Image forming apparatus, information processing apparatus

Abstract

To predict a residual amount of a developer with high accuracy.SOLUTION: An image forming apparatus includes an image formation part (20) forming an image based on image data on a transfer material by using a developer, a data processing part 406 for calculating a consumption amount of the developer on the basis of the image data, and a toner amount management part 405 for calculating a correction value α of a toner consumption amount per 1 dot by a total soft count value X showing an amount of the developer stored by a new image formation part (20) and a total soft count value Y obtained by integrating consumption amounts. The toner amount management part 405 calculates a prediction value of a use amount of the developer by the total soft count value X, the total soft count value Y, and the correction value α, and calculates a residual amount of the developer by the prediction value.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an image forming apparatus such as a printer, a copier, a facsimile machine, and a multifunction peripheral.

Background Art

[0002] In an electrophotographic image forming apparatus, there is one that calculates the consumption amount of a developer every time an image is formed and displays the remaining amount of the developer on a display unit. As a method for detecting the remaining amount of the developer, there is a method using a sensor. When using a sensor, there are structural constraints due to miniaturization and space saving of the image forming apparatus. In addition, an increase in cost due to addition of parts and design changes is expected. Therefore, a method for estimating the consumption amount of a developer from image data representing an image to be formed has been proposed. Patent Documents 1 and 2 exemplify such an estimation method.

[0003] Patent Document 1 discloses a method for calculating the toner consumption amount that calculates the density value of each pixel from the image data before the intermediate tone correction process and calculates the toner consumption amount for each pixel from the calculated density value. This method for calculating the toner consumption amount accumulates the toner consumption amount for each pixel for each page and calculates the toner consumption amount for each page. The intermediate tone correction process is a process for correcting the input signal value so that the relationship between the input signal value in the tone portion and the image density becomes a certain state as desired. In such a method for calculating the toner consumption amount, by calculating the toner consumption amount using the image data before the intermediate tone correction process, the toner consumption amount in the tone portion can be accurately calculated.

[0004] Patent Document 2 discloses a method for calculating toner consumption that takes into account the phenomenon (edge ​​effect) in which printed dots placed at the edges of an image consume more toner than printed dots in solid areas. This method of calculating toner consumption involves preparing weight coefficients for each pixel in advance according to the continuity of the printed pixels. The toner consumption per pixel is calculated by multiplying each pixel by the corresponding weight coefficient, and the toner consumption for one page of the image is calculated by accumulating these values ​​for all pixels in the image. Such a method of calculating toner consumption can accurately calculate the toner consumption of text areas, which are strongly affected by the edge effect. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2007-114593 [Patent Document 2] Japanese Patent Publication No. 2009-98185 [Overview of the project] [Problems that the invention aims to solve]

[0006] The toner consumption calculation method described in Patent Document 1 can calculate toner consumption in the grayscale area with high accuracy, but the accuracy of calculating toner consumption in areas strongly affected by edge effects (e.g., text areas) is not high. Conversely, the toner consumption calculation method described in Patent Document 2 can calculate toner consumption in the text area with high accuracy, but the accuracy of calculating toner consumption in the grayscale area, where the on / off patterns of the image are densely repeated and many complex dot patterns exist, is not high. Furthermore, the actual toner consumption due to development is not necessarily a constant amount due to variations in the environment and equipment characteristics. As a result, there is an error between the estimated toner consumption and the actual toner consumption. Normally, toner is attached to the photoreceptor from the developer. If there is an error in the estimated toner consumption, the accuracy of predicting the precise remaining toner amount in the developer decreases.

[0007] In view of the above-mentioned problems, the present invention aims to predict the remaining amount of developer with high accuracy. [Means for solving the problem]

[0008] The present invention includes an image forming apparatus comprising a container for containing a developer, an image forming means for forming an image based on image data using the developer in the container, and a calculation means for calculating the amount of developer consumed based on the image data. before Correction value of developer consumption per dot of the image to be formed by the image forming means means for determining the correction value and , the above This indicates the amount of developer contained in the container. Count value and , the above The amount of consumption calculated by the calculation method Cumulative value and , Determined by the correction value determination means The aforementioned correction value Based on to determine the remaining amount of developer in the container. Remaining amount A means of making a decision, and The correction value determination means, when a storage container is replaced, determines a correction value for the storage container after replacement from the count value of the storage container before replacement and the cumulative value at the time of replacement. The remaining amount determination means, if the correction value determined by the correction value determination means is equal to or greater than the upper limit, uses the upper limit as the correction value to determine the remaining amount. It is characterized by the following. Another image forming apparatus of the present invention includes a container for containing a developer, and comprises: an image forming means for forming an image based on image data using the developer in the container; a calculation means for calculating the amount of developer consumed based on the image data; a correction value determination means for determining a correction value for the amount of developer consumed per dot of the image to be formed by the image forming means; and a remaining amount determination means for determining the remaining amount of developer in the container based on a count value indicating the amount of developer contained in the container, an integrated value of the consumption calculated by the calculation means, and the correction value determined by the correction value determination means, wherein when the container is replaced, the correction value determination means determines a correction value for the container after replacement from the count value of the container before replacement and the integrated value at the time of replacement, and the remaining amount determination means determines the remaining amount using the lower limit as the correction value if the correction value determined by the correction value determination means is less than or equal to a lower limit. The present invention is an information processing apparatus that includes a container for containing a developer, and is communicably connected to a printer engine having an image forming means for forming an image based on image data using the developer in the container, and includes a calculation means for calculating the amount of developer consumed based on the image data, before Correction value of developer consumption per dot of the image to be formed by the image forming means A means for determining the correction value, The aforementioned This indicates the amount of developer contained in the container. Count value and , the above The amount of consumption calculated by the calculation method Cumulative value and , Determined by the correction value determination means The aforementioned correction value Based on to determine the remaining amount of developer in the container. Remaining amount A means of making a decision, and The correction value determination means, when a storage container is replaced, determines a correction value for the storage container after replacement from the count value of the storage container before replacement and the cumulative value at the time of replacement. The remaining amount determination means, if the correction value determined by the correction value determination means is equal to or greater than the upper limit, uses the upper limit as the correction value to determine the remaining amount. It is characterized by the following. Another information processing apparatus of the present invention is an information processing apparatus that includes a container for containing a developer and is communicably connected to a printer engine having an image forming means for forming an image based on image data using the developer in the container, and comprises: a calculation means for calculating the amount of developer consumed based on the image data; a correction value determination means for determining a correction value for the amount of developer consumed per dot of an image to be formed by the image forming means; a remaining amount determination means for determining the remaining amount of developer in the container based on a count value indicating the amount of developer contained in the container, an integrated value of the consumption amount calculated by the calculation means, and the correction value determined by the correction value determination means, wherein when the container is replaced, the correction value determination means determines a correction value for the container after replacement from the count value of the container before replacement and the integrated value at the time of replacement, and the remaining amount determination means determines the remaining amount using the lower limit as the correction value if the correction value determined by the correction value determination means is less than or equal to a lower limit. [Effects of the Invention]

[0009] According to the present invention, the remaining amount of developer can be predicted with high accuracy. [Brief explanation of the drawing]

