Image forming apparatus

Abstract

To prevent the image quality reduction due to dew condensation in such a situation that dew condensation may occur and prevent the temporal printing efficiency from being reduced.SOLUTION: An image formation apparatus comprises: a dew condensation determination unit which determines whether or not there is such a possibility that dew condensation occurs in the image formation apparatus by using dew condensation determination information including the measured in-apparatus temperature; a preparation processing execution unit which performs preparation processing for executing a print function; and a preparation standby time setting unit which sets the preparation standby time indicating a period in which the preparation processing is performed. The image formation apparatus, when determining that there is such a possibility that dew condensation occurs in the image formation apparatus in a case where the power of the image formation apparatus is turned on, sets the preparation standby time by using the dew condensation determination information, starts the preparation processing, starts counting of the preparation standby time, and cancels the preparation processing when the counted preparation standby time elapses after determining that the periodically-measured fixation temperature reaches a prescribed target temperature.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus having a function of reducing the influence of dew condensation.

Background Art

[0002] Conventionally, image forming apparatuses have been used, and in addition to a printing function capable of single-sided or double-sided printing of documents, multi-functional printers having a document reading (scanning) function, a network connection function, etc. have also been used. When the image forming apparatus is not in use, components necessary for image formation such as a photoreceptor are at a low temperature. However, when it is used, in order to operate the components necessary for image formation normally, a preparation operation (warm-up operation) is required to raise the inside of the image forming apparatus and the periphery of components such as the photoreceptor to a predetermined temperature.

[0003] Normally, the heater of the fixing device is activated to perform the preparation operation. However, if the temperature of components such as the photoreceptor rises rapidly, dew condensation may occur on the components necessary for image formation. For example, if printing is executed with dew condensation remaining on the surface of the photoreceptor, image quality deterioration will occur. Also, when performing double-sided printing, after printing on the first printing surface (front surface), the transported paper may absorb water during the conveyance process of inverting the printed paper. Even when printing is performed on the second printing surface (back surface) with the paper having absorbed water, image quality deterioration will occur. Therefore, conventionally, countermeasures for preventing dew condensation have been proposed.

[0004] For example, Patent Document 1 describes measuring the temperature inside an image forming apparatus and, when the initial temperature inside the image forming apparatus when the main switch of the image forming apparatus is turned on is lower than the set temperature, while switching the on / off of a heater that raises the temperature inside the image forming apparatus several times, gradually raising the temperature inside the image forming apparatus to the set temperature within the warm-up time so that the temperature inside the image forming apparatus does not rise suddenly, preventing a dew condensation phenomenon, and extending the warm-up time if the temperature inside the image forming apparatus cannot be set to the set temperature within the warm-up time, and an image forming apparatus that displays that the warm-up time is extended is described.

[0005] Also, when performing double-sided printing, after printing on the front surface of the paper, the paper is dried by waiting for a certain period of time or more in a conveyance path that reverses the paper, and then printing is performed on the back surface.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, like a conventional image forming apparatus, even if the occurrence of image quality deterioration due to a dew condensation phenomenon can be reduced by gradually raising the temperature inside the image forming apparatus to the set temperature, the warm-up time becomes long, and the time required until printing processing can start becomes long. Actually, even when dew condensation has not occurred and the warm-up time may be short, uniformly, the time required until printing processing can start becomes long.

[0008] Also, when performing double-sided printing for the first time immediately after the elapse of the warm-up time, there are cases where dew condensation has not been sufficiently removed, and image quality deterioration may occur. Furthermore, when performing double-sided printing, even if the paper is made to wait for a certain period of time in the conveyance path where the paper is reversed, it is not guaranteed that the paper can be sufficiently dried, and making the paper wait in the conveyance path may induce paper jams. Also, when performing single-sided printing, since it is not necessary to reverse the paper as in double-sided printing, it is considered that the influence of dew condensation is less than that of double-sided printing. However, always setting a long warm-up time means that it takes time until the printing process for single-sided printing can start, resulting in poor printing efficiency in terms of time.

[0009] Therefore, the present invention has been made in consideration of the above circumstances. In a situation where dew condensation may occur, when performing double-sided printing, it is an object to provide an image forming apparatus capable of preventing image quality degradation due to dew condensation, and when performing single-sided printing, preventing image quality degradation due to dew condensation and preventing a decrease in printing efficiency in terms of time.

Means for Solving the Problems

[0010] The present invention relates to an image forming apparatus having a printing function, comprising: an in-machine temperature measurement unit that measures the in-machine temperature inside the image forming apparatus; a dew condensation determination unit that determines whether there is a possibility of dew condensation occurring inside the image forming apparatus by using predetermined dew condensation determination information including the measured in-machine temperature; a fixing temperature measurement unit that measures the fixing temperature of a fixing device; a target temperature determination unit that determines whether the measured fixing temperature has reached a predetermined target temperature; a preparation process execution unit that performs a preparation process for executing the printing function; and a preparation standby time setting unit that sets a preparation standby time indicating a period for performing the preparation process. When the power of the image forming apparatus is turned on, the in-machine temperature measurement unit measures the current in-machine temperature. When the dew condensation determination unit determines that there is a possibility of dew condensation occurring inside the image forming apparatus, the preparation standby time setting unit sets the preparation standby time by using the dew condensation determination information, and the preparation process execution unit starts the preparation process. After starting the preparation process and starting the measurement of the preparation standby time, the fixing temperature measurement unit periodically measures the current fixing temperature. After the target temperature determination unit determines that the periodically measured fixing temperature has reached a predetermined target temperature and when the measured preparation standby time has elapsed, the preparation process execution unit stops the preparation process. An image forming apparatus is provided, which is characterized by the above.

[0011] Furthermore, the image forming apparatus further comprises a print request confirmation unit that confirms that a print request for starting the printing function has been made. When the dew condensation determination unit determines that there is a possibility of dew condensation occurring inside the image forming apparatus, and after the target temperature determination unit determines that the periodically measured fixing temperature has reached a predetermined target temperature and before the set preparation standby time has elapsed, if the print request confirmation unit confirms that a print request for single-sided printing, which prints only on one surface of the printing paper, has been made, after the preparation process execution unit stops the preparation process, the image forming apparatus performs the requested single-sided printing.

[0012] Furthermore, it further includes a print request confirmation unit that confirms that a print request to start the printing function has been made, and a print hold processing unit that holds a print job for which a print request has been made. When the dew condensation determination unit determines that there may be dew condensation inside the image forming apparatus, after the target temperature determination unit determines that the regularly measured fixing temperature has reached a predetermined target temperature, before the set preparation standby time elapses, if the print request confirmation unit confirms that a print request for double-sided printing, which prints on both sides of the printing paper, has been made, the print hold processing unit holds the print job for the requested double-sided printing, and after the set preparation standby time has elapsed, the preparation process execution unit aborts the preparation process and executes the requested double-sided printing.

[0013] Also, in a state where the print hold processing unit is holding the print job for the requested double-sided printing, if the print request confirmation unit confirms that a print request for single-sided printing has been made, before the set preparation standby time elapses, the preparation process execution unit aborts the preparation process, executes the requested single-sided printing, and then executes the held double-sided printing.

[0014] Furthermore, it further includes a humidity measurement unit that measures the humidity inside the image forming apparatus, a power-off time measurement unit that measures the power-off time, which is the time during which the power of the image forming apparatus is turned off, and a storage unit that stores dew condensation determination condition information including a predetermined temperature determination value, humidity determination value, and power time determination value. The dew condensation determination information further includes the measured humidity and the measured power-off time. The dew condensation determination unit determines that there may be dew condensation when the measured internal temperature of the apparatus is lower than the temperature determination value, the measured humidity is higher than the humidity determination value, and the measured power-off time is longer than the power time determination value.

[0015] Further, the preparation standby time setting unit sets the preparation standby time to a time obtained by adding correction values obtained by converting the measured in-cabin temperature, the measured humidity, and the measured power-off time by predetermined correction coefficients, respectively, to a predetermined extension reference time.

[0016] Further, the preparation standby time set by the preparation standby time setting unit is adjusted by subtraction in consideration of the usage time of the image forming apparatus up to the present.

[0017] Further, after it is determined by the target temperature determination unit that the regularly measured fixing temperature has reached a predetermined target temperature, and before the set preparation standby time elapses, if a predetermined stop condition for aborting the preparation process occurs, even before the set preparation standby time elapses, the preparation process execution unit aborts the preparation process.

[0018] Further, the stop conditions for aborting the preparation process include a print request for single-sided printing, a read request for a document that does not require printing, an operation of opening a door attached to the image forming apparatus, and a request to shift to the sleep state.

[0019] Further, when a predetermined restart condition for restarting the preparation process occurs after the preparation process is aborted due to the occurrence of the stop condition, and when the dew condensation determination unit determines that there is a possibility that dew condensation has occurred inside the image forming apparatus, the preparation process execution unit restarts the preparation process.

[0020] Furthermore, the present invention is an image forming apparatus having a printing function, comprising: an in-machine temperature measurement unit that measures the in-machine temperature inside the image forming apparatus; a dew condensation determination unit that determines whether there is a possibility of dew condensation occurring inside the image forming apparatus by using predetermined dew condensation determination information including the measured in-machine temperature; a preparation standby time setting unit that sets a preparation standby time by using the dew condensation determination information when the dew condensation determination unit determines that there is a possibility of dew condensation occurring inside the image forming apparatus; a preparation process execution unit that performs a preparation process for executing the printing function when the power of the image forming apparatus is turned on; and a fixing temperature measurement unit that measures the fixing temperature of a fixing device. When the preparation process is started, the counting of the preparation standby time is started, and after it is determined that the current fixing temperature measured by the fixing temperature measurement unit has reached a predetermined target temperature and the counted preparation standby time has elapsed, the preparation process execution unit stops the preparation process. The present invention provides an image forming apparatus characterized by the above.

[0021] Moreover, the present invention is a method for preventing condensation in an image forming apparatus having a printing function, which includes: an in-machine temperature measurement step of measuring the in-machine temperature inside the image forming apparatus when the power of the image forming apparatus is turned on; a condensation determination step of determining whether there is a possibility of condensation occurring inside the image forming apparatus by using predetermined condensation determination information including the measured in-machine temperature; a preparation standby time setting step of setting a preparation standby time by using the condensation determination information when it is determined in the condensation determination step that there is a possibility of condensation occurring inside the image forming apparatus; a preparation process execution step of starting a preparation process for executing the printing function; a timing start step of starting the timing of the preparation standby time when the preparation process is started; a current fixing temperature measurement step of periodically measuring the current fixing temperature of a fixing device during the execution of the preparation process; a target temperature determination step of determining that the periodically measured fixing temperature has reached a predetermined target temperature; and a cancellation step of canceling the preparation process after it is determined that the periodically measured fixing temperature has reached the predetermined target temperature and when the timed preparation standby time has elapsed. The present invention provides a method for preventing condensation in an image forming apparatus, characterized by comprising the above steps.

