JP2010002752A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means for estimating temperatures at a plurality of places other than the place where an environment sensor is installed by one environment sensor, and controlling the temperature and applied voltage at the temperature estimation place. <P>SOLUTION: Based on the information from the environment sensor which is installed near a secondary transfer roller and detects the temperature and (or) humidity, the temperatures outside a machine are estimated and a secondary transfer voltage is corrected. In addition, based on the detection information of the sensor, the internal temperature near a toner cartridge, the temperature near a photoreceptor drum, and the temperature near an intermediate transfer body cleaner blade are estimated, and the temperatures at the places are controlled by stopping continuous printing and driving a cooling fan in order to prevent a harmful effect on parts of the temperature estimation places due to increase of the internal temperature during continuous printing. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an improvement in control of an internal environment for protecting a main in-device part in performing control of a secondary transfer voltage and image forming operation in an image forming apparatus such as an electrostatic copying type printer.

In an image forming apparatus such as a copying machine, a toner image formed on an image bearing member such as a photosensitive drum or an intermediate transfer belt is transferred to a sheet using an electrostatic force generated by a transfer voltage applied to a transfer member such as a transfer roller. An image is formed by transferring to a transfer medium.
A cassette containing a medium to be transferred such as a sheet is usually installed at a position closest to the outside of the image forming apparatus (hereinafter referred to as “outside of the machine”) because of the necessity of replenishment, and can be easily opened and closed. It is not in the state that was done. Accordingly, the moisture content of the sheet at the sheet feeding slot is easily affected by the environment outside the apparatus, and the resistance value of the sheet changes with the change in the environment outside the apparatus, and as a result, the optimum secondary transfer voltage that can obtain a good transfer image. Variation occurs.

  However, the optimum secondary transfer voltage is affected not only by the external environment but also by the internal environment. In the image forming apparatus, heat is generated from the exposure device and the fixing device during the operation, causing a temperature rise in each part in the apparatus. Specifically, for example, in the exposure apparatus, heat is generated by turning on an exposure lamp when reading an original, and in the fixing apparatus, the sheet is passed through a fixing roller heated by a heater to melt and fix unfixed toner on the sheet. For this reason, heat is generated from the heater, and the heat is radiated to the surroundings to heat each device inside the image forming apparatus. For the purpose of avoiding an adverse effect on secondary transfer characteristics due to an excessive temperature rise caused by such heating, Patent Document 1 includes a means for detecting the surface temperature of the intermediate transfer member in the image forming apparatus, and the surface temperature of the intermediate transfer member. Discloses a method of interrupting the image forming operation when the value becomes equal to or greater than a predetermined threshold.

Further, when the temperature inside the image forming apparatus rises excessively, adverse effects such as toner aggregation and damage to electronic components inside the apparatus occur. Therefore, in Patent Document 2, the temperature rise in the image forming apparatus during continuous image formation is estimated from the temperature information of the temperature sensor that detects the temperature of the fixing roller, and the rotation speed of the cooling fan is switched to change the internal speed of the apparatus. A method for suppressing temperature rise is disclosed.
JP 2002-55538 Japanese Laid-Open Patent Publication No. 2006-133279

In addition to the above-described events, the photosensitive drum cleaner blade and the intermediate transfer member cleaner blade are softened and wound into the photosensitive drum or intermediate transfer member in addition to the above-described events. There is a problem that it falls.
However, if a temperature sensor is installed at each of these locations to manage the temperature, an additional burden is generated in terms of cost.

  The present invention uses a sensor (hereinafter referred to as “environmental sensor”) that detects the temperature and / or humidity of one in the image forming apparatus, and does not incur the cost of installing a new environmental sensor. It is an object of the present invention to provide a method for controlling temperatures at a plurality of locations inside an image forming apparatus in which adverse effects occur due to an increase.

