present invention, when the apparatus power is turned on, if the surface temperature of the fixing body detected by the fixing temperature detection means is lower than the surface reference temperature, the heating element by the power supply means Until the surface temperature of the fixing body reaches the fixing temperature, the automatic document reading means is operated in the low power operation mode until the surface temperature of the fixing body reaches the fixing temperature, so that the surface of the fixing body of the fixing means is not impaired. The warm-up operation until the temperature is raised to the fixing temperature can be completed in a short time.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an internal configuration of an image forming apparatus according to a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view showing a main part configuration of the fixing device 32 of FIG.
3 shows the positional relationship between an area where the magnetic flux generated by the exciting coil-magnetic core unit 403 in the fixing roller 401 in FIG. 2 interlinks with the fixing roller 401 and the shielding plate 408 in the circumferential direction of the fixing roller 401. FIG. FIG.
4 is a block diagram illustrating a configuration of a temperature control device of the fixing device 32 of FIG. 3. FIG.
FIG. 5 is a longitudinal sectional view showing a main part configuration of the fixing device 32 of FIG. 1;
FIG. 6 is a block diagram illustrating a configuration of a drive circuit that performs constant voltage control of a fixing device including one halogen heater.
7 is a bar graph showing power distribution to each apparatus in each state of normal (output enabled state), power-on, and sleep mode (power saving) in the image forming apparatus of FIG. 1. FIG.
8 is a diagram schematically showing initial alignment of the sorter tray when the image forming apparatus of FIG. 1 is ON. FIG.
9 is a flowchart showing an operation procedure when the image forming apparatus of FIG. 1 is turned on.
FIG. 10 is a flowchart showing an operation procedure when the power of the image forming apparatus according to the second embodiment of the present invention is turned on.
FIG. 11 is a flowchart illustrating an operation procedure at the time of power-on of an image forming apparatus according to a third embodiment of the present invention.
[Explanation of symbols]
12 Automatic document reader (DF)
13 Sorter
32 Fixing device
370, 380, 390, H1 Halogen heater
403 Excitation coil-magnetic core unit
401, 601 Fixing roller
409 Temperature detection sensor
603 control device
701 DC controller

Claims (1)

A power switch to turn on the device,
A fixing unit having a fixing member and a heating element for heating the fixing member;
Fixing temperature detecting means for detecting the surface temperature of the fixing body;
Automatic document reading means having a plurality of operation modes including a low power operation mode;
Power supply means for variably supplying power to the heating element of the fixing means so that the surface temperature of the fixing body reaches the fixing temperature;
If the surface temperature of the fixing body detected by the fixing temperature detecting means is lower than the reference surface temperature when the apparatus power is turned on by the power switch, the power supply means supplies power to the heating element. And an image forming apparatus including a control unit configured to control the automatic document reading unit to operate in the low power operation mode until the supply amount is increased and the surface temperature of the fixing body reaches the fixing temperature. Forming equipment.

Images