JP4140545B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus capable of appropriately setting a toner shortage level in accordance with an initial capacity of toner in a developing device.

  In general, in an electrophotographic image forming apparatus employed in a copying machine, a facsimile machine, a printer, or the like, an electrostatic latent image is formed by an exposure device on the surface of a photosensitive drum charged by a charging device. The latent image is developed by a toner type developing device provided with a developing roller. Further, the image forming apparatus transfers the developed toner image from the photosensitive drum onto the recording paper by the transfer device, and fixes the toner image on the recording paper as a permanent image by the fixing device provided on the downstream side of the transfer device. It has become.

Usually, the developing device is unitized and is detachably attached to the main body of the image forming apparatus. When the toner stored in the developing device runs out, a toner shortage alarm is displayed, so the developing device in the toner shortage state is replaced with a developing device full of toner. The setting value of the toner shortage level of the developing device is set to a constant value as the absolute value of the toner capacity in the developing device. That is, when the signal detected by the toner capacity sensor reaches a predetermined value, a toner shortage alarm is displayed on the display device from the control device. (See Patent Document 1)
Japanese Patent Laid-Open No. 06-194907

  The toner stored in the developing device deteriorates with time due to factors such as changes in environmental conditions. For this reason, the toner when the storage amount decreases is deteriorated in quality, and defects such as density unevenness occur in the image printed on the recording paper, so that the toner is left in a predetermined capacity. Yes. At this time, the proper toner capacity that must be left varies depending on the initial toner capacity. That is, if the developing device has a large amount of initial toner, a large amount of toner is left, and if the developing device has a small initial capacity of toner, a small amount of toner may be left. However, conventionally, in consideration of a developing device having a large amount of initial toner capacity, a fixed amount of toner that is constant in absolute value is used, and a constant amount of toner is left in the developing device and discarded. In particular, in the case of a developing device with a small initial capacity of toner, the toner shortage level is too high, and it is discarded even though there is still enough quality toner to be used. There was a problem that waste was generated.

  The present invention solves the above-mentioned problems in the prior art, and sets the toner shortage level appropriately in accordance with the initial capacity of the toner stored in the developing device or the toner cartridge so as to effectively use the toner. An object of the present invention is to provide an image forming apparatus capable of performing the above.

In order to solve the above problems, the invention described in claim 1 forms an electrostatic latent image on the surface of the photosensitive member charged by the charging means by the exposure means, and the electrostatic latent image is converted into a toner-based image. In the image forming apparatus developed by the developing unit and the developed toner image is transferred onto the recording paper by the transfer unit, the developing unit or the developing unit main body is detachably attached to the main body of the image forming apparatus. An initial capacity determining means for determining a version of the toner cartridge that is mounted and determining an initial capacity of the toner stored in the developing device or the toner cartridge; and a toner capacity stored in the developing device or the toner cartridge. According to the determination result of the toner capacity by the toner capacity detecting means for detecting the remaining amount and the initial capacity determining means, the initial capacity is large. As a toner shortage level setting means for setting a change to the storage means a set value so as to increase the set value of the toner shortage level, the remaining amount of toner detected by the toner capacity detecting means said toner shortage level The gist of the present invention is to provide a toner shortage notifying means for performing a toner shortage notification when the value is equal to or less than the set value .

The invention according to claim 2, in claim 1, an initial capacity determining means before Symbol toner storing version data including data of the initial volume of the pre-equipped are Rutotomoni least toner to the developing device or the toner cartridge The gist of the invention is that the data of the initial capacity of the toner is read from the version data storage means.

  A third aspect of the present invention is characterized in that, in the second aspect, the version data storage means is a chip in which data of an initial capacity of toner provided in a developing device or a toner cartridge is stored.

  According to the present invention, the initial capacity of the toner stored in the developing device or the toner cartridge is determined by the toner initial capacity determination means, and the set value of the toner shortage level suitable for the determination result is stored in the storage means. Remembered. For this reason, according to the initial capacity of the toner stored in the developing unit or the toner cartridge, the set value of the toner shortage level is appropriately set to reduce the amount of toner to be discarded and to effectively use the toner. Can do.

