JP2014029405A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device configured to reduce effects on power consumption or the lifetime of a fixing roller, while reducing first-copy-output time in a job after power-on.SOLUTION: An image forming device includes: an imaging device for forming a toner image on a recording material; a fixing device 234 for heating the toner image formed by the imaging device to be fixed on the recording material; and a CPU 801 that performs imaging start operation for adjusting the imaging device, fixing start operation for heating the fixing device 234 to a predetermined temperature, and temperature control operation that performs fixing preparation operation for maintaining the predetermined temperature, in parallel after power-on. The CPU 801 changes the temperature control operation according to the time required for the imaging start operation.

Description

  The present invention relates to an image forming apparatus that performs a print preparation operation according to a start-up adjustment time of an image forming device in start-up control of a fixing device.

  Conventionally, in the start-up control of the fixing device, after the start-up is completed, the fixing temperature control has shifted to a standby state. However, in starting up the image forming apparatus, in addition to fixing start-up control, start-up control of the image forming apparatus is performed in parallel. If it takes a long time to complete the start-up control of the image forming device, the temperature of the fixing device that has completed the start-up control decreases at the timing when the image forming device completes all the start-up control and shifts to standby. ing. For this reason, when a job is input immediately after the transition to the standby mode, it is necessary to perform restart control of the fixing device, and there is a problem that the job cannot be executed quickly.

  Therefore, in recent years, the following method has been proposed as means for improving the FCOT (First Copy Output Time) of a job that is input immediately after the start-up of the image forming apparatus is completed. In other words, a method has been proposed in which after the start-up of the image forming apparatus is completed, the idling temperature control operation is performed for a predetermined time so that the job can be executed after the start-up of the image forming apparatus is completed. FCOT refers to the time from when the original is set and the start button is pressed until the first recording material after image formation is discharged.

JP 2004-12759 A

  In the prior art, the end timing of the start-up control of the fixing device and the image forming device that are performed in parallel when the image forming apparatus is started up may be different. In some cases, the start-up control of the fixing device is terminated first, and the start-up control of the image forming device is not completed. In such a case, since the start-up control of the image forming device is incomplete, the fixing device executes the idling temperature control operation from the time when the start-up control is completed even though the job cannot be executed immediately. Resulting in. Therefore, unnecessary idling temperature control is performed even while the job cannot be received, and there is a possibility that the power consumption cannot be reduced and the life of the fixing roller belt may be affected.

  The present invention has been made under such circumstances, and reduces the influence on the power consumption and the life of the fixing roller while shortening the first copy output time of the job after the image forming apparatus is turned on. With the goal.

  In order to solve the above-described problems, the present invention has the following configuration.

  (1) Image forming means for forming a toner image on a recording material, fixing means for heating and fixing the toner image formed by the image forming means to the recording material, and adjusting the image forming means Control for performing image forming start-up operation, fixing start-up operation for heating the fixing unit to a predetermined temperature, and temperature control operation for performing a fixing preparation operation for maintaining the predetermined temperature in parallel after the power is turned on And an image forming apparatus, wherein the control means changes the temperature control operation according to a time required for the image forming start-up operation.

  According to the present invention, it is possible to reduce the influence on the power consumption and the life of the fixing roller while shortening the first copy output time of the job after the image forming apparatus is powered on.

Overall configuration diagram and operation unit configuration diagram of image forming apparatuses according to first and second embodiments Configuration diagrams of the automatic document feeder, the image reading unit, and the image forming unit of the first and second embodiments Block diagram of image forming apparatus according to first and second embodiments Timing chart of fixing start-up control of embodiment 1 Flow chart of fixing start-up control according to the first embodiment. Timing chart of fixing start-up control of Example 2 Flowchart of fixing start-up control according to the second embodiment.

  An embodiment of the present invention is shown below. The individual embodiments described below will help to understand various concepts, such as superordinate concepts, intermediate concepts and subordinate concepts of the present invention. Further, the technical scope of the present invention is determined by the scope of the claims, and is not limited by the following individual embodiments.

