JP2010181445A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus in which a dehumidication measure is applied, and a heating time for heating the inside of the appartus by a heater is finely controlled according of a degree of a change of an atmosphere in which the apparatus is installed. <P>SOLUTION: The image forming apparatus includes the heater 13, a setting receiving means 19, and a control means 10. In the setting receiving means 19, a reference heating time is set in advance as a heating time to be set, the reference heating time used to indicate a time required for decreasing a humidity value to a first humidity value at which condensation is prevented from occurring in the apparatus from a second humidity value under a reference environmental condition used as a reference for the environmental condition at which the apparatus is installed. The control means 10 sets heating times in the setting receiving means 19 as heating times to be set. That is, the heating times are decreased sequentially from the reference heating time as the time required for the humidity value of air in the apparatus to increase from the first humidity value to the second humidity value under the currently set environmental condition, exceeds a reference time required for the humidity value of air in the apparatus to increase from the first humidity value to the second humidity value under the reference environmental condition. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus that dehumidifies the inside of the apparatus by periodically heating the inside of the apparatus with a heater in order to prevent dew condensation from occurring inside the apparatus.

  2. Description of the Related Art Conventionally, in image forming apparatuses such as multifunction peripherals, facsimile machines, and copiers, measures have been taken to prevent condensation within the image forming apparatus.

  Japanese Patent Application Laid-Open No. 2004-228561 exemplifies an image forming apparatus in which this kind of countermeasure is taken. In this type of image forming apparatus, condensation is prevented from occurring at least in an image reading system for reading an image, an image forming system for forming an image, a paper feeding system for feeding a document, and a transport system for transporting a document. Therefore, the following measures are taken.

  That is, in this type of image forming apparatus, the heaters heat each of the systems in the energy saving mode in which the power supply level supplied to each of the systems is suppressed or stopped. In addition, when the power supply level supplied to each of the systems is changed from the energy saving mode to the normal mode in which the power supply level returns to the original level, the temperature of the machine installation environment at that time may be equal to or lower than a preset threshold value. For example, the heater heats each of the systems for a time corresponding to the temperature of the machine installation environment.

JP 2006-44221 A

  By the way, in this type of image forming apparatus, in the energy saving mode, the time during which the heater heats each of the systems does not correspond to the temperature of the machine installation environment. As a result, power consumption can be wasted.

  In addition, the time for which the heater heats each of the systems corresponds to the temperature of the machine installation environment at a certain point in time indicating the transition from the energy saving mode to the normal mode. Therefore, the time during which the heater heats each of the systems does not change in accordance with the degree of change represented by the rate of increase or decrease in the temperature of the machine installation environment. Therefore, the time for the heater to heat each of the systems is constant regardless of the degree of change in the temperature of the machine installation environment. Accordingly, power is wasted.

  In this way, in this type of image forming apparatus, the time for which the heater heats each of the systems does not change finely according to the degree of change in the environment in which the apparatus is installed, resulting in wasted power consumption. . Therefore, it is desired to control the heater so that the time for heating each of the systems changes finely according to the degree of change in the environment in which the apparatus is installed.

  The present invention has been made in order to solve the above-described problem, and is an image forming apparatus in which measures against dehumidification are taken, and a heater heats the inside of the apparatus in accordance with the degree of change in the environment in which the apparatus is installed. It is an object of the present invention to provide an image forming apparatus in which the heating time for performing the control is finely controlled.

  An image forming apparatus according to one aspect of the present invention is configured to receive a setting for a heater for heating air inside the apparatus and a setting heating time representing a heating time for heating the air inside the apparatus by the heater. Each time the humidity value of the air inside the apparatus reaches a second humidity value at which condensation occurs inside the apparatus in a state where the air inside the apparatus is not heated by the heater, the setting reception is performed Control means for heating the inside of the apparatus by the heater during the set heating time set in the means, and the setting receiving means is an environment in which the apparatus is installed as the set heating time. Time for dropping the humidity value from the second humidity value to the first humidity value in which dew condensation does not occur inside the device is performed under a reference environmental condition that is a condition criterion. The reference heating time is set in advance, and the control means sets the humidity value of the air inside the apparatus in a state where the air inside the apparatus is not heated by the heater under the environmental conditions where the apparatus is actually installed. The time required to increase from the first humidity value to the second humidity value is the air inside the device when the air inside the device is not heated by the heater under the reference environmental condition. As the humidity value becomes larger than the reference required time required to increase from the first humidity value to the second humidity value, the heating time sequentially reduced from the reference heating time is set to the set value. It sets to the said setting reception means as heating time, It is characterized by the above-mentioned (Claim 1).

