Image forming apparatus

Abstract

To prevent the occurrence of an adverse effect on an image caused by deterioration of toner, in an image forming apparatus of a toner supply system.SOLUTION: An image forming apparatus 100 can perform a supply operation of supplying toner from a toner pack 40 that is removably attached to a supply port 32a, and comprises: a first toner remaining amount sensor 51 and a second toner remaining amount sensor 52 that detect the amount of toner stored in a developer container 8; a toner remaining amount panel 400 that notifies that the timing to perform the supply operation is reached; and a control unit 90 that controls the toner remaining amount panel 400 to notify that the timing to perform the supply operation is reached when the amount of toner detected by the first toner remaining amount sensor 51 and the second toner remaining amount sensor 52 becomes less than a threshold. When the printing rate after the supply operation is equal to or more than a predetermined printing rate, the control unit 90 sets the threshold to a first threshold, and when the printing rate is less than the predetermined printing rate, sets the threshold to a second threshold larger than the first threshold (S57(S62), S58, S60).SELECTED DRAWING: Figure 13

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus for forming an image on a recording material. [Background technology]

[0002] In general, electrophotographic image forming apparatuses form images by transferring a toner image formed on the surface of a photosensitive drum to a transfer material as a transfer medium. Known developer replenishment methods include, for example, a process cartridge method and a toner container replenishment method. The process cartridge method is a method in which a photosensitive drum and a developer container are integrated into a process cartridge, and when the developer in the developer container falls below a predetermined amount, the process cartridge is replaced with a new one. On the other hand, the toner container replenishment method is a method in which when the toner in the developer container falls below a predetermined amount, toner is replenished to the developer container from a toner container such as a toner pack or a toner bottle.

[0003] Conventionally, a toner pack system has been proposed as a toner container refill system (see, for example, Patent Document 1). In this system, when the amount of toner in the developing container falls below a predetermined amount, a display is displayed to encourage the user to replenish toner, and the user can refill the toner by supplying toner from a refill toner pack that contains toner to the developing container. At this time, the amount of toner in the developing container is detected by a sensor or the like, which is a detection means provided on the image forming apparatus, detecting the presence or absence of toner at a predetermined position in the developing container. The image forming apparatus has a control means, and the control means (sequence) determines the amount of toner in the developing container based on the result of the detection means. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-154302 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a cycle of using up a predetermined amount of toner in a developing container and then replenishing toner is repeated as in the past, toner fogging may occur. In the conventional toner replenishing, new toner is replenished to a developing container in which deteriorated toner remains. When replenishing toner, the average number of times each toner particle remaining in the developing container is rubbed (hereinafter, the number of rubs) is naturally greater than that of new toner. Therefore, when replenishing is required again, the toner remaining in the developing container will have been rubbed more times than the previous time of replenishing, and will be more deteriorated toner. Repeated toner replenishing causes deteriorated toner to accumulate in the developing container, which may result in frequent fogging due to toner deterioration.

[0006] The present invention has been made under such circumstances, and has an object to suppress the occurrence of image defects caused by toner deterioration in an image forming apparatus that uses a toner supply system. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the present invention has the following configuration.

[0008] (1) An image forming apparatus comprising: an image carrier that carries a toner image and is configured to be rotatable; a developing rotor that supplies toner to the image carrier; and a developing container that contains toner and has a supply port for replenishing toner, and is capable of performing a replenishing operation to replenishing toner from a replenishing container that is detachable from the replenishing port, the image forming apparatus comprising: a detection means that detects the amount of toner contained in the developing container; a notification means that notifies the user that it is time to perform the replenishing operation; and a control means that controls the notification means to notify the user that it is time to perform the replenishing operation when the amount of toner detected by the detection means becomes less than a threshold value, wherein the control means sets the threshold value to a first threshold value when a print rate after a previous replenishing operation is equal to or greater than a predetermined print rate, and sets the threshold value to a second threshold value greater than the first threshold value when the print rate is less than the predetermined print rate.

[0009] (2) An image forming apparatus comprising: an image carrier that carries a toner image and is configured to be rotatable; a developing rotor that supplies toner to the image carrier; and a developing container that contains toner and has a supply port for replenishing toner, and is capable of performing a replenishing operation to replenishing toner from a replenishing container that is detachable from the replenishing port, the image forming apparatus comprising: a detection means that detects the amount of toner contained in the developing container; a notification means that notifies the user that it is time to perform the replenishing operation; a control means that controls the notification means to notify the user that it is time to perform the replenishing operation when the amount of toner detected by the detection means becomes less than a threshold value; and an environmental detection means that detects the amount of moisture in the surrounding environment of the image forming apparatus, wherein the control means sets the threshold value to a first threshold value when the amount of moisture detected by the environmental detection means is equal to or greater than a predetermined moisture amount, and sets the threshold value to a fourth threshold value that is greater than the first threshold value when the amount of moisture is less than the predetermined moisture amount. Effect of the Invention

[0010] According to the present invention, in an image forming apparatus that uses a toner supply system, it is possible to suppress image defects caused by deterioration of toner. [Brief description of the drawings]

[0011] [Figure 1] Overall schematic diagram showing an image forming apparatus according to embodiments 1 to 3 [Diagram 2] FIG. 1 is a perspective view showing a developing container and a toner pack according to Examples 1 to 3; [Diagram 3] 40A-40A sectional view and 40B-40B sectional view of FIG. 2 in Examples 1 to 3 [Figure 4] FIG. 1 is a perspective view showing a toner pack according to one embodiment of the present invention; [Diagram 5] FIG. 1 is a cross-sectional view showing a first toner remaining amount sensor and a second toner remaining amount sensor according to first to third embodiments; [Figure 6] FIG. 1 is a circuit diagram showing a first toner remaining amount sensor and a second toner remaining amount sensor according to first to third embodiments; [Figure 7] 1 is a cross-sectional view showing a developing container when the remaining amount of toner is different in Examples 1 to 3. [Figure 8] FIG. 1 is a block diagram showing a control system of an image forming apparatus according to first to third embodiments. [Figure 9] FIG. 11 is a perspective view showing a toner remaining amount panel when the remaining toner amounts of Examples 1 to 3 are different; [Figure 10] FIG. 1 is a flowchart showing a toner supply process according to the first to third embodiments; [Figure 11] Flowchart showing remaining toner amount detection process in the first to third embodiments [Figure 12] 1 is a cross-sectional view showing a state when toner is replenished in Examples 1 to 3. [Figure 13] Flowchart showing remaining toner amount display process according to the first embodiment [Figure 14] Flowchart showing remaining toner amount display processing according to the second embodiment [Figure 15] Flowchart showing remaining toner amount display processing according to the third embodiment DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The image forming apparatus according to the present invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in the following examples may be changed as appropriate depending on the configuration of the apparatus to which the invention is applied and various conditions, and the scope of the invention is not limited to the following examples. In addition, the recording materials used in the image forming apparatus include various sheet materials of different materials, such as paper such as plain paper and cardboard, plastic films such as sheets for overhead projectors, sheets of special shapes such as envelopes and index paper, and cloth. EXAMPLES

[0013] [Overall configuration] The image forming apparatus 100 of the first embodiment is an electrophotographic monochrome laser beam printer. As shown in FIG. 1, the apparatus main body M of the image forming apparatus 100 is equipped with a direct transfer process unit 9. The process unit 9 has a photosensitive drum 1, a charging roller 2 arranged around the photosensitive drum 1, a developing device 20, a charge removing device 11, and a brush member 12. The apparatus main body M also has a scanner unit 10 that irradiates the photosensitive drum 1 with laser light to form an electrostatic latent image, and a transfer roller 13 that forms a transfer nip portion N1 between the photosensitive drum 1 and the transfer roller 13 and transfers a toner image to a recording material P at the transfer nip portion N1. The transfer roller 13 contacts the surface 1a of the photosensitive drum 1 and transfers the toner image on the photosensitive drum 1. In the first embodiment, the process unit 9 is configured to be detachable from the apparatus main body M, but is not limited thereto. For example, the process unit 9 may be configured to be non-detachable from the apparatus main body M.

[0014] The photosensitive drum 1, which is an image carrier, is a cylindrically shaped photosensitive body that can rotate around a rotation axis CP extending in the axial direction J1 (see FIG. 2(b) and the like). The photosensitive drum 1 of the first embodiment has a photosensitive layer formed of a negatively charged organic photosensitive body on a drum-shaped base body formed of aluminum. More specifically, the photosensitive drum 1 is a rigid body formed by successively applying a resistance layer, an undercoat layer, and a photosensitive layer to the outer peripheral surface of an aluminum cylinder having a diameter of 24 mm by a dipping coating method, and the photosensitive layer has a charge generating layer and a charge transport layer. The film thickness of the charge transport layer is 22 μm. The photosensitive drum 1 is driven to rotate at a predetermined peripheral speed in the direction of the arrow L around the rotation axis CP by a drive motor. The peripheral speed of the photosensitive drum 1 determines the speed of image formation by the image forming apparatus 100, and is therefore also called the process speed.

[0015] The charging roller 2, which is a charging member, contacts the photosensitive drum 1 with a predetermined pressure contact force to form a charging section N2. A charging voltage, which is a DC voltage, is applied from a charging voltage application circuit (not shown), so that the surface 1a of the photosensitive drum 1 is uniformly charged to a predetermined potential. The charging roller 2 of the first embodiment applies a charging voltage of -1400V so that the surface potential (pre-exposure potential VD) of the photosensitive drum 1 becomes -800V. That is, the photosensitive drum 1 is charged by the charging roller 2 to the pre-exposure potential VD, which is a fourth potential, in the negative polarity direction that is the same as the polarity of the toner. The charging roller 2 has a core metal with a diameter of 6 mm, a base layer of hydrin rubber, and a surface layer of urethane, and is configured to have an outer diameter of 12 mm. The resistance of the charging roller 2 is 1×10 6 The hardness is 70 degrees measured by an MD-1 rubber hardness tester. Although a DC voltage is used as the charging voltage in the first embodiment, the present invention is not limited to this and may be a voltage in which an AC voltage is superimposed on a DC voltage.

