JP2003084507A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate an abnormality in image or failure in passage of paper generated by the type of paper. SOLUTION: In the apparatus, each controlling condition is varied by a control part taking into reference control data in a control part based on information obtained by having the maker, the model number and weight information of paper information inputted by an operating part of the image forming apparatus. In this case, the quantity of variation in a roll provided to a paper passing part in concern with transfer paper that is being fed is further detected, the paper thickness of the transfer paper is estimated from the quantity of variation and compensation is carried out based on the value to the varied quantity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus such as a copying machine, a printer or a fax machine which forms a fixed image on a transfer sheet by an electrophotographic method.

[0002]

2. Description of the Related Art Conventionally, an electrostatic latent image corresponding to image information is formed on a photoconductor, the electrostatic latent image formed on the photoconductor is visualized in a developing section and transferred onto a transfer paper, Various printers and copying machines have been proposed in which a toner image transferred onto a transfer sheet is fixed on the transfer sheet at a fixing unit. Since image forming conditions such as optimum transfer conditions and fixing conditions for image formation are related to the quality of the transfer paper, it is possible to input information such as thick paper and thin paper depending on the image forming apparatus, and the user makes a vague judgment and selection. Image forming conditions are also set based on paper quality information input.

[0003]

Regarding the transfer paper to be used, when the user makes a vague paper type determination or when a transfer paper not specified is used, an abnormal image may be formed or a paper passing defect may occur. was there. According to the present invention, by previously inputting a paper type (manufacturer, model number, and weight) of a transfer paper, each control value at the time of image formation is switched and an image of high quality can be obtained without an abnormal image or a paper passing defect. apparatus,
Another object of the present invention is to provide an image forming apparatus in which the actual paper quality is detected, the control value switched according to the detection result is corrected, and the image quality is further improved.

[0004]

The first object of the present invention is to:
From the operation unit of the image forming apparatus,
An image forming apparatus characterized in that by inputting model number and weight information, the control unit changes each control condition by referring to control data in the control unit based on the obtained information (invention of claim 1). Achieved by

A second object of the present invention is to input information on the manufacturer, model number, and weight of paper information data from the operation unit of the image forming apparatus, so that the control unit performs control in the control unit based on the obtained information. Change each control condition by referring to the data, monitor the paper feed system motor current during paper feed, and estimate the paper thickness of the transfer paper from the amount of change in the current value of the paper feed system motor. The operation unit is obtained by inputting the manufacturer, model number, and weight of the paper information data from the operation unit of the image forming apparatus (the invention of claim 2) and the image forming apparatus characterized by performing the correction The control data in the control unit is referenced based on the information, and each control condition is changed, and the paper surface condition and paper thickness of the transfer paper at the time of paper passing are estimated by the optical sensor or ultrasonic sensor installed in the paper passing unit. However, it is special that the amount of change is corrected according to that value. By inputting the information of the maker, model number, and weight of the paper information data from the image forming apparatus (the invention of claim 3) and the operation section of the image forming apparatus, the control section stores information in the control section based on the obtained information. Each control condition is changed by referring to the control data, the displacement amount of the roller provided in the paper passing portion at the time of paper passing is detected, the paper thickness of the transfer paper is estimated from the displacement amount, and the change amount is used as the change amount. This is achieved by an image forming apparatus (invention of claim 4) characterized by performing correction.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION (1) First, an image forming apparatus to which the present invention is applied will be described with reference to the sectional configuration diagram shown in FIG. However, the present invention is not limited to the image forming apparatus shown in FIG. 1, but is widely applied to an image forming apparatus that forms an image by an electrophotographic method.

Rotating photoconductor drum 10 for image formation
Around the periphery of the charger 11, the image exposure device 12, the developing device 13,
A pre-transfer exposure device 14, a transfer device 15, a separator 16, and a cleaning device 17 are provided. In forming an image, the peripheral surface of the photosensitive drum 10 is uniformly charged by the charger 11 using a scorotron charger or the like. Then, the image exposure device 12 modulates the laser light based on the image information signal,
An electrostatic latent image is formed by projecting light onto the uniformly charged surface of the photoconductor. The electrostatic latent image is developed by the developing device 13 to which a developing bias is applied, and a toner image is formed on the photosensitive drum 10.

The pre-transfer exposure device 14 irradiates the image surface with light to erase charges on the toner and photoconductor surfaces as a transfer assisting means for the purpose of improving transfer efficiency.

