JP2004040563A - Image reader and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To fast and continuously read a plurality of originals while feeding the paper of the documents without providing a large-capacity memory only for special image processing that needs a memory of large capacity. <P>SOLUTION: When image processing of an original that is currently read is special image processing that needs the large-capacity memory, a first read mode is selected for once stopping the next original on an original transporting path before reading the next original and then starting to read the original is selected. In the case of normal image processing that does not need the large-capacity memory, a second reading mode is selected for starting to read the next original without stopping on the original transporting path before reading the next original. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image reading apparatus including an automatic document feeder for performing reading while continuously feeding a plurality of documents, and an image forming apparatus including the image reading apparatus.
[0002]
[Prior art]
2. Description of the Related Art Generally, an image reading apparatus including an automatic document feeder for reading while continuously feeding a plurality of documents is known.
[0003]
As this type of image reading device, for example,
(1) JP-A-2001-016416
(2) JP-A-9-233269
(3) JP-A-9-284514
(4) JP-A-10-313381
Is known.
[0004]
The invention disclosed in the above publication (1) includes a first storage unit that stores image information read by a document reading unit, a compression unit that compresses the image information stored in the first storage unit, A second storage unit for storing the image information compressed by the compression unit, and detecting a full standby state in which the free space of the second storage unit is smaller than the threshold based on a preset threshold. And a control means for controlling the document reading means to interrupt document feeding and document reading when the full state is detected by the preliminary detecting means, thereby preventing occurrence of memory full. A large number of originals are read reliably and restrained.
[0005]
The invention disclosed in the above publication (2) discloses a first reading mode in which an original is moved and an exposing unit is fixed and read by a reading unit, and a second reading mode in which an original is fixed and an exposing unit is moved and read by a reading unit. And a first recording mode in which the image read by the reading unit is stored in the storage unit and then read out and recorded by the recording unit, and a first recording mode in which the image read by the reading unit is stored in the storage unit without being stored in the storage unit. A second recording mode for recording; and a selection unit for selecting any one of the first and second recording modes. The recording is performed according to the mode selected by the selection unit, and the storage unit is stored according to the reading mode. It is designed to be used efficiently.
[0006]
The invention disclosed in the above-mentioned publication (3) is based on the fact that the controller manages the storage amount of the print buffer memory, the attribute data of the document feeding device, the attribute data of the finishing device, and the setting content of the operation unit. The reading order of the images is switched by the controller, and the order of reading the images from the storage means is controlled in accordance with the setting.
[0007]
The invention disclosed in the above publication (4) is a first image reading means for reading an image of a document at a reading position, a document feeding means for feeding the document to the image reading position, and an image of the fed document. Image reading means for reading the image by the document feeding means, image storing means for storing images read by the first and second image reading means, detecting means for detecting the number of fed documents, and detecting The reading operation of the first and second image reading means is controlled based on the number of read originals, thereby speeding up the reading operation.
[0008]
[Problems to be solved by the invention]
In such a device, in order to pursue the high speed of continuous paper feeding, unless a large-capacity memory is provided, reading of the next document is started before image processing of the previous document is not completed, which hinders the operation sequence. And other problems occur. That is, when a large-capacity memory is provided and there is no reading timing and no image processing, there is a problem that continuous feeding cannot be performed at high speed. On the other hand, if the data transfer time can be secured when reading a document, high-speed reading is possible without using a large-capacity memory. Therefore, if the data transfer time and the document feed stop control are combined, it is considered that the data transfer can be performed without overlapping the timings of the image processing and the document feed. However, in each of the above-mentioned prior arts, no special consideration is given to feed stop control before reading of a document to be read, that is, so-called registration stop control (registration stop condition). The technology associated with is not known.
[0009]
In view of the above-described problems of the conventional example, the present invention relates to document feed control and data transfer, and can read a plurality of documents at a high speed one by one without using a large-capacity memory. It is an object of the present invention to provide a possible image reading device and an image forming apparatus provided with such an image reading device.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a first means is an image reading apparatus provided with an automatic document feeder for reading a document by a reading means while feeding a plurality of documents one by one. A first reading mode in which reading is started after the document is temporarily stopped on a transport path, and a second reading mode in which reading is started without stopping the document on the document transport path before reading the document. And switching means for switching the reading mode of the next document to the first or second reading mode in accordance with image processing of the document being read.