Hereinafter, an embodiment in which the present invention is embodied in an electrophotographic image forming apparatus employed in a copying machine, a facsimile machine, a printer, or the like will be described with reference to FIGS.
This image forming apparatus forms an electrostatic latent image on the surface of a photosensitive drum as a photosensitive member charged by a charger as a charging unit (not shown) by an exposure unit as an exposure unit. Development is performed by a toner type developing device provided with a developing roller. The image forming apparatus transfers the developed toner image from a photosensitive drum onto a recording sheet by a transfer unit as a transfer unit, and permanently transfers the toner image by a fixing unit as a fixing unit provided on the downstream side of the transfer unit. It is fixed on recording paper as an image.

  The developing device is unitized and is detachably mounted at a predetermined position of the image forming apparatus main body. When the toner stored in the developing device is consumed by the printing operation and the toner becomes low, the toner near empty is displayed.After that, when the set value of the toner shortage level is reached, the toner empty alarm is displayed. It is displayed on the screen of the display device. The developing device that has consumed the toner is replaced with another developing device that stores the full toner.

  Next, based on FIG. 1, when the image forming apparatus is packed and shipped, when the developing device is set in the image forming apparatus main body or when the old and new developing devices are replaced, the image forming apparatus is stored in the developing device. A control system for setting the toner missing level setting value to an appropriate value in accordance with the initial toner capacity will be described.

  This control system includes a control device 11 having a computer for controlling various operations. The control device 11 includes a central processing unit (CPU) 12 for calculating various bias potentials necessary for the recording process based on various data, and storage means for storing various data and operation programs. A read only memory (ROM) 13, a random access memory (RAM) 14 capable of reading and writing various data, a power supply circuit (not shown), and the like are provided.

  On the other hand, the developing device is provided with a chip 15 as a version data storage means including at least the initial capacity data of the toner. In addition to the initial toner capacity data, the chip 15 prestores data such as the date of manufacture of the toner, the destination, or the type of toner.

  The image forming apparatus main body is provided with a reader 16 for reading various data stored in the chip 15 when the developing device is set in the main body. Data read by the reader 16 is input to the CPU 12 via an input / output device 17A on the control device 11 side. Then, the toner of the developing unit is managed based on the data of the developing unit read by the control device 11.

  On the image forming apparatus main body side, a toner capacity sensor 18 is provided as a toner capacity detecting means for detecting the actual storage capacity of toner in the developing device, and a detection value signal of the sensor 18 is input / output device. It is input to the CPU 12 via 17A. As the toner capacity sensor 18, a light projecting / receiving photo interrupter is used. Then, the toner storage height in the developing device is detected and sent to the CPU 12 as a capacity (weight or volume).

  An operation unit 19 for inputting various data such as a keyboard or a mouse is connected to the CPU 12 via the input / output device 17B. Further, the CPU 12 is connected to a display device 21 as a toner shortage forecast or toner shortage notification means for displaying various data on the operating state of the image forming apparatus via the input / output device 17c.

  The CPU 12 is provided with a version determination means 22 as an initial capacity determination means for determining a version such as an initial capacity of toner of the developing device based on data read by the reader 16. The determination means 22 determines the initial toner capacity Wft of the developing device. The CPU 12 is provided with a toner shortage level setting means 23 for setting an appropriate setting value of the toner shortage level according to the magnitude of the initial toner capacity Wft determined by the determination means 22.

  The data table 25 of the ROM 13 stores in advance a plurality of stages of initial capacity Wft of toner of the developing device and a plurality of stages of set values Wet at a toner shortage level suitable for the initial capacity Wft. For example, as the initial capacity Wft increases to 200 g, 300 g, 400 g, and 500 g, the set value Wet of the toner shortage level is stored as a data list so as to increase stepwise as 30 g, 45 g, 60 g, and 75 g. Has been. The toner shortage level setting means 23 reads out the toner shortage level setting value Wet suitable for the actual initial capacity Wft from the data list of the data table 25 stored in the ROM 13, and uses this to read out the toner shortage level in the ROM 13. It is stored in the level set value storage unit 26. The CPU 12 is provided with a developing device replacement counter setting means 27 for counting the number of times of replacement when the developing device is replaced with another developing device.

  Next, the operation of setting the toner shortage level when a new developing device is set based on the control system of the image forming apparatus configured as described above will be described with reference to FIG.

  In FIG. 2, when the developing device is set in the image forming apparatus main body, the version data stored in the chip 15 on the developing device side in step S1 by the reader 16 provided on the image forming apparatus main body side. Can be read. The version data read by the reader 16 is sent to the determination means 22 of the CPU 12 via the input / output device 17A. In step S2, the determination unit 22 determines the version of the developing device. At this time, the initial capacity Wft of the toner of the developing device is determined.

  Next, based on the determination result of the initial capacity Wft of the toner, a set value Wet of the toner shortage level suitable for the initial capacity Wft is selected, and the toner shortage level setting value storage unit 23 stores the toner shortage level setting value storage unit. 26. For example, when the initial toner capacity Wft of the developing device is 200 g, the setting value Wet of the toner shortage level is stored in the setting value storage unit 26 as 30 g.

Next, a method for setting the toner shortage level when the image forming apparatus is shipped and packed will be described with reference to the flowchart shown in FIG.
First, when the developing device is set, the CPU 12 determines whether or not it is the first developing device in step S1. This determination is made when the CPU 12 senses the fusing detection signal because the fuse provided on the developing device side is blown when the developing device is first attached to the image forming apparatus main body. If it is determined as YES in step S1, the number of replacements of the developing device is counted by the developing device replacement counter setting means 27 and set to "1" in the ROM 13 in step S2. In step S3, the initial capacity Wft (for example, 200 g) of the toner of the developing device is determined by reading the chip 15 described above, and based on this, the initial toner missing level setting value (for example, 30 g) is obtained from the data table 25. This is read and stored in the toner shortage level setting value storage unit 26 of the ROM 13.

  On the other hand, if it is determined NO in step S1 described above, it is determined in step S4 whether the version is manually set by a salesman, for example. If YES, the salesman is determined in step S5. Thus, the version is set, and the initial capacity Wft (for example, 300 g) of the toner of the developing device is set by the salesman. Based on this, a set value Wet (for example, 45 g) of the toner shortage level is read from the data table 25 and stored in the ROM 13.

  On the other hand, if it is determined in step S4 that the salesman does not set the version manually, in step S7, the toner missing level setting value Wet (for example, 60 g) similar to the toner missing level setting operation described above is performed. ) Is set.

As a result of the toner low level setting operation described above, the image forming apparatus enters a standby state in which printing on recording paper is possible.
Next, the operation when the printing operation is actually performed from the standby state and the toner capacity of the developing device is reduced will be described with reference to the flowchart of FIG.

  As shown in step S1 from the standby state, when printing is performed, based on the toner capacity detection signal from the toner capacity sensor 18, the CPU 12 determines whether or not the toner near is empty in step S2. If YES is determined in step S2, a toner shortage forecast is displayed on the screen of the display device 21 in step S3.

  On the other hand, if it is determined NO in step S2, whether or not the toner is empty by the CPU 12 based on the toner capacity detection signal from the toner capacity sensor 18 in step S4, that is, whether the set value Wet has been reached. If the answer is yes, a toner shortage alarm is displayed on the screen of the display device 21 in step S5. On the other hand, if it is determined NO in step S4, a standby state is entered.

According to the image forming apparatus of the embodiment, the following effects can be obtained.
(1) In the above embodiment, the version data stored in the chip 15 provided in the developing device is read by the reading device 16, and based on this data, the determination unit 22 determines the initial capacity Wft of the toner of the developing device. On the basis of the determination result, the toner missing level setting means 23 sets the toner missing level setting value Wet to an appropriate value. Therefore, it is possible to easily set an appropriate toner shortage level setting value Wet according to the initial toner capacity Wft of the developing device, and to effectively use the toner according to the initial toner capacity Wft of the developing device. be able to.