  In order to solve the above problems, an image forming apparatus according to the present invention determines a suitable transfer voltage based on a detection result of at least a temperature of a temperature and humidity near a transfer member, and a detection result of the detection means. An image forming apparatus having a transfer unit that transfers a toner image on an image carrier onto another image carrier or a recording sheet by a transfer member to which the transfer voltage is applied, and is detected by the detector Based on the temperature, control target temperature estimation means for estimating the temperature in the temperature control target part other than the transfer part that requires temperature management, and the temperature in the temperature control target part based on the estimated temperature is a predetermined threshold value It is characterized by comprising a temperature rise suppression means for suppressing the above.

This suppresses the occurrence of adverse effects inside the image forming apparatus due to an excessive temperature rise in other parts without providing a new detector other than the transfer section.
Here, the control target temperature estimating means corresponds to the outside temperature estimating means for estimating the outside temperature based on the temperature detected by the detector, the detected temperature and the estimated outside temperature. First holding means for holding the temperature at the temperature control target portion determined in advance as a table, and based on the estimated outside temperature and the detected temperature, the table of the first holding means is Referring to the temperature control target region, the temperature may be estimated.

Thereby, based on the temperature detected by the detector in the image forming apparatus, the temperature at the temperature control target part can be estimated more appropriately.
Further, the outside temperature estimating means includes a second holding means for holding a relationship between a change in the state of the image forming operation and a change in the detected temperature as a table for a specific outside temperature, and a current image forming operation. An acquisition means for acquiring information relating to the situation, and compares the current temperature detected by the detection means with the temperature corresponding to the situation of the current image processing operation in the table of the second holding means; An outside temperature may be estimated.

Thereby, the temperature outside the apparatus can be accurately estimated according to the image forming operation status.
Further, the information regarding the status of the image forming operation may include a continuous image forming time, an image forming operation stop time, and an operating status of the temperature rise suppression unit.
Here, a fan device or an image forming operation control unit is instructed as the temperature rise suppression unit, and the temperature control target region is increased by decreasing the number of times of image formation per short time or by stopping the image forming operation. Inhibiting temperature may be included.

Furthermore, the time of temperature increase suppression processing that is executed when the estimated temperature of the temperature control target part becomes equal to or higher than a predetermined threshold may be changed according to the estimated outside temperature.
Thereby, it is possible to accurately prevent the temperature inside the image forming apparatus from excessively rising according to the temperature outside the apparatus.
Further, the temperature control target part may be any of the vicinity of the toner cartridge, the vicinity of the cleaner blade of the photosensitive drum, the vicinity of the cleaner blade of the intermediate transfer member, or any combination of the three locations.

  This determines the transfer voltage and prevents excessive temperature rise, thereby preventing the toner cartridge from coagulating and solidifying, or reducing the cleaning function due to softening of the cleaner drum of the photosensitive drum and the cleaner blade of the intermediate transfer member. prevent.

Hereinafter, an embodiment according to the present invention will be described with reference to the drawings, taking as an example a case where the embodiment is applied to a tandem type digital color printer. (Hereafter, simply called “printer”)
(1) Overall Configuration of Printer FIG. 1 is a schematic cross-sectional view showing the overall configuration of a printer 100 according to an embodiment of the present invention, and includes an image forming unit 10, a paper feeding unit 20, a transfer unit 30, a fixing device 40, The controller 50, the environment sensor 71, the cooling fan 8, the louver 9 and the like are provided.

When the printer 100 is connected to a network (for example, LAN: Local Area Network) and receives an instruction to execute a print job from an external terminal device (not shown), cyan, magenta, yellow, and black are received based on the instruction. A toner image of each color is formed, and these are multiple transferred to form a full color image.
Hereinafter, the reproduction colors of cyan, magenta, yellow, and black are represented as C, M, Y, and K, and the C, M, Y, and K are added as subscripts to the numbers of the components related to the reproduction colors.

The image forming unit 10 includes image forming units 1C, 1M, 1Y, and 1K, an optical unit 15, an intermediate transfer belt 31, and the like.
The image forming units 1C to 1K include photosensitive drums 11C to 11K, chargers 12C to 12K, developing units 13C to 13K, primary transfer rollers 34C to 34K, and photosensitive drums 11C to 11K disposed around the photosensitive drums 11C to 11K, respectively. Cleaners 14C to 14K for cleaning the toner, and C to K color toner images are formed on the photosensitive drums 11C to 11K, respectively.

