JP2012252364A - Image forming system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform startup processing with high usability in an image forming apparatus mounted with two fixing devices.SOLUTION: A startup mode corresponding to an image forming mode using two fixing devices and a startup mode corresponding to an image forming mode using only one fixing device are prepared so that a user can instruct and register either of them. Therefore, for the user who mainly uses only one fixing device, startup time can be shortened.

Description

  The present invention relates to an image forming system for forming a toner image on a sheet. This image forming system is used in, for example, an electrophotographic copying machine, a printer, a facsimile, or a multifunction machine having a plurality of these functions.

A conventional electrophotographic image forming apparatus is equipped with a fixing device that fixes a toner image formed on a sheet by heating and pressing.
Recently, an image forming apparatus in which a plurality (two) of such fixing devices are mounted has been proposed (Patent Documents 1 to 3).

  This is because, in stores and the like where photo printing is performed, it is desired to output a high gloss image such as a photo image. In this case, two fixing devices are used.

  On the other hand, in general offices or the like, it is desired to output low gloss images such as black and white documents and business color documents. In this case, only one fixing device is used.

JP 2000-221821 A Japanese Patent Laid-Open No. 06-348159 JP 2006-259365 A

  However, in the apparatuses disclosed in Patent Documents 1 to 3 including a plurality of such fixing devices, image formation can be started until the warm-up (hereinafter also referred to as start-up) processing of the plurality of fixing devices is completed. Can not.

  In other words, for a user who wants to quickly output a low gloss image such as a black and white document or a business color document, a wasteful wait time occurs, which is inconvenient.

  Therefore, an object of the present invention is to provide an image forming system with improved usability.

  Other objects of the present invention will become apparent upon reading the following detailed description with reference to the accompanying drawings.

The present invention
Image forming means for forming a toner image on a sheet;
First image heating means for heating the toner image on the sheet by the first heating unit;
A second image heating unit that heats the toner image on the sheet heated by the first image heating unit by a second heating unit;
A first warm-up mode in which the first image heating means is preferentially started over the second image heating means when the main power is turned on, and the first image heating means is turned on when the main power is turned on. Designating means for designating one of a plurality of warm-up modes including one image heating means and a second warm-up mode for neutrally starting up the second image heating means;
Storage means for storing the warm-up mode designated by the designation means;
Control means for controlling the power supplied to the first image heating means and the second image heating means during the warm-up process according to the warm-up mode stored by the storage means;
It is characterized by having.

  According to the present invention, an image forming system with improved usability can be provided.

1 is a schematic sectional view of an image forming apparatus. FIG. 3 is a schematic cross-sectional view for explaining a fixing device and a recording material conveyance path. It is a block diagram which controls a fixing device. 4A and 4B are schematic diagrams illustrating a setting screen of a user interface unit, where FIG. 5A is a screen for setting the type of recording material, FIG. It is a screen. 3 is a flowchart illustrating a startup sequence of a fixing device. Regarding the start-up mode for the coated paper mode, (A) is a timing chart showing the power supply to the heaters H1 and H3, and (B) shows the temperature transition of the fixing devices 9A and 9B corresponding to this timing chart. FIG. Regarding the startup mode for the plain paper mode, (A) is a timing chart showing the power supply to the heaters H1 and H3, and (B) shows the temperature transition of the fixing devices 9A and 9B corresponding to this timing chart. It is a figure.

  The image forming system according to the present invention will be specifically described below with reference to the drawings. It should be noted that the scope of the present invention is not limited only to the configuration of the embodiment described later, and can be changed to other known configurations within the scope of the concept of the present invention unless otherwise specified. Needless to say.

  In the following, an image forming apparatus in which an image forming unit and two image heating units are housed in one housing will be described as an example of an image forming system. However, for example, the following example may be used.

  Specifically, an image forming apparatus in which an image forming unit and one image heating unit are housed in one housing, and an image forming apparatus in which the other image heating unit is housed in a single housing and includes an optional device. It may be a system. In this case, the optional device can be attached according to the user's request.

(Image forming means)
FIG. 1 is a schematic cross-sectional view of an image forming apparatus. In this image forming apparatus, various image forming apparatuses, that is, image forming means, which will be described later, are involved in forming a toner image on a sheet (hereinafter, recording material P).

  In the upper part of the apparatus, first to fourth image forming portions Pa to Pd as image forming means are provided for each toner color. These image forming units have a function of forming toner images of respective colors through an electrophotographic process.