<Configuration of image forming apparatus>
With reference to FIG. 1A, a configuration of an image forming apparatus 1000 according to the present embodiment will be described. The image forming apparatus 1000 includes an automatic document feeder (DF) 100, an image reading unit 200, an image forming unit 300, and an operation unit 600. As shown in FIG. 1A, the image reading unit 200 is placed on the image forming unit 300. Furthermore, an automatic document feeder 100 is placed on the image reading unit 200. The automatic document feeder 100 automatically conveys a document onto a platen glass. The image reading unit 200 reads a document conveyed from the automatic document conveying device 100 and outputs image data. The image forming unit 300 is a recording material (recording paper) according to image data of a document conveyed by the automatic document conveying device 100 and read by the image reading unit 200 or image data input from an external device connected via a network. An image is formed on. The operation unit 600 has a GUI (Graphical User Interface) and presents information to the user and accepts various operations.

<Operation unit>
The configuration of the operation unit 600 of the present embodiment will be described with reference to FIG. The operation unit 600 presents information to the user as shown in FIG. 1B, and further, a touch panel display 601 for performing various operations from the user, and for inputting various data such as the number of prints. A plurality of data input buttons 602. The operation unit 600 further includes a reset button 603 for resetting copy job settings, a cancel button 604 for performing a copy job cancel operation, and a start button 605 for performing a copy job start operation. The operation buttons displayed on the screen of the touch panel display 601 include a magnification setting button 607 for setting copy magnification, and a paper selection button 608 for setting printing paper information. The operation buttons include a duplex mode button 609 for setting single-sided printing or double-sided printing, an application setting button 610 for setting settings related to the entire image forming apparatus 1000, a density setting button 606 for setting printing density, and the like. .

<Image reading unit>
The operation of the automatic document feeder 100 of this embodiment will be described with reference to FIG. FIG. 2A is a cross-sectional view schematically showing the automatic document feeder 100 and the image reading unit 200. In the automatic document feeder 100, when the document detection sensor 114 detects that the document bundle S is set on the document tray 130 and the start button 605 is pressed, the DF paper feed roller 101 detects the uppermost surface of the document bundle S. Start feeding from the document. The fed document is separated by the separation roller 102 and the separation pad 121, and when it is detected by the double feed detection sensor 110 that it is not double feed, it is conveyed to the DF registration roller 104 by the DF conveyance roller pair 103. Then, the skew of the document is eliminated by the DF registration roller 104. On the downstream side of the DF registration roller 104, a paper feed path is provided for feeding the document that has passed through the DF registration roller 104 and conveying it in the direction of the reading glass 201. The timing sensor 112 disposed downstream of the DF registration roller 104 detects that the document has passed, and reading of an image in the image reading unit 200 is started when a predetermined time has elapsed. The document sent to the paper feed path is sent onto the platen by the large roller 107 and the DF feed roller 105. The document passes through the DF conveyance roller 106, moves between the roller 116 and the moving glass 117, is conveyed by the DF sheet discharge roller 108, and is detected by the sheet discharge sensor 113 to be discharged to the document sheet discharge tray 131. The The document size of the document bundle S is detected by a document width detection sensor (not shown), a pre-DF registration sensor 111, a document length detection sensor (not shown), and a document length detection auxiliary sensor 115.

  The image reading unit 200 optically reads image information recorded on a document, photoelectrically converts it, and acquires it as image data. The image reading unit 200 includes a flow reading glass 201, a platen glass 202, a scanner unit 209 having a lamp 203 and a mirror 204, mirrors 205 and 206, a lens 207, a CCD sensor 428, and the like. The white plate 210 is a white plate for creating white level reference data by shading. The DF open / close detection sensor 211 detects that the automatic document feeder 100 has been opened by the user in order to set the document on the platen glass 202.

<Image forming unit>
With reference to FIG. 2B, an image forming operation of the image forming unit 300 controlled by the controller unit 460 will be described. Note that the image forming unit 300 of this embodiment employs an electrophotographic system. In addition, alphabets Y, M, C, and K shown at the end of the reference numerals in FIG. 2B indicate engines corresponding to yellow, magenta, cyan, and black toners, respectively. In the following, when an engine corresponding to all toners is shown, the alphabets Y, M, C, and K at the end are omitted, and the symbols are described. Is added and described.

