JPH09166936A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform both-side copying and to improve the both-side copying speed by simply carrying an original without turning the original upside down. SOLUTION: This device is constituted of an analog copying part provided with an analog optical part 4, a digital reading part 7 transducing image information as original reflected light into an electric signal so as to make the image information treatable as digital image information, and a digital writing part 8 writing and recording the digital image information read by the part 7 on a photoreceptor by using a light emitting element. An original surface which is copied by an analog copying part is different from an original surface read by the part 7, and the parts 4 and 7 are arranged on positions respectively opposite to each other with an interposed original carrying path.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an analog / digital device having an analog copying section and a digital writing section in one device.
The present invention relates to an improvement of a digital mixed image forming apparatus, in particular, when a double-sided original is copied using an automatic original feeding device, it is possible to quickly read the double-sided images without inverting the originals and form the image quickly. The present invention relates to an image forming apparatus. Further, the present invention can solve the drawbacks of a digital copying machine such as a slow copying speed and the drawbacks of an analog copying machine that the read image information cannot be taken out as an electric signal to the outside of the copying machine. The present invention relates to a mixed analog / digital image forming apparatus.

[0002]

2. Description of the Related Art When a conventional image forming apparatus is used to copy a double-sided original having images on both sides of the original onto one side of a recording medium such as recording paper, image information obtained by first reading the front side of the original. Is copied on one side of a certain recording paper, the original is inverted by the original inverting means, and the back side is read, so that the image information obtained is copied on another recording paper. Further, when copying is performed on both sides of the recording paper, the recording paper also has to be reversed by the reversing means, and the copying speed is remarkably reduced as compared with the case of copying a single-sided original. Especially in a digital copying machine, this decrease in copying speed is a serious problem. Further, in an analog copying machine, the image information of an original read by an analog optical section is converted into an image by forming an image on the photoconductor by optically scanning the image information without electrically converting it. However, since the image information cannot be taken out as an electric signal to the outside of the copying machine, the usable range of the obtained image information is extremely limited. Also, by electrically converting the image information that is read optically, a copier,
Although a digital multi-function peripheral that enables functions such as a printer, a facsimile, and a scanner to be included in a single machine has been put into practical use, the digital copying machine is currently an analog copying machine in terms of copying speed. In reality, it cannot be the same as above.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate or mitigate the problem of the copying speed decrease which is a problem when copying a two-sided original by an image forming apparatus of the related art, and one side of the original is analog-copied. And at the same time,
Alternatively, it is proposed to increase the copying speed at the time of copying a double-sided original by reading the back side of the original with a digital reading unit at the time of feeding the original or discharging the original. That is, according to claim 1, the analog optical section and the digital reading section are arranged on the opposite sides of the original conveyance path so that the double-sided original is simply conveyed without being inverted and both front and back side image reading is performed. The purpose is to enable copying. The second object of the present invention is to install the digital reading unit in the document feeding unit of the automatic document feeder or the document discharging unit, thereby reducing the size of the machine and simplifying the structure. According to a third aspect of the present invention, one side of a double-sided original is analogly copied, the other side is digitally copied, and the copying speeds of the two sides of the original are switched and controlled to efficiently and quickly copy the double-sided original. It is an object of the present invention to make it possible to alternately copy an image on each side of a double-sided original on one side or both sides of a recording medium in an analog and digital manner, and to select either one. According to a fifth aspect of the present invention, it is possible to copy a plurality of copies by providing a unit for reversing and storing a plurality of recording sheets on which images are formed on the first side and re-feeding the sheets. In claim 6, since the analog optical unit and the digital reading unit are located on the opposite sides of the document feeding path, the recording medium is discharged to the paper discharging unit unless the document placement and the feeding order are set correctly. Since the page order of the originals will be out of order when paper is printed, make sure that the originals placed in the automatic document feeder can be fed from both the top and bottom, The purpose is to correct the order. According to the present invention, by providing the storage means capable of storing the image information for a plurality of pages read by the digital reading unit, it is not always necessary to perform analog copying when copying a double-sided original.
The purpose is to efficiently copy double-sided originals without the need to repeat digital copying. In claim 8, when the number of double-sided originals is large, the storage capacity of the storage means is actually limited. Therefore, it is an object of the present invention to make maximum use of the storage capacity and efficiently copy double-sided originals. And In the ninth aspect, since the number of recording media that can exist in the original feeding path is limited during continuous copying, it is an object of the present invention to efficiently copy a double-sided original with a minimum required storage capacity. Another object is to eliminate the need for means for detecting the remaining storage capacity.

