JP2004191720A - Image forming apparatus and toner consumption calculating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately calculate toner consumption in an image forming apparatus for forming an image with the toner. <P>SOLUTION: When an image signal formed by a CPU 111 based on image data received by an I/F 112 is inputted to an exposure unit 6 through a modulation signal generation part 210 and an exposure power control part 123, the toner consumption is calculated based on the counted value by a dot counter 200. On the other hand, when an image signal corresponding to a prescribed image pattern is inputted from a pattern forming module 125 to the exposure unit 6 through the exposure power control part 123, an offset value corresponding to the image pattern is extracted from a memory 127, and then, the toner consumption is calculated based on the offset value. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technique for determining toner consumption in an image forming apparatus that forms an image using toner.
[0002]
[Prior art]
2. Description of the Related Art In an image forming apparatus such as a printer, a copying machine, and a facsimile apparatus that forms an image using toner, it is necessary to grasp the amount of toner consumption or the amount of toner remaining for maintenance such as toner supply. In view of this, the present applicant has already disclosed a toner consumption detection method and apparatus capable of accurately calculating the toner consumption with a simple configuration (see Patent Document 1). In this detection method and apparatus, in view of the fact that the relationship between the value of a print dot and the amount of toner consumed is non-linear and changes depending on the state of a print dot adjacent to the print dot, the print dot row is divided into two isolated dots. The pattern is divided into three patterns of dots and intermediate value dots, the number of the formed patterns is counted for each of these patterns, and the toner consumption is calculated based on the counted value.
[0003]
[Patent Document 1]
JP-A-2002-174929 (page 4)
[0004]
[Problems to be solved by the invention]
Meanwhile, FIGS. 2 and 4 of the above-mentioned conventional Patent Document 1 describe only a route for inputting a pulse signal obtained by modulating a print dot by a pulse modulation circuit as a route for inputting a signal to the laser driving unit. However, an image forming apparatus having a configuration in which there are a plurality of routes for inputting signals to a laser driving unit as an image forming unit may be considered. For example, in addition to the above-mentioned route (hereinafter, referred to as “one route”), an image forming apparatus having another route for inputting a signal irrelevant to the print dot and capable of forming an image different from the print dot can be considered.
[0005]
In such an image forming apparatus, when a signal is input via the one route to perform an image forming operation based on a print dot, the amount of toner consumed by the image formation is determined according to the above-described conventional Japanese Patent Application Laid-Open No. H11-150572. Can be requested. However, in a case where an image forming operation that is not based on print dots is performed by inputting a signal via the another route, the amount of toner consumed by the image formation cannot be obtained in the above-described conventional Patent Document 1. . As a result, the amount of toner consumption of the entire apparatus cannot be accurately obtained.
[0006]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and even in an image forming apparatus having a configuration in which a plurality of routes for inputting signals to an image forming unit exist, a signal input through each route may be used. An object of the present invention is to provide an image forming apparatus and a method for calculating the amount of toner consumption, which can accurately detect the amount of toner consumed by image formation based on the image forming apparatus, and thereby can accurately determine the amount of toner consumption.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, an image forming apparatus according to the present invention consumes image forming means for forming a toner image on an image carrier based on an input image signal, and toner image formation by the image forming means. Detecting means for detecting the toner amount, wherein the image forming apparatus obtains the toner consumption based on the integrated value of the toner amount detected by the detecting means, wherein the image signal is input to the image forming means as a route. , A first route, and a second route different from the first route are provided, and the detecting unit is configured to detect a first toner amount based on an image signal input to the image forming unit via the first route. The detection process is different from the second toner amount detection process based on an image signal input to the image forming means via the second route.
[0008]
According to the invention configured as described above, the first toner amount detection process based on the image signal input to the image forming unit via the first route and the image signal input to the image forming unit via the second route are performed. Since the amount of toner consumed by the toner image formation by the image forming unit is detected by making a difference from the second toner amount detection process based on the second toner amount detection process, the toner amount can be accurately detected by an appropriate detection process corresponding to each route. Thus, the toner consumption can be accurately obtained.
[0009]
A first control unit for receiving image data, generating an image signal corresponding to the image data, and transmitting the image signal to the image forming unit via the first route; And a second control unit that sends an image signal corresponding to the image forming unit to the image forming unit via the second route, wherein the image forming unit is input from the first control unit via the first route. Forming a toner image corresponding to the image data based on the received image signal, and forming a toner image corresponding to the image pattern based on an image signal input from the second control means via the second route. The detecting means detects the toner amount based on the image data as the first toner amount detecting process, and detects the toner amount based on the image pattern as the second toner amount detecting process. It is also possible to detect.
[0010]
According to the invention configured as described above, a toner image corresponding to image data is formed based on an image signal input from the first control unit via the first route, and the first toner amount is detected based on the image data. While the amount is detected, a toner image corresponding to the image pattern is formed based on the image signal input from the second control means via the second route, and the toner amount is determined based on the image pattern as a second toner amount detection process. Is detected. As described above, since the toner amount detection processing is performed for each toner image to be formed, each toner amount can be accurately detected.
[0011]
The image forming apparatus further includes a storage unit configured to store, as an offset value, a toner amount consumed when a toner image corresponding to the image pattern is formed, wherein the detection unit transmits the toner amount from the second control unit via the second route. When an image signal is input to the image forming means, the offset value may be used as the toner amount. That is, since the image pattern is set in advance, the amount of toner consumed by forming the toner image corresponding to the image pattern can be experimentally obtained in advance. Therefore, if the toner amount is stored in the storage unit as an offset value, the toner amount can be easily and accurately detected.