[0010] [Figure 1] Configuration diagram of an image forming apparatus. [Figure 2] Configuration diagram of a printer engine. [Figure 3] Explanation diagram of a control unit. [Figure 4] Explanation diagram of a video controller. [Figure 5] Explanation diagram of a data processing unit. [Figure 6] Explanation diagram of an image density correction processing unit. [Figure 7] Explanation diagram of a first toner amount calculation unit. [Figure 8] Explanation diagram of a first toner consumption amount. [Figure 9] Exemplification diagram of a weight coefficient table. [Figure 10] Explanation diagram of a second toner amount calculation unit. [Figure 11] Exemplification diagram of the relationship between the number of consecutive printing dots and the correction coefficient. [Figure 12] Flowchart representing toner remaining amount calculation processing. [Figure 13] Flowchart representing the update processing of the toner remaining amount. [Figure 14] Flowchart representing the acquisition processing of the total soft count value X. [Figure 15] Flowchart representing the acquisition processing of the total soft count value Y. [Figure 16] Flowchart representing the update processing of the correction value α of the toner consumption coefficient. [Figure 17] Flowchart representing the calculation processing of the predicted value Z of the toner usage amount. [Figure 18] Explanation diagram of the effect. [Figure 19] Flowchart representing the update processing of the correction value α of the toner consumption coefficient. [Figure 20] Flowchart representing the update processing of the correction value α of the toner consumption coefficient.

Modes for Carrying Out the Invention

[0011] Preferred embodiments of this invention will be described in detail below with reference to the drawings. However, unless otherwise specifically stated, the relative arrangements, numerical values, etc., of the components described in these embodiments are not intended to limit the scope of this invention to those components alone.

[0012] (Image forming apparatus) Figure 1 is a diagram showing the configuration of the image forming apparatus of this embodiment. The image forming apparatus 102 of this embodiment is a color image forming apparatus that forms images using four colors: yellow (Y), magenta (M), cyan (C), and black (K). The image forming apparatus 102 may also be a monochrome or image forming apparatus that uses transparent toner, gold toner, or silver toner. In this embodiment, the image forming apparatus 102 is described as printing at a resolution of 600 [dpi], but the resolution is not limited to this.

[0013] The image forming apparatus 102 includes a video controller 103 that performs various control and data processing, and a printer engine 104 that forms an image visualized on a transfer material. The transfer material is sometimes called a recording material, recording medium, sheet, or transfer paper. The image forming apparatus 102 is connected to a host computer 101, etc., via a network, parallel interface, serial interface, etc. The host computer 101 instructs the image forming apparatus 102 to perform printing. The video controller 103 rasterizes the print data transmitted from the host computer 101 along with the print execution instruction into image data, performs data processing as described later, and transmits it to the printer engine 104.

[0014] (Printer engine) Figure 2 is a diagram showing the configuration of the printer engine 104. Figure 3 is an explanatory diagram of the control unit that controls the operation of the printer engine 104. The printer engine 104 of this embodiment uses four toners as developers: yellow, magenta, cyan, and black. The printer engine 104 is a tandem type in which four image forming units 20Y, 20M, 20C, and 20K corresponding to the four colors of yellow, magenta, cyan, and black are provided along the intermediate transfer body 27. The four image forming units 20Y, 20M, 20C, and 20K have the same configuration. The four image forming units 20Y, 20M, 20C, and 20K and their respective components are identified by adding Y, M, C, and K to the end of their reference numerals to distinguish the corresponding colors, but the Y, M, C, and K at the end of the reference numerals are omitted when it is not necessary to explain them by color.

[0015] The printer engine 104 includes an engine control unit 301 and an engine mechanism unit 302. The engine mechanism unit 302 controls image formation on the transfer material 11 by operating in accordance with various instructions received from the engine control unit 301.

[0016] The engine mechanism 302 comprises a laser scanner system 308, an image formation system 309, a paper feed and transport system 310, and a sensor system 311. The laser scanner system 308 and the image formation system 309 form an image on the transfer material 11. The paper feed and transport system 310 transports the transfer material 11 during image formation. The sensor system 311 has multiple sensors that monitor the operation of each part of the engine mechanism 302. The detection results from the sensor system 311 are transmitted to the engine control unit 301.

[0017] The imaging system 309 of the engine mechanism 302 includes four image forming units 20, an intermediate transfer body 27, a transfer roller 28 for transferring a toner image onto a transfer material 11, and a fuser 30. The imaging system 309 also has a high-voltage power supply that generates various bias voltages (high voltages) necessary for imaging. The laser scanner system 308 of the engine mechanism 302 includes an exposure unit 24.

[0018] Each of the four image forming units 20 is an integrated unit comprising a photosensitive drum 22, a charger 23, and a developer 26, and is a detachable cartridge attached to the main body of the printer engine 104. Therefore, when replacing an image forming unit 20, the photosensitive drum 22, charger 23, and developer 26 are replaced together. Each of the four image forming units 20 has a non-volatile memory device.

[0019] The photosensitive drum 22 is a drum-shaped photoreceptor having a photosensitive layer on its surface, and is designed to rotate around the drum axis. The charger 23 uniformly charges the surface of the rotating photosensitive drum 22. The charger 23 has a charging sleeve 23S, and the photosensitive drum 22 is charged by applying a bias voltage to the charging sleeve 23S. The photosensitive drum 22, whose surface has been uniformly charged, is exposed by the exposure unit 24 (described later) to form an electrostatic latent image corresponding to the image data. The developer unit 26 reveals the electrostatic latent image formed on the photosensitive drum 22 by attaching toner as a developer. The developer unit 26 contains toner as a developer and has a developer sleeve 26S. The developer sleeve 26S attaches the toner to the electrostatic latent image. This forms a toner image on the photosensitive drum 22.

[0020] The exposure unit 24 includes a laser light-emitting element, a laser driver, a scan motor, a rotating polyhedron mirror, and a scan driver. Based on a laser drive signal, the exposure unit 24 emits laser light from the laser light-emitting element and reflects the laser light off the rotating polyhedron mirror to expose and scan the photosensitive drum 22. The laser drive signal indicates the exposure time of the laser light and is obtained from the video controller 103. By selectively exposing the surface of the photosensitive drum 22 with laser light, an electrostatic latent image is formed on the surface of the photosensitive drum 22.

[0021] The toner images formed on the photosensitive drums 22Y, 22M, 22C, and 22K of each image forming unit 20Y, 20M, 20C, and 20K are superimposed and transferred to the intermediate transfer body 27. A yellow toner image is formed on the photosensitive drum 22Y. A magenta toner image is formed on the photosensitive drum 22M. A cyan toner image is formed on the photosensitive drum 22C. A black toner image is formed on the photosensitive drum 22K. The toner images of each color transferred to the intermediate transfer body 27 are transferred collectively to the transfer material 11 by the transfer roller 28. The transfer material 11 with the transferred toner images is fixed by the fuser 30.

[0022] The intermediate transfer body 27 is an endless belt that is wrapped around multiple rollers such as the drive roller 25. The intermediate transfer body 27 is rotationally driven by the drive roller 25 and sequentially transfers toner images from the photosensitive drums 22Y, 22M, 22C, and 22K. By rotating, the intermediate transfer body 27 transports the transferred toner images to the transfer roller 28. The transfer material 11 is transported to the transfer roller 28 in time with the toner images being transported by the intermediate transfer body 27. A cleaning section 29 is provided downstream of the transfer roller 28 in the direction of rotation of the intermediate transfer body 27.

