JP2010230966A - Apparatus for detecting the amount of remaining toner and image forming apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for detecting the amount of toner remaining in a toner storage container with high accuracy while preventing influence of environmental disturbances of temperature, humidity or the like, or fog and an image density change, and to provide an image forming apparatus using the same. <P>SOLUTION: The device includes: a driving time detecting means for accumulating and detecting the driving time of a toner supply means for supplying toner to a developing device from the toner storage container; an image density detecting means for accumulating and detecting the image densities of an image developed by the developing device; and a remaining toner amount detecting means for converting the accumulated driving time detected by the driving time detecting means and the accumulated image densities detected by the image density detecting means into a common variable, and detecting the amount of toner remaining in the toner storage container, based on a predetermined condition, using at least one of the accumulated driving time and accumulated image densities converted into the common variable. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a toner remaining amount detecting device and an image forming apparatus using the same.

  Conventionally, the image forming apparatus predicts the remaining amount of toner in the toner cartridge that supplies toner to the developing device, and when the remaining amount of toner in the toner cartridge is nearly empty, a message for replacing the toner cartridge is displayed in the user interface It is configured to be displayed on the printer driver.

  At this time, as a technique for detecting the remaining amount of toner in the toner cartridge, for example, those disclosed in Japanese Patent Application Laid-Open No. 7-175368 and Japanese Patent Application Laid-Open No. 2008-70796 have already been proposed.

  The image recording apparatus according to the above-mentioned Japanese Patent Laid-Open No. 7-175368 performs image recording using a developer stored in a storage container, and supplies the developer to the storage container with a certain replenishment amount. In the image recording apparatus capable of replenishing each, a black pixel counting means for counting the number of black pixels of the recorded image, a replenishment detecting means for detecting that the storage container has been replenished, and the black pixels A toner remaining amount monitoring process for monitoring the remaining amount of the developer in the storage container based on the count value of the counting unit and the detection result of the replenishment detecting unit, and performing a predetermined process according to the remaining amount of the developer Means.

In addition, the toner consumption calculation device according to the above-mentioned Japanese Patent Application Laid-Open No. 2008-70796 forms an image using toner, and forms the image in a predetermined unit in the image forming apparatus having the first image carrier. A toner consumption calculation device for obtaining a toner consumption amount consumed at the time,
A temperature and humidity sensor for detecting the temperature and humidity inside the main body of the image forming apparatus;
Density detecting means for detecting the density of an image formed on the first image carrier or the second image carrier to which an image is transferred from the first image carrier;
A counter that counts the cumulative number of rotations of the first image carrier;
Storage means for storing relevant information having toner consumption derivation information related to toner consumption calculation;
Calculating means for calculating a toner consumption amount during image formation of the image forming apparatus using the related information stored in the storage means;
Calculating means for calculating a cumulative value of the toner consumption calculated by the calculating means;
Determination means for determining whether or not the cumulative value of the toner consumption amount is equal to or greater than a predetermined value;
Based on the detection result of the temperature / humidity sensor, the detection result of the density detection means, and the count value of the cumulative number of rotations of the first image carrier detected by the calculation means, the optimum information is selected from the related information. The information for deriving the toner consumption is selected and used to calculate the toner consumption.

  As described above, the technology for detecting the remaining amount of toner in the toner cartridge can be roughly divided into means using a count value of a pixel counter that counts the number of pixels of a recorded image, and a dispense rate of a toner dispense motor that supplies toner. It can be divided into the means used.

Japanese Patent No. 7-175368 JP 2008-70796 A

  By the way, the problem to be solved by the present invention is a toner that is not easily affected by environmental disturbances such as temperature and humidity, fogging and image density fluctuation, and can accurately detect the remaining amount of toner in the toner container. An object of the present invention is to provide a remaining amount detection device and an image forming apparatus using the same.

That is, the invention described in claim 1 is a drive time detecting means for accumulating and detecting the drive time of the toner supply means for supplying toner from the toner container to the developing device;
An image density detecting means for accumulating and detecting an image density of an image developed by the developing device;
The cumulative drive time detected by the drive time detector and the cumulative value of the image density detected by the image density detector are converted into a common variable, and the common variable is determined based on a predetermined condition. A toner remaining amount detecting means for detecting the remaining amount of toner in the toner container using at least one of the accumulated driving time and the accumulated value of the image density. It is a quantity detection device.

  According to a second aspect of the present invention, the toner remaining amount detecting means may be one of the cumulative drive time converted to the common variable or the cumulative value of the image density based on the image density or environmental condition of the image. The image forming apparatus according to claim 1, wherein the remaining amount of toner in the toner container is detected by using the value of.

  Further, in the invention described in claim 3, the toner remaining amount detecting means determines a contribution ratio of the cumulative driving time converted into the common variable and the cumulative value of the image density based on the image density of the image. The remaining amount of toner in the toner storage container is detected in consideration of the cumulative driving time and the cumulative value of the image density converted into a common variable according to the determined contribution rate. The image forming apparatus according to Item 1.

  According to a fourth aspect of the present invention, the toner remaining amount detecting means determines a contribution ratio of the cumulative driving time and the cumulative value of the image density converted into the common variable based on an environmental condition, 2. The remaining amount of toner in the toner container is detected in consideration of an accumulated drive time and an accumulated image density converted to a common variable in accordance with the determined contribution rate. The image forming apparatus described in the above.

  Further, in the invention described in claim 5, the toner remaining amount detecting means is configured to convert the accumulated driving time and the accumulated image density into the common variables based on both the image density and the environmental condition of the image. And the remaining amount of toner in the toner container is detected in consideration of the cumulative driving time and the cumulative value of the image density converted into common variables according to the determined contribution rate. The image forming apparatus according to claim 1.

  According to a sixth aspect of the present invention, the toner remaining amount detecting means refers to the table based on both the image density and the environmental condition of the image, so that the cumulative driving converted into the common variable is performed. 6. The image forming apparatus according to claim 5, wherein a contribution ratio of a cumulative value of time and image density is determined.

Furthermore, the invention described in claim 7 includes an image carrier that is rotationally driven,
Image exposing means for performing image exposure on the surface of the image carrier to form an electrostatic latent image;
Developing means for developing the electrostatic latent image formed on the surface of the image carrier with toner;
A toner container that contains toner to be supplied to the developing device;
Toner supply means for supplying toner from the toner container to the developing device;
Drive time detection means for accumulating and detecting the drive time of the toner supply means;
An image density detecting means for accumulating and detecting an image density of an image developed by the developing device;
The drive time detected by the drive time detection means and the accumulated value of the image density detected by the image density detection means are converted into a common variable, and converted into a common variable according to a predetermined condition. An image forming apparatus comprising: a toner remaining amount detecting unit that detects a remaining amount of toner in the toner container by switching between the driving time or the accumulated value of the image density.

  According to the first aspect of the present invention, the toner remaining in the toner container is less affected by environmental disturbances such as temperature and humidity, fogging and image density fluctuations, etc. The amount can be detected with high accuracy.

  According to the second aspect of the present invention, the remaining amount of toner can be detected in consideration of the image density of the image and environmental conditions.

  According to the third aspect of the present invention, the remaining amount of toner can be detected in consideration of both the cumulative drive time and the cumulative value of image density.

  According to the fourth aspect of the present invention, it is possible to detect the remaining amount of toner in consideration of both the cumulative drive time and the cumulative value of the image density even when the environmental conditions fluctuate. .

  Further, according to the fifth aspect of the present invention, even when both the image density and the environmental condition of the image fluctuate, the toner remaining amount is considered in consideration of both the cumulative drive time and the cumulative value of the image density. The amount can be detected.

  According to the sixth aspect of the present invention, both the image density and the environmental condition of the image can be arbitrarily set.

  According to the seventh aspect of the present invention, compared to the case without the present configuration, it is less susceptible to environmental disturbances such as temperature and humidity, fogging and image density fluctuations, and the like. The remaining amount of toner can be detected with high accuracy, and it can be avoided that the image forming apparatus cannot be used due to a shortage of remaining toner.

1 is a block diagram showing a control circuit of a color image forming apparatus as an image forming apparatus to which a toner remaining amount detecting apparatus according to Embodiment 1 of the present invention is applied. FIG. 2 is a block diagram showing a color image forming apparatus as an image forming apparatus to which the toner remaining amount detecting apparatus according to the first embodiment of the present invention is applied. FIG. 3 is a flowchart showing the operation of the color image forming apparatus as the image forming apparatus to which the toner remaining amount detecting apparatus according to the first embodiment of the present invention is applied. FIG. 4 is a flowchart showing the operation of the color image forming apparatus as the image forming apparatus to which the toner remaining amount detecting apparatus according to the first embodiment of the present invention is applied. FIG. 5 is a graph showing the prediction result of the remaining amount of toner based on the cumulative value of image density at the time of low area coverage. FIG. 6 is a flowchart showing the operation of the color image forming apparatus as the image forming apparatus to which the toner remaining amount detecting apparatus according to the second embodiment of the present invention is applied. FIG. 7 is a graph showing the contribution ratio due to the cumulative value of image density. FIG. 8 is a flowchart showing the operation of the color image forming apparatus as the image forming apparatus to which the toner remaining amount detecting apparatus according to the third embodiment of the present invention is applied. FIG. 9 is a graph showing the contribution rate due to the cumulative drive time. FIG. 10 is a graph showing a predicted value of the remaining amount of toner based on the cumulative driving time. FIG. 11 is a graph showing a predicted value of the remaining amount of toner based on the cumulative value of image density. FIG. 12 is a flowchart showing the operation of the color image forming apparatus as the image forming apparatus to which the toner remaining amount detecting apparatus according to the fourth embodiment of the present invention is applied. FIG. 13 is a block diagram showing a control circuit of a color image forming apparatus as an image forming apparatus to which the toner remaining amount detecting apparatus according to the fifth embodiment of the present invention is applied. FIG. 14 is a flowchart showing the operation of the color image forming apparatus as the image forming apparatus to which the toner remaining amount detecting apparatus according to the fifth embodiment of the present invention is applied. FIG. 15 is a table showing a table used in a color image forming apparatus as an image forming apparatus to which the toner remaining amount detecting apparatus according to the fifth embodiment of the present invention is applied.

  Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1
FIG. 2 shows a color image forming apparatus as an image forming apparatus to which the remaining toner amount detecting apparatus according to the first embodiment of the present invention is applied. In addition to the function as a printer for printing image data sent from a personal computer (PC) 2, the color image forming apparatus 1 copies an image of a document (not shown) read by the image reading device 3 or image information. It is also configured to function as a copying machine that transmits and receives data and a facsimile.

  In the color image forming apparatus 1, as shown in FIG. 2, shading correction and position shift correction are performed on image data sent from a personal computer (PC) 2 or an image reading device 3 as necessary. An image processing unit 4 for performing predetermined image processing such as brightness / color space conversion, gamma correction, frame erasing, color / moving editing, and the like is provided, and image processing is performed by the image processing unit 4. A control unit 5 is provided for controlling the color image forming operation based on the received image signal.

  Then, the image signal that has been subjected to the predetermined image processing by the image processing unit 4 as described above is processed by the image processing unit 4 in the same manner as yellow (Y), magenta (M), cyan (C), and black (K). And output as a full-color image or a monochrome image by the image output unit 6 provided inside the color image forming apparatus 1 as described below.

  The image data converted into the four color image signals of yellow (Y), magenta (M), cyan (C), and black (K) by the image processing unit 4 is yellow (Y), magenta (M), cyan. (C) and black (K) image forming units 7Y, 7M, 7C, and 7K, which are sent to the image forming units 7Y, 7M, 7K, and 7K, which emit LED light emitting elements according to the corresponding color image signals. Image exposure is performed by light emitted from the array.

  Inside the main body 100 of the color image forming apparatus 1, as shown in FIG. 2, four image forming units (image forming units) of yellow (Y), magenta (M), cyan (C), and black (K) are provided. 7Y, 7M, 7C, and 7K are horizontal so that the yellow (Y) image forming unit 7Y of the first color is relatively high and the black (K) image forming unit 7K of the final color is relatively low. They are arranged in parallel at a predetermined interval in a state inclined by a predetermined angle with respect to the direction.

  In this way, the four image forming units 7Y, 7M, 7C, and 7K of yellow (Y), magenta (M), cyan (C), and black (K) are arranged in an inclined state by a predetermined angle. As a result, the distance between the image forming units 7Y, 7M, 7C, and 7K can be set shorter than in the case where these four image forming units 7Y, 7M, 7C, and 7K are arranged horizontally, and a color image can be set. The forming apparatus 1 can be reduced in size by reducing the width.

  These four image forming units 7Y, 7M, 7C, and 7K are basically configured in the same manner except for the color of the image to be formed. As shown in FIG. A photosensitive drum 10 as an image carrier that is rotationally driven at a predetermined speed along the A direction, a charging roll 11 for primary charging that uniformly charges the surface of the photosensitive drum 10, and the photosensitive drum An image exposure device 8 comprising an LED print head that exposes an image corresponding to a predetermined color on the surface of the body drum 10 to form an electrostatic latent image, and an electrostatic latent image formed on the photosensitive drum 10 Is developed with a toner of a predetermined color, and a cleaning device 13 for cleaning the surface of the photosensitive drum 10.

  The photosensitive drum 10 is, for example, formed in a drum shape with a diameter of 30 mm and having a surface coated with an organic photoconductor, and is driven at a predetermined speed along the direction of arrow A by a drive motor (not shown). Driven by rotation.

  Further, as the charging roll 11, for example, a roll-shaped charger in which a conductive layer made of synthetic resin or rubber and having an adjusted electric resistance is coated on the surface of the core metal is used. A predetermined charging bias is applied.

  As shown in FIG. 2, the image exposure apparatus 8 is individually arranged for each of the four image forming units 7Y, 7M, 7C, and 7K, and is provided in each of the image forming units 7Y, 7M, 7C, and 7K. The image exposure apparatus 8 includes an LED light-emitting element array in which LED light-emitting elements are linearly arranged along the axial direction of the photosensitive drum 10 at a predetermined pixel density (for example, 600 dpi to 2400 dpi), and the LED light emission. A device provided with a SELFOC lens (trade name) array that images light emitted from each LED light emitting element of the element array in a spot shape on the photosensitive drum 10 is used. Further, as shown in FIG. 2, the image exposure device 8 is configured to scan and expose an image on the photosensitive drum 10 from below.

  The image exposure device 8 is not limited to an LED light-emitting element array, and may naturally use a device that deflects and scans a laser beam along the axial direction of each photosensitive drum 10. In this case, one image exposure device 8 is provided for the four image forming units 7Y, 7M, 7C, and 7K.

  From the image processing unit 4, the image exposure device 8Y provided individually for each of the image forming units 7Y, 7M, 7C, and 7K for each color of yellow (Y), magenta (M), cyan (C), and black (K). , 8M, 8C, and 8K, corresponding color image signals are sequentially output, and light beams emitted from these image exposure apparatuses 8Y, 8M, 8C, and 8K in accordance with the image signals are output from the corresponding photosensitive drums 10. The surface is scanned and exposed to form an electrostatic latent image corresponding to the image signal. The electrostatic latent image formed on the photosensitive drum 10 is converted into yellow (Y), magenta (M), cyan (C), and black (K) colors by developing devices 12Y, 12M, 12C, and 12K, respectively. Developed as a toner image.

  The yellow (Y), magenta (M), cyan (C), and black (K) toner images sequentially formed on the photosensitive drums 10 of the image forming units 7Y, 7M, 7C, and 7K are as follows. Four intermediate transfer rolls 15Y, 15M, 15C, and 15K are provided on an intermediate transfer belt 14 as an endless belt-like intermediate transfer member disposed in an inclined state over the image forming units 7Y, 7M, 7C, and 7K. Primary transfer is sequentially performed in multiples.

  The intermediate transfer belt 14 is an endless belt member stretched by a plurality of rolls, and the lower side running region of the belt member is relatively low on the downstream side along the running direction and relatively on the upstream side. It is arranged in a state inclined with respect to the horizontal direction so as to be higher.

  That is, as shown in FIG. 2, the intermediate transfer belt 14 is wound around the drive roll 16, the back support roll 17, the tension applying roll 18, and the driven roll 19 with a constant tension. By a drive roll 16 that is rotationally driven by a drive motor with excellent constant speed (not shown), it is circulated at a predetermined speed along the arrow B direction. As the intermediate transfer belt 14, for example, a flexible synthetic resin film such as polyimide or polyamideimide formed in an endless belt shape is used. The intermediate transfer belt 14 is arranged in contact with the photosensitive drums 10Y, 10M, 10C, and 10K of the image forming units 7Y, 7M, 7C, and 7K in the lower side running region.

  Further, as shown in FIG. 2, the intermediate transfer belt 14 is disposed at one end of the upper running area of the intermediate transfer belt 14, and the toner image primarily transferred onto the intermediate transfer belt 14 is transferred onto the recording medium 21. A secondary transfer roll 20 as a secondary transfer means for secondary transfer is disposed so as to abut on the surface of the intermediate transfer belt 14 stretched by the back support roll 17.

  The yellow (Y), magenta (M), cyan (C), and black (K) toner images transferred on the intermediate transfer belt 14 in a multiple manner onto the back support roll 17 as shown in FIG. The recording sheet 21 that has been secondarily transferred by electrostatic force onto a recording sheet 21 as a recording medium by a secondary transfer roll 20 that is in pressure contact with the intermediate transfer belt 14 and onto which the toner images of these colors have been transferred, Is conveyed to the fixing device 30 positioned above. The secondary transfer roll 20 is in pressure contact with the side of the back support roll 17 so that the toner images of the respective colors are secondarily transferred collectively onto the recording paper 21 that is conveyed upward from below in the vertical direction. It has become.

  As the secondary transfer roll 20, for example, an elastic body layer made of a conductive elastic body such as a rubber material to which a conductive agent is added is coated on the outer periphery of a metal core made of a metal such as stainless steel to a predetermined thickness. Used.

  The recording paper 21 onto which the toner images of the respective colors have been transferred is subjected to a fixing process by heat and pressure by the fixing device 30, and is then placed on a discharge tray 23 provided at the upper end of the apparatus main body 100 by a discharge roll 22. Ejected with the image side down.

  As shown in FIG. 2, the recording paper 21 is of a predetermined size and material from a paper feed tray 24 arranged at the bottom of the apparatus main body 100, and includes a paper feed roll 25 and a paper separating / conveying roll. The paper is fed one by one by 26 and is once transported to the resist roll 27 and stopped. Then, the recording paper 21 supplied from the paper feed tray 24 is sent to the secondary transfer position of the intermediate transfer belt 14 by a registration roll 27 that rotates at a predetermined timing. As the recording paper 21, in addition to plain paper, it is also possible to supply thick paper such as coated paper whose surface or both sides are coated, and the recording paper 21 made of coated paper includes a photographic image. Are also output.

  Residual toner and the like are removed from the surface of the intermediate transfer belt 14 after the secondary transfer process of the toner image by the belt cleaning device 28 to prepare for the next image forming process. In FIG. 2, reference numeral 29 denotes a power supply unit that supplies power to each unit of the color image forming apparatus 1.

  In this embodiment, as shown in FIG. 2, the yellow (Y), magenta (M), cyan (C), and black (K) image forming units 7Y, 7M, 7C, and 7K developing devices 12Y and 12M. , 12C, and 12K, toner cartridges 30Y, 30M, 30C, and 30K are provided as toner storage containers that supply at least toner of colors corresponding to the colors. These toner cartridges 30Y, 30M, 30C, and 30K contain yellow (Y), magenta (M), cyan (C), and black (K) toners or a developer composed of a toner and a carrier, respectively. ing.

  These toner cartridges 30Y, 30M, 30C, and 30K are driven to rotate through dispenser motors (not shown) by rotating dispense motors 31Y, 31M, 31C, and 31K as toner supply means at a predetermined timing. The developing device 12Y, 12M, 12C, and 12K corresponding color toners or a developer composed of toner and a carrier are supplied.

  FIG. 1 is a block diagram showing a control circuit of a color image forming apparatus as an image forming apparatus to which the remaining toner amount detecting apparatus according to the first embodiment is applied.

  In FIG. 1, 7Y, 7M, 7C, and 7K denote yellow (Y), magenta (M), cyan (C), and black (K) image forming units. 7M, 7C, and 7K are input with yellow (Y), magenta (M), cyan (C), and black (K) image signals 101 from the image processing unit 4, and each of the image signals 101 corresponds to each image signal 101. Image exposure is performed by the image exposure devices 8 of the image forming units 7Y, 7M, 7C, and 7K. Each of the image forming units 7Y, 7M, 7C, and 7K is provided with a pixel number counter (ICDC) 102 that cumulatively counts the number of pixels of the image signal 101 input to the image exposure apparatus 8. The image processing unit 4 includes a page memory (not shown) that develops an image signal for each page of the recording paper 21, and an image density (area coverage) that is an area ratio of the image signal in one page is the image processing unit 4. Sought by. The pixel number counter 102 may be provided not in the image forming units 7Y, 7M, 7C, and 7K but in the image processing unit.

  Reference numeral 5 denotes a control unit that also functions as a toner remaining amount detecting unit having a calculation function. In this control unit 5, the drive times of the dispense motors 31Y, 31M, 31C, and 31K are accumulated individually. A signal from a dispense counter (Disp) 103 for counting is input, and a detection signal from an environmental sensor 104 for detecting at least one of temperature and humidity inside the color image forming apparatus main body 100 is input.

  In the above configuration, the color image forming apparatus to which the toner remaining amount detecting apparatus according to this embodiment is applied is not easily affected by environmental disturbances such as temperature and humidity, fogging, and image density fluctuations as follows. Thus, it is possible to accurately detect the remaining amount of toner in the toner container.

  That is, in this embodiment, as shown in FIG. 2, the image forming units 7Y, 7M, 7C, and 7K for yellow (Y), magenta (M), cyan (C), and black (K) are individually provided. Corresponding color image signals 101 are output from the image processing unit 4 to the image exposure apparatuses 8Y, 8M, 8C, and 8K. In these image exposure apparatuses 8Y, 8M, 8C, and 8K, the photosensitive drum 10 The surface is subjected to image exposure according to the image signal 101 to form an electrostatic latent image, and the electrostatic latent image formed on the photosensitive drum 10 is visualized by the developing device 12 to be toner. Become a statue. The toner images formed on the photosensitive drums 10 of the yellow (Y), magenta (M), cyan (C), and black (K) image forming units 7Y, 7M, 7C, and 7K are transferred to the intermediate transfer belt 14. Then, the images are sequentially transferred onto the recording paper 21 from the intermediate transfer belt 14 and then subjected to a fixing process by the fixing device 30 and discharged onto the discharge tray 23.

  At this time, the yellow (Y), magenta (M), cyan (C), and black (K) image forming units 7Y, 7M, 7C, and 7K are formed on the surface of the photosensitive drum 10. When developing the electrostatic latent image, toner is gradually consumed.

  In this embodiment, the control unit 5 detects the amount of toner consumed to develop the electrostatic latent image formed on the photosensitive drum 10 by each of the developing devices 12Y, 12M, 12C, and 12K. The obtained toner amount is obtained cumulatively, and the toner consumption in the developing devices 12Y, 12M, 12C, and 12K is determined at a predetermined timing, such as every time an image is formed on a predetermined number of recording sheets 21. Then, the dispense motors 31Y, 31M, 31C, and 31K are driven, and the corresponding color toner is supplied to the developing device 12 from the corresponding toner cartridges 30Y, 30M, 30C, and 30K.

  As described above, the toner cartridges 30Y, 30M, 30C, and 30K are supplied with toner from the toner cartridges 30Y, 30M, 30C, and 30K to the toner cartridges 30Y, 30M, 30C, and 30K as follows. The toner remaining amount is predicted and detected. When the controller 5 determines that the remaining amount of toner in any of the toner cartridges 30Y, 30M, 30C, and 30K has reached a predetermined amount (for example, 250 g), the corresponding toner cartridge 30Y, The user is notified that the remaining amount of toner in 30M, 30C, and 30K is in the near-empty state, which is a state before the empty state, and the remaining amount of toner in the toner cartridges 30Y, 30M, 30C, and 30K is further increased. It is in a near empty state when it is determined that the amount of toner has reached a level that is nearly empty, for example, an image having an image density of about 30% and capable of forming about 50 A4 size images. To the user, and when the remaining amount of toner in the toner cartridges 30Y, 30M, 30C, and 30K further decreases and becomes empty. It controls to forcibly stop the color image forming apparatus.

  As shown in FIG. 1, the control unit 5 of the color image forming apparatus performs each image as shown in FIG. 3 and FIG. 4 based on the image signal 101 output from the image processing unit 4 to the image exposure device 8. The area coverage (cumulative value of image density) of the image developed by the developing device 12 of the forming units 7Y, 7M, 7C, and 7K is 5% or more and 20% or less, or based on a detection signal from the environment sensor 102. Then, it is determined whether or not the temperature and humidity are not less than a predetermined lower limit value and not more than a lower limit value (step 101).

  Then, the control unit 5 determines that the area coverage of the image is not less than 5% and not more than 20% as shown in FIG. 3, or the temperature and humidity are not less than a predetermined lower limit and an upper limit as shown in FIG. If it is determined that it is not less than the value, a remaining amount prediction value is obtained by multiplying the remaining amount prediction ICCD value, which is a cumulative value of the number of pixels for predicting the remaining amount of toner based on the image density, by the conversion coefficient _ICDC (step 102) The obtained remaining amount prediction value is added to the remaining amount prediction integrated value to determine the remaining amount prediction integrated value (step 103). The accumulated value for remaining amount prediction is an initial value set to 0 when the use of the toner cartridge is started or replaced with a new one, and the obtained remaining amount predicted value is cumulatively added.

  Here, the conversion coefficient_ICDC is a remaining amount prediction_ICDC value that is a value for predicting the remaining amount of toner based on the image density, based on the accumulated driving time of the dispense motors 31Y, 31M, 31C, and 31K. It means a coefficient for conversion into a variable (parameter) that is a value common to the remaining amount prediction _Disp value that is a value for predicting the remaining amount.

