JPH04274267A - Image forming device - Google Patents

Abstract

PURPOSE:To produce no futileness in a recording medium of image forming operation at a mode in which an image is continuously formed in a state of being almost no conveying interval of the recording medium. CONSTITUTION:Image information formed on an image information holding medium by an image information forming means is transferred onto a recording medium by a first image forming mode being transferred to a recording medium from the image information holding medium in use of one image information transfer means, or a second image forming mode being transferred to plural recording media from the image information holding medium in use of plural image information transfer means. At this juncture, when a fact that an indicating sheet number of the second image forming mode is an odd number is detected by an indicating sheet number detecting means, in regard to the image formation of one sheet in the odd numbers, the image forming mode is selected from the second mode to the first mode by a selector control means, through which the image formation takes place in the shape of one latent image and one transfer.

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 that forms images on a large number of sheets, such as a copying machine or a laser printer.

0002

[Prior Art] For example, in an image forming apparatus that employs an electrophotographic method, an image is generally formed once on a photoreceptor, and the formed image is transferred each time to form a transferred image on a transfer medium. It is supposed to be done. Therefore, there is a limit to the image forming speed. Therefore, various proposals have been made to overcome this limitation and increase the productivity of image formation, for example, copying.

One of these techniques is disclosed in Japanese Patent Application Laid-open No. 7855/1983. This technique is designed to improve copying productivity by simultaneously forming two electrostatic latent images of the same original on one photoconductor in one exposure process. Furthermore, in this technique, in order to improve the productivity of double-sided copying, two transfer means are provided and each transfer means is operated continuously to perform double-sided copying.

[0004] Also, as another technique, Japanese Patent Application Laid-Open No. 55-1
There is a technique disclosed in Japanese Patent No. 63549. This technique is designed to improve copying productivity by simultaneously forming two electrostatic latent images of the same original on two photoconductors in one exposure step.

However, in the above-mentioned conventional technology, it has been conventionally performed to simultaneously form two electrostatic latent images for the same original, ie, hard information from the document and soft information from the image signal, in one exposure process. A special optical system is required compared to the case where one electrostatic latent image is formed in one exposure process. Specifically, the number of parts such as lenses and mirrors is large, and the structure is complicated, leading to an increase in cost. Further, although the above structure has improved productivity, it is still insufficient.

[0006] In other words, in order to increase productivity,
The following methods can be considered.

[0007] As a first method, the resulting copied recording sheets are conveyed and discharged by the image forming apparatus without any gaps between them. In other words, the recording sheets are conveyed and discharged with no space between them.

[0008] The second method is to copy onto a plurality of recording sheets from one electrostatic latent image formed by one exposure process.

[0009] As a method for transporting and discharging recording sheets within an image forming apparatus without paper spacing, it is possible to eliminate the interval between electrostatic latent images of image information formed on a photoconductor, which is a photoreceptor. I can think about it. However, JP-A-61-78
In the copying productivity improvement technology disclosed in Publication No. 55,
The distance between the electrostatic latent images formed on the photoconductor becomes wider to some extent, and this creates a space between successive recording sheets, which ultimately reduces copying productivity. .

[0010] This is because there is a limit to reducing the distance between electrostatic latent images in an analog type optical system using full exposure like this known technique or known slit exposure. This means that, even if a digital optical system uses a laser beam, for example, unless it is equipped with a storage means to temporarily store image information, the interval between electrostatic latent images will be reduced in the same way as an analog system. There are limits to things.

[0011] Even if it is possible to eliminate the interval between electrostatic latent images of image information, recording sheets cut to a certain length must be continuously fed and conveyed from the recording sheet accommodating section without paper gaps. However, there is no disclosure of a recording sheet feeding/conveying means or a feeding/conveying method that allows the leading edge of each fed and conveyed memory sheet to match the leading edge of an electrostatic latent image, and this is not well known in the prior art. With these feeding and conveying means and methods, recording sheets cannot be fed and conveyed without paper gaps. Therefore, the first method has not yet been fully implemented.

[0012] Furthermore, nothing is described in this prior art example regarding the second method.

On the other hand, although the copying productivity improvement technique disclosed in JP-A No. 55-163549 is promising for implementing the first method in the field of composite/multicolor copying, Since at least two or more sets of process means surrounding the body are required, the cost is inevitably high, and due to the configuration of the paper conveyance path, there is a considerable distance between the third and more recording sheets during copying, i.e. Paper gaps occur, reducing copying productivity.

[0014] Also in this conventional example, nothing is described regarding the second method.

[0015]

[Problem to be solved by the invention] From the above,
In order to form an image on a recording sheet with almost no gap between the recording sheets, in other words, with no gap between sheets, the applicant uses a toner image obtained from one latent image to print on two recording sheets. A method and apparatus for forming an image were proposed. However, when images are formed on two recording sheets using toner images obtained from one latent image in this way, one toner image or one recording sheet is wasted when an odd number of sheets are copied.

The present invention was made in view of the above technical background, and its purpose is to eliminate unnecessary image formation when forming images on two recording media from one latent image,
An object of the present invention is to provide an image forming apparatus that does not reduce copying productivity.

[0017]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an image information holding medium (90) and an image information forming means (950) for forming image information on the image information holding medium (90). ) and the image information holding medium (90).
Image information transfer means (231, 232) for transferring the image information formed on the recording medium (P1, P2),
The image information formed on the image information holding medium is transferred to the recording medium (P
1, P2), the image information formed on the image information holding medium (90) is transferred to at least one image information transfer means (231, 23).
2), a first image forming mode in which the image information holding medium (90) is transferred to the recording medium (P1, P2);
One piece of image information formed on the image information holding medium (90) is transferred from the image information holding medium (90) to a plurality of recording media (
an image forming control means (504) having a second image forming mode for transferring images to P1, P2); an instructed sheet number detecting means (504) for detecting the inputted image forming instruction number of sheets; and a second image forming mode. When the designated number of sheets detected by the designated number of sheets detecting means is an odd number, switching control means for switching the image forming operation on one of the recording media from the second image forming mode to the first image forming mode 50
4).

Note that the image forming control means, abnormality detection means and switching control means described above specifically apply to the copying machine (50
0) is incorporated in the system control circuit (504).

[0019]

[Operation] In the above means, the image information formed on the image information holding medium (90) by the image information forming means (950) is transferred to the image information holding medium (90) using one image information transfer means (231, 232). (90) to the recording medium (P1
, P2), or transfer one image information formed on the image information holding medium (90) to the image information holding medium using a plurality of image information transfer means (231, 232). (90) to multiple recording media (P
The image is transferred to the recording medium (P1, P2) by the second image forming mode in which the image is transferred to the recording medium (P1, P2). At this time, when the instructed number of sheets detection means (504) detects that the instructed number of sheets in the second image forming mode is an odd number, the switching control means (504) controls the number of sheets for forming one of the images.
The image forming mode is switched from the second image forming mode to the first image forming mode. As a result, image formation is performed in the form of one latent image and one transfer. Note that in this case, one sheet means at least one sheet including an odd number, and does not necessarily have to be only one sheet, but from the viewpoint of copying productivity, only one sheet is desirable.

Specifically, this effect is related to the section (9) Operation timing described later, especially (9-1) A4, timing in one-to-one copying operation (FIGS. 60 to 62) and (
9-2) Timing when copying multiple sheets simultaneously on A4 landscape (Figure 6)
3 to 65).

[0021]

[Examples] Examples of the present invention will be described below.

(1) Overall Overview First, an overall overview of the copying machine according to the embodiment will be described.

FIGS. 1 and 2 show schematic configuration diagrams of a copying machine according to an embodiment. FIG. 1 shows the configuration when both the first transfer station and the second transfer station use corona discharge, and FIG. 2 shows the configuration when the first transfer station uses corona discharge and the second transfer station uses corona discharge.
The configuration when the transfer station is belt transfer is shown.

In FIG. 1, the copying apparatus includes a writing optical system 909 that guides a laser beam reflected by a polygon mirror 63 to a belt-shaped photoreceptor (hereinafter simply referred to as a photoreceptor) 90.
is written by the writing optical system 909 and written on the photoreceptor 90.
A developing section 910 and a developing section 91 that develop the latent image formed on the
A first transfer station 231 transfers the developed image developed by 0 onto a transfer paper;
a first separation charger 100 that separates the image from the transfer paper 0, a second transfer station 232 that further transfers the image to a different transfer paper from the transfer paper transferred at the first transfer station 231, and a fixing unit that fixes the image to the transfer paper to which the image has been transferred. 190, an image forming system 950 consisting of a cleaning unit 920 that cleans the photoreceptor 90 after image transfer; a static eliminator 930 that neutralizes the photoreceptor 90 after cleaning; and a charger 940 that charges the photoreceptor 90 after the static electricity is removed; It basically consists of a transfer paper conveying system 960 for supplying and discharging transfer paper.

The conveyance system 960 is configured to alternately convey the transfer paper to the first transfer station 231 and the second transfer station 232, respectively. The details will be explained in the later section of the transfer system together with the operation.

In the embodiment shown in FIG. 1, the second transfer station 232 has a known belt transfer type transfer structure. On the other hand, in the embodiment shown in FIG. 2, the second transfer station 232 is only set as a corona transfer type, and all other parts are the same as those in the embodiment shown in FIG. 1, so a description thereof will be omitted.

This device has three types of modes: (A) latent image gapless development transfer system (B) 1 latent image (development) 2 transfer system (C) normal mode transfer. An overview will be explained.

Furthermore, before explaining each transfer system, the image forming system will be explained. (The image creation process is the same as the conventional known process.) (2) Image creation system (2-1) Optical system The optical system of this mechanism is configured to be detachable and uses a digital optical system and an analog optical system. It can also be used as an online printer (without a reading section).

(2-1-1) Digital optical system FIG. 3 shows the structure of the scanner section, and FIG. 4 shows the structure of the scanner drive section.

The light emitted from the fluorescent lamp 51 hits the original and
The light passes through the mirror 52 → second mirror 53 → third mirror 54 → lens 55 and reaches the CCD in the image reading plate 56. A first scanner 5 consisting of a fluorescent lamp 51 and a first mirror 52
7 is reading the original, and the scanner motor 58
Driven by. The image of the original read by the scanner is reduced by a lens 55 and formed on a CCD. CCD
Since the image signal read by the A/D is an analog value,
After being converted and image processed, it is converted into a digital signal. Image information after image processing is written on the photoreceptor in the form of a collection of light points by scanning with laser light in a writing section. Note that the second scanner 59 is composed of a second mirror 53 and a third mirror 54. Further, in FIG. 3, the reference numeral 60 is a filter, and the reference numeral 61 is a contact glass on which a document is placed.

FIGS. 5(a) and 5(b) show the structure of the writing section.

[0032] The writing section includes a laser diode unit (
(hereinafter referred to as LD unit) 62, polygon mirror 6
3. It basically consists of an fθ lens 64 and a mirror 66 that makes laser light incident on the photoreceptor 65. The laser beam emitted from the LD unit 62 passes through the cylinder lens 6.
7, the light is polarized by a polygon mirror 63 which is rotated at high speed by a polygon motor 68. The polarized laser beam passes through the fθ lens 64, enters the mirror 66, is reflected by the mirror 66, passes through the dustproof glass 69, and enters the surface of the photoreceptor 65. However, the laser beam at the start of main scanning enters the synchronous reflection plate 70, and the synchronous detection plate 71
A synchronization signal in the main scanning direction is generated by the detection signal from this detection plate.

(2-1-2) Analog optical system FIG. 6 shows the configuration of the analog optical system.

The structure of the optical system drive section is the same as the digital scanner drive section shown in FIG.

The light emitted from the exposure lamp 72 hits the original, passes through the first mirror 52 → second mirror 53 → third mirror 54 → lens 55 → fourth mirror 73 → dustproof glass 69, and reaches the photosensitive drum 65, forming a latent image. Formation of

(2-2) Photoreceptor part The photoreceptor 90 has a belt-like shape (Figs. 1 and 2), and when a digital optical system is used, the image part is exposed, and when an analog optical system is used, it is used for the background exposure process. Partial exposure process is typical. The photosensitive member 90 is uniformly charged by corona discharge from the charging charger 940, and the potential is lowered by applying light using an optical system.

The electrostatic latent image thus formed is exposed to the developing section 9.
10, toner is applied and visualized. The bias applied to the charging charger 910 and the developing sleeve in the developing section 910 in this apparatus is set to be changeable.

The toner image visualized on the photoreceptor 90 is 2
two transfer stations (first transfer station 231,
The second transfer station 232) transfers the image to the fixing unit 19.
After fixing at 0, post-processing is performed and the paper is ejected. Photoreceptor 90
After the remaining toner is cleaned in the cleaning section 920, the residual potential is removed in the static eliminating section 930, and the device is used repeatedly.

