JP2001278489A - Sheet carrying device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet carrying device and an image forming device to equalize a position where a sheet is loaded on a carrying belt and improve durability of the carrying belt. SOLUTION: In each position on the carrying belt, the loading position of a sheet is controlled based on memory data of a memory means to store the number of sheet loading times in respective positions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying apparatus for conveying a sheet while electrostatically adsorbing the sheet on a conveying belt, and an image forming apparatus having the sheet conveying apparatus.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as an ink jet printer or a copying machine, a sheet (paper) is adsorbed on a conveying belt by utilizing a suction effect of a dielectric substance by an electrostatic force. There is known a device provided with a sheet conveying device for conveying a sheet.

In the case of such a sheet conveying apparatus, for example, a comb-shaped pattern is formed as a temporary fixing means (electrostatic attraction means) of a sheet utilizing a suction effect of a dielectric substance by an electrostatic force. There is known a method in which an electrostatic electrode plate is placed under a transport belt and a sheet is transported while being attracted to the transport belt by static electricity generated by the electrostatic electrode plate (hereinafter, referred to as an electrostatic electrode plate method).

In addition, there is also a system (hereinafter referred to as an electrostatic conveyor belt system) that uses a conveyor belt having an electrostatic electrode formed in a comb-like pattern to adsorb and convey a sheet by generated static electricity. Are known.

In such an apparatus, a high potential of about several kilovolts is supplied to a power-supplied portion provided on an electrostatic electrode (plate) through a power supply member such as a power supply brush. Is done.

Here, it is considered that the negative electrode is connected to the ground potential or a negative voltage is applied. However, depending on actual mounting conditions such as required functions and performance of the equipment, either of them is considered. Is selected.

[0007] When the belt rotates with respect to the fixed power supply member, a voltage is applied only to the contact portion between the power supply member and the power-receiving portion divided for each comb. For example, when the paper is to be moved in a straight line, the feeding unit and the belt may be configured to be in a straight line by the distance to be moved while being sucked. Hereinafter, the electrode belt in the section to which power is supplied is referred to as an adsorption unit.

With such a configuration, when the sheet placed on the rotating belt reaches the suction portion, the sheet made of a dielectric such as paper is polarized by the electric field generated between the electrodes on the belt. As a result, attractive electrostatic force is generated, and the sheet and the belt are attracted.

As described above, the sheet is conveyed while attracting the sheet to the belt by utilizing the electrostatic force.

[0010]

However, in the case of the above-described prior art, the following problems have occurred.

As described above, in the sheet conveying mechanism using the comb electrode pattern, the degree of deterioration of the conveying belt is different between the place where the sheet is mounted and the place where the sheet is not mounted. However, it is experimentally known that the deterioration proceeds.

As for the cause, it is considered that the influence of a decrease in electric resistance due to the mounting of the sheet or a rarely occurring discharge phenomenon is considered as a possibility thereof, but it is not well understood.

On the other hand, conventionally, in a sheet transport mechanism in an actual machine, an integer number of sheets are simultaneously mounted on a belt circumference or a next mounted sheet and a next sheet are mounted for the purpose of enhancing transport efficiency. It is designed and controlled in consideration of maintaining a certain physical distance.

However, when this is applied to the electrostatic transport belt system, the deterioration of the belt due to the sheet mounting position is not taken into consideration, so that when the mounting position becomes unbalanced, the deterioration is concentrated. In some cases, advancing portions may be generated, and as a result, the durability of the belt may be reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. It is an object of the present invention to improve the durability of a conveyor belt by balancing the positions of sheets mounted on the conveyor belt. It is an object of the present invention to provide a sheet conveying apparatus and an image forming apparatus.

[0016]

In order to achieve the above object, a sheet conveying apparatus according to the present invention comprises: a conveying belt for conveying a sheet fed from an upstream side to a downstream side; An electrode that generates static electricity for electrostatically attracting the sheet to the storage unit, and a storage unit that stores the number of times the previously conveyed sheet is mounted at each position on the conveyance belt,
Control means for controlling a mounting position of the fed sheet on the transport belt based on data stored in the storage means.

