JP7346990B2 - image forming device - Google Patents

Description

The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunctional device thereof.

Conventionally, in image forming apparatuses such as copying machines and printers, a technique is known in which a fan is installed in a ventilation passage (opening) of the image forming apparatus main body in order to cool the inside of the image forming apparatus (for example, (See Patent Documents 1 and 2.)
Also known are techniques for installing a filter in addition to a fan in the ventilation path of the image forming apparatus main body, and techniques for installing an internal temperature sensor that detects the internal temperature of the image forming apparatus (for example, Patent Document 1, (See 2).

On the other hand, Patent Document 2 discloses a technique for detecting clogging of a filter (dust-proof filter) based on the internal temperature detected by an internal temperature sensor.

In conventional image forming apparatuses, ventilation (intake or exhaust) in the ventilation path may occur due to clogged filters, obstacles such as walls near the ventilation port, or dirt in the ventilation path. ) could not be performed satisfactorily. If the printing operation continues in such a state, sufficient cooling cannot be achieved through ventilation, and the internal temperature of the image forming apparatus increases, resulting in problems such as abnormal images.
To deal with this, it is possible to apply the technology of Patent Document 2 to detect poor ventilation in the ventilation passage of the image forming apparatus main body based on the temperature inside the machine detected by the temperature sensor inside the machine, but in such a case However, poor ventilation could not be detected with sufficient detection accuracy.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an image forming apparatus that can accurately detect poor ventilation in a ventilation path of an image forming apparatus main body.

The image forming apparatus according to the present invention includes a fan that is installed in a ventilation path of the image forming apparatus main body to take in or exhaust air to the image forming apparatus main body, and a fan that detects the internal temperature of the image forming apparatus main body. an internal temperature sensor, an external temperature sensor that detects an external temperature of the image forming apparatus main body, and a filter installed in the ventilation path, and the internal temperature sensor detects the temperature during continuous printing operation. When the internal temperature of the machine becomes higher than a predetermined temperature, the continuous printing operation is interrupted while the fan continues to be driven, and the continuous printing operation is resumed under conditions where the internal temperature of the machine does not rise compared to the continuous printing operation. A control mode is executed in which the printing is terminated, and when the control mode is executed, it is determined whether or not poor ventilation has occurred in the ventilation path based on the outside temperature detected by the outside temperature sensor. If the control unit determines that poor ventilation has occurred in the ventilation path, a predetermined period of time has not elapsed since the use of the new or cleaned filter started. When it is determined by the control unit, the display unit displays a message indicating that the ventilation port of the ventilation path may be blocked by an obstruction, and the use of the new or cleaned filter is started. When the control unit determines that the predetermined time has elapsed since the air flow, and the control unit has not determined that a ventilation failure has occurred in the ventilation path until then; The display section displays that the filter needs to be replaced or cleaned.

According to the present invention, it is possible to provide an image forming apparatus that can accurately detect poor ventilation in a ventilation path of an image forming apparatus main body.

1 is an overall configuration diagram showing an image forming apparatus in an embodiment of the present invention. FIG. 1 is a schematic perspective view showing an image forming apparatus. It is a schematic diagram showing a ventilation path. 7 is a graph illustrating an example of a change in internal temperature when a cooling mode is executed during continuous paper feeding. It is a graph showing the temperature change until the internal temperature of the machine is saturated during continuous paper feeding. It is a graph showing a change in the temperature inside the machine when the filter is normal and a change in the temperature inside the machine when the filter is abnormal. 3 is a flowchart showing control during continuous printing. FIG. 3 is a diagram showing a state in which a vent in the ventilation path is blocked by an obstacle. 7 is a graph showing a change in internal temperature when the filter is normal, a predicted change in internal temperature, and a change in internal temperature when the filter is abnormal in the image forming apparatus according to Modification Example 1. 7 is a flowchart illustrating control during continuous printing of the image forming apparatus in Modification 1. FIG. 7 is a graph illustrating an example of a change in internal temperature when a cooling mode is executed in an image forming apparatus in Modification 2. FIG. 7 is a schematic diagram showing a ventilation path of an image forming apparatus in Modification 3. FIG. 7 is a schematic diagram showing a ventilation path of an image forming apparatus in Modification 4. FIG.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and repeated explanations thereof will be simplified or omitted as appropriate.

First, referring to FIG. 1, the overall configuration and operation of image forming apparatus 100 will be described.
In FIG. 1, 100 is a printer as an image forming device, 2 is a photoreceptor drum on whose surface a toner image is formed, and 7 is a photoreceptor drum to which exposure light L is applied based on image information input from an input device such as a personal computer. Reference numeral 9 indicates an exposure section (writing section) that irradiates light onto the photoreceptor drum 2, and a transfer roller 9 that transfers the toner image carried on the photoreceptor drum 2 onto a sheet P that is conveyed to a transfer nip section (transfer position).
Reference numeral 12 denotes a paper feed section (paper feed cassette) in which a sheet P such as paper is stored, and 16 a registration roller (a paper feed cassette) that conveys the sheet P toward the transfer nip section where the photoreceptor drum 2 and the transfer roller 9 come into contact. timing roller), 20 is a fixing device that fixes an unfixed image on the sheet P, and 30 is an internal temperature sensor that detects the temperature inside the image forming apparatus main body 100 (inside temperature).