Effect of the Invention

[0022] According to the present invention, when the power of the image forming apparatus is turned on, if the condensation determination unit determines that there is a possibility of condensation occurring inside the image forming apparatus, a preparation standby time is set by using the condensation determination information, the preparation process execution unit starts the preparation process, and after it is determined that the periodically measured fixing temperature has reached a predetermined target temperature and when the timed preparation standby time has elapsed, the preparation process is canceled. Therefore, in a situation where condensation may occur, especially when double-sided printing is performed, it is possible to prevent image quality degradation due to condensation.

Brief Description of the Drawings

[0023]

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Mode for Carrying Out the Invention

[0024] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited by the following description of the embodiments.

[0025] <Configuration of Image Forming Apparatus> FIG. 1 shows a configuration block diagram of an embodiment of the image forming apparatus of the present invention. The image forming apparatus (hereinafter also referred to as MFP: Multifunction Peripheral, or multi-function machine) 1 is an apparatus that processes image data, and is, for example, an electronic device having functions such as a copying function, a printing function, a document reading (scanning) function, a document editing function, a document storage function, a document transmission (fax, FAX) function, and a communication function. In the following embodiments, the image forming apparatus 1 of the present invention will be described as particularly having a printing function and a document reading (scanning) function, but it may also have other functions.

[0026] In FIG. 1, the image forming apparatus (MFP) 1 of the present invention mainly includes a control unit 11, an operation unit 12, a display unit 13, an image processing unit 14, a temperature measurement unit 21 (an in-machine temperature measurement unit 21a and a fixing temperature measurement unit 21b), a humidity measurement unit 22, a power-off time measurement unit 23, a dew condensation determination unit 24, a target temperature determination unit 25, a standby time setting unit 26, a standby process execution unit 27, a printing request confirmation unit 28, a printing reservation processing unit 29, a function execution unit 30, and a storage unit 40. The image processing unit 14 mainly includes an image input unit 15, an image forming unit 16, and an image output unit 17.

[0027] The control unit 11 controls the operations of each component such as the operation unit and the image processing unit, and is mainly realized by a microcomputer composed of a CPU, a ROM, a RAM, an I / O controller, a timer, etc. Based on the control program stored in advance in the ROM etc., the CPU organically operates various hardware to execute the image forming function, the dew condensation determination function, etc. of this invention.

[0028] Among the above components, the power-off time measurement unit 23, the dew condensation determination unit 24, the target temperature determination unit 25, and the standby time setting unit 26 are functional blocks in which the CPU executes respective processes based on a predetermined program.

[0029] The operation unit 12 is a part where the user of the image forming apparatus inputs information, and is an input device for performing a predetermined input operation to operate the image forming apparatus. For example, it is a part for inputting information such as characters and for selecting input of functions, and a keyboard, a mouse, a touch panel, etc. are used. Keys operated by the user include an operation start key, a function selection key, a setting key, etc. The user causes the printing function, the setting function, etc. to be executed by, for example, performing a contact operation on the touch panel or an operation of inputting a start key for functions such as printing and reading.

[0030] The display unit 13 is a part for displaying information, and displays information necessary for the execution of each function, the result of the execution of the function, etc. to inform the user. For example, an LCD, an organic EL display, etc. are used, and when a touch panel is used as the operation unit 12, the display unit 13 and the touch panel are arranged in an overlapping manner. On the display unit 13, for example, settings of setting items used for printing etc. of the image forming apparatus, information necessary for executing functions such as the printing function and the document reading function, an operation screen of the selected function, etc. are displayed using characters, symbols, figures, images, icons, animations, videos, etc. In particular, in this invention, when the required duplex printing process is on hold, a screen indicating that the dew condensation countermeasure control process is being executed is displayed on the display unit 13.

[0031] The image processing unit 14 is a part that executes the image forming function, which is a main function of the image forming apparatus, and mainly consists of an image input unit 15, an image forming unit 16, and an image output unit 17. Mainly, the image input unit 15 is a part that inputs predetermined image data, the image forming unit 16 is a part that converts the input image data into information that can be printed, etc., and the image output unit 17 is a part that outputs the formed print information, etc. to printing paper, etc.

[0032] The image input unit 15 is a part that inputs image data of a document on which an image, characters, graphics, etc. are described, for example, a part that reads a document placed on a document table, etc. As the image input unit 15, a scanner (reading device) that reads a document on which information is described is used. The image forming apparatus 1 includes a document placement table (document table) on which a document is placed and a document cover that holds down the document in order to read the document. Further, the image forming apparatus 1 may include an automatic document feeder (ADF: Automatic Document Feeder) that places a plurality of documents and automatically conveys and reads the plurality of documents one by one. In this case, a document on which an image, etc. is described is read by a scanner, and the image data of the document is stored in the storage unit 40.

[0033] Also, there are various methods for inputting image information. For example, an interface for connecting an external storage medium such as a USB memory corresponds to the image input unit 15. Save the electronic data file such as the image information to be input to an external storage medium such as a USB memory, connect the USB memory or the like to an input interface such as a USB terminal, and perform a predetermined input operation with the operation unit 12, so that the desired electronic data file stored in the USB memory or the like can be read out and stored in the storage unit 40 as input image data.

[0034] When printing the input image data on a recording medium, for example, the image forming unit 16 generally performs each process of charging, exposure, development, transfer, cleaning, charge removal, and fixing continuously to form the input image data on the recording medium. In the developing process, toner is supplied from the toner cartridge to the developing device, the electrostatic latent image formed on the surface of the charged photosensitive drum is developed, and a toner image corresponding to the electrostatic latent image is formed. The toner image formed on the surface of the photosensitive drum is transferred onto the recording medium by the transfer device, and then fixed on the recording medium by being heated by the fixing device. In addition, the image forming unit 16 converts the input image data into information in a form that can be transferred or displayed.

[0035] The image output unit 17 is a part that outputs the formed input image data. For example, it corresponds to a printer that prints information such as input image data, and prints the input image data of the read manuscript on a predetermined printing paper (paper medium). However, the output of the input image data is not limited to printing, and also includes storage of the input image data of the scanned manuscript, FAX transmission of the input image data of the scanned manuscript, and the like. For example, storing the input image data of the read manuscript in an external storage medium such as a USB memory, transmitting the input image data to another image forming device or server via a network such as the Internet, and classifying and storing it in a specific storage folder also correspond to image output.

[0036] The internal temperature measurement unit 21a is a part that measures the temperature inside the image forming apparatus (referred to as the internal temperature), and a temperature sensor for normal temperature range is used. The temperature sensor 21a may be a conventionally used one. For example, a semiconductor temperature sensor, a thermistor, etc. can be used. Also, the temperature sensor 21a is preferably arranged near a place where condensation is likely to occur. For example, it is preferably arranged near the fixing device of the image forming apparatus. The control unit 11 periodically detects an electrical signal corresponding to the temperature output from the temperature sensor 21a, converts the detected electrical signal into a temperature, and stores it in the storage unit 40 as the current internal temperature value (measured internal temperature value 41a). Since the current internal temperature value (measured internal temperature value 41a) is used for dew condensation determination, when the power of the image forming apparatus is turned on, it is preferable that the internal temperature measurement unit 21a measures the current temperature.

[0037] The fixing temperature measurement unit 21b is a part that measures the temperature of the fixing device (referred to as the fixing temperature), and a temperature sensor for high temperature ranges is used. The temperature sensor 21b may be a conventionally used one. For example, a thermistor, etc. can be used. The control unit 11 periodically detects an electrical signal corresponding to the temperature output from the temperature sensor 21b, converts the detected electrical signal into a temperature, and stores it in the storage unit 40 as the current fixing temperature value (measured fixing temperature value 41b). The current fixing temperature value (measured fixing temperature value 41b) is used to determine the end of the preparation process for executing the printing function.

[0038] The humidity measurement unit 22 is a part that measures the humidity inside the image forming apparatus, and a humidity sensor is used. The humidity sensor 22 may be a conventionally used one. For example, a resistive sensor IC, a capacitive sensor IC, etc. can be used. Also, the humidity sensor 22 is preferably arranged near a place where condensation is likely to occur. For example, it is preferably arranged near the fixing device of the image forming apparatus. The control unit 11 periodically detects an electrical signal corresponding to the humidity output from the humidity sensor 22, converts the detected electrical signal into humidity, and stores it in the storage unit 40 as the current humidity value (measured humidity value 42). Since the current humidity value (measured humidity value 42) is also used in the dew condensation determination, it is preferable that the humidity measurement unit 22 measures the current humidity when the power of the image forming apparatus is turned on.

[0039] The power-off time measurement unit 23 is a part that measures the power-off time, which is the time during which the power of the image forming apparatus is turned off. The power-off time means the time when the power of the image forming apparatus is not turned on (power-off time), and mainly corresponds to the time when the fixing device and various motors are in a cooled state. For example, measure the period during which the main power supply of the image forming apparatus is not turned on. Alternatively, even when the main power supply is turned on, the time during which the fixing device and various motors are not energized inside the image forming apparatus may be measured.

[0040] The measurement of the power-off time is, for example, the control unit 11 stores the time when the main power supply of the image forming apparatus is turned off (OFF), and then stores the time when the main power supply of the image forming apparatus is turned on (ON), and the time from when the main power supply is turned off (OFF) to when the main power supply is turned on (ON) is stored in the storage unit 40 as the power-off time measurement value 43 described later. Since the power-off time measurement value 43 is also used in the dew condensation determination, it is preferable that the power-off time measurement unit 23 measures the power-off time when the power of the image forming apparatus is turned on.

[0041] The dew condensation determination unit 24 is a part that determines whether there is a possibility of dew condensation occurring inside the image forming apparatus by using predetermined dew condensation determination information. The dew condensation determination information is information used in the following dew condensation determination conditions, and includes, for example, the internal temperature measured by the internal temperature measurement unit 21a, the humidity measured by the humidity measurement unit 22, and the power-off time measured by the power-off time measurement unit 23. In particular, among the components arranged inside the image forming apparatus, it is determined whether dew condensation may have occurred on the photosensitive drum, the guide members of the paper conveyance path, etc.

[0042] Since dew condensation mainly occurs when the internal temperature rises rapidly, the dew condensation determination is performed when the power of the image forming apparatus is turned on. Also, it may be performed when returning from the so-called sleep state to the normal operation state.

[0043] Whether or not dew condensation may have occurred is mainly determined by the following three conditions. Dew condensation determination condition 1: The current temperature (measured internal temperature value: Ta1) measured by the internal temperature measurement unit 21a is lower than a predetermined temperature (temperature determination value: Th) (Ta1 < Th) Dew condensation determination condition 2: The current humidity (humidity measurement value: H1) measured by the humidity measurement unit 22 is higher than a predetermined humidity (humidity determination value: Hh) (H1 > Hh) Dew condensation determination condition 3: The power-off time measurement value 43 (PT) measured by the power-off time measurement unit 23 is longer than a predetermined time (power time determination value: Ph) (PT > Ph)

[0044] When all of the above three dew condensation determination conditions are satisfied, it is determined that dew condensation may have occurred. On the other hand, if there is any condition that does not satisfy even one of the above three dew condensation determination conditions, it is determined that dew condensation is not likely to have occurred. As will be described later, when dew condensation may have occurred, information indicating the presence of dew condensation possibility (for example, 1) is set in the dew condensation determination result KH. When dew condensation is not likely to have occurred, information indicating the absence of dew condensation possibility (for example, 0) is set in the dew condensation determination result KH.