  Thereafter, the control unit 5 executes a predetermined remaining amount determination process based on the obtained remaining amount prediction integrated value (step 104). In this remaining amount determination process, based on the obtained remaining amount prediction integrated value, a value obtained by subtracting the remaining amount prediction integrated value from the amount of toner initially stored in the toner cartridge is in the plenia empty state. It is determined by determining whether the value has reached the value, the value of the near empty state, or the empty state, and displaying a corresponding message on a user interface (not shown).

  On the other hand, the control unit 5 determines that the area coverage of the image is not 5% or more and 20% or less as shown in FIG. 3, or the temperature and humidity are more than a predetermined lower limit value as shown in FIG. If it is determined that it is less than or equal to the upper limit value, the remaining amount prediction Disp value, which is a value for predicting the remaining amount of toner based on the cumulative driving time of the dispense motors 31Y, 31M, 31C, 31K, is multiplied by the conversion coefficient _Disp. Then, the remaining amount prediction value is obtained (step 105), and the obtained remaining amount prediction value is added to the remaining amount prediction integrated value to obtain the remaining amount prediction integrated value (step 103). Thereafter, the control unit 5 executes a predetermined remaining amount determination process based on the obtained remaining amount prediction integrated value (step 104).

  Thus, in Embodiment 1 described above, the area coverage of the image is not 5% or more and 20% or less by the control unit 5, or the temperature and humidity of the environment are not less than the predetermined lower limit and not more than the upper limit. If it is determined that there is, the remaining amount prediction Disp value, which is a value for predicting the remaining amount of toner based on the cumulative driving time of the dispense motors 31Y, 31M, 31C, 31K, is multiplied by the conversion coefficient _Disp. Based on the value converted into the common value, a toner remaining amount prediction integrated value is obtained.

  For this reason, in an image with low area coverage, as in the case where the area coverage of the image is less than 5%, the toner is consumed more than the cumulative value of the number of pixels detected due to the influence of fogging, etc. When there is a possibility that it cannot be predicted, the remaining amount of toner can be accurately predicted by predicting the remaining amount of toner based on the cumulative driving time of the dispense motors 31Y, 31M, 31C, 31K. It becomes.

  More specifically, for example, when an image with an area coverage of 1% is continuously printed, the remaining amount of toner is predicted based on the cumulative value of the number of pixels, as shown in FIG. It can be seen that the predicted value of the remaining toner amount is greatly deviated from the target value.

  In contrast, when images with 1% area coverage are continuously printed, the remaining amount of toner is predicted based on the cumulative driving time of the dispense motors 31Y, 31M, 31C, and 31K. As shown, it can be seen that the predicted value of the remaining amount of toner in the toner cartridge is substantially close to the target value.

  Further, in the first embodiment, the area coverage of the image is not less than 5% and not more than 20% by the control unit 5, or the temperature and humidity of the environment are not less than the predetermined lower limit and not more than the upper limit. When the determination is made, the remaining amount of toner is predicted based on the cumulative value of the number of pixels, so that the remaining amount of toner can be accurately predicted without being affected by the image density.

Embodiment 2
FIG. 6 shows the second embodiment of the present invention. The same reference numerals are given to the same parts as those in the first embodiment. In the second embodiment, the area coverage value is set according to the area coverage value. Thus, the remaining amount of toner is predicted by determining the contribution rate due to the cumulative value of the number of pixels and the contribution rate due to the cumulative drive time of the dispense motor.

  That is, in the first embodiment, the cumulative value of the number of pixels and the cumulative driving time of the dispense motor are switched and used in accordance with the area coverage of the image or the temperature and humidity of the environment.

  On the other hand, in the second embodiment, as shown in FIG. 6, the control unit 5 causes the contribution ratio between the cumulative value of the number of pixels and the cumulative driving time of the dispense motor according to the image density (area coverage). Is calculated (step 201).

  Here, for example, as shown in FIG. 7, when the image density is 1% or more and less than 5%, the contribution rate is a cumulative value of the number of pixels for predicting the remaining amount of toner based on the image density. The contribution rate is set to change linearly from 100% to 0%.

  In addition, when the image density is less than 1%, the contribution ratio of the cumulative number of pixels is 0%, and when the image density is 1% or more and less than 5%, the contribution ratio of the cumulative number of pixels. When the image density is 5% or more and 20% or less so that the rate changes linearly from 0% to 100%, the cumulative value of the number of pixels for predicting the remaining amount of toner based on the image density When the image density exceeds 20% so that the contribution rate becomes 100%, the image density is set to a predetermined reference value α (for example, set to about 70%, but may be other than this). The contribution ratio of the cumulative value of the number of pixels for predicting the remaining amount of toner based on the image density is set from 100% to the first contribution ratio β (about 25 to 50%), and the image density is When the predetermined reference value α is exceeded, the first contribution rate β is set.

  Next, according to the contribution rate obtained as described above, the control unit 5 multiplies the remaining amount prediction _ICDC value by the ICDC_contribution rate and the conversion coefficient, and sets the remaining amount prediction _ICDC value to the ICDC_contribution rate. The value estimated by multiplying the conversion coefficient is added to calculate the remaining amount prediction value (step 202).

  Then, the control unit 5 adds the calculated remaining amount prediction value to the remaining amount prediction integrated value to determine the remaining amount prediction integrated value (step 203). Thereafter, the control unit 5 executes a predetermined remaining amount determination process based on the obtained remaining amount prediction integrated value (step 204).

  As described above, in the second embodiment, the contribution ratio between the cumulative value of the number of pixels for predicting the remaining amount of toner based on the image density and the cumulative driving time of the dispense motor is changed according to the image density. Thus, compared to the first embodiment, it is possible to predict the toner remaining amount that is closer to the actual.

  Since other configurations and operations are the same as those of the first embodiment, description thereof is omitted.

Embodiment 3
FIG. 8 shows a third embodiment of the present invention. The same reference numerals are given to the same parts as those in the first embodiment, and the second embodiment will be described in accordance with the area coverage value. Whereas the contribution rate due to the cumulative value of the number of pixels and the contribution rate due to the cumulative drive time of the dispense motor are determined, in the third embodiment, the contribution due to the cumulative value of the number of pixels based on environmental conditions. The remaining amount of toner is predicted by determining the rate and the contribution rate due to the cumulative driving time of the dispense motor.

  That is, in the third embodiment, as shown in FIG. 8, the control unit 5 calculates the contribution rate based on the environmental conditions (step 301).

  Here, the contribution rate is, for example, as shown in FIG. 9, the humidity detected by the environmental sensor 104 is an upper value of normal humidity (for example, set to about 55%, but may be other than this). For example, when it is 55% or less, the contribution rate due to the cumulative driving time of the dispense motor is set to 100%, and the environmental humidity exceeds 55% and is set to a predetermined humidity upper limit value (for example, about 70%). However, it is set so that the contribution rate due to the cumulative drive time of the dispense motor changes linearly from 100% to 0% until it reaches (but may be other than this).

  The contribution rate is set so that the contribution rate due to the cumulative driving time of the dispense motor is 0% when the environmental humidity exceeds a predetermined value (for example, 80%).

  Next, according to the contribution rate obtained as described above, the control unit 5 multiplies the remaining amount prediction _ICDC value by the ICDC_contribution rate and the conversion coefficient, and sets the remaining amount prediction _ICDC value to the ICDC_contribution rate. A value that is multiplied by the conversion coefficient is added to calculate the remaining amount prediction value (step 302).

  Then, the control unit 5 adds the obtained remaining amount prediction value to the remaining amount prediction integrated value to determine the remaining amount prediction integrated value (step 303). Thereafter, the control unit 4 performs a predetermined remaining amount determination process based on the obtained remaining amount prediction integrated value (step 304).

  As described above, in the third embodiment, the contribution ratio between the cumulative value of the number of pixels for predicting the remaining amount of toner based on the image density and the cumulative driving time of the dispense motor is changed according to the environmental conditions. Thus, compared to the first embodiment, it is possible to predict the remaining amount of toner with high accuracy even when the environmental conditions fluctuate.

  More specifically, when the environmental humidity exceeds a predetermined value (for example, 80%), the remaining amount of toner is predicted based on the cumulative driving time of the dispense motor. As shown in FIG. Due to the influence of aggregation of the toner, more toner than the actual target value is supplied, and it is difficult to accurately predict the remaining amount of toner.

  On the other hand, even when the environmental humidity exceeds a predetermined value (for example, 80%), the toner remaining amount is predicted based on the cumulative value of the number of pixels, as shown in FIG. It is possible to accurately predict the remaining amount.

  Since other configurations and operations are the same as those of the first embodiment, description thereof is omitted.

Embodiment 4
FIG. 12 shows a fourth embodiment of the present invention. The same reference numerals are given to the same parts as those in the first embodiment, and in this fourth embodiment, the area coverage value, It is configured to predict the remaining amount of toner in consideration of both environmental conditions.

  That is, in the fourth embodiment, as shown in FIG. 12, the controller 5 determines whether or not the image density is 1% or less (step 401), and determines that the image density is 1% or less. If so, it is determined whether the humidity is equal to or lower than the upper limit of normal humidity (step 402). ,

  When the control unit 5 determines that the humidity is equal to or lower than the upper value of the normal humidity, the control unit 5 obtains the remaining amount prediction value by multiplying the remaining amount prediction_Disp value by the conversion coefficient _Disp (step 403). The amount prediction value is added to the remaining amount prediction integrated value to obtain the remaining amount prediction integrated value (step 404). Thereafter, the control unit 5 executes a remaining amount determination process based on the obtained remaining amount prediction integrated value (step 405), and ends the operation.

  If the control unit 5 determines in step 401 that the image density exceeds 1%, or if it is determined in step 402 that the humidity exceeds the upper value of the normal humidity, the remaining amount prediction_ICDC is determined. After the value is multiplied by the conversion coefficient _ICDC to determine the remaining amount prediction value (step 406), the remaining amount prediction value is added to the remaining amount prediction integrated value to determine the remaining amount prediction integrated value (step 404). . Thereafter, the control unit 5 executes a remaining amount determination process based on the obtained remaining amount prediction integrated value (step 405), and ends the operation.

  As described above, in the fourth embodiment, since the remaining amount of toner is predicted in consideration of both the area coverage value and the environmental conditions, the remaining amount of toner can be predicted with higher accuracy.

  Since other configurations and operations are the same as those of the first embodiment, description thereof is omitted.

Embodiment 5
FIG. 13 shows a fifth embodiment of the present invention. The same reference numerals are given to the same parts as those in the first embodiment. In the fifth embodiment, the area coverage value, When estimating the remaining amount of toner in consideration of both environmental conditions, the contribution ratio between the cumulative value of the number of pixels and the cumulative driving time of the dispense motor is determined using a reference table.

That is, in the fifth embodiment, as shown in FIG. 13, the control unit 5 calculates the cumulative value of the number of pixels and the cumulative driving time of the dispense motor according to both the area coverage value and the environmental condition. A reference table (LUT) 110 for determining the contribution rate is provided.
As shown in FIG. 14, the control unit 5 uses the reference table (LUT) 110 according to both the area coverage value and the environmental condition, and uses the cumulative number of pixels, the cumulative driving time of the dispense motor, Is determined (step 501).

  As shown in FIG. 15, the reference table (LUT) 110 has an area coverage value in a vertical column and a relative humidity in a horizontal column, and is based on a detection signal from a pixel counter and an environmental sensor. Thus, the control unit 5 determines the contribution rate of the cumulative value of the number of pixels.

  Then, according to the contribution rate obtained as described above, the control unit 5 converts the remaining amount prediction_ICDC value by the ICDC_contribution rate and the conversion coefficient, and converts the remaining amount prediction_ICDC value into the ICDC_contribution rate and the conversion rate. The value estimated by multiplying the coefficient is added to calculate the remaining amount prediction value (step 502).

  Then, the control unit 5 adds the calculated remaining amount prediction value to the remaining amount prediction integrated value to determine the remaining amount prediction integrated value (step 503). Thereafter, the control unit 4 performs a predetermined remaining amount determination process based on the obtained remaining amount prediction integrated value (step 504).

  As described above, in the fifth embodiment, the contribution of the cumulative value of the number of pixels and the cumulative driving time of the dispense motor in predicting the remaining amount of toner in consideration of both the area coverage value and the environmental conditions. By determining the rate using a reference table, the contribution rate between the cumulative value of the number of pixels and the cumulative drive time of the dispense motor is set in detail, taking into consideration both the area coverage value and the environmental conditions. The remaining amount of toner can be predicted with higher accuracy. In addition, it is possible to cope with various cases by simply rewriting the reference table.

  In this case, the sum of the contribution ratio between the cumulative value of the number of pixels and the cumulative drive time of the dispense motor does not necessarily need to be 100%, and the contribution ratio may be set so as to actually match.

  Since other configurations and operations are the same as those of the first embodiment, description thereof is omitted.

  5: control unit, 7Y, 7M, 7C, 7K: yellow (Y), magenta (M), cyan (C), black (K) image forming unit, 8: image exposure apparatus, 101: image signal, 102: Pixel number counter, 103: Dispense counter, 104: Environmental sensor.

Claims (7)

Drive time detecting means for accumulating and detecting the drive time of toner supply means for supplying toner from the toner container to the developing device;
An image density detecting means for accumulating and detecting an image density of an image developed by the developing device;
The cumulative drive time detected by the drive time detector and the cumulative value of the image density detected by the image density detector are converted into a common variable, and the common variable is determined based on a predetermined condition. A toner remaining amount detecting means for detecting the remaining amount of toner in the toner container using at least one of the accumulated driving time and the accumulated value of the image density. Quantity detection device. The toner remaining amount detecting means uses one of the cumulative driving time or the cumulative value of the image density converted into the common variable based on the image density or environmental condition of the image, The toner remaining amount detection device according to claim 1, wherein the toner remaining amount is detected. The toner remaining amount detecting means determines a contribution rate of the cumulative drive time and the cumulative value of the image density converted into the common variable based on the image density of the image, and is common according to the determined contribution rate. 2. The toner remaining amount detecting device according to claim 1, wherein the remaining amount of toner in the toner container is detected in consideration of the accumulated driving time and the accumulated value of the image density converted into the variable of 1. The toner remaining amount detecting means determines a contribution rate of the cumulative driving time and the cumulative value of the image density converted into the common variable based on an environmental condition, and the common variable according to the determined contribution rate. 2. The toner remaining amount detecting device according to claim 1, wherein the remaining amount of toner in the toner container is detected in consideration of the accumulated driving time and the accumulated value of the image density converted to 1. The toner remaining amount detecting means determines the contribution ratio of the cumulative drive time converted into the common variable and the cumulative value of the image density based on both the image density and the environmental condition of the image, and the determined contribution 2. The toner remaining amount in the toner container according to claim 1, wherein the toner remaining amount in the toner container is detected in consideration of an accumulated driving time and an accumulated image density converted to a common variable according to a rate. Quantity detection device. The toner remaining amount detecting means refers to a table based on both the image density of the image and the environmental condition, and determines the contribution ratio of the accumulated driving time converted into the common variable and the accumulated value of the image density. The toner remaining amount detecting device according to claim 5, wherein A rotationally driven image carrier;
Image exposing means for performing image exposure on the surface of the image carrier to form an electrostatic latent image;
Developing means for developing the electrostatic latent image formed on the surface of the image carrier with toner;
A toner container that contains toner to be supplied to the developing device;
Toner supply means for supplying toner from the toner container to the developing device;
Drive time detection means for accumulating and detecting the drive time of the toner supply means;
An image density detecting means for accumulating and detecting an image density of an image developed by the developing device;
The drive time detected by the drive time detection means and the accumulated value of the image density detected by the image density detection means are converted into a common variable, and converted into a common variable according to a predetermined condition. An image forming apparatus comprising: a toner remaining amount detecting unit that detects a remaining amount of toner in the toner container by switching between the driving time or the accumulated value of the image density.

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