JP6537023B2 - Image forming apparatus, image forming method, and image forming program - Google Patents

Description

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

  In the electrophotographic image forming apparatus, the amount of consumption of toner in each printing is generally calculated based on image data. The toner consumption can be calculated based on the correlation between the toner consumption and the number of dots in the toner image. The calculation result of the toner consumption amount is used, for example, to control toner replenishment to the developing device. Regarding the toner consumption calculation method, even if it is data of the same number of dots, the toner consumption is different due to the influence of the edge electric field etc. Therefore, attributes of image data (photograph data, vector data, character data, line data), edge Techniques have also been proposed to improve accuracy by determining whether or not a pixel is present (Patent Documents 1 and 2). On the other hand, Patent Document 3 proposes a technology for printing a solid image while suppressing end accumulation when developing with an amorphous silicon photosensitive member having a high relative dielectric constant.

JP, 2009-198917, A JP, 2013-20076, A JP, 2015-161704, A

  However, sufficient consideration has not been made on the estimation of toner consumption in electrophotography in which development is performed with a photosensitive member having a high relative dielectric constant while suppressing end accumulation.

  The present invention has been made in view of such circumstances, and provides a technology for improving the estimation accuracy of toner consumption in electrophotography in which development is performed with a photosensitive member having a high relative dielectric constant while suppressing end accumulation. The purpose is

  The image forming apparatus according to the present invention includes a photosensitive body, an exposure unit that exposes the photosensitive body to form an electrostatic latent image, and a developing unit that causes toner to adhere to the photosensitive body based on the electrostatic latent image. And a calibration unit that performs calibration using at least one of a developing bias potential and a dot area ratio of the developing unit, and consumption of a developer used to form an image based on image data A consumption amount prediction unit for predicting an amount, wherein the consumption amount prediction unit performs the calibration by adjusting the dot area ratio in a state where the development bias potential is set to a limit value. Predict the consumption using the adjusted dot area ratio.

  According to the image forming method of the present invention, a photosensitive body, an exposing portion that exposes the photosensitive body to form an electrostatic latent image, and a developing portion that causes toner to adhere to the photosensitive body based on the electrostatic latent image Used for forming an image based on an image forming process of forming an image using, a calibration process of performing calibration using at least one of a developing bias potential and a dot area ratio of the developing unit, and And a consumption amount prediction step of predicting the consumption amount of the developer to be performed, wherein the consumption amount prediction step adjusts the dot area ratio in a state where the development bias potential is set to the limit value. And if the adjusted dot area ratio is used to predict the consumption.

  The present invention is an image forming unit including a photosensitive member, an exposing unit that exposes the photosensitive member to form an electrostatic latent image, and a developing unit that causes toner to adhere to the photosensitive member based on the electrostatic latent image. An image forming program for controlling an image forming apparatus having the The image forming program is configured to perform calibration using at least one of a developing bias potential and a dot area ratio of the developing unit, and consumption of a developer used to form an image based on image data. The image forming apparatus functions as a consumption prediction unit for predicting an amount, and the consumption prediction unit adjusts the dot area ratio in a state where the development bias potential is set to a limit value, and the calibration is performed. If done, the adjusted dot area rate is used to predict the consumption.

  According to the present invention, it is possible to provide a technique for improving the estimation accuracy of the toner consumption amount in electrophotography in which development is performed with a photosensitive member having a high relative dielectric constant while suppressing end accumulation.

1 is a block diagram showing a functional configuration of an image forming apparatus 1 according to an embodiment of the present invention. FIG. 1 is a cross-sectional view showing an entire configuration of an image forming apparatus 1 according to an embodiment. FIG. 7 is a side cross-sectional view showing the structure of the developing unit 100k according to an embodiment. 5 is a flowchart showing the contents of a half patch calibration procedure of the image forming apparatus 1 according to an embodiment. It is a graph explaining the contents of toner amount table TD concerning one embodiment. It is a graph explaining the contents of amendment in toner amount table TD concerning one embodiment. It is a graph explaining the contents of toner amount table TD concerning a modification.

  Hereinafter, modes for carrying out the present invention (hereinafter, referred to as “embodiments”) will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a functional configuration of an image forming apparatus 1 according to an embodiment of the present invention. The image forming apparatus 1 includes a control unit 10, an image forming unit 20, a storage unit 40, an image reading unit 50, and a fixing unit 80. The image reading unit 50 reads an image from a document and generates an image data ID which is digital data.

