JP2008129337A - Image forming apparatus and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of performing process control in accordance with an environment even under a low temperature environment. <P>SOLUTION: A temperature receiving part 200 receives the surface temperature of a fixing device 26 detected by a temperature sensor 66. A voltage receiving part 202 receives a voltage value measured by a voltage measuring device 64. An environment determination part 208 determines the environment section to be controlled. Concretely, the environment determination part 208 determines the environment section for the process control based on a first environment section estimated based on the temperature detected by the temperature sensor 66 and a second environment section estimated based on the voltage measured by the voltage measuring device 64. A process control part 210 performs the process control based on the determined environment section for the process control. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a printer, a facsimile machine, and a copying machine.

  In this type of image forming apparatus, it is possible to perform printing with fewer image defects by optimizing the process conditions based on the temperature and humidity environment in which the apparatus is placed. Particularly in a low temperature environment, image defects such as image density reduction and fog due to drum sensitivity reduction are likely to occur. Therefore, it is important to correctly detect that the device is in a low temperature environment. Generally, the temperature / humidity environment is accurately detected by a temperature / humidity sensor mounted on the apparatus. However, such a temperature / humidity sensor is expensive. In addition, in order to perform stable and reliable detection, it is necessary to twist a certain amount of space in the apparatus.

  A method in which the environment of the apparatus is estimated from the current-voltage characteristics of the transfer member is known. In this method, the environment is detected by utilizing the resistance change of the transfer member due to the absolute moisture content in the atmosphere. However, since the absolute moisture amount is almost the same in a normal temperature and normal humidity environment, a low temperature and high humidity environment, and a high temperature and low humidity environment, these methods cannot be distinguished by this method. For this reason, especially in a low temperature and high humidity environment, there is a case where control for water-containing paper cannot be applied in transfer control even though the risk of water containing water is high.

  In Patent Document 1, the temperature is detected based on the temperature of the fixing device when the power is turned on, and the humidity is calculated and detected using the detected temperature and the current-voltage characteristics of the transfer roll stored in advance in the apparatus. An image forming apparatus is disclosed. However, when it is detected that the temperature of the fixing device is a temperature at which the image forming apparatus is assumed to be used (for example, about 0 to 40 ° C.), the environmental temperature is a result of the image forming apparatus being left for a long time. It is not possible to determine whether the temperature has reached or the environmental temperature is lower than the temperature, and the temperature of the fixing device is in the process of being lowered. For this reason, an incorrect environment may be detected.

JP 2004-333792 A

  The present invention has been made from the above-described background, and an object thereof is to provide an image forming apparatus capable of performing process control according to the environment even in a low temperature environment.

  In order to achieve the above object, an image forming apparatus according to the present invention includes an image carrier, a transfer member that transfers a toner image formed on the image carrier to a recording medium, and a recording medium that is transferred by the transfer member. A fixing device that performs a fixing process on the transfer member, a voltage / current measuring device that measures a voltage or current when a predetermined current or voltage is applied to the transfer member, and a temperature detection device that detects the temperature of the fixing device And a first environment category estimated based on the temperature detected by the temperature detection device, and a second environment category estimated based on the voltage or current measured by the voltage / voltage measurement device. And an environment classification determination unit that determines the classification of the environment to be controlled. According to the present invention, process control according to the environment can be performed even in a low temperature environment.

  Preferably, when the temperature detected by the temperature detection device is greater than or equal to a first threshold and less than or equal to a second threshold, the environment category determination means determines whether the first environment category and the second environment category are The environmental division between them is the environmental division for process control. According to the present invention, effective process control can be performed even when the environmental temperature is lower than the temperature of the fixing device and the temperature of the fixing device is being lowered.

  Preferably, when the temperature detected by the temperature detection device is equal to or lower than a first threshold value, the environment category determination unit sets the first environment category as an environment category for process control. According to the present invention, it can be detected that the image forming apparatus is left in a low temperature environment.

  Preferably, when the first environment classification is different from the second environment classification, the environment classification determination unit sets the second environment classification as an environment classification for process control. According to the present invention, process control according to the environment can be performed even in a low temperature and high humidity environment.