  Next, the image forming unit Pa will be described in detail as an example. The image forming units Pb to Pd have the same configuration as that of the image forming unit Pa, and thus description thereof is omitted. The image forming portions Pa to Pd are for magenta toner, cyan toner, yellow toner, and black toner.

  In the image forming portion Pa, a photosensitive drum 3a as an image carrier is provided to be rotatable in the arrow direction. Around the photosensitive drum 3a, a charger 2a, a developing unit 1a, a primary transfer charger 24a, and a cleaner 4a are installed. Further, a light source device and a polygon mirror (not shown) are installed on the upper part.

  First, the surface of the photosensitive drum 3a is charged uniformly by the charger 2a so as to have a predetermined potential.

  Then, the laser beam emitted from the light source device is scanned by a polygon mirror, the light beam of the scanning beam is deflected by a reflection mirror, and is condensed and exposed on the generatrix of the photosensitive drum 3a by an fθ lens.

  As a result, an electrostatic latent image corresponding to the image signal is formed on the photosensitive drum 3a.

  This electrostatic latent image is developed by the developing device 1a. That is, a magenta toner image is formed by attaching magenta toner as a developer to the electrostatic latent image. When the toner in the developing device 1a is consumed during image formation, the replenishment toner is appropriately replenished from the toner replenishment mechanism Ea.

  The magenta toner image formed on the photosensitive drum 3a is primarily transferred to an intermediate transfer body 130 as image forming means that rotates in the A direction. At this time, a primary transfer bias is applied to the primary transfer charger 24a. The photosensitive drum 3ad after the primary transfer is cleaned by the cleaner 4a and is prepared for the next subsequent image formation.

  A full color toner image is formed on the intermediate transfer 130 by performing the image forming process so far in the image forming portions Pb to Pd. Here, the intermediate transfer member 130 is suspended by rollers 13 to 15, and the secondary transfer charger 11 is installed on the opposite portion of the roller 14.

  Then, the full color toner image on the intermediate transfer body 130 is secondarily transferred onto the recording material P all at once. At this time, a secondary transfer bias is applied to the secondary transfer charger 11.

  The recording material P is stored in the cassette 10, and the recording material P is sent out from the cassette by the transport mechanism.

  Then, the recording material P sent out from the cassette is configured to be conveyed by the registration roller 12 so as to match the timing of the secondary transfer.

  After the secondary transfer, the toner remaining on the intermediate transfer member 130 and the belt cleaner 22 are cleaned. This belt cleaner has a configuration using a web (nonwoven fabric).

  The recording material P to which the full color toner image has been transferred is then conveyed to a fixing device 9A described later.

  Then, if necessary, it is conveyed to the fixing device 9B and discharged to the paper discharge tray 18.

  As will be described later, the recording material subjected to the fixing process by the fixing device 9A may be discharged to the paper discharge tray 18 without passing through the fixing device 9B.

(Image heating means)
FIG. 2 is a schematic cross-sectional view of a fixing device 9A (also referred to as a fixing unit) as a first image heating unit and a fixing unit 9B (also referred to as a glossing unit) as a second image heating unit.

  The fixing device 9A and the fixing device 9B are installed in series along the conveyance direction of the recording material. In other words, the fixing device 9A (hereinafter referred to as the first fixing 9A) is installed upstream of the fixing device 9B in the recording material conveyance direction, and the fixing device 9B (hereinafter referred to as the second fixing 9B) is the fixing device 9A. It is installed more downstream than the recording material carrying direction.

  Both the fixing devices 9A and 9B in this example employ a heat roller system. Details will be described below.

(1) Fixing device 9A
In the fixing device 9A, a fixing roller 51 and a pressure roller 52 are installed so as to be rotatable in the direction of the arrow shown in the drawing.

  A fixing roller 51 as a fixing rotating member is formed by coating a hollow cored bar 51a made of aluminum having an outer diameter φ of 45 mm with a silicon rubber layer 51b having a thickness of 2.5 mm, and further having a thickness of 50 μm. PFA tube is covered. As a result, the outer diameter φ of the fixing roller 51 is about 48 mm.

  Inside the fixing roller 51, a halogen heater H1 is installed as a heating source with power consumption of 900W. Further, a thermistor TH1 as a temperature detecting means is installed so as not to contact the outer surface of the fixing roller 51. This is for controlling the surface temperature of the fixing roller by the control unit 100 described later.

