JP5061428B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  In an image forming apparatus, it is common to notify a user when there are few remaining consumables remaining in a consumable unit such as a toner cartridge that holds consumables such as toner. For this reason, the consumption amount of the consumables is estimated by integrating the operation amount (for example, the number of prints) of the image forming operation, and the remaining amount of the consumables is estimated by calculating backward from the amount of consumables held at the time of the new product. A technique for notifying a user by a screen display or the like is known.

  The image forming apparatus described in Patent Document 1 is provided with a plurality of types of consumable units provided with means for discriminating the initial amount of consumables that are held in different amounts. When the integrated value of the operation amount reaches a predetermined value determined according to the initial possession amount, the fact that the remaining amount of consumables is low is notified.

  Further, in the image forming apparatus, it is necessary to detect that all the consumables are consumed and remain and issue an alarm or prohibit the image forming operation. However, since the consumption amount of the consumables is not always constant (for example, the amount of toner consumed varies depending on the image to be printed), there is an error in the remaining amount of consumables predicted from the integrated value of the operation amount. It is not possible to determine whether or not consumables remain. In particular, in a consumable unit with a large capacity, the difference between the predicted value and the actual remaining amount may be large.

  Conventionally, a sensor for directly detecting the remaining amount of consumables is provided in order to detect that all the consumables are consumed and not left, but there is a problem that the cost is high. Therefore, in the image forming apparatus described in Patent Document 2, a decrease in toner density of the formed image is detected to indirectly detect that no toner remains. Since the toner density also increases / decreases depending on the operation status of the image forming apparatus, the image forming apparatus disclosed in Patent Document 2 determines that no toner remains in accordance with the operation and stop time in order to correctly determine that the toner has run out. The threshold value of the toner density to be changed is changed.

However, the toner density is lowered not only when the remaining amount of toner and the operation status, but also when a toner supply failure occurs due to a failure or the like. For this reason, there has been a problem that it is difficult to distinguish whether the decrease in toner density is due to no toner remaining or due to malfunction such as a failure.
Japanese Examined Patent Publication No. 7-21657 Japanese Patent No. 2583993

  In view of the above problems, an object of the present invention is to provide an image forming apparatus that can determine that all consumables have been consumed without being confused with an operation failure such as a failure.

In order to solve the above problems, the image forming apparatus according to the present invention has different initial holding amounts of consumables, and each can be equipped with a plurality of types of consumable units having a memory storing information indicating the initial holding amount. And a remaining amount detecting means for detecting a change amount correlated with the remaining amount of the consumables, and a remaining amount estimating means for calculating an estimated remaining amount of the consumables based on an operation amount of the image forming apparatus. When the estimated remaining amount is less than or equal to a predetermined first estimated amount threshold value, a notification is made that the remaining amount of the consumable item is low, and the change amount indicates a threshold value indicating that all of the consumable item has been consumed. And when the estimated remaining amount is less than or equal to a predetermined second estimated amount threshold, a warning is given that all of the consumables have been consumed, and the first estimated amount threshold is the same value regardless of the initial holding amount, the second estimated amount threshold Ri is set to a small value, the second estimated amount threshold, as towards the smaller supply units of the initial stockpile becomes smaller than the larger supply units of the initial holdings, to the initial holdings Accordingly, different values are set for each of the consumable units, and all of the consumables are consumed, earlier than the remaining amount detecting means detects that the change amount has reached the change amount threshold, The estimated remaining amount calculated by the remaining amount estimating means is set to a value that becomes the second estimated amount threshold value .

  According to this configuration, the average operation amount from when the estimated remaining amount calculated from the operation amount of the image forming operation is less than the first estimated amount threshold until all the consumables are actually consumed is constant. Therefore, the user can know in advance with a certain grace period that the consumables need to be replaced. Even if the amount of change correlated with the remaining amount of consumables is smaller than the change amount threshold, if the estimated remaining amount is greater than the second estimated threshold, it is unlikely that all the consumables are actually consumed. Therefore, it can be determined that it is due to malfunction. Further, based on the initial amount of consumables in the consumable unit, the second estimated amount threshold is considered to be that all consumables are not consumed even when the actual remaining amount is the smallest than the estimated remaining amount. By setting the value as small as possible within a certain range, the possibility of misidentifying that all the consumables have been consumed due to a decrease in the amount of change due to malfunction is extremely low.

In the image forming apparatus of the present invention, when the amount of change detected by the remaining amount detecting unit reaches the change amount threshold and the estimated remaining amount is larger than the second estimated amount threshold, A warning that an abnormality has occurred may be issued.

Further, in the image forming apparatus of the present invention, if the consumable is toner and the consumable unit is a toner cartridge, it is possible to appropriately determine the necessity of replacing the toner cartridge with the highest frequency and notify the user. . In the image forming apparatus of the present invention, if the remaining amount detecting means is a toner density sensor and the amount of change is the toner density, a dedicated sensor is not required and the cost is low.

  According to the present invention, after the estimated remaining amount based on the operation amount becomes smaller than the second estimated amount threshold set to the smallest possible value in consideration of the consumable unit initial holding amount of the consumable unit, the consumable item Since it is determined whether or not all the consumables have been consumed based on the amount of change that correlates with the remaining amount, there is a low possibility that a consumable item will not remain even if the amount of change is reduced due to a malfunction.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an image forming apparatus 1 according to an embodiment of the present invention. The image forming apparatus 1 includes four developing units 2Y, 2M, 2C, and 2K that form images with yellow, magenta, cyan, and black toners (consumables), a transfer belt 3, and developing units 2Y, 2M, and 2M, respectively. The primary transfer rollers 4Y, 4M, 4C, and 4K that transfer the toner images formed by 2C and 2K to the transfer belt 3 by electrostatic force, respectively, and the toner images transferred to the transfer belt 3 are transferred to the recording paper S by electrostatic force The secondary transfer roller 5 that heats, the fixing device 6 that fixes the toner image on the recording paper S by heating, and the yellow, magenta, cyan, and black toners are supplied to the developing units 2Y, 2M, 2C, and 2K, respectively. Toner cartridges (consumables units) 7Y, 7M, 7C, and 7K.

  Each of the toner cartridges 7Y, 7M, 7C, and 7K stores information such as a model and toner color, and is written with operation information such as a state of a toner replenishing motor (not shown) that drives a screw that conveys the toner. A memory 8 is provided. In addition, the toner cartridge 7K that supplies black toner is illustrated as having a larger amount of toner (initial holding amount) when it is new (a large capacity cartridge) than the other toner cartridges 7Y, 7M, and 7C. However, a small-capacity cartridge having the same initial amount as the other toner cartridges 7Y, 7M, and 7C can alternatively be mounted. The memory 8 also stores information indicating the initial amount of toner held (whether it is a large capacity cartridge or a small capacity cartridge).

  The developing units 2Y, 2M, 2C, and 2K respectively expose the rotating drum-shaped photoconductor 9, the charger 10 that charges the photoconductor 9, and the charged photoconductor 9 to form an electrostatic latent image. An exposure unit 11, a developing unit 12 that forms a toner image by attaching toner to the electrostatic latent image, and a toner density sensor (residual amount) that measures the toner density (change amount) of the developer contained in the developing unit 12. (Quantity detecting means) 13 and a cleaner 14 for scraping off the toner on the surface of the photosensitive member 9. The toner density sensor 14 may measure the density of the toner image formed on the photoconductor 9.

  The transfer belt 3 is stretched over a driving roller 15 to be driven, a free roller 16, and a tension roller 17 that applies tension, and is rotated in the direction of the arrow by the driving roller 15. Further, the image forming apparatus 1 is provided with a cleaner unit 18 that removes toner remaining on the surface of the transfer belt 3.

  The recording paper S is supplied to the paper supply unit 19, fed one by one by the supply roller 20, transported to the secondary transfer roller 5 by the transport roller 21, and discharged to the paper discharge unit 22 through the fixing device 6. .

Next, FIG. 2 shows the relationship between the number of prints in the image forming apparatus 1 and the amount of toner remaining in the toner cartridge 7K. Initial stockpile of large capacity cartridge 7K and small-capacity cartridge is C _L and C _S, respectively. The image forming apparatus 1 calculates an estimated remaining amount of toner from the number of printed sheets as indicated by a solid line. The estimated remaining amount is expressed in terms of how many toners remain in terms of the rotation of a toner replenishing motor that supplies toner from the toner cartridge 7K to the developing unit 2K, and is subtracted every time a printing operation is performed. It is grasped by an amount counter (remaining amount estimating means).

For example, when the image forming apparatus 1 confirms that the large-capacity toner cartridge 7K is mounted by reading the information stored in the memory 8, the value of the remaining toner counter is set to the initial holding amount _CL . (for small capacity cartridge, set to N _CS corresponding to the initial holding amount C _S) the number of prints to be printed can estimated by the toner set to N _CL expressed in revolutions toner supply motor to.

Further, FIG. 3 shows a flow of determination of “toner empty” in which all the toner is consumed and remains in the image forming apparatus 1, and will be described in detail with reference to FIG. After performing the image forming (printing) operation in step S01, the image forming apparatus 1 subtracts the remaining toner counter by the number of rotations of the toner supply motor in step S02. In step S03, if the toner remaining amount counter is equal to or less than the near empty threshold N _NE indicating that the estimated remaining amount of toner is the predetermined first estimated amount threshold value T _NE , the toner remaining amount is determined in step S04. "Near empty" indicating that the remaining amount of the battery is low is notified to the user.

  Next, regardless of whether it is “near empty”, the process proceeds to step S05, and the toner density sensor 13 detects the toner density. If the toner density is equal to or lower than the predetermined decrease threshold in step S06, the remaining toner counter is confirmed in step S07. If the toner remaining amount counter is equal to or less than the empty threshold corresponding to the value when the estimated remaining amount of toner becomes the second estimated amount threshold, it is determined that the toner is “toner empty”, and is “toner empty” in step S08. A warning message is displayed.

In step S07, if the toner cartridge 7K large capacity cartridge, empty threshold, using N _EL estimated remaining amount of toner becomes second estimated amount threshold T _EL, if the toner cartridge 7K is a small capacity cartridge, empty threshold, using _{N ES} estimated remaining amount of toner becomes second estimated amount threshold _{T ES.} In step S06, the toner remains if the toner remaining amount counter is larger than the empty threshold N _EL (N _{ES in} the case of a small-capacity cartridge) in step S07 even though the toner density is equal to or lower than the predetermined decrease threshold. However, it is determined that the toner density has been lowered due to some abnormality, and the “toner density abnormal drop” is displayed in step S09.

As shown in FIG. 2, the value of the near empty threshold value N _{NE is} a value estimated that the remaining amount of toner is a predetermined amount T _NE , and is always constant regardless of the initial amount of toner held in the toner cartridge 7K. is there. As a result, the average number of printable sheets from when the user is notified of “near empty” until the toner is completely consumed and becomes “toner empty” can be prevented from changing depending on the size of the toner cartridge 7K. .

  In addition, the image forming apparatus 1 determines whether the toner remaining amount is equal to or lower than the empty threshold when the toner density is reduced to the lower threshold, depending on whether the estimated toner remaining amount is equal to or lower than the empty threshold. Is determined. Therefore, it is desirable to set the empty threshold as small as possible. However, even when the actual toner consumption is larger than the standard, the estimation is performed earlier than when the toner is completely consumed and the toner density falls to the lower threshold. It is necessary to set the value so that the remaining amount is equal to or less than the empty threshold.

As shown in FIG. 2, the greater the initial toner holding amount, the greater the error that can occur between the estimated remaining amount and the actual remaining amount. Therefore, the second estimated amount threshold value T _ES (empty threshold value N _ES ) of the small capacity cartridge is set smaller than the second estimated amount threshold value T _EL (empty threshold value N _EL ) of the large capacity cartridge. As described above, the estimated remaining amount becomes smaller than the second estimated amount threshold value at a timing as late as possible before all the toner is consumed even when the amount of toner consumed is large according to the initial amount of toner held. By doing so, the risk of confusion between “toner empty” and “toner density abnormal reduction” can be minimized.

1 is a schematic diagram showing a configuration of an image forming apparatus according to the present invention. FIG. 4 is a diagram illustrating a change in the remaining amount of the toner cartridge in FIG. 1. 2 is a flowchart of toner empty determination in the image forming apparatus of FIG.

Explanation of symbols

1 Image forming device 7K toner cartridge (consumable unit)
8 Memory 13 Toner concentration sensor (remaining amount detection means)

Claims (4)

The initial holding amount of consumables is different, and each can be equipped with a plurality of types of consumable units having a memory storing information indicating the initial holding amount,
A remaining amount detecting means for detecting a change amount correlated with the remaining amount of the consumables;
A remaining amount estimating means for calculating an estimated remaining amount of the consumable based on an operation amount of the image forming apparatus,
When the estimated remaining amount is less than or equal to a predetermined first estimated amount threshold, a notice that the remaining amount of the consumable item is low,
When the amount of change reaches a change amount threshold that is a threshold indicating that all of the consumables are consumed, and the estimated remaining amount is equal to or less than a predetermined second estimated amount threshold, all of the consumables are consumed. Warn you that
The first estimated amount threshold is the same value regardless of the initial possessed amount, and is set to a value smaller than the second estimated amount threshold;
The second estimated amount threshold is set for each consumable unit according to the initial holding amount so that the consumable unit having a small initial holding amount has a smaller value than the consumable unit having a large initial holding amount. Calculated by the remaining amount estimating means earlier than when the consumables are all consumed and the remaining amount detecting means detects that the change amount has reached the change amount threshold. An image forming apparatus, wherein the estimated remaining amount is set to a value that becomes the second estimated amount threshold value . When the amount of change detected by the remaining amount detecting means reaches the amount of change threshold and the estimated remaining amount is greater than the second estimated amount threshold, a warning is given that an abnormality has occurred. The image forming apparatus according to claim 1.   The image forming apparatus according to claim 1, wherein the consumable is a toner, and the consumable unit is a toner cartridge.   The image forming apparatus according to claim 3, wherein the remaining amount detecting unit is a toner density sensor, and the amount of change is a toner density.

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