(3) Image forming process (3-1) Image forming Since the image forming process is determined by the exposure process,
Each image creation process will be described in detail below.

(3-1-1) As an example of the image forming process during exposure of the image area, the case where the photoreceptor surface potential and the toner are negatively charged will be described. This method is mainly used in digital copying machines.

FIG. 7 shows the image forming potential and timing in this method, and FIG. 8 shows the relationship between control items and charging potential in the image forming mode.

(3-1-1-1) The image forming pattern photoreceptor in the normal mode is -700V as shown by the solid line (7-1) in FIG.
The image area is exposed to light using a laser diode to form a latent image. The post-exposure potential at this time is -100V. After that, development is performed to adhere toner to the exposed areas. At this time, the difference between the exposed part potential -100V and the development bias -500V shown by the dashed line (7-2) is the development potential 4.
It becomes 00V. The toner is negatively charged, and development is performed by adhering it to the exposed area on the photoreceptor by applying a negative bias on the developing sleeve.

(3-1-1-2) Since it is necessary to increase the adhesion amount when developing the image formation pattern during 1 development and 2 transfer (transfer from one developing section to two transfer elements) ( Adhesion amount approx. 2
(times), it is necessary to increase the development potential. Therefore, the developing bias is changed from -500V to -800V as shown by the two-dot chain line (7-3). As a result, the development potential becomes 700V. However, in this case, the charging potential will be lower than the developing bias of -800V, so the charging potential will be -700V as shown by the chain line (7-4).
Change from V to -1000V. Furthermore, by changing the charging potential, if the output of the laser diode is the same, the potential after exposure becomes higher, so the output of the laser diode is increased to increase the amount of exposure, and the potential after exposure is kept constant.

(3-1-2) As an example of the image forming process for non-image area exposure, a case will be described in which the surface potential of the photoreceptor is a minor potential and the toner is positively charged. This method is mainly used in analog copying machines.

FIG. 9 shows the image forming potential and timing in this method, and FIG. 10 shows the relationship between control items and charging potential in the image forming mode.

(3-1-2-1) The image forming pattern photoreceptor in the normal mode is -8 as shown by the solid line (9-1) in FIG.
It is charged with 00V and exposed to halogen light in the non-image area to form a latent image. The lowest value of the potential after exposure at this time varies depending on the image, but is about -50V. Next, toner is applied to the non-exposed areas and development is performed. The difference between the charging potential of -800V at this time and the developing bias of -400V shown by a dashed line (9-2) becomes the development potential. Since the toner is positively charged, it is attracted by the potential difference between the charging potential and the developing bias.

(3-1-2-2) Image forming pattern during 1 development and 2 transfer (transfer from one developing section to two transfer elements) Adhesion amount as in the above-mentioned image forming process during image area exposure Since it is necessary to increase the voltage, the charging potential is set to -900V as shown by a chain line (9-3), and the developing bias is set to -200V as shown by a two-dot chain line (9-4). As a result, the development potential becomes 700V. Further, in order to increase the amount of adhesion, the linear velocity ratio of the developing sleeve of the photosensitive pair is increased. This linear velocity ratio is conventionally about 3.3, but in this case it is about 6.6, that is, about twice that of the conventional one.

(4) Transfer process When the first transfer station 231 uses corona discharge and the second transfer station 232 uses belt transfer (FIG. 1),
Transfer station 231, second transfer station 232
The transfer process will be explained by classifying it into two methods, both of which are corona discharge (FIG. 2).

(4-1) First transfer station 231,
When both the second transfer station 232 has a corona discharge configuration (4-1-1) Casing cleaning If the corona discharge becomes dirty with paper dust, toner, etc., the discharge state will be different, so the transfer of the first transfer station 231 and the second transfer station 232 Clean the charger casing. The cleaning timing is set to be performed when the power is turned on, after copying a predetermined number of sheets, and at the end of repeat.

(4-1-2) Measurement of distribution ratio: Initial setting of the transfer drum current of the first transfer station 231 By measuring the total current from the power pack of the corona discharge of the transfer charger and the casing current of the transfer charger. The distribution ratio and drum current of the first transfer station 231 are determined.

(4-1-3) Detection of paper condition environment As shown in the circuit diagram of FIG. The current value detected by the electrode is converted into a voltage value by a current detection circuit 303 to determine the state of the transfer paper. Based on the state of the transfer paper, the transfer drum current of the first transfer station 231 is determined from the graph of FIG. 12 showing the characteristics of the transfer paper drum current and transfer efficiency.

(4-2) When the first transfer station 231 has a corona discharge configuration and the second transfer station 232 has a belt transfer configuration (4-2-1) Casing cleaning If the corona discharge is dirty with paper powder, toner, etc., the discharge state Since the transfer charger of the first transfer station 231 is different, the casing of the transfer charger of the first transfer station 231 is cleaned. Second transfer station 232
The transfer charger is located below the transfer belt, so it is not cleaned. Note that the cleaning timing is set to be performed when the power is turned on and when a predetermined number of copies have been completed.

(4-2-2) Measurement of distribution ratio The total current from the corona discharge power pack of the transfer charger and the casing current of the transfer charger are measured at the first transfer station 231.
and second transfer station 232 to determine the distribution ratio.

(4-2-3) First transfer station 23
The initial setting of the transfer drum current of 1 using a reflective optical sensor, the first transfer station 231
The transfer drum current of the first transfer station 231 is determined by calculating the transfer efficiency of the belt transfer efficiency of the second transfer station 232. Note that FIG. 13 is a schematic explanatory diagram of the area around the transfer belt in FIG.
, 22, 23 are shown. In this case, the first P sensor 21 is at position A facing the conveying roller 307 portion on the upstream side in the rotational direction of the belt-shaped photoreceptor 90 of the first transfer station 231, and the second P sensor 22 is at the position A of the second transfer station 232. The third P sensor 23 is located at position B facing the conveyance roller 308 on the downstream side in the rotational direction of the belt-shaped photoreceptor 90, and the third P sensor 23 is located on the downstream side in the rotational direction of the second transfer station 232 of the transfer belt 233 at position C. is set up.

[0055] Here, differences in calculation of transfer efficiency corresponding to the positions of the P sensors 21, 22, and 23 will be explained.

(a) After the amount of toner developed on the belt-shaped photoreceptor 90 is detected by the first P sensor 21 when using the first and second P sensors installed at the A position and the B position , the toner is transferred to the transfer belt 233 at the second transfer station 232, and the remaining amount of toner is transferred to the second P.
Detected by the sensor 22 and transferred to the second transfer station 232
Calculate the transfer efficiency of

(b) When using the first and third P sensors installed at the A position and the C position, the amount of toner developed on the belt-shaped photoreceptor 90 and after being detected by the first P sensor 21 , the second transfer station 232 transfers the toner onto the transfer belt 233, and the amount of transferred toner is transferred to the third P.
It is detected by a sensor and the transfer efficiency of the second transfer station 232 is calculated.

(c) When using the second and third P sensors installed at the B position and the C position, the toner image developed on the belt-shaped photoreceptor 90 is transferred to the second transfer station 2.
After the image is transferred onto the transfer belt 233 in step 32, the second and third P sensors 22 and 23 detect the image and calculate the transfer efficiency.

[0059] In order to calculate the above transfer efficiency, the method shown in Fig. 14 is used.
This is done based on the graph showing the toner concentration and sensor potential level. In this figure, LA, LB, and LC are the first,
MA, MB, and MC indicate the levels of the second and third P sensors 21, 22, and 23, and the corresponding toner concentrations, respectively.

Toner density control is based on the transfer efficiency of the second transfer station 232 and the first transfer station 23.
The transfer drum current of the second transfer station 232 is adjusted so that the transfer efficiency of the second transfer station 232 is obtained when the efficiency of the first transfer station 231 is the target value (30 to 50%) based on the transfer efficiency relationship of 1. Find it by varying it.

Note that when the second and third P sensors 22 and 23 are arranged at the B and C positions in (c), the transfer efficiency of the second transfer station 232 is not calculated and both P sensors 22 and 23 are , 23 makes it possible to control the transfer efficiency of the second transfer station 232. For example, if you want to set it to 50%, both P sensors 22
, 23 are equal or not by comparing them. With this control, toner density M/A, P
It is possible to eliminate errors in calculating transfer efficiency due to sensor detection level VSP/VSG characteristics.

The toner concentration detection pattern of the first P sensor 21 at the A position in (a) and (b) is based on the toner concentration M/A.
, since the detection level of the P sensor is calculated in a sensitive range of the VSP/VSG characteristics, an intermediate concentration range is used.

In cases (a) and (b), the transfer efficiency of the second transfer station 232 can be controlled by comparing the detection levels of the P sensors without calculating the transfer efficiency of the second transfer station 232. . For example, if you want the transfer efficiency of the second transfer station 232 to be 50%, the difference in detection level between the P sensors 21 and 22 at the A position and the B position or between the P sensors 21 and 23 at the A position and the C position is set to a preset constant value. This can be determined by whether the value of

(5) Copying multiple sheets at the same time (1 development, 2 transfer)
Transfer current control in the mode (5-1) Transfer current control when the corona discharge method is performed in the first transfer station 231 and the second transfer station 232 FIG. 15 is a flowchart showing the control procedure in this method. In this control procedure, first, it is checked whether the power is turned on (step S15-1, hereinafter referred to as S15-
1), if it is immediately after being turned on, the copy number counter is cleared (S15-2) and the above-mentioned cleaning of the casing of the first transfer station 231 is executed (S15-2).
15-3). After executing the subroutine for cleaning the casing of the first transfer station 231, the cleaning end flag is checked to see if the cleaning is completed (S15-4). Then, when cleaning of the casing of the first transfer station 231 is completed, the casing of the second transfer station 232 is cleaned (S15-5). When cleaning is finished (S1
5-6) Turn on the transfer charger of the first transfer station 231 (S15-7) and at the same time turn on the drum drive motor to prevent drum fatigue.

After turning on the transfer charger of the first transfer station 231, the first transfer station 231 and the second transfer station
Calculate the aforementioned distribution ratio of the transfer station 232 (S1
5-8) The transfer drum current applied at the first transfer station 231 is calculated with reference to a table prepared separately (S15-9). This table shows the transfer drum current ID of the first transfer station 231 and the first transfer drum current ID shown in FIG.
It was created based on a graph showing the relationship between the transfer efficiency η of the transfer station 231.

After calculating in step S15-9, the total current in the first transfer station 231 is further calculated based on the distribution ratio (S15-10), and the actual measured value of the total transfer current in the first transfer station 231 is the calculated value. Check whether they are equal (S15-11). If they are not equal, the first
Change the total transfer current of the transfer station 231 (S15
-12), increment the loop counter (S1
5-13). Next, as shown in the flowchart of FIG. 17, it is checked whether the value of the loop counter is less than 10 (S15-14), and if it is 10 or more, the first transfer station 231 is equal to or higher, and the first transfer station abnormality flag is set (S15-14). S15-15), turn off the first transfer station transfer charger and return.

Further, if the actual measured value of the total transfer current of the first transfer station 231 is not equal to the calculated value in step S15-11, the transfer charger of the first transfer station 231 is turned off (S15-17), and the loop counter is turned on. Clear (S15-18) As shown in the flowchart of FIG.
Calculate the transfer drum current corresponding to 00% (S15-
19). Then, from the distribution ratio, the second transfer station 23
2 is calculated (S15-20), and it is checked whether the actual measured value and the calculated value of the total transfer current are equal (S15-20).
15-21). If they are equal, clear the loop counter (S15-22) and return; if not, change the total transfer current of the second transfer station 232 (S15-22).
15-23). Thereafter, the loop counter is incremented (S15-24) and it is checked whether the loop counter is less than 10 (S15-25). This step S1
If the result of 5-25 is less than 10, step S15-2 is performed again.
Execute the processing after 0, and if it is 10 or more, the output of the second transfer station 232 is abnormal, so set the second transfer station output abnormality flag (S15-26) and turn off the transfer charger of the second transfer station 232. (S15-27).

On the other hand, in step S15-1, the power is turned on.
If it is determined that it is not immediately after, it is checked whether copying is in progress (S15-28), and if copying is not in progress, it is checked whether the copy number counter is greater than 500 (S15-29). If it is greater than 500, the process from step S15-2 onward is executed, and if it is less than 500, the process returns.

