JP2877990B2 - Image forming device - Google Patents

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 for forming a document image on a sheet.

[0002]

2. Description of the Related Art An image forming apparatus such as a digital copying machine reads a document image by a scanner, temporarily stores the image data of the document in a readable / writable memory, and converts the image data into various types in an image processing unit as needed. After the processing, the image data is stored in the memory again, the processed image data is read out, and a visible image is formed on a sheet in an image forming unit such as a laser printer.

This conventional image forming apparatus is configured to form an image in synchronization with reading of a document image.

[0004]

In such a conventional image forming apparatus, since the reading operation of the original image and the image forming operation are synchronized, for example, a paper jam occurs in the automatic original supply device of the scanner. When the original image cannot be read, as in the case of
Further, there is a problem that the document image cannot be read when image formation is impossible, for example, when a paper jam occurs in the paper transport path to the laser printer.
That is, there is a problem that a state in which one of the document image reading unit and the image forming unit is inoperable affects the operation of the other.

Accordingly, the present invention provides an image reading section and an image forming section which are inoperable even if one of them is inoperable due to a paper jam or a process for recovery, if the other is operable. An object of the present invention is to provide an image forming apparatus capable of continuing processing.

[0006]

Document reading means for reading a document image; storage means for storing image data read by the document reading means;
Image processing means for performing image processing on the processed image data,
Image forming means for forming an image on a sheet based on image data processed by the image processing unit, a document reading
Detecting means for detecting abnormalities in the printer or image forming means
An image forming apparatus comprising a stage, and control means for controlling an original reading means and the image processing means and image forming means operably independently control means, abnormality detection
If the notification means detects an abnormality in the document reading means,
Continue processing of the image processing unit and the image forming unit, and
If the detecting means detects an abnormality in the image forming means,
The processing by the document reading means and the image processing means is continued .

[0007]

The control means causes the abnormality detecting means to read the original.
If an abnormality is detected in the image processing means,
Processing with the forming unit is continued, and the abnormality detecting unit
If an error is detected in the scanner,
Processing with the image processing means is continued . Therefore, even if one of the document reading means and the document forming means is inoperable due to a paper jam or a process for recovery, if the other is operable, the processing can be continued , and the image processing can be continued.
Processing of physical means also Ru can continue. That is, when the document reading means becomes inoperable, image processing and image processing of the document data already read by the document reading means are performed .
The image processing means and the image forming means are controlled by the control means so that the image formation can be performed. When the document forming unit becomes inoperable, in order to prepare for image formation, the document reading unit reads the image data of the remaining document in addition to the image data of the already read document.
Further, the image processing means forms the image data of the read original image.
The control means controls the image processing .

[0008]

Embodiments of the present invention will be described below with reference to the drawings. Here, an example is shown in which the image forming apparatus according to the present invention is applied to a digital copying machine.

FIG. 2 is a sectional view showing the overall configuration of a digital copying machine as an embodiment of the image forming apparatus according to the present invention.

As shown in FIG. 1, a digital copying machine 10 according to this embodiment includes a scanner unit 11, a laser printer unit 12, a multi-stage paper feed unit 13, and a sorter 14.

A double-sided automatic document feeder (RDF) 15 is installed above the scanner unit 11.
Is composed of a document table 16 made of transparent glass, a movable scanner unit 17, and a position control device for controlling the position of the scanner unit 17.

This position control device is a scanner unit.
The position control device includes a scanner motor 18, a pulley 19 that drives the scanner 17, and a wire 20 stretched between the scanner motor 18 and the pulley 19, and the position control device moves the scanner unit 17 along the longitudinal direction of the document table 16. It is configured to be able to move and stop at a predetermined position.

The scanner unit 17 includes a lamp reflector assembly 21 for exposing a document, a CCD (photoelectric conversion element) linear image sensor 22, and a plurality of reflection mirrors 2 for guiding a reflected light image from the document to the CCD linear image sensor 22.
3, and a lens 24 for imaging the reflected light image from the original on the CCD linear image sensor 22.

When scanning a document placed on the document table 16, the scanner unit 11 reads the document image while the scanner unit 17 moves along the lower surface of the document table 16 and uses the RDF 15. In this case, the document image is read while the document is being conveyed while the scanner unit 17 is stopped at a predetermined position below the RDF 15.

The image data obtained by reading the original image by the scanner unit 17 is subjected to various processes by an image processing control unit included in the digital copying machine 10 and described later. The image data is temporarily stored in a memory provided therein, and the image data in the memory is provided to the laser printer unit 12 in response to an output instruction to form an image on paper.

The multi-stage paper feeding unit 13 includes a first cassette 28,
It has a second cassette 29, a third cassette 30, and a fourth cassette 31 which can be added by selection. In the multi-stage paper feed unit 13, the sheets are sent out one by one from the sheets stored in these cassettes, and are conveyed to the laser printer unit 12.

The laser printer unit 12 includes a manual document tray 2
5. It has a laser writing unit 26 and an electrophotographic processing unit 27 for forming an image.

The laser writing unit 26 includes a semiconductor laser that emits a laser beam corresponding to the image data from the memory, a polygon mirror that deflects the laser beam at a constant angular velocity,
It has an f-θ lens and the like for correcting the laser beam deflected at a constant angular velocity so as to be deflected at a constant speed on the photosensitive drum 27a of the electrophotographic process unit 27.

The electrophotographic process section 27 is configured by arranging a charging device, a developing device, a transfer device, a peeling device, a cleaning device, a static eliminator, and a fixing device 32 around a photosensitive drum 27a according to a well-known mode. .