[0016] The scanner unit 10 uses a rotating polygon mirror to irradiate the photosensitive drum 1 with laser light corresponding to image information input from an external device, thereby scanning and exposing the surface 1a of the photosensitive drum 1. This exposure forms an electrostatic latent image corresponding to the image information on the surface 1a of the photosensitive drum 1. The scanner unit 10 is a semiconductor laser, and irradiates a laser with a wavelength of 800 nm, and can change the amount of laser light. The scanner unit 10 is not limited to a laser scanner device, and may be, for example, an LED exposure device having an LED array in which a plurality of LEDs are arranged along the longitudinal direction of the photosensitive drum 1.

[0017] The developing device 20 has a developing container 8 which is a frame of the developing device 20, a developing roller 4, and a supply roller 5 which supplies toner to the developing roller 4. Inside the developing container 8 which is a storage section, a storage chamber 8a which stores toner (developer) and a developing chamber 8b which uses the developing roller 4 are formed. The developing roller 4 and the supply roller 5 are rotatably supported by the developing container 8. The developing roller 4 is disposed at an opening of the developing container 8 so as to face the photosensitive drum 1. The supply roller 5 is in rotatable contact with the developing roller 4, and the toner stored in the developing container 8 is applied to the surface of the developing roller 4 by the supply roller 5.

[0018] The developing device 20 uses a contact development method as a development method. That is, the toner layer carried by the developing roller 4 comes into contact with the photosensitive drum 1 at a development portion N3 where the photosensitive drum 1 and the developing roller 4 face each other. In other words, the developing roller 4, which is a developing rotator, forms the development portion N3 between the photosensitive drum 1 and the developing roller 4. A development voltage, which is a direct current voltage, is applied to the developing roller 4 from a development voltage application portion (not shown). Under the development voltage, the toner carried by the developing roller 4 is transferred from the developing roller 4 to the surface 1a of the photosensitive drum 1 according to the potential distribution of the surface 1a, so that the electrostatic latent image is developed into a toner image. Note that in the first embodiment, a reversal development method is adopted. That is, the toner image is formed by adhering to the surface 1a area of ​​the photosensitive drum 1, which is charged in a charging process and then exposed in an exposure process, where the charge amount is attenuated.

[0019] In addition, in the first embodiment, a toner having a particle size of 6 μm and a normal charging polarity of negative polarity is used. As an example, the toner in the first embodiment is a polymerized toner produced by a polymerization method. The toner in the first embodiment does not contain a magnetic component, and is a so-called non-magnetic one-component developer in which the toner is carried on the developing roller 4 mainly by intermolecular forces and electrostatic forces (image forces). However, a one-component developer containing a magnetic component may be used. In addition, the one-component developer may contain additives (e.g., wax or silica fine particles) for adjusting the fluidity and charging performance of the toner in addition to the toner particles. In addition, a two-component developer composed of a non-magnetic toner and a magnetic carrier may be used as the developer. When a magnetic developer is used, for example, a cylindrical developing sleeve with a magnet arranged inside is used as the developer carrier. In addition, the developing device 20 may be a non-contact developing type in which a predetermined gap is provided between the developing device 20 and the photosensitive drum 1.

[0020] The developing roller 4 has a core metal with a diameter of 6 mm, and a surface layer of urethane rubber is applied to a base layer of silicone rubber so that the outer diameter of the developing roller 4 is 15 mm. The resistance value of the developing roller 4 is 1×10 4 ~1×10 12 The supply roller 5 is a conductive elastic sponge roller having a foam layer formed on the outer periphery of a core metal having a diameter of 6 mm. The resistance value of the supply roller 5 is 1×10 4 ~1×10 8 The hardness of the supply roller 5 in Example 1 is a value measured by a load when a flat plate having a longitudinal width (length in the axial direction J1) of 50 mm is inserted 1 mm into the surface of the supply roller 5.

[0021] An agitating member 7 is provided inside the developing container 8. The agitating member 7 is driven by a drive motor to rotate, thereby agitating the toner in the developing container 8 and sending the toner toward the developing roller 4 and the supply roller 5. The agitating member 7 also circulates, within the developing container 8, the toner that has not been used in development and has been peeled off from the developing roller 4, and plays a role in making the toner in the developing container 8 uniform.

[0022] A developing blade 6 is disposed at the opening of the developing container 8 in which the developing roller 4 is disposed, to regulate the amount of toner carried by the developing roller 4. The toner supplied to the surface of the developing roller 4 passes through the opposing portion with the developing blade 6 as the developing roller 4 rotates, whereby the toner is uniformly formed into a thin layer and is negatively charged by frictional charging.

[0023] The developing blade 6 is a 0.1 mm thick SUS sheet metal made of metal, and is disposed in contact with the developing roller 4 such that its free end is on the downstream side in the rotation direction of the developing roller 4. The developing blade 6 used in Example 1 is made of SUS sheet metal, the tip of which is cut from the contact surface side with the developing roller 4. The tip portion of the developing blade 6 is bent in the cutting direction by the cutting process.

[0024] The transfer roller 13, which is the transfer section, has a base layer of ion conductive sponge so that the outer diameter is 15 mm with respect to a core metal with a diameter of 6 mm. The resistance value of the transfer roller 13 is 4×10 7 The hardness is 30 degrees as measured by an Asker C rubber hardness tester manufactured by Kobunshi Keiki Co., Ltd.

[0025] [Image formation operation] When an image formation command is output to the image forming apparatus 100, an image formation process is started based on image information input from an external computer or the like connected to the image forming apparatus 100. When the image formation process is started, the photosensitive drum 1 is driven by a drive source (not shown) and rotated at a predetermined process speed in the direction of arrow L in Fig. 1. In the first embodiment, the process speed of the photosensitive drum 1 is 140 rpm.

[0026] The process unit 9 is provided with a static eliminator 11 that eliminates static electricity from the photosensitive drum 1, downstream of the transfer nip portion N1 and upstream of the charging portion N2 in the rotation direction (direction of arrow L) of the photosensitive drum 1. More specifically, the static eliminator 11, which is a static eliminator, is disposed between the brush member 12 and the charging roller 2 in the rotation direction of the photosensitive drum 1. The static eliminator 11 eliminates the surface potential of the photosensitive drum 1 before it reaches the charging portion N2 in order to generate a stable discharge at the charging portion N2.

[0027] The charging roller 2 uniformly charges the rotating photosensitive drum 1 so that the surface potential (pre-exposure potential VD) is -800 V. The scanner unit 10 irradiates the photosensitive drum 1 with laser light based on input image information. As a result, an electrostatic latent image is formed on the uniformly charged surface 1a of the photosensitive drum 1. In the first embodiment, the scanner unit 10 irradiates the photosensitive drum 1 with a light amount of 0.45 μJ / cm so that the post-exposure potential VL of the photosensitive drum 1 is -100 V. 2 The laser beam is irradiated at .

[0028] At this time, a toner layer charged to a predetermined polarity is formed on the surface of the developing roller 4. Then, a developing voltage is applied to the developing roller 4 from a developing voltage application unit (not shown), whereby the electrostatic latent image on the photosensitive drum 1 is developed in the developing unit N3 to form a toner image on the photosensitive drum 1. In the first embodiment, a developing voltage of −400 V is applied to the developing roller 4.

[0029] In parallel with the above-mentioned image forming process, a recording material P stored in the lower part of the image forming apparatus 100 is fed. The recording material P is transported to the transfer nip portion N1 in accordance with the timing when the toner image formed on the photosensitive drum 1 reaches the transfer nip portion N1. A transfer voltage, which is a DC voltage, is applied to the transfer roller 13 from a transfer voltage application circuit (not shown) in accordance with the timing when the toner image formed on the photosensitive drum 1 reaches the transfer nip portion N1. As a result, the toner image carried on the photosensitive drum 1 is transferred to the recording material P passing through the transfer nip portion N1. In the first embodiment, a transfer voltage of +1500V is applied to the transfer roller 13.

[0030] The recording material P onto which the toner image has been transferred is conveyed to the fixing device 14. The fixing device 14 is of a thermal fixing type that performs a fixing process of the image by heating and melting the unfixed toner on the recording material P. The fixing device 14 includes a fixing film 14a, a fixing heater such as a ceramic heater that heats the fixing film 14a, and a pressure roller 14b that is in pressure contact with the fixing film 14a. When the recording material P passes through the nip portion between the fixing film 14a and the pressure roller 14b, the toner image is heated and pressurized. This melts the toner particles, which then become fixed, thereby fixing the toner image to the recording material P. The recording material P that has passed through the fixing device 14 is discharged to the outside of the image forming apparatus 100 by a pair of discharge rollers (not shown).

[0031] The image forming apparatus 100 also has an environment detection unit 54 which is an environment detection means (see FIG. 8). The environment detection unit 54 is disposed inside the image forming apparatus 100 and detects the surrounding temperature and humidity. Based on the detection results of the environment detection unit 54, corrections are made to the control of the voltages applied to the charging roller 2 and the developing roller 4, the scanner unit 10, the transfer roller 13, the fixing device 14, etc.

