JPH08152751A - Image forming method and image forming device using the same - Google Patents

Abstract

PURPOSE: To recover image density in the early stages by resetting toner end display and an image forming processing-unfeasible state set when the remaining quantity of toner is insufficient in accordance with the density of a patch image formed with supplied toner. CONSTITUTION: When the ratio of a density detection signal for the toner image of a reference density of reference density plate on a photoreceptor drum to a toner density detection signal for the surface part of the photoreceptor drum is larger than a specified reference value, a control part 48 turns on toner supply clutches 49 and 50, thereby a toner supply roller is rotated for a specified time so as to supply the toner to a developing part. When the ratio of the density detection signal calculated again after supply is larger than the reference value, the control part 48 performs a toner near end display and the image forming processing is set to the unfeasible state. Furthermore, toner supply action is continuously performed plural times so as to discriminate whether or not the ratio of the density detection signal is equal to or larger than the reference value. When it is not equal to or larger than the reference value, the toner end display and the image forming processing action unfeasible state are reset.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method and an image forming apparatus using the same.

[0002]

2. Description of the Related Art Generally, an image forming apparatus such as a copying machine, a printer or a facsimile machine uses an electrophotographic system. In this method, the photoconductor is uniformly charged,
An electrostatic latent image corresponding to an original image or written information is formed on a photosensitive member, which is one of image carriers, and the electrostatic latent image is formed by using a developer having a polarity opposite to the charging polarity of the electrostatic latent image. The visible image processing is performed, the visible image is electrostatically transferred to a transfer material, and the transferred image is fixed to obtain a copy.

One of the developers used for the visible image processing of an electrostatic latent image is a two-component system developer in which charged toner is attached to a magnetic carrier. This developer is capable of performing visible image processing of the electrostatic latent image by electrostatically adsorbing toner to the electrostatic latent image. Toner is consumed by developing the electrostatic latent image on the photoconductor, and the toner is replenished from the toner replenishing unit equipped with the toner cartridge. Therefore,
It is known that the toner concentration of the two-component developer in the developing section is controlled to be constant by controlling the toner replenishment from the toner replenishing section to the developing section by the toner concentration control device (for example, Japanese Patent Application Laid-Open No. 2000-242242) JP-A-61-243481, JP-A-62-95561, JP-A-63-75770 and JP-A-64-44472).

In a toner density control device, for example, in a copying machine, a reference density plate provided at the front end of a document table is illuminated by a light source, and the reflected light is applied to a photosensitive drum to illuminate the reference density plate. An image is written to form an electrostatic latent image, the electrostatic latent image is developed by a developing unit with a two-component developer, and then the density thereof is optically detected by a toner density sensor to detect the toner density sensor. Is compared with a reference value, and the toner replenishment from the toner replenishing unit to the developing unit is controlled according to the comparison result.

The toner concentration control device is provided with a function for coping with the toner replenishing section in a state of no toner. When the detection signal of the toner concentration sensor exceeds a predetermined value, the toner replenishing section is operated. The toner near end of the toner replenishing section is determined to be close to a state where there is no toner in the toner replenishing section, and the toner near end of the toner replenishing section is displayed on the display section. Then, after a preset number of image forming operations have been performed, the toner near end display on the display unit is automatically switched to toner end (state in which there is no toner in the toner supply unit) to disable the image forming operation. There is. The user looks at the toner near-end display on the display unit, turns off the power of the image forming apparatus, opens the cover, and then replaces the toner cartridge to replenish the toner to the toner replenishing unit or directly to the toner replenishing unit. After replenishing the toner, the cover is closed and the power is turned on, but the toner near end display or the toner end display on the display section is reset by turning the power on / off or opening / closing the cover at the time of toner replenishment to enable the image forming operation. There is.

The following method is known as a method for resetting the toner near-end display or the toner-end display to enable the image forming operation. In a developer presence / absence detector configured to detect the presence / absence of developer in a developer supply container, an output signal is generated by being set by a developer absence detection signal from the developer presence / absence detector. A storage device and a container detector that is activated by the displacement of the container when replenishing the developer are provided, and the storage device is reset by the operation of the container detector. No. 53-110852). As an alternative to the method described in the above publication, a switch that operates in conjunction with the opening and closing of the door to replenish the developing device with toner (particularly one-component toner) is provided. A method for controlling the automatic rotation of the toner remaining amount detecting device by rotating the magnet roller of the developing device so that the toner is sufficiently distributed to the magnet roller by the operation (for example, JP-A-55-151).
(Publication No. 667)

[0007]