  The image forming unit 20 includes a color conversion processing unit 21, a halftone processing unit 22, a density sensor 28 for calibration, an exposure unit 29, and photosensitive drums (image carriers) 30c to 30k, which are amorphous silicon photosensitive members. , And developing units 100c to 100k and charging units 25c to 25k. The color conversion processing unit 21 performs color conversion of image data ID, which is RGB data, into CMYK data. The halftone processing unit 22 performs halftone processing on the CMYK data to generate CMYK halftone data.

  The control unit 10 includes a main storage unit such as a RAM and a ROM, and a control unit such as an MPU (Micro Processing Unit) and a CPU (Central Processing Unit). The control unit 10 also has a controller function related to interfaces such as various I / O, USB (Universal Serial Bus), bus, and other hardware, and controls the entire image forming apparatus 1.

  The storage unit 40 is a storage device including a hard disk drive or a flash memory, which is a non-temporary recording medium, and stores control programs and data of processing executed by the control unit 10. In the present embodiment, the storage unit 40 further stores the calibration image data CD and the toner amount table TD.

  The calibration image data CD stores calibration image data CD for forming CMYK gradation calibration adjustment patches and CMYK half patches. A half patch is a patch that has a dot area ratio of less than 100% and represents a solid image. The solid image is expressed by the half patch, which will be described later in detail, because an amorphous silicon photosensitive member is adopted for the photosensitive drums 30c to 30k.

  The toner amount table TD is also referred to as a toner consumption amount table, and includes a table representing the relationship between the image data value and the toner consumption amount, and a correction coefficient. The toner amount table TD is used to calculate the consumed amount of toner. The toner amount table TD includes a first toner amount table used when the dot area of a half patch representing a solid image is an initial value (70%), and the dot area of a half patch representing a solid image is 70% And a correction table. The half patch is formed by forming a half latent image on the photosensitive drums 30c to 30k at the exposure unit 29.

  The dot area ratio means the area ratio occupied by dots when it is assumed that each dot has a preset area, and corresponds to the area ratio of the latent image in the half latent image. In practice, the dot size fluctuates according to, for example, the toner layer forming potential difference ΔV (described later) between the developing bias potential Vslv and the magnetic roller potential Vmag, and this corresponds to the area ratio of optical viewpoint (density. It is different from). On the other hand, the solid density means a density that makes it appear that the printing medium is covered without gaps by dots from an optical point of view.

  FIG. 2 is a cross-sectional view showing the overall configuration of the image forming apparatus 1 according to an embodiment. The image forming apparatus 1 of the present embodiment is a tandem type color printer. In the image forming apparatus 1, photosensitive drums (image carriers) 30 m, 30 c, 30 y and 30 k are arranged in a line in a casing 70 corresponding to each color of magenta, cyan, yellow and black. Developing units 100m, 100c, 100y and 100k are disposed adjacent to the photosensitive drums 30m, 30c, 30y and 30k, respectively.

  The laser beams Lm, Lc, Ly and Lk for the respective colors are irradiated from the exposure unit 29 to the photosensitive drums 30m, 30c, 30y and 30k. By this irradiation, electrostatic latent images are formed on the photosensitive drums 30m, 30c, 30y and 30k. The developing units 100m, 100c, 100y and 100k cause the toner to adhere to the electrostatic latent images formed on the surfaces of the photosensitive drums 30m, 30c, 30y and 30k while stirring the toner. Thus, the developing process is completed, and toner images of respective colors are formed on the surfaces of the photosensitive drums 30c to 30k.

  The image forming apparatus 1 has an endless intermediate transfer belt 27. The intermediate transfer belt 27 is stretched around a tension roller 24, a drive roller 26a and a driven roller 26b. The intermediate transfer belt 27 is driven to circulate by the rotation of the drive roller 26 a.