[0011]
With this configuration, the reading operation in the first reading mode temporarily stops the original before reading, so that the reading operation in the second reading mode is different from the reading operation in the motor deceleration and acceleration time and the stop time for the reading operation in the second reading mode. Although the productivity is reduced, the data transfer of the read image data can be performed during this time. Therefore, by switching the first reading mode and the second reading mode to the optimum conditions, the large-capacity memory can be stored. High reading productivity can be obtained without using it.
[0012]
The second means is such that, in the first means, when the image processing of the original being read is a processing of adding white data to the rear end of the read image data, the switching means sets the reading mode of the next original to It is characterized by switching to the first reading mode. With this configuration, the transfer of the white data is continued for a while after the reading is completed. Therefore, by switching to the first reading mode, the data transfer can be prevented from overlapping.
[0013]
The third means is that, in the first or second means, when the image processing of the document being read is variable magnification, the switching means switches the reading mode of the next document to the first reading means. Features. With this configuration, when electrical scaling is performed by thinning out an image or adding an image, data transfer may be continued even after reading is completed. However, switching to the first reading mode may reduce data transfer. Can be prevented.
[0014]
A fourth means is the third means, wherein the switching means switches the reading mode of the next original to the first reading means when the magnification is enlarged. With this configuration, the transfer data amount is larger than the read data at the time of zooming, so that a transfer delay occurs. However, by switching to the first reading mode, the data transfer can be prevented from overlapping.
[0015]
The fifth means is the first to fourth means, wherein the first means has a first storage means for temporarily storing the read image, and a second storage means capable of storing a plurality of images, If the image transfer start timing from the first storage unit to the second storage unit is delayed with respect to the start of reading of the original being read, the switching unit changes the reading mode of the next original to the first reading mode. It is characterized by switching to means. With this configuration, when the image transfer start timing from the first storage unit to the second storage unit is delayed, the data transfer can be prevented from being overlapped by switching to the first reading unit. .
[0016]
The sixth means is characterized in that the image reading apparatus comprises the image reading device according to the first to fifth means and an image forming means for forming an image on an image forming medium. By configuring the image forming apparatus in this manner, a plurality of documents can be read while being fed one by one at a high speed without providing a large-capacity memory only for special image processing requiring a large-capacity memory. Can be output.
[0017]
In the following embodiments, the first and second reading modes are set by a CPU that controls the image reading apparatus, and the CPU also functions as a mode switching unit.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing an embodiment of an image reading apparatus and an image forming apparatus according to the present invention.
[0019]
The image forming apparatus shown in FIG. 1 includes an automatic document feeder (hereinafter, ADF) 1 and an image forming apparatus main body. A sheet document bundle placed on the document table 2 of the ADF 1 with the image side of the document facing up is detected by the document set detection sensor 9 and the start (PRINT) key 34 on the operation unit 30 shown in FIG. Is fed from the uppermost document, and stops when the leading edge of the document reaches the registration sensor 5. The document that has reached the position of the registration sensor 5 is restarted and read at the ADF document reading position 10 on the image forming apparatus main body side. In the case of single-sided reading, the original is discharged to the document discharge tray 7 as it is. In the case of double-sided reading, the reverse side is read by reversing the original on the document discharge tray 7 by the document branching claws 6 and re-feeding. A book document or the like is placed on the contact glass 8 and read by the reading unit 50.
[0020]
The transfer sheets stacked on the first tray 11, the second tray 12, and the third tray 13 on the image forming apparatus main body side are respectively separated by the first sheet feeding device 14, the second sheet feeding device 15, and the third sheet feeding device 16. The sheet is fed, and is then conveyed by a common vertical conveying unit 17 to a position where it contacts the photoconductor 18. The image data read by the reading unit 50 is written on the photoreceptor 18 by the laser beam from the writing unit 57 and passes through the developing unit 27 to form a toner image. The toner image on the photoconductor 18 is transferred while the transfer paper is being conveyed by the conveyance belt 19 at the same speed as the rotation of the photoconductor 18. Thereafter, the image on the transfer paper is fixed by the fixing unit 20, and the transfer paper on which the image is fixed is discharged to the paper discharge tray 21.