  When image formation is started, the recording material stored in the cassettes 240 and 241 or the manual paper feed unit 253 is conveyed to the paper feed roller pair 235 one by one by the pickup rollers 238, 239, or 254. When the recording material is conveyed to the registration roller 255 by the pair of paper feed rollers 235, the registration sensor 256 immediately before the recording material detects passage of the recording material. In this embodiment, when the registration sensor 256 detects the passage of the recording material, the conveyance operation is temporarily interrupted after a predetermined time has elapsed, and the recording material conveyance direction is skewed with respect to the conveyance path. Is corrected. After the skew correction, the recording material is supplied to the secondary transfer device 231 by starting the registration roller 255.

  Next, a voltage is applied to the primary charger 221 so that the surface of the photosensitive drum 225, which is an image carrier rotating in the direction of the arrow, is negatively charged uniformly at a predetermined charging portion potential by a motor. Subsequently, exposure is performed by an exposure device 218 including a laser scanner unit so that a charged image portion on the photosensitive drum 225 has a predetermined exposure unit potential, and a latent image is formed. The laser scanner unit has a polygon mirror for reflecting and scanning the laser beam. The exposure device 218 rotates a polygon mirror by a polygon mirror rotation motor (hereinafter simply referred to as a polygon motor), and forms a latent image corresponding to the image by turning on and off the laser beam based on the image data to be formed.

  Further, a developing voltage set in advance for each color is applied to the developing roller of the developing device 223. The latent image formed on the photosensitive drum 225 is developed with each color toner when passing through the position of the developing roller, and is visualized as a single color toner image on each photosensitive drum 225. Each toner image is sequentially transferred onto the transfer belt 226 by the transfer device 220, and a full-color toner image is formed on the transfer belt 226. The transfer belt 226 is stretched around a drive roller 227, a tension roller 228, and a backup roller 229. The driving roller 227 is coupled to a driving source and drives the transfer belt 226. The tension roller 228 adjusts the tension of the transfer belt 226. Further, the backup roller 229 performs backup of the transfer roller as the secondary transfer device 231. The transfer roller attaching / detaching unit 250 is a drive unit for causing the secondary transfer device 231 to adhere to or separate from the transfer belt 226. A cleaner blade 232 provided downstream of the transfer belt 226 after passing through the secondary transfer device 231 scrapes off the toner remaining on the transfer belt 226.

  Further, after the full-color toner image on the transfer belt 226 is transferred to the recording material conveyed from the paper feeding unit by the secondary transfer device 231, it passes through a post-registration conveyance path 268 and is fixed via the fixing conveyance belt 230. It is conveyed to the device 234. In the fixing device 234, the toner is charged by pre-fixing chargers 251 and 252 for supplementing toner adsorption force to prevent image disturbance, and an unfixed toner image is thermally fixed by a fixing roller 233 including a heater 280. . Thereafter, the recording material is discharged to a discharge tray 242 by a discharge roller 270. The toner remaining on the photosensitive drum 225 is removed and collected by the cleaner device 222. Finally, the photosensitive drum 225 is uniformly discharged to near 0 volts by the charge removing device 271 to prepare for the next image forming cycle.

  Since the color image formation start timing by the image forming apparatus 1000 is simultaneous transfer of Y, M, C, and K, it is possible to form an image at an arbitrary position on the transfer belt 226. However, it is necessary to determine the image formation start timing while shifting the shift of the position where the toner images on the photosensitive drums 225Y, M, and C are transferred in a timing manner.

  The operation in the case of double-sided printing in which an image is also formed on the back surface of the recording material is as follows. When an image is formed on the back surface of the recording material, image formation on the surface of the recording material is first performed in advance. In the case of image formation only on the front surface, the toner image is thermally fixed by the fixing device 234 and then discharged to the discharge tray 242 as it is. On the other hand, when the back side image formation is performed subsequently, the recording material is conveyed to the double-sided reverse path 261. Then, the image surface on which the image is formed is directed upward, and is transported to the double-sided path 263 by driving the double-sided path transport roller 262, transported toward the re-feed roller 264, and detected by the re-feed sensor 265. The refeed roller 264 temporarily stops the conveyance and corrects the skew of the recording material. The recording material is conveyed again onto the paper feed path 266 with the front and back sides reversed. The subsequent image forming operation is the same as the above-described surface image forming operation, and is therefore omitted here. The recording material on which images are formed on both the front and back sides is discharged to a discharge tray 242.

<Explanation of block diagram>
Next, the control circuit configuration of the image forming apparatus 1000 will be described with reference to the block diagram of FIG. The CPU circuit unit 800 included in the controller unit 460 includes a CPU 801, a ROM 802, and a RAM 803. The CPU 801 controls the image forming apparatus shown in FIG. The ROM 802 stores a program for the CPU 801 to operate. The RAM 803 is used for the CPU 801 to temporarily store data. The operation display device control unit 804 controls devices related to the display on the touch panel display 601 of the operation unit 600 in FIG. The backup RAM 805 is used to record information set in the operation of the image forming apparatus 1000 even when the power is turned off, and is powered by a backup battery (not shown). The data input control unit 806 controls devices related to input such as the touch panel display 601, the magnification setting button 607, the paper selection button 608, the duplex mode button 609, and the application setting button 610 of the operation unit 600 in FIG. The fixing device control unit 807 controls devices related to fixing, such as the fixing device 234 in FIG.

  The image forming device control unit 808 is not fixed such as the primary charger 221, the photosensitive drum 225, the exposure device 218, the developing device 223, the transfer device 220, the transfer belt 226, and the secondary transfer device 231 in FIG. The apparatus related to the image forming operation for forming the toner image is controlled. The paper transport device control unit 809 controls devices related to paper transport operations such as the registration roller 255, the paper feed roller pair 235, and the pickup rollers 238, 239, and 254 shown in FIG. The DF reader control unit 810 controls the automatic document feeder 100 and the image reading unit 200 shown in FIG. The timer 811 measures an arbitrary time necessary for the operation of the image forming apparatus 1000.

<Technical idea of the present invention>
In order to explain the technical idea of the present invention, the startup operation of a known image forming apparatus will be described below. When the known image forming apparatus 1000 is turned on, for example, from a power-off state, the state of each device such as the fixing device 234 constituting the image forming apparatus is indefinite. Therefore, in preparation for job execution, the CPU 801 performs a plurality of startup operations for setting each device in a certain state in parallel after power-on. For example, the fixing start-up operation of the fixing device 234 is performed with a predetermined start-up for the purpose of bringing the fixing roller 233 whose temperature is lowered to about 23 degrees by turning off the power to 180 degrees where the job can be executed and increasing the heat storage amount. Heat to target temperature (predetermined temperature). Further, when the fixing roller 233 is heated, rotation driving control of the fixing roller 233 is accompanied for the purpose of uniformly heating the surface. Then, after the fixing roller 233 reaches a predetermined target temperature, about 30 seconds at the target temperature for fixing, which can fix the toner image on the recording material, in preparation for job input immediately after the start-up operation of the image forming apparatus 1000 is completed. The process proceeds to a fixing preparation operation for performing temperature control for a predetermined time. By the fixing start-up operation and the fixing preparation operation of the fixing device 234, the image forming apparatus 1000 realizes the first copy output time (hereinafter referred to as FCOT) as short as possible with respect to the job input immediately after the power is turned on.

  Further, for example, the following operation is known as a start-up operation of devices related to the image forming operation such as the primary charger 221 and the photosensitive drum 225 controlled by the image forming device control unit 808. That is, there is known control in which a toner pattern image of each color is formed on the transfer belt 226, the toner pattern is read by an optical sensor, and the operation at the time of image formation is adjusted from the read result. The adjustment control performed by forming the toner pattern image includes, for example, simple adjustment performed by forming one pattern and adjustment performed by forming a plurality of patterns, and the time required for the adjustment control is different. Also, as an apparatus start-up operation related to the image forming operation, for example, there is output adjustment of the primary charger 221 and the like.