[0045] The three determination values (Th, Hh, Ph) used for the dew condensation determination are stored in the storage unit 40 in advance as fixed values. These three determination values (Th, Hh, Ph) may be set to the same numerical values for all image forming apparatuses. However, since the possibility of dew condensation is considered to be different for each image forming apparatus, it is preferable to set them for each image forming apparatus in consideration of the installation environment of the image forming apparatus, the arrangement configuration of internal components, the installation region, etc. For example, the temperature determination value Th may be set in consideration of the air temperature of the installation environment and the like. The humidity determination value Hh may be set in consideration of the temperature and humidity of the installation environment and the like. The power-on time determination value Ph may be set in consideration of the natural cooling rate of the image forming apparatus and the like.

[0046] The dew condensation determination conditions are not limited to the above three conditions, and other conditions may be adopted. In the above description, when all three dew condensation determination conditions are satisfied, it is determined that there may be dew condensation. However, considering the installation location of the image forming apparatus and the like, when two of the three dew condensation determination conditions (for example, dew condensation determination condition 1 and dew condensation determination condition 2) are satisfied, it may be determined that there may be dew condensation.

[0047] The target temperature determination unit 25 is a part that determines whether the current fixing temperature (measured fixing temperature value: Tb1) measured by the fixing temperature measurement unit 21b has reached a predetermined target temperature (target temperature value: T0). When the measured fixing temperature value Tb1 becomes equal to or higher than the predetermined target temperature value T0, it is determined that the target temperature has been reached. The target temperature value T0 means the lowest temperature at which the fixing device can exhibit stable fixing performance, and is preset and stored in advance based on, for example, the printing speed, the installation region, and the like. When there is no dew condensation and the measured fixing temperature value Tb1 reaches the target temperature value T0, the preparation process of the image forming apparatus is terminated.

[0048] The preparation process is a process for enabling the normal execution of functions executable by the image forming apparatus, and is a so-called warm-up process. Since the image forming apparatus of the present invention particularly has a printing function, the preparation process means a process for executing the printing function and is also referred to as a printing preparation process. When the printing preparation process ends, in the image forming apparatus, at least the printing function can be normally executed. That is, printing with the set image quality can be performed.

[0049] The preparation standby time setting unit 26 is a part that sets a preparation standby time indicating a period for performing the preparation process. The preparation standby time (also referred to as an extension time) is calculated and set by a predetermined calculation formula as described later using the dew condensation determination information. Even when there is no dew condensation in the image forming apparatus, the printing preparation process is executed only for the period until the measured fixing temperature value Tb1 reaches the target temperature value T0 so that the developing process and the fixing process of the image forming apparatus are normally performed. When there is no dew condensation, when the measured fixing temperature value Tb1 reaches the target temperature value T0, the printing preparation process ends, and thereafter, it becomes a state where a printing job can be executed (printing job executable state).

[0050] On the other hand, when there is dew condensation, in order to remove the dew condensation, it is preferable to execute the printing preparation process (warming-up process) for a longer period. Therefore, when there is dew condensation, the period for executing the printing preparation process (warming-up process) is extended according to the degree of dew condensation. That is, when the dew condensation determination unit 24 determines that there may be dew condensation inside the image forming apparatus, the preparation standby time setting unit 26 sets the preparation standby time using the dew condensation determination information.

[0051] When there is dew condensation, even if the measured fixing temperature value Tb1 has reached the target temperature value T0, the execution period of the printing preparation process is extended. The extended execution period of the printing preparation process corresponds to the preparation standby time NT. As will be described in detail later, as the preparation standby time NT, for example, a time obtained by adding, to a predetermined extension reference time N0, corrected values obtained by converting a measured in-machine temperature (measured in-machine temperature value Ta1), a measured humidity (humidity measurement value H1), and a measured power-off time (power-off time measurement value PT) by respective predetermined correction coefficients is set.

[0052] In the case of dew condensation, in principle, after starting the printing preparation process, until the preparation standby time NT elapses, the printing preparation process is being performed, so it is in a state where the execution of a print job is not possible (print job execution impossible state), and after the preparation standby time NT elapses, it becomes a state where the execution of a print job is possible (print job execution possible state).

[0053] Also, in a case where the image forming apparatus is installed at a position where dew condensation is unlikely to occur, when it is desired to emphasize the efficiency of the printing time, the preparation standby time NT set by the preparation standby time setting unit 26 may be adjusted by subtraction in consideration of the usage time of the image forming apparatus up to the present.

[0054] The preparation process execution unit 27 is a part that performs a preparation process for enabling normal execution of functions such as printing of the image forming apparatus, and particularly performs a printing preparation process for executing the printing function. In the preparation process (warm-up process), for example, processes such as temperature adjustment processing of the fixing device, output voltage adjustment processing of the image forming unit, and motor startup of the laser unit are performed. In the temperature adjustment processing of the fixing device, a motor for rotating a fixing roller provided in the fixing device is started, and a heater provided in the fixing device is started to generate heat. When generating heat with the heater, the temperature of the air around the heater is gradually increased so that dew condensation does not occur on guide members or transport rollers in the paper transport path due to the heat of the heater.

[0055] As described above, the printing preparation process, in principle, ends when the measured fixing temperature value Tb1 reaches the target temperature value T0 in the case of no dew condensation, and ends when the preparation standby time NT elapses in the case of dew condensation.

[0056] However, as described later, even when the condition for canceling the printing preparation process is satisfied, the printing preparation process may be terminated. Details will be described later. After it is determined by the target temperature determination unit 25 that the periodically measured temperature has reached a predetermined target temperature, and before the set preparation standby time NT has elapsed, if a predetermined cancellation condition for canceling the preparation process occurs, even before the set preparation standby time NT has elapsed, the preparation process execution unit 27 cancels the preparation process.

[0057] The cancellation conditions for canceling the preparation process include, for example, a printing request for single-sided printing, a reading request for a manuscript that does not require printing, an open operation of a door attached to the image forming apparatus, and a request to shift to the sleep state. For example, when there is dew condensation, after the measured fixing temperature value Tb1 reaches the target temperature value T0, if a single-sided printing request is input during the execution of the printing preparation process, the printing preparation process is terminated.

[0058] Also, after the preparation process is canceled due to the occurrence of a cancellation condition, if a predetermined restart condition for restarting the preparation process occurs, when the dew condensation determination unit 24 performs a dew condensation determination and determines that there may be dew condensation inside the image forming apparatus, the preparation process execution unit 27 may restart the preparation process. The restart conditions for restarting the preparation process include, for example, a reading cancellation request for a manuscript, a closing operation of a door attached to the image forming apparatus, and a request to return from the sleep state to the normal operation state.

[0059] The print request confirmation unit 28 is a part that confirms that a print request for starting the printing function has been made. For example, it is confirmed whether or not a print request input operation has been performed by the user. When the operation unit 12 is provided with a dedicated print start key, the print request confirmation unit 28 checks whether or not the print start key has been input. When the print start key is input, it is determined that a print request input operation has been performed.

[0060] Also, when there are printing setting items of "single-sided printing" and "double-sided printing", the print request confirmation unit 28 confirms which of "single-sided printing" and "double-sided printing" is selected. When "single-sided printing" is selected and the print start key is input, a print job for "single-sided printing" is executed. When "double-sided printing" is selected and the print start key is input, a print job for "double-sided printing" is executed.

[0061] In the present invention, as described in the following embodiments, when the dew condensation determination unit 24 determines that there may be dew condensation inside the image forming apparatus, after the fixing temperature regularly measured by the target temperature determination unit 25 is determined to have reached a predetermined target temperature, and before the set preparation standby time elapses, when the print request confirmation unit 28 confirms that a print request for single-sided printing, which prints only on one surface of the printing paper, has been made, after the preparation process execution unit 27 aborts the preparation process, the requested single-sided printing is executed.

[0062] The print hold processing unit 29 is a part that holds the print job for which a print request has been made. During the execution of the print preparation process for dew condensation countermeasures, there may be a case where the dew condensation has not been sufficiently eliminated yet. Therefore, if a print request is input during the execution of the print preparation process and the requested print job is executed, it may not be possible to print with normal image quality. Therefore, in principle, during the execution of the print preparation process, since it may not be possible to print with normal image quality, the requested print job should not be executed.

[0063] If all the input print requests are canceled, since the burden on the user to re-operate the print request is large, in a state where the image forming apparatus should not execute printing, the requested print request job is held. In particular, when there is a print request for a double-sided printing job during the execution of the print preparation process, if the print job is immediately executed, there is a high possibility of image quality deterioration. Therefore, the print request job for double-sided printing is held.

[0064] When retaining a printed requested print job, information regarding the requested print job (print request information) is stored in the storage unit 40 as print retention information 46. Also, for example, it is preferable to display on the display unit 13 that preparations for normal printing, such as "Printing on hold" or "Dew condensation countermeasures in progress", are currently being executed, and to notify the user that it is in a standby state. When the print preparation process is completed, printing for the held print job is automatically executed.

[0065] In the present invention, in particular, as described in the following embodiments, when the dew condensation determination unit 24 determines that there is a possibility of dew condensation occurring inside the image forming apparatus, and after the target temperature determination unit 25 determines that the fixing temperature periodically measured has reached a predetermined target temperature, before the set preparation standby time elapses, if the print request confirmation unit 28 confirms that a print request for double-sided printing, which prints on both sides of the printing paper, has been made, the print retention processing unit 29 retains the print job for the requested double-sided printing. Thereafter, after the set preparation standby time has elapsed, the preparation process execution unit 27 aborts the preparation process and executes the requested double-sided printing.

[0066] Also, when the print retention processing unit 29 is retaining the print job for the requested double-sided printing and the print request confirmation unit 28 confirms that a print request for single-sided printing has been made, Before the set preparation standby time elapses, the preparation process execution unit 27 may abort the preparation process, execute the requested single-sided printing, and then execute the retained double-sided printing.

[0067] The function execution unit 30 is a part that executes the function selected by the user using the operation unit 12. This selected function is, in principle, executed based on the set values of the currently set setting items. For example, when the user inputs an operation on the print start key while the printing function is selected, based on the current setting values of the setting items related to the printing function (for example, double-sided printing, number of printed sheets, original size, black and white printing, etc.), original reading and printing processing are executed.

