JP3724777B2 - Image forming apparatus - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, or a complex machine thereof. Specifically, in particular, charging and writing are performed on the image carrier to form an electrostatic latent image, and the electrostatic latent image is developed by attaching toner, and the image obtained by the development is transferred, The present invention relates to an electrophotographic image forming apparatus for recording on a recording medium such as paper or a card.
[0002]
[Prior art]
In this type of electrophotographic image forming apparatus, when the toner is consumed with use and the toner end of the developing device is detected, the toner replenishing container provided in the developing device is replaced with a new one. Was replenished.
[0003]
However, as the toner supply is repeated several times, the developing device or each part of the process cartridge having the developing device gradually deteriorates, and the image quality deteriorates with time. The extent to which this reduction in image quality can be tolerated varies depending on each user.
[0004]
For this reason, in the past, the guaranteed life of the developer or process cartridge was set at the stage of image quality acceptable to most users, and when the guaranteed life was reached, notification was given to replace or the operation of the main unit was stopped. In other words, a new developer or a process cartridge is to be replaced before the image quality is significantly deteriorated.
[0005]
However, if the developer or process cartridge is replaced immediately when the guaranteed life is reached, the toner will remain in the developer, and the image quality will be drastically reduced for users who do not have much image quality problems. It was uneconomical because quality did not decrease.
[0006]
In the conventional image forming apparatus, when it is considered that the developing unit or the process cartridge reaches the guaranteed life before the used toner is used up, the image quality is emphasized. For example, Japanese Patent Laid-Open No. 4-51259 As described in the official gazette, some developers or process cartridges are replaced with new ones without replenishing toner.
[0007]
In some cases, emphasizing economic efficiency, as described in JP-A-9-190068, toner is replenished by the amount of toner consumed until the developing device or process cartridge reaches the guaranteed life.
[0008]
[Problems to be solved by the invention]
However, in the former, it goes without saying that it is uneconomical to replace a sufficiently usable developer or process cartridge. In the latter case, for example, it is necessary to prepare a plurality of types of toner supply containers having different toner capacities, which increases the cost.
[0009]
Accordingly, an object of the present invention is to maximize the quality required by each user in the image forming apparatus as described above, in view of the difference in image quality required by each user. It is to make it possible to use a developing device or a process cartridge, and to improve economy.
[0010]
[Means for Solving the Problems]
Therefore, according to the first aspect of the present invention, the image forming apparatus main body 10 is detachably equipped with the image forming process cartridge 35 having the developing device 14 or the developing device 14 as in the embodiment described with reference to the following drawings. The developing unit 14 is provided with a replaceable toner replenishing container 25 for replenishing the toner 21, and when the toner end of the developing unit 14 is detected, the replacement of the toner replenishing container 25 is notified, while the developing unit 14 In the image forming apparatus that notifies the replacement when the guaranteed life of the container 14 or the process cartridge 35 is set and reaches the guaranteed life, when the replacement of the toner supply container 25 is notified, the replaced toner supply container 25 When the above-mentioned guaranteed life is reached before the toner in the inside is used up, and a notice to that effect is reached and the guaranteed life is reached It is possible to select whether to notify the replacement of the developing device 14 or the process cartridge 35 or to notify the replacement of the developing device 14 or the process cartridge 35 when a toner end is detected thereafter. .
[0011]
According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the number of recorded images on the recording medium 29 is counted and the count value is calculated as in the embodiment described with reference to the following drawings, for example. When the set number of lifetimes has been exceeded, it is determined that the guaranteed lifetime has been reached. On the other hand, when a toner end is detected, the number of images that can be recorded with one toner supply from the number of image recordings up to that point and the number of toner replenishments. The guaranteed life is reached before the toner 21 in the toner replenishing container 25 after replacement is used up, depending on whether or not the number obtained by adding the calculated number to the number of images recorded so far is larger than the life number. It is characterized by determining whether or not to do.
[0012]
According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, for example, a certain value is counted and the count value is set as in the embodiment described with reference to the following drawings. When the service life count value is exceeded, it is determined that the guaranteed service life has been reached. At the time of replacement notification of the toner supply container 25, the toner 21 in the toner supply container 25 after replacement is exceeded after the service life count value is exceeded. It displays the count value until it is used up.
