JPH05150578A - Image forming method and device for it - Google Patents

Abstract

PURPOSE:To obtain stable excellent transfer performance by making condition of a transfer, separating, carrying, etc., different, for producing a reference image out of the image region of a photosensive body, and transferring it, and then, detecting transfer performance for determining each condition of the transfer, separating, carrying, etc. CONSTITUTION:A microprocessor 704 inputs a digital signal VT from an convertor 701 and a digital signal DELTAVT from a differential circuit 703, and estimates them as the synthesis of the membership functions of information signal, to execute the fuzzy operation of transfer, separating, and carrying conditions, etc., and outputs a control signal, based on the result of the fuzzy operation to control a transfer power source 705. Consequently, residual toner on a photosensitive drum is detected, so that the transfer performance, for instance, when an ambient temperature is changed, can be maintained, control accuracy is improved, and residual transfer toner can be always kept to irreducible minimum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to transfer, separation of recording paper,
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method and apparatus for controlling conveyance, and in particular, by deducing transfer, separation, and conveyance states as a combination of membership functions of various information, transfer, separation, conveyance conditions, and auxiliary conditions for each of the above conditions. And an apparatus for forming the image.

[0002]

2. Description of the Related Art A conventional image forming apparatus or image forming method for controlling transfer, separation and conveyance of a recording sheet is disclosed in Japanese Patent Application Laid-Open No. 58-125074 entitled "Dehumidification of recording sheet for copying machine". There is a device. In this apparatus, a humidity sensor for detecting the humidity in the apparatus and a conveying means provided with a heater for dehumidifying the recording paper are provided, and the conveying means is operated based on the detection signal from the humidity sensor. By controlling and adjusting the conveying speed of the recording paper, the recording paper is always kept in a good condition and the image quality is improved.

Further, the "electrostatic copying method" disclosed in Japanese Patent Laid-Open No. 57-64270 discloses that the thickness and the specific resistance value of the recording paper are measured before the transfer processing after the feeding of the recording paper. By executing processing and controlling various conditions of transfer and separation based on the result of the calculation, the separability of the recording paper is improved irrespective of the kind of the recording paper used or the environmental condition, and the transfer and separation are performed. It is intended to prevent deterioration of image quality in the process.

Further, in the conventional image forming method, as a method for measuring the transfer performance, for example, a reference image (a detection pattern for detecting an image density related value) is formed outside the image area on the photoconductor, A transfer performance measuring method is used in which the density of a developed image is optically measured using an optical sensor after developing the image. In this transfer performance measuring method, generally, a reference image is created under a predetermined control condition at a rate of once for every 10 copies, and this is fed back to the control of image formation for control.

[0005]

However, in the above-mentioned prior art, individual control information, for example, a detection signal from the humidity sensor (Japanese Patent Laid-Open No. 58-125074), or the thickness and the specific resistance of the recording paper are used. Value (JP-A-57-642)
70), the transfer, separation, and transfer conditions are determined. In other words, the transfer, separation, and transfer conditions are set as fixed values or appropriate values in a typical state are set. Electrical characteristics, physical characteristics, environmental information,
It does not comprehensively judge complicated mutual relationships such as time information.

That is, even if the state of the recording paper that affects the transfer / separation / conveyance performance is changed, the image is not greatly deteriorated, or even if the image is slightly deteriorated, a paper jam occurs and the system malfunctions. The conditions are set so that the above conditions do not occur, and as a result, the conditions are not necessarily optimal for each situation, but the standard conditions are set so that problems do not occur relatively easily. Transcription,
There is a problem in that the optimum values cannot be calculated for the separation and conveyance conditions and the auxiliary conditions of the above conditions, and it is not possible to always obtain stable and good images in various situations.

Generally, the relationship between the characteristics of the recording paper and the transfer / separation / conveyance performance is such that thin recording paper such as thin paper such as 35 kg paper has poor separability, and color paper containing pigment etc. and moisture absorption. The transferability of the recording paper whose electric resistance is lowered due to such reasons is poor. Further, the transferability of recording paper having a rough surface such as bond paper is also inferior.

As for images, if there is no toner image at the leading edge of the recording paper, the separability is poor, and in the case of images such as dots and lines and halftone images, the images deteriorate under excessive transfer conditions. In addition, as a time factor, there is a complicated relationship such that similar performance cannot be obtained under the same conditions due to performance deterioration of the transfer / separation device over time.

Further, according to the prior art, since the transfer, separation, and conveyance conditions are set as fixed values or appropriate values in a typical state are set, there is a problem that fine control cannot be performed.

Further, in the conventional image forming method, the reference image is unconditionally created once every 10 copies, and the transfer performance is detected. Therefore, the wasteful toner amount cannot be ignored, and ， There was a problem that it took time.

The present invention has been made in order to solve the above-mentioned problems, and involves transfer / separation / transfer to / from recording paper.
As a result of improving transport performance, regardless of paper quality and environmental conditions, stable and good images are always obtained, and transfer / transfer is performed.
A first object is to significantly reduce the number of paper jams in the separation section.

Secondly, by minimizing the residual toner amount on the photoconductor after the transfer process, the cleaning performance is improved, and the wasteful toner consumption amount is reduced to shorten the control time. The purpose of.

Further, the remaining amount of transfer toner, the amount of toner before transfer,
A third object of the present invention is to detect the transfer toner amount so that the transfer performance including factors of the recording paper can be reliably estimated and the control accuracy is improved.

Further, by forming a single detecting means for detecting the amount of toner before transfer and the amount of transfer toner remaining, it is possible to reduce variations in the detected values among the detecting elements and to reduce the cost of the apparatus. The fourth purpose.

A fifth object is to further improve the control accuracy by detecting the transfer ratio.

The sixth point is that fine control can be performed.
The purpose of.

[0017]

In order to achieve the above object, the present invention provides an image forming method for forming an image by transferring a toner image formed on a photoconductor to a recording paper to form an image outside the image area. By detecting the transfer toner remaining amount of the reference image, and inferring the transfer performance to the recording paper as a composition of the membership function of the transfer toner remaining amount, transfer, separation,
The present invention provides an image forming method for determining a conveyance condition and auxiliary conditions for each of the above conditions and executing control based on the determination.

It is also preferable that the pre-transfer toner amount of the reference image is detected and inferred as a combination of membership functions including the pre-transfer toner amount as input information.

Further, the transfer performance to the recording paper is obtained by synthesizing the detection means for detecting the transfer toner remaining amount of the reference image formed outside the image area and the membership function of the transfer toner remaining amount detected by the detecting means. An image forming apparatus provided with a fuzzy calculation means for inferring is provided with a check mode for detecting the transfer toner remaining amount.

Further, a detecting means for detecting the amount of toner before transfer of the reference image formed outside the image area, a detecting means for detecting the remaining amount of transfer toner of the reference image, and a member of information detected by the detecting means. In an image forming apparatus provided with a fuzzy calculation means for inferring transfer performance to recording paper as composition of a ship function, a detection means for detecting the toner amount before transfer and a detection means for detecting the transfer toner remaining amount. An image forming apparatus configured as a single detection unit is provided.

