JP5982913B2 - Image forming apparatus and program - Google Patents

Description

  The present invention relates to an image forming apparatus and a program.

  In Patent Document 1, a charging unit that charges the surface of the photosensitive drum, an exposure unit that exposes the surface of the photosensitive drum to form a latent image, and a latent image formed on the surface of the photosensitive drum are developed. In an image forming apparatus comprising: a developing unit that develops with a developer; and a transfer roll that transfers a developer image formed on the surface of the photosensitive drum to a transfer material; a temperature detected by a temperature detecting unit of the fixing device; An image forming apparatus that applies a voltage for environment detection to the transfer roll and calculates the humidity of the surrounding environment based on the relationship between the magnitude of the voltage applied to the transfer roll and the magnitude of the current flowing through the transfer roll Is disclosed.

JP 2004-333792 A

  An object of the present invention is to provide an image forming apparatus and a program for estimating a change in humidity with high accuracy.

In order to achieve the above object, the image forming apparatus according to claim 1 stores a two-component developer with respect to an electrostatic latent image formed in a formation region based on image information indicating an image. A developing unit that develops the electrostatic latent image by supplying colored particles contained in the two-component developer from a reservoir, and the colored particles that are consumed as the electrostatic latent image is developed by the developing unit First estimation means for estimating the amount of consumption of the toner based on the image information, and estimating the amount of the colored particles contained in the storage portion with the two-component developer contained in the storage portion as a measurement target Measuring means for measuring a physical quantity to be provided to the image forming apparatus, and second estimation for estimating a consumption amount of the colored particles consumed by developing the electrostatic latent image by the developing means based on the physical quantity measured by the measuring means. Means and the first estimating means When the estimated consumption is smaller than the consumption estimated by the second estimating means, high humidity information indicating that the humidity is higher than a predetermined humidity is output, and the first estimation Output means for outputting low humidity information indicating that the humidity is lower than the predetermined humidity when the consumption estimated by the means is greater than the consumption estimated by the second estimation means; and the output When the high-humidity information is output from the means, the predetermined humidity is determined by adding a high-humidity-side divergence amount assuming a divergence amount from the predetermined humidity to the high-humidity side to the predetermined humidity. When the low humidity information is output from the output means, the low humidity side deviation amount assuming a deviation amount from the predetermined humidity to the low humidity side is subtracted from the predetermined humidity. By And updating means for updating the predetermined humidity, and configured to include.

In the image forming apparatus according to claim 1 , as in the invention according to claim 2 , by developing the electrostatic latent image by the developing unit, an image indicated by the image information is applied to the formation area. Forming means for forming, and each of the high-humidity-side divergence amount and the low-humidity-side divergence amount is determined by a forming operation amount when the image indicated by the image information is formed in the formation region by the forming means. It was determined in advance so as to increase in accordance with the increase.

According to a second aspect of the present invention, in the image forming apparatus according to the third aspect , the density instruction that instructs the density of the developed image obtained by the developing unit to develop the electrostatic latent image by the developing unit. When the image is formed in the formation area according to the value and the high-humidity information is output from the output means, a density lower by the high-humidity side deviation amount than the density instructed by the current density instruction value. When the low humidity information is output from the output means, the concentration indication value is controlled to indicate, and when the low humidity information is output, a concentration higher than the concentration indicated by the current concentration indication value is indicated by the low humidity side deviation amount And further comprising a control means for controlling the concentration instruction value.

According to a third aspect of the present invention, in the image forming apparatus according to the fourth aspect , the forming means charges the forming area to form the electrostatic latent image, and the charging Further comprising: latent image forming means for exposing the formation area charged by the means to form the electrostatic latent image; and voltage applying means for applying a developing voltage to the developing means. Means controls at least one of the charge amount of the formation area, the exposure amount to the formation area, and the magnitude of the developing voltage applied to the developing means by controlling the density instruction value; It was supposed to be controlled.

According to a fourth aspect of the present invention, in the image forming apparatus according to the fifth aspect of the present invention, the forming unit may store the replenishment amount in the storage unit with a replenishment amount corresponding to the consumption amount estimated by the first estimation unit. A replenishing means for replenishing the colored particles is further included.

The image forming apparatus according to claim 1 , as in the invention according to claim 6 , includes the developing unit, and indicates the density of a developed image obtained by developing the electrostatic latent image by the developing unit. When the high humidity information is output by the forming unit that forms the image in the formation area according to the density instruction value and the output unit, a density lower than the density indicated by the current density instruction value is indicated. When the low humidity information is output by the output means, the concentration instruction value is controlled so as to indicate a concentration higher than the concentration indicated by the current concentration instruction value. And a control means.

The program according to claim 7 is included in the two-component developer from a storage portion in which the two-component developer is stored with respect to an electrostatic latent image formed in a formation area based on image information indicating an image. The developing means for developing the electrostatic latent image by supplying the colored particles to be measured and the two-component developer contained in the storage portion as an object to be measured, the amount of the colored particles contained in the storage portion is estimated A computer that controls an image forming apparatus including a measuring unit that measures a physical quantity to be used for the image processing, and the amount of the colored particles that is consumed as the electrostatic latent image is developed by the developing unit. First estimation means for estimating the color particle consumption based on the physical quantity measured by the measurement means, based on the physical quantity measured by the measurement means. Means, said first When the consumption estimated by the estimation means is smaller than the consumption estimated by the second estimation means, high humidity information indicating that the humidity is higher than a predetermined humidity is output, and the second Output means for outputting low humidity information indicating that the humidity is lower than the predetermined humidity when the consumption estimated by the first estimation means is greater than the consumption estimated by the second estimation means ; and When the high-humidity information is output from the output means, the high-humidity side deviation amount assuming the deviation amount from the predetermined humidity to the high-humidity side is added to the predetermined humidity. When the predetermined humidity is updated and the low-humidity information is output from the output means, the low-humidity-side deviation amount assuming the deviation amount from the predetermined humidity to the low-humidity side is determined from the predetermined humidity. It was assumed to function as update means for updating the humidity defined the advance by calculation to.

According to the invention which concerns on Claim 1 and Claim 7, when the consumption estimated by the 1st estimation means is smaller than the consumption estimated by the 2nd estimation means, it is higher than predetermined humidity. High humidity information indicating the presence is output, and when the consumption estimated by the first estimation means is larger than the consumption estimated by the second estimation means, the humidity is lower than a predetermined humidity. As compared with the case where the configuration for outputting the low humidity information is not provided, an effect that the change in humidity is estimated with high accuracy is obtained.

According to the first aspect of the present invention, when high humidity information is output from the output means, the predetermined humidity is updated by adding the high humidity side deviation amount to the predetermined humidity, and the output means The effect that, when low humidity information is output, the humidity is estimated with high accuracy compared to the case where there is no configuration for updating the predetermined humidity by subtracting the low humidity side deviation amount from the predetermined humidity. Is obtained.