In the toner density control devices described in the above publications, after the toner near end of the toner replenishing portion is displayed on the display portion, the image forming operation is automatically performed after a preset number of image forming operations are performed. The image forming operation can be disabled by switching the toner near end display on the display unit to toner end. For this reason, a predetermined number of images can be formed after the toner replenishing unit is near the toner end, while the toner with a small remaining amount in the developing unit is continuously consumed and the toner concentration of the developer decreases. The degree of toner density decrease depends on the size of the image formed after the toner near end display and the ratio of solid black areas, but the density of the formed image does not immediately increase even if toner is replenished after the toner near end display. However, in the worst case, problems such as carrier adhesion to the photoreceptor occur.

Further, it is considered that the toner is replenished artificially by turning the power on / off or opening / closing the cover, and the toner near end display or the toner end display on the display unit is reset to enable the image forming operation. Therefore, the image forming operation may be enabled without replenishing the toner.
Then, when the image forming operation is performed without replenishing the toner, the toner concentration of the developer is lowered, and problems such as carrier adhesion to the photoconductor occur.

Therefore, in order to solve such a problem, once toner is replenished, an image corresponding to the reference density is formed again, and the image density is detected to determine whether resetting is possible or not. There is proposed a method of determining whether the image forming operation is immediately restarted even when the toner is actually replenished (for example, Japanese Patent Laid-Open No. 5-66669).

By the way, when the toner near end or the toner end is displayed, the toner must be replenished, but the replenished toner is not always the one having the same characteristics. For this reason, even if it is replenished, it may interfere with the reset decision. For example, when the charging ability of the toner to be replenished is low and a large amount of toner is replenished at one time by the forced toner replenishment operation, it takes time for the charging characteristic obtained by stirring the toner to reach a predetermined characteristic. During this period, the toner may be scattered from the developing device to the outside by stirring.
If the toner is scattered, the toner adheres to the background of the photoconductor in the vicinity of the developing device, causing the so-called background stain of the photoconductor, and the toner cannot be accurately detected by the density sensor. However, the toner near-end display and the toner-end display cannot be reset, which causes a situation in which the image forming operation cannot be performed at the bottom even though the toner is replenished. In addition to this, in the case of toner having a high aggregation degree and poor fluidity of the toner to be replenished, it becomes difficult for the toner to be replenished to the photoreceptor even though the toner is forcibly replenished. There is a case where the waiting time from resetting the toner near end display or the toner end display until the image forming operation is performed becomes long, or the resetting is not accurately performed in an unstable state.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional image forming method, and in particular, in view of the problem at the time of restarting image formation after the toner replenishing process, regardless of the characteristics of the toner to be replenished, a toner near end display or a toner end is displayed. An object of the present invention is to provide an image forming method and an image forming apparatus using the same capable of resetting the display and smoothly restarting the image forming operation to enable early restoration of image density and maintenance of a stable state. .

[0012]

To achieve this object, the invention according to claim 1 forms an image corresponding to a reference image having a reference density as a patch image on a photoconductor,
The density of this batch image is detected by the density sensor to control the toner density and detect the remaining toner amount, and when the insufficient remaining toner amount is detected, the toner end display is displayed or the image forming process is disabled together with the display. Whether or not to form the patch image again with the replenished toner and reset the toner end display or the display together with the toner end display according to the density detection result of the patch image In the image forming method for determining the above, the reset condition is changed according to the characteristics of the replenished toner.

According to a second aspect of the present invention, an image corresponding to a reference image having a reference density is formed as a patch image on a photoconductor, and the density of the batch image is detected by a density sensor to control the toner density and the residual toner. When the amount of toner is detected and the insufficient toner amount is detected, the toner end display or the image formation processing together with the display is set to the non-capable state, and the patch image is formed again by the supplied toner, and the patch image is formed. In the image forming method of determining whether or not to reset the toner end display or reset the display together with the image density detection result according to the image density detection result, in accordance with the characteristics of the replenished toner. It is characterized in that the condition for judging whether or not to reset is changed.

According to the third aspect of the present invention, an image corresponding to the reference image having the reference density is formed as a patch image on the photoconductor, and the density of the batch image is detected by the density sensor to control the toner density and the residual toner. When the amount of toner is detected and the insufficient toner amount is detected, the toner end display or the image formation processing together with the display is set to the non-capable state, and the patch image is formed again by the supplied toner, and the patch image is formed. In the image forming method of determining whether or not to reset the toner end display or reset the display together with the image density detection result according to the image density detection result, in accordance with the characteristics of the replenished toner. The feature is that the toner replenishment time is changed.