In addition, in the image forming method for forming an image by transferring the toner image formed on the photoconductor to the recording paper,
By detecting the transfer toner amount of the reference image formed outside the image area and inferring the transfer performance to the recording paper as the composition of the membership function of the transfer toner amount, the transfer, separation, conveyance conditions and the above conditions An image forming method for determining an auxiliary condition and executing control based on the determination.

Further, in the image forming method for forming an image by transferring the toner image formed on the photoconductor to the recording paper,
By obtaining the transfer ratio of the reference image formed outside the image area and inferring the transfer performance to the recording paper as the composition of the membership function of the transfer ratio, the transfer, separation, conveyance conditions and auxiliary conditions for each of the above conditions are determined. An image forming method for determining and performing control based on the determination.

Further, in the image forming method of forming an image by transferring the toner image formed on the photoconductor to the recording paper,
The transfer condition, the separation condition, the transport condition, and the auxiliary conditions of each of the conditions are changed to form a reference image outside the image area of the photoconductor, and after the transfer, the transfer performance is detected to determine the transfer condition,
(EN) An image forming method for controlling image formation by determining a separation condition, a conveyance condition, and an auxiliary condition of each of the above conditions.

Further, the transfer performance is preferably inferred as a composition of membership functions of a plurality of detection targets.

Further, when the determined control condition is out of the range of the condition changed when the transfer performance is detected, it is desirable to change the condition again, detect the transfer performance, and determine the control condition.

Further, it is desirable that the timings of creating the reference image, detecting the transfer performance, and determining the control conditions are determined by other input information and sensor information.

Further, the timing of creating the reference image, detecting the transfer performance, and determining the control conditions are as follows:
When manually input by the user, when creating a certain number of sheets,
After a certain period of time, when replacing the paper cassette, when replenishing toner,
Information of temperature / humidity sensor, such as when the developer is replaced and the photoconductor is replaced.
It is desirable to be determined by the information of the potential sensor and toner concentration sensor.

Further, in the image forming method of transferring the toner image formed on the photosensitive member to the recording paper to form an image,
The transfer characteristics of the reference image formed outside the image area are detected, and the transfer, separation, conveyance conditions and auxiliary conditions of each of the above conditions are fuzzy inferred from these membership functions, and a plurality of conditions including the above conditions are inferred from this inference result. An image forming method for controlling conditions is provided.

Further, in the image forming method for forming an image by transferring the toner image formed on the photoconductor to the recording paper,
The transfer function, the separation condition, the transport condition, and the auxiliary conditions for each of the conditions are changed to form a reference image outside the image area of the photoconductor, and after the transfer, the transfer performance is detected to determine the membership function of these. From transfer conditions, separation conditions, transport conditions,
Also, the present invention provides an image forming method for fuzzy inference of the auxiliary conditions of the respective conditions and controlling a plurality of conditions including the above conditions based on the inference result.

[0030]

The image forming method and apparatus according to the present invention are provided with a pre-transfer toner amount that greatly contributes to transfer / separation / conveyance performance.
By detecting the remaining transfer toner amount, the transfer toner amount, or the transfer ratio of those information, the transfer performance to the recording paper and the separation / conveyance performance of the recording paper are estimated as the composition of each membership function, and the transfer and separation are performed. By determining and controlling the carrying conditions and the auxiliary conditions of each of the above conditions, optimum conditions are set in each situation, and stable image quality and carrying quality are always obtained.

Further, in the image forming method according to the present invention, a plurality of reference images created under a plurality of control conditions are transferred, the transfer performance thereof is detected, and the image formation is controlled under the best control condition. Moreover, fine control is possible by inferring the transfer performance as a composition of the membership functions of multiple detection targets. Further, by deciding the timing of creating the reference image, detecting the transfer performance, and deciding the control condition based on other input information and sensor information, unnecessary toner consumption, control time, etc. are reduced.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below.
FIG. 1 is an explanatory diagram showing a configuration of an image forming apparatus using an image forming method according to the present invention. In the drawing, 100 is an image reading unit, and 110 is image information read by the image reading unit on a recording paper. It is an image forming part that is transferred to.

The image reading unit 100 includes a contact glass 101 on which an original is placed and a light source 102 which irradiates the original placed on the contact glass 101 with light while moving.
A mirror 103 that moves with the light source 102 and deflects the reflected light from the original, mirrors 104 and 105 that similarly deflect the reflected light from the mirror 103 in a predetermined direction, and a lens that focuses the reflected light from the mirror 105. 106 and a CCD 107 that reads the light from the lens 106.

The image forming section 110 rotates at a high speed and scans the laser beam at an equal angle, and the laser beam scanned by the polygon mirror 111 at an equal angle on the surface of the photosensitive drum 114 at equal intervals. Fθ lens 112 that corrects so that the laser beam from the fθ lens 112 is guided to the photoconductor drum 114.
3, a photosensitive drum 114 that forms an electrostatic latent image, a charging charger 115 that uniformly charges the surface of the photosensitive drum 114, and an exposure by a laser beam guided by a mirror 113 after charging processing by the charging charger 115. Developing unit 116 that visualizes the electrostatic latent image formed by
Have and.

Further, a paper feed cassette 11 which stores recording paper of a predetermined size and is detachably attached to the main body of the apparatus.
7, 118, and paper feed rollers 117a, 1 that convey the recording papers one by one from the paper feed cassettes 117, 118 toward the transfer unit.
18a, a registration roller 119 that feeds the recording paper fed by the paper feed rollers 117a and 118a to the transfer unit at a predetermined timing, and a transfer belt 12 that grips and conveys the recording paper fed by the registration roller 119.
0, an image on the photoconductor drum 114, which is arranged on the back side of the transfer belt 120, is connected to a transfer power source (not shown), and is held by the transfer belt 120, a predetermined transfer voltage is applied. A transfer roller 121 that transfers by applying a voltage and separates the recording paper from the photosensitive drum 114.
A fixing unit 122 for fixing the image on the recording paper after the transfer processing, and the photosensitive drum 1 after the transfer processing.
14 a cleaning unit 123 (123a is a cleaning blade) for removing the residual toner on the surface, and a charge eliminating lamp 12 for removing the residual charge on the surface of the photosensitive drum 114.
4 and. Reference numeral 126 is a detection sensor for detecting the remaining amount of transfer toner, 127 is a detection sensor for detecting the amount of toner before transfer, 128 is a potential sensor for detecting the latent image potential of the reference image, and 129 is a detection sensor for detecting the amount of transfer toner. , 130 is a PTL.

The operation of the above configuration will be described. First, in the image reading unit 100, the document placed on the contact glass 101 is illuminated by the light source 102, and the reflected light is read by the CCD 107 via the mirrors 103, 104, 105 and the lens 106. C
The image information read by the CD 107 undergoes predetermined image processing and is emitted as a laser beam from a semiconductor laser (not shown).

The laser beam is a polygon mirror 111, f
Photosensitive drum 1 via θ lens 112 and mirror 113
You are led to 14. On the other hand, the surface of the photosensitive drum 114 is uniformly charged by the charging charger 115 in advance, and is exposed by the laser beam to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum 114 is visualized by the developing unit 116, and the visualized image is fed from the sheet feeding cassettes 117 and 118 to the sheet feeding rollers 117a and 118.
a and a registration roller 119, the transfer roller 121 transfers the recording paper to the recording paper held by the transfer belt 120.

