JP3915409B2 - Image reading apparatus and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet-through type image reading apparatus, an image reading method, and an image forming apparatus for reading an image of a document.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, scanners for reading an image of a document include a sheet-through type in which reading is performed by a fixed reading unit while moving the document, and a belt type ADF type in which reading is performed while moving the reading unit with respect to a stationary document. However, since the load on the main body side of the reading apparatus increases, the belt-type configuration is generally a sheet-through type.
[0003]
In addition, in order to be able to read a double-sided original with a sheet-through type scanner, a method of circulating the original and reading both sides with one reading unit and a surface (both sides) that conflict with each other in one paper passing pass are provided. There is a method in which two reading units are arranged at positions facing each other so that they can be read simultaneously. In this case, productivity decreases in a single-sided original reading mode other than the double-sided simultaneous reading mode.
[0004]
Further, in an image reading apparatus capable of reading a color document, it is preferable to set different reading conditions for a color document and a monochrome document. Generally, when reading a color original, detailed reading must be performed as compared to a monochrome original. Therefore, the reading speed needs to be slower than the reading speed of a monochrome original. By applying the color document reading speed to all documents, it is possible to read both monochrome and color documents, but the monochrome document reading speed is matched to the color document reading speed. Reading speed will be slow. For this reason, in the image reading apparatus, it is possible to solve the problem of a decrease in the reading speed of a monochrome document if it is determined in advance whether the document is a monochrome document or a color document and reading is performed under a reading condition suitable for each.
[0005]
Conventionally, reading according to the mode by selection from the operation display unit is performed for the above problem. In this case, the user has to select and instruct the type of document, which is cumbersome and inconvenient.
[0006]
On the other hand, in the fixed document scanning type, after the document is fed onto the platen and stopped (fixed), preliminary scanning (also referred to as “pre-scan”) for determining the document type is performed in advance to determine the document type. The original image was read (also referred to as “main scan”). In this case, since the document is stopped and stopped, the reading speed is delayed only during the stop period.
[0007]
On the other hand, as a method for discriminating each document type from a document group in which a monochrome document and a color document are mixedly loaded in the document movement scanning type with respect to the document fixed scanning type, each document group is circulated in advance. A method of reading a document under a reading condition corresponding to a monochrome document or a color document corresponding to each document after performing a determination process of determining a document type can be applied, but only one reading unit is provided. When it is not, the document must be circulated and conveyed twice to the reading unit, which takes time to read.
Furthermore, in the case where each original size is discriminated and read from a group of originals mixed with different size originals, the size discriminating step of judging the respective original sizes by circulating the original group in advance as described above. After performing the above, a method of reading a document under a reading condition corresponding to each document size is applied, and the document must be circulated and transported twice to the reading unit, which takes time. It was.
[0008]
[Problems to be solved by the invention]
In the present invention, in view of the above-described problems of the prior art, a read original is a single-side original or a double-side original, a color original, a case where a color original and a monochrome original are mixed, and a different size. An object of the present invention is to provide an image reading apparatus, an image reading method, and an image forming apparatus which can efficiently read an original when the originals are mixedly loaded and have extremely high productivity.
[0009]
[Means for Solving the Problems]
  In order to achieve the above object, the present inventionPaintingThe image reader(1) In an image reading apparatus comprising an original table on which an original is placed, a plurality of reading units that read original images while conveying the original, and a paper discharge tray on which the original to be discharged is stacked. The plurality of reading units include a first reading unit and a second reading unit arranged on the downstream side of the first reading unit, and are arranged on one side of a conveyance path through which the document is conveyed, Between the plurality of reading units, at least one of the plurality of conveyance paths having a length longer than the maximum size of the readable document, switching means for switching the plurality of conveyance paths, and a conveyance path depending on the paper type And control means for controlling the conveyance of the document so as to be switched.
[0010]
  According to this image reading apparatus,Between the plurality of reading units, at least one of the plurality of conveyance paths having a length longer than the maximum size of the readable document, switching means for switching the plurality of conveyance paths, and a conveyance path depending on the paper type By providing a control unit that controls the conveyance of the document so as to be switched, it is possible to select the conveyance path corresponding to the reading of the document of various sizes and read the document more efficiently., Productivity can be improved.
[0011]
  (2) The control unit sequentially conveys a plurality of documents at a first conveyance speed to a first reading unit and a second reading unit arranged downstream of the first reading unit, Conveying multiple originals at the second conveyance speed while reading the original images on the same side of the multiple originals, and discharging the originals after reading at the third conveyance speed The above (1) is preferable, in which the speed is controlled. According to this image reading apparatus, the first, second, and third conveyance speeds are controlled to be different from each other, for example, the first and third conveyance speeds that are not related to the document reading speed are increased. Thus, the document can be efficiently conveyed and the productivity can be improved.
[0012]
  (3) In the above (1) or (2), it is preferable that each of the plurality of reading units simultaneously reads images on the same side of a plurality of documents, so that the documents can be read more efficiently and productivity can be improved. Can be improved.
[0014]
  (4) In any one of (1) to (3),Providing a plurality of image processing units corresponding to the plurality of reading unitsIs preferredSince the read image can be processed in parallel, rapid image processing can be performed and productivity can be improved.
[0019]
  (5) In the above (1),The first reading unit performs reading for obtaining document information.,in frontThe second reading unit is controlled to read a document image based on the document information.RukoAnd are preferred. As a result, document information can be acquired and the document image can be read based on the document information only by passing the document once, improving the reading efficiency and improving the productivity.
[0030]
  (6) In the image reading apparatus that performs reading by the second reading unit based on the document information acquired by the first reading unit in (5), the document information acquired by the first reading unit is added to the document information acquired by the first reading unit. On the basis of this, it is preferable to have a determination unit that determines whether the document is a monochrome document or a color document, and can cope with a case where a monochrome document and a color document are mixed.
[0031]
  (7) In the above (6), control means for controlling to change a conveyance speed for reading a document image of the document by the second reading unit based on a determination result by the determination unit. preferable.
[0032]
  (8) In the above (7),The control means controls the monochrome document and the color document to be mixed by controlling the conveyance speed for reading the document image of the monochrome document to be higher than the conveyance speed for reading the document image of the color document. In this case, each reading can be performed at an appropriate conveyance speed, so that efficient reading can be performed and productivity is improved.
[0033]
  (9) Any one of (5) to (8)It is preferable to provide a monochrome mode for reading a document image of a monochrome document and a color mode for reading a document image of a color document.
[0034]
  (10) In (9) abovePreferably, the image forming apparatus further includes a selection unit that selects the monochrome mode and the color mode. For example, when the original to be read is determined in advance as one of monochrome and color, the original can be efficiently read by the two reading units, and productivity can be improved.
[0035]
  (11) In any one of (1) to (10)Since the second reading unit also serves as a reading unit for original fixing scanning, it is possible to cope with reading a document such as a book or a book.
[0036]
  (12)An image forming apparatus according to the present invention includes:Any one of (1) to (11) aboveAnd an image forming apparatus main body that forms an image based on the image data read by the image reading apparatus.
[0037]
  According to this image forming apparatus, an original is a single-sided original.In the articleIn some cases, whether it is a color document, a mixed color document and a monochrome document, or a mixed-size document, the document can be read efficiently, so the image can be efficiently , And productivity can be improved.
[0038]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view conceptually showing an image reading apparatus according to an embodiment of the present invention.
[0039]
As shown in FIG. 1, the image reading apparatus includes a document table 20 on which a sheet-shaped read document is placed, a feeding roller 19 that feeds the document from the document table 20 into the apparatus one by one for reading. A first transport roller pair 21 that transports a document, a first reading unit 11 that reads a document image on one surface S1 (upper surface in FIG. 1) of the document S sent from the first transport roller pair 21, and a first A second conveyance roller pair 22 for sending the document read by the reading unit 11, and a large-size conveyance path 31 and a small-size conveyance path for guiding the document S to the lower side of the figure by the second conveyance roller pair 22. 32, a conveyance roller pair 26 provided in the middle of the large-size conveyance path 31, and a third conveyance that conveys a document guided and conveyed by the large-size conveyance path 31 or the small-size