JP3825835B2 - Electrophotographic image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates for example a printer or image forming apparatus utilizing an electrophotographic method which is a copying machine.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, electrophotographic image forming apparatuses such as printers or copiers include general-purpose monochrome image forming apparatuses and color image forming apparatuses.
[0003]
As the above color image forming apparatus, a process for transferring a recording image formed by charging, laser exposure, and development onto a photosensitive drum, which is an electrophotographic photosensitive member, is repeated a plurality of times on the transfer belt. There is known a color image forming apparatus in which a color image is formed, and then the image is transferred to a transfer sheet to obtain a color-printed transfer sheet.
[0004]
[Problems to be solved by the invention]
The capacity of the waste toner box (container) provided in the photosensitive drum unit of the color image forming apparatus of this type is usually set to 2 to 3 times the life of the photosensitive drum. For this reason, it is unlikely that the waste toner overflows and scatters in the color image forming apparatus and stains the inside of the apparatus. For safety, the photosensitive drum unit is provided with a check window for the user to check.
[0005]
The present invention is a further development of the above-described electrophotographic image forming apparatus.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic image forming apparatus capable of accurately detecting the amount of waste toner in a waste toner container at low cost.
[0007]
[Means for Solving the Problems]
The above object is achieved by the electrophotographic image forming apparatus according to the present invention. In summary, the present invention relates to an electrophotographic image forming apparatus that performs printing by irradiating an electrophotographic photosensitive member using a laser and transferring a recording image developed using toner onto a recording material.
The electrophotographic photosensitive member, a waste toner container for collecting toner remaining on the electrophotographic photosensitive member, a non-volatile memory for storing the number of prints of the recording material, and a waste toner amount in the waste toner container are detected. A drum cartridge having a waste toner full sensor provided with a light emitting unit and a light receiving unit ,
Control means for receiving the light received by the light receiving unit of the waste toner full sensor as a pulse width and detecting the amount of waste toner based on the pulse width ;
The control means sets a plurality of detection levels of the waste toner full sensor corresponding to the number of prints , and sets the pulse width value received from the waste toner full sensor and one of the set detection levels. In comparison, when the value of the pulse width is larger than the detection level , the electrophotographic image forming apparatus is characterized by displaying a warning indicating that the amount of waste toner is erroneously detected .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the electrophotographic image forming apparatus according to the present invention will be described in more detail with reference to the drawings.
[0012]
Example 1
First, Embodiment 1 of the color image forming apparatus of this embodiment will be described with reference to FIG.
[0013]
In FIG. 8, a transfer paper cassette 6 for storing the transfer paper 5 is provided at the lower part of the apparatus, and a paper feed roller 7 is installed at the upper part. In addition, a scanner unit 8 for irradiating the photosensitive drum 12 with light is disposed at the upper part of the apparatus. There is a laser (not shown) inside the scanner unit 8, and light emitted from the laser is converted into horizontal scanning by a scanner mirror 10 connected to a high-speed motor 9. The scanned light is reflected by the folding mirror 11 and irradiates the photosensitive drum 12 provided in the photosensitive drum unit 1.
[0014]
A toner scraping roller 13 for cleaning the toner remaining on the surface of the photosensitive drum 12 is provided in the photosensitive drum unit 1.
[0015]
On the other hand, four developing device units 2 a, 2 b, 2 c, and 2 d are arranged in the developing cartridge unit 2, and toners 14 that are visualized according to the electrostatic potential of the photosensitive drum 12 are respectively stored. In the case of a color image forming apparatus, the color of each toner is composed of cyan, magenta, yellow, and black. The developing unit 2a, 2b, 2c, 2d includes a developing roller 15 and a toner container 16 for containing toner 14.
[0016]
Cyan, magenta, black, and yellow images developed by the photosensitive drum 12 and the developing roller 15 are sequentially transferred to the transfer belt 3, and a color image is formed on the transfer belt 3. When a color image is formed on the transfer belt 3, the transfer paper 5 is fed from the transfer paper cassette 6 by a paper feed roller 7 rotated by a drive motor (not shown).
[0017]
The fed transfer paper 5 passes while contacting the lower part of the transfer belt 3, whereby the color image on the transfer belt 3 is transferred to the transfer paper 5. Further, the paper is transported by the paper transport belt 17, heated and fixed by the fixing unit 4, and loaded on the paper discharge stacker 19 by the transport belt 18.