In the transfer area, a bias having a polarity opposite to that of the toner is applied from the back of the transfer paper P, which will be described below, in the transfer area, and the toner image on the photosensitive drum 10 is transferred onto the transfer paper P. Transfer paper P carrying a toner image transferred
The AC bias and the DC bias are superimposed and applied by the separator 16 to be separated from the photosensitive drum 10.
The toner remaining on the photoconductor drum 10 after the transfer paper P is separated is removed from the photoconductor surface by the cleaning device 17.

On the other hand, with respect to the conveyance of the transfer paper P, there are transfer papers P in a stacked state in the plurality of paper feed cassettes 21A, 21B and 21C, and the separation feeding roller 2
The sheet is separated and conveyed to one sheet by 2 and reaches the registration roller 24 via the sheet feeding roller 23. Registration roller 24
Temporarily stops the front end of the transfer paper, corrects the paper curl, and is conveyed in synchronization with the toner image formed on the photoconductor drum 10. The recording paper P to which the toner image is transferred in the transfer area is conveyed. The toner image is conveyed on the belt 25, and is nipped and conveyed by the fixing device 30 including the heating roller 30a and the pressure roller 30b, and the toner image is fixed and fixed on the transfer sheet P by heating and pressurization therebetween.

The transfer paper P, which has been fixed, is ejected outside the apparatus by the paper ejection roller 31. Also, during double-sided image formation,
The transfer sheet P having the front surface image is guided to the reversal conveyance path 40, and is conveyed by the conveyance roller 41 and the reversal conveyance roller 42 that conveys the transfer sheet P after the reversal, and the registration roller 2
Leads to 4. The toner image on the back surface newly formed on the photoconductor drum 10 is the transfer paper P reversed in the transfer area.
Is transferred to the back side of the sheet, the back side image is fixed by the fixing device 30, and then the sheet is discharged by the sheet discharge roller 31 to the outside of the apparatus. In this embodiment, the paper feed roller 23 is a paper feed motor M1 and the fixing device 30 is a fixing drive motor M2.
Accordingly, the transport roller 41 is driven and rotated by the transport motor M3, and the reverse transport roller 42 is driven and rotated by the transport motor M4, so that the transfer sheet P is fed and transported. Stepping motors or DC motors are used as the motors M1 to M4, and current control is performed at the time of sheet feeding / conveying.

(2) In the paper feed path described above, a paper thickness detection sensor ST for detecting the paper thickness of the transfer paper P, and a paper type detection sensor SF for detecting the surface gloss and roughness of the transfer paper P. Is provided.

FIG. 2 shows the structure of the paper thickness detection sensor ST provided on the paper feed roller 23. The paper feed roller 23 is composed of a lower paper feed roller 23a supported by a fixed bearing and an upper paper feed roller 23b supported by a movable bearing that is movable in a direction perpendicular to the transfer paper transport surface. And
In order to make the contact pressure on the recording paper P nipped between the lower paper feed roller 23a and the upper paper feed roller 23b constant, both shaft end portions of the lower paper feed roller 23a and the upper paper feed roller 23b are formed. A ring-shaped coil spring 23c is attached to the. The paper thickness detection sensor ST is a sensor having a laser displacement meter function that is integrally incorporated with a laser light emitting element, a photodiode, and a power supply unit, and is arranged close to the position where the outer peripheral surface of the upper paper feed roller 23b is irradiated with a laser beam. Transfer paper P
Paper thickness detection is performed by the output change of the photodiode that detects the amount of displacement of the roller surface that moves up and down according to the paper thickness.

FIG. 3 shows the configuration of the paper type detection sensor SF. The transfer paper P is detected along the guide member 23e at a stable conveyance position in the paper feed path, for example, near the position where the transfer paper P is nipped and conveyed by the paper feed roller 23. Is done. Paper type sensor SF
Is a light emitting diode LD that irradiates the vertical surface of the moving transfer paper P at an angle of θ, and a light emitting diode LD.
The photodiode PD1 that receives light in the regular reflection direction and the photodiode PD2 that receives light in the vertical direction with respect to the irradiation position of are provided to detect the paper type state. Depending on the photodiode PD1, the transfer paper P
The surface gloss of the transfer paper P is measured by the photodiode PD2. In addition to the optical detection method described above, the paper type detection sensor SF is
It can also be detected by a detection method using ultrasonic waves.

(3) In the above-described image forming apparatus, the operation unit is provided with the paper type input unit for inputting the paper type, and the paper information data of the manufacturer, the model number, and the weight of the transfer paper to be printed are input. It can be configured. FIG. 4 shows an example of the paper type input section, in which the upper and middle stages, the lower and upper stages of the paper feed cassettes, the manufacturer names A to E, the model numbers J to N, and the weight a are displayed on the touch-sensitive liquid crystal display panel. ~ E are displayed. When a transfer paper is newly loaded into any of the paper feed cassettes 21A (B, C), the paper feed cassette to be loaded and the paper information data written on the wrapping paper of the transfer paper are touched on the paper type input section. input. FIG. 4 shows the upper sheet feed cassette 21A.
In the figure, the state is shown in which a maker B, a model number M, and a transfer amount c are loaded and input.

In the image forming apparatus, among the control conditions at the time of image formation, the control conditions that need to be changed / corrected depending on the paper type are the exposure light amount before transfer, the transfer voltage / current, and the separation. There are voltage / current, fixing temperature, fixing speed, and conveyance speed. The image forming apparatus is compatible with an average paper type. The standard control data shown in FIG. 5 is stored in the control unit as a memory. When the image formation is performed without inputting the paper information data, the image formation is performed by the standard control data stored in the control unit.

Further, in the control section, changes / correction amounts of the control data items 1 to 3 corresponding to the paper information data are stored as a table memory. FIG. 6 shows a paper type control table showing control data corresponding to the paper information data.

In the present embodiment, the control unit calls up the control condition change / correction data corresponding to the input paper information data. For example, when the paper information data of the manufacturer B, the model number M, and the weight c is input, the control unit sets the exposure light amount before transfer as p as the change / correction data of the control condition.
(BMc), t (BM
c), the separation voltage / current is s (BMc), the fixing temperature is ft (BMc), the fixing speed is fs (BMc), and the transport speed is v (BMc). Changed against
Make a correction. FIG. 7 shows the paper type control data which is changed / corrected based on the paper information data and stored in the memory. When an image is formed based on the corrected control data, it is possible to eliminate the abnormal image and the sheet passing problem due to the paper type, and to improve the image quality.

(4) In the above-described image forming apparatus, by inputting the maker, model number, and weight of the paper information data from the operation unit, the control unit refers to the data in the control unit based on the obtained information. The image forming apparatus to be described next, in addition to changing the above control conditions, monitors the current of the sheet feeding system motor during sheet feeding and changes the current value of the sheet feeding system motor. The paper thickness of the transfer paper is estimated by detecting the amount, and the change amount is corrected based on the value, which will be described below.

In the image forming apparatus shown in FIG. 1, the sheet feeding roller 23 provided in the sheet feeding path is driven and rotated by the sheet feeding motor M1 to convey the transfer sheet. Here, the paper feed motor M1
Since the motor current of is closely related to the paper thickness of the transfer paper, various transfer papers having different paper thicknesses are previously fed, and the monitor current I (M1) of the paper feed motor M1 and the paper thickness W are fed. Can be obtained as W = f (I (M1)). That is, the paper thickness W of the transfer paper can be estimated by monitoring the monitor current I (M1) of the paper feed motor M1.

Further, when the transfer paper having the paper thickness W is used, the optimum control condition is that the image forming test using the transfer paper having the paper thickness W is performed in advance, and the exposure light amount before transfer is P (I ), T (I) for transfer voltage / current,
S (I) for the separation voltage / current, FT (I) for the fixing temperature, FS (I) for the fixing speed, and V (I) for the conveying speed are obtained as the optimum control conditions during image formation.

In the present embodiment, the correction values shown in the table of FIG. 7 which are changed according to the paper information data are corrected by further monitoring the paper feeding system motor current at the time of paper passing. Further correction is made based on the actually measured transfer sheet information at the time of passing the sheet, so that the abnormal image due to the sheet type and the sheet passing defect can be eliminated, and the image quality can be further improved.

(5) In the image forming apparatus described in the above (3), by inputting information on the manufacturer, model number, and weight of paper information data from the operation unit, the control unit stores the information in the control unit based on the obtained information. Each control condition is changed with reference to the data of the above. However, in addition to the above change of each control condition, the image forming apparatus described here transfers images by an optical sensor or an ultrasonic sensor provided in the paper passage. The paper surface condition and the paper thickness of the paper are estimated, and the change amount is corrected based on the values, which will be described below.