[0013]
According to a fourth aspect of the present invention, in the image forming apparatus according to the first, second, or third aspect, the developing unit 14 or the process cartridge 35 continues to be used as in the embodiment described with reference to the following drawings, for example. A test image recording mode for determining whether or not the image can be used is provided.
[0014]
The invention according to claim 5 is an image forming apparatus according to an embodiment described with reference to the following drawings, for example:
An image forming process cartridge 35 having a developing device 14 or a developing device 14 detachably provided in the image forming apparatus main body 10;
A toner supply container 25 that is replaceably provided in the developing unit 14 and supplies toner 21 thereto;
Toner end detecting means 38 for detecting the toner end of the developing device 14;
A life detecting means 42 for detecting the developer 14 or the process cartridge 35 reaching the guaranteed life;
When the toner end is detected by the toner end detection means 38, the replacement of the toner supply container 25 is notified. On the other hand, when the end of the guaranteed life is detected by the life detection means 42, the developing device 14 or the process cartridge is detected. Notification means 41 for notifying the exchange of 35,
At the time of replacement notification of the toner supply container 25, it is determined whether or not the guaranteed life is reached before the toner 21 in the toner supply container 25 after replacement is used up. Determination means 40 for informing the effect,
When it is determined by the determination means 40 that the guaranteed life is reached before the toner 21 is used up, the replacement of the developing device 14 or the process cartridge 35 is notified when the guaranteed life is reached, or the toner end is detected thereafter. Selection means 43 and 44 for selecting whether to notify the replacement of the developing device 14 or the process cartridge 35,
It is characterized by comprising.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a schematic configuration of an electrophotographic image forming apparatus according to the present invention. Reference numeral 10 in the figure denotes an image forming apparatus main body. A drum-shaped image carrier 12 is rotatably provided at substantially the center of the apparatus main body 10.
[0016]
Around the image carrier 12, a roll-type charging device 13, a developing device 14, a roll-type transfer device 15, a cleaning device 16 and the like are provided in order in the rotation direction indicated by the arrow. A writing device 17 is provided on the cleaning device 16, and a fixing device 18 is provided on the left side.
[0017]
The developing device 14 contains a toner 21 that is a one-component high-resistance developer in a developing case 20. The developing case 20 is provided with an opening on the image carrier 12 side, and a sleeve-like developing roller 22 is rotatably provided therein. A bias voltage is applied to the developing roller 22 from the developing bias power source 23, and the tip of the thinning blade 24 is pressed against the outer periphery. The developing case 20 is also provided with a replaceable toner supply container 25.
[0018]
When an image is formed, the image carrier 12 is rotated in the direction indicated by the arrow in the drawing by a motor (not shown) provided in the apparatus main body 10, and the peripheral surface of the image carrier 12 is charged by the charger 13 along with the rotation. Then, the laser beam L emitted from the writing device 17 is reflected by the mirror 26 and irradiated onto the peripheral surface of the image carrier 12, and writing is performed on the image carrier 12. An electrostatic latent image is formed on the surface.
[0019]
In the developing device 14, the driving force transmitted from the apparatus main body 10 side sends the toner 21 to the developing roller 22 while stirring the toner 21 with a toner stirring supply member (not shown), and the toner 21 adhering to the developing roller 22 is thinly layered. The image forming blade 24 thins the film and charges it, and then adheres to the image carrier 12 and develops it to make the electrostatic latent image on the image carrier 12 visible.
[0020]
At the same time, the sheet feeding roller 27 is rotated along with the rotation of the image carrier 12 to sequentially feed the sheet-like recording medium 29 from the sheet feeding cassette 28, guided by a guide member 30 and abutted between registration rollers (not shown). The registration roller is rotated in synchronization with the leading edge of the image formed on the image carrier 12 and sent between the image carrier 12 and the transfer unit 15.
[0021]
The image formed on the image carrier 12 as described above is transferred by the transfer device 15 to the recording medium 29 sent between the image carrier 12 and the transfer device 15 as described above. Then, the transferred recording medium 25 is put into the fixing device 18 through the paper discharge path 31, where the transferred image is fixed, and then discharged out of the apparatus main body 10.
[0022]
On the other hand, the image carrier 12 after the image transfer is rotated, and the residual toner 21 on the peripheral surface is removed by the cleaning blade 32 of the cleaning device 16. The removed toner 21 is stored in a cleaning case 33.
[0023]
By the way, in such an image forming apparatus, considering the convenience at the time of maintenance, the above-described image carrier 12, charger 13, developing unit 14, and cleaning unit 16 are assembled together in a predetermined arrangement, and collectively shown in FIG. An integral image forming process cartridge 35 as shown is formed. And as shown in FIG. 1, it positions on the support member 36 reliably and is provided in the apparatus main body 10 so that attachment or detachment is possible.
[0024]
Although not described above, a toner end detecting means 38 is provided in the developing case 20 of the developing device 14. The toner end detecting means 38 detects the toner end in the developing case 20 by utilizing the change in electrostatic capacity between the developing roller 22 and the antenna in accordance with the amount of toner.
[0025]
As shown in FIG. 3, signal processing means 40 is connected to the toner end detection means 38. The signal processing means 40 measures the current flowing through the antenna of the toner end detection means 38 and determines whether or not the toner end has been reached from the measured value. When it is determined that the toner end is reached, the front display unit (notification unit) 41 of the apparatus main body 10 notifies the replacement of the toner supply container 25.
[0026]
When this notification is given, the user installs a new toner supply container 25 in place of the attached toner supply container 25, releases the seal member (not shown), etc., and releases the seal. To replenish.
[0027]
Incidentally, the signal processing means 40 is also connected to a life detecting means 42 for detecting that the process cartridge 35 has reached the guaranteed life. In the illustrated example, the life detecting means 42 detects the number of rotations of the image carrier 12.
[0028]
Since the cleaning blade 32 and the charger 13 are in contact with each other, the peripheral photosensitive layer of the image carrier 12 is worn. When worn, the charger 13 cannot be charged up to a predetermined potential, so that the image quality is deteriorated. Therefore, the signal processing means 40 receives the detection signal from the life detecting means 42 and stores the number of rotations of the image carrier 12 to determine the degree of deterioration of the image carrier 12 so that the process cartridge 35 reaches the guaranteed life. Determine whether or not.
[0029]
When it is determined that the guaranteed life has been reached, the front display unit 41 displays the replacement of the process cartridge 35.
[0030]
The signal processing means 40 also communicates with a host device 43 such as a computer connected to the apparatus body 10.
[0031]
In the image forming apparatus as shown in the figure, when the replacement of the toner supply container 25 is notified, the process cartridge 35 may reach the guaranteed life before the toner 21 in the replaced toner supply container 25 is used up. . For example, when the guaranteed life of the process cartridge 35 is converted into the number of recorded images on the recording medium 29, it is 30,000 sheets. When the toner capacity of the toner supply container 25 is about 3,000 sheets, the image is recorded on the 28,000-sheet recording medium 29. By the way, the toner end may occur.
[0032]
In such a case, this is determined by the signal processing means 40, and the following (1) to (3) are notified by the front display unit 41. You may alert | report by recording an image on the recording medium 29 and outputting it.
[0033]
(1) The toner supply container 25 needs to be replaced.
{Circle around (2)} The process cartridge 35 reaches the guaranteed life before the toner 21 in the replaced toner replenishing container 25 is used up for recording about 2,000 images.
(3) The user should select whether to notify the replacement of the process cartridge 35 when the guaranteed life is reached or when the toner end is detected thereafter.
[0034]
The user operates the operation unit 44 of the front display unit 41 or determines whether the notification of the replacement of the process cartridge 35 is when the guaranteed life is reached or when the toner end is detected afterwards. 43 is selected.
[0035]
When image recording with a large image area is continued, the toner end may be detected again before reaching the guaranteed life of the process cartridge 35. In this case, the notifications (1) to (3) are similarly performed. To do.
[0036]
By the way, even if the toner capacity of the toner replenishing container 25 is about 3,000 sheets, this is only a guideline, and the number of sheets varies depending on the output image ratio. Therefore, in the illustrated image forming apparatus, when the toner end is detected, the number of images that can be recorded with one toner replenishment is calculated from the number of image recordings up to that point and the number of toner replenishments. Whether or not the guaranteed life is reached before using up the toner in the replaced toner replenishing container 25 is determined depending on whether or not the number added to the number of recorded sheets is larger than the life number.