[0032] [Recovery of residual toner after transfer] The toner remaining on the photosensitive drum 1 without being transferred to the recording material P (hereinafter, referred to as transfer residual toner) is removed in the following process. The photosensitive drum 1 after the transfer process is attracted by the transfer voltage applied when passing through the transfer nip portion N1, and the surface potential is reduced. The surface potential of the photosensitive drum 1 after the transfer process in the first embodiment is -150V. After the transfer process, the photosensitive drum 1 is neutralized by the charge neutralizing device 11 so that the surface potential remaining on the photosensitive drum 1 becomes 0V, and the photosensitive drum 1 rotates toward the charging portion N2. The transfer residual toner includes a mixture of positively charged toner and negatively charged toner that does not have sufficient charge. The charge neutralizing device 11 neutralizes the photosensitive drum 1 after transfer, and the charging roller 2 generates a uniform discharge, so that the transfer residual toner is charged negatively again. The transfer residual toner that has been charged negatively again in the charging portion N2 reaches the developing portion N3 as the photosensitive drum 1 rotates. Then, the surface area of ​​the photosensitive drum 1 that has passed the charging section N2 is exposed to light by the scanner unit 10 and an electrostatic latent image is written thereon, with the residual toner still adhering to the surface.

[0033] Here, the behavior of the transfer residual toner that has reached the development unit N3 will be described separately for the exposed and non-exposed parts of the photosensitive drum 1. The transfer residual toner adhering to the non-exposed part of the photosensitive drum 1 is transferred to the development roller 4 in the development unit N3 due to the potential difference between the pre-exposure potential VD of the non-exposed part of the photosensitive drum 1 and the development voltage, and is then collected in the development container 8. This is because the normal charging polarity of the toner is negative, and the development voltage applied to the development roller 4 is positive relative to the pre-exposure potential VD of the non-exposed part. The toner collected in the development container 8 is stirred and dispersed together with the toner in the development container 8 by the stirring member 7, and is carried by the development roller 4 for use again in the development process.

[0034] On the other hand, the transfer residual toner adhering to the exposed portion of the photosensitive drum 1 does not transfer from the photosensitive drum 1 to the developing roller 4 at the developing portion N3, but remains on the surface 1a of the photosensitive drum 1. This is because the normal charging polarity of the toner is negative, and the developing voltage applied to the developing roller 4 has a potential that is more negative than the pre-exposure potential VD of the exposed portion. The transfer residual toner remaining on the surface 1a of the photosensitive drum 1 is carried by the photosensitive drum 1 together with other toner transferred from the developing roller 4 to the exposed portion, and moves to the transfer nip portion N1, where it is transferred to the recording material P.

[0035] Thus, in the first embodiment, the process unit 9 has a cleaner-less configuration in which the transfer residual toner is collected and reused in the developing device 20. By making the process unit 9 a cleaner-less configuration, it becomes unnecessary to install space for a collection container for collecting the transfer residual toner and the like, which enables the image forming apparatus 100 to be further miniaturized, and also makes it possible to reduce printing costs by reusing the transfer residual toner.

[0036] [Developer container and toner pack configuration] Next, the configurations of the developing container 8 and the toner pack 40, which is a supply container, will be described. Fig. 2(a) is a perspective view showing the developing container 8 and the toner pack 40, and Fig. 2(b) is a front view showing the developing container 8 and the toner pack 40. Fig. 3(a) is a cross-sectional view taken along line 40A-40A in Fig. 2(b), and Fig. 3(b) is a cross-sectional view taken along line 40B-40B in Fig. 2(b).

[0037] As shown in FIG. 2(a) to FIG. 3(b), the developing container 8 has a storage chamber 8a in which the stirring member 7 is disposed, and the storage chamber 8a, which is a storage section for storing the developer, extends in the longitudinal direction of the developing container 8 (the left-right direction in FIG. 2(b), the axial direction J1). The storage chamber 8a is integrally formed with a frame that rotatably supports the developing roller 4 and the supply roller 5, and stores the developer to be carried by the developing roller 4. The developing container 8 has an inclined portion 37, which is a protruding portion that protrudes obliquely upward from one end in the longitudinal direction of the storage chamber 8a and communicates with the storage chamber 8a. An attachment portion 57 to which the toner pack 40 can be attached is provided at the upper end (tip) of the inclined portion 37, and a supply port 32a is formed in the attachment portion 57 for supplying the developer from the toner pack 40 to the storage chamber 8a. The toner pack 40 can be attached to the attachment portion 57 in a state where it is exposed to the outside of the device.

[0038] The developing container 8 is configured so that the toner supplied from the supply port 32a reaches the stirring member 7 by its own weight alone. Here, "by its own weight alone" means that when the developing container 8 is supplied while installed (mounted) in the main body, the developing container 8 is configured so that the toner reaches the stirring member 7 by its own weight without providing a stirring member (conveying member) that rotates or swings to transport the toner between the supply port 32a of the developing container 8 and the stirring member 7. In the developing container 8, the stirring member 7 is the rotating body closest to the supply port 32a and is arranged so that the toner in the storage chamber 8a reaches the developing roller 4 or the supply roller 5 by rotating.

[0039] The grip portion 39 has a knob portion 39a that a user can grip by hooking his / her fingers, and the knob portion 39a is formed to protrude upward from the top surface of the grip portion 39. The inclined portion 37 is formed to be hollow inside, and a supply port 32a is formed on the upper surface. The supply port 32a is configured to be connectable to a toner pack 40.

[0040] The toner pack 40 is configured to be detachably attached to the mounting portion 57 of the inclined portion 37. The toner pack 40 has a shutter member 41 provided at the opening and capable of opening and closing, and a plurality of (three in the first embodiment) protrusions 42 formed corresponding to a plurality of (three in the first embodiment) grooves 32b formed in the mounting portion 57. When replenishing toner to the developing container 8, the user aligns the toner pack 40 so that the protrusions 42 pass through the grooves 32b of the mounting portion 57, and connects the toner pack 40 to the mounting portion 57. Then, when the toner pack 40 is rotated 180 degrees in this state, the shutter member 41 of the toner pack 40 abuts against an abutment portion (not shown) of the mounting portion 57, rotating the toner pack 40 relative to the main body of the toner pack 40, and the shutter member 41 is opened. As a result, the toner contained in the toner pack 40 leaks out of the toner pack 40, and the leaked toner enters the hollow inclined portion 37 through the replenishing port 32a. The shutter member 41 may be provided on the supply port 32a side.

[0041] The inclined portion 37 has a slope 37a at a position facing the opening of the supply port 32a, and the slope 37a slopes downward toward the storage chamber 8a. Therefore, the toner supplied from the supply port 32a is guided to the storage chamber 8a by the slope 37a. As shown in FIG. 3, the agitator 7 has an agitator shaft 7a extending in the longitudinal direction, and a blade portion 7b fixed to the agitator shaft 7a and extending radially outward from the agitator shaft 7a. The blade portion 7b is a flexible sheet. The agitator 7 rotates around the agitator shaft 7a.

[0042] The toner supplied from the supply port 32a arranged on the upstream side in the conveying direction of the stirring member 7 is sent toward the developing roller 4 and the supply roller 5 as the stirring member 7 rotates. The conveying direction of the stirring member 7 is parallel to the longitudinal direction of the developing container 8. The supply port 32a and the inclined portion 37 are arranged at one end of the developing container 8 in the longitudinal direction, and the toner spreads over the entire length of the developing container 8 by repeatedly rotating the stirring member 7. In the first embodiment, the stirring member 7 is composed of the stirring shaft 7a and the blade portion 7b, but a spiral stirring shaft may be used as a configuration for spreading the toner over the entire length of the developing container 8.

[0043] In the first embodiment, the toner pack 40 is made of a plastic bag that is easily deformed as shown in FIG. 4(a) and FIG. 4(b), but is not limited thereto. For example, the toner pack may be made of a bottle container 40B having a substantially conical shape as shown in FIG. 4(c), or may be made of a paper container 40C made of paper as shown in FIG. 4(d). In any case, the toner pack may be made of any material and any shape. In addition, the method of discharging the toner from the toner pack is preferably a method in which the user squeezes the toner pack 40 or the paper container 40C with the fingers, and in the case of the bottle container 40B, it is preferable that the user shakes the container by tapping it to cause the toner to leak out. In addition, a discharge mechanism may be provided in the bottle container 40B to discharge the toner from the bottle container 40B. Furthermore, the discharge mechanism may be configured to be engaged with the device main body M and receive a driving force from the device main body M.

[0044] Also, in any of the toner packs, the shutter member 41 may be omitted, or a sliding type shutter member may be applied instead of the rotating type shutter member 41. Also, the shutter member 41 may be configured to be destroyed when the toner pack is attached to the supply port 32a or when the toner pack is rotated in the attached state, or may have a removable lid structure such as a seal.

[0045] [How to detect remaining toner] Next, a method for detecting the amount of toner remaining in the developing container 8 will be described with reference to Fig. 5 to Fig. 7. The developing device 30 of the first embodiment is provided with a first toner remaining sensor 51 and a second toner remaining sensor 52, which are detection means for detecting a state according to the amount of toner remaining in the developing container 8.

[0046] The first toner remaining amount sensor 51 has a light emitting portion 51a and a light receiving portion 51b, and the second toner remaining amount sensor 52 has a light emitting portion 52a and a light receiving portion 52b. Fig. 6 is a circuit diagram showing an example of the circuit configuration of the first toner remaining amount sensor 51 and the second toner remaining amount sensor 52. In the following description, the circuit configuration of the first toner remaining amount sensor 51 will be described, and the description of the circuit configuration of the second toner remaining amount sensor 52 will be omitted.

[0047] In FIG. 6, an LED is used for the light-emitting section 51a, and a phototransistor that is turned on by the light from the LED is used for the light-receiving section 51b, but this is not limited thereto. For example, a halogen lamp or a fluorescent lamp may be applied to the light-emitting section 51a, and a photodiode or an avalanche photodiode may be applied to the light-receiving section 51b. A switch (not shown) is provided between the light-emitting section 51a and the power supply voltage Vcc, and by turning on the switch, a voltage from the power supply voltage Vcc is applied to the light-emitting section 51a, and the light-emitting section 51a is brought into a conductive state. On the other hand, a switch (not shown) is also provided between the light-receiving section 51b and the power supply voltage Vcc, and by turning on the switch, the light-receiving section 51b is brought into a conductive state by a current corresponding to the detected amount of light.