  A pressure roller 52 as a pressure rotator is formed by coating a hollow metal core 52a made of aluminum having an outer diameter φ of 36 mm on a silicon rubber layer 52b having a thickness of 2 mm, and further having a thickness of 50 μm thereon. PFA tube is covered. As a result, the outer diameter φ of the pressure roller 52 is about 39 mm.

  Inside the pressure roller 52, a halogen heater H2 is installed as a heating source with power consumption of 300W. Further, a thermistor TH2 as a temperature detecting means is installed so as not to contact the pressure roller 52. This is for controlling the surface temperature of the pressure roller by the control unit 100 described later.

  In this fixing device 9A, the fixing roller 51 and the pressure roller 52 are brought into pressure contact with a total pressure of 700 N, whereby a fixing nip portion NA (first heating portion) having a length of about 8 mm in the recording material conveyance direction is obtained. Is formed. In the fixing nip NA serving as the nip portion, the toner image on the recording material is heated and pressed to perform a toner image fixing process (image heating process).

(2) Fixing device 9B
In the fixing device 9B, a fixing roller 151 and a pressure roller 152 are installed so as to be rotatable in the direction indicated by the arrows.

  A fixing roller 151 as a fixing rotator is formed by coating a hollow cored bar 151a made of aluminum having an outer diameter φ of 47 mm with a silicon rubber layer 151b having a thickness of 1.5 mm, and further having a thickness of 50 μm on the hollow cored bar 151a. The PFA tube 151c is covered. As a result, the outer diameter φ of the fixing roller 151 is about 49 mm.

  Inside the fixing roller 151, a halogen heater H3 is installed as a heating source with power consumption of 900W. Further, a thermistor TH3 as a temperature detecting means is installed so as not to contact the outer surface of the fixing roller 151. This is for controlling the surface temperature of the fixing roller 151 by the control unit 100 described later.

  A pressure roller 152 as a pressure rotator is formed by coating a hollow cored bar 152a made of aluminum having an outer diameter φ of 37 mm with a silicon rubber layer 152b having a thickness of 1.5 mm, and further having a thickness thereon. A 50 μm PFA tube 152c is covered. As a result, the outer diameter φ of the pressure roller 152 is about 39 mm.

  Inside the pressure roller 152, a halogen heater H4 is installed as a heating source with power consumption of 300W. Further, a thermistor TH4 as temperature detecting means is installed so as not to contact the pressure roller 152. This is for controlling the surface temperature of the pressure roller 152 by the control unit 100 described later.

  In the fixing device 9B, the fixing roller 151 and the pressure roller 152 are brought into pressure contact with a total pressure of 1000 N, whereby a fixing nip NB (second heating unit) having a length of about 4 mm in the recording material conveyance direction is formed. Is formed. In the fixing nip NB serving as the nip portion, the toner image on the recording material is heated and pressed to perform a fixing process (image heating process) of the toner image.

(3) Temperature Control of Fixing Units 9A and 9B Next, temperature control of the fixing units 9A and 9B will be described. FIG. 3 shows a block diagram of the temperature control system of the fixing devices 9A and 9B.

  Reference numeral 100 denotes a main body control unit (CPU) as control means, which controls the entire image forming operation sequence control of the image forming apparatus including temperature control of the fixing devices 9A and 9B. E1 to E4 are power supply units for the heaters H1 to H4, respectively.

  In the fixing device 9A, power is supplied from the power supply unit E1 to the heater H1, and the fixing roller 51 is heated by the heat of the heater H1. The surface temperature of the fixing roller 51 is detected by the thermistor TH1, and this temperature detection information is transmitted to the main body control unit 100. The main body control unit 100 then transfers the power supply unit E1 to the heater H1 based on temperature detection information from the thermistor TH1 so that the fixing roller surface temperature becomes a predetermined fixing target temperature (first set temperature) T11. Control the power supplied. In this example, T11 is 180 ° C.

  In the fixing device 9A, power is supplied from the power supply unit E2 to the heater H2, and the pressure roller 52 is heated by the heat of the heater H2. The surface temperature of the pressure roller 52 is detected by the thermistor TH2, and this temperature detection information is transmitted to the main body control unit 100. Then, the main body control unit 100 controls the power supplied from the power supply unit E2 to the heater H2 based on the temperature detection information from the thermistor TH2, so that the pressure roller surface temperature information becomes a predetermined target temperature. In this example, the pressure roller 52 is adjusted to 140 ° C.