[0021]
When an image is formed on both sides of the transfer sheet, the transfer sheet is not conveyed from the fixing unit 20 to the sheet discharge tray 21, but is once conveyed to a double-sided conveyance path 112 by a branching claw 111 for path switching. Thereafter, the transfer paper in the two-sided conveyance path 112 is re-fed to transfer the toner image formed on the photoreceptor 18 again, and when the toner image is transferred, the paper is discharged through the discharge tray 21 via the fixing unit 20. Is led to. As described above, the double-sided conveyance path 112 is used when forming images on both sides of the transfer paper.
[0022]
FIG. 2 is a diagram illustrating the operation unit 30. The operation unit 30 has a liquid crystal touch panel 31, numeric keys 32, a clear / stop (CL / STOP) key 33, a print (PRINT) key 34, a mode clear key 35, and an initial setting key 38. A key 37, the number of copies, a message indicating the state of the image forming apparatus, and the like are displayed.
[0023]
FIG. 3 is a diagram showing a display example of the liquid crystal touch panel 31 of the operation unit 30. When an operator touches a key displayed on the liquid crystal touch panel 31, a key indicating a selected function is displayed in black. You. If the details of the function need to be specified (for example, if it is a variable magnification, a magnification key is touched), the detailed function setting screen is displayed by touching the function key (magnification key). As described above, since the liquid crystal touch panel 31 uses the dot display, it is possible to graphically perform an optimal display at that time.
[0024]
In the upper left of FIG. 3, a message area for displaying a message such as "Ready to copy" or "Please wait" is displayed. On the right is a copy number display area for displaying the set number of sheets. Automatic density key, automatic paper selection key to automatically select the transfer paper, sort key to specify the process of arranging copies one by one in the page order, stack key to specify the process of sorting copies by page, and 1: 1 magnification , A scaling key for setting an enlargement / reduction ratio, a double-sided key for setting a double-sided mode, and an erase / move key for setting a binding margin mode and the like. The selected mode is shaded with keys.
[0025]
Next, with reference to FIG. 1, the image reading means and the operation up to the formation of a latent image on a recording surface according to the present invention will be described. A latent image is a potential distribution generated by converting an image into optical information and irradiating the image on the photoreceptor surface. The reading unit 50 includes a contact glass 8 on which a document is placed and an optical scanning system. The optical scanning system includes an exposure lamp 51, a first mirror 52, a second mirror 55, a third mirror 56, and a lens 53. , A CCD image sensor 54 and the like. The exposure lamp 51 and the first mirror 52 are fixed on a first carriage (not shown), and the second mirror 55 and the third mirror 56 are fixed on a second carriage (not shown).
[0026]
When reading the original image on the contact glass 8, the first carriage and the second carriage are mechanically scanned at a relative speed of 2: 1 so that the optical path length does not change. This optical scanning system is driven by a scanner drive motor (not shown). On the other hand, when reading the original image while feeding the original by the ADF 1, the first carriage equipped with the exposure lamp 51 and the first mirror 52 and the second carriage equipped with the second mirror 55 and the third mirror 56 are shown in FIG. It is fixed at the position shown. The document image is read by the CCD image sensor 54, converted into an electric signal, and processed.
[0027]
The writing unit 57 includes a laser output unit 58, an imaging lens 59, and a mirror 60. Inside the laser output unit 58, a rotating polygon mirror (polygon mirror) that rotates at a high speed at a constant speed by a laser diode as a laser light source and a motor. ) Is provided. The laser light emitted from the laser output unit 58 is deflected by a polygon mirror that rotates at a constant speed, passes through an imaging lens 59, is turned back by a mirror 60, and condenses and forms an image on the surface of the photoconductor 18. The deflected laser beam is exposed and scanned in a direction (main scanning direction) orthogonal to the direction in which the photoconductor 18 rotates, and a line of an image signal output from an output data selector 104 (see FIG. 5) of an image processing unit described later. Record the unit. An image (electrostatic latent image) is formed on the photoconductor surface by repeating main scanning at a predetermined cycle corresponding to the rotation speed of the photoconductor 18 and the recording density.
[0028]
As described above, the laser beam output from the writing unit 57 is applied to the photoconductor 18 of the image forming system. Although not shown, a beam sensor that generates a main scanning synchronization signal is disposed at a position near one end of the photoconductor 18 where the laser beam is irradiated. Based on the main scanning synchronization signal, control of image recording start timing in the main scanning direction and generation of a control signal for inputting / outputting an image signal are performed.
[0029]
FIG. 4 is a block diagram illustrating a configuration of an image processing unit (an image reading unit and an image writing unit) according to the present embodiment. Hereinafter, the image processing will be described with reference to FIG. The light emitted from the exposure lamp 51 irradiates the original surface, and the reflected light from the original surface is imaged, received and photoelectrically converted by an imaging lens 53 and a CCD image sensor 54, and is digitally converted by an A / D converter 61. Converted to a signal. The image signal converted into the digital signal is subjected to shading correction by the shading correction unit 62 and then subjected to MTF correction, γ correction and the like by the MTF correction unit 63.
[0030]
The image data that has passed through the MTF correction unit 63 is temporarily stored in the scanner memory 64. This is for adjusting the transfer timing to the scaling unit 71 and the memory controller 65 thereafter. In the scaling unit 71, the read image data is scaled down or an image is added to the read image data in accordance with the scaling ratio. The scaled image data is transferred to the memory controller 65 and stored in the image memory 66. Conversely, the image data stored in the image memory 66 is transferred to the writing unit 57 via the memory controller 65. These units are controlled by a CPU (not shown) that controls the image reading unit 50. The CPU executes various controls by executing a program stored in a ROM (not shown) while using a RAM (not shown) as a work area.
[0031]
The details of the memory controller 65 and the image memory 66 in FIG. 4 will be described with reference to FIG. FIG. 5 is a block diagram showing details of the memory controller 65 and the image memory 66. The memory controller 65 has an input data selector 101, an image synthesizing unit 102, a primary compression / expansion unit 103, an output data selector 104, and a secondary compression / expansion unit 105. The image memory 66 includes primary and secondary storage devices 106 and 107.
[0032]
The primary storage device 106 performs high-speed access to, for example, a DRAM or the like so that data can be written to the memory 66 substantially in synchronization with the transfer speed of input image data or data can be read from the memory 66 at the time of image output. Use available memory. Further, the primary storage device 106 has a configuration (an interface unit with the memory controller 65) that can be divided into a plurality of areas according to the size of image data to be processed and can simultaneously execute input / output of image data. The interface with the memory controller 65 is connected to the interface with the memory controller 65 by two sets of address and data lines for reading and writing so that input and output of image data can be executed in parallel in each divided area. This enables an operation of outputting (reading) an image from area # 2 while inputting (writing) an image to area # 1.
[0033]
The secondary storage device 107 is a large-capacity memory for storing data for synthesizing and sorting input images. If elements that can be accessed at high speed are used for both the primary and secondary storage devices 106 and 107, data processing can be performed without distinction between primary and secondary, and control is relatively easy. Although the access speed to the secondary storage device 107 is not so high because of its cost, the configuration is such that an inexpensive, large-capacity recording medium is used, and input / output data processing is performed via the primary storage device. By employing the configuration of the image memory 66 as described above, it is possible to realize an image forming apparatus capable of inputting / outputting, storing, processing, and the like of a large amount of image data with an inexpensive and relatively simple configuration. become.
[0034]
Next, an outline of the operation of the memory controller 65 will be described.
[0035]
<Image input (storage in image memory 66)>
The input data selector 101 selects image data to be written into the image memory 66 (primary storage device 106) from a plurality of data. The image data selected by the input data selector 101 is supplied to the image synthesizing unit 102 and is synthesized with the data already stored in the image memory 66. The image data processed by the image synthesis unit 102 is compressed by the primary compression / decompression unit 103, and the compressed data is written to the primary storage device 106. The data written in the primary storage device 106 is further compressed by the secondary compression / decompression unit 105 as necessary, and then stored in the secondary storage device 107.
[0036]
<Image output (reading from image memory 66)>
At the time of image output, image data stored in the primary storage device 106 is read. If the image to be output is stored in the primary storage device 106, the primary compression / decompression unit 103 decompresses the image data from the primary storage device 106, and outputs the decompressed data or the decompressed data. The output data selector 104 selects and outputs the data after the image synthesis of the input data and the input data.
[0037]
The image synthesizing unit 102 synthesizes the data in the primary storage device 106 with the input data (has a function of adjusting the phase of the image data), selects the output destination of the synthesized data (outputs the image to the primary storage device 106). Such as write-back and simultaneous output to both output destinations). If the image to be output is not stored in the primary storage device 106, the image data to be output stored in the secondary storage device 107 is decompressed by the secondary compression / decompression unit 105, and After the data is written to the primary storage device 106, the above-described image output operation is performed.
[0038]
(1) Next, features of the present invention will be described. FIG. 6 shows the positions of the first document (1) and the second document (2) in the automatic document feeder 1. Reading of the first document (1) has been completed, and the rear end of the document (1) is located at the ADF reading position 10 (point C). The leading edge of the document (2) has reached the position (point A) of the registration sensor 5, and paper feeding starts from this point A.
[0039]
<First reading mode>
Here, the point at which the document (2) being fed is decelerated and temporarily stopped between A and C is point B. In the first reading mode, after the feeding of the second original (2) from the point A is started, the document is temporarily stopped at the point B and waits for a predetermined time, and then the conveyance is restarted from the point B, and the conveyance speed is constant. When the speed is reached, the leading edge of the document reaches point C and reading is started. The waiting time of document (2) is determined by the image data transfer waiting time at the document position.
[0040]
<Second reading mode>
In the second reading mode, even when the reading of the first original document (1) is completed, the conveyance of the second original document (2) does not stop at the point B, but reaches the point C and the original document (2) does not stop. Start reading ▼.
[0041]
FIGS. 7 and 8 are timing charts showing the operation of the transport drive motor when four documents (1) to (4) are read by the ADF 1. FIG. FIG. 7 shows the case of the first reading mode, and FIG. 8 shows the case of the second reading mode.
[0042]
<Description of FIG. 7 (first reading mode)>
T1: Start feeding the first original (1)
T2: Arrive at point A on the leading edge of the first original document (1) (start deceleration)
T3: Stops at point B on the leading edge of the first original document (1)
T4: Transport resumes from point B on the leading edge of the first original document (1) (acceleration starts)
T5: Reach point C of the leading edge of the first original document (1) (start reading)
T6: Rear end point C of first original document (1) (reading completed)
Reaching the point A of the leading end of the second original (2) (starting deceleration)
T7: Stops at point B on the leading edge of the second original document (2)
T8: Resumption of conveyance from point B on the leading edge of the second original document (2) (acceleration start)
T9: Point C of the second original (2) reaches (starts reading)
T10: The rear end of the second document (2) reaches point C (reading completed)
Arrive at point A of the third original document (3) (start deceleration)
T11: Stop at the point B on the leading edge of the third original document (3)
T12: Resumption of conveyance from point B on the leading end of third original document (3) (acceleration start)
T13: The leading edge C of the third original document (3) is reached (reading starts)
T14: The rear end C point of the third original document (3) is reached (reading completed)
Arrive at point A of the fourth document (4) (start deceleration)
T15: Stops at point B on the leading edge of the fourth original document (4)
T16: Resume conveyance from start point B of the fourth original document (4) (start acceleration)
T17: Point C of the front end of the fourth original document (4) is reached (reading starts)
T18: The rear end point C of the fourth original document (4) is reached (reading completed → delivery started)
T19: Fourth original document (4) Discharge completed
<Description of FIG. 8 (second reading mode)>
T1: Start feeding the first original (1)
T2: Arrive at point A on the leading edge of the first original document (1) (start deceleration)
T3: Stops at point B on the leading edge of the first original document (1)
T4: Conveying starts from point B on the leading edge of the first original document (1) (acceleration starts)
T5: Reach point C of the leading edge of the first original document (1) (start reading)
T6: Rear end point C of first original document (1) (reading completed)
T7: Reaching the point C of the leading edge of the second original document (2) (reading starts)
T8: Rear end point C of the second original document (2) (reading completed)
T9: The leading edge C of the third original document (3) is reached (reading starts)
T10: The rear end C point of the third original document (3) is reached (reading completed)
T11: Point C of the fourth original document (4) reaches point C (reading starts)
T12: The rear end C point of the fourth original document (4) is reached (reading completed → delivery started)
T13: 4th original document (4) Discharge completed
In the first reading mode, the reading productivity is reduced by the motor deceleration and acceleration time and the stop time as compared with the second reading mode. Therefore, by switching the first reading mode and the second reading mode to optimal conditions, the maximum reading productivity can be obtained.
[0043]
(2) Here, when an A4 landscape original image as shown in FIG. 9A is read and written at the same size on the upper half of A3 transfer paper as shown in FIG. The memory 66 stores image data for A3. For this reason, after reading an A4 landscape document, white data is generated at a place such as the scaling section 71 shown in FIG. 4 and the image data is transferred to the memory controller.
[0044]
In this case, after the reading is completed, the transfer of the white data to the memory controller 65 is continued for a while. Therefore, when the reading of the next original starts during the transfer, if there is the scanner memory 64, the scanner memory containing the image being transferred is stored. In an apparatus that requires an area different from that of the memory controller 64 or that transfers data directly to the memory controller 65 without the scanner memory 64, the transfer may be duplicated. Therefore, in such a case, the above-described problem can be prevented by switching to the first reading mode.
[0045]
(3) When electrical scaling is performed by thinning or adding an image in the scaling unit 71 shown in FIG. 4, image data may be temporarily stored in the scanner memory 64 in some cases. Then, the transfer to the memory controller 65 is performed for a while after the reading is completed. Also in this case, the above problem can be prevented by switching to the first reading mode.
[0046]
(4) Further, even when the magnification can be changed at the same time as the reading, the amount of data transferred to the memory controller 65 is larger than the read data at the time of enlargement, so that a transfer delay occurs. The transfer will take place for a while. Also in this case, the above problem can be prevented by switching to the first reading mode.
[0047]
(5) Further, when the transfer to the image memory 66 cannot be started immediately at the start of the reading, the reading is performed while the data is stored in the scanner memory 64, and when the image memory 66 becomes accessible at a certain point, the transfer to the memory controller 65 is performed. Also when starting, the transfer to the memory controller 65 is performed for a while after the reading is completed. The case where the image memory 66 cannot be temporarily accessed includes, for example, a case where a printer image is being transferred from an external device (such as a host computer) not shown.
[0048]
Here, if the scanner memory 64 is prepared for a plurality of pages, high-speed reading can be performed in the second reading mode even if the cases (2) to (5) occur, Is performed, document image data for a plurality of pages is accumulated in the scanner memory 64, and it is necessary to prepare a huge amount of memory. In the present invention, by setting the first reading mode only under certain conditions, the amount of memory can be reduced, and the maximum reading productivity can be obtained at low cost.
[0049]
FIG. 10 is a timing chart showing the data transfer timing and the drive timing of the document conveying motor in the above cases (2) to (5).
[0050]
T1: Start feeding the first document (1)
T2: The leading edge A of the first original document (1) is reached (start of deceleration)
T3: Stops at point B on the leading edge of the first document (1)
T4: Conveying starts from point B on the leading edge of the first document (1) (acceleration starts)
T5: The leading edge C of the first document (1) is reached (reading started)
T6: The rear end C point of the first original document (1) is reached (reading completed)
Reaching the point A of the leading end of the second original (2) (starting deceleration)
T7: Stop at the point B on the leading edge of the second original document (2)
T8: Conveying starts from point B on the leading edge of second original document (2) (acceleration starts)
T9: The leading edge C of the second original document (2) is reached (reading starts)
T10: The rear end C of the second original document (2) arrives at point C (reading completed → paper discharge started)
T11: Second original document (2) Discharge completed
In FIG. 10, R1 represents the reading period in the second reading mode, and the image transfer period in the above cases (2) to (5) is shown below. In case (2), the white data is transferred even after the reading of the first original (1) is completed. In case (3), the image is transferred while changing the magnification after the reading of the first original (1) is completed. In case (4), image transfer is performed simultaneously with reading of the first original document (1), but transfer of image data continues for a while after reading is completed. In case (5), the image transfer is delayed from the reading start timing T5 of the first original document (1) and starts at timing T12. In any case, since the image transfer of the first document (1) and the reading period R1 overlap, the reading of the second document (2) starts after the image transfer is completed.
[0051]
FIG. 11 shows a flowchart for realizing the present invention. First, the presence or absence of a document on the document table 2 on the ADF 1 is checked (step S1), and if there is a document, feeding is started (step S3). If not, the process ends (step S1 → S2). When the document reaches the position of the registration sensor 5 (point A in FIG. 6) (YES in step S4), it is determined whether the previous document is being read (step S5). If there is no document being read (NO in step S5), the document feeding is temporarily stopped (step S12), and reading is started (step S13). The stop in this case includes, for example, a waiting time for shading adjustment or the like before starting reading. If there are no waiting factors during paper feeding, reading is started without stopping as indicated by the dotted line (step S5 → S13).
[0052]
If there is an original being read in step S5, the reading mode of the previous original is checked (step S6). If the reading mode of the previous document adds white to the rear end of the read image (YES in step S7), the first reading mode is set. That is, the document is stopped (step S10), and reading is started after the image data transfer of the previous document is completed (step S11).
[0053]
If the reading mode of the previous document is variable magnification (YES in step S8), the first reading mode is also set. That is, the document is stopped (step S10), and reading is started after the image data transfer of the previous document is completed (step S11). The first reading mode may be selected based on determination of enlargement instead of magnification. If the start of image transfer is delayed from the start of reading (YES in step S9), the first reading mode is set. That is, the document is stopped (step S10), and reading is started after the image data transfer of the previous document is completed (step S11). If the above conditions are not met, the second reading mode is set. That is, reading is started without stopping the document (step S9 → S13). When the reading is completed, the document is discharged (step S14).
[0054]
【The invention's effect】
As described above, according to the present invention, the first reading mode in which the document is temporarily stopped on the document transport path before reading and then reading is started, and the document is read on the document transport path before reading the document. A second reading mode for starting reading without stopping the original is set, and the reading mode for the next original is switched to the first or second reading mode in accordance with image processing of the original being read. It is possible to increase document reading productivity with an optimal memory amount without providing a large-capacity memory only for special image processing that requires a large-capacity memory, thereby improving the productivity of image formation. Can also be achieved.
[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating an embodiment of an image reading apparatus and an image forming apparatus according to the present invention.
FIG. 2 is a configuration diagram illustrating an operation unit of the image forming apparatus of FIG. 1;
FIG. 3 is an explanatory diagram showing a display example of the touch panel in FIG. 2;
FIG. 4 is a block diagram illustrating an image processing unit of the image forming apparatus of FIG. 1;
FIG. 5 is a block diagram illustrating a memory controller and an image memory of FIG. 4 in detail.
FIG. 6 is a configuration diagram showing a main part of the automatic document feeder of FIG. 1;
FIG. 7 is a timing chart illustrating a first reading mode of the image forming apparatus of FIG. 1;
FIG. 8 is a timing chart illustrating a second reading mode of the image forming apparatus of FIG. 1;
FIG. 9 is an explanatory diagram illustrating a process of adding white data to the rear end of the document in the image forming apparatus of FIG. 1;
FIG. 10 is an explanatory diagram showing a data transfer timing and a drive timing of a document conveying motor in a first reading mode of the image forming apparatus of FIG. 1;
FIG. 11 is a flowchart illustrating a document reading process of the image forming apparatus of FIG. 1;
[Explanation of symbols]
1 Automatic Document Feeder (ADF)
5 Registration sensor
50 reading unit
51 Exposure lamp
52 1st mirror
53 imaging lens
54 CCD Image Sensor
55 Second mirror
56 Third mirror
65 Memory Controller
66 Image memory
106 Primary storage device
107 Secondary storage device

Claims (6)

In an image reading apparatus provided with an automatic document feeder for reading a document by a reading unit while feeding a plurality of documents one by one,
A first reading mode in which the document is temporarily stopped on the document transport path before the document is read, and then reading is started;
A second reading mode for starting reading without stopping the document on the document conveying path before reading the document;
While setting
An image reading apparatus comprising: a switching unit that switches a reading mode of a next document to the first or second reading mode in accordance with image processing of a document being read. When the image processing of the original being read is processing for adding white data to the rear end of the read image data, the switching unit switches the reading mode of the next original to the first reading mode. The image reading device according to claim 1. 3. The image reading apparatus according to claim 1, wherein the switching unit switches the reading mode of the next document to the first reading mode when the image processing of the document being read is variable magnification. 4. The image reading apparatus according to claim 3, wherein when the magnification is enlarged, the switching unit switches a reading mode of a next document to the first reading mode. A first storage unit that temporarily stores the read image, and a second storage unit that can store a plurality of images,
If the image transfer start timing from the first storage unit to the second storage unit is delayed with respect to the start of reading of the original being read, the switching unit changes the reading mode of the next original to the first reading mode. The image reading apparatus according to claim 1, wherein the mode is switched to a mode. An image reading apparatus according to any one of claims 1 to 5,
Image forming means for forming an image on an image forming medium;
An image forming apparatus comprising:

Images