According to the invention of claim 2 , each of the high-humidity-side divergence amount and the low-humidity-side divergence amount is used to increase the forming operation amount when the image indicated by the image information is formed in the formation region by the forming unit. As compared with a case where the predetermined configuration is not set so as to increase accordingly, an effect that the humidity is estimated with high accuracy is obtained.

According to the third aspect of the present invention, when the high humidity information is output from the output means, the concentration instruction value so as to indicate a concentration that is lower than the concentration indicated by the current concentration instruction value by the high humidity side deviation amount. When the low humidity information is output from the output means, the concentration indication value is not controlled so as to indicate a concentration higher than the concentration indicated by the current concentration indication value by the low humidity side deviation amount As compared with the above, an effect is obtained that an image in which a deviation from the density assumed in advance is suppressed is formed.

According to the invention of claim 4 , by controlling the density instruction value, at least one of the charge amount of the formation area, the exposure amount to the formation area, and the magnitude of the developing voltage applied to the developing means As compared with the case where there is no configuration for controlling the image, an effect of easily forming an image in which deviation from the density assumed in advance is suppressed is obtained.

According to the invention which concerns on Claim 5 , compared with the case where it does not have the structure which replenishes colored particles to a storage part with the replenishment amount equivalent to the said consumption estimated by the 1st estimation means, actual humidity is predetermined. Even when the humidity deviates, there is an effect that it is not necessary to control the replenishment amount of the colored particles according to the concentration instruction value.

According to the invention of claim 6, when high humidity information is output by the output means, the concentration instruction value is controlled so as to indicate a concentration lower than the concentration indicated by the current concentration instruction value, and the output means When the low humidity information is output by, the deviation from the concentration assumed in advance is compared to the case where there is no configuration that controls the concentration indication value to indicate a concentration higher than the concentration indicated by the current concentration indication value. The effect that an image in which the image is suppressed is formed is obtained.

3 is a functional block diagram illustrating an example of main functions of the image forming apparatus according to the embodiment. FIG. 1 is a block diagram illustrating an example of a main configuration of an electric system of an image forming apparatus according to an embodiment. 1 is a configuration diagram illustrating an example of a main configuration of an image forming apparatus according to an embodiment. FIG. 2 is a configuration diagram illustrating an example of a main configuration of a developing device included in an image forming apparatus according to an embodiment. FIG. 2 is a block diagram illustrating an example of a main configuration of an electrical system of an image forming unit included in the image forming apparatus according to the embodiment. 5 is a flowchart illustrating an example of a flow of image forming processing according to the embodiment. It is a flowchart which shows an example of the flow of the density | concentration instruction | indication value update process which concerns on embodiment. It is a time chart which shows an example of TC change with respect to actual humidity transition, the change of the estimated humidity, and the change of developability. 6 is a time chart showing an example of a transition of potential on the outer peripheral surface of a photosensitive drum included in the image forming apparatus according to the embodiment. Transition of the image area ratio when the ratio of the absolute value of the difference between the charging potential and the developing bias potential and the absolute value of the difference between the developing bias potential and the exposure potential is changed before and after density adjustment. It is a graph which shows an example.

  Hereinafter, an example of an embodiment of the disclosed technology will be described in detail with reference to the drawings. In the following description, electrostatic charging is performed with a two-component developer in which a toner that is an example of colored particles and a carrier that plays a role of transporting the toner using an electrostatic force to adhere the toner to an electrostatic latent image. An image forming apparatus that develops a latent image will be described as an example. However, the disclosed technique is not limited to this, and the disclosed technique can be applied to any image forming apparatus that develops an electrostatic latent image with a two-component developer. .

  FIG. 1 shows an example of main functions of the image forming apparatus 10 according to the present embodiment. The image forming apparatus 10 includes a developing unit 12, a first estimation unit 14, a measurement unit 16, a second estimation unit 18, an output unit 20, an update unit 22, a formation unit 24, and a control unit 26. The developing unit 12 supplies toner contained in the two-component developer from the storage unit storing the two-component developer to the electrostatic latent image formed in the formation region based on the image information indicating the image. Thus, the electrostatic latent image is developed. Here, the “formation region” refers to, for example, the outer peripheral surface of the photosensitive drum whose outer peripheral surface is charged. As will be described in detail later, an example of the developing unit 12 is a developing roll that is applied by transferring toner to an electrostatic latent image formed in a formation region. Accordingly, in this case, an example of the “reservoir” referred to here is a reservoir where toner to be supplied to the developing roll is stored.

  In the image forming apparatus 10 according to the present embodiment, an electrostatic latent image corresponding to the image indicated by the input image information is formed on the formation region. The formed electrostatic latent image is developed by the developing unit 12 in accordance with the image indicated by the image information. That is, the toner determined according to the image indicated by the image information is developed by being applied to the electrostatic latent image by the developing unit 12, so that the toner consumption can be estimated from the image information. Therefore, in the present embodiment, the first estimation unit 14 estimates the amount of toner consumed as the electrostatic latent image is developed by the developing unit 12 based on image information (ICDC (image density as an example)). To do.

  The measurement unit 16 measures a physical quantity that is used to estimate the amount of toner contained in the storage unit using the two-component developer contained in the storage unit as a measurement target. Since the two-component developer is a developer mainly composed of non-magnetic particle toner and magnetic particle carrier, the amount of toner contained in the reservoir can be estimated by measuring the magnetic permeability. Therefore, in the present embodiment, a magnetic permeability sensor that measures the magnetic permeability of the two-component developer contained in the storage unit is employed as an example of the measurement unit 16. However, the present invention is not limited to this, and a sensor that measures the amount of toner replenishment to the storage unit every time it is replenished may be employed.

  In the image forming apparatus 10 according to the present embodiment, the amount of toner consumed as the electrostatic latent image is developed by the developing unit 12 can be estimated from the amount of change over time in the amount of toner contained in the storage unit. Therefore, in the present embodiment, the second estimation unit 18 estimates the amount of toner consumed as the electrostatic latent image is developed by the development unit 12 based on the physical quantity measured by the measurement unit 16.

  By the way, in the image forming apparatus 10 according to the present embodiment, the amount of toner consumed in association with the development is predicted on the assumption that the toner is used under the humidity assumed in advance, and the amount of toner consumed is predicted. Thus, the supply amount of toner to be supplied to the developing unit 12 is determined. Therefore, if the humidity is higher than the humidity assumed in advance, the amount of toner consumed is larger than the predicted amount of consumption, so that the toner replenished to the developing unit 12 becomes insufficient. On the other hand, if the humidity is lower than the humidity assumed in advance, the amount of toner consumed is less than the estimated amount of consumption, so that the toner supplied to the developing unit 12 becomes excessive.

  Therefore, in the present embodiment, the humidity is estimated with high accuracy by utilizing the phenomenon that the toner is insufficient or excessive according to the humidity. That is, in the present embodiment, the output unit 20 uses the predetermined humidity when the toner consumption estimated by the first estimation unit 14 is smaller than the toner consumption estimated by the second estimation unit 18. High humidity information indicating that the humidity is also high. Further, the output unit 20 indicates that the humidity is lower than a predetermined humidity when the toner consumption estimated by the first estimation unit is larger than the toner consumption estimated by the second estimation unit 18. Output low humidity information.