[0012]
Note that this offset value is not limited to a single value. That is, when the second control means is configured to be capable of transmitting image signals corresponding to a plurality of preset image patterns to the image forming means, respectively, the toner image forming operation corresponding to each image pattern is performed. Are different from each other. Therefore, the amount of toner consumed when a toner image corresponding to the plurality of image patterns is formed is stored in the storage unit as an offset value, and the detection unit transmits the second control unit from the second control unit. When an image signal is input to the image forming unit via two routes, an offset value of an image pattern corresponding to the image signal may be extracted from the storage unit, and the offset value may be used as the toner amount. This makes it possible to easily and accurately detect the amount of toner consumed in the toner image forming operation of each image pattern.
[0013]
Further, the image forming means includes an exposing means for forming an electrostatic latent image on the image carrier, and a developing means for adhering toner to the image carrier to visualize the electrostatic latent image. Wherein the second control means stores in advance a modulation signal corresponding to the image pattern as a modulation signal for controlling an exposure amount of the exposure means, and uses the modulation signal as the image signal in the second route. May be sent to the exposure means via a.
[0014]
In the invention configured as above, the second control means stores in advance a modulation signal corresponding to an image pattern as a modulation signal for controlling the exposure amount of the exposure means, and uses the modulation signal as an image signal as the exposure means. Therefore, the electrostatic latent image corresponding to the image pattern can be formed with a simple configuration without performing processing such as generation of print dot data. Further, since the toner image is formed without generating the print dot data, the toner amount cannot be detected based on the number of print dots, but by detecting the toner amount based on the image pattern, the toner amount is determined. The amount can be detected with high accuracy.
[0015]
Further, in order to detect the amount of toner consumed by forming the toner image corresponding to the image data, for example, the image forming unit further includes a counting unit electrically connected to the first control unit. An exposure unit for forming an electrostatic latent image on an image carrier, and a developing unit for adhering toner to the image carrier to visualize the electrostatic latent image, wherein the first control unit is Generating print dot data based on the image data, transmitting the print dot data to the counting means, and generating a modulation signal for controlling an exposure amount of the exposure means based on the print dot data; As the image signal to the exposure unit via the first route. The counting unit counts the number of print dots forming the toner image corresponding to the image data in advance. When the image signal is inputted from the first control means to the image forming means via the first route, the detecting means counts based on the print dot data. The toner amount may be detected based on the number of printing dots. This makes it possible to detect the toner amount only by calculation, so that a sensor or the like for measuring the toner amount is unnecessary, and the apparatus configuration and control can be simplified.
[0016]
In addition, since the amount of toner consumption can be accurately determined by the above-described method, the degree of toner reduction in the apparatus can be accurately grasped. Therefore, a determination function may be provided for determining that the toner is exhausted when the toner consumption thus obtained exceeds a predetermined value. This predetermined value can be determined based on the amount of toner initially contained in the apparatus and the minimum amount of toner required in the apparatus to form an image with a predetermined image quality in the apparatus.
[0017]
According to another aspect of the present invention, there is provided a method for calculating a toner consumption amount, comprising: an image forming unit configured to form a toner image on an image carrier based on an input image signal; In an image forming apparatus in which a first route and a second route different from the first route are provided as routes input to the forming unit, an image signal input to the image forming unit via the first route is provided. A first detection step of detecting an amount of toner consumed by toner image formation by the image forming means, and an image signal input to the image forming means via the second route. Detection step for detecting the amount of toner consumed by toner image formation by the first and second detection steps, and an integrated value obtained by integrating the toner amounts detected in the first and second detection steps. And a step of obtaining a toner consumption, in the first detection step and the second detection step, is characterized by detecting the amount of toner by a different process.
[0018]
According to the invention having such a configuration, the amount of toner consumed by toner image formation is detected based on the image signal input to the image forming unit via the first route, and the image forming unit is connected to the image forming unit via the second route. The amount of toner consumed by toner image formation is detected based on the input image signal, but the detection steps are different from each other. Can be. Thus, the total consumed toner amount can be accurately obtained based on the integrated value obtained by integrating the toner amounts.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a diagram showing an embodiment of an image forming apparatus according to the present invention. FIG. 2 is a block diagram showing an electrical configuration of the image forming apparatus of FIG. This image forming apparatus forms a full-color image by superimposing four color toners of yellow (Y), magenta (M), cyan (C), and black (K), or uses only black (K) toner. To form a monochrome image. In this image forming apparatus, when a print command and image data are given to the main controller 11 of the control unit 1 from an external device such as a host computer, the main controller 11 outputs a control command to each unit of the device and outputs the given image. Based on the data, an image signal is generated for each toner color that represents an image to be formed as a print dot array of multiple gradation levels, and is output to the engine controller 12. Then, in response to a command from the main controller 11, the engine controller 12 controls each part of the engine EG to form an image corresponding to the image signal on the sheet S.
[0020]
In this engine EG, the photoconductor 2 is provided rotatably in the arrow direction D1 in FIG. A charging unit 3, a rotary developing unit 4, and a cleaning unit 5 for charging the surface of the photoconductor 2 to a predetermined surface potential are arranged around the photoconductor 2 along the rotation direction D1. The charging unit 3 is applied with a charging bias from the charging bias generation unit 121 and uniformly charges the outer peripheral surface of the photoconductor 2.
[0021]
Then, the light beam L is emitted from the exposure unit 6 toward the outer peripheral surface of the photoconductor 2 charged by the charging unit 3. As shown in FIG. 2, the exposure unit 6 is electrically connected to an exposure power control unit 123, and the exposure power control unit 123 controls each unit of the exposure unit 6 based on an input image signal (modulation signal). Then, the photosensitive member 2 is exposed by the light beam L to form an electrostatic latent image on the photosensitive member 2 corresponding to an image signal.
[0022]
For example, when print dot data is generated by the CPU 111 based on image data provided from an external device such as a host computer via the interface 112, the print dot data is subjected to, for example, pulse width modulation (PWM) by the modulation signal generation unit 210. PWM). Then, when the modulation signal is given to the exposure power control unit 123, each unit of the exposure unit 6 is controlled by the exposure power control unit 123, and the photoconductor 2 is exposed by the light beam L based on the modulation signal, and An electrostatic latent image corresponding to the data is formed on the photoconductor 2. On the other hand, as described later, when an image forming operation of a predetermined image pattern is performed, a modulation signal corresponding to the image pattern is provided from the pattern creation module 125 to the exposure power control unit 123, and the exposure Each unit of the exposure unit 6 is controlled by the power control unit 123, and an electrostatic latent image corresponding to the image pattern is formed. Note that the modulation method of the modulation signal generator 210 is not limited to PWM, and various pulse modulation methods such as pulse amplitude modulation (PAM) can be adopted.
[0023]
The electrostatic latent image thus formed is visualized by the rotary developing unit 4. That is, in this embodiment, as the developing unit 4, a developing unit 4K for black, a developing unit 4C for cyan, a developing unit 4M for magenta, and a developing unit 4Y for yellow are provided rotatably about the axis. . The developing units 4K, 4C, 4M, and 4Y are rotationally positioned, and the developing rollers 40K, 40C, 40M, and 40Y of the developing units 4K, 4C, 4M, and 4Y are selectively provided with respect to the photosensitive member 2. The toner of the selected color is supplied to the surface of the photoreceptor 2 from the developing roller by the developing roller 126 being applied with a developing bias by the developing bias generating unit 126. Thus, the electrostatic latent image on the photoconductor 2 is visualized in the selected toner color. As described above, in this embodiment, the photoconductor 2 corresponds to the “image carrier” of the present invention, the exposure unit 6 corresponds to the “exposure unit” of the present invention, and the rotary developing unit 4 corresponds to the “developing” of the present invention. The exposure unit 6 and the rotary developing unit 4 correspond to the "image forming means" of the present invention.
[0024]
The toner image developed by the developing unit 4 as described above is primarily transferred onto the intermediate transfer belt 71 of the transfer unit 7 in the primary transfer area TR1. Further, a cleaning unit 5 is disposed at a position in the circumferential direction (rotational direction D1 in FIG. 1) from the primary transfer area TR1, and the toner remaining on the outer peripheral surface of the photoconductor 2 after the primary transfer. Is scraped off by the cleaning blade 51. Further, the surface potential of the photoconductor 2 is reset by a charge removing unit (not shown) as necessary.
[0025]
The transfer unit 7 includes an intermediate transfer belt 71 stretched over a plurality of rollers, and a driving unit (not shown) for driving the intermediate transfer belt 71 to rotate. When the color image is transferred to the sheet S, the color image is formed by superimposing the toner images of each color formed on the photoreceptor 2 on the intermediate transfer belt 71, and a predetermined secondary transfer area TR2 is formed. , The color image is secondarily transferred onto the sheet S taken out of the cassette 8. Further, the sheet S on which the color image is formed is conveyed via the fixing unit 9 to a discharge tray provided on the upper surface of the apparatus main body. After the secondary transfer, the toner remaining on the intermediate transfer belt 71 is removed from the intermediate transfer belt 71 by a cleaning unit (not shown).
[0026]
Further, a patch sensor PS is disposed to face the surface of the intermediate transfer belt 71, and when performing an image forming condition adjusting operation described later, the optical density of the patch image formed on the outer peripheral surface of the intermediate transfer belt 71 is determined. Measure.
[0027]
Further, as shown in FIG. 2, the developing units 4K, 4C, 4M, and 4Y are provided with unit-side communication units 41K, 41C, 41M, and 41Y, respectively, and the unit-side communication units 41K, 41C, 41M, and 41Y are provided. Are electrically connected to the memories 42K, 42C, 42M, and 42Y, respectively. The memories 42K, 42C, 42M, and 42Y store various data relating to the production lots, use histories, characteristics of the built-in toner, the remaining amount of the toner, and the like of each of the developing devices 4K, 4C, 4M, and 4Y. Further, the apparatus main body is provided with a main body side communication unit 128 electrically connected to the CPU 124.
[0028]
When the developing rollers 40K, 40C, 40M, and 40Y of the developing devices 4K, 4C, 4M, and 4Y are selectively positioned opposite to the photoconductor 2, the unit-side communication unit of the selected developing device is It is configured to face the main body side communication unit 128 within a predetermined distance, for example, within 10 mm, and can transmit and receive data in a non-contact state with each other by wireless communication such as infrared rays. As a result, the CPU 124 manages various types of information such as detection of mounting of the developing device, detection of a new product, and management of life.
[0029]
In this embodiment, data is transmitted and received in a non-contact manner using electromagnetic means such as wireless communication. However, for example, connectors are provided on the apparatus main body and each of the developing devices 4K, 4C, 4M, and 4Y. When each of the developing devices 4K, 4C, 4M, and 4Y is selectively positioned to face the photoconductor 2, the connector of the apparatus main body is mechanically fitted with the connector of the developing device to transmit and receive data mutually. It may be performed. The memories 42K, 42C, 42M, and 42Y are preferably non-volatile memories that can store data even when the power is off or the developing units 4K, 4C, 4M, and 4Y are removed from the apparatus main body. As the non-volatile memory, for example, an EEPROM such as a flash memory, a ferroelectric memory (Ferroelectric RAM), or the like can be used.
[0030]
In FIG. 2, an image memory 113 provided in the main controller 11 is for storing image data given via an interface 112 from an external device such as a host computer. Further, the memory 127 provided in the engine controller 12 includes a ROM for storing a control program executed by the CPU 124 and a RAM for temporarily storing a calculation result in the CPU 124, control data for controlling the engine EG, and the like. Become. Further, a dot counter 200 is provided in the main controller 11 of the image forming apparatus.
[0031]
FIG. 3 is a block diagram showing the configuration of the dot counter. FIG. 4 is a diagram for explaining a counting procedure by the dot counter, and shows an example of a tone value of a printing dot. The dot counter 200 determines the type of print dots formed on the photoreceptor 2 based on an image signal output from the CPU 111 of the main controller 11 and counts the number of print dots. More specifically, the dot counter 200 includes a comparison circuit 201, a determination circuit 202, and three counters 203 to 205.
[0032]
As shown in FIG. 3, print dot data generated by the CPU 111 is input to the comparison circuit 201 as an image signal output from the CPU 111 of the main controller 11. Then, the comparison circuit 201 compares the gradation level of the image signal corresponding to each print dot with predetermined thresholds L1 and L2. The threshold value L1 is set to a value close to the gradation 0 (that is, 1/63 of the maximum gradation MAX), and the threshold value L2 is set to a value close to the maximum gradation MAX (that is, 48 / MAX of the solid image). 63). Then, the comparison circuit 201 outputs the value “11” to the determination circuit 202 when the gradation level is equal to or larger than the threshold L2, and outputs the value “00” when the gradation level is smaller than the threshold L1. In response to this, the determination circuit 202 determines the continuous state of each print dot, that is, whether or not there is a dot adjacent to the target print dot, and outputs a signal corresponding to the result to the subsequent counters 203 to 205. Output to
[0033]
The operation of the determination circuit 202 will be described in more detail. The discriminating circuit 202 outputs a signal “1” to the counter 203 every time an output signal “11” indicating that a print dot having a gradation level equal to or larger than the threshold value L2 is output from the comparing circuit 201. Therefore, the counter 203 accumulates the number C1 of print dots having gradation levels equal to or greater than the threshold L2. In FIG. 4, print dots 1, 2, 3, 6, and 13 correspond, and C1 = 5.
[0034]
In addition, the determination circuit 202 outputs a signal “1” to the counter 204 when three or more print dots having a gradation level equal to or greater than the threshold L2 continue. Therefore, the counter 204 accumulates the number C2 of three or more continuous dots. In FIG. 4, print dots 1 to 3 correspond, and C2 = 1.
[0035]
Further, a signal “1” is output to the counter 205 when there are no dots equal to or larger than the threshold value L1 on the left and right of the target print dot, that is, when the print dot is an isolated dot. Therefore, the number C3 of the isolated dots is accumulated in the counter 205. In FIG. 4, print dots 6 and 13 correspond to isolated dots, and C3 = 2.
[0036]
In this way, each of the counters 203 to 205 accumulates the number C1 of high tone print dots, the number C2 of three or more continuous dots and the number C3 of isolated dots among them, and for example, one color toner These values are stored in the memory 211 each time one image is formed. These values are transmitted from the memory 211 to the CPU 124 of the engine controller 12 at a predetermined timing (for example, when the formation of toner images of four colors is completed or when data is requested from the CPU 124), and stored in the memory 127 as necessary. Then, it is used for calculating the remaining amount of toner described later.
[0037]
In the image forming apparatus configured as described above, when a print command is given from an external device such as a host computer, a normal image forming operation for forming an image corresponding to the print command is executed. Specifically, a print command, which is an image formation request from an external device, and image data corresponding to the content of an image to be formed are input to the main controller 11 via the interface 112. The CPU 111 of the main controller 11 decomposes the received image data for each toner color, develops the image data into an image signal composed of print dot data having multiple gradation levels, and converts the image signal into a modulation signal generation unit 210. Output to the engine controller 12 via the In response to this, the CPU 124 of the engine controller 12 controls each part of the engine EG to execute the above-described series of image forming operations, whereby a desired image is formed on the sheet S.
[0038]
FIG. 5 is a flowchart illustrating a toner counting operation when a normal image forming operation is performed. In this image forming apparatus, the CPU 124 of the engine controller 12 executes the toner counting operation (1) shown in FIG. The remaining amount of toner of the device 4Y and the like is calculated. Here, a method of obtaining the remaining amount of toner in the developing device 4Y will be described using the yellow color as an example, but the operation is the same for other toner colors.
[0039]
In the toner counting operation (1) in FIG. 5, first, the count values C1, C2, and C3 of the print dots by the dot counter 200 are obtained (step S1). Then, a value Ts obtained by multiplying each of these values by a predetermined coefficient is obtained (step S2). That is,
Ts = Kx · (K1 · C1 + K2 · C2 + K3 · C3)
It is. Here, Kx, K1, K2, and K3 are weighting coefficients set in advance for each toner color. In this way, the printing dots are grouped and counted for each continuous dot number, and each number is multiplied by a weighting coefficient and integrated, whereby the amount of toner adhering to the photoreceptor 2 as an image carrier is accurately determined. You can often ask for it. The method of calculating the amount of toner is described in detail in Patent Document 1 mentioned above, and thus the description thereof is omitted here.
[0040]
Next, the remaining toner amount Tr of the developing device 4Y stored in the memory 127 of the engine controller 12 is read (step S3). Then, a value obtained by subtracting the value Ts obtained above from this value Tr is set as a new toner remaining amount Tr (step S4).
[0041]
Further, it is known that in this type of image forming apparatus, a small amount of toner is consumed even when an image forming operation in which a white image, that is, no print dot is formed, is executed. This is because a part of the incompletely charged toner or the oppositely charged toner moves from the developing device 4Y onto the photoreceptor 2 during the image forming operation, or a part of the toner scatters inside the apparatus. When attached to an image, it is visually recognized as fog.
[0042]
In view of the fact that toner is lost due to such a phenomenon, in this embodiment, the drive offset value Tod corresponding to the drive time of the developing device is set. The drive offset value Tod is obtained by multiplying the drive time of the developing device 4Y by a value obtained by an experiment or the like in advance as a toner scattering amount per unit time in the developing device 4Y (step S5). Here, the driving time of the developing device 4Y may be a time during which a developing bias is applied to the developing device 4Y, or a developing roller 40Y that conveys the toner contained in the developing device 4Y to a position facing the photosensitive member 2. And the like can be used. In addition, if the paper size is constant, the developing device driving time per sheet is generally substantially constant. Therefore, the drive offset value Tod may be determined in advance for each paper size and stored in the memory 127. In this case, the drive offset value Tod corresponding to the formed image size may be extracted from the memory 127 in step S5.
[0043]
By subtracting the drive offset value Tod thus obtained from the remaining toner amount Tr obtained in step S4 (step S6), a new remaining toner amount Tr after forming one image is obtained. This value Tr is updated and stored in the memory 127 (step S7).
[0044]
As described above, the sum (Ts + Tod) of the product sum Ts of each dot count value C1 and the like and the weighting coefficient K1 and the like and the drive offset value Tod (Ts + Tod) is the amount of toner consumed when one sheet of image is formed. become. Then, the amount of toner consumed every time one image is formed is calculated and subtracted from the amount of toner remaining immediately before the image formation, thereby obtaining the remaining amount of toner Tr in the developing device 4Y at the present time (at the end of image formation). Can be requested.
[0045]
In this embodiment, the remaining toner amount in the developing device at each time is obtained by subtracting the toner consumption amount for each image from the initial toner storage amount of each developing device. Needless to say, this is in principle equivalent to calculating the total amount of consumed toner by integrating the toner consumption for each image. As described above, in this embodiment, the CPU 111, the interface 112, and the modulation signal generation unit 210 correspond to the “first control unit” of the present invention, and the CPU 124 corresponds to the “detection unit” of the present invention. 1) corresponds to the “first toner amount detection process” of the present invention. The route from the modulation signal generator 210 to the exposure unit 6 via the exposure power controller 123 corresponds to the “first route” of the present invention.
[0046]
Here, in the developing device 4Y or the like which is configured to be detachable from the apparatus main body, before each developing device is detached from the apparatus main body, the toner remaining amount Tr in the developing device determined above is stored in the memory 42Y. It is preferable that the information is stored in the storage device. When the developing device is mounted on the apparatus main body, the remaining amount of toner in the developing device stored in the memory 42Y or the like is read and used as an initial value of the remaining toner amount Tr in the toner counting operation (1). This facilitates the life management of the developing device. Of course, in a new developing device, the loaded amount of toner at the time of shipment of the developing device may be stored.
[0047]
Returning to FIG. 5, in this embodiment, the toner end of the developing device 4Y is determined based on the remaining amount Tr of the toner after image formation. That is, the remaining toner amount Tr obtained as described above is compared with the minimum toner amount Tmin preset for the developing device 4Y (step S8), and the remaining toner amount Tr falls below the minimum toner amount Tmin. If so, it is determined that the toner has run out, and the fact is notified to the main controller 11 (step S9). On the other hand, if the remaining toner amount Tr is equal to or more than the minimum toner amount Tmin, the toner counting operation ends.
[0048]
The minimum toner amount Tmin is the minimum amount of toner required for the developing device 4Y in order to form a good image using the developing device 4Y. That is, if an image is formed while the toner amount in the developing device is less than the value Tmin, there is a high possibility that serious image quality deterioration such as insufficient image density or blurring of the image occurs. Therefore, as described above, when the toner remaining amount Tr falls below the minimum toner amount Tmin, it is determined that the toner is out, so that it is possible to accurately grasp the replacement time of the developing device 4Y.
[0049]
The operation of the main controller 11 when receiving the notification of the toner end from the engine controller 12 is optional. For example, a message notifying the user of the toner end may be displayed on a display (not shown) to prompt the user to replace the developing device. At this time, the image forming operation may be further continued, or the image forming operation may be prohibited. Further, for example, when the developing device determined to be out of toner is other than the black developing device 4K, only the formation of a monochrome image using black toner may be permitted.
[0050]
By the way, in this image forming apparatus, in addition to the above-described normal image forming operation of forming an image corresponding to external image data, some operations can be performed as an operation of forming an image of a predetermined image pattern. Has become. Then, the amount of toner consumed when each operation is executed is obtained in advance, and is stored in the memory 127 as a test pattern offset value Totn (n is 1, 2, 3, 4 in this embodiment) as described later. Is stored. Hereinafter, these operations will be described in order.
[0051]
(Image formation condition adjustment operation)
FIG. 6 is a flowchart showing the image forming condition adjusting operation. The image forming condition adjusting operation is for adjusting the image forming conditions and controlling the image density to the target density at a predetermined timing such as immediately after the power of the apparatus is turned on or when the number of image forming sheets reaches the predetermined number. In this image forming condition adjusting operation, a patch image of a predetermined pattern is formed while changing and setting the developing bias as a density control factor affecting the image density in multiple stages (step S11). Next, at the timing when each patch image transferred on the intermediate transfer belt 71 is conveyed to a position facing the patch sensor PS, the respective image densities are detected by the patch sensor PS (Step S12), and the image densities are determined. The correlation with the developing bias is determined. Then, based on the correlation thus obtained, a value of the developing bias is calculated so that the image density matches the target density, and the calculated value is set as the optimum value of the developing bias (step S13).
[0052]
When the optimum value of the developing bias is determined in this way, the image forming is executed while setting the developing bias to the optimum value, so that the image can be formed at the target image density. It should be noted that, as such a density control technique, many techniques have been proposed conventionally, and any technique including these known techniques can be applied to the image forming condition adjusting operation of this embodiment. Here, detailed description is omitted.