[0004]

In order to achieve the object of the present invention, the present invention provides an analog optical system for analog copying, a digital reading section using a solid-state image pickup device such as a CCD, an LED, an LD and the like. And a digital writing unit that uses a solid-state image sensor such as a CCD when performing digital copying such as image processing and selecting a digital function such as image processing. So that the original can be handled as electrical image information.
Also, when copying a two-sided original, the first side (front or back) of the original
Analog copy, the second surface (back surface or front surface) of the original is read by a solid-state image sensor (digital reading unit) such as a CCD without reversing the original during conveyance of the original, and both sides of the recording medium (recording paper) are read. Or, copy on one side to increase the copying speed. Further, a storage means capable of storing a plurality of pages of image information read by the digital reading unit is provided.

That is, according to the first aspect of the invention, an image forming portion for forming an image by an electrophotographic process and reflected light of an original obtained by irradiating an original with light source light are formed on a photoreceptor of the image forming portion. An analog copying section having an analog optical section for forming an electrostatic latent image, a digital reading section for converting image information as document reflected light into an electric signal and handling it as digital image information, and the digital reading section In an image forming apparatus having a digital writing unit for writing and recording digital image information read by a light emitting element using a light emitting element, a document surface to be copied by the analog copying unit and a document to be read by the digital reading unit. The surface is different, and the analog optical section and the digital reading section are located on opposite sides of the original feeding path. Characterized in that it is location.

According to a second aspect of the present invention, the image reading apparatus according to the first aspect is equipped with an automatic document feeder which automatically conveys a sheet-like document to enable continuous copying.
It is characterized in that the digital reading unit is arranged in a document feeding unit or a document discharging unit of the automatic document feeder. According to a third aspect of the invention, in the image forming apparatus according to the first or second aspect, when a double-sided original having image information on both sides is copied, the single-sided original is fed by an automatic original feeder. In the process of transporting the double-sided document on the same transport path as when transporting, the first surface of the double-sided document is read by the analog optical unit or the digital reading unit,
The second surface is read by the analog optical unit or the digital reading unit.

According to a fourth aspect of the present invention, in the image forming apparatus according to the first, second, and third aspects, the first side and the second side of a double-sided original are provided on one side of different recording media, respectively. Double-sided originals that are alternately and continuously copied by the digital copying unit Single-sided copying work and double-sided originals on both sides of the same recording medium
The present invention is characterized in that it has a control unit for selectively controlling a double-sided document double-sided copy work for alternately and continuously copying the first side and the second side by the analog copying section and the digital copying section. According to a fifth aspect of the present invention, the means for copying the double-sided document according to the fourth aspect on both sides of the recording medium stores the plurality of reversed recording media and the means for inverting the recording medium on which the image is formed on the first surface. It is realized by means that can be stored and means that re-feeds the stored recording medium.

The invention of claim 6 is based on claims 1, 2, 3,
In the image forming apparatus described in 4 or 5, an upper paper feeding unit for feeding the original placed in the automatic original feeding apparatus from the top,
It has a lower sheet feeding means for feeding sheets from the bottom. According to a seventh aspect of the present invention, there is provided a storage means capable of storing a plurality of pages of image information read by the digital reading unit. The invention of claim 8 has means for detecting the remaining capacity of the storage means, and when a plurality of double-sided originals are continuously double-sided copied, the first side of the double-sided original is read and copied by the analog copying section. Then, the second side of the double-sided original is read by the digital reading section and the read image information is stored in the storage means sequentially or in parallel, and when the storage capacity of the storage means is exhausted, the first side is analog. A control unit for stopping copying, sequentially sending the digital image information of the second side stored in the storage means to the digital writing unit to perform digital copying, and then sequentially restarting analog copying and digital copying again. Is characterized by. The invention of claim 9 is characterized in that the capacity of the storage means corresponds to the number of recording sheets that can be present in the transport path during continuous copying.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. FIG. 1 is a block diagram of an analog / digital mixed image forming apparatus to which the present invention is applied. The image forming apparatus 1 has an automatic document feeder (ADF) 2 on the upper surface thereof, and is directly under a contact glass 3. Has an analog optical section 4. Analog optics 4
The image forming section 5 formed by the electrophotographic process is located below
And the sheet feeding section 6 is disposed immediately below the image forming section. Further, a contact type image sensor (CCD, digital reading unit) 7 is arranged in the document feeding unit inside the automatic document feeder (ADF) 2 above the analog optical unit 4. Further, the digital writing unit 8 is arranged on the upstream side of the developing unit 53 of the photoconductor 51. The analog optical unit 4 and the image forming unit 5 form an analog copying unit, and the digital reading unit 7, the digital writing unit 8 and the image forming unit 5 form a digital copying unit. The ADF 2 has a function of feeding from the lowermost original placed on the original table 21 (lower paper feeding means) and a function of feeding from the uppermost original (upper paper feeding means). However, the configuration is such that either one can be selected.
A document fed by any one of the sheet feeding means is reversed by the sheet feeding roller 22 and then conveyed on the contact glass 3 by the belt 23, and the contact glass is removed after the document is read by the analog optical unit 4. After passing, the sheet is discharged onto the sheet discharge section 25 by the sheet discharge roller 24.