The recording paper on which the image is transferred is the photosensitive drum 1
After being separated from the sheet 14, the sheet is conveyed by the transfer belt 120, enters the fixing unit 122, undergoes a fixing process, and is then discharged to the outside of the apparatus. After the transfer processing is completed, the cleaning unit 123 removes the residual toner and the static elimination lamp 124 removes the residual charge, and then the photosensitive drum 114 is in a standby state in preparation for the next image forming processing.

Further, as the detection sensor 126 for detecting the remaining amount of transferred toner, a light emitting element 126a is used as shown in FIG.
A reflective optical sensor including a light emitting diode (for example, a light emitting diode) and a light receiving element 126b (for example, a phototransistor) can be effectively used. The relationship between the toner adhesion amount [mg / cm ² ] per unit area and the detection output [V _T ] of the detection sensor 126 is as shown in FIG. 3, and the detection sensor 126 for detecting the transfer toner remaining amount is As shown in FIG. 1, it is arranged between the transfer unit and the cleaning unit 123.

Next, as the reference image, for example, the toner adhesion amount per unit area after the development processing is about 0.7 [mg].
/ Cm ² ]. In this embodiment,
The reference image formed outside the image forming area is the transfer belt 1
20. The residual toner image of the reference image remains on the photosensitive drum 114, and the detection sensor 126 detects the residual amount of the transferred toner.

As described above, the transfer characteristic and the separation characteristic are closely related to each other. Generally, if the power output applied to the transfer roller 121 is increased to improve the transfer performance, the separation performance is deteriorated. In some cases, if the transfer performance is excessively improved, the amount of toner conveyed to the cleaning unit 123 becomes too small, so that the frictional force between the cleaning blade 123a and the photoconductor drum 114 increases and the tip of the cleaning blade 123a is damaged. There is a problem of causing it. That is, the transfer toner remaining amount does not have to be simply reduced, but the transfer toner remaining amount suitable for the system is required. Considering the above situation, the following control rule is created to control the transfer current.

[0042]

[Table 1]

[0043]

[Table 2]

FIGS. 4 and 5 show membership functions of the difference (ΔV _T = V _T −V _T0 ) between the output of the detection sensor 126 for detecting the remaining amount of transfer toner to be detected and the previous detection output. is there. FIG. 6 shows a transfer roller 121 which is a control target.
It is a membership function of the current value of the power supply output in. Here, when the detection outputs V _T = 2.2 V and ΔV _T = + 0.1 V as shown by the dotted lines in FIGS. 4 and 5, the transfer current output according to the above control rules 1 to 7 is Control as follows.

That is, for each input value at the beginning, the value of the intersection with each membership function is calculated, and then the inference result is obtained by referring to the control rule. as a result,
As shown in FIG. 6, the respective inference results are combined, and finally the center of gravity is taken to obtain the control value It = 430 μA.

FIG. 7 is a block diagram schematically showing a control system of an image forming apparatus which realizes the image forming method according to the first embodiment. An analog information signal from the detection sensor 126 is inputted to a digital signal. A / D converter 701 for converting
And a difference between the latch circuit 702 that inputs and latches the digital signal output from the A / D converter 701 and the previous detection output latched by the latch circuit 702 (Δ
V _T = V _T −V _T0 ) difference circuit 703 and A / D
The digital signal V _T from the converter 701 and the difference circuit 70
A microprocessor 704 for calculating (fuzzy operation) transfer conditions, separation conditions, conveyance conditions and auxiliary conditions for each condition by inputting the digital signal ΔV _T from the signal No. 3 and estimating it as a combination of membership functions of the above information signals.
And a transfer power source 705 as a control target that outputs and controls a control signal based on a fuzzy calculation result by the microprocessor 704.

As a result, by detecting the transfer toner remaining amount on the photosensitive drum 114, for example, the transfer performance can be maintained when the ambient environment changes, the control accuracy is improved, and the transfer toner remaining amount is improved. Can always be minimized.

Next, a second embodiment according to the present invention will be described. In the image forming apparatus shown in FIG. 1, a detection sensor 127 for detecting the amount of toner before transfer is provided to detect the amount of toner before transfer, and also a potential sensor provided between the exposure unit and the developing unit 116. At 128, the potential of the electrostatic latent image forming the reference image is detected. By detecting the electrostatic latent image potential that forms the reference image and the amount of toner before the transfer of the reference image, the PTL 130 that is an auxiliary unit of the transfer process.
The exposure amount of is controlled to an appropriate value. As the reference image, the same pattern as in the first embodiment is used.

The toner before transfer adheres to the photoconductor drum 114 by the electrostatic adhesion force of the electrostatic latent image and the triboelectric charge of the toner, and the toner image is transferred onto the recording paper. In order to do so, it is necessary to form an electric field that overcomes this electrostatic adhesion force.

Therefore, pre-transfer exposure is performed as a means for weakening the electrostatic adhesion force before the transfer process. However, good results are not always obtained when the latent image potential and the toner adhesion amount before the transfer process are different from each other, and the electrostatic adhesion force between the pre-transfer toner and the electrostatic latent image is not obtained in the transfer process. It is important that the appropriate value is approximately constant. If the exposure amount of the pre-transfer exposure is constant, the latent image potential is high, and if the pre-transfer toner amount is large, the electrostatic adhesive force can hardly be weakened and the pre-transfer exposure function cannot be exhibited. On the contrary, when the electrostatic latent image potential is low or the amount of toner before transfer is small, the exposure amount becomes excessive and the electrostatic adhesive force suddenly weakens, so that the toner is scattered around the toner image and the resolving power is reduced. However, there is a problem that the image quality deteriorates. Considering the above situation, create the following control rule,
The exposure amount before transfer is controlled.

[0051]

[Table 3]

[0052]

[Table 4]

8 and 9 show the membership output function of the latent image potential detected by the potential sensor 128 and the detection output of the detection sensor 127 for detecting the amount of toner before transfer which is the object of detection. FIG. 10 is a membership function of the exposure amount before transfer which is a control target.

FIG. 11 is a block diagram schematically showing a control system of an image forming apparatus which realizes the image forming method according to the second embodiment. The detection sensor 127 and the potential sensor 1 are shown in FIG.
A / D converter 1101 for inputting an analog information signal from 28 and converting it into a digital signal, and the A / D converter 11
A microprocessor 110 for calculating (fuzzy calculation) transfer, separation, conveyance conditions and auxiliary conditions of each condition by inputting a digital signal output from the signal 01 and estimating it as a combination of membership functions of the above information signals.
2 and a pre-transfer exposure power source 1103 as a control target that outputs and controls a control signal based on a fuzzy calculation result by the microprocessor 1102.

Here, V as shown by the dotted lines in FIGS.
_{When P} = 0.3 V and V _S = 600 V are input, the pre-transfer exposure amount is set as shown in FIG. 10 by the same method as in the first embodiment according to the control rules 1 to 9 described above. A control value PTL = 29 μW / cm ² is obtained. As a result, by detecting the pre-transfer toner amount and the latent image potential on the photosensitive drum 114, it becomes possible to maintain the transfer performance when these changes, and a stable image quality is secured.