According to a fourth aspect of the present invention, an image corresponding to a reference image having a reference density is formed as a patch image on a photoconductor, and the density of the batch image is detected by a density sensor to control the toner density and the residual toner. When the amount of toner is detected and the insufficient toner amount is detected, the toner end display or the image formation processing together with the display is set to the non-capable state, and the patch image is formed again by the supplied toner, and the patch image is formed. In the image forming method of determining whether or not to reset the toner end display or reset the display together with the image density detection result according to the image density detection result, in accordance with the characteristics of the replenished toner. The feature is that the supply amount per unit time is changed.

According to a fifth aspect of the present invention, in the image forming method according to one of the first to fourth aspects, at least the characteristics of the toner correspond to charging characteristics, fluidity, and cohesiveness. It is characterized by that.

According to a sixth aspect of the present invention, there is provided an apparatus using the image forming method according to any one of the first to fifth aspects, which displays information regarding the characteristics of the toner replenished to a part of the surface. It is characterized in that it is provided with a toner cartridge having a display portion and a toner replenishing portion having means for reading the contents of the display portion of the toner cartridge.

[0018]

According to the invention described in claims 1 to 5, the conditions for resetting are adjusted according to the characteristics of the toner, and the determination as to whether resetting is possible or not is optimized.

According to the sixth aspect of the invention, the toner replenishing section can determine the characteristics of the toner, and the condition adjustment for the reset can be executed.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the embodiments shown in the drawings.

FIG. 1 is a diagram showing a main configuration of a copying machine which is an example of an image forming apparatus used in an embodiment of the present invention. The embodiment shown in FIG. 1 is an example of an electrophotographic copying machine, and an original 11 is a transparent original table 1 as shown in FIG.
The reference density plate 13 having the reference density is placed on the top of the original 2, and the reference density plate 13 having the reference density is arranged on the front side of the leading end of the original 11 and attached to the front end of the original table 12.
In FIG. 1, the photoconductor drum 14 is driven to rotate in the direction of arrow b by the main motor and is charged by the charging charger 15.
Are uniformly charged, and an image is written by the exposure device to form an electrostatic latent image.

In the exposure apparatus shown in FIG. 1, a document 11 placed on a document table 12 shown in FIG. 2 is illuminated by a light source 15, and the reflected light is reflected by mirrors 16 to 18 and a lens 1.
9. An image is formed on the photosensitive drum 14 via the mirrors 20 to 22. The movable optical system including the light source 15 and the mirrors 16, 20, 21 is driven by the drive mechanism in the direction of arrow a (see FIG. 2).
The original 11 on the reference density plate 13 and the original table 12 is sequentially scanned by being driven to the home position by being driven to, and the images of the reference density plate 13 and the original 11 on the original table 12 are displayed on the photosensitive drum 14. After being written, the movable optical systems 15, 16, 20, and 21 return to their home positions. Further, the color filter 23 is provided so as to be insertable between the mirrors 21 and 22, and the color filter 23 is provided to the mirrors 21 and 22.
When it is inserted in the optical path between the two, the color components corresponding to the color filters 23 in the image of the original 11 are written on the photosensitive drum 14.

On the photosensitive drum 14, an unnecessary area where an image has not been written after the image has been written by the exposure device is erased by the eraser 24, and the color developing portion 25 of the color developing device or the black developing device The black developing unit 26 develops with a color two-component developer or a black two-component developer to form a toner image.

The transfer paper is fed from the paper feeding device in the direction of arrow c and sent to the registration roller 27, and the registration roller 2
The toner image on the photosensitive drum 14 is transferred to the original 11 by the transfer charger 28, which is sent between the photosensitive drum 14 and the transfer charger 28 in accordance with the toner image to be transferred on the photosensitive drum 14. To be done. The transfer sheet is separated from the photosensitive drum 14 by the separation charger 29 and the separation claw 30 and is conveyed by the conveyance belt 31, the toner image is fixed by the fixing device, and the transfer sheet is ejected to the outside as a copy. After the transfer paper is separated from the photosensitive drum 14, the density of the toner image on the reference density plate 13 is detected by the toner density sensor 32, the cleaning device 33 removes the residual toner, and the static eliminator 34 erases the residual charge. .

When the image of the original 12 is copied in black, only the black developing section 26 is moved to the developing position by the driving mechanism, the color filter 23 is retracted from the optical path between the mirrors 21 and 22, and the photosensitive drum is moved. An exposure device 14 has an original 11
Image is written as it is and is developed by a black two-component developer by the black developing unit 26 to form a black toner image.