  Preferably, the environment classification determining unit determines that the second environment classification is an environment classification for process control when a predetermined period has elapsed since at least one of the time of startup and the return from the power saving mode. And According to the present invention, even when the temperature rises from a low-temperature environment due to execution of printing processing and air conditioning, process control optimized for the temperature can be performed.

  Preferably, when the predetermined number of sheets has been printed from at least one of the time of startup and the return from the power saving mode, the environment classification determination unit determines the second environment classification as an environment classification for process control. And According to the present invention, even when the temperature rises from a low temperature environment due to the execution of the printing process, the process control optimized for the temperature can be performed.

Preferably, the apparatus further includes control means for performing process control based on the environmental classification determined by the environmental classification determination means.
Preferably, the apparatus further comprises storage means for storing the environment classification determined by the environment classification determination means, and the control means performs process control based on the environment classification stored in the storage means. Do. According to the present invention, even when the power is turned on / off in a low temperature environment, the process control optimized in the low temperature environment can be performed.

  Preferably, the control means controls at least one of a charging bias, an exposure amount, a developing bias, a transfer bias, and a peeling bias fixing set temperature. According to the present invention, a good image can be printed regardless of the environment of the image forming apparatus.

  Further, the program according to the present invention fixes a computer, an image carrier, a transfer member that transfers a toner image formed on the image carrier to a recording medium, and a recording medium that is transferred by the transfer member. An image having a fixing device that performs processing, a voltage / current measuring device that measures a voltage or current when a predetermined current or voltage is applied to the transfer member, and a temperature detecting device that detects the temperature of the fixing device In the forming apparatus, a first environment classification estimated based on the temperature detected by the temperature detection device and a second environment estimated based on the voltage or current measured by the voltage / current measurement device. A determination step for determining a division of an environment to be controlled based on the division of the image, and a control step for performing process control based on the determined division of the environment. To be executed by a device of the computer.

  According to the present invention, process control according to the environment can be performed even in a low temperature environment.

First, an image forming apparatus 10 according to an embodiment of the present invention will be described.
FIG. 1 is a diagram illustrating an image forming apparatus 10 according to an embodiment of the present invention.
The image forming apparatus 10 includes an image forming apparatus main body 12. For example, a one-stage sheet feeding cassette 24 is disposed at a lower portion of the image forming apparatus main body 12, and an image is displayed on the upper portion of the image forming apparatus main body 12. A discharge unit 36 for discharging the formed recording medium (paper) is provided.

  In the image forming apparatus main body 12, for example, a print head device (Print Head Device) 14 that performs full-color image formation is disposed in a substantially central portion. The print head device 14 includes photosensitive drums 16a, 16b, 16c, and 16d as image carriers for yellow (Y), magenta (M), black (K), and cyan (C), and these photosensitive drums. Developing devices 20a, 20b, 16b for developing electrostatic latent images formed on 16a, 16b, 16c, 16d with toners of yellow (Y), magenta (M), black (K), and cyan (C). 20c, 20d, a first primary intermediate transfer drum 38 as an intermediate transfer member that contacts two of the four photosensitive drums 16a, 16b, and the other two photosensitive drums 16c, 16d. A second primary intermediate transfer drum 40 that contacts, a secondary intermediate transfer drum 42 that contacts the first and second primary intermediate transfer drums 38 and 40, and a contact that contacts the secondary intermediate transfer drum 42. And the final transfer roll 44 as a transfer member. In the case where any one of a plurality of constituent parts such as the photoconductive drums 16a, 16b, 16c, and 16d is indicated without being specified, the photoconductive drum 16 may be simply abbreviated.

