JP2012194360A - Image forming apparatus and method for supplying toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply a toner by a required amount with high accuracy.SOLUTION: An image forming apparatus includes: a development unit developing an electrostatic latent image on a photoreceptor drum by using reserved toner; a calculation unit 110 calculating a toner consumption consumed by the development; a first detection unit detecting a toner amount reserved in the development unit to be at a first threshold; a second detection unit detecting the toner amount reserved in the development unit to be at a second threshold; and a control unit 130 for calculating a correction value for the toner consumption by using a first toner consumption being a sum of the toner consumption calculated by the calculation unit 110 in a period from the time of detecting the first threshold until that of detecting the second threshold, and by using a second toner consumption being a toner amount actually consumed within the above period determined by the first threshold and the second threshold. The calculation unit 110 calculates a toner consumption to be newly calculated, by using the correction value. The control unit 130 supplies a toner in the same amount as the newly calculated toner consumption from a toner supply unit to the development unit.

Description

  The present invention relates to an image forming apparatus and a toner replenishing method.

  In an electrophotographic image forming apparatus, toner is supplied from a toner container to a developing unit, and the developing unit develops an electrostatic latent image on a photosensitive drum using toner in the developing unit to form a toner image.

  Since the deterioration state is different between the toner replenished from the toner container and the toner in the developing unit, the development process becomes unstable if the ratio is largely lost. As a result, for example, background stains (background fogging) and density fluctuations occur. Therefore, in such an image forming apparatus, it is desired that an appropriate amount of toner commensurate with the amount of consumed toner can be accurately supplied from the toner container to the developing unit.

  For example, in Patent Document 1, the amount of toner consumed for development of the developing device is calculated, the amount of toner in the developing device is detected at two levels, and when the amount of toner is detected at a lower level than the amount of toner consumed A technology is disclosed in which a large amount of toner is replenished from a toner container to a developing device, and when a toner amount is detected at a high level, a toner amount smaller than the toner consumption amount is replenished from the toner container to the developing device.

  In the conventional technology as described above, although toner is replenished in consideration of an error between the toner consumption actually consumed by development and the toner consumption estimated to be consumed by development, the error is large. I do not know exactly. For this reason, it has been difficult to accurately supply a necessary amount of toner with the conventional technology as described above.

  An object of the present invention is to provide an image forming apparatus and a toner replenishing method capable of accurately replenishing a necessary amount of toner.

  In order to solve the above-described problems and achieve the object, an image forming apparatus according to one embodiment of the present invention stores an image carrier on which an electrostatic latent image is formed, toner, and stored toner. A developing unit for developing the electrostatic latent image on the image carrier, a calculating unit for calculating a toner consumption amount consumed by the development, and a toner amount stored in the developing unit is a first threshold value. A first detection unit that detects that the amount of toner stored in the developing unit is a second threshold value that is smaller than the first threshold value, and the first threshold value. A first toner consumption amount that is a sum of toner consumption amounts calculated by the calculation unit within a period from when it is detected that the second threshold value is detected; The amount of toner determined from the second threshold, which is actually within the period A control unit that calculates a correction value using a second toner consumption amount that is a consumed toner amount, and the calculation unit calculates a new toner consumption amount to be calculated using the correction value. The control unit supplies the same amount of toner as the newly calculated toner consumption from the toner replenishing unit to the developing unit.

  An image forming apparatus according to another aspect of the present invention includes an image carrier on which an electrostatic latent image is formed, a toner that is stored, and the electrostatic toner on the image carrier using the stored toner. A developing unit that develops the latent image, a first detecting unit that detects that the amount of toner stored in the developing unit is a first threshold value, and a toner amount stored in the developing unit is the first threshold value. A second detection unit that detects that the second threshold value is smaller than the second threshold value, and a toner replenishment unit from the time that the second threshold value is detected to the time that the first threshold value is detected. The first toner supply amount determined from the period and unit toner supply amount per unit time, and the toner amount determined from the first threshold value and the second threshold value, and is actually supplied within the period. Second toner replenishment amount that is the toner amount A control unit that calculates a correction value and a calculation unit that calculates a toner consumption amount consumed by the development, the control unit using the unit toner replenishment amount and the correction value, A supply time required for supplying the same amount of toner as the consumption amount is calculated, and the calculated supply time is supplied from the toner supply unit to the developing unit.

  A toner replenishing method according to another aspect of the present invention comprises: a developing step for developing an electrostatic latent image formed on an image carrier using toner stored in a storage unit; A first consumption calculation step for calculating a toner consumption amount, a first detection step for detecting that the toner amount stored in the storage unit is a first threshold, and a toner stored in the storage unit A second detection step of detecting that the amount is a second threshold smaller than the first threshold, and a period from when it is detected that the amount is the first threshold to when it is detected that the amount is the second threshold The first toner consumption amount that is the sum of the toner consumption amounts calculated by the first consumption amount calculation step, and the toner amount determined from the first threshold value and the second threshold value, and actually consumed within the period Toner amount A correction value calculation step for calculating a correction value using a certain second toner consumption amount, a second consumption amount calculation step for calculating a new toner consumption amount using the correction value, and a new calculation And a replenishment step of replenishing the storage unit with the same amount of toner as the toner consumption amount.

  A toner replenishing method according to another aspect of the present invention includes a developing step of developing an electrostatic latent image formed on an image carrier using toner stored in a storage unit, and storing in the storage unit. A first detection step of detecting that the amount of toner being stored is a first threshold, and a second of detecting that the amount of toner stored in the storage unit is a second threshold smaller than the first threshold. A detection step, a period from when the second threshold is detected until the first threshold is detected, the toner supply unit supplies toner to the storage unit, and the period and unit time A first toner supply amount determined from a unit toner supply amount and a second toner supply amount that is a toner amount determined from the first threshold value and the second threshold value and actually supplied within the period are used. The correction value A correction value calculating step, a consumption amount calculating step for calculating a toner consumption amount consumed by the development, and a toner replenishment of the same amount as the toner consumption amount using the unit toner replenishment amount and the correction value. A replenishment step of calculating a replenishment time required for the toner and replenishing the calculated replenishment time from the toner replenishment unit to the storage unit.

  According to the present invention, there is an effect that a necessary amount of toner can be replenished with high accuracy.

FIG. 1 is a mechanical configuration diagram illustrating an example of a printing apparatus according to the first embodiment. FIG. 2 is a mechanical configuration diagram illustrating an example of the developing device according to the first embodiment. FIG. 3 is a diagram illustrating an example of the stirring member according to the first embodiment. FIG. 4 is a diagram illustrating an example of the stirring member according to the first embodiment. FIG. 5 is a graph showing the relationship between the mixing ratio of the deteriorated toner and the undegraded toner and the background level. FIG. 6 is a block diagram illustrating an example of an electrical configuration of the printing apparatus according to the first embodiment. FIG. 7 is a flowchart illustrating an example of a consumption correction coefficient calculation process performed by the printing apparatus according to the first embodiment. FIG. 8 is a flowchart illustrating an example of a normal toner supply process performed by the printing apparatus according to the first embodiment. FIG. 9 is a block diagram illustrating an example of an electrical configuration of the printing apparatus according to the second embodiment. FIG. 10 is a flowchart illustrating an example of a supply amount correction coefficient calculation process performed by the printing apparatus according to the second embodiment. FIG. 11 is a flowchart illustrating an example of a normal toner supply process performed by the printing apparatus according to the second embodiment. FIG. 12 is a block diagram illustrating an example of a hardware configuration of the printing apparatus according to each embodiment.