When a specific color component in the image of the original 11 is also copied, the black toner image is formed at the first rotation of the photosensitive drum 14 as described above, and then only the color developing section 25 is driven by the driving mechanism. Moves to the developing position and the color filter 23 is inserted in the optical path between the mirrors 21 and 22. As a result, at the second rotation of the photosensitive drum 14, the specific color component in the image of the original 11 is changed by the color filter 23 by the exposure device.
Is written on the photoconductor drum 14 through the color developing unit 25.
Is developed with a color two-component developer to form a toner image of a specific color on the black toner image.

The black developing section 26 contains therein a two-component developer composed of black toner and carrier, and the developer is conveyed by the conveying roller 35 to the agitator 36 and agitated by the agitator 36. It is conveyed to the developing roller 37. Then, the developing roller 37 conveys the developer while magnetically attracting the developer, and after the developer is adjusted to a certain amount by the doctor 38, the developer is supplied to the photoconductor drum 14 to supply the electrostatic latent image on the photoconductor drum 14. Develop the image. In the black developing device, the toner replenishing unit 39 is attached to the developing unit 26, and the toner replenishing unit 39 stores black toner. In the toner replenishing unit 39, the toner replenishing roller 40 is rotationally driven by the drive source when the toner replenishing clutch is turned on, and replenishes toner to the developing unit 26 by the toner replenishing roller 40.

The color developing section 25 contains therein a two-component type developer consisting of color toner and carrier, and the developer is agitated by the agitators 41 and 42 and conveyed to the developing roller 43. The developing roller 43 conveys the developer while magnetically attracting the developer, and after the developer is adjusted to a certain amount by the doctor 44, the developer is supplied to the photosensitive drum 14 to supply the electrostatic latent image on the photosensitive drum 14. To develop. In the color developing device, a toner replenishing unit 45 is attached to the developing unit 25, and the toner replenishing unit 45 stores toner of a color corresponding to the color filter 23. In the toner replenishing section 45, the toner replenishing roller 46 is rotatably driven by the drive source when the toner replenishing clutch is turned on, and the toner is replenished with the toner replenishing roller 46.
To supply to the developing unit 25.

The toner replenishing parts 39 and 45 use toner cartridges containing toner. At the time of toner end, the user turns off the power of the copying machine and then opens the cover to replace the toner cartridges. The toner is replenished, and then the user closes the cover and turns on the power. The toner replenishing units 39 and 45 may be those in which the user directly replenishes the toner at the time of toner end.

The toner supply units 39 and 45 have the structure shown in FIG. In FIG. 3, among the toner supply units,
Although the toner replenishing section 39 of the developing section 26 in the black developing apparatus is shown as a target, the developing section 2 in the color developing apparatus is shown.
The toner replenishing section 45 installed in No. 6 has the same structure. The toner replenishing section 39 is composed of a toner hopper into which the toner cartridge 100 containing the replenishment toner shown in FIG. 4 can be inserted. An opening 39A is formed in a part of the peripheral wall of the toner hopper that forms the toner supply unit 39, and a bar code reader 101 is arranged on the outer surface of the peripheral wall corresponding to the opening 39A. An identification label 102 is attached to a part of the peripheral wall of the toner cartridge 100 at a position facing the opening 39A of the toner hopper forming the toner replenishing unit 39. The identification label 102 constitutes a display unit for displaying information on the characteristics of the replenishment toner accommodated in the toner cartridge 100 by a bar code.
Information about the charging characteristics, fluidity and cohesiveness of the toner is set. As other information, it is possible to add a manufacturing lot number or the like for determining the expiration date of the toner.

When the toner cartridge 100 is inserted into the toner hopper forming the toner replenishing section 39, the identification label 102 provided on the peripheral wall of the toner cartridge 100 is positioned so that it can face the bar code reader 101 on the toner hopper side. Has become.

The two-component type developer in the developing sections 25 and 26 consumes toner by developing the electrostatic latent image on the photosensitive drum 14 by the developing rollers 37 and 43, and the toner gradually decreases. Therefore, as the toner consumption progresses, the density of the toner image on the photosensitive drum 14 decreases. Therefore, after the image of the reference density plate 13 is written on the photosensitive drum 14 and developed by the developing units 25 and 26, the density is detected by the toner density sensor 32, and the toner density sensor 3
2 based on the toner concentration detection signal from the toner replenishing unit 3
The toner replenishment from the developing units 25 and 26 from the developing units 25 and 26 is controlled by controlling the toner concentration of the developer in the developing units 25 and 26.

FIG. 5 is a circuit diagram for carrying out toner density control. The control unit 48 shown in the figure turns on the light source 15 and moves the movable optical system including the light source 15 and the mirrors 16, 20 and 21 from the home position in the direction of arrow a to move the reference density plate 13 To make the image of the reference density plate 13 written on the photosensitive drum 14, and develop the electrostatic latent image by the color developing section 25 or the black developing section 26 to form a toner image, and then detect the density. "Vsp / Vsg", which will be described later, is obtained by the sensor 32 and the toner concentration detection signal from the toner concentration detection sensor 32. The toner image on the reference density plate 13 on the photosensitive drum 14 passes through the transfer charger 28, the separation charger 29, and the separation claw 30 as it is and is sent to the toner density detection sensor 32.

The toner density detection signal from the toner density sensor 32 is A / D converted by the A / D converter 47 and input to the control unit 48, which controls the reference density plate 13 on the photosensitive drum 14. A / D for standard density toner image
The eraser 2 is used before and after the toner density detection signal Vsp from the converter 47 and the toner image of the reference density on the photosensitive drum 14.
4, the toner concentration detection signal V from the A / D converter 47 for the background portion where the charge is erased and the toner does not adhere
The sg ratio “Vsp / Vsg” is obtained for each of the developing devices 25 and 26, and this Vsp / Vsg is compared with a predetermined reference value REF, for example, a value of 10%.

The control unit 48 sends Vsp to the developing unit 26.
When / Vsg becomes larger than the reference value REF, the toner replenishing clutch 49 is turned on to forcibly rotate the toner replenishing roller 40 for a predetermined time or a predetermined number of times to replenish toner from the toner replenishing section 39 to the developing section 26. Further, the controller 48 controls the toner replenishment clutch 50 when the Vsp / Vsg of the developing unit 25 becomes larger than the reference value REF.
Is turned on to forcibly rotate the toner replenishing roller 46 for a fixed time or a predetermined number of times to replenish toner from the toner replenishing section 45 to the developing section 25. The control unit 48 again calculates the value of Vsp / Vsg after the forced toner replenishment, and this value is the reference value REF.
If it is larger than the above value, the toner near end display is displayed, and it is determined whether or not the value of Vsp / Vsg when the toner replenishing operation is further repeated a plurality of times is greater than or equal to the reference value REF. It is determined whether or not the display or the state in which the image forming processing operation is disabled is continued together with the display, or whether the state in which the display and the image forming processing operation is disabled is reset. When the toner replenishment control is not performed, the photosensitive drum 1
4 causes the eraser 24 to erase the electrostatic latent image on the reference density plate 13 above.

The control unit 48 is adapted to change the condition for performing the toner end display after the toner is replenished and the reset of the disabled state of the image forming operation and the reset availability determination condition according to the characteristics of the toner. The reason is as follows. The reference value R is used for resetting the toner end display and the disabled state of the image forming processing operation and for determining whether resetting is possible.
The result of comparison between the EF and the above Vsp / Vsg value serves as a reference.
If the reference value REF is fixed, the above-mentioned Vsp / Vs may be generated due to the characteristics of the toner even though the toner is replenished.
The value of g may fluctuate, and in comparison with the reference value REF, it may be determined that the toner end display and the disabled state of the image forming processing operation cannot be reset. For example, if the toner has low charge characteristics, if a large amount of toner is replenished at one time, the toner that does not have the charge potential required for electrostatic attraction with the carrier will scatter, and the background stain on the photosensitive drum will occur. As a result, the value of Vsg corresponding to the ground potential decreases. When the toner having a normal charging characteristic is replenished, the background potential is about Vsg = 4.0 ± 0.2V, whereas in the case of the toner having a low charging characteristic, it drops to Vsg = 3V or less. Resulting in. Therefore, as the value of the denominator in the value of Vsp / Vsg decreases, as a result, the reference value R
A value larger than EF is obtained, and the toner end display and the image forming processing operation are not reset even though the toner is replenished.
Therefore, in the control unit 48, when the barcode reader 101 recognizes that the toner having low charging characteristics is replenished by the configuration shown in FIGS. 3 and 4, the coefficient (α) corresponding to the decrease amount of Vsg. Is determined by an experiment, and the value of the reference value REF for Vsp / Vsg is updated. Incidentally, as shown in FIG. 6, the time required for replenishment with respect to the charging characteristics is related to the stirring time for obtaining the charging amount required for adsorption to the carrier, and the better the charging characteristics, the shorter the time can be. Further, with respect to the fluidity, the same result is obtained as shown in FIG. On the other hand, regarding the cohesiveness, as shown in FIG. 8, the higher the cohesiveness, the longer the stirring time. Based on such a relationship, an experiment was conducted to change the time required for toner replenishment, or the replenishment amount per unit time to change the Vsp corresponding to the reset condition.
The coefficient (α) with respect to the value of / Vsg is derived to determine the reset condition and reset possibility according to the characteristics of the toner.

In order to change the time required for toner replenishment or the replenishment amount per unit time, the drive amount of the replenishment member connected to the output side of the control unit 48 is changed. In this case, The drive amount is changed by adding a coefficient for a predetermined time or a predetermined number of times.

The control unit 48 is constituted by using a microcomputer, and controls the copying operation and the like by controlling each unit of this copying machine. The control unit 48 has an operation display unit 51.
Various operation signals are taken in from and the various displays are displayed on the display of the operation display unit 51. Further, the control unit 48 takes in information from the bar code reader 101 installed in the toner replenishment units 39 and 45, and outputs a drive signal for a replenishment member connected to the output side described later. There is. Further, the control unit 48 drives the developing motor 52, and the developing motor 52 causes the conveying roller 3 of the developing unit 26 to move.
5, the stirrer 36 and the developing roller 37 are rotated, and
The developing motor 53 is driven to rotate the agitators 41 and 42 and the developing roller 43 of the developing unit 25 by the developing motor 53.

Since this embodiment has the configuration as described above,
The operation will be described with reference to the flowchart showing the operation of the control unit 48, as shown in FIG. In FIG. 9, when the toner in the toner supply units 39 and 45 is used up, Vsp / Vsg increases. Control unit 48
Indicates that Vsp / Vsg is the above-mentioned reference value REF in step S3.
It is determined for each toner replenishment section 39, 45 whether or not the toner is near end, by determining for each toner replenishment section 39, 45 whether or not it becomes smaller than Vs0 described later when it is larger than a larger fixed reference value. . In this decision,
When Vsp / Vsg is equal to or larger than a certain reference value larger than the reference value REF and becomes smaller than Vs0 described later and the toner near end is reached, the toner near end is set for each of the toner replenishing portions 39 and 45 and the original is copied. The copy counter is counted after the toner near end. In step S4, it is determined whether the toner end has been reached by determining whether the count value of the copy counter after toner near end has reached the reference value of 50 sheets or more. If the count value of the copy counter after toner near end is not 50 sheets or more, the control unit 48 resets the flag Fm2 to 0 in step S7 and causes the display of the operation display unit 51 to display toner near end. To warn. In the control unit 48, when the count value of the copy counter after toner near end reaches 50, it is judged as toner end and the process proceeds from step S4 to step S5 and the flag F is entered.
m2 is set to 1 and the toner end display flag Fm1 is set to 1 in step S6 to display the toner end on the indicator of the toner end operation display section 51 to disable the copying operation. Therefore, after the toner near end is displayed, the user can copy up to 50 sheets without replenishing the toner, but cannot copy 51 sheets or more.

The user sees the toner end display on the display of the operation display unit 51, turns off the power of the copying machine, opens the cover, replenishes the toner by replacing the toner cartridge, and then closes the cover to turn on the power. Turn on.

In step S8, the control unit 48 determines whether the cover is opened and closed (or is turned on after the power of the copying machine is turned off) based on the detection signal from the door switch 54. If the cover is opened and closed (or turned on after the power of the copying machine is turned off), it is checked in steps S9 and S10 whether or not the flags Fm1 and Fm2 are set to "1".

If both flags Fm1 and Fm2 are set to 1, the control unit 48 fetches the toner characteristic information from the bar code reader 101 in step S11, and in step 12, a coefficient (α) corresponding to the toner characteristic. ) To determine the timer T1 (α). When the timer T1 (α) is determined, the timer T1 (α) is set and clocked in step S13, and step S1
In step 4, one of the toner replenishment clutches 49, 50 corresponding to the toner replenishment section that has become toner end or toner near end is turned on to replenish toner from the toner replenishment section to the developing section. At the same time, the one of the developing motors 52 and 53 corresponding to the toner replenishing portion which has become the toner end or the toner near end is turned on to convey the toner replenishing portion with the conveying roller, the agitator, and the developing device. By rotating the roller, the toner and the developer from the toner replenishing section are sufficiently agitated.

In the control unit 48, Vsp / Vsg when the toner replenishing unit reaches the toner end (or the toner replenishing unit at the toner near end) is determined by the timer T1 (α) determined according to the characteristics of the toner. Is set to a time corresponding to the value Vs0 of (Vsp / Vsg) immediately before the toner replenishment is performed, that is, Vs influenced according to the characteristics of the toner.
The amount of toner lacking the developer in the developing unit is experimentally determined by 0, and the timer T1 (α) is set according to the relationship between this toner amount and the toner replenishing amount obtained by the rotation of the toner replenishing roller of the toner replenishing unit. The time to be kept is decided.

Next, the control unit 48 checks in step S15 whether or not the timer T1 (α) has timed out, and if the timer T1 (α) has timed up, step S15.
At 16, the toner replenishing clutch is turned off to stop the toner replenishing roller of the toner replenishing section, and the developing motor is stopped to stop the developing section. Next, the control unit 48 executes the toner density detection routine a plurality of times in step S17 to obtain Vsp / Vsg a plurality of times as described above. That is,
The control unit 48 controls the light source 15 as described in FIG.
Is turned on to move the movable optical system including the light source 15 and the mirrors 16, 20, 21 from the home position in the direction of arrow a to scan the reference density plate 13 and cause the photosensitive drum 14 to move the reference density plate 13 to the reference position. After the image is written and the electrostatic latent image is developed by the color developing unit 25 or the black developing unit 26 to form a toner image, the toner density sensor 32 detects the density and the toner density from the toner density sensor 32 is detected. By performing the operation of obtaining Vsp / Vsg based on the detection signal a plurality of times n, a plurality of times of Vspn / Vsg can be obtained.
Find n. In this case, the toner image on the reference density plate 13 on the photosensitive drum 14 passes through the transfer charger 28, the separation charger 29, and the separation claw 30 and is sent to the toner density sensor 32.

Next, the control unit 48 at step S18. Is calculated to obtain the average value Vs of Vsp / Vsg,
The value of Vsp / Vsg at the time when the toner replenishment section becomes the toner end corresponds to Vs0 (α) corresponding to the reference value updated according to the toner characteristics in step S19.
It is determined whether or not the above.

Then, in the control unit 48, Vs is Vs0.
If (α) or more, in step S20, the flag Fm1,
Fs2 is reset to 0, the toner end or toner near end display of the display on the operation display unit 51 is turned off, and a reset process for enabling a copying operation is executed, and Vs is V
If s0 (α) or more, the flag Fm1 is determined in step S18.
Is set to 1 and the toner end is displayed on the display on the operation display unit 51. Further, when the power is turned on at the toner end, the control unit 48 determines whether Vs is Vs0 (α) or more in step S1 as in step S19. If the toner supply section has reached the toner end, the flag Fm1 is set to 1 in step S2, and the toner end is displayed on the display on the operation display section 51.

As described above, in the present embodiment, after the toner is replenished, the density detection processing by the toner density detection signal from the toner density sensor 32 is updated based on the characteristics of the replenished toner, and the toner replenishment section is updated. Since the toner replenishing operation and the developer agitating operation of the developing unit are controlled, the toner is replenished to the developer and the developer is agitated by the time the copying operation is enabled, and the density of the formed image after replenishing the toner is stabilized. be able to. Further, the time to be counted by the timer T1 is Vsp / when the toner replenishment section is in the toner end state by the toner concentration detection signal from the toner concentration sensor 32.
Vsg (or Vsp / Vsg immediately before the toner is replenished in the toner replenishing unit at the toner near end), which is a value Vs obtained by adding a coefficient (α) according to the toner characteristics to the value Vs0.
By changing the value to 0 (α), the time for the toner replenishing operation of the toner replenishing section and the developer stirring operation of the developing section is set to a condition that matches the characteristics of the toner. In addition to suppressing the toner replenishment, it is possible to prevent scumming and toner scattering due to insufficient agitation of the toner replenished from the toner replenishing unit to the developing unit and the developer.

Further, a value corresponding to the judgment reference value when the toner density detection subroutine is executed after toner replenishment and the toner density detection signal from the toner density sensor 32 is reset is a coefficient ( Since the value is updated to Vs0 (α) with α added,
The toner replenishment of the toner replenishing portion can be reliably determined, and the copy image density can be stabilized after the toner replenishment as before the toner end.

[0049]

As described above, according to the first to fifth aspects of the present invention.
In the invention described above, the condition for resetting is adjusted according to the characteristics of the toner, and the determination as to whether resetting is possible or not is optimized. Therefore, regardless of the characteristics of the toner to be replenished, the toner end display and the image forming processing operation can be performed. By accurately determining whether the reset of the disabled state is possible, it is possible to quickly restore the image density after the toner end display reset and maintain the stable state.

According to the sixth aspect of the present invention, the toner replenishing section can determine the toner characteristic and adjust the condition for resetting. Therefore, regardless of the toner characteristic, the toner end display or the image forming processing operation is performed. It becomes possible to easily and accurately make a reset determination of the disabled state.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of an image forming apparatus that is similar to the image forming method of the present invention.

FIG. 2 is a sectional view showing a part of an exposure device in the image forming apparatus shown in FIG.

FIG. 3 is a cross-sectional view of essential parts showing a configuration of a toner supply unit in the image forming apparatus shown in FIG.

FIG. 4 is a perspective view showing a configuration of a toner cartridge used in the toner replenishing section shown in FIG.

5 is a block diagram showing a configuration of a circuit unit used in the image forming apparatus shown in FIG.

FIG. 6 is a diagram for explaining the relationship between a charging characteristic, which is one of the characteristics of toner, and a stirring time that affects replenishment time.

FIG. 7 is a diagram for explaining the relationship between the fluidity, which is one of the characteristics of toner, and the stirring time that affects the replenishment time.

FIG. 8 is a diagram for explaining the relationship between the cohesiveness, which is one of the characteristics of toner, and the stirring time that affects the replenishment time.

9 is a flowchart for explaining the operation of the circuit unit shown in FIG.

[Explanation of symbols]

 1 Copier which is one of image forming apparatuses 2 Photoconductor 39 which is one of image carriers 39, 45 Toner replenishing section 48 Control section 100 Toner cartridge 101 Bar code reader 102 Identification label

Claims (6)

[Claims] 1. An image corresponding to a reference density plate having a reference density is formed as a patch image on a photoconductor, and the density of the patch image is detected by a density sensor to control the toner density and detect the remaining toner amount, When the toner remaining amount is detected to be insufficient, the toner end display is displayed or the image forming process is set to the status with the display, and the patch image is formed again by the supplied toner, and the density detection result of the patch image In the image forming method of determining whether or not the toner end display is reset or the display is reset and the image forming process can be reset to the enabled state according to the above, the reset condition is determined according to the characteristics of the toner to be replenished. An image forming method characterized by changing the. 2. An image corresponding to a reference image having a reference density is formed as a patch image on a photoconductor, and the density of the batch image is detected by a density sensor to control the toner density and detect the remaining toner amount. When a state of insufficient remaining amount is detected, the toner end display or the image display processing together with that display is set to the disabled state, the above-mentioned patch image is formed again by the supplied toner, and the density detection result of the patch image is displayed. According to the image forming method for determining whether or not to reset the toner end display or reset the display according to the property of the toner to be replenished. An image forming method, characterized in that a condition for judging whether or not it is acceptable is changed. 3. An image corresponding to a reference image having a reference density is formed as a patch image on a photoconductor, and the density of the batch image is detected by a density sensor to control the toner density and detect the toner remaining amount, When a state of insufficient remaining amount is detected, the toner end display or the image display processing together with that display is set to the disabled state, the above-mentioned patch image is formed again by the supplied toner, and the density detection result of the patch image is displayed. Accordingly, in the image forming method for determining whether or not the toner end display is reset or the display is reset and whether the image forming process can be reset to the enabled state, the toner replenishment time is set according to the characteristics of the replenished toner. An image forming method characterized by changing. 4. An image corresponding to a reference image having a reference density is formed as a patch image on a photoconductor, and the density of the batch image is detected by a density sensor to control the toner density and detect the remaining toner amount. When a state of insufficient remaining amount is detected, the toner end display or the image display processing together with that display is set to the disabled state, the above-mentioned patch image is formed again by the supplied toner, and the density detection result of the patch image is displayed. Accordingly, in the image forming method for determining whether or not the toner end display is reset or the display is reset and whether or not the image forming process can be reset to the enabled state, the replenishment per unit time is performed according to the characteristics of the replenished toner. An image forming method characterized by changing an amount. 5. The image forming method according to claim 1, wherein the characteristics of the toner are at least charging characteristics, fluidity,
An image forming method characterized in that cohesiveness is equivalent. 6. An apparatus using the image forming method according to any one of claims 1 to 5, wherein the toner cartridge has a display section for displaying information on the characteristics of the toner supplied to a part of the surface. An image forming apparatus comprising: a toner replenishing section having means for reading the content of the display section of the toner cartridge.