JP2004085805A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus for using used paper sheets (the rear side of paper sheet) preferentially. <P>SOLUTION: In the case where a double-sided mode is executed as an automatic paper selection mode, when image data is double-sided data (YES in step S1), paper storage parts excepting a paper storage part corresponding to used paper are searched for and detemination is made (step S2). In the case where image data is single-side data (NO in step S1), when it is not determined that staple processing is executed (NO in step S4), all the paper storage parts including the paper storage part corresponding to the used paper are searched for and determination is made (step S5). <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine.
[0002]
[Prior art]
Some digital copiers as an example of an image forming apparatus include a plurality of sheet storage units for storing sheets to be used. Each paper storage unit has a size (for example, Japanese Industrial Standards (JIS) A row 4 (A4), B row 5 (B5), etc.) and type (plain paper for black-and-white printing, Paper such as color paper).
[0003]
At the time of image formation, by operating an operation panel provided in the copying machine main body, a paper storage unit storing paper of a desired size and type is selected, and a sheet sent from the paper storage unit is selected. An image can be formed based on image data of a document read by the image reading unit or image data read from an external device (such as a personal computer).
As the paper, not only paper on which an image has not yet been formed on both sides (unused paper), but also paper on which an image has been formed on one side (used paper (so-called back paper)) can be used. By operating the operation panel at the time of image formation and selecting a paper storage unit that stores used paper, an image can be formed on used paper.
[0004]
Some copiers are capable of performing image formation by selecting either a single-sided mode for forming an image on one side of a sheet or a double-sided mode for forming an image on both sides of a sheet. There is. If the used paper is used in the duplex mode, the image will be formed on the surface on which the image is already formed.Therefore, in this type of copying machine, when the duplex mode is selected, the used paper is It is not possible to select the paper storage unit that is stored.
[0005]
[Problems to be solved by the invention]
However, not all image data to be formed are image data of both sides. That is, image data of a document read by the image reading unit or image data read from an external device may include both-side image data and one-side image data.
Therefore, if the configuration is such that the used paper cannot be used when the duplex mode is selected, as in a conventional copier, even if the image data on one side has only one side, an image is formed. Since the used paper could not be used, it could not be said that the used paper was sufficiently used.
[0006]
The present invention has been made under such a background, and has as its object to provide an image forming apparatus capable of preferentially using used paper (backing paper).
[0007]
Means for Solving the Problems and Effects of the Invention
According to a first aspect of the present invention, there is provided an image forming apparatus (1) including an image forming unit (3) for forming an image on a sheet, wherein an image is still formed on both sides. Unused paper storage section (4A, 4B) capable of storing unused unused paper, and used paper storage section (4C) capable of storing used paper (back paper) having an image already formed on one surface. And an image to be formed on both sides of a sheet (an image based on double-sided data) is formed on both sides of unused paper stored in the unused paper storage section. To execute a duplex mode in which an image to be formed on one side of the sheet (an image based on the one-sided data) can be formed on the other side of the used paper stored in the used paper storage section. Image form characterized by including double-sided mode execution means (41) It is a device.
[0008]
It should be noted that the alphanumeric characters in parentheses indicate corresponding components and the like in embodiments described later. Hereinafter, the same applies in this section.
According to this configuration, in the double-sided mode, images to be formed on both sides of the sheet (images based on double-sided data) are formed on both sides of unused paper, and images to be formed on one side of the sheet (images based on single-sided data) Can be formed on the surface of the used paper on which the image is not yet formed (the other surface), so that the used paper can be used preferentially.
[0009]
In this case, as in the second aspect of the invention, the duplex mode execution means (41) is configured to select a predetermined priority from a predetermined one of the plurality of paper storage units (4A to 4C). According to the order, the paper storage unit that stores the paper to be used (paper of the same size as the image based on the image data) is automatically selected (step T3), and the paper stored in the selected paper storage unit is selected. For the image to be formed on one side of the paper, the used paper storage section (4C) is included in the predetermined paper storage section (step S5), and the image is formed on both sides of the paper. For an image to be formed, the used paper storage section may not be included in the predetermined paper storage section (step S2).
[0010]
The invention according to claim 3 further includes a staple mode executing means (41, 32) for executing a staple mode for stapling a sheet bundle after image formation, and the double-sided mode executing means (41) includes the staple mode. 3. The image forming apparatus according to claim 1, wherein in the mode, an image is formed only on unused paper stored in the unused paper storage units (4A, 4B).
For example, in the staple mode, central binding can be performed in which the center of the sheet bundle in the longitudinal direction is stapled along the lateral direction. The sheet bundle bound at the center is folded along a staple at the center by a folding device, for example, to form a booklet.
[0011]
An image is formed on both sides of unused paper, an image is formed on the other side of used paper on which an image has already been formed on one side, and a bundle of those sheets is bound at the center, and then folded by a folding device. When folded into a booklet, the pages of the image formed at the time of image formation and the pages of the image already formed on the one side of the used paper are included in the pages of the booklet-shaped printed matter. It is not preferable because it is mixed.
According to the configuration of the present invention, when executing the staple mode, an image is not formed on the used paper even for an image to be formed on one side of the paper, so that the above-mentioned adverse effect can be prevented.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
FIG. 1 is a schematic diagram showing a configuration of an image forming apparatus 1 and a post-processing apparatus 2 according to an embodiment of the present invention. The image forming apparatus 1 is, for example, a digital copying machine, and forms an image based on image data on a sheet to be used. The post-processing device 2 is disposed adjacent to the image forming apparatus 1 and performs a punching process for punching a hole in a predetermined position of a sheet after image formation, a stapling process for stapling a sheet bundle after image formation, and the like. Things.
[0013]
The image forming apparatus 1 includes an image forming unit 3 including a photoconductor 11, a main charger 12, a developing device 13, a transfer device 14, and a cleaning device 15. The photoconductor 11 is, for example, a cylindrical body extending in the front-rear direction, and is driven to rotate clockwise in FIG. During image formation, the surface of the photoconductor 11 is uniformly charged by the discharge of the main charger 12.
Above the image forming unit 3, a laser scanning unit (LSU) 16 is arranged. The surface of the photoconductor 11 charged by the main charger 12 is selectively exposed by irradiation light from the laser scanning unit 16 based on image data. As a result, a so-called electrostatic latent image is formed on the surface of the photoconductor 11.
[0014]
The developing device 13 attaches toner to the surface of the photoreceptor 11 on which the electrostatic latent image is formed, thereby forming a toner image to be transferred to a sheet. The toner image formed on the surface of the photoreceptor 11 is transferred onto the sheet sent to the image forming unit 3 by the transport belt 17 when the sheet passes between the photoreceptor 11 and the transfer device 14. You. The toner remaining on the surface of the photoconductor 11 after the transfer of the toner image is collected by the cleaning device 15.
[0015]
The sheets to be used are stored in a plurality of (for example, three) sheet storage units 4A, 4B, and 4C arranged below the image forming unit 3. Each of the paper storage units 4A to 4C has a size (for example, A column 4 (A4) or B column 5 (B5) of Japanese Industrial Standard (JIS)) and a type (plain paper for black and white printing, color). Paper sheets of different colors (for printing, etc.) can be accommodated, and a sheet is selected from any one of these sheet accommodation sections 4A to 4C via a sheet conveyance path 18 and Is sent.
[0016]
As the paper, not only paper on which an image has not yet been formed on both sides (unused paper), but also paper on which an image has been formed on one side (used paper (so-called back paper)) can be used. The lowermost sheet storage section 4C of the three sheet storage sections 4A to 4C is, for example, a large-capacity deck capable of storing about 3000 sheets of paper, and used paper is stored in the sheet storage section 4C. Is also good.
The sheet sent from the sheet storage units 4A to 4C to the image forming unit 3 via the sheet conveyance path 18 is temporarily stopped when the leading end thereof reaches the registration roller 19. The registration roller 19 is adjusted so that the timing at which the toner image formed on the surface of the photoconductor 11 faces the transfer device 14 coincides with the timing at which the paper passes between the photoconductor 11 and the transfer device 14. The paper is rotated and the paper is sent to the image forming unit 3.
[0017]
The sheet on which the toner image has been transferred by the image forming unit 3 is guided to the fixing device 20 by the transport belt 17, and after the fixing device 20 performs the fixing process of the toner image, is sent to the switchback device 21.
The image forming apparatus 1 can not only form an image on one side of a sheet but also form an image on both sides of a sheet. When an image is formed on one side of a sheet, the sheet on which the image is formed is once sent to the switchback device 21, the traveling direction is reversed, and the sheet is sent to the discharge roller 22. The sheet is sent to the post-processing device 2 such that the cut surface faces downward.
[0018]
On the other hand, when an image is formed on both sides of the sheet, the sheet on which the image is formed on one side is sent to the switchback device 21, the traveling direction is reversed, and the sheet is sent again to the image forming unit 3. The front and back can be reversed. Then, the sheet on which the image is formed on the other surface in the image forming unit 3 is sent from the discharge roller 22 to the post-processing device 2 via the fixing device 20.
The data of the image to be formed on the paper can be read into the image forming apparatus 1 from an external device (such as a personal computer), or the image of the document can be read by the image reading unit 5 disposed above the image forming apparatus 1. Can also be obtained by
[0019]
At the top of the image forming apparatus 1, an automatic document feeder (DF) 6 for automatically sending one or a plurality of documents set on a document tray 61 to the image reading unit 5 one by one to be read. Is arranged.
The automatic document feeder 6 has a configuration similar to that of the switchback device 21, and can reverse a document to be sent from the document tray 61 to the image reading unit 5. Therefore, it is possible to obtain only one-sided image data (single-sided data) by causing the image reading unit 5 to read only one-sided image of the document, or to read both-sided images of the document by the image reading unit 5 and obtain two-sided image data. (Two-sided data) can also be obtained.
[0020]
The automatic document feeder 6 is, for example, openable and closable about its rear end. When the automatic document feeder 6 is opened, a contact glass as a mounting table when the image reading unit 5 reads an image of a document is provided. (Not shown) appear. With this configuration, it is possible to open the automatic document feeder 6, set documents one by one on the contact glass, and read the image by the image reading unit 5, or place one or more documents on the document tray 61. The automatic document feeder 6 supplies originals one by one to the image reading unit 5 so that the images can be read (so-called drift reading). The image data of the document is obtained by detecting reflected light of light emitted toward the document from a scanner provided in the image reading unit 5 with a CCD image sensor (not shown) and converting the light into an electric signal.
[0021]
In the post-processing device 2, a punching device 31 for performing a punching process on the paper sent from the image forming device 1, a stack of a plurality of sent papers (storage), and the A stapling device 32 for performing stapling processing on the stacked sheet bundle is provided. Whether to perform the punching process and the stapling process is determined, for example, by operating an operation panel (not shown) arranged on the upper surface of the image forming apparatus 1.
[0022]
The sheet sent from the image forming apparatus 1 to the post-processing apparatus 2 is first sent to the punching device 31, and if it is determined that the punching process is to be performed, a hole is formed at a predetermined position of the sheet in the punching device 31. Can be opened. On the other hand, when it is not determined that the punching process is to be performed, the sheet passes through the punching device 31 without being punched.
If it is not determined that the stapling process is to be performed, the sheet that has passed through the punching device 31 is sent to the discharge roller 33. On the other hand, when it is determined that the stapling process is performed, the sheet that has passed through the punching device 31 is sent to the stapling device 32 disposed below the punching device 31. The stapling device 32 stacks a plurality of sheets and then staples the leading end of the stacked sheet bundle with staples, or centrally binds the longitudinal center of the sheet bundle with staples along the short direction. Stapling process can be performed.
[0023]
The sheet bundle after the leading end stapling is sent upward toward the discharge roller 33. A discharge tray 34 and a plurality of job trays 35 arranged vertically above the discharge tray 34 are provided on the end surface of the post-processing device 2 on the discharge roller 33 side. The sheets (or sheet bundle) discharged from the post-processing device 2 via the discharge rollers 33 can be collectively discharged to a discharge tray 34, or the plurality of job trays 35 can be individually or integrally moved up and down. Thus, the discharged paper can be sorted to each job tray 35.
[0024]
Below the stapling device 32, a folding device 36 for bending the centrally bound sheet bundle along the staples at the center is arranged. The bundle of sheets stapled at the center in the stapling device 32 is sent to a folding device 36, where the sheet bundle is folded in a booklet shape, and then discharged to a booklet tray 37 provided below the discharge tray 34. .
FIG. 2 is a block diagram illustrating an electrical configuration of the image forming apparatus 1. The control unit 40 includes, for example, a microcomputer, and includes a CPU 41, a RAM 42, a ROM 43, and a memory copy unit 44 for storing image data.
[0025]
An operation panel 7, a hard disk (HDD) 8, an image reading unit 5, a printer controller 9, an image forming unit 3, and the like are connected to the control unit 40 via an interface (I / F) 45 so as to be able to input and output. .
The hard disk 8 is for compressing and storing image data. At the time of image formation, the image data stored in the hard disk 8 is expanded and expanded in the memory copy unit 44, and the expanded image data is transferred to the laser scanning unit 16 of the image forming unit 3. In the memory copy unit 44, for example, image data for 10 pages (one-sided data for one page and two-sided data for two pages) can be developed.
[0026]
The image reading unit 5 includes a scanner 23, an automatic document feeder 6, a CCD image sensor 24, and the like. The image data of the document read by the image reading unit 5 is sent from the CCD image sensor 24 to the control unit 40 and stored in the memory copy unit 44.
The printer controller 9 is connected in parallel to an external device such as a personal computer (PC) 10A, and can send image data from the personal computer 10A to the control unit 40 via the printer controller 9. The image data sent from the printer controller 9 to the control unit 40 is stored in the memory copy unit 44.
[0027]
The printer controller 9 is connected to another personal computer 10B via a network, and can send image data from the other personal computer 10B to the control unit 40 via the printer controller 9. I have.
The post-processing device 2 is electrically connected to the image forming device 1 via the interface 45 of the image forming unit 3. When it is determined that the punching process or the stapling process is to be performed by operating the operation panel 7 of the image forming apparatus 1, a signal to that effect is sent to the post-processing device 2, and the post-processing device 2 performs the processing. Be executed.
[0028]
The operation panel 7 includes a key input unit 71 such as a numeric keypad, a liquid crystal display unit 72, an LED display unit 73, and the like.
FIG. 3 is a plan view showing the configuration of the operation panel 7.
The key input unit 71 is arranged, for example, at the right end of the operation panel 7 and is operated when setting the number of prints or when starting / stopping the image forming operation in the image forming apparatus 1.
[0029]
The liquid crystal display unit 72 is arranged, for example, at the center left of the operation panel 72. The liquid crystal display unit 72 has a touch panel, for example, and can set various functions in the image forming apparatus 1 by touching keys displayed on the display screen. At this time, the selected key is displayed in reverse video (in FIG. 3, the highlighted key is hatched).
[0030]
When an operation is performed on the key input unit 71 or the liquid crystal display unit 72, an input signal corresponding to the operation is provided to the control unit 40. In addition, the driving mode is controlled by controlling the display mode of the liquid crystal display section 72 and the light emitting modes of the LED display sections 73 disposed on the left and rear of the liquid crystal display section 72 based on the output signal from the control section 40. Information related to the status and the setting status of the function is displayed.
Information on the size and type of paper stored in each of the paper storage units 4A to 4C can be stored in association with the RAM 42 of the control unit 40 by operating the operation panel 7. I have. When the image forming apparatus 1 is in a standby state, a plurality of paper selection keys 721 for selecting a paper to be used are displayed on the liquid crystal display unit 72 of the operation panel 7. By touching, it is possible to select the paper storage units 4A to 4C corresponding to the size and type of the paper used at the time of image formation. At the time of image formation, a sheet is sent out from the selected sheet storage units 4A to 4C, and an image is formed on the sheet.
[0031]
Among the plurality of paper selection keys 721, an automatic paper key for setting a mode (automatic paper selection mode) for automatically selecting paper of the same size according to the size of the image based on the image data is provided. 721A. When the automatic paper selection mode is selected (at this time, the automatic paper key 721A is highlighted as shown in FIG. 3), the paper storage units 4A to 4C each storing paper of a different size or type (search target). Is automatically determined (automatic paper selection processing) corresponding to the size of the image based on the image data, and at the time of image formation, the paper is fed from the determined paper storage unit.
[0032]
Each of the sheet storage units 4A to 4C does not necessarily store sheets of different sizes. That is, there are cases where sheets of the same size and different types (for example, plain paper, color paper, used paper, etc.) are stored in a plurality of paper storage units. In this embodiment, the user can operate the operation panel 7 to determine which type of paper is preferentially selected during the automatic paper selection process. When the automatic paper selection mode is selected, at the time of the automatic paper selection processing, paper having the same size as the size of the image based on the image data is automatically selected according to a predetermined priority.
[0033]
In this embodiment, by operating the operation panel 7, it is possible to select one of a single-sided mode for forming an image on one side of a sheet and a double-sided mode for forming an image on both sides of a sheet to form an image. It has become. When the one-sided mode is executed in the automatic paper selection mode, the image data is output from the search targets including the paper storage unit (for example, the paper storage unit 4C) corresponding to the used paper in accordance with a predetermined priority. The paper storage unit corresponding to the size of the image based on the image is automatically determined.
[0034]
The data of the image to be formed is not always double-sided data. That is, double-sided data and single-sided data may be mixed in the image data of the original read by the image reading unit 5 or the image data read from the personal computers 10A and 10B.
In this embodiment, when the duplex mode is executed in the automatic paper selection mode, the paper storage unit 4C corresponding to the used paper is included in the search target for the simplex data, and the used paper is included in the duplex paper for the duplex data. The corresponding paper storage unit 4C is not included in the search target. Thereby, in the duplex mode, an image corresponding to the duplex data can be formed on both sides of the unused paper, and an image corresponding to the simplex data can be formed on the surface of the used paper on which the image has not been formed. Used paper can be used preferentially.
[0035]
FIG. 4 is a flowchart for explaining the flow of control by the CPU 41 during the automatic paper selection process.
When the automatic paper selection mode is selected in the double-sided mode, the CPU 41 determines whether or not each image data to be developed in the memory copy unit 44 is double-sided data (step S1). .
If the image data is two-sided data (YES in step S1), the CPU 41 determines the sheet storage units 4A and 4B other than the sheet storage unit 4C corresponding to the used paper as search targets (step S2). From the search targets, the paper storage unit corresponding to the paper to be used is determined according to a predetermined priority (paper storage unit determination process; step S3).
[0036]
On the other hand, if the image data is not double-sided data, that is, if the image data is single-sided data (NO in step S1), CPU 41 determines whether or not it has been determined to execute the stapling process (step S4). If it is determined that the stapling process is to be performed (YES in step S4), the CPU 41 determines the sheet storage units 4A and 4B other than the sheet storage unit 4C corresponding to the used paper as search targets (step S4). S2), a paper storage unit determination process is performed (step S3).
[0037]
An image based on double-sided data is formed on both sides of unused paper, and an image based on single-sided data is formed on the other side of used paper on which an image has already been formed on one side. Then, when the sheet is folded into a booklet by the folding device 36, the pages of the image formed based on the image data at the time of image formation are included in the pages of the booklet-shaped printed matter, and This is not preferable because the image page already formed on one surface is mixed. As described above, when it is determined that the stapling process is to be executed, the sheet storage unit 4C corresponding to the used paper is not included in the search target. Is executed, no image is formed on the used paper even for single-sided data, so that the above-mentioned adverse effects can be prevented.
[0038]
If it is not determined that the stapling process is to be performed (NO in step S4), the CPU 41 determines all the sheet storage units 4A to 4C including the sheet storage unit 4C corresponding to the used paper as a search target (step S4). S5), a paper storage unit determination process is performed (step S3).
FIG. 5 is a flowchart for explaining the flow of control by the CPU 41 during the paper storage unit determination process.
[0039]
When the paper storage unit determination process is started, the CPU 41 searches for a first search target according to a predetermined priority (step T1). Then, the CPU 41 determines whether or not the size of the paper corresponding to the paper storage units 4A to 4C to be searched matches the size of the image based on the image data (step T2).
If the sizes match (YES in step T2), the sheet storage units corresponding to the sheets to be used are determined as the sheet storage units 4A to 4C (step T3), and the sheet storage unit determination processing ends.
[0040]
On the other hand, if the sizes do not match (NO in step T2), and the search of all the search objects has not been completed yet (NO in step T4), the CPU 41 searches for the next search object according to a predetermined priority order. Then, it is determined whether or not the size of the sheet corresponding to the sheet storage units 4A to 4C to be searched matches the size of the image based on the image data (step T2).
In this manner, until the size of the paper corresponding to the paper storage units 4A to 4C to be searched matches the size of the image based on the image data (YES in step T2), or until all the search targets have been searched. (YES in step T4), the control in steps T2, T4, and T5 is repeated.
[0041]
When all the search targets have been searched (YES in step T4), the CPU 41 determines that there is no sheet storage unit corresponding to the size of the image based on the image data (step T6), and the CPU 41 determines that there is no paper storage unit. A message for prompting the user to set paper (for example, a message such as "Please set A4 paper") is displayed on the liquid crystal display section 72 of the operation panel 7 (error display; step T7).
[0042]
The present invention is not limited to the contents of the above embodiments, and various modifications can be made within the scope of the claims.
For example, instead of providing the post-processing device 2 separately, a punch device 31 and a stapling device 32 may be provided in the image forming device 1.
Although the digital copying machine has been described as an embodiment of the present invention, the present invention is not limited to the digital copying machine, but can be applied to other image forming apparatuses such as a printer and a facsimile.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a configuration of an image forming apparatus and a post-processing apparatus according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating an electrical configuration of the image forming apparatus.
FIG. 3 is a plan view showing a configuration of an operation panel.
FIG. 4 is a flowchart illustrating a flow of control by a CPU during an automatic paper selection process.
FIG. 5 is a flowchart illustrating a flow of control performed by a CPU during a paper storage unit determination process.
[Explanation of symbols]
1 Image forming apparatus
3 Image forming unit
4A-4C paper storage section
32 staple device
41 CPU

Claims (3)

An image forming apparatus including an image forming unit for forming an image on paper,
A plurality of paper storage units each having an unused paper storage unit that can store unused paper on which an image has not been formed on both sides and a used paper storage unit that can store used paper that has an image already formed on one surface. Paper storage unit,
An image to be formed on both sides of the paper is formed on both sides of the unused paper stored in the unused paper storage section, and an image to be formed on one side of the paper is stored in the used paper storage section. And a duplex mode execution unit for executing a duplex mode that can be formed on the other side of the used paper. The double-sided mode execution means includes:
A paper storage unit storing paper to be used is automatically selected from predetermined paper storage units among the plurality of paper storage units in accordance with a predetermined priority, and the selected paper storage unit is selected. Forming an image on the paper accommodated in the
For an image to be formed on one side of the paper, the used paper storage section is included in the predetermined paper storage section, and for an image to be formed on both sides of the paper, the used paper storage section is The image forming apparatus according to claim 1, wherein the image forming apparatus is not included in a predetermined sheet storage unit. A staple mode execution unit that executes a staple mode for stapling the sheet bundle after image formation, further comprising:
The image forming apparatus according to claim 1, wherein the double-sided mode execution unit forms an image only on unused paper stored in the unused paper storage unit in the staple mode. 4. .

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