  Hereinafter, embodiments of an image forming apparatus and a toner supply method according to the present invention will be described in detail with reference to the accompanying drawings. In the following embodiments, the image forming apparatus of the present invention is an electrophotographic color printing apparatus, specifically, four colors of yellow (Y), magenta (M), cyan (C), and black (K). However, the present invention is not limited to this example. The image forming apparatus of the present invention can be applied to any color and monochrome as long as it is an apparatus that forms an image by an electrophotographic method. For example, an electrophotographic facsimile machine, a copying machine, and a multifunction peripheral (MFP) ) Etc. Note that a multifunction peripheral is a device having at least two functions among a printing function, a copying function, a scanner function, and a facsimile function.

(First embodiment)
First, the configuration of the printing apparatus according to the first embodiment will be described.

  FIG. 1 is a mechanical configuration diagram illustrating an example of a printing apparatus 1 according to the first embodiment. As illustrated in FIG. 1, the printing apparatus 1 includes an image forming unit 10, an optical scanning unit 30, an intermediate transfer belt 40, support rollers 41 and 42, a paper feeding unit 50, a paper feeding roller 51, and a pad. 52, a transport roller pair 53, a secondary transfer roller 60, a fixing unit 70, a paper discharge roller pair 80, and a paper discharge table 81.

  The image forming unit 10 includes process cartridges 11Y, 11M, 11C, and 11K corresponding to yellow, magenta, cyan, and black, respectively. The process cartridges 11Y, 11M, 11C, and 11K have image forming portions 12Y, 12M, 12C, and 12K, respectively. As shown in FIG. 1, the moving direction of the intermediate transfer belt 40 (direction of arrow S) is as shown in FIG. From the upstream side, the image forming units 12Y, 12M, 12C, and 12K are arranged along the intermediate transfer belt 40 in this order. As described above, the printing apparatus 1 according to the present embodiment uses a so-called tandem system in which the image forming units of the respective colors are arranged along the intermediate transfer belt 40, but is not limited thereto.

  The image forming unit 12Y includes a photosensitive drum 13Y, a charging roller 14Y, a developing device 20Y, a primary transfer roller 15Y, and a cleaning device 16Y. The image forming unit 12Y and the optical scanning unit 30 perform an image forming process (a charging process, an exposure process, a developing process, a transfer process, and a cleaning process) on the photosensitive drum 13Y, so that a yellow color is formed on the photosensitive drum 13Y. A toner image is formed and transferred to the intermediate transfer belt 40.

  The image forming units 12M, 12C, and 12K all have the same components as the image forming unit 12Y, and the image forming unit 12M forms a magenta toner image by performing an image forming process. The image forming unit 12C forms a cyan toner image by performing an image forming process, and the image forming unit 12K forms a black toner image by performing an image forming process. Therefore, in the following, description will be made mainly on the components of the image forming unit 12Y, and the components of the image forming units 12M, 12C, and 12K will be denoted by Y attached to the reference numerals of the components of the image forming unit 12Y. Instead, only M, C, and K are attached, and the description thereof is omitted. In this embodiment, non-magnetic one-component toner is used as the toner, but the present invention is not limited to this.

  The photosensitive drum 13Y is an image carrier and is rotationally driven in the direction of arrow a by a photosensitive drum driving device (not shown).

  First, in the charging step, the charging roller 14Y in contact with the photosensitive drum 13Y initializes and charges the surface of the rotationally driven photosensitive drum 13Y uniformly at a high potential in the dark.

Then, in the exposure step, (an example of an exposure unit) The optical scanning unit 30, the laser beam L _Y which is optically modulated on the charged surface of the photosensitive drum 13Y, not shown ASIC (Application Specific Integrated Circuit) image such as Based on the image data that has been subjected to image processing by the processing unit, selective exposure scanning is performed to form an electrostatic latent image corresponding to the yellow color component image on the surface of the photosensitive drum 13Y. As a result, the laser beam L _Y at exposure scanned low potential portions electrostatic latent image potential on the surface portion of the photosensitive drum 13Y is attenuated (image portion), and a high laser beam L _Y does not change the potential not irradiated The potential part becomes the background part. In the present embodiment, the optical scanning unit 30, LEDA (light-emitting diode array: Light Emitting Diode Array) that exposes the photosensitive drum 13Y by emitting a laser beam L _Y is used to form an electrostatic latent image However, the present invention is not limited to this.

  Subsequently, in the developing process, the developing device 20Y develops the electrostatic latent image formed on the photosensitive drum 13Y with yellow toner, and forms a yellow toner image on the photosensitive drum 13Y. Specifically, the developing device 20Y forms a yellow toner image on the photosensitive drum 13Y by transferring yellow toner to the low potential portion of the photosensitive drum 13Y to visualize the electrostatic latent image. To do. The developing device 20Y may transfer yellow toner to the high potential portion of the photosensitive drum 13Y to form a yellow toner image on the photosensitive drum 13Y.

  Subsequently, in the transfer process, the primary transfer roller 15Y transfers the yellow toner image formed on the photosensitive drum 13Y to the intermediate transfer belt 40. A small amount of untransferred toner remains on the photosensitive drum 13Y even after the toner image is transferred.

  Subsequently, in the cleaning process, the cleaning device 16Y wipes off the untransferred toner remaining on the photosensitive drum 13Y.

  The intermediate transfer belt 40 is an endless belt wound around a plurality of rollers such as support rollers 41 and 42, and moves endlessly in the arrow S direction when one of the support rollers 41 and 42 is driven to rotate. First, a yellow toner image is transferred to the intermediate transfer belt 40 by the image forming unit 12Y, then a magenta toner image by the image forming unit 12M, a cyan toner image by the image forming unit 12C, and the image forming unit 12K. Black toner images are sequentially superimposed and transferred. As a result, a full-color toner image is formed on the intermediate transfer belt 40.

  A plurality of recording sheets are accommodated in the sheet feeding unit 50 in an overlapping manner. The paper feed roller 51 is in contact with the recording paper located at the top of the paper supply unit 50 and feeds the recording paper in contact therewith. The pad 52 is separated into one recording sheet when a plurality of recording sheets are fed by the sheet feeding roller 51. The transport roller pair 53 transports the recording paper fed by the paper feed roller 51 between the support roller 41 and the secondary transfer roller 60 at a predetermined timing.

  The secondary transfer roller 60 collectively transfers the full-color toner image conveyed by the intermediate transfer belt 40 onto the recording paper conveyed by the conveyance roller pair 53.

  The fixing unit 70 fixes the full-color toner image on the recording paper by heating and pressing the recording paper on which the full-color toner image is transferred.

  The paper discharge roller pair 80 discharges the recording paper on which the full-color toner image is fixed by the fixing unit 70 to the paper discharge table 81.

  FIG. 2 is a mechanical configuration diagram illustrating an example of the developing device 20Y according to the first embodiment. As illustrated in FIG. 2, the developing device 20 </ b> Y includes a developing unit 21, a toner detection unit 22, and a toner container 23.

  The developing unit 21 stores toner and develops the electrostatic latent image on the photosensitive drum 13Y using the stored toner. The developing unit 21 includes a housing 210, a developing roller 211, a supply roller 212, A developing blade 213, a stirring member 214, and transmission windows 215a and 215b are provided.

  The housing 210 (an example of a storage unit) is a developing tank that stores toner used as a developer, and has an opening at the top.

  The developing roller 211 is a toner carrier and rotates in the direction of arrow b in the developing process. Thereby, the electrostatic latent image on the photosensitive drum 13Y is visualized with toner. The developing roller 211 has a metal core, and the outer periphery is made of conductive rubber (for example, conductive urethane rubber or silicone rubber) whose volume resistance value is adjusted to about 10E5 to 10E7Ω. In the present embodiment, the developing roller 211 has a rubber hardness Hs75, a core metal diameter φ6, and a rubber part outer diameter φ12, but is not limited thereto.

  The supply roller 212 is a toner supply member, and is in contact with the developing roller 211 so as to be rotatable. As the supply roller 212, for example, a sponge roller in which foamed polyurethane made semiconductive by mixing carbon with the outer periphery of a metal core is attached. In this embodiment, the supply roller 212 has a core metal diameter of φ6 and a rubber part outer diameter of φ12, a nip with the developing roller 211 is set to 2 mm, and a rotation speed ratio is set to 1. It is not limited to. For example, in this embodiment, the contact nip between the supply roller 212 and the developing roller 211 is set to about 1 to 3 mm, and the supply roller 212 is rotated with respect to the developing roller 211 in the direction of the arrow c. The function of efficiently transporting the toner inside the housing 210 to the surface layer of the developing roller 211 is obtained.

  The developing blade 213 is in contact with the developing roller 211 to control the toner layer thickness on the surface of the developing roller 211 conveyed by the supply roller 212 to a predetermined amount, and at the same time, removes the toner on the surface of the developing roller 211. Frictionally charged. In this embodiment, the developing blade 213 is made of a SUS material having a plate thickness of 0.1 mm, a linear pressure of 45 N / m, a nip position of 0.2 mm from the tip, and a length from the support end to the free end (free length) ) Is set to 14 mm, but is not limited to this. For example, in this embodiment, the developing blade 213 can be formed of a metal plate, the contact pressure of the developing blade 213 with respect to the developing roller 211 is a normal linear pressure of 20 to 60 N / m, and the contact nip position is 0 from the tip of the developing blade 213. By setting it to about .5 ± 0.5 mm, a stable toner thin layer can be formed on the developing roller 211. These values are adjusted to the characteristics of the toner used, the developing roller, the supply roller, etc. To be determined as appropriate.

  The stirring member 214 rotates in the direction of the arrow d and stirs the toner inside the housing 210. As a result, it is possible to reduce toner powder pressure inside the housing 210 from being concentrated on the supply roller 212 and increasing the load. An example of the stirring member 214 is shown in FIGS. As shown in FIG. 3, the stirring member 214 has a paddle having a shape in which both ends of a metal rod having a diameter of about 0.8 to 2 mm are bent, and a rotary shape that stirs the rotating shaft and toner as shown in FIG. This can be realized by using a resin paddle that is molded in a single piece. The stirring member 214 may be realized by an agitator having the same configuration as an agitator that is a toner loosening member of the toner container 23 described later.

  The transmission windows 215a and 215b constitute a part of the side wall of the housing 210 and are arranged to face each other.

  The toner detection unit 22 is a sensor that detects the amount of toner stored in the development unit 21, and a first detection unit 220 that detects that the amount of toner stored in the development unit 21 is the first threshold value. And a second detection unit 221 that detects that the amount of toner stored in the development unit 21 is a second threshold value smaller than the first threshold value.

  The first detection unit 220 includes a light emitting element 220a disposed above the transmission window 215a and a light receiving element 220b disposed above the transmission window 215b. The second detection unit 221 includes a lower side of the transmission window 215a. And a light receiving element 221b disposed below the transmission window 215b. The light emitting element 220a and the light receiving element 220b are arranged such that light generated from the light emitting element 220a passes through the transmission windows 215a and 215b and is received by the light receiving element 220b. The light emitting element 221a and the light receiving element 221b are arranged in the light emitting element 221a. The light generated from the light is transmitted through the transmission windows 215a and 215b and is received by the light receiving element 221b.

  When the toner is sufficiently left inside the housing 210, the light generated from the light emitting elements 220a and 221a is blocked by the toner inside the housing 210 and does not reach the light receiving elements 220b and 221b. However, when the printing apparatus 1 repeats the printing operation and the consumption of the toner inside the housing 210 proceeds, the draft surface of the toner inside the housing 210 decreases, and first, the light generated from the light emitting element 220a reaches the light receiving element 220b. After that, the light generated from the light emitting element 221a also reaches (receives) the light receiving element 221b.

  In the present embodiment, the remaining amount of toner in the housing 210 when the light generated from the light emitting element 220a reaches the light receiving element 220b is set as the first threshold, and the light generated from the light emitting element 221a. The amount of toner remaining in the housing 210 at the time when the toner reaches the light receiving element 221b is set as the second threshold value. For this reason, in the present embodiment, it is possible to grasp whether or not the remaining amount of toner in the housing 210 has reached the first threshold value and whether or not the second threshold value has been reached from the presence or absence of light detection of the light receiving elements 220b and 221b. .

  In the present embodiment, the toner detection unit 22 is realized by an optical sensor. However, the toner detection unit 22 may be realized by a powder detection sensor using a piezoelectric vibration element. The powder detection sensor is capable of detecting the presence or absence of toner because the detection surface constantly vibrates and vibration is suppressed when the toner contacts the detection surface.

  A toner container 23 (an example of a toner replenishing unit) is a container that contains toner to be replenished to the developing unit 21, and is detachably attached to the upper portion of the housing 210. The toner container 23 includes an agitator 230 and a toner supply roller 231.

  The agitator 230 rotates in the direction of arrow e to loosen the toner inside the toner container 23. The agitator 230 can be realized by, for example, a member in which a sheet-shaped honey is adhered to a rotating shaft. The agitator 230 and the toner supply roller 231 are driven in synchronization.

  The toner supply roller 231 rotates to supply the toner contained in the toner container 23 to the housing 210 through an opening provided in the upper part of the housing 210 of the developing unit 21. Here, the toner supply amount from the toner container 23 to the developing unit 21 is determined by the driving time of the toner supply roller 231. Therefore, the toner supply amount from the toner container 23 to the developing unit 21 can be controlled by controlling the drive time of the toner supply roller 231. If the drive time is increased, the toner supply amount increases, and if the drive time is decreased, the toner is increased. Replenishment amount decreases.

  When the driving speed of the toner supply roller 231 is variable, the toner supply amount can be controlled by changing the driving speed even when the driving time of the toner supply roller 231 is fixed. If the amount increases and the drive speed decreases, the toner replenishment amount decreases.

  Since the developing devices 20M, 20C, and 20K have the same components as the developing device 20Y except that the toner colors are different, detailed description thereof is omitted.

  FIG. 5 is a graph showing the relationship between the mixing ratio of the deteriorated toner and the undegraded toner and the background level. Here, the deteriorated toner refers to toner stored in the developing unit. The toner stored in the developing unit is subjected to physical stress as the developing unit is driven, and its characteristics are deteriorated as compared to a completely unused toner. . The undegraded toner refers to toner that is replenished from the toner container to the developing unit. The toner container is driven only when the toner is replenished, has few members that give stress to the contained toner, and has almost no deterioration in characteristics as compared with a completely unused toner. Called.

  The graph shown in FIG. 5 shows the result of mixing the deteriorated toner remaining inside the developing unit after printing durability and the undegraded toner stored in the toner container, filling the developing unit again, and measuring the background stains. Is shown. In the example shown in FIG. 5, non-magnetic one-component toner is used, and as the deteriorated toner, the toner after a printing endurance time of 25 hours assuming deterioration due to a normal use state, and the deterioration level is further deteriorated. Two types of toner are used, which are toners after 50 hours of printing durability. The horizontal axis of the graph shown in FIG. 5 shows the ratio of the deteriorated toner to the mixed toner obtained by mixing the deteriorated toner and the undegraded toner, and the vertical axis of the graph shown in FIG. The background level is shown when 1 is 1 (reference).

  From the graph shown in FIG. 5, the background level is best when only undegraded toner (100% undegraded toner) is used, and undegraded toner when only degraded toner (100% deteriorated toner) is used. It can be seen that the level of soiling is worse than that of using only the soil. This is because the deteriorated toner in the developing unit is continuously subjected to physical stress, and the external additive of the toner is peeled off or the toner itself is cracked. This is because the chargeability and fluidity) have changed (deteriorated). Specifically, the deteriorated toner in the developing unit is usually conveyed to the developing roller by the supply roller, and after the amount of adhesion on the developing roller is optimized by the developing blade, the developed toner is developed at the nip portion with the photosensitive member, and developed. The deteriorated toner that has not been used in the above process is repeatedly recovered by the supply roller, so that physical stress continues to be applied.

  From the graph shown in FIG. 5, it can be seen that when the deteriorated toner and the undegraded toner are mixed, the background level is further deteriorated as compared with the case where only the deteriorated toner is used. This is because when the deteriorated toner and the undegraded toner are mixed, the toners interact with each other and the chargeability of the toner becomes more unstable.

  Here, since the ground level on the image that is acceptable for actual use is normally 0.97 or more, in order to maintain good image quality when assuming toner deterioration due to normal use conditions, mixing is required. The ratio of the deteriorated toner to the toner needs to be 78% or more or 35% or less. This is 22% or less or 65% or more in terms of the toner supply ratio from the toner container to the developing unit. The toner replenishment ratio refers to a ratio of toner (undegraded toner) replenished from the toner container to the developing unit by one replenishment and toner stored in the developing unit (deteriorated toner). Indicates the ratio of undegraded toner to degraded toner.

  If the toner replenishment ratio is 65% or more, the amount of toner replenishment from the toner container to the developing unit at one time increases, leading to an increase in the size of the developing device. In addition, if the amount of toner replenished at one time increases, development conditions that should be appropriately set, for example, development bias before and after the replenishment change greatly, and the image forming system becomes unstable. .

  On the other hand, when the toner replenishing ratio is 22% or less, the amount of toner replenished from the toner container to the developing unit at one time can be reduced, and the developing device can be downsized. Also, if the amount of toner replenished at one time is small, there is little fluctuation in the toner characteristics inside the developing unit before and after replenishment, so that the image forming system can be maintained stably.

  That is, a smaller toner replenishment ratio is preferable. When the deteriorated state of the deteriorated toner is further deteriorated (when the printing endurance time is 50 hours or more), the toner replenishment ratio that can tolerate the background level becomes a narrower region, so the toner replenishment ratio is less than 15%. It is desirable to make it.

  The toner used in the example shown in FIG. 5 has a volume average particle size of 8.5 μm, a polyester resin as a main component, silica 1 with respect to 100 parts of a toner base prepared by mixing and crushing wax and pigment. This is manufactured by externally adding a part, and has almost the same characteristics as various toners used in general laser beam printers.

  Further, in the example shown in FIG. 5, the non-magnetic one-component pulverized toner is used. However, the characteristics of the toner shown in FIG. Shows the same characteristics. Even if the toner to be used is a magnetic one-component toner or a two-component toner, it is preferable that the amount of toner replenished at one time is small in order to suppress a change in toner characteristics before and after toner replenishment. Therefore, other toners may be used instead of the non-magnetic one-component pulverized toner, and the same effect as when the non-magnetic one-component pulverized toner is used can be obtained.

  FIG. 6 is a block diagram illustrating an example of an electrical configuration of the printing apparatus 1 according to the first embodiment. As illustrated in FIG. 6, the printing apparatus 1 includes a calculation unit 110, a storage unit 120, a control unit 130, and a timer unit 140. Here, the processing for the developing device 20Y of the calculation unit 110, the storage unit 120, the control unit 130, and the timer unit 140 will be described, and the processing for the developing devices 20M, 20C, and 20K is the same as the processing for the developing device 20Y. Therefore, the description is omitted.

  The calculating unit 110 calculates the amount of toner consumed by the development of the developing unit 21, and is hardware such as a dot counter, for example. However, the present invention is not limited to this, and the calculation unit 110 may be software.

Here, the electrostatic latent image on the photosensitive drum 13Y is laser light L _Y from the optical scanning unit 30 is formed by being irradiated, the electrostatic latent image itself to generate the electrostatic latent image This is a set of dots determined according to the image to be printed used. The toner consumption amount per dot is determined by various settings of the developing unit 21 (for example, bias and laser beam output power), usage environment (temperature and humidity), and dot formation conditions (dots are continuous). (Information such as (solid image) or not). For this reason, the toner consumption consumed by the development of the developing unit 21 can be calculated (estimated) from the printing amount (printing area) that is the number of dots of the image to be printed. However, an error occurs between the toner consumption estimated from the printing amount and the toner consumption actually consumed by the development of the developing unit 21.

  Therefore, in the present embodiment, the calculation unit 110 calculates the toner consumption consumed by the development of the development unit 21 using the correction value. Specifically, the calculation unit 110 multiplies the consumption amount of toner per dot by the print amount (number of dots) of the image to be printed, and further refers to a correction coefficient (hereinafter referred to as “consumption correction coefficient”). ) To calculate the toner consumption. The correction value (consumption correction coefficient) is calculated by the control unit 130 described later.

  The storage unit 120 stores various programs executed by the printing apparatus 1 and various information used for various processes performed by the printing apparatus 1. The storage unit 120 is, for example, magnetic, optical, or electrical such as a hard disk drive (HDD), a solid state drive (SSD), a memory card, an optical disk, a read only memory (ROM), and a random access memory (RAM). This can be realized by at least one of existing storage devices that can be stored.

  The control unit 130 controls the entire printing apparatus 1 and can be realized by an existing control apparatus such as a CPU (Central Processing Unit). The control unit 130 is calculated by the calculation unit 110 within a period from when the first detection unit 220 detects the first threshold value to when the second detection unit 221 detects the second threshold value. Using the first toner consumption amount that is the sum of the toner consumption amounts and the second toner consumption amount that is the toner amount that is determined from the first threshold value and the second threshold value and that is actually consumed within the period. The correction value is calculated. For example, the control unit 130 calculates the consumption correction coefficient by dividing the second toner consumption amount by the first toner consumption amount.

  The control unit 130 sets the toner amount stored in the developing unit 21 to be the first threshold before performing the adjustment process in which the electrostatic latent image formed on the photosensitive drum 13Y is not developed by the developing unit 21. Alternatively, the toner supply from the toner container 23 to the developing unit 21 may be controlled to calculate a correction value. Here, the adjustment processing is processing that does not require image formation on recording paper, such as density adjustment processing and color matching adjustment processing.

  In addition, the control unit 130 determines whether or not the printing amount of the image to be printed used for generating the electrostatic latent image is equal to or greater than a predetermined amount. The correction value may be calculated by controlling toner replenishment from the toner container 23 to the developing unit 21 so that the amount of toner that is applied becomes the first threshold value. Thereby, for example, when the image to be printed is a solid image, calculation of the correction value can be started.

  Further, the control unit 130 determines whether or not a change with time of the developing unit 21 satisfies a predetermined condition, and when determining that the predetermined condition is satisfied, the amount of toner stored in the developing unit 21 is the first threshold value. The toner supply from the toner container 23 to the developing unit 21 may be controlled so that the correction value is calculated. Here, the predetermined condition can be set, for example, when the number of printed sheets reaches a predetermined number or when the travel distance of any part of the printing apparatus 1 reaches a predetermined distance.

  In addition, the control unit 130 causes the developing unit 21 to supply toner of the same amount as the toner consumption amount newly calculated by the calculation unit 110 after the correction value is calculated. Specifically, the control unit 130 replenishes toner from the toner container 23 to the developing unit 21 for replenishing the same amount of toner as the toner consumption calculated by the calculation unit 110 from the unit toner replenishment amount per unit time. Calculate time. Then, the control unit 130 counts the calculated replenishment time by the timer unit 140 and replenishes toner from the toner container 23 to the developing unit 21 while the timer unit 140 is counting.

  The timer unit 140 is hardware that counts various times such as a replenishment time. However, the present invention is not limited to this, and the timer unit 140 may be software.

  Next, the operation of the printing apparatus according to the first embodiment will be described. Here, the processing for the developing device 20Y will be described, and the processing for the developing devices 20M, 20C, and 20K is the same as the processing for the developing device 20Y, and thus description thereof is omitted.

  In the following description, the case where the first threshold toner amount is 100 g, the second threshold toner amount is 90 g, and the remaining amount of toner stored in the developing unit 21 changes from 90 g to 100 g will be described as an example. In this case, since the toner replenishment ratio is 10/90% even during the consumption correction coefficient calculation process described in FIG. 7, it is less than 15%.

  Although different depending on the configuration of the developing unit, in the general developing unit configuration as in the first embodiment, in order to maintain a good image quality for an image with a high image printing ratio such as a solid image, In addition, it is necessary to leave 30 to 40 g or more of toner. In addition, it is necessary to consider the toner consumed until it is determined that the toner container is empty, the toner consumed after the toner container is empty and replaced with a new toner container, and the like. is there. For this reason, in the first embodiment, the numerical values as described above are set, but each numerical value is not limited to this and can be set as appropriate.

  FIG. 7 is a flowchart illustrating an example of a consumption correction coefficient calculation process performed by the printing apparatus 1 according to the first embodiment. Note that the consumption correction coefficient calculation process described in FIG. 7 is executed when a consumption correction coefficient calculation is triggered.

  First, when the consumption correction coefficient calculation is triggered, the control unit 130 replenishes toner from the toner container 23 to the developing unit 21 (step S110), and the remaining amount of toner in the developing unit 21 is 100 g or less (in step S112). No), the process of step S110 is continued. Here, the execution timing of the consumption correction coefficient calculation process is, for example, the adjustment process execution timing, the start of solid image printing, and the change in the development unit 21 with time satisfy a predetermined condition. This is applicable to cases where the weight is less than 90 g, but is not limited thereto. Note that when the remaining amount of toner is 100 g or more, the consumption correction coefficient calculation process may be triggered. In this case, the process starts from step S114.

  Subsequently, when the remaining amount of toner in the developing unit 21 reaches 100 g (Yes in step S112), the printing apparatus 1 starts printing. Therefore, the calculation unit 110 calculates the toner consumption amount from the print amount of the image to be printed. And added to the first toner consumption (step S114). Here, it is assumed that the first toner consumption amount is 0 when the remaining amount of toner in the developing unit 21 reaches 100 g. Further, when the consumption correction coefficient has been calculated by the control unit 130, the calculation unit 110 calculates the toner consumption by correcting with the consumption correction coefficient.

  Subsequently, the developing unit 21 develops the electrostatic latent image formed on the photosensitive drum 13Y using the toner in the developing unit 21 (step S116).

  Then, while the remaining amount of toner in the developing unit 21 is 90 g or more (No in step S118), the calculating unit 110 and the developing unit 21 repeat the processes in steps S114 and S116, respectively. Note that toner replenishment is not performed while the remaining amount of toner in the developing unit 21 is 90 g or more (No in step S118). When the consumption correction coefficient calculation process is performed at the start of printing the solid image, the solid image is printed in the first step S116.

  Subsequently, when the remaining amount of toner in the developing unit 21 reaches 90 g (Yes in step S118), the control unit 130 calculates a consumption correction coefficient using the first toner consumption amount and the second toner consumption amount. (Step S120). Here, the second toner consumption amount is 10 g since the toner amount of the first threshold is 100 g and the toner amount of the second threshold is 90 g. Therefore, for example, when the first toner consumption amount is 10.5 g, the consumption amount correction coefficient is 10 / 10.5. When the consumption correction coefficient calculation process is performed at the timing of executing the adjustment process, the adjustment process is started thereafter.

  FIG. 8 is a flowchart illustrating an example of normal toner replenishment processing performed by the printing apparatus 1 according to the first embodiment. The toner replenishment process described in FIG. 8 is performed every time the printing apparatus 1 performs printing except during the consumption correction coefficient calculation process.

  First, when the printing apparatus 1 starts printing, the calculation unit 110 calculates a toner consumption amount from a print amount of an image to be printed and a consumption correction coefficient calculated by a consumption correction coefficient calculation process (step S130). For example, as described above, when the value of the consumption correction coefficient is 10 / 10.5, the calculation unit 110 multiplies the toner consumption calculated from the print amount of the image to be printed by 10 / 10.5. Thus, the corrected toner consumption is calculated. This eliminates an error between the toner consumption calculated (estimated) from the printing amount and the toner consumption actually consumed by development of the developing unit 21, and is actually consumed by the toner consumption calculated from the printing amount and development. The toner consumption can be matched.

  Subsequently, the developing unit 21 develops the electrostatic latent image formed on the photosensitive drum 13Y using the toner in the developing unit 21 (step S132).

  Subsequently, the control unit 130 replenishes the developing unit 21 with the same amount of toner calculated by the calculation unit 110 from the toner container 23 (step S134).

  As described above, according to the first embodiment, the toner consumption amount is estimated (calculated) from the print amount by correcting the error from the toner consumption amount actually consumed by the development of the developing unit 21. As a result, the same amount of toner that is actually consumed can be replenished with high accuracy. Thereby, the toner replenishment ratio can be stabilized.

  In particular, as in the first embodiment, when an LEDA is used for the optical scanning unit, each of a plurality of light emitting devices arranged in the main scanning direction reproduces dots by irradiating a laser. When estimating the quantity, the error of each light emitting device is superimposed and the error becomes larger, which is more effective.

  If the correction value is calculated before the adjustment process as in the first embodiment, the background stain is not noticeable in the adjustment process. Therefore, the influence of the background stain due to the change in the toner supply ratio accompanying the calculation of the correction value. Can be reduced.

  Further, as in the first embodiment, if the correction value is calculated when the printing amount is equal to or larger than the predetermined amount (solid image), when the LEDA is used for the optical scanning unit, many light emitting devices are used. Since the toner consumption amount can be calculated and the correction value can be calculated while the electrostatic latent image is formed, the error can be corrected with high accuracy.

  In addition, as in the first embodiment, if the correction value is calculated when the change with time of the developing unit satisfies a predetermined condition, the error variation due to the change with time of the developing unit is also taken into consideration. Can be corrected.

(Second Embodiment)
In the second embodiment, an example of correcting an error in toner replenishment amount will be described. In the following, differences from the first embodiment will be mainly described, and components having the same functions as those in the first embodiment will be given the same names and symbols as those in the first embodiment, and description thereof will be given. Is omitted.

  First, the configuration of the printing apparatus according to the second embodiment will be described.

  FIG. 9 is a block diagram illustrating an example of an electrical configuration of the printing apparatus 301 according to the second embodiment. As illustrated in FIG. 9, in the printing apparatus 301 according to the second embodiment, a calculation unit 310 and a control unit 330 are different from the printing apparatus 1 according to the first embodiment. Here, the processing for the developing device 20Y of the calculation unit 310 and the control unit 330 will be described. The processing for the developing devices 20M, 20C, and 20K is the same as the processing for the developing device 20Y, and thus the description thereof is omitted.

  The calculation unit 310 calculates a toner consumption amount consumed by development of the development unit 21. Specifically, the calculation unit 310 calculates the toner consumption amount by multiplying the toner consumption amount per dot by the printing amount (number of dots) of the image to be printed.

  The control unit 330 sets the toner from the toner container 23 to the developing unit 21 during a period from when the second detection unit 221 detects the second threshold value to when the first detection unit 220 detects the first threshold value. To replenish. Specifically, when the second detection unit 221 detects that the second threshold value is the second threshold value, the control unit 330 starts toner supply from the toner container 23 to the developing unit 21 and starts counting in the timer unit 140. Let Further, when the first detection unit 220 detects that the first threshold value is the first threshold value, the control unit 330 ends the toner supply from the toner container 23 to the developing unit 21 and causes the timer unit 140 to end the counting. Accordingly, it is possible to measure the toner replenishment execution period, which is a period from when the second threshold is detected until the first threshold is detected.

  Then, the control unit 330 has the first toner replenishment amount determined from the toner replenishment execution period and the unit toner replenishment amount per unit time, and the toner amount determined from the first threshold value and the second threshold, and is actually within the toner replenishment execution period. The correction value is calculated using the second toner supply amount that is the supplied toner amount. For example, the control unit 330 calculates a correction coefficient (hereinafter referred to as “replenishment amount correction coefficient”) by dividing the second toner supply amount by the first toner supply amount.

  Note that the control unit 330 has detected that the second detection unit 221 detects that the electrostatic latent image formed on the photosensitive drum 13Y is the second threshold value before performing the adjustment process in which the development unit 21 does not develop the electrostatic latent image. The correction value may be calculated by supplying toner from the toner container 23 to the developing unit 21 for a period until the first detection unit 220 detects the first threshold value.

  Further, the control unit 330 determines whether or not the change with time of the toner container 23 satisfies a predetermined condition, and if it is determined that the predetermined condition is satisfied, the second detection unit 221 detects that the second threshold value is reached. The toner may be supplied from the toner container 23 to the developing unit 21 for a period from when the first detection unit 220 detects that the first threshold value is reached, to calculate a correction value.

  Further, the control unit 330 uses the unit toner replenishment amount and the correction value to calculate a replenishment time required for replenishing the same amount of toner as the toner consumption amount newly calculated by the calculation unit 310 after calculating the correction value. The toner is supplied from the toner container 23 to the developing unit 21 with the calculated supply time. Specifically, the control unit 330 calculates the replenishment time by dividing the toner consumption amount newly calculated by the calculation unit 310 by the unit toner replenishment amount and further correcting with the unit replenishment amount correction coefficient. Then, the control unit 330 counts the calculated replenishment time by the timer unit 140 and replenishes toner from the toner container 23 to the developing unit 21 while the timer unit 140 is counting.

  Next, the operation of the printing apparatus according to the second embodiment will be described. Here, the processing for the developing device 20Y will be described, and the processing for the developing devices 20M, 20C, and 20K is the same as the processing for the developing device 20Y, and thus description thereof is omitted. In the following, as in the first embodiment, the first threshold toner amount is 100 g, the second threshold toner amount is 90 g, and the remaining amount of toner stored in the developing unit 21 changes from 90 g to 100 g. The description is given by way of example, but the present invention is not limited to this.

  FIG. 10 is a flowchart illustrating an example of a supply amount correction coefficient calculation process performed by the printing apparatus 301 according to the second embodiment. Note that the replenishment amount correction coefficient calculation process described in FIG. 10 is executed when a replenishment amount correction coefficient calculation is triggered.

  First, when the replenishment amount correction coefficient calculation is triggered and the printing apparatus 301 starts printing, the developing unit 21 develops the electrostatic latent image formed on the photosensitive drum 13Y using the toner in the developing unit 21. (Step S210). Thereafter, while the remaining amount of toner in the developing unit 21 exceeds 90 g (No in step S212), the developing unit 21 performs step S210 each time a new electrostatic latent image is formed on the photosensitive drum 13Y. Repeat the process. During this time, the control unit 330 does not supply toner from the toner container 23 to the developing unit 21. Here, the replenishment amount correction coefficient calculation trigger corresponds to, for example, the adjustment processing execution timing, the case where the change over time of the toner container 23 satisfies a predetermined condition, or the case where the remaining amount of toner exceeds 100 g. However, the present invention is not limited to this. It should be noted that the case where the remaining amount of toner is 90 g or less may be the trigger for executing the replenishment amount correction coefficient calculation process. In this case, the process starts from step S214.

Subsequently, when the remaining amount of toner in the developing unit 21 reaches 90 g (Yes in step S212),
The control unit 330 replenishes toner from the toner container 23 to the developing unit 21 (step S214), and the timer unit 140 measures a toner replenishment execution period (step S216).

  Then, while the remaining amount of toner in the developing unit 21 is less than 100 g (No in step S218), the control unit 330 and the timer unit 140 continue the processes of steps S214 and S216, respectively. Note that printing (development of an electrostatic latent image) is not performed while the remaining amount of toner in the developing unit 21 is less than 100 g (No in step S218).

  Subsequently, when the remaining amount of toner in the developing unit 21 reaches 100 g (Yes in step S218), the control unit 330 calculates a supply amount correction coefficient using the first toner supply amount and the second toner supply amount. (Step S220). Here, the first toner replenishment amount is a value obtained by multiplying the toner replenishment execution period measured in step S216 by the unit toner replenishment amount, and when the replenishment amount correction coefficient has already been calculated by the control unit 330. Further, the value is corrected by the supply amount correction coefficient. The second toner supply amount is 10 g because the toner amount of the first threshold is 100 g and the toner amount of the second threshold is 90 g. Therefore, for example, when the first toner replenishment amount is 10.5 g, the replenishment amount correction coefficient is 10 / 10.5. If the replenishment amount correction coefficient calculation process is performed at the timing of executing the adjustment process, the adjustment process is started thereafter.

  FIG. 11 is a flowchart illustrating an example of a normal toner supply process performed by the printing apparatus 301 according to the second embodiment. The toner replenishing process described in FIG. 11 is performed every time the printing apparatus 301 performs printing except during the replenishment amount correction coefficient calculation process.

  First, when the printing apparatus 301 starts printing, the calculation unit 310 calculates a toner consumption amount from the printing amount of an image to be printed (step S230).

  Subsequently, the developing unit 21 develops the electrostatic latent image formed on the photosensitive drum 13Y using the toner in the developing unit 21 (step S232).

  Subsequently, the control unit 330 calculates the replenishment time necessary for replenishing the toner of the same amount as the toner consumption amount calculated by the calculation unit 310 from the unit toner replenishment amount and the replenishment amount correction coefficient, and the calculated replenishment time toner. The developing unit 21 is replenished from the container 23 (step S234). For example, as described above, when the value of the supply amount correction coefficient is 10 / 10.5, the control unit 330 divides the toner consumption amount calculated by the calculation unit 310 by the unit toner supply amount, The corrected replenishment time is calculated by multiplying by 10.5. Thus, an error between the toner supply amount calculated (estimated) from the supply time and the toner supply amount actually supplied is eliminated, and the toner supply amount calculated from the supply time and the toner supply amount actually supplied are matched. be able to.

  As described above, according to the second embodiment, since the error from the toner replenishment amount actually replenished is estimated (calculated), the toner consumption amount actually consumed by development is calculated. The same amount of toner can be replenished with high accuracy. Thereby, the toner replenishment ratio can be stabilized.

  Even in the second embodiment, if the correction value is calculated before the adjustment process, the background stain is not noticeable in the adjustment process. Can be reduced.

  Further, as in the second embodiment, if the correction value is calculated when the change in the toner container over time satisfies the predetermined condition, the error change due to the change in the toner container over time is taken into account. Can be corrected.

(Hardware configuration)
FIG. 12 is a block diagram illustrating an example of a hardware configuration of the printing apparatus according to each of the embodiments. As shown in FIG. 12, the printing apparatus according to each of the embodiments has a configuration in which a controller 910 and an engine unit (Engine) 960 are connected by a PCI (Peripheral Component Interconnect) bus. The controller 910 is a controller that controls the entire MFP, drawing, communication, and input from the operation display unit 920. The engine unit 960 is a printer engine that can be connected to a PCI bus, and is, for example, a monochrome plotter, a 1-drum color plotter, a 4-drum color plotter, a scanner, or a fax unit. The engine unit 960 includes an image processing part such as error diffusion and gamma conversion in addition to a so-called engine part such as a plotter.

  The controller 910 includes a CPU 911, a north bridge (NB) 913, a system memory (MEM-P) 912, a south bridge (SB) 914, a local memory (MEM-C) 917, and an ASIC (Application Specific Integrated Circuit). 916 and a hard disk drive (HDD) 918, and the North Bridge (NB) 913 and the ASIC 916 are connected by an AGP (Accelerated Graphics Port) bus 915. The MEM-P 912 further includes a ROM 912a and a RAM 912b.

  The CPU 911 performs overall control of the printing apparatus, has a chip set including the NB 913, the MEM-P 912, and the SB 914, and is connected to other devices via the chip set.

  The NB 913 is a bridge for connecting the CPU 911 to the MEM-P 912, SB 914, and the AGP bus 915, and includes a memory controller that controls reading and writing to the MEM-P 912, a PCI master, and an AGP target.

  The MEM-P 912 is a system memory used as a memory for storing programs and data, a memory for developing programs and data, a memory for drawing printers, and the like, and includes a ROM 912a and a RAM 912b. The ROM 912a is a read-only memory used as a memory for storing programs and data, and the RAM 912b is a writable and readable memory used as a program / data development memory, a printer drawing memory, and the like.

  The SB 914 is a bridge for connecting the NB 913 to a PCI device and a peripheral device. The SB 914 is connected to the NB 913 via a PCI bus, and a network interface (I / F) unit and the like are also connected to the PCI bus.

  The ASIC 916 is an IC (Integrated Circuit) for image processing having hardware elements for image processing, and has a role of a bridge for connecting the AGP bus 915, the PCI bus, the HDD 918, and the MEM-C 917, respectively. The ASIC 916 includes a PCI target and an AGP master, an arbiter (ARB) that forms the core of the ASIC 916, a memory controller that controls the MEM-C 917, and a plurality of DMACs (Direct Memory) that perform image data rotation by hardware logic and the like. Access Controller) and a PCI unit that performs data transfer between the engine unit 960 via the PCI bus. A universal serial bus (USB) 940 and an IEEE 1394 (the Institute of Electrical and Electronics Engineers 1394) interface 950 are connected to the ASIC 916 via a PCI bus. The operation display unit 920 is directly connected to the ASIC 916.

  The MEM-C 917 is a local memory used as a copy image buffer and a code buffer, and the HDD 918 is a storage for storing image data, programs, font data, and forms.

  The AGP bus 915 is a bus interface for a graphics accelerator card proposed for speeding up graphics processing. The AGP bus 915 speeds up the graphics accelerator card by directly accessing the MEM-P 912 with high throughput. It is.

(Modification)
In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, the first and second embodiments may be combined. In the second embodiment, a predetermined amount of toner may be replenished when the amount of remaining toner is equal to or less than the second threshold, instead of every time the toner is consumed.

DESCRIPTION OF SYMBOLS 1,301 Printing apparatus 10 Image formation part 11Y, 11M, 11C, 11K Process cartridge 12Y, 12M, 12C, 12K Image formation part 13Y, 13M, 13C, 13K Photosensitive drum 14Y, 14M, 14C, 14K Charge roller 15Y, 15M, 15C, 15K Primary transfer roller 16Y, 16M, 16C, 16K Cleaning device 20Y, 20M, 20C, 20K Developing device 21 Developing unit 22 Toner detection unit 23 Toner container 30 Optical scanning unit 40 Intermediate transfer belt 41, 42 Support roller 50 Paper feed unit 51 Paper feed roller 52 Pad 53 Transport roller pair 60 Secondary transfer roller 70 Fixing unit 80 Paper discharge roller pair 81 Paper discharge table 110, 310 Calculation unit 120 Storage unit 130, 330 Control unit 140 Timer unit 210 Housing 211 Development Roller 212 Feed roller 213 developing blade 214 agitating member 215a, 215b transmitting window 220 first detection section 221 second detection unit 220a, 221a light emitting elements 220b, 221b light-receiving element 230 agitator 231 toner supply roller 910 Controller 911 CPU
912 System memory 912a ROM
912b RAM
913 North Bridge 914 South Bridge 915 AGP Bus 916 ASIC
917 Local memory 918 Hard disk drive 920 Operation display unit 940 USB
950 IEEE1394 interface 960 engine part

JP 2006-65079 A

Claims (12)

An image carrier on which an electrostatic latent image is formed;
A developing section for storing toner and developing the electrostatic latent image on the image carrier using the stored toner;
A calculation unit for calculating a toner consumption amount consumed by the development;
A first detection unit that detects that the amount of toner stored in the developing unit is a first threshold;
A second detection unit for detecting that the amount of toner stored in the developing unit is a second threshold value smaller than the first threshold value;
A first toner consumption amount that is a sum of toner consumption amounts calculated by the calculation unit within a period from when the first threshold value is detected until the second threshold value is detected; A control unit that calculates a correction value using a second toner consumption amount that is a toner amount determined from the first threshold value and the second threshold value and that is actually consumed within the period;
The calculation unit calculates a toner consumption to be newly calculated using the correction value,
The image forming apparatus, wherein the control unit causes the toner replenishing unit to replenish toner of the same amount as the newly calculated toner consumption amount from the toner replenishing unit.   The controller controls the amount of toner stored in the developing unit to be the first threshold before performing an adjustment process in which the electrostatic latent image formed on the image carrier is not developed by the developing unit. The image forming apparatus according to claim 1, wherein toner correction from the toner supply unit to the developing unit is controlled to calculate the correction value.   The control unit determines whether or not a printing amount of an image to be printed used for generating the electrostatic latent image is equal to or larger than a predetermined amount, and when it is determined that the printing amount is equal to or larger than the predetermined amount, 3. The correction value is calculated by controlling toner replenishment from the toner replenishing unit to the developing unit so that a stored toner amount becomes the first threshold value. Image forming apparatus.   The controller determines whether or not a change with time of the developing unit satisfies a predetermined condition, and when determining that the predetermined condition is satisfied, the amount of toner stored in the developing unit is the first amount. The image forming apparatus according to claim 1, wherein the correction value is calculated by controlling toner replenishment from the toner replenishing unit to the developing unit so as to be a threshold value.   The image forming apparatus according to claim 1, wherein the calculation unit calculates a toner consumption amount from a printing amount of an image to be printed used for generating the electrostatic latent image. .   The image forming apparatus according to claim 1, further comprising an exposure unit that forms an electrostatic latent image on the image carrier using an LED (Light Emitting Diode). An image carrier on which an electrostatic latent image is formed;
A developing section for storing toner and developing the electrostatic latent image on the image carrier using the stored toner;
A first detection unit that detects that the amount of toner stored in the developing unit is a first threshold;
A second detection unit for detecting that the amount of toner stored in the developing unit is a second threshold value smaller than the first threshold value;
A period from when the second threshold value is detected until the first threshold value is detected, toner is supplied from the toner supply unit to the developing unit, and the unit toner supply amount per unit period and unit time And a second toner supply amount that is a toner amount that is determined from the first threshold value and the second threshold value and that is actually supplied within the period. A control unit for calculating
A calculation unit for calculating a toner consumption amount consumed by the development,
The control unit calculates a replenishment time necessary for replenishing the same amount of toner as the toner consumption amount using the unit toner replenishment amount and the correction value, and calculates the calculated replenishment time from the toner replenishment unit to the development. An image forming apparatus, wherein toner is supplied to a part.   The control unit replenishes toner from the toner replenishing unit to the developing unit before the adjustment process in which the electrostatic latent image formed on the image carrier is not developed by the developing unit, and corrects the correction value. The image forming apparatus according to claim 7, wherein:   The controller determines whether or not a change over time of the toner replenishing unit satisfies a predetermined condition, and determines that the predetermined condition is satisfied, and supplies toner from the toner replenishing unit to the developing unit during the period The image forming apparatus according to claim 7, wherein the correction value is calculated.   The image forming apparatus according to claim 7, wherein the calculation unit calculates a toner consumption amount from a print amount of an image to be printed used for generating the electrostatic latent image. . A development step of developing the electrostatic latent image formed on the image carrier using toner stored in a storage unit;
A first consumption amount calculating step for calculating a toner consumption amount consumed by the development;
A first detection step of detecting that the amount of toner stored in the storage unit is a first threshold;
A second detection step of detecting that the amount of toner stored in the storage unit is a second threshold value smaller than the first threshold value;
The first toner consumption that is the sum of the toner consumption amounts calculated by the first consumption amount calculation step within the period from the detection of the first threshold value to the detection of the second threshold value. Correction value calculation for calculating a correction value using the amount and a second toner consumption amount that is a toner amount determined from the first threshold value and the second threshold value and that is actually consumed within the period Steps,
A second consumption amount calculating step of calculating a toner consumption amount to be newly calculated using the correction value;
A replenishment step of replenishing toner from the toner replenishment unit to the storage unit with the same amount of toner as the newly calculated toner consumption;
And a toner replenishing method. A development step of developing the electrostatic latent image formed on the image carrier using toner stored in a storage unit;
A first detection step of detecting that the amount of toner stored in the storage unit is a first threshold;
A second detection step of detecting that the amount of toner stored in the storage unit is a second threshold value smaller than the first threshold value;
A period from when the second threshold value is detected until the first threshold value is detected, toner is supplied from the toner supply unit to the storage unit, and the unit toner supply amount per unit period and unit time And a second toner supply amount that is a toner amount that is determined from the first threshold value and the second threshold value and that is actually supplied within the period. A correction value calculating step for calculating
A consumption calculating step for calculating a toner consumption consumed by the development;
Using the unit toner replenishment amount and the correction value, a replenishment time required for replenishing the same amount of toner as the toner consumption amount is calculated, and the calculated replenishment time replenishes toner from the toner replenishment unit to the storage unit. A replenishment step,
And a toner replenishing method.

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