[0068] The storage unit 40 is a part that stores information and programs necessary for executing each function of the image processing apparatus of the present invention, and semiconductor storage elements such as ROM, RAM, and flash memory, storage devices such as HDD and SSD, and other storage media are used. In the storage unit 40, for example, the measured internal temperature value 41a, the measured fixing temperature value 41b, the measured humidity value 42, the power-off time measurement value 43, the preparation standby time 44, the print request information 45, the print hold information 46, the life priority setting information 47, the dew condensation determination condition information 48, the target temperature value 49, the extension reference time 50, the dew condensation determination result 51, etc. are stored. The dew condensation determination condition information 48 includes a temperature determination value 48a, a humidity determination value 48b, and a power time determination value 48c. FIG. 9 shows an explanatory diagram of an example of information stored in the storage unit 40 of the image forming apparatus. FIG. 9 also shows specific numerical examples of each stored information.

[0069] The measured internal temperature value 41a is the current internal temperature (Ta1) measured by the above-described internal temperature measurement unit 21a. The measured fixing temperature value 41b is the current fixing temperature (Tb1) measured by the above-described fixing temperature measurement unit 21b. The measured humidity value 42 is the current humidity (H1) measured by the above-described humidity measurement unit 22.

[0070] The power-off time measurement value 43 is the power-off time (PT) measured by the above-described power-off time measurement unit 23. The measured internal temperature value 41a (Ta1), the measured humidity value 42 (H1), and the power-off time measurement value 43 (PT) correspond to the above-described dew condensation determination information. The preparation standby time 44 is the time (NT) set by the above-described preparation standby time setting unit 26.

[0071] The print request information 45 is information regarding a print job requested by a user. For example, as shown in FIG. 9, the print request information 45 includes a print surface, the number of printed sheets, color / black-and-white distinction, original size, paper size for printing, and print file name. In the print request information 45 of FIG. 9, a print job is stored with the print file name being "FL001", the original size being "A4", the paper size for printing being "A4", the number of printed sheets being "2 sheets", and a setting for single-sided black-and-white printing.

[0072] The print hold information 46 is information regarding a print job held by the print hold processing unit 29 as described above. For example, similar to the print request information 45, the print hold information 46 includes a print surface, the number of printed sheets, color / black-and-white distinction, original size, paper size for printing, and print file name as shown in FIG. 9. In the print hold information 46 of FIG. 9, a print job is stored with the print file name being "FL200", the original size being "B5", the paper size for printing being "B5", the number of printed sheets being "4 sheets", and a setting for double-sided color printing.

[0073] The life priority setting information 47 is information for setting whether to consider the life (actual operation time) etc. of the image forming apparatus when setting the standby time NT. As shown in FIG. 9, either valid (1) or invalid (0) shall be set in the life priority setting information 47. As described above, from the viewpoint of ensuring sufficient dew condensation countermeasures, it is preferable to set the standby time NT to a relatively long time.

[0074] However, when the usage pattern of the image forming apparatus is mostly single-sided printing and double-sided printing is not performed, it is considered that the influence of dew condensation is small, so even if the standby time NT is shortened, there is almost no problem in using the image forming apparatus. Alternatively, increasing the preparation standby time NT and performing the printing preparation process for a long time will shorten the lifespan of components such as the fixing device. Therefore, there may be cases where you do not want to increase the preparation standby time NT. Furthermore, in cases where the image forming apparatus is installed in a location where condensation hardly occurs, etc., there is almost no need to consider image quality degradation due to condensation. Rather, when emphasizing improvement of component lifespan and efficiency of printing time over print image quality, the preparation standby time NT may be short.

[0075] Therefore, when prioritizing the lifespan (operating time) etc. of the image forming apparatus, the lifespan priority setting information 47 is set to valid (1). When the lifespan priority setting information 47 is set to valid (1), as will be described later, the preparation standby time NT is shortened. When the lifespan priority setting information 47 is set to valid (1), the preparation standby time NT set by the preparation standby time setting unit 26 is shortened by a predetermined time and used.

[0076] On the other hand, when wanting to fully implement countermeasures against condensation rather than the lifespan (operating time) etc. of the image forming apparatus, the lifespan priority setting information 47 is set to invalid (0). When the lifespan priority setting information 47 is set to invalid (0), the preparation standby time NT set by the preparation standby time setting unit 26 is used as it is.

[0077] The condensation determination condition information 48 is information regarding conditions for determining whether there is a possibility of condensation. When determining the possibility of condensation using the above three conditions (condensation determination conditions), the condensation determination condition information 48 includes a temperature determination value 48a, a humidity determination value 48b, and a power - on time determination value 48c.

[0078] The temperature determination value 48a (Th) is information for making a determination regarding temperature among the condensation determination conditions. In FIG. 9, for example, 10 (degrees) is set as the temperature determination value Th. As described above, when the temperature value Ta1 inside the measuring machine is lower than the temperature determination value Th, this condensation determination condition is satisfied. However, although the temperature determination value Th is set and stored in advance, it is not a fixed value. It is preferably set for each image forming apparatus in consideration of the installation environment of the image forming apparatus, the arrangement configuration of internal components, the installation area, and the like.

[0079] The humidity determination value 48b is information for making a determination regarding humidity among the condensation determination conditions. In FIG. 9, for example, 50 (%) is set as the humidity determination value Hh. As described above, when the humidity measurement value H1 is higher than the humidity determination value Hh, this condensation determination condition is satisfied. However, although the humidity determination value Th is also set and stored in advance, it is not a fixed value. It is preferably set for each image forming apparatus in consideration of the installation environment of the image forming apparatus, the arrangement configuration of internal components, the installation area, and the like.

[0080] The power-off time determination value 48c is information for making a determination regarding the power-off time among the condensation determination conditions. In FIG. 9, for example, 5 (hours) is set as the power-off time determination value Ph. As described above, when the power-off time measurement value PT is higher than the power-off time determination value Ph, this condensation determination condition is satisfied. However, although the power-off time determination value Ph is also set and stored in advance, it is not a fixed value. It is preferably set for each image forming apparatus in consideration of the installation environment of the image forming apparatus, the natural cooling rate of the image forming apparatus, and the like.

[0081] The target temperature value 49 is information for setting the fixing temperature at which the printing preparation process is terminated in principle when there is no condensation. In FIG. 9, for example, 160 (degrees) is set as the target temperature value T0. Generally, when the image forming apparatus is not in use, the power of the image forming apparatus is turned off, so the inside of the image forming apparatus is cooled and the internal temperature is relatively low. When the image forming apparatus is powered on, the printing preparation process is started for dew condensation countermeasures, and the temperature inside the image forming apparatus rises. However, when the measured fixing temperature value Tb1 reaches the target temperature value T0, the printing preparation process is terminated. The target temperature value T0 may be set and stored in advance as a fixed value, or may be set for each image forming apparatus in consideration of the installation environment of the image forming apparatus, the printing speed, the installation area, and the like.

[0082] The extension reference time 50 is information used when the preparation standby time setting unit 26 sets the preparation standby time NT, and is information serving as a reference for determining the execution time of the printing preparation process. In FIG. 9, for example, 4 (minutes) is set as the extension reference time N0. As will be described later, the preparation standby time NT is set to a time longer than the extension reference time N0 with reference to the extension reference time N0. The extension reference time N0 may be set and stored in advance as a fixed value, or may be set for each image forming apparatus in consideration of the installation environment of the image forming apparatus, the expected strength of dew condensation, and the like.

[0083] Further, as information used when setting the preparation standby time NT, the following correction coefficients are set and stored in advance. For example, as will be described later, a temperature correction coefficient KA, a humidity correction coefficient KB, and a power-off time correction coefficient KC are set and stored in advance, and are respectively used to calculate a temperature correction value Tc, a humidity correction value Hc, and a power-off time correction value Pc.

[0084] The temperature correction value Tc is a value obtained by multiplying the measured temperature inside the machine value Ta1 by the temperature correction coefficient KA (Tc = Ta1 × KA). The humidity correction value Hc is a value obtained by multiplying the humidity measurement value H1 by the humidity correction coefficient KB (Hc = H1 × KB). The power-off time correction value Pc is a value obtained by multiplying the power-off time measurement value PT by the power-off time correction coefficient KC (Pc = PT × KC). As described below, the preparation standby time NT is calculated, for example, by adding the temperature correction value Tc, the humidity correction value Hc, and the standing time correction value Pc to the extension reference time N0 (NT = N0 + Tc + Hc + Pc).

[0085] The dew condensation determination result 51 is information indicating the result of the dew condensation determination. For example, when it is determined that there is a possibility of dew condensation, 1 is set in the dew condensation determination result (KH) 51. Also, when it is determined that there is no possibility of dew condensation, 0 is set in the dew condensation determination result (KH) 51.

[0086] <Example of Dew Condensation Countermeasure Control (Printing Preparation Process)> Hereinafter, an example of a process related to the printing preparation process executed in the dew condensation countermeasure control of the present invention will be described. The dew condensation countermeasure control is executed when the power of the image forming apparatus is turned on or the like. In the present invention, when the power is turned on, mainly, for example, the following processes are executed to take dew condensation countermeasures.

[0087] <<Outline of Dew Condensation Countermeasure Method for Image Forming Apparatus>> "In-machine Temperature Measurement Step" When the power of the image forming apparatus is turned on, the in-machine temperature measurement unit 21a measures the temperature inside the image forming apparatus. "Dew Condensation Determination Step" The dew condensation determination unit 24 determines whether there is a possibility of dew condensation occurring inside the image forming apparatus by using predetermined dew condensation determination information including the measured in-machine temperature. "Preparation Standby Time Setting Step" In the dew condensation determination step, when it is determined that there is a possibility of dew condensation occurring inside the image forming apparatus, the preparation standby time setting unit 26 sets the preparation standby time NT by using the dew condensation determination information.

[0088] "Preparation Process Execution Step" The preparation process execution unit 27 starts the preparation process for executing the printing function. "Step of Starting the Measurement of the Preparation Standby Time" When the preparation process is started, the measurement of the preparation standby time NT is started. Here, the control unit 11 activates a timer for checking the elapse of the preparation standby time NT.

[0089] "Step of Measuring the Current Fixing Temperature" During the execution of the preparation process, the fixing temperature measurement unit 21b periodically measures the current fixing temperature. "Step of Judging the Target Temperature" The target temperature judging unit 25 judges whether the fixing temperature periodically measured has reached a predetermined target temperature. "Step of Canceling the Preparation Process" After it is judged that the fixing temperature periodically measured has reached the predetermined target temperature and when the measured preparation standby time NT has elapsed, the preparation process execution unit 27 cancels the preparation process.

[0090] (Example 1: Dew Condensation Countermeasure Control (Printing Preparation Process) in the Absence of Dew Condensation) FIG. 2A shows an explanatory diagram of an example of the time related to the dew condensation countermeasure control (printing preparation process) in the absence of dew condensation. Here, the dew condensation countermeasure control is started, and in the case of no dew condensation, the case where the dew condensation countermeasure control is terminated when the current measured fixing temperature value Tb1 reaches a predetermined target temperature value T0 will be described. The process executed in the dew condensation countermeasure control is also called the printing preparation process or the dew condensation countermeasure process. For example, when the power of the image forming apparatus is turned on by the user, the dew condensation countermeasure control is started. In the dew condensation countermeasure control, first, the dew condensation judging unit 24 performs a dew condensation judging process, and checks the above three dew condensation judging conditions.

