JP2007297199A - Paper feed device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the frequency of detection of unsupplied paper jam by judging the presence or absence of the occurrence of unsupplied paper jam based on proper conditions. <P>SOLUTION: In this image forming device, the drive time of a paper feed roller is recorded in a paper feed roller cumulative drive counter. A reference table is stored in the image forming device beforehand. In this reference table, the number of times of the retry of paper supply, the rotational speed of a paper feed roller motor, and an unsupplied paper jam time value are so indicated as to correspond to each other in increments of the life drive time of the paper feed roller of 120 Ksec. A CPU specifies the number of times of the retry of paper supply, the rotational speed of the paper feed roller motor, and the unsupplied paper jam timer value based on the reference table and the drive time of the paper feed roller. Then, based on the specified values, the CPU performs the conveying of recording paper and the judgment of the unsupplied paper jam. Consequently, proper processing can be performed according to the drive time of the paper feed roller. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to, for example, a paper feeding device that supplies recording paper to an image forming unit in an image forming apparatus such as an electronic copying machine, a printer device, or a facsimile machine, and an image forming apparatus equipped with the paper feeding device.

2. Description of the Related Art Image forming apparatuses such as an electronic copying apparatus, a printer apparatus, and a facsimile apparatus include a paper feeding apparatus that supplies recording paper (hereinafter referred to as paper) to an image forming unit that actually forms an image.
The sheet feeding device is configured to perform a conveying process of taking out sheets one by one from a predetermined sheet storage unit and sending them to the image forming unit using a plurality of rollers.
In the paper feeding device, the contact surface of the roller used for transporting the paper is gradually worn as the number of fed paper sheets increases.
When the degree of wear of the roller exceeds a predetermined level, that is, when the roller reaches the end of its life, the paper feeding capability is reduced, and the paper is not properly conveyed and jamming (paper jam) occurs.

Therefore, conventionally, a technique for detecting the life of a roller in a paper feeder has been proposed in the following patent document.
JP-A-6-156815 JP 7-172614 A JP-A-8-085671

Patent Document 1 proposes a technique for determining the life of a paper feeding device (roller) based on the number of operations of the paper feeding device and the number of successful paper feedings.
Patent Document 2 proposes a technique for detecting the life of a roller member when the rubber of the roller has a two-layer structure with different colors and the color of the lower rubber layer appears due to wear of the upper rubber layer. ing.
Further, Patent Document 3 measures the time when the paper is detected by the first paper detection sensor and the time when the paper is detected by the next sensor on the conveyance path when the paper is fed. A technique for determining the life of a roller based on a measurement result has been proposed.

As described above, in the conventional apparatus, the occurrence rate of a non-paper jam is suppressed by detecting a roller that has reached the end of its life and prompting the user to replace the part.
SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet feeding device and an image forming apparatus capable of suppressing the frequency of detecting a non-paper jam by determining whether or not a non-paper jam has occurred based on an appropriate condition. And

  According to the first aspect of the present invention, a sheet feeding unit that separates and transports the recording sheets one by one from the recording sheet storage unit, a measuring unit that measures a driving time of the sheet feeding unit, and at least the sheet feeding unit An acquisition means for acquiring a reference table in which a driving time of the paper and a non-paper jam detection timer value used as a condition for determining whether or not a non-paper jam has occurred are associated with each other, and the measurement means Based on the driving time of the paper feeding means and the reference table acquired by the acquiring means, a specifying means for specifying a non-paper feeding jam detection timer value, and a non-paper feeding jam detection specified by the specifying means The above-mentioned object is achieved by providing a judging means for judging whether or not a non-feed jam has occurred based on a timer value.

  According to a second aspect of the present invention, in the paper feeding device according to the first aspect, the acquisition unit includes a driving time of the paper feeding unit measured by the measuring unit, and a paper feeding speed value in the paper feeding unit. Is acquired, and the specifying unit calculates a sheet feeding speed value in the sheet feeding unit based on the driving time of the sheet feeding unit measured by the measuring unit and the reference table. In particular, the paper feeding means conveys the recording paper based on the paper feed speed value specified by the specifying means.

  According to a third aspect of the present invention, in the paper feeding device according to the first or second aspect, the acquisition unit includes a driving time of the paper feeding unit measured by the measuring unit and a feeding time for transporting the recording paper again. A reference table associated with the number of times of paper retry processing is acquired, and the specifying unit is configured to determine the sheet feeding unit based on the driving time of the sheet feeding unit measured by the measuring unit and the reference table. The number of times of paper feed retry processing is specified, and the paper feeding means performs paper feed retry processing based on the number of paper feed retry processing specified by the specifying means when the recording paper transport fails. Features.

  According to a fourth aspect of the present invention, in the paper feeding device according to the third aspect, the reference table has a non-paper jam detection timer value set low when the number of times of paper feed retry processing is set high. It is characterized by that.