When it is determined in step S15-28 that copying is in progress, it is checked whether the registration sensor 9 is ON as shown in the flowchart of FIG. 19 (S15-30). If it is not ON, return; if it is ON, execute the subroutine for checking the transfer current control data acquisition timing according to the paper type described above (S15-31), and then execute the subroutine for acquiring transfer current control data according to the paper type. Execute (S15-32). Then, a subroutine for calculating the transfer drum current in the first transfer station 231 for transfer current control based on the paper type is executed (S15-33), and the total current of the first transfer station 231 is calculated based on the distribution ratio (S15-34).
). After calculating in this step, check whether the actual measured value of the total transfer current of the first transfer station 231 and the calculated value are equal (S15-35), and if they are equal, clear the loop counter (S15-36) and return. If they are not equal, the total transfer current value of the first transfer station 231 is changed (S15-37). Thereafter, the loop counter is incremented (S15-38), and it is further checked whether the loop counter is less than 10 (S15-39). If it is determined in step S15-39 that the number is less than 10, the process returns to step S15-34 and the subsequent processes are executed, and if it is determined that the number is 10 or more, the first
Since the output of the transfer station 231 is abnormal, a first transfer station abnormality flag is set (S15-40). In other words, if the measured value and the calculated value of the total transfer current are checked 10 times and they do not match, the first transfer station 23
An output abnormality flag for the first or second transfer station 232 is set. Then, step S15-40
When the processing is completed, the transfer charger of the first transfer station 231 is turned off (S15-41) and the process returns.

(5-2) Transfer current control when the first transfer station 231 uses corona discharge and the second transfer station 232 uses the belt transfer method FIG. 20 is a flowchart showing the control procedure in this method. In this control procedure, first, it is checked whether the power has been turned on (S20-1), and if the power has just been turned on, the copy number counter is cleared (S20-2) and the above-mentioned first
The casing of the transfer station 231 is cleaned (S20-3). After executing the subroutine for cleaning the casing of the first transfer station 231, the cleaning completion flag is checked to see if the cleaning has been completed (S20-4). Then, when cleaning of the casing of the first transfer station 231 is completed, the transfer charger of the first transfer station 231 is turned on (S20-5) and at the same time, the drum drive motor is turned on to prevent drum fatigue. Further, the developing bias is turned on to prevent toner from adhering to the drum.

After turning on the transfer charger of the first transfer station 231, the first transfer station 231 and the second transfer station
Calculate the aforementioned distribution ratio of the transfer station 232 (S2
0-6), the transfer shutter turned on in step S20-5 is turned off (S20-7). After that, in the case of a digital copying machine, it is determined whether the polygon motor is at the specified speed (S20-8), and if it is not at the specified speed, the process returns; if it is, the laser diode output is as specified. (S20-9)
). If the output of the laser diode does not rise to the specified level, it will not be possible to write, so return.
If it is up, turn on the drum motor (S20-1
0).

Next, as shown in the flowchart of FIG. 21, the static elimination lamp, cleaning bias and PCC are successively turned on (S20-11, 12, 13). Furthermore, turn on the charger, developing motor, laser diode for writing, and developing bias in this order (S
20-14, 15, 16, 17). This step S20
- The steps from 14 to 17 are processes for creating a P sensor pattern, and create a halftone pattern.In the case of a digital copier, the writing laser diode creates a solid black pattern and develops it. Make a halftone by adjusting the bias. In the case of an analog copying machine, there is no need to turn on the writing laser diode (S20-16).
A pattern is created by turning the charger ON/OFF, and a halftone is created by adjusting the potential. When the process in step S20-17 is completed, the transfer charger of the second transfer station 232 is turned on (S20-18), the initial transfer current control subroutine is executed (S20-19), and the load is turned off.
Set it to FF (S20-20) and return.

On the other hand, in step S20-1, the power is turned on.
If it is determined that it is not immediately after, it is checked whether copying is in progress (S20-21), and if copying is not in progress, it is checked whether the copy number counter is greater than 500 (S15-22). If it is greater than 500, the process from step S20-2 onwards is executed, and if it is less than 500, the process returns.

Further, when it is determined in step S20-22 that copying is in progress, it is checked whether the registration sensor 9 is ON as shown in the flowchart of FIG. 22 (S20-23). If it is not ON, return; if it is ON, execute the subroutine for checking the transfer current control data acquisition timing according to the paper type (S20-24), and then execute the subroutine for acquiring transfer current control data according to the paper type. Execute (S20-25). Then, a subroutine for calculating the transfer drum current at the first transfer station 231 for transfer current control based on the paper type is executed (S20-26), and as shown in the flowchart of FIG.
1 is calculated (S20-27). After calculating in this step, it is checked whether the actual measured value of the total transfer current of the first transfer station 231 and the calculated value are equal (S2
0-28), if they are equal, clear the loop counter (
S20-29) Return, and if not equal, change the total transfer current value of the first transfer station 231 (S20-29).
30). Then increment the loop counter (
S20-31), and further checks whether the loop counter is less than 10 (S20-32). If step S
If it is determined in step S15-39 that the value is less than 10, the process returns to step S20-27 and the subsequent processing is executed. If it is determined that the value is 10 or more, the output of the first transfer station 231 is abnormal, so the first A transfer station abnormality flag is set (S20-33). In other words, if the measured value and the calculated value of the total transfer current are checked ten times and they do not match, the output abnormality flag of the first transfer station 231 is set. Then, step S20-34
When the processing is completed, the transfer charger of the first transfer station 231 is turned off (S20-35) and the process returns.

(5-3) Cleaning operation of transfer charger, wire, and casing The cleaning operation of the transfer charger, wire, and casing performed in the above step will be described below.

The processing procedure for this operation is shown in the flowchart of FIG. In this process, first, it is checked whether cleaning has been completed (S24-1). If cleaning has been completed, the process returns; if not, it is checked whether the motor is rotating in reverse (S24-2). If the motor is not rotating in reverse, check if the motor is rotating in the forward direction (
S24-3). If the motor is not rotating in the normal direction, the motor is started in the normal direction (S24-4), and at the same time a timer is started (S24-5). It goes without saying that in step S24-4, the motor is rotated in the normal direction even when the motor is stopped.

After starting the timer in step S24-5, it is checked whether the time set in the return position (RP) has elapsed (S24-6).
. The return position refers to the time it takes for the motor to shift from normal rotation to reverse rotation, as shown in FIG. Note that in the figure, HP indicates the home position.

When the return position set time has passed, the forward rotation of the motor is stopped (S24-7).
), the motor is now reversed (S24-8). That is, when the cleaner reaches the return position, the motor is reversed to return the cleaner, and the timer is cleared and started (S24-9). Next, it is confirmed whether the motor has returned to the home position (S24-10), and when the motor returns to the home position, the reverse rotation of the motor is stopped (S24-11). As a result, the timer is cleared (S24-12), the cleaning is completed, and a cleaning completion flag is set (S24-13).

On the other hand, if it is determined in step S24-10 that the home position has not been reached, it is checked whether the error set time has passed (S24-14);
If the time has not passed, the cleaner returns, and if it has passed, it means that the cleaner has not come to the return position or home position for a certain period of time, which indicates that some kind of abnormality has occurred in the cleaner, so set the cleaner abnormality flag. (S24-15) Return.

Further, when it is confirmed in step S24-2 that the motor is reversely rotated, step S24-2 is confirmed.
The process skips to step S24-10 and the subsequent processes are executed, and when it is determined in step S24-3 that the motor is rotating normally, the process skips to step S24-6 and the subsequent processes are executed. Further, if it is determined in step S24-6 that the return position set time has not yet elapsed, the process moves to step S24-14 and the subsequent processes are executed.

(5-4) Calculation of Transfer Current Distribution Ratio The transfer current distribution ratio described above is processed according to the flowchart shown in FIG. That is, in this process, first, the total transfer current is read (S26-1), and the transfer casing current is read (S26-2). Next, the distribution ratio is calculated from the formula: distribution ratio=(total transfer current−transfer casing current)/total transfer current (S26-3).

Once the distribution ratio is calculated, the transfer drum current is calculated from the formula: transfer drum current=transfer total current×distribution ratio (S26-4).

(5-5) Initial transfer current control when the first transfer station uses corona discharge and the second transfer station uses belt transfer FIG. 27 is a flowchart showing the processing procedure for initial transfer current control in this case. In this process, it is first checked whether initial transfer current control has been completed (S27-1),
If it has been completed, the process returns; if it has not been completed, the transfer efficiency of the second transfer station 232 is calculated based on the P sensor output (S27-2). Note that this calculation uses two P sensors to calculate the transfer efficiency of the second transfer station 232, and there are three methods depending on the position of the P sensors. Details will be explained with reference to a flowchart described later.

After calculating the transfer efficiency of the second transfer station 232 by executing the subroutine of step S27-2, the transfer efficiency of the first transfer station 231 is calculated from the transfer efficiency of the second transfer station 232 and the table (S27 -3). Note that the table is set such that the transfer efficiency η1 of the first transfer station 231 can be determined from the transfer efficiency η2ST of the second transfer station 232 in the characteristic diagram of FIG.

After executing the subroutine of step S27-3 and calculating the transfer efficiency of the first transfer station 231, the transfer efficiency of the first transfer station 231 is 50%.
It is checked whether or not (S27-4). If it is 50%, set the control end flag (S
27-5) Return, and if not, change η to Δη2
The absolute value of the difference between 2A and η2ST (|Δη2A−η2S
T
-7). Note that in steps S27-4 and S27-5, the control end flag is set when the transfer efficiency of the first transfer station 231 is 50%, but when the transfer efficiency is 40%, the control end flag is set.
If the control is terminated in the range of 5 to 50%, the control time can be shortened. Further, the calculation of the difference ΔI2 in transfer drum current is performed in accordance with the characteristic diagram shown in FIG. 29 showing the relationship between the transfer drum current and the transfer efficiency η1, η2. In this figure, the solid line is data in the standard environment, and the broken line is actual data. In this figure, if the IS transfer drum current is currently flowing to the second transfer station 232, the second transfer station 232
The transfer efficiency of 32 is η2A. Also, η2ST is η
1 shows the transfer efficiency of the second transfer station 232 when 50%.

[0086] Upon completion of the process of step S27-7,
The magnitudes of η2A and η2ST are compared (S27-8). Then, if η2ST is greater than or equal to η2A, (IST+ΔI2) is substituted for the transfer drum current IA (S27-
9) After calculating the total transfer current based on the distribution ratio (S27
-10), if η2A is smaller than η2ST, (IST-ΔI2) is substituted for the transfer drum current IA (S27-
11) Apply feedback and execute the processing from step S27-2 onwards. Note that if the number of times of feedback is so large that the transfer efficiency of the first transfer station 231 does not reach 50%, or does not fall within the range of 45 to 50%, the second transfer station output or higher flag is set. Further, the control end flag may be set after the process in step S27-10. That is, when performing feedback, settings are made such that steps S27-2, 3, and 4 are omitted and the process proceeds to step S27-5. As a result, only one P sensor pattern is required.

(5-6) Second transfer station transfer efficiency calculation using P sensor output (5-6-1) When using P sensors at positions A and B, use reflective sensors at positions A and B in Figure 13 In other words, the procedure for calculating the transfer efficiency of the second transfer station 232 using the first and second P sensors 21 and 22 will be described with reference to the flowcharts in FIGS. 30 and 31. .

First, a latent image of a P sensor pattern (20 mm x 20 mm) of a halftone solid image is created (S
30-1), the pattern is developed (S30-2). Next, a subroutine for measuring the potential VSG of the background area is executed in which the first P sensor 21 measures the potential of the background area outside the P sensor pattern formation area five times and calculates the average value (S30-3). , it is confirmed whether the potential VSG of the background portion shows an abnormal value (S30-4).

If it is determined that an abnormal value is indicated, a sensor abnormality flag is set (S30-5).
If it returns and does not show an abnormal value, as shown in the flowchart of FIG. 31, measure the potential of the P sensor pattern section at position A five times with the first P sensor 21, and calculate the average value of the P sensor pattern potential. The VSP measurement subroutine is executed (S30-6), and the potential VS of the P sensor pattern section is
Check whether P shows an abnormal value (S30
-7). If it is determined that the check indicates an abnormal value, the sensor abnormality flag is set in step S30-5 and the process returns. If it is a normal value, calculate the pattern potential level VSP/VSG at position A (S30-8).
, the toner density M/A is calculated from the pattern potential level VSP/VSG at position A with reference to a table of M/A-(VSP/VSG) characteristics (S30-9).

Next, the P sensor 22 at position B measures the skin potential VSG on which no P sensor pattern is formed five times and takes the average (S30-10), and this time it is determined that the P sensor 22 at position B is abnormal. It is confirmed whether or not a value is indicated (S30-11). If an abnormal value is shown, a sensor abnormality flag is set (S30-12), and if an abnormal value is not shown, the potential of the P sensor pattern section at position B is measured five times with the second P sensor 22, and the potential of the P sensor pattern section at position B is measured five times. Calculate the average value (S30
-13), it is checked whether the potential VSP of the P sensor pattern section shows an abnormal value (S30-14). If it is determined that the check indicates an abnormal value, the sensor abnormality flag is set in step S30-12 and the process returns. If it is a normal value, calculate the pattern potential level VSP/VSG at the B position (S30-15), and calculate the toner concentration M/A from the pattern potential level VSP/VSG at the B position as M/A-(VSP/VSG). Calculation is performed with reference to the characteristic table (S30-16). Then, the transfer efficiency of the second transfer station 232 is calculated from the M/A of the A position and the B position (S30-17).

(5-6-2) When using P sensors at positions A and C In this process, instead of position B in 4-6-1,
Calculate toner density at position C. Therefore, FIG.
If the process for the B position in Steps S30-10 to S17 of 1 is replaced with the process for the C position, the process can be performed in the same procedure. Note that when the background potential VSG or the P pattern potential VSP at the C position shows an abnormal value, a sensor abnormality flag is similarly set.

(5-6-3) When using P sensors at B and C positions In this process, instead of A position in 4-6-1,
Calculate toner density at position C. Therefore, FIG.
If the process for the A position in Steps S30-3 to S30-9 of 1 is replaced with the process for the C position, the process can be performed in the same procedure. Note that when the background potential VSG or the P pattern potential VSP at the C position shows an abnormal value, a sensor abnormality flag is similarly set. In this case, without calculating the transfer efficiency of the second transfer station 232, the output values of the two sensors at positions B and C are compared, and if they are equal, the transfer efficiency is increased.
It can also be determined as 0%.

(5-7) Transfer current control by paper type detection (
5-7-1) Data fetching timing check The processing procedure for checking the data fetching timing in paper type detection is shown in FIG. In this process, first, the magnitude of the registration timer and set time is checked (S32-1). In this check, if the value of the registration timer is greater than the set time, that is, after the preset time has elapsed after the paper passes the registration sensor, the counter electrode
02, the paper type check flag is set (S32-2). Next, it is checked whether the check completion flag has been set (S32-3), and if it has not been set yet, that is, if the paper type check has not been completed, an interruption for paper type check is permitted (S32-3).
32-4) Return. On the other hand, if the check completion flag is set and the check has been completed, interruption of paper type check is prohibited (S32-5), the pointer is cleared (S32-6), and the process returns. Further, when the registration timer has not advanced to the set time in step S32-1, the paper has not come under the counter electrode.
Interruptions for checking the paper type are prohibited (S32-5), the pointer is cleared (S32-6), and the process returns.

(5-7-2) Data fetching Data fetching is processed according to the procedure shown in FIG. This process is an interrupt routine that occurs every 2 msec. In this routine, it is checked whether the paper type check flag is set (S33-1), and when it is determined that the paper type check flag is not set, , the pointer is cleared (S33-2), and when it is determined that it is set, it is further determined whether the pointer is less than 10 (S33-3). If it is less than 10 in this judgment, the paper type data is read (S33-4) and the paper type data is entered in the paper type flag (S33-5). This step S33-5
The processing is based on the paper type flag.

[0] ~

The paper type data is sequentially entered into the array [9]. Step S33-5
After completing the process, increment the pointer and return.

On the other hand, in step S33-3, the pointer becomes 1.
If it is determined that the value is 0 or more, the average paper type data is calculated by taking the average of the 10 paper type data (S33-7).
, it is checked whether the calculated average paper type data is between the preset upper limit and lower limit (S33
-8). If it is present, a check completion flag is set (S33-9), and if it is not, a counter electrode abnormality flag is set (S33-10) and the process returns. Note that if the counter electrode abnormality flag is set in step S33-10, transfer current control based on paper type detection is not performed. At the same time, an LED display is set to inform the operator that transfer current control based on paper type detection is not being performed.

(5-7-3) Transfer current determination The transfer current is determined in accordance with the processing procedure shown in the flowchart of FIG. In this process, it is first determined whether the adjustment end flag is set (S34-1). If the adjustment completion flag is set in this judgment, the process returns; if it is not set, the first transfer station 231
Change the table based on the transfer current standard value IS (S3
4-2). This table is the first transfer station 231
When both the transfer station 232 and the second transfer station 232 are in the corona discharge state, the transfer current standard value IS is calculated from the solid line in FIG. 35 as a table. Furthermore, when the first transfer station 231 uses corona discharge and the second transfer station 232 uses belt transfer, the transfer current standard value IS moves to the IS1 or IS2 position as shown by the broken line in FIG. 35 by setting the transfer efficiency using the P sensor pattern. . Depending on this amount of movement,
Shift the table to use in subsequent processing.

After executing the subroutine of step S34-2, the average paper type data VA becomes the standard paper type data VST.
It is checked whether they are equal to each other (S34-3). This check is performed by calculating the potential difference between the opposing electrodes of the standard paper and the transfer paper, as shown in FIG. and,
VST to the potential difference ΔVA between paper type data of standard paper and transfer paper
The difference between and VA is substituted (S34-4). after that,
The potential difference ΔVA of paper type data is converted to the transfer drum current difference ΔIA
is converted using a table (a table of FIG. 37) to obtain the transfer drum current difference ΔIA (S34-5
). Next, average paper type data VA and standard paper type data V
ST (S34-6), average paper type data VA
If is larger than the standard paper type data VST, the transfer drum current difference ΔIA depending on the paper type is subtracted from the currently output transfer drum current IS, and the result is substituted for the transfer drum current IA (S34-7), and then the adjustment is completed. Set the flag (
S34-8) Return. If step S34-6
If the average paper type data VA is less than or equal to the standard paper type data VST, the transfer drum current difference ΔIA depending on the paper type is added to the currently output transfer drum current IS, and the result is substituted for the transfer drum current IA. After doing so (S34-9), the adjustment end flag is set (S34-8) and the process returns. The relationship among the transfer drum current difference ΔIA, the transfer drum current IA, and the currently output transfer drum current IS in steps S34-7 and S34-9 is as shown in FIG.

(6) Copy Mode Selection The copy mode, ie, the method for selecting the copy mode, will be explained below.

Copy mode depends on each option, second transfer station unit, page memory printer mode, etc. - 1:1 mode - simultaneous multiple copy mode (number of copies is 2 or more) - 1st transfer station only mode (usually 4 modes can be selected: (copy operation) - 2nd transfer station only mode (normal copy operation).

[0100] Then, there is a method of automatically selecting a mode from among these four modes and executing copying based on the state of the copying machine including options, a so-called automatic selection method, and a method of automatically selecting a mode from among these four modes and executing copying based on the state of the copying machine including options. There are two methods: a so-called manual selection method, in which the operator manually selects the mode by operating the "mode selection key". In automatic selection, the selection is made according to the procedure shown in the flowcharts of FIGS. 40 and 41, which will be described later. In the case of manual selection, the selection is made according to the state of the copying machine and the key input state as shown in the flowchart of FIG. 43. . In the case of this manual selection, it is set to warn of inappropriate operation by a warning display means for inappropriate modes such as "number confirmation" and "paper confirmation".

A general control flow for this copy mode selection is shown in FIG. This process starts when a program start command is sent from the system control. First, when this program start command is received (S39-1), the input and output status of the port and the RAM are initialized. (S39-2), and further performs initial processing of each control unit, for example, write and drive control units, and checks the connection status of peripheral devices (S39-3).
). Next, standby processing, such as fixing heater control, door opening, initial jam check, and other process controls of the first transfer station and the second transfer station,
Laser diode output control (APC), polygon motor drive, transfer paper size, and other checks are performed, and data on each state is sent to system control (S39-4).

[0102] After sending, it enters the reload state (S39-
5) When copying is started (S39-6), a copy mode is selected (S39-7), and copying is executed (S39-6).
-8). Then, step S39 is continued until the copying is completed.
-7, and when the copying is completed, step S39-
The process returns to step 4 and executes subsequent processing (S39-9).

(6-1) Copy mode selection process (6-1
-1) Auto selection FIGS. 40 and 41 are flowcharts of the auto selection copy mode selection process.

In this process, as shown in FIG. 40, first, if the auto selection switch is set (S40-
1) Check that the length of the transfer paper is 216 mm or less (
S40-2). If it is below 216 mm, check whether the output of the first transfer station and the cleaner abnormality flag are set (S40
-3). With this check, the first transfer station 23
When it is determined that the output of No. 1 and the cleaner are normal, it is checked whether the second transfer station unit is connected (S40-4), and further it is confirmed whether the output from the second transfer station unit is normal. (S40-5). If it is confirmed that the copy is normal, normal copying is performed using only the second transfer station unit (S40-6) and the process returns. In this case, the mode selection key 309 is pressed so that the fine mode LED (FLED) 304 in the explanatory diagram of the operation panel in FIG. 42 lights up.

[0105] Furthermore, if it is determined in step S40-4 that the second transfer station unit is not connected, the copying operation is prohibited (S40-7).
Return. Further, if the output from the second transfer station unit is determined to be abnormal in the check in step S40-5, copying cannot be performed normally, so the copying operation is also prohibited (S40-7).
). Further, if it is determined in the check in step S40-3 that the output from the first transfer station unit and the cleaner are normal, normal copying using only the first transfer station unit is performed (S40-8
) Return. In this case, mode selection key 3 in FIG.
09, the fine mode LED (FLED) 304 is pressed so that it lights up.

On the other hand, in step S40-2, the transfer paper length is 2.
If it is determined that it is larger than 16 mm, the cleaner abnormality flag and the first
The output abnormality flags of the transfer station and the second transfer station unit are checked (S40-9), and if the abnormality flag is set, that is, it is abnormal, the process from step S40-3 onward is executed, and if normal, the output 2. Check whether the transfer station unit is connected (S40-10). If it is not connected,
The processes after step S40-3 are executed, and a copy operation is performed using only the first transfer station unit. If it is connected, it is checked whether the optional page memory is connected (S40-11). When this page memory is connected, when scanning a document with a scanner, the space between documents (each page) during exposure (when forming a latent image) will be (latent image interval) disappears. This is because document scanning time+scanner return time<exposure time (latent image formation time).

[0107] When it is determined in step S40-11 that the scanner is not connected, it is further checked whether the printer mode is set (S40-12);
If the printer mode is not set, the number of copies is confirmed (S40-13). If the number of copies is 1, the process from step S40-3 onward is executed to copy only 1 copy, and if the number is 2 or more, the first transfer station unit and the second transfer station unit are used. Copy multiple sheets at the same time (S40-14), set process conditions and timing conditions for the multiple simultaneous mode (S40-14)
S40-15) Return. In this case, the mode selection key 309 is pressed so that the speed mode LED (SLED) 305 lights up. Also, step S40-
If it is determined in step S40-11 that the page memory is not connected, or if it is determined in step S40-12 that the printer mode is not set, the first transfer station unit using the first transfer station unit and the second transfer station unit A one-to-one copy is executed (S40-16), process conditions and timing conditions for the one-to-one mode are set (S40-17), and the process returns. In this case, the mode selection key 309 is pressed so that the fine/speed mode LED (FSLED) 306 lights up.

[0108] In this embodiment, in both the one-to-one mode and the simultaneous multiple mode, the LT horizontal (8.5 inches: 216 mm
)Only the following transfer paper can be used due to the layout. Therefore, when LT horizontal>transfer paper longitudinal length, two types of copying are selected: normal copying that uses only the first transfer station unit, and normal copy that uses only second transfer station unit. In addition, when LT width ≦ longitudinal length of transfer paper, ・1-to-1 mode (no gap between latent images) ・Simultaneous multiple mode (copying 2 sheets from 1 latent image) ・1st
Four types of copying can be selected: normal copying using only the transfer station and normal copying using only the second transfer station.

(6-1-2) Manual Selection FIG. 43 is a flowchart showing the processing procedure of the manual selection mode. This process starts when the manual selection switch is turned on (S43-1). Then, if the second transfer station unit is connected (S43-
2) Check whether the mode selection key 309 is turned on (S43-3). Mode selection key 309
If it is not ON, return; if it is, the FLED is 1, that is, fine mode LE.
Check whether D is ON (S43-4), and
If it is N, check whether the first transfer station output abnormality flag and the second transfer station output abnormality flag are each set (S43-5).
. If it is determined in this step S43-5 that there is no abnormality, it is checked whether the cleaner abnormality flag is set (S43-6), and if it is not abnormal, the sensor abnormality flags 2 and 3, in other words, the second P sensor 22 And it is checked whether a flag indicating an abnormality of the third P sensor 23 is set (S43-7). If each is normal, check whether the copy number is 2 or more (S43-8), and if it is not 2 or more, "Check the number of copies"
Turn on the display (S43-9) and the transfer paper length is 216 m.
Check whether it is less than or equal to m (S43-10). If it is determined in step S43-8 that the number of copies is 2 or more, step S43-9 is skipped and step S43-10 is directly performed. If step S4
If it is determined in step 3-10 that the transfer paper length is greater than 216 mm, turn on the "Paper confirmation" display (S4
3-11) Set FLED to 0, SLED to 1, and FSLED to 0 (S43-12). Also, step S4
If it is determined in 3-10 that the transfer paper length is 216 mm or less, the process directly advances to step S43-12. After executing the process in step S43-12, simultaneous multiple copies using the first transfer station unit and the second transfer station unit were executed (S43-13), and process conditions and timing conditions for the simultaneous multiple mode were set ( After S43-14), the buzzer sounds once to notify completion of the setting (S43-15) and returns.

On the other hand, if it is determined in step S43-2 that the second transfer station unit is not connected, it is checked whether the cleaner abnormality flag is set (S43-16). This step S43
-16 When it is determined that the cleaner is not abnormal,
It is checked whether the first transfer station output abnormality flag is set (S43-17). If there is no abnormality, set FLED to 1, SLED to 0, FSLED
After setting 0 to 0 (S43-18), execute normal copy using only the first transfer station unit (
S43-19) Return.

[0111] Also, steps S43-16 and S43
-17, when it is determined that each is abnormal, the FLED
set to 1, SLED to 0, and FSLED to 0 (S4
3-20), prohibits the copy operation (S43-21), and returns.

[0112] In the above step S43-4, FLED is set to 1.
When it is determined that the SLED is set to 1, as shown in the flowchart of FIG. 44, it is checked whether the SLED is set to 1 (S43-22). It is confirmed whether or not this has been carried out (S43-23). If the "Confirm number of settings" display is displayed, the display is erased (S43-24) and a check is made to see if the page memory is connected (S43-24).
25). Note that if it is determined in step S43-23 that the "Confirm number setting" display is not being performed, there is no need to erase the display of "Confirm number setting", so the process directly returns to Step S43.
Skip to -25. Furthermore, step S43-25
If it is determined that page memory is not connected, check whether it is in printer mode (
S43-26), if it is not in printer mode, “
Check whether "Paper Check" is displayed (S43-
27). If the "Paper Confirmation" display is displayed in step S43-27, erase the display (S43-28) and press FLE.
Set D to 1, SLED to 0, and FSLED to 0 (S
43-29), executes the counter check subroutine described below using only either the first transfer station unit or the second transfer station unit (S
43-30), the buzzer to indicate the end of execution sounds once (S43
-31). In addition, in step S43-27, "Paper confirmation"
is not displayed, directly proceed to step S43-
29 is executed.

[0113] Furthermore, if it is determined in step S43-22 that the SLED is not set to 1, the display of "Confirm Number of Placements" and the display of "Confirm Paper" are erased (S43-22).
-32, 33), and processes from step S43-29 onwards.

Furthermore, when it is determined in step S43-25 that the page memory is connected, or when it is determined that the printer mode is in step S43-26, it is determined whether the transfer paper length is 216 mm or less. Check (S43-34). Transfer paper length is 216m
m or less, erase the “Paper confirmation” display (S43-
35) If the transfer paper length is greater than 216 mm, the "Paper Check" display is lit (S43-36) and the FLED is set to 0.
, set SLED to 0 and FSLED to 1 (S43
-37) Execute one-to-one copy mode using the first transfer station unit and the second transfer station unit (S43-38). Then, process conditions and timing conditions for the one-to-one copy mode are set (S4
3-39), sound the buzzer once to complete the setting (S43)
-40) Return.

[0115] When it is determined in step S43-5 that the output abnormality flag of either the first transfer station or the second transfer station is set,
As shown in the flowchart in Figure 45, check which station's output abnormality flag is set (S
43-41, 42), and when it is determined that both outputs are abnormal, the copy operation is prohibited (S43-43);
When the first transfer station is normal, copying using only the first transfer station unit is executed (S4
3-44), when the second transfer station is normal,
Copying using only the second transfer station unit is executed (S43-45) and the process returns.

If it is determined in step S43-6 that the cleaner is abnormal, execute the process in step S43-45 of the flowchart of FIG. 45, that is, normal copying using only the second transfer station unit, and return. do.

[0117] Sensor abnormality flags 2 and 3 are set in step S43-7, that is, sensors 2 and 3 are set.
3 is determined to be abnormal, it is checked whether the page memory is connected (S43-46) as shown in the flowchart of FIG. 46, and if it is not connected, it is further checked whether the printer mode is set. (S43-47). If the page memory is not connected, or if the page memory is connected but not in printer mode, execute the process from step S43-34 in the flowchart of FIG. 44 to connect the page memory. If not, and the printer mode is not set, the process from step S43-29 onwards is executed.

[0118] Furthermore, the FLED and SLED on the operation panel
, FSLED LED light emission rotation is as shown in FIG. Note that this rotation includes key rotation when some abnormality occurs, and the ○ mark in the figure indicates the lighting state of the LED.

(6-1-3) Counter Check Process The contents of the counter check subroutine in step S43-30 described above are as shown in the flowchart of FIG. This subroutine can be used for both the first transfer station and the second transfer station, and if only one unit is used, the subroutine selects the unit with the larger number of sheets/jams at the first transfer station or the second transfer station, i.e. This is a process of selecting the one with the lower jam rate.

In this process, the counter of the first transfer station is set to (number of copies at the first transfer station/first transfer station).
Enter the number of jams at the transfer station (S48-1
), enter (number of copies at the second transfer station/number of jams at the second transfer station) in the counter of the second transfer station (S48-2), and compare which counter has a larger value (S48-3). ). As a result, the first
If the counter value of the transfer station is greater than or equal to the counter value of the second transfer station, normal copying using only the first transfer station unit is performed (S48-4).
Returns and the counter value of the first transfer station becomes the second transfer station.
If it is smaller than the counter value of the transfer station, normal copying using only the second transfer station unit is performed (S48-5) and the process returns.

[0121] During the copying operation, the following counter is counted up each time the transfer paper is ejected. These counters include a copy number counter at the first transfer station, a copy number counter at the second transfer station, a total copy number counter at both the first transfer station and the second transfer station, and a main switch O.
This is a counter for the number of copies made after turning on the main switch.
is backed up by .

[0122] Further, as counters at the time of a jam, a total jam counter, a first transfer station jam counter, a second transfer station jam counter, a paper feed jam counter, a fixing jam counter, a paper discharge jam counter,
A double-sided jam counter, a reversal jam counter, a conveyance jam counter, and a sorter/stapler jam counter are provided, all of which are backed up by non-volatile RAM. (7) Functional Diagram of Reading Control Circuit and Reading Drive Device FIG. 49 shows a control block diagram of the entire copying machine according to the embodiment. The system of this copying machine includes a reading device (scanner) 400, a copying device 500, an automatic document feeder (ADF) 600, a floppy disk drive (FD) 700, an optical disk drive (OD) 800, and a sorter/stapler device 90.
It is basically constructed from 0. The reading device includes an image reading circuit (VPU) 401 and an image processing circuit (IPU) 402.
, a reading drive device 403, and a reading control circuit 404, and the copying apparatus 500 includes an image information storage device 501,
It is composed of a copying circuit 502 and an operating device 503. Below, the main devices will be explained one by one. In addition,
FIG. 49 schematically shows the overall configuration, and the configurations of each main part are shown as block diagrams in FIGS. 50 to 55, respectively. Also, although the connection state of each part can be seen from Fig. 49, the lines A to H and L1, L in Figs. 50 to 55 are
2 is attached to clarify the connection state.

(7-1) Read control circuit The read control circuit 404 shown enlarged in the diagram 50 receives a signal from the main system control circuit 504 at L1, and controls each part of the read drive device 403 and the ADF device 600. . The various parts are as follows.

- Rotational speed control of scanner motor 410 - Control of fluorescent lamp heater 411 - Lighting instruction for fluorescent lamp 412 - Control of ADF stop claw solenoid 413 -
Control of the filter solenoid 414 for detecting the document size and control of the scanner power supply cooling fan 415.
The control of the DF device 600 and the control of the ADF stop pawl solenoid 413 are performed when the ADF is installed as an option. The reading control circuit 404 also includes an encoder 443 that detects the rotational state of the scanner motor 410.
A frequency dividing circuit rotation direction detection circuit 427 is provided which sends a rotation direction signal of the scanner motor 410 to a first gate array 420 of the image processing circuit 402, which will be described later, in accordance with the output of the image processing circuit 402.

[0125] Furthermore, when the ADF device 600 is optionally attached, the reading control circuit 404 inputs and outputs control signals between the ADF device 600 and the ADF device 600. ADF device 600
includes an ADF control circuit 601 and an ADF control device 60.
2 are provided.

(7-2) Image reading circuit The image reading circuit (VPU) 401 is as shown in FIG.
A CCD 415 for photoelectric conversion, amplifiers 416a and 416b for amplifying the signal converted by the CCD 415, a switching element 417 for performing signal synthesis according to the input of a switching clock, and an output from the switching element 417 for amplifying according to AGC data. Amplifier 418 and AD
AD output from amplifier 418 according to clock input
It is composed of an AD converter 419 for conversion. This configuration provides the following functions.

- Photoelectric conversion: The reflected light from the original is converted into a 400 dpi analog signal by the CCD 415.

- Signal amplification: The signal from the CCD 415 is divided into odd numbers (ODD) and even numbers (EVEN) and amplified by amplifiers 416a and 416b, respectively. In this case, since the time per pixel is very short,
It is divided into two parts depending on the amplifier.

・Signal synthesis: ODD, EVE
A switching element 417 converts N into a serial analog signal.

・Variable amplification: Image processing circuit (
Amplification is performed using AGC data from IPU) 402. In this case, AGC (auto gain control) is C
Fluctuations in brightness of fluorescent lamp 412 read by CD415 (
In order to correct for fluctuations due to temperature, changes over time, etc., the amplification degree (gain) is instructed to the image reading plate based on the output obtained by reading the reference white board with the CCD 415. That is,
If the fluorescent lamp 412 is dark, the amplification degree is increased, and if it is bright, the amplification degree is decreased to keep the output to the next step constant.

- Signal digitization: The variably amplified analog signal is converted into a digital signal by an AD converter in accordance with the input of the AD clock, and is output via line A to the image processing circuit 402 side.

(7-3) Image processing circuit The image processing circuit (IPU) 402 has five gate arrays 420, 421, 422, 423,
424, ROM 425, and RAM 426, and processes input from the image reading circuit 401. In addition, a clock generation circuit 42 outputs a reference clock for these circuits.
8 is provided. The functions of each of these gate arrays are as follows.

・First gate array: Light amount detection shading correction timing control command control data editing, output CCD drive clock generation ・Second gate array: Magnification change in main scanning direction ・Third gate array: Halftone processing 2 Value conversion processing Original size detection - Fourth gate array: Character/halftone separation Hollow out image - Fifth gate array: Mark area detection Note that the image processing procedure is as shown in FIG. That is,
After performing shading correction and MTF correction on the CCD output in the first and second gate arrays 420 and 421 and performing magnification in the main scanning direction, the third and fourth gate arrays
The gate arrays 422 and 423 perform processing according to each mode: text mode, photo mode, text photo mode, hollowing out, and black and white inversion.

[0134] Binarization is performed in the text mode, halftone processing is performed using the dither method in the photo mode, and in the text and photo mode,
The text and the photo are separated, the text is binarized, and the photo is subjected to halftone processing using the dither method, and then outputted to the copying apparatus 500 via line D. Further, in the case of hollowing out, the image is converted into a binary value after performing the hollowing process, and in the case of black-and-white inversion, it is converted into a binary value, written to an inverter, inverted, and outputted to the copying apparatus 500 through line D.

(7-4) System Control Circuit The system control circuit 504 is included in the image information storage device 501 together with the image memory unit 505 as shown in FIG. 53, and controls the entire system and issues instructions for reading and writing image information. conduct. Control of the entire system and instructions for reading and writing image information are as follows.

・Control of the entire system: Monitoring of system readiness status Transfer paper information such as paper size and remaining amount Original reading start Scanner copy mode Printer copy mode Others ・Image data reading and writing instructions: Understanding remaining memory amount Image data Note that the control of the entire system includes the floppy disk drive 700, optical disk drive 800,
Needless to say, the operating device 503 and the sorter/stapler device 900 are also included. The operating device 503 includes
An operation control circuit 520 is included, and the operation control circuit 520 controls the lighting of an LCD 522 and an LED 523 by operating a key 521. Also, the sorter/stapler device 900 is optionally connected via line H;
As shown in FIG. 55, this apparatus includes a sorter/stapler control circuit 901 and a sorter/stapler driving device 902.

(7-5) Image Memory Section The image memory section 505 is composed of a memory board and a memory control board. An image signal sent from the reading device 400 via a coaxial cable (line D) is sent to a memory section 506 provided on a memory board. The memory capacity of this memory section 506 is 1 Mbit DRAM.
Equipped with 6 pieces, which corresponds to 4 pages (506a, 506b,
506c, 506d), that is, a total of 64 Mbits. FIG. 57 shows an outline of this memory section. As can be seen from this figure, one page 506a of this memory section 506
corresponds to one A4 size page of 217.6 mm x 310.9 mm, and in the case of A3, two pages, for example 506a and 506b, are used.

[0138] One memory control board per memory board.
In other words, they are provided on a one-to-one basis. Regarding writing and reading from memory, it is impossible to write and read at the same time, and if there is an empty page in the memory, that is, there is a writable page, then writing is performed sequentially. That is, in this case, the copy start key is turned ON.

(7-6) Writing device The writing device 507 consists of a line driver circuit 508, a laser driver circuit 509, a laser diode (LD) 510, and a read synchronization control circuit 511, and the writing device 507 is composed of a line driver circuit 508, a laser driver circuit 509, a laser diode (LD) 510, and a readout synchronization control circuit 511. The received signal is taken in from line F, processed by line driver circuit 508 and laser driver circuit 509, and drives laser diode 510. At this time, a read synchronization signal is output from the read synchronization control circuit 511 to the laser driver circuit 509 to synchronize the laser, and a write drive control circuit 513, which is also connected to the drive device 512, outputs a write drive signal to the laser driver circuit 509. Output to driver circuit 509. In addition, the write drive control circuit 513
also outputs a drive control signal to the laser driver 510.

[0140] In this writing device 507, the wavelength is 780n.
A GaAs laser diode 510 with a near-infrared ray of m and an output of 10 mW is used. This laser diode 5
10 has the advantage of being small and compact and easy to control, but also has the disadvantage that the output may become unstable due to temperature changes. This temperature change includes one due to self-heating and one due to ambient temperature (outside air temperature). In order to minimize these effects,
A heater is placed around the laser diode 510,
If the temperature is below °C, the heater is turned on. In addition, a detector (
The monitor light is detected by a photodiode) and fed back to the drive current of the laser diode 510, and an automatic power
A control (APC) circuit is provided. And 1
The laser power (APC) is reset every time a line is written.

(7-7) Write drive control Write drive control circuit 5 in the copying circuit 502 shown in FIG.
13 is shown in detail in FIGS. 58 and 59. This circuit 513 is
Basically CPU530, ROM531, RAM532
and four first to fourth I/O gates 533, 53.
4,535,536, an AD conversion input section 537 that AD converts and inputs the output from each section 543 to be detected to the CPU 530, and first and second I/O gates 533.
, 534 to input the output from each section 543.
38 and a driver 539 and a fourth gate 536 for driving each section 544 to be controlled in accordance with control signals from the third and fourth I/O gates 535 and 536 in accordance with instructions from the CPU 530. The drive controller 540 is configured with an H-type driver 540 for driving each section 544 to be controlled in accordance with a drive control signal. In addition, ROM5
31 and RAM 532 and each I/O gate 533, 53
A latch 541 is inserted in the bus between 4,535, and 536. TxD terminal and Rx of CPU530
The D terminals are each connected to a system control circuit. Further, reference numeral 542 is a decoder.

[0142] The CPU 53 via the AD conversion input section 537
The signal input to 0 is the first to third P sensor 21
, 22, 23, the output of the laser diode 510, the fixing thermistor, the output of the first transfer station 231 and the second transfer station 232, and the output of the counter electrode.

[0143] First and second I/O from input section 538
CPU 530 or R via gates 533 and 534
The blocks (543, 5
44).

(8) Transfer System Next, each transfer system in the copying machine according to the embodiment will be explained.

(8-1) Development and transfer system without latent images The development and transfer system without between latent images will be explained with reference to FIGS. 1 and 2. Note that although it is redundant, FIG. 1 shows a state in which the second transfer station is in use as a transfer belt, and FIG. 2 shows a state in which the second transfer station is in a state in which corona transfer is being performed.

[0146] The flow of the transfer paper will be explained below, and as a typical example, the case where paper is fed from the uppermost paper feed port will be explained.

[0147] The first transfer paper is fed by the feed roller 201, and the first transfer paper is fed by the feed roller 201.
After branching by the branching claw 202 , it enters the first conveyance path 203 . The transfer paper in the conveyance path 203 is transferred to the intermediate roller 20
4 and waits at the registration roller 205 section. Detection of the transfer paper is performed by the first registration sensor 9.

[0148] The second transfer paper is fed by the feed roller 201 in the same way as the first transfer paper at a certain timing from the start of conveyance of the first transfer paper, and after being branched by the first branch claw 202, it is transferred to the second conveyance path. Transfer paper stack section 211 via 212
enter into. The leading edge of the transfer paper in the stack section 211 is the second
The trailing edge of the transfer paper is regulated by registration rollers 206 and detected by first relay sensor 7 . The rear end of the transfer paper is fed by the intermediate roller 207 of the stack section until it is detected by the first relay sensor 7, and the transfer paper is completely stored in the transfer paper stack section 211.

The transfer paper stack section 211 is composed of different inclined surfaces, and has a substantially V-shape with respect to the surface of the photoreceptor 90.
Since the sheets are stored in this V-shaped stack section in a curved manner, it is possible to increase the space length in the sheet conveyance direction. In addition, an elastic member 208 is provided in the stack portion.
Because of this provision, even when the transfer paper is stored in a curved manner, it is possible to reliably hold the transfer paper in the nip of the second registration roller 206. The first transfer paper is fed again at a timing synchronized with the leading edge of the image on the photoreceptor 90, transferred at the first transfer station 231, and separated at the first separation station 100. The separated transfer paper is transferred to the first conveyance section 209 and the second conveyance section 2.
10 and is then fixed in a fixing section 190.

The second transfer paper is fed again at a timing synchronized with the leading edge of the image formed immediately after the first transfer paper image, and transfer is performed at the second transfer station 232. The separated transfer paper passes through the third conveyance section 234 and then reaches the fixing section 190.
It is established in

Next, the relationship between the latent image on the photoreceptor 90 (including after development) and the transfer paper will be described.

[0152] Latent images are formed on the photoreceptor 90 at minute intervals with almost no gap between latent images. By alternately transferring the latent images at the first and second transfer stations 231 and 232 and making the distance between the transfer sheets minute, the number of copies per unit time is increased. In the conventional system having only one transfer station, it is not possible to prevent the occurrence of transfer paper gaps due to the transfer paper stop time during registration adjustment of the transfer paper. The feeding order of the first and second transfer paper is that the transfer paper corresponding to the second formed latent image is fed out before the transfer paper corresponding to the first formed latent image, and the first transfer paper is fed first. The transfer paper may be fed to the stack section 211 via the second conveyance path 212, and subsequently transferred to the first conveyance path 203 for the second time.

Next, the configuration of the conveyance path will be described.

The path length of the first conveyance path 203 is set to be longer than the maximum transfer paper size that can be stored in the transfer paper stack section 211, so that during registration standby, the first conveyance path 203 is completely
It is stored within 3.

The transfer paper stack section 211, the second transfer station 232, and the third conveyance section 234 are detachable, so that the first transfer station 231 alone can be used. Further, at this time, the mode selection for only the first transfer station 231 is automatically set.

First transfer station 23 on photoreceptor 90
1. Since the distance between the second transfer stations 232 is longer than the maximum transfer paper size stored in the transfer paper stack section 211, even if development is performed without latent image interval,
It is possible to perform the transfer with one transfer station.

First transfer station 23 on photoreceptor 90
The distance between the second transfer station 232 and the fixing nip (the distance between the third transfer station 232 and the third transfer station 232)
4) plus the distance from the first transfer station 231
The configuration is such that the interval is equal to the distance between the first and second conveyance sections 209 and 210. Also, the linear velocity of the photoreceptor and the first, second, third
The linear speeds of the transport units 209, 210, 234 and the first and second registration rollers 205, 206 are approximately equal. That is, when the first transfer paper is transferred at the first transfer station 231 and fixed via the first and second conveyance sections 209 and 210, the trailing edge of the first transfer paper is transferred to the second transfer station 231.
32 and is located at almost no interval from the leading edge of the second transfer paper, which is fixed via the third conveyance section 234. This transfer paper interval is approximately equal to the interval between latent images. However, there are cases where the transfer paper interval is slightly wider than the latent image interval due to transport slips, etc., but this is a very small interval.

[0158] The first and second of the first transfer paper and the second transfer paper
The linear speed up to the registration rollers 205 and 206 is
The linear speed is approximately twice that of the first to third conveyance sections 209, 210, 234 (the linear speed of the feed roller 201, intermediate roller 1 (204), intermediate roller 2 (213), and stack section intermediate roller 207). ). These rollers 201,
Due to the relationship that the linear velocity of 204, 213, and 207 is approximately twice that of the photoreceptor 90, it is possible to prevent contact between the transfer papers at the intersection A of the first transfer paper and the second transfer paper. . That is, at intersection A, the second transfer paper passes in front of the first transfer paper. The third and fourth transfer papers also pass through the same path as the first and second transfer papers to the first transfer station and the second transfer station 23, respectively.
1,232 and are sequentially transferred. For details of the transfer paper conveyance timing, please refer to the timing chart described later.

(8-2) 1 latent image (development) 2 transfer paper system In this image forming system, approximately twice the amount of toner as in the normal mode is deposited on the photoreceptor in advance, and the first transfer station 23
1, about 30 to 50% of the toner is transferred to the first transfer paper, and the remaining toner is transferred to the second transfer paper at the second transfer station 232. First transfer station 2 at this time
31, the transfer current is determined by measuring the state of the transfer paper using the distribution ratio measuring counter electrode 230 of the first transfer station 231 (
(performed at the first transfer station 231), or by using the second transfer station 232 as the transfer belt 233, a measurement pattern is actually formed on the transfer belt 233 and transferred, and the transfer efficiency is evaluated. There is a method of calculating with the first to third P sensors 22, 21, and 23 of the reflective type sensor and determining the value of the second transfer station 231, as described above. Also, latent image (development) 2
The interval between latent images in the transfer system is determined by adding a minute interval to the length of the transfer paper.

[0160] The conveyance paths of the first transfer paper and the second transfer paper are the same as those of the latent imageless development transfer system described above, but when the first and second transfer paper are conveyed at the leading edge timing of each image, the 1. Since the leading edge of the second transfer paper is at the same position (overlapping), it is necessary to stop the transfer paper on the conveyance path. The stop time at this time (
The distance) is determined by adding a minute interval (inter-latent image interval) to the length of the transfer paper (an interval including the time for the transfer paper transferred at the second transfer station 232 to enter between the latent image intervals). The transfer paper is stopped on the transfer paper that has been transferred at the first transfer station 231. First conveyance section 2 on the first transfer paper path
A trailing edge detection sensor 5 is installed between the transfer sheet 09 and the second conveying section 210, and detects the trailing edge of the transfer paper and stops the second conveying section. Further, the second conveyance section 210 is designed to be a conveyance section that can sufficiently stop the maximum transfer paper size in a one-latent image (development) and two-transfer system. In this case, the first transfer paper (odd-numbered transfer paper) stops on the second conveyance section, so it is conveyed immediately after the second transfer paper.

(8-3) At the time of normal mode transfer, when the transfer paper size is A4 portrait or higher, the transfer paper in the transfer paper stack unit 211 is It becomes impossible to store the transfer paper, and it is not possible to make the transfer paper interval (after fixing) minute. As a result, the first and second transfer stations 231 and 232 do not perform the transfer alternately, but only one of the transfer stations performs the transfer. Usually the first transfer station 23
1, and when an abnormality occurs in the first transfer station 231, the second transfer station 232 is set to be used. In this mode, the transfer paper is not completely stored in the transfer paper stack section, but is kept on standby in the registration section and re-fed.

(8-3-1) Double-sided printing Automatic duplexing (reversal paper ejection) is possible in the previously described latent image gapless development transfer paper system and 1 latent image (development) 2 transfer system. .

That is, the transfer paper discharged by the paper discharge roller 214 after fixing is branched by the second branch claw 215 which is linked to the branch paper discharge solenoid 101, and when double-sided copying is performed, the transfer paper is branched by the second branch claw 215 which is linked to the branch paper discharge solenoid 101.
16. It passes through the rollers on the third conveyance path 216, is conveyed through the fourth conveyance path 218 by the third branching pawl 217 linked to the downstream branching and reversing solenoid 102, and is discharged to the double-sided stack section 250 by the downstream rollers 251.