A charger 4, a developing device 5, a cleaning device 3, and the like are arranged around the photosensitive drum 2, and these members 2 to 5 constitute an image forming section 1 (see FIG. 3).
Further, as shown in FIG. 2, a display panel 80 as a display unit is provided in the upper exterior part of the image forming apparatus 100, and a ventilation hole 40a and external temperature A sensor 35 is provided.
The display panel 80 functions as a display section on which various information regarding the image forming apparatus 100 is displayed. Further, the ventilation port 40a is an opening for taking air into the ventilation path 40 (see FIG. 3) from outside the image forming apparatus main body 100 in order to cool the inside of the image forming apparatus main body 100. A louver is removably installed in the vent 40a.
The external temperature sensor 35 detects the temperature outside the image forming apparatus main body 100 (external temperature). By detecting the external temperature using the external temperature sensor 35, it is possible to understand the environment in which the image forming apparatus 100 is installed and changes therein. Note that the external temperature sensor 35 does not necessarily have to be exposed outside the device, and may be embedded in the exterior, for example, as long as it can detect the external temperature.

Referring to FIG. 1, a printing operation during normal image formation in image forming apparatus 100 will be described.
First, when image information is transmitted from an input device such as a personal computer to the exposure section 7 of the image forming apparatus 100, the exposure section 7 emits exposure light L (laser light) based on the image information onto the surface of the photoreceptor drum 2. issued towards.
On the other hand, the photosensitive drum 2 is rotating in the direction of the arrow (clockwise). First, the surface of the photosensitive drum 2 is uniformly charged at the portion facing the charging charger 4 (this is a charging process). In this way, a charged potential (approximately -900V) is formed on the photoreceptor drum 2. Thereafter, the charged surface of the photosensitive drum 2 reaches the irradiation position of the exposure light L. Then, the potential of the portion irradiated with the exposure light L becomes a latent image potential (approximately 0 to -100V), and an electrostatic latent image is formed on the surface of the photoreceptor drum 2 (in the exposure process). ).

Thereafter, the surface of the photosensitive drum 2 on which the electrostatic latent image is formed reaches a position facing the developing device 5. Then, toner is supplied onto the photoreceptor drum 2 from the developing device 5, and the latent image on the photoreceptor drum 2 is developed to form a toner image (this is a developing process).
Thereafter, the surface of the photosensitive drum 2 after the development process reaches a transfer nip portion (transfer position) with the transfer roller 9. Then, at the transfer nip between the transfer roller 9 and the transfer roller 9, a transfer bias (a bias with a polarity different from that of the toner) is applied from the power source to the transfer roller 9, so that the sheet is conveyed by the registration roller 16. The toner image formed on the photoreceptor drum 2 is transferred onto P (this is a transfer process).

After the transfer process, the surface of the photosensitive drum 2 reaches a position facing the cleaning device 3. At this position, untransferred toner remaining on the photosensitive drum 2 is mechanically removed by the cleaning blade and collected into the cleaning device 3 (this is a cleaning process).
In this way, a series of image forming processes on the photoreceptor drum 2 are completed.

On the other hand, the sheet P conveyed to the transfer nip portion (transfer position) between the photosensitive drum 2 and the transfer roller 9 operates as follows.
First, the uppermost sheet P stored in the paper feed section 12 is fed by the paper feed roller 15 toward the conveyance path.
Thereafter, the sheet P reaches the position of the registration rollers 16. Then, the sheet P that has reached the position of the registration roller 16 is placed at the transfer nip portion (between the transfer roller 9 and the photoreceptor drum 2) at the right time to be aligned with the image formed on the photoreceptor drum 2. (the contact position).

The sheet P after the transfer process passes through the transfer nip portion (transfer roller 9) and then reaches the fixing device 20 via the conveyance path. The sheet P that has reached the fixing device 20 is fed between the fixing roller 21 and the pressure roller 22, and the image is fixed by the heat received from the fixing roller 21 and the pressure received from both members 21 and 22. . The sheet P on which the image has been fixed is sent out from between the fixing roller 21 and the pressure roller 22 (which is a fixing nip portion), and then is discharged from the image forming apparatus main body 100.
In this way, a series of image forming processes (printing operations) are completed.
Note that during continuous printing, the above-described image forming process is continuously performed on a plurality of sheets P in one job.

The configuration and operation of image forming apparatus 100, which are characteristic of this embodiment, will be described in detail below.
As shown in FIG. 3, the image forming apparatus 100 is provided with a ventilation path 40 (cooling path) for cooling the inside of the image forming apparatus main body 100.
Specifically, in the present embodiment, the ventilation passage 40 directs air taken into the apparatus from the ventilation port 40a (see FIGS. 2 and 3) functioning as an intake port toward the image forming unit 1 from the exhaust port 40b. It is meant to be exhausted. As a result, the inside of the image forming apparatus main body 100 is cooled, and various problems occur when the inside of the apparatus reaches a high temperature (for example, malfunctions due to excessive temperature rise of the exposure section 7, PSU, motor, etc.). is reduced. In particular, in this embodiment, the exhaust port 40b of the ventilation path 40 is directed toward the image forming section 1, and the image forming section 1 is actively air-cooled, so that the toner in the developing device 5 may be agglomerated due to high temperature. Problems such as abnormal images caused by sticking or thermal deterioration of the members constituting the image forming section 1 can be reduced.
Note that the ventilation passage 40 is a duct having a ventilation port 40a formed at one end and an exhaust port 40b formed at the other end, and allows air to flow in the direction of the white arrow in FIG. 3.