  According to this configuration, the humidity value of the air inside the apparatus is changed from the first humidity value to the second humidity value in a state where the air inside the apparatus is not heated by the heater under the environmental conditions where the apparatus is actually installed. The time required to increase the humidity value of the air inside the apparatus from the first humidity value to the second humidity value in a state where the air inside the apparatus is not heated by the heater in the standard environmental condition As the reference required time required for the heating becomes larger, the heating time for the heater to heat the inside of the apparatus is sequentially reduced from the reference heating time.

  Therefore, the rate of increase in the humidity value of the air inside the device under the environmental conditions where the device is actually installed (hereinafter referred to as the rate of increase) is the rate of increase in the humidity value of the air inside the device under the standard environmental conditions ( Hereinafter, the heating time gradually decreases from the reference heating time as it becomes smaller than the reference increase rate.

  Therefore, the heating time by the heater is set to an appropriate time according to the small increase rate compared to the reference increase rate. Therefore, the heating time by the heater is finely controlled according to the degree of change in the environment where the apparatus is installed. Therefore, there is no waste in power consumption.

  The said structure WHEREIN: The said control means can be set as the structure which calculates | requires the heating time made small sequentially from the said reference | standard heating time according to the following formulas.

(formula)
T '+ TB = T + TA
However, T ′ indicates the heating time sequentially reduced from the reference heating time, T indicates the reference heating time, TA indicates the reference required time, and TB indicates the required time.

  According to this configuration, the heating time sequentially reduced from the reference heating time is obtained according to the calculation formula. Therefore, the heating time sequentially reduced from the reference heating time is such that the humidity value inside the apparatus is changed from the first humidity value to the second humidity value under the reference environmental condition in a state where the air inside the apparatus is not heated by the heater. The humidity value inside the apparatus changes from the first humidity value to the first required humidity under the environmental conditions in which the apparatus is actually installed in a state where the reference required time required for the rise and the air inside the apparatus is not heated by the heater. The time required to increase to a humidity value of 2 is the optimum heating time based on the required time.

  In the above configuration, at least the execution of the energy saving mode is stopped after the execution of the energy saving mode in which the power supply level supplied to the fixing unit for fixing the image transferred onto the recording sheet is suppressed or stopped is started. The energy saving mode execution time measurement process for measuring the energy saving mode execution time representing the time until the power supply level returns to the original power supply level is executed for a certain period, and the energy saving mode execution executed for the certain period is performed. An average value calculating unit that calculates an average value of the energy saving mode execution time measured by the time measurement process, and the control unit, as the average value of the energy saving mode execution time becomes smaller than the required time. , The heating time sequentially reduced from the reference heating time, the set heating As between, it may be configured to be set in the setting accepting means (claim 3).

  According to this configuration, as the average value of the energy saving mode execution time becomes smaller than the time required for the humidity value inside the apparatus to rise from the first humidity value to the second humidity value, The heating time for heating the inside of the apparatus is sequentially reduced from the reference heating time. Therefore, as the time when the energy saving mode is assumed to be executed becomes shorter than the required time, the heating time is sequentially reduced from the reference heating time. Therefore, the heating time is finely controlled according to the difference between the required time and the time when the energy saving mode is assumed to be executed. Therefore, power consumption is suppressed.

  In the above configuration, the control means is the set heating time set in the setting reception means by the heater every time the humidity value inside the apparatus reaches the second humidity value, and the reference By heating the inside of the apparatus for the set heating time that is smaller than the heating time, the humidity value inside the apparatus is changed to a third humidity value between the first humidity value and the second humidity value. It can be set as a humidity value, and it can be set as the structure which then stops the heating by the said heater during the time represented by the said average value (Claim 4).

  According to this configuration, each time the humidity value inside the device reaches the second humidity value, the control means heats the inside of the device for a heating time smaller than the reference heating time, and sets the humidity value inside the device. A third humidity value between the first humidity value and the second humidity value is set. Thereafter, the heating inside the apparatus is stopped for the time represented by the average value. Therefore, when the time when it is assumed that the energy saving mode has elapsed has been heated by the heater, the humidity value inside the apparatus is a third between the first humidity value and the second humidity value. Humidity value. Then, in the image forming job assumed to be started immediately after that, heating by the fixing heater is performed, and the humidity value inside the apparatus can be set to the first humidity value B. For this reason, the inside of the apparatus is not heated unnecessarily by the heater. Therefore, power consumption is suppressed.

  According to the present invention, the heating time by the heater is set to an appropriate time according to the small increase rate of the humidity value of the air inside the apparatus compared to the reference increase rate. Therefore, the heating time by the heater is finely controlled according to the degree of change in the environment where the apparatus is installed. Therefore, there is no waste in power consumption.

1 is a block diagram illustrating an example of a functional configuration of an image forming apparatus according to an embodiment of the present invention. It is a time chart for demonstrating an example of a heating time control process. It is a flowchart which shows an example of the outline | summary of pre-processing. It is a flowchart which shows an example of the outline | summary of a heating time control process. It is a time chart for demonstrating the other example of a heating time control process. It is a flowchart which shows the other example of the outline | summary of pre-processing. It is a flowchart which shows the other example of the outline | summary of a heating time control process.

  Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described. FIG. 1 is a block diagram illustrating an example of a functional configuration of an image forming apparatus according to an embodiment of the present invention.

  An image forming apparatus 1 shown in FIG. 1 includes a control unit (control unit) 10, an image reading unit 11, an image memory 12, a heater 13, an image forming unit 14 having an image fixing unit (fixing unit) 15, a power supply unit 16, A humidity value measuring unit 17, a required time measuring unit 18, a storage unit (setting receiving unit) 19, and an average value calculating unit (average value calculating unit) 20 are provided.

  In the image forming apparatus 1 shown in FIG. 1, the control unit 10 is configured by a microcomputer or the like. Such a control unit 10 controls the image forming apparatus 1 by transferring control signals and data through a control bus (for example, a CPU bus) and a data bus. Moreover, the control part 10 performs the various processes mentioned later.

  The image reading unit 11 reads an image of a document and generates image data. The image memory 12 stores the image data generated by the image reading unit 11. The heater 13 heats at least the air around the image reading unit 11 or the image forming unit 14 in order to prevent condensation from forming inside the image forming apparatus 1. Note that the heater 13 is not limited to the air around the image reading unit 11 or the image forming unit 14, but the image forming quality deteriorates if dehumidification is not performed on the conveyance roller, the conveyance path, the reverse roller, the reverse path, and the like. It is also possible to heat the air around the resulting component.

  The image forming unit 14 includes the image fixing unit 15 as described above. Such an image forming unit 14 forms an image. That is, the image data stored in the image memory 12 is printed on the recording paper. Therefore, the image forming unit 14 charges the image carrier, exposes the image carrier, a toner image forming step of forming a toner image by attaching toner to the image carrier, and transferring the toner image to the recording paper. And a fixing step for fixing the toner image transferred onto the recording paper. In the fixing process, the image fixing unit 15 rotates a fixing roller including a fixing heater (not shown) to fix the toner image transferred onto the recording paper.

  The power source unit 16 converts the AC power source into a DC power source, and then transforms the voltage to a predetermined voltage value. At least the control unit 10, the image reading unit 11, the heater 13, and image formation are performed on the transformed voltage value. Applied to the unit 14, the humidity value measuring unit 17, the required time measuring unit 18, the storage unit 19, and the average value calculating unit 20. Here, the application of voltage by the power supply unit 16 is hereinafter referred to as power feeding. The humidity value measurement unit 17 includes a humidity sensor, and measures the humidity value of the air inside the apparatus, for example, around the image reading unit 11 or the image forming unit 14.

  Here, the air inside the apparatus is at least air around the image reading unit 11 or the image forming unit 14. In the following description, air around the image reading unit 11 or the image forming unit 14 is illustrated as air inside the apparatus. Note that the air inside the apparatus is not only the air around the image reading unit 11 or the image forming unit 14 but also the quality of image formation unless dehumidification is performed, such as a conveyance roller, a conveyance path, a reverse roller, a reverse path, and the like. Include air around components that can degrade.

  The required time measuring unit 18 is configured so that the heater 13 does not heat the air around the image reading unit 11 or the image forming unit 14 under the environmental conditions where the image forming apparatus 1 is actually installed. The humidity value of the air around the image forming unit 14 is a second humidity value that causes condensation in the image reading unit 11 or the image forming unit 14 from a first humidity value that does not cause condensation in the image reading unit 11 or the image forming unit 14. Measure the time required to rise to the humidity value. The required time measuring unit 18 also measures a reference required time to be described later. Here, the environmental condition includes at least one of an installation place where the image forming apparatus 1 is installed and an installation time when the image forming apparatus 1 is installed.

  The storage unit 19 receives the setting of the set heating time that represents the heating time for heating the air around the image reading unit 11 or the image forming unit 14 by the heater 13. A reference heating time to be described later is set in advance as a set heating time by being stored in the storage unit 19. The storage unit 19 stores the required time and the reference required time. Furthermore, the storage unit 19 also stores an energy saving mode execution time, which will be described later, and an average value of an energy saving mode execution time, which will be described later.

  The average value calculation unit 20 executes a process (energy saving mode execution time measurement process) of measuring an energy saving mode execution time in which an energy saving mode described later is executed for a certain period (for example, one month). The average value calculation unit 20 includes a timer (not shown) in order to execute such an energy saving mode execution time measurement process. Details of such energy saving mode execution time measurement processing are as follows.

  That is, the average value calculation unit 20 executes the energy saving mode execution time measurement process every time the execution of the energy saving mode is started, and executes the energy saving mode execution time measurement process every time the execution of the energy saving mode is stopped. Stop. Thereafter, the average value calculation unit 20 causes the storage unit 19 to store the energy saving mode execution time measured by the energy saving mode execution time measurement process. With this process, each time the energy saving mode is executed, the energy saving mode execution time in which the energy saving mode is executed is stored in the storage unit 19.

  The average value calculation unit 20 executes such an energy saving mode execution time measurement process for a certain period (one month in the present embodiment). By such energy saving mode execution time measurement processing, the energy saving mode execution time of the energy saving mode for the number of times executed during a certain period is stored in the storage unit 19.

  Then, the average value calculation unit 20 calculates the average value of the energy saving mode execution times of the energy saving modes for the number of times executed during a certain period, and stores the calculated average value of the energy saving mode execution times in the storage unit 19. Remember me.

  Here, the energy saving mode is a mode in which at least the power supply level supplied to the image fixing unit 15 is suppressed or stopped. The energy saving mode execution time is a time from when the execution of the energy saving mode is started until the execution of the energy saving mode is stopped until the power supply level supplied to the image fixing unit 15 returns to the original power supply level. . Here, in the energy saving mode, not only the image fixing unit 15 but also the power supply level supplied to the image reading unit 11, the image memory 12, the required time measuring unit 18, the storage unit 19, and the average value calculating unit 20 is suppressed or reduced. It may be stopped. In the energy saving mode, it is necessary to maintain the power supply level to the humidity value measurement unit 17. This is because the heating time by the heater 13 is controlled according to the humidity value measured by the humidity value measuring unit 17 in the energy saving mode, as will be described later.

  In the image forming apparatus 1 shown in FIG. 1, the following basic processing is executed. That is, the following processing is executed by the control unit 10. That is, the control unit 10 determines that the humidity value of the air around the image reading unit 11 or the image forming unit 14 is the image in a state where the air around the image reading unit 11 or the image forming unit 14 is not heated by the heater 13. Each time the second humidity value (humidity value A shown in FIG. 2) at which condensation occurs in the reading unit 11 or the image forming unit 14 is reached, the air around the image reading unit 11 or the image forming unit 14 is heated by the heater 13. The air around the image reading unit 11 or the image forming unit 14 is heated by the heater 13 during a reference heating time (a reference heating time T shown in FIG. 2) stored in advance as a set heating time for this purpose.

  As a result, the humidity value of the air around the image reading unit 11 or the image forming unit 14 is the first humidity value at which no condensation occurs in the image reading unit 11 or the image forming unit 14 (humidity value B shown in FIG. 2). It becomes. Thus, every time the humidity value of the air around the image reading unit 11 or the image forming unit 14 reaches the second humidity value (humidity value A shown in FIG. 2), a preset reference heating time ( Heating is performed by the heater 13 during the reference heating time T) shown in FIG. 2 to obtain a first humidity value (humidity value B shown in FIG. 2). Therefore, it is possible to prevent condensation in the image reading unit 11 or the image forming unit 14.

  FIG. 2 is a time chart for explaining an example of the heating time control process executed by the control unit 10. In FIG. 2, the solid line (1) indicates the humidity of the air around the image reading unit 11 or the image forming unit 14 measured by the humidity value measuring unit 17 under the environmental conditions in which the image forming apparatus 1 is actually installed. The value is shown. Here, in the environmental conditions in which the image forming apparatus 1 is actually installed, as described above, at least the place where the image forming apparatus 1 is actually installed and the image forming apparatus 1 are actually installed. One of the periods is included.

  In FIG. 2, a two-dot chain line (3) indicates the humidity value of the air around the image reading unit 11 or the image forming unit 14 measured by the humidity value measuring unit 17 under the reference environmental condition. Here, the reference environmental conditions include at least a specific place (for example, a factory or a test laboratory) where the image forming apparatus 1 is installed and a specific time (for example, spring, summer, autumn, etc.) where the image forming apparatus 1 is installed. One of the winter) is included. A solid line (2) indicates the humidity value of the air around the image reading unit 11 or the image forming unit 14 when heated by the heater 13.

  In FIG. 2, a dotted line (4) indicates a first humidity value A representing a humidity value (critical humidity value) at which condensation occurs in the image reading unit 11 or the image forming unit 14. In FIG. 2, a dotted line (5) indicates a second humidity value B representing a humidity value at which no condensation occurs in the image reading unit 11 or the image forming unit 14.

  As shown in FIG. 2, when executing the basic process, the control unit 10 is indicated by a two-dot chain line (3) measured under the reference environmental condition as shown in the period F1. When the humidity value indicated by the solid line (1) measured under the environmental conditions in which the image forming apparatus 1 is currently set reaches the second humidity value A, the heater performs the reference heating time. During T, the image reading unit 11 or the image forming unit 14 is heated.

  The control part 10 can perform the heating time control process shown below besides the said basic process. Such a heating time control process is a process shown below. That is, as indicated by a period F2 in FIG. 2, the humidity value of air around the image reading unit 11 or the image forming unit 14 (solid line (1)) under the environmental conditions in which the image forming apparatus 1 is actually installed. The required time TB required for the first humidity value B to rise from the first humidity value B to the second humidity value A is the periphery of the image reading unit 11 or the image forming unit 14 under the reference environmental conditions. As the humidity value of the air (humidity value indicated by the two-dot chain line (3)) becomes larger than the reference required time TA required to increase from the first humidity value B to the second humidity value A, In this process, the heating time T ′ is sequentially reduced from the reference heating time T.

  In such a heating time control process, a heating time T ′ that satisfies the calculation formula “T ′ + TB = T + TA” is obtained. In this calculation formula, T is a constant because it is a preset reference heating time and TA is a reference required time measured under reference environmental conditions. On the other hand, TB is a variable because it is the required time measured under the environmental conditions in which the image forming apparatus 1 is actually installed. Therefore, the heating time T ′ is sequentially decreased from the reference heating time T as the value of the required time TB increases.

  Thus, in the heating time control process, the heating time T ′ is sequentially reduced from the reference heating time T as the required time TB becomes larger than the reference required time TA. Therefore, the increase rate of the humidity value of the air inside the apparatus (the increase rate of the humidity value indicated by the solid line (1)) compared with the reference increase rate (the increase rate of the humidity value indicated by the two-dot chain line (3)) is small. Depending on the thickness, the heating time by the heater is set to an appropriate time. Therefore, the heating time T ′ is finely controlled according to the degree of change in the environment where the image forming apparatus 1 is installed. Therefore, there is no waste in power consumption.

  According to such an image forming apparatus 1, the heating time T ′ is sequentially decreased from the reference heating time T as the required time TB becomes longer than the reference required time TA. Therefore, when the image forming job is executed during the required time TB, the power consumption of the heater 13 is suppressed. The reason why such an effect is achieved is as follows.

  That is, the required time TB required until the humidity value of the air around the image reading unit 11 or the image forming unit 14 increases from the first humidity value B to the second humidity value A is the reference required time TA. Is larger, the possibility that the image forming job is executed before the humidity value reaches the second humidity value A increases. When such an image forming job is executed, the fixing heater is operated to heat the air around the image forming unit 14 and the humidity value of the air around the image forming unit 14 is lowered.

  In the image forming apparatus 1, as described above, the heating time T ′ is sequentially reduced from the reference heating time T as the required time TB becomes longer than the reference required time TA. Therefore, as the possibility that the image forming job is executed during the required time TB becomes higher, it is expected that the image forming job is executed during the required time TB and heated by the fixing heater. Heating by the heater 13 is performed. Therefore, useless power consumption by the heater 13 is suppressed.

  Since the heating time control process described above is executed, the following pre-process is executed. FIG. 3 is a flowchart showing an example of an outline of pre-processing executed before the heating time control processing is executed. Such preprocessing is executed by the control unit 10.

  The control unit 10 measures the reference required time TA under the reference environmental condition by the required time measuring unit 18 (step S1). Then, the control unit 10 stores the measured reference required time TA in the storage unit 19 (step S2). Here, it is desirable that the reference environmental condition is an environmental condition in which the increase rate of the humidity value is large. In the heating time control process, the rate of increase in the humidity value of the air inside the apparatus compared to the reference rate of increase (the rate of increase of the humidity value indicated by the two-dot chain line (3) in FIG. 2) (in FIG. 2 by the solid line (1)) This is because the heating time T ′ by the heater 13 is set to an appropriate time according to the small increase rate of the indicated humidity value.

  FIG. 4 is a flowchart illustrating an example of an outline of the heating time control process. That is, the control unit 10 determines that the humidity value of the air around the image reading unit 11 or the image forming unit 14 is the first humidity under the environmental conditions where the image forming apparatus 1 is actually installed by the required time measuring unit 18. The time TB required to increase from the value B to the second humidity value A is measured (step S10). And the control part 10 memorize | stores the measured required time TB in the memory | storage part 19 (step S11).

  Next, the control unit 10 compares the required time TB with the reference required time TA and determines whether or not the required time TB is larger than the reference required time TA (step S12). When determining that the required time TB is greater than the reference required time TA (YES in step S12), the control unit 10 calculates a heating time T ′ that satisfies the above-described calculation formula “T ′ + TB = T + TA”. (Step S13). On the other hand, when it is determined that the required time TB is not greater than the reference required time TA (NO in step S12), the heating time T 'is set as the reference heating time T (step S14). Then, the control unit 10 sets the heating time T ′ as a set heating time for heating the air around the image reading unit 11 or the image forming unit 14 by the heater 13 (step S15). In the process shown in step S <b> 15, the set heating time is set by storing the heating time T ′ in the storage unit 19.

  FIG. 5 is a time chart for explaining another example of the heating time control process executed by the control unit 10. In FIG. 5, the solid line (1) and the two-dot chain line (6) indicate the image reading unit 11 or the image forming unit measured by the humidity value measuring unit 17 under the environmental conditions where the image forming apparatus 1 is actually installed. 14 shows the humidity value of air around 14. A solid line (2) indicates the humidity value of the air around the image reading unit 11 or the image forming unit 14 when heated by the heater 13.

  In FIG. 5, a dotted line (4) indicates a second humidity value A representing a humidity value (critical humidity value) at which condensation occurs in the image reading unit 11 or the image forming unit 14. In FIG. 5, a dotted line (5) indicates a first humidity value B representing a humidity value at which no condensation occurs in the image reading unit 11 or the image forming unit 14. A dotted line (7) indicates a third humidity value C between the first humidity value B and the second humidity value B.

  As shown in FIG. 5, when the control unit 10 is executing the basic process, as shown in the period F1, the humidity value measured under the environmental conditions in which the apparatus is actually installed. When the (humidity value indicated by the solid line (1)) reaches the second humidity value A, the heater 13 heats the image reading unit 11 or the image forming unit 14 during the reference heating time T. As a result, the humidity value is set to the first humidity value B.

  The control part 10 can perform the heating time control process shown below besides the said basic process. Such a heating time control process is a process executed during the period F2 in FIG. That is, as indicated by the period F2 in FIG. 5, the heating time T as the average value (hereinafter referred to as average value) T (AVE) of the energy saving mode execution time described above becomes smaller than the required time TB. 'Is a process of decreasing sequentially from the reference heating time T.

  In such a heating time control process, a heating time T ′ that satisfies the calculation formula “T ′ = {T × T (AVE)} / TB” is obtained. Such a calculation formula is a calculation formula derived as shown below. That is, as shown in FIG. 5, the triangle formed by the corners b, c, and d is similar to the triangle formed by the corners g, h, and i. Therefore, the calculation formula “T (AVE): T ′ = TB: T” holds. When such a calculation formula is modified, the calculation formula becomes “T ′ = {T × T (AVE)} / TB”. The calculation formula derived in this way is the above calculation formula.

  In this calculation formula, T is a constant because it is a preset reference heating time. On the other hand, T (AVE) is a variable because it is an average value obtained by executing the energy saving mode execution time measurement process for a certain period. TB is a variable because it is a required time measured under the environmental conditions in which the image forming apparatus 1 is actually installed.

  However, as described above, the heating time control process is a process in which the heating time T ′ is sequentially reduced from the reference heating time T as the average value T (AVE) becomes smaller than the required time TB. It is assumed that the value T (AVE) is smaller than the required time TB. Therefore, in the above calculation formula, as the average value T (AVE) becomes smaller than the required time TB, the difference between the average value T (AVE) and the required time TB increases. Therefore, the average value T (AVE) is required. As the time becomes smaller than the time TB, the heating time T ′ is sequentially reduced from the reference heating time T.

  Thus, in the heating time control process, the heating time T ′ is sequentially reduced from the reference heating time T as the average value T (AVE) becomes smaller than the required time TB. Therefore, the heating time T ′ is sequentially reduced from the reference heating time T as the time when the energy saving mode is assumed to be executed becomes shorter than the required time TB. Therefore, the heating time T ′ is finely controlled according to the difference between the required time TB and the time when the energy saving mode is assumed to be executed. Therefore, power consumption is suppressed.

  Since such a heating time control process is executed, the following heating process is executed in the image forming apparatus 1. Such a heating process is a process executed by the control unit 10 during the period F1 and the period F2. That is, when the humidity value of the air around the image reading unit 11 or the image forming unit 14 (humidity value indicated by the solid line (1)) reaches the second humidity value A during execution of the energy saving mode ( “A” shown in FIG. 5), the air around the image reading unit 11 or the image forming unit 14 is heated by the heater 13 for the heating time T ′. As a result, the humidity value of the air around the image reading unit 11 or the image forming unit 14 continues to decrease toward the first humidity value B as indicated by the solid line (2).

  However, since the heating time T ′ is shorter than the reference heating time T, the humidity value of the air around the image reading unit 11 or the image forming unit 14 is the first humidity value B and the second humidity value A. It falls to the 3rd humidity value C in the meantime ("b" shown in FIG. 5). Thereafter, heating by the heater 13 is stopped for a time represented by an average value (AVE).

  As a result, the humidity value of the air around the image reading unit 11 or the image forming unit 14 reaches the second humidity value A (“c” shown in FIG. 5) as indicated by a two-dot chain line (6). To rise. Then, the heating by the heater 13 is performed during the heating time T ′, and the humidity value of the air around the image reading unit 11 or the image forming unit 14 is the third humidity value as indicated by the solid line (2). It descends to C (“d” shown in FIG. 5).

  Thereafter, the humidity value of the air around the image reading unit 11 or the image forming unit 14 rises to the second humidity value A (“e” shown in FIG. 5) as indicated by a two-dot chain line (6). After that, as indicated by the solid line (2), the temperature falls to the third humidity value C ("f" shown in FIG. 5). As described above, during the execution of the energy saving mode, the air around the image reading unit 11 or the image forming unit 14 repeatedly rises and falls between the third humidity value C and the second humidity value A.

  Thus, during execution of the energy saving mode, every time the humidity value reaches the second humidity value A, the heating by the heater 13 is performed for a heating time T ′ that is smaller than the reference heating time T, The humidity value is a third humidity value C between the first humidity value B and the second humidity value A. Then, the heating by the heater 13 is stopped during the time represented by the average value T (AVE). Therefore, when the time represented by the average value T (AVE), that is, the time when the energy saving mode is assumed to have elapsed, the heater 13 is heated and the humidity value is changed to the first humidity. The third humidity value C is between the value B and the second humidity value A. Then, in an image forming job that is assumed to be started immediately thereafter, heating by a fixing heater is performed, and the humidity value can be set to the first humidity value B. For this reason, the image reading unit 11 or the image forming unit 14 is not heated unnecessarily by the heater 13. Therefore, power consumption is suppressed.

  In order to execute the heating time control process described above, the following pre-process is executed. FIG. 6 is a flowchart showing another example of the outline of the pre-process executed before the heating time control process is executed. Such preprocessing is executed by the average value calculation unit 20.

  That is, the average value calculation unit 20 executes an energy saving mode execution time measurement process for measuring an energy saving mode execution time representing a time during which the energy saving mode is executed every time the energy saving mode is executed. That is, when the execution of the energy saving mode is started (YES in step S20), the average value calculation unit 20 starts measuring time by using a timer built in the average value calculation unit 20 (step S21). When the execution of the energy saving mode is stopped (YES in step S22), the time measurement is ended (step S23), and the timer is reset (step S24). And the average value calculation part 20 memorize | stores the time measured in the memory | storage part 19 as energy saving mode execution time (step S25).

  And when the average value calculation part 20 performed the above energy saving mode execution time measurement process for a fixed period (YES of step S26), the average of all the energy saving mode measurement time measured during the fixed period A value T (AVE) is calculated (step S27), and the calculated average value T (AVE) is stored in the storage unit 19 (step S28).

  FIG. 7 is a flowchart illustrating another example of the outline of the heating time control process. That is, the control unit 10 changes the humidity value of the air around the image reading unit 11 or the image forming unit 14 from the first humidity value B to the second humidity value A under the environmental conditions in which the apparatus is actually installed. The time TB required for the rise is counted (step S30). And the control part 10 memorize | stores the measured required time TB in the memory | storage part 19 (step S31).

  Next, the control unit 10 determines whether or not the average value T (AVE) is smaller than the required time TB (step S32). When determining that the average value T (AVE) is smaller than the required time TB (YES in Step S32), the control unit 10 satisfies the calculation formula “T ′ = {T × T (AVE)} / TB”. The heating time T ′ is calculated (step S33), and the calculated heating time T ′ is set as the set heating time (step S35). On the other hand, when the control unit 10 determines that the average value T (AVE) is not smaller than the required time TB (NO in step S32), the heating time T ′ is set as the reference heating time T (step S34), The set heating time is set (step S35). In the process shown in step S <b> 35, the set heating time is set by storing the heating time T ′ in the storage unit 19.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 10 Control part 13 Heater 15 Image fixing part 16 Power supply part 18 Time required part 19 Memory | storage part 20 Average value calculation part A 2nd humidity value B 1st humidity value C 3rd humidity value T Reference heating Time T 'Heating time TA Standard required time TB Required time

Claims (4)

A heater for heating the air inside the device;
Setting accepting means for accepting a setting of a set heating time indicating a heating time for heating the air inside the apparatus by the heater;
Each time the humidity value of the air inside the device reaches a second humidity value at which condensation occurs inside the device in a state where the air inside the device is not heated by the heater, the setting reception unit sets the air. Control means for heating the inside of the apparatus by the heater during the set heating time;
With
The setting accepting means sets the humidity value as the set heating time from the second humidity value in a reference environmental condition that is a reference of an environmental condition in which the apparatus is installed. A reference heating time representing a time for dropping to a humidity value of 1 is preset,
The control means includes
The humidity value of the air inside the device rises from the first humidity value to the second humidity value in a state where the air inside the device is not heated by the heater under the environmental conditions where the device is actually installed. The time required for this is that the humidity value of the air inside the device is changed from the first humidity value to the second humidity in a state where the air inside the device is not heated by the heater in the reference environmental condition. An image characterized in that a heating time sequentially reduced from the reference heating time is set in the setting receiving means as the set heating time as it becomes longer than a reference required time required to rise to a value. Forming equipment. The control means includes
The image forming apparatus according to claim 1, wherein the heating time sequentially reduced from the reference heating time is obtained according to the following calculation formula.
(formula)
T '+ TB = T + TA
However, T ′ indicates the heating time sequentially reduced from the reference heating time, T indicates the reference heating time, TA indicates the reference required time, and TB indicates the required time. The execution of the energy saving mode is stopped after the execution of the energy saving mode in which the power supply level supplied to the fixing means for fixing the image transferred onto the recording paper is suppressed or stopped, and the power supply level is stopped. Execute energy saving mode execution time measurement processing for a certain period of time to measure the energy saving mode execution time that represents the time to return to the original power supply level,
An average value calculating means for calculating an average value of the energy saving mode execution time measured by the energy saving mode execution time measuring process executed for the predetermined period;
The control means includes
As the average value of the energy saving mode execution time becomes smaller than the required time, the heating time sequentially reduced from the reference heating time is set as the set heating time in the setting reception unit. The image forming apparatus according to claim 1 or 2. The control means includes
Each time the humidity value inside the apparatus reaches the second humidity value, the set heating time that is set by the heater in the setting reception unit and is smaller than the reference heating time. By heating the inside of the apparatus for a time, the humidity value inside the apparatus is set to a third humidity value between the first humidity value and the second humidity value, and then by the heater The image forming apparatus according to claim 3, wherein heating is stopped during a time represented by the average value.

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