  In the fixing device 9B, power is supplied from the power supply unit E3 to the heater H3, and the fixing roller 151 is heated by the heat of the heater H3. The surface temperature of the fixing roller 151 is detected by the thermistor TH3, and this temperature detection information is transmitted to the main body control unit 100. Then, the main body control unit 100 controls the heater from the power supply unit E3 based on the temperature detection information from the thermistor TH3 so that the surface temperature of the fixing roller 151 becomes a predetermined fixing target temperature (second set temperature) T21. The power supplied to H3 is controlled. In this example, T21 is 180 ° C.

  In the fixing device 9B, power is supplied from the power supply unit E4 to the heater H4, and the pressure roller 152 is heated by the heat of the heater H4. The surface temperature of the pressure roller 152 is detected by the thermistor TH4, and this temperature detection information is transmitted to the main body control unit 100. The main body control unit 100 controls the power supplied from the power supply unit E4 to the heater H4 based on the temperature detection information from the thermistor TH4 so that the surface temperature of the pressure roller 152 becomes a predetermined target temperature. . In this example, the pressure roller 152 is adjusted to 140 ° C.

(Image formation mode)
In this example, an image forming mode (hereinafter referred to as a plain paper mode) for forming a low gloss image on a sheet having a small heat capacity such as plain paper is used as the type of recording material. This plain paper mode is mainly for office users who print on plain paper such as high-quality paper, and is most suitable for users who frequently use color low-gloss images and black and white text originals. In this plain paper mode, as will be described later, the fixing process (image heating process) is performed using only the fixing device 9A without using the fixing device 9B.

  On the other hand, it also has an image forming mode (hereinafter referred to as a coated paper mode) for forming a high gloss image on a sheet having a large heat capacity such as a coated paper as a type of recording material. This coated paper mode is for users who often print high-gloss images on highly glossy recording materials such as coated paper, and is optimal for users who use high-quality color printing. In this coated paper mode, it is also possible to select this mode when it is desired to output a high gloss image even for a sheet having a small heat capacity. In this coated paper mode, as will be described later, fixing processing (image heating processing) is performed using both the fixing device 9A and the fixing device 9B.

(Recording material conveyance control according to image forming mode)
When the plain paper mode is selected, the main body controller 100 introduces the recording material P onto which the toner image has been transferred into the fixing device 9A, and then avoids the fixing device 9B by the flapper 27 serving as switching means. Change the course to the transport path. Accordingly, the recording material is discharged to the paper discharge tray 18 without going through the fixing device 9B.

  On the other hand, when the coated paper mode is selected, the main body control unit 100 introduces the recording material P onto which the toner image has been transferred into the fixing device 9A, and then introduces the recording material P into the fixing device 9B by the flapper 27. Change the course. Accordingly, the recording material is sequentially introduced into the fixing device 9A and the fixing device 9B, is subjected to two fixing processes, and is then discharged to the paper discharge tray 18.

  When the double-sided print mode is selected in the plain paper mode or the coated paper mode, the recording material that has undergone the fixing process is reversed to the front and back, and is transported to the secondary transfer unit. It is conveyed.

(Specify image forming mode)
Reference numeral 101 denotes a UI (user interface) unit serving as a designation unit, which is disposed in the upper front portion of the image forming apparatus and is controlled by the main body control unit 100. The UI 101 is a liquid crystal display device as display means.

  This UI section is provided with a key (FIG. 4A) for setting the type of recording material. Specifically, keys for designating plain paper, coated paper, cardboard, and OHP sheet are provided. In addition, when the “return” key is pressed, the screen returns to the top screen of the setting screen.

  When the type of the recording material is set by the user, the main body control unit 100 switches the image forming mode based on the instruction result. The UI unit is also provided with a key for selecting the gloss level of the image. When the user sets the gloss level of the image, the main body control unit 100 switches the image forming mode based on the instruction result. I do.

  In this example, a setting screen for setting the gloss level of the image is prepared, and keys (FIG. 4B) for specifying “low” and “high” as the gloss level of the image are provided. Yes. The “return” key is for returning the setting screen to the top screen. When “high” is selected, even if the recording material to be used is plain paper, an image forming sequence is performed in which fixing processing is performed by the fixing device 9A and the fixing device 9B. On the other hand, when “low” is selected as the gloss level of the image, an image forming sequence is performed in which the fixing process is performed only by the fixing device 9A.