As described above, if high humidity information is output from the output unit 20, an image having a higher density than the expected density is formed, and if low humidity information is output from the output unit 20, higher than the expected density. It can be expected that even lower density images will be formed. When high humidity information or low humidity information is output from the output unit 20, if it is determined how much the current humidity deviates from the predetermined humidity to the high humidity side or the low humidity side, the degree of deviation can be determined. Compared with the case where there is no image density, the image density can be adjusted appropriately. Therefore, in the present embodiment, when the high humidity information is output from the output unit 20, the updating unit 22 can determine a high humidity side deviation amount assuming a deviation amount from a predetermined humidity to the high humidity side. The predetermined humidity is updated by adding to the determined humidity. In addition, when the low humidity information is output from the output unit 20, the update unit 22 preliminarily subtracts the low humidity side deviation amount assuming a deviation amount from the predetermined humidity to the low humidity side from the predetermined humidity. Update the specified humidity. Hereinafter, when it is not necessary to distinguish between the high-humidity-side divergence amount and the low-humidity-side divergence amount, they are referred to as “humidity divergence amount”.

  The forming unit 24 develops the electrostatic latent image by the developing unit 12 to form an image indicated by the image information in the formation region. As will be described in detail later, an example of the forming unit 24 is an image forming unit 50 shown in FIGS. The amount of toner consumption increases as the amount of image formation by the forming unit 24 increases. That is, as the operation amount of the forming unit 24 increases, the toner consumption amount is likely to increase as compared with the case where the operation amount does not increase. Therefore, in the present embodiment, the high-humidity-side divergence amount and the low-humidity amount are increased according to an increase in the forming operation amount of the forming unit 24 when the image indicated by the input image information is formed in the formation region by the forming unit 24. It was decided in advance to increase each of the side deviation amounts. Here, the “formation operation amount” is a physical quantity that increases or decreases in accordance with an increase or decrease in the consumption amount of toner that is actually used to form a toner image. That is, it is not a physical quantity that increases as the blank area included in the image indicated by the input image information increases, but a physical quantity that increases as the image density of the image indicated by the input image information increases. is there.

  In addition, the forming unit 24 forms an image indicated by the input image information in the formation region according to a density designation value that designates the density of the developed image obtained by developing the electrostatic latent image by the developing unit 12. The density of the developed image is likely to be higher as the degree of deviation toward the higher humidity side is higher than in other cases. Therefore, in the present embodiment, a density designation value for designating the density of the developed image is determined in advance, and when the control unit 26 outputs high humidity information from the output unit 20, the density instruction set at the present time is set. The concentration indication value is controlled so as to indicate a concentration that is lower than the concentration value indicated by the value by the high-humidity side deviation amount. That is, the concentration instruction value is controlled by adjusting the concentration instruction value by an adjustment amount uniquely determined with respect to the high-humidity side deviation amount. As an example of a method for deriving the adjustment amount from the high-humidity-side divergence amount, there is a derivation method using a table or an arithmetic expression in which the high-humidity-side divergence amount is input and the adjustment amount is output.

  In addition, the density of the developed image is likely to be lower as the degree of deviation toward the lower humidity side is higher than in other cases. Therefore, in the present embodiment, when the low humidity information is output from the output unit 20, the control unit 26 indicates a concentration that is higher by the low humidity side deviation amount than the concentration value specified by the concentration instruction value set at the present time. The density instruction value is controlled to That is, the concentration instruction value is controlled by adjusting the concentration instruction value by an adjustment amount uniquely determined with respect to the low-humidity side deviation amount. As an example of a method for deriving the adjustment amount from the low-humidity-side divergence amount, there is a derivation method using a table or an arithmetic expression in which the low-humidity-side divergence amount is input and the adjustment amount is output.

  The forming unit 24 includes a charging unit 28 that charges a forming region to form an electrostatic latent image, and a latent image forming unit that exposes the forming region charged by the charging unit 12 to form an electrostatic latent image. 30 and a voltage applying unit 32 that applies a developing voltage to the developing unit 28. The density of the developed image is adjusted by controlling at least one of the charge amount of the formation area, the exposure amount to the formation area, and the magnitude of the developing voltage applied to the developing unit 12. Therefore, in the present embodiment, the control unit 26 controls the density instruction value, whereby the charge amount of the formation region, the exposure amount to the formation region, and the magnitude of the developing voltage applied to the development unit 12 are controlled. Control at least one of

  In the present embodiment, as described above, the developed image is controlled by controlling at least one of the charge amount of the formation region, the exposure amount to the formation region, and the magnitude of the developing voltage applied to the developing unit 12. The density of is adjusted. Therefore, the density of the developed image is adjusted even when toner is replenished to the storage unit with a toner replenishment amount corresponding to the toner consumption amount estimated by the first estimation unit 14. Therefore, in the present embodiment, the forming unit 24 further includes a replenishing unit 34 that replenishes the storage unit with the toner replenishment amount corresponding to the toner consumption amount estimated by the first estimating unit 14. Yes.

  The first estimating unit 14, the measuring unit 16, the second estimating unit 18, the output unit 20, the updating unit 22, the forming unit 24, and the control unit 26 are, for example, included in the image forming apparatus 10 shown in FIG. Realized. FIG. 2 shows an example of the main configuration of the electrical system of the image forming apparatus 10. As shown in FIG. 2, the image forming apparatus 10 includes a computer 52. The computer 52 includes a CPU (Central Processing Unit) 52A, a ROM (Read Only Memory) 52B, a RAM (Random Access Memory) 52C, and a secondary storage unit (a hard disk device as an example) 52D. The CPU 52A governs the overall operation of the image forming apparatus 10. The ROM 52B functions as a storage unit that stores in advance a control program for controlling the operation of the image forming apparatus 10, various parameters, and the like. The RAM 52C is used as a work area when executing various programs. The secondary storage unit 52D functions as a nonvolatile storage unit that stores various types of information that must be retained even when the power switch of the apparatus is turned off. The CPU 52A, ROM 52B, RAM 52C, and secondary storage unit 52D are connected to each other via a bus 53 that includes an address bus, a system bus, and the like. Therefore, the CPU 52A reads information from the ROM 52B, RAM 52C, and secondary storage unit 52D, and writes information to the RAM 52C and secondary storage unit 52D.

  An image forming apparatus 10 is an input / output interface (I / O) that electrically connects a computer 52 and various input / output devices to control transmission and reception of various information between the computer 52 and various input / output devices. ) 54. In the first embodiment, as an input / output device that is electrically connected to the computer 52 via the bus 53 by being connected to the I / O 54, the image forming unit 50, the receiving unit 56, the display unit 58, and the communication Part 60 is provided.