Here, as shown in FIG. 3, a fan 41 and a filter 42 are installed in the ventilation path 40. Further, the image forming apparatus 100 is provided with an internal temperature sensor 30 and an external temperature sensor 35.
The fan 41 is an intake fan for sucking air into the image forming apparatus main body 1, and is for forming an air flow in the direction of the arrow in FIG. 3 in the ventilation path 40. In this embodiment, the fan 41 is in a drivable state while the main switch of the image forming apparatus 100 is turned on. Specifically, the fan 41 may be turned on or off in conjunction with the on/off of the main switch, or the on/off timing of the fan 41 may be adjusted and controlled depending on the temperature inside the machine or the temperature outside the machine. In some cases, the rotation speed is adjusted and controlled.
The filter 42 takes only air into the image forming apparatus 100 from outside and collects it to prevent foreign matter such as dust from entering the apparatus. The filter 42 is removably (replaceably) installed between the vent 40a and the fan 41. By providing the filter 42, problems such as foreign matter adhering to the sheet conveyance path of the image forming apparatus 100 resulting in poor conveyance of the sheet P, and foreign matter adhering to the photoreceptor drum 2 resulting in abnormal images can be alleviated. That will happen.

The internal temperature sensor 30 detects the internal temperature inside the image forming apparatus main body 100. In particular, in this embodiment, since the in-machine temperature sensor 30 is installed near the image forming section 1, the effect of reducing malfunctions in the image forming section 1 by executing the "cooling mode" described later is efficient. It will be demonstrated in
The external temperature sensor 35 detects the external temperature outside the image forming apparatus main body 100. In particular, in the present embodiment, when the "cooling mode" is executed, it is determined whether or not poor ventilation has occurred in the ventilation path 40 based on the external temperature detected by the external temperature sensor 35. However, this will be explained in detail later.

In this embodiment, during continuous printing operation, when the internal temperature detected by the internal temperature sensor 30 becomes higher than the predetermined temperature Tc, the fan 41 continues to be driven (air intake into the apparatus is stopped). A "control mode" is executed in which the continuous printing operation is interrupted, and the continuous printing operation is restarted and completed under conditions where the internal temperature of the machine does not rise compared to the continuous printing operation. Hereinafter, such a control mode will be appropriately referred to as a "cooling mode."
Note that the predetermined temperature Tc is a temperature that is set so that if the printing operation continues beyond the temperature Tc, problems such as abnormal images due to excessive temperature rise may occur. Although this predetermined temperature Tc varies depending on the model, it is set to about 50 degrees in this embodiment.

Specifically, in the present embodiment, the "cooling mode (control mode)" means that the temperature Ts detected by the internal temperature sensor 30 reaches a predetermined temperature Tc (first temperature Tc) during continuous printing operation, as shown in FIG. When the temperature Ts detected by the internal temperature sensor 30 becomes higher than the second predetermined temperature Tb (the first predetermined temperature Tc), the continuous printing operation is interrupted while the fan 41 continues to be driven. The continuous printing operation is resumed after the temperature becomes lower than
Note that the second predetermined temperature Tb is a temperature that is set so that, if the inside of the apparatus is cooled to the temperature Tb, no defects such as an abnormal image will occur even if the printing operation is restarted.

During continuous printing, as the number of sheets printed increases, the time during which the image forming apparatus 100 operates continuously becomes longer, and therefore the internal temperature is more likely to rise. Therefore, by executing such a cooling mode (control mode), printing operations will not be performed when the temperature inside the device becomes too high, reducing the occurrence of defects such as abnormal images due to high temperatures. Can be done. In particular, in this embodiment, the temperature in the vicinity of the image forming section 1 is detected by the in-machine temperature sensor 30, and the cooling mode is executed based on the detection result, so that the temperature of the image forming section 1 may rise excessively. This makes it possible to efficiently reduce problems such as abnormal images with good responsiveness.

Here, in the present embodiment, when the "cooling mode (control mode)" is executed, poor ventilation occurs in the ventilation path 40 based on the external temperature Te detected by the external temperature sensor 35. We are determining whether or not there is.
Specifically, when the cooling mode (control mode) is executed and the external temperature Te detected by the external temperature sensor 35 is below the threshold T0, it is assumed that poor ventilation has occurred in the ventilation path 40. Deciding.
Specifically, immediately after the execution of the cooling mode (control mode) is started, the external temperature Te is detected by the external temperature sensor 35, and when the detected external temperature Te is equal to or lower than the threshold T0, the air passage 40, a display panel 80 (see FIGS. 2 and 3) serving as a display section displays a message indicating that poor ventilation has occurred.

As shown in FIG. 8, the causes of poor ventilation in the ventilation path 40 include the case where the ventilation port 40a is blocked by an obstacle 200 such as a wall surface, or the inside of the ventilation path 40 becomes dirty and clogged over time. In some cases, the filter 42 becomes clogged with collected substances over time. In either case, sufficient air intake through the ventilation path 40 will not be carried out, resulting in a decrease in cooling efficiency.

The reason why it is possible to determine whether there is poor ventilation based on the external temperature Te detected by the external temperature sensor 35 when the cooling mode is executed will be described below.
If the filter 42 is not clogged and there is no poor ventilation, the cooling efficiency of the fan 41 is maintained and the outside temperature Te detected by the outside temperature sensor 35 is low (if the outside temperature is low). , the cooling mode (control mode) is never executed. Specifically, referring to the broken line R2 and the dashed-dotted line R3 in FIG. 5, when the outside temperature Te (outside temperature) is 20 degrees or 25 degrees, even if the inside temperature Ts reaches the saturation temperature due to continuous printing Since the temperature does not rise to the predetermined temperature Tc (approximately 50 degrees), the cooling mode is never executed.
On the other hand, if the outside temperature Te detected by the outside temperature sensor 35 is high (if the outside air temperature is high), the temperature of the air taken into the device 100 will also be high, resulting in a decrease in cooling efficiency and The temperature Ts tends to rise. Specifically, referring to the solid line R1 in FIG. 5, when the outside temperature Te (outside air temperature) is 30 degrees, etc., the outside temperature Te is set to the threshold T0 (in this embodiment, it is 25 degrees). If it exceeds the predetermined temperature Tc, the internal temperature Ts may exceed the predetermined temperature Tc due to continuous printing operations. Therefore, the cooling mode is executed so that the internal temperature Ts does not exceed the predetermined temperature Tc.