  For example, the black toner image on the photosensitive drum 30k is primarily transferred to the intermediate transfer belt 27 by the intermediate transfer belt 27 being driven to circulate by nipping the intermediate transfer belt 27 between the photosensitive drum 30k and the primary transfer roller 23k. Ru. The same applies to the three colors of cyan, yellow and magenta. A full-color toner image is formed on the surface of the intermediate transfer belt 27 by performing primary transfer so as to be superimposed on each other at a predetermined timing. Thereafter, the full-color toner image is secondarily transferred to the printing paper P supplied from the paper feed cassette 60 and fixed on the printing paper P by the fixing roller pair 81 of the fixing unit 80.

  FIG. 3 is a side sectional view showing the structure of the developing unit 100k according to an embodiment of the present invention. The developing units 100m, 100c, and 100y have the same configuration as the developing unit 100k, and are also simply referred to as the developing unit 100. The developing unit 100 includes two stirring and conveying members 141 and 142, a magnetic roller 143, a developing roller (developer carrier) 144, a developing container 145, and a regulating blade 146.

  The developing container 145 constitutes the outer shell of the developing unit 100. At the lower part of the developing container 145, a partition part 145b is provided. The partitioning portion 145 b partitions the inside of the developing container 145 into a first transfer chamber 145 a and a second transfer chamber 145 c. The first transfer chamber 145a and the second transfer chamber 145c extend in a columnar shape in the direction perpendicular to FIG. 3, and accommodate a two-component developer (also referred to simply as a developer) composed of a magnetic carrier and a black toner.

  The developing container 145 further rotatably holds the magnetic roller 143 and the developing roller 144. The developing container 145 is formed with an opening 147 for exposing the developing roller 144 toward the photosensitive drum 30 (30 k).

  The two stirring and conveying members 141 and 142 move the developer cyclically while stirring the developer in the first conveyance chamber 145a and the second conveyance chamber 145c, respectively. The stirring and conveying member 142 supplies the charged developer to the magnetic roller 143 as a magnetic brush. The magnetic roller 143 has a nonmagnetic rotation sleeve 143a and a fixed magnet body 143b fixed inside the rotation sleeve 143a. The magnetic roller 143 and the developing roller 144 face each other with a predetermined clearance. The regulation blade 146 adjusts the magnetic brush to a predetermined height.

  The developing roller 144 has a nonmagnetic developing sleeve 144 a and a developing roller side magnetic pole 144 b fixed inside the developing sleeve 144 a. The magnetic roller potential Vmag is applied to the magnetic roller 143. The developing bias potential Vslv is applied to the developing roller 144. On the developing roller 144, a toner thin layer having a thickness corresponding to the toner layer forming potential difference ΔV between the developing bias potential Vslv and the magnetic roller potential Vmag is formed. As described above, since the thickness of the toner thin layer on the developing roller 144 fluctuates according to the toner layer forming potential difference ΔV, the adjustment of the toner layer forming potential difference ΔV is used in the developing bias calibration process (described later).

  The developing roller 144 forms a toner image on the surface of the photosensitive drum 30 via an opposing portion (developing nip) having a predetermined clearance with the photosensitive drum 30. The toner image is formed based on the potential difference between the electrostatic latent image on the surface of the photosensitive drum 30 and the developing bias potential Vslv applied to the developing roller 144.

  FIG. 4 is a flowchart showing the contents of the half patch calibration process procedure of the image forming apparatus 1 according to an embodiment. In the present embodiment, since the amorphous silicon photosensitive members are adopted for the photosensitive drums 30c to 30k, the image forming apparatus 1 is configured to express a solid by a half patch in order to suppress the problem of the rear end accumulation. There is.

  The amorphous silicon photosensitive member is characterized in that the relative dielectric constant is about 3 times as high as that of the organic photosensitive member (OPC), and the amount of toner which can be held by the photosensitive member is large with respect to the development contrast voltage. For this reason, the amorphous silicon photosensitive member can hold more toner than the solid density which is usually used. Therefore, when used in a saturated state, the amorphous silicon photosensitive member is held in excess of the amount required for the solid density. Therefore, the amorphous silicon photosensitive member is used in the non-saturated state even in the solid density, and the toner formed on the developing roller 144 is almost entirely developed on the photosensitive member and the solid density is determined by the completion of the development. May be used for

  However, at the time of solid development, the surface of the developing roller 144 in which the toner is not consumed exists near the rear end portion of the solid. When the developing roller 144 rotates faster than the photosensitive drums 30c to 30k, the surface on which the toner is not consumed passes the trailing end of the solid latent image on the amorphous silicon photosensitive member 30 at a nip (not shown). It will be. At this time, since the amorphous silicon photosensitive member 30 is in a non-saturated state, the toner is further developed from the surface of the developing roller 144 where the toner is not consumed. By this development, the trailing edge stagnation as a solid density higher than the density assumed in advance becomes apparent.

  Furthermore, even in the reproduction of images such as characters and thin lines, the surface of the developing roller 144 where the toner has not been consumed exists in the vicinity, so a phenomenon occurs in which the density becomes higher than the density assumed in advance.

  Such a problem of the rear end accumulation can be suppressed by expressing a solid with a half patch as disclosed in Patent Document 3 as well. According to the half patch, for example, an electric field can be formed with a halftone dot latent image (half latent image). As a result, an amorphous silicon photosensitive member can be used to form an electric field (development contrast voltage) strong enough for development, and the toner can be saturated by adhesion of an appropriate amount of toner to the amorphous silicon photosensitive member. Can.

  The dot area ratio in the halftone dot-like latent image for realizing such a state is previously set from the above viewpoint, and is 70% in this example. However, there are cases where sufficient density can not be realized with the dot area ratio of 70% only by adjusting the development contrast voltage. In such a case, the dot area rate is increased from 70% to realize a solid density, but according to the inventor's knowledge, the above-mentioned problems such as the rear end accumulation etc. become apparent again. Become.

  In step S10, the control unit 10 executes development bias calibration processing. In the developing bias calibration process, the control unit 10 controls the image forming unit 20 to form on the intermediate transfer belt 27 a chart having a plurality of half patches in which the toner layer formation potential difference ΔV is changed stepwise. In the present embodiment, the change of the toner layer formation potential difference ΔV is realized by fixing the developing bias potential Vslv and adjusting the magnetic roller potential Vmag.

  Specifically, the control unit 10 sets the intermediate transfer belt to a chart having a plurality of half patches in which the toner layer formation potential difference ΔV differs stepwise in the dot area ratio (70% in this example) as an initial value before calibration. Form 27. The plurality of half patches include those in which the toner layer formation potential difference ΔV is the maximum value (limit value).

  The use of a plurality of half patches in which the toner layer formation potential difference ΔV is stepwise changed identifies the toner layer formation potential difference ΔV capable of forming a thin toner layer having a sufficient thickness to form a solid toner image. It is for. A plurality of half patches are formed for each of CMYK. Hereinafter, the cyan (C) half patch will be described as an example.

  The control unit 10 measures the density of the cyan (C) patch using the calibration density sensor 28. In the present embodiment, the calibration concentration sensor 28 emits infrared light from, for example, an LED (not shown), transmits the polarization filter that transmits only the P wave, and irradiates the P wave of the infrared light to the patch The density is detected based on the ratio of P wave and S wave of the reflected light detected by the light receiving element. The calibration density sensor 28 also has a regular reflection method for detecting regular reflection light from a patch and a diffuse reflection method for detecting diffuse reflection light from a patch. Further, the calibration density sensor 28 may measure the amount of red reflected light which is in a complementary color relationship of cyan (C).

  The control unit 10 executes calibration of the toner layer formation potential difference ΔV. For calibration of the toner layer formation potential difference ΔV, for example, among the plurality of cyan (C) half patches in which the toner layer formation potential difference ΔV is stepwise changed, patches having reached a solid image target density set in advance are selected. If present, it is executed by selecting the patch. Specifically, when there is a half patch whose patch density is equal to or greater than a preset threshold, the control unit 10 corrects the toner layer formation potential difference ΔV, which is the lowest among the half patches, after the toner layer is calibrated. The formation potential difference ΔV is set.

  In step S20, if calibration is possible within the adjustment range of development bias (bias controllable state), control unit 10 proceeds to step S30 and calibration is not possible within the adjustment range of toner layer formation potential difference ΔV. If it is (bias control impossible state), the process proceeds to step S30a. The case where half patch calibration is not possible within the adjustment range of development bias means that there is no patch which has reached a preset solid image target density among a plurality of cyan (C) patches. ing.

  Generally, the inventors of the present invention have confirmed that although one of the plurality of half patches reaches the solid image target density, the solid image target density is not reached in a state where the toner charge amount is increased due to, for example, environmental fluctuations. .

