JPH0466452A - Image forming device having jam elimination function - Google Patents

Abstract

PURPOSE:To enable accurate decision on jam frequencies in the respective paper containing sections by providing a decision means to decide whether the jam frequencies have reached a predetermined level or not, on the basis of the memory of a jam memory means, for a paper sheet containing section containing the size of a paper sheet specified by a specifying means. CONSTITUTION:When one of paper sizes is specified by a specifying means of a key panel 46, a decision means 61 decides whether jam frequency has reached a predetermined level or not, on the basis of the memory of a jam memory means 62 for a paper containing section containing the size of a paper sheet specified by a specifying means. In this case, the decision means 61 makes a decision on the jam frequency not only for each paper containing section but also for a size of the paper sheet as a parameter, to enable more accurate decision. Consequently, the problems can be eliminated of dropping the use efficiency of paper containing sections more than necessary.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus, and particularly to an image forming apparatus with a jam removal function.

[Conventional technology]

For example, a copying machine generally includes an image forming section that converts image information of a document into a toner image, and a paper transport section that supplies paper to the image forming section.

Some paper transport units can be equipped with a paper storage unit (for example, a paper feed cassette) that separately stores paper of a plurality of sizes.

As a structure for handling a jam in such a copying machine, Japanese Patent Laid-Open No. 64-38359 discloses a structure in which the use of paper feed trays where jams are likely to occur is prohibited. With this configuration, the jam occurrence rate is calculated for each paper feed stage, and if the jam occurrence rate is high, the use of that paper feed stage is prohibited.

[Problem to be solved by the invention]

When looking at the jam occurrence rate in a copying machine, not only does the occurrence rate differ for each paper feed stage, but also the ease with which jams occur varies depending on the paper size in each paper feed stage. That is, even if the paper feed stage has a high jam occurrence rate, jams may hardly occur depending on the size of the paper used. In addition, even if the paper feed stage has a low jam occurrence rate,
Depending on the size of the paper used, jams may occur easily.

However, in the conventional configuration, the jam occurrence rate is calculated for each paper feed stage without considering the paper size. For this reason, a paper feed tray whose use is prohibited due to a high jam occurrence rate cannot be used even if the paper is of a size that has a low jam occurrence rate. Therefore, in the conventional configuration, a problem arises in that the usage efficiency of the paper feeding section is lowered more than necessary.

Further, in the conventional configuration, if the paper feed tray has a relatively low overall jam occurrence rate, it is not possible to avoid using paper of a specific size that has a high jam occurrence rate. In other words, in the conventional configuration, it is difficult to know which paper size is most likely to occur in which paper feed stage, and the operator selects the combination of paper feed stage and paper size that has a high jam occurrence rate. This may cause problems such as jams occurring repeatedly.

An object of the present invention is to provide a jam handling function that can more accurately determine the frequency of jams in a paper storage section in which paper of a specified size is stored, regarding jams that occur during paper conveyance from a paper storage section to an image forming section. An object of the present invention is to provide an image forming apparatus with an attached image forming apparatus.

[Means to solve the problem]

An image forming apparatus with a jam handling function according to the present invention includes an image forming section, a plurality of paper storage sections capable of storing paper of a plurality of different sizes, and a transport system for supplying paper from the paper storage sections to the image forming section. jam recording means 1 and 9 for storing the number of jams that have occurred during conveyance of paper; specifying means for specifying one of paper sizes from 11; It is equipped with a judgment means for making judgments.

The front 8C jam storage means is a means for storing the number of jams that occur during conveyance of paper as a number for each paper size for each paper storage section. The determining means is configured to determine whether a paper of a paper size designated by the designation means is stored in the paper storage section based on the memory of the jam storage means.
, is means for determining whether or not the frequency has reached a predetermined level.

[Effect]

In the image forming apparatus according to the present invention, an image is formed on a sheet of paper in the image forming section. This paper is supplied from the paper storage section to the image forming section via the conveyance path. Then, the jam storage means counts and stores the number of jams that occur during conveyance of the paper in the conveyance path for each paper size in each paper storage section.

When one of the paper sizes is designated by the designation means, the determination means determines whether or not the paper size is jammed based on the memory of the jam storage means for the paper storage section in which the paper of the size designated by the designation means is stored. It is determined whether the frequency has reached a predetermined level. In this case, the determination means not only makes a determination for each paper storage unit, but also uses the paper size as a parameter to determine the frequency, so a more accurate determination is uJ fii. As a result, this solves, for example, the problem that the usage efficiency of the paper storage section is lowered more than necessary, and the problem that even if paper of a certain size is jammed frequently in a paper storage section, that paper is not used. can.

[Embodiment] FIG. 1 shows a copying machine as an embodiment of the present invention.

In the figure, the copying machine includes a case 1, a copy processing section 2 placed at the bottom of the case 1, and a document reading section 3 placed at the top of the case 1.

The copy processing section 2 includes a photoreceptor drum 4 on the surface of which an electrostatic latent image is formed. Around the photoreceptor drum 4, there is a main charging corona discharger 5 that charges the photoreceptor drum 4 to a predetermined charge, a developing device 6 that develops the electrostatic latent image on the photoreceptor drum 4, and a sheet of paper. A transfer corona discharger 7 for transferring a toner image to the photoreceptor drum 4, a separation corona discharger 8 for separating the paper from the photoreceptor drum 4, and a cleaning device 9 for removing residual toner etc. on the photoreceptor drum 4. On the downstream side (on the left side in the figure) of the zero-separation corona discharger 8 where the 0-separation corona discharger 8 is located, in order from the corona discharger 8 side, there is a conveying device 11 and a fixing device 12 for fixing the transferred image on the paper. and a paper discharge tray I3 for receiving the paper after fixing are arranged. A discharge switch 14 for detecting paper discharge is arranged between the fixing device 12 and the paper discharge tray 13. This ejection switch 14 also serves as a base tp for determining whether or not a jam has occurred at the paper ejection portion.

The document reading section 3 includes a document mounting table 15 made of transparent glass and arranged on the top surface of the case 1, and a document presser 16 arranged on the table so as to be openable and closable. Manuscript! ! A document scanning device 17 is arranged below the mounting table 5 .

The document scanning device 17 includes a light source, a lens unit 19, and the like. A document size detection sensor 45 for detecting the size of the document placed on the document R placement table 15 is further arranged below the original f9%vi placement table 15.

moreover,? On the right side of the fi'T processing section 2, there is a paper supply section 2.
0 is placed. The paper supply section 20 is connected to the copy processing section 2
a main path 21 arranged toward the corona discharger 7 side;
Paper feed cassettes 25, 2 that store paper 22, 23, 24
6.27, the main path 21 and each paper feed cassette 25.26.
It mainly has branch routes 28, 29, and 30, which respectively connect between 27 and 27.

The upstream end of each branch route 2B, 29.30, that is, the branch route 2B, 29.30 of each paper feed cassette 25, 26.27.
30 side end, one sheet of paper 22, 23, 24 in each paper feed cassette 25, 26, 27 is connected to each branch path 2B, 29.
．． Feed rollers 31, 32, and 33 for feeding the paper to 30 are arranged.

In addition, the main path 21 includes a copy processing unit 201! A pair of registration rollers 34 are arranged to determine the timing of supplying paper to I. Each branch route 28°29.30
, branch path 2B is formed by paper feed rollers 31, 32, and 33.
Three pairs of transport rollers 35, 36, and 37 are arranged to further transport the sheets 22, 23, and 24 that have been transported into the registration rollers 34 side.

A registration switch 38 is provided on the main path 21 upstream of the registration roller 34 .

The registration switch 38 is a switch for detecting that the paper has been conveyed to the registration roller 34 side. In addition, each branch route 2B, the conveyance roller 35 of 29.30
．． Conveyance switches 39 and 40.41 are arranged upstream of 36.37, respectively. These transport switches 39, 40 and 41 are switches for determining whether or not there is paper in the branch paths 2B, 29, 30.

Registration switch 38 and transport switch 39, 40.4
1 and the above-mentioned ejection switch 14 are the paper feed cassette 25.
, 26, 27 to the paper discharge tray 13, it is also a criterion for determining whether or not a paper jam has occurred.

Paper feed rollers 31° 32. of paper feed cassettes 25, 26, 27.
33, there is a vapor empty detection switch 42,
43 and 44 are provided respectively. This detection switch 42, 43.44 is connected to the paper feed cassette 25, 26.27.
This switch is used to detect the end of the paper sheets 22, 23, 24 within. Paper feed force Cera) 25.26 branch route 28.
29 side end face and branch route 28.29 opposite to that end face
Paper size detection sensors 55 and 56 for detecting the size of the paper sheets 22 and 23 stored in the paper feed cassette 1-25 and 26 are provided between the paper feed cassettes 1-25 and 26. The detection sensors 55 and 56 are sensors that detect the paper size by arranging the poles of a plurality of magnets. Further, in the large paper feed cassette 27, a paper size detection sensor 57 for determining the size of the paper 24 is arranged at the bottom thereof.

On the top surface of the case 1, next to the document mounting table 15, there are
A key panel 46 is arranged for the operator to input commands and read information. As shown in FIG. 2, the key panel 46 includes a numeric keypad 47 for inputting numerical information, a print key 48 for instructing the start of a copying operation, and a size key 4 for specifying the paper size.
9, a jam rate setting key 50 for setting the upper limit of the jam rate to be described later, a screen change key 51 to change the type of both sides of the jam processing display to be described later, and other general input keys. have. Further, the key panel 46 is provided with a general liquid crystal panel 51 for displaying the number of copies, etc., and a liquid crystal panel 52 for displaying information for clearing jams.

This copying machine has a control section 60 as shown in FIG. The control unit 60 includes a CPU 61. ROM62. R
It includes a microcomputer equipped with AM63 and the like.

The control unit 60 includes the above-mentioned key panel 46, ejection switch I4, registration switch 38, and transport switches 39, 40.
, 41, paper empty detection switch 42, 43,
44, a document size detection sensor 45, paper size detection sensors 55, 56, 57, and other outgoing horn parts are connected. The control section 60 has a function of operating the copying machine according to a control program stored in the ROM 62 as described below. Also, RAM
63, as shown in FIG. 4, the number of times of use for each paper size in each paper feed stage (the installation stage of paper feed force rollers 25, 26, and 27), the number of jams in each, and the jam rate in each. Various storage areas are provided including a storage area for storing the upper limit of .

Next, the operation of the above embodiment will be explained.

When the program starts, initial setting operations such as heating the fixing device 12 to a predetermined temperature are performed. In this initial setting operation, in addition to general settings such as setting the number of copies to 1 and setting the paper feed cassette usage priority order starting from the bottom, the display screen on the liquid crystal panel 52 is Initial settings unique to this embodiment, such as setting the first screen, are also performed.

When the initial settings are completed, interrupt processing is started based on a timer that times up every 1 to 2 msec. In FIG. 5A showing timer interrupt processing,
In step S1, which branch to execute is determined by referring to the scan table. Among the branches executed based on the determination in step Sl based on the scan table, branch B1 performs processing based on key human power. In branch B2, automatic detection of the document size is performed, and in branch B3, processing associated with replacing the paper feed cassettes 25, 26 and 27 is performed. In branch B4, based on paper empty detection switches 42, 43, 44,
At branch 0 B5, where processing related to paper out detection is performed, processing associated with the occurrence of a paper jam is performed. At branch B6, processing regarding the display content on the liquid crystal panel 52 is performed. Further, other processing is performed at branch B7 and subsequent branches.

The processes of these branches B1, B2, etc. are executed one after another each time the interrupt timer times up.

Note that, at the first stage, key manual processing of branch B1 is executed.

In the 2-manpower processing, step S is performed as shown in FIG. 5B.
In step 2, it is determined whether the print key 48 has been pressed by the operator. Further, in step S3, it is determined whether or not the size key 49 has been pressed. In step S4, it is determined whether or not the jam rate setting key 50 has been pressed. In step S5, it is determined whether the screen change key 51 has been pressed. Processes other than those based on key human power are performed in step S6. When the process in step S6 is finished, the process in branch B1 ends.

If the print key 48 is pressed here, the program moves from step S2 to step S7, and a command to start a copying operation is issued. As a result, the copying machine starts a series of copying operations. First, in the paper supply unit 20, a paper cassette with a high priority is selected from among the paper cassettes storing paper of a predetermined size, and from there, the registration roller 34
Paper is fed to the side. On the other hand, in the document reading section 3,
The image information of the original placed on the original placing table I5 is read by the original scanning device 17. The read image information is developed in a portion constituted by the photoreceptor drum 4, etc., and converted into a toner image.The toner image is transferred to the supplied paper, and the paper with the image transferred is transferred to the fixing device 12. After being subjected to fixing processing, the paper is discharged to the paper discharge tray 13.

If the size key 49 is pressed, the progera l moves from step S3 to step S8.

In step S8, the paper size to be used is reset based on the input command. In step S9, it is determined whether or not the jam rate of the paper feed cassette containing the paper of the designated size exceeds the permissible limit for the paper feed cassette that is the destination of the IF. This determination is made by calculation based on the number of uses, the number of jams, and the jam Uto r@ (FIG. 4) stored in the RAM 63 of the control unit 60. If the ratio does not exceed the limit, there is no problem in using the determined paper feed cassette, and the process of branch B1 ends. Judgment in step S9 is Yes
If so, the process moves to step SIO.

In step SIO, the use priority of the paper feed stage for the specified paper size is lowered. This is because the jam rate exceeds the upper limit, so the paper feed stage is not used for the paper size as much as possible. In step Sll, a 0 determination is made to determine whether or not paper of the specified size is also set in other paper feed trays.
In the case of s, the process returns to step S9, and it is determined whether or not the jam rate exceeds the upper limit for that paper feed stage.

If the upper limit is not exceeded, it is sufficient to use the paper in the newly designated paper feed stage, and the processing at branch B1 ends.

If the determination in step Sll is NO, step S1
Move to 2. In step S12, an available paper feed stage is searched for the specified paper size.
Based on the content regarding paper jams stored in the AM 63 (FIG. 4), the jam rate for each paper size is calculated for each paper feed stage. Then, it is determined whether or not each of the obtained jam rates has reached its upper limit. In step S13, it is determined whether there is a usable paper feed stage. If there is a usable paper feed stage, step S14
to move to. In step S14, the available paper feed stages are displayed on the LCD panel 52. For example, if the specified paper size is A4 and it is determined that the lower paper feed tray can be used, "A4
Please set the cassette on the lower shelf.'' LCD panel 5
When the 9 display processing displayed at 2 is completed, the processing at branch B1 ends. If it is determined in step S13 that there is no usable stage, the process moves to step S15. In step S15, instead of displaying in step S14,
[Please be careful of jam occurrence] is displayed. When the process in step 315 is finished, the process in branch B1 ends.

To change the jam rate upper limit, which is the criterion in step S9 and step S13, press the jam rate setting key 50.
is pressed. In this case, the process moves from step S4 in FIG. 5B to step S16. In step S16, the upper limit of the jam rate for each paper size in each paper feed stage can be set.

When the process in step S16 is finished, the process in branch B1 is finished.

When changing the display screen (described later) displayed at the bottom of the liquid crystal panel 52, the screen change key 51 is pressed. In this case, the program moves from step S5 in FIG. 5B to step S17.

In step S17, the number of the screen that is requested to be displayed among the three types of display double sides described later is set. When the process in step S17 is finished, the process in branch B1 is finished.

The processing at branch B2, which performs automatic size detection, is performed as shown in FIG. 5C.

In FIG. 5C, in step 31B, it is determined whether or not the detection of the manuscript quiz has been completed. Detection of the original size is performed by the original size detection sensor 45 detecting the size of the original placed on the original placing table 15 . When the detection of the document size is completed, the process moves from step 31B to step S19.

In step S19, it is determined whether or not a sheet of the same size as the original is being used.

If there is no paper, the process moves to step S20. In step S20, for the paper size that matches the original size,
Calculate available paper feed stages. In this case as well, based on the information regarding the jam rate stored in the RAM 63 (FIG. 4), a paper feed tray that can use paper of a size corresponding to the document size is searched.

In step S21, a cassette replacement display is performed so that a paper feed cassette containing sheets corresponding to the document size is set in an available paper feed tray.

For example, if the document size is A4 and it is determined in step S20 that A4 size paper can be used in the lower row, then the LCD panel 52 displays the message "Please set the rA4 cassette in the lower row."

When the process in step 521 is finished, the process in branch B2 ends.

If it is determined in step S19 that paper of the same size as the original is set, the paper size (that is, the original size) is displayed on the liquid crystal panel 51 (FIG. 2) in step S22. Next, in step S23, it is determined whether or not the paper jam rate for the paper size exceeds the upper limit for the paper feed stage in which paper of the same size as the original is set. If the upper limit is not exceeded, there is no problem even if paper of the specified size is used in that paper feed stage, and the processing at minute@B2 ends. If the determination in step S23 is Yes, the process moves to step S24.

In step S24, the use priority of the target paper feed tray is lowered for the size. In step S25, it is determined whether or not sheets of the relevant size are set in other paper feed trays. If it is set, the program returns to step S23, and the step for that paper feed stage is set.
Step S23 and subsequent processes are performed.

If the determination in step S25 is NO, step 32
Move to 6. In step 326, usable paper feed stages are calculated based on the data in the RAM 63 for the paper size that matches the manuscript quiz. Then, step S27
, it is determined whether or not there is a usable paper feed stage. If there is a usable paper feed stage, the usable paper feed stage is displayed in step 32B.

For example, if the manuscript quiz is A4 and it is determined that A4 size paper can be used in the lower row, the LCD panel 52 will display the message "Please set rA4 kat paper in the lower row." Once the processing in step 32B is completed, branch B2
The process ends. In step S27, the determination is N.
If o, the process moves to step S29. Step S2
In step S9, since the copying machine must be operated in a state where the probability of jam occurrence is high, a display calling for attention to the occurrence of a jam is performed in place of the display in step S2[1.

When the process in step S29 is finished, the process in branch B2 ends.

Branch B3, which performs the process associated with replacing the paper feeding power cent, is a normal process, and therefore its explanation will be omitted.

In branch B4, which performs processing related to out-of-paper detection, branch 51]
In step 330 shown in the figure, each paper feed cassette 25
, 26, 27, it is determined whether paper empty has occurred in the currently used (designated) paper feed cassette. This paper empty signal 4L is detected by paper empty detection switches 42, 43, and 44. When paper empty is detected, the process moves to step 331.

In step S31, it is determined whether there is another paper feed tray set with paper of the same size as the paper feed tray in which paper empty was detected. If the same -JJ size paper is not set in any other paper feed stage, the process moves to step S32. In step S32, usable paper feed trays are calculated for the paper size in which paper empty has occurred. In step S33, based on the calculation result, it is determined whether there is a usable paper feed stage for the paper size. If there is a usable paper feed stage, the process moves to step S34, and the position of the usable paper feed stage is displayed. For example, if a paper empty occurs for paper size Δ4, and it is determined that paper size Δ4 can be set in the lower stage,
``Please set the rA4 cassette in the lower row.'' is displayed on the liquid crystal panel 52. Judgment in step S33 is NO
In this case, the process moves to step S35, and a display is performed to warn of the occurrence of a jam. When the process in step S34 or step S35 is finished, the process in branch B4 is finished.

If it is determined in step S31 that paper of the relevant size is set in another paper feed stage, the process moves to step 336. In step S36, it is determined whether or not the jam rate for the paper size in that paper feed tray exceeds the upper limit. If it exceeds the upper limit,
The process moves to step 337. In step S37, the use priority of the paper feed stage is lowered for the paper size.

Once the process in step S37 is finished, step S33 is completed again.
1 and repeat the subsequent processing, step 336
If the determination in step 53B is NO, the process moves to step 53B.

In this case, since the newly selected paper feed cassette is a paper feed cassette that poses no problem in use, this paper feed cassette will be used for subsequent copying operations. When the process in step S3B is finished, the process in branch B4 is finished.

During the jam check copying operation, the ejection switch 14. If it is determined that a jam has occurred in the paper being conveyed based on the signals from the register (, switch 38, conveyance switch 39, 40, 41), the process of branch B5 in FIG. 5A is executed.

In FIG. 5E, in step S39, it is determined whether or not a paper jam has occurred. If a jam occurs, the process moves to step S40.

In step 340, the jam counter is incremented by 1 for each paper size in use in the paper feed tray in use.
- to do. That is, rl is added to the numerical value 1□9 recorded in the storage area of the corresponding number of jams at the back of the storage area of the RAM 63. In step S41, it is determined whether or not the jam rate exceeds the upper limit for the paper size in use in the paper feed stage in use. If the upper limit is not exceeded, the process at branch B5 ends, since the combination U is not one in which jams occur frequently. If the determination in step S41 is Yes, the process moves to step S42.

In step S42, the existence of a usable paper feed stage is calculated for the paper size in which the jam has occurred.

In step S43, based on the calculation result, it is determined whether there is another usable paper feed stage for the size. If there is a usable paper feed stage, the process moves to step S44. In step S44, a message is displayed to the effect that since the paper feed tray currently in use has a high jam occurrence rate, the paper should be reset to an appropriate paper feed tray. For example, if a jam occurs when A4 size paper is being used in the middle of the paper feed stages, and as a result of calculation it is determined that A4 size paper can be used in the upper stage, the LCD panel 5- 2 is displayed at the top of ``Please replace the middle A4 cassette with the upper cassette.'' Once the process in step S44 is completed, the process in branch B5 ends. Since there is no paper feed stage with a low jam occurrence rate for the size, step S44
In place of the display at step S/15, a display calling attention to the occurrence of Ja 1 is made in step S/15. When the process in step S52 is finished, the process in branch B5 is finished.

Since the processing at display branch B6 is normal processing, the explanation will be omitted.

Note that the present invention is not limited to copying machines, and can be similarly applied to, for example, laser printers. Furthermore, as a direct means for specifying the paper feed tray by the operator, a paper feed tray designation key may be provided on the key panel 46, and the designation control based on the key may be performed in the same way as in FIG. 5D.

〔Effect of the invention〕

In the image forming apparatus according to the present invention, the determining means can determine the frequency of paper jams in the paper storage unit with respect to the size specified by the specifying means. For this reason, it becomes possible to accurately determine the number of sheets of paper of a specified size in each paper storage section.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of an embodiment of the present invention, FIG. 2 is a schematic plan view of its key panel, FIG. 3 is a schematic diagram of its control section, and FIG. The schematic partial diagrams, FIGS. 5Δ to 5E, are control flowcharts. 2... Copy processing unit, 14... Paper discharge switch, 22°23.24... Paper, 25.26.27... Paper feed cassette, 38... Registration switch, 39, 40.4
1... Conveyance switch, 42, 43. 44... Paper empty detection sensor, 45... Document size detection sensor, 55, 56.57... Paper size detection center,
60...Control unit, 61...CP tJ, 63...
RAM, 46...Key panel, 49...Size key
52...Liquid crystal panel. Patent Applicant Sant-TI Industrial Co., Ltd. Agent Patent Attorney Yukio Ono Figure 3 Figure 4 Figure 5C Figure 5E

Claims (1)

[Claims] (1) an image forming section; a plurality of paper storage sections capable of storing paper of multiple sizes; a transport path for supplying paper from the paper storage section to the image forming section; jam storage means for counting and storing the number of jams for each paper size for each paper storage unit; designation means for designating one of the sizes; An image forming apparatus with a jam handling function, comprising: a determining means for determining whether or not a jam frequency has reached a predetermined level based on the memory of the jam storing means for a paper storing section in which sheets are stored.