On the other hand, when poor ventilation occurs due to clogging of the filter 42, the cooling efficiency of the fan 41 decreases even if the outside temperature Te (outside air temperature) detected by the outside temperature sensor 35 is low. As a result, the internal temperature Ts tends to rise. Therefore, even if the external temperature Te detected by the external temperature sensor 35 is below the threshold T0, the cooling mode is executed and the temperature does not change as shown in the solid line R in FIG. The temperature changes as shown by the broken line Q. For this reason, even at the outside temperature Te at which the cooling mode is not normally executed, the temperature Ts detected by the inside temperature sensor 30 becomes high and the cooling mode is executed, resulting in a decrease in cooling efficiency due to poor ventilation. It can be determined that it is a thing. That is, if the external temperature Te detected by the external temperature sensor 35 when the cooling mode is executed is below the predetermined threshold T0, it is determined that poor ventilation in the ventilation path 40 has occurred. I can do it.
When it is determined that poor ventilation has occurred, a message to that effect will be displayed on the display panel 80.

Here, in the present embodiment, when the control unit 90 determines that poor ventilation has occurred in the ventilation path 40, the display panel 80 (display unit) displays a message indicating that the filter 42 needs to be replaced or cleaned. It can also be displayed.
Specifically, if a long time has not elapsed since the use of a new (or cleaned) filter 42, it is unlikely that the air passage 40 will have poor ventilation due to clogging of the filter 42; 40a is likely to be blocked by an obstruction 200 (see Figure 8), the display panel 80 will display the message ``The ventilation port on the side of the device may be blocked by an obstruction. Please either remove the object or move the device away from the obstruction.'' In addition, if a long time has passed since the new (or cleaned) filter 42 was used and poor ventilation in the ventilation path 40 has not been detected until then, the ventilation port 40a may become an obstruction. There is a low possibility that the air passage 200 is blocked, and there is a possibility that the air passage 40 is contaminated and the air passage 40 is not properly ventilated, especially the filter 42 is clogged. Please follow the steps below to maintain the filter.If the maintenance message still appears, further maintenance is required, please call a service person.'' will be displayed. Note that the usage time of the filter 42 can be measured by time measurement using a timer 81 (see FIG. 2).
By displaying a specific work level on the display panel 80 in this manner, when poor ventilation occurs in the ventilation path 40, more appropriate measures can be taken at the optimal timing.

By performing such control, the ventilation in the ventilation path 40 may be prevented due to the filter 42 becoming clogged, an obstacle 200 such as a wall near the ventilation port 40a, or the ventilation path becoming dirty. Even if (inhalation) cannot be performed sufficiently, such a state can be detected with high accuracy. Therefore, it is possible to reduce problems such as abnormal images caused by performing a printing operation while the internal temperature of the image forming apparatus 100 is increased. In addition, such control can be relatively easily performed by providing the external temperature sensor 35 instead of providing a special detection device for detecting poor ventilation, so the image forming apparatus 100 can be performed at a high cost. It will not become larger or larger.
Furthermore, when a ventilation failure in the ventilation path 40 is detected, the information is immediately displayed (notified) on the display panel 80, so that obstacles 200 near the ventilation port 40a can be removed or the image forming apparatus 100 itself can be removed. Appropriate measures can be taken at optimal timing, such as by moving away from the obstacle 200 or performing maintenance such as replacing or cleaning the filter 42.

Furthermore, the effects of the present invention will be supplemented.
When detecting poor ventilation due to a clogged filter 42, etc. only from the inside temperature Ts, whether the cooling efficiency has decreased due to poor ventilation due to a clogged filter 42, etc., and the inside temperature Ts has become high, or whether the outside temperature Te Since it is not possible to distinguish whether the cabin temperature Ts has increased due to an increase in the outside temperature, a notification (warning) is issued to the effect that poor ventilation has occurred even though there is no poor ventilation. There is a possibility that you may end up doing this.
In contrast, in this embodiment, since the presence or absence of poor ventilation due to clogging of the filter 42 is determined based on the outside air temperature when normal continuous printing shifts to the cooling mode, the inside temperature Ts due to poor ventilation is determined. It is possible to distinguish whether the increase in temperature inside the machine is due to an increase in the outside temperature Te or the increase in the internal temperature due to an increase in the outside temperature Te, and it is possible to improve the accuracy of detecting poor ventilation.
Furthermore, by determining the presence or absence of poor ventilation when executing the cooling mode, it is possible to display an alert on the display panel 80 only when the user's productivity is reduced due to poor ventilation. In addition, by determining whether or not there is a ventilation failure at the start of cooling mode, an alert will be displayed if the machine interior temperature Ts is low and printing can be performed at a temperature that does not cause problems such as toner sticking, even if there is a ventilation failure. The user can continue printing without printing. Then, if printing continues with poor ventilation and the internal temperature Ts rises to a point where problems such as toner sticking occur, and the cooling mode is executed, an alert will be displayed to allow the device to Downtime can be kept to a minimum.

Hereinafter, control during continuous printing will be summarized using the flowchart of FIG. 7.
When continuous printing is started, first, the inside temperature Ts of the inside of the machine is detected at regular intervals (in this embodiment, every second) by the inside temperature sensor 30 (step S1). Each time, it is determined whether the internal temperature Ts exceeds a predetermined temperature Tc (step S2).
As a result, if it is determined that the internal temperature Ts exceeds the predetermined temperature Tc, the cooling mode is started (step S3). Then, at approximately the same timing, the external temperature Te is detected by the external temperature sensor 35 (step S3). Then, it is determined whether the detected outside temperature Te is lower than a threshold T0 (step S5).
As a result, if it is determined that the outside temperature Te is lower than the threshold T0, it is assumed that poor ventilation has occurred, and an abnormality is notified on the display panel 80 (step S6). Then, when it is confirmed that the last sheet P of the job has been discharged, the cooling mode is ended and continuous printing is ended (steps S7, S8).
On the other hand, if it is determined in step S5 that the outside temperature Te is not lower than the threshold T0, it is assumed that no ventilation failure has occurred, and the abnormality is not notified to the display panel 80, and step S7 Continuous printing is ended through the subsequent flow (steps S7 and S8).

Further, if it is determined in step S2 that the internal temperature Ts does not exceed the predetermined temperature Tc, it is determined whether the internal temperature Ts exceeds the predetermined temperature Tb (<Tc) (step S9). . As a result, if it is determined that the internal temperature Ts exceeds the predetermined temperature Tb, it is determined whether the cooling mode was executed immediately before (step S10). As a result, if it is determined that the cooling mode was being executed in the immediately previous state, the cooling mode is continued to be executed (step S3). On the other hand, if it is determined in step S10 that the cooling mode has not been executed immediately before, continuous printing is ended when the ejection of the last sheet P of the job is confirmed (step S11). .
Further, if it is determined in step S9 that the internal temperature Ts is lower than the predetermined temperature Tb, it is determined whether the cooling mode was executed immediately before that (step S12). As a result, if it is determined that the cooling mode was being executed in the previous state, the cooling mode is ended (step S13), and continuous printing is performed when the ejection of the last sheet P of the job is confirmed. (Step S14).
On the other hand, if it is determined in step S12 that the cooling mode has not been executed immediately before, continuous printing is ended when the ejection of the last sheet P of the job is confirmed (step S14). .

<Modification 1>
Also in Modification 1, similarly to the present embodiment, when the "cooling mode (control mode)" is executed, the temperature in the ventilation passage 40 is determined based on the external temperature Te detected by the external temperature sensor 35. Determining whether or not there is poor ventilation.
However, in Modification 1, unlike the present embodiment, when the cooling mode (control mode) is executed, the predicted temperature Td of the machine interior temperature is based on the machine exterior temperature Te detected by the machine exterior temperature sensor 35. is determined, and based on the magnitude of the temperature difference (Tc - Td) between the predicted temperature Td and the predetermined temperature Tc, it is determined whether or not poor ventilation has occurred in the ventilation path 40.
Specifically, when the cooling mode (control mode) is executed, the external temperature Te detected by the external temperature sensor 35, the printing time (printing time) in the continuous printing operation, and the printing time are determined. When the predicted temperature Td of the cabin temperature, which is calculated from It is determined that a defect has occurred.
That is, in Modification 1, the inside temperature of the machine is predicted from the outside temperature Te (outside temperature) and the operating conditions of the apparatus during continuous printing, and the predicted temperature Td is used as the criterion for determining whether or not to execute the cooling mode. The presence or absence of poor ventilation is determined based on how much the temperature is different from the temperature Tc (predetermined temperature). This point differs from the present embodiment, in which the presence or absence of poor ventilation is determined based on whether the outside temperature Te is equal to or lower than the threshold value T0.

The reason for performing the control as in Modified Example 1 is as follows.
The internal temperature Ts of the image forming apparatus 100 is obtained in advance as data such as an increase curve of the internal temperature during printing, a temperature decrease curve during cooling during standby, a temperature decrease curve during natural cooling when the power is turned off, etc. Therefore, it is possible to make predictions. Therefore, it is possible to calculate the predicted inside temperature Td from the outside temperature Te acquired by the outside temperature sensor 35 and the printing time and standby time of the image forming apparatus 100.
In FIG. 9, a solid line R shows an example of a change in the cabin temperature Ts in a normal state where the filter 42 is not clogged and poor ventilation occurs, and a dashed line W shows a change in the predicted cabin temperature Td at that time, A broken line Q indicates a change in the internal temperature Ts in an abnormal state where the filter 42 is clogged and poor ventilation occurs. As shown by the solid line R and the dashed-dotted line W, the predicted temperature Td when the internal temperature Ts detected by the internal temperature sensor 30 in the normal state reaches the predetermined temperature Tc in the cooling mode is defined as T1. At this time, as shown by the broken line Q, in the abnormal state, the cooling efficiency decreases and the actual temperature inside the machine increases, so the timing to shift to the cooling mode is earlier than in the normal state (solid line R). On the other hand, the predicted temperature Td (dotted chain line W) predicts the internal temperature from the external temperature Te, printing time, and standby time on the premise that the apparatus is in a normal state. As shown by the broken line Q and the dashed-dotted line W, the predicted temperature Td when the internal temperature Ts detected by the internal temperature sensor 30 reaches the predetermined temperature Tc of the cooling mode in the case where poor ventilation occurs is defined as T2. In an abnormal state where poor ventilation occurs, the temperature inside the machine tends to rise, so the timing to start executing the cooling mode becomes earlier, and the temperature T2 becomes lower than the temperature T1. Therefore, the temperature difference (Tc - Td) between the predetermined temperature Tc at the start of the cooling mode and the predicted temperature Td at that time is equal to or greater than the predetermined value Tw (in this embodiment, it is set to about 3 degrees). If this occurs, it can be determined that poor ventilation is occurring due to clogging of the filter 42 or the like.

FIG. 10 is a flowchart showing control during continuous paper passing in Modification 1 , and corresponds to FIG. 7 in this embodiment described above.
Also in the first modification, when continuous printing is started, the inside temperature Ts is first detected by the inside temperature sensor 30 at regular intervals (in this embodiment, at one second intervals). Further, the predicted temperature Td obtained based on the outside temperature Te detected by the outside temperature sensor 35 and the printing operation (printing time, standby time) is updated at regular intervals (in this embodiment, every second). (Step S20). Each time, it is determined whether the internal temperature Ts exceeds a predetermined temperature Tc (step S2).
As a result, if it is determined that the internal temperature Ts exceeds the predetermined temperature Tc, the cooling mode is started (step S3). Then, it is determined whether the temperature difference (Tc - Td) between the predetermined temperature Tc and the predicted temperature Td at the start of the cooling mode is higher than the predetermined value Tw (step S21).
As a result, if it is determined that the temperature difference (Tc-Td) is higher than the predetermined value Tw, it is assumed that poor ventilation has occurred, and an abnormality is notified on the display panel 80 (step S6). Then, when it is confirmed that the last sheet P of the job has been discharged, the cooling mode is ended and continuous printing is ended (steps S7, S8).
On the other hand, if it is determined in step S5 that the outside temperature Te is not lower than the threshold T0, it is assumed that no ventilation failure has occurred, and the abnormality is not notified to the display panel 80, and step S7 Continuous printing is completed through the subsequent flow (steps S7 and S8).
Note that if it is determined in step S2 that the internal temperature Ts does not exceed the predetermined temperature Tc, the flow of steps S9 to S14 will be performed in the same manner as described with reference to FIG.
Also in the first modification, the cooling mode is executed based on the temperature Ts (inside the machine) detected by the inside temperature sensor 30, and at that time, the cooling mode is executed based on the temperature Te (outside the machine) detected by the outside temperature sensor 35. Anomaly detection is being performed. Thereby, in Modification 1 as well, poor ventilation in the ventilation path 40 can be detected with high accuracy, similar to the present embodiment.

<Modification 2>
In Modification 2, as in the present embodiment, the cooling mode is executed as necessary based on the machine interior temperature Ts detected by the machine interior temperature sensor 30. Specifically, during continuous printing operation, when the temperature Ts (inside the machine temperature) detected by the internal temperature sensor 30 becomes higher than the predetermined temperature Tc, the continuous printing operation is interrupted while the fan 41 continues to be driven. , the continuous printing operation is resumed and completed under conditions where the internal temperature of the machine does not rise compared to the continuous printing operation.
However, Modification 2 differs in the form of the cooling mode (a method in which the continuous printing operation is restarted under conditions where the internal temperature Tc does not rise compared to the normal continuous printing operation).
Specifically, in the cooling mode shown in FIG. 11A, when the internal temperature Ts reaches a predetermined temperature Tc, the process linear speed (rotational speed of the image forming member such as the photoreceptor drum 2, The image forming apparatus 100 is operated at a process line speed that is slower by a predetermined percentage (about 30% in the example of FIG. 11A) than the transport speed of the sheet P. That is, in the example of FIG. 11(A), the internal temperature of the machine is lowered by lowering the printing speed and lowering productivity.
On the other hand, in the cooling mode shown in FIG. 11(B), printing and printing stop are repeated at regular intervals when the internal temperature Ts reaches the predetermined temperature Tc. In the example shown in FIG. 11B, when the mode shifts to the cooling mode, a cycle of printing 10 sheets and then stopping printing for 30 seconds is repeated until the designated number of sheets has been printed. That is, in the example of FIG. 11(B), continuous printing is performed intermittently to reduce productivity, thereby lowering the internal temperature of the machine.
Also in the second modification, the cooling mode is executed based on the temperature Ts (inside the machine) detected by the inside temperature sensor 30, and at that time, the cooling mode is executed based on the temperature Te (outside temperature) detected by the outside temperature sensor 35. Anomaly detection is being performed. Thereby, in the second modification as well, it is possible to detect poor ventilation in the ventilation path 40 with high accuracy, as in the present embodiment.

<Modification 3>
The image forming apparatus 100 in the third modification is different from the image forming apparatus main body 100 in that, as shown in FIG. This is different from the present embodiment in that a fan (intake fan) is used to draw air into the air.
Furthermore, in Modification 3, a plurality of ventilation passages 40A and 40B are provided in which fans 41A and 41B having different rotation speeds are provided, unlike the present embodiment in which only one ventilation passage 40 is provided. differ. Specifically, as shown in FIG. 12, the first ventilation path 40A is for exhausting air taken in from an intake port 40b near the image forming section 1 to the outside of the apparatus through a ventilation port 40a that functions as an exhaust port. . Further, the second ventilation path 40B is for exhausting air taken in from the intake port 40b near the fixing device 20 to the outside of the device from the ventilation port 40a functioning as an exhaust port. As a result, the hot air inside the image forming apparatus 100 flows (exhausts) in the direction of the white arrow in FIG. 9, and the inside of the image forming apparatus main body 100 is cooled.
Here, in Modification 3 as well, filters 42A and 42B are installed between the ventilation port 40a and the fan 41, but the first filter 42A installed in the first ventilation path 40A is It is preferable that the second filter 42B installed in the second air passage 40B collects ozone, fine particles (UFP), and foreign odors. Preferably, it is one that collects UFP) and the like. In order to collect such multiple types of collectors, the optimal one is selected from multiple types of filters (ozone filters, VOC filters, electrostatic filters, deodorizing filters, etc.) and installed in each ventilation path. They may be installed in parallel in 40A and 40B. By using such filters 42A and 42B, it is possible to prevent problems such as ozone, VOC, UFP, and foreign odor from being discharged outside the apparatus.

Further, in the third modification, the rotation speed of the first fan 41A installed in the first ventilation path 40A is set to be larger than the rotation speed of the second fan 41B installed in the second ventilation path 40B. has been done. This is because the influence of an increase in internal temperature is greater in the vicinity of the image forming section 1 than in the vicinity of the fixing device 20, and it is desired to actively cool the vicinity of the image forming section 1.
In Modification 3, the in-machine temperature sensor 30 is installed in the air path 40A, 40B, where the fan with the highest rotation speed (the first fan 41A) among the multiple fans 41A, 41B is installed. 1 is installed near the part to be cooled (which is the image forming part 1) by the ventilation path 40A.
This is because the air flow is stronger in the first ventilation path 40A where the fan 41A with a high rotation speed is installed, compared to the second ventilation path 40B where the fan 41B with a low rotation speed is installed, and the filter is clogged. This is because poor ventilation is likely to occur due to such factors. Therefore, it is useful to install the in-machine temperature sensor 30 near the part to be cooled (image forming part 1) in the first air passage 40A and to perform the cooling mode based on the detected temperature Ts (in-machine temperature). become.
Also in the third modification, the cooling mode is executed based on the temperature Ts (inside machine temperature) detected by the inside temperature sensor 30, and at that time, the cooling mode is executed based on the temperature Te (outside temperature) detected by the outside temperature sensor 35. Anomaly detection is being performed. Thereby, in the third modification as well, it is possible to detect poor ventilation in the ventilation passages 40A and 40B with high accuracy, as in the present embodiment.

<Modification 4>
As shown in FIG. 13, the image forming apparatus 100 in Modification 4 is provided with a plurality of ventilation passages 40A and 40B in which fans 41A and 41B having different operating rates are installed. Note that although FIG. 13 is a schematic diagram showing the image forming section 1 (image forming apparatus 100) in the width direction (the direction perpendicular to the paper surface of FIG. 1), it is easy to understand the configuration of the ventilation passages 40A and 40B. For this reason, the directions of the filters 42A, 42B, fans 41A, 41B (intake fans), etc. are rotated approximately 90 degrees in the illustration.
Specifically, as shown in FIG. 13, the first ventilation path 40A directs the air taken in from the ventilation port 40a to one end in the width direction of the image forming section 1 (the drive source side where various drive motors are installed). ). Further, the second ventilation path 40B exhausts the air taken in from the ventilation port 40a toward the vicinity of the other end in the width direction (the non-driving source side) of the image forming section 1. As a result, air flows (intakes) inside the image forming apparatus 100 in the direction of the white arrow in FIG. 13(A), and the inside of the image forming apparatus main body 100 is cooled in the width direction.
Furthermore, in the fourth modification, the operation rate of the first fan 41A installed in the first ventilation path 40A is set to be higher than the operation rate of the second fan 41B installed in the second ventilation path 40B. has been done. Specifically, the first fan 41A is turned on and off in conjunction with the on/off of the main switch of the device main body 100, and has an operating rate of 100%, whereas the second fan 41B is Even if the main switch of the main switch is turned on, it is repeatedly turned on and off at predetermined intervals (for example, at an operating rate of about 70%). That is, the cooling air taken toward the image forming section 1 is appropriately controlled between a state as shown by the white arrow in FIG. 13(A) and a state as shown by the white arrow in FIG. 13(B). can be switched to This is because the temperature rise on the drive source side of the image forming apparatus 100 is greater than on the non-drive source side, and it is desired to actively cool the drive source side. This is also because it is desired to save energy by setting the operating rate of the second fan 41B to the minimum necessary.
In Modification 4, the in-machine temperature sensor 30 is installed in the air path 40A, 40B, where the fan with the highest operating rate (the first fan 41A) among the fans 41A, 41B is installed. It is installed near the part to be cooled (on the drive source side of the image forming part 1) by the 1 ventilation path 40A.
This is because the first air passage 40A, in which the fan 41A with a high operating rate is installed, has a larger air flow per unit time than the second air passage 40B, in which the fan 41B, which has a low operating rate, is installed. This is because poor ventilation is likely to occur due to filter clogging. Therefore, an in-machine temperature sensor 30 is installed near the part to be cooled (on the drive source side of the image forming section 1) in the first air passage 40A, and the cooling mode is set based on the detected temperature Ts (in-machine temperature). It will be useful to do so.
Also in the fourth modification, the cooling mode is executed based on the temperature Ts (inside machine temperature) detected by the inside temperature sensor 30, and at that time, the cooling mode is executed based on the temperature Te (outside temperature) detected by the outside temperature sensor 35. Anomaly detection is being performed. Thereby, in the third modification as well, it is possible to detect poor ventilation in the ventilation passages 40A and 40B with high accuracy, as in the present embodiment.

As described above, in the image forming apparatus 100 according to the present embodiment, the fan 41 for sucking in (or exhausting) air into the image forming apparatus main body 100 is installed in the ventilation passage 40, and the image forming apparatus main body 100 An internal temperature sensor 30 that detects an internal temperature Ts inside the image forming apparatus body 100 and an external temperature sensor 35 that detects an external temperature Te of the image forming apparatus main body 100 are installed. Further, during continuous printing operation, when the internal temperature Ts detected by the internal temperature sensor 30 becomes higher than the predetermined temperature Tc, the continuous printing operation is interrupted while the fan 41 continues to be driven, and the continuous printing operation is stopped. A "cooling mode (control mode)" is executed in which the continuous printing operation is restarted and the printing is completed under conditions in which the internal temperature Ts does not rise compared to the above conditions. Then, when the cooling mode is executed, it is determined whether or not poor ventilation has occurred in the ventilation path 40 based on the external temperature Te detected by the external temperature sensor 35.
Thereby, poor ventilation in the ventilation passage 40 of the image forming apparatus main body 100 can be detected with high accuracy.

Note that in this embodiment, the present invention is applied to the monochrome image forming apparatus 100, but the present invention can of course be applied to a color image forming apparatus.
Further, in this embodiment, the present invention is applied to the electrophotographic image forming apparatus 100, but the present invention is not limited to this, and the present invention is applicable to other image forming apparatuses (for example, inkjet image forming apparatuses). The present invention can of course be applied to image forming apparatuses such as image forming apparatuses, offset printing machines, etc.).
Further, in this embodiment, the present invention is applied to the image forming apparatus 100 in which the filter 42 is installed in the air passage 40, but the present invention can also be applied to an image forming apparatus in which a filter is not installed in the air passage. Can be applied. However, in such a case, the poor ventilation of the ventilation path cannot be caused by clogging of the filter, but is caused by the ventilation opening being blocked by an obstruction.
Even in those cases, effects similar to those of this embodiment can be obtained.

Note that it is clear that the present invention is not limited to this embodiment, and that this embodiment can be modified as appropriate within the scope of the technical idea of the present invention in addition to what is suggested in this embodiment. be. Further, the number, position, shape, etc. of the constituent members are not limited to those in this embodiment, and can be set to a number, position, shape, etc. suitable for implementing the present invention.

Note that in this specification and the like, the term "near the image forming section" is defined to include not only a position close to the image forming section, but also a position in contact with the image forming section and inside the image forming section. Therefore, "near the image forming section" includes a position close to or in contact with the photoreceptor drum, a position close to or in contact with the developing device, a position close to or in contact with the cleaning device, a position close to or in contact with the process cartridge, and a position close to or in contact with the process cartridge. This will also include the inside of the cartridge.
In addition, the above-mentioned "near position" is a position where the temperature change of the target object is reflected, that is, a position where the temperature changes in the same way even if the absolute value of the temperature changes when the temperature of the target object changes. Define something.

1 image forming section,
30 In-flight temperature sensor (in-flight temperature detection means),
35 External temperature sensor (external temperature detection means)
40 ventilation path (cooling path),
40a vent,
41 Fan (cooling fan),
42 filter,
80 Display panel (display section),
81 Timer,
90 control unit,
100 Image forming apparatus (image forming apparatus body).

Patent No. 5161539 Japanese Patent Application Publication No. 2014-167949

Claims (6)

a fan installed in a ventilation path of an image forming apparatus main body to take in or exhaust air to the image forming apparatus main body;
an internal temperature sensor that detects an internal internal temperature of the image forming apparatus main body;
an external temperature sensor that detects an external temperature of the image forming apparatus main body;
a filter installed in the ventilation path;
Equipped with
During continuous printing operation, when the temperature inside the machine detected by the inside temperature sensor becomes higher than a predetermined temperature, the continuous printing operation is interrupted while the fan continues to be driven, and the inside temperature of the machine is lower than that of the continuous printing operation. A control mode is executed to restart the continuous printing operation and finish printing under conditions where the temperature does not rise,
When the control mode is executed, the control unit determines whether or not poor ventilation has occurred in the ventilation path based on the external temperature detected by the external temperature sensor;
When the control unit determines that poor ventilation has occurred in the ventilation path,
When the control unit determines that a predetermined time has not elapsed since the use of the new or cleaned filter started, there is a possibility that the vent of the ventilation path is blocked by an obstruction. Display a message to that effect on the display,
When the control unit determines that the predetermined time has elapsed since the use of the new or cleaned filter started , and until then, ventilation failure has occurred in the ventilation path. An image forming apparatus characterized in that, when the control unit does not determine that the filter needs to be replaced or cleaned, the display unit displays a message that the filter needs to be replaced or cleaned. The control unit may determine that poor ventilation has occurred in the ventilation path when the external temperature detected by the external temperature sensor is below a threshold value when the control mode is executed. The image forming apparatus according to claim 1, characterized in that: When the control mode is executed, the control unit calculates the temperature from the outside temperature detected by the outside temperature sensor, and the time when printing was performed and the time when printing was not performed in the continuous printing operation. The image forming apparatus according to claim 1, wherein the image forming apparatus determines that poor ventilation has occurred in the ventilation passage when a predicted internal temperature of the machine is lower than the predetermined temperature by more than a predetermined value. . Claims 1 to 3, characterized in that when the control unit determines that poor ventilation has occurred in the ventilation path, the display unit displays a message that poor ventilation has occurred in the ventilation path. The image forming apparatus according to any one of Item 3. The image forming apparatus according to claim 1, wherein the in-machine temperature sensor is installed near an image forming section. A plurality of the ventilation passages are provided in which the fans having different operating rates or rotational speeds are installed,
The in-machine temperature sensor is installed in the vicinity of a part to be cooled by the plurality of air passages, in which a fan with the highest operating rate or rotational speed among the plurality of fans is installed. The image forming apparatus according to any one of claims 1 to 5.

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