The analog optical section 4 includes a first traveling body 41.
And a second traveling body 42, a lens 43, and a mirror group 44. The first traveling body 41 includes a light source 41a and a first mirror 41.
b, the second traveling body 42 has a third and a fourth mirror 42.
a, 42b. The light emitted from the light source 41a onto the original on the contact glass 3 is reflected on the original surface, passes through each mirror and lens, and is applied to the writing position on the photoconductor 51. The electrophotographic image forming unit 5 includes a photoconductor 51, a charging device 52, a developing device 53, a transfer / separation device 54,
It has a fixing device 55 and the like. The electrophotographic process is well known and will not be described in detail here. The paper feeding unit 6 has a plurality of paper feeding trays 61, and the recording paper (recording medium) fed by a paper feeding roller 62 is fed to a transfer position by a registration roller 63 to form a toner image on the photoconductor. After being transferred, the sheet is conveyed to the fixing device 55 to be fixed, and then the discharge tray 6
It is discharged to 4. Reference numeral 9 denotes a double-sided unit, which does not discharge the recording paper fixed on one side during double-sided copying, but temporarily stacks it on the double-sided tray 92 through the reversing path 91, and then records on one side at a predetermined timing. After reversing the recording paper, the recording paper is re-fed to the transfer position to receive the toner image on the photoconductor on the back surface, and then the toner image is fixed and discharged. In the control circuit provided on the printed circuit board of the electrical component section (not shown), a page memory for temporarily storing the image data digitally read by the contact image sensor 7 is provided to reduce the capacity of the page memory. Have at least one or more.

Next, FIG. 2 is a block diagram of a control system of the image forming apparatus of the present invention, in which the main controller 100 executes various processes according to a preset program.
01, a ROM 102 storing a program, a RAM 103 storing processing results and data, and an input / output device (I / O) not shown. C of the main control unit 100
The PU 101 outputs a command to the image processing unit 104 to execute image processing, and also outputs a command to the digital reading unit 7, digital writing unit 8 and the like to execute a predetermined operation. Further, the CPU 101 outputs a command to the analog optical unit 4 to execute the reading operation of the original image. In the operation unit 105, an operation of a selection key or a start button is performed, an operation signal is output to the CPU 101, or C
Display is performed on the display unit according to a command from the PU. ADF
The document transport unit (document transport motor, etc.) 106 included in
Driving is controlled by a command from the CPU 101.

A first embodiment in which copying is performed from a double-sided original by the image forming apparatus having the above structure will be described below. <At the time of analog copying of one-sided original> For high-speed analog copying of one-sided original, the original is placed on the original table 21 of the ADF 2 and the original is placed on the contact glass 3 sequentially from the bottom by the lower sheet feeding means of the ADF 2. Is automatically fed, and the analog optical unit 4 optically scans to form an electrostatic latent image on the photoconductor 51 for copying. <During single-sided original digital copying> When digitally copying a single-sided original, place the original face down on the original table 21 and set the AD
The document is automatically fed from the top by the upper sheet feeding means of F2, and in the process of feeding, the document image is sequentially read by the contact image sensor (digital reading section) 7 installed in the document feeding section. . Thereafter, the image processing unit 104 performs predetermined image processing (magnification, various processing, angle conversion, etc.) on the digital image information that is sequentially converted into an electric signal, and then a digital writing unit including an LED, an LD, and the like. Then, the digital writing unit 8 performs digital writing on the photoconductor to form an electrostatic latent image and perform copying.

<During Double-sided Original Analog / Digital Copying> First, the operation in the case where the images on the front and back sides of a double-sided original are alternately digitally and analog copied on one side of the recording paper will be described. The number of originals is 3, and the number of copies is 1. When copying a double-sided original on one side of a plurality of recording papers, the original is placed on the original table 21 with the surface of the original facing upward. The bottom document (third sheet) of the ADF 2 is conveyed to the position of the contact image sensor (digital reading section) 7 of the document feeding section and the back side of the third document (page 6). ) Read. The image processing unit 104 performs image processing on the read image data, and sends the image data to the digital writing unit 8.
Digitally write to 1. The electrostatic latent image formed on the photoconductor in this way is developed by the developing device 53, then conveyed from the paper feed tray 61, and a copy image is formed on the recording paper which is kept waiting by the registration roller 63. The recording paper is fixed by the fixing device 55 and is discharged to the paper discharge tray 64. The ejected state of the first recording sheet that has been recorded on only one side is face-up.

Next, the back side of the third document (page 6)
While the digital copy is being performed using the image information obtained by performing the digital reading, the original is automatically fed onto the contact glass with the front side facing down. After the digital copying operation in the image forming section 5 is completed, the analog optical section 4 causes the surface (5
Page)), the reflected light of the original obtained by this optical scanning is irradiated on the photoconductor 51 to form an electrostatic latent image, and after the electrostatic latent image is formed into a toner image by the developing device 53, Transfer to the next new recording paper that was kept waiting at the registration roller 63,
After fixing, the sheet is discharged onto the sheet discharge tray 64. The discharged state of the second recording sheet that has been recorded on only one side is face-up. By the same operation as described above, digital copying is performed on both sides of the second document and the third document in sequence, alternately.
Make an analog copy. Two sheets of recording paper are ejected for each double-sided original. Since each recording sheet is discharged face up, by repeating the above operation, the recording sheet (6
Will be stacked.

Next, a description will be given of the operation when the front and back surfaces of a double-sided original are alternately digitally copied and analog copied on both sides of the recording paper. The number of originals is 3, and the number of copies is 1. When copying a two-sided original on both sides of the recording paper, first set the original table 21.
The document is placed with the front side facing up, and the bottom document (third sheet) of the ADF 2 is fed to the position of the contact image sensor (digital reading unit) 7 of the document feeder. Then, the back side (6th page) of the third original is read. The image processing unit 104 performs image processing on the read image data and sends it to the digital writing unit 8 to perform digital writing on the photoconductor 51. The electrostatic latent image thus formed on the photoconductor is developed by the developing device 53 and then conveyed from the paper feed tray 61 to the registration roller 63.
A copy image is formed on the first sheet of recording paper that was kept in standby. After the recording paper is fixed by the fixing device 55, the recording paper is guided to the double-sided path 91 to guide the double-sided tray 9 of the double-sided unit 9.
Stack once in 2.

Next, the back side of the third document (page 6)
During the digital copying using the image information obtained by performing the digital reading of, the original is automatically fed onto the contact glass with the surface (fifth page) facing downward. After the completion of the digital copying operation in the image forming unit 5, the analog optical unit 4 optically scans the surface (fifth page) of the document on the contact glass, and the photoconductor 51 is irradiated with the reflected light of the document obtained by this optical scanning. To form an electrostatic latent image, and after the electrostatic latent image is formed into a toner image by the developing device 53, the toner is re-fed from the double-sided unit 9 and the registration roller 63 is fed.
The recording sheet is transferred and fixed on the other side of the first sheet of recording paper (one side of which has been recorded) that has been made to stand by and is discharged onto the discharge tray 64. The ejected state of the first recording sheet on which recording has been performed on both sides is upward, that is, the front side, that is, the side with the smallest page number (fifth page). By the same operation as described above, digital copying and analog copying are alternately performed on both surfaces of the second and third originals on the second recording paper and the third recording paper, respectively. By repeating the above operation, the paper is discharged to the paper discharge tray 64 in the same page order as the original.

By performing the series of copying operations by the image forming apparatus having the above-described structure, the complicated operation of reversing the original in the ADF unit 2 which is performed by the conventional image forming apparatus can be omitted. . As a result, it is possible to increase the copying speed when copying a double-sided original. When the number of copies is plural, each original surface to be read by the digital reading unit 7 is digitally read only once and stored in the memory, and the same number of times as the number of copies is made. It is repeatedly read and digitally copied. For analog copying, it is necessary to repeat each operation for the number of copies. In this case, the sorting may be performed by the sorting function of the discharge tray. When making a two-sided copy of a plurality of copies, the required number of copies of the recording paper on which one side has been recorded, on which the images of the same document surface have been copied, are temporarily stacked in the duplex unit 9, and the images of the other sides are copied in the duplex unit. Then, the sheets are transferred and fixed on the other side of the recording sheet on which the one-side recording has been performed, which are sequentially re-fed.

FIG. 3 shows a modification of the first embodiment described above. In this embodiment, the digital reading unit 7 is AD.
There is no difference from the form example of FIG. 1 except that the image is placed on the side of the document discharge unit of F2 and the image on the back side of the document to be discharged is read, but in this case, analog copying (reading, image Since (formation) precedes digital copying (reading, image formation), the direction of the double-sided document set on the document table 21 of the ADF is opposite to that of the above embodiment. That is, the case of the above embodiment (3 originals, 1 copy)
Part) is used as it is, the uppermost original (the last original, the third sheet) is used by using the upper paper feeding means with the front side facing down.
Paper feeding is started from, and the final page (6 pages) of the final document is read by the analog optical unit 4 on the contact glass,
An image is formed on the first sheet of recording paper. After completion of the reading, the surface (5 pages) of the final document discharged from the contact glass 3 to the right by the belt 23 is read by the digital reading unit 7 arranged in the document discharge unit, and an image is formed on the next new recording paper. Do (one-sided copy). The original is ejected as it is. In this way, all of the recording papers (6 sheets) with one-sided recording discharged onto the discharge tray have the copy surface facing upward and are discharged from the last page, so the stacking order is from top to bottom. Has become. Next, also in the case of performing double-sided copying, the original is set on the original table 21 in the setting direction with the front side facing down, and then the final page is fed on the contact glass by the upper feeding means as in the above. The analog optical unit 4 reads the image and forms an image on one side of the recording paper. This recording paper is once stacked on the duplex unit 9. After the analog reading is completed, the same document is conveyed to the digital reading unit 7 and the
The page is read, an image is formed on the back surface of the document re-fed from the duplex unit, and the document is ejected. The discharge order of the two-sided copied recording paper (three sheets) discharged onto the discharge tray is the same as that of the original because the last page is facing down. By performing the series of copying operations by the image forming apparatus having the above-described configuration, it is possible to omit the complicated operation of reversing the original in the ADF unit 2 performed by the conventional image forming apparatus. As a result, it is possible to increase the copying speed when copying a double-sided original.