[0053]
In the image forming condition adjusting operation, a plurality of patch images are formed as described above. Each patch image only needs to have a size (for example, several cm square) that can be detected by the patch sensor PS, and its pattern is relatively simple, such as a solid image or an image in which dots are regularly arranged. Things. Therefore, for such a patch image, a pattern can be independently created in the engine controller 12 without supplying an image signal from the main controller 11. In this embodiment, the pattern creation module 125 (FIG. 2) provided in the engine controller 12 has a function of creating a pattern as a patch image. That is, in the image forming condition adjustment operation, the CPU 124 outputs a control command to the pattern creation module 125 to output an image signal corresponding to the patch image. As a result, the output of the pattern creation module 125 is input to the exposure power control unit 123, and an electrostatic latent image corresponding to the patch image pattern is formed on the photoconductor 2.
[0054]
The image forming condition adjusting operation is for adjusting the operating condition of the engine EG to obtain a desired image density, and can be performed independently of the operation of the main controller 11. Therefore, by generating the patch image pattern in the engine controller 12 in this manner, the main controller 11 does not need to be involved in the operation, and during that time, processing of an image to be formed next is executed. Thus, the processing efficiency of the main controller 11 can be improved.
[0055]
Executing the image forming condition adjusting operation also consumes the toner in the developing device. The toner consumption at this time cannot be obtained from the image signal from the main controller 11. Thus, in this embodiment, as shown in FIG. 6, after optimizing the developing bias, the amount of toner consumed in the image forming condition adjusting operation is obtained. Performs a different toner counting operation (2) (step S14).
[0056]
In the image forming condition adjusting operation, since the pattern of the patch image to be formed is known, it is possible to estimate in advance the amount of toner adhering to the photoconductor 2 as the patch image. Therefore, the toner amount is obtained in advance by an experiment, for example, and stored in the memory 127 as the test pattern offset value Tot1. Then, in the toner counting operation (2), every time a patch image is formed, the offset value Tot1 is subtracted from the immediately preceding toner remaining amount to determine the remaining toner amount in the developing device. This is a major difference from the toner counting operation (1) for obtaining the number of print dots from the image signal. The specific procedure of the toner counting operation (2) will be described later with reference to FIG.
[0057]
(Test pattern formation operation)
In this apparatus, an operation of forming a toner image on the sheet S as a test pattern for the user to visually confirm the image quality is performed. This test pattern is also output from the pattern creation module 125. For this reason, the toner consumption amount at the time of executing this operation is also obtained in advance as the test pattern offset value Tot2 corresponding to the test pattern and stored in the memory 127, and the toner count operation (2) shown in FIG. ), The remaining toner amount Tr at the end of the operation is obtained.
[0058]
(Refresh operation)
In this device, a refresh operation is performed. In the developing units 4K, 4C, 4M, and 4Y, the toner is supplied from the built-in toner container to the developing rollers 40K, 40C, 40M, and 40Y, and the toner layers formed on the developing rollers 40K, 40C, 40M, and 40Y are formed. The thickness is configured to be constant by the regulating blade. Note that, in FIG. 1, for convenience, only the regulating blade 43M of the developing device 4M is denoted by a reference numeral. Then, if image formation with a low image occupation ratio (ratio of the number of print dots to the total number of pixels constituting the toner image) continues, the amount of toner staying at the same location in the developing units 4K, 4C, 4M, and 4Y increases. In addition, the possibility that filming, which is a phenomenon in which an external additive of toner or the toner itself adheres to the surface of the developing roller or the regulating blade, increases.
[0059]
Therefore, in this apparatus, at a predetermined timing (for example, prior to execution of the image forming condition adjusting operation), an image having a preset pattern is formed on the photosensitive member 2 to thereby reduce the fatigue of the developing units 4K, 4C, 4M, and 4Y. A refresh operation for restoring the state is performed. Due to the forced consumption of the toner by the refresh operation, the stagnation of the toner in the developing units 4K, 4C, 4M, and 4Y can be eliminated, thereby preventing the deterioration of the image quality due to the occurrence of filming. .
[0060]
The image pattern formed by this refresh operation is equal to the maximum image range that can be formed in the main scanning direction on the photoconductor 2 (the rotation axis direction of the photoconductor 2), the image occupation ratio is a relatively large value, and It is preferable that the print dots are distributed substantially uniformly in the main scanning direction.
[0061]
An image pattern formed on the photoconductor 2 for this refresh operation is also output from the pattern creation module 125. Therefore, the amount of toner consumption when executing this operation is also obtained in advance as a test pattern offset value Tot3 corresponding to the image pattern and stored in the memory 127, and the toner count operation (2) shown in FIG. ), The remaining toner amount Tr at the end of the operation is obtained.
[0062]
(Special image forming operation)
In this apparatus, a special image forming operation is performed. In recent years, with the improvement of the performance of the color image forming apparatus, there has been a possibility that the color image forming apparatus may be illegally used. A special image that can specify the image forming apparatus is superimposed and printed. The special image is manufactured by using an output color component (for example, yellow) which is least noticeable to human eyes among output color components (magenta, cyan, yellow, and black in the present embodiment) of the image forming device. It represents a number or the like and is set in advance. Therefore, the amount of toner consumed by the special image formation is also obtained in advance as the test pattern offset value Tot4 corresponding to the special image and stored in the memory 127.
[0063]
Then, a special image to be formed on the photoconductor 2 for this special image forming operation is also output from the pattern creation module 125. On the other hand, a modulation signal corresponding to image data received from the outside is output from the modulation signal generation unit 210, and both are superposed by the exposure power control unit 123 and sent to the exposure unit 6. Therefore, the toner consumption amount when executing this operation is determined by executing the toner counting operation (1) shown in FIG. 5 and then executing the toner counting operation (2) shown in FIG. 7 described below. The remaining toner amount Tr at the end of the operation is obtained.
