JP2017181702A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect the initial developer amount of the developer of a developer replenishment container.SOLUTION: An image forming apparatus 100 includes a developing container 37 which stores toner 90, a stirring member 36a and a stirring member 36b which supply the toner 90 to the developing container 37 from a toner bottle 34, an antenna remaining amount value AD detection part 47 which detects the toner 90 supplied from the toner bottle 34 by the stirring member 36a and the stirring member 36b, and a CPU 39 which determines the amount of the toner in the toner bottle 34 on the basis of the variance state of the detection result of the antenna remaining amount value AD detection part 47.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, or a facsimile machine that forms an image using a developer supplied to a developer container.

  2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus using a developer, a developer (toner) accommodated in a developer accommodating portion is supplied by a developing sleeve to an electrostatic latent image formed on the surface of a photosensitive drum. As a result, a developer image is formed (visualized) on the photosensitive drum.

  In such an image forming apparatus, the developer stored in the developer container is consumed every time an image forming operation is performed. Then, the image forming apparatus detects that the remaining amount of the developer in the developer accommodating portion has been reduced to a predetermined amount by the developer remaining amount detecting means provided in the developer accommodating portion, and supplies the developer. A mechanism is provided to indicate and communicate the need.

  The developer remaining amount detecting means measures the induced voltage between the developing sleeve provided inside the developer accommodating portion and the rod-shaped antenna electrode arranged in parallel to the developing sleeve, and develops from the measured value. A configuration for detecting the remaining amount of the developer in the agent container is used.

  Specifically, the voltage that is applied to the developing sleeve and induced in the antenna electrode varies depending on the capacitance of the capacitor formed by the antenna electrode and the developing sleeve. That is, the induced voltage increases as the capacitance of the capacitor increases, and the induced voltage decreases as the capacitance of the capacitor decreases.

  The capacitance of the capacitor formed by the developing sleeve and the antenna electrode varies depending on the distance between the developing sleeve and the antenna electrode. Specifically, the capacitance C of the capacitor formed by the antenna electrode and the developing sleeve is a relational expression C = area S × dielectric constant μ ÷ distance L. Further, the capacitance of the capacitor formed by the developing sleeve and the antenna electrode varies depending on the dielectric constant of the substance existing between the developing sleeve and the antenna electrode.

  Since the developing sleeve and the antenna electrode are fixed to the developer accommodating portion, the distance L between them does not change. The amount of the developer present in the space between the developing sleeve and the antenna electrode varies depending on the remaining amount of the developer in the developer accommodating portion. For this reason, the induced voltage generated between the developing sleeve and the antenna electrode changes according to a change in the amount of the developer existing in the space between the developing sleeve and the antenna electrode. Therefore, it is possible to detect the remaining amount of the developer in the developer container using the magnitude of the induced voltage generated between the developing sleeve and the antenna electrode.

  Conventionally, the initial developer amount of the developer in the developer replenishing container is detected based on the integrated average value of the induced voltage between the developing sleeve and the antenna electrode, and based on the detected developer amount, An image forming apparatus that determines the state of the developer is known. Here, the state of the developer in the developer accommodating portion is, for example, that the remaining amount of developer in the developer accommodating portion is at a toner shortage level selected according to the initial amount of developer in the developer supply container. It has reached the state (for example, Patent Document 1).

JP-A-2005-300685

  However, in the conventional image forming apparatus that determines the state of the developer in the developer accommodating portion, even if the initial amount of the developer in the developer supply container is the same, it depends on the aggregation state of the developer. The integrated average value of the induced voltage may be different. In this case, there is a problem that the initial developer amount of the developer in the developer supply container cannot be accurately detected, and the state of the developer in the developer accommodating portion cannot be accurately determined.

  An object of the present invention is to provide an image forming apparatus capable of accurately detecting an initial developer amount of a developer in a developer supply container.