The intermediate transfer belt 31 is an endless belt, is stretched around a driving roller 32 and a driven roller 33 and is driven to rotate in the direction of arrow A.
The optical unit 15 includes a light emitting element such as a laser diode, emits a laser beam L for image formation of C to K colors in accordance with a drive signal from the control unit 50, and scans the photosensitive drums 11C to 11K.

By this exposure scanning, electrostatic latent images are formed on the photosensitive drums 11C to 11K charged by the chargers 12C to 12K. The electrostatic latent images are developed by the developing units 13C to 13K so that toner images of colors C to K are primarily transferred onto the photosensitive drums 11C to 11K at the same position on the intermediate transfer belt 31. It is executed at different timings.
The toner images of the respective colors are sequentially transferred onto the intermediate transfer belt 31 by the electrostatic force acting on the primary transfer rollers 34C to 34K to form a full color toner image, and further move toward the secondary transfer position 36.

  On the other hand, the paper feeding unit 20 includes a paper feeding cassette 21 that accommodates the sheets S, a feeding roller 22 that feeds the sheets S in the paper feeding cassette 21 one by one onto the conveying path 23, and a second feeding of the fed sheets S. A timing roller pair 24 and the like for taking the timing to send to the transfer position 36 are provided, and the sheet S is fed from the paper supply unit 20 to the secondary transfer position 36 in accordance with the movement timing of the toner image on the intermediate transfer belt 31. Then, the toner image on the intermediate transfer belt 31 is collectively transferred onto the sheet S by the action of electrostatic force by the secondary transfer roller 35.

The sheet S that has passed through the secondary transfer position 36 is further conveyed to the fixing device 40, and after the toner image (unfixed image) on the sheet S is fixed to the sheet S by heating and pressing in the fixing device 40, The paper is discharged onto the discharge tray 62 via the discharge roller pair 61.
In order to cool the inside of the image forming apparatus, outside air is sucked into the inside of the image forming apparatus by the cooling fan 8 and circulated through the apparatus, and is then discharged from the louver 9.

  FIG. 2 is a block diagram illustrating a configuration of the control unit 50. As shown in the drawing, the control unit 50 includes, as main components, a CPU (Central Processing Unit) 51, a communication interface (I / F) unit 52, a ROM (Read Only Memory) 53, a RAM (Random Access Memory) 54, An EEPROM (Electrically Erasable and Programmable Read Only Memory) 55 is provided.

The communication I / F unit 52 is an interface for connecting to a LAN, such as a LAN card or a LAN board, and receives print job data from the outside.
The CPU 51 reads a necessary program from the ROM 53, controls the operations of the image forming unit 10, the paper feeding unit 20, the transfer unit 30, and the fixing device 40 in a unified manner with timing, and the communication I / F unit 52 The printing operation based on the received print job data is smoothly executed. Further, the transfer voltage to be applied to the secondary transfer roller 35 is determined with reference to the detection value of the environment sensor 71. Further, temperature estimation is performed for a plurality of temperature control target parts inside and outside the image forming apparatus that require temperature management, and the temperature estimation is made based on an excessive increase in the temperature inside the image forming apparatus during continuous printing based on the estimated temperature of the part. In order to prevent the occurrence of adverse effects on the location, as a temperature rise suppression means that suppresses the estimated temperature from exceeding the predetermined threshold at the temperature control target portion, continuous print execution and stop and cooling fan drive control are performed. Do. Details will be described later.

The EEPROM 55 is a storage unit composed of a nonvolatile memory, and stores acquired environmental information, transfer voltage information, estimated temperature information, and the like.
(2) Outline of Secondary Transfer Voltage Control Transfer members such as the primary transfer rollers 34C to 34K and the secondary transfer roller 35 are generally formed of an elastic material having conductivity, and the resistance value thereof is such as temperature and humidity. It is known that it fluctuates depending on the environmental conditions around, especially the temperature.