[0164] The linear speed of the feed roller is determined by the discharge roller 214,
The rollers on the third conveyance path 216 and the rollers at the upper middle part of the fourth conveyance path 218 are set at the linear velocity of the photoconductor, and the other rollers are set at approximately twice the linear velocity of the photoconductor (the registration rollers 205 and 206 are set at the linear velocity of the photoconductor). ). When double-sided printing is performed, the interval between transfer sheets is extremely small, so when double-sided stacking is performed, there is a risk that the page order will be reversed, with the transfer sheet entering under the previous transfer sheet.

[0165] As mentioned above, in this machine, the linear speed is approximately twice that of the downstream roller of the fourth conveyance path 218 (the discharge roller to the double-sided stack section) and the upstream roller thereof. This has the effect of widening the interval between transfer sheets, and can prevent the page order from being reversed.

The trailing edge of the transfer paper discharged to the double-sided stack section 250 is detected by the double-sided paper discharge sensor 6, and fed in the direction of the re-feed roller 220 by the shifting roller 219 interlocked with the shifting roller solenoid 106, and then moved to the jogger motor 1.
Jogging will be held at Joyogger 221 linked to 07. After jogging, the pinch solenoid 150 is activated and the call lever 229 comes into contact with the call roller 222. At the same time, the call solenoid 109 is turned on to prepare for paper feeding.

Next, when the conveyance motor is turned on, the transfer paper is sequentially conveyed. When it is double-sided, it is sent out to the fifth conveyance path 224 by the fourth branching pawl 223 interlocked with the branching double-sided solenoid 110.

At the time of reversal discharge, the fourth branching pawl 223 sends the sheet to the sixth conveyance path 225, and the branching and reversing solenoid 1
20 from the fifth branching claw 226 to the seventh conveyance path 227
The paper is transported to and ejected. At this time, the contact and separation solenoid 1
03, the contact/separation roller 228 is pressurized.

(8-3-2) When reversing the normal mode Since it is impossible to store the transfer paper in the double-sided stack section 250 in the normal mode, the transfer paper is reversed at a separate location.

[0170] The second
The third branching claw 21 is conveyed to the third conveyance path 216 by the branching claw 215 and is also linked to the branching and reversing solenoid 102.
7 to the seventh conveyance path 227.

When the rear end of the transfer paper is detected by the reversing entrance sensor 3, the approaching/separating roller 2 is activated in conjunction with the approaching/separating solenoid 103.
28 is pressurized, and the transfer paper is switched back and discharged. At this time, the leading edge of the transfer paper is moved to the first paper feed cassette 252 by the fifth branching pawl 226 that is linked to the branching and reversing solenoid 102.
be led upwards.

(9) Operation timing FIG. 6 shows the relationship between the operation and timing of the copying apparatus that copies as described above.
This will be explained with reference to timing charts shown in FIGS. 0 to 68.

(9-1) Timing in one-to-one copying operation for A4 landscape The timing when copying one-to-one on A4 landscape transfer paper is shown in FIGS. 60 to 62. In the operation based on this timing chart, after setting the number of sheets, mode, etc.
Copying starts when copying is possible.

a. 100 after main motor trigger ON
After ms (startup of the motor), the transfer paper is transferred 1 and 2 (first
, the second transfer station 231, 232) side, and turns on the branch paper feed solenoid 114 that switches the paper feed path to the transfer 1 (
Start feeding paper to the first transfer station 231) (
The timing difference between the branch paper feed solenoid 114 and the first paper feed clutch 115 takes into account the delay of the solenoid).

b. After paper feeding starts, at a certain timing (3
70 ms), the first paper feed clutch 115 is turned off, but the paper is fed to the first registration sensor 9 via the intermediate sensor 10 by the rollers driven by the first relay clutch 113.

At the timing when the leading edge of the transfer paper reaches the intermediate sensor 10, the trailing edge of the transfer paper is moved to the branch paper feed solenoid 114.
Since the paper has passed through the claw driven by the paper, the branch paper feed solenoid 114 is turned off and the paper feed path is switched to the transfer 2 (second transfer station 232) side. At the same time, the first paper feed clutch 115 is turned on to start paper feeding.

c. The transfer paper fed to the transfer 2 (second transfer station 232) side is transferred to the first relay sensor 11,
It passes through the second relay sensor 12 and is fed to the second registration sensor 4.

d. During the timing when the transfer 1 (first transfer station 231) side is being fed to the transfer 2 (second transfer station 232) in c above, the registration start timing is reached, and the first resist clutch 11
1 is turned on, and the transfer paper is conveyed at the same speed as the image forming system.

e. The leading edge of the transfer paper whose registration was started in step d above is transferred to transfer 2 (second transfer station 232)
This indicates the timing at which the feed path reaches the position where it intersects with the feed path. f. The second resist clutch 105 is turned on at the timing when the toner image formed before the toner image to be transferred in the transfer 1 (first transfer station 231) starts to register on the transfer 2 (second transfer station 232) side. .

g. When the trailing edge of the transfer paper reaches the intermediate sensor 10 after being transported by the registration rollers at the speed of the image forming system on the transfer 1 side, after a certain timing, it becomes the repeat timing, and the repeat copy operation is set repeatedly from a to f (timings a to f). Perform copying operations for the number of sheets.

[0181] The above timing describes feeding from the first paper feed, but when feeding the transfer paper from the second and third paper feeds or LCT, the registration linear speed≈(1/2) x feeding line Since the transfer paper is fed at a speed close to the claw driven by the branch paper feed solenoid 114 and then stopped, the timing similar to the above timing can be achieved. In addition, in the case of a two-page spread document (original size: A3 → transfer paper size A4 landscape + A4
(horizontal), the ON time of the exposure (LD) shown in the figure is only doubled, and the timing of paper feeding and conveyance on the transfer paper side may be the timing shown in the figure.

(9-2) Timing chart for simultaneous multi-sheet copying on A4 landscape 63, 64, and 65 are timing charts showing the timing for simultaneous multi-sheet copying on A4 horizontal.

[0183] a to e, g are A4 horizontal 1 of the above (8-1)
Since this is the same as the one-to-one copy, the explanation here will be omitted.

h. The toner image on the photoreceptor 90, on which the toner adhesion amount has been increased in advance during charging, exposure, and development, is partially transferred to the transfer paper on the transfer 1 (first transfer station 231) side at the timing d. When the toner image left by the rotation of the photoreceptor 90 reaches the registration start timing on the transfer 2 (second transfer station 232) side, the second resist clutch 10 is applied to the same toner image.
5 is turned on to perform the transfer operation.

i. The transfer paper on the transfer 2 (second transfer station 232) side has a longer registration waiting time, so the second registration sensor 4 has a shorter paper interval (OFF) time. The second resist clutch 105 is turned off.

[0186]j. With the above configuration, two sheets of transfer paper (copies) can be created with one latent image, so if the set number of sheets is an odd number, the image formation and transfer timing of the first transfer paper or the last transfer paper will be charged and charged according to the above timing. exposure,
Image forming conditions such as transfer are changed from simultaneous multi-sheet transfer to single-sheet transfer (normal copy mode).

k. When the trailing edge detection sensor 5 detects the falling edge (the trailing edge of the transfer paper), the conveyance clutch 104 is turned off and the transfer paper stops on the conveyance section. When stopped, the transfer paper from the transfer 2 side is conveyed to the fixing unit and fixed. Therefore, after the transfer paper on the transfer 2 side turns on the fixing sensor 2, after a certain timing (even if the transfer paper stopped on the transport unit is conveyed to the fixing unit, it will not overlap with the transfer paper on the transfer 2 side at the fixing section). timing), the conveyance clutch 104 is turned on and the transfer paper is conveyed to the fixing unit.

(9-2-1) Processing and timing when an odd number of sheets are placed in simultaneous multi-sheet mode In simultaneous multi-sheet mode, two copies are created with one latent image, so the number of sheets placed is odd. In the case of , only the last paper or first paper is 1
Two latent images correspond to one copy. Therefore, the process conditions differ greatly between two-sheet copying and one-sheet copying. Therefore, in the embodiment, the number of ON times of charging during latent image formation is counted, and the timing of changing the process conditions is controlled. In the flowcharts shown in FIGS. 69 to 72, the first paper is 1.
This shows a case where one copy is made from two latent images (only in simultaneous multi-copy mode). Note that "SLED" in the flowchart indicates the LED on the operation panel in the simultaneous multi-copy mode.

In this process, as shown in the flowchart of FIG. 69, when copying starts (S69-1)
Check whether the jam has been recovered (S69-2
), and when the jam recovery is completed, the charging counter is reset (S69-3).

In the charging process in this mode, FIG.
As shown in the flowchart of 0, first, when the charging ON timing comes (S70-1), the charging counter is set to 1.
It counts up (S70-2) and checks whether the SLED is set (S70-3). SLE
If D is set, it is checked whether the number of copies placed is an odd number (S70-4), and if it is an odd number, it is checked whether the charging counter is 1 (S70-5). If the charging counter is not 1, the simultaneous multi-copy condition is output, the photoreceptor 90 is charged (S70-6), and the process returns. If the number set in step S70-4 is an even number,
Skip step S70-5 and step S70-6
Execute the process. Also, in step S70-3, SLE
When D is not set, and step S70-
If the charging counter does not reach 1 in step 5, it is charged as is (S70-7) and the process returns.

On the other hand, regarding the developing bias, as shown in the flowchart of FIG. 71, when the bias is turned on (S71-1), it is checked whether the SLED is set (S71-2), and if it is not set. If so, it is checked whether the number of copies is set to an odd number (S71-3). If an odd number of sheets are set, check whether the charge counter is set to 1 (S7
1-4), turn on the developing bias under the simultaneous multi-copy condition (S71-5) and return. If the number set in step S71-3 is an even number, step S71-4
is skipped and the process of step S71-5 is executed. Further, if the SLED is not set in step S71-2, and if the counter is 1 in step S71-4, the developing bias is turned on (S71-6) and the process returns.

Furthermore, regarding the laser diode control procedure, as shown in FIG. 72, when the exposure timing comes (S72-1), it is checked whether the SLED is set (S72-2), and if it is not set. If so, check whether the number of cards placed is an odd number (S72-3)
. If the number of sheets is odd, check whether the charge counter is 1 (S72-4), and if it is not 1, turn on the laser diode under the simultaneous multi-sheet mode condition.
(S72-5) and return. If step S7
If the number of sheets is an even number in 2-3, step S72
-4 is skipped and the process of step S72-5 is executed. Further, if the SLED is not set in step S72-2, and if the charging counter is not 1 in step S72-4, the laser diode is turned on and the process returns (S72-6).

(9-3) Copy timing chart for A4 landscape, inverted, and double-sided portions 66, 67, and 68 are timing charts showing the copy timing for A4 landscape, reversed, and double-sided portions.

l. The fused transfer paper is guided by a pawl driven by a branch paper discharge solenoid 101, and the conveyance speed is increased through the internal path of the machine, whereupon it is transferred to a duplex unit (double-sided paper discharge sensor).
is released.

m. The falling edge (during ejection) of the double-sided paper ejection sensor 6 serves as a timing reference for the alignment means (jogging, etc.) described below. At the same time as the sensor 6 falls, the shifting roller solenoid 106 is turned on (the shaded area in the figure is the actual operation of the shifting roller 219 due to the solenoid delay time), and the transfer paper is shifted toward the paper refeeding port.

n. After another 150ms, the jiyogar (Fens) 2 is used for alignment by the jiyoga motor 107.
21 to the forward side (the direction in which the paper is arranged). After 150 ms after alignment, the jiyoger motor 107 moves the jiyoga (fence) 221 to the return side (retreat side).

o. At the time of reversal (when discharging the back side), the call solenoid 109 for refeeding the paper at the same timing as n.
, pinch roller solenoid 150, paper refeed motor 108
Turn on to start paper refeeding operation. (The diagonal lines (dashed lines) in the figure represent the load delay and rise time.) When duplexing is being performed, the sheet refeeding operation is not performed until all the transfer sheets are ejected from the duplex sheet ejection sensor 6.

p. Same timing as shown in paper refeed mode n for duplex printing.

q. The paper refeed motor 108 is turned off at the fall of the next transfer paper (at the time of ejection). This is because the mode is transferred to the alignment means.

The states of the transfer paper corresponding to the timing charts shown in FIGS. 60 to 62 are shown in FIGS. 73 to 7.
9.