Accordingly, by controlling the mounting position by the control means based on the data stored in the storage means, imbalance in the mounting position of the sheet can be prevented.

A plurality of indices provided on the transport belt, a detecting means for detecting these indices, and a recognizing means for recognizing a position of the transport belt based on a detection result of the detecting means. Good.

One of the plurality of indices is a reference index, and the other indices are arranged at equal intervals, and the detecting means includes a first sensor for reading passage of the reference index, A second sensor for reading the passage of the index, wherein the recognition means recognizes the position of the conveyor belt based on the number of the index read by the second sensor after the first sensor reads the reference index. Good.

The control means mounts the fed sheet at a position where the index is provided which does not exceed the average number of times of mounting of the sheet at the position where all the indexes are provided and which can be mounted in the shortest time. It is good to perform the control which performs.

The control means reads out the first procedure for selecting the nearest index on which the sheet conveyed from the upstream side can be mounted, reads the number of times the sheet is mounted at the position where the selected index is provided, and A second step of dividing the total number of mounting times at the position where the index is provided by the number of indices to obtain the average number of mounting times; a mounting number read out in the second step; A third step of comparing the average number of times of mounting, and if the read number of times exceeds the average number of times of mounting as a result of the comparison in the third step, the next mountable index is selected. As a result of the comparison between the fourth procedure and the third procedure, which returns to the second procedure again, if the read mounting frequency does not exceed the average mounting frequency, the position of the selected index is set to the mounting position of the sheet. And the number of times the index is mounted is 1 A fifth procedure for terminating the increase was a value and stored as a new mounting number processing, it may perform control based on.

The control means may be provided with an index which does not exceed an average number of times of mounting sheets at a position where all the indexes are provided within a predetermined allowable range and which can be mounted in the shortest time. Control for mounting the fed sheet at the position can also be performed.

The control means includes a first step of selecting the nearest index on which the sheet conveyed from the upstream side can be mounted, reading the number of times of mounting the sheet at the position where the selected index is provided, A second procedure of dividing the total number of mounting times at the position where the index is provided by the number of indices to obtain the average number of mounting times, and calculating a bias from the difference between the average number of mounting times and the read number of mounting times And a third procedure for comparing the bias calculated in the second procedure with a predetermined allowable number of times;
As a result of the comparison in the third procedure, if the calculated bias exceeds a predetermined allowable number, the fourth procedure selects an index that can be mounted next and returns to the second procedure again; As a result of the comparison by the procedure, when the calculated bias does not exceed the predetermined allowable number, the position of the selected index is determined as the mounting position of the sheet, and the value obtained by increasing the mounting number of the index by one is determined. The control may be performed based on a fifth procedure of storing the new mounting count and ending the processing.

The control means controls the mounting of the fed sheet at the position where the index listed in the list is provided and the position where the index which can be mounted in the shortest time is provided. It is also preferable that the list is composed of indices in which the number of times of mounting the sheet at the provided position does not exceed the number of mountings at the position where all other indices are provided.

The control means includes a first step of checking whether or not a candidate index is present in the list; and, as a result of the check in the first step, if there is no candidate, A second procedure for creating a list of indices, and as a result of the inspection in the first procedure, if there is a candidate, or if a list is created by the second procedure, A third procedure of selecting an index, a fourth procedure of determining the position of the index selected by the third procedure as a seat mounting position, deleting the selected index from the list, and ending the processing; , The control should be performed.

In the image forming apparatus of the present invention,
An image forming means for forming an image on a sheet conveyed by the sheet conveying apparatus is provided.

[0027]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The materials, shapes, relative arrangements, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

In each of the embodiments described below, control related to mounting of a sheet in a sheet conveying apparatus will be mainly described.

It should be noted that the sheet conveying device may function as a part of a device requiring a conveying device, as represented by an image forming apparatus such as a printer or a copying machine, rather than using the sheet conveying device alone. As an application example in the world, it is more general, and a case in which the sheet conveying device in the following description is a part constituting an apparatus such as an image forming apparatus will be described as an example.

In the following description, as an example of an image forming apparatus, a case where a sheet conveying device is applied to an ink jet printer will be described.