[0091] In FIG. 2A, when it is judged in the check of the dew condensation judging conditions that there is no possibility of dew condensation, the printing preparation process is started. In the printing preparation process, the temperature adjustment of the fixing device is performed. For example, the heater of the fixing device is operated, and the motor for rotating the fixing roller of the fixing device is activated. The printing preparation process is performed until the temperature Tb1 measured by the fixing temperature measurement unit 21b reaches the target temperature value T0. That is, when there is no dew condensation, when the current measured fixing temperature value Tb1 reaches the target temperature value T0, the printing preparation process ends and the printing job can be executed. When the current measured fixing temperature value Tb1 reaches the target temperature value T0, it is in a state where printing processing etc. can be executed with normal image quality even if printing processing etc. is performed.

[0092] FIG. 5 shows an explanatory diagram of an example when a printing request is made after dew condensation countermeasure control (printing preparation process) in the case of no dew condensation. In the printing job executable state, as shown in FIG. 5, when an input operation of a printing request is made, printing processing is immediately started based on the printing request information 45.

[0093] Also, when the power of the image forming apparatus has already been turned on and a state where the image forming apparatus is not used has elapsed for a predetermined time or more, it enters the sleep state to save power. In the sleep state, since power is not supplied to the fixing device etc., the periphery of the fixing device etc. is cooled. In the sleep state, for example, when a key operation of the operation unit 12 of the image forming apparatus is performed, it returns from the sleep state to the normal operation state. Also in this case, as shown in FIG. 2A, the printing preparation process is started in order to enable normal execution of the printing function etc.

[0094] (Example 2: Dew condensation countermeasure control (printing preparation process) in the case of dew condensation) FIG. 2B shows an explanatory diagram of an example of the time related to dew condensation countermeasure control (printing preparation process) in the case of dew condensation. Here, the case where dew condensation countermeasure control is started and, in the case of dew condensation, even when the current measured fixing temperature value Tb1 reaches a predetermined target temperature value T0, the dew condensation countermeasure control is continued and the dew condensation countermeasure control ends when the preparation standby time NT has elapsed will be described. Similar to the above-described Example 1, for example, when the power of the image forming apparatus is turned on by the user, the dew condensation countermeasure control is started, the dew condensation determination unit 24 performs the dew condensation determination process, and the three dew condensation determination conditions are checked.

[0095] In FIG. 2B, even when it is determined that there is a possibility of dew condensation in the check of the dew condensation determination condition, the printing preparation process is started, but before that, the preparation standby time setting process is performed. In the preparation standby time setting process, the preparation standby time NT is set in consideration of the three measured values for performing the dew condensation determination. That is, the time for extending the period during which the printing preparation process is executed is set.

[0096] When the printing preparation process is started, the timer for the preparation standby time NT is started, and the printing preparation process is continued even after the current measured fixing temperature value Tb1 reaches the predetermined target temperature value T0. During the execution of the printing preparation process, the printing job cannot be executed, and during this period, even if there is a printing request for double-sided printing, the printing request is waited until the printing preparation process ends. When the timer for the preparation standby time NT times out, the printing preparation process ends and the printing job can be executed.

[0097] In the case of dew condensation, if the printing process or the like is executed after the current measured fixing temperature value Tb1 becomes equal to or higher than the target temperature value T0 and the preparation standby time NT has elapsed, it is considered that the influence of dew condensation is reduced and printing can be performed with normal image quality. Therefore, in the case of dew condensation, by executing the printing preparation process for a longer time than in the case of no dew condensation and setting the printing job executable state after the preparation standby time NT has elapsed, it is possible to prevent a decrease in printing image quality. In the printing job executable state, when a printing request is input, the printing process is immediately started.

[0098] (Example 3: When a condition for canceling the dew condensation countermeasure control (printing preparation process) occurs) FIG. 3A and FIG. 3B show an explanatory diagram of an embodiment when a condition for canceling the dew condensation countermeasure control (print preparation process) occurs. Here, the dew condensation countermeasure control is started, and when there is dew condensation, after the current measured fixing temperature value Tb1 reaches a predetermined target temperature value T0 and the dew condensation countermeasure control is continued, when a predetermined cancellation condition occurs, the case where the dew condensation countermeasure control (print preparation process) is canceled (ended) will be described.

[0099] As shown in the above-described Embodiment 2, when there is dew condensation, in principle, the print preparation process is executed until the preparation standby time NT elapses. However, even during the execution of the print preparation process, when the following cancellation conditions occur, it is preferable to cancel (end) the dew condensation countermeasure control (print preparation process).

[0100] Examples of the conditions for canceling the dew condensation countermeasure control are as follows. Cancellation Condition 1 (single-sided print request): When a single-sided print request is input Cancellation Condition 2 (original document reading request): When an original document reading request is input Cancellation Condition 3 (sleep transition request): When a request to transition to the sleep state is input Cancellation Condition 4 (panel opening operation): When the door (panel) of the image forming apparatus is opened Cancellation Condition 5 (preheating transition instruction): When an instruction to transition to the preheating state occurs Cancellation Condition 6 (exclusive SIM transition request): When a transition by the exclusive SIM is requested

[0101] When the single-sided print request of Cancellation Condition 1 (single-sided print request) is input, it is considered that the influence of dew condensation is relatively small compared to the case of double-sided printing, and it is considered that there is no need to hold the requested single-sided print until the preparation standby time NT elapses. That is, when there is dew condensation, after the current measured fixing temperature value Tb1 reaches the predetermined target temperature value T0 and before the preparation standby time NT elapses, if a single-sided print request is input, the dew condensation countermeasure control (print preparation process) is canceled and the single-sided print process is executed. As a result, single-sided printing is not postponed until the preparation standby time NT elapses, so that the execution efficiency of the single-sided printing process can be prevented from decreasing.

[0102] When a document reading request of suspension condition 2 (document reading request) is input, only the document reading function (scanning function) for a document that does not require printing is executed. In the document reading function, a light source such as an LED is lit to read the document. However, components such as the light source related to document reading of the image forming apparatus are considered to be relatively less affected by dew condensation. When there is no printing until the preparation standby time NT elapses, it is considered that there is no need to postpone the requested document reading. That is, when dew condensation is present and a document reading request is input after the current measured fixing temperature value Tb1 reaches a predetermined target temperature value T0 and before the preparation standby time NT elapses, the dew condensation countermeasure control (print preparation process) is aborted and the document reading process is executed. As a result, document reading is not postponed until the preparation standby time NT elapses, so that the execution efficiency of the document reading process can be prevented from decreasing.

[0103] When a request to shift to the sleep state of suspension condition 3 (sleep shift request) is input, power saving of the image forming apparatus is performed, and it should not be necessary to immediately execute functions such as printing, so there is no need to perform dew condensation countermeasure control (print preparation process) either. Conversely, continuing the dew condensation countermeasure control (print preparation process) to shift to the sleep state would result in performing unnecessary processing, which is not preferable. Therefore, when dew condensation is present and a request to shift to the sleep state is input after the current measured fixing temperature value Tb1 reaches a predetermined target temperature value T0 and before the preparation standby time NT elapses, the dew condensation countermeasure control (print preparation process) is aborted.

[0104] When the door (panel) of the image forming apparatus for suspension condition 4 (panel opening operation) is opened, for example, it is conceivable that the user opens the door (panel) attached to the image forming apparatus in order to perform trouble shooting operations such as replenishing printing paper and removing jammed paper. That is, when the panel is opened, since it takes time for trouble shooting operations etc., it should not be necessary to immediately execute functions such as printing, so it should not be necessary to perform dew condensation countermeasure control (print preparation process) either. Therefore, when there is dew condensation, if the panel of the image forming apparatus is opened after the current measured fixing temperature value Tb1 reaches the predetermined target temperature value T0 and before the preparation standby time NT has elapsed, the dew condensation countermeasure control (print preparation process) is aborted.

[0105] When a transition instruction to the preheating state for suspension condition 5 (preheating transition instruction) occurs, for example, the use of the image forming apparatus is stopped and only the fixing device of the image forming apparatus is preheated to transition to a state where only the minimum temperature adjustment for printing is performed. The transition instruction to the preheating state occurs, for example, when left for a preset time, when the user manually performs an execution operation, etc. That is, when transitioning to the preheating state, it should not be necessary to immediately execute functions such as printing, so it should not be necessary to perform dew condensation countermeasure control (print preparation process) either. Therefore, when there is dew condensation, if a transition instruction to the preheating state is given after the current measured fixing temperature value Tb1 reaches the predetermined target temperature value T0 and before the preparation standby time NT has elapsed, the dew condensation countermeasure control (print preparation process) is aborted and the temperature is adjusted by preheating.

[0106] When a transition by the exclusive SIM for suspension condition 6 (exclusive SIM transition request) is requested, for example, the service technician transitions to a state where maintenance of the image forming apparatus is performed. Exclusive SIM transition means changing to a special mode in which various loads can be operated by manual operation of the service technician. When the state has shifted to this state, it can be said that maintenance is in progress. Therefore, it is not necessary to immediately execute functions such as printing, and it is not necessary to perform dew condensation countermeasure control (print preparation process). Therefore, when dew condensation occurs, after the current measured fixing temperature value Tb1 reaches a predetermined target temperature value T0 and before the preparation standby time NT has elapsed, if a transition by the exclusive SIM is requested, the dew condensation countermeasure control (print preparation process) is aborted.

[0107] FIG. 3A shows an explanatory diagram of an embodiment when an abort condition other than a single-sided print request and a transition instruction to the preheating state occurs among the conditions for aborting the dew condensation countermeasure control (print preparation process). Similar to the above-described Example 2, for example, when the user turns on the power of the image forming apparatus, the dew condensation countermeasure control is started, the dew condensation determination unit 24 performs a dew condensation determination process, and three dew condensation determination conditions are checked.

[0108] Also in FIG. 3A, when it is determined in the check of the dew condensation determination condition that there is a possibility of dew condensation, the print preparation process is started, but before that, a preparation standby time setting process is performed. In the preparation standby time setting process, the preparation standby time NT is set in consideration of three measurement values for performing dew condensation determination. When the print preparation process is started, the timer for the preparation standby time NT is started, and the print preparation process is continued even after the current measured fixing temperature value Tb1 reaches a predetermined target temperature value T0.

[0109] When an abort condition occurs during the execution of the print preparation process, the print preparation process is aborted. During the execution of the print preparation process, the print job cannot be executed. However, when an abort condition other than a single-sided print request and a transition instruction to the preheating state occurs, it is preferable that the print job remains in a state where it cannot be executed thereafter.