In the image forming apparatus shown in FIG. 1, the paper thickness W of the transfer paper P being fed is detected by the paper thickness detection sensor ST provided in the paper passage. Further, the paper type detection sensor SF detects the paper surface state of the transfer paper P being passed. In this embodiment, when the transfer paper having the detected paper thickness W and the paper surface state is used, the optimum control condition is the paper thickness W in advance.
By performing image formation monitoring using the transfer paper of the paper surface state, the pre-transfer light amount is P (W), the transfer voltage / current is T (W), and the separation voltage / current is S (W). , For the fixing temperature FT (W),
FS (W) is the optimum value for the fixing speed and V (W) is the optimum value for the conveying speed.

In the present embodiment, the correction values shown in the table of FIG. 7 changed by the paper information data are corrected by further using the detection data by the paper thickness detection sensor ST and / or the paper type detection sensor SF. Is done. Further correction is made based on the transfer sheet information actually measured at the time of passing the sheet, so that the abnormal image due to the sheet type and the sheet passing defect are further eliminated, and the image quality can be improved.

(6) FIG. 8 is a control block diagram of the image forming apparatus described above. All controls are control board B0
It is performed by the CPU B1 in the inside. The image formation control data is stored in the memory B2, and this control data is stored in FIG.
By inputting the paper type in the display input section B3 shown in FIG. 6, various control conditions of the paper type processing device B4 are changed by the change / correction table of the control data shown in FIG.

The motor current detecting device B5 detects the motor current of the paper feeding system during paper passing, and the detection data processing device B6 performs correction processing to further correct the changed values of various control conditions. Is done.

By performing a correction process by the paper thickness detection sensor ST at the time of passing the paper and the detection data processing device B6 based on the paper type data detected by the paper type detection sensor SF, the changed values of various control conditions are corrected. Further correction is performed.

As one of the control units for changing the control condition, there is a change / correction of the transfer bias of the transfer device 15. A transfer bias voltage having a polarity opposite to that of the toner is applied to the transfer device 15 by constant current control or constant voltage control.
Here, the constant current value or the constant voltage value is changed / corrected by the high voltage power supply output correction device B7 ().

As one of the control units for changing the control condition, there is a change / correction of the separation bias for the separator 16. A separation bias voltage in which alternating current and direct current are superposed is applied to the separator 16 by constant current control or constant voltage control. Here, the constant current value or constant voltage value is changed / corrected by the high-voltage power output correction device B7. Done ().

As one of the control units for changing the control conditions, the change amount of the charge erasing light for the pre-transfer exposure device 14 is changed.
There is a correction. The charge erasing light source is preferably an LED
Is used, and the light amount is changed by the PWM control, and the light amount control is performed by the charge erasing light amount control device B8 ().

The fixing device 30 is one of the control units for changing the control conditions. Regarding the fixing device 30, there are a temperature change / correction of the heating roller 30a and a transfer paper conveyance speed change / correction in the fixing unit. The temperature change / correction is performed by the roller temperature control device B9, and the change / correction of the transfer paper transport speed is performed by the transport speed control device B10 that controls the transport speed of the fixing drive motor M2 ().

As one of the control units for changing the control condition, there is a change / adjustment of the current value for the motor using the stepping motor among the transfer sheet conveying motors M1 to M4. The load at the time of driving and conveying the transfer sheet varies depending on the quality of the sheet. In the stepping motor that carries the transfer paper, the motor current control device B11 performs necessary and sufficient current control so that a current amount that does not cause step out is secured and an excessive current amount is not supplied.

As one of the control units for changing the control condition, control for changing the paper feed start interval of the second paper feed / first paper feed is performed. As shown in FIG. 9A, the transfer paper that is guided and conveyed at a predetermined interval has different paper conveyance paths for thick paper and thin paper. When the paper transport paths are different, the motor drive time required to transport the transfer paper over a certain distance is different. FIG. 9B shows that the paper feed start interval is different between thick paper and thin paper. The motor drive control device B12 controls the motor drive depending on the paper type.

(7) The block diagram shown in FIG. 10 is a control block diagram of the correction system based on the paper information detection already described in (4) and (5). This indicates that the control data corrected according to the paper type is controlled to be further corrected by the transfer paper information measured when the paper is passed by the detection means provided in the paper feed path.

The flowchart shown in FIG. 11 is a correction system showing a process in which image formation is performed by further correcting the control data that has been corrected in accordance with the paper type based on the transfer paper information actually measured during paper passing. It is a flowchart.