  Here, the fixing start-up operation of the fixing device 234 controlled by the fixing device control unit 807 is, for example, several seconds to several tens of seconds until the fixing roller 233 having a room temperature of 23 degrees reaches a predetermined start target temperature of 180 degrees. Time is required. On the other hand, if the apparatus start-up operation related to the image forming operation controlled by the image forming apparatus control unit 808 is a plurality of known adjustment controls, for example, the control using the above-described toner pattern, the color misalignment adjustment is performed. There are adjustment control and adjustment control for gradation correction. Further, there are a plurality of adjustment modes that combine these adjustment controls. Depending on the combination of adjustment control, there are an adjustment mode with a short time to completion of the start-up operation and an adjustment mode with a long time. As a short adjustment mode that is completed in several tens of seconds until the start-up operation is completed, for example, there is an image forming adjustment mode 1 in which only color misregistration adjustment is performed and the start-up is completed in 30 seconds. As a long adjustment mode that requires several minutes, for example, in addition to the adjustment mode 1, there is an image formation adjustment mode 2 in which the toner density adjustment and gradation correction adjustment are performed and the start-up is completed in 2 minutes. The CPU 801 selects a mode to be executed from a plurality of adjustment controls according to the situation when the image forming apparatus 1000 is started up.

  The technical idea of the present invention pays attention to a time difference until completion of parallel startup operations of a fixing device (fixing means) and an apparatus related to image formation (hereinafter referred to as an image forming apparatus (image forming means)). Therefore, the present invention is not limited to the color image forming apparatus described with reference to FIG. 2B. For example, an image forming apparatus such as a monochrome image forming apparatus in which the fixing device and the image forming device are started up in parallel. If applicable. Since the start-up operation of the image forming apparatus such as the image forming unit 300 excluding the fixing apparatus 234 is executed by selecting from the plurality of adjustment modes described above, fixing is performed according to the time required for the adjustment mode of the selected image forming apparatus. The startup operation of the device 234 is changed. As a result, it is possible to reduce the fixing preparation operation time of the fixing device 234, which is redundantly performed until the start-up operation of the image forming apparatus is completed. Then, it is possible to shorten the FCOT of a job input after the start-up operation of the image forming apparatus and to suppress the influence on the power consumption and the life of the fixing roller belt.

<Fixing preparation operation according to the completion status of image forming operation>
4 illustrates a temperature control operation (fixing temperature control) of the fixing device 234 and an image forming device start-up operation performed when the image forming apparatus 1000 according to the first exemplary embodiment is turned on (power-on), and status transition of the image forming apparatus 1000 ( It is a figure showing the timing of (main body status). Hereinafter, the start-up operation of the image forming apparatus is referred to as an image start-up operation. The temperature control operation of the fixing device 234 includes a fixing start-up operation for heating the fixing device 234 to the target temperature and a fixing preparation operation for maintaining the fixing device 234 at the fixing preparation target temperature. FIG. 4A is a timing chart in the case of image formation adjustment mode 1 in which image formation adjustment control (image formation adjustment), which is an image formation start-up operation, is completed earlier or substantially simultaneously with the completion of the fixing start-up operation. It is. For this reason, when the fixing start-up operation is completed, the main body status changes from being prepared to being ready for printing. In the fixing temperature control, after the fixing start-up operation is completed, a fixing preparation operation is performed in preparation for job input.

  FIG. 4B is a timing chart in the case of the image forming adjustment mode 2 in which the image forming start-up operation is completed later than the completion of the fixing start-up operation. For this reason, even if the fixing start-up operation is completed, the main body status remains in preparation. In the fixing temperature control, the temperature control is finished when the fixing start-up operation is completed, and the temperature control is started again from the time when the image forming adjustment mode 2 is completed. That is, the temperature control is restarted and the fixing preparation operation is executed. doing. In this embodiment, the image forming adjustment mode that requires a shorter time than the time required for the fixing start-up operation is set as the image forming adjustment mode 1, and the image forming adjustment mode that requires a long time is set as the image forming adjustment mode 2. Furthermore, there may be a plurality of image forming adjustment modes.

  Next, a control flow of the fixing startup operation in the CPU 801 that realizes the startup operation of FIG. 4 will be described with reference to FIG. When the control flow of the fixing startup operation is started (fixing initialization is started), the CPU 801 starts driving the fixing motor to rotate the fixing roller 233 in step (hereinafter referred to as S) 1001. After completing the start of driving of the fixing motor in S1001, in S1002, the CPU 801 sets the target temperature in the fixing device control unit 807 in order to raise the temperature of the fixing roller 233 to the target temperature, for example, 180 degrees by the heater 280. In step S <b> 1003, the CPU 801 turns on the heater 280 (simply referred to as a heater in the drawing) by the fixing device control unit 807 and starts temperature control.

  In step S1004, the CPU 801 determines whether the temperature of the fixing roller 233 has reached the target temperature by detecting the temperature of the fixing roller 233 using, for example, a thermistor disposed near the fixing roller 233. If the CPU 801 determines in step S1004 that the temperature of the fixing roller 233 has not reached the target temperature, the processing in step S1004 is repeated. If the CPU 801 determines in S1004 that the temperature of the fixing roller 233 has reached the target temperature, the fixing start-up operation of the fixing device 234 is completed in S1005. In step S <b> 1006, when the CPU 801 completes the fixing startup operation of the fixing device 234, the CPU 801 starts measuring the elapsed time after the fixing startup operation by the timer 811.

  In step S <b> 1007, the CPU 801 determines whether the image forming start-up operation is the image forming adjustment mode 1. As described above, the CPU 801 sets a mode to be executed from a plurality of adjustment controls according to the situation when the image forming apparatus 1000 is started up, and thus makes a determination in S1007 based on the information at the time of setting. Note that the image forming adjustment mode may be set by the user using the operation unit 600, and a plurality of operations are executed during the start-up operation of the image forming apparatus 1000, and any image forming adjustment mode is executed from other operations. It is good also as a structure which receives the notification of whether to do. If the CPU 801 determines in step S1007 that the image forming start-up operation is the image forming adjustment mode 1 (corresponding to FIG. 4A), the fixing temperature control is performed as follows. That is, the CPU 801 refers to the timer 811 that started the measurement in step S1006, and based on the value of the timer 811, the temperature control is kept valid for a predetermined time (hereinafter referred to as a fixing preparation time), for example, 30 seconds. Continue to enter the fixing preparation operation state. In step S <b> 1008, the CPU 801 determines whether a predetermined fixing preparation time has elapsed by referring to the timer 811. If the CPU 801 determines in step S1008 that the predetermined fixing preparation time has not elapsed, the process returns to step S1008. If the CPU 801 determines in S1008 that the predetermined fixing preparation time has elapsed, the heater 280 is turned off in S1009, the driving of the fixing motor is stopped in S1010, and the fixing startup flow is ended.

  If the CPU 801 determines in S1007 that the image forming operation is not the image forming adjustment mode 1, that is, if the image forming operation is the image forming adjustment mode 2 (corresponding to FIG. 4B), S1011 Proceed to the process. In step S1011, the CPU 801 once turns off the heater 280, stops driving the fixing motor in step S1012, and sets the temperature control of the fixing device 234 to a standby state. In step S <b> 1013, the CPU 801 refers to the timer 811 that started measurement in step S <b> 1006 and determines whether the end time of the image forming adjustment mode 2 has come based on the value of the timer 811. If the CPU 801 determines in step S1013 that the end time of the image forming adjustment mode 2 has not been reached, the process returns to step S1013.

  If the CPU 801 determines in S1013 that it is the end time of the image formation adjustment mode 2, it starts driving the fixing motor to start temperature control again in S1014. In this embodiment, when the image forming start-up operation is the image forming adjustment mode 2, even when the fixing start-up operation is completed, the main body status remains in preparation, and when the image forming adjustment mode 2 is completed. The main unit status shifts from preparation to printable state. In S1015, the CPU 801 resets the fixing preparation target temperature after completion of the driving start of the fixing motor, for example, 170 degrees lower than 180 degrees from the viewpoint of power saving, turns on the heater 280 in S1016, and performs the processing from S1008 onward. Run.

  It should be noted that the fixing start-up flow may be terminated in S1012. As a result, when the completion timing of the image forming start-up operation is delayed, the preparatory operation of the fixing device 234 can be omitted, and the influence on the further power saving and the life of the fixing device can be reduced.

  As described above, in this embodiment, in the start-up operation of the image forming apparatus, the preparatory operation of the fixing device is performed in accordance with the completion of the start-up operation of the image forming apparatus. That is, when the time required for the image forming start-up operation is shorter than the time required for the fixing start-up operation, the fixing preparation operation is started after the fixing start-up operation is completed. On the other hand, when the time required for the image forming start-up operation is longer than the time required for the fixing start-up operation, the fixing preparation operation is started after the image forming start-up operation ends. Thus, it is possible to reduce the influence on the power consumption and the life of the fixing roller while shortening the first copy output time of the job after turning on the power of the image forming apparatus.

<Fixing preparation operation according to image adjustment operation time>
FIG. 6 is a diagram illustrating a fixing start-up operation and an image forming start-up operation performed when the image forming apparatus 1000 according to the second embodiment is turned on, and a status transition timing of the image forming apparatus 1000. FIG. 6A shows a case where the image forming start-up operation is in the image forming adjustment mode 1 which is completed earlier than the completion of the fixing start-up operation. For this reason, the start-up operation of the fixing device 234 is started at the same time as the start-up operation of the image forming device, and when the start-up operation of the fixing device 234 is completed, the main body status changes from being prepared to being ready for printing, and the fixing temperature control is performed. Fixing preparation operation is performed in preparation for job submission.

  FIG. 6B shows a case where the image forming start-up operation is completed in the image forming adjustment mode 2 which is completed later than the completion of the fixing start-up operation. For this reason, the fixing temperature control delays the start of the start-up for a predetermined time, and when the start-up operation of the image forming device is completed, the fixing start-up operation of the fixing device 234 is completed and the fixing preparation operation is executed. In the present embodiment, in the case of FIG. 6B, since the fixing start-up operation is started with a predetermined delay, when the fixing start-up operation is completed, the main body status changes from being prepared to being ready for printing. To do.

  Next, a control flow of the fixing start-up operation in the CPU 801 that realizes the start-up operation of FIG. 6 will be described with reference to FIG. When the control flow is started, in step S2001, the CPU 801 checks the image forming start-up operation mode of the image forming apparatus, and determines whether the image forming start-up operation is the image forming adjustment mode 1. If the CPU 801 determines in step S2001 that the image forming adjustment mode 1 is not set, the process advances to step S2011. In step S <b> 2011, the CPU 801 starts measuring the start waiting time of the start-up preparation operation of the fixing device 234 using the timer 811 in order to match the completion of the start-up operation of the fixing device 234 with the completion of the image forming start-up operation.

  Here, the CPU 801 determines a predetermined time for delaying the start of the fixing start-up operation from the start of the image forming adjustment mode 2 as follows. For example, it is known in advance that it takes about 2 minutes from the start to the end of the image forming adjustment mode 2 and about 30 seconds from the start to the end of the fixing start-up operation. In this case, the CPU 801 determines the predetermined time as follows. That is, the CPU 801 determines 1 minute 30 seconds obtained by subtracting the fixing start-up time (for example, 30 seconds) from the image forming start time (for example, 2 minutes) as the predetermined time. In step S2012, the CPU 801 determines whether or not a predetermined time (for example, 1 minute 30 seconds) determined in this way (referred to as a fixing preparation start waiting time in the figure) has elapsed, and if the predetermined time has not elapsed. If it is determined, the process of S2012 is repeated. If the CPU 801 determines in step S2012 that the predetermined time has elapsed, the process advances to step S2002.