[0048] A power supply voltage Vcc and a current limiting resistor R1 are connected to the light-emitting unit 51a, and the light-emitting unit 51a emits light with a current determined by the current limiting resistor R1. The light emitted from the light-emitting unit 51a passes through an optical path Q1 as shown in FIG. 5 and is received by the light-receiving unit 51b. A power supply voltage Vcc is connected to the collector terminal of the light-receiving unit 51b, and a detection resistor R2 is connected to the emitter terminal. The light-receiving unit 51b, which is a phototransistor, receives the light emitted from the light-emitting unit 51a and outputs a signal (current) according to the amount of light received. This signal is converted to a voltage V1 by the detection resistor R2 and input to an A / D conversion unit 95 of the control unit 90 (see FIG. 8). In addition, the light receiving element 52b of the second toner remaining sensor 52 receives light emitted from the light emitting element 52a and passing through the optical path Q2, and outputs a voltage V2 according to the amount of light received, which is input to the A / D conversion unit 95 of the control unit 90.

[0049] The control unit 90 (CPU 91) judges whether the light receiving units 51b, 52b have received light from the light emitting units 51a, 52a based on the input voltage level. The control unit 90 (CPU 91) calculates the amount of toner in the developing container 8 based on the length of time that the light receiving units 51b, 52b detected each light and the intensity of the received light when the toner in the developing container 8 was stirred for a certain time by the stirring member 7. That is, the ROM 93 stores in advance a table that can output the remaining toner amount from the light receiving time and light intensity when the toner is transported by the stirring member 7, and the control unit 90 predicts / calculates the remaining toner amount based on the input to the A / D conversion unit 95 and the table.

[0050] More specifically, the optical path Q1 of the first toner remaining amount sensor 51 is set to intersect with the rotation locus Tr of the agitating member 7. The time during which the optical path Q1 is blocked by the toner splashed up by the agitating member 7 when the agitating member 7 rotates once, i.e., the time during which the light receiving portion 51b does not detect the light from the light emitting portion 51a, varies depending on the amount of remaining toner. The intensity of the received light at the light receiving portion 51b also varies depending on the amount of remaining toner.

[0051] That is, when the remaining amount of toner is large, the light path Q1 is easily blocked by the toner, so the time during which the light receiving portion 51b receives light is short, and the light receiving intensity of the light received by the light receiving portion 51b is low. On the other hand, when the remaining amount of toner is small, the time during which the light receiving portion 51b receives light is long, and the light receiving intensity of the light received by the light receiving portion 51b is strong. Therefore, the control portion 90 can determine whether the remaining amount of toner is at a low level or a mid level, as described below, based on the light receiving time and light receiving intensity of the light receiving portion 51b. For example, as shown in FIG. 7(a), when there is a small amount of toner in the storage chamber 8a of the developing container 8, it is determined that the remaining amount of toner is at a low level. Note that the state in which the remaining amount of toner is at a low level refers to a state in which there is enough remaining toner to print several tens to several hundreds of sheets at a predetermined printing rate (for example, a printing rate of 5%). Here, the printing rate is a number indicating the percentage of pixels corresponding to the pixels to which toner is attached among the number of pixels corresponding to the printable area on the sheet surface. Here, a pixel is a unit element constituting an electrostatic latent image formed on the photosensitive drum 1 by laser irradiation (light irradiation). Specifically, the printing rate is 100% when a solid black image is formed on the entire image forming area (letter size) on the recording material P, and the printing rate is 0% when no toner image is formed on the recording material P. In the above description, the second toner remaining sensor 52 is disposed so as not to intersect with the rotation locus Tr of the stirring member 7, but it may be disposed so as to intersect with the rotation locus Tr of the stirring member 7, similar to the above-mentioned first toner remaining sensor 51.

[0052] Further, the optical path Q2 of the second toner remaining sensor 52 is set above the rotation locus Tr of the stirring member 7 so as not to intersect with the rotation locus Tr. The light receiving portion 52b of the second toner remaining sensor 52 does not detect light from the light emitting portion 52a when the optical path Q2 is blocked by the toner, and detects light from the light emitting portion 52a when the optical path Q2 is not blocked by the toner. Therefore, the control portion 90 judges whether the toner remaining amount is at the Full level as described later based on whether the light receiving portion 52b receives light, regardless of the rotation operation of the stirring member 7. For example, as shown in FIG. 7(b), when there is a large amount of toner in the storage chamber 8a of the developing container 8, it is judged that the toner remaining amount is at the Full level. In the above description, the second toner remaining sensor 52 is arranged so as not to intersect with the rotation locus Tr of the stirring member 7, but it may be set so as to intersect with the rotation locus Tr of the stirring member 7, similar to the first toner remaining sensor 51 described above.

[0053] The method of detecting / estimating the remaining toner amount is not limited to the optical toner remaining amount detection method described in FIG. 5, and various well-known methods of detecting / estimating the remaining toner amount can be adopted. For example, two or more metal plates or conductive resin sheets extending in the longitudinal direction of the developing roller may be arranged on the inner wall of the developing container 8, which is a frame, and the electrostatic capacitance between the two metal plates or conductive resin sheets may be measured to detect / estimate the remaining toner amount. Also, a load cell may be provided to support the developing device 30 from below, and the CPU 91 may calculate the remaining toner amount by subtracting the weight of the developing device 30 when the toner is empty from the weight measured by the load cell. Also, the first toner remaining amount sensor 51 may be omitted, and the control unit 90 (CPU 91) may calculate the remaining toner amount from the detection result of the second toner remaining amount sensor 52 and the emission state of the laser light.

[0054] [How to detect printing rate] In the first embodiment, a pixel count detection unit 96 is used as a method for detecting the printing rate, which is a measuring unit capable of counting the number of pixels emitted by the scanner unit 10. The pixel count detection unit 96 may be configured by the control unit 90 as shown in FIG. 8, or may be provided separately from the control unit 90. Pixel counting refers to counting individual image signals that form image dots of an image to be formed. The control unit 90 also functions as an acquisition unit for acquiring the printing rate. The control unit 90 estimates the amount of toner required to develop an image as the toner consumption amount x [%] used by printing on one sheet of paper from the number of pixels emitted by the scanner unit 10.

[0055] In the first embodiment, a detection system for detecting the printing rate by pixel counting is used as a means for detecting the printing rate, but the present invention is not limited to this. For example, the printing rate may be detected from the detection result of the weight of the developing container at the timing of the previous toner supply, the detection result of the current weight of the developing container, and the number of sheets of paper passed between them.

[0056] [Image forming device control system] 8 is a block diagram showing a control system of the image forming apparatus 100. A control unit 90, which is a control means of the image forming apparatus 100, has a CPU 91 as a calculation device, a RAM 92 used as a work area for the CPU 91, and a ROM 93 for storing various programs. The control unit 90 also has an I / O interface 94 as an input / output port connected to an external device, and an A / D conversion unit 95 for converting an analog signal into a digital signal.

[0057] The input side of the control unit 90 is connected to a first remaining toner amount sensor 51, a second remaining toner amount sensor 52, an attachment sensor 53, and an environment detection unit 54. The attachment sensor 53 detects that the toner pack 40 is attached to the supply port 32a of the developing container 8. For example, the attachment sensor 53 is provided in the supply port 32a, and is configured of a pressure-sensitive switch that outputs a detection signal when pressed by the protrusion 42 of the toner pack 40.

[0058] The control unit 90 is also connected to an operation unit 300, the image forming unit 60, and a toner remaining amount panel 400 that is a notification unit capable of notifying information related to the remaining amount of toner. The operation unit 300 has a display unit 301 that can display various setting screens, physical keys, etc. The display unit 301 is configured, for example, from a liquid crystal panel. The image forming unit 60 has a motor M1 that is a drive source that drives the photosensitive drum 1, the developing roller 4, the supply roller 5, the stirring member 7, etc. Note that the photosensitive drum 1, the developing roller 4, the supply roller 5, and the stirring member 7 may be configured to be driven by separate motors, respectively.

[0059] [Toner Remaining Panel] 9, the toner remaining amount panel 400 is provided on the right side of the front surface of the housing of the apparatus main body M, i.e., on the opposite side to the operation unit 300 provided on the left side, and displays information related to the amount of toner remaining in the developing container 8. In the first embodiment, the toner remaining amount panel 400 is a panel member consisting of multiple scales (three in the first embodiment) arranged vertically, and each scale corresponds to the above-mentioned Low level, Mid level, and Full level.

[0060] That is, as shown in FIG. 9(a), when only the lower scale is lit, the toner remaining amount in the developing container 8 indicates a low level, which is the third state. As shown in FIG. 9(b), when the lower and center scales are lit and the upper scale is off, the toner remaining amount in the developing container 8 indicates a mid level, which is the second state. As shown in FIG. 9(c), when all three scales are lit, the toner remaining amount in the developing container 8 indicates a full level, which is the first state. The display (notification) shown in FIG. 9(a) corresponds to the display (low level display or toner empty display) when the toner remaining amount is the lowest among the display forms (notification forms) that the toner remaining amount panel 400 can display. This display shown in FIG. 9(a) can inform the user that toner replenishment is necessary, and can prevent blank areas in images due to toner depletion.

[0061] In the following description, the control unit 90 determines that it is time to perform a replenishing operation based on the amount of toner detected by the first toner remaining sensor 51 and the second toner remaining sensor 52 falling below a judgment threshold, but is not limited to this. For example, an optical sensor does not have to be used to detect the amount of remaining toner, and the timing of the replenishing operation may be determined based on a parameter for determining that the amount of remaining toner is low exceeding a judgment threshold.