When the toner image is transferred, the potential on the peripheral surface of the secondary transfer roller 35 that is in contact with the sheet surface greatly influences, so that the potential on the peripheral surface of the secondary transfer roller 35 does not change according to the temperature change as described above. In addition, by properly controlling the transfer voltage applied to the axis of the secondary transfer roller 35, a good transfer image can be obtained.
Therefore, in this embodiment, an appropriate secondary transfer voltage is obtained mainly as follows.
(A) Optimal Transfer Voltage Determination Process This process is to determine an optimum transfer voltage by actually measuring a value indicating the resistance value of the secondary transfer roller 35.

  Here, the “value indicating the resistance value” is not limited to the resistance value itself in the radial direction of the secondary transfer roller 35, and a value having a certain correlation with the resistance value, for example, a constant voltage is used as the secondary transfer roller. A constant current is supplied between the shaft core of the driving roller 32 of the intermediate transfer belt 31 and the current value when applied between the shaft core of the intermediate transfer belt 31 and the driving roller 32 of the intermediate transfer belt 31. It is a concept including the voltage measured when

A value indicating the resistance value of the secondary transfer roller 35 is actually measured, and an optimum transfer voltage is determined with reference to a table showing a correlation between the index value obtained in advance and the optimum transfer voltage value. (Hereinafter, this process is referred to as “ATVC (Auto Transfer Voltage Control)”).
In the present embodiment, as an example, a constant current is supplied to the axis of the secondary transfer roller 35, and the secondary transfer roller 35 and the secondary transfer roller 35 are rotated at a predetermined sampling interval while the roller rotates once (800 ms in this example). The voltage value obtained by measuring the voltage between the shafts of the driving roller 32 of the intermediate transfer belt 31 and averaging it is regarded as a value indicating the resistance value of the secondary transfer roller, and is correlated therewith. ATVC processing is performed using a predetermined table.

(B) Transfer voltage correction process Since the above-described "value indicating the resistance value" requires a certain amount of time, if the ATVC process is executed every time the in-machine temperature changes, the image formation productivity can be improved. Incurs a decline.
Therefore, in this embodiment, instead of executing the ATVC process, secondary transfer voltage correction according to the temperature change amount is executed.

A constant current was supplied to the secondary transfer roller 35 in a state where no sheet is present in the transfer portion in order to flow an appropriate current that realizes good toner transfer regardless of the variation in the resistance value of the transfer member as described above. The time voltage (this voltage is called “secondary transfer monitor voltage”) is detected as a substitute value for the electrical resistance value, and the image is transferred onto the sheet based on the detected voltage and a preset table and arithmetic expression. In general, a method for determining an optimal secondary transfer voltage to be applied at a constant voltage is used.
(C) Specific Content of Secondary Transfer Voltage Control FIG. 3 is a flowchart showing the content of secondary transfer voltage control executed by the control unit 50 in the present embodiment.

First, when a print job is received from an external terminal via a LAN, an environmental step indicating the magnitude of the absolute humidity is acquired based on the temperature and humidity information detected by the environmental sensor 71 (step S1: YES, step S2). ).
FIG. 4 shows a table for determining this environmental step. As shown in the table, in the present embodiment, the absolute humidity obtained in accordance with the temperature (° C.) and the relative humidity (%) detected by the environmental sensor 71 is used as an index. Are classified into 8 stages.

In step S3, the above-described ATVC process is executed, and the secondary transfer roller 35 is subjected to secondary calculation using the following equation 1 based on the measured voltage value of the secondary transfer roller 35 (secondary transfer monitor voltage) and the environmental step. Acquire the transfer voltage.
Note that the secondary transfer voltage acquired here is an optimum transfer voltage to be applied at the time of execution of the ATVC, but is a reference voltage in the transfer voltage correction process described later. This is referred to as “secondary transfer reference voltage”.
(Expression 1) Secondary transfer reference voltage (V) = secondary transfer monitor voltage (V) × slope a + offset value In the above formula 1, the slope a and the offset value are optimal for each level of the environment step by repeating experiments in advance. Therefore, the secondary transfer reference voltage is required to be obtained.