  If the CPU 801 determines in step S2001 that the image formation start-up operation is the image formation adjustment mode 1, the process advances to step S2002. In step S2002, the CPU 801 starts driving the fixing motor. In S2003, the CPU 801 causes the fixing device control unit 807 to set the temperature of the fixing roller 233 to be raised to the target temperature by the heater 280, and turns on the heater 280 in S2004. In step S2005, the CPU 801 determines whether or not the fixing roller 233 has reached the target temperature. If the CPU 801 determines that the target temperature has not been reached, the process returns to step S2005. Whether the CPU 801 has reached the target temperature is determined based on the detection result of a thermistor or the like that detects the temperature of the fixing roller 233, as in the first embodiment. If the CPU 801 determines in step S2005 that the fixing roller 233 has reached the target temperature, in step S2006, the CPU 801 completes the start-up operation. Here, as shown in FIG. 6B, in this embodiment, even when the image forming start-up operation is the image forming adjustment mode 2, the fixing start-up operation and the image forming adjustment mode 2 are completed. The printer status changes from being prepared to ready to print.

  In step S2007, the CPU 801 starts measuring the fixing preparation operation time using the timer 811. In step S2008, the CPU 801 determines whether or not a predetermined fixing preparation time has elapsed in preparation for job submission. If the CPU 801 determines in step S2008 that the predetermined fixing preparation time has not elapsed, the process returns to step S2008. That is, the CPU 801 shifts to a fixing preparation operation state in which the temperature control of the fixing device 234 is continued until a predetermined fixing preparation time elapses. If the CPU 801 determines in step S2008 that the predetermined fixing preparation time has elapsed, the heater 280 is turned off in step S2009, the driving of the fixing motor is stopped in step S2010, and the fixing start-up flow ends.

  As described above, in this embodiment, in the start-up operation of the image forming apparatus, the completion of the start-up operation of the fixing device 234 is matched with the completion of the start-up operation of the image forming apparatus. That is, when the time required for the image forming start-up operation is shorter than the time required for the fixing start-up operation, the fixing start-up operation is started together with the image forming start-up operation. On the other hand, when the time required for the image forming start-up operation is longer than the time required for the fixing start-up operation, the fixing start-up operation is started after a predetermined time has elapsed since the image forming start-up operation started. In either case, the fixing preparation operation is started after the fixing startup operation is completed. As a result, the FCOT of the job can be shortened, and in the control operation of the fixing device 234, the waiting state for completion of image formation can be prevented. In addition, it is possible to reduce the influence on the power consumption and the life of the fixing roller while shortening the first copy output time of the job after the image forming apparatus is turned on.

218 Exposure device 220 Transfer device 221 Primary charger 223 Development device 225 Drum 226 Transfer belt 231 Secondary transfer device 234 Fixing device 801 CPU

Claims (4)

An image forming means for forming a toner image on a recording material;
Fixing means for heating and fixing the toner image formed by the image forming means to the recording material;
An image forming operation for adjusting the image forming unit, a fixing operation for heating the fixing unit to a predetermined temperature, and a temperature control operation for performing a fixing preparation operation for maintaining the predetermined temperature. , A control means for performing in parallel after power-on,
With
The image forming apparatus, wherein the control unit changes the temperature control operation according to a time required for the image forming start-up operation. The control means includes
When the time required for the image forming startup operation is shorter than the time required for the fixing startup operation, the fixing preparation operation is started after the fixing startup operation is completed.
2. The fixing preparation operation is started after the completion of the image forming operation when the time required for the image forming operation is longer than the time required for the fixing operation. The image forming apparatus described in 1. The control means includes
When the time required for the image forming start-up operation is shorter than the time required for the fixing start-up operation, the fixing start-up operation is started together with the image forming start-up operation,
When the time required for the image forming start-up operation is longer than the time required for the fixing start-up operation, the fixing start-up operation is started after a lapse of a predetermined time from the start of the image forming start-up operation. The image forming apparatus according to claim 1.   The image forming apparatus according to claim 3, wherein the control unit starts the fixing preparation operation after the fixing start-up operation is completed.

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