  The accepting unit 56 accepts operation input from, for example, a user of the image forming apparatus 10 or a supplier who performs maintenance / inspection of the image forming apparatus 10. Examples of the receiving unit 56 include input devices such as a transmissive touch panel that is used to overlap the display, an operation button for turning on the power, an operation button for setting various information, and a scroll key.

  The display unit 58 displays various information. An example of the display unit 58 is a liquid crystal display. In the present embodiment, a touch panel display formed by superimposing a touch panel which is a part of the receiving unit 56 on a liquid crystal display as the display unit 58 is employed.

  The communication unit 60 is connected to a communication network such as a LAN (Local Area Network) or the Internet, for example, and controls transmission / reception of various information to / from an information processing apparatus (for example, a personal computer) connected to the communication network. . In the present embodiment, the communication unit 60 receives image formation request information from an information processing apparatus connected to a communication network. The “image formation request information” here refers to information requesting to form a single image or a plurality of images on a recording medium. The image formation request information includes an image indicating an image to be formed on a sheet. Contains information. In this embodiment, the CPU 52 </ b> A acquires image formation request information via the communication unit 60 and transfers the acquired image formation request information to the image forming unit 50.

The image forming unit 50 forms an image on a sheet, which is an example of a recording medium, by a xerographic method based on the image formation request information input from the CPU 52A. That is, image formation is performed by transferring a toner image corresponding to an image indicated by image information included in the input image formation request information to a sheet. FIG. 3 shows an example of a main configuration of the image forming unit 50. The image forming unit 50 includes a photosensitive drum 62, a charger 64 that is an example of the charging unit 28, an exposure unit 66 that is an example of the latent image forming unit 30, and a developing unit 68 that is an example of the developing unit 12. The photosensitive drum 62 is disposed so that the outer peripheral surface faces the paper P, and is predetermined in a predetermined direction (the direction of the arc arrow G shown in FIG. 3) upon receiving a driving force from a motor (not shown). Rotate at the specified speed. The charger 64 is disposed on the outer peripheral surface of the photosensitive drum 62. The charger 64 includes a charging roll 64 </ b> A for charging the outer peripheral surface of the photosensitive drum 62. The charging roll 64 </ b> A is a conductive roll, the outer peripheral surface thereof is in contact with the outer peripheral surface of the photosensitive drum 62, and rotates following the rotational operation of the photosensitive drum 62. The charging roll 64A includes a power source 64B, and a voltage in which a DC (direct current) component and an AC (alternating current) component are superimposed is applied from the power source 64B so as to follow the rotation of the photosensitive drum 62. While rotating, the outer peripheral surface of the photosensitive drum 62 is charged to a predetermined potential over the entire area.

  An exposure device 66 is provided on the downstream side of the charger 64 in the rotation direction of the photosensitive drum 62. The exposure device 66 forms an electrostatic latent image by exposing the outer peripheral surface of the photosensitive drum 62 in a state where the outer peripheral surface of the photosensitive drum 62 is charged by the charger 64. The exposure device 66 according to this embodiment includes an LED array in which a plurality of LEDs (light emitting diodes) are arranged along the main scanning direction (the front-rear direction in FIG. 3) during image formation. This LED array irradiates while scanning a light beam based on input image information in the axial direction of the photosensitive drum 62 whose outer peripheral surface is charged by the charging roll 64A. The potential of the region irradiated with the light beam by the exposure device 66 rises, and an electrostatic latent image is formed on the outer peripheral surface of the photosensitive drum 62.

  A developing device 68 is provided on the downstream side of the exposure device 66 in the rotation direction of the photosensitive drum 62. The developing device 68 develops the electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 62 with toner of a predetermined color (here, black as an example) to form a toner image which is an example of a developed image. . As shown in FIG. 4 as an example, the developing device 68 includes a developer housing 72 in which a two-component developer is stored. On the bottom surface of the developer housing 72, a magnetic permeability sensor 73, which is an example of the measurement unit 16, is stood and fixed on the inner wall of the developer housing 72. Therefore, the magnetic permeability sensor 73 is buried in the two-component developer. In this state, the magnetic permeability sensor 73 measures the magnetic permeability of the two-component developer stored in the developer housing 72.

  Inside the developer housing 72, a developing roll 74 is provided so as to be rotatable about an axis so as to be adjacent to the outer peripheral surface of the photosensitive drum 12. Further, the developer housing 72 is disposed adjacent to the developing roll 74, and transports the two-component developer in the developer housing 72 and transports the toner contained in the two-component developer to the developing roll 74. A developer transport roll 76 is provided.

  In the developer housing 72, the two-component developer stored in the developer housing 72 is agitated by rotating the agitation paddle 75 and the agitation screw 78 in response to a driving force from a motor (not shown), and the toner is a carrier. Electrostatically adsorbed on. The carrier to which the toner is attached in this manner is attracted to the developer transporting roll 76 having magnetism by a magnetic force and transported to the developing roll 74, and is attracted to the developing roll 74, which is a magnet roll, by the magnetic force. The developing device 68 includes a power source 68B, and a developing bias voltage, which is a developing voltage, is supplied from a power source 68B, which is an example of the voltage applying unit 32, to the developing roll 74 facing the outer peripheral surface of the photosensitive drum 62. Applied. The “development bias voltage” here refers to, for example, a DC (direct current) component (development bias potential component) and AC (alternating current) having the same polarity as the outer peripheral surface of the photosensitive drum 62 (in this embodiment, negative polarity). It means a predetermined voltage on which a component is superimposed.

  In this way, the developing bias voltage is applied to the developing roll 74 and the developing roll 74 receives a driving force of a motor (not shown) and rotates in a predetermined direction (the direction indicated by the circular arc in FIG. 4). The toner is transferred to the outer peripheral surface of the photosensitive drum 62. That is, the toner adhering to the outer peripheral surface of the developing roll 74 is transferred from the developing roll 74 to the region irradiated with the light beam on the outer peripheral surface of the photosensitive drum 62, whereby the electrostatic latent image is developed.

  A toner replenishing device 80 is provided above the developer housing 72. The toner replenishing device 80 includes a toner cartridge 80A that contains toner, and a replenishing flow path 80B that communicates the inside of the toner cartridge 80A and the inside of the developer housing 72. Inside the toner cartridge 80A, an auger 82 is provided as a conveying member for conveying toner. The auger 82 rotates upon receiving a driving force of a motor (not shown). Accordingly, the toner accommodated in the toner cartridge 80A is replenished into the developer housing 72 through the replenishment flow path 80B as the auger 82 rotates. In this embodiment, the amount of toner replenished inside the developer housing 72 is adjusted by the rotation time of the auger 82. In the present embodiment, a configuration is adopted in which the carrier is not replenished inside the developer housing 72 and only the toner is replenished.