[0110] FIG. 3B shows an explanatory diagram of an embodiment when a transition instruction to the preheating state occurs among the conditions for aborting the dew condensation countermeasure control (print preparation process). Also shown is the case where a preheating cancellation instruction is given after the preheating process is executed. Also in FIG. 3B, similar to FIG. 3A described above, the dew condensation determination unit 24 performs dew condensation determination processing (checking of three dew condensation determination conditions). If it is determined in the check of the dew condensation determination conditions that there is a possibility of dew condensation, the printing preparation process is started. Before that, a preparation standby time setting process is performed, and a preparation standby time NT is set. When the printing preparation process is started, the timer for the preparation standby time NT is started, and the printing preparation process is continued even after the current measured fixing temperature value Tb1 reaches a predetermined target temperature value T0.

[0111] During the execution of the printing preparation process, if a condition for canceling the transition instruction to the preheating state occurs, the printing preparation process is canceled, the preheating state is entered, and the preheating process is executed. During the execution of the printing preparation process and during the execution of the preheating process, the printing job execution is disabled. However, in order to end the preheating process, for example, if a preheating cancellation instruction is input by the user, after the preheating process is ended, the printing job may be made executable. If the preheating process is executed for a certain period of time or more, it can be determined that the heat has penetrated into the machine and the dew condensation has disappeared, so there is no need to resume the standby of the printing preparation process.

[0112] Therefore, after a preheating cancellation instruction is given, for example, if a double-sided printing request is input, the double-sided printing job may be executed without holding the request. The preheating cancellation instruction is performed by an input operation by the user. In addition, in other cases such as receiving a print instruction or detecting the approach of a person, the preheating cancellation instruction may be automatically input. Note that, as will be described later, when a condition for canceling the single-sided printing request occurs, the printing preparation process is also canceled, but the single-sided printing job can be executed.

[0113] (Example 4: When a condition for resuming the dew condensation countermeasure control (printing preparation process) occurs) Fig. 4 shows an explanatory diagram of an embodiment when a condition for restarting the dew condensation countermeasure control (print preparation process) occurs. Here, the dew condensation countermeasure control is started. When there is dew condensation, after the current measured fixing temperature value Tb1 reaches a predetermined target temperature value T0 and the dew condensation countermeasure control continues, when a predetermined stop condition occurs and then a predetermined restart condition occurs, the case will be described.

[0114] As described above, when a predetermined stop condition occurs, the dew condensation countermeasure control (print preparation process) is stopped (ended). However, when the following restart conditions occur, the dew condensation determination unit 24 performs dew condensation determination processing (checking of three dew condensation determination conditions). When it is determined that there is a possibility of dew condensation, the dew condensation countermeasure control (print preparation process) is restarted. Among the stop conditions, when an instruction to shift to the preheating state is given, the dew condensation countermeasure control (print preparation process) is stopped (ended). However, as described above, when an instruction to cancel the preheating state is given, the dew condensation countermeasure control (print preparation process) is not restarted.

[0115] As conditions for restarting the dew condensation countermeasure control, for example, there are the following conditions. Restart condition 1 (document reading cancellation request): When a document reading cancellation request is input Restart condition 2 (sleep return request): When a request to return from the sleep state to the normal operation state is input Restart condition 3 (panel closing operation): When the panel of the image forming apparatus is closed Restart condition 4 (exclusive SIM return request): When a return by the exclusive SIM is requested

[0116] When the document reading cancellation request of restart condition 1 (document reading cancellation request) is input, the execution of the document reading function (scan function) for a document that does not require printing is ended. After ending the execution of the document reading function (scan function), in order to confirm whether a print job can be executed, dew condensation determination processing is performed. When it is determined that there is a possibility of dew condensation, the dew condensation countermeasure control (print preparation process) is restarted. If it is determined that there is no possibility of condensation, the print job can be executed without executing condensation countermeasure control (print preparation process).

[0117] When a request to return from the sleep state to the normal operating state is input as in Resume Condition 2 (sleep return request), a condensation determination process is performed before returning to the normal operating state, and if it is determined that there is a possibility of condensation, condensation prevention control (print preparation process) is resumed. If it is determined that there is no possibility of condensation, the print job can be executed without executing condensation countermeasure control (print preparation process).

[0118] When the panel of the image forming apparatus is closed in accordance with restart condition 3 (panel closing operation), it is possible that the user has finished replenishing printing paper or has finished troubleshooting, for example. Therefore, in order to check whether it is acceptable to return to the normal operating state, a condensation determination process is performed, and if it is determined that there is a possibility of condensation, condensation countermeasure control (print preparation process) is resumed. If it is determined that there is no possibility of condensation, the print job can be executed without executing condensation countermeasure control (print preparation process).

[0119] When a request to return from a transition due to an exclusive SIM in the restart condition 4 (exclusive SIM return request) is made, for example, a process such as an automatic reboot of the control system or a restart of the print preparation process is executed. When this process is executed, a condensation determination process is performed to check whether it is okay to return to the normal operating state, and if it is determined that there is a possibility of condensation, condensation prevention control (print preparation process) is resumed. If it is determined that there is no possibility of condensation, the print job can be executed without executing condensation countermeasure control (print preparation process).

[0120] In FIG. 4, when it is determined that there is a possibility of condensation and condensation countermeasure control (print preparation process) is being executed, if a condition for stopping the condensation countermeasure control (print preparation process) occurs, the print preparation process is stopped. After that, when the resumption conditions as described above occur, in order to confirm whether it is possible to return to the normal operating state, a dew condensation determination process is performed to check whether there is a possibility of dew condensation. In the check of the dew condensation determination conditions, if it is determined that there is a possibility of dew condensation, the printing preparation process is resumed, but before that, a preparation standby time setting process is performed. In the preparation standby time setting process, considering the three measured values for dew condensation determination, the preparation standby time NT is set, and then the timer for the preparation standby time NT is started, and the printing preparation process is started. Even after the printing preparation process is resumed, in principle, the printing job execution is still in an unavailable state until the timer for the preparation standby time NT times out and the printing preparation process ends.

[0121] (Example 5: When there is dew condensation and a single-sided printing request is made) FIG. 6 shows an explanatory diagram of an example when a single-sided printing request is made while performing dew condensation countermeasure control (printing preparation process) in the case of dew condensation. Here, among the above-described suspension conditions, it corresponds to the case where a single-sided printing request is input. If it is determined that there may be dew condensation and during the execution of the dew condensation countermeasure control (printing preparation process), when the current measured fixing temperature value Tb1 is equal to or higher than the target temperature value T0 and a single-sided printing request is input before the preparation standby time NT has elapsed, the dew condensation countermeasure control (printing preparation process) is aborted and single-sided printing is started.

[0122] In FIG. 6, similar to the above-described Example 2, for example, when the power of the image forming apparatus is turned on by the user, the dew condensation countermeasure control is started, the dew condensation determination process is performed by the dew condensation determination unit 24, and the check of the three dew condensation determination conditions is performed. Also in FIG. 6, in the check of the dew condensation determination conditions, if it is determined that there is a possibility of dew condensation, the printing preparation process is started, but before that, a preparation standby time setting process is performed. In the preparation standby time setting process, considering the three measured values for dew condensation determination, the preparation standby time NT is set.

[0123] When the printing preparation process is started, the timer for the preparation standby time NT is activated, and the printing preparation process is continued even after the current measured fixing temperature value Tb1 reaches the predetermined target temperature value T0. During the execution of the printing preparation process, in principle, the printing job cannot be executed. However, if a single-sided printing request is input during the period before the preparation standby time NT elapses, the printing preparation process is aborted and the single-sided printing process is started without waiting for the preparation standby time NT to elapse. That is, when a single-sided printing request is input, the printing job can be executed. This is because, after the current measured fixing temperature value Tb1 reaches the predetermined target temperature value T0, even if the single-sided printing process is executed, condensation is less likely to have an adverse effect on the print quality of the image to be single-sided printed.

[0124] Therefore, if a single-sided printing request is input after the current measured fixing temperature value Tb1 reaches the predetermined target temperature value T0 and before the preparation standby time NT elapses, the printing preparation process is forcibly aborted and the single-sided printing process is started. As a result, with respect to the single-sided printing process, it is not necessary to wait until the preparation standby time NT elapses, and the single-sided printing can be efficiently executed.

[0125] (Example 6: When a double-sided printing request is made in the presence of condensation) Fig. 7 shows an explanatory diagram of an example when a double-sided printing request is made while performing condensation countermeasure control (printing preparation process) in the presence of condensation. Here, the processing when a double-sided printing request is input before the preparation standby time NT elapses is shown. When it is determined that there may be condensation and a double-sided printing request is input during the execution of the condensation countermeasure control (printing preparation process), while the current measured fixing temperature value Tb1 is equal to or higher than the target temperature value T0 and before the preparation standby time NT elapses, the double-sided printing request is put on hold. When the preparation standby time NT elapses, the condensation countermeasure control (printing preparation process) is terminated and double-sided printing is started.

[0126] As described above, when performing double-sided printing, after printing on one side (front side) of the printing paper, the printing paper is guided to the reversing path. However, if dew condensation has occurred, during conveyance to the reversing path, the printing paper absorbs water, and image quality degradation may occur when printing on the other side (back side) of the printing paper. Therefore, in order to sufficiently eliminate dew condensation and prevent image quality degradation in double-sided printing, the time for performing dew condensation countermeasure control (print preparation processing) is extended, and after the preparation standby time NT has elapsed, double-sided printing is started.

[0127] In FIG. 7, similar to the above-described second embodiment, for example, when the power of the image forming apparatus is turned on by the user, dew condensation countermeasure control is started, and a dew condensation determination process is performed by the dew condensation determination unit 24, and three dew condensation determination conditions are checked. Also in FIG. 7, if it is determined in the check of the dew condensation determination condition that there is a possibility of dew condensation, the print preparation process is started, but before that, a preparation standby time setting process is performed. In the preparation standby time setting process, the preparation standby time NT is set in consideration of the three measurement values for performing dew condensation determination.

[0128] When the print preparation process is started, the timer for the preparation standby time NT is started, and the print preparation process is continued even after the current measured fixing temperature value Tb1 reaches the predetermined target temperature value T0. During the execution of the print preparation process, in principle, the print job cannot be executed. Therefore, if a double-sided print request is input during the period before the preparation standby time NT has elapsed, the double-sided print request is put on hold until the preparation standby time NT has elapsed. Here, the print request information 45 regarding the double-sided print request is stored as print hold information 46.

[0129] Therefore, until the preparation standby time NT has elapsed, the print preparation process is executed. When the preparation standby time NT has elapsed, the print preparation process is terminated, and then the held double-sided print process is started. Thus, when it is determined that there may be dew condensation, the period for executing the printing preparation process is extended, and the printing preparation process is performed until the extended preparation standby time NT elapses. After sufficiently eliminating the dew condensation, the duplex printing process is started, so that it is possible to prevent the occurrence of image quality degradation in duplex printing.

[0130] (Example 7: When there is dew condensation and a single-sided printing request and a duplex printing request are made) FIG. 8 shows an explanatory diagram of an embodiment when a single-sided printing request and a duplex printing request are made while performing dew condensation countermeasure control (printing preparation process) in the case of dew condensation. Here, the processing when printing requests for single-sided printing and duplex printing are continuously input before the preparation standby time NT elapses is shown.

