JP2003306251A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device which can accurately detect the generation of paper feeding jam with the optimal number of re-try per each kind of transfer paper and which can accurately carry the transfer paper. <P>SOLUTION: This image forming device for carrying the transfer paper from a paper feeding start position to the downstream in a transfer paper carrying passage and for transferring a toner image to the transfer paper for heat fusing is provided with a kinds of paper detecting means for manually or automatically detecting kinds of the transfer paper, a jam detecting time setting means for setting paper feeding jam detecting time at a preset time per each kind of the transfer paper detected by the kind of paper detecting means, and a first control means for controlling by judging the generation of paper jam when each transfer paper does not reach a transfer paper detecting position, which is provided in the downstream of the paper feeding start position in the transfer paper carrying passage and wherein existence of passing of the transfer paper is detected, through the predetermined distance within the paper feeding jam detecting time set per each kind of transfer paper. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, and more particularly to feeding a transfer sheet used in the image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, as an image forming apparatus, a predetermined distance from a paper feed start position of a transfer paper to a transfer paper detection position provided on a downstream side of a transfer paper conveyance path is set within a predetermined paper feed jam detection time. There is known a device that detects a transfer paper feed jam when the transfer paper does not reach the transfer paper detection position.

[0003]

However, in the past, the paper jam detection time was constant regardless of the type of transfer paper. Therefore, when using plain paper and special paper, special paper with a long feeding time is used. Requires a long jam detection time, and if the jam detection time is long due to the special paper, there is a problem that the print processing speed of plain paper cannot be maintained.

An object of the first invention is to provide a transfer paper for each paper type.
An object of the present invention is to provide an image forming apparatus capable of accurately detecting a paper feed jam with an optimum paper feed jam detection time and further accurately conveying a transfer sheet.

Further, conventionally, the number of repeats of the sheet feeding retry, which is the repeated feeding operation of the transfer sheet, is constant regardless of the type of the transfer sheet. Therefore, the number of repetitions is based on the plain paper which can be stably fed. When set to, there is a problem that it is difficult to accurately feed special paper.

An object of the second invention is to provide a transfer paper for each paper type.
An object of the present invention is to provide an image forming apparatus capable of accurately detecting a paper feed jam by an optimum number of retries and further accurately transferring a transfer sheet.

Further, since the feeding jam detection time is constant regardless of the type of the transfer paper and the number of times of retrying the feeding of the transfer paper is also constant, when the plain paper and the special paper are used, Because the special paper requires a long time for paper jam detection, the print processing speed of plain paper cannot be increased, and if you set the repeat count based on plain paper that can be fed stably, special paper will not be printed. There was a problem that it was difficult to feed accurately.

A third object of the present invention is to detect a paper feed jam with high accuracy by using an optimum paper feed jam detection time and an optimum number of retries for each paper type of transfer paper, and at an optimum print processing speed. An object of the present invention is to provide an image forming apparatus that can accurately convey a transfer sheet.

[0009]

The object of the first invention is achieved by the following means.

(1) In an image forming apparatus in which a transfer sheet is conveyed downstream of a transfer sheet conveying path from a sheet feeding start position, a toner image is transferred onto the transfer sheet and heat-fixed, the type of the transfer sheet is set to manual or automatic. Paper type detection means for detecting the paper type detection means, for each type of the transfer paper detected by the paper type detection means, jam detection time setting means for setting a predetermined paper feed jam detection time, and each transfer paper, A predetermined distance from the paper feed start position to the transfer paper detection position, which is provided downstream of the transfer paper conveyance path and detects whether or not the transfer paper has passed, within the paper feed jam detection time set for each type of transfer paper. An image forming apparatus comprising: a first control unit that controls a paper jam when the transfer paper detection position is not reached.

The object of the second invention is achieved by the following means. (2) In an image forming apparatus that conveys a transfer sheet from a sheet feeding start position to a downstream side of a transfer sheet conveyance path, transfers a toner image to the transfer sheet and thermally fixes the type, the type of the transfer sheet is detected manually or automatically. A paper type detection means, and a paper feed retry number setting means for setting a predetermined number of times of a paper feed retry, which is a repeated feeding operation of the transfer paper, for each type of the transfer paper detected by the paper type detection means. , A predetermined distance from the paper feed start position to the transfer paper detection position, which is provided downstream of the transfer paper conveyance path and detects whether or not the transfer paper has passed, within a predetermined paper jam detection time. When the transfer paper detection position is not reached, the number of repetitions determined for each type of transfer paper is performed, and when the transfer paper does not reach the transfer paper detection position even after performing the number of repetitions. Is salary An image forming apparatus comprising: the second control means to jam, a.

The object of the third invention is achieved by the following means. (3) In the image forming apparatus that conveys the transfer paper from the feeding start position to the downstream side of the transfer paper conveyance path, transfers the toner image to the transfer paper and thermally fixes it, the type of the transfer paper is detected manually or automatically. Paper type detection means, and jam detection time setting means for setting a predetermined paper feed jam detection time for each type of the transfer paper detected by the paper type detection means,
For each type of the transfer paper detected by the paper type detection means, a paper feed retry setting means for setting a predetermined number of repetitions of paper feed retry which is a repeated feeding operation of the transfer paper, and each transfer paper is The predetermined distance from the paper feed start position to the transfer paper detection position, which is provided downstream of the transfer paper conveyance path and detects whether or not the transfer paper has passed, is set within the predetermined paper feed jam detection time for each type of transfer paper. If the transfer paper detection position is not reached, the repeat number of times determined for each type of transfer paper is executed. An image forming apparatus comprising: a third control unit that is a paper jam.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A schematic structure of an image forming apparatus according to an embodiment of the present invention will be described first. 1 is a sectional view showing a schematic mechanical structure of an image forming apparatus according to an embodiment of the present invention, and FIG. 2 is a view showing a schematic electric structure of an image forming apparatus according to an embodiment of the present invention.

In FIG. 1, this color image forming apparatus is called a tandem type color image forming apparatus, and a plurality of sets of image forming units 10Y, 10M, 10C and 10 are provided.
K, an intermediate transfer unit 7, a sheet feeding / conveying unit and a fixing unit 24. A document image reading device SC is arranged above the device main body A of the image forming device.

Image forming unit 1 for forming a yellow image
0Y has a charging unit 2Y, an exposing unit 3Y, a developing unit 4Y, a primary transfer roller 5Y as a primary transfer unit, and a cleaning unit 6Y arranged around a photosensitive drum 1Y as a first image carrier. The image forming unit 10M that forms a magenta image includes a photosensitive drum 1M as a first image carrier, a charging unit 2M, an exposure unit 3M, a developing unit 4M, a primary transfer roller 5M as a primary transfer unit,
It has a cleaning means 6M. The image forming unit 10C that forms a cyan image includes a photosensitive drum 1C as a first image carrier, a charging unit 2C, an exposing unit 3C, a developing unit 4C, and a primary transfer roller 5 as a primary transfer unit.
C, and a cleaning means 6C. Further, the image forming unit 10K that forms a black image includes a photosensitive drum 1K as a first image carrier, a charging unit 2K, an exposing unit 3K, a developing unit 4K, and a primary transfer roller 5 as a primary transfer unit.
K, cleaning means 6K.

The intermediate transfer unit 7 has a semi-conductive endless belt-shaped intermediate transfer member 70 as a second image bearing member which is wound by a plurality of rollers and is rotatably supported.

Image forming units 10Y, 10M, 10C, 10
The image of each color formed by K is the primary transfer roller 5Y,
By 5M, 5C, and 5K, the color images are sequentially transferred onto the rotating intermediate transfer member 70 to form a combined color image.
The transfer paper P as a recording medium accommodated in the trays 20A, 20B, 20C is fed by the paper feeding means 21, passes through the plurality of intermediate rollers 22A, 22B, 22C, 22D, and the registration rollers 23, and is secondarily transferred. Transported to the means 5A,
A color image is collectively transferred onto the transfer paper P. The transfer paper P on which the color image has been transferred is fixed by the fixing means 24, is sandwiched by the paper discharge rollers 25, and is discharged outside the apparatus to the paper discharge tray 2
6 is placed.

On the other hand, after the color image is transferred to the transfer paper P by the secondary transfer means 5A, the residual toner is removed by the cleaning means 6A from the intermediate transfer body 70 in which the transfer paper P is separated by the curvature. The residual toner is collected in a box by a device (not shown).

During the image forming process, the primary transfer roller 5K is constantly in pressure contact with the photosensitive drum 1K. The other primary transfer rollers 5Y, 5M, and 5C are in pressure contact with the corresponding photoconductor drums 1Y, 1M, and 1C only when forming a color image. The secondary transfer means 5A comes into pressure contact with the intermediate transfer member 70 only when the transfer paper P passes through here and the secondary transfer is performed.

Next, in FIG. 2, reference numeral 31 is a control section for controlling each section of the image forming apparatus and for detecting a paper jam in the present embodiment. An image processing unit 36 receives the information on the writing position determined by the control unit 31 and controls the displacement of the writing position in the main scanning direction. Three
3Y, 33M, 33C, and 33K receive a processing result in the image processing unit, and write an image with a laser beam on the photoconductor drums 1Y, 1M, 1C, and 1K. A C writing unit and a K writing unit. Also, 10
Reference numeral 0 is a paper feeding unit.

Further, 29A, 29B and 29C are transfer paper P.
Is a no-feed sensor provided at a transfer paper detection position for detecting the presence or absence of passage of a sheet, and has a light emitting portion and a light receiving portion. Reference numeral 27 denotes a paper feed motor for driving the feed rollers 21A, 21B, 21C, which is controlled by a paper feed motor ON / OFF signal from the control unit 31. Also 28
A, 28B, and 28C indicate the rotational force of the paper feed motor 27 in accordance with a signal from the control unit 31 and feed rollers 21A and 21C.
It is a clutch that transmits to B and 21C.

In this embodiment, 20A is a tray on which plain paper is stacked, 20B is a tray on which thick paper is stacked, and 20C is a tray on which special paper is stacked.
Further, 35 is an operation unit capable of various settings by manual operation, and 34 is a memory unit for storing information and the like for each type of transfer paper P.

Further, the feeding start position H1 of the transfer sheet P is the position of the delivery rollers 21A, 21B, 21C provided near the trays 20A, 20B, 20C for storing the transfer sheet P. The transfer sheet detection position H2 is formed within the range of the registration roller 23 located downstream of the delivery roller in the conveying path, and the transfer sheet P
It is a position where the presence or absence of passage of the transfer paper P provided on the downstream side of the conveyance path is detected. The predetermined distance S is the distance from the paper feed start position H1 to the transfer paper detection position H2.

Next, embodiments of each invention will be described in detail with reference to the schematic configuration of the image forming apparatus described above.

(Embodiment 1) Embodiments according to claims 1, 4, 5 and 6 will be described with reference to the drawings. FIG. 3 is a block diagram showing the electrical configuration of the image forming apparatus of the first embodiment, and FIG. 4 is a flowchart of the operation of the main parts of the image forming apparatus of the first embodiment.

In FIGS. 1, 2 and 3, the portion of the image forming apparatus relating to the conveyance of the transfer paper is composed of paper type detection means, jam detection time setting means, first control means and the like.

In the first embodiment, the paper type is detected by setting the type of the transfer paper P for each of the trays 20A, 20B and 20C from the operation unit 35. In this embodiment, the tray 20A is loaded with plain paper, the tray 20B is loaded with thick paper, and the tray 20C is loaded with special paper. Note that the paper type may be automatically detected, and the manual setting of the paper type is performed on the operation unit 35 in the embodiment, but may be performed on a printer driver (not shown). (Paper type detection means).

In the embodiment, a predetermined paper jam detection time is set by the operation unit 35 (FIG. 1) for each detected paper type. The paper feed jam detection time for each paper type is stored in the paper type paper jam time setting area of the memory unit 34A. The paper feed jam detection time may be set arbitrarily (jam detection time setting means).

A predetermined distance S from the paper feed start position H1 to the transfer paper detection position H2 for detecting the presence or absence of the transfer paper P provided on the downstream side of the transfer paper P transport path is defined as the transfer paper P. When the transfer paper detection position H2 is not reached within the paper feed jam detection time predetermined for each type, it is detected as a paper feed jam of the transfer paper P (first control means).

In FIG. 3, the control section 31A is an electric section of the first control means, and controls the paper feed jam timer. The operation unit 35A can also set the paper type for each tray and the paper jam time for each paper type. In addition, the memory unit 34
A stores in the tray-specific sheet type setting area and the sheet-type sheet feeding jam time setting area, respectively. Further, the paper feeding unit 100A drives the paper feeding motor 27 (FIG. 2) and detects the no-feed sensor 29A (FIG. 2).

As shown in FIG. 3, the signal direction lines between the blocks are as follows. a is a signal direction line for print start, c is a signal direction line for setting a paper jam time for each paper feed, and d is a signal direction line for a paper feed setting for each tray. Further, e is a signal direction line for storing set values, and f is a signal direction line for setting call. Further, g indicates a signal direction line for print start (feeding start), and h indicates a signal direction line for sensor information.

The operation of plain paper will be described with reference to FIGS. 1, 2, 3, and 4.

First, in step S01, the tray 2
Starting to feed plain paper from 0A. In step S02, the detection time of the paper jam of plain paper is set. In step S03, the paper jam jam timer is started. In step S04, it is checked whether or not the paper jam detection time for plain paper has been reached. If YES, the process proceeds to step 07, and if NO, the process proceeds to step S05. In step S07, the occurrence of a paper jam of plain paper is detected. In step S05, it is checked whether or not the plain paper has reached the position of the no-feed sensor. If YES, the paper feeding operation after step S06 is executed, and if NO,
Return to the step before step S04.

As described above, the paper feed jam can be accurately detected by the optimum paper feed jam detection time for each paper type of the transfer paper P, and the transfer paper can be accurately conveyed.

(Embodiment 2) Embodiments according to claims 2, 4, 5 and 7 will be described with reference to the drawings. FIG. 5 is a block diagram showing the electrical configuration of the image forming apparatus according to the second embodiment, and FIG. 6 is an operation flowchart of the main parts of the image forming apparatus according to the second embodiment.

In FIGS. 1, 2 and 5, the portion of the image forming apparatus relating to the conveyance of the transfer paper P is composed of paper type detecting means, jam detection time setting means, second control means and the like.

In the second embodiment, the operation unit 35 is connected to the tray 2
The paper type is detected by manually setting the paper type for each of 0A, 20B, and 20C. Note that the paper type is manually set on the operation unit 35 in the embodiment, but may be set on a printer driver (not shown) (paper type detection unit).

In the embodiment, the number of paper feed retries set in advance is set by the operation unit 35 (FIG. 1) for each detected paper type. The number of repetitions for each paper type is the memory unit 3
It is stored in the sheet type retry count setting area 4B (paper feed retry setting means).

A predetermined distance S from the paper feed start position H1 to the transfer paper detection position H2, which is provided downstream of the transfer paper P conveyance path and detects whether or not the transfer paper P has passed, is defined as the transfer paper P. If the transfer paper detection position H2 is not reached within the paper feed jam detection time that is predetermined for each type, the paper feed jam of the transfer paper P is detected (second control means).

As shown in FIG. 5, the control section 31B is an electric section of the second control means and counts the number of sheet feeding retries. The operation unit 35B also sets the paper type for each tray, sets the number of sheet feeding retries for each paper, and the like. In addition, the memory unit 34B
Stores in the tray-specific paper type setting area and the paper-type paper feed retry count setting area. Paper feeding unit 1
00B drives a paper feed motor, detects a no-feed sensor, and the like.

As shown in FIG. 5, the signal direction lines between the blocks are as follows. a is a signal direction line for starting printing, b is a signal direction line for the number of sheet feeding retries for each sheet, and d is a signal direction line for tray-specific sheet feeding setting. Also,
e is a signal direction line for storing the set value, and f is a signal direction line for setting call. Further, g is a signal direction line for print start, and h is a signal direction line for sensor information.

The operation of the special paper will be described with reference to FIGS. 1, 2, 5, and 6.

First, in step S11, the operation unit 3
The special paper is detected as the paper type of the transfer paper P by the paper type setting from 5B. In step S12, the operation unit 35B
In this example, the number of paper feed retries is determined to be 3 times by the paper type setting from the above. In step S13, feeding of special paper from the tray 20C is started. In step S14,
Start the paper feed jam timer, step S15
Is 1200, which is the time for detecting a paper jam of special paper.
It is checked whether or not ms has been reached, and if YES, the process proceeds to step S18, and if NO, the process proceeds to step S16. In step S16, the special paper is the no-feed sensor 29.
It is checked whether or not C has been reached, and if YES, step S1
7, the process returns to the step before step S15 if NO. In step S17, the subsequent paper feeding operation is executed, and in step S18
Then, the paper feed retry counter is incremented. Next, in step S19, it is checked whether or not the number of paper feed retries has reached three times. If NO, the process proceeds to step S20, and if YES, the process proceeds to step S21. In step S20, the temporary paper feeding is stopped, and the process returns to the step before step S13. Further, in step S21, occurrence of a paper feed jam of special paper is detected.

As described above, the paper feed jam can be detected with high accuracy by the optimum number of retries for each type of transfer paper.

(Embodiment 3) Embodiments according to claims 3, 4, 5, 6 and 7 will be described with reference to the drawings. FIG. 7 is a block diagram showing the electrical configuration of the image forming apparatus of the third embodiment, and FIG. 8 is an operation flowchart of essential parts of the image forming apparatus of the third embodiment.

In FIGS. 1, 2 and 7, the portion related to the feeding of the transfer paper P of the image forming apparatus is composed of a paper type detecting means, a jam detecting time setting means, a paper feeding retry setting means, a third control means and the like. Has been done.

In the third embodiment, the operation unit 35 is connected to the tray 2
The paper type is detected by manually setting the paper type for each of 0A, 20B, and 20C. Note that the paper type is manually set on the operation unit 35 in the embodiment, but may be set on a printer driver (not shown) (paper type detection unit).

A predetermined paper jam detection time can be set for each detected paper type. The paper feed jam detection time for each paper type is stored in the paper type paper jam time setting area of the memory unit 34C. The paper feed jam detection time may be set arbitrarily (jam detection time setting means).

In the embodiment, the number of paper feed retries set in advance is set for each detected paper type through the operation unit 35 (FIG. 1). The number of repetitions for each paper type is stored in the paper type retry count setting area of the memory unit 34C (paper feed retry setting means).

A predetermined distance S from each paper feed start position H1 to the paper transfer detection position H2 for detecting the presence or absence of the paper transfer P provided on the downstream side of the paper transport path of the paper transfer P is set to a predetermined distance S. If the transfer paper detection position H2 is not reached within the predetermined paper feed jam detection time for each type, the paper feed jam of the transfer paper P is detected (third control means).

In FIG. 7, the control section 31C is an electric section of the third control means, and activates a paper feed jam timer, counts paper feed retries, and the like. The operation unit 35C also sets the tray-specific paper type, the paper-type paper feed jam time, and the paper-type paper feed retry count. Further, the memory unit 34C stores in the tray-specific sheet type setting area, the sheet-type sheet feeding jam time setting area, and the sheet-type sheet feeding retry count setting area, respectively. Further, the paper feeding unit 10
0C drives the paper feed motor and detects the no-feed sensor.

In FIG. 7, the signal direction lines between the blocks are as follows. a is a signal direction line for print start, b is a signal direction line for the number of paper feed retries for each paper feed,
Reference numeral c is a signal direction line for setting the paper feed jam time for each paper feed, and d is a signal direction line for the paper feed setting for each tray. Further, e is a signal direction line for storing set values, and f is a signal direction line for setting call. Further, g is a signal direction line for print start (feeding start), and h is a signal direction line for sensor information.

Here, the operation in the case of thick paper will be described with reference to FIGS. 1, 2, 3 and 8. First,
In step S31, thick paper is detected as the paper type of the transfer paper P by the paper type setting from the operation unit 35C. In step S32, the paper type setting from the operation unit 35C determines the number of paper feed retries once in this example. In step S33, feeding of thick paper from the tray 20B is started. In step S34, 1000 ms is set as the paper type paper jam detection time. In step S35,
The paper jam timer starts. Next, in step S36, it is checked whether or not the paper feed jam detection time for thick paper has been reached, and if YES, the process proceeds to step S38,
On the other hand, if NO, the process proceeds to step S37. Step S3
In 7, it is checked whether or not the thick paper reaches the no-feed sensor 29B. If YES, the process proceeds to step S39, and if NO, the process returns to step S36. Step S3
In 9, the subsequent paper feeding operation is executed.

If YES at step S36,
In step S38, the paper feed retry counter is incremented. Next, in step S40, it is checked whether or not the number of paper feed retries, which is one, has been reached. If NO, the process proceeds to step S41, and if YES, the process proceeds to step S42. In step S41, temporary paper feeding is stopped, and the process returns to step S33. Further, in step S42, occurrence of a paper feed jam of thick paper is detected.

As described above, for each paper type of the transfer paper P, the optimum paper jam detection time and the optimum number of retries are used.
The paper jam can be detected with high accuracy, and the transfer paper can be accurately conveyed at the optimum print processing speed.

In the first to third embodiments, the transfer paper P
Although the paper type setting has been described as an example of being manually performed from the operation unit, it may be automatically detected by a paper type detecting device that can detect the type of the transfer paper P near the tray of the transfer paper P.

[0057]

As constructed above, the following effects can be obtained.

According to the first aspect of the present invention, it is possible to detect the paper feed jam with high accuracy by the optimum paper feed jam detection time for each paper type of the transfer paper, and further it is possible to accurately convey the transfer paper. Became.

According to the second aspect of the present invention, it is possible to accurately detect the paper feed jam by the optimum number of retries for each paper type of the transfer paper, and it is also possible to accurately convey the transfer paper. .

According to the third aspect of the present invention, the paper feed jam can be accurately detected by the optimum paper feed jam detection time and the optimum number of retries for each paper type of the transfer paper, and the optimum print can be performed. Transfer paper can now be conveyed accurately at processing speed.

[Brief description of drawings]

FIG. 1 is a sectional view showing a schematic mechanical configuration of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a schematic electrical configuration of an image forming apparatus according to an embodiment of the present invention.

FIG. 3 is a block diagram showing an electrical configuration of the image forming apparatus according to the first embodiment.

FIG. 4 is a main part operation flowchart of the image forming apparatus according to the first embodiment.

FIG. 5 is a block diagram showing an electrical configuration of the image forming apparatus according to the second embodiment.

FIG. 6 is a main part operation flowchart of the image forming apparatus according to the second embodiment.

FIG. 7 is a block diagram showing an electrical configuration of an image forming apparatus according to a third embodiment.

FIG. 8 is a main part operation flowchart of the image forming apparatus according to the third embodiment.

[Explanation of symbols]

21A, 21B, 21C Sending roller 23 Registration rollers 29A, 29B, 29C No-feed sensor (paper type detecting means) 35, 35A, 35B, 35C Operation unit (jam detection time setting means, paper feed retry number setting means) P Transfer paper S Predetermined distance H1 Paper feed start position H2 Transfer paper detection position

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 21/00 510 G03G 21/00 510 5C062 21/14 H04N 1/00 108J H04N 1/00 108 G03G 21 / 00 372 F-term (reference) 2C061 AQ06 HJ02 HK07 HK23 2H027 DA38 DC02 DC15 DC19 DE09 ED17 EE02 EE05 EK15 FA30 FA35 HA04 HB07 HB16 2H072 AA02 AA12 AA16 AA22 AB27 EA05 EA11 3F048 AA01 AB01 BA14 BB05 BD01 CA09 CC01 CC11 3F343 FA02 FB01 FC04 GA03 GB01 GC01 GD01 MA03 MA15 MA45 MA56 MB15 5C062 AA05 AB08 AB22 AB32 AC11 AC66 AC69 AF00

Claims (7)

[Claims] 1. An image forming apparatus that conveys a transfer sheet from a sheet feeding start position to a downstream side of a transfer sheet conveyance path, transfers a toner image to the transfer sheet and thermally fixes the transfer sheet, and selects the type of the transfer sheet manually or automatically. Paper type detection means for detecting, jam detection time setting means for setting a predetermined paper feed jam detection time for each type of the transfer paper detected by the paper type detection means, and each transfer paper, The predetermined distance from the paper feed start position to the transfer paper detection position, which is provided downstream of the transfer paper conveyance path and detects whether or not the transfer paper has passed, is set within the paper feed jam detection time set for each type of transfer paper. An image forming apparatus, comprising: a first control unit that controls a paper jam when a transfer sheet detection position is not reached. 2. An image forming apparatus that conveys a transfer sheet downstream of a transfer sheet conveyance path from a sheet feeding start position, transfers a toner image onto the transfer sheet and thermally fixes the transfer sheet, and selects the type of the transfer sheet manually or automatically. Paper type detection means for detecting, and paper feed retry count setting for setting a predetermined number of times of paper feed retry, which is a repeated feeding operation of transfer paper, for each type of the transfer paper detected by the paper kind detection means Means and a predetermined distance from each of the transfer papers to the transfer paper detection position, which is provided downstream of the transfer paper conveyance path and detects whether or not the transfer paper has passed, and a predetermined paper feed jam detection time. If the transfer paper detection position is not reached within the range, the number of repetitions determined for each type of transfer paper is executed, and the transfer paper does not reach the transfer paper detection position even if the number of repetitions is executed. If An image forming apparatus, comprising: a second control unit that is a paper feed jam. 3. An image forming apparatus that conveys a transfer sheet to a downstream side of a transfer sheet conveyance path from a sheet feeding start position, transfers a toner image to the transfer sheet and thermally fixes the transfer sheet, and selects the type of the transfer sheet manually or automatically. Paper type detection means for detecting, jam detection time setting means for setting a predetermined paper feed jam detection time for each type of the transfer paper detected by the paper type detection means, and detection by the paper type detection means For each type of the transfer paper, the paper feed retry setting means for setting a predetermined number of repetitions of the paper feed retry, which is the repeated feeding operation of the transfer paper, and each transfer paper from the paper feed start position to the transfer paper. The predetermined distance to the transfer sheet detection position, which detects whether or not the transfer sheet has passed, is provided at the downstream of the transfer path, and does not reach the transfer sheet detection position within the predetermined paper feed jam detection time for each type of transfer sheet. Place If the transfer paper does not reach the transfer paper detection position after the number of repetitions is determined, the paper feed jam is performed. An image forming apparatus comprising: 4. The feeding start position of the transfer paper is a position of a feed roller provided in the vicinity of a tray for storing the transfer paper,
The image forming apparatus according to claim 1, 2, or 3, wherein the transfer paper detection position is a position formed within a range from the delivery roller to a registration roller located downstream of the transport path. 5. The manual detection of the paper type detection means is detected by a manual operation on an operation unit formed on the image forming apparatus or on a printer driver. The image forming apparatus described. 6. The paper feed jam detection time can be set to an arbitrary detection time by a manual operation on an operation unit formed in an image forming apparatus or a printer driver. The image forming apparatus according to Item 1 or 3. 7. The number of repetitions of the sheet feeding retry can be set to an arbitrary number of repetitions by a manual operation on an operation unit formed in the image forming apparatus or a printer driver. The image forming apparatus according to claim 2.