  On the other hand, in FIG. 3, a transfer roll 84 is provided on the downstream side of the developing device 68 in the rotation direction of the photosensitive drum 62. A power supply (not shown) is connected to the transfer roll 84, and a positive bias voltage is applied to the transfer roll 84. The sheet P is conveyed at a predetermined speed between the outer peripheral surface of the photosensitive drum 62 and the outer peripheral surface of the transfer roll 84. Accordingly, the transfer roll 84 is applied with a positive bias voltage while the paper P is passing between the outer peripheral surface of the photoconductive drum 62 and the outer peripheral surface of the transfer roll 84, so that the photoconductive drum 62 is provided. The toner image formed on the outer peripheral surface is transferred onto the paper P.

  In the conveyance path of the paper P on which the toner image is transferred in this way, a fixing device 86 configured by disposing the pressure roll 86A and the heating roll 86B is provided. The paper P transported to the fixing device 86 is sandwiched and transported between the pressure roll 86A and the heating roll 86B, whereby the toner image on the paper P is melted and pressed against the paper P to be fixed on the paper P. .

  FIG. 5 shows an example of the main configuration of the electrical system of the image forming unit 50. The 1st estimation part 14, the 2nd estimation part 18, the output part 20, the update part 22, and the control part 26 are implement | achieved by the computer 90 shown, for example in FIG. The computer 90 includes a CPU 92, a memory 94, and a nonvolatile storage unit 96, and these are connected to each other via a bus 98.

  The storage unit 96 is realized by, for example, a hard disk device or a flash memory. The storage unit 96 stores a density instruction value 99A. In the present embodiment, as an example of the density instruction value 99A, a control value used in a density control process that is an example of a density adjustment method for controlling the density of an image is employed. In the present embodiment, surface potential control processing is employed as an example of density control processing. The surface potential control process refers to a process of adjusting the image density by controlling the potential applied to the outer peripheral surface of the photosensitive drum 62. In this case, the charge amount of the outer peripheral surface of the photosensitive drum 62, the amount of light beam emitted from the exposure device 66, the magnitude of the voltage applied to the developing roll 74, and the magnitude of the bias voltage applied to the transfer roll 84 A control value for uniformly controlling the thickness corresponds to the density instruction value 99A.

  In addition, the storage unit 96 stores humidity information 99 </ b> B indicating a predetermined humidity as the humidity inside the housing of the current image forming apparatus 10. In the present embodiment, 55% is adopted as an example of the humidity at the time of initial setting of a predetermined humidity, but the present invention is not limited to this.

The storage unit 96 stores a deviation amount table 99C. The deviation amount table 99 </ b> C is a table in which a formation operation amount predetermined as the formation operation amount of the forming unit 24 and a humidity deviation amount predetermined as the humidity deviation amount are associated with each other. That is, the divergence amount table 99C has a predetermined humidity divergence amount that is determined in advance so that the high-humidity-side divergence amount increases at a predetermined rate as the formation operation amount of the forming unit 24 increases. Corresponding to the amount. It should be noted that the amount of humidity deviation corresponding to the forming operation amount may be determined from the results obtained by performing experiments or simulations using an actual machine.

The storage unit 96 stores a density instruction value adjustment table 99D. The density instruction value adjustment table 99D is a table in which a humidity deviation amount predetermined as a humidity deviation amount is associated with an adjustment amount for adjusting the density instruction value 99A. In other words, the concentration instruction value table 99D has a predetermined adjustment amount corresponding to the high-humidity side deviation amount so that the higher the high-humidity side deviation amount, the smaller the concentration instruction value 99A. It is attached. As for the low-humidity-side divergence amount, a predetermined adjustment amount is associated according to the low-humidity-side divergence amount so that the concentration instruction value 99A increases as the low-humidity-side divergence amount increases. Note that the amount of adjustment to be associated with the amount of humidity divergence may be determined from the results obtained through experiments or simulations using actual machines.

  The storage unit 96 stores an image formation processing program 100. The CPU 92 reads the image formation processing program 100 from the storage unit 96 and expands it in the memory 94, and sequentially executes the processes included in the image formation processing program 100. The image forming processing program 100 includes a first estimation process 102, a second estimation process 104, an output process 106, an update process 108, and a control process 110. The CPU 92 operates as the first estimation unit 14 illustrated in FIG. 1 by executing the first estimation process 102. Further, the CPU 92 operates as the second estimation unit 18 illustrated in FIG. 1 by executing the second estimation process 104. Further, the CPU 92 operates as the output unit 20 illustrated in FIG. 1 by executing the output process 106. Further, the CPU 92 operates as the update unit 22 illustrated in FIG. 1 by executing the update process 108. Furthermore, the CPU 92 operates as the control unit 26 illustrated in FIG. 1 by executing the control process 110.

  Although the case where the image forming processing program 100 is read from the storage unit 96 is illustrated here, it is not necessarily stored in the storage unit 96 from the beginning. For example, each program is first stored in an arbitrary “portable physical medium” such as a flexible disk connected to the computer 90, so-called FD, CD-ROM, DVD disk, magneto-optical disk, IC card, and the like. It may be left. Then, the computer 90 may acquire and execute each program from these portable physical media. Alternatively, each program may be stored in another computer or server device connected to the computer 90 via the Internet, a LAN, or the like, and the computer 90 may acquire and execute each program therefrom.

  The image forming unit 50 includes an external I / F (interface) 111. The external I / F 111 electrically connects the I / O 54 and the bus 98, and controls transmission / reception of various information between the image forming unit 50 and the computer 52 shown in FIG.

  The image forming unit 50 includes an I / O 112 that electrically connects the computer 90 and various input / output devices to control transmission / reception of various information between the computer 90 and various input / output devices. In the present embodiment, as an input / output device that is electrically connected to the computer 90 via the bus 98 by being connected to the I / O 112, the charger 64, the exposure device 66, the developing device 68, and the magnetic permeability sensor 73. And a drive source 114. The drive source 114 is configured to include a plurality of motors that generate a rotational drive force for a member that rotates by receiving a rotational drive force among members provided in the image forming unit 50. An example of a motor included in the drive source 114 is a motor that applies a rotational driving force to the transport roll in order to rotate a transport roll (not shown) for transporting the paper P. In addition, a motor that applies a rotational driving force to the photosensitive drum 62, a motor that applies a rotational driving force to the charging roll 64A, a motor that applies a rotational driving force to the stirring paddle 75, and a rotational driving force to the stirring screw 78. The motor which provides is mentioned. Further, a motor that applies a rotational driving force to the developing roll 74, a motor that applies a rotational driving force to the developer transport roll 76, a motor that applies a rotational driving force to the auger 82, and a rotational driving force that is applied to the transfer roll 84. A motor is also mentioned.

  Next, as an operation of the present embodiment, an image forming process performed by the image forming apparatus 10 when the CPU 92 executes the image forming process program 100 will be described with reference to FIG. In the image forming process shown in FIG. 6, first, in step 150, the CPU 92 determines whether image forming request information has been received. In step 150, if the image formation request information is not received by the CPU 92, the determination is denied and step 100 is repeated. If the image forming request information is received by the forming unit 24 in step 150, the determination is affirmed and the process proceeds to step 152.

  In step 152, the image information included in the image formation request information received in step 150 is acquired by the forming unit 24. In the next step 154, the first estimation unit 14 estimates the toner consumption amount A consumed when the developing unit 12 develops the electrostatic latent image based on the image information acquired in step 152. In the next step 156, the density instruction value 99 </ b> A is acquired from the storage unit 96 by the forming unit 24.

  In the next step 158, the image is formed by the forming unit 24 forming the image indicated by the image information acquired in step 152 on the paper P according to the density instruction value 99A acquired in step 156. In the next step 160, the forming unit 24 overwrites and saves the operation amount (formation operation amount) of the forming unit 24 after the image formation is started in step 158 in the predetermined storage area α of the storage unit 96. The forming operation amount stored in the storage area α is updated. In the present embodiment, as an example of the forming operation amount stored in the predetermined storage area α, from the start of image formation in step 158 to the end of image formation indicated by the image information acquired in step 152. The accumulated time is adopted. However, the present invention is not limited to this. For example, the rotation amount of the photosensitive drum 62, the rotation amount of the developing roller 74, the rotation amount of the charging roller 64A, or the rotation amount of the transfer roller 84 may be adopted. Further, the calculation amount of the CPU 92 from the start of image formation in step 158 to the end of image formation indicated by the image information acquired in step 152 may be employed.

  In the next step 162, the forming unit 24 determines whether or not the formation of the image indicated by the image information acquired in step 152 on the paper P has been completed. If it is determined in step 162 that the image indicated by the image information acquired in step 152 has not been formed on the paper P, the determination is negative and the process returns to step 160. In step 162, when the formation of the image indicated by the image information acquired in step 152 on the paper P is completed, the determination is affirmed and the process proceeds to step 164.

  In the next step 164, density instruction value update processing is performed by the measurement unit 16, the second estimation unit 18, the output unit 20, the update unit 22, and the control unit 26.

  Next, the density instruction value update processing will be described with reference to FIG. In the density instruction value update process shown in FIG. 7, first, in step 200, the permeability is measured by the measurement unit 16 using the two-component developer stored in the developer housing 72 as a measurement target. In the present embodiment, a process of correcting the reading value of the magnetic permeability sensor 73 is executed prior to the process of step 200 described above. This is because an increase in the number of rotations of the stirring screw 78 means that the amount of stirring of the two-component developer is large, and the degree of deterioration (damage) of the two-component developer also increases. In the present embodiment, for example, a configuration is adopted in which the correction amount for correcting the read value of the magnetic permeability sensor 73 is increased in accordance with an increase in the cumulative amount of rotation of the stirring screw 78 from the time when the toner cartridge 80A is attached to the present time. Yes. However, the disclosed technique is not limited to this. For example, the correction amount of the magnetic permeability sensor 73 is increased in accordance with the increase in the accumulated rotation amount of the developing roll 74, the stirring paddle 75, or the developer transport roll 76. Also good. Further, if at least one of the developing roller 74, the stirring paddle 75, the developer conveying roller 76, and the stirring screw 78 rotates following the rotation of the photosensitive drum 62, the rotational accumulation amount of the photosensitive drum 62 increases. Accordingly, the correction amount of the reading value of the magnetic permeability sensor 73 may be increased. Note that examples of the accumulated rotation amount include an accumulated value of the rotation speed and an accumulated value of the rotation time.

  In the next step 202, the second estimation unit 18 estimates the consumption amount B of toner consumed in association with the development of the electrostatic latent image by the development unit 12 based on the magnetic permeability measured in step 200. In step 204, the output unit 20 determines whether or not the consumption amount A estimated in step 154 is smaller than the consumption amount B estimated in step 202. In step 204, when the consumption amount A estimated in step 154 is smaller than the consumption amount B estimated in step 202, the determination is affirmed and the process proceeds to step 206. In step 204, if the consumption A estimated in step 154 is not less than the consumption B estimated in step 202, the determination is negative and the routine proceeds to step 208.

  In step 208, the output unit 20 determines whether or not the consumption amount A estimated in step 154 is greater than the consumption amount B estimated in step 202. In step 208, when the consumption A estimated in step 154 is larger than the consumption B estimated in step 202, the determination is affirmed and the routine proceeds to step 210. In step 208, if the consumption A estimated in step 154 is not greater than the consumption B estimated in step 202, the determination is negative and the concentration instruction value update process ends. Note that the comparison between the consumption A and the consumption B in steps 204 and 208 is performed with a predetermined error taken into account, and this error is a value obtained in advance by performing experiments or simulations with an actual machine. Should be adopted.

  In step 206, the output unit 20 outputs high humidity information indicating that the humidity is higher than a predetermined humidity, and then the process proceeds to step 212. In step 210, high humidity information indicating that the humidity is higher than the predetermined humidity is output by the output unit 20, and then the process proceeds to step 212. In step 212, the forming operation amount stored in the predetermined storage area α is acquired by the update unit 22. In the next step 214, the update unit 22 acquires the humidity divergence amount corresponding to the forming operation amount acquired in step 212 from the divergence amount table 99C. That is, when the high humidity information is output in step 206, the high humidity side divergence amount previously associated with the formation operation amount acquired in step 212 is acquired from the divergence amount table 99C. When the low humidity information is output in step 210, the low humidity side deviation amount associated in advance with the formation operation amount obtained in step 212 is obtained from the deviation amount table 99C. In the present embodiment, the humidity divergence amount is derived from the divergence amount table 99C. However, the present invention is not limited to this, and the humidity divergence amount is calculated using an arithmetic expression that substitutes the forming operation amount and outputs the humidity divergence amount as a solution. It may be calculated.

  In the next step 216, the updating unit 22 changes the humidity information 99 </ b> B based on the humidity deviation amount acquired in step 214 with respect to the predetermined humidity indicated by the humidity information 99 </ b> B stored in the storage unit 96. Updated. That is, when the high-humidity-side divergence amount is acquired in step 214, the humidity information 99B is updated by adding the high-humidity-side divergence amount acquired in step 214 to the predetermined humidity. When the low-humidity-side divergence amount is acquired in step 214, the humidity information 99B is updated by subtracting the low-humidity-side divergence amount acquired in step 214 from the predetermined humidity.

  In the next step 218, the control unit 26 updates the concentration instruction value 99A stored in the storage unit 96 based on the humidity deviation amount acquired in step 214. That is, the control unit 26 acquires an adjustment amount that is associated in advance with the humidity deviation amount acquired in step 214 from the concentration instruction value adjustment table 99D, and adjusts the concentration instruction value 99A according to the acquired adjustment amount. It is updated by this. In the present embodiment, the concentration instruction value 99A is adjusted according to the adjustment amount included in the concentration instruction value adjustment table 99D. However, the present invention is not limited to this, and the calculation that outputs the adjustment amount as a solution by substituting the humidity deviation amount. The concentration instruction value 99A may be adjusted after calculating the adjustment amount using an equation. Alternatively, the concentration instruction value 99A may be calculated using an arithmetic expression that substitutes the humidity divergence amount and outputs the concentration instruction value 99A as a solution.