The configuration and the like of the entire image forming apparatus are well-known in the art, and thus the description thereof will not be repeated. In addition, a sheet to be conveyed applied to the sheet conveying apparatus according to the embodiment of the present invention is a sheet formed of a dielectric substance polarized by an electric field, and one of them is described below. It is described as a sheet.

(First Embodiment) A sheet conveying apparatus and an image forming apparatus according to a first embodiment of the present invention will be described with reference to FIGS.

Here, FIG. 1 is a block diagram of an image forming apparatus provided with a sheet conveying device according to an embodiment of the present invention, and FIG. 2 is a diagram showing electrodes of the sheet conveying device according to the embodiment of the present invention. FIG. 3 is a schematic plan view showing the situation, and FIG. 3 is a schematic view showing a belt mechanism of the sheet conveying apparatus according to the embodiment of the present invention ((A) is a schematic plan view, (B) is a schematic side view). FIG. 4 is a schematic view of the sheet conveying apparatus according to the embodiment of the present invention ((A) is a schematic plan view, and (B) is a schematic side view).

FIG. 5 is a schematic diagram ((A) is a schematic plan view, (B) is a schematic side view) of a power feeding member of the sheet conveying apparatus according to the embodiment of the present invention, and FIGS. FIG. 7 is an explanatory diagram illustrating a configuration for recognizing the position of the transport belt of the sheet transport device according to the embodiment of the present invention.

FIG. 8 is a flow chart of the operation control of the sheet conveying apparatus according to the first embodiment of the present invention.

First, the configuration of the entire image forming apparatus will be described with reference to FIG.

In FIG. 1, a block diagram relating to the control of the image forming apparatus main body is shown in the upper part, and a schematic perspective view of a sheet conveying device included in the image forming apparatus is shown in the lower part.

As shown in FIG. 1, the image forming apparatus is provided with a sheet conveying device.
, A motor belt 9 for transmitting the driving force of the motor 8, a belt pulley 10 that rotates by transmitting the driving force by the motor belt 9, and a transport belt 11 that rotates in the direction in which the belt pulley 10 transports the sheet. And

With such a configuration, the sheet conveying device conveys the sheet fed from the sheet feeding direction on the upstream side in the direction of the arrow in FIG.

Then, an image is formed on a sheet conveyed while being attracted to the conveying belt 11 by a print head 13 as an image forming means, and the sheet on which the image is formed is discharged to the outside of the image forming apparatus. Is done.

Here, the hardware configuration will be described in more detail.

First, the print head 13 is, for example, 1 cm
A long head of an ink-jet system in which several hundred or more ink ejection nozzles are integrally formed so as to be arranged substantially linearly at a rate of several hundred or more per head can be applied.

As the mechanical mechanism, there are mainly a paper transport mechanism, an electrostatic attraction mechanism, and an ink supply mechanism. The paper transport mechanism is a mechanical mechanism for feeding paper to be printed at a predetermined speed. Is used,
The electrostatic attraction mechanism is a mechanism for attracting the transport belt 11 and the paper 14 using static electricity, and the ink supply mechanism is a mechanism for supplying and recovering ink to and from the print head 13.

As the electric mechanism, there are mainly a head driving mechanism, a mechanical driving mechanism, an edge detecting mechanism, and a time measuring mechanism. The head driving mechanism is an electric circuit (print data control circuit 15) for supplying print data to the print head 13. And a head drive circuit 12), and the mechanical drive mechanism includes an electric circuit for driving the entire mechanical drive mechanism and a motor drive circuit 7 for a mechanical drive power source such as a motor 8.
The edge detection mechanism includes a marker indicating an edge of the comb electrode,
The time measuring mechanism is constituted by a counting circuit for measuring the time after the edge detection.

Further, a control mechanism for comprehensively controlling each of the above elements is provided. The control mechanism stores a central control unit MPU1 having a computing unit 4 and an input / output unit 5, and a control procedure. ROM 2 and RA for temporarily storing data
M3 and NVRAM to save data even if power is turned off
(Non-volatile storage element) 6.

In addition, there are sensor means for detecting information such as the mechanical state and the surrounding environment, an interface circuit with an external device or a peripheral electric circuit, and the like. Input means for taking in data and output means for providing control information to a controlled object such as a mechanism are provided.