  The image forming apparatus main body 12 includes an exposure device 18 that performs image exposure on the four photosensitive drums 16a, 16b, 16c, and 16d of the print head device 14, and developing devices 20a, 20b, 20c for each color of the print head device 14. Four toner cartridges 22a, 22b, 22c, and 22d that supply toner of a color corresponding to 20d, a fixing device 26 that performs a fixing process on the recording medium onto which the toner image is transferred from the print head device 14, and the fixing A double-sided conveyance path 28 for conveying a recording medium having an image fixed on one side by the apparatus 26 to the transfer unit of the print head device 14 in a state where the front and back sides are reversed, and a desired outside from the image forming apparatus main body 12 The manual sheet feeding means 30 for feeding the recording medium, and the secondary intermediate transfer drum through the paper feeding process (not shown). A sheet conveying roll 46 fed to the nip portion of the final transfer roll 44 and a control section 32 including a control circuit for controlling the operation of the image forming apparatus 10 and an image processing circuit for performing image processing on an image signal. Is provided.

  An operation unit 48 is provided on the upper surface of the image forming apparatus main body 12, for example. The operation unit 48 displays control information and instruction information of the image forming apparatus 10 and accepts input by the user such as instruction information. The operation unit 48 is configured by a user interface device such as a touch panel, for example.

  A voltage measuring device 64 is provided in the vicinity of the final transfer roll 44. The voltage measuring device 64 measures the voltage when a predetermined current is applied to the final transfer roll 44. More specifically, the voltage measuring device 64 applies a predetermined current to the final transfer roll 44, measures the output voltage value of the final transfer roll 44 in a state where the current is applied, and controls this measured value. To the unit 32. The voltage measurement is performed, for example, during the pre-rotation of the photosensitive drum 16 at the start of the print job.

  Further, a temperature sensor 66 as a temperature detecting device for detecting the temperature of the fixing device 26 is provided in the vicinity of the fixing device 26. The temperature sensor 66 is, for example, a thermocouple that detects the surface temperature of the fixing device 26. The temperature sensor 66 outputs the detected temperature to the control unit 32.

FIG. 2 is a diagram illustrating a hardware configuration of the control unit 32.
As shown in FIG. 2, the control unit 32 transmits and receives data to and from a CPU 50, a memory 52, a storage device 54 such as a hard disk drive that stores data in a readable / writable manner, and an external computer via a network (not shown). A communication device 56 that performs reception, a power source 58 that supplies a voltage to each component of the image forming apparatus 10, and an input / output interface (IF) that inputs and outputs signals between the voltage measurement device 64 and the temperature sensor 66. ) 60. These components are connected to each other via a bus 62.

Next, the resistance value characteristic of the final transfer roll 44 as a transfer member of the image forming apparatus 10 according to the present embodiment will be described.
FIG. 3 is a diagram showing the relationship between the resistance value of the final transfer roll 44 and the absolute water content.
As shown in FIG. 3, the resistance value of the final transfer roll 44 (hereinafter also referred to as BTR resistance value) varies depending on the absolute moisture content in the atmosphere. Specifically, the BTR resistance value (Ω) is linearly related to the absolute moisture content (g / m 3) in the atmosphere, for example, as a straight line indicated by an arrow A in the figure.

  The BTR resistance value is obtained based on a predetermined current value applied to the final transfer roll 44 and an output voltage value when the current value is applied. Therefore, when this voltage value is measured by the voltage measuring device 64 and output to the control unit 32, the control unit 32 applies the applied current value, the measured voltage value, and the resistance value of the final transfer roll 44. Based on the characteristics, the absolute water content is calculated.

Next, the environmental classification determined by the control unit 32 will be described.
FIG. 4 is a diagram illustrating the division of the environment used for process control.
As illustrated in FIG. 4, the relationship between temperature (° C.) and absolute humidity (Rh%) changes based on the absolute water content. The environment is classified based on temperature (° C.), absolute humidity (Rh%), and absolute moisture content. In this example, ten categories of environmental categories 1 to 10 are set in advance as environmental categories. In FIG. 4, the number of the environmental classification is represented by a number surrounded by a rectangle.

  For example, in the environmental category 2, the solid line indicating the relationship between temperature and absolute humidity when the absolute moisture content is 0.75, and the relationship between temperature and absolute humidity when the absolute moisture content is 1.75 are shown. It is the range surrounded by the solid line shown. Further, for example, in the environmental category 7, the solid line indicating the relationship between the temperature and the absolute humidity when the absolute moisture content is 11, and the broken line indicating the relationship between the temperature and the absolute humidity when the absolute moisture content is 15 It is the range surrounded by.