[0062] [Toner supply process] Next, a toner supply process (supply operation) for supplying the toner in the toner pack 40 to the developing container 8 will be described. As shown in FIG. 10, when the toner supply process starts, the control unit 90 executes the process from step (hereinafter, referred to as S) 1 onward. In S1, the control unit 90 judges whether or not a supply operation start instruction has been issued. In the first embodiment, the supply operation start instruction is a user operation by the operation unit 300, as shown in FIG. 10(b). Specifically, the user operates the operation unit 300, and in a state where a message prompting the user to operate the button 1 is displayed on the display unit 301, the supply operation start instruction is output by pressing the button 1. Note that the supply operation start instruction may be output not only by pressing the button 1, but also by a touch operation on the display unit 301 or in response to the mounting sensor 53 detecting that the toner pack 40 is mounted in the supply port 32a. In addition, a sensor may be provided that detects that the shutter member 41 of the toner pack 40 is opened, and the supply operation start instruction may be output based on the detection result of this sensor. Furthermore, the supply operation start instruction may be an operation on an external device such as a personal computer.

[0063] If the control unit 90 determines in S1 that there is no instruction to start the replenishing operation, it returns the process to S1, and if it determines that there is an instruction to start the replenishing operation, it proceeds to S2. In S2, the control unit 90 initializes parameters of a timer T1 (described later) to initial values ​​(e.g., zero) and starts the timer T1. In S3, the control unit 90 drives the motor M1 to rotate the stirring member 7.

[0064] In S4, the control unit 90 executes a toner remaining amount detection process. Fig. 11 is a diagram for explaining the toner remaining amount detection process in S4 of Fig. 10(a). In S41, the control unit 90 causes the light-emitting units 51a and 52a of the first toner remaining amount sensor 51 and the second toner remaining amount sensor 52 to emit light. In S42, the control unit 90 converts the voltages V1 and V2 output by the light-receiving units 51b and 52b of the first toner remaining amount sensor 51 and the second toner remaining amount sensor 52, respectively, into digital signals (hereinafter referred to as A / D conversion values) by the A / D conversion unit 95.

[0065] In S43, the control unit 90 judges whether the A / D conversion value of the voltage V2 indicates that the optical path Q2 is blocked. Here, the control unit 90 judges whether the optical path Q2 is blocked by judging whether the A / D conversion value exceeds a threshold value. If the control unit 90 judges in S43 that the A / D conversion value indicates that the optical path Q2 is blocked, the process proceeds to S44. In S44, the control unit 90 causes the toner remaining panel 400 to display that the toner remaining amount is at the Full level, and returns to the process of FIG. 10(a). That is, as shown in FIG. 9(c), all three scales of the toner remaining panel 400 are lit.

[0066] If the control unit 90 determines in S43 that the A / D conversion value of the voltage V2 does not indicate that the optical path Q2 is blocked, the process proceeds to S45. In S45, the control unit 90 calculates the remaining amount of toner in the developing container 8 based on the A / D conversion value of the voltage V1. In S46, the control unit 90 displays that the remaining amount of toner is at a low level or a mid level on the toner remaining amount panel 400 according to the remaining amount information of toner calculated in S45, and returns to the process of FIG. 10(a). That is, the first toner remaining amount sensor 51 and the second toner remaining amount sensor 52 output remaining amount information according to the amount of developer contained in the developing container 8 while the stirring member 7 is operating.

[0067] Here, an example of toner remaining amount detection will be described. For example, the time from when the motor M1 starts to drive until it ends (threshold value α, described later) is set to 30 seconds. During these 30 seconds, the supplied toner is evened out in the longitudinal direction inside the developing container 8. If the time required for the motor M to make one revolution is, for example, 1.24 seconds, the toner remaining amount detection is performed by averaging the detection results of the first toner remaining amount sensor 51 and the second toner remaining amount sensor 52 obtained during five revolutions. That is, during this time, 1.24 seconds (one revolution) x 5 revolutions = 6.2 seconds are required. Note that the toner remaining amount may be detected continuously over the above-mentioned 30 seconds, or the toner remaining amount may be detected at the timing when the toner is evened out in the longitudinal direction. For example, the toner remaining amount panel 400 may be displayed based on the detection results obtained during the last five revolutions of the above-mentioned 30 seconds. In this case, more specifically, 23.8 seconds after the start of driving the motor M, the first toner remaining sensor 51 and the second toner remaining sensor 52 start to detect the remaining amount, and the toner remaining panel 400 displays the result of one detection (five rotations). Even if the result is obtained from the average value of the last five rotations, the accuracy is improved because the detection is performed after the toner is evened out in the longitudinal direction.

[0068] Return to the process of FIG. 10(a). In S5, the control unit 90 judges whether the timer T1 is equal to or greater than the threshold value α. The threshold value α is a value that is set in advance as described above, and corresponds to the drive time of the motor M1 and the stirring member 7 in the toner supply process. If the control unit 90 judges in S5 that the timer T1 is less than the threshold value α, the process returns to S4. If the control unit 90 judges in S5 that the timer T1 is equal to or greater than the threshold value α, the process proceeds to S6. In S6, the control unit 90 stops the drive of the motor M1, and ends the toner supply process. For example, if the threshold value α is set to 30 seconds, it will be 30 seconds from when the motor M1 starts to drive in S3 to when the motor M1 is stopped in S6.

[0069] In the above-described toner supply process, when toner drops from the toner pack 40 into the developing container 8 as shown in Fig. 12(a), the toner passes through the inclined portion 37 and enters the storage chamber 8a. Since the supply port 32a and the inclined portion 37 are disposed at one end in the longitudinal direction of the developing container 8, the toner is supplied to the storage chamber 8a all at once toward the one end side.

[0070] Here, consider a case where the agitator 7 is not rotating when the toner is supplied to the storage chamber 8a. When the toner is dropped from the toner pack 40 into the developing container 8, if the agitator 7 is not rotated in the storage chamber 8a that stores the toner, it takes time for the dropped toner to spread over the entire longitudinal area of ​​the photosensitive drum 1. If this time is long, it takes time for the user performing the toner supply operation to confirm that the toner has been supplied into the storage chamber 8a, which reduces usability.

[0071] Therefore, in the first embodiment, the agitator 7 is driven for a predetermined time (threshold value α) from the start of the toner supply process. As a result, as shown in Figs. 12(b) and 12(c), the toner supplied from the toner pack 40 to one end of the developer container 8 is quickly leveled over the entire length of the storage chamber 8a of the developer container 8 in the longitudinal direction by the agitator 7. This shortens the time it takes for the user to confirm that the toner supply has been completed, improving usability. In addition, since the toner contained in the developer container 8 is leveled, the accuracy of detection of the remaining toner amount information by the first remaining toner amount sensor 51 and the second remaining toner amount sensor 52 can be improved.

[0072] During the toner replenishment process, the first toner remaining sensor 51 and the second toner remaining sensor 52 detect information on the remaining amount of toner in the developing container 8 at predetermined time intervals (for example, the above-mentioned 6.2 seconds). For example, as shown in FIG. 9(a), when the toner remaining panel 400 indicates that the remaining amount of toner is at a low level, the user replenishes toner from the toner pack 40 to the developing container 8. Then, the toner remaining panel 400 indicates that the remaining amount of toner is at a mid level as shown in FIG. 9(b), and then indicates that the remaining amount of toner is at a full level as shown in FIG. 9(c). This allows the user to reliably recognize that toner has been replenished from the toner pack 40 to the developing container 8, thereby improving usability.

[0073] Here, the cross-sectional views of Fig. 12(a)-(c) show the cross-section taken along line 16A-16A of Fig. 3. Fig. 12(a) and (b) show that the light-emitting portion 52a is disposed near one end of the developing container 8 in the longitudinal direction (axial direction J1). More specifically, in Fig. 12, the light-emitting portion 52a is disposed on the opposite side to the side where the supply port 32a is provided in the axial direction J1. Also, the light-emitting portion 51a and the light-receiving portions 51b and 52b are disposed at the same / almost the same positions in the longitudinal direction of the photosensitive drum 1. Due to restrictions on the arrangement of the sensors in the main body M of the apparatus, the sensors may be disposed as shown in Fig. 12(a) and (b). Even in such a case, the rotation of the stirring member 7 during toner supply can improve the usability as described above.

[0074] In some cases, the sensor may be disposed immediately below the supply port 32a. In such a case, as shown in FIG. 12(b), the supplied toner may be biased to the left side, and it may take time for the toner surface to be leveled over the entire area in the longitudinal direction of the photosensitive drum 1. In order to accurately detect the toner supply state, the toner surface needs to be leveled over the entire area in the longitudinal direction of the photosensitive drum 1. However, even in such a case, in the first embodiment, the rotation of the stirring member 7 during toner supply allows the toner surface to be leveled over the entire area in the longitudinal direction of the photosensitive drum 1 in a short time, improving usability.

[0075] <Example 1> A configuration for switching the timing of toner replenishment according to information on the usage status of the image forming apparatus 100 (history information on the usage status) will be described below. In the first embodiment, an example is shown in which toner fogging caused by toner deterioration is suppressed by changing the timing of toner replenishment according to the printing rate. That is, in the first embodiment, the information on the usage status corresponds to the printing rate. With reference to FIG. 13, the low level display process of the first embodiment will be described in detail. When the image forming apparatus 100 is in a ready state in S50, the control unit 90 receives a print signal in S51. In S52, the control unit 90 starts an image forming operation (printing operation). The control unit 90 starts a printing operation such as rotating the developing roller 4 and forming an electrostatic latent image on the photosensitive drum 1 at an appropriate timing. In S53, the control unit 90 detects the remaining toner amount by the first toner remaining amount sensor 51 and the second toner remaining amount sensor 52, and updates the remaining toner amount T[g]. In S54, the control unit 90 updates the number of replenishment times N (N is an integer equal to or greater than 1) (if there is no history of replenishment, N=1), which indicates the timing of replenishment. The control unit 90 manages the number of replenishment times N, for example, using a counter or the like.