(Start-up mode according to the image formation mode)
In this example, when the main switch (main power supply) of the image forming apparatus is turned on (powered on), start-up processing (warm-up processing) of various devices in the image forming apparatus is performed. It has become. A start-up mode as a warm-up mode is prepared for each image forming mode. In particular, in this example, the time required for the start-up processing of the fixing devices 9A and 9B is longer than that of other devices. From the viewpoint of usability, the start-up processing of the fixing devices 9A and 9B is performed. It is preferable to shorten it.

  Therefore, in this example, the startup processing of the fixing devices 9A and 9B is devised so as to meet the user's request. That is, a start-up process (warm-up process) with a low waiting time is prepared for an office user who mainly uses the above-described plain paper mode.

  FIG. 4C shows a startup mode setting screen displayed on the liquid crystal display device.

  The startup mode setting screen displays a startup mode for the plain paper mode (first warm-up mode) and a startup mode for the coated paper mode (second warm-up mode). The user selects and designates one of the two modes, so that the designated startup mode is registered in the memory 100a as the storage means in the main body control unit 100. The “return” key is for returning the setting screen to the top screen. When the main switch of the image forming apparatus is turned on, the main body control unit 100 reads the registered start-up mode and executes the following start-up mode.

  FIG. 5 is a flowchart illustrating a startup sequence when the image forming apparatus is powered on. This startup sequence is executed by the main body control unit 100 controlling various devices.

  (Step 1) The main power supply of the image forming apparatus is turned on.

  (Step 2) The setting of the start-up mode registered by the user in the memory 100a is referred to.

  At this time, in the case of the plain paper mode, the control is sequentially performed according to the flow shown in “Yes”. On the other hand, in the case of the coated paper mode, the control is sequentially performed according to the flow indicated by “No”.

(Start-up mode in code paper mode)
First, a case where the coated paper mode is instructed will be described.

  In the coated paper mode, since the fixing device 9B is used in addition to the fixing device 9A, it is preferable that both the fixing device 9A and the fixing device 9B start up substantially at the same time. In view of this, the ratio of distributing the available power allocated to the fixing device 9A and the fixing device 9B to the fixing device 9A and the fixing device 9B at the start-up in the image forming apparatus is devised. That is, the power supplied to the heaters mounted on the fixing device 9A and the fixing device 9B is made substantially equal so that both the fixing device 9A and the fixing device 9B start up substantially simultaneously. In this example, as will be described later, by setting the power distribution ratio to the fixing device 9A and the fixing device 9B to 1: 1, the startup time of the two fixing devices 9A and 9B is minimized. Note that the power distribution ratio may not be 1: 1 as long as both the fixing device 9A and the fixing device 9B can start up at substantially the same time. That is, the power distribution ratio may not be the above example as long as both the fixing device 9A and the fixing device 9B are configured to stand up at the same time at the shortest. In this example, it is assumed that the power supplied to the heaters mounted on the fixing device 9A and the fixing device 9B is substantially neutral.

  When the power distribution ratio is 1: 1, the power consumed by the two fixing devices is 900 W + 300 W + 900 W + 300 W = 2400 W, which exceeds the allowable power of the commercial power supply.

  (Step 3) Therefore, control is performed so that only one of the heaters H1 and H3 is turned on, and the ratio of the power to be input is set to 1: 1. As a result, the warm-up time of the two fixing devices until the fixing is possible is made substantially the same while suppressing the power consumed by the two fixing devices.

  Specifically, as shown in FIG. 6A, the heater H3 is turned off when the heater H1 is turned on, and the heater H1 is turned off when the heater H3 is turned on. That is, by setting the ON / OFF ratio to 1: 1, the ratio of the input power to the fixing device 9A and the fixing device 9B is set to 1: 1.

  Similarly, the heaters H2 and H4 of the pressure roller are also turned on at a ratio of 1: 1, so that the ratio of input power is 1: 1.

  Since the heaters H1 and H3 are 900 W heaters and the heaters H2 and H4 are 300 W heaters, an average power of 450 W is applied to the fixing rollers and an average power of 150 W is applied to the pressure rollers.

  (Step 4) The heater ON permission is lowered, and the temperature of the fixing roller is increased while following the heater lighting control described above. FIG. 6B is a diagram showing the temperature rise of the fixing rollers of both fixing units after the main power is turned on in the coated paper mode. A solid line indicates the surface temperature of the fixing roller 51 of the fixing device 9A, and a broken line indicates the surface temperature of the fixing roller 151 of the fixing device 9B. At this time, since the power supply ratio to the fixing device 9A and the fixing device 9B is set to 1: 1, as shown in FIG. 6B, the fixing device 9A and the fixing device 9B tend to have substantially the same temperature rise. .