  Accordingly, one environmental category is selected based on the absolute water content. For example, when the absolute water content is 1.50, the absolute water content is 0.75 or more and less than 1.75, so the second environmental category is selected. In addition, one environmental category is selected based on temperature and absolute humidity. For example, when the temperature is 10 ° C. and the absolute humidity is 15 Rh%, the second environmental category is selected.

  The environmental division may be estimated based on the temperature and a straight line indicated by an arrow B in the figure. In this case, the environment is presumed to be one of low temperature and low humidity, normal temperature and normal humidity, and high temperature and high humidity. For example, if the temperature is 10 ° C., the third segment is selected based on the straight line indicated by the arrow B.

Next, the control program 2 that operates in the image forming apparatus 10 according to the embodiment of the present invention will be described.
FIG. 5 is a diagram showing a functional configuration of the control program 2 operating in the control unit 32 of the image forming apparatus 10 according to the present invention.
As shown in FIG. 5, the control program 2 includes a temperature reception unit 200, a voltage reception unit 202, a resistance value calculation unit 204, an absolute water content calculation unit 206, an environment determination unit 208, a process control unit 210, a time measurement unit 212, A print number storage unit 214 and a determination result storage unit 216 are included. The control program 2 uses these components to estimate the first environment classification based on the temperature detected by the temperature sensor 66 and the second voltage estimated based on the voltage measured by the voltage measuring device 64. Process control is performed based on the environmental classification. The control program 2 is loaded into the memory 52 of the control unit 32 and executed by the CPU 50.

In the control program 2, the temperature receiving unit 200 receives the surface temperature of the fixing device 26 detected by the temperature sensor 66 through the input / output IF 60 and outputs the received temperature to the environment determining unit 208.
The voltage receiving unit 202 receives the voltage value measured by the voltage measuring device 64 and outputs it to the resistance value calculating unit 204.

The resistance value calculation unit 204 calculates a resistance value based on the current value applied to the final transfer roll 44 and the voltage value input from the voltage receiving unit 202 when this current is applied, and calculates the resistance value. Output to the absolute water content calculation unit 206.
The absolute moisture amount calculation unit 206 calculates an absolute moisture amount corresponding to the input resistance value based on the resistance value characteristic shown in FIG. 3, and outputs this absolute moisture amount to the environment determination unit 208.

  The time measurement unit 212 measures the elapsed time from the start of the image forming apparatus 10 and the return from the power saving mode, and outputs the measured time to the environment determination unit 208. Specifically, the time measurement unit 212 is configured to operate after the power source is turned on or shifted from the power saving mode to the normal mode and the power source 58 starts supplying a predetermined voltage to each component of the image forming apparatus 10. Measure time.

  The printed sheet number storage unit 214 stores the number of recording media printed by the image forming apparatus 10. The printed sheet number storage unit 214 is realized by a non-volatile storage device such as the storage device 54.

  The environment determination unit 208 selects an environment category for process control from a plurality of predetermined environment categories (FIG. 4). More specifically, the environment determination unit 208 estimates the first environment based on the temperature measured by the temperature sensor 66 and the voltage measured by the voltage measurement device 64. The environment classification to be controlled is determined based on the two environmental classifications. The environment determination unit 208 outputs the selected environment classification for process control to the process control unit 210.

  The environment determination unit 208 receives the time measured by the time measurement unit 212, and when a predetermined period has elapsed from at least one of the time of startup and the return from the power saving mode, the second environment classification is It is classified into the environment for process control. In addition, the environment determination unit 208 refers to the number of printed pages stored in the number of printed sheets storage unit 214, and when the predetermined number of sheets has been printed from at least one of when starting up and returning from the power saving mode, The environmental classification is the environmental classification for process control. The number of sheets may be changed depending on the number of single-sided and double-sided printing. The environment classification determination processing by the environment determination unit 208 will be described in detail later.

  The determination result storage unit 216 stores the determination result of the environment classification by the environment determination unit 208 and the date and time when the determination process was performed. The determination result storage unit 216 is realized by at least one of the memory 52 and the storage device 54.