  The image forming apparatus according to the present invention includes a developer container that contains a developer, a developer supply unit that supplies the developer from a developer supply container to the developer container, and the developer supply unit that performs the development. Detection means for detecting the developer supplied from the developer supply container, and determination means for determining the amount of developer in the developer supply container based on the variation state of the detection result of the detection means. Features.

  According to the present invention, it is possible to accurately detect the amount of developer in the developer supply container.

1 is a configuration diagram of an image forming apparatus according to an embodiment of the present invention. Configuration diagram of a developing device according to an embodiment of the present invention The block diagram which shows the structure of the control part which concerns on embodiment of this invention The figure which showed the state which consumes the toner supplied to the image development apparatus concerning embodiment of this invention. The figure which shows the relationship between the induced voltage which concerns on embodiment of this invention, and the residual amount of a toner. The figure which shows the time transition of the induced voltage after the supply start of the toner with respect to the developing container which concerns on embodiment of this invention. The figure which shows disturbance of the induced voltage for every toner amount of a toner bottle and toner property which concerns on embodiment of this invention. The flowchart which shows the toner amount determination process based on Embodiment of this invention The figure which shows the ratio for every detection range of the induced voltage which concerns on embodiment of this invention. The figure which shows the ratio for every detection range of the induced voltage which concerns on embodiment of this invention, and every toner amount of a toner bottle

  Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings as appropriate.

<Configuration of image forming apparatus>
The configuration of the image forming apparatus 100 according to the embodiment of the present invention will be described in detail with reference to FIG.

  The image forming apparatus 100 includes a photosensitive drum 1, a charging roller 2, an exposure device 4, a developing device 5, a transfer roller 7, and a cleaner 10.

  The photosensitive drum 1 as an image carrier is cylindrical and has a photosensitive layer on the surface. The photosensitive drum 1 rotates in the direction of arrow A in FIG.

  The charging roller 2 is provided around the photosensitive drum 1 and uniformly charges the surface of the photosensitive drum 1.

  The exposure device 4 performs exposure corresponding to the image signal on the uniformly charged surface of the photosensitive drum 1 to form an electrostatic latent image on the surface of the photosensitive drum 1.

  The developing device 5 includes a developing sleeve 5 a that is rotatably attached to a developing container 37 that is a developer container, and an antenna electrode 33 that is attached to the developing container 37. The developing device 5 visualizes the electrostatic latent image by supplying toner as a developer to the electrostatic latent image formed on the surface of the photosensitive drum 1 by the developing sleeve 5a to form a toner image. To do. The developing device 5 detects the remaining amount of toner as a developer in the developing container 37 using the developing sleeve 5 a and the antenna electrode 33. Details of the configuration of the developing device 5 will be described later.

  The transfer roller 7 holds the recording medium P conveyed in synchronism with the formation of the toner image between the photosensitive drum 1 and transfers the toner image formed on the photosensitive drum 1 to the recording medium P. .

  The cleaner 10 removes the transfer residual toner remaining on the surface of the photosensitive drum 1 after the transfer of the toner image or the paper powder transferred from the recording medium P by the cleaning blade 10a.

<Configuration of developing device>
The configuration of the developing device 5 according to the embodiment of the present invention will be described in detail with reference to FIG.

  The developing device 5 includes a developing sleeve 5a, a developing bias power source 6, an antenna electrode 33, a toner bottle 34, a toner regulating member 35, a stirring member 36a, a stirring member 36b, a stirring member 36c, and a developing container 37. And have.

  The developing sleeve 5 a also serves as a first electrode to which a predetermined developing bias voltage is applied from the developing bias power source 6. The developing sleeve 5a is rotatably attached to the developing container 37 and rotates in the direction of arrow B in FIG. The developing sleeve 5 a carries toner stored in the developing container 37 and supplies it to the photosensitive drum 1.

  The developing bias power source 6 applies a developing bias voltage (bias signal) obtained by superimposing a DC voltage and an AC voltage to the developing sleeve 5 a, and the toner coated on the developing sleeve 5 a is statically applied to the surface of the photosensitive drum 1. Fly to the electric latent image.

  The antenna electrode 33 as the second electrode has a thin rod shape and is provided inside the developing container 37. The antenna electrode 33 is disposed to face the developing sleeve 5a so as to have a predetermined distance from the developing sleeve 5a (for example, an interval of about 5 mm to 50 mm from the surface of the developing sleeve 5a). The antenna electrode 33 is connected to the control unit 101 described later via the detection terminal 40a and is grounded via the resistor 40. Since the developing sleeve 5a to which an AC voltage is applied is present near the antenna electrode 33, an electrostatic induction current flows due to an AC electric field generated by the developing sleeve 5a.

  The detection terminal 40a is provided between the resistor 40 and the antenna electrode 33, and is connected to the control unit 101 described later.

  The toner bottle 34, which is a developer supply container, is detachably accommodated in the developing container 37 and can be replaced. The toner bottle 34 supplies the toner to the developing container 37 before the toner in the developing container 37 is completely exhausted.

  The toner regulating member 35 is in contact with the developing sleeve 5a and forms a uniform toner coat on the developing sleeve 5a. The toner regulating member 35 sandwiches and conveys the toner with the developing sleeve 5a, thereby charging the toner with a constant charge by frictional charging between the toner and the developing sleeve 5a.

  The agitating member 36a and the agitating member 36b, which are developer supply means, agitate the toner in the developing container 37 to convey the toner in the developing container 37 in the direction of the developing sleeve 5a. The agitating member 36 a agitates the toner 90 between the developing sleeve 5 a and the antenna electrode 33. The agitating member 36 c conveys the toner in the toner bottle 34 into the developing container 37 by agitating the toner in the toner bottle 34.

  The developing container 37 forms a frame of the developing device 5 and contains toner supplied from the toner bottle 34 so that a large amount of image forming operation can be continuously performed. The toner stored in the developing container 37 is consumed by performing an image forming operation.

  The developing device 5 detects the remaining amount of toner using two members, the developing sleeve 5 a and the antenna electrode 33. The capacitance formed by the antenna electrode 33 and the developing sleeve 5a, which are the two electrodes, is the tolerance of the distance between the two electrodes, the tolerance of the outer diameter of the two electrodes, and the linearity of the two electrodes ( It is determined by the warping of the wire). For this reason, the electrostatic capacitance formed by the antenna electrode 33 and the developing sleeve 5a is the individual difference between the antenna electrode 33 and the developing sleeve 5a (the tolerance of the distance between the two electrodes, the tolerance of the outer diameter, the tolerance of the linearity). ) Causes variation.

  Here, the distance between the two electrodes is a distance between the antenna electrode 33 and the developing sleeve 5a. The outer diameters of the two electrodes are the outer diameters of the antenna electrode 33 and the developing sleeve 5a. The linearity of the two electrodes is the linearity of each of the antenna electrode 33 and the developing sleeve 5a.

  The developing device 5 is not limited to detecting the remaining amount of toner using the developing sleeve 5a, but may be provided with a separate electrode member to detect the remaining amount of toner.

<Configuration of control unit>
The configuration of the control unit 101 according to the embodiment of the present invention will be described in detail with reference to FIG.

  The control unit 101 includes a ROM 38, a CPU 39, a motor driver 41, a RAM 42, an antenna reference value AD detection unit 45, and an antenna remaining value AD detection unit 47. The control unit 101 is included in the developing device 5. Here, the developing sleeve 5a, the antenna electrode 33, and the remaining antenna value AD detection unit 47 constitute detection means.

  The ROM 38 stores programs, data (arithmetic expressions), and the like. The ROM 38 stores in advance determination criteria used when executing a toner amount determination process described later.

  The CPU 39 as the determination unit reads a predetermined program stored in the ROM 38 from the ROM 38 and executes the read program. The CPU 39 outputs a control signal to the developing bias power source 6 and causes the developing bias power source 6 to apply a developing bias voltage to the developing sleeve 5a. The CPU 39 controls the operation of the motor driver 41 by outputting a control signal to the motor driver 41.

  The CPU 39 executes a toner amount determination process to determine the toner amount of the toner bottle 34 (developer amount in the developer supply container). Specifically, the CPU 39 determines the amount of toner in the toner bottle 34 based on the variation state of the detection result input from the antenna remaining amount AD detection unit 47 when the toner is being stirred by the stirring member 36a. The CPU 39 determines the variation state based on the detection result input from the antenna reference value AD detection unit 45 and the remaining antenna value AD detection unit 47 and the determination criterion stored in the ROM 38. The CPU 39 causes the RAM 42 to store toner amount information indicating the toner amount of the toner bottle 34 determined by executing the toner amount determination process.

  The CPU 39 sets a threshold based on the toner amount information stored in the RAM 42. The CPU 39 compares the voltage value obtained by comparing the detection result input from the antenna reference value AD detection unit 45 with the detection result input from the antenna remaining value AD detection unit 47, and the set threshold value. The state of the toner 90 in the developing container 37 is determined. The CPU 39 performs notification or the like for prompting the replacement of the toner bottle 34 when the voltage value becomes equal to or less than the threshold value.

  The motor driver 41 is connected to the motor 43, and by driving the motor 43, the photosensitive drum 1, the charging roller 2, the developing sleeve 5a, the transfer roller 7, the stirring member 36a, the stirring member 36b, and the stirring member 36c. To drive.

  The RAM 42 is used as a work area for calculation of the CPU 39. The RAM 42 stores toner amount information.

  The antenna reference value AD detection unit 45 detects the voltage of the reference electrode 46 serving as a reference value when the developing bias voltage is applied to the developing sleeve 5 a from the developing bias power source 6 and outputs the detection result to the CPU 39.

  The remaining antenna value AD detection unit 47 detects the toner supplied from the toner bottle 34 to the developing container 37 by the stirring member 36a and the stirring member 36b. Specifically, the remaining antenna value AD detection unit 47 detects an induced voltage between the developing sleeve 5a and the antenna electrode 33 when a developing bias voltage is applied from the developing bias power source 6 to the developing sleeve 5a. The remaining antenna value AD detection unit 47 outputs the detection result to the CPU 39.

<Toner remaining amount detection method>
A method for detecting the remaining amount of toner according to the embodiment of the present invention will be described in detail with reference to FIGS.

  In FIG. 4, FIG. 4A shows a state in which the remaining amount of the toner 90 before the toner 90 is consumed after the toner 90 is supplied into the developing container 37 is 100%. FIG. 4B shows a state in which the consumption of the toner 90 in the developing container 37 has progressed and the remaining amount of the toner 90 has reached 20%. FIG. 4C shows a state in which the consumption of the toner 90 in the developing container 37 is further advanced and the remaining amount of the toner 90 is 15%.

  In the new state, since the toner 90 is not contained in the developing container 37, all the space between the antenna electrode 33 and the developing sleeve 5a is filled with air. Therefore, the electrostatic capacitance generated between the antenna electrode 33 and the developing sleeve 5a has a value corresponding to the relative dielectric constant of air.

  As shown in FIG. 4A, when the toner 90 in the developing container 37 is 100% full, the space between the antenna electrode 33 and the developing sleeve 5a is filled with the toner 90. Yes. For this reason, the capacitance formed by the antenna electrode 33 and the developing sleeve 5 a becomes a value corresponding to the relative dielectric constant of the toner 90.

  As shown in FIG. 4B, since the antenna electrode 33 is exposed from the toner 90 when the remaining amount of the toner 90 in the developing container 37 is 20%, the space between the antenna electrode 33 and the developing sleeve 5a is A portion where the toner 90 exists and a portion where air exists exist. Therefore, the electrostatic capacitance formed by the antenna electrode 33 and the developing sleeve 5a is smaller than that in the case of FIG.

  As shown in FIG. 4C, when the remaining amount of the toner 90 in the developing container 37 is 15%, most of the space between the antenna electrode 33 and the developing sleeve 5a is occupied by air. For this reason, the electrostatic capacitance formed by the antenna electrode 33 and the developing sleeve 5a is significantly smaller than that in the case of FIG.

  In the empty state where the remaining amount of toner 90 in the developing container 37 is 0%, the entire space between the antenna electrode 33 and the developing sleeve 5a is filled with air. Therefore, the capacitance formed by the antenna electrode 33 and the developing sleeve 5a has a value corresponding to the relative dielectric constant of air. The relative dielectric constant of air is about 1, and the relative dielectric constant of toner 90 is about 3.

  As shown in FIG. 5, the magnitude of the induced voltage gradually decreases from the vicinity where the remaining amount of toner 90 in the developing container 37 is less than about 20%. The induced voltage decreases as the remaining amount of toner 90 decreases. That is, by measuring the magnitude of the induced voltage between the antenna electrode 33 and the developing sleeve 5a, the remaining amount of toner 90 in the developing container 37 can be known.

  For example, in FIG. 5, when the induced voltage is 1.00V, the remaining amount of toner 90 is 0%, when the induced voltage is 1.25V, the remaining amount of toner 90 is 10%, and when the induced voltage is 1.50V. The remaining amount of toner 90 is 15%. Further, the remaining amount of toner 90 when the induced voltage is 1.75V is 20%, and the remaining amount of toner 90 when the induced voltage is 2.00V is 23 to 100%.

  As a result, when the induced voltage between the antenna electrode 33 and the developing sleeve 5a falls below 1.5V, the image forming apparatus 100 displays that no toner 90 is approaching. Further, when the induced voltage between the antenna electrode 33 and the developing sleeve 5a is less than 1V, an operation such as prohibition of printing is performed until the toner 90 is supplied.

<Time transition of induced voltage after starting toner supply to developer container>
The time transition of the induced voltage after the start of supply of the toner 90 to the developing container 37 according to the embodiment of the present invention will be described in detail with reference to FIG.

  FIG. 6 shows the relationship between the induced voltage and the time t when the toner 90 is supplied from the toner bottle 34 to the developing container 37 when the remaining amount of the toner 90 in the developing container 37 is 0%. In FIG. 6, a solid line indicates a case where 500 g of toner 90 having good fluidity is supplied from the toner bottle 34 to the developing container 37. A broken line indicates a case where 500 g of poorly fluid toner 90 is supplied from the toner bottle 34 to the developing container 37. Furthermore, a one-dot chain line indicates a case where 250 g of toner 90 is supplied from the toner bottle 34 to the developing container 37. Here, the aggregation state of the toner 90 varies depending on the fluidity of the toner 90.

  From FIG. 6, the solid line induced voltage and the broken line induced voltage differ after 60 seconds. This is because the time from when the supply of the toner 90 from the toner bottle 34 is started until the toner 90 is transported between the antenna electrode 33 and the developing sleeve 5a differs depending on the fluidity of the toner 90. It is.

  On the other hand, the induced voltage of the solid line and the induced voltage of the broken line 4 become the same E1 after a lapse of 180 seconds after a sufficient time has elapsed since the start of the supply of the toner 90. Therefore, the controller 101 can determine that the amount of toner in the solid-line toner bottle 34 and the broken-line toner bottle 34 is 500 g when a sufficient time has elapsed since the start of the supply of the toner 90. However, in this case, the user is kept waiting for a long time of 180 seconds or more.

  In the present embodiment, by executing the toner amount determination process, the amount of toner 90 in the toner bottle 34 is determined without causing the user to wait for a long time. Next, the toner amount determination process of the present embodiment will be described in detail.

<Toner amount determination processing>
The toner amount determination process according to the embodiment of the present invention will be described in detail with reference to FIGS. FIG. 7 shows the average value and state of the induced voltage when 60 seconds elapse in FIG.

  As shown in FIG. 7, in both cases where the initial toner amount is 500 g and 250 g, the average value of the induced voltage between the antenna electrode 33 and the developing sleeve 5a in the toner 90 having poor fluidity is fluidity. The toner 90 is smaller than the good toner 90. Therefore, when the toner amount is detected using the average value of the induced voltage, there is a possibility that the toner amount cannot be detected accurately or a toner amount is erroneously detected before a sufficient time has elapsed.

  Here, the state of the induced voltage between the antenna electrode 33 and the developing sleeve 5a differs depending on the amount of toner in the toner bottle 34 and the stirring cycle of the stirring member 36a. In the present embodiment, the control unit 101 measures the disturbance of the induced voltage while the toner 90 is being conveyed from the toner bottle 34 to the developing container 37.

  Specifically, when the initial toner amount is 500 g, the density of the toner 90 between the antenna electrode 33 and the developing sleeve 5a is large. As a result, the state of the toner 90 between the antenna electrode 33 and the developing sleeve 5a does not change greatly even if it is stirred by the stirring member 36a. Therefore, since the induced voltage does not change greatly, the disturbance of the induced voltage is small. Further, when the initial toner amount is 250 g, the density of the toner 90 between the antenna electrode 33 and the developing sleeve 5a is small. As a result, the state of the toner 90 between the antenna electrode 33 and the developing sleeve 5a changes greatly when stirred by the stirring member 36a. Accordingly, since the induced voltage changes greatly, the disturbance of the induced voltage is large.

  In this embodiment, even after a predetermined time has elapsed before a sufficient time has elapsed by paying attention to the disturbance of the induced voltage indicating the variation state of the detection result input from the antenna remaining amount AD detection unit 47. The initial toner amount can be detected accurately or without error. Here, the predetermined time is preferably 180 seconds after the start of the supply of the toner 90 from the toner bottle 34 to the developing container 37 after the replacement of the toner bottle 34. Here, the predetermined time is exemplified by 60 sec from the start of supply of the toner 90 from the toner bottle 34 to the developing container 37.

  Hereinafter, the toner amount determination processing according to the embodiment of the present invention will be described more specifically.

  As shown in FIG. 8, first, the CPU 39 of the control unit 101 determines the induction voltage a predetermined number of times in a certain cycle from the detection result of the induction voltage between the antenna electrode 33 and the developing sleeve 5a input from the antenna remaining amount AD detection unit 47. Sampling is performed (S1). Here, the number of samplings is exemplified 30 times. In addition, the fixed cycle is exemplified here as the same cycle as the stirring cycle of the stirring member 36a.

  Specifically, the CPU 39 sets the induced voltage detected at time t1 as S1, and uses it as a reference for stability detection. Thereafter, the CPU 39101 samples the induced voltage at regular intervals, and sets the induced voltages detected by sampling as S2, S3,..., S30, as shown in FIG. In FIG. 9A, the horizontal axis indicates time and the vertical axis indicates induced voltage, and the induced voltage is sampled every 100 msec.

  Next, as shown in FIG. 9B, the CPU 39 calculates the ratio of each induced voltage from S1 to S30 entering each detection range for each of a plurality of predetermined detection ranges (S2). In this way, the CPU 39 extracts the characteristics of the induced voltage waveform. The detection range is determined in consideration of the ripple of the induced voltage in a stable state as the developing device 5. Here, the detection range is exemplified by four sections A, B, C, and D at 1V intervals.

  The ROM 38 of the control unit 101 stores in advance a determination criterion indicating a reference ratio for each of a plurality of detection ranges for each toner amount (for each developer amount) of the toner bottle 34. Specifically, the ROM 38 has a judgment criterion A for each detection range when the initial toner amount shown in FIG. 10A is 500 g, and a case where the initial toner amount shown in FIG. 10B is 250 g. A determination criterion B for each detection range is stored. The determination criteria A and the determination criteria B are set in advance based on the disturbance of the induced voltage that varies depending on the initial toner amount.

  The CPU 39 refers to the table shown in FIG. 10A stored in the ROM 38 to determine whether or not the calculated ratio of entering each detection range satisfies the criterion A (S3).

  The CPU 39 determines that the initial toner amount of the toner bottle 34 is 500 g when the calculated ratio of entering each detection range satisfies the determination criterion A (S3: Yes) (S4).

  Specifically, as illustrated in FIG. 10A, the CPU 39 determines that the ratio of the toner bottle 34 that falls within the detection range A of the a type is 7% and satisfies the determination criterion A that is 10% or less. . The CPU 39 determines that the ratio of the toner bottle 34 that falls within the a-type detection range B is 46% and satisfies the determination criterion A that is 50% or less. The CPU 39 determines that the ratio of the toner bottle 34 entering the detection range C of the a type is 39% and satisfies the determination criterion A that is 40% or less. The CPU 39 determines that the ratio of the toner bottle 34 that falls within the a-type detection range D is 8% and satisfies the determination criterion A that is 10% or less.

  Therefore, since the CPU 39 can determine that the determination criterion A is satisfied in all the detection ranges, the CPU 39 determines that the initial toner amount of the a-type toner bottle 34 is 500 g.

  Further, the CPU 39 determines that the ratio of the toner bottle 34 entering the b-type detection range A is 5% and satisfies the determination criterion A that is 10% or less. The CPU 39 determines that the ratio of the toner bottle 34 entering the b-type detection range B is 49% and satisfies the criterion A that is 50% or less. The CPU 39 determines that the ratio of the toner bottle 34 entering the b-type detection range C is 37% and satisfies the determination criterion A that is 40% or less. The CPU 39 determines that the ratio of the toner bottle 34 entering the b-type detection range D is 9%, and satisfies the determination criterion A that is 10% or less.

  Accordingly, since the CPU 39 can determine that the determination criterion A is satisfied in all the detection ranges, the CPU 39 determines that the initial toner amount of the b-type toner bottle 34 is 500 g.

  On the other hand, when the calculated ratio of entering each detection range does not satisfy the determination criterion A (S3: No), the CPU 39 determines whether the calculated ratio of entering each detection range satisfies the determination criterion B (S5). ).

  Specifically, as shown in FIG. 10A, the CPU 39 has 28% of the toner bottle 34 that falls within the c-type detection range A, and does not satisfy the criterion A that is 10% or less. to decide. Therefore, the CPU 39 can determine that the determination criterion A is not satisfied in all detection ranges.

  CPU39 returns to the process of S2, when the ratio which falls into each calculated detection range does not satisfy the criteria B (S5: No).

  On the other hand, the CPU 39 determines that the initial toner amount of the toner bottle 34 is 250 g when the calculated ratio of entering the detection ranges satisfies the determination criterion B (S5: Yes) (S6).

  Specifically, as shown in FIG. 10B, the CPU 39 determines that the ratio of the toner bottle 34 entering the c-type detection range A is 28% and satisfies the determination criterion B that is 15% or more. . The CPU 39 determines that the ratio of the toner bottle 34 that falls within the c-type detection range B is 20% and satisfies the determination criterion B that is 20% or less. The CPU 39 determines that the ratio of the toner bottle 34 that falls within the c-type detection range C is 17% and satisfies the determination criterion B that is 20% or less. The CPU 39 determines that the ratio of the toner bottle 34 that falls within the c-type detection range D is 35% and satisfies the determination criterion B that is 20% or more.

  Therefore, since the CPU 39 can determine that the determination criterion B is satisfied in all the detection ranges, the CPU 39 determines that the initial toner amount of the c-type toner bottle 34 is 250 g.

  After the process of S4 or S6, the CPU 39 stores toner amount information indicating the determined initial toner amount in the RAM 42 as a storage unit (S7).

  It should be noted that appropriate values are set for the number of samplings, the detection range, the determination criterion A or the determination criterion B depending on the configuration of the developing device 5 and the material of the toner 90.

  In the present embodiment, the induced voltage between the developing sleeve 5a and the antenna electrode 33 when the toner is being stirred by the stirring member 36a is detected a predetermined number of times. In this embodiment, the toner amount in the toner bottle 34 is detected based on the degree of variation in the induced voltage detected a predetermined number of times, and the toner state in the developing container 37 is determined based on the toner amount. As a result, the initial amount of toner in the toner bottle 34 can be accurately detected regardless of the state of the toner 90.

  In the present invention, the type, shape, arrangement, number, and the like of the members are not limited to the above-described embodiment, and the gist of the invention is appropriately replaced such that the constituent elements are appropriately replaced with those having the same operational effects. Of course, it can be changed as appropriate without departing from the scope.

  Specifically, in the above-described embodiment, the detection unit that detects the developer has been described as a configuration that measures the induced voltage between the developing sleeve 5a and the antenna electrode 33. However, the detection unit is not limited thereto. For example, a detection unit that detects a developer using a sensor such as a piezo sensor or a magnetic sensor may be used.

  In the present embodiment, the toner amount of the toner bottle 34 having a toner amount of 500 g or 250 g is detected. However, the toner amount of the toner bottle 34 having a toner amount other than 500 g and 250 g may be detected.

  The present invention is suitable for an image forming apparatus such as a copying machine, a printer, or a facsimile using an electrophotographic system that supplies a developer to the developer container from the developer container accommodated in the developer container.

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Charging roller 4 Exposure apparatus 5 Developing apparatus 5a Developing sleeve 6 Developing bias power supply 7 Transfer roller 10 Cleaner 10a Cleaning blade 33 Antenna electrode 34 Toner bottle 35 Toner regulating member 36a Stirring member 36b Stirring member 36c Stirring member 37 Developer container 38 ROM
39 CPU
40 Resistor 40a Detection Terminal 41 Motor Driver 42 RAM
43 motor 45 antenna reference value AD detection unit 46 reference electrode 47 remaining antenna value AD detection unit 90 toner 100 image forming apparatus 101 control unit

Claims (5)

A developer accommodating portion for accommodating the developer;
Developer supply means for supplying a developer from a developer supply container to the developer container;
Detection means for detecting the developer supplied from the developer supply container by the developer supply means;
A determination unit that determines a developer amount in the developer supply container based on a variation state of a detection result of the detection unit;
An image forming apparatus comprising: The detection means includes a first electrode that is disposed in the developer container and to which a predetermined voltage is applied, and a second electrode that is provided to face the first electrode with a predetermined interval therebetween. With
The determination unit is configured to perform the development based on a variation state of the detection result of the induced voltage between the first electrode and the second electrode when the predetermined voltage is applied to the first electrode. The image forming apparatus according to claim 1, wherein the developer amount in the agent supply container is determined. The variation state of the detection result is
A ratio for each of a plurality of predetermined detection ranges including each of the induced voltages detected a predetermined number of times;
The determination means includes
Determining the amount of developer in the developer supply container based on the ratio;
The image forming apparatus according to claim 2. A storage unit that preliminarily stores, for each developer amount in the developer supply container, a determination criterion that indicates the ratio that serves as a reference for each of the plurality of detection ranges;
The determination means includes
Determining the amount of developer in the developer supply container in which the ratio of each of the induced voltages detected the predetermined number of times satisfies the determination criterion;
The image forming apparatus according to claim 3. The determination means includes
After the replacement of the developer supply container, a developer amount in the developer supply container is determined after a predetermined time has elapsed since the developer supply means started supplying the developer.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.

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