  (Step 5) It is determined whether or not both of the fixing devices 9A and 9B reach 180 ° C. which is the temperature control temperature.

  (Step 6) When the temperature of the two fixing devices reaches 180 ° C., the start of image formation is permitted (allowed). That is, it becomes a print ready and enters a print waiting state.

  (Step 7) If there is a print reservation, the process proceeds to Step 16. If a print signal is received in the print waiting state, the process proceeds to step 16.

  (Step 16) The printing operation is started by the print signal.

  In this coated paper mode, it took about 5 minutes from when the main power supply was turned on until the printer was ready.

(Start-up mode in plain paper mode)
Next, the case of the plain paper mode will be described using the flowchart of FIG. In this plain paper mode, since only the fixing device 9A is used and the fixing device 9B is not used, the start-up process of the fixing device 9A is preferentially performed over the fixing device 9B.

  (Step 8) Therefore, the ratio of the electric power supplied to the fixing device 9A and the fixing device 9B is set to 2: 1. That is, the time required for starting up the fixing device 9A is shorter than the time required for starting up the coated paper mode. However, when the fixing device 9A is started up, the fixing device 9B is not started up. In this way, in this example, while supplying power to the fixing device 9B, power is supplied preferentially to the fixing device 9A until the fixing device 9A can be fixed.

  That is, in this example, the power supply to the fixing device 9A is given priority over the fixing device 9B. In other words, the power to the fixing device 9A is set so that the fixing device 9A rises earlier than the fixing device 9B. It means to supply.

  Specifically, as shown in FIG. 7A, the heater H3 is turned off when the heater H1 is turned on, and the heater H1 is turned off when the heater H3 is turned on. That is, by controlling the lighting time ratio of the heaters H1 and H3 to 2: 1, the ratio of the input power to the fixing device 9A and the fixing device 9B is set to 2: 1.

  Similarly, the heaters H2 and H4 of the pressure roller are also turned on at a ratio of 2: 1, so that the ratio of input power is 2: 1.

  In this plain paper mode, the fixing device 9A is supplied with an average power of 600 W to the heater H1 and an average of 200 W to the heater H2, that is, a total of 800 W. On the other hand, the fixing device 9B is supplied with an average power of 300 W to the heater H3 and an average of 100 W to the heater H4, that is, a total of 400 W.

  (Step 9) Then, the heater ON permission is lowered, and the temperature of the fixing roller rises while following the heater lighting control described above. FIG. 7B is a diagram showing a temperature rise on the surface of the fixing roller of both fixing units after the main power is turned on in the plain paper mode. A thick solid line indicates the surface temperature of the fixing roller 51 of the fixing device 9A, and a thick broken line indicates the surface temperature of the fixing roller 151 of the fixing device 9B. For reference, the thin solid line indicates the surface temperature of the fixing roller 51 of the fixing device 9A in the start-up mode for the coated paper mode.

  (Step 10) Since the fixing device 9A is rapidly warmed up with the power of 800 W, the temperature reaches 180 ° C. which is the temperature adjustment temperature at about 3 minutes 30 seconds, and the fixing device 9A becomes ready for fixing. That is, it takes about 3 minutes 30 seconds from when the main power is turned on until the warm-up process of the fixing device 9A is completed.

  (Step 11) With the end of the warm-up process of the fixing device 9A, regardless of whether or not the fixing device 9B is up (having reached 180 ° C.), the printing in the plain paper mode is set to be ready. In this example, the warm-up process of the fixing device 9B is not completed at this stage.

  (Step 12) If there is a print reservation, the process proceeds to Step 16. If a print signal is received in the print waiting state, the process proceeds to step 16.

  (Step 13) It is determined whether or not the image forming job according to the print command uses the fixing device 9B.

  (Step 16) In the case of low-gloss printing using plain paper that does not use the fixing device 9B, the printing operation is started immediately.

  (Step 14) On the other hand, when a job using the fixing device 9B is received, it is necessary to start printing after the fixing device 9B reaches 180 ° C., which is the temperature control temperature. At this time, since the fixing device 9A is in a standing state, it is not necessary to input a large amount of power, and the minimum power necessary for maintaining a temperature of 180 ° C. is sufficient.