  In step S30, the control unit 10 executes gamma correction calibration processing. In the gamma correction calibration process, an input / output characteristic is obtained such that the image density becomes a target value of the image forming apparatus 1 with respect to the input image data value of CMYK (the data value of cyan in the above example). This is a calibration process for creating a table of output image data values (image density) with respect to input image data values.

  In step S40, the control unit 10 sets a dot area ratio. Since calibration is possible within the adjustment range of development bias, the dot area ratio is set to 70% of the initial value.

  In step S50, the control unit 10 selects a first toner amount table. The first toner amount table is used to calculate the consumed amount of toner at the time of printing in the bias controllable state. The first toner amount table is a table used when the dot area of a half patch expressing a solid image is 70% of the initial value in the bias controllable state. The first toner amount table is used to calculate a consumption amount of toner consumed for printing characters and thin lines, and a photographic table used for calculation of consumption amount of toner consumed for printing photographs and patches. And a text reference table.

  FIG. 5 is a graph for explaining the contents of the toner amount table TD according to one embodiment. FIG. 5 shows a photographic curve C1 showing the characteristics of the photographic table, a character reference curve C2 showing the characteristics of the character reference table, and a character showing the characteristics obtained by correcting the character reference table The correction curve C3 is shown. These curves are obtained in advance by product testing or the like and statistically processed.

  In the bias controllable state, the photographic curve C1 and the character reference curve C2 are selected. The photographic curve C1 and the character reference curve C2 have almost the same characteristics as can be seen from FIG. In the bias-controllable state, by using the half latent image, it is possible to achieve saturation by adhesion of an appropriate amount of toner to the amorphous silicon photosensitive member.

  In step S60, the control unit 10 acquires calibration data. The calibration data includes the calibration value of the toner layer formation potential difference ΔV, the dot area ratio set to 70% of the initial value, and the selection of the first toner amount table.

  On the other hand, in step S30a, the control unit 10 executes gamma correction calibration processing. The gamma correction calibration process of step S30a includes the process of setting the toner layer formation potential difference ΔV to the maximum value (limit value) within the adjustment range and increasing the dot area ratio from 70% to realize the solid density. This is different from the gamma correction calibration process of step S30 in that it is common to other points.

  As a result, since the dot area ratio is increased from 70%, a phenomenon in which the density becomes higher than the density assumed in advance, that is, the toner is consumed more than the amount assumed in advance. There is. This is because the dot area rate is raised from 70%, and problems such as rear end accumulation are manifested again.

  In step S40a, the control unit 10 sets a dot area ratio. In step S40a, the control unit 10 sets the toner layer formation potential difference ΔV to the maximum value within the adjustment range, and forms on the intermediate transfer belt 27 a plurality of half patches in which the dot area ratio is increased stepwise from 70%. The calibration density sensor 28 is used to set as a dot area ratio AR (for example, 85%) for realizing a solid density.

  In step S41, the control unit 10 calculates a correction coefficient. The correction coefficient is a correction coefficient for compensating for the increase in the amount of consumption of toner due to the problem of the trailing end accumulation and the like.

  FIG. 6 is a graph for explaining the contents of correction in the toner amount table TD according to an embodiment. FIG. 6A is an enlarged view of the high side (near 70% to 100%) of the image data of FIG. FIG. 6B shows the relationship between the set dot area ratio and the correction coefficient C. The set dot area rate is the dot area rate (in this example, the dot area rate AR (85%)) set in step S40a. The correction coefficient C is a ratio of the character reference curve C2 to the character correction curve C3 (C = character correction curve C3 / character reference curve C2).

  The correction coefficient C is calculated using the graph of FIG. In this example, since the dot area ratio AR is 85%, the correction coefficient C is 1.065. The correction curve C3 for characters is multiplied by the correction coefficient C (1.065) when the image data value is 80% to 100%, and the correction coefficient C (1 to 1.065) is inclined when the image data value is 70% to 80%. And multiply. As a result, the character correction curve C3 secures the continuity and corresponds to the development of the excess toner which significantly occurs in the printing of characters and thin lines on the side where the image data is high in the bias uncontrollable state.

  In step S42, the control unit 10 executes a table creation process. In the table creation process, the character correction curve C3 includes the character reference curve C2 and the correction coefficient C (1 to 1.065 for image data values of 70% to 80%, and 1. for image data values of 80% to 100%). 065) and calculated. The character correction curve C3 is created as, for example, a LUT (Look Up Table).

  In step S50a, the control unit 10 selects a second toner amount table. The second toner amount table is used to calculate the consumed amount of toner at the time of printing in the bias uncontrollable state.

  The second toner amount table is a table used when the dot area of a half patch representing a solid image exceeds 70% in the bias uncontrollable state. The second toner amount table is a table for photography (corresponding to curve C1 for photography) used to calculate the consumption of toner consumed for printing photos and patches, and toner consumed for printing characters and thin lines And the character correction table (corresponding to the character correction curve C3) used to calculate the amount of consumption of the image.

  In step S60, the control unit 10 acquires calibration data. The calibration data includes the calibration value (maximum value as the limit value) of the toner layer formation potential difference ΔV, the dot area ratio set to the dot area ratio AR (85%), and the selection of the second toner amount table. It contains. The calculation of the toner consumption is performed by the control unit 10 that functions as a consumption prediction unit.

  As described above, according to the image forming apparatus 1 according to the embodiment, in electrophotography in which development is performed with a photosensitive member having a high relative dielectric constant while suppressing end pooling, it occurs at the time of reproduction of images such as characters and thin lines. The amount of consumed toner can be estimated in consideration of the consumption of toner caused by factors such as adhesion of excess toner to the photosensitive member and end accumulation. As a result, the display of the amount of remaining toner and the toner replenishment can be made appropriate.

  The present invention can be implemented not only in the above embodiment but also in the following modifications.

  Modification Example 1: The above embodiment calibrates the toner layer formation potential difference ΔV by adjusting the magnetic roller potential Vmag of the developing units 100c to 100k, and adjusts the dot area ratio when calibration can not be performed by adjusting the magnetic roller potential Vmag. And proofreading. However, the invention is not limited to the magnetic roller potential Vmag and the dot area ratio, and calibration may be performed by adjusting the light amount of exposure by the exposure unit 29. Further, the change of the toner layer formation potential difference ΔV is not limited to the adjustment of only the magnetic roller potential Vmag, and can be realized by adjusting at least one of the magnetic roller potential Vmag and the development bias potential Vslv.

  However, when calibrating by adjusting the light quantity of exposure, it is preferable to use the adjustment of the light quantity of exposure preferentially for calibration rather than the dot area ratio. In the present invention, regardless of the light amount of exposure, when the calibration can not be performed by the adjustment of the toner layer forming potential difference ΔV, the dot area ratio is adjusted and calibrated.

  Modification 2: In the above embodiment, the correction curve C3 is created from the character reference curve C2 using the correction coefficient C. However, the present invention is not limited to such a method, and the character correction curve may be created by another method. C3 can be created. Specifically, for example, the character correction curve C4 for the dot area ratio AR (100%) is prepared in advance, and the distance between the character reference curve C2 and the character correction curve C4 for the dot area ratio AR (100%) The character correction curve C3 may be created by interpolation processing by interpolation of. Furthermore, the number of curves serving as the reference is not limited to two, and three or more may be prepared in advance, and interpolation processing by interpolation may be performed in a section between adjacent curves.

  Modified Example 3 In the above embodiment, although the method of measuring the consumption of toner is not particularly described, it may be measured, for example, by an apparatus capable of measuring the amount of toner falling from the toner container or a magnetic permeability sensor. However, since these methods measure changes in the amount of toner over a long period of time, they can not be used in real time, but verification or correction of photographic curve C1, character reference curve C2, and character correction curve C3 Available to

  Modified Example 4 In the above embodiment, although an amorphous silicon photosensitive member is used, the present invention is not limited to the use of an amorphous silicon photosensitive member. The present invention can be generally applied to an image forming apparatus that reproduces solid density with a photoconductor having a high relative dielectric constant.

Reference Signs List 1 image forming apparatus 10 control unit 20 image forming unit 21 color conversion processing unit 28 density sensor 29 for calibration exposure unit 40 storage unit 50 image reading unit 60 sheet feeding cassette 70 housing

Claims (6)

An image forming apparatus,
A photosensitive member that forms a solid image in a non-saturated state ; an exposure unit that exposes the photosensitive member to form an electrostatic latent image; and a developing unit that deposits toner on the photosensitive member based on the electrostatic latent image An image forming unit having
A calibration unit that performs calibration using at least one of a toner layer formation potential difference and a dot area ratio which is a potential difference between a magnetic roller of the development unit and a development sleeve ;
A consumption prediction unit that predicts the consumption of the developer used to form the image based on the image data;
Equipped with
When the calibration is performed by adjusting the toner layer formation potential difference at a predetermined dot area ratio set in advance for forming the solid image , the consumption amount prediction unit performs the image data. The toner consumption is predicted using a first toner amount table representing the relationship between the toner consumption and the toner consumption, and in the state where the toner layer formation potential difference is set to the maximum value , the dot area ratio is the predetermined dot area. if the calibration by Rukoto increased from rate is performed, the consumption is predicted using the second toner amount table,
The second toner amount table includes a developer consumption consumed for forming an image of characters and thin lines formed using the first toner amount table and a dot area ratio exceeding the predetermined dot area ratio. An image forming apparatus including a character correction table for predicting an amount . The image forming apparatus according to claim 1,
When the proofreading is performed by raising the dot area rate from the predetermined dot area rate, the consumption amount prediction unit uses the dot area rate used in the image formation of the character and the thin line and the character An image forming apparatus for predicting the consumption amount using a correction table . An image forming apparatus according to claim 1 or 2, wherein
The image forming unit has an intermediate transfer belt for transferring a toner image from the photosensitive member,
The calibration unit, an image forming apparatus having a concentration sensor for measuring the concentration of half-patch intermediate transfer multiple belt that is formed. The image forming apparatus according to any one of claims 1 to 3, wherein
The photoreceptor, an image forming apparatus is an amorphous silicon photoconductor. An image forming method,
A photosensitive member that forms a solid image in a non-saturated state ; an exposure unit that exposes the photosensitive member to form an electrostatic latent image; and a developing unit that deposits toner on the photosensitive member based on the electrostatic latent image Forming an image using an image forming process;
A calibration process of performing calibration using at least one of a toner layer formation potential difference and a dot area ratio which is a potential difference between a magnetic roller of the development unit and a development sleeve ;
A consumption prediction step of predicting consumption of a developer used for forming an image based on image data;
Equipped with
In the consumption prediction step, when the calibration is performed by adjusting the toner layer formation potential difference at a predetermined dot area ratio set in advance for forming the solid image, the image data The toner consumption is predicted using a first toner amount table representing the relationship between the toner consumption and the toner consumption, and in the state where the toner layer formation potential difference is set to the maximum value , the dot area ratio is the predetermined dot area. if the calibration by Rukoto increased from rate is performed, the consumption is predicted using the second toner amount table,
The second toner amount table includes a developer consumption consumed for forming an image of characters and thin lines formed using the first toner amount table and a dot area ratio exceeding the predetermined dot area ratio. An image forming method comprising: a text correction table for predicting an amount . A photosensitive member that forms a solid image in a non-saturated state ; an exposure unit that exposes the photosensitive member to form an electrostatic latent image; and a developing unit that deposits toner on the photosensitive member based on the electrostatic latent image an image forming program for controlling an image forming apparatus having an image forming portion having,
Calibration unit for calibrating using at least one of the potential difference at which the toner layer forming a potential difference and the dot area ratio between the magnetic roller and the developing sleeve with the previous SL developing unit, and images based on the image data Causing the image forming apparatus to function as a consumption prediction unit that predicts the consumption of the developer used for forming the toner;
When the calibration is performed by adjusting the toner layer formation potential difference at a predetermined dot area ratio set in advance for forming the solid image , the consumption amount prediction unit performs the image data. The toner consumption is predicted using a first toner amount table representing the relationship between the toner consumption and the toner consumption, and in the state where the toner layer formation potential difference is set to the maximum value , the dot area ratio is the predetermined dot area. if the calibration by Rukoto increased from rate is performed, the consumption is predicted using the second toner amount table,
The second toner amount table includes a developer consumption consumed for forming an image of characters and thin lines formed using the first toner amount table and a dot area ratio exceeding the predetermined dot area ratio. An image forming program including a character correction table for predicting an amount .