Next, a second embodiment of the present invention will be described with reference to FIG. 2. This embodiment is characterized in that the copying conditions for analog copying and digital copying are set as follows. Is. During analog copying: Both the linear velocity of the photoconductor and the scanning speed of the analog optical part are a (mm / s) Document transport speed c (mm / s) During digital copying: Linear velocity of the photoconductor b (mm / s) Document transport speed during reading d (mm / s) (a> b, c> d) Further, at least the page memory 110 (FIG. 2) corresponding to the number of recording sheets that may exist in the transport path during continuous copying is provided. This is a feature of the example.

A specific embodiment of copying from a double-sided original by the image forming apparatus of the second embodiment having the above structure will be described below. <At the time of analog copying of one-sided original> For high-speed analog copying of one-sided original, the original is set on the original table 21 and the lower paper feeding means of the ADF 2 sequentially places the lower original on the contact glass 3 in sequence. The paper is automatically fed at the conveying speed c (mm / s), and the analog optical unit 4 speeds a (mm / s).
In s), an optical operation is performed to form an electrostatic latent image on the photoconductor 51, and analog copying is performed in the image forming unit 5. <During single-sided original digital copying> When digitally copying a single-sided original, the original is placed on the original table 21 face down and AD
F2 top feeding means speed c from top document first
The sheets are automatically fed at a speed of (mm / s), and are sequentially read at a speed of d (mm / s) by the digital reading unit 7 installed in the document discharge section of the ADF. Thereafter, the digital image information sequentially converted into the electric signal is subjected to image processing, and then LE
It is sent to the digital writing unit 8 composed of D, LD, etc., and b
(Mm / s) digitally writes on the photoconductor 51,
An electrostatic latent image is formed and digital copying is performed in the image forming section 5.

<During Double-sided Original Analog / Digital Copying> Copying of a double-sided original is carried out in cooperation with the analog copying section (4, 5) and the digital copying section (5, 7, 8). One embodiment will be described by setting the following conditions. In the continuous copying, the maximum number of recording sheets that can exist in the transport path is three, and the maximum capacity of the page memory (storage unit) is three.・ The number of copies of double-sided originals is limited to one. (If there are multiple copies, see below.) ・ Set the number of double-sided originals to four. When copying a double-sided original under the above conditions, first, the original is set on the original table 21 so that the surface of the original faces upward. The top page is the first page and the bottom page is the eighth page. The top document of the ADF 2 automatically feeds the top document onto the contact glass 3 at a speed c (mm / s).
The second page is optically scanned at a (mm / s), is conveyed from the paper feed tray 61 by an electrophotographic process, and a copy image is formed on the first surface of the recording paper which is held by the registration roller 63. After that, it is fixed by the heat fixing device 55. After that, the one-sided copied recording paper is conveyed to the two-sided unit 9 and temporarily stocked without being discharged. Before the first document is discharged onto the ADF paper discharge unit 25, the digital reading unit 7 scans the back side (second page) of the document with the document conveyance speed d (mm / s).
And the read image information is stored in the page memory 110. Subsequently, similarly, the image on the front surface (third page) of the second original is analog-copied on the first surface of the next new recording paper, and then stocked on the stock recording paper in the duplex unit 9. Further, when the second original is ejected, the digital reading unit 7 moves the back side of the original to the original conveyance speed d (mm
/ S), and the read image information is stored in the page memory. Similarly, the image on the front surface (fifth page) of the third document is similarly analogically copied to the first surface of the next new recording paper, and then stocked on the stock recording paper in the duplex unit 9. Further, when the third original is discharged, the back side (sixth page) of the original is read by the digital reading unit 7 at the original conveying speed d (mm / s), and the read image information is stored in the page memory. The operation of reading the back surface and the operation of storing the image information in the memory up to this point are performed in parallel during the front surface analog copying operation to reduce the copying speed.