  The process control unit 210 performs process control based on the environment classification for process control determined by the environment determination unit 208. Specifically, the process control unit 210 controls at least one of a charging bias, an exposure amount, a developing bias, a transfer bias, and a peeling bias fixing set temperature. In this manner, the image forming apparatus 10 is controlled based on the determined environmental classification, and prints an image on a recording medium.

Next, the determination method of the classification of the environment to be controlled by the environment determination unit 208 will be described in detail.
The environment determination unit 208 estimates the first environment classification based on the temperature input from the temperature reception unit 200. Here, the environment determination unit 208 estimates the environment classification based on the straight line indicated by the arrow B in FIG. For example, when the temperature is 8 ° C., the environment determination unit 208 selects the environment category 2 as the first environment category. The straight line is merely an example. Therefore, as long as it is possible to determine each environment of low temperature and low humidity, normal temperature and normal humidity, and high temperature and high humidity, the determination criterion may be a straight line with a different slope or may be based on an arbitrary mathematical expression. Good.

  The environment determination unit 208 estimates the second environment category based on the absolute water content input from the absolute water content calculation unit 206. Here, the environment determination unit 208 estimates the environment classification based on the straight line indicated by the arrow B in FIG. For example, when the absolute water content is 1.00, the environment determination unit 208 selects the environment category 2 as the second environment category. For example, when the absolute water content is 13, the environment determination unit 208 selects the environment category 7 as the second environment category.

In addition to the first environmental classification and the second environmental classification selected in this manner, the environment determination unit 208 further based on the temperature detected by the temperature sensor 66 and input from the temperature reception unit 200. Select an environmental category for process control.
Hereinafter, the case classification performed based on the detected temperature will be described. The detected temperature is also referred to as a fixing device temperature.

  When the fixing device temperature is equal to or lower than a first threshold T1 (for example, 12 ° C.), the environment determination unit 208 selects the first environment category as the environment category for process control. However, when the fixing device temperature is equal to or lower than the first threshold value and the first environment classification and the second environment classification are different, the environment determination unit 208 determines the second environment classification. Select as an environmental category for process control.

  Specifically, when there is a certain difference or more between the first environment category and the second environment category (for example, when there are three or more steps), the second environment category is the process control Is selected as an environmental category. For example, when the fixing device temperature is 10 ° C., the environment category 3 is selected as the first environment category, and the environment category 6 is selected as the second environment category, the environment determination unit 208 selects the environment Category 6 is selected as the environment category for process control. In this case, the environment determination unit 208 determines that the environment of the image forming apparatus 10 is the environment category 6 and is under low temperature and high humidity.

  When the fixing device temperature is not less than the first threshold value T1 and not more than the second threshold value T2 (for example, 15 ° C.), the environment determination unit 208 determines the environment between the first environment category and the second environment category. (For example, an intermediate category between these categories) is an environment category for process control. However, if the first environment category and the second environment category are different, the environment determination unit 208 determines that the second fixing unit temperature is equal to or lower than the first threshold value, as in the case where the second fixing unit temperature is equal to or lower than the first threshold value. Select the environmental category as the environmental category for process control.

  For example, when the environment category 3 is selected as the first environment category and the environment category 5 is selected as the second environment category, the environment determination unit 208 selects the environment category between these categories. An environment category 4 is selected as an environment category for process control. On the other hand, when the environmental category 3 is selected as the first environmental category and the environmental category 6 is selected as the second environmental category, the environment determination unit 208 selects the environmental category 6 for process control. It is selected as an environmental category, and it is determined that the image forming apparatus 10 is under low temperature and high humidity.

Next, the operation of the image forming apparatus 10 according to the embodiment of the present invention will be described.
FIG. 6 is a flowchart showing an environment classification selection process (S10) by the control program 2.
As shown in FIG. 6, in step 100 (S <b> 100), the temperature sensor 66 detects the surface temperature of the fixing device 26 and outputs it to the control unit 32. In the control unit 32, the control program 2 is operating. The temperature receiving unit 200 of the control program 2 receives the temperature detected by the temperature sensor 66 and outputs it to the environment determining unit 208.