FIG. 5 shows an example of a table when the sheet is plain paper, and is stored in the ROM 53. When actually transferring, the moisture absorption state of the sheet also greatly affects, and therefore, the slope a and the offset value are set using the environmental step having a certain correlation with the moisture absorption state as a parameter.
Further, the above-mentioned table corresponding to each type of sheet such as plain paper, thick paper, OHP paper, glossy paper, postcard, etc. is similarly stored in the ROM 53.

The secondary transfer reference voltage determined by the ATVC process as described above is stored in the EEPROM 55.
Next, the temperature change amount Δt in the secondary transfer unit 36 is acquired (step S4). The control unit 50 monitors the temperature detected by the environment sensor 71 and obtains the amount of temperature change in the secondary transfer unit since the execution of the ATVC as Δt.

Then, based on the secondary transfer reference voltage determined in step S3 and the value of Δt, a corrected secondary transfer voltage is calculated by the arithmetic expression shown in the following expression 2 (transfer voltage correction process: step S4).
(Expression 2) Secondary transfer voltage (V) = secondary transfer reference voltage (V) + Δt (° C.) × slope s (V / ° C.)
FIG. 6 is a table showing the value of the slope s. The table is obtained in advance by experiments so as to obtain an optimal correction amount according to the value of the secondary transfer reference voltage and the level of the environmental step at that time, and the ROM 53 Is stored inside.

The secondary transfer voltage corrected in this way is stored in the EEPROM 55.
The control unit 50 controls the application of the secondary transfer reference voltage to the secondary transfer roller 35 to perform a job execution process for forming an image on the sheet by the series of operations described above, and the job is completed. Whether or not (steps S5 and S6).
The header of the print job data received from the external terminal includes information related to the number of pages N1 to be printed. The control unit 50 counts the number of pages N2 where image formation has been completed, and the value of N1-N2 is Whether or not the job is completed can be determined based on whether or not it is “0”.

If the determination at step S6 is affirmative, the secondary transfer voltage control is terminated as it is, but if there is still a job, the temperature change amount Δt at the secondary transfer portion is acquired next (step S).
6: NO, step S4).
(4) Outline of temperature estimation inside and outside of image forming apparatus by environmental sensor In order to suppress temperature rise inside the apparatus due to heat generated during operation, the image forming apparatus drives the cooling fan 8 to take in outside air, and The heat inside is discharged from the louver 9. Accordingly, the temperature inside the image forming apparatus is affected by the temperature outside the apparatus.

  FIG. 7 shows changes in temperature detected by the environment sensor 71 during continuous printing at the environment temperatures of 25 ° C. and 30 ° C., and FIG. 7 shows changes in temperature detected by the environment sensor 71 during standby (when printing is stopped). FIG. 9 shows changes in temperature detected by the environmental sensor 71 when the cooling fan is driven at the environmental temperature. As can be seen from these figures, the temperature change in the vicinity of the environmental sensor 71 during continuous printing, standby, and cooling fan driving is affected by the temperature outside the apparatus. Therefore, the temperature outside the apparatus can be estimated from the temperature of the environmental sensor 71. Further, since the temperature control target location other than the location where the environmental sensor 71 is installed in the image forming apparatus is naturally considered to be similarly affected by the temperature outside the device, the estimated temperature outside the device and the detected temperature of the environment sensor are also used. It is possible to estimate the temperature of the temperature control target location. Therefore, in the present embodiment, the temperature of the location is controlled based on the estimated temperature of the temperature control target location.

(5) Specific contents of temperature control In the printer 100 shown in FIG. 1, the temperature outside the apparatus is estimated from the temperature detected by the environmental sensor 71 installed in the vicinity of the secondary transfer roller, and the estimated temperature outside the apparatus is estimated. Based on the above, the temperature near the toner cartridge is estimated, and the temperature near the toner cartridge is controlled so as not to exceed the temperature at which toner aggregation occurs. Specifically, control is performed by the method described below in accordance with the temperature control flowchart shown in FIG.

The estimated detection temperature table of the environmental sensor 71 is controlled based on the actual measurement data shown in FIGS. 7, 8, and 9 when the installation environmental temperature is 25 ° C. and 30 ° C. during continuous printing, standby, and driving of the cooling fan 8. The information is stored in the ROM 53 (see FIG. 2) of the unit 50.
First, when a print job is received from the external terminal via the LAN, it is determined whether or not a first fixed time has elapsed from the start of the job (100 msec in the present embodiment) (step S1).

  When 100 msec elapses, the estimated change amount of the detected temperature by the environment sensor 71 when the installation environment temperature is 25 ° C. and 30 ° C. is acquired from the temperature change estimation table according to the operation performed at that time, respectively. T_25 (estimated detection temperature of the environmental sensor 71 at an arbitrary point in time when the image forming apparatus installation environment temperature is 25 ° C.) and T_30 (image formation apparatus installation) The estimated temperature of the environmental sensor 71 at an arbitrary time when the environmental temperature is 30 ° C. is calculated (step S1: YES, step S2). FIG. 11 shows the temperature change estimation table when the environmental temperature is 25 ° C., and FIG. 12 shows the temperature change estimation table when the environmental temperature is 30 ° C.

Next, it is determined whether or not a second fixed time has elapsed from the start of the job (in this embodiment, 5 minutes) (step S3).
When 5 minutes have elapsed, T_25 and T_30 are compared with the measured temperature T_s detected by the environment sensor 71, and the estimated outside temperature is classified into a plurality of stages according to the table shown in FIG. In the case of this form, three steps of low temperature, normal temperature, and high temperature) (step S3: YES, step S4).

FIG. 14 is a graph showing the measured temperature near the toner cartridge and the temperature detected by the environment sensor 71 for each of the three stages. From the figure, the detection temperature of the environmental sensor when toner aggregation starts to occur is determined for each of the three stages.
After that, according to the classified stages, the preset operation time shown in FIG. 15, that is, the continuous print permission time, the continuous print interruption time, and the cooling fan 8 drive time are obtained, and each operation is performed for each set time. (Step S5), return and repeat this routine.

By the method described above, the temperature in the vicinity of the toner cartridge is controlled so as not to rise above the temperature at which toner aggregation occurs.
Note that the operation time setting values shown in FIG. 15 are prepared for toner cartridges of C to K colors, respectively.
<Modification>
The present invention has been described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and includes the following modifications.
(1) In the above embodiment, the target for temperature change estimation and temperature control is the vicinity of the toner cartridge, but other locations inside the image forming apparatus, for example, the vicinity of the photosensitive drum or the cleaner blade of the intermediate transfer member It is good.

When the target of temperature change estimation and temperature control is, for example, in the vicinity of the photosensitive drum, the control information acquired in step S5 is the control information shown in FIG. 17 preset from the actual measurement data shown in FIG. In the case of the vicinity of the intermediate transfer member cleaner blade, the control information acquired in step S5 is the control information shown in FIG. 19 preset from the actual measurement data shown in FIG.
(2) In the above embodiments and modifications, the tandem type color printer has been described. However, the present invention is not limited to this. A monochrome printer may be used, a four-cycle color image forming apparatus, and other copying. The present invention is generally applied to an image forming apparatus generally equipped with a transfer device, such as a copying machine, a facsimile machine, and a multifunction machine of these.

  Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and the contents of the above-described embodiments and modifications may be combined.

  According to the temperature control method of the present invention, the temperature at a plurality of locations other than the location where the environmental sensor is installed is estimated by one environmental sensor in the image forming apparatus without causing a burden of the cost of installing a new environmental sensor. This is useful as a control technology.

1 is a schematic cross-sectional view showing a schematic configuration of an image forming apparatus according to Embodiment 1 of the invention. The block diagram which shows the structure of the control part of the said image forming apparatus. Secondary transfer voltage calculation flowchart Environmental step table Table of slope a and offset for calculating secondary transfer reference voltage Table of slope s for secondary transfer voltage correction Graph representing temperature change detected by environmental sensor during continuous printing at image forming apparatus installation environment temperature of 25 ° C. and 30 ° C. Graph representing temperature change detected by environmental sensor during standby (continuous print interruption) at image forming apparatus installation environment temperature of 25 ° C. and 30 ° C. Graph showing temperature change detected by environmental sensor when driving fan at environmental temperature of 25 ° C. and 30 ° C. where image forming apparatus is installed Flow chart for estimating and controlling the temperature near the toner cartridge Table for calculating estimated temperature of detected temperature of environment sensor at image forming apparatus installation environment temperature of 25 ° C. Table for calculating estimated temperature of detected temperature of environment sensor at image forming apparatus installation environment temperature 30 ° C. Table to estimate the outside temperature A graph showing the relationship between the temperature detected by the environmental sensor and the temperature in the vicinity of the toner cartridge for each estimated temperature Operation setting table for preventing toner aggregation according to the temperature outside the estimator A graph showing the relationship between the temperature detected by the environmental sensor and the temperature near the photoconductor drum, by temperature outside the estimator Operation setting table to prevent adverse effects on the photoreceptor drum cleaner blade due to the temperature outside the estimator A graph showing the relationship between the temperature detected by the environmental sensor and the temperature near the intermediate transfer member cleaner blade for each estimated temperature Operation setting table to prevent adverse effects on the intermediate transfer body cleaner blade due to the temperature outside the estimator

Explanation of symbols

1 Printer 8 Cooling Fan 15 Developer 17 Photosensitive Drum Cleaner Blade 38 Intermediate Transfer Body Cleaner Blade 71 Environmental Sensor

Claims (8)

A detector that detects at least the temperature and humidity in the vicinity of the transfer member, and an appropriate transfer voltage is determined based on the detection result of the detection means, and the transfer member to which the transfer voltage is applied is applied to the image carrier. An image forming apparatus having a transfer unit for transferring a toner image onto another image carrier or recording sheet,
Based on the temperature detected by the detector, the control target temperature estimation means for estimating the temperature in the temperature control target part other than the transfer unit that requires temperature management,
An image forming apparatus comprising: a temperature rise suppression unit that suppresses the temperature from exceeding a predetermined threshold at the temperature control target portion based on the estimated temperature. The control target temperature estimating means includes
Based on the temperature detected by the detector, an external temperature estimating means for estimating an external temperature,
First holding means for holding, as a table, the temperature at the temperature control target portion determined in advance corresponding to the detected temperature and the estimated outside temperature;
With
2. The image according to claim 1, wherein a temperature at a temperature control target part is estimated by referring to a table of the first holding unit based on the estimated outside temperature and the detected temperature. Forming equipment. The outside temperature estimating means has a second holding means for holding, as a table, a relationship between a change in the status of the image forming operation and a change in the detected temperature for a specific outside temperature,
Acquisition means for acquiring information on the current image forming operation status;
With
The outside temperature estimation means compares the current temperature detected by the detection means with the temperature corresponding to the current image processing operation status in the table of the second holding means, and calculates the temperature outside the machine. The image forming apparatus according to claim 1, wherein the image forming apparatus is estimated.   4. The image forming apparatus according to claim 1, wherein the information on the status of the image forming operation includes a continuous image forming time, an image forming operation stop time, and an operating status of the temperature rise suppression unit. 5. .   The image forming apparatus according to claim 1, wherein the temperature rise suppression unit is a fan device. An image forming operation control means for controlling the image forming operation;
The temperature increase suppression unit instructs the image forming operation control unit to reduce the number of times of image formation per short time, or to suppress the temperature increase of the temperature control target part by stopping the image forming operation. The image forming apparatus according to claim 1, wherein: The temperature rise suppression means is
The time of temperature rise suppression processing to be executed when the estimated temperature of the temperature control target part is equal to or higher than a predetermined threshold is changed in accordance with the estimated outside temperature. 5. The image forming apparatus according to any one of 4 above.   2. The temperature control target part is any one of a vicinity of a toner cartridge, a vicinity of a cleaner blade of a photosensitive drum, a vicinity of a cleaner blade of an intermediate transfer body, or a combination of any of the three locations. 8. The image forming apparatus according to any one of items 1 to 7.

Images