Next, since the maximum capacity of the page memory (storage means) of this embodiment is three sheets (the maximum number of recording sheets that can exist in the conveyance path of the image forming apparatus), both sides of the page memory (storage means) at this point. Of the stock recording paper in the unit 9, the lowest one (the first page of the first page is copied = the first recording paper) is re-fed to the transfer position of the photoconductor and stored in the page memory. The image information on the back side of the first document that has been read is read out and sent to the digital writing unit 8, and the linear velocity b (mm / s)
Digitally write on the photoconductor 51 of the
The image forming section 5 performs digital copying on the surface, and the fixing device 5
After passing 5 to fix the image, the recording paper is ejected onto the paper ejection tray 64 so that the second surface (second page) faces down. Hereinafter, the main control unit 100 controls the digital image (the image on the back side of each document) copied on the second side of each recording sheet in the duplex unit 9 to follow the page order of the original document.
Of course, it is controlled by.

Next, the front side image (7th page) of the 4th original is analog-copied on the 1st side of the 4th new recording paper and stocked in the duplex unit 9. Immediately before the fourth document is ejected from the ADF, its back surface (8th page) is read by the digital reading unit 7. The page memory stores the image data of the back side of the first original that has already been digitally copied and is no longer needed.
An image on the back surface (8th page) of the original 4 is stored in that portion.
After that, the second sheet stocked in the duplex unit 9,
The third and fourth recording sheets are sequentially re-fed to the transfer position, and the image information on the back side of each of the second, third, and fourth originals is read from the page memory, and the corresponding Make a copy on the back of the recording paper. Thereafter, the second surface (rear surface) of each recording sheet faces upward, and the recording sheets are sequentially ejected onto the ejection tray 64. As a result,
The recording sheets on the discharge tray are stacked in the same page order as the originals (FIG. 4). According to the present embodiment, the capacity of the page memory is set in advance to the number of recording sheets that can be present in the recording sheet conveying path of the image forming apparatus, so that a means for detecting the remaining storage capacity is required. It can be lost. If a larger capacity page memory can be used, a means for detecting the remaining capacity of the storage capacity may be provided.

Next, FIGS. 5 and 6 are flowcharts showing the operation of double-sided copying when the number of originals is N, which overlaps with the above description. Therefore, in brief description, first, the power source of the image forming apparatus is turned on. When the double-sided original is set on the original table 21 of the ADF 2 in the loaded state, the double-sided copy mode is selected, and the start button is turned on, the original 1 (first original) is fed onto the contact glass 3. The paper is printed, the first surface is read by the analog optical unit 4, and is analog-copied on the first recording paper. After that, the document is ejected by the paper ejection unit
In the process of discharging the document, the back side of the document is read by the digital reading unit 7 and stored in the page memory 110. During this time, the first recording sheet is stocked in the duplex unit 9 (steps 1 to 7). Next, if there is no document remaining in step 8, the process proceeds to step 30 and the first recording sheet in the duplex unit 9 is re-fed to the transfer position and the back side of the first document is transferred to the back side. Transfer the image. After the transfer, the image is fixed and discharged (ST31). If there is a document remaining in step 8, analog and digital reading is sequentially performed on both sides of the second document in the same manner as above, and the second recording sheet on which one side has been recorded is one sheet in the duplex unit 9. The image information of the back side is stored in the page memory on the recording sheet of the eye (ST9 to ST11).

If there is no document remaining in step 12, the first transfer sheet in the double-sided unit 9 is sequentially re-fed and the corresponding back side image is written. If there is a document in step 12, analog and digital reading is performed on each side of the third document, and the third recording sheet on which one side has been recorded is the second recording sheet in the duplex unit 9. The image information on the back side is stored in the page memory (ST13 to 15). In parallel with this, the first sheet of recording paper is re-fed into the duplex unit, and the image of the second page corresponding to the back side is read from the page memory and copied (ST.
16, 17). If there is no document in step 18, the process proceeds to step 36 and subsequent steps to copy the images (4th and 6th pages) corresponding to the back surfaces of the second and third recording sheets.

If there is a document in step 18 and this document is the Nth document (N ≧ 4), the image on the front surface of the Nth document is displayed on the first surface of the new Nth recording sheet. Analog copy to, digitally read the image on the back side, and store it in the page memory. If the page memory is full, the data of the back image already copied is deleted in advance. The Nth recording sheet is stocked in the duplex unit 9 (ST19, 20, 21). Immediately after the end of the analog copying, the N-2th recording sheet, which is the lowermost recording sheet in the duplex unit 9, is re-fed to the transfer position, and the image on the back side of the N-2th document is printed on the back side thereof. Digitally copy (ST22, 23). After this, if more originals exist, the process returns to step 19, but if they do not exist, the process proceeds to step 25, and the N-1th recording paper which is the lowermost recording paper in the duplex unit 9 is transferred. The sheet is re-fed to the position and the image on the back side of the (N-1) th original is digitally copied on the back side (second side) (ST26). Next, the Nth recording sheet, which is the lowermost recording sheet in the duplex unit 9, is re-fed to the transfer position, and the image on the back side of the Nth original is digitally copied on the back side (second side). (ST27, 28). As is apparent from this flow, in the present embodiment, when there are a plurality of copies, the analog copy unit repeats each operation by the number of copies, and the digital reading operation and the operation of storing the image information in the page memory 110 are not performed. , It may be done once for each original. In the digital writing operation, each image information stored in the page memory is repeatedly read as many times as the number of copies, and digital copying is performed.

Next, a modification of the second embodiment will be described. In this modified example, as shown in FIG. 1, the digital reading unit 7 is located on the paper feed side of the ADF 2. In this embodiment, the digital reading is performed prior to the analog reading when the original is fed. In this case, the original is placed on the original table 21 with the surface thereof facing downward, and the original is fed from the bottom. Paper, digitally read the back of the original, then read the front on the contact glass. The other operations are almost the same as those of the above-described embodiment, and therefore the description thereof will be omitted.

Next, FIG. 7 is a sectional view showing the structure of an example of the digital reading section 7.
Arranges the image sensor 73 supported on the control board 72 in the casing 71, and arranges the light emitting element 74 such as an LED array inside the transparent plate 71a arranged in the opening of the casing 71. The light emitted from the light emitting element 74 to the document surface and reflected is received by the image sensor 73 through the rod lens array 75. The reading unit 7 is a contact type equal-magnification image sensor that is widely used in facsimile machines and the like, and uses an LED as a light source.
Using an array, the width of the light receiving portion of the image sensor 73 is equal to or larger than the reading width. The rod lens array 75 is a unit for forming an original image on the image sensor at an equal size, and the optical path thereof is extremely short. For this reason, it is possible to arrange it in a small space in the ADF. In the claims and the detailed description, the first side and the second side of a double-sided document are not limited to the first side being the front side and the second side being the back side. The surface to be read is the first surface, and the surface to be read next is the second surface. Similarly, the first side of the recording sheet is the side to be recorded first, and the second side is the side to be recorded next.

Incidentally, JP-A-58-111480 and 5
Japanese Patent Laid-Open No. 8-111481 makes it easy to copy a double-sided original by providing first and second reading units for reading the first and second sides of the original in the original feeding path in the reader section of the copying machine. However, the technologies described in these publications are merely those using digital reading means, and are clearly different from the present invention. Japanese Laid-Open Patent Publication No. 63-11969 comprises an exposure unit for analog copying and an exposure unit for digital copying, both exposure units having a common light source.
Techniques for realizing copying of analog information only, copying of digital information only, and copying of both analog information and digital information are disclosed. However, the technique described in this publication does not have a digital reading means, but an analog copying machine and a printer are made to coexist in one device. Further, it is possible to perform digital editing by digital writing during analog copying, which is different from the present invention. Japanese Utility Model Laid-Open No. 63-192664 discloses first reading means for reading the front side of a document, second reading means for reading the back side, first recording means for recording image information on the front side of recording paper, and recording. A configuration having a second recording unit that records image information on the back surface of paper is disclosed. However, the technique described in this publication does not have an analog copying means other than the digital copying means, and both sides are read and copied at the same time or with a time lag, so that the present invention is different from the present invention. .

[0030]

According to the first aspect of the present invention, by arranging the analog optical section and the digital reading section on opposite sides of the original feeding path, an image on each side of one double-sided original is fed. Since the analog optical unit and the digital reading unit can read the data at different times, it is possible to perform double-sided copying by simply conveying the document without inverting it, thus improving the double-sided copying speed. According to the second aspect of the present invention, by installing the digital reading unit in the document feeding unit of the automatic document feeding device or the sheet discharging unit, the image on one side of the document can be read in the process of conveyance, and Since the installation space of the digital reading unit is extremely small, it can be installed in a small space in the existing ADF, and the size of the machine can be reduced (prevention of increase in size) and the structure can be simplified.

According to the third aspect of the present invention, in the process of conveying the double-sided document by the automatic document feeder, one side of the document is analog copied (read, image formed) and the other side is digitally copied (read, image). Since it is formed), copying of a double-sided original can be performed efficiently and quickly. According to the invention of claim 4, it is possible to alternately copy each image of the double-sided original on one side or both sides of the recording paper in analog and digital, and it is possible to select single-sided copying or double-sided copying.

According to the fifth aspect of the present invention, a unit (double-sided unit) for reversing and storing a plurality of recording sheets having an image formed on the first side and re-feeding them is provided to copy a plurality of copies. It becomes possible. According to the sixth aspect of the invention, since the analog optical section and the digital reading section are on opposite sides of the document feeding path, the recording medium is discharged to the paper discharging section unless the document is placed and the feeding order is correct. When you print the original
Since it is different from the order, you can feed the original placed on the automatic document feeder from both the top and bottom,
You can correct the page order when ejecting paper.

According to the seventh aspect of the present invention, by providing the storage means for storing the image information for a plurality of pages read by the digital reading section, it is not always necessary to perform analog copying or digital copying when copying a double-sided original. It is possible to efficiently copy a double-sided original without the necessity of repeating the above. According to the invention of claim 8, the storage capacity of the storage means is actually limited when the number of double-sided originals is large.
You can copy double-sided originals. According to the ninth aspect of the present invention, since the number of recording media that can exist in the original conveyance path is limited during continuous copying, it is possible to efficiently copy a double-sided original with a minimum required storage capacity. it can. Further, it is possible to eliminate the need for means for detecting the remaining capacity of the storage capacity.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory view of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a control system.

FIG. 3 is an explanatory diagram of a configuration of an image forming apparatus according to a modified example of the present invention.

FIG. 4 is a diagram showing the order of ejecting recording paper that has undergone double-sided document double-sided copying according to an embodiment of the present invention.

FIG. 5 is a flowchart showing the operation of the second example of the present invention.

FIG. 6 is a flowchart showing the operation of the second embodiment of the present invention.

FIG. 7 is a sectional view of an example of a digital reading unit used in the present invention.

[Explanation of symbols]

1 image forming apparatus, 2 automatic document feeder (ADF),
3 contact glass, 4 analog optical section, 5 image forming section, 6 paper feeding section, 7 contact image sensor (C
CD, digital reading unit), 8 digital writing unit, 9 double-sided unit, 100 main control unit, 101
CPU, 102 ROM, 103 RAM, 104
Image processing unit, 110-page memory (storage unit).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H04N 1/00 H04N 1/00 E

Claims (9)

[Claims] 1. An electrostatic latent image is formed by forming an image forming portion for forming an image by an electrophotographic process and a reflected light of an original obtained by irradiating an original with light source light on a photoconductor of the image forming portion. An analog copying section having an analog optical section, a digital reading section for converting image information as reflected light of a document into an electric signal and handling it as digital image information, and a digital image information read by the digital reading section. In an image forming apparatus having a digital writing unit for writing and recording on a photosensitive member using a light emitting element, the original surface to be copied by the analog copying unit and the original surface to be read by the digital reading unit are different surfaces, The analog optical section and the digital reading section are arranged at positions opposite to each other across the document conveyance path. That the image forming apparatus. 2. The image reading apparatus according to claim 1 is equipped with an automatic document feeder that automatically conveys a sheet-like document to enable continuous copying, and the digital reading unit is provided. An image forming apparatus arranged in a document feeding section or a document discharging section of the automatic document feeding apparatus. 3. The image forming apparatus according to claim 1 or 2, wherein when a double-sided original having image information on both sides is copied, a single-sided original is conveyed by an automatic original feeding device. In the process of transporting the double-sided document through the same transport path as the case, the first surface of the double-sided document is read by the analog optical unit or the digital reading unit, and the second surface is read by the digital reading unit or the analog optical unit. An image forming apparatus characterized by the above. 4. The image forming apparatus according to claim 1, 2, or 3, wherein the first side of a double-sided original is provided on one side of a different recording medium.
A double-sided original single-sided copying work in which the first and second sides are alternately and continuously copied by the analog copying section and the digital copying section, respectively.
Having a control unit for selectively controlling a double-sided document double-sided copying operation in which the first side and the second side of a double-sided original are alternately and continuously copied by an analog copying unit and a digital copying unit on both sides of the same recording medium. An image forming apparatus characterized by. 5. A means for copying the double-sided original according to claim 4 on both sides of a recording medium, means for inverting a recording medium having an image formed on the first side, and a plurality of reversed recording media stored therein. An image forming apparatus, which is realized by a means for storing the recording medium and a means for re-feeding the stored recording medium. 6. The image forming apparatus according to claim 1, 2, 3, 4, or 5, an upper paper feeding means for feeding the original placed on the automatic original feeding device from the top. An image forming apparatus comprising: a lower sheet feeding unit that feeds sheets from the bottom. 7. The image forming apparatus according to claim 1, further comprising a storage unit capable of storing a plurality of pages of image information read by the digital reading unit. 8. When reading and copying the first side of a double-sided original by the analog copying unit, when a plurality of double-sided originals are continuously double-sided by having means for detecting the remaining capacity of the storage means. Second side of double-sided original by digital reading unit
The surface is read and the read image information is stored in the storage means sequentially or in parallel. When the storage capacity of the storage means is exhausted, the analog copying of the first side is stopped and stored in the storage means. 8. The image forming apparatus according to claim 7, further comprising a control unit that sequentially sends the digital image information on the second surface to the digital writing unit to perform digital copying, and then sequentially starts analog copying and digital copying again. apparatus. 9. The image forming apparatus according to claim 7, wherein the storage means has a capacity corresponding to the number of recording sheets that can be present in the conveyance path during continuous copying.