  Therefore, after the warm-up process of the fixing device 9A is completed, power is preferentially supplied to the fixing device 9B over the fixing device 9A until the warm-up process of the fixing device 9B is completed. Specifically, the lighting ratio of the heaters H1 and H3 is changed to 1: 5, and the lighting ratio of the heaters H2 and H4 is also changed to 1: 5. As a result, at this time, an average of 750 W is applied to H3 and an average of 250 W is applied to H4.

  (Step 15) Thereafter, the fixing device 9B rises rapidly, and it is determined whether or not the fixing device 9B has reached the target temperature of 180 ° C.

  (Step 16) When the fixing device 9B reaches the target temperature of 180 ° C., the printing operation is started.

  As described above, even when the start-up mode for the plain paper mode is set, the following cases can be dealt with by preferentially supplying power to the fixing unit 9B after the fixing unit 9A is started up. can do. Specifically, it is possible to cope with a case where an office user rarely requests image formation on coated paper. That is, it is possible to prevent the standby time from being prolonged for the image formation on the coated paper. Further, it is possible to cope with the case where a high gloss image is formed on plain paper by performing the fixing process using both the fixing device 9A and the fixing device 9B.

  In the above-described example, plain paper and coated paper are described as the types of recording materials. However, the present invention can be similarly applied to other types of recording materials.

  That is, in the above description, only “plain paper” is cited as a representative example of the recording material to be subjected to the fixing process using only the fixing device 9A, and the recording material to be subjected to the fixing process using only the fixing device 9A. You can use anything other than plain paper. For example, thin paper can be used, and in this case, control similar to that in the plain paper mode is performed. Similarly, only “coated paper” is mentioned as a representative example of the recording material to be subjected to the fixing process using the fixing unit 9A and the fixing unit 9B, and the fixing process is performed using the fixing unit 9A and the fixing unit 9B. Any other recording material may be used as long as the recording material is applied. For example, thick paper can be cited, and in this case, the same control as in the coated paper mode is performed.

  Further, the power supply ratio to the fixing device 9A and the fixing device 9B in the start-up mode has been specifically described above, but the present invention is not limited to this. In other words, the power supply ratio may be set to other values within a range in which similar effects can be obtained.

  As described above, by preparing a plurality of start-up modes and allowing the user to select and register them, the waiting time can be shortened for the office user. Also, for users who mainly want to output high-gloss images, the start-up mode for the coated paper mode is prepared and can be selected and registered, which increases the time required for the warm-up process. Can be prevented.

  In this way, it is possible to provide an image forming system with high usability.

  Next, examples will be described. Since components other than those described later are the same as those of the first embodiment, detailed description thereof will be omitted by adding the same reference numerals.

  In this example, when there is one cassette 10 mounted on the image forming apparatus, the start-up mode is automatically selected and executed according to the type of recording material accommodated in the cassette 10. In other words, the difference from the first embodiment is that the start mode is not set / registered by the user, but is automatically selected based on the information of the recording material stored in the cassette registered in the main body control unit 100. It is a point to execute.

  After setting a predetermined number of recording materials in the cassette 10, the user designates / registers with the key for setting the type of recording material displayed on the setting screen of the UI unit 101. Information corresponding to the type of the recording material is stored in a non-volatile memory 100 a serving as a storage unit in the main body control unit 100. The type of recording material includes information corresponding to the size of the recording material and the basis weight of the recording material.

  The control flow related to the startup mode in this example is as follows. This control flow is controlled by the main body control unit 100 as in the first embodiment.

  First, when the main power supply of the image forming apparatus is turned on, the main body control unit 100 reads information corresponding to the type of recording material preset and registered in the memory 100a.

  From this read information, the main body control unit 100 determines whether the recording material set in the cassette 10 is plain paper or coated paper.

  When it is determined that the coated paper is set, the start-up mode for the coated paper mode is automatically executed. The start-up mode for the coated paper mode is the same as that described in the first embodiment.

  On the other hand, when it is determined that plain paper is set, the startup mode for the plain paper mode is automatically executed. The start-up mode for this plain paper mode is the same as that described in the first embodiment.

  The main body control unit 100 sets the print ready when the warm-up process is completed regardless of the startup mode.

  Thus, even if the start-up mode is not set and registered as in the first embodiment, an image forming system with high usability can be provided as in the first embodiment.

  Next, Example 3 will be described. Since components other than those described later are the same as those of the first embodiment, detailed description thereof will be omitted by adding the same reference numerals.

  In this example, a plurality of cassettes 10 are provided.

