JP2013086320A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce running cost and improve productivity by reducing the amount of wasteful ink consumption.SOLUTION: An air detection number counter 101 counts the number of times of air detection that detects mixture of air into a sub ink tank by an air detection means. When the number of times of air detection counted by the counter 101 reaches a predetermined threshold value including the number of times of detection of air mixture of a case in which an apparatus is normal, a determination means 102 determines that a trouble has occurred in the apparatus, and the result of the determination is output by a determination result outputting means 103.

Description

  The present invention relates to an image forming apparatus.

  In an ink jet recording apparatus used as an image forming apparatus such as a printer, a facsimile machine, or a copying machine, air is mixed into an ink supply path for supplying ink from an ink cartridge as a main ink tank to a head tank as a sub ink tank for temporarily storing ink. There are things to do. The air mixed in the ink supply path is carried along with the ink to the head tank through the ink supply path. Thereafter, the air in the head tank also enters the liquid chamber of the recording head communicating with the head tank together with the ink. When air enters the liquid chamber of the recording head, the negative pressure of the recording head is broken, and problems such as ink dripping from the nozzles of the recording head and defective ejection occur. As a cause of air mixing into the ink supply path, the connection of the connection part between the ink cartridge and the head tank of the tube constituting the ink supply path that connects the ink cartridge and the head tank is loosened with the operation of the apparatus for a long time. Air may enter the tube from the loose connection. Or, for example, when supplying ink to the head tank after replacing the ink cartridge, dust adheres to the air release valve when the air release valve provided in the head tank is opened, and then attaches when the air release valve is about to close. There is a case where a gap is generated between the air release valve and the opening edge due to the dust and air is mixed into the head tank from the gap. Therefore, it is important to prevent air from entering the liquid chamber of the recording head.

  There is known a method for detecting that air is mixed in order to discharge air mixed in the head tank. As a method for detecting that the air is mixed, there is a method using a liquid level detection mechanism provided in the head tank. As this liquid level detection mechanism, the one described in Patent Document 1 is known. In the liquid level detection mechanism disclosed in Patent Document 1, two electrode pins are provided downward from an upper inner wall constituting an ink storage portion in the head tank. When ink is supplied to the ink storage section, the two electrode pins become conductive, and when the ink level is further increased and the liquid level rises, the area of the electrode pins covered with ink increases, resulting in electrical conduction. Increasing the degree increases the current value between the electrode pins. Conversely, when ink is ejected from the recording head and decreases, the current value between the electrode pins decreases. The liquid level position of the ink is detected by detecting the current value between the electrode pins. When air is mixed into the ink supply path when a predetermined amount of ink is being supplied to the head tank, and the mixed air enters the ink storage part of the head tank, the air accumulates above the ink level in the head tank. The ink level drops slightly. For this reason, there is a difference between the current value of the electrode pin when the predetermined amount of ink is consumed without air mixing and the current value when the predetermined amount of ink is consumed due to air mixing. Arise. It is detected that air is mixed into the head tank based on the difference in current value. Thereafter, the mixed air supplies ink into the head tank, raises the liquid level in the head tank, opens the air release valve provided on the upper wall surface of the head tank, and discharges it from the opening.

  However, the air detection method of Patent Document 1 also detects air contamination that occurs during replacement of an ink cartridge, which is normal and the apparatus is operating normally. In the air discharge process for discharging the mixed air, a small amount of ink is discharged from the opening together with the air. The air is discharged due to the air contamination due to the abnormality of the apparatus when the ink cartridge is exchanged, which is a normal operation in which the apparatus is not abnormal. Therefore, the ink is wasted and the running cost is increased. And since the apparatus main body is temporarily stopped in order to suspend operation | movement of an apparatus and to perform an air discharge process, productivity deteriorates.

  The present invention has been made in view of the above problems, and an object of the present invention is to reduce air discharge processing due to air intrusion into the recording head and to reduce wasteful ink consumption to reduce running costs. And providing an image forming apparatus capable of improving productivity.

  To achieve the above object, a replaceable main ink tank, a sub ink tank for temporarily storing ink from the main ink tank, and an ink supply means for feeding ink from the main ink tank to the sub ink tank And an air detection unit that detects that air has been mixed into the sub ink tank, and the number of times of air detection in which the air detection unit has detected that air has been mixed into the sub ink tank. On the basis of the air detection frequency counting means for counting the air detection frequency, the air detection frequency counted by the air detection frequency counting means, and a predetermined threshold value including the frequency of air contamination detection when the device is normal. A judgment means for judging that an abnormality has occurred; and a judgment result output means for outputting a judgment result of the judgment means. It is intended to.

  In the present invention, air may be mixed into the sub ink tank even by a normal operation of replacing the ink cartridge, for example, performed when the apparatus is normal. The above-mentioned threshold value includes the number of times air is mixed by the normal operation. Then, the above-mentioned threshold value is compared with the number of counts detected by the air detection frequency counting means, without distinguishing between air mixing in normal operation and air mixing in the apparatus failure. Conventionally, a threshold that does not include the number of detections of air contamination in normal operation has been erroneously determined based on the number of detections including the number of detections of air contamination in normal operation. The threshold value is a numerical value including the number of detections of air contamination due to normal operation when the apparatus is normal. Therefore, the abnormality of the apparatus can be accurately determined only when the threshold value is exceeded by the determining means. Then, the judgment result output by the judgment means is outputted by the judgment result output means. Thereafter, for example, air is discharged based on the determination result, or processing for repairing the abnormality of the apparatus is performed as necessary. As a result, it is possible to reduce air discharge processing due to air intrusion into the recording head, thereby reducing wasteful ink consumption and reducing running costs. The productivity can be improved by minimizing the execution of the air discharge process and reducing the stoppage of the apparatus operation.

  According to the present invention, it is possible to obtain a specific effect that the wasteful ink consumption can be reduced, the running cost can be reduced, and the productivity can be improved.

1 is a schematic configuration diagram illustrating a configuration example of an ink supply device in an ink jet recording apparatus according to an embodiment of the present invention. It is a perspective view which shows the structure of the head tank of this inkjet recording device. It is a figure explaining the mode of the ink supply to the head tank in this inkjet recording device. It is a figure explaining the mode of the ink supply to the head tank in this inkjet recording device. It is a figure explaining the mode of the ink supply to the head tank in this inkjet recording device. It is a figure explaining the mode of the ink supply to the head tank in this inkjet recording device. It is a block diagram which shows the structural example of the apparatus failure judgment apparatus in this inkjet recording device. It is a flowchart which shows an example (henceforth a 1st example) of the apparatus failure warning transmission procedure in this inkjet recording device. FIG. 5 is a diagram illustrating a state in which air enters an ink supply path or a head tank when replacing an ink cartridge. It is a flowchart which shows the other example (henceforth 2nd example) of the apparatus failure warning procedure in this inkjet recording device. It is a flowchart which shows the other example (henceforth a 3rd example) of the apparatus failure warning procedure in this inkjet recording device.

The configuration of an ink jet recording apparatus will be described below as an embodiment of an image forming apparatus to which the present invention is applied.
FIG. 1 is a schematic configuration diagram illustrating a configuration example of an ink supply device in an ink jet recording apparatus according to an embodiment of the present invention. In the ink supply device 10, ink is supplied from an ink cartridge 11 that is a main ink tank to a head tank 13 that is a sub ink tank via an ink supply unit 12. The ink supply unit 12 includes a tube pump 12-1, and can supply ink to the head tank 13 via the ink supply tube 14 or suck ink in the head tank 13.

  FIG. 2 is a perspective view showing the structure of the head tank in the ink jet recording apparatus of this embodiment. In the head tank 13, a negative pressure lever 13-1 is provided inside the head tank. The negative pressure lever 13-1 is in contact with the outer surface of the film 13-2 while being biased, and is a lever that pivots. The negative pressure lever 13-1 is displaced in accordance with the consumption amount of ink stored in the head tank in which negative pressure is generated by a spring (not shown) that biases the film 13-2. 2 to move following the movement of the outer surface. The supply port 13-3 is a supply port through which ink is supplied from the ink cartridge 11 of FIG. 1 via the tube pump 12-1 and the ink supply tube 14. The air release pin 13-4 is a pin that opens the inside of the head tank to the atmospheric state as necessary. Further, an electrode pin detection mechanism 13-5 for detecting ink level or air contamination is provided. A recording head 15 for ejecting ink droplets is attached below the head tank 13.

  3 to 6 are schematic views for explaining the state of ink supply to the head tank in the ink jet recording apparatus. In each figure, the same reference numerals as those in FIG. 2 denote the same components. Ink is empty in the ink storage portion 13-6 of the head tank 13 in FIG. At this time, the film 13-2 is deflated to the ink empty state, and the negative pressure lever 13-1 is also located at the ink empty position. Then, as shown in FIG. 4, the air release valve 13-4 of the head tank 13 is opened, and the ink 20 is supplied from an ink cartridge (not shown) to the ink storage portion 13-6 via the supply port 13-3. At this time, the film 13 in FIG. 4 bulges outward by the biasing force, and the two negative pressure levers 13-1 move so as to spread outward. Then, after the ink 20 is supplied to the ink storage portion 13-6 until the predetermined amount of ink liquid is full, the air release valve 13-4 is closed as shown in FIG. At this time, the film 13-2 tends to bulge outward by the spring 13-7 of the elastic member. Then, ink suction is performed by a tube pump (not shown). For this reason, as shown in FIG. 6, the inside of the ink storage portion 13-6 of the head tank 13 is in a negative pressure state.

  FIG. 7 is a block diagram illustrating a configuration example of the apparatus failure determination apparatus according to the present embodiment. The apparatus failure determination apparatus 100 includes an air detection frequency counter 101 that counts the number of times of air detection in which it is detected that air has entered the sub ink tank, and the number of air detections counted by the air detection frequency counter 101 is determined by the apparatus. A determination unit 102 that determines that an abnormality has occurred in the apparatus when a predetermined threshold value including the number of times of detection of air contamination when normal is reached, and a determination result output unit 103 that outputs a determination result of the determination unit 102 are provided. doing. The threshold value is stored in the threshold memory 104.

FIG. 8 is a flowchart showing an example of a device failure warning transmission procedure (hereinafter referred to as a first example) in the inkjet recording apparatus.
First, when the ink jet recording apparatus is in a standby state (step S101), if the air pin is detected by the electrode pin in the ink storage section in the head tank, the count value of the air detection number counter that counts the number of air detections is obtained. +1 is written (steps S102 and S103). Then, the air detection date / time at this time is overwritten and stored in the air detection date / time memory, and +1 is also written in the count value of the diagnostic air detection frequency counter for counting the number of times of diagnostic air detection (steps S104 and S105). The timer of the air detection failure diagnosis period is started (step S106). Here, an air detection frequency counter, an air detection date / time memory, a diagnostic air detection frequency counter and a timer are provided in the host device. When the ink jet recording apparatus is again in a standby state, if the electrode pin detects that air has entered the ink storage section in the head tank (steps S107 and S108), +1 is written to the count value of the air detection frequency counter (step S109). At this time, it is determined whether or not the timer of the air detection failure diagnosis period has passed for 10 days or more (step S110). If the diagnosis period of 10 days or more has elapsed as a result of the determination, the count value of the diagnostic air detection frequency counter is cleared to 0, the timer of the air detection failure diagnosis period is cleared to 0, and the process returns to step S105 (step S105). S110: YES, steps S111, S112).

  On the other hand, if the determined diagnosis period is less than 10 days, the count value of the diagnostic air detection number counter is incremented by 1 (step S110: NO, step S113). It is determined whether or not the count value of the diagnostic air detection frequency counter is less than 17 times (step S114). If the determination result is still less than 17 times, the process returns to step S107 (YES in step S114). If the determination result is 17 times or more, it is determined that the device has failed, and a warning of device failure is issued to the user (step S114: NO, step S115). The operation flow of the first example uses two counters, an air detection number counter and a diagnostic air detection number counter. The air detection frequency counter counts the total number of air detections, and is an air detection frequency counter from the initial operation. Since the count value is a count value used during maintenance of the apparatus, only the air detection frequency counter of FIG. 7 is used. The air contamination may be counted. In order to detect air even in the normal operation of replacing the ink cartridge, naturally, for example, the threshold is a warning based on the above-mentioned threshold that takes into account the frequency of air detection in the normal operation of 17 times in 10 days. Thus, it is possible to distinguish between air contamination due to normal operation such as ink cartridge replacement in a normal device and air contamination due to a failure of the device, and to improve the reliability of device failure detection. The threshold value for determination is an example, and the threshold value is not necessarily required. The detection timing of air mixing may be at the start of printing or at the end of printing, and is not particularly limited. Although a predetermined diagnosis period is used as a determination criterion, the total apparatus operation time from the initial operation, the total number of printed sheets, and the ink consumption may be used as the determination criterion.

  Next, how the air is mixed into the ink supply path and the ink storage part in the head tank when the ink cartridge is replaced in the normal operation will be described. As shown in FIG. 9A, printing is performed while the ink supply unit 12 supplies the ink 20 to the ink storage portion 13-6 of the head tank 13 from the ink cartridge 11 that is the main tank, and the ink cartridge 11 is eventually added. In addition, the ink storage portion 13-6 is also emptied. Then, as shown in FIG. 9B, when the empty ink cartridge 11 is removed for replacement, the negative pressure in the ink supply path is released, and the ink supply needle 12-2 is moved to the ink cartridge 11. When removed from the supply port 11-1, air is taken into the ink supply path via the ink supply needle 12-2. After that, as shown in FIG. 9C, a new ink cartridge 11 is loaded and the tube pump 12-1 of the ink supply unit 12 is driven, so that ink is stored in the head tank 13 from the new ink cartridge 11. When supplied to the section 13-6, the air 21 mixed in the ink supply path is supplied into the ink storage section 13-6 together with the ink. Despite the ink cartridge replacement, which is a normal operation, since air is mixed in, air mixing is detected and counted as the number of times of air detection. For this reason, the count value of the number of times of air detection includes the number of times of detection of air contamination due to normal operation, which reduces the accuracy of self-diagnosis for determining device failure and the reliability of device failure detection. . However, as in the first example of the device failure warning transmission procedure in the ink jet recording apparatus shown in FIG. 8, a device failure warning is issued by detecting air contamination after taking into account air contamination due to normal operation. The accuracy of self-diagnosis and the reliability of device failure detection can be improved.

FIG. 10 is a flowchart showing another example of the apparatus failure warning procedure (hereinafter referred to as a second example) in the inkjet recording apparatus.
First, when the ink jet recording apparatus is in a standby state (step S201), when the air pin is detected by the electrode pin in the ink storage section in the head tank, +1 is written to the count value of the air detection number counter (step S202). , S203). Then, the air detection date and time at this time is overwritten and stored in the air detection date and time memory, and +1 is also written in the count value of the diagnostic air detection frequency counter (steps S204 and S205). The timer of the air detection failure diagnosis period is started (step S206). When the ink jet recording apparatus is again put into the standby state and air contamination into the ink storage portion in the head tank is detected by the electrode pin (steps S207 and S208), +1 is written to the count value of the air detection frequency counter (step S209). Then, it is determined whether or not the ink cartridge of the corresponding ink color has been replaced (step S210). Whether or not the ink cartridge has been replaced is detected based on a signal exchanged between the electronic circuit chip mounted on the ink cartridge and the apparatus main body side. If the ink cartridge has been replaced, the process returns to step S207 (step S210: YES). When not being replaced, it is determined whether the air detection failure diagnosis period has passed for 10 days or more (step S210: NO, step S211). If the diagnosis period of 10 days or more has elapsed as a result of the determination, the count value of the diagnostic air detection frequency counter is cleared to 0, the timer of the air detection failure diagnosis period is cleared to 0, and the process returns to step S205 (step S205). S211: YES, steps S212 and S213).

  On the other hand, if the determined diagnosis period is less than 10 days, the count value of the diagnostic air detection frequency counter is incremented by 1 (step S211: NO, step S214). It is determined whether or not the count value of the diagnostic air detection frequency counter is less than 17 times (step S215). If the determination result is still less than 17 times, the process returns to step S207 (step S215: YES). If the determination result is 17 times or more, it is determined that the device is out of order and a warning is issued to the user (step S215: NO, step S216). In the second example, the number of times air detection is performed due to air mixing due to normal operation is not written in the count value of the diagnostic air detection number counter. For this reason, the normal operation of ink cartridge replacement is taken into account, and a device failure warning is issued after that, so that the accuracy of self-diagnosis and the reliability of device failure detection can be improved.

FIG. 11 is a flowchart showing another example of the apparatus failure warning procedure (hereinafter referred to as a third example) in the inkjet recording apparatus.
First, when the ink jet recording apparatus is in a standby state (step S301), when the air pin is detected by the electrode pin in the ink storage section in the head tank, +1 is written to the count value of the air detection number counter (step S302). , S303). Then, the air detection date and time at this time is overwritten and stored in the air detection date and time memory, and +1 is also written to the count value of the diagnostic air detection frequency counter (steps S304 and S305). The timer of the air detection failure diagnosis period is started (step S306). When the ink jet recording apparatus is again set to the standby state and air contamination into the ink storage portion in the head tank is detected by the electrode pins (steps S307 and S308), +1 is written to the count value of the air detection counter (step S309). Then, it is determined whether or not the ink cartridge of the corresponding ink color has been replaced (step S310). If the ink cartridge has been replaced, the process returns to step S307 (step S310: YES). If not, it is determined whether the ink supply amount after replacement of the ink cartridge of the corresponding ink color is 2 cc or more (step S311). If it is not 2 cc or more, it is determined whether the diagnosis period has passed for 10 days or more (step S311: NO, step S312). If it is determined that the diagnostic period has exceeded 10 days, the count value of the diagnostic air detection frequency counter is cleared to 0, the timer for the air detection failure diagnosis period is cleared to 0, and the process returns to step S305 (step S305). S312: YES, steps S313 and S314).

  If the ink supply amount after replacement of the ink cartridge of the corresponding ink color is 2 cc or more in step S311, the air mixed by the replacement of the ink cartridge has reached the detectable position in the head tank, and the ink It is determined whether the number of times of air detection after the color ink cartridge replacement is the first time (step S311: YES, step S315). That is, since the number of times of air detection when the apparatus is installed and the ink cartridge is loaded is not used for apparatus abnormality determination, the process returns to step S307 if it is the first time (step S315: YES). By this process, it is determined that the ink cartridge is aerated when the ink cartridge is loaded during the initial operation of the ink jet recording apparatus, so that the apparatus is not subject to device failure diagnosis. Next, if the count of the number of times of air detection after ink cartridge replacement is not the first time in step S315, it is determined whether or not the diagnosis period has passed for 10 days or more (step S315: NO, step S312). If it is determined that the diagnostic period has exceeded 10 days, the count value of the diagnostic air detection frequency counter is cleared to 0, the timer for the air detection failure diagnosis period is cleared to 0, and the process returns to step S305 (step S305). S312: YES, steps S313 and S314). On the other hand, if the determined diagnosis period is less than 10 days, the count value of the diagnostic air detection counter is incremented by 1 (step S312: NO, step S316). It is determined whether or not the count value of the diagnostic air detection frequency counter is less than 17 times (step S317). If the determination result is still less than 17 times, the process returns to step S307 (step S317: YES). If the determination result is 17 times or more, it is determined that the device has failed, and a warning is issued to the user (step S317: NO, step S318).

  In the third example, when the ink level is not used when the ink cartridge is replaced, the volume in the ink supply path is temporarily set to 2 cc, and it is determined whether the ink supply amount in the supply path has already been sent. Diagnose with. Normal air detection is performed only when the air that has entered the ink supply path when the cartridge is replaced reaches the location where air is detected. For this reason, air detection until the ink supply amount from the replaced ink cartridge is larger than the capacity of the ink cartridge and the location where air is detected should be used for diagnosis. In such a state, there is often a phenomenon in which air detection occurs twice continuously. If the frequency is 17 times for 10 days, the diagnosis result is not greatly affected. However, it is effective when severely diagnosing, for example, twice for 1 day. In addition, once the capacity for the supply path has been supplied, air cannot be mixed in during normal operation, and all subsequent detections can be used for diagnosis. It is preferable to determine whether it is the first time not on the cartridge but on the main body side. This is because the ink cartridge may be reused.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
When the air detection means counts the number of air detections when the air detection means detects that air has entered the sub ink tank, the number of air detections counted by the air detection number count means, and when the device is normal And a judgment result output means for outputting the judgment result of the judgment means. The judgment means judges that an abnormality has occurred in the apparatus based on a predetermined threshold value including the number of times of detection of air contamination. According to this, as described in the above embodiment, air may be mixed into the head tank 13 even when the ink cartridge 11 is replaced, for example, when the apparatus is operating normally. The above-mentioned threshold value includes the number of times air is mixed by the normal operation. Then, the above-mentioned threshold value is compared with the number of counts at which it is detected that air is mixed without distinguishing between air mixing in normal operation and air mixing in apparatus abnormality. The threshold value is a numerical value including the number of detections of air contamination due to normal operation when the apparatus is normal. Therefore, the abnormality of the apparatus can be accurately determined only when the threshold value is exceeded by the determining means. As a result, it is possible to reduce air discharge processing due to air intrusion into the recording head, thereby reducing wasteful ink consumption and reducing running costs. The productivity can be improved by minimizing the execution of the air discharge process and reducing the stoppage of the apparatus operation.
(Aspect B)
In (Aspect A), the predetermined threshold is a number of times corresponding to a predetermined period, a predetermined apparatus operating time, a predetermined number of output sheets, or a predetermined amount of ink consumption liquid. According to this, as described in the above embodiment, it is possible to accurately determine that an abnormality has occurred in the apparatus because the threshold value is a threshold value that also considers the number of times air is mixed in during normal operation. For this reason, the reliability with respect to the failure detection of an apparatus can be improved by outputting the determination result that abnormality occurred in the apparatus.
(Aspect C)
In (Aspect A) or (Aspect B), the ink supply means is provided with a drive control mechanism for supplying a predetermined amount of ink, and when a predetermined amount of ink is supplied using the drive control mechanism, If the predetermined ink level cannot be detected, the ink supply is stopped by the drive control mechanism and the replacement of the main ink tank is urged. According to this, as described in the above embodiment, when the predetermined ink liquid level cannot be detected by the electrode pin 13-5 in the ink storage portion 13-2 of the head tank 13, the tube pump 12-1 performs ink. Thus, the ink in the ink cartridge 11 can be used up.
(Aspect D)
In (Aspect A) or (Aspect B), the ink supply means is provided with a drive control mechanism for supplying a predetermined amount of ink, and when a predetermined amount of ink is supplied using the drive control mechanism, If the change in volume of the ink cannot be detected, the ink supply is stopped by the drive control mechanism and the replacement of the main ink tank is prompted. According to this, as described in the above embodiment, when the volume change in the ink storage portion 13-2 of the head tank 13 cannot be detected by the negative pressure lever 13-1, the tube pump 12-1 supplies ink. The liquid can be stopped and the ink in the ink cartridge 11 can be used up.
(Aspect E)
In any one of (Aspect A) to (Aspect D), the detection that the air is mixed for the first time after the main ink tank is loaded at the time of installation of the apparatus is not used for apparatus abnormality determination. According to this, as described in the above embodiment, it is possible to improve the determination accuracy by not using the detection that the air is mixed when the ink cartridge 11 is replaced in the abnormality determination.
(Aspect F)
In any one of (Aspect A) to (Aspect D), after supplying the ink corresponding to the volume of the ink supply path from the main ink tank to the sub ink tank after the main ink tank is loaded when the apparatus is installed The detection that the first air is mixed is not used for the apparatus abnormality determination. According to this, as described in the above embodiment, the detection that the air is mixed when the predetermined ink liquid amount is supplied to the head tank 13 after the ink cartridge 11 is replaced is not used for the abnormality determination. The determination accuracy can be improved.
(Aspect G)
In any one of (Aspect A) to (Aspect F), an operation day counting unit that counts the number of operation days of the apparatus is provided, and counting by the operation day counting unit is started from the time of detection that the first air is mixed. The apparatus abnormality determination is performed based on the ratio of the number of working days counted by the working day counting means to the number of detections of mixing and a predetermined value. According to this, as described in the above-described embodiment, the determination accuracy is improved by comparing the ratio of the number of detection times that air is mixed with respect to the total number of days in which the ink jet recording apparatus is operating to a predetermined value. be able to.

DESCRIPTION OF SYMBOLS 10 Inkjet recording device 11 Ink cartridge 12 Ink supply unit 12-1 Tube pump 13 Head tank 13-1 Negative pressure lever 13-2 Ink storage part 13-3 Ink supply port 13-4 Atmospheric release valve 13-5 Electrode pin 13- 6 Ink storage section 13-7 Spring 14 Ink supply tube 15 Recording head 20 Ink 21 Air

JP 2010-052415 A

Claims (7)

A replaceable main ink tank, a sub ink tank for temporarily storing ink from the main ink tank, an ink supply means for feeding ink from the main ink tank to the sub ink tank, and an inside of the sub ink tank In an image forming apparatus comprising an air detection means for detecting that air has been mixed,
An air detection frequency counting means for counting the number of times of air detection in which it is detected by the air detection means that air is mixed into the sub ink tank;
Determining means for determining that an abnormality has occurred in the apparatus based on the number of times of air detection counted by the number of times of air detection and a predetermined threshold value including the number of times of detection of air contamination when the apparatus is normal;
An image forming apparatus comprising: a determination result output unit that outputs a determination result of the determination unit. The image forming apparatus according to claim 1.
The predetermined threshold is a number of times including the number of times of detection of air mixing when the apparatus is normal based on a predetermined period, a predetermined apparatus operating time, a predetermined number of output sheets, or a number corresponding to a predetermined amount of ink consumption liquid. An image forming apparatus, comprising: The image forming apparatus according to claim 1, wherein
The ink supply means includes a drive control mechanism for feeding a predetermined amount of ink, and can detect a predetermined ink liquid level in the sub ink tank when the predetermined amount of ink is fed using the drive control mechanism. An image forming apparatus characterized by prompting replacement of the main ink tank by stopping ink feeding by the drive control mechanism when there is no ink. The image forming apparatus according to claim 1, wherein
The ink supply means includes a drive control mechanism for feeding a predetermined amount of ink, and when the predetermined amount of ink is fed using the drive control mechanism, the volume change in the sub ink tank cannot be detected. An image forming apparatus, wherein the drive control mechanism stops ink feeding and prompts replacement of the main ink tank. The image forming apparatus according to claim 1,
2. An image forming apparatus according to claim 1, wherein when the apparatus is installed, detection of the first air mixing after the main ink tank is loaded is not used for determining an apparatus abnormality. The image forming apparatus according to claim 1,
When the apparatus is installed, it is detected that the air is mixed for the first time after ink corresponding to the volume of the ink supply path from the main ink tank to the sub ink tank is loaded after the main ink tank is loaded. An image forming apparatus that is not used for determination. The image forming apparatus according to claim 1,
An operating day counting means for counting the number of operating days of the apparatus is provided, and counting by the operating day counting means is started from the time of detection that the first air is mixed, An image forming apparatus that performs apparatus abnormality determination based on a ratio of counted working days and a predetermined value.

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