[0131] As described above, when there is a single-sided printing request before the preparation standby time NT elapses, the single-sided printing is executed without holding the single-sided printing request. When performing single-sided printing, since a certain amount of time is required for the single-sided printing process, after the execution of the single-sided printing process, the preparation standby time NT may have elapsed. Also, when performing single-sided printing, the temperature around the fixing device or the photosensitive member may rise due to the single-sided printing process, and dew condensation may be eliminated before the preparation standby time NT elapses.

[0132] Therefore, when there is a single-sided printing request during the dew condensation countermeasure control (printing preparation process) and then a duplex printing request continuously follows, even before the preparation standby time NT elapses after the single-sided printing process is completed, the duplex printing is executed.

[0133] In FIG. 8, until a single-sided printing request is input, the same processing as in FIG. 6 is performed. That is, in FIG. 8, for example, when the power of the image forming apparatus is turned on by the user, the dew condensation countermeasure control is started, the dew condensation determination unit 24 performs a dew condensation determination process, and checks for three dew condensation determination conditions are performed. Also in FIG. 8, when it is determined that there is a possibility of condensation in the check of the condensation determination condition, the printing preparation process is started. Before that, the preparation standby time setting process is performed. In the preparation standby time setting process, the preparation standby time NT is set in consideration of three measured values for condensation determination.

[0134] When the printing preparation process is started, the timer for the preparation standby time NT is activated, and the printing preparation process is continued even after the current measured fixing temperature value Tb1 reaches a predetermined target temperature value T0. During the execution of the printing preparation process, in principle, the printing job cannot be executed. However, if a single-sided printing request is input during the period before the preparation standby time NT elapses, the printing preparation process is aborted and the single-sided printing process is started even if the preparation standby time NT has not elapsed.

[0135] After that, when a certain time has elapsed since the start of the single-sided printing process, the single-sided printing process ends. As shown in FIG. 8, when a double-sided printing request is input after the single-sided printing process ends and before the preparation standby time NT elapses, since the current measured fixing temperature value Tb1 has reached the predetermined target temperature value T0 and the single-sided printing process is being executed, the double-sided printing process is started. Also, if a double-sided printing request is input before the single-sided printing process ends and before the preparation standby time NT elapses, the double-sided printing request is put on hold until the single-sided printing process ends. However, after the single-sided printing process ends, the double-sided printing process is started.

[0136] Thereby, even when there is a possibility of condensation occurring, if single-sided printing and double-sided printing requests are continuously input in this order, the double-sided printing process can be started earlier before the preparation standby time NT elapses, and it is possible to prevent a decrease in the image quality of double-sided printing caused by condensation.

[0137] <Flowchart of Condensation Countermeasure Control (Printing Preparation Process)> (Main Flowchart of Condensation Countermeasure Control) FIGS. 10 and 11 show the main flowchart of an embodiment of condensation countermeasure control. In this main flowchart, the occurrence of the above-mentioned stop conditions is not considered. When the user turns on the power of the image forming apparatus or when it returns from the sleep state to the normal operation state, this dew condensation countermeasure control is started.

[0138] In step S1 of FIG. 10, dew condensation determination information is acquired. Here, the in-machine temperature measurement unit 21a acquires the measured in-machine temperature value Ta1, the humidity measurement unit 22 acquires the humidity measurement value H1, and the power-off time measurement unit 23 acquires the power-off time measurement value PT.

[0139] In step S2, the dew condensation determination unit 24 performs a dew condensation determination process. In the dew condensation determination process, using the measured in-machine temperature value Ta1, the humidity measurement value H1, the power-off time measurement value PT, and the dew condensation determination condition information 48 (Th, Hh, Ph), it is determined whether there is a possibility of dew condensation. If it is determined that there is a possibility of dew condensation, 1 is set in the dew condensation determination result (KH) 51, and if there is no possibility of dew condensation, 0 is set in the dew condensation determination result (KH) 51. The detailed flowchart of the dew condensation determination process in step S2 is shown in FIG. 12 described later.

[0140] In step S3, if the dew condensation determination result is "there is a possibility of dew condensation (KH = 1)", the process proceeds to step S7, and if "there is no possibility of dew condensation (KH = 0)", the process proceeds to step S4. In step S4, since there is no possibility of dew condensation, the printing preparation process is started without setting the preparation standby time. As described above, the printing preparation process is a preparation process for heating the heater and raising the temperature of the components of the image forming apparatus so that the functions of the image forming apparatus can be normally executed without dew condensation occurring. If the printing preparation process has already been started, the printing preparation process is continued as it is.

[0141] In step S5, the fixing temperature measurement unit 21b acquires the current fixing temperature (measured fixing temperature value Tb1). In step S6, it is checked whether the current fixing temperature (measured fixing temperature value Tb1) has reached the target temperature value T0. If it has not reached (Tb1 < T0), the process returns to step S4 to continue the printing preparation process. On the other hand, when the current fixing temperature (measured fixing temperature value Tb1) has reached the target temperature value T0 (Tb1 ≥ T0), the process proceeds to step S12, the printing preparation process ends, and this flowchart ends.

[0142] In step S7, the preparation standby time setting unit 26 performs a preparation standby time setting process. In the preparation standby time setting process, for example, using the measured in-machine temperature value Ta1, the humidity measurement value H1, the power-off time measurement value PT, the extension reference time N0, and their correction values (KA, KB, KC), the preparation standby time NT is set. The detailed flowchart of the preparation standby time setting process in step S7 is shown in FIG. 13 described later. However, when considering the life of the image forming apparatus, instead of FIG. 13, the flowchart of FIG. 14 described later may be used.

[0143] In step S8, a timer that counts the elapse of the set preparation standby time NT is started. Unless the above-described stop condition occurs, the printing preparation process continues until the preparation standby time NT elapses.

[0144] In step S9, similar to step S4, the printing preparation process is started. If the printing preparation process has already been started, the printing preparation process is continued while keeping the above timer started. In step S10, similar to step S5, the fixing temperature measurement unit 21b acquires the current fixing temperature (measured fixing temperature value Tb1).

[0145] In step S11, similar to step S6, it is checked whether the current fixing temperature (measured fixing temperature value Tb1) has reached the target temperature value T0. If it has not reached (Tb1 < T0), the process returns to step S9 and the printing preparation process is continued. On the other hand, if the current fixing temperature (measured fixing temperature value Tb1) has reached the target temperature value T0 (Tb1 ≥ T0), the process proceeds to step S21 in FIG. 11.

[0146] In step S21 in FIG. 11, the count timer of the preparation standby time NT is checked. If the timer has expired, that is, if the preparation standby time NT has elapsed since the start of the printing preparation process, the process proceeds to step S33; otherwise, the process proceeds to step S22.

[0147] In step S22, the print request confirmation unit 28 checks whether there is a print request. Here, for example, in the image forming apparatus, it is checked whether an input operation meaning a print request has been performed. If there is a print request, information such as the number of printed sheets set before making the print request is stored as print request information 45. In step S23, if there is a print request, the process proceeds to step S24; otherwise, the process returns to step S21.

[0148] In step S24, if there is a print request, the setting content of the print request is confirmed. If the setting of the print surface is "double-sided printing", the process proceeds to step S25; if the setting of the print surface is "single-sided printing", the process proceeds to step S27.

[0149] In step S25, since the preparation standby time NT has not elapsed, a print hold process is performed. Here, the setting content stored in the print request information 45 is stored as print hold information 46. The print job to be held is a job with "double-sided printing" set, and a job with "single-sided printing" set is not held.

[0150] In step S26, notify the user who made the printing request on the image forming apparatus that the double-sided printing job requested for printing is currently on hold. For example, display messages such as "Performing dew condensation countermeasures", "Printing on hold due to dew condensation countermeasures", "Preparing for printing, printing will start automatically when ready" on the display unit 13 to notify the user that the printing job is currently on hold. After step S26, return to step S21.

[0151] If the requested job is "single-sided printing", since the printing process is performed without waiting for the preparation standby time NT to elapse, in step S27, reset the preparation standby time NT (NT = 0) and stop the timer.

[0152] In step S28, check the print hold information 46 and confirm whether there is a printed job on hold. In step S29, if there is a print job in the print hold information 46, proceed to step S30; otherwise, proceed to step S31.

[0153] In step S30, change the printing order to prioritize "single-sided printing". That is, change the printing order so that the "single-sided printing" job is printed first, and after the "single-sided printing" job is printed, the "double-sided printing" job on hold is printed.

[0154] If there is a print job in the print hold information 46, since the job on hold is "double-sided printing", printing the "double-sided printing" job that was on hold without the preparation standby time NT having elapsed may result in poor print quality. Therefore, when the preparation standby time NT has not elapsed, it is preferable to first print the "single-sided printing" job, which is considered less likely to be affected by dew condensation, and after "single-sided printing" is completed, print the "double-sided printing" job that was on hold. By printing the job of "double-sided printing" after the job of "single-sided printing", it is possible to prevent the print quality from deteriorating in the printing of the job of "double-sided printing" that has been held over.

[0155] Also, when multiple "double-sided printing" print jobs are held in the print hold information 46, the print order is changed so that the "single-sided printing" print job is printed first, and after the printing of the "single-sided printing" print job is completed, the printing of the multiple "double-sided printing" print jobs that are held is performed. After step S30, proceed to step S31.

[0156] In step S31, the print preparation process is aborted. In step S32, the printing process is started. Here, if there is no held "double-sided printing" print job, only the "single-sided printing" print job is printed. If there is a held "double-sided printing" print job, the "single-sided printing" print job is printed, and after the printing of the "single-sided printing" print job is completed, the "double-sided printing" print job is printed. After all the print jobs requested for printing are completed in step S32, this flowchart ends.

[0157] If the preparation standby time NT has elapsed, since the dew condensation countermeasures are sufficient, it is considered that no image quality degradation will occur regardless of whether "single-sided printing" or "double-sided printing" is executed. That is, after the preparation standby time NT has elapsed, it is in a state where "double-sided printing" can be executed. In step S33, similar to step S28, the print hold information 46 is checked to confirm whether there is a held print job. In step S34, if there is a print job in the print hold information 46, proceed to step S35; otherwise, end this flowchart.

[0158] In step S35, similar to step S31, the print preparation process is aborted. In step S36, start the printing process for the held "duplex printing" print job. After all the print jobs of "duplex printing" that are held are printed in step S36, end this flowchart.

[0159] (Flowchart of dew condensation determination process: Step S2) Fig. 12 shows a flowchart of an embodiment of the dew condensation determination process. The dew condensation determination process is the process executed in step S2 of Fig. 10 described above. In step S51 of Fig. 12, obtain the dew condensation determination condition information 48 from the storage unit 40. That is, read out the temperature determination value Th, the humidity determination value Hh, and the power-off time determination value Ph that are stored in advance in the storage unit 40.

[0160] In step S52, check the dew condensation determination conditions. Here, in order to check whether it is a state in which dew condensation may have occurred, compare the already obtained measured internal temperature value Ta1, humidity measurement value H1, and power-off time measurement value PT with the corresponding dew condensation determination condition information 48, respectively. That is, check whether the conditions of Ta1 < Th, H1 > Hh, and PT > Ph are satisfied.