Next, a third embodiment of the image forming method according to the present invention will be described. In the image forming apparatus shown in FIG.
A detection sensor 127 that detects the amount of toner before transfer and a detection sensor 126 that detects the remaining amount of transfer toner are provided to control the developing bias potential and the transfer current to appropriate values. The method of forming and detecting the reference image is the same as that of the first embodiment.

The toner image on the recording paper is the photosensitive drum 11
4 is obtained by transferring the toner image on No. 4, and the obtained image is not always good even if the transfer characteristics are proper. For example, when the toner adhesion amount on the photosensitive drum 114 is very small, the image density of the image on the recording paper is lowered, and an appropriate value cannot be obtained even if the transfer condition is changed. Further, there is a problem such as the damage of the cleaning blade 123a as described above. On the contrary, when the toner adhesion amount on the photoconductor drum 114 is very large, the remaining amount of transfer toner is large and a large amount of toner is conveyed to the cleaning unit 123 or the like for cleaning even if the image density is proper. There was a problem in that the burden on the In consideration of the above situation, the following control rule is created to control the developing bias potential and the transfer current.

[0058]

[Table 5]

[0059]

[Table 6]

The membership functions relating to the outputs of the detection sensors 126 and 127 for detecting the pre-transfer toner amount and the transfer residual toner amount are the same as the membership functions shown in the first and second embodiments, respectively. FIG. 12 is a membership function of the developing bias potential to be controlled.
The membership function of the transfer current is the same as that shown in the first embodiment.

FIG. 13 is a block diagram schematically showing the control system of the image forming apparatus which realizes the image forming method of the third embodiment according to the present invention. The analog information signals from the detection sensors 126 and 127 are input. A / D converter 1301 for converting into a digital signal, and the digital signal output from the A / D converter 1301 is input and estimated as a synthesis of the membership function of each information signal, thereby A microprocessor 1302 that calculates (fuzzy calculation) the separation and conveyance conditions and the auxiliary conditions of the above conditions;
It has a developing bias power supply 1303 and a transfer power supply 1304 which are control objects for outputting and controlling a control signal based on a fuzzy calculation result by the microprocessor 1302.

By the above control, the amount of toner before transfer and the amount of residual toner after transfer are always controlled within proper ranges, and the transfer performance and image characteristics, and further the cleaning property are maintained well.
A more stable image can be obtained for a long period of time.

Further, the detection sensor 127 for detecting the amount of toner before transfer and the detection sensor 126 for detecting the amount of residual toner after transfer may be configured as a single unit. That is, a reference image is formed before and after the original image forming process, one transfer amount is used as the pre-transfer toner amount on the photosensitive drum 114 without transfer, and the other transfer process is performed. The transfer residual toner amount of As a result, by using the detection sensor in common, variation in each sensor is eliminated as compared with the case where a plurality of sensors are used. Therefore, the detection accuracy is improved and the number of parts is reduced to save space and reduce cost. It will be possible.

In the image forming apparatus shown in FIG. 1, a check mode is provided when the power is turned on or in the operation mode to form a reference image on the recording paper, and the pre-transfer toner amount and the transfer residual toner amount at this time are detected. It may be configured to do so. That is, by adopting a configuration in which the transfer performance including the actual recording paper is detected, a stable image can be obtained even when the characteristics of the recording paper are different.

In each of the above-described embodiments, the image forming apparatus using the transfer belt is used for explanation, but the present invention is not limited to this, and the transfer residual toner amount can be obtained even when the toner image is not transferred onto the transfer belt. Since it is possible to detect the above, the present invention can be applied to an image forming apparatus using a corotron charger instead of the transfer belt.

Next, a fourth embodiment of the image forming method according to the present invention will be described. As described above, in the image forming apparatus shown in FIG. 1, the toner image formed on the photosensitive drum 114 is transferred onto the recording paper by applying the transfer voltage to the transfer roller 121 via the transfer belt. To be done.

Detection sensor 1 for detecting the amount of transferred toner
As 29, a reflection-type optical sensor including a light-emitting element (for example, a light-emitting diode) and a light-receiving element (for example, a phototransistor) and a transmission-type optical sensor via the transfer belt 120 can be effectively used. The relationship between the toner adhesion amount per area and the detection output is as shown in FIG. Detection sensor 12 for detecting the amount of transferred toner
9 is arranged between the transfer portion and the fixing unit 122 as shown in FIG.

The reference image here is, for example,
After the development process, the toner adhesion amount per unit area is about 0.7
A pattern image of mg / cm ² is used. In this embodiment, the reference image formed outside the image forming area is transferred onto the transfer belt 120, and the amount of the transferred toner is detected by the transmission type detection sensor 129.

As described above, the transfer characteristics are not always constant but proper changes mainly due to the surrounding environment, changes in characteristics of the apparatus over time, etc. Transfer performance gradually improves or decreases. When the transfer performance is deteriorated, naturally, the image quality is deteriorated, and at the same time, the load on the cleaning is increased and the toner is wasted.

On the other hand, if the transfer performance is excessively improved, the amount of toner conveyed to the cleaning unit 123 becomes too small, so that the frictional force between the cleaning blade 123a and the photosensitive drum 114 increases and the tip of the cleaning blade 123a increases. However, there is a problem in that That is, it is not simply that the transfer toner image is completely eliminated, but the transfer toner amount suitable for the system is required. Taking the above situation into consideration, the following control rule is created and the transfer voltage is controlled.

[0071]

[Table 7]

[0072]

[Table 8]

FIGS. 15 and 16 show the membership function of the difference (ΔT _T = T _T −T _T0 ) between the output of the detection sensor 129 for detecting the amount of transfer toner to be detected and the previous detection output. .. FIG. 17 is a membership function of the transfer voltage that is the control target. Here, the detection output T _T = 0.5 V and ΔT _T = shown by the dotted lines in FIGS.
When 0.125V is input, the transfer voltage is controlled as follows according to the above control rule.

That is, first, the value of the intersection with each membership function is calculated for each input value, and then the inference result is obtained by checking the control rule. As a result, as shown in FIG. 17, the respective inference results are combined, and finally the center of gravity is taken to obtain the control value T _B = 1.75 kv. Therefore, by detecting the transfer toner amount on the transfer belt 120, for example, the transfer performance can be maintained even when the ambient environment changes, the control accuracy is improved, and the transfer toner remaining amount is always kept to the minimum necessary amount. Can be suppressed to.

The structure of the control system of the image forming apparatus for realizing the image forming method according to the fourth embodiment is the same as that shown in FIG.

Next, a fifth embodiment of the image forming method according to the present invention will be described. In this embodiment, a detection sensor 127 for detecting the amount of toner before transfer and a detection sensor 129 for detecting the amount of transfer toner are provided, and the detection output ratio corresponding to the transfer ratio of them is calculated. The transfer voltage is controlled to an appropriate value based on the calculated detection output ratio.

In order to estimate the transfer performance more accurately,
It is desirable to detect the transfer rate, and as described above, there is a problem that the cleaning blade 123a is damaged when the transfer rate is increased, and conversely, when the transfer rate is decreased, the image quality is deteriorated and the cleaning unit 12 is also deteriorated.
There is a problem that the load on 3 becomes large. Considering the above situation, the following control rule is created and the transfer voltage control is executed.