[0037]
The illustrated image forming apparatus counts the number of image recordings, and determines that the guaranteed life has been reached when the count value reaches 30,000 sheets, which is the set life count value. On the other hand, when the replacement of the toner supply container 25 is notified, the number of sheets (1,000 sheets in this example) from when the life count value of 30,000 sheets is reached until the toner in the toner supply container 25 after replacement is used up is displayed on the front display unit 41. Display it.
[0038]
Further, in the illustrated image forming apparatus, the process cartridge 35 is configured by integrally forming the image carrier 12, the charger 13, the developing device 14, and the cleaning device 16. The lifetime is assumed to be when the charged potential decreases due to wear of the photosensitive layer of the image carrier 12.
[0039]
The problem on the image due to this is a background smearing phenomenon in which the toner adheres to the background portion in the reverse development method in which toner is attached to the writing portion, and the image in the normal development method in which toner is attached to the non-writing portion. It is a decrease in concentration.
[0040]
The following test image recording mode is provided as means for confirming the margin until reaching this phenomenon, and the user can arbitrarily record the test image. During the test image recording, the absolute value of the DC component of the voltage applied to the charger 13 is controlled so as to decrease gradually or stepwise from the front end to the rear end of the test recording image.
[0041]
When such control is performed, for example, in the case of the reversal development method, the test recording image is gradually soiled toward the rear end of the image. However, as the deterioration of the image carrier 12 progresses and the charging potential decreases more drastically, the background stain becomes more conspicuous from the front end portion of the image. The carrier 12 has a sufficient life.
[0042]
When the replacement of the toner supply container 25 is informed, this test image can be recorded and confirmed, and it can be more accurately determined whether or not the process cartridge 35 is to be continuously used after the toner is supplied.
[0043]
It should be noted that it may be determined by the user's own judgment as to how much the process cartridge 35 should be replaced as a result of recording the test image, but it is desirable to present a reference standard.
[0044]
When a component other than the image carrier 12 determines the life of the process cartridge 35, a test image recording method can be set in accordance with the deterioration of the component.
[0045]
For example, in the case of the cleaning blade 32, the toner slips through the cleaning blade 32 due to wear of the contact edge with the image carrier 12 and appears on the image as dirt. As a method for checking this phenomenon in advance, if a non-transferred toner image is formed on the image carrier 12 and a blank image is recorded immediately after that in the test image recording mode, a cleaning failure occurs for excessive toner. Therefore, it is possible to know the wear of the cleaning blade 32 in advance.
[0046]
Further, in the case of the charger 13, it is conceivable that uneven charging potential occurs due to the contamination. However, if this phenomenon is changed by changing the development bias in the test image recording mode and outputting a halftone image, the potential is changed. The unevenness can be detected by replacing the unevenness in the density of the image.
[0047]
In the above-described embodiment, the case where the process cartridge 35 having the developing device 14 is applied to the image forming apparatus that is detachably attached to the apparatus main body 10 has been described. However, the present invention can be similarly applied to an image forming apparatus that does not constitute a process cartridge using a developing device but includes the developing device detachably with respect to the apparatus main body.
[0048]
【The invention's effect】
Therefore, according to the first to fifth aspects of the present invention, a user who is concerned about the deterioration of the image quality is notified of replacement of the developing device or the process cartridge when the guaranteed life is reached. For users who place importance on economic efficiency rather than fearing a decrease in toner, the replacement of the developer or the process cartridge is notified when the toner end is detected after reaching the guaranteed life.
[0049]
This makes it possible to maximize the use of each developer or process cartridge within the range in which each user can ensure the quality required by the user, considering that the image quality required by each user is different. Can be increased.
[0050]
According to the second aspect of the present invention, when the toner end is detected, the number of images that can be recorded with one toner supply is calculated from the number of image recordings up to that point and the number of toner replenishments. It is determined whether or not the guaranteed life is reached before the toner in the toner supply container after replacement is used up, depending on whether or not the number added to the number of recorded images is greater than the lifespan number. It is possible to determine whether or not the guaranteed life is reached before the toner is used up with a certain degree of accuracy according to the use situation.