  In step 102 (S102), the environment determination unit 208 selects a first environment category from a plurality of environment categories (FIG. 4) based on the input temperature. Here, the first environment category is selected based on the straight line A shown in FIG. 4, for example, assuming that the environment is low temperature and low humidity, normal temperature and normal humidity, or high temperature and high humidity.

  In step 104 (S 104), the voltage measuring device 64 measures the voltage when a predetermined current is applied to the final transfer roll 44, and outputs this voltage value to the control unit 32. In the control unit 32, the voltage receiving unit 202 of the control program 2 receives the voltage value measured by the voltage measuring device 64 and outputs it to the resistance value calculating unit 204.

  In step 106 (S106), the resistance value calculation unit 204 calculates a resistance value based on the current-voltage characteristics of the final transfer roll 44, and outputs the resistance value to the absolute water content calculation unit 206. The absolute moisture amount calculation unit 206 calculates an absolute moisture amount corresponding to the input resistance value based on the resistance value characteristic, and outputs the absolute moisture amount to the environment determination unit 208. The environment determination unit 208 selects a second environment category from a plurality of environment categories based on the input absolute moisture content. Here, the second environment category is selected based on, for example, the straight line B shown in FIG. 4 assuming that the environment is low temperature and low humidity, normal temperature and normal humidity, or high temperature and high humidity.

  In step 108 (S108), the environment determination unit 208 determines the temperature input from the temperature reception unit 200. Specifically, the environment determination unit 208 determines whether the temperature is T1 or less, T1 or more and T2 or less, or T2 or more. The environment determination unit 208 proceeds to the process of S110 when the temperature is equal to or lower than T1, proceeds to the process of S116 when equal to or higher than T1 and equal to or lower than T2, and proceeds to the process of S126 when equal to or higher than T2.

  In step 110 (S100), the environment determination unit 208 determines whether or not the selected first environment category and the second environment category are different. The environment determination unit 208 proceeds to the process of S112 when the first environment classification and the second environment classification deviate, and otherwise proceeds to the process of S114.

In step 112 (S112), the environment determination unit 208 selects the second environment category as the environment category for process control. Therefore, the environment determination unit 208 determines that the image forming apparatus 10 is placed in a low temperature environment, that is, under a low temperature and high humidity in the second environment category.
In step 114 (S114), the environment determination unit 208 selects the first environment category as the environment category for process control.

  In step 116 (S116), the environment determination unit 208 determines whether or not the selected first environment category and the second environment category are the same. The environment determination unit 208 proceeds to the process of S118 when the first environment classification and the second environment classification are the same, and otherwise proceeds to the process of S120.

In step 118 (S118), the environment determination unit 208 selects the second environment category as the environment category for process control.
In step 120 (S120), the environment determination unit 208 determines whether or not the selected first environment category and the second environment category are different. The environment determination unit 208 proceeds to the process of S122 when the first environment classification and the second environment classification deviate, and otherwise proceeds to the process of S124.

In step 122 (S122), the environment determination unit 208 selects the second environment category as the environment category for process control. Therefore, the environment determination unit 208 determines that the image forming apparatus 10 is placed in a low temperature environment, that is, under a low temperature and high humidity in the second environment category.
In step 124 (S124), the environment determination unit 208 determines an intermediate environmental classification between the first environmental classification and the second environmental classification as the environmental classification for process control. Select as the environmental category.

  In step 126 (S126), the environment determination unit 208 selects the second environment category as the environment category for process control.

  In this way, an environmental segment for process control is selected. The selected environment category, date and time, temperature detected by the temperature sensor 66, and voltage value detected by the voltage measuring device 64 are stored in the determination result storage unit 216 by the environment determination unit 208.

FIG. 7 is a flowchart showing the operation (S20) immediately after the start of the image forming apparatus 10 according to the embodiment of the present invention.
As shown in FIG. 7, when the power of the image forming apparatus 10 is turned on or when the image forming apparatus 10 returns from the power saving mode, an environment classification selection process (S10; FIG. 6) is executed. In the image forming apparatus 10, the control unit 32 performs process control based on the selected environment classification. Here, the time measuring unit 212 of the control program 2 operating on the control unit 32 measures the elapsed time since activation.