[0064]
FIG. 7 is a flowchart showing the toner counting operation (2). That is, in the toner counting operation (2), first, the test pattern offset value Totn corresponding to the operation is extracted from the memory 127 (step S141). That is, the test pattern offset value Tot1 is extracted for the image forming condition adjustment operation, the test pattern offset value Tot2 is extracted for the test pattern formation operation, and the test pattern offset value Tot3 is extracted for the refresh operation. In the case of a special image forming operation, the test pattern offset value Tot4 is extracted. As described above, in the toner counting operation (2), the amount of toner adhering to the photoconductor 2 as a toner image is simply given as an offset value according to the image pattern without calculation.
[0065]
If the amount of toner adhering to the photoreceptor 2 as a toner image is thus known, the subsequent operation is the same as the toner counting operation (1) shown in FIG. That is, the remaining toner amount Tr up to the present time is read from the memory 127, and the offset value Totn and the drive offset value Todn are subtracted from the values, thereby obtaining the remaining toner amount Tr after the execution of the operation (steps S142 to S146). . If the value Tr is smaller than the minimum toner amount Tmin, it is determined that the toner has run out (steps S147 and S148). As described above, the remaining toner amount Tr after executing the image forming condition adjusting operation, the test pattern forming operation, the refresh operation, and the special image forming operation is obtained.
[0066]
In the image forming condition adjusting operation, the test pattern forming operation, the refresh operation, and the special image forming operation, since the image pattern to be formed is determined, the drive offset value Todn is also considered to be constant. Therefore, an offset value Ton corresponding to the sum (Totn + Todn) of the test pattern offset value Totn and the drive offset value Todn is stored in the memory 127 corresponding to each formation pattern, and the formed pattern is used in the toner counting operation (2). May be extracted from the memory 127 and used for calculating the remaining amount of toner.
[0067]
As described above, in this embodiment, the sum (Totn + Todn) of the test pattern offset value Totn and the drive offset value Todn is determined by the toner amount consumed in the image forming condition adjustment operation, the test pattern formation operation, the refresh operation, and the special image formation operation. The CPU 124, the pattern creation module 125, and the memory 127 correspond to “second control means” of the present invention, the CPU 124 corresponds to “detection means” of the present invention, and the toner counting operation (2) Second toner amount detection process. " The route from the pattern creation module 125 to the exposure unit 6 via the exposure power control unit 123 corresponds to the “second route” of the present invention.
[0068]
As described above, in this embodiment, when the image forming operation based on the image signal input from the CPU 111 via the modulation signal generation unit 210 and the exposure power control unit 123 is performed, the number of print dots is determined based on the image signal. Is counted, and the count value is multiplied by a predetermined coefficient and integrated to determine the toner consumption (toner counting operation (1); FIG. 5). On the other hand, when an image forming operation based on an image signal input from the pattern creation module 125 via the exposure power control unit 123 is executed, an offset value obtained in advance as an amount of toner consumed by the operation is set to the toner value at that time. This is the consumption amount (toner counting operation (2); FIG. 7). As described above, since the respective toner amount detection processes are different, the toner consumption amount can be obtained by an appropriate method corresponding to the operation to be performed, and the toner consumption amount in each developing device can be accurately obtained. Is possible. In addition, the amount of toner consumption in each operation mode can be obtained only by calculation, so that the processing is simple.
[0069]
In particular, offset values corresponding to a plurality of operations are stored in the memory 127 as operations for forming a predetermined image pattern, and offset values corresponding to operations to be executed are extracted from the memory 127. It is possible to easily and accurately obtain the toner consumption amount for various operations.
[0070]
Then, the amount of toner consumption obtained for each operation is sequentially subtracted from the immediately preceding remaining amount of toner each time each operation is performed, thereby grasping the amount of toner remaining in each developing device at each time. Can be.
[0071]
The present invention is not limited to the above-described embodiment, and various changes other than those described above can be made without departing from the gist of the present invention. For example, in the above-described embodiment, the dot counter 200 is configured as an independent functional block. However, for example, the dot counter may be configured as software executed by a CPU provided in either the main controller 11 or the engine controller 12. The above may be realized.
[0072]
Further, for example, in the above-described embodiment, the CPU 124 of the engine controller 12 calculates the toner consumption based on the count value of the dot counter 200 provided in the main controller 11 and the offset value corresponding to the predetermined image pattern forming operation. However, the present invention is not limited to this. For example, the CPU 111 of the main controller 11 may receive the offset value from the engine controller 12 and calculate the toner consumption. May be provided on the engine controller 12 side.
[0073]
Further, for example, in the above-described embodiment, the remaining amount of toner is obtained every time one image is formed in the normal image forming operation. However, the timing of obtaining the remaining amount of toner is not limited to this. Optional. For example, when there is an image formation request corresponding to a plurality of images, the remaining toner amount may be obtained after forming all the images or every time a predetermined number of images are formed.
[0074]
Further, for example, in the above-described embodiment, the toner end is determined when the remaining toner amount Tr is less than the minimum toner amount Tmin, but the toner consumption amount or the remaining toner amount obtained by calculation is determined. Thus, other controls can be performed. For example, the timing at which the above-described image forming condition adjustment operation is performed may be determined based on the remaining amount of toner. That is, the image forming condition adjusting operation may be executed when the remaining amount of toner reaches a predetermined value. Since the toner characteristics in the developing device gradually change, and the image density may fluctuate accordingly, determining the execution timing of the image forming condition adjustment operation based on the remaining amount of the toner depends on the image density. This is effective in achieving stability. Further, for example, the amount of toner removed from the photoconductor 2 by the cleaning blade 51 of the cleaning unit 5 and collected in a waste toner tank (not shown) of the cleaning unit 5 is estimated from the total amount of consumed toner. The empty capacity of the waste toner tank may be estimated based on the value.