  In this example, control is performed such that the cassette having the largest number of recording materials set among the plurality of cassettes 10 is given priority. In this example, the number of recording materials to be set together with the type of recording material is stored in the memory 100 a in the main body control unit 100 for each cassette.

  Specifically, when the main power of the apparatus is turned on, the main body control unit 100 reads the number of recording materials set for each cassette from the memory 100a and determines the cassette with the largest number of recording materials set. Then, based on the information corresponding to the type of recording material stored in the cassette with the largest number of recording materials set, either the normal paper mode or coated paper mode startup mode is automatically selected and executed To do.

  As described above, in this example, an image forming system with high usability can be provided even when a plurality of cassettes 10 are mounted.

  Next, Example 4 will be described. Since components other than those described later are the same as those of the first embodiment, detailed description thereof will be omitted by adding the same reference numerals.

  Also in this example, a plurality of cassettes 10 are mounted.

  In this example, the start-up mode is selected and executed in accordance with the type of the recording material on which image formation was performed last, that is, the cassette 10 used last. The memory 100a in the main body control unit 100 stores information on the type of recording material set for each cassette, and also stores information on the cassette used in the last image formation among a plurality of cassettes. Is done.

  Specifically, when the main power of the apparatus is turned on, the main body control unit 100 selects and executes the start-up mode according to the type of recording material on which image formation was last performed, that is, the cassette 10 used.

  That is, when the main power supply of the apparatus is turned on, the main body control unit 100 reads information on the cassette used in the last image formation from the memory 100a. Based on this read information, either the normal paper mode or the coated paper mode is set up and executed automatically.

  As described above, in this example, an image forming system with high usability can be provided even when a plurality of cassettes 10 are mounted.

  As described above, in the first to fourth embodiments, the example in which the startup mode is for the plain paper mode and the coated paper mode has been described. However, the configuration may be such that the startup mode has three or more startup modes. In this case, the main body control unit 100 is configured to selectively execute one of three or more prepared startup modes.

  In the first to fourth embodiments, an example in which the fixing process is performed using only the fixing device 9A in the plain paper mode has been described. For example, the fixing process is performed using only the fixing device 9B in the plain paper mode. A configuration in which processing is performed may be used.

  Further, in Examples 1 to 4, an example in which two fixing devices as image heating means are mounted has been described. However, the present invention is similarly applied to an example in which three or more fixing devices are mounted as necessary. Is possible.

9A, 9B Fixing device 51 Fixing roller 52 Pressure roller 100 Main body control unit 100a Memory 101 User interface unit H1 to H4 Halogen heater TH1 to TH4 Thermistor P Recording material

Claims (7)

Image forming means for forming a toner image on a sheet;
First image heating means for heating the toner image on the sheet by the first heating unit;
A second image heating unit that heats the toner image on the sheet heated by the first image heating unit by a second heating unit;
A first warm-up mode in which the first image heating means is preferentially started over the second image heating means when the main power is turned on, and the first image heating means is turned on when the main power is turned on. Designating means for designating one of a plurality of warm-up modes including one image heating means and a second warm-up mode for neutrally starting up the second image heating means;
Storage means for storing the warm-up mode designated by the designation means;
Control means for controlling the power supplied to the first image heating means and the second image heating means during the warm-up process according to the warm-up mode stored by the storage means;
An image forming system comprising:   When the first warm-up mode is designated, the control unit is configured so that the warm-up process of the first image heating unit is completed earlier than the warm-up process of the second image heating unit. 2. The image forming system according to claim 1, wherein power supplied to the first image heating unit and the second image heating unit is controlled.   The control means makes the power supplied to the first image heating means larger than the power supplied to the second image heating means when the first warm-up mode is designated. The image forming system according to claim 1 or 2.   When the warm-up process of the first image heating unit is completed, the control unit supplies power supplied to the second image heating unit until the warm-up process of the second image heating unit is completed. 4. The image forming system according to claim 3, wherein the size is larger than that of the image heating means.   When the second warm-up mode is designated, the control means causes the first image heating means and the second image heating means to finish the warm-up process at substantially the same time. 5. The image forming system according to claim 1, wherein power supplied to the image heating unit and the second image heating unit is controlled.   2. The control unit according to claim 1, wherein when the second warm-up mode is designated, the power supplied to the first image heating unit and the second image heating unit is substantially equal. The image forming system according to any one of 1 to 5.   7. The image forming system according to claim 1, wherein the specifying unit includes a display unit that performs display for selecting a warm-up mode.

Images