[0023] As the transfer roller 28 rotates with the transfer material 11 sandwiched between it and the intermediate transfer body 27, the transfer material 11 is held and transported by the intermediate transfer body 27 and the transfer roller 28. At this time, a transfer bias voltage is applied to the transfer roller 28, so that the four-color toner images on the intermediate transfer body 27 are transferred to the transfer material 11 all at once. The transfer roller 28 is biased toward the intermediate transfer body 27 and contacts the transfer material 11 while transferring the toner image onto the transfer material 11, and separates from the intermediate transfer body 27 when the transfer is complete. The transfer material 11 with the transferred toner image is transported to the fuser 30. The cleaning unit 29 removes any toner remaining on the intermediate transfer body 27 after each transfer.

[0024] The fuser 30 includes a fuser roller 31 for heating the transfer material 11 and a pressure roller 32 for pressing the transfer material 11 against the fuser roller 31. The fuser roller 31 and the pressure roller 32 are hollow and each has heaters 33 and 34 inside. The fuser 30 grips and conveys the transfer material 11 using the fuser roller 31 and the pressure roller 32. At this time, the transfer material 11 is heated by the heaters 33 and 34 and pressurized by the fuser roller 31 and the pressure roller 32. As a result, the toner image is melted and fixed to the transfer material 11. The transfer material 11 with the image fixed by the fuser 30 is discharged outside the image forming apparatus 102 as a printed product.

[0025] The paper feeding and transport system 310 feeds and transports the transfer material 11. The paper feeding and transport system 310 comprises various transport system motors, a paper feeding section (paper feeding cassette 21a and paper feeding tray 21b), and various transport rollers including a paper feeding roller and a paper discharge roller. The paper feeding and transport system 310 feeds the transfer material 11 one sheet at a time from the paper feeding cassette 21a or paper feeding tray 21b to the transfer roller 28 in accordance with the operation of the image creation system 309.

[0026] The sensor system 311 is a group of sensors that collect information necessary for controlling the laser scanner system 308, the image formation system 309, and the paper feed and transport system 310. The sensor group includes a temperature sensor for detecting the fixing temperature of the fuser unit 30, an image density sensor 40 for detecting the image density of the toner image, a sensor for detecting color misalignment, a paper size sensor, a paper leading edge detection sensor, a paper transport detection sensor, and the like. In this embodiment, the image density sensor 40 is provided downstream of the photosensitive drum 22K in the rotational direction of the intermediate transfer body 27 in order to detect the image density of the toner image formed on the intermediate transfer body 27. The image density sensor 40 may also be provided at a position to detect the image density of the toner image formed on the photosensitive drum 22 or the transfer material 11. The detection results detected by the sensor system 311 are transmitted to the engine control unit 301.

[0027] The engine control unit 301 is an information processing device equipped with a CPU (Central Processing Unit) 303, RAM (Random Access Memory) 305, and non-volatile memory 306. The engine control unit 301 also includes an ASIC (Application Specific Integrated Circuit) 304, a dedicated device for controlling the operation of the engine mechanism 302, and an engine I / F 307. The CPU 303 and ASIC 304 write and read various types of information to and from the non-volatile memory devices provided in each of the four image forming units 20Y, 20M, 20C, and 20K. This information includes the number of images formed, operating time, cartridge type, toner level, and remaining lifespan. The engine I / F 307 is a communication interface that controls communication between the engine control unit 301 and the video controller 103.

[0028] The CPU 303, ASIC 304, RAM 305, memory 306, and engine I / F 307 are interconnected via a system bus 312, enabling them to communicate with each other. The system bus 312 also connects to the various components of the engine mechanism 302, and communication between the engine control unit 301 and the engine mechanism 302 takes place via the system bus 312. The system bus 312 includes an address bus and a data bus.

[0029] The CPU 303 uses the RAM 305 as main memory and work area, and controls the operation of the engine mechanism 302 by executing various control programs stored in the memory 306. The CPU 303 acquires detection results detected by the sensor system 311 and controls the printing sequence.

[0030] When the CPU 303 receives a print execution instruction from the video controller 103 via the engine I / F 307, it first drives the image formation system 309 and charges the surface of the photosensitive drum 22 with the charger 23. The CPU 303 drives the laser scanner system 308 with a laser drive signal generated based on the image data and forms an electrostatic latent image on the photosensitive drum 22 with the exposure unit 24.

[0031] Next, the CPU 303 drives the image formation system 309 to develop the electrostatic latent image in the developer unit 26, forming single-color toner images corresponding to each of the photosensitive drums 22Y, 22M, 22C, and 22K. The CPU 303 uses the image formation system 309 to sequentially transfer these single-color toner images onto the intermediate transfer material 27, thereby forming a multi-color toner image on the intermediate transfer material 27. Simultaneously with driving the image formation system 309, the CPU 303 controls the paper feed transport system 310 to feed paper from the paper feed section onto the transfer material 11 using the paper feed roller. The CPU 303 uses the image formation system 309 to transfer the multi-color toner image onto the transfer material 11, and then controls the fuser unit 30 to fix the multi-color toner image on the transfer material 11.

[0032] The ASIC304 controls the motors and high-voltage power supplies such as the development bias, which are necessary for executing various printing sequences, in response to instructions from the CPU303. The ASIC304 works in cooperation with the CPU303 to control the operation of the engine mechanism 302. The ASIC304 may have at least some of the functions of the CPU303, and conversely, the CPU303 may have at least some of the functions of the ASIC304. Alternatively, at least some of the functions of the CPU303 and ASIC304 may be implemented by separate dedicated hardware.

[0033] (Video controller) Figure 4 is an explanatory diagram of the video controller 103. The video controller 103 is an information processing device comprising a CPU 401, memory 402, and RAM 403. The video controller 103 includes a host I / F 404, a toner amount management unit 405, an image density correction processing unit 411, a data processing unit 406, a DMA control unit 407, an operation display unit 408, and an engine I / F 409. Each component of the video controller 103 is connected to each other so as to be able to communicate via a system bus 410. The system bus 410 has an address bus and a data bus.

[0034] The CPU 401 controls the operation of the video controller 103 by executing computer programs stored in the memory 402. The memory 402 is non-volatile and stores various control codes (computer programs) and data used for control that the CPU 401 executes. The memory 402 is composed of, for example, ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), a hard disk, etc. The RAM 403 functions as the main memory and work area of ​​the CPU 401.

[0035] The host I / F 404 is a communication interface that receives print execution instructions, print data, control data, etc., from the host computer 101. The print data received by the host I / F 404 is stored in the RAM 403. The print data consists of bitmap data that has undergone halftone processing on the host computer 101, etc., and PDL (Page Description Language) data. PDL data is data described in the page description language to create image data. The print data usually includes drawing instructions for images such as characters, graphics, and images.

[0036] The DMA control unit 407, upon instruction from the CPU 401, transfers the data stored in the RAM 403 to the engine I / F 409 and the data processing unit 406. The data processing unit 406, upon instruction from the CPU 401, uses the image data acquired from the RAM 403 to perform various data processing operations (for example, estimating toner consumption). The detailed operation of the data processing unit 406 will be described later.