[0075]
In the above-described embodiment, the image forming apparatus is configured to be able to form a full-color image using four color toners of yellow, cyan, magenta, and black. The present invention is not limited to this, and is arbitrary. For example, the present invention can be applied to an apparatus that forms a monochrome image using only black toner.
[0076]
Further, in the above embodiment, the present invention is applied to a printer that receives image data from outside the apparatus and executes an image forming operation based on an image signal corresponding to the image data. An image signal is created inside the apparatus in response to the pressing of the copy button, and a copier that performs an image forming operation based on the image signal or receives image data given via a communication line to execute the image forming operation. It goes without saying that the present invention is also applicable to a facsimile machine to be executed.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of an image forming apparatus according to the present invention.
FIG. 2 is a block diagram illustrating an electrical configuration of the image forming apparatus of FIG. 1;
FIG. 3 is a block diagram showing a configuration of a dot counter.
FIG. 4 is a diagram illustrating a dot counting procedure.
FIG. 5 is a flowchart illustrating a toner counting operation (1).
FIG. 6 is a flowchart illustrating an image forming condition adjustment operation.
FIG. 7 is a flowchart illustrating a toner counting operation (2).
[Explanation of symbols]
2 photoreceptor (image carrier), 4 developing unit (image forming means, developing means), 6 exposure unit (image forming means, exposing means), 11 main controller, 12 engine controller, 111 CPU ( Interface (first control means), 124 CPU (detection means), 125 pattern creation module (second control means), 127 memory (storage means, second control means), 200 ... Dot counter (counting means), 210... Modulation signal generator (first control means)

Claims (8)

Image forming means for forming a toner image on an image carrier based on an input image signal;
Detecting means for detecting an amount of toner consumed by toner image formation by the image forming means,
In an image forming apparatus for obtaining a toner consumption amount based on an integrated value obtained by integrating the toner amounts detected by the detection unit,
As a route for inputting the image signal to the image forming unit, a first route and a second route different from the first route are provided.
The detection unit detects a first toner amount based on an image signal input to the image forming unit via the first route, and detects an image signal input to the image forming unit via the second route. And a second toner amount detection process based on the second toner amount detection process. First control means for receiving image data, generating an image signal corresponding to the image data, and sending the image signal to the image forming means via the first route;
A second control unit that sends an image signal corresponding to a preset image pattern to the image forming unit via the second route,
The image forming means forms a toner image corresponding to the image data based on an image signal input from the first control means via the first route, and forms a toner image corresponding to the image data via the second route from the second control means. Forming a toner image corresponding to the image pattern based on the input image signal.
2. The image according to claim 1, wherein the detection unit detects the toner amount based on the image data as the first toner amount detection process, and detects the toner amount based on the image pattern as the second toner amount detection process. 3. Forming equipment. A storage unit that stores a toner amount consumed when a toner image corresponding to the image pattern is formed as an offset value,
3. The image forming apparatus according to claim 2, wherein the detecting unit sets the offset value to the toner amount when an image signal is input from the second control unit to the image forming unit via the second route. The second control unit is configured to be capable of transmitting image signals corresponding to a plurality of image patterns set in advance to the image forming unit,
The storage unit stores, as an offset value, a toner amount consumed when a toner image corresponding to the plurality of image patterns is formed,
When an image signal is input to the image forming unit from the second control unit via the second route, the detecting unit extracts an offset value of an image pattern corresponding to the image signal from the storage unit. 4. The image forming apparatus according to claim 3, wherein the offset value is the toner amount. The image forming means includes an exposing means for forming an electrostatic latent image on the image carrier, and a developing means for adhering toner to the image carrier to visualize the electrostatic latent image. ,
The second control means previously stores a modulation signal corresponding to the image pattern as a modulation signal for controlling an exposure amount of the exposure means, and uses the modulation signal as the image signal via the second route. The image forming apparatus according to claim 2, wherein the image is sent to the exposure unit. A counting unit electrically connected to the first control unit;
The image forming means includes an exposing means for forming an electrostatic latent image on the image carrier, and a developing means for adhering toner to the image carrier to visualize the electrostatic latent image. ,
The first control unit generates print dot data based on the image data, sends the print dot data to the counting unit, and outputs a modulation signal for controlling an exposure amount of the exposure unit based on the print dot data. Generating and sending the modulated signal as the image signal to the exposure unit via the first route.
The counting means counts the number of print dots forming the toner image corresponding to the image data based on the print dot data,
When an image signal is input from the first control unit to the image forming unit via the first route, the detection unit detects the toner amount based on the number of the printing dots counted by the counting unit. The image forming apparatus according to claim 2, wherein the detection is performed. The image forming apparatus according to claim 1, further comprising a determination function of determining that the toner is exhausted when the calculated toner consumption exceeds a predetermined value. An image forming unit that forms a toner image on an image carrier based on an input image signal,
In an image forming apparatus, a first route and a second route different from the first route are provided as routes through which the image signal is input to the image forming unit.
A first detection step of detecting an amount of toner consumed by the image forming unit to form a toner image based on an image signal input to the image forming unit via the first route;
A second detection step of detecting an amount of toner consumed by the image forming unit to form a toner image based on an image signal input to the image forming unit via the second route;
Obtaining a toner consumption amount based on an integrated value obtained by integrating the toner amounts detected in the first detection step and the second detection step,
A method for calculating a toner consumption amount in an image forming apparatus, wherein the toner amount is detected by different steps in the first detection step and the second detection step.

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