  In step 200 (S200), the environment determination unit 208 of the control program 2 refers to the time measured by the time measurement unit 212 and determines whether or not a predetermined time has elapsed since the activation. If the predetermined time has elapsed, the control program 2 proceeds to the process of S202, and otherwise returns to the process of S10.

  In step 202 (S202), the environment determination unit 208 selects the second environment category as the environment category for process control. Therefore, when a predetermined time has elapsed since the activation, the process control is performed based on the second environment classification.

  Note that the environment determination unit 208 may determine whether or not a predetermined number of sheets have been printed since the activation, instead of determining whether or not a predetermined time has elapsed since the activation. In this case, when a predetermined number of sheets have been printed since activation, the process control is performed based on the second environment classification.

Next, a printing operation of the image forming apparatus 10 according to the present embodiment will be described.
In the printing operation, the charging bias of the photosensitive drum 16, the exposure amount of the exposure device 18, the developing bias of the developing device 20, the transfer bias of the primary intermediate transfer drum 38, the secondary intermediate transfer drum 42, and the final transfer roll 44, and the peeling bias. The fixing set temperature of the fixing device 26 is set to a value corresponding to the environmental category selected for the process processing.

  When a print command is transmitted from an external computer or the like to the image forming apparatus 10, the photosensitive drum 16 is uniformly charged, and the charged photosensitive drum 16 is exposed to the exposure device 18 based on the image signal. A light beam is emitted from. The light beam from the exposure device 18 exposes the surface of the photosensitive drum 16 to form a latent image. The latent images on the photosensitive drums 16a, 16b, 16c, and 16d formed by the exposure device 18 are yellow and magenta by the developing devices 20a, 20b, 20c, and 20d supplied with toner from the toner cartridges 22a, 22b, 22c, and 22d. The black and cyan toner images are developed and primary-transferred on the primary intermediate transfer drums 38 and 40.

  The control unit 32 outputs a paper feed signal at a predetermined paper interval timing. Accordingly, the paper fed from the manual paper feeding means 30 (or the paper stored in the paper feed cassette 24) is subjected to a paper feeding process (not shown) and is secondarily performed at a predetermined paper interval by the paper transport roll 46. It is fed into the nip portion between the intermediate transfer drum 42 and the final transfer roll 44. When the sheet is guided between the secondary intermediate transfer drum 42 and the final transfer roll 44, the toner image primarily transferred to the primary intermediate transfer drums 38 and 40 is transferred by the secondary intermediate transfer drum 42 and the final transfer roll 44. Secondary transferred onto paper. The sheet on which the toner image has been transferred is guided to the fixing device 26 to fix the toner image. The sheet on which the toner image is fixed is discharged from the discharge port to the discharge unit 36.

  The number of printed sheets is stored in the print number storage unit 214 of the control program 2. Further, the value stored in the print number storage unit 214 may be changed based on the difference between single-sided printing and double-sided printing.

  Note that in the image forming apparatus 10, the voltage measuring device 64 is applied when a predetermined current is applied to any one of the primary intermediate transfer drums 38 and 40 and the secondary intermediate transfer drum 42, not the final transfer roll 44. The voltage may be measured.

  Further, the image forming apparatus 10 may have a current measuring device instead of the voltage measuring device 64 or together with the voltage measuring device 64. In this case, the current measuring device measures the current when a predetermined voltage is applied to the final transfer roll 44 and the like, and outputs it to the control unit 32. In the control unit 32, the control program 2 operating on the control unit 32 calculates a resistance value based on the current, and selects a second environment category based on the resistance value and the resistance value characteristic. Therefore, the control program 2 includes a first environment category estimated based on the temperature detected by the temperature sensor 66, and a second environment category estimated based on the current measured by the current measuring device. Based on the above, the environment category to be controlled is determined, and the process control is performed based on the selected environment category.