Next, with respect to the transport belt and the like, particularly, FIG.
This will be described in more detail with reference to FIGS.

As shown in the figures, positive electrode plates 20 and negative electrode plates 21 are alternately formed on the conveyor belt 11 in a comb shape.

The positive electrode plate 20 and the negative electrode plate 21 are provided with power-supplied portions 18 and 19, respectively, at the ends outside the paper transport area.

On the other hand, a pair of power supply members 1
6 and 17 are provided, and the power supply member 16 is
8 is electrically in contact with the power supply member 1.
7 is in electrical contact with the power-supplied portion 19.

As shown in FIG.
As shown in (1), a high voltage is applied from the high voltage generator 22, whereby positive and negative voltages are applied to the positive electrode plate 20 and the negative electrode plate 21 via the power-supplied portions 18 and 19, respectively.

With such a configuration, the conveying belt 11 is fixed to the power supply members 16 and 17 fixed to the apparatus main body.
Rotates, the positive electrode plate 20 and the negative electrode plate 21 formed on the conveyor belt 11 apply a voltage only to the area electrically connected by the power supply members 16 and 17 (the suction unit 23 in FIG. 4). Applied.

Accordingly, an electric field is generated only in the area of the attraction section 23, and within this area, the paper is polarized and attracted onto the belt by electrostatic force.

As the power supply members 16 and 17, for example, as shown in FIG. 5, a member having a portion in contact with the power supplied portions 18 and 19 formed in a brush shape can be used. By providing the voltage connection point 24, a high voltage is applied from this portion by the high voltage generator 22, and a voltage can be applied from the brush portion to the power-supplied portions 18 and 19.

Next, referring particularly to FIGS. 6 and 7,
Recognition means for recognizing the position of the conveyor belt will be described.

As shown in FIG. 6, a plurality of scales (encoders) 11a as indices are arranged on the conveyor belt 11 at equal intervals, while on the apparatus body side, detection means for reading the scale 11a is provided. Second sensor 2
5 are provided.

Further, as shown in FIG.
On the upper side, a marker 11b is provided as a reference index, while on the device body side, a first sensor 27 is provided as detecting means for reading the marker 11b.

With this configuration, first, the marker 11b is read by the first sensor 27, and then the scale 11a is read by the second sensor 25, whereby the position of the conveyor belt 11 can be recognized based on the number of readings. Can be.

More specifically, a marker 11b is installed at an appropriate position on the conveyor belt 11, and a scale having a resolution equal to or higher than the unit in which the paper mounting position is to be dispersed is desired. 11a is the conveyor belt 11
Printing is performed over the entire circumference, and as described above, the pulse signal output by reading the scale 11a by the second sensor 25 is counted by a counter provided on the apparatus main body side, so that the position of the transport belt 11 is Can be recognized.

The main body of the apparatus is provided with various positions (scale 11a) on the conveyor belt based on the recognition means as described above.
Is provided at each position), the storage means for storing the number of times the paper is loaded at each position.

Next, referring particularly to FIG. 8, the first embodiment of the present invention will be described.
A software configuration of the sheet conveying apparatus according to the embodiment will be described. The software is a semiconductor ROM
Or a floppy (registered trademark) disk or other fixed or portable storage medium.

Here, the control means described below relates to the control for determining the paper loading position after a request for loading the paper on the conveyor belt 11 has occurred. Is temporarily stopped by the registration roller 26 shown in FIG. 6, and is again sent out by the registration roller 26 so as to be mounted at the position determined based on the control means.

Hereinafter, the control procedure will be described in order with reference to the flowchart shown in FIG.

(Step 1 (first procedure)) Conveyor belt 1
1 from the current position of n.
(The position where the index is provided) is selected. Then, the process proceeds to step 2.

(Step 2 (second procedure)) The number of mounting times Cn for the selected position n is read. This is the mounting frequency at the mounting desired position at that time. Then, by dividing the sum total of all the times of the sheet mountable position list by the number of position lists, the average number of times Cave at that time is obtained.
Then, the process proceeds to step 3.

(Step 3 (Third Procedure)) The number of mountings Cn at the desired mounting position is compared with the average number of mountings Cave. If the number of mountings Cn exceeds the average number of mountings Cave, the process proceeds to step 4; otherwise, the process proceeds to step 5.

(Step 4 (fourth procedure)) A position n + 1 next to the position n is set as a new position n. And step 2
Return to

(Step 5 (fifth procedure)) The selected position n is determined as the current paper mounting position. Then, the value of the number of times of mounting Cn corresponding to the selected position n is increased by one, this is stored as a new value, and the control of the mounting position determination is ended.

In this way, the position at which the paper is loaded is determined.

As described above, in the present embodiment,
When the paper is loaded on the transport belt 11, the loading position is controlled such that the paper is loaded at a location where the number of loading is less than the average value of the number of loading times. In addition, it is possible to prevent a location where the number of mounting times is prominent from occurring.

In addition, since the positions which are adjacent to each other are selected in order from the nearest mounting candidate position first and whether or not mounting is checked, the physical distance to the determined mounting position is not lengthened unnecessarily. In addition, the time required for the process of determining a mounting candidate does not become unnecessarily long, and the bias in the number of mountings can be corrected while minimizing the decrease in the sheet conveyance speed.

As described above, since local deterioration of the transport belt 11 can be suppressed, the life of the transport belt 11 can be extended, and as a result, transport stability when transporting the paper can be improved, and In addition, it is possible to expect an effect of improving the performance of the device that the transport efficiency can be improved by reducing the transport accident caused by the transport belt.

Further, by improving the transport stability, it is expected that the margin of design of the constituting mechanism is improved, and as a result, an economic effect such that the production cost of the mechanism can be reduced can be expected.

Further, various effects can be expected, such as an effect of reducing wasteful disposal of paper by reducing the number of transport accidents and an effect of suppressing wasteful use of global forest resources.

In the above description, a solution procedure for realizing the control step by software has been described.
It may be realized by a hardware logic circuit having a similar control function.

(Second Embodiment) FIG. 9 shows a second embodiment. In the present embodiment, the basic configuration of the hardware and the like is the same as that of the first embodiment, and after the request for loading the paper on the conveyor belt 11 is generated, the paper loading position is changed. Only the control content of the control to be determined is different.

Accordingly, in the following description, only such a control procedure will be described with reference to FIG. FIG. 9 is a flowchart of the operation control of the sheet conveying apparatus according to the second embodiment of the present invention.

(Step 1 (first procedure)) Conveyor belt 1
1 from the current position of n.
(The position where the index is provided) is selected. Then, the process proceeds to step 2.

(Step 2 (second procedure)) The number of mounting times Cn for the selected position n is read. This is the mounting frequency at the mounting desired position at that time. Then, by dividing the sum total of all the times of the sheet mountable position list by the number of position lists, the average number of times Cave at that time is obtained.
Then, the average number of mounting times Cav of the read number of mounting times Cn
The bias Cd for e is calculated by Cd = Cn-Cave. Then, the process proceeds to step 3.

(Step 3 (third procedure)) The calculated C
d is compared with the bias value Cdlim of the allowable number of mountings. If Cd exceeds the bias value Cdlim, the process proceeds to step 4; otherwise, the process proceeds to step 5.

(Step 4 (fourth procedure)) The position n + 1 next to the position n is set as a new position n. And step 2
Return to

(Step 5 (Fifth Procedure)) The selected position n is determined as the current paper mounting position. Then, the value of the number of times of mounting Cn corresponding to the selected position n is increased by one, this is stored as a new value, and the control of the mounting position determination is ended.

In this way, the mounting position of the sheet is determined.

As described above, in the present embodiment,
When the paper is loaded on the transport belt 11, the loading position is controlled so that the paper is loaded while avoiding a loading location that exceeds the deviation of the allowable number of loading times.
It is possible to prevent the occurrence of a location where the number of mounting times is prominent among the mountable positions around the entire circumference.

In addition, there are the same effects as in the case of the first embodiment.

In the above description, a solution procedure for realizing the control step by software has been described.
It may be realized by a hardware logic circuit having a similar control function.

(Third Embodiment) FIG. 10 shows a third embodiment. In the present embodiment,
The basic configuration of the hardware and the like is the same as that of the first embodiment. Only the control contents of the control for determining the paper loading position after the request for loading the paper on the conveyor belt 11 is generated. Are different.

Therefore, in the following description, only such a control procedure will be described with reference to FIG. FIG.
FIG. 11 is a flowchart of operation control of the sheet conveying apparatus according to the third embodiment of the present invention.

(Step 1 (first procedure)) It is checked whether or not a candidate position exists in the mounting candidate list. And
If it does not exist, the process proceeds to step 2, and if it exists, the process proceeds to step 3.

(Step 2 (Second Procedure)) A list of all positions where papers may be loaded is created. This is the initial mounting candidate list. Then, the process proceeds to step 3.

(Step 3 (Third Procedure)) From the mounting candidate list, the nearest position n on which paper can be mounted is selected from the current position of the conveyor belt 11. Then, the process proceeds to step 4.

(Step 4 (fourth procedure)) The selected position n is determined as the current paper mounting position. Then, the position n selected this time is deleted from the mounting candidate list, and the control of the mounting position determination ends.

In this way, the mounting position of the sheet is determined.

The above list is composed of indices in which the number of times of mounting the sheet at the provided position does not exceed the number of mountings at the position where all other indices (scale 11a) are provided. .

Specifically, first, in the initial state, all indices are listed, and according to the above control procedure,
By loading paper once at the position where all the indices are provided, there are no more indices that are candidates for the list.

At this time, by repeating the procedure of listing all indices in the list again according to the above control procedure, the imbalance in the number of times of mounting is within 1 for the position where all indices are provided.

As described above, in the present embodiment,
When the paper is loaded on the transport belt 11, the loading position is controlled so that the paper is loaded so that the bias of the loading frequency is within 1 with respect to all the available positions.
It is possible to prevent a location where the number of times of mounting is protruded from occurring in a position where the belt can be mounted on the entire circumference of the conveyor belt 11.

In addition, there are the same effects as in the case of the first embodiment.

In the above description, the solution procedure for realizing the control steps by software has been described.
It may be realized by a hardware logic circuit having a similar control function.

[0100]

As described above, according to the present invention, the mounting position is controlled by the control means based on the data stored in the storage means. The durability can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of an image forming apparatus including a sheet conveying device according to an embodiment of the present invention.

FIG. 2 is a schematic plan view showing a state of an electrode of the sheet conveying device according to the embodiment of the present invention.

FIG. 3 is a schematic diagram showing a belt mechanism of the sheet conveying device according to the embodiment of the present invention.

FIG. 4 is a schematic diagram of a sheet conveying device according to an embodiment of the present invention.

FIG. 5 is a schematic diagram of a power feeding member of the sheet conveying device according to the embodiment of the present invention.

FIG. 6 is an explanatory diagram illustrating a configuration for recognizing a position of a conveying belt of the sheet conveying apparatus according to the embodiment of the present invention.

FIG. 7 is an explanatory diagram illustrating a configuration for recognizing a position of a transport belt of the sheet transport device according to the embodiment of the present invention.

FIG. 8 is a flowchart of operation control of the sheet conveying apparatus according to the first embodiment of the present invention.

FIG. 9 is a flowchart of an operation control of the sheet conveying apparatus according to the second embodiment of the present invention.

FIG. 10 is a flowchart illustrating operation control of a sheet conveying apparatus according to a third embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 central control unit MPU 2 ROM 3 RAM 4 arithmetic unit 5 input / output unit 6 NVRAM (non-volatile storage element) 7 motor drive circuit 8 motor 9 motor belt 10 belt pulley 11 transport belt 11a scale 11b marker 12 head drive circuit 13 print head DESCRIPTION OF SYMBOLS 14 Paper 16, 17 Power supply member 20 Positive electrode plate 21 Negative electrode plate 25 Second sensor 27 First sensor

Claims (10)

[Claims] A transport belt for transporting a sheet fed from an upstream side to a downstream; an electrode for generating static electricity for electrostatically attracting the sheet on the transport belt; Storage means for storing the number of times a sheet conveyed in the past in the position is mounted; and control means for controlling the mounting position of the fed sheet with respect to the transport belt based on data stored in the storage means. A sheet conveying device, characterized in that: 2. A method according to claim 1, further comprising: a plurality of indices provided on the transport belt; a detecting unit detecting the indices; and a recognizing unit recognizing a position of the transport belt based on a detection result of the detecting unit. The sheet conveying device according to claim 1, further comprising: 3. One of the plurality of indices is a reference index, and the other indices are arranged at equal intervals. The detection means includes: a first sensor for reading passage of the reference index; A second sensor for reading the passage of another index, wherein the recognizing means determines the position of the conveyor belt based on the number of indices read by the second sensor after the first sensor reads the reference index. 3. The sheet conveying device according to claim 2, wherein the sheet is recognized. 4. The control means according to claim 1, wherein said control means is adapted to control the sheet fed to a position provided with the index which can be mounted in the shortest time without exceeding an average number of times of mounting the sheets at the position provided with all the indexes. The sheet conveyance device according to claim 2, wherein control for mounting is performed. 5. The control device according to claim 1, further comprising: a first step of selecting a nearest index on which a sheet conveyed from an upstream side can be mounted; reading a number of sheets mounted at a position where the selected index is provided; A second procedure of dividing the sum of the number of mountings at the position where all the indices are provided by the number of indices to obtain the average number of mountings; a mounting number read out in the second procedure; A third procedure of comparing the average number of times of mounting obtained in step 3; and, as a result of the comparison by the third step, if the read number of times of mounting exceeds the average number of times of mounting, If the read number of times of mounting does not exceed the average number of mounting times as a result of the fourth step of selecting and returning to the second step again, and the third step, the position of the selected index is set on the sheet. Determined as the mounting position, and the number of mounting of the index Sheet conveying device according to claim 4, wherein one increased value and a fifth procedure for ending the process is stored as a new mounting times, to carry out control based on. 6. The controller according to claim 1, wherein said control means does not exceed an average number of seating times at a position where all the indices are provided and does not exceed a number of times within a predetermined allowable range, and is capable of providing an index which can be mounted in a shortest time. The sheet conveying apparatus according to claim 2, wherein control is performed to mount the fed sheet at a set position. 7. The control device according to claim 1, further comprising: a first step of selecting an index closest to the sheet on which the sheet conveyed from the upstream side can be mounted, reading the number of sheets mounted at a position where the selected index is provided, and Dividing the total number of mounting times at the position where all the indexes are provided by the number of indices to obtain the average number of mounting times, and calculating a bias from the difference between the average number of mounting times and the read number of mounting times. A second procedure, a third procedure for comparing the bias calculated in the second procedure with a predetermined allowable number of times, and as a result of the comparison in the third procedure, the calculated bias exceeds a predetermined allowable number of times. A fourth procedure for selecting the next mountable index and returning to the second procedure again; and, as a result of the comparison in the third procedure, if the calculated bias does not exceed a predetermined allowable number of times, The position of the selected index is 7. The control according to claim 6, wherein the control is performed on the basis of a fifth procedure of determining a value, incrementing the number of times of mounting of the index by one, storing the value as a new number of times of mounting, and ending the processing. Sheet transport device. 8. The control means controls the mounting of the fed sheet at the position where the index listed in the list is provided and at the position where the index which can be mounted in the shortest time is provided. And the list is configured by an index in which the number of times of mounting of the sheet at the provided position does not exceed the number of mountings at the position where all other indices are provided. 4. The sheet conveying device according to 3. 9. The control device according to claim 1, wherein the control unit checks whether a candidate index exists in the list.
If there is no candidate as a result of the inspection in the first procedure, a second procedure for creating a list of all indicators that can be mounted, and if there is a candidate as a result of the inspection in the first procedure Or if the list is created by the second procedure, a third procedure of selecting the nearest index from the list, and mounting the position of the index selected by the third procedure on the sheet 9. The sheet conveying apparatus according to claim 8, wherein control is performed based on a fourth procedure of determining the position, deleting the selected index from the list, and ending the processing. 10. An image forming apparatus comprising: an image forming means for forming an image on a sheet conveyed by the sheet conveying apparatus according to claim 1. Description: