JPH08328319A - Image forming device and paper carrying method - Google Patents

Abstract

PURPOSE: To provide an image forming device capable of housing rear side copying papers in a specific cassette, when the rear side copying papers coexist with double-sided white copying papers. CONSTITUTION: The image forming device provided with a white copying paper mode for forming an image on the white copying paper unprinted on both sides or a rear side copying paper mode for forming the image on the rear copying paper having the formed image on the rear side as one side is constituted of plural cassettes 12 and 13 for housing the white copying papers and the rear copying papers respectively, an image forming part for forming the image, rear side printing deciding parts 38a and 38b for deciding whether the paper carried from the plural cassettes 12 and 13 to an image forming means is printed on the rear side or not and means G1, G2, 45 and 46 for returning an improper paper out of the papers decided to be ones printed on the rear sides, in the papers carried from the plural cassettes 12 and 13 to the image forming means, by the rear side printing deciding parts 38a and 38b.

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 having a function of forming an image on the other back surface of a paper sheet already printed on one back surface.

[0002]

2. Description of the Related Art At present, copiers for copying manuscripts are frequently used in companies and schools. In order to reuse the copy paper (hereinafter referred to as back copy paper) that is no longer needed after copying an original using this copying machine, the back copy paper is stored in a cassette and the back copy paper is stored. -It is designed to form an image on the blank side of the paper.

[0003]

However, the back side copy paper has to be stored in the cassette one by one as described above, and the work is troublesome. The present invention has been made in view of the above points, and an object thereof is to copy the back side copy paper when the back side copy paper is mixed in the double-sided white copy paper.
An object of the present invention is to provide an image forming apparatus that stores paper in a specific cassette.

[0004]

According to a first aspect of the present invention, there is provided a first mode in which a white copy paper whose both sides are unprinted is required at the time of image formation and a white paper is provided only on one side at the time of image formation. In an image forming apparatus provided with a necessary second mode, a first paper storing means for storing the double-sided white copy paper, a second paper storing means for storing the single-sided white copy paper,
The take-out means for taking out the paper from either the first paper storage means or the second paper storage means, the image forming means for forming an image on the paper taken out by the take-out means, and the take-out means are the first. Detecting means for detecting that the paper is a single-sided white copy paper despite the fact that the paper is taken out from the paper storage means, and the paper taken out by the detection means is a single-sided white copy paper. If
And a means for conveying the paper to be stored in the second paper storage means.

An image forming apparatus according to a second aspect is the image forming apparatus according to the first aspect.
The detecting means of (1) has two sensors for detecting whether an image has already been formed on one side of the sheet taken out from the first sheet storing means.

According to a third aspect of the present invention, there is provided the image forming apparatus according to the second aspect.
From the image forming means to the second paper storage means for reversing and storing the paper, and when one surface on which an image is formed by the two sensors is different, the reversal is performed. Means for reversing by the means and storing in the second sheet storage means, and discharging means for discharging the sheet to the outside when the two sensors detect that images are formed on both sides. Is provided.

The image forming apparatus according to claim 4 is the image forming apparatus according to claim 1.
In the first mode, the counting means counts the number of sheets which are the one-sided white copy sheets taken out from the first sheet storing means, and the alarming means for giving an alarm to stop the image forming means. And a means for deciding whether the predetermined number has been exceeded by the counting means, and a means for terminating the operation of the image forming means and activating the alarm means when the predetermined number is exceeded by the determining means. Is characterized by.

According to a fifth aspect of the present invention, there is provided a first mode in which a white copy sheet whose both sides are unprinted is required during image formation and a second mode in which only one side is white sheet during image formation. In an image forming apparatus having a sheet, if the sheet is a single-sided white copy sheet even though it is taken out from the first sheet storage means for storing a double-sided white copy sheet, the single-sided white copy sheet is used.
It is characterized in that the sheet is stored in the second sheet storage means for storing the sheet.

[0009]

According to the first and fifth aspects of the invention, there are provided a first mode in which white copy paper whose both sides are unprinted is required during image formation and a second mode in which white paper is required only on one side during image formation. In the image forming apparatus having the first structure, a first side for storing double-sided white copy paper is provided.
If the paper is a one-sided white copy paper despite being taken out from the paper storage means, the second paper storage means for storing the one-sided white copy paper is stored.

In the second and third aspects, when one surface on which an image is formed by the two sensors is different from each other, the two papers are reversed by the reversing means and then stored in the second paper storing means. When the sensor detects that the image is formed on both sides, the sheet is discharged to the outside.

According to a fourth aspect of the present invention, the number of sheets which are single-sided white copy sheets taken out from the first sheet storing means at the time of setting the first mode is counted, and it is determined whether the counted value exceeds a predetermined number. If it is determined that the number of sheets exceeds the predetermined number, the operation of the image forming unit is stopped and the alarm unit is activated.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An image forming apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a copying machine. In FIG. 1, 11 is a copying machine main body.
At the lower part of the main body of the copying machine 11, a dedicated cassette 12 for storing backing copy paper and a dedicated white copy paper cassette 13 are installed from the upper side.

Further, on the side surface of the copying machine main body 11, there is provided a paper discharge tray 14 for discharging the image-formed paper. A control panel 15 as shown in FIG. 2 is provided on the upper surface of the copying machine main body 11.

On the control panel 15, a start key 21 to be operated when starting copying, a numeric keypad 22 for inputting the number of copying machines, etc., the number of copying machines and other data are displayed. A liquid crystal display unit 23, a switch 24 for designating a white copy paper mode in which an image is formed on a white copy paper whose both sides are not printed, and an image is formed on a back copy paper having an image formed on the back surface of one side. Switch 25 for specifying the back copy paper mode, and recycle switch 26 for forcibly discharging the copied paper to the cassette 13 dedicated to the back copy paper
Is provided.

Next, the internal structure of the copying machine will be described with reference to FIG. In FIG. 3, a pickup roller 31 is provided above the cassette 13 to take out the stored white copy sheets one by one. The sheets taken out by the pickup roller 31 are separated one by one in a sheet separating section consisting of a paper feeding roller 32 and a separating roller 32 'installed inside the take-out end of the cassette 13. To be separated. The separated sheets are fed into the copying machine by the conveyance roller 33.

A pickup roller 3 is provided above the cassette 12 to take out the back copy sheets stored one by one.
4 are provided. The paper taken out by the pickup roller 34 is fed by a paper feeding roller 35 installed above the inside of the take-out end of the cassette 12.

From the transfer roller 33 to the photosensitive drum 36.
A sheet feeding / transporting path 37 is provided over the entire length. The paper feeding / conveying path 37 has a distance L from the photosensitive drum 36.
A first optical sensor 38a provided for determining whether a character or the like is printed on the back surface of the sheet conveyed to a position separated by 1 and for determining whether or not a character or the like is printed on the front surface of the sheet. A second optical sensor 38b is provided.
The first optical sensor 38a is arranged so as to be opposed to the sheet feeding conveyance path 37 with a slight deviation therebetween, and the second optical sensor 38b is arranged closer to the photosensitive drum 36.

The first and second optical sensors 38a and 38a
The configuration of 8b will be described later with reference to FIG. Further, the positional relationship between the first photosensor 38a and the second photosensor 38b and the photoconductor drum 36 will be described later with reference to FIG.

Then, the electrostatic latent image formed on the photosensitive drum 36 is developed by the developing device 39 and transferred onto the paper conveyed through the paper feed conveying path 37.
Is transferred. The sheet after the transfer by the transfer charger 40 is peeled off by the peeling charger 41 and is conveyed by the fixing device 42 via the conveying belt. The sheet on which the developed image is fused and fixed by the fixing device 42 is ejected to the sheet ejection tray 14 via the sheet ejection roller 43.

G1 is provided immediately before the paper discharge tray 14. The gate 51 is a gate for separating whether the paper conveyed through the fixing device 42 is discharged to the discharge roller 43 or the conveyance path 44 for returning the paper to the tray 12. . The gate G1 is switched to the side for discharging the paper to the discharge roller 43 in the normal state.

Further, the transport path 44 is branched into a transport path 45 and a transport path 46 just before the tray 12. The transfer path 45 and the transfer path 46 are separated from each other by the gate G2. This gate G2 is normally closed on the side of the conveyance path 45. When the gate G2 is turned on, the transport path 44
And the transport path 46 are connected.

The transport path 45 is formed so as to extend straight and obliquely forward toward the tray 12. Therefore,
The first optical sensor 3 for the sheet conveyed on the sheet conveying path 37
The surface on the side 8a is stored as the back surface of the tray 12.

Further, the end of the transport path 46 is formed so as to extend straight and obliquely rearward toward the tray 12. Therefore, the surface of the paper conveyed through the paper feed / conveyance path 37 on the side of the second optical sensor 38a is accommodated on the front side of the tray 12.

Next, the structure of the first and second optical sensors 38a and 38b will be described with reference to FIG. Since the first and second optical sensors 38a and 38b have the same configuration, the configuration will be described taking the first optical sensor 38a as an example. As shown in FIG. 4A, the first optical sensor 38 is composed of a contact type CCD line sensor, and has a width (= X + α) wider than the maximum paper width X of the paper used in the copying machine by α. Have

In FIG. 4A, the A4 sheet is conveyed in the arrow direction, and the first optical sensor 38 is arranged so as to extend in the direction orthogonal to the arrow direction. Next, FIG.
The configuration of the first photosensor 38a will be described with reference to FIG. In the figure, 51 is an LED lamp. The light emitted from the LED lamp 51 is reflected by the glass surface 52 and then condensed by the SELFOX lens 53,
Collected on the CCD chip 54. Paper P is glass surface 52
Is conveyed in the direction of the arrow. That is, the image of the document P is taken by the CCD chip 54.

Next, the arrangement of the first and second optical sensors 38a and 38b will be described with reference to FIG. That is,
When the distance between the center of the photosensitive drum 36 and the second optical sensor 38b is L1 and the length L2 in the transport direction of A4 paper is L2, L1> L2. This is because the condition is that the leading edge of the A4 sheet has not reached the photoconductor drum 36 even when the trailing edge of the A4 sheet has passed the second optical sensor 38b.

That is, in order to make it possible to stop the copying operation in time before the A4 sheet reaches the photoconductor drum 36 after the rear end of the A4 sheet passes the second optical sensor 38b. is there.

Next, a control block diagram of the copying machine will be described with reference to FIG. In FIG. 6, reference numeral 61 is a CPU (central processing unit) that controls the copying machine as a whole. The system bus 61a from the CPU 61 has a RAM 62 for storing various work areas, a ROM 63 for storing the control programs shown in FIGS. 7 and 8, a scanner unit 64 for reading an original placed on an original table, and the above-mentioned drawings. 2, a control panel section 65, an image forming section 66, and a conveyance control section 6 that perform control according to various switches of the control panel 15 shown in FIG.
7, the first optical sensor 38a, and the second optical sensor 38b are connected. The RAM 62 is provided with a counter 62c that counts the number of copy sheets of the backing copy paper returned to the cassette 12.

The image forming unit 66 includes an exposure lamp and a charging charger.
An image is formed on a sheet by controlling a jar or the like. The transport controller 67 controls the paper feed transport path 37, the transport belts constituting the transport paths 45 and 46, various rollers, and gates G1 and G2.

Next, the operation of the embodiment of the present invention constructed as above will be described with reference to the flowcharts of FIGS. 7 and 8. First, the operator uses the switch 2 when copying from the control panel 15 to white copy paper.
4. When copying on the backing copy paper, the copy mode is set by operating the switch 25.

Then, the CPU 61 determines what is set as the copy mode (step S1). When the switch 24 is operated and "white copy paper" is selected in the determination in step S1, the white copy paper dedicated cassette 13 is selected (step S2). On the other hand, the switch 25 is operated in the judgment of step S1 and the "backing paper copy"
When "paper" is selected, the cassette 12 is selected (step S3).

In this manner, the cassette 13 containing the white copy paper or the cassette 12 containing the back copy paper is selected according to the operation of the switches 24 and 25.
The operation when the switch 24 is operated to select white copy paper will be described below.

First, it is determined whether or not the start key-21 has been pressed (step S4). Until the determination in step S4 is "YES", the wait process is performed. When the determination in step S4 is "YES", the paper feed process is performed (step S4).
5).

That is, the paper taken out by the pickup roller 31 is transferred to the paper separating section consisting of the paper feeding roller 32 and the separating roller 32 'installed above the inside of the take-out end of the cassette 13. Are separated one by one.

This sheet is conveyed through the paper feed / conveyance path 37. The first optical sensor 3 is provided on both sides of the paper feed / conveyance path 37.
8a and the 2nd optical sensor 38b are installed. Then, the first optical sensor 38a and the second optical sensor 38
If no character or the like is detected by b, it is determined that nothing is printed on both sides of the paper. That is, the sheet is determined to be blank.

In step S6, it is determined whether the paper is blank (step S6). Here, since the sheet is a blank sheet as an example, it is determined to be "YES" and the copy operation is performed (step S7). That is, the electrostatic latent image formed on the photoconductor drum 36 is developed by the developing device 39 and transferred by the transfer charger 40 onto the paper conveyed through the paper feed conveyance path 37. The sheet after the transfer by the transfer charger 40 is peeled off by the peeling charger 41 and is conveyed by the fixing device 42 via the conveying belt.

Then, it is determined whether the recycle switch 26 of the control panel 15 has been operated (step S8). When the determination in step S8 is "NO", the sheet on which the developed image is melted and fixed by the fixing device 42 is discharged onto the sheet discharge tray 14 via the sheet discharge roller 43.
Is discharged to.

In this way, the sheet taken out from the tray 13 is conveyed through the path as shown in FIG. 9 (a). On the other hand, if the result of the determination in step S8 is "YES", the sheet is returned to the cassette 12 by the processing in step S14 and subsequent steps in FIG. In other words, if the operator finds that the copy is a miscopy due to a different original copy or the like, the recycle switch 26 is operated to eject the copy.
The sheet can be returned to the tray 12 once and reused without being discharged from the sheet 4. The detailed operation after step S14 will be described in the process of operation when "NO" is determined in step S6.

Next, the operation when the above step S6 is determined to be "NO" will be described. Step S6
If it is determined to be "NO", the sheet is conveyed, but the copying operation is not performed.

That is, the exposure lamp of the image forming apparatus 66,
Then, the transfer charger is turned off and the above-described copying operation is not performed (step S10). Next, by the processing of step S11 and subsequent steps, which conveyance path the sheet is returned to the tray 12, or the tray 12
It is determined whether the sheet is discharged to the discharge tray 14 without being returned to.

That is, in step S11, the contents detected by the first and second optical sensors 38a and 38b are determined. In the flowchart of FIG. 8 and FIG. 9, the first optical sensor 38a is referred to as sensor A, and the second optical sensor 38b is referred to as sensor B.

That is, when a character or the like is detected only by the second optical sensor 38b, steps S12 and S13,
The sheet is returned to the tray 12 by the process of step S16. First, the gate G1 is turned on to guide the paper conveyed through the fixing device 42 to the conveyance path 44. Further, the gate G2 is controlled so that the sheet guided to the transport path 44 is stored in the tray 12 via the transport path 45.

On the other hand, if the characters are detected only by the first optical sensor 38a in the determination at step S11, the paper is returned to the tray 12 by the processing at steps S14, S15 and S16. First, the gate G1 is turned on to guide the paper conveyed through the fixing device 42 to the conveyance path 44. Further, the gate G2 is turned on, and the transport path 44
The paper guided to the tray is stored in the tray 12 via the transport path 46.

That is, when a character or the like is detected by the second optical sensor 38b while being conveyed through the paper feed / conveyance path 37, the tray is conveyed through the conveyance path 45 as shown in FIG. 9B. Returned to 12.

On the other hand, when a character or the like is detected by the first optical sensor 38a while being conveyed through the sheet feeding / conveying path 37, the tray is conveyed through the conveying path 46 as shown in FIG. 9C. Returned to 12. That is, the front and back states of the sheets returned to the tray 12 are reversed between when the paper is fed through the transport path 45 and the transport path 46.

When a character or the like is detected by both the first optical sensor 38a and the second optical sensor 38b, the paper is ejected to the ejection tray 14 as shown in FIG. 9 (d). . That is, when the double-sided printed paper is mixed in the tray 13 which should contain the blank copy paper, the paper is discharged to the discharge tray 14 (step S19).

After the backing copy paper is stored in the cassette 12, the number of sheets is counted by the counter 62c, and when the count value is 10, the warning information is displayed on the liquid crystal display section 23 of the control panel section 65. Is displayed (step S18).
For example, "There is no blank copy paper in cassette 13, so copy will be stopped. Message such as "" may be issued.

By the way, in the mode determination of step S1 described above, the back copy paper mode in which the switch 25 is operated is selected.
Cassette is selected, the cassette 12 is selected. Then, when the start key-21 is pressed, the paper is fed (step S5), the copy operation is performed (step S7), and if the recycle switch 26 is not pressed, as shown in FIG. 9 (e). The sheet is discharged to the discharge tray 14 (step S9). Although the analog copying machine is described in the above embodiment, the same can be said for the digital copying machine.

[0049]

As described above in detail, according to the present invention, when the back side copy paper is mixed in the double-sided white copy paper, the back side copy paper is automatically stored in a specific cassette. Can be made.

[Brief description of drawings]

FIG. 1 is a side view of an image forming apparatus according to the present invention.

FIG. 2 is a plan view of a control panel.

FIG. 3 is a cross-sectional view showing an internal structure of a main part of the image forming apparatus.

FIG. 4 is a diagram showing a structure of first and second optical sensors.

FIG. 5 is a diagram showing a positional relationship between the first and second photosensors and a photosensitive drum.

FIG. 6 is a block diagram showing a system configuration of the image forming apparatus.

FIG. 7 is a part of a flowchart for explaining the operation.

FIG. 8 is a part of a flowchart for explaining the operation.

FIG. 9 is a diagram for explaining the flow of paper.

[Explanation of symbols]

11 ... Copying machine main body, 12, 13 ... Cassette, 15 ... Control panel, 31 ... Pickup roller, 32 ... Paper feeding roller, 32 '... Separation roller, 33 ... Conveying roller, 3
7 ... Paper feed / conveyance path, 38a ... First optical sensor, 38b ...
Second optical sensor, 39 ... Developing device, 40 ... Transfer charger, 41 ... Peeling charger, 42 ... Fixing device.

Claims (5)

[Claims] 1. An image forming apparatus provided with a first mode in which white copy paper whose both sides are unprinted is required during image formation and a second mode in which white paper is required only on one side during image formation. A first paper storage means for storing the double-sided white copy paper, a second paper storage means for storing the single-sided white copy paper, the first paper storage means and the second paper storage A take-out means for taking out the paper from any one of the means, an image forming means for forming an image on the paper taken out by the take-out means, and a means for taking out the paper even though the take-out means takes out the paper from the first paper storing means. Detecting means for detecting that the paper is a single-sided white copy paper, and when the paper taken out by this detecting means is a single-sided white copy paper, this paper is transferred to the second paper storage means. A means to convey to store An image forming apparatus comprising: 2. The detector according to claim 1, further comprising two sensors for detecting whether or not an image has already been formed on one side of the sheet taken out of the first sheet storage means. Image forming apparatus. 3. A case in which one side on which an image is formed by the two sensors is different from each other, wherein the image forming means includes a reversing means for reversing and accommodating the paper in the second paper accommodating means. Means to store the paper in the second paper storage means after reversing it by the reversing means, and when the two sensors detect that images are formed on both sides, the paper is transferred to the outside. The image forming apparatus according to claim 2, further comprising: a discharging unit configured to discharge. 4. A counting means for counting the number of sheets which are single-sided white copy sheets taken out from the first sheet storing means at the time of setting the first mode, and a warning for stopping the image forming means. Warning means, judging means for judging whether the predetermined number has been exceeded by the counting means, and means for stopping the operation of the image forming means and activating the alarm means when it is judged by the judging means that the predetermined number has been exceeded. 2. The method according to claim 1, further comprising:
The image forming apparatus described. 5. An image forming apparatus provided with a first mode in which white copy paper whose both sides are unprinted is required during image formation and a second mode in which white paper is required only on one side during image formation. In the case, when the paper is a single-sided white copy paper despite being taken out from the first paper storage means for storing a double-sided white copy paper, a second paper storage for storing the single-sided white copy paper A method for transporting a sheet, characterized in that the sheet is stored in a means.