[0076] In S55, the control unit 90 determines whether the replenishment count is N = the first time (that is, there is no replenishment history at all). If, in S55, the control unit 90 determines that the replenishment count is N = the first time, the process proceeds to S56. In S56, the control unit 90 updates the printing rate w% since the image forming apparatus 100 was installed, that is, from the initial stage. In S57, the control unit 90 determines whether the printing rate w% updated in S56 is less than the threshold value x% which is the predetermined printing rate. If, in S57, the control unit 90 determines that w% is less than the threshold value x% (less than the predetermined printing rate), the process proceeds to S58.

[0077] In S58, the control unit 90 determines whether the toner remaining amount T [g] updated in S53 is less than the amount A [g] which is the second threshold value (remaining amount threshold value). If, in S58, the control unit 90 determines that the toner remaining amount T [g] is less than A [g], the process proceeds to S59. In S59, the control unit 90 sets it to Low level display and displays it on the toner remaining amount panel 400 as shown in Fig. 9(a).

[0078] If, in S57, the control unit 90 determines that the printing rate w% is equal to or more than the threshold value x% (equal to or more than the predetermined printing rate), the process proceeds to S60. In S60, the control unit 90 determines whether the toner remaining amount T [g] is less than the amount B [g] (<A) which is the first threshold value (remaining amount threshold value). If, in S60, the control unit 90 determines that the toner remaining amount T [g] is less than B [g], the process proceeds to S59. In this case, it becomes Low level display and Fig. 9(a) is displayed. Note that the amount B [g] is a value used for the determination of the conventional Low level display.

[0079] In this way, when the printing rate w% is less than the threshold value x%, the control unit 90 performs Low level display when the toner remaining amount T [g] becomes less than the amount A [g] which is more than the amount B [g]. On the other hand, when the printing rate w% is equal to or more than the threshold value x%, the control unit 90 performs Low level display when the toner remaining amount T [g] becomes less than the amount B [g] which is less than the amount A [g]. That is, the control unit 90 switches the timing for performing Low level display according to the printing rate w%, and performs Low level display at an earlier timing when the printing rate w% is low.

[0080] If the control unit 90 determines in S55 that the number of replenishments is not N=1 (i.e., there is a replenishment history), it advances the process to S61. In S61, the control unit 90 updates the printing rate v% based on the pixel count immediately after the previous replenishment. Here, "immediately after the previous replenishment" means after the first replenishment if the current number of replenishments is N=2, for example, and the printing rate v% is obtained based on the pixel count from after the first replenishment to the present time.

[0081] In S62, the control unit 90 judges whether the printing rate v% is less than the threshold value x%. In S62, if the control unit 90 judges that v% is less than the threshold value x%, the control unit 90 advances the process to S58. In S62, if the control unit 90 judges that the printing rate v% is equal to or greater than the threshold value x%, the control unit 90 advances the process to S60. In S58, if the control unit 90 judges that the remaining toner amount T[g] is equal to or greater than the amount A[g], and in S60, if the control unit 90 judges that the remaining toner amount T[g] is equal to or greater than the amount B[g], the control unit 90 returns the process to S50. In S58, if the control unit 90 judges that the remaining toner amount T[g] is less than the amount A[g], and in S60, if the control unit 90 judges that the remaining toner amount T[g] is less than the amount B[g], the control unit 90 advances the process to S59 and displays the Low level.

[0082] In this way, even after the number of replenishments N=2, if the printing rate v% is below the threshold value x%, the control unit 90 displays the Low level when the remaining toner amount T[g] falls below the amount A[g] which is greater than the amount B[g]. On the other hand, if the printing rate v% is equal to or greater than the threshold value x%, the control unit 90 displays the Low level when the remaining toner amount T[g] falls below the amount B[g] which is less than the amount A[g]. In other words, even after the number of replenishments N=2, the control unit 90 switches the timing of the Low level display depending on the printing rate v%, and displays the Low level earlier when the printing rate v% is low.

[0083] Here, when an image with a high printing rate is output, most of the toner on the developing roller 4 is consumed and replaced with toner inside the developing container 8. On the other hand, when an image with a low printing rate is output, most of the toner on the developing roller 4 is not consumed, but remains on the developing roller 4, and is continuously subjected to a rubbing load by the developing blade 6 and the supply roller 5. For this reason, when an image with a low printing rate is output, toner deterioration progresses compared to when an image with a high printing rate is output. Therefore, with low printing, the toner in the developing container 8 decreases, and the toner is in the most deteriorated state just before new toner is replenished.

[0084] In the first embodiment, in a low printing rate usage situation where toner deterioration progresses, new toner is replenished when the amount of toner remaining in the developing container 8 is large, that is, before the degree of toner deterioration becomes too large. In this way, by controlling the degree of toner deterioration in the developing container 8 not to exceed a certain level, toner fogging can be suppressed. The toner remaining amount panel 400 is not limited to a liquid crystal panel, and may be composed of a light source such as an LED or an incandescent lamp and a diffusion lens. In the example shown in FIG. 9, the toner remaining amount panel 400 is described as a notification means for indicating the amount of toner remaining, but is not limited to this. For example, the display in FIG. 9(a) may be a display indicating that toner replenishment is necessary, the display in FIG. 9(b) may be a display indicating that toner replenishment is not necessary, and the display in FIG. 9(c) may be a display indicating that toner replenishment has been performed sufficiently. The toner remaining amount panel 400 is merely a notification means and does not restrict the operation of the device main body M. In response to this display, the user can freely select whether to replenish toner or continue using the device without replenishment of toner.

[0085] [Experiment 1] Here, an experiment using a comparative example will be described to show the effect of the first embodiment. In this experiment, an image with a print rate of 1% was printed until the end of the printer's life in an environment of 23°C and 50% humidity, and an evaluation was performed to see whether toner fogging occurred. Conventionally, it takes five toner replenishments using a toner pack before the printer reaches the end of its life.

[0086] Toner fogging is disadvantageous in that the timing when the toner in the developing container 8 is least is just before replenishing the toner. Therefore, the determination of toner fogging is performed by measuring the fogging density at the timing just before the toner remaining amount is displayed as being at the Low level and toner is replenished from the toner pack, and is evaluated in three levels: ○ (less than 1%: no problem with image quality), △ (1% or more and less than 5%: there is some influence but no problem), and × (5% or more: there is a problem). For the measurement of fogging, a reflection densitometer (Model TC-MOR-45, manufactured by Tokyo Denshoku Co., Ltd., using a green filter) was used to measure the reflectance (%). For the fogging measurement, a sticker or the like was attached to a part of the paper to be printed to form a plain image, and the paper was output. The reflectance of the part where the sticker attached to the output paper was removed was used as the reference reflectance of the paper itself, and the fogging measurement was performed. The reflectance varies depending on the measurement part, and the difference between the measurement value of the part where the value is minimum and the measurement value (reference reflectance) of the part where the sticker was attached is measured as the fogging value. The smaller the numerical value of the measured fogging value, the less the amount of fogging, indicating good image quality.

[0087] In this experiment, two conditions, condition 1 and condition 2, were set for the toner remaining amount at which the Low level is displayed, and the evaluation of toner fogging was performed for each. Condition 1 is a configuration in which the toner remaining amount is amount A [g] and the Low level is displayed (Low level display at an early timing), and condition 2 is a configuration in which the toner remaining amount is amount B [g] (<A) and the Low level is displayed. The configurations of condition 1 and condition 2 and the results of each experiment are shown in Table 1.

[0088]

Table 1

[0089] In the case of the configuration of condition 2, since the toner remaining amount decreases to amount B [g] (<A) before the toner is replenished, new toner is replenished in a state where the degree of toner deterioration in the developing container 8 has advanced. Furthermore, each time the Low level is reached, more deteriorated toner accumulates, so that the toner fogging phenomenon due to toner deterioration becomes prominent at the end of the main body life.

[0090] On the other hand, in the case of the configuration under condition 1, new toner is replenished when the remaining toner amount reaches amount A [g], which is greater than amount B [g], i.e., before the degree of toner deterioration reaches a certain level or more, so that the degree of toner deterioration can be maintained at a low level. Under condition 1, toner is replenished earlier than under condition 2, so that the sixth replenishment, which is more than before, is performed before the end of the main body life. Under condition 1, when the sixth replenishment is performed, good results can be obtained even if the same amount of toner was replenished as under condition 2. Therefore, toner fogging caused by toner deterioration can be suppressed.

[0091] As described above, according to the first embodiment, in an image forming apparatus that uses a toner supply system, it is possible to suppress image defects caused by toner deterioration. EXAMPLES

[0092] A configuration of the second embodiment for switching the timing of toner replenishment according to information on the usage status of the image forming apparatus 100 will be described below. In the second embodiment, the information on the usage status corresponds to the environmental temperature and humidity, specifically, the amount of moisture. In the second embodiment, the display process of the toner remaining amount panel 400 in the first embodiment is changed. For this reason, the same configuration as in the first embodiment will be described with the same reference numerals or omitted from the illustration.

[0093] [Low level display processing] The Low level display process of the second embodiment will be described in detail with reference to Fig. 14. Note that the processes from S61 to S64 are similar to the processes from S50 to S53 in Fig. 13, and therefore will not be described. In S65, the control unit 90 detects the surrounding environment using the environment detection unit 54 and calculates the absolute moisture amount y [g / m 3 In S66, the control unit 90 updates the absolute moisture content y [g / m 3 ] is the threshold z [g / m 3 In S66, the control unit 90 determines whether the absolute moisture content y [g / m 3 ] is the threshold z [g / m 3 If it is determined that the moisture content is less than the predetermined moisture content, the process proceeds to S67.

[0094] In S67, the control unit 90 determines whether the toner remaining amount T [g] is less than the amount C (> A) [g] which is the fourth threshold value. When the control unit 90 determines in S67 that the toner remaining amount T [g] is less than the amount C [g], the process proceeds to S68. In S68, the control unit 90 performs a Low level display and displays as shown in Fig. 9(a). In S66, the control unit 90... absolute moisture content y [g / m 3 is greater than or equal to the threshold value z [g / m 3 (equal to or greater than the predetermined moisture content), the process proceeds to S69. In S69, the control unit 90 determines whether the toner remaining amount is less than the amount B [g] (< A) which is the first threshold value. When the control unit 90 determines in S69 that the toner remaining amount T [g] is less than B [g], the process proceeds to S68, and a Low level display is performed and displayed as shown in Fig. 9(a). When the control unit 90 determines in S67 that the toner remaining amount T [g] is greater than or equal to the amount C [g], and when the control unit 90 determines in S69 that the toner remaining amount T [g] is greater than or equal to the amount B [g], the control unit 90 returns the process to S61.

[0095] Thus, in the second embodiment, when the absolute moisture content y [g / m 3 is less than the threshold value z%, if the toner remaining amount T [g] becomes less than the amount C [g] which is more than the amount A [g], a Low level display is performed. On the other hand, if the absolute moisture content y [g / m 3 is greater than or equal to the threshold value z%, if the toner remaining amount T [g] becomes less than the amount B [g] which is less than the amount A [g], a Low level display is performed. That is, in the second embodiment, the control unit 90 switches the timing of performing the Low level display according to the absolute moisture content y [g / m 3 , and when the absolute moisture content y [g / m 3 is small, that is, in a low humidity environment, the Low level display is performed at an earlier timing.

[0096] Here, in a low-temperature and low-humidity environment, the charge of the charged toner is difficult to escape, and a part of the toner carried on the developing roller 4 becomes excessively charged. The excessively charged toner is firmly fixed by the mirror force acting between the developing roller 4, exceeds the regulating force of the developing blade 6, and a regulation failure occurs, which is a disturbance of the toner layer on the developing roller 4. When a regulation failure occurs, more developer than necessary is used for development, so the amount of toner developed on the blank part of the image increases.

[0097] In Example 2, in the usage situation of a low-temperature and low-humidity environment where toner fogging due to regulation failure is disadvantageous, new toner is replenished when the remaining amount of toner in the developing container 8 is large, that is, before the degree of toner deterioration becomes too large. By controlling in this way so that the degree of toner deterioration in the developing container 8 does not exceed a certain level, toner fogging can be suppressed. In Example 2, C > A is set, but C = A may also be used, or B < C < A may also be used. Also, it may be combined with Example 1. In this case, in the case of low printing and low temperature and low humidity, replenishment will be performed when the remaining amount of toner is the largest.

[0098] [Experiment 2] Here, to show the effect of Example 2, an experiment using a comparative example will be described. In this experiment, in an environment of a temperature of 15°C and a humidity of 10%, an image with a printing rate of 1% was printed until the life of the main body, and an evaluation was made as to whether toner fogging occurred.

[0099] In this experiment, three conditions of toner remaining amounts where Low level is displayed, namely Condition 3, Condition 4, and Condition 5, were set, and evaluations of toner fogging for each were performed. Condition 3 is a configuration where the remaining amount of toner is amount C [g] and Low level is displayed. Condition 4 is the same as Condition 1 of Experiment 1, where the remaining amount of toner is amount A [g] (< C) and Low level is displayed, and Condition 5 is the same as Condition 2 of Experiment 1, where the remaining amount of toner is amount B [g] (< A) and Low level is displayed. The configurations of Condition 3, Condition 4, and Condition 5, and the results of each experiment are shown in Table 2.

[0100]

Table 2

[0101] In particular, in the case of the configuration of condition 5, the increase in the mirror force due to the low temperature and low humidity environment and the increase in adhesion due to toner deterioration overlap, so the toner fog phenomenon occurred at an even earlier timing than in experiment 1. On the other hand, in the case of condition 3, although there is an increase in the mirror force due to the low temperature and low humidity environment, the degree of toner deterioration is maintained at a certain level or less, so toner fog can be suppressed. Note that condition 4 was marked "△" earlier than condition 3, but was not marked "X" like condition 5. Note that condition 4 replenishes toner earlier than condition 5, so better results were obtained than condition 5.

[0102] As described above, according to the second embodiment, in an image forming apparatus that uses a toner supply system, it is possible to suppress image defects caused by toner deterioration. EXAMPLES

[0103] A configuration for switching the timing of toner replenishment according to information on the usage status of image forming apparatus 100 in embodiment 3 will be described below. In embodiment 3, the information on the usage status corresponds to the number of replenishments. In embodiment 3, the display process of remaining toner panel 400 in embodiment 1 is changed. For this reason, the same configuration as embodiment 1 will be described with the same reference numerals in the drawings, or will be omitted from the illustration.

[0104] [Low level display processing] The low level display process of the third embodiment will be described in detail with reference to Fig. 15. Note that the processes from S70 to S74 are the same as those from S50 to S54 in Fig. 13, and therefore the description will be omitted. In S75, the control unit 90 updates the remaining toner amount threshold to the Nth amount (≦the Nth+1th amount). For example, if the number of replenishments N updated in S74 is the second time, it is updated to the second amount [g]. Note that the ROM 93 stores a table or the like that associates the number of replenishments N with the Nth amount of the remaining toner amount threshold, and the control unit 90 updates the Nth amount [g] by reading information from the ROM 93.

[0105] In S76, the control unit 90 determines whether the remaining toner amount T[g] is less than the Nth amount. If the control unit 90 determines in S76 that the remaining toner amount T[g] is less than the Nth amount [g], the process proceeds to S77. In S77, the control unit 90 displays a low level, i.e., as shown in FIG. 9(a). If the control unit 90 determines in S76 that the remaining toner amount T[g] is equal to or greater than the Nth amount [g], the control unit 90 returns the process to S70.

[0106] The Nth amount [g], which is the toner remaining amount threshold, is set so that "Nth amount [g]≦N+1th amount [g]" as described above. For example, if the first amount [g] is A (>B), the second amount [g] is D (>A), the third amount [g] is E (>D), the fourth amount [g] is F (>E), etc. In this way, in the third embodiment, the control unit 90 sets the toner remaining amount threshold to a larger value as the number of replenishments increases, thereby accelerating the timing of displaying the Low level as the number of replenishments increases.

[0107] Here, in the toner pack method, toner is replenished to the developing container 8 in which deteriorated toner remains, so the number of times of rubbing is greater than for new toner. Therefore, when the low state is reached again, the toner remaining in the developing container 8 is in a more deteriorated state, having been rubbed more times than in the previous low state. Repeated occurrences of the low state and toner replenishment cause more deteriorated toner to accumulate in the developing container 8, resulting in an increase in the occurrence of fogging due to toner deterioration.

[0108] In the third embodiment, in a situation where the number of replenishments is increased and toner fogging due to toner deterioration is disadvantageous, new toner is replenished when the remaining toner amount is greater, that is, before the degree of toner deterioration becomes too large. In this way, by controlling the degree of toner deterioration in the developing container 8 so that it does not exceed a certain level, toner fogging can be suppressed.

[0109] [Experiment 3] Here, to show the effects of Example 3, the experiments conducted using comparative examples will be described. Similar to Experiment 1, in this experiment, in an environment with a temperature of 23°C and a humidity of 50%, an image with a printing rate of 1% was printed until the main body reached its lifespan, and an evaluation was made as to whether toner fogging occurred.

[0110] In this experiment, the toner remaining amount at which Low level is displayed was set as Condition 6, and an evaluation of toner fogging was performed. Condition 6 has the following configuration.

[0111] At the first replenishment, the toner remaining amount is A [g] and Low level is displayed, At the second replenishment, the toner remaining amount is D [g] (>A) and Low level is displayed, At the third replenishment, the toner remaining amount is E [g] (>D) and Low level is displayed, At the fourth replenishment, the toner remaining amount is F [g] (>E) and Low level is displayed, At the fifth replenishment, the toner remaining amount is G [g] (>F) and Low level is displayed, At the end of the main body lifespan, the toner remaining amount is H [g] (>G) and Low level is displayed Also, as examples for comparing effects, the experiments were similarly conducted under Conditions 1 and 2 of Experiment 1, and an evaluation of toner fogging was performed. The configurations of Condition 6, Condition 1, and Condition 2, and the results of each experiment are shown in Table 3.

[0112]

Table 3

[0113] In the case of the configuration of Condition 2, regardless of the number of replenishments, since the toner remaining amount decreases to B [g] (<A), new toner is replenished in a state where the degree of deterioration of the toner in the developing container 8 has advanced. Furthermore, each time the Low level is reached, more deteriorated toner accumulates, so that at the end of the main body lifespan, the toner fogging phenomenon caused by toner deterioration becomes prominent.

[0114] In the case of the configuration under condition 1, new toner is replenished when the remaining toner amount reaches amount A [g], which is greater than amount B [g], i.e., before the degree of toner deterioration reaches a certain level or more, so that the toner deterioration can be maintained at a milder level than under condition 2.

[0115] On the other hand, in the case of the configuration of condition 6 in Example 3, as the number of replenishments increases, new toner is replenished with more toner remaining in the developer container 8, so the toner in the developer container 8 can be maintained in a state of milder deterioration. Therefore, toner fogging caused by toner deterioration can be suppressed. In an image forming apparatus that uses a toner container replenishment method, the occurrence of fogging caused by toner deterioration can be suppressed. In Table 3, both condition 1 and condition 6 are displayed as "◯" for the main body life, but more specifically, condition 6 was even better than condition 1 in terms of toner fogging.

[0116] As described above, according to the third embodiment, in an image forming apparatus that uses a toner supply system, it is possible to suppress image defects caused by toner deterioration.

[0117] [Other Examples] The information (history information) on the usage status of the image forming apparatus 100 may be, for example, the amount of toner consumption. In this case, the control unit 90 stores the number of rotations of the developing roller 4 in the RAM 92, which is a storage unit. The number of rotations of the developing roller 4 can be converted into a travel distance, and the travel distance may be used. The control unit 90 calculates the unit consumption amount, which is the amount of toner consumption per one rotation number of the developing roller 4 (or the amount of toner consumption per one travel distance) since the previous supply operation, based on the amount of toner consumption and the number of rotations of the developing roller 4. When the unit consumption amount is equal to or greater than a predetermined consumption amount, the control unit 90 switches the threshold to a first threshold, and when the unit consumption amount is less than the predetermined consumption amount, the control unit 90 switches to a third threshold that is greater than the first threshold. Even in this case, the toner in the developing container 8 can be maintained in a state where the degree of deterioration is milder. Therefore, toner fogging caused by toner deterioration can be suppressed. Although the number of rotations of the developing roller 4 is used when acquiring the unit consumption amount, for example, the number of rotations of the motor M1 or the number of printed sheets may be used.

[0118] Furthermore, the control unit 90 may use the number of rotations of the developing roller 4 as information relating to the usage status of the image forming apparatus 100, and set the threshold value according to the number of rotations of the developing roller 4. The control unit 90 sets the threshold value to a larger value as the number of rotations of the developing roller 4 increases. In other words, when the number of rotations of the developing roller 4 at a certain point in time is Rx, and the number of rotations of the developing roller 4 thereafter is Ry (>Rx), Remaining amount threshold at Rx≦Remaining amount threshold at Ry The control unit 90 sets the remaining amount threshold to a larger value as the number of rotations of the developing roller 4 increases. Even in this case, it is possible to suppress image defects caused by toner deterioration in an image forming apparatus that uses a toner supply system.

[0119] The disclosure of this embodiment includes the following configuration. (Configuration 1) an image carrier configured to be rotatable and carrying a toner image; a developing rotor for supplying toner to the image carrier; a developer container for accommodating toner, the developer container having a refill port for refilling the toner; and an image forming apparatus capable of performing a replenishing operation of replenishing toner from a replenishing container that is detachable from the replenishing port, a detection means for detecting an amount of toner contained in the developing container; a notification means for notifying that it is time to perform the replenishment operation; a control means for controlling the notifying means to notify that it is time to perform the replenishing operation when the amount of toner detected by the detection means becomes less than a threshold value; Equipped with The image forming apparatus is characterized in that the control means sets the threshold to a first threshold when the printing rate after the previous replenishment operation is equal to or greater than a predetermined printing rate, and sets the threshold to a second threshold greater than the first threshold when the printing rate is less than the predetermined printing rate. (Configuration 2) A storage means for storing the number of rotations of the developing rotor is provided, The above-mentioned image forming device is characterized in that the control means obtains a unit consumption amount, which is the amount of toner consumed per rotation number of the developing rotor after the previous replenishment operation, based on the toner consumption amount, which is the amount of toner consumed after the previous replenishment operation, and the rotation number stored in the memory means, and sets the threshold to a first threshold amount if the unit consumption amount is equal to or greater than a predetermined consumption amount, and sets the threshold to a third threshold amount greater than the first threshold amount if the unit consumption amount is less than the predetermined consumption amount. (Configuration 3) an environment detection unit for detecting a moisture content in an environment surrounding the image forming apparatus; The above-mentioned image forming apparatus, characterized in that the control means sets the threshold to a first threshold when the moisture amount detected by the environmental detection means is equal to or greater than a predetermined moisture amount, and sets the threshold to a fourth threshold which is greater than the first threshold when the moisture amount is less than the predetermined moisture amount. (Configuration 4) The image forming apparatus according to any one of the above, wherein the control unit sets the threshold value to a larger value as the number of replenishments, which is the number of times the toner has been replenished to the developing container, increases. (Configuration 5) A storage means for storing the number of rotations of the developing rotor is provided, The image forming apparatus according to claim 1, wherein the control means sets the threshold value to a larger value as the number of rotations increases. (Configuration 6) an image carrier configured to be rotatable and carrying a toner image; a developing rotor for supplying toner to the image carrier; a developer container for accommodating toner, the developer container having a refill port for refilling the toner; and an image forming apparatus capable of performing a replenishing operation of replenishing toner from a replenishing container that is detachable from the replenishing port, a detection means for detecting an amount of toner contained in the developing container; a notification means for notifying that it is time to perform the replenishment operation; a control means for controlling the notifying means to notify that it is time to perform the replenishing operation when the amount of toner detected by the detection means becomes less than a threshold value; an environment detection unit that detects the amount of moisture in the surrounding environment of the image forming apparatus; Equipped with The image forming apparatus is characterized in that the control means sets the threshold to a first threshold when the moisture amount detected by the environmental detection means is equal to or greater than a predetermined moisture amount, and sets the threshold to a fourth threshold that is greater than the first threshold when the moisture amount is less than the predetermined moisture amount. (Configuration 7) A storage means for storing the number of rotations of the developing rotor is provided, The above-mentioned image forming device is characterized in that the control means obtains a unit consumption amount, which is the amount of toner consumed per rotation number of the developing rotor after the previous replenishment operation, based on the toner consumption amount, which is the amount of toner consumed after the previous replenishment operation, and the rotation number stored in the memory means, and sets the threshold to a first threshold amount if the unit consumption amount is equal to or greater than a predetermined consumption amount, and sets the threshold to a third threshold amount greater than the first threshold amount if the unit consumption amount is less than the predetermined consumption amount. (Configuration 8) The image forming apparatus according to any one of the above, wherein the control unit sets the threshold value to a larger value as the number of replenishments, which is the number of times the toner has been replenished to the developing container, increases. (Configuration 9) A storage means for storing the number of rotations of the developing rotor is provided, The image forming apparatus according to claim 1, wherein the control means sets the threshold value to a larger value as the number of rotations increases. [Explanation of symbols]

[0120] 1 Photosensitive drum 4 Developing roller 8 Developer container 51 First toner remaining sensor 52 Second toner remaining sensor 90 Control section 400 Toner Remaining Panel

Claims

1. an image carrier configured to be rotatable and carrying a toner image; a developing rotor for supplying toner to the image carrier; a developer container for accommodating toner, the developer container having a refill port for refilling the toner; and an image forming apparatus capable of performing a replenishing operation of replenishing toner from a replenishing container that is detachable from the replenishing port, a detection means for detecting an amount of toner contained in the developing container; a notification means for notifying that it is time to perform the replenishment operation; a control means for controlling the notifying means to notify that it is time to perform the replenishing operation when the amount of toner detected by the detection means becomes less than a threshold value; Equipped with The image forming apparatus is characterized in that the control means sets the threshold to a first threshold when the printing rate after the previous replenishment operation is equal to or greater than a predetermined printing rate, and sets the threshold to a second threshold greater than the first threshold when the printing rate is less than the predetermined printing rate.

2. A storage means for storing the number of rotations of the developing rotor is provided, The image forming apparatus according to claim 1, characterized in that the control means obtains a unit consumption amount, which is the amount of toner consumed per rotation number of the developing rotor after the previous replenishment operation, based on the toner consumption amount, which is the amount of toner consumed after the previous replenishment operation, and the rotation number stored in the memory means, and sets the threshold to a first threshold amount if the unit consumption amount is equal to or greater than a predetermined consumption amount, and sets the threshold to a third threshold amount greater than the first threshold amount if the unit consumption amount is less than the predetermined consumption amount.

3. an environment detection unit for detecting a moisture content in an environment surrounding the image forming apparatus; The image forming apparatus according to claim 1, wherein the control means sets the threshold to a first threshold when the moisture amount detected by the environment detection means is equal to or greater than a predetermined moisture amount, and sets the threshold to a fourth threshold which is greater than the first threshold when the moisture amount is less than the predetermined moisture amount.

4. 2. The image forming apparatus according to claim 1, wherein the control unit sets the threshold value to a larger value as the number of replenishment times, which is the number of times the toner has been replenished to the developing container, increases.

5. A storage means for storing the number of rotations of the developing rotor is provided, 2. The image forming apparatus according to claim 1, wherein the control unit sets the threshold value to a larger value as the number of rotations increases.

6. an image carrier configured to be rotatable and carrying a toner image; a developing rotor for supplying toner to the image carrier; a developer container for accommodating toner, the developer container having a refill port for refilling the toner; and an image forming apparatus capable of performing a replenishing operation of replenishing toner from a replenishing container that is detachable from the replenishing port, a detection means for detecting an amount of toner contained in the developing container; a notification means for notifying that it is time to perform the replenishment operation; a control means for controlling the notifying means to notify that it is time to perform the replenishing operation when the amount of toner detected by the detection means becomes less than a threshold value; an environment detection unit that detects the amount of moisture in the surrounding environment of the image forming apparatus; Equipped with The image forming apparatus is characterized in that the control means sets the threshold to a first threshold when the moisture amount detected by the environmental detection means is equal to or greater than a predetermined moisture amount, and sets the threshold to a fourth threshold that is greater than the first threshold when the moisture amount is less than the predetermined moisture amount.

7. A storage means for storing the number of rotations of the developing rotor is provided, The image forming apparatus according to claim 6, wherein the control means obtains a unit consumption amount, which is the amount of toner consumed per rotation number of the developing rotor after the previous replenishment operation, based on the toner consumption amount, which is the amount of toner consumed after the previous replenishment operation, and the rotation number stored in the memory means, and sets the threshold to a first threshold amount if the unit consumption amount is equal to or greater than a predetermined consumption amount, and sets the threshold to a third threshold amount greater than the first threshold amount if the unit consumption amount is less than the predetermined consumption amount.

8. 7. The image forming apparatus according to claim 6, wherein the control unit sets the threshold value to a larger value as the number of replenishment times, which is the number of times the toner has been replenished to the developing container, increases.

9. A storage means for storing the number of rotations of the developing rotor is provided, 7. The image forming apparatus according to claim 6, wherein the control unit sets the threshold value to a larger value as the number of rotations increases.

Images