[0018]
As shown in FIG. 1, in the photosensitive drum unit 1, a photosensitive drum 12 and a waste toner box 20 are integrally formed. The waste toner box 20 is provided with a check window 21 for checking the amount of waste toner. The drum unit 1 is equipped with an EEPROM (nonvolatile memory) 22 which will be described later.
[0019]
As shown in FIG. 2, the electrophotographic image forming apparatus of the present embodiment is connected to the EEPROM 22 and connected to the microcomputer 23 for controlling the operation of the image forming apparatus, and a display for notifying the user of information. A unit 24 is provided. FIG. 2 shows only those related to the present invention.
[0020]
The operation flow of the image forming apparatus configured as described above is shown in the flowchart of FIG.
[0021]
First, the microcomputer 23 determines whether the photosensitive drum unit 1 has been replaced or mounted (S1). If it is mounted, the microcomputer 23 reads the number of prints stored in the EEPROM 22 attached to the photosensitive drum unit 1 and stores it in a register CNT in the microcomputer 23 (S2).
[0022]
Next, it is determined whether or not the image forming apparatus has performed printing (S3). When printing is performed, the number of printed sheets is stored in the EEPROM 22 (S4), and the contents of the CNT register are increased one by one (S5).
[0023]
The number of prints is stored in the EEPROM 22, and it is checked whether the content of the CNT register has reached 5000 (S6). If it exceeds the limit, a warning is displayed on the display unit 24, for example, “The number of drums printed on the photosensitive drum unit currently in use has exceeded the prescribed 5000. The waste toner box may be full. Please check with the check window "is displayed (S7).
[0024]
Next, after confirming the check window, it is determined whether the photosensitive drum unit 1 has been removed (S8), and printing is performed again, or the operation is terminated.
[0025]
As described above, in this embodiment, the waste toner capacity of the waste toner box 20 is designed to be sufficiently larger than the life of the photosensitive drum 12, but in the unlikely event that the user inadvertently performs many printings, In order to prevent in-flight scattering, warning display is performed to improve usability without incurring costs.
[0026]
Example 2
In the first embodiment, the case where the capacity of the waste toner box can be increased due to the structure of the mechanism has been described. However, if there is not enough space, the capacity of the waste toner box must be designed to the limit of the life of the photosensitive drum. There may not be. In the second embodiment, in consideration of such a case, it is possible to accurately detect waste toner full without increasing costs.
[0027]
As shown in FIG. 4, the photosensitive drum unit (drum cartridge) 1 according to the present exemplary embodiment includes a photosensitive drum 12 and a waste toner box 20 that are integrally formed. The waste toner box 20 stores waste toner behind the waste toner box 20. And a feed flapper 26 for sending waste toner to the back, and are driven to rotate by a motor (not shown).
[0028]
The waste toner box 20 is provided with a light emitting unit 28 such as an LED or a lamp and a light receiving unit 27 for receiving the light at a passing point of the feed flapper 26.
[0029]
The amount of light entering the light receiving unit 27 is input every time the feed flapper 26 rotates, but when the amount of waste toner increases, no light is incident. The light entering the light receiving unit 27 has a pulse width and is input to the microcomputer 23 (see FIG. 5). That is, as the amount of waste toner increases, the pulse width decreases.
[0030]
When the waste toner box 20 is filled with waste toner, the light is not incident at all even though the feed flapper 26 is rotating. This is a case where the waste toner cannot be stored in the waste toner box 20.
[0031]
However, even if the feed flapper 26 rotates normally, the light entering the light receiving unit 27 often does not always match the amount of waste toner. The cause is due to the fluidity of the waste toner. When the humidity is high, the fluidity becomes extremely poor, indicating that the amount of waste toner is small even though the amount of waste toner is large. A long pulse width is output.
[0032]
As shown in FIG. 5, in the system configuration of this embodiment, the photosensitive drum unit 1 is provided with an EEPROM 22, a light emitting unit 28 , and a light receiving unit 27. A microcomputer 23 is connected to the photosensitive drum unit 1, and the microcomputer 23 is further connected. Is connected to a display unit 24 for notifying the user of information.