[0037] The operation display unit 408 is a user interface provided on the main body of the image forming apparatus 102. The operation display unit 408 accepts various settings and instructions from the user via its input interface and displays various information about the image forming apparatus 102 via its output interface. The engine interface 409 is a communication interface with the printer engine 104. The engine interface 409 transmits, for example, the laser drive signal output from the data processing unit 406 to the printer engine 104.

[0038] The toner quantity management unit 405 updates and manages the remaining toner in the developer units 26Y, 26M, 26C, and 26K of each image forming unit 20Y, 20M, 20C, 20K, and 20K based on the toner consumption per page notified by the data processing unit 406. The updated toner quantity is displayed on the operation display unit 408. This notifies the user of the remaining toner. The toner quantity management unit 405 may also notify the host computer 101 of the remaining toner quantity via the host I / F 404.

[0039] The image density correction processing unit 411 performs image density correction processing based on instructions from the CPU 401 or from the printer engine 104 via the engine I / F 409. The image density correction processing unit 411 generates a gradation correction table used during image density correction. The detailed operation of the image density correction processing unit 411 will be described later.

[0040] The functions of the data processing unit 406 may be implemented as an ASIC or dedicated hardware, and at least a portion of its functions may be implemented by the CPU 401. Furthermore, at least a portion of the functions of the video controller 103 may be implemented by an external device such as a host computer 101.

[0041] (Data volume) Figure 5 is an explanatory diagram of the data processing unit 406. The data processing unit 406 comprises a RIP (Raster Image Processor) unit 501, a color conversion unit 502, an image density correction unit 503, a halftone unit 504, and a PWM (Pulse Width Modulation) unit 506. These components are used to perform predetermined image processing on image data and generate a laser drive signal, which is a PWM signal that controls the emission of light from the exposure unit 24. In addition, the data processing unit 406 comprises a first toner amount calculation unit 510, a second toner amount calculation unit 505, and a print density calculation unit 511 for calculating the amount of toner to be consumed from the image data.

[0042] The RIP unit 501 analyzes the image data described in PDL (PDL data) acquired from the RAM 403 to generate intermediate language data, and then rasterizes the intermediate language data to generate raster image data. The raster image data is stored in a predetermined area within the RAM 403 as image data for each of the following colors: R (red), G (green), and B (blue).

[0043] The color conversion unit 502 performs color matching processing to convert the image data of each color stored in the RAM 403 into device RGB signals that match the color reproduction range of the image forming apparatus 102. Furthermore, the color conversion unit 502 converts the device RGB signals into YMCK signals, which are the toner colors of the image forming apparatus 102. In this way, the color conversion unit 502 sequentially converts the image data of each RGB color generated by the RIP unit 501 into image data of the Y, M, C, and K colors and stores them in a predetermined area in the RAM 403.

[0044] The image density correction unit 503 performs a halftone correction process that converts the image data of each color (Y, M, C, K) stored in the RAM 403 using a gradation correction table. This process is performed to establish a predetermined relationship between the gradation values ​​of the image data of each color (Y, M, C, K) and the density of the image output onto the transfer material 11 by the printer engine 104.

[0045] The halftone unit 504 performs halftone processing (such as systematic dithering) on ​​the multi-level (in this case, 8-bit) Y, M, C, and K image data corrected by the image density correction unit 503. Through halftone processing, the Y, M, C, and K image data is quantized into 1-bit image data that can be reproduced by the printer engine 104. The 1-bit image data is stored in the image memory in RAM 403. The PWM unit 506 converts the 1-bit image data after halftone processing stored in the image memory into a laser drive signal (laser exposure time) using PWM processing.

[0046] The first toner amount calculation unit 510 calculates the amount of toner consumed per page (first toner consumption) for each color based on the image data of each color (Y, M, C, K) generated by the color conversion unit 502 and stored in the RAM 403. The print coverage calculation unit 511 calculates the print coverage per page for each color based on the toner consumption per page for each color calculated by the first toner amount calculation unit 510. The second toner amount calculation unit 505 calculates the amount of toner consumed per page (second toner consumption) for each color based on the 1-bit image data of each color (Y, M, C, K) generated by the halftone unit 504.

[0047] The first toner consumption and second toner consumption calculated by the first toner amount calculation unit 510 and the second toner amount calculation unit 505, along with the print rate calculated by the print rate calculation unit 511, are transmitted to the toner amount management unit 405. The detailed operations of the first toner amount calculation unit 510, the print rate calculation unit 511, the second toner amount calculation unit 505, and the toner amount management unit 405 will be described later.

[0048] (Image density correction processing unit) Figure 6 is an explanatory diagram of the image density correction processing unit 411. The image density correction processing unit 411 includes a gradation characteristic detection unit 601 and a correction table calculation unit 602. The image density correction processing unit 411 creates a gradation correction table used for processing by the image density correction unit 503 and stores it in the RAM 403.

[0049] The gradation characteristic detection unit 601 detects the gradation characteristics of the image forming apparatus 102 (gamma characteristics of the printer engine 104). The image forming apparatus 102 forms a detection image on the intermediate transfer body 27. This detection image is pre-stored in the memory 306 (Figure 3) for each toner color. This detection image is read by the image density sensor 40. The gradation characteristic detection unit 601 obtains data (density data) related to the image density of the detection image from the reading result of the detection image read by the image density sensor 40. The gradation characteristic detection unit 601 generates gradation characteristics (gamma characteristics of the printer engine 104) by correlating the density data with the gradation levels of the detection images for each color. The gradation characteristic detection unit 601 transmits the generated gradation characteristics to the correction table calculation unit 602.

[0050] The correction table calculation unit 602 generates a tone correction table that converts the image data so that the measured tone characteristics of the printer engine 104 become ideal tone characteristics, based on the tone characteristics (gamma characteristics) obtained from the tone characteristics detection unit 601. The method for generating the tone correction table from the tone characteristics (gamma characteristics) obtained from the tone characteristics detection unit 601 and the ideal tone characteristics can be done by known techniques. Therefore, a detailed explanation of the method for generating the tone correction table is omitted. The correction table calculation unit 602 records the newly generated tone correction table in the memory 402 (Figure 4).

[0051] The image density correction unit 503 converts the tonal values ​​of the image data for each color (Y, M, C, K) using the generated tonal correction table. Then, an image is formed based on the converted image data. As a result, regardless of variations in the gamma characteristics of the image forming apparatus 102 (printer engine 104) or changes over time, the relationship between the tonal values ​​of the image data for each color (Y, M, C, K) and the density of the image formed on the transfer material 11 is maintained at a predetermined ideal relationship.

[0052] (Video controller operation) In this configuration, the video controller 103 receives a print execution command from the host computer 101 and transmits the data necessary for image formation to the printer engine 104. The flow of this process will now be explained.

[0053] The video controller 103 receives a print execution command from the host computer 101 via the host interface 404. Upon receiving the print execution command, the CPU 401 of the video controller 103 retrieves print data from the host computer 101 via the host interface 404. The CPU 401 stores the retrieved print data in the RAM 403.

[0054] The CPU 401 controls the RIP unit 501 of the data processing unit 406 to rasterize the image data stored in the RAM 403. The CPU 401 controls the color conversion unit 502 to perform color conversion processing on the rasterized image data. The CPU 401 controls the image density correction unit 503 to perform image density correction processing on the color converted image data. The CPU 401 controls the halftone unit 504 to perform halftone processing on the image data after image density correction processing. The CPU 401 controls the PWM unit 506 to perform PWM processing on the image data after halftone processing.

[0055] The CPU 401 transmits the laser drive signal generated by PWM processing to the printer engine 104 via the engine I / F 409. Simultaneously, the CPU 401 controls the first toner amount calculation unit 510 and the second toner amount calculation unit 505 to calculate the toner consumption. The CPU 401 controls the print coverage calculation unit 511 to calculate the print coverage. The CPU 401 causes the first toner amount calculation unit 510, the second toner amount calculation unit 505, and the print coverage calculation unit 511 to notify the toner amount management unit 405 of their respective calculation results.

[0056] (First toner quantity calculation unit and print density calculation unit) The processing of the first toner amount calculation unit 510 and the print coverage calculation unit 511 will be explained in detail. Figure 7 is an explanatory diagram of the first toner amount calculation unit 510. Here, the calculation of the first toner consumption for black (K) will be explained, but the first toner usage for other chromatic colors (yellow, magenta, cyan) is calculated by the same process. The first toner amount calculation unit 510 calculates the first toner consumption based on the multi-level (8-bit) pixel values ​​obtained from the black color conversion image data stored in the RAM 403. The black color conversion image data stored in the RAM 403 is data before the halftone correction processing by the image density correction unit 503. The first toner amount calculation unit 510 includes an image data correction unit 701, an integration unit 702, and a toner consumption calculation unit 703.

[0057] Figure 8 is an explanatory diagram of the first toner consumption. The first toner consumption is correlated with the pixel value of the image data processed by the color conversion unit 502. However, the inventors' investigations revealed that the first toner consumption does not have a proportional relationship with the pixel value of the image data processed by the color conversion unit 502 as shown in graph L4, but rather a nonlinear relationship as shown in graph L5. Therefore, the first toner amount calculation unit 510 pre-determines a correction value weighted by a predetermined coefficient to eliminate the difference between the first toner consumption required for each pixel value and the standard toner consumption, using the toner consumption required for a predetermined pixel value as a reference.

[0058] Figure 9 is an example of a weighting coefficient table showing the correspondence between pixel values ​​(input pixel values) from image data input to the first toner amount calculation unit 510 and weighted correction values ​​(corrected pixel values) corresponding to each pixel value. The weighting coefficient table allows the correction pixel values ​​corresponding to the input pixel values ​​to be obtained.

[0059] The image data correction unit 701 obtains the color-converted image data (pixel values) from the RAM 403 and derives the corrected pixel values ​​using the weight coefficient table in Figure 9. For example, if the pixel value of the color-converted image data obtained from the RAM 403 is "31", the image data correction unit 701 refers to the weight coefficient table and obtains the corrected pixel value "23". The image data correction unit 701 transmits the obtained corrected pixel value to the integration unit 702.

[0060] The integration unit 702 integrates the corrected pixel values ​​acquired sequentially from the image data correction unit 701. The toner consumption calculation unit 703 calculates the first toner consumption using the integrated value of the corrected pixel values ​​from the integration unit 702 and a predetermined calculation formula. The toner consumption calculation unit 703 transmits the calculated first toner consumption to the toner amount management unit 405.

[0061] The print rate calculation unit 511 calculates the print rate using the first toner consumption per page calculated by the toner consumption calculation unit 703, based on the toner consumption when the image on the page is a solid color image covering the entire page. The print rate calculation unit 511 transmits the calculated print rate to the toner amount management unit 405. The print rate is, for example, the value obtained by dividing the first toner consumption per page calculated by the toner consumption calculation unit 703 by the standard toner consumption. For example, when a solid color image is formed on an A4 size transfer material 11, if the standard toner consumption is 300 [mg] and the first toner consumption calculated by the toner consumption calculation unit 703 is 30 [mg], the print rate will be 10 [%].

[0062] (Second Toner Quantity Calculation Unit) Figure 10 is an explanatory diagram of the second toner amount calculation unit 505. Here, the consumption of the second toner for black (K) is explained, but the amount of second toner used for other chromatic colors (yellow, magenta, cyan) is calculated by a similar process. The second toner amount calculation unit 505 calculates the consumption of the second toner based on the line width of the printed pixels and the number of printed pixels contained in the image data of black after halftone processing, which is stored in the image memory of RAM 403. This image data is data quantized to 1 bit by halftone processing. The second toner amount calculation unit 505 includes a pattern detection unit 1001, a dot counting unit 1002, a calculation unit 1003, and a toner consumption calculation unit 1004.

[0063] The pattern detection unit 1001 analyzes the binary data of the 1-bit image data after halftone processing and detects regions corresponding to predetermined pixel patterns with different line widths (number of consecutive printed dots). Specifically, the pattern detection unit 1001 detects multiple pixel patterns from the dot arrangement of the target image, each with a number of consecutive printed dots varying in the range of 1 to 8.

[0064] The dot counting unit 1002 counts how many image patterns there are with a predetermined number of consecutive printed dots (here, 1 to 8). The number of pixels corresponding to a pixel pattern with a line width of 1 pixel is counted as "Count1". The number of pixels corresponding to a pixel pattern with a line width of 2 pixels is counted as "Count2". Similarly, the number of pixels corresponding to a pixel pattern with a line width of 3 to 8 pixels is counted as "Count3" to "Count8". The number of pixels corresponding to a pixel pattern with a line width of 9 pixels or more is counted as "Count*_*".

[0065] In this embodiment, the pattern detection unit 1001 detects a corresponding region based on a predetermined line width in the scanning direction of the laser beam in the exposure unit 24. The dot counting unit 1002 counts the number of pixels included in that region.

[0066] The calculation unit 1003 calculates an integrated value by multiplying the number of printed pixels, counted for each consecutive number of printed dots, by a correction coefficient corresponding to that category. The correction coefficient is a numerical value that can be determined in advance based on actual measurements. For example, it is preferable to set the amount of toner consumed by one pixel of a solid image without edges as "1", measure the amount of toner consumed per pixel for each pixel pattern with a different line width, and determine the rate of change as the correction coefficient. Figure 11 is an illustrative diagram of the relationship between the number of consecutive printed dots and the correction coefficient.

[0067] The toner consumption calculation unit 1004 calculates a second toner consumption amount based on the cumulative value calculated by the calculation unit 1003 and the toner consumption amount per unit pixel. The toner consumption calculation unit 1004 transmits the calculated second toner consumption amount to the toner amount management unit 405.

[0068] The second toner amount calculation unit 505 may be configured to be located outside the data processing unit 406, provided that it can acquire data quantized to one bit by halftone processing. For example, the second toner amount calculation unit 505 may be located in the printer engine 104.

[0069] (Toner quantity management department) The toner quantity management unit 405 determines, based on the print density obtained from the print density calculation unit 511, whether to use the first or second toner consumption obtained from the first toner quantity calculation unit 510 or the second toner quantity calculation unit 505 to calculate the toner consumption. Based on the toner consumption per page, the toner quantity management unit 405 updates the remaining toner in the developer units 26Y, 26M, 26C, and 26K of each image forming unit 20Y, 20M, 20C, and 20K. The toner quantity update result is displayed on the operation display unit 408 by the CPU 401.

[0070] Generally, printed materials with text-centric images have a low print density, while printed materials with graphic-centric images containing many grayscale areas have a medium to high print density. For this reason, in the case of a low print density, the remaining toner is calculated using the second toner consumption amount calculated by the second toner amount calculation unit 505, which can accurately calculate the toner consumption of the text portion. In the case of a medium to high print density, the remaining toner is calculated using the first toner consumption amount calculated by the first toner amount calculation unit 510, which can accurately calculate the toner consumption of the grayscale area.

[0071] Figure 12 is a flowchart showing the toner remaining amount calculation process by the toner amount management unit 405. The toner amount management unit 405 calculates the remaining toner in the developer units 26Y, 26M, 26C, and 26K of each image forming unit 20Y, 20M, 20C, and 20K each time the printer engine 104 outputs an image. The toner amount management unit 405 performs this process under the control of the CPU 401.

[0072] The toner quantity management unit 405 obtains the print density within each page from the print density calculation unit 511 (S1201). The toner quantity management unit 405 determines whether the obtained print density is below a predetermined threshold (S1202). Here, the threshold is, for example, 10%. However, the threshold is not limited to this value and may be any value determined by experiment as appropriate. If the print density is 10% or less (S1202:Y), the toner quantity management unit 405 determines the toner consumption to be the second toner consumption amount obtained from the second toner quantity calculation unit 505 (S1203). If the print density is greater than 10% (S1202:N), the toner quantity management unit 405 determines the toner consumption to be the first toner consumption amount obtained from the first toner quantity calculation unit 510 (S1204).

[0073] The toner quantity management unit 405 stores the toner consumption amount determined in processing S1203 or S1204 as a β value in the memory 306 of the engine control unit 301 (S1205). In this embodiment, the print density threshold was set to 10% as a criterion for deciding whether to use the toner consumption amount calculated by the first toner quantity calculation unit 510 or the second toner quantity calculation unit 505. The print density threshold may be set for each color, Y, M, C, and K. For example, chromatic colors (Y, M, C) are not frequently used in character images and are often used in graphic images that contain many gradations. For this reason, the print density threshold for black (K) may be set to 10%, and the print density threshold for chromatic colors may be set to 5%, prioritizing the accuracy of calculating the toner consumption of the gradation.

[0074] The toner quantity management unit 405 updates the toner quantity by subtracting the toner consumption amount determined in process S1203 or S1204 from the previous toner quantity (S1206). The toner quantity management unit 405 notifies the operation display unit 408 of the updated toner quantity and terminates the process (S1207). The operation display unit 408 displays the updated toner quantity.

[0075] Figure 13 is a flowchart illustrating the toner level update process for S1206. The toner level update process includes the following five steps. S2001: Processing to obtain the base total soft count value X S2002: Processing to obtain the current total soft count value Y of the image forming unit. S2003: Update process for the correction value α of the toner consumption coefficient S2004: Calculation process for the predicted value Z of toner usage. S2005: Toner level update process

[0076] Figures 14 to 17 illustrate the processes in S2001 to S2004. Figure 14 is a flowchart showing the process of acquiring the reference total soft count value X. Figure 15 is a flowchart showing the process of acquiring the current total soft count value Y of the developer unit 26. Figure 16 is a flowchart showing the process of updating the correction value α of the toner consumption coefficient. Figure 17 is a flowchart showing the process of calculating the predicted value Z of toner usage.

[0077] Figure 14 illustrates the "acquisition process of the reference total soft count value X" in S2001. As described above, the four image forming units 20Y, 20M, 20C, and 20K of the image forming system 309 in the engine mechanism unit 302 each have a non-volatile memory device.

[0078] The engine control unit 301 initiates communication with the memory devices of each image forming unit 20Y, 20M, 20C, and 20K (S2101). The engine control unit 301 obtains a pre-set reference total soft count value X from each memory device for each type of image forming unit 20Y, 20M, 20C, and 20K (S2102). The total soft count value X is set for each cartridge type, for example, as follows. The cartridge type indicates the type (size, etc.) of the image forming unit 20 (developer 26).

[0079] Cartridge type A: 500000000 Cartridge type B: 400000000 Cartridge type C: 300000000 Other: 0

[0080] Here, the standard total soft count value X is assumed to be "500000000". For example, in the case of cartridge type A, "500000000" is stored in the memory 306 of the engine control unit 301 as the standard total soft count value X. Note that the standard total soft count value X is the amount of toner that the image forming unit 20 can use from new to the end of its lifespan, converted into a soft value, and is not limited to the number shown as an example. In other words, the standard total soft count value X is a value that indicates the amount of toner (amount of developer) contained in a new image forming unit 20 (developer 26). The number and capacity of the cartridge type can be set arbitrarily.

[0081] Figure 15 illustrates the "Acquisition process of the current total soft count value Y of the image forming unit" in S2002. The current total soft count value Y is the current cumulative value of the toner consumption (first toner consumption, second toner consumption) calculated by the data processing unit 406, and is calculated by each of the image forming units 20. The current total soft count value Y of each of the image forming units 20 is stored in the memory 306 of the engine control unit 301, and the initial value is "0". The total soft count value Y is a value that indicates the accumulated toner consumption.

[0082] The toner quantity management unit 405 acquires the β value stored in the memory 306 of the engine control unit 301 (S2201). As described above, the β value is either the first toner consumption calculated by the first toner quantity calculation unit 510 or the second toner consumption calculated by the second toner quantity calculation unit 505. The toner quantity management unit 405 calculates a new total soft count value Y by adding the β value to the current total soft count value Y of the image forming units 20Y, 20M, 20C, and 20K (S2202). The toner quantity management unit 405 updates the current total soft count value Y stored in the memory 306 of the engine control unit 301 with the newly calculated total soft count value Y (S2203).

[0083] As a result of the processing in S2001 and S2002, the memory 306 of the engine control unit 301 stores the reference total soft count value X and the current total soft count value Y for each image forming unit 20 (for each color). In other words, the memory 306 of the engine control unit 301 stores the initial value (initial amount) and the current consumption amount of toner in the developer unit 26.

[0084] Figure 16 illustrates the "updating process of the toner consumption coefficient correction value α" in S2003. The toner consumption coefficient correction value α has an initial value stored in the memory 306 of the engine control unit 301. The initial value of the correction value α is "1.0". In this embodiment, the toner consumption coefficient is the amount of toner consumed per dot. When the image forming unit 20 is replaced, the toner consumption value α indicates the toner consumption rate (ratio of consumption to initial amount) of the replaced image forming unit 20. The toner consumption coefficient correction value α makes it possible to correct individual differences between image forming units 20 and errors due to the usage environment.

[0085] The toner quantity management unit 405 determines whether or not the image forming unit 20 has been replaced (S2301). If it has not been replaced (S2301:N), the toner quantity management unit 405 terminates processing without updating the correction value α of the toner consumption coefficient (S2306). If it has been replaced (S2301:Y), the toner quantity management unit 405 obtains the total soft count value X, which is the reference value of the replaced image forming unit 20 before replacement, from the memory 306 of the engine control unit 301 (S2302). Here, we will explain the case where the total soft count value X is "500000000".

[0086] The toner quantity management unit 405 obtains the total soft count value Y when the image forming unit 20 is replaced from the memory 306 of the engine control unit 301 (S2303). Here, we will explain the case where the total soft count value Y is "450000000".

[0087] The toner quantity management unit 405 calculates a correction value α for the toner consumption coefficient (S2304). The correction value α is the value obtained by dividing the total soft count X by the total soft count value Y. In other words, the correction value α is obtained by the following formula. α=X / Y=500000000 / 450000000=1.11

[0088] The toner quantity management unit 405 updates the correction value α stored in the memory 306 of the engine control unit 301 using the calculated correction value α of the toner consumption coefficient (S2305). Here, the correction value α of the toner consumption coefficient is updated from the initial value "1.0" to "1.11".

[0089] The toner quantity management unit 405 may store the correction value α of the toner consumption coefficient without updating it each time the image forming unit 20 is replaced, and may use the average of multiple correction values ​​α as the correction value α of the toner consumption coefficient. The averaging process is not limited to a simple average; moving averages, exponential averages, peak averages, Olympic methods, etc., can be used. By averaging, it is possible to converge the prediction error of the remaining toner quantity over the long term. α = (α1 + α2 + α3 + ... + αn) / n

[0090] Figure 17 illustrates the "calculation process of the predicted toner usage value Z" in S2004. The predicted toner usage value Z has an initial value that is stored in the memory 306 of the engine control unit 301. The initial value of the predicted toner usage value Z is "0".

[0091] The toner quantity management unit 405 obtains the reference total soft count value X, the current cartridge's total soft count value Y, and the toner consumption coefficient correction value α from the engine control unit 301's memory 306 (S2401, S2402, S2403). The toner quantity management unit 405 calculates the predicted toner usage Z of the image forming unit 20 using the following formula based on the obtained total soft count values ​​X, Y, and correction value α (S2404). Z = (Y × α) / X × 100

[0092] The toner quantity management unit 405 updates the predicted value stored in the memory 306 of the engine control unit 301 using the calculated predicted value Z (S2405). The toner quantity management unit 405 updates (calculates) the remaining toner amount using the predicted value Z (S2005).

[0093] As described above, the toner level is updated. Figure 18 is an explanatory diagram illustrating the effects of the above-described process performed by the image forming apparatus 102 of this embodiment.

[0094] The horizontal axis represents the predicted toner level. The vertical axis represents the actual toner level [%]. The solid line and black circles show the relationship between the predicted toner level and the baseline value of "100%" predicted with a toner consumption coefficient of "1". The dotted line and black triangles show the relationship between the predicted toner level and the toner level when the image forming unit 20 is replaced and the toner level value of "90%". The dashed line and black squares show the relationship between the predicted toner level and the toner level when the image forming unit 20 is replaced and the toner level value of "110%".

[0095] Disturbances such as the usage environment and application cause differences in toner consumption, resulting in discrepancies between the predicted result and the baseline value of "100%" predicted with a toner consumption coefficient of "1". In this embodiment, by correcting the toner consumption coefficient with a correction value α, it becomes possible to accurately calculate toner consumption regardless of disturbances such as the usage environment and application. Furthermore, by averaging the correction value of the toner consumption coefficient each time the image forming unit 20 is replaced, the prediction error of the remaining toner can be converged over the long term, making it possible to predict the remaining toner with high accuracy.

[0096] (Variation 1) There are variations of the "Toner Consumption Coefficient Correction Value α Update Process" in S2003. Figure 19 is a flowchart showing the update process of the toner consumption coefficient correction value α in variation 1. In this case, an upper limit and a lower limit are set for the toner consumption coefficient correction value α.

[0097] The determination of whether or not the image forming unit 20 has been replaced, the acquisition of the total soft count value Y, the acquisition of the total soft count value Y, and the calculation of the toner consumption coefficient correction value α are the same processes as in S2301 to S2304 in Figure 16 (S2501 to S2504). If the image forming unit 20 has not been replaced (S2501:N), the toner quantity management unit 405 terminates the process without updating the toner consumption coefficient correction value α (S2512).

[0098] The toner quantity management unit 405 determines the upper limit of the correction value α for the toner consumption coefficient (S2505). Here, the upper limit of the correction value α is set to "1.3". If the correction value α calculated in the process of S2504 is "1.3" or greater (S2505:Y), the toner quantity management unit 405 sets the correction value α for the toner consumption coefficient to the upper limit of "1.3" (S2506). The toner quantity management unit 405 updates the correction value α stored in the memory 306 of the engine control unit 301 using the set correction value α for the toner consumption coefficient (S2507). Here, the correction value α for the toner consumption coefficient is updated from the initial value "1.0" to the upper limit of "1.3".

[0099] If the correction value α calculated in the S2504 process is less than "1.3" (S2505:N), the toner quantity management unit 405 determines the lower limit of the correction value α of the toner consumption coefficient (S2508). Here, the lower limit of the correction value α is set to "0.7". If the correction value α calculated in the S2504 process is "0.7" or less (S2508:Y), the toner quantity management unit 405 sets the correction value α of the toner consumption coefficient to the lower limit of "0.7" (S2509). The toner quantity management unit 405 updates the correction value α stored in the memory 306 of the engine control unit 301 using the set correction value α of the toner consumption coefficient (S2510). Here, the correction value α of the toner consumption coefficient is updated from the initial value "1.0" to the upper limit of "0.7".

[0100] If the correction value α calculated in the S2504 process is greater than "0.7" (S2508:N), the toner quantity management unit 405 sets the correction value α of the toner consumption coefficient to the value calculated in the S2504 process. The toner quantity management unit 405 updates the correction value α stored in the memory 306 of the engine control unit 301 using the set correction value α of the toner consumption coefficient (S2511). Here, the correction value α of the toner consumption coefficient is updated to the value calculated in the S2504 process.

[0101] As described above, the correction value α for the toner consumption coefficient is set to the upper limit if it is above the upper limit, and to the lower limit if it is below the lower limit. Therefore, the correction value α will be a value between the upper limit and the lower limit. Note that the upper and lower limits are examples, and other values ​​may be used. In this type of processing, by setting upper and lower limits for the correction value α of the toner consumption coefficient, the risk of excessive correction regardless of external disturbances such as the usage environment and usage purpose can be suppressed.

[0102] (Modification 2) As described above, the image forming unit 20 is composed of a photosensitive drum 22, a charger 23, and a developer 26. The image forming unit 20 is replaced not only when toner is consumed in the developer 26, but also when the photosensitive drum 22 or charger 23 reach the end of their product life. Therefore, if the correction value α is updated when the image forming unit 20 is replaced for reasons other than toner consumption, it may actually become difficult to accurately grasp the amount of toner consumed. In the modified example 2, the "update processing of the correction value α of the toner consumption coefficient" in S2003 is performed taking this point into consideration.

[0103] Figure 20 is a flowchart showing the update process for the toner consumption coefficient correction value α in Modification Example 2. Modification Example 2 is a modified version of Modification Example 1, in which upper and lower limits are set for the toner consumption coefficient correction value α. However, Modification Example 2 is also valid in configurations where upper and lower limits are not set.

[0104] The toner quantity management unit 405 determines whether or not the image forming unit 20 has been replaced (S2601). If it has not been replaced (S2601:N), the toner quantity management unit 405 terminates processing without updating the correction value α of the toner consumption coefficient (S2613). If it has been replaced (S2601:Y), the toner quantity management unit 405 determines whether or not the reason for the replacement is the toner end in the developer unit 26 (S2602).

[0105] The determination of toner depletion is made, for example, based on the remaining toner amount calculated by the previous toner amount calculation process. In this case, the toner amount management unit 405 determines that toner depletion has occurred if the remaining toner amount calculated by the previous toner amount calculation process is below a predetermined amount.

[0106] If it is not the toner end (S2602:N), the toner quantity management unit 405 terminates processing without updating the correction value α of the toner consumption coefficient (S2613). If it is the toner end (S2602:Y), the toner quantity management unit 405 updates the correction value α of the toner consumption coefficient by processing S2502 to S2511 in Figure 19 (S2603 to S2612).

[0107] In this type of processing, if the image forming unit 20 is replaced for reasons other than toner consumption, the correction value α of the toner correction coefficient is not updated. This is to prevent excessive toner level prediction if the image forming unit 20 is replaced while toner remains. Therefore, the risk of excessive correction regardless of external disturbances such as the usage environment or application can be suppressed.

[0108] Furthermore, in the above description, the toner is stored in the image forming unit 20 (developer 26), and the toner is replenished by replacing the developer 26. However, the toner may be stored in a separate container housing from the developer 26, and this container may be detachable from the image forming apparatus 102. With this configuration, the toner can be replenished to the developer 26 by replacing the container, and the costs incurred by replacing the developer 26 can be reduced.

Claims

1. An image forming means includes a container for containing a developer, and uses the developer in the container to form an image based on image data, A calculation means for calculating the amount of developer consumed based on the image data, A correction value determination means for determining a correction value for the amount of developer consumed per dot of the image to be formed by the image forming means, The system includes a count value indicating the amount of developer contained in the container, a cumulative value of the consumption amount calculated by the calculation means, and a correction value determined by the correction value determination means, which determines the remaining amount of developer in the container. The correction value determination means, when a storage container is replaced, determines a correction value for the storage container after replacement from the count value of the storage container before replacement and the cumulative value at the time of replacement. The remaining amount determination means is characterized in that, if the correction value determined by the correction value determination means is equal to or greater than the upper limit value, it uses the upper limit value as the correction value to determine the remaining amount. Image forming apparatus.

2. The correction value determination means is characterized in that, when a storage container is replaced, it determines the correction value for the storage container after replacement by dividing the count value of the storage container before replacement by the accumulated value at the time of replacement. The image forming apparatus according to claim 1.

3. The system further includes an image density correction means that performs midtone correction processing on the image data and transmits it to the image forming means, The calculation means is characterized by calculating the amount of developer consumed based on the image data before the halftone correction processing is performed by the image density correction means. The image forming apparatus according to claim 1.

4. The system further includes an image density correction means that performs midtone correction processing on the image data and transmits it to the image forming means, The calculation means is characterized by calculating the amount of developer consumed based on the image data after the intertone correction processing has been performed by the image density correction means. The image forming apparatus according to claim 1.

5. The system further includes an image density correction means that performs midtone correction processing on the image data and transmits it to the image forming means, The calculation means calculates a first amount of developer consumption based on the image data before the halftone correction processing is performed by the image density correction means, calculates the print density per page based on the first amount of consumption, and calculates a second amount of developer consumption based on the image data after the halftone correction processing is performed by the image density correction means. The calculation means is characterized in that, when the print density is below a threshold, the amount of developer consumed for the page is set as the first consumption amount, and when the print density is greater than the threshold, the amount of developer consumed for the page is set as the second consumption amount, and the cumulative value is calculated accordingly. The image forming apparatus according to claim 1.

6. An image forming means includes a container for containing a developer, and uses the developer in the container to form an image based on image data, A calculation means for calculating the amount of developer consumed based on the image data, A correction value determination means for determining a correction value for the amount of developer consumed per dot of the image to be formed by the image forming means, The system includes a count value indicating the amount of developer contained in the container, a cumulative value of the consumption amount calculated by the calculation means, and a correction value determined by the correction value determination means, which determines the remaining amount of developer in the container. The correction value determination means, when a storage container is replaced, determines a correction value for the storage container after replacement from the count value of the storage container before replacement and the cumulative value at the time of replacement. The remaining amount determination means is characterized in that, if the correction value determined by the correction value determination means is less than or equal to the lower limit value, it uses the lower limit value as the correction value to determine the remaining amount. Image forming apparatus.

7. The correction value determination means is characterized in that, when a storage container is replaced, it determines the correction value for the storage container after replacement by dividing the count value of the storage container before replacement by the accumulated value at the time of replacement. The image forming apparatus according to claim 6.

8. The system further includes an image density correction means that performs midtone correction processing on the image data and transmits it to the image forming means, The calculation means is characterized by calculating the amount of developer consumed based on the image data before the halftone correction processing is performed by the image density correction means. The image forming apparatus according to claim 6.

9. The system further includes an image density correction means that performs midtone correction processing on the image data and transmits it to the image forming means, The calculation means is characterized by calculating the amount of developer consumed based on the image data after the intertone correction processing has been performed by the image density correction means. The image forming apparatus according to claim 6.

10. The system further includes an image density correction means that performs midtone correction processing on the image data and transmits it to the image forming means, The calculation means calculates a first amount of developer consumption based on the image data before the halftone correction processing is performed by the image density correction means, calculates the print density per page based on the first amount of consumption, and calculates a second amount of developer consumption based on the image data after the halftone correction processing is performed by the image density correction means. The calculation means is characterized in that, when the print density is below a threshold, the amount of developer consumed for the page is set as the first consumption amount, and when the print density is greater than the threshold, the amount of developer consumed for the page is set as the second consumption amount, and the cumulative value is calculated accordingly. The image forming apparatus according to claim 6.

11. An information processing device that includes a container for containing a developer and is communicably connected to a printer engine having an image forming means for forming an image based on image data using the developer in the container, A calculation means for calculating the amount of developer consumed based on the image data, A correction value determination means for determining a correction value for the amount of developer consumed per dot of the image to be formed by the image forming means, The system includes a count value indicating the amount of developer contained in the container, a cumulative value of the consumption amount calculated by the calculation means, and a correction value determined by the correction value determination means, which determines the remaining amount of developer in the container. The correction value determination means, when a storage container is replaced, determines a correction value for the storage container after replacement from the count value of the storage container before replacement and the cumulative value at the time of replacement. The remaining amount determination means is characterized in that, if the correction value determined by the correction value determination means is equal to or greater than the upper limit value, it uses the upper limit value as the correction value to determine the remaining amount. Information processing device.

12. An information processing device that includes a container for containing a developer and is communicably connected to a printer engine having an image forming means for forming an image based on image data using the developer in the container, A calculation means for calculating the amount of developer consumed based on the image data, A correction value determination means for determining a correction value for the amount of developer consumed per dot of the image to be formed by the image forming means, The system includes a count value indicating the amount of developer contained in the container, a cumulative value of the consumption amount calculated by the calculation means, and a correction value determined by the correction value determination means, which determines the remaining amount of developer in the container. The correction value determination means, when a storage container is replaced, determines a correction value for the storage container after replacement from the count value of the storage container before replacement and the cumulative value at the time of replacement. The remaining amount determination means is characterized in that, if the correction value determined by the correction value determination means is less than or equal to the lower limit value, it uses the lower limit value as the correction value to determine the remaining amount. Information processing device.

Images