[0161] In step S53, if Ta1 < Th, proceed to step S54; otherwise, proceed to step S57. In step S54, if H1 > Hh, proceed to step S55; otherwise, proceed to step S57. In step S55, if PT > Ph, proceed to step S56; otherwise, proceed to step S57.

[0162] From the above, if all three conditions of Ta1 < Th, H1 > Hh, and PT > Ph are satisfied, it is determined that dew condensation may have occurred, and proceed to step S56. Also, if none of these three conditions are met, it is determined that there is no possibility of condensation occurring, and the process proceeds to step S57.

[0163] In step S56, if it is determined that there is a possibility of condensation occurring, information indicating "possibility of condensation" is set in the condensation determination result KH (KH = 1). In step S57, if it is determined that there is no possibility of condensation occurring, information indicating "no possibility of condensation" is set in the condensation determination result KH (KH = 0). After steps S56 and S57, the process ends, returns to FIG. 10, and proceeds to step S3.

[0164] (Flowchart of preparation standby time setting process: step S7) FIG. 13 shows a flowchart of an embodiment of the preparation standby time setting process. When setting the preparation standby time NT without considering the life of the image forming apparatus, the flowchart of FIG. 13 is used. The preparation standby time setting process is the process executed in step S7 of FIG. 10 described above.

[0165] In step S71 of FIG. 13, information used to set the preparation standby time NT is read from the storage unit 40. As described above, as information used to set the preparation standby time NT, an extension reference time N0 and correction coefficients (temperature correction coefficient KA, humidity correction coefficient KB, power-off time correction coefficient KC) are stored in advance, so these information are read from the storage unit 40. Each correction coefficient is a coefficient that converts the corresponding measured value (Ta1, H1, PT) into a numerical value corresponding to time.

[0166] In step S72, in the same manner as step S1 of FIG. 10, condensation determination information is acquired. That is, the in-machine temperature measurement unit 21a acquires the in-machine temperature value Ta1, the humidity measurement unit 22 acquires the humidity measurement value H1, and the power-off time measurement unit 23 acquires the power-off time measurement value PT.

[0167] In step S73, the temperature correction value Tc is calculated by Tc = Ta1 × KA using the in-measuring instrument temperature value Ta1 and the temperature correction coefficient KA. In step S74, the humidity correction value Hc is calculated by Hc = H1 × KB using the humidity measurement value H1 and the humidity correction coefficient KB. In step S75, the standby time correction value Pc is calculated by Pc = PT × KC using the power-off standby time measurement value PT and the power-off standby time correction coefficient KC.

[0168] In step S76, the preparation standby time NT is calculated by NT = NO + Tc + Hc + Pc using the extension reference time N0 and the above three correction values (Tc, Hc, Pc). After step S76, the process ends, returns to FIG. 10, and proceeds to step S8.

[0169] (Flowchart of preparation standby time setting process considering lifespan: Step S7) FIG. 14 shows a flowchart of an embodiment of the preparation standby time setting process considering the lifespan of the image forming apparatus. When setting the preparation standby time considering the lifespan of the image forming apparatus, the flowchart of FIG. 14 is used in step S7 of FIG. 10 described above.

[0170] Also, when the lifespan priority setting information 47 is set to "valid (1)", the preparation standby time NT is adjusted by subtraction considering the lifespan of the image forming apparatus. The adjustment time X for subtraction adjustment described later may be set by multiplying the usage time MT of the image forming apparatus up to the present by a predetermined coefficient K (X = MT × K), or may be set and stored fixedly in advance.

[0171] In the steps of FIG. 14, the same step numbers are assigned to those performing the same processing as the steps of FIG. 13. In FIG. 14, from step S71 to step S76, the same processing as in FIG. 13 is executed. That is, using the dew condensation determination information (Ta1, H1, PT) and correction coefficients (KA, KB, KC), three corrected values (Tc, Hc, Pc) are calculated, and the extended reference time N0 and the three corrected values (Tc, Hc, Pc) are added together to calculate the preparation standby time NT.

[0172] In step S77, the lifetime priority setting information 47 is read from the storage unit 40. In step S78, if the setting content of the lifetime priority setting information 47 is "valid (1)", the process proceeds to step S79. On the other hand, if the setting content of the lifetime priority setting information 47 is "invalid (0)", the process ends, returns to FIG. 10, and proceeds to step S8.

[0173] In step S79, the preparation standby time NT is adjusted by subtraction using a predetermined adjustment time X. For example, the usage time MT of the image forming apparatus up to the present is obtained, and a value obtained by multiplying this usage time MT by a predetermined coefficient K is set as the adjustment time X (X = MT × K). The usage time MT of the image forming apparatus up to the present is the actual operating time (actual working time) of the image forming apparatus. For example, after the image forming apparatus is initially installed, the time T during which the power is constantly turned on is measured, and it corresponds to a value obtained by adding this time T up to the present. The preparation standby time NT is calculated using the extended reference time N0 and the adjustment time X, NT = N0 - X. In this case, the preparation standby time NT is shortened by the amount of the adjustment time X. After step S79, the process ends, returns to FIG. 10, and proceeds to step S8.

Explanation of Reference Numerals

[0174] 1 Image forming apparatus (MFP), 11 Control unit, 12 Operation unit, 13 Display unit, 14 Image processing unit, 15 Image input unit, 16 Image forming unit, 17 Image output unit, 21 Temperature measurement unit, 21a Internal temperature measurement unit, 21b Fixing temperature measurement unit, 22 Humidity measurement unit, 23 Power-off time measurement unit, 24 Dew condensation determination unit, 25 Target temperature determination unit, 26 Preparation standby time setting unit, 27 Preparation process execution unit, 28 Printing requirement confirmation unit, 29 Printing hold processing unit, 30 Function execution unit, 40 Memory unit, 41a Measured internal temperature value, 41b Measured fixing temperature value, 42 Measured humidity value, 43 Measured power-off time value, 44 Preparation standby time, 45 Printing requirement information, 46 Printing hold information, 47 Life priority setting information, 48 Dew condensation determination condition information, 48a Temperature determination value, 48b Humidity determination value, 48c Power time determination value, 49 Target temperature value, 50 Extension reference time, 51 Dew condensation determination result

Claims

1. An internal temperature measuring unit for measuring an internal temperature of an apparatus; A humidity measuring unit that measures the humidity inside the aircraft; a power-on standby time measurement unit for measuring a power-on standby time, which is a time during which the power supply is turned off; a storage unit that stores condensation determination condition information including a predetermined temperature determination value, a humidity determination value, and a power supply time determination value; a condensation determination unit that determines whether or not condensation may have occurred inside the apparatus by using predetermined condensation determination information including the measured internal temperature, the measured humidity, and the measured power-on standby time; and a fixing temperature measuring unit for measuring a fixing temperature of a fixing device; a target temperature determination unit that determines whether the measured fixing temperature has reached a predetermined target temperature; a print request confirmation unit that confirms that a print request has been made to start a print function; a preparation processing execution unit that performs preparation processing for executing the printing function; a preparation standby time setting unit that sets a preparation standby time indicating a period during which the preparation process is performed, When the power is turned on, The condensation determination unit, The measured internal temperature is smaller than the temperature judgment value, The measured humidity is greater than the humidity judgment value, and When the measured power-on left-on time is greater than the power-on time judgment value, It is determined that condensation may have occurred, When the condensation determination unit determines that there is a possibility that condensation has occurred inside the apparatus, the preparation standby time setting unit sets the preparation standby time by using the condensation determination information; the preparation process execution unit starts the preparation process, the preparation process execution unit stops the preparation process when the measured fixing temperature has reached a predetermined target temperature after the preparation standby time has started to be measured when the preparation process is started and the measured preparation standby time has elapsed; If the print request confirmation unit confirms that a print request for single-sided printing has been made before the set preparation waiting time has elapsed, the single-sided printing of the print request is executed if the temperature is equal to or higher than the target temperature even if the preparation waiting time has not elapsed, The preparation waiting time setting unit, an image forming apparatus characterized in that the preparation standby time is set to a predetermined extended reference time plus correction values ​​obtained by converting the measured internal temperature, the measured humidity, and the measured power-on left-on time using predetermined correction coefficients.

2. a print request confirmation unit that confirms that a print request for starting the printing function has been made; further comprising a print hold processing unit that holds a print job for which a printing requirement has been made, when the dew condensation determination unit determines that there is a possibility of dew condensation occurring inside the machine, after the fixing temperature measured by the target temperature determination unit is determined to have reached a predetermined target temperature and before the set preparation standby time has elapsed, if the print request confirmation unit confirms that a print request for double-sided printing, which prints on both sides of the printing paper, has been made, the print hold processing unit holds the print job for the double-sided printing requested for printing, after the set preparation standby time has elapsed, the preparation process execution unit aborts the preparation process and executes the requested double-sided printing. The image forming apparatus according to claim 1, characterized in that.

3. when the print hold processing unit is holding the print job for the double-sided printing requested for printing and the print request confirmation unit confirms that a print request for single-sided printing has been made, before the set preparation standby time has elapsed, the preparation process execution unit aborts the preparation process, executes the requested single-sided printing, and then executes the held double-sided printing. The image forming apparatus according to claim 2, characterized in that.

4. The image forming apparatus according to any one of claims 1 to 3, characterized in that the preparation standby time set by the preparation standby time setting unit is adjusted by subtraction in consideration of the usage time up to the present.

5. an internal temperature measurement unit that measures the internal temperature of the machine, a dew condensation determination unit that determines whether there is a possibility of dew condensation occurring inside the machine by using predetermined dew condensation determination information including the measured internal temperature, a fixing temperature measurement unit that measures the fixing temperature of the fixing device, a target temperature determination unit that determines whether the measured fixing temperature has reached a predetermined target temperature, a preparation process execution unit that performs a preparation process for executing a printing function, comprising a preparation standby time setting unit that sets a preparation standby time indicating a period for performing the preparation process, when the power is turned on, when the dew condensation determination unit determines that there is a possibility of dew condensation occurring inside the machine, the preparation standby time setting unit uses the dew condensation determination information to set the preparation standby time, the preparation process execution unit starts the preparation process, After starting the measurement of the preparation standby time when the preparation process is started, after it is determined that the measured fixing temperature has reached a predetermined target temperature, and when the measured preparation standby time has elapsed, the preparation process execution unit stops the preparation process. The stop conditions for stopping the preparation process include a printing request for single-sided printing, a reading request for a document that does not require printing, an operation to open a door attached to the image forming apparatus, and a request to shift to a sleep state. When a predetermined restart condition for restarting the preparation process occurs after the preparation process is stopped due to the occurrence of the stop condition. The dew condensation determination unit determines whether there is a possibility that dew condensation has occurred. When it is determined that there is a possibility that dew condensation has occurred, the preparation process execution unit restarts the preparation process. An image forming apparatus characterized by this.

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