[0051]
According to the third aspect of the present invention, when a certain value is counted and the count value exceeds the set life count value, when it is determined that the guaranteed life has been reached, when the replacement of the toner supply container is notified, the life Since the count value from when the count value is exceeded until the toner in the same toner supply container after replacement is used up is displayed, in addition, the user can refer to the display when the developer life or process cartridge is reached. It is possible to select whether to notify the replacement of the developing device or to notify the replacement of the developing device or the process cartridge when the toner end is detected after reaching the guaranteed life.
[0052]
According to the fourth aspect of the invention, since the test image recording mode for determining whether or not the developing device or the process cartridge can be continuously used is provided, the test image is actually recorded and the image quality is deteriorated. The developer or process cartridge replacement is notified when the guaranteed life is reached, or the developer or process cartridge replacement is notified when the toner end is detected after the guaranteed life is reached. can do.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an electrophotographic image forming apparatus according to the present invention.
FIG. 2 is a perspective view of an image forming process cartridge used in the image forming apparatus.
FIG. 3 is an enlarged schematic configuration diagram of the process cartridge portion.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Image forming apparatus main body 12 Image carrier 13 Charger 14 Developing device 15 Transfer device 16 Cleaning device 20 Developing case 21 Toner 22 Developing roller 24 Thinning blade 25 Toner supply container 29 Recording medium 32 Cleaning blade 33 Cleaning case 35 Image formation Process cartridge 36 Support member 38 Toner end detection means 40 Signal processing means (determination means)
41 Front display (notification means)
42 Life detection means 43 Host device (selection means)
44 Operation part (selection means)

Claims (5)

An image forming process cartridge having a developing device or a developing device is detachably provided in the main body of the image forming apparatus, and a toner supply container for supplying toner to the developing device is replaceably provided to detect a toner end of the developing device. In the image forming apparatus that notifies the replacement of the toner replenishing container while setting the guaranteed life of the developing unit or the process cartridge and reaches the guaranteed life, the toner replenishing container When the replacement is notified, when the guaranteed life is reached before the toner in the toner supply container after replacement is used up, the fact is notified, and when the guaranteed life is reached, the developer or the process cartridge is replaced. When the toner end is detected, the developer or the process cartridge is replaced. It made as a possible choice to notify the image forming apparatus. When the number of recorded images on the recording medium is counted and the counted value exceeds the set number of lifetimes, it is determined that the guaranteed lifetime has been reached. The number of images that can be recorded with one toner replenishment is calculated from the number of times of replenishment, and the toner replenishment after replacement is performed depending on whether the calculated number of images added to the previous number of image recordings is greater than the lifespan number. 2. The image forming apparatus according to claim 1, wherein it is determined whether or not the guaranteed life is reached before the toner in the container is used up. When a certain value is counted and the count value exceeds the set life count value, it is determined that the guaranteed life has been reached. The image forming apparatus according to claim 1, wherein a count value until the toner in the toner supply container after replacement is used up is displayed. The image forming apparatus according to claim 1, 2 or 3, further comprising a test image recording mode for determining whether or not the developing device or the process cartridge can be continuously used. An image forming process cartridge having a developing device or a developing device detachably provided in the image forming apparatus main body;
A toner replenishing container which is replaceably provided in the developing unit and replenishes toner,
Toner end detecting means for detecting the toner end of the developing device;
A life detecting means for detecting the end of the guaranteed life of the developing device or the process cartridge;
When the toner end is detected by the toner end detection means, the replacement of the toner replenishing container is notified. On the other hand, when the end of the guaranteed life is detected by the life detection means, the replacement of the developer or the process cartridge is notified. Notification means for
When notifying the replacement of the toner replenishing container, it is determined whether or not the guaranteed life is reached before the toner in the toner replenishing container after the replacement is used up. Judgment means,
When it is determined by the determination means that the guaranteed life is reached before the toner is used up, the replacement of the developing device or the process cartridge is notified when the guaranteed life is reached, or when the toner end is detected after that, the developing is performed. Selecting means for notifying the replacement of the container or the process cartridge;
An image forming apparatus comprising:

Images