A transport path 33 is provided downstream of the fixing device 32 in the transport direction of the sheet on which an image is to be formed.
Reference numeral 33 denotes a transport path 34 leading to the sorter 14 and a multi-stage paper feed unit.
It branches to a transport path 35 leading to 13.

The transport path 35 branches off in the multi-stage paper feed unit 13, and a reverse transport path 36 and a double-sided / composite transport path 37 are provided as transport paths after branching.

The reversing transport path 36 is a transport path for reversing the front and back of the sheet with respect to the image forming position of the photosensitive drum 27a in a duplex copying mode for copying both sides of a document. The duplex / composite transport path 37 is a reverse transport path in the duplex copying mode.
In the single-sided composite copy mode, where the paper is transported from 36 to the image forming position of the photosensitive drum 27a, or a composite copy is performed on one side of the paper to form an image of a different original or an image with a different color toner, the sheet is exposed without reversing. This is a transport path for transporting the drum 27a to the image forming position.

The multi-stage paper feed unit 13 includes a common conveyance path 38, and the common conveyance path 38 transfers sheets from the first cassette 28, the second cassette 29, and the third cassette 30 to the electrophotographic processing unit 27. It is configured to be carried out.

The common transport path 38 joins the transport path 39 from the fourth cassette 31 on the way to the electrophotographic processing section 27 and communicates with the transport path 40.

The transport path 40 joins the double-sided / composite transport path 37 and the transport path 41 from the manual document tray 25 at a junction 42 to form an image between the photosensitive drum 27a of the electrophotographic process unit 27 and the transfer unit. These are configured to communicate with the forming position.
The junction 42 of the two transport paths is provided at a position close to the image forming position.

Accordingly, in the laser writing unit 26 and the electrophotographic processing unit 27, the image data read from the above-mentioned memory is scanned by the laser beam by the laser writing unit 26 to thereby form the photosensitive drum 27a.
The toner image formed as an electrostatic latent image on the surface of the sheet and visualized by the toner is electrostatically transferred and fixed onto the surface of the sheet conveyed from the multi-stage sheet feeding unit 13. The sheet on which the image has been formed in this manner is fed from the fixing device 32 to the conveyance paths 33 and 34.
Via the transport paths 33 and 35 and to the reverse transport path 36.

Next, the configuration and operation of the RDF 15 will be described.

FIG. 3 is a sectional view of the RDF 15 attached to the scanner section 11 of the digital copying machine 10 of FIG.

The RDF 15 converts a plurality of set originals into one.
The document is automatically fed to the scanner unit 11 one sheet at a time, and one or both sides of the document can be read by the scanner unit 17 in FIG. 2 according to the operator's selection.

As shown in FIG. 3, the RDF 15 includes a document tray 50 for setting a document 51, a document pickup roller 52 driven via an electromagnetic clutch (not shown), a pair of conveyance rollers 53, and a conveyance path of the document 51. Solenoid-driven change lever 54 that can switch between two directions (document support drum (platen roller) that can rotate in two directions (the direction of the arrow shown in the figure)
55, left and right supply rollers 56L and 56R for feeding the document 51 in cooperation with the platen roller 55, a transparent document support glass 57,
Left and right document guides 58L and 58R, left and right document discharge rollers
Left and right movable guides 60L and 60 driven by solenoids cooperating with 59L and 59R and original discharge rollers 59L and 59R, respectively.
R, solenoid driven original discharge movable guide 61, original discharge conveyance path 62, discharge roller pair 63, discharge tray 64, solenoid driven rotatable original reverse guide 65, original reverse guide 65
, A reversing conveyance path 66 having one side formed, a pair of reversing conveyance rollers 67 driven via an electromagnetic clutch, and a rotating shaft 68.

It is desirable that the distance between the platen roller 55 and the document supporting glass 57 is set to be larger than the thickness of the document 51.

The original detection sensors S1 to S1
S5 is provided, and signals output from the document detection sensors S1 to S5 when the document 51 is detected are sent to a central control unit (not shown) which will be described later.

The central control unit is configured to operate the various electromagnetic clutches and solenoids at a predetermined timing to control the original 51 to be conveyed through the original reading position (exposure position) P as described later. I have.

Next, the operation of the RDF 15 will be described.

When copying only one side of the original 51, a plurality of originals 51 are set on the original tray 50 and input keys on an operation panel, which will be described later, provided on the digital copying machine 10 shown in FIG. A copy mode (single-sided original scanning, number of copies, copy density, etc.) is input.

When a print switch on the operation panel of the digital copying machine is pressed, a main motor (not shown) of the RDF 15 starts rotating.

Next, the clutch of the original pickup roller 52 is turned on, and the rotating original pickup roller 52 is rotated.
Feeds only the top document of the plurality of documents 51 set on the document tray 50. At this time,
The 53 clutch is also turned on at the same time, and the transport roller pair 53
Is also driven to rotate.

When the leading end of the fed document 51 reaches the first document detection sensor S1, the solenoid of the change lever 54 is excited, and the change lever 54 is moved from the position indicated by the dashed line to the position indicated by the solid line in FIG. Is switched to Further manuscript 51
As the feeding of the document 51 is continued, the leading end of the document 51 is guided along the side surface of the change lever 54, and is guided in the direction of the fourth document detection sensor S4.

After the leading edge of the document 51 is detected by the fourth document detection sensor S4, the conveyance of the document 51 is temporarily stopped in synchronization with the timing at which the document 51 is supported by the platen roller 55 and the right supply roller 56R. I do.

Next, at a predetermined timing, the clutch of the right conveying roller 56R is turned on, and the original supporting glass 57 is turned on.
The feeding of the document 51 to the exposure position P is started again.

The platen roller 55 rotates the exposure position P clockwise in a state where the document 51 is pressed against the surface of the platen roller 55 by the right document guide 58R. Pass from right to left. At the exposure position P, image data of the document 51 is read by the scanner unit 17 in FIG.

The document 51 that has passed the exposure position P passes under the left document guide 58L, and passes through the left document discharge roller 59L.
Transported to The leading edge of the document 51 is the document discharge roller 59L
The left movable guide 60L
The movable guide 60L is pressed against the original discharge roller 59L while the original 51 is sandwiched.

As a result, the original discharge roller 59
The document 51 is guided along the upper surface of the document discharge movable guide 61 by the conveyance force due to the frictional force of
After passing through 62, the sheet is discharged onto a sheet discharge tray 64 by a sheet discharge roller pair 63.

A fifth document detection sensor S5 provided in the document discharge conveyance path 62 detects the rear end of the document 51, and
Is determined to be discharged onto the paper discharge tray 64.

When a plurality of originals 51 are set on the original tray 50, the next original is fed at the timing when the rear end of the previous original passes the exposure position P.

The document tray 50 is provided with a document detection sensor (not shown) for detecting whether or not the document 51 is set, and the above operation is repeated until the last document 51 is exhausted.

Next, when copying both sides of the document 51,
When the print switch on the operation panel of the digital copying machine is pressed, the original pickup roller 52 feeds only one of the uppermost originals of the plural originals 51 set on the original tray 50.

When the leading end of the fed document 51 reaches the first document detection sensor S1, the clutch of the pair of transport rollers 53 is turned on, and the pair of transport rollers 53 is also driven to rotate. At this time, the solenoid of the change lever 54 is in a non-excited state, and the change lever 54 is at a position indicated by a dashed line in FIG. 3, and the leading end of the document 51 is guided toward the second document detection sensor S2. Is done.

Document 51 that has passed through second document detection sensor S2
With the leading end of the document 51 sandwiched between the platen roller 55 and the left supply roller 56L, the clutch of the left transport roller 56L is turned off, and the transport of the document 51 is temporarily stopped.

Next, at a predetermined timing, the conveying rollers 56L
Is turned on again, and feeding of the document 51 to the exposure position P of the document supporting glass 57 is started again.

The platen roller 55 rotates the exposure position P in a counterclockwise direction while the document 51 is pressed against the surface of the platen roller 55 by the left document guide 58L.
The document 51 passes through the exposure position P from left to right in FIG.
Thus, exposure scanning of one side of the document 51 is started.

The document 51 that has passed through the exposure position P passes under the right document guide 58R and passes through the right document discharge roller 59R.
Sent to. The solenoid of the right movable guide 60R is excited at the timing when the leading edge of the document 51 reaches the document discharge roller 59R, and the movable guide 60R is pressed against the document discharge roller 59R with the document 51 sandwiched.

The document 51 conveyed by being sandwiched between the movable guide 60R and the document discharge roller 59R is guided to the reversing conveyance path 66, and conveyed by the pair of reversing conveyance rollers 67 toward the third document detection sensor S3. You.

When the leading end of the document 51 reaches the third document detection sensor S3, the solenoid of the document reversing guide 65 is excited, and the document reversing guide 65 is moved from the position shown by the solid line about the rotation shaft 68 to a dashed line. Is rotated along the arrow shown in the figure to the position shown by, and the reverse conveyance path 66 is opened. At the same time, the solenoid of the change lever 54 is excited, and the change lever 54
Is switched from the position indicated by the dashed line to the position indicated by the solid line.

The leading end of the original 51 is further moved by a pair of reverse conveying rollers 67.
Is guided to the transport roller pair 53, and is guided to the fourth document detection sensor S4 along the side surface of the change lever 54 switched to the position shown by the solid line. Then, when the leading end of the document 51 is sandwiched between the platen roller 55 and the right supply roller 56R, the conveyance of the document 51 is temporarily stopped.

In this state, the reverse conveyance path length (from the contact point between the platen roller 55 and the supply roller 56R, the fourth document detection sensor S4, the change lever 54, the conveyance roller pair 53, the third document detection sensor S3, When the length of the original is longer than the length of the original passing through the pair of transport rollers 67 and the reverse transport path 66 to the contact point between the movable guide 60R and the original discharge roller 59R), the rotation of the original reverse guide 65 causes Since the reversing conveyance path 66 is open, even when the leading end of the document is stopped, the portion of the document subsequent to the reversing conveyance roller pair 67 moves from the position between the reversing conveyance roller pair 67 to the movable guide 60R. A natural bending is formed up to the position between the document discharge roller 59R and the document discharge roller 59R.

The reversing conveyance path by the rotation of the document reversing guide 65
The degree of opening 66 depends on the size of the document detected by a document size detection device capable of detecting the size of the document (not shown) or the size of the document input by the operator via the input keys on the operation panel. The degree of opening may be set in advance so that the reverse conveyance path 66 is opened.

Next, after the rear end of the original 51 has passed the exposure position P, the original is again fed to the exposure position P of the original supporting glass 57 at a timing with the scanner unit 17.

The platen roller 55 has an original guide 58 for the original 51.
While being pressed against the surface of the platen roller 55 by R, the exposure position P is rotated clockwise, and the document 51 passes through the exposure position P from right to left in FIG. At the exposure position P, the image data of the original 51 is
Read by.

The document 51 that has passed through the exposure position P passes under the left document guide 58L, and passes through the left document discharge roller 59L.
Transported to The leading edge of the document 51 is the document discharge roller 59L
The left movable guide 60L
The movable guide 60L is pressed against the original discharge roller 59L while the original 51 is sandwiched, and the original 51
Is transported.

When the reading of the image on the second side of the document 51 is completed, the solenoid of the document reversing guide 65 is de-energized, and the document reversing guide 65 returns to the position shown by the solid line, and the leading edge of the next document 51 is returned. To the reverse conveying roller pair 67.

The document 51 conveyed by being sandwiched between the movable guide 60L and the document discharge roller 59L is guided along the upper surface of the document discharge movable guide 61, passes through a document discharge and conveyance path 62, and forms a pair of discharge rollers. The paper is ejected onto the paper ejection tray 64 by 63.

When a plurality of originals 51 are set on the original tray 50, at the time of scanning and exposing the second side of the previous original, the next trailing end of the original passes through the exposure position P in accordance with the timing. Are sent.

The above operation is repeated until the last original 51 is left on the original tray 50.

FIG. 4 is a plan view of a document size detecting device which can be provided in the scanner section 11 of the digital copying machine 10 of FIG. FIG. 5 is a plan view A of the document size detecting device of FIG.
It is sectional drawing which followed the -A line.

The scanner section 11 of the digital copying machine 10 of this embodiment can be provided with a document size detecting device as shown in these figures.

This document size detecting device includes a plurality of pairs of light emitting elements 71 and light receiving elements 72.

The plurality of pairs of the light emitting element 71 and the light receiving element 72 are arranged such that the line connecting the pair of light emitting element 71 and the light receiving element 72 is parallel to the line connecting the other pair of the light emitting element 71 and the light receiving element 72. The individual light emitting elements 71 are arranged on the document table 16.
Is configured to detect the size of the original depending on whether the light emitted from reaches the corresponding light receiving element 72 or does not reach the corresponding light receiving element 72 after being interrupted by the original placed on the original placing table 16. I have.

The detected original size is displayed together with the paper size on an operation / display panel, which will be described later, provided at the top of the digital copying machine. The document size detecting device is described in more detail in Japanese Patent Application Laid-Open No. 2-140603 of the present applicant.
Can be referred to.

It should be noted that a similar document size detecting device can be provided in the document tray 50 for storing the document of the RDF 15 shown in FIG.

Next, the operation / display panel provided on the upper part of the digital copying machine 10 of FIG. 2 will be described.

FIG. 6 is an external view of an operation panel of the digital copying machine 10 of FIG. 2, FIG. 7 is an enlarged view of a basic screen of a display section of the operation panel of FIG. 6, and FIG. 8 is a view of a display section of the operation panel of FIG. FIG. 9 is an explanatory diagram showing a magnification setting screen, FIG. 9 is an explanatory diagram showing a paper size setting screen on the display unit of the operation panel in FIG. 6, FIG. 10 is an explanatory diagram showing a copy density setting screen on the display unit of the operation panel in FIG.
FIG. 11 is an explanatory diagram showing a copy number setting screen on the display unit of the operation panel in FIG. 6, and FIG. 12 is an explanatory diagram showing a copy mode setting screen on the display unit of the operation panel in FIG.

As shown in FIG. 6, the operation panel 80 is provided with a display section 80a also serving as an input section at substantially the center thereof, and a print switch 80b and a clear key 80c at the right end. The display unit 80a may be configured by a transparent touch panel on the display surface of a dot matrix liquid crystal display unit, for example.

FIG. 7 shows a state in which the basic screen when the power is turned on is enlarged and displayed on the display section 80a of FIG.
In the upper part of the display section 80a, a magnification selection area 81 in which a copy magnification can be selected, a paper size selection area 82 in which a paper size can be selected, a copy density selection area 83 in which a copy density can be selected, and a copy in which the number of copies can be selected. A sorter selection area 85 in which the sorter type can be selected and a lower right part of the display unit 80a, for example,
A plus function selection area 86 is provided for selecting a copy mode such as performing double-sided copying from a single-sided original.

When touching the magnification selection area 81 of the display section 80a, the operation panel 80 displays the magnification setting screen shown in FIG. 8, and when touching the paper size selection area 82, displays the paper size setting screen shown in FIG. When the user touches 83, the screen is switched to the copy density setting screen shown in FIG. 10, and when the user touches the copy number selection area 84, the screen is switched to the copy number setting screen shown in FIG.

The operation panel 80 has a sorter selection area 85
Touch to switch the display in the order of “Non-sort”, “Sort”, “Group”, “Staple sort”, and “Saddle stitching setting screen”. Touch the plus function selection area 86 to display the copy mode shown in FIG. It is configured to switch to a setting screen.

In the magnification setting screen shown in FIG. 8, when the user touches the reduction selection area 81a or the enlargement selection area 81b, the fixed magnification is selected, and the fixed magnification selected in the magnification display area 81c at the upper left of the display section 80a (for example, FIG. 141%) is displayed. The zoom-down selection area 81d and the zoom-up selection area 81e are selection areas in which the copy magnification can be set arbitrarily in units of 1%.
f is a selection area selected when returning the copy magnification to the same magnification, and an automatic magnification selection area 81g is used to select a mode in which the apparatus automatically sets the copy magnification based on the document size and the paper size. Area.

In the paper size setting screen shown in FIG.
The first cassette 28, the second cassette 29, the third cassette 30, the fourth cassette 31 that can be added by the selection of the operator, and the first cassette 28 included in the multi-stage paper feeding unit 13 of the digital copying machine 10 are shown. The size of the paper stored in the paper feeding unit such as the fifth cassette does not match the selection area 82a.
, 82b, 82c, 82d and 82e, respectively. Selection areas 82a, 82b, 82 displaying cassettes containing paper of the size desired by the operator
By touching any one of c, 82d and 82e, the corresponding cassette is selected, and the display area 82f displays the number of the selected cassette (for example, number 2 shown in the figure) and the paper size (for example, 81/2 shown in the figure). × 11) is displayed.
The display area 82g is also configured to simultaneously display the size of the document (for example, 11 × 17 shown in the figure) detected by the document size detecting device shown in FIGS. In the copy density setting screen shown in FIG. 10, a "light" selection area 83a and a "dark" selection area 83b, which can arbitrarily adjust the copy density, determine the density of the original and automatically set an appropriate copy density. An "automatic density" selection area 83c for selecting a mode to be set and a "halftone enhancement" selection area 83d for selecting a mode for enhancing a halftone image such as a photograph are provided.

The copy number setting screen shown in FIG. 11 is provided with a selection area 84a corresponding to a number from 0 to 9 for inputting the number of copies and a selection area 84c for clearing. When the number of copies is input, the number of copies (for example, 999 shown in the figure) set and input is displayed in the display area 84b.

The copy mode etc. setting screen shown in FIG.
At the approximate center, a selection area is selected to create a two-sided copy from a one-sided original (the number of originals is even), a two-sided copy from a one-sided original (odd number of originals), a two-sided copy from a two-sided original, and a one-sided copy from a two-sided original. 86a, 86b,
86c and 86d are provided. If the user touches one of the selection areas 86a, 86b and 86c for performing duplex copying and then touches the "return" selection area 86e, the screen returns to the basic screen of FIG.

Next, a description will be given of the state of paper transport when a document image is formed in the digital copying machine 10 of FIG.

FIGS. 13 and 14 show the digital copying machine shown in FIG.
FIG. 10 is a schematic diagram for explaining a sheet conveyance state when a document image is formed in FIG.

FIGS. 13A to 13E show how these sheets are transported when an original image is formed on both sides of a plurality of sheets. FIGS. FIG. 14 illustrates a process in which a sheet is transported when a document image is formed.
(A) to (D) sequentially show a process in which a sheet is conveyed when a document image is formed on the other surface of the sheet.

The paper transport process can be configured to be controlled and executed by a central control unit described later.

FIG. 13A shows a paper feed cassette 91, a carry-in transport path 90a guided from the paper feed cassette 91, and an image forming transport path 90 including an image forming position where a document image is formed on a sheet.
b, a reversing conveyance path 90c for reversing the front and back of the sheet with respect to the image forming position;
A transport path 90d leading to the sheet feeding tray 90b, a discharge transport path 90e leading to a discharge tray (not shown), and a photosensitive drum 92 are shown.

The paper feed cassette 91 and the carry-in conveyance path 90 shown in FIG.
a, the reverse transport path 90c, the transport path 90d, and the photosensitive drum 92
The cassette for paper feed included in the multi-stage paper feed unit 13 of the digital copying machine 10 of FIG. 2 corresponds to the common transport path 38, the reverse transport path 36, the duplex / composite transport path 37, and the photosensitive drum 27a, respectively. ing.

Referring to FIGS. 13A to 13E, four sheets 1
A process in which a sheet is transported when a document image is formed on one of the surfaces 1A to 4A of the first to fourth surfaces will be described.

As shown in FIG. 13A, the first sheet 1
Is transported from the paper feed cassette 91 to the image forming position between the image forming transport path 90b and the photosensitive drum 92 via the transport path 90a, and then, as shown in FIG. An image is formed on 1A, and the second sheet 2 is carried into the carry-in conveyance path 90a. Next, as shown in FIG. 13C, the sheet 1 is sent to the reverse conveyance path 90c, and
An image is formed on one side 2A of the sheet 2, and the third sheet 3 is carried into the carry-in path 90a. Then, FIG.
As shown in (D), the paper 1 is moved from the reverse conveyance path 90c to the conveyance path.
The paper 2 is transported to the reverse transport path 90c, an image is formed on one side 3A of the sheet 3, and the fourth sheet 4 is transported into the transport path 90a. Then, FIG.
As shown in FIG. 3 (E), sheet 1 is reversed and conveyed to image forming conveyance path 90b, and sheet 2 is conveyed from reversing conveyance path 90c to conveyance path 90c.
The paper 3 is transported to the reverse transport path 90c, and an image is formed on one surface 4A of the paper 4.

Next, following the state shown in FIG.
4 (A) to 4 (D), a description will be given of a process in which a sheet is conveyed when a document image is formed on the other surface 1B-4B of the sheets 1-4.

The transport path 90d is reversed in FIG.
As shown in FIG. 14A, an image is formed on the other side 1B of the first sheet 1 transported into the image forming transport path 90b from the printer, and the inverted second sheet 2 is transferred to the transport path 90b. 90d, the third sheet 3 is conveyed from the reverse conveying path 90c to the conveying path 90d, and the fourth sheet 4 is sent to the reverse conveying path 90c. Next, as shown in FIG. 14B, the sheet 1 is moved from the image forming conveying path 90b to the discharging conveying path.
90e, the image is formed on the other side 2B of the sheet 2, and the inverted sheet 3 is fed from the conveying path 90d to the image forming conveying path.
The paper 4 is transported to the reverse transport path 90c and transported to the transport path 90c.
conveyed to d. Next, as shown in FIG. 14C, the sheet 2 is transported from the image forming transport path 90b to the discharge transport path 90e, an image is formed on the other surface 3B of the sheet 3, and the inverted sheet 4 is transported. From 90d, it is carried into the image forming conveyance path 90b. Next, as shown in FIG. 14D, the sheet 3 is transported from the image forming transport path 90b to the discharge transport path 90e, an image is formed on the other side 4B of the sheet 4, and the fifth sheet 5 is supplied. The paper is transferred from the paper cassette 91 to the transfer path 90a.

Next, a control system of the digital copying machine 10 shown in FIG. 2 will be described.

FIG. 15 is a block diagram showing the configuration of a control system of the digital copying machine 10 of FIG. In the figure, thick arrows between blocks indicate the flow of image data, solid arrows indicate the flow of control signals, and dashed two-way arrows indicate communication control lines.

As shown in FIG. 1, the digital copying machine 10 includes a control system for controlling the operation of the digital copying machine 10. The control system includes a central control unit (PCU) 101, an image processing unit (ICU) 102, Substrate unit (OPU) 10
3, a sorter control unit (FCU) 104, an input data pre-processing unit (CCU) 105, and a laser control unit 106.

PCU 101 is a central processing unit (CPU)
So that each unit of the digital copying machine 10 is controlled in a centralized manner, that is, the ICU 102, the OPU 103, and the FCU 104
Is controlled by communication (broken arrow shown in the figure).

The OPU 103 controls the operation panel 80 shown in FIG. 6, and the FCU 104 controls the sorter 14.

A load 107 such as a motor and a solenoid related to the scanner unit 11 and a load 108 such as a motor, a solenoid and a high voltage unit related to the laser printer unit 12 in FIG.
The sequence control of the load 109 such as the motor, clutch and switch related to the RDF 15 and the load 110 such as the motor, clutch and sorter related to the multi-stage paper feeding unit 13 or the desk is configured to be directly controlled by the PCU 101. .

Processing of image data described later is directly performed by a CPU included in the ICU 102. As shown in FIG. 15, the ICU 102 preprocesses the image data from the CCD linear image sensor 22 of FIG.
2 for storing in the main memory 102a included in
The CU 105 and the laser control unit 106 for outputting the data stored in the main memory 102a to the laser printer unit 12 can be controlled in parallel.

The CCU 105, the ICU 102, and the laser control unit 106 are independent control units, and the control units of the CCU 105, the ICU 102, and the laser control unit 106 operate in parallel unless the data to be processed in each control unit is the same. And can operate independently without being affected by the processing status of other control units.
However, the CPU included in the PCU 101 is the ICU 102
Can be controlled by communication.

Next, processing from input to output of image data will be described.

FIG. 16 is a block diagram of an image processing control unit included in the digital copying machine 10 shown in FIG. 2 for performing processing from input to output of image data.

As shown in the figure, the image processing control unit includes an image data input unit 111, an image data processing unit 112, an image data output unit 113, and a memory 114 including a RAM (random access memory). .

Image data input unit 111, image data processing unit
The CCU 105 in FIG.
, ICU 102 and laser control unit 106. Therefore, the image data processing unit 112 is connected to the PCU 101 through the ICU 102 as shown in FIG.
Is configured to control the operation of the image processing control unit together with the CPU. The memory 114 is a memory corresponding to the main memory 102a of the ICU 102.

The image data input section 111 includes a CCD section 111a, a histogram processing section 111b, and an error diffusion processing section 111c.

The image data input unit 111 binarizes and converts the image data of the original read from the CCD linear image sensor 22 shown in FIG. Is stored in the memory 114 once.

That is, in the CCD section 111a, after an analog electric signal corresponding to each pixel density of the image data is A / D (analog / digital) converted, MTF correction, black-and-white correction or gamma correction is performed, and 256 levels are performed. It is output to the histogram processing unit 111b as a digital signal of a key (8 bits).

In the histogram processing section 111b, the CCD section 11
The digital signal output from 1a is added for each pixel density of 256 gradations to obtain density information (histogram data), and if necessary, the obtained histogram data is sent to the CPU of the ICU 102. Is sent to the error diffusion processing unit 111c.

The error diffusion processing section 111c performs an error diffusion process which is a kind of pseudo halftone process. That is, the error diffusion processing unit 111c converts the 8-bit / pixel digital signal output from the CCD unit 111a into one bit (binary) by reflecting the binarization error in the binarization determination of the adjacent pixel. The conversion is performed, and a redistribution operation is performed to faithfully reproduce the local area density in the document.

The operation of the image data input unit 111 is started by the PC
The PCU 101 instructs the load 10 associated with the scanner unit 11 shown in FIG. 2 on condition that the print switch 80b of the operation panel 80 shown in FIG. 6 is pressed.
While initiating the sequence control of step 7, an instruction is given to the ICU 102 at the command level in accordance with the leading synchronization signal. However, PCU101 is the main memory of ICU102.
The usage status of 102a is constantly monitored by communication, and before the reading operation by the scanner unit is started, the amount of image data to be input is compared with that confirmed by the document size detection device shown in FIGS. It is determined whether or not the capacity can be stored in the memory 102a, and if it is not possible, the situation can be displayed by a message or the like.

The image data processing section 112 includes a multi-value processing section 112a.
And 112b, a synthesis processing unit 112c, a density conversion processing unit 112d, a scaling processing unit 112e, an image processing unit 112f, and an error diffusion processing unit 112g.
And a compression processing unit 112h.

The image data processing section 112 is a processing section for finally converting the input image data into image data desired by the operator, and stores the image data in the memory 114 as finally converted output image data. Until the processing is performed, the processing is performed in this processing unit.

The respective processing units included in the image data processing unit 112 function as needed, and the functions may not be executed in some cases.

In the multi-value processing sections 112a and 112b, the data binarized by the error diffusion processing section 111c is converted again into 256 gradations.

The synthesis processing unit 112c performs a logical operation for each pixel,
That is, the operation of a logical sum, a logical product, or an exclusive logical sum is selectively performed. The data to be subjected to this calculation is stored in the memory 114
, And bit data from a pattern generator (PG).

The density conversion processing section 112d arbitrarily sets the relationship between the input density and the output density with respect to the 256-level digital signal based on a predetermined tone conversion table.

In the scaling unit 112e, pixel data (density value) for the target pixel after scaling is obtained by performing an interpolation process based on the input known data in accordance with the designated scaling factor. After the scan is scaled, the main scan is scaled.

In the image processing section 112f, various kinds of image processing are performed on the input pixel data, and information collection such as feature extraction can be performed on the data sequence.

The error diffusion processing section 112g performs the same processing as the error diffusion processing section 111c of the image data input section 111.

The compression processing section 112h compresses the binary data by encoding called run length. As for the compression of the image data, the compression functions in the final processing loop when the final output image data is completed.

The operation of the image data processing unit 112 is based on the function set by the operator on the operation panel 80 shown in FIG. 6, and the data to be processed in the operation of the image data input unit 111 is stored in the memory 114. Is started, when the PCU 101 transmits an image processing command to the ICU 102.

The image data output section 113 includes a restoration section 113a, a multi-value processing section 113b, an error diffusion processing section 113c, and a laser output section 113d.

The image data processing unit 113 restores the image data stored in the memory 114 in a compressed state,
The laser output unit 11 converts the data into 6 gradations again, and performs error diffusion of the quaternary data that provides a smoother halftone representation than the binary data.
It is configured to transfer data to 3d.

That is, in the decompression unit 113a, the image data compressed by the compression processing unit 112h is decompressed.

In the multi-value processing section 113b, an image data processing section
The same processing as that performed by the multi-value processing sections 112a and 112b of 112 is performed.

The error diffusion processing section 113c performs the same processing as the error diffusion processing section 111c of the image data input section 111.

In the laser output section 113d, digital pixel data is converted into an ON (ON) / OFF (OFF) signal for driving the laser based on a control signal from the PCU 101, and the laser is turned on / off. .

The data handled by the image data input unit 111 and the image data output unit 113 is basically converted into binary data in order to reduce the capacity of the memory 114.
4 but taking into account the degradation of image data
It is also possible to process in the form of value data.

The condition for starting the operation of the image data output unit 113 is determined by the processing desired by the operator (the operation panel shown in FIG. 6).
The image data for which the function set by 80) has been completed is stored in memory.
114. Whether the image data stored in the memory 114 has been processed is determined by the PC.
It is managed by U101.

The scanner section 11 shown in FIG. 2 is an embodiment of the document reading means of the present invention. The laser printer unit 12 shown in FIG. 2 is an embodiment of the image forming means of the present invention. PC of FIG.
U101 is an embodiment of the control means of the present invention. The main memory 102a in FIG. 15 or the memory 114 in FIG. 16 is an embodiment of the storage means of the present invention.

Next, the operation of the digital copying machine 10 when a paper jam (jamming) occurs in the document transport path of the RDF 15 shown in FIG. 3 or in the paper transport path of the digital copying machine 10 shown in FIG. I do.

FIG. 1 is a schematic diagram showing a procedure for processing image data in a digital copying machine as an embodiment of the image forming apparatus according to the present invention. FIG. 1A shows a state in which the fifth document is jammed in the document transport path of the RDF 15 before the processing of the input image data of the fifth document performed before being stored in the memory 114 of FIG. FIG. 1B is a schematic diagram showing a procedure for processing image data when the image is raised, and FIG.
FIG. 9 is a schematic diagram illustrating a processing procedure of image data when jamming occurs in a sheet transport path of No. 10; In these figures, the horizontal axis represents the time axis, and the frames in the figures and the numbers in the frames are 1
Represents the image data of the fifth to fifth originals.

The upper row of FIG. 1A shows the image data of the first to fourth originals input from the CCD linear image sensor 22 of FIG. 2 before being stored in the memory 114 of FIG. The processing to be performed is completed by the CCU 105, that is, by the image data input unit 111, and represents a point in time when jamming occurs in the fifth document before the preprocessing of the input image data is completed. The center column in FIG. 1A shows the image data of the first to third original documents, for which the preprocessing of the input image data has been completed, in which the image processing by the ICU 102, that is, the image data processing unit 112, has been completed. At the time when the image data of the fourth document for which the pre-processing has been completed is under image processing. The lower row in Fig. 1 (A)
Based on the image data of the first and second originals for which the image processing has been completed, the laser control unit 106, that is, the image data output unit 113 completes the formation of a plurality of (N) copied images, and the third This represents a point in time when a plurality of copy images are being formed based on the image data of the document.

The PCU 101 shown in FIG. 15 is provided on the RDF 15 for detecting jamming of a document.
The normal transport timing of the document is monitored based on the signals sent from the document detection sensors S1 to S5.

As shown in FIG. 1A, before the preprocessing of the input image data of the fifth document is completed, the fifth document is
Assuming that jamming occurs in the document transport path of the DF15, the PCU 101 stops the sequence operation of the RDF15 when the jamming of the fifth document is detected.
The image processing of the image data of the fourth document being processed and the formation of a plurality of copied images of the image data of the third document forming the copied image are continued irrespective of the occurrence of jamming. To complete. Further, when the image processing of the image data of the fourth document is completed, the PCU 101 controls to form a plurality of copied images based on the image data of the fourth document subjected to the image processing.

The upper row of FIG. 1B shows the image data of the first to fifth originals input from the CCD linear image sensor 22 of FIG. 2 before being stored in the memory 114 of FIG. The CCU 105 to be performed, that is, the completion of the processing by the image data input unit 111, or the point during the processing. The central row in FIG. 1B shows the completion of image processing by the ICU 102, that is, the image data processing unit 112, or the processing of the image data of the first to fifth originals for which the pre-processing of the input image data has been completed. Represents a point in time. The lower row in FIG. 1 (B) shows the laser control unit based on the image data of the first document after image processing has been completed.
That is, the point in time when the formation of a plurality of (N) copy images by the image data output unit 113 is completed and jamming occurs during the formation of the third copy image based on the image data of the second document. Represent.

The PCU 101 monitors the normal paper transport timing based on a signal sent from a sensor (not shown) provided in the paper transport path of the laser printer unit 12 and the multi-stage paper feed unit 13 in FIG. The jam of the sheet in the conveyance path is detected by detecting an abnormality in the conveyance timing.

As shown in FIG. 1B, based on the image data of the first document, the laser control unit 106, that is, the image data output unit 113 completes the formation of a plurality of copied images, and the second Assuming that the paper jams in the paper transport path of the digital copying machine 10 during the formation of the third copy image based on the image data of the original, the PC
When U101 detects jamming, the laser printer unit 12
The control sequence of the image forming process and the control sequence of the sheet conveyance are stopped, but the preprocessing and the image processing of the input image data of the document are continued as long as the main memory 102a or the memory 114 of the ICU 102 permits. .

Therefore, even if the paper jam occurs during the formation of the copy image, after the processing such as removing the jammed paper is performed, the completion of the image processing stored in the main memory 102a or the memory 114 is completed. Using the image data of the second and subsequent originals, a copy image can be formed continuously.

It should be noted that the main memory 102a or the memory 114
As for the timing of clearing the image data for which the image processing has been completed, the clearing is performed when the paper on which the formation of the copy image is completed is completely discharged.

According to the above-described embodiment, even if one of the original image reading unit and the image forming unit is inoperable due to a paper jam or a process for recovery or the like, the other can operate. If so, the processing can be continued.
Therefore, the image forming apparatus fully utilizes its ability and can form an image at high speed and efficiently.

[0140]

As described above, the present invention provides a document reading means for reading a document image, a storage means for storing image data read by the document reading means, and a storage means.
Image processing for performing image processing on image data stored in
Image forming means for forming an image on paper based on image data image-processed by the image processing means,
Detects an abnormality in the document reading unit or the image forming unit
An image forming apparatus comprising: an abnormality detecting unit; and a control unit that controls the document reading unit, the image processing unit, and the image forming unit so as to be independently operable.
Indicates that the abnormality detection means has detected an abnormality in the document reading means.
In this case, the processing of the image processing unit and the image forming unit is continued.
The abnormality detection means detects an abnormality in the image forming means.
In this case, the processing of the original reading means and the image processing
Since to continue, thus, also one of the reading unit and the image forming portion of the original image is in the inoperable state by reason of processing secondary for paper jams and recovery, the other continues to operate if the process And the processing of the image processing means continues.
Ru can line.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a processing procedure of image data in a digital copying machine which is an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a cross-sectional view illustrating an entire configuration of a digital copying machine which is an embodiment of the image forming apparatus according to the present invention.

FIG. 3 is a sectional view of an RDF attached to a scanner unit of the digital copying machine of FIG. 2;

FIG. 4 is a plan view of a document size detecting device that can be provided in a scanner section of the digital copying machine of FIG. 2;

FIG. 5 is a cross-sectional view taken along line AA of the plan view of the document size detecting device of FIG. 4;

6 is an external view of an operation panel of the digital copying machine shown in FIG.

7 is an enlarged view of a basic screen of a display unit of the operation panel in FIG.

8 is an explanatory diagram illustrating a magnification setting screen of a display unit of the operation panel in FIG. 6;

9 is an explanatory diagram illustrating a paper size setting screen of a display unit of the operation panel in FIG. 6;

FIG. 10 is an explanatory diagram showing a copy density setting screen of a display unit of the operation panel in FIG. 6;

11 is an explanatory diagram showing a copy number setting screen on a display unit of the operation panel in FIG. 6;

12 is an explanatory diagram showing a copy mode etc. setting screen on a display unit of the operation panel in FIG. 6;

FIG. 13 is a schematic diagram for explaining a sheet conveyance state when a document image is formed in the digital copying machine of FIG. 2;

FIG. 14 is a schematic diagram for explaining a sheet conveyance state when a document image is formed in the digital copying machine in FIG. 2;

FIG. 15 is a block diagram showing a configuration of a control system of the digital copying machine of FIG. 2;

FIG. 16 is a block diagram of an image processing control unit included in the digital copying machine shown in FIG. 2, which performs processing from input to output of image data.

[Explanation of symbols]

 10 Digital copier 11 Scanner unit 12 Laser printer unit 13 Multi-stage paper feed unit 15 RDF 101 PCU 102 ICU 105 CCU 106 Laser control unit

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) H04N 1/00 H04N 1/21 H04N 1/40

Claims (1)

(57) [Claims] 1. A and original reading means for reading an original image, a storage means for storing image data read by the document reading unit, image de stored in the storage means
Image processing means for performing image processing on data,
Image forming means for forming an image on a sheet based on the image data subjected to image processing by the processing means, the document reading
Abnormality detection for detecting abnormality in the image forming means or the image forming means.
An image forming apparatus comprising: a knowledge unit, and control means for controlling operably said the document reading unit and the image processing unit <br/> and said image forming means independently before
The control means may be configured such that the abnormality detection means is configured to read the original document.
If an abnormality of the stage is detected, the image processing means and the
The processing with the image forming means is continued, and the abnormality detecting means
When the abnormality of the image forming unit is detected, the
An image forming apparatus , wherein processing by a reading unit and the image processing unit is continued .