When the paper type data of the manufacturer, model number and weight is input to the paper type input section shown in FIG. 4 (F1), C
The PUB1 calls the process data corresponding to the relevant paper type from the paper type control table shown in FIG. 6 (F2), and corrects the control data for the image formation control data B2 stored in advance. Data correction processing is performed, and the control data shown in FIG. 7 is corrected (F
3).

When the user depresses the start button for continuous printing, the preceding one sheet of the transfer sheet P is passed through the sheet feeding path (F).
4). In the paper feed path, the paper thickness of the transfer paper P is estimated from the monitor current of the paper feed motor M1, or the paper thickness and paper surface information are input to the CPUB1 from the paper thickness detection sensor ST and the paper type detection sensor SF (F5). .

No image is formed on the preceding first transfer sheet P that has passed through the sheet feeding path, and the sheet is discharged to another tray different from the sheet discharge tray designated by the user in a blank state.
The preceding first sheet is not reflected on the counter display such as the total counter (F6).

The CPU B1 creates detection correction control data based on the paper information (F5) detected by the detection data processing device B6 (F7). It is checked whether the detection correction control data obtained here is within the range of the control correction permitted for the control data shown in FIG. 7 obtained previously (F8).

When the detection correction control data is out of the range of the allowable control correction based on the paper type information, that is, when the control data based on the previously input paper type data is detected, the preceding first sheet is detected. When the control data based on the data is significantly different, it is determined that the control condition is abnormal, and an alarm display or alarm display is performed to stop the image forming operation (F9).

When the detection correction control data is within the allowable control correction range based on the paper type information, the previously input paper for the image formation performed subsequent to the preceding first sheet. The control output value is changed / corrected from the seed control data to the detection correction control data obtained by detecting the actual sheet passing (F10), and the subsequent image formation is performed.

A specific example of the above flows (F8) to (F10) will be described. For example, the pre-transfer exposure amount P + p corrected as optimum by the paper type control data
In this state, the pre-transfer exposure allowable range is {(P + p) + Δ (P + p)} to {(P + p) −Δ (P
+ P)} is set at the same time.

When the pre-transfer exposure light amount created based on the detection result of the paper thickness detection sensor ST and / or the paper type detection sensor SF is P (W), {(P + p) + Δ (P + p)} > P (W)> {(P +
p) −Δ (P + p)} is checked, and in the case of NO, that is, P (W)> {(P + p) + Δ (P + p)} or {(P + p) −Δ (P + p)} When it is> P (W), an alarm message "A paper different from the input paper type is used" is displayed. Also, Y
In the case of ES, that is, {(P + p) + Δ (P + p)} ≧ P (W) ≧ {(P +
p) −Δ (P + p)}, the detected pre-transfer data is emphasized, and the subsequent pre-transfer exposure light amount is switched to P (W) to perform image formation.

[0045]

According to the first aspect of the present invention, by inputting the paper information data from the operation unit, the control condition suitable for the paper quality is set, and the abnormal image and the communication caused by the paper type that often occur conventionally are displayed. An image forming apparatus that eliminates paper problems and can obtain an image with improved image quality is provided.

According to the second to fourth aspects of the present invention, the paper information is input from the operation unit and the paper information in the paper passing is input by the detection means provided in the paper passing unit, and the transfer paper is overprinted. Since the control condition suitable for the confirmed paper quality and the confirmed paper quality are set, there is no abnormal image or paper passing defect caused by the paper type, and an image forming apparatus capable of obtaining an image with improved image quality is provided. It became a thing.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram of an image forming apparatus.

FIG. 2 is a configuration diagram of a paper thickness detection sensor.

FIG. 3 is a configuration diagram of a paper type detection sensor.

FIG. 4 is an explanatory diagram showing an example of a paper type input unit.

FIG. 5: Control data stored in memory.

FIG. 6 is a stored paper type control table.

FIG. 7 is paper type control data stored in memory.

FIG. 8 is a control block diagram.

FIG. 9 is an explanatory diagram showing a relationship between paper thickness and a paper feed state.

FIG. 10 is a control block diagram of a correction system.

FIG. 11 is a flowchart of a correction system.

[Explanation of symbols]

10 Photosensitive drum 11 charger 12 Image exposure device 13 Developer 14 Pre-transfer exposure device 15 Transfer device 16 separator 21,21A (B, C) Paper feed cassette 23 Paper feed roller 24 Registration roller 30 fixer ST Paper thickness detection sensor SF paper type detection sensor M1 paper feed motor M2 fixing drive motor

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/20 109 G03G 15/20 109 2H200 21/00 386 21/00 386 3F048 500 500 21/08 372 21 / 14 342 (72) Hideo Yamane 2970 Ishikawa-cho, Hachioji, Tokyo Konica Stock Company F-term (reference) 2C061 AP01 AP03 AP04 AQ06 AS02 HJ01 HK05 HK07 HK11 HN04 HN15 2H027 DA20 DC02 DE02 DE07 DE10 EA03 EA08 EA10 EA10 EA10 EA10 EA10 EC11 ED16 ED24 ED25 ED26 EE03 EE05 EF09 EH10 EK03 2H033 AA03 AA14 CA04 CA09 CA20 CA30 CA36 CA37 2H035 AA11 AB01 AC02 AC07 2H072 AA07 AA09 AA16 GB30 GA02 GA30 GA02 JA30 JA02 JA03 HA02 AB03 AB02 CA02 CA02 CA02 CA02 CA02 CA02 CA02 CA02 CA02 CA02 CA02 CA02 CA05 CA02 CA02 CA02 HA12 JA02 JA29 KA02 KA07 KA29 PA02 PA23 PA28 PB25 PB33 3F048 AA02 AA04 AA05 AB01 BA 06 BA09 BB02 BB05 BB08 BC03 BD07 CA02 CC02 DA06 DB02 DB11 DC14 EA02 EB22 EB29 EB37

Claims (16)

[Claims] 1. The control unit refers to the control data in the control unit based on the information obtained by inputting information on the manufacturer, model number, and weight of the paper information data from the operation unit of the image forming apparatus. An image forming apparatus characterized by changing conditions. 2. The control unit refers to the control data in the control unit based on the information obtained by inputting the information of the maker, model number, and weight of the paper information data from the operation unit of the image forming apparatus. By changing the conditions, monitoring the paper feed system motor current at the time of paper feed, estimating the paper thickness of the transfer paper from the current value change amount of the paper feed system motor, and correcting the change amount based on that value Image forming apparatus. 3. By inputting information on the manufacturer, model number, and weight of paper information data from the operation unit of the image forming apparatus, the operation unit refers to the control data in the control unit based on the obtained information and performs each control. By changing the conditions, the paper surface condition and the paper thickness of the transfer paper at the time of paper passing are estimated by the optical sensor or ultrasonic sensor provided in the paper passing portion, and the amount of change is corrected based on that value. Image forming apparatus. 4. The control unit refers to the control data in the control unit based on the information obtained by inputting the maker, model number, and weight of the paper information data from the operation unit of the image forming apparatus. It is characterized in that the conditions are changed, the displacement amount of the roller provided in the paper passing portion at the time of paper passing is detected, the paper thickness of the transfer paper is estimated from the displacement amount, and the change amount is corrected based on the value. Image forming apparatus. 5. The image forming apparatus according to claim 1, wherein one of the control conditions is a transfer voltage / current. 6. The image forming apparatus according to claim 1, wherein one of the control conditions is separation voltage / current. 7. The image forming apparatus according to claim 1, wherein one of the control conditions is a light amount of a charge erasing unit. 8. The image forming apparatus according to claim 7, wherein PWM control is used as a method of changing the light amount of the charge erasing means. 9. One of the control conditions is a fixing temperature of a fixing roller.
The image forming apparatus according to item. 10. The image forming apparatus according to claim 1, wherein one of the control conditions is a transfer paper conveyance speed in fixing. 11. The image forming apparatus according to claim 1, wherein one of the control conditions is to change a current value of a paper transport stepping motor. 12. The method according to claim 1, wherein one of the control conditions is to change a paper feed start interval of the second paper feed or the first paper feed. Image forming apparatus. 13. The image forming apparatus according to claim 2, wherein an alarm is displayed or operation is stopped when a correction value for correction exceeds a correction allowable range. 14. The image forming apparatus according to claim 2, wherein the paper type detection is performed on the first sheet of paper, and no image is formed on the first sheet of transfer paper. . 15. The image forming apparatus according to claim 14, wherein the first sheet of transfer paper is discharged to a tray different from a discharge tray designated by the user. 16. The image forming apparatus according to claim 14, wherein the first sheet passing is not reflected on a counter display such as a total counter.