  By performing the image forming process shown in FIG. 6 as described above, the actual humidity transition is shown by TC (toner concentration) and humidity information 99B based on the ATC measurement result as shown in FIG. 8 as an example. The predetermined humidity and developability change. Here, “ATC” refers to the magnetic permeability measured by the magnetic permeability sensor 73. Further, TC is a physical quantity represented by a relational expression of “(amount of toner stored in developer housing 72) / (amount of two-component developer stored in developer housing 72)”. Therefore, if the magnetic permeability measured by the magnetic permeability sensor 73 is higher than a predetermined magnetic permeability (the magnetic permeability at the time of initial setting), the TC is lowered. On the contrary, if the magnetic permeability measured by the magnetic permeability sensor 73 is lower than the magnetic permeability at the time of initial setting, the TC increases. The “developability” here is a concept representing the degree to which the toner image is transferred to the paper P, and the actual consumption of toner is larger than the assumed consumption (image formed on the paper P). The density of the toner is higher than the expected density) is called “high developability”. Conversely, the fact that the actual toner consumption is less than the assumed consumption (the density of the image formed on the paper P is lower than the assumed density) is called “low developability”.

  As shown in FIG. 8, when the actual humidity is higher than the predetermined humidity at the time of initial setting, the amount of toner consumed becomes larger than the amount of toner replenished, so that the TC decreases. In this case, the high humidity side deviation amount is added to the predetermined humidity, and the humidity information 99B is thereby updated (step 216). Further, in this case, since it is determined that the developability is high at the present time, the density instruction value 99A is also set so as to lower the image density by the high-humidity-side deviation amount added to the predetermined humidity. It is updated (step 218). On the other hand, when the actual humidity is lower than the predetermined humidity at the time of initial setting, the toner replenishment amount becomes larger than the toner consumption amount, so that TC increases. In this case, the low-humidity side deviation amount is subtracted from the predetermined humidity, whereby the humidity information 99B is updated (step 216). Further, in this case, since it is determined that the developability at the present time is low, the density instruction value 99A is also updated so that the density of the image is increased by the low humidity side deviation amount subtracted from the predetermined humidity. (Step 218). While the above operation is repeated, the high humidity environment and the low humidity environment exhibit opposite behaviors, but in any case, the toner consumption and the toner replenishment amount gradually balance (estimated). Humidity approaches actual humidity). Eventually, when the amount of toner consumed and the amount of toner replenished are balanced, the predetermined humidity and density instruction value 99A will be maintained.

  As described above, the concentration instruction value 99A varies depending on the humidity. This means that the control value applied in the surface potential control process in the image formation performed in step 158 changes. When the control value applied in the surface potential control process changes, the potential at which the outer peripheral surface of the photosensitive drum 62 is charged (charging potential) and the bias potential for development (development) used when the developing device 68 performs development. The ratio between the absolute value of the difference between the bias potential and the absolute value of the difference between the developing bias potential and the potential of the region irradiated with the light beam by the exposure device 66 (exposure potential) is maintained before and after the change of the control value. I am trying to change within the range. For example, as shown in FIG. 9, when a single image A and a single image A ′ having a single image A having a high density are continuously formed on a sheet P, the charging potential and the developing bias potential are The control value is changed within a range in which the ratio between the absolute value of the difference between the two and the absolute value of the difference between the developing bias potential and the exposure potential is maintained at 1: 3. That is, after forming a single image A, when forming a single image A ′, the development bias potential remains fixed, the absolute value of the difference between the charging potential and the development bias potential, the development bias potential, The control value is changed after widening the difference between the charging potential and the exposure potential so that the ratio of the difference between the exposure potential and the absolute value is maintained at 1: 3. Conversely, when forming a single image A ′ after forming a single image A ′, the absolute value of the difference between the charging potential and the developing bias potential and the absolute value of the difference between the developing bias potential and the exposure potential The ratio to the value may be maintained when the single image A ′ is formed and when the single image A is formed. This means that the image is output while maintaining the tone density characteristics. In other words, the overall density is changed without destroying the visual impression received from the image output before and after the density adjustment. It is. As described above, the reason why the ratio between the absolute value of the difference between the charging potential and the developing bias potential and the absolute value of the difference between the developing bias potential and the exposure potential is kept constant is the level of the image formed on the paper P. This is to maintain the tone adjustment characteristic (tone characteristic curve).

  FIG. 10 shows the ratio between the absolute value of the difference between the charging potential and the developing bias potential and the absolute value of the difference between the developing bias potential and the exposure potential when changed before and after the density adjustment. An example of the transition of the image area ratio is shown. In the example shown in FIG. 10, when Cin (image area ratio) is increased by 0.1 (from 1.4 to 1.5), the ratio is maintained at 1: 3 and the ratio is decreased to 1: 2. In the case where the ratio is maintained at 1: 3, the density difference of the intermediate density is smaller when the ratio is maintained at 1: 2 than when the ratio is decreased to 1: 2. Therefore, the change in the visual impression received from the output image before and after the density change is smaller when the ratio is maintained at 1: 3 than when the ratio is reduced to 1: 2. Note that “the change in visual impression is small” here means that, for example, if the output image includes an image showing hair and an image showing blue sky, the image showing hair is crushed, And an image showing a blue sky is prevented from being completely white.

  As described above, in the image forming apparatus 10 according to the present embodiment, the toner consumption estimated by the first estimation unit 14 by the output unit 20 is greater than the toner consumption estimated by the second estimation unit 18. If it is less, high humidity information is output. Further, when the toner consumption estimated by the first estimation unit 14 is larger than the toner consumption estimated by the second estimation unit 18, low humidity information is output. Therefore, a change in humidity is estimated with higher accuracy than in the case without this configuration. As described above, since the change in humidity is estimated with high accuracy, the image forming apparatus 10 is controlled with high accuracy as compared with the case where the present configuration is not provided.

  In addition, when high humidity information is output, the predetermined humidity is updated by adding the high humidity side deviation amount to the predetermined humidity, and when low humidity information is output, the predetermined humidity The predetermined humidity is updated by subtracting the low-humidity-side deviation amount from. Therefore, the current humidity can be grasped with high accuracy compared to the case without this configuration. As described above, the image forming apparatus 10 is controlled with high accuracy by comparing the humidity with the degree of composition as compared with the case where the present structure is not provided.

  In the image forming apparatus 10 according to the present embodiment, the control unit 26 controls the density of the toner image to be lower by the high-humidity side deviation amount added to the predetermined humidity when the humidity is predetermined. The Further, the control unit 26 performs control so that the density of the toner image is increased by a low-humidity-side deviation amount subtracted from the predetermined humidity at the predetermined humidity. Therefore, an image in which a deviation from the density assumed in advance is suppressed as compared with the case where the present configuration is not provided. However, the disclosed technique is not limited to this. For example, when high humidity information is output by the control unit 26, the concentration is lower than the concentration indicated by the concentration indication value 99A set at the present time. The concentration instruction value 99A may be controlled so as to instruct. Further, when the low humidity information is output by the control unit 26, the concentration instruction value 99A may be controlled so as to indicate a concentration higher than the concentration specified by the concentration instruction value 99A set at the present time.

  In the above embodiment, the predetermined humidity indicated by the humidity information 99B is a relative humidity, but the absolute humidity is calculated from the temperature measured by the temperature sensor and the predetermined humidity indicated by the humidity information 99B. Then, the calculated absolute humidity may be used for the control of the image forming apparatus 10.

  Moreover, although the aspect in the case of implement | achieving the measurement part 16 with the magnetic permeability sensor 73 was shown in the said embodiment, the technique of an indication is not limited to this. For example, the image forming unit 50 forms a reference patch image on the outer peripheral surface of the photosensitive drum 62 or the paper P, and the density of the formed reference patch image is measured by a density sensor, whereby toner stored in the developer housing 72 is stored. It may be measured as a physical quantity that is used to estimate the amount of. An example of the density sensor is an optical sensor. Then, the ratio (toner occupancy) of the toner per unit area is calculated by the second estimation unit 18 from the density of the reference patch image measured in this way, and the toner consumption is calculated from the calculated toner occupancy. The amount may be estimated.

  In the above embodiment, the mode in which the information output from the output unit 20 (information indicating the estimated change in humidity) is used for image density adjustment is illustrated, but the disclosed technology is not limited thereto. Absent. For example, based on the information output by the output unit 20, if the humidity is deviated to the high humidity side, that fact is displayed on the display unit 58, and if the humidity is deviated to the low humidity side, A message may be displayed on the display unit 58. Further, it may be transmitted to an external device via the communication unit 60. Further, the fact that the humidity has changed may be formed on the paper P and discharged, or the fact that the humidity has changed may be output by voice using an audio reproduction device (not shown). Further, it may be stored in the secondary storage unit 52D or the storage unit 96.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Development part 14 1st estimation part 16 Measurement part 18 2nd estimation part 20 Output part 22 Update part 24 Formation part 26 Control part 28 Charging part 30 Latent image formation part 32 Voltage application part 34 Supply part

Claims (7)

By supplying colored particles contained in the two-component developer to the electrostatic latent image formed in the formation area based on image information indicating an image, from the storage portion in which the two-component developer is stored Developing means for developing the electrostatic latent image;
First estimating means for estimating a consumption amount of the colored particles consumed in association with the development of the electrostatic latent image by the developing means based on the image information;
Measuring means for measuring a physical quantity that is used to estimate the amount of the colored particles contained in the reservoir, with the two-component developer contained in the reservoir as a measurement target;
Second estimating means for estimating a consumption amount of the colored particles consumed by developing the electrostatic latent image by the developing means based on a physical quantity measured by the measuring means;
When the consumption estimated by the first estimation means is smaller than the consumption estimated by the second estimation means, high humidity information indicating that the humidity is higher than a predetermined humidity is output. When the consumption estimated by the first estimation means is larger than the consumption estimated by the second estimation means, an output for outputting low humidity information indicating that the humidity is lower than the predetermined humidity Means,
When the high-humidity information is output from the output means, the high-humidity-side divergence amount assuming the divergence amount from the predetermined humidity to the high-humidity side is added to the predetermined humidity. When the predetermined humidity is updated and the low-humidity information is output from the output means, the low-humidity-side deviation amount assuming the deviation amount from the predetermined humidity to the low-humidity side is subtracted from the predetermined humidity. Updating means for updating the predetermined humidity by:
An image forming apparatus including: The image forming apparatus further includes a forming unit that develops the electrostatic latent image by the developing unit to form an image indicated by the image information in the forming region.
Each of the high-humidity-side divergence amount and the low-humidity-side divergence amount is increased according to an increase in the forming operation amount when the image indicated by the image information is formed in the formation region by the forming unit. The image forming apparatus according to claim 1, which is predetermined. The forming unit forms the image in the formation region according to a density instruction value indicating a density of a developed image obtained by developing the electrostatic latent image by the developing unit;
When the high humidity information is output from the output means, the concentration instruction value is controlled so as to indicate a concentration that is lower than the concentration indicated by the current concentration instruction value by the high humidity side deviation amount, When the low humidity information is output from the output unit, the control unit further includes a control unit that controls the concentration instruction value so as to instruct a concentration that is higher by the low humidity side deviation amount than the concentration instructed by the current concentration instruction value. The image forming apparatus according to claim 2 . The forming means includes a charging means for charging the formation area to form the electrostatic latent image, and a latent image for forming the electrostatic latent image by exposing the formation area charged by the charging means. An image forming unit; and a voltage applying unit that applies a developing voltage to the developing unit.
The control means controls the density instruction value to thereby control at least one of the charge amount of the formation area, the exposure amount to the formation area, and the magnitude of the developing voltage applied to the development means. The image forming apparatus according to claim 3 , wherein one of the two is controlled. The image forming apparatus according to claim 4 , wherein the forming unit further includes a replenishing unit that replenishes the storage portion with the colored particles with a replenishment amount corresponding to the consumption amount estimated by the first estimating unit. Forming means for forming the image in the formation area in accordance with a density instruction value indicating the density of a developed image obtained by developing the electrostatic latent image by the developing means;
When the high humidity information is output by the output means, the concentration instruction value is controlled to indicate a concentration lower than the concentration indicated by the current concentration instruction value, and the low humidity information is output by the output means. The image forming apparatus according to claim 1, further comprising a control unit that controls the density instruction value so as to instruct a density higher than the density instructed by the current density instruction value when output. By supplying colored particles contained in the two-component developer to the electrostatic latent image formed in the formation area based on image information indicating an image, from the storage portion in which the two-component developer is stored Measurement that measures a physical quantity that is used to estimate the amount of the colored particles contained in the storage unit, with a developing unit that develops the electrostatic latent image and the two-component developer contained in the storage unit as a measurement target And a computer for controlling the image forming apparatus,
First estimating means for estimating a consumption amount of the colored particles consumed in association with the development of the electrostatic latent image by the developing means based on the image information;
A second estimation unit configured to estimate a consumption amount of the colored particles consumed with the development of the electrostatic latent image by the development unit based on a physical quantity measured by the measurement unit;
When the consumption estimated by the first estimation means is smaller than the consumption estimated by the second estimation means, high humidity information indicating that the humidity is higher than a predetermined humidity is output. When the consumption estimated by the first estimation means is larger than the consumption estimated by the second estimation means, an output for outputting low humidity information indicating that the humidity is lower than the predetermined humidity Means ,
And when the high-humidity information is output from the output means, by adding a high-humidity side deviation amount assuming a deviation amount from the predetermined humidity to the high-humidity side to the predetermined humidity When the predetermined humidity is updated and the low humidity information is output from the output means, the low humidity side deviation amount assuming the deviation amount from the predetermined humidity to the low humidity side is set to the predetermined humidity. program for operating as a updating means for updating the humidity defined the advance by subtracting from.