[0078]

[Table 9]

[0079]

[Table 10]

18 and 19 show the detection output ratio corresponding to the above-mentioned transfer ratio to be detected and its previous difference (ΔA
= A−A ₀ ) membership function. As the membership function of the transfer voltage to be controlled, the same one as in FIG. 17 is used. As a result, it is possible to more accurately estimate the transfer performance, and it is possible to always maintain stable transfer performance even when there are variations in latent image conditions and development conditions.

FIG. 20 is a block diagram schematically showing a control system of an image forming apparatus which realizes the image forming method according to the fifth embodiment, in which analog information signals from a plurality of detection sensors 127 and 129 are input. An A / D converter 2001 for converting into a digital signal, an arithmetic unit 2002 for inputting a digital signal output from the A / D converter 2001 to calculate a transfer ratio A, and a signal from the arithmetic unit 2002. The difference between the latch circuit 2003 for latching and the previous detection output latched by the latch circuit 2003 (ΔA = A−
A ₀ ) is input to the differential circuit 2004, the digital signal A from the arithmetic unit 2002, and the digital signal ΔA from the differential circuit 2004, and is estimated as a synthesis of the membership function of each of the above information signals. A microprocessor 2005 that calculates (fuzzy calculation) the separation and conveyance conditions and auxiliary conditions of the above conditions, and a transfer power source 2 as a control target that outputs and controls a control signal based on the fuzzy calculation result by the microprocessor 2005.
006 and.

In the fifth embodiment, instead of the transfer ratio A, the transfer ratio B = (4- _VT )-(4- _VP ) = V
It may be _P -V _T. The other structure is the same as that of the fifth embodiment. However, in the fifth embodiment, A = L
→ B = H, A = H → B = L, ΔA = N → ΔB = P, ΔA
= P → ΔB = N is changed. 21 and 22 show B above.
3 is a graph showing membership functions of ΔB and ΔB.

In the image forming apparatus shown in FIG. 1, a check mode is provided when the power is turned on or in the operation mode, a reference image is formed on the recording paper, and the transfer toner amount at this time is detected. Good. That is, by adopting a configuration in which the transfer performance including the actual recording paper is detected, a stable image can be obtained even when the characteristics of the recording paper are different.

Next, a sixth embodiment will be described. In the configuration shown in FIG. 1, at a predetermined detection timing such as when the power is turned on, the transfer condition of the initial setting (or the transfer condition of the current setting) and the conditions before and after the transfer condition are set outside the image forming area on the photosensitive drum 114. A reference image (toner image) is formed under the conditions, transferred onto the transfer belt 120, and the transfer toner amount transferred under the plurality of conditions is detected. Here, as the reference image, for example, a pattern having a toner adhesion amount per unit area after development of about 0.7 mg / cm ² is used.

As a sensor for detecting the amount of transferred toner, a reflective optical sensor including a light emitting element and a light receiving element and a transmissive optical sensor via the transfer belt 120 can be effectively used. In this embodiment, a reflection type optical sensor is used, and although not shown, it is installed between the transfer position and the fixing device. The relationship between the toner adhesion amount per unit area and the detection output is as shown in FIG.

Here, the reference image is the initial setting value T _B = + 750 V of the transfer voltage, and the conditions before and after that are T _B1 = + 5.
The transfer toner amount is transferred onto the transfer belt under the conditions of 00V, T _B2 = + 1000V, and the amount of the transferred toner is detected by the above-mentioned optical sensor, and V _T = 0.15 V and V _T1 = 0 which is the conditions before and after the transfer. It was 0.50V and V _T2 = 0.10V.
The transfer toner amount is about 0.5 to 0.65 mg / cm
It is desirable that the toner amount of ² is transferred, and the output of the optical sensor corresponds to about 0.10V to 0.30V. In this case, the transfer voltage setting value is not changed because there is no problem with the initial setting value. Next, the transfer characteristics change due to changes in the surrounding environment, etc., and V _T1 = 1.
Assuming that 50 V, V _T = 0.45 V, and V _T2 = 0.22 V are obtained, the transfer voltage is changed to T _B2 = + 1000 V.

The operation of the above configuration and method will be described with reference to the flowchart shown in FIG.
First, a reference image is created (S301). Transfer with transfer voltages T _B , T _B1 , and T _B2 (S302), V _T , V _T1 ,
_VT2 is detected (S303). Next, in S304, it is determined whether V _T is less than 0.1, 0.1 or more and 0.3 or less, or greater than 0.3.

When V _T is less than 0.1, it is determined whether V _T1 is 0.1 or more and 0.3 or less, and 0.1 or more and 0.
If it is 3 or less, set T _B0 (control value of transfer voltage to be used) to T
_{The value} is set to _B1 (S305, S306), and the process ends.
On the other hand, if V _T1 is not 0.1 or more and 0.3 or less, an abnormal state is displayed (S310).

In S304, V _T is 0.1 or more and 0.
If it is determined that it is 3 or less, T _B0 is set to T _B (S307), and the process is terminated.

In S304, if V _T is larger than 0.3, it is determined whether V _T2 is 0.1 or more and 0.3 or less,
If 0.1 or more and 0.3 or less, set T _B0 to T _B2 (S
308, S309), and the process ends. On the other hand, if V _T2 is not 0.1 or more and 0.3 or less, an abnormal state is displayed (S310).

By controlling in this way, even if the transfer characteristics change due to deterioration over time, changes in environmental characteristics, toner characteristics, etc., proper transfer characteristics can always be maintained. In other words, it is possible to always maintain stable and good transfer performance by changing the conditions relating to transfer / separation in advance to detect the transfer performance and controlling the transfer performance under the optimum condition.

Next, the seventh embodiment will be described. In the sixth embodiment, based on V _T , V _T1 , and V _T2 detected by the optical sensor, T _B0 (control value of transfer voltage to be used) is set to initial transfer voltage T _B = + 750.
_{V, T B1 = + 500V,} T B2 = + was set to one of 1000V, V _T has been detected by an optical sensor in the seventh embodiment, by using a _{V T1 ,, V T2, V T0} ( characteristic of The optimum transfer voltage T _B0 is determined by calculation so as to obtain the control value). The other construction is similar to that of the sixth embodiment, and the description and illustration thereof are omitted.

The method of calculating the optimum transfer voltage T _B0 in the seventh embodiment will be shown below in _Equation 1. The transfer voltage T _B0 is
If the value of V _T is 0.20 or more, the A value is used and V _T
If the value of is less than 0.20, the B value shall be used.

[0094]

[Equation 1]

For example, V _T = 0.15 V, V _T1 = 0.5
In the case of 0 V and V _T2 = 0.10 V, V _T is smaller than 0.2, and therefore T _B0 = 714 V using the B value. Also, V
_T1 = 1.50V, V _T = 0.45V, V _T2 = 0.22V
In the case of, V _T is 0.2 or more, so T is
_B0 = 1022V.

The operation of the above method will be described with reference to the flowchart shown in FIG. First, a reference image is created (S401). Transfer voltage T _B , T _B1 , T _B2
Is transferred (S402), and V _T , V _T1 , and V _T2 are detected (S403). Next, in S404, V _T is 0.2
It is determined whether it is 0 or more. If V _T is 0.20 or more, the A value shown in Equation 1 is obtained, T _B0 = A, and the process ends (S406). If V _T is not equal to or greater than 0.20, the B value shown in _Equation 1 above is calculated and T _B0 = B,
The process ends (S405).

By controlling in this way, even when the transfer characteristics change due to deterioration over time, changes in environmental characteristics, toner characteristics, etc., proper transfer characteristics can always be maintained. In other words, it is possible to always maintain stable and good transfer performance by changing the conditions relating to transfer / separation in advance to detect the transfer performance and controlling the transfer performance under the optimum condition. Naturally, when the determined control condition (transfer voltage T _B0 ) is excessive or excessive, the upper and lower limit values of the control condition are set, or it is determined that there is some abnormality, and the initial setting value or the current setting value is set. It is desirable to display abnormal conditions.

Next, the eighth embodiment will be described. The eighth embodiment is the same as the image forming method of the sixth embodiment.
Further, the transfer voltage is controlled according to the control rule. In other words, the transfer performance is inferred as a composition of membership functions of a plurality of detection targets. Further, in the image forming apparatus as shown in FIG. 1, the relationship between the transfer voltage and the transfer toner amount tends to be as shown in FIG. It is known that this relationship varies depending on deterioration over time, environmental characteristics, and toner characteristics while maintaining the general tendency shown in FIG.
That is, when the transfer voltage is low, the amount of transfer toner sharply decreases, and when the transfer voltage is high, it gradually decreases. Further, if the voltage is excessively high, an abnormal image such as white spots due to transfer occurs.

From the above findings, Table 11 in the eighth embodiment
The transfer voltage T _B0 is controlled using the control rule shown in FIG.
Further, Table 12 is a symbolic representation of the control rules of Table 11.

[0100]

[Table 11]

[0101]

[Table 12]

27, 28, and 29 are initial setting values (or current setting values) of the transfer voltage to be detected.
Is a membership function of the output of the optical sensor for detecting the transfer toner amount, the difference between the detection outputs when the transfer voltage is decreased, and the difference between the detection outputs when the transfer voltage is increased. Further, FIG. 30 shows a membership function of a transfer voltage which is a control target.

Here, as shown by the dotted lines in FIGS. 27, 28, and 29, the detection outputs V _T = 0.30 V, V _T1
= 0.60V, V _T2 = 0.23V input,
The transfer voltage is controlled as follows according to the above control rules 1 to 7. That is, first, for each input value, the value at the intersection with each membership function is calculated. next,
Obtain inference results against the control rules. After that, as shown by the shaded area in FIG. 30, the respective inference results are combined and the center of gravity thereof is taken to obtain the control value T _B = 795V.
As a result, by inferring the transfer performance from the transfer toner amount, it is possible to always maintain appropriate conditions even when the transfer performance changes due to changes in the surrounding environment. Also, fine control can be performed.

Next, a ninth embodiment will be described. The ninth embodiment is the image forming method of the sixth embodiment to which a pre-transfer exposure amount control is further added by a control rule. In the image forming apparatus as shown in FIG.
The relationship between the pre-transfer exposure amount and the transfer toner amount tends to be as shown in FIG. It is known that this relationship varies depending on deterioration over time, environmental characteristics, and toner characteristics while maintaining the general tendency shown in FIG. That is, when the exposure amount before transfer is small,
When the transfer toner amount decreases and the pre-transfer exposure amount is large, the transfer toner amount does not change much. However, if the exposure amount is excessively large, there are problems such as deterioration of image quality due to occurrence of toner dust due to transfer and further deterioration of photosensitive characteristics of the photoconductor.

From the above findings, in the ninth embodiment, Table 13
The pre-transfer exposure amount (PTL) is controlled using the control rule shown in FIG. Table 14 is a symbolic representation of the control rules of Table 13.

[0106]

[Table 13]

[0107]

[Table 14]

32, 33, and 34 show the output of the optical sensor for detecting the transfer toner amount at the initial setting value (or the current setting value) of the pre-transfer exposure amount to be detected, and the pre-transfer exposure. It is a membership function of the difference between the detection output when the amount is decreased and the difference between the detection output when the pre-transfer exposure amount is increased. Further, FIG. 35 shows a membership function of the exposure amount before transfer which is a control target. By performing the control in this way, the transfer performance can be inferred from the transfer toner amount, so that even when the transfer performance changes due to changes in the surrounding environment, for example, it is possible to always maintain appropriate conditions. ..

Next, a tenth embodiment will be described.
The tenth embodiment is the same as the eighth embodiment except that the detection timing of the transfer toner amount and the control timing of the transfer voltage are determined by the detection output of the humidity sensor. The transfer characteristics are greatly affected by the surrounding environment. For example, when the humidity is high, the proper value fluctuates toward the higher transfer voltage, and when the humidity is low, the proper value fluctuates toward the lower transfer voltage. Therefore, when the humidity changes by 20% RH according to the detection output of the humidity sensor (not shown), the control of the eighth embodiment is performed by using this as a detection timing (trigger), and the transfer toner amount is changed. Detect and control the transfer voltage. That is, the number of detections of the transfer toner amount can be suppressed to a small level by unconditionally changing the detection to once every 10 copies and performing the detection when necessary. The control time can be reduced.

Next, the eleventh embodiment will be described.
The eleventh embodiment is the same as the eighth embodiment except that the detection timing of the transfer toner amount and the control timing of the transfer voltage are determined by the detection output of the toner density sensor. The transfer characteristic is largely contributed by the toner charge amount, and the toner charge amount decreases as the toner concentration increases.
It tends to increase as the toner density decreases. When the toner charge amount is high, the proper value fluctuates toward the higher transfer voltage, and when the toner charge amount is low, the proper value fluctuates toward the lower transfer voltage. Therefore, the toner concentration is 0.5 wt% according to the detection output of the toner concentration sensor (not shown).
When it fluctuates, this is the detection timing (trigger)
As the control of the eighth embodiment, the transfer toner amount is detected and the transfer voltage is controlled. That is, the number of detections of the transfer toner amount can be suppressed to a small amount by unconditionally changing the detection to once every 10 copies and performing the detection when necessary. The time can be reduced.

Next, the twelfth embodiment will be described.
The twelfth embodiment is the same as the seventh embodiment _except that T _B0 = + 1
After calculating 022V, the voltage becomes higher than T _B2 = + 1000V, so that T _B = + 850V and T _B1 = + 600 next.
V, T _B2 = + 1100V is changed, and the transfer toner amount is detected again. At this time, V _T = 0.38V, V
_When the detection outputs of _T1 = 0.95V and V _T2 = 0.18V are obtained, T _B0 = + 1 by the method shown in the seventh embodiment.
It is determined to be 075V. That is, since the transfer toner is set within the range of the transfer voltage set at the time of detection, excessive control is not performed and an abnormal image can be prevented from occurring.

Next, a thirteenth embodiment will be described.
The final image obtained by transferring the toner image formed on the photoconductor to the recording paper is naturally not determined only by the transfer performance, but the electrostatic latent image property, the developing property, and the cleaning property. The characteristics and the like are maintained in a good state, and an appropriate image is maintained.

In addition, the transfer performance itself may not be sufficient by just optimizing the conditions related to the direct transfer such as the transfer voltage and the transfer current. For example, if the toner adhesion amount on the photoconductor is very small, the final image quality will be insufficient even if the transfer conditions are appropriate, and if the surface potential of the photoconductor is very high. Similarly, even if the transfer conditions are appropriate, the adhesion between the recording paper and the photoconductor increases, the separation performance deteriorates significantly, and paper jams frequently occur. Furthermore, recording paper with weak stiffness such as thin paper of 35 kg paper or less has poor transferability even though the transfer performance is good. That is, in order to maintain good transfer / separation performance, it is necessary to control image forming conditions other than the transfer / separation conditions in relation to the transfer / separation conditions.

An example in which the pre-transfer exposure amount and the transfer voltage are controlled by detecting the transfer toner remaining amount and the pre-transfer toner amount will be described below. In the toner image on the photoconductor after the development processing, especially the toner which is in close contact with the surface of the photoconductor has a large adhesive force, and the transferability cannot always be obtained by simply adjusting the transfer voltage. For this reason, it is used in combination with pre-transfer exposure, but if the exposure amount is excessive, there is a problem that toner scattering around the toner image and electrostatic deterioration of the photoconductor are likely to occur.

From the above viewpoints, the control routes shown in Tables 15 and 16 were prepared, and the exposure amount before transfer and the transfer voltage were controlled.

[0116]

[Table 15]

[0117]

[Table 16]

Next, a fourteenth embodiment will be described.
An example in which the developing bias voltage and the transfer voltage are controlled by detecting the transfer toner remaining amount and the fluctuation amount thereof will be described below. When the remaining amount of transfer toner is completely exhausted, the cleaning blade is likely to be caught or lost, and when the remaining amount of transfer toner is excessively large, the image quality is deteriorated and the burden on the cleaning unit is increased. There is a point. For this reason, it is difficult to properly maintain the image quality and the transfer toner remaining amount only by changing the transfer condition. From the above viewpoints, create the control rules shown in Table 17 and Table 18,
The developing bias voltage and the transfer voltage are controlled.

[0119]

[Table 17]

[0120]

[Table 18]

By the above control processing, the remaining amount of transfer toner is properly controlled, and the image quality and transfer characteristics, and further the cleaning performance is maintained in a good condition.

Next, the fifteenth embodiment will be described.
An example in which the transfer voltage is detected in advance under conditions of an initial set value (T _B ) and a higher value (T _B2 ) than that, and the transfer voltage and the pre-transfer exposure amount are controlled is shown below. In consideration of the transferability when the transfer conditions are changed in advance, and because good transfer characteristics may not be obtained only by the transfer conditions as described above, the transfer conditions and the pre-transfer exposure amount are related to each other, and the aptitude value is simultaneously adjusted. Must be set to. From the above perspective, Table 19,
The control rules shown in Table 20 are created to control the transfer voltage and the pre-transfer exposure amount.

[0123]

[Table 19]

[0124]

[Table 20]

[0125]

As described above, according to the image forming method of the present invention, in the image forming method of transferring the toner image formed on the photoconductor onto the recording paper, the transfer condition, the separation condition, the transport condition, And a supplementary condition of each of the above conditions is made different to create a reference image outside the image area of the photoconductor, and after transfer, the transfer performance is detected to determine the transfer condition, separation condition, transport condition, and each of the above conditions. Since the auxiliary conditions are determined and the image formation is controlled, stable and good transfer performance can always be obtained.

Further, in the image forming method of the present invention, since the transfer performance is inferred as the composition of the membership functions of a plurality of detection targets in the above-mentioned method, fine control can be performed.

Further, in the image forming method of the present invention, in the above method, when the determined control condition is out of the range of the condition changed at the time of detecting the transfer performance, the condition is changed again,
Since the transfer performance is detected and the control conditions are determined, fine control can be performed and the occurrence of abnormal images can be prevented.

Furthermore, the image forming method of the present invention is based on the other input information and sensor information in the above-mentioned method.
Since the timing of creating the reference image, detecting the transfer performance, and determining the control condition is determined, it is possible to reduce wasteful toner consumption and control time.

Further, according to the image forming method of the present invention, in the image forming method of transferring the toner image formed on the photoconductor onto the recording paper, the transfer condition, the separation condition, the transport condition, and A reference image is created outside the image area of the photoconductor with different auxiliary conditions, and after transfer, the transfer performance is detected to determine transfer conditions, separation conditions, transport conditions, and auxiliary conditions for each of the above conditions. Since the image formation is controlled, stable and good transfer performance can always be obtained.

Further, in the image forming method of the present invention, since the transfer performance is inferred as the composition of the membership functions of a plurality of detection targets in the above-mentioned method, fine control can be performed.

Further, in the image forming method of the present invention, in the above method, when the determined control condition is out of the range of the condition changed at the time of detecting the transfer performance, the condition is changed again,
Since the transfer performance is detected and the control conditions are determined, fine control can be performed and the occurrence of abnormal images can be prevented.

Furthermore, the image forming method of the present invention is based on the other input information and sensor information in the above-mentioned method.
Since the timing of creating the reference image, detecting the transfer performance, and determining the control condition is determined, it is possible to reduce wasteful toner consumption and control time.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of an image forming apparatus to which an image forming method according to the present invention is applied.

FIG. 2 is an explanatory diagram showing a configuration of a detection sensor used in the image forming apparatus shown in FIG.

FIG. 3 is a graph showing a relationship between a detection output and a toner adhesion amount.

FIG. 4 is a graph showing a membership function of a difference between an output of a detection sensor that detects a remaining amount of transfer toner that is a detection target and a previous detection output.

FIG. 5 is a graph showing a membership function of a difference between an output of a detection sensor that detects a remaining amount of transfer toner that is a detection target and a previous detection output.

FIG. 6 is a graph showing a membership function of a current value of a power output of a transfer roller which is a control target.

FIG. 7 is a block diagram schematically showing a control system of the image forming apparatus that realizes the image forming method of the present invention.

FIG. 8 is a graph showing a membership function of a detection output of a detection sensor that detects a pre-transfer toner amount that is a detection target.

FIG. 9 is a graph showing a membership function of a latent image potential detected by a potential sensor.

FIG. 10 is a graph showing a membership function of a pre-transfer exposure amount which is a control target.

FIG. 11 is a block diagram schematically showing a control system of the image forming apparatus that realizes the image forming method of the present invention.

FIG. 12 is a graph showing a membership function of a developing bias potential which is a control target.

FIG. 13 is a block diagram schematically showing a control system of the image forming apparatus that realizes the image forming method of the present invention.

FIG. 14 is a graph showing the relationship between the detection output and the toner adhesion amount.

FIG. 15 is a graph showing the membership function of the difference between the output of the detection sensor that detects the amount of transfer toner that is the detection target and the previous detection output.

FIG. 16 is a graph showing the membership function of the difference between the output of the detection sensor that detects the amount of transfer toner that is the detection target and the previous detection output.

FIG. 17 is a graph showing a membership function of a transfer power supply that is a control target.

FIG. 18 is a graph showing a detection output ratio corresponding to a transfer ratio that is a detection target and a membership function of a difference between the detection output ratio and the previous detection output ratio.

FIG. 19 is a graph showing a detection output ratio corresponding to a transfer ratio which is a detection target and a membership function of the difference between the detection output ratio and the previous detection output ratio.

FIG. 20 is a block diagram schematically showing a control system of an image forming apparatus which realizes the image forming method of the present invention.

FIG. 21 is a graph showing a detection output ratio corresponding to a transfer ratio which is a detection target and a membership function of the difference between the detection output ratio and the previous detection output ratio.

FIG. 22 is a graph showing a detection output ratio corresponding to a transfer ratio that is a detection target and a membership function of the difference between the detection output ratio and the previous detection output ratio.

FIG. 23 is a graph showing the relationship between the toner adhesion amount per unit area and the detection output.

FIG. 24 is a flowchart showing an example of control operation of the image forming apparatus according to the present invention.

FIG. 25 is a flowchart showing an example of control operation of the image forming apparatus according to the present invention.

FIG. 26 is a graph showing the relationship between transfer voltage and transfer toner amount.

FIG. 27 is a membership function of the detection output of the optical sensor that detects the transfer toner amount at the initial setting value (or the current setting value) of the transfer voltage.

FIG. 28 is a membership function of the difference between the detection output of the initial setting value of the transfer voltage and the detection output when the transfer voltage is lowered.

FIG. 29 is a membership function of the difference between the detection output of the initial setting value of the transfer voltage and the detection output when the transfer voltage is increased.

FIG. 30 is a membership function of a transfer voltage to be controlled.

FIG. 31 is a graph showing the relationship between the pre-transfer exposure amount and the transfer toner amount.

FIG. 32 is a membership function of the detection output of the optical sensor that detects the transfer toner amount at the initial setting value (or the current setting value) of the transfer voltage.

FIG. 33 is a membership function of the difference between the detection output of the initial setting value of the transfer voltage and the detection output when the transfer voltage is lowered.

FIG. 34 is a membership function of the difference between the detection output of the initial setting value of the transfer voltage and the detection output when the transfer voltage is increased.

FIG. 35 is a membership function of a pre-transfer exposure amount that is a control target.

[Explanation of symbols]

100 image reading unit 110 image forming unit 114 photoconductor drum 120 transfer belt 121 transfer roller 123 cleaning unit 123a cleaning blade 126 detection sensor 127 detection sensor 128 potential sensor 129 detection sensor 130 PT
L 701 1101 1301 2001 A / D converter 704 1102 1302 2005 Microprocessor 705 1304 2006 Transfer power supply 702 2003 Latch circuit 703 20
04 Difference circuit 1103 Pre-transfer exposure power supply 1303 Development bias power supply 2002 Operation unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical indication location H04N 1/29 E 9186-5C Z 9186-5C (72) Inventor Mitsuhisa Kanaya Nakamagome, Ota-ku, Tokyo Ricoh stock company 1-36

Claims (13)

[Claims] 1. An image forming method for forming an image by transferring a toner image formed on a photoconductor onto a recording sheet, detecting the transfer toner remaining amount of a reference image formed outside an image area,
Determining the transfer performance to the recording paper as a composition of the membership function of the remaining amount of transferred toner to determine transfer, separation, conveyance conditions and auxiliary conditions of each condition, and execute control based on the determination. And an image forming method. 2. The image forming method according to claim 1, wherein the pre-transfer toner amount of the reference image is detected, and the result is inferred as a combination of membership functions including the pre-transfer toner amount as input information. 3. A transfer performance to a recording paper is obtained by synthesizing a detection means for detecting a transfer toner remaining amount of a reference image formed outside the image area and a membership function of the transfer toner remaining amount detected by the detecting means. An image forming apparatus provided with a fuzzy calculation means for inferring, having an check mode for detecting the remaining amount of transfer toner. 4. A detecting means for detecting a pre-transfer toner amount of a reference image formed outside an image area, a detecting means for detecting a transfer toner remaining amount of the reference image, and a member of information detected by the detecting means. In an image forming apparatus provided with a fuzzy calculation means for inferring transfer performance to recording paper as composition of a ship function, a detection means for detecting the toner amount before transfer and a detection means for detecting the transfer toner remaining amount. An image forming apparatus configured as a single detection unit. 5. An image forming method for forming an image by transferring a toner image formed on a photoconductor to a recording paper, detecting the transfer toner amount of a reference image formed outside the image area, and transferring the toner to the recording paper. An image characterized in that the transfer performance is inferred as a composition of the membership function of the transferred toner amount to determine transfer, separation, and conveyance conditions and auxiliary conditions for each of the conditions, and control is executed based on the determination. Forming method. 6. An image forming method for forming an image by transferring a toner image formed on a photoconductor onto a recording paper, to obtain a transfer ratio of a reference image formed outside an image area, and transferring performance to the recording paper. Is determined as the composition of the membership function of the transfer ratio, the transfer, separation, and conveyance conditions and the auxiliary conditions of the respective conditions are determined, and the control is executed based on the determination. 7. An image forming method for forming an image by transferring a toner image formed on a photoconductor onto a recording paper, wherein transfer conditions, separation conditions, conveyance conditions, and auxiliary conditions of the respective conditions are made different. A reference image is created outside the image area of the photoconductor, and after transfer, the transfer performance is detected to determine transfer conditions, separation conditions, conveyance conditions, and auxiliary conditions for each of the conditions,
An image forming method characterized by controlling image formation. 8. The image forming method according to claim 7, wherein the transfer performance is inferred as a combination of membership functions of a plurality of detection targets. 9. If the determined control condition is outside the range of the condition changed at the time of detecting the transfer performance, the condition is changed again, the transfer performance is detected, and the control condition is determined. The image forming method according to claim 7. 10. The image forming method according to claim 7, wherein the timing of creating the reference image, detecting the transfer performance, and determining the control condition is determined by other input information and sensor information. 11. The timing for creating the reference image, detecting the transfer performance, and determining the control condition is set at the time of power-on,
When manually input by the user, when creating a certain number of sheets,
After a certain period of time, when replacing the paper cassette, when replenishing toner,
Information of temperature / humidity sensor, such as when the developer is replaced and the photoconductor is replaced.
8. The image forming method according to claim 7, wherein the image forming method is determined by information from a potential sensor and a toner density sensor. 12. An image forming method for forming an image by transferring a toner image formed on a photoconductor onto a recording paper, detecting transfer characteristics of a reference image formed outside an image area, and determining a membership function of these. An image forming method characterized by fuzzy inferring transfer, separation, conveyance conditions and auxiliary conditions of each of the above conditions, and controlling a plurality of conditions including the above conditions from the inference result. 13. An image forming method for forming an image by transferring a toner image formed on a photoconductor onto a recording paper, wherein transfer conditions, separation conditions, conveyance conditions, and auxiliary conditions of the respective conditions are made different. A reference image is created outside the image area of the photoconductor, the transfer performance is detected after transfer, and the transfer conditions, separation conditions, transport conditions, and auxiliary conditions for each of the conditions are fuzzy inferred from these membership functions. Then, an image forming method characterized by controlling a plurality of conditions including the above conditions from the result of the inference.