  According to a fifth aspect of the present invention, in the paper feeding device according to any one of the first to fourth aspects, the paper type obtaining means for obtaining the paper type information of the recording paper to be fed is provided. The acquisition unit acquires a reference table in which a driving time of the paper feeding unit measured by the measurement unit and a paper type non-feed jam detection timer value are associated with each other; A non-paper jam detection timer value is specified based on the driving time of the paper feeding means measured by the measuring means, the paper type information obtained by the paper type obtaining means, and the reference table. And

  According to a sixth aspect of the present invention, in the paper feeding device according to any one of the first to fourth aspects, the paper type obtaining means for obtaining the paper type information of the recording paper to be fed is provided. The acquisition unit acquires a reference table in which a driving time of the paper feeding unit measured by the measurement unit and a paper feed speed value of a paper type are associated with each other; The paper feed speed value in the paper feed means is specified based on the driving time of the paper feed means measured by the paper type, the paper type information acquired by the paper type acquisition means, and the reference table. To do.

  According to a seventh aspect of the present invention, in the paper feeding device according to any one of the first to fourth aspects, the paper type obtaining means for obtaining the paper type information of the recording paper to be fed is provided. The acquisition unit acquires a reference table in which the driving time of the paper feeding unit measured by the measurement unit is associated with the number of times of paper type paper feeding retry processing; Based on the driving time of the paper feeding unit measured by the measuring unit, the paper type information obtained by the paper type obtaining unit, and the reference table, the number of times of paper feeding retry processing in the paper feeding unit is specified. It is characterized by that.

  According to an eighth aspect of the present invention, in the paper feeding device according to any one of the first to seventh aspects, a detection unit that detects a state of a usage environment of the paper feeding device includes: The obtaining unit obtains a reference table in which the driving time of the paper feeding unit measured by the measuring unit is associated with a non-paper jam detection timer value for each use environment condition, and the specifying unit includes: Identifying a non-paper jam detection timer value based on the driving time of the paper feeding unit measured by the measuring unit, the detection result of the state of the use environment acquired by the detection unit, and the reference table. Features.

  According to a ninth aspect of the present invention, in the paper feeding device according to any one of the first to seventh aspects, a detection unit that detects a state of a usage environment of the paper feeding device includes: The obtaining means obtains a reference table in which the driving time of the paper feeding means measured by the measuring means is associated with the paper feeding speed value for each use environment condition, and the specifying means is obtained by the measuring means. A sheet feeding speed value in the sheet feeding unit is specified based on the measured driving time of the sheet feeding unit, a detection result of a use environment state acquired by the detecting unit, and the reference table. And

  According to a tenth aspect of the present invention, the paper feeding device according to any one of the first to seventh aspects further comprises a detection unit that detects a state of a usage environment of the paper feeding device, The acquisition unit acquires a reference table in which the driving time of the sheet feeding unit measured by the measuring unit is associated with the number of times of sheet feeding retry processing for each use environment condition, and the specifying unit is configured to measure the measurement Based on the driving time of the paper feeding means measured by the means, the detection result of the state of the use environment acquired by the detection means, and the reference table, the number of times of paper feeding retry processing in the paper feeding means is specified. It is characterized by doing.

  In the invention according to claim 11, the object is achieved by mounting the sheet feeding device according to any one of claims 1 to 7.

  According to the first aspect of the present invention, it is possible to determine whether or not a non-paper jam has occurred by using a reference table in which the driving time of the paper feeding unit and the non-paper jam detection timer value are associated with each other. The non-paper jam detection timer value used as a condition can be set to an appropriate value corresponding to the driving time of the paper feeding means. Accordingly, it is possible to appropriately determine whether or not a non-paper jam has occurred, corresponding to the driving time of the paper feeding unit, that is, corresponding to the deterioration state of the paper feeding unit.

According to the second aspect of the invention, by using the reference table in which the driving time of the paper feeding unit and the paper feeding speed value are associated with each other, an appropriate paper feeding speed value corresponding to the driving time of the paper feeding unit is obtained. Based on this, the recording paper can be conveyed.
According to the third aspect of the present invention, by using the reference table in which the driving time of the paper feeding unit and the number of times of paper feeding retry processing are associated, an appropriate paper feeding retry corresponding to the driving time of the paper feeding unit is performed. The number of processes can be set.
According to the fourth aspect of the present invention, when the number of times of paper feed retry processing is set high in the reference table, the non-paper jam detection timer value is set low, so The change of power can be given appropriately.

According to the fifth aspect of the present invention, it is determined whether or not a non-paper jam has occurred by using a reference table in which the driving time of the paper feed unit and the paper type non-paper jam detection timer value are associated with each other. The non-paper jam detection timer value used as a condition for the printing can be set to an appropriate value corresponding to the paper type.
According to the invention described in claim 6, by using the reference table in which the driving time of the paper feeding means and the paper feeding speed value of the paper type are associated, it is based on an appropriate paper feeding speed value corresponding to the paper type. The recording paper can be conveyed.
According to the seventh aspect of the present invention, by using the reference table in which the driving time of the paper feed unit and the number of paper type paper feed retry processes are associated with each other, an appropriate paper feed retry process corresponding to the paper type is used. The number of times can be set.

According to the eighth aspect of the present invention, by using the reference table in which the driving time of the paper feeding unit and the non-paper jam detection timer value for each use environment condition are associated with each other, whether or not a paper jam has occurred is determined. It is possible to set the non-paper jam detection timer value used as a condition for determining the value to an appropriate value corresponding to the use environment condition.
According to the ninth aspect of the present invention, by using the reference table in which the driving time of the sheet feeding unit and the sheet feeding speed value for each use environment condition are associated, an appropriate sheet feed speed corresponding to the use environment condition is used. The recording paper can be conveyed based on the value.
According to the tenth aspect of the present invention, by using the reference table in which the driving time of the sheet feeding unit and the number of times of sheet feeding retry processing for each use environment condition are associated, an appropriate supply corresponding to the use environment condition is performed. The number of paper retry processes can be set.

  According to the eleventh aspect of the invention, the object is achieved by mounting the paper feeding device according to any one of the first to tenth aspects on the image forming apparatus.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS.
FIG. 1 is a diagram showing a schematic configuration of an image forming apparatus 1 according to the present embodiment.
In the present embodiment, an example of the image forming apparatus 1 will be described using the configuration of an electronic copying apparatus.
As shown in FIG. 1, the image forming apparatus 1 includes a main body cassette 2, a second paper feed cassette 3, and a manual paper feed cassette 4. Each cassette stores recording paper for printing.

The main body cassette 2 is provided with a paper feed roller 13 for feeding recording papers stacked in the main body cassette 2 one by one and a paper detection sensor 14 for detecting the presence or absence of recording paper in the main body cassette 2. It has been.
Similarly, in the second paper feed cassette 3, a paper feed roller 15 for feeding recording papers stacked in the second paper feed cassette 3 one by one, and recording in the second paper feed cassette 3. A paper detection sensor 16 that detects the presence or absence of paper is provided.

The manual paper feed cassette 4 detects the presence of a paper feed roller 17 for feeding the recording papers stacked in the manual paper feed cassette 4 one by one, and the presence of the recording paper in the manual paper feed cassette 4. A paper detection sensor 18 is provided.
In the image forming apparatus 1, a second paper feed vertical conveyance sensor 19 that detects recording paper fed from the second paper feed cassette 3 is provided downstream of the paper feed roller 15.
The paper feed rollers 13, 15, and 17 function as pickup rollers for taking out the recording paper in each cassette.
Further, the paper feed rollers 13, 15, and 17 turn on / off the transmission of the rotational power of the paper feed roller drive motor, that is, the paper feed rollers 13, 15 by driving a paper feed roller clutch (not shown) ON / OFF. , 17 (rotation) / stop control is performed.

The image forming apparatus 1 includes an image forming unit including a writing unit 5, an image forming unit 6, a transfer unit 7, and a fixing unit 8.
The image forming unit 6 performs development processing on the electrostatic image formed by writing on the photosensitive member by the writing unit 5 using a developing device.
The image developed by the image forming unit 6 is transferred to the recording paper in the transfer unit 7 and then fixed by applying heat and pressure to the recording paper in the fixing unit 8.
The recording paper on which the image is fixed is discharged to the paper discharge unit 11 by the paper discharge roller 10.

  The image forming apparatus 1 is provided with a double-sided printing function. When images are formed on both sides of the recording paper, the recording paper on which an image is formed on one side in the image forming unit is sent to the switchback path 12 by the paper discharge roller 10. The recording paper is conveyed again from the switchback path 12 to the image forming unit.

In the image forming apparatus 1, a registration roller 20 for adjusting the speed and timing of the recording paper conveyed (inserted) to the image forming unit is provided on the upstream side of the image forming unit.
In addition, a registration sensor 21 for detecting the recording paper passing through the registration roller 20 is provided in the vicinity of the registration roller 20.
The driving of the registration roller 20 is configured to be interlocked with the detection result of the registration sensor 21.
The registration roller 20 is provided with a registration clutch (not shown). This registration clutch can maintain the rotation stop state of the registration roller 20 by turning OFF until the recording paper is conveyed to the registration roller 20.

In the image forming apparatus 1, a reading unit 9 that reads an image of a document is provided above the image forming unit.
Based on the original image data optically read by the reading unit 9, an electrostatic image formed by the image forming unit 6 is formed.

Here, a procedure for conveying recording paper (paper) in the image forming apparatus 1 configured as described above will be described.
The recording sheets separated one by one from the main body cassette 2, the second paper feed cassette 3 or the manual feed cassette 4 by rotating the paper feed rollers 13, 15, 17 are first conveyed to the registration rollers 20.
At this time, if the time from the rotation of the paper feed rollers 13, 15, 17 to the time when the registration sensor 21 is turned on exceeds a certain reference, a paper jam that occurs without proper paper feed processing, that is, non-feeding. It is determined that a paper jam has occurred, and the image forming apparatus 1 enters a non-paper jam error state.

When the recording paper is normally fed, when the leading edge of the recording paper hits the registration roller 20 and a certain amount of deflection is formed on the recording paper, the rotation of the paper feeding rollers 13, 15, 17 ( Drive) is stopped.
During this time, the rotation of the registration roller 20 can be stopped by turning off the registration clutch.
In this way, before the recording paper is conveyed to the image forming unit, that is, by giving the recording paper an appropriate deflection at the registration roller 20, the distortion (leading skew) at the leading edge of the recording paper is corrected to some extent. be able to.

The recording paper conveyed to the registration roller 20 is conveyed to the image forming unit by restarting the rotation of the registration roller 20 and the paper supply rollers 13, 15, and 17.
At that time, the leading end printing position accuracy can be appropriately ensured by conveying the image forming timing in the image forming unit 6 together with the positional relationship between the leading end of the recording paper.

Normally, in the case of single-sided printing, the recording paper fed from each cassette is discharged as it is after the image developed by the image forming unit 6 is transferred by the transfer unit 7 and the image is fixed by the fixing unit 8. The paper is discharged to the paper discharge unit 11 by the paper roller 10.
In the case of duplex printing, the recording paper on which an image is formed on one side in the image forming unit is discharged to the paper discharge unit 11 by the paper discharge roller 10. At this time, as shown in FIG. It is stopped at the position of the recording paper state.
Thereafter, the paper discharge roller 10 is reversed and sent to the switchback path 12. The recording sheet is conveyed again from the switchback path 12 to the image forming unit.

FIG. 2 is a block diagram showing a configuration of the electric control circuit in the image forming apparatus 1 according to the present embodiment.
As shown in FIG. 2, the image forming apparatus 1 includes a CPU (central processing unit) 31, a FLASH_ROM (flash ROM) 32, an SRAM (static ram) 33, an NVRAM (nonvolatile ram) 34, and an I / O control. LSI 35, Laser (laser) writing unit 36, image data memory 37, PSU (power supply unit) 38, HVP (high voltage pulse power source) 39, PC_I / F control circuit 40, each of which has a bus line 42. Connected through.

The CPU 31 is a central processing unit that controls the entire image forming apparatus 1.
The FLASH_ROM 32 is a rewritable memory that stores an instruction code executed by the CPU 31.
The SRAM 33 is a cache memory that temporarily stores data necessary for software control (program control).

The NVRAM 34 is a non-volatile memory that stores data necessary for software control (program control). Data stored in the NVRAM 34 is not erased even when the power is turned off.
The NVRAM 34 stores reference table data used in processing of the image forming apparatus 1 described later.
The I / O control LSI 35 controls I / O (input / output) related components such as a motor driver for driving various rollers and the like, a driver for a light source of a scanner device in the reading unit 9, various sensors, and a motor. For large-scale integrated circuits.
Various drivers 41 to be controlled are connected to the I / O control LSI 35.
The Laser writing unit 36 controls the driving of the laser light emitted from the writing unit 5 in order to form an image (image data image) on the photoreceptor in the image forming unit 6.
The image data memory 37 is a memory that temporarily stores several pages of image data (image data) that have been subjected to various image processes by an image processing LSI (not shown) in the reading unit 9.

The NVRAM 34 includes a paper feed roller drive timer A, a non-paper feed jam timer B, a paper feed roller drive motor rotational speed C, a paper feed retry counter D, and the number of paper feed retries used in processing of the image forming apparatus 1 described later. An area for storing each value of E is provided.
The paper feed roller drive timer A indicates the count (measurement) value of the drive time of the paper feed rollers 13, 15, and 17.
The non-paper jam timer B indicates a set time (reference time) until the image forming apparatus 1 detects (recognizes) a non-paper jam (paper jam that occurs without appropriate paper feed processing).
That is, in a state where a predetermined non-feed jam recognition condition (satisfaction condition) is satisfied, when the time of the non-feed jam timer B has elapsed, the CPU 31 causes a non-feed jam to occur in the image forming apparatus 1. Is detected.
Note that the value of the non-paper jam timer B functions as a non-paper jam detection timer.

The paper feed roller drive motor rotational speed C indicates a set value of the rotational speed of the paper feed roller drive motor that drives the paper feed rollers 13, 15, and 17.
The paper feed retry counter D indicates the count value of the recording paper retry (re-pickup).
The paper feed retry count E indicates the number of paper feed retries (re-pickup) allowed before the image forming apparatus 1 determines that a paper-feed jam error has occurred.

The PSU 38 is a power supply device for supplying power to each unit of the image forming apparatus 1.
The HVP 39 is a high-voltage power supply circuit for charging the photosensitive member and the developing unit, which is necessary when forming an electrophotographic (electronic copy).
The PC_I / F control circuit 40 is an I / F (interface) circuit for connecting the image forming apparatus 1 and a PC.

Although not shown, the image forming apparatus 1 includes a storage device that stores various control programs for executing processing in the image forming apparatus 1.
The image forming apparatus 1 includes an operation unit for receiving an instruction (input) from an operator, and a display unit for displaying a processing result of the CPU 31 and error information.
The image forming apparatus 1 is provided with a humidity sensor that detects the humidity inside the image forming apparatus 1.
The image forming apparatus 1 is provided with a paper type sensor that detects the type of recording paper (plain paper, slippery paper, slippery paper).
Instead of providing a paper type sensor, the operator inputs the type of recording paper used for image formation via the operation unit, and the type of recording paper to be used based on the input data (plain paper, slippery). (Paper, non-slip paper) may be recognized.

Next, the operation of the image forming apparatus 1 configured as described above will be described.
3 and 4 are flowcharts showing the procedure of the recording paper transport processing operation in the image forming apparatus 1 according to the present embodiment.
In the image forming apparatus 1 according to the present embodiment, a recording sheet conveyance process and a non-feed jam detection process are performed using a pre-defined (set) reference table.
First, the CPU 31 of the image forming apparatus 1 feeds paper feed rollers 13, 15, and 17 provided in a designated cassette (used cassette) among the main body cassette 2, the second paper feed cassette 3, and the manual paper feed cassette 4. The driving time of the paper feed rollers 13, 15 and 17 (hereinafter referred to as the corresponding paper feed rollers 13, 15 and 17) and the humidity in the image forming apparatus 1 are detected.
Further, the CPU 31 recognizes the type (type) of the recording paper.

Note that the drive time of the corresponding paper feed rollers 13, 15, 17 indicates the total drive time of the paper feed rollers 13, 15, 17 from the replacement to a new roller, that is, the accumulated operation time. The driving time of the corresponding paper feed rollers 13, 15, and 17 is obtained, for example, by measuring the total time from when the paper feed rollers 13, 15, and 17 are rotated until the registration sensor 21 is turned on.
This accumulated data (driving time value) is stored (stored) in a paper feed roller cumulative drive counter in the NVRAM 34.
Further, the humidity in the image forming apparatus 1 is obtained from the monitoring result of the humidity sensor.
The type (type) of the recording paper is obtained based on the detection result of the paper type sensor or input information from the operator.

  Then, the CPU 31 reads the reference table stored in the NVRAM 34, and based on the reference table, the driving time of the corresponding paper feed rollers 13, 15, and 17, the detection result of humidity, and the type of recording paper, the number of paper feed retries E, determine (specify) the values of the feed roller drive motor rotation speed C and the non-feed jam timer B (step 11).

FIG. 5 is a diagram showing an example of a reference table used in the image forming apparatus 1 according to the present embodiment.
The reference table is based on the driving time of the paper feed rollers 13, 15, and 17 in a single paper feed operation designed and calculated in advance in a normal transport operation. , 15 and 17 are set by counting the driving time for each sheet feeding operation.
In the reference table shown in FIG. 5, for example, it is assumed that the life of the paper feed rollers 13, 15, and 17 is 960 Ksec. The paper roller motor rotation speed and the non-feed jam timer value are associated (defined).
As described above, the image forming apparatus 1 according to the present embodiment can extend the non-paper jam timer value, that is, the timer time serving as a reference for determining the non-paper jam.
As shown in FIG. 5, the non-feed jam timer value is defined for each type of recording paper (plain paper, slippery paper, slippery paper).
The non-feed jam timer value is defined as an addition value (correction value) applied when the humidity is 30% or less.

Based on the value defined (set) in the row corresponding to the measured driving time of the paper feed rollers 13, 15, 17, the number of paper feed retries E, the paper feed roller drive motor rotational speed C Each value of the non-feed jam timer B is determined.
Specifically, the value (number value) shown in the column of the number of paper feed retries in the reference table is stored (stored) in the number of paper feed retries E in the NVRAM 34.

Further, the value shown in the column of the feed roller drive motor rotation speed in the reference table is stored (stored) in the feed roller drive motor rotation speed C in the NVRAM 34.
Further, the value shown in the non-feed jam timer value column corresponding to the type of recording paper recognized by the CPU 31 is stored (stored) in the non-feed jam timer B in the NVRAM 34.
When the humidity detection value satisfies a predetermined condition (30% or less), a value obtained by adding the corresponding correction value is stored (stored) in the non-paper jam timer B in the NVRAM 34.
For example, when the drive time of the paper feed roller 13 is 300 Ksec and the humidity is 50%, the paper feed retry count E is “1”, the paper feed roller drive motor rotational speed C is “800 rpm”, and the non-paper jam timer B Is identified as “5 seconds”.

Next, the CPU 31 clears (deletes) the data of the paper feed retry counter D in the NVRAM 34 (step 12), and further clears (erases) the data of the paper feed roller drive timer A in the NVRAM 34 (step 13).
Subsequently, the CPU 31 starts the rotation of the paper feed roller drive motor at the paper feed roller drive motor rotational speed C by controlling the driver of the paper feed roller drive motor via the I / O control LSI 35 (step 14). ).
The CPU 31 controls the paper feed roller clutch via the I / O control LSI 35 to turn on the paper feed roller clutch, and the rotational power of the corresponding paper feed roller drive motor is supplied to the paper feed rollers 13, 15, 17. (Step 15).

Next, the CPU 31 starts (starts) counting by the paper feed roller drive timer A (step 16).
The CPU 31 determines whether or not the registration sensor 21 is in an ON state (step 17).
When the registration sensor 21 is in the ON state (step 17; Y), that is, when the registration sensor 21 detects that the recording paper has reached the registration sensor 21, the image forming apparatus 1 is located upstream of the image forming unit. Deflection is formed on the recording paper (step 18).

Subsequently, the CPU 31 turns off the paper feed roller clutch, and temporarily stops the registration roller 20 and the paper feed rollers 13, 15, and 17 (step 19).
The time until that point (the operation time of the paper feed roller drive timer A) is measured. Note that the measurement time of the paper feed roller drive timer A is stored in the NVRAM 34 in units of seconds (rounded down to the second).
Then, the CPU 31 adds and sets the value of the paper feed roller drive timer A to the paper feed roller cumulative drive counter (step 20).
In this way, the value of the paper feed roller cumulative drive counter is configured to be updated as needed.

Next, the CPU 31 clears (deletes) the data of the paper feed roller drive timer A in the NVRAM 34 (step 21).
The CPU 31 stops the rotation of the paper feed roller drive motor (step 22).
Thereafter, the CPU 31 determines whether or not it is the timing of refeeding (rotating) the registration roller 20 based on the condition of the image leading edge timing (recording paper transport timing) with the image forming unit 6 (image forming unit). Judgment is made (step 23).
If it is not the timing for re-feeding (rotating) the registration roller 20 (step 23; N), the processing of step 23 is repeated again.
On the other hand, when it is the timing of re-feeding (rotating) the registration roller 20 (step 23; Y), the CPU 31 controls the driver of the paper feed roller drive motor via the I / O control LSI 35, thereby supplying the paper. The rotation of the paper feed roller drive motor is started at the paper roller drive motor rotational speed C (step 24).

The CPU 31 controls the paper feed roller clutch via the I / O control LSI 35 to turn on the paper feed roller clutch and to apply the rotational power of the paper feed roller drive motor to the corresponding paper feed rollers 13, 15, 17. (Step 25).
Further, the CPU 31 controls the registration roller clutch via the I / O control LSI 35 to turn on the registration roller clutch and transmit the rotational power of the registration roller drive motor to the registration roller 20 (step 26).
Subsequently, the CPU 31 starts (starts) counting by the paper feed roller driving timer A (step 27).

Next, the CPU 31 determines that the trailing edge of the recording paper is separated from the recording paper that forms the image of the next page based on the monitoring results of the paper detection sensors 14, 16, and 18, and then set to + α (set in the cassette. It is determined whether or not the recording sheet has been conveyed (moved) by the length of the recording sheet (step 28).
If not conveyed by α (step 28; N), the process of step 28 is repeated again.
On the other hand, if the sheet has been conveyed by α (step 28; Y), the CPU 31 turns off the paper feed roller clutch and stops the registration roller 20 and the paper feed rollers 13, 15, and 17 (step 29).
The time until that point (the operation time of the paper feed roller drive timer A) is measured. Note that the measurement time of the paper feed roller drive timer A is stored in the NVRAM 34 in units of seconds (rounded down to the second).

Then, the CPU 31 adds and sets the value of the paper feed roller drive timer A to the paper feed roller cumulative drive counter (step 30).
The CPU 31 clears (erases) the data of the paper feed roller drive timer A in the NVRAM 34 (step 31).
Subsequently, the CPU 31 continues the paper discharge (conveyance) operation of the recording paper (step 32). Finally, the recording paper is transported to the paper discharge unit 11 by the paper discharge roller 10, and the process ends.

If it is determined in step 17 that the registration sensor 21 is not in the ON state (step 17; N), that is, if the recording paper has not reached the registration sensor 21, the CPU 31 sets the paper feed roller drive timer A. The value of the non-paper jam timer B is compared to determine whether or not the paper feed roller drive timer A is greater than the non-paper jam timer B (step 33).
When the value of the paper feed roller drive timer A is smaller than the value of the non-paper jam timer B (step 33; N), the process returns to step 17 and is repeated.
On the other hand, when the value of the paper feed roller drive timer A is larger than the value of the non-paper jam timer B (step 33; Y), the CPU 31 adds 1 to the paper feed retry counter D in the NVRAM 34 (step 34).
Even when the value of the paper feed roller drive timer A is equal to the value of the non-paper feed jam timer B, it is determined that the value of the paper feed roller drive timer A is larger than the value of the non-paper feed jam timer B.

Next, the CPU 31 determines whether or not the value of the paper feed retry counter D is larger than the value of the paper feed retry count E (step 35).
When the value of the paper feed retry counter D is smaller than the value of the paper feed retry count E (step 35; N), the CPU 31 turns off the paper feed roller clutch and stops the registration roller 20 and the paper feed rollers 13, 15, and 17. (Step 36).
Then, the CPU 31 stops the rotation of the paper feed roller drive motor (step 37), and then returns to step 14 to repeat the processing.

On the other hand, when the value of the paper feed retry counter D is larger than the value of the paper feed retry count E (step 35; Y), the CPU 38 has caused a non-paper jam, that is, the recording paper is not properly conveyed. It is detected that a jam (paper jam) has occurred (step 38), and the process is terminated.
Even when the value of the paper feed retry counter D is equal to the value of the paper feed retry count E, it is determined that the value of the paper feed retry counter D is larger than the value of the paper feed retry count E.
When the CPU 31 detects a non-paper jam, for example, the CPU 31 displays a warning indicating that a non-paper jam has occurred on the display unit.

Note that units of timer counters such as a paper feed roller driving timer A, a non-paper jam timer B, and a paper feed roller cumulative drive counter provided in the NVRAM 34 are configured in seconds. The timer counter is composed of, for example, a 4-byte second counter.
By using the 4-byte second counter in this way, it is possible to count up to a value that is more than 12 times longer than the lifetime of the image forming apparatus 1 (or each roller).

Normally, when the sheet feeding operation is performed, the sheet feeding rollers 13, 15, and 17 have a reduced conveying force due to surface wear, paper dust adhesion, and the like. Accordingly, there is a tendency that non-feeding tends to occur.
However, according to the present embodiment, an appropriate value is set by setting the value of the non-feed jam timer B in consideration of the degree of deterioration of the conveyance force based on the cumulative driving time of the feed rollers 13, 15, and 17. Based on various determination conditions, it is possible to perform processing for detecting a non-paper jam. Thereby, it is possible to suppress the detection rate (occurrence probability) of a non-paper jam.
Further, according to the present embodiment, based on the cumulative drive time of the paper feed rollers 13, 15, and 17, the number of paper feed retries E and the paper feed roller drive motor rotational speed C in consideration of the degree of deterioration of the transport force. Since the value can be set, the conveyance performance can be improved. As a result, it is possible to effectively suppress the detection rate (occurrence probability) of the non-paper jam.
Thereby, the quality and convenience of the image forming apparatus 1 can be improved.

According to the present embodiment, the value of the non-feed jam timer B is set (defined) in consideration of the humidity condition, which is one of the usage environment conditions, so that more appropriate (optimum) recording paper can be obtained. Since the paper feeding operation process can be realized, it is possible to improve the convenience of the image forming apparatus 1 while suppressing the occurrence frequency of non-paper feeding jams.
Further, according to the present embodiment, more appropriate (optimal) paper feeding is performed by setting (defining) the value of the non-feed jam timer B in consideration of the type of recording paper to be conveyed. Since the operation process can be realized, it is possible to improve the convenience of the image forming apparatus 1 while suppressing the occurrence frequency of the non-paper jam.

The reference table can be arbitrarily changed according to the design conditions of the image forming apparatus 1.
FIG. 6 is a diagram illustrating an example of a modification of the reference table.
As shown in FIG. 6, settings may be made to increase the number of paper feed retries compared to the reference table shown in FIG. In this way, when the number of paper feed retries is increased, the non-paper jam timer value is set to be short.
By stopping the paper feed rollers 13, 15, and 17, the conveyance force can be changed from static friction to dynamic friction.
By increasing the number of paper feed retries, the number of stop operations of the paper feed rollers 13, 15, and 17 is increased, so that a greater change in the conveying force can be given. Thereby, the success probability of the paper feed process can be improved.

In the image forming apparatus 1 according to the above-described embodiment, the non-feed jam timer B is set according to the value of the feed roller cumulative drive counter, that is, the drive cumulative time of the feed rollers 13, 15, and 17. Not only the value but also the value of the paper feed retry count E and the paper feed roller drive motor rotation speed C are set to corresponding values.
However, the value of the number of paper feed retries E and the value of the paper feed roller drive motor rotation speed C are not necessarily changed according to the value of the paper feed roller cumulative drive counter.
For example, values set in advance as default values (reference values) may be used for the number of paper feed retries E and the paper feed roller drive motor rotational speed C.

Further, in the image forming apparatus 1 according to the present embodiment, as shown in the reference table of FIG. 5, the paper feed retry count E is set to a number corresponding to the value of the paper feed roller cumulative drive counter. Has been. The paper feed retry count E set (defined) here can be arbitrarily set.
For example, by setting all the paper feed retry counts E to “0”, it is possible to prevent paper feed retries from being executed when recording paper is transported. Further, for example, by setting the number of paper feed retries E to either “0” or “1”, it is possible to simply set whether or not there is a paper feed retry (once) during conveyance of the recording paper. Is possible.

In the image forming apparatus 1 according to the present embodiment, the value of the non-paper jam timer B is set (defined) in consideration of the humidity condition which is one of the conditions of the use environment and the type of recording paper.
However, in the case of an apparatus that does not have optional functions such as a humidity sensor and a recording paper type identification function, the non-feed jam timer B and the feed retry count E are simply determined from the value of the feed roller cumulative drive counter. Alternatively, a reference table in which the value of the sheet feeding roller drive motor rotational speed C can be uniquely specified may be set and used.
In addition, considering the humidity condition and the type of recording paper, which are one of the conditions of the use environment, not only the value of the non-paper jam timer B but also the number of paper feed retries E and the paper feed roller drive motor rotational speed C A value may be set (defined).

In addition, in consideration of the humidity condition, which is one of the conditions of the use environment, in detail, using a reference table in which the value of the feed roller motor rotation speed is set (defined) for each humidity condition, the humidity condition is appropriately set. The corresponding paper feed roller motor rotational speed C may be specified.
Similarly, in consideration of the humidity condition, which is one of the conditions of the use environment, in detail, a reference table in which the number of paper feed retries is set (defined) for each humidity condition is used to appropriately cope with the humidity condition. The number E of paper feeding retries may be specified.

In addition, considering the difference in the type of recording paper, more specifically, a reference table in which the value of the feed roller motor rotation speed is set (defined) for each type of recording paper is used to appropriately cope with the type of recording paper. The feed roller motor rotation speed C may be specified.
Similarly, in consideration of the difference in the type of recording paper, more specifically, using a reference table in which the number of paper feeding retries is set (defined) for each type of recording paper, paper feeding appropriately corresponding to the type of recording paper is used. The number E of retries may be specified.

1 is a diagram illustrating a schematic configuration of an image forming apparatus according to an exemplary embodiment. 3 is a block diagram showing a configuration of an electric control circuit in the image forming apparatus according to the present embodiment. FIG. 6 is a flowchart illustrating a procedure of recording paper conveyance processing operation in the image forming apparatus according to the exemplary embodiment. 6 is a flowchart illustrating a procedure of recording paper conveyance processing operation in the image forming apparatus according to the exemplary embodiment. 6 is a diagram showing an example of a reference table used in the image forming apparatus according to the present embodiment. FIG. It is the figure which showed an example of the modification of a reference table.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Main body cassette 3 2nd paper feed cassette 4 Manual paper feed cassette 5 Writing unit 6 Image forming unit 7 Transfer part 8 Fixing part 9 Reading unit 10 Paper discharge roller 11 Paper discharge part 12 Switchback path 13 Paper feed Roller 14 Paper detection sensor 15 Paper feed roller 16 Paper detection sensor 17 Paper feed roller 18 Paper detection sensor 19 Second paper feed vertical conveyance sensor 20 Registration roller 21 Registration sensor 31 CPU
32 FLASH_ROM
33 SRAM
34 NVRAM
35 I / O control LSI
36 Laser writing unit 37 Image data memory 38 PSU
39 HVP
40 PC_I / F control circuit 41 Various drivers 42 Bus line

Claims (11)

Paper feeding means for separating and transporting the recording paper one by one from the recording paper storage unit;
Measuring means for measuring the driving time of the paper feeding means;
An acquisition means for acquiring a reference table in which at least a driving time of the paper supply means and a non-paper jam detection timer value used as a condition for determining whether or not a non-paper jam has occurred;
Specifying means for specifying a non-paper jam detection timer value based on the driving time of the paper feeding means measured by the measuring means and the reference table acquired by the acquisition means;
Determining means for determining whether or not a non-feed jam has occurred based on a non-feed jam detection timer value specified by the specifying means;
A paper feeding device comprising: The acquisition unit acquires a reference table in which a driving time of the sheet feeding unit measured by the measuring unit is associated with a sheet feeding speed value in the sheet feeding unit;
The specifying unit specifies a sheet feeding speed value in the sheet feeding unit based on the driving time of the sheet feeding unit measured by the measuring unit and the reference table;
2. The sheet feeding device according to claim 1, wherein the sheet feeding unit conveys the recording sheet based on a sheet feeding speed value specified by the specifying unit. The acquisition unit acquires a reference table in which the driving time of the paper feeding unit measured by the measuring unit is associated with the number of times of paper feeding retry processing for conveying the recording paper again.
The specifying unit specifies the number of times of paper feed retry processing in the paper feeding unit based on the driving time of the paper feeding unit measured by the measuring unit and the reference table,
3. The paper feeding retry process according to claim 1, wherein the paper feeding unit performs the paper feeding retry process based on the number of paper feeding retry processes specified by the specifying unit when the conveyance of the recording paper fails. The paper feeder described.   4. The sheet feeding device according to claim 3, wherein the reference table has a non-paper jam detection timer value set low when the number of times of paper feed retry processing is set high. A paper type acquisition means for acquiring paper type information of the recording paper to be fed;
The acquisition unit acquires a reference table in which a driving time of the paper feeding unit measured by the measuring unit and a paper type non-feed jam detection timer value are associated with each other,
The specifying means determines a non-feed jam detection timer value based on the driving time of the paper feeding means measured by the measuring means, the paper type information obtained by the paper type obtaining means, and the reference table. The sheet feeding device according to any one of claims 1 to 4, wherein the sheet feeding device is specified. A paper type acquisition means for acquiring paper type information of the recording paper to be fed;
The acquisition unit acquires a reference table in which a driving time of the paper feeding unit measured by the measuring unit is associated with a paper feed speed value of a paper type,
The specifying unit is configured to determine a sheet feeding speed in the sheet feeding unit based on the driving time of the sheet feeding unit measured by the measuring unit, the sheet type information acquired by the sheet type acquiring unit, and the reference table. The sheet feeding device according to any one of claims 1 to 4, wherein a value is specified. A paper type acquisition means for acquiring paper type information of the recording paper to be fed;
The acquisition unit acquires a reference table in which the driving time of the paper feeding unit measured by the measuring unit and the number of paper type paper feed retry processes are associated with each other;
The specifying unit is configured to perform a sheet feeding retry in the sheet feeding unit based on the driving time of the sheet feeding unit measured by the measuring unit, the sheet type information acquired by the sheet type acquiring unit, and the reference table. The sheet feeding device according to any one of claims 1 to 4, wherein the number of times of processing is specified. A detection means for detecting the state of the use environment of the paper feeder;
The acquisition unit acquires a reference table in which the driving time of the paper feeding unit measured by the measuring unit is associated with a non-paper feeding jam detection timer value for each use environment condition,
The specifying means is a non-paper jam detecting timer based on the driving time of the paper feeding means measured by the measuring means, the detection result of the state of the use environment acquired by the detecting means, and the reference table. The sheet feeding device according to claim 1, wherein a value is specified. A detection means for detecting the state of the use environment of the paper feeding device;
The acquisition unit acquires a reference table in which the driving time of the sheet feeding unit measured by the measuring unit is associated with the sheet feeding speed value for each use environment condition,
The specifying unit is configured to supply the paper in the paper feeding unit based on the driving time of the paper feeding unit measured by the measuring unit, the detection result of the state of the use environment acquired by the detection unit, and the reference table. The paper feeding device according to any one of claims 1 to 7, wherein a paper speed value is specified. A detection means for detecting the state of the use environment of the paper feeder;
The acquisition unit acquires a reference table in which the driving time of the sheet feeding unit measured by the measuring unit is associated with the number of sheet feeding retry processes according to use environment conditions,
The specifying unit is configured to supply the paper in the paper feeding unit based on the driving time of the paper feeding unit measured by the measuring unit, the detection result of the state of the use environment acquired by the detection unit, and the reference table. The paper feeding device according to claim 1, wherein the number of times of paper retry processing is specified.   An image forming apparatus comprising the paper feeding device according to any one of claims 1 to 10.

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