  (2) In the above embodiment, by utilizing the toner initial capacity Wft in the version information of the chip 15 provided in the developing device, the CPU 12 is operated to operate the operation unit 19 to determine the determination unit 22 and the toner shortage. It is only necessary to provide a software processing program for the level setting means 23. For this reason, it is not necessary to newly prepare a dedicated component (hardware), and the manufacturing cost can be reduced.

  (3) In the above-described embodiment, when the image forming apparatus is packaged and shipped, the CPU 12 determines whether or not it is the first developing device, and when it is determined that it is the first developing device. The number of replacement of the developing device is counted by the developing device replacement counter setting means 27 and the number of times is set to “1”, and the function of displaying on the display device 21 is given. For this reason, the number of replacements of the developing device can be easily confirmed by the display device 21.

  (4) In the above embodiment, even when the developing device is replaced, the version data of the developing device is read, and the set value Wet of the toner shortage level is read from the data table 25 based on the initial capacity Wft of the toner. And stored in the ROM 13. Therefore, it is possible to easily set the set value Wet of the toner shortage level suitable for the replaced developing device.

In addition, you may change the said embodiment as follows.
○ As a means for discriminating the version of the developing device, for example, a developing device version of another company's model is provided by incompatible pins provided on the developing device side or a plurality of sensors embedded on the image forming apparatus main body side. It may be determined whether or not. In this case, the toner shortage level is set as shown in the flowchart of FIG.

  In place of the method in which the entire developing device can be replaced, a developing device in which only the toner cartridge storing toner in the developing device main body can be replaced may be used. In this case, an appropriate toner deficient level set value Wet is set in accordance with the initial capacity Wft of the toner by reading the data of the chips provided in the toner cartridges of different versions.

  In the above-described embodiment, an appropriate toner missing level setting value Wet is selected from a data table representing the relationship between the initial toner capacity Wft and the toner missing level setting value Wet. Instead of this, the toner missing level setting value Wet suitable for the initial toner capacity Wft may be calculated using an arithmetic expression for obtaining the toner missing level setting value Wet. As this arithmetic expression, the following expressions can be considered.

  Wet = Wft × (15/100)

FIG. 3 is a block circuit diagram showing an example of a control system for setting a toner shortage level of the developing device of the image forming apparatus of the present invention. 6 is a flowchart for explaining a toner missing level setting method. 6 is a flowchart for explaining a toner missing level setting method. 9 is a flowchart for explaining an operation of displaying a toner shortage forecast or a toner shortage alarm of the image forming apparatus. 6 is a flowchart showing a toner shortage level setting method according to another embodiment of the present invention.

Explanation of symbols

  Wet ... set value, Wft ... initial capacity, 15 ... chip, 22 ... version determination means, 23 ... toner deficient level setting means.

Claims (3)

An electrostatic latent image is formed on the surface of the photosensitive member charged by the charging unit by an exposure unit, the electrostatic latent image is developed by a toner type developing device, and the developed toner image is formed on a recording paper by a transfer unit. In the image forming apparatus adapted to transfer,
An initial capacity of the toner stored in the developing device or the toner cartridge by judging a version of the developing device that is detachably attached to the main body of the image forming apparatus or a toner cartridge that is detachably attached to the main body of the developing device. Initial capacity determination means for determining
Toner capacity detecting means for detecting the remaining amount of toner stored in the developing device or toner cartridge;
In accordance with the determination result of the initial capacity of the toner by the initial capacity determination means, the toner shortage level for changing the setting value so as to increase the setting value of the toner shortage level as the initial capacity increases is set in the storage means. Setting means ;
An image forming apparatus comprising: a toner shortage notifying unit that performs a toner shortage notification when a remaining amount of toner detected by the toner capacity detection unit is equal to or less than a set value of the toner shortage level . In claim 1, the initial capacity determining means before Symbol toner, the developing device or previously provided to the toner cartridge Rutotomoni least from the version data storage means for storing version data including data of the initial volume of the toner in the toner initial capacity An image forming apparatus configured to read the data. 3. The image forming apparatus according to claim 2, wherein the version data storage means is a chip in which data of an initial capacity of toner provided in a developing device or a toner cartridge is stored .

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