[0033]
In this embodiment, as shown in FIG. 6, the amount of waste toner is related to the number of printed sheets, and the detection levels at the time of printing 5000 sheets, 7000 sheets, and 9000 sheets are t3, t2, and t1, respectively. It is set. The normal waveform is shown in the A column, the abnormal waveform is shown in the B column, and it is shown that an abnormal waveform having a pulse longer than the normal pulse width is output when the number of printed sheets is 9000.
[0034]
The operation flow of the image forming apparatus in this embodiment will be described with reference to the flowchart of FIG.
[0035]
First, the microcomputer 23 determines whether the photosensitive drum unit 1 has been replaced or mounted (S11). When mounted, the microcomputer 23 reads the number of prints stored in the EEPROM 22 mounted on the photosensitive drum unit 1 and stores it in a register CNT in the microcomputer 23 (S12).
[0036]
Next, it is determined whether or not the image forming apparatus has performed printing (S13). When printing is performed, the contents of the CNT register are incremented by one (S14), and the number of printed sheets is stored in the EEPROM 22 (S15).
[0037]
Next, according to the values stored in the EEPROM 22, the waste toner full detection level is set as shown in FIG. That is, the detection level is t1 → T (S16, S17) when the number of printed sheets is 9000 or more, t2 → T (S18, S19) when the number is 7000 or more, and t3 → T (S20, S21) when the number is 5000 or more. Is set to be variable.
[0038]
Then, the detection pulse of the detection unit (light receiving unit) 27 is taken into the PCNT register in the microcomputer 23 (S22), and PCNT and T are compared (S23) . In the case of status) , a warning is displayed on the operator panel 24 to inform the user (S24).
[0039]
Next, after confirming the check window, it is determined whether the photosensitive drum unit 1 has been removed (S25), and printing is performed again, or the operation is terminated.
[0040]
In the present embodiment described above, even when it is difficult to detect the accurate amount of waste toner due to the fluidity of the waste toner, it is possible to display a warning that the amount of waste toner has been erroneously detected.
[0041]
【The invention's effect】
As is apparent from the above description, according to the present invention, it is possible to provide an electrophotographic image forming apparatus that can warn of erroneous detection of the amount of waste toner caused by the deterioration of fluidity of waste toner .
[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating a photosensitive drum unit according to a first exemplary embodiment.
FIG. 2 is a system configuration diagram of the first embodiment.
FIG. 3 is a flowchart showing an operation flow of the first embodiment.
FIG. 4 is a configuration diagram illustrating a photosensitive drum unit according to a second exemplary embodiment.
FIG. 5 is a system configuration diagram of a second embodiment.
6 is a waveform diagram showing detection levels in Example 2. FIG.
FIG. 7 is a flowchart showing an operation flow of the second embodiment.
FIG. 8 is a configuration diagram of an electrophotographic image forming apparatus to which the embodiment is applied.
[Explanation of symbols]
1 Photosensitive drum unit (drum cartridge)
12 Photosensitive drum (electrophotographic photosensitive member)
20 Waste toner box (waste toner container)
21 Check window 22 EEPROM (nonvolatile memory)
23 Microcomputer 24 Display unit (display unit)
27 Light receiver (waste toner full sensor)
28 Light emitting part (waste toner full sensor)

Claims (1)

In an electrophotographic image forming apparatus that performs printing by irradiating an electrophotographic photosensitive member using a laser and transferring a recording image developed using toner onto a recording material,
The electrophotographic photosensitive member, a waste toner container for collecting toner remaining on the electrophotographic photosensitive member, a non-volatile memory for storing the number of prints of the recording material, and a waste toner amount in the waste toner container are detected. A drum cartridge having a waste toner full sensor provided with a light emitting unit and a light receiving unit ,
Control means for receiving the light received by the light receiving unit of the waste toner full sensor as a pulse width and detecting the amount of waste toner based on the pulse width ;
The control means sets a plurality of detection levels of the waste toner full sensor corresponding to the number of prints , and sets the pulse width value received from the waste toner full sensor and one of the set detection levels. In comparison, when the value of the pulse width is larger than the detection level , an electrophotographic image forming apparatus that displays a warning indicating that the amount of waste toner is erroneously detected .

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