1 is a diagram illustrating an image forming apparatus 10 according to a first embodiment of the present invention. 3 is a diagram illustrating a hardware configuration of a control unit 32. FIG. It is a figure which shows the relationship between the resistance value of the last transfer roll 44, and an absolute water content. It is a figure which illustrates the division of the environment used for process control. FIG. 3 is a diagram illustrating a functional configuration of a control program 2 that operates in a control unit 32 of the image forming apparatus 10 according to the present invention. It is a flowchart which shows the selection process (S10) of the environment division by the control program 2. 6 is a flowchart illustrating an operation (S20) immediately after the image forming apparatus 10 according to the embodiment of the present invention is activated.

Explanation of symbols

2 Control Program 10 Image Forming Device 16 Photosensitive Drum 18 Exposure Device 20 Developing Device 26 Fixing Device 32 Control Units 38, 40 Primary Intermediate Transfer Drum 42 Secondary Intermediate Transfer Drum 44 Final Transfer Roll 50 CPU
52 Memory 54 Storage Device 56 Communication Device 58 Power Supply 60 Input / Output IF
62 Bus 64 Voltage measurement device 66 Temperature sensor 200 Temperature reception unit 202 Voltage reception unit 204 Resistance value calculation unit 206 Absolute water content calculation unit 208 Environment determination unit 210 Process control unit 212 Time measurement unit 214 Number of printed sheets storage unit 216 Determination result storage unit

Claims (10)

An image carrier,
A transfer member for transferring a toner image formed on the image carrier to a recording medium;
A fixing device that performs a fixing process on the recording medium transferred by the transfer member;
A voltage / current measuring device for measuring the voltage or current when a predetermined current or voltage is applied to the transfer member;
A temperature detection device for detecting the temperature of the fixing device;
A first environment category estimated based on the temperature detected by the temperature detection device, and a second environment category estimated based on the voltage or current measured by the voltage / voltage measurement device. An image forming apparatus comprising: an environment classification determining unit that determines an environment classification to be controlled based on the environment classification determining unit. When the temperature detected by the temperature detection device is not less than the first threshold and not more than the second threshold, the environment category determination means The image forming apparatus according to claim 1, wherein the classification is an environment classification to be controlled. 3. The environment classification determination unit, when the temperature detected by the temperature detection device is equal to or lower than a first threshold value, sets the first environment classification as an environment classification to be controlled. Image forming apparatus. The environment classification determination means sets the second environment classification as the environment classification to be controlled when the first environmental classification and the second environmental classification are different. The image forming apparatus described. The environment classification determination unit sets the second environment classification as the environment classification to be controlled when a predetermined period has elapsed since at least one of the time of startup and the return from the power saving mode. 5. The image forming apparatus according to any one of items 4 to 4. The environment classification determination means sets the second environment classification as the environment classification to be controlled when a predetermined number of sheets has been printed from at least one of startup and return from the power saving mode. 6. The image forming apparatus according to any one of items 1 to 5. The image forming apparatus according to claim 1, further comprising a control unit that performs process control based on an environmental classification determined by the environmental classification determination unit. Storage means for storing the environmental classification determined by the environmental classification determination means;
The image forming apparatus according to claim 7, wherein the control unit performs process control based on a classification of an environment stored in the storage unit. The image forming apparatus according to claim 7, wherein the control unit controls at least one of a charging bias, an exposure amount, a developing bias, a transfer bias, and a peeling bias fixing set temperature. A computer, an image carrier, a transfer member that transfers a toner image formed on the image carrier to a recording medium, a fixing device that performs a fixing process on the recording medium transferred by the transfer member, and the transfer An image forming apparatus comprising: a voltage / current measuring device that measures a voltage or current when a predetermined current or voltage is applied to a member; and a temperature detecting device that detects a temperature of the fixing device.
A first environment category estimated based on the temperature detected by the temperature detection device, and a second environment category estimated based on the voltage or current measured by the voltage / current measurement device. A determination step for determining a classification of the environment to be controlled based on
A program for causing a computer of the image forming apparatus to execute a control step of performing process control based on the determined environmental classification.

Images