FIG. 73 shows that the leading edge of the transfer paper P1 is located at the intermediate sensor 1.
74 shows a state in which the transfer paper P1 reaches the first registration sensor 9, the transfer paper P2 is pulled out by the feed roller 201, and the transfer paper P2 is waiting in the paper feed tray 921. The tip of the transfer paper P2 is the first branch claw 2
FIG. 75 shows a state in which the transfer paper P1 is in contact with the photoreceptor 90 and the transfer paper P2 is in the transfer paper stack section 2.
FIG. 76 shows the state in which the transfer paper P2 is stacked on the paper 11 and on standby at the timing e in the timing chart, that is, the transfer paper P2 is in the registration state with the second registration roller and the trailing edge is retracted from the section A. The transfer paper P1 is transferred to the first conveyance section 2
09, FIG. 77 shows the state when the leading edge of the transfer paper P1 reaches the trailing edge detection sensor 5, and the leading edge of the transfer paper P2 enters the fixing section 190. FIG. 78 shows the state when the leading edge of the transfer paper P1 enters the fixing section 190.
FIG. 79 shows a state in which the leading edge of the transfer paper P1 reaches the fixing sensor 2 and the transfer paper P1 is transported by the second transport section 210.
The leading edge reaches the ejection sensor 1, and the transfer paper P1 is transferred to the fixing section 19.
Each state is shown when it has been conveyed to just before zero.

[0202]

Effects of the Invention As is clear from the above description, the first method for transferring image information formed on an image information holding medium from the image information holding medium to a recording medium using at least one image information transfer means and a second image forming mode in which one image information formed on an image information holding medium is transferred from the image information holding medium to a plurality of recording media using a plurality of image information transfer means. When the instructed number of sheets inputted from the instructed number of sheets detection means in the second image forming mode is an odd number, one of the instructed number of sheets is detected. The image forming operation on the recording medium is performed in the second
According to the present invention, when an odd number of images are formed in the second image formation, one image formation mode is switched from the first image formation mode to the first image formation mode. Since the image is formed by using the above method, it is possible to form the image without waste, and there is no risk of reducing copying productivity.

[Brief explanation of the drawing]

FIG. 1 is for explaining an embodiment of the present invention;
FIG. 2 is a schematic configuration diagram of a copying apparatus according to an embodiment in which transfer at a transfer station and a second transfer station are both performed by corona discharge.

FIG. 2 is a schematic configuration diagram of a copying apparatus according to an embodiment in which transfer at a first transfer station is performed by corona discharge and transfer at a second transfer station is performed by belt transfer.

FIG. 3 is a schematic configuration diagram of a scanner section that employs a digital optical system according to an embodiment.

FIG. 4 is a perspective view showing a schematic configuration diagram of a scanner driving section that drives a scanner section.

FIG. 5 is a schematic configuration diagram showing an outline of a writing section.

FIG. 6 is an explanatory diagram showing a schematic configuration of an analog optical system for writing.

FIG. 7 is an explanatory diagram showing the image forming potential and timing on the surface of the photoreceptor in the image forming process during image area exposure.

FIG. 8 is an explanatory diagram showing the relationship between control items and charging potential in the image forming process during image area exposure.

FIG. 9 is an explanatory diagram showing the image forming potential and timing in the image forming process of non-image area exposure.

FIG. 10 is an explanatory diagram showing the relationship between control items and image forming potentials in the image forming process of non-image area exposure.

FIG. 11 is a circuit diagram showing a transfer paper state environment detection circuit.

FIG. 12 is a characteristic diagram showing the relationship between transfer drum current and transfer efficiency.

13 is a schematic configuration diagram showing the configuration around the transfer belt in FIG. 1. FIG.

FIG. 14 is a characteristic diagram showing toner concentration and sensor potential level used for calculating transfer efficiency.

FIG. 15 is a flowchart showing a part of the control procedure of transfer current control when a corona discharge method is adopted at the first transfer station and the second transfer station in the 1-development, 2-transfer mode.

FIG. 16 is a characteristic diagram showing the relationship between the transfer drum current of the first transfer station and the transfer efficiency of the first transfer station.

FIG. 17 is a flowchart showing a part of the control procedure of transfer current control when a corona discharge method is adopted at the first transfer station and the second transfer station in the 1-development, 2-transfer mode.

FIG. 18 is a flowchart showing a part of the control procedure of transfer current control when a corona discharge method is adopted at the first transfer station and the second transfer station in the 1-development, 2-transfer mode.

FIG. 19 is a flowchart showing a part of the control procedure of transfer current control when a corona discharge method is adopted at the first transfer station and the second transfer station in the 1-development, 2-transfer mode.

FIG. 20 is a flowchart showing a part of the control procedure of transfer current control when a corona discharge method is adopted at the first transfer station and a belt transfer method is adopted at the second transfer station in the one-development, two-transfer mode.

FIG. 21 is a flowchart showing a part of the control procedure of transfer current control when a corona discharge method is adopted at the first transfer station and a belt transfer method is adopted at the second transfer station in the 1-development, 2-transfer mode.

FIG. 22 is a flowchart showing a part of the control procedure for transfer current control when a corona discharge method is adopted at the first transfer station and a belt transfer method is adopted at the second transfer station in the 1-development, 2-transfer mode.

FIG. 23 is a flowchart showing a part of the control procedure of transfer current control when a corona discharge method is adopted at the first transfer station and a belt transfer method is adopted at the second transfer station in the 1-development, 2-transfer mode.

FIG. 24 is a flowchart showing a procedure for cleaning the transfer charger, wire, and casing.

FIG. 25 is a timing chart showing the relationship between the return position and home position and the rotational direction and timing of the motor.

FIG. 26 is a flowchart showing a procedure for calculating a transfer current distribution ratio.

FIG. 27 is a flowchart showing a part of the control procedure for initial transfer current control when a corona discharge method is adopted at the first transfer station and a belt transfer method is adopted at the second transfer station in the 1-development, 2-transfer mode.

FIG. 28 is a characteristic diagram for configuring the table for calculating the transfer efficiency of the first transfer station from the transfer efficiency of the second transfer station and the table.

FIG. 29 is a characteristic diagram showing the relationship between transfer drum current and transfer efficiency.

FIG. 30 is a flowchart showing part of the control procedure when calculating the transfer efficiency of the second transfer station using the first and second P sensors.

FIG. 31 is a flowchart showing part of the control procedure when calculating the transfer efficiency of the second transfer station using the first and second P sensors.

FIG. 32 is a flowchart illustrating a processing procedure for checking data capture timing in paper type detection.

FIG. 33 is a flowchart showing a processing procedure for data acquisition in paper type detection.

FIG. 34 is a flowchart showing a procedure for determining a transfer current.

FIG. 35 is a characteristic diagram for creating a table for calculating a transfer current standard value, showing the relationship between transfer efficiency and transfer drum current.

FIG. 36 is a characteristic diagram for calculating whether average paper type data and standard paper type data are equal, and shows the relationship between the potential of average paper type data and transfer drum current.

FIG. 37 is a diagram showing the relationship between the potential difference in paper type data and the current difference in transfer drum current.

FIG. 38 is a characteristic diagram showing the relationship between transfer drum current difference and transfer efficiency depending on the paper type.

FIG. 39 is a flowchart showing a general control procedure for copy mode selection.

FIG. 40 is a flowchart showing a part of the control procedure of automatic selection copy mode selection processing.

FIG. 41 is a flowchart showing a part of the control procedure of automatic selection copy mode selection processing.

FIG. 42 is an explanatory diagram of an operation panel.

FIG. 43 is a flowchart showing a part of the control procedure of manual selection copy mode selection processing.

FIG. 44 is a flowchart showing a part of the control procedure of manual selection copy mode selection processing.

FIG. 45 is a flowchart showing a part of the control procedure of manual selection copy mode selection processing.

FIG. 46 is a flowchart showing a part of the control procedure of manual selection copy mode selection processing.

[Figure 47] FLED, SLED, FSL on the operation panel
It is an explanatory view showing light emission rotation of LED of ED.

FIG. 48 is a flowchart showing the contents of a counter check subroutine.

FIG. 49 is a control block diagram of the entire copying machine according to the embodiment.

FIG. 50 is a block diagram showing details of a reading control circuit and an ADF device.

FIG. 51 is a block diagram showing details of an image reading circuit.

FIG. 52 is a block diagram showing details of an image processing circuit.

FIG. 53 is a block diagram showing details of an image information storage device including a system control circuit and an operating device.

FIG. 54 is a block diagram showing a write drive control circuit in the copying circuit.

FIG. 55 is a block diagram showing details of the sorter/stapler device.

FIG. 56 is a diagram showing the procedure of image processing in the image processing circuit.

FIG. 57 is an explanatory diagram schematically showing a memory map of the image memory section.

FIG. 58 is a block diagram showing details of a portion of the write drive control circuit in the copying circuit.

FIG. 59 is a block diagram showing details of a portion of the write drive control circuit in the copying circuit.

FIG. 60 is a timing chart showing the timing when copying one-to-one on A4 horizontal transfer paper, and FIG.
FIG. 62 shows the timing of the entire process.

FIG. 61 is a timing chart showing the timing of one-to-one copying on A4 horizontal transfer paper.

FIG. 62 is a timing chart showing the timing of one-to-one copying on A4 horizontal transfer paper.

FIG. 63 is a timing chart showing the timing when making multiple copies simultaneously on A4 horizontal transfer paper; FIGS. 64 and 65 show the timing of the entire process.

FIG. 64 is a timing chart showing the timing when making multiple copies simultaneously on A4 horizontal transfer paper.

FIG. 65 is a timing chart showing the timing when making multiple copies simultaneously on A4 horizontal transfer paper.

FIG. 66 is a timing chart showing the timing when reversing and making a double-sided copy on A4 horizontal transfer paper, and FIGS. 67 and 68 are timing charts for the entire process.

FIG. 67 is a timing chart showing the timing when reversing and making a double-sided copy on A4 horizontal transfer paper.

FIG. 68 is a timing chart showing the timing when making a double-sided copy by inverting it onto A4 horizontal transfer paper.

FIG. 69 is a flowchart showing the processing procedure when the number of copies is an odd number when making multiple copies simultaneously on A4 horizontal transfer paper.

FIG. 70 is a flowchart showing the charging process procedure when the number of copies is an odd number when making multiple copies simultaneously on A4 horizontal transfer paper.

FIG. 71 is a flowchart showing a developing bias control procedure when the number of copies is an odd number when making multiple copies simultaneously on A4 horizontal transfer paper;

FIG. 72 is a flowchart showing a laser diode control procedure.

73 is an explanatory diagram illustrating the state of the transfer paper corresponding to the timing charts of FIGS. 60 to 62, and shows a state in which the leading edge of the transfer paper P1 has reached the intermediate sensor. FIG.

74 is an explanatory diagram illustrating the state of the transfer paper corresponding to the timing charts of FIGS. 60 to 62, and shows a state in which the transfer paper P1 has reached the first registration sensor. FIG.

75 is an explanatory diagram illustrating the state of the transfer paper corresponding to the timing charts of FIGS. 60 to 62, and shows a state in which the transfer paper P1 is in contact with the photoreceptor. FIG.

76 is an explanatory diagram illustrating the state of the transfer paper corresponding to the timing charts of FIGS. 60 to 62, and shows the state of the timing e in the timing chart. FIG.

77 is an explanatory diagram illustrating the state of the transfer paper corresponding to the timing charts of FIGS. 60 to 62, and shows a state in which the leading edge of the transfer paper P1 has reached the trailing edge detection sensor. FIG.

78 is an explanatory diagram illustrating the state of the transfer paper corresponding to the timing charts of FIGS. 60 to 62, and shows a state in which the leading edge of the transfer paper P2 has reached the fixing sensor. FIG.

79 is an explanatory diagram illustrating the state of the transfer paper corresponding to the timing charts of FIGS. 60 to 62, and shows a state in which the leading edge of the transfer paper P2 has reached the ejection sensor. FIG.

[Explanation of symbols]

90 Photoreceptor 190 Fixing section 231 First transfer station 232 Second transfer station 402 Image processing device 500 Copying device 502 Operation control circuit 503 Operation device 504 System control circuit 507 Writing device 909 Writing optical system 910 Developing section 920 Cleaning department 940 Charger 950 Imaging system 960 Conveyance system P1 First transfer paper P2 Second transfer paper

Claims (1)

[Claims] 1. An image information holding medium, an image information forming means for forming image information on the image information holding medium, and an image information transfer unit for transferring the image information formed on the image information holding medium to a recording medium. In an image forming apparatus that transfers image information formed on an image information holding medium to a recording medium to form an image, the image information forming apparatus includes at least one image information transfer means that transfers image information formed on the image information holding medium to a recording medium. a first image forming mode in which one image information formed on the image information holding medium is transferred from the image information holding medium to a recording medium using a plurality of image information transfer means; an image forming control means having a second image forming mode in which images are transferred from the image to a plurality of recording media, an instructed number of sheets detecting means for detecting an input number of sheets of an instruction to form an image, and an instructed number of sheets detecting means in the second image forming mode. switching control means for switching an image forming operation on one of the recording media from a second image forming mode to a first image forming mode when the instructed number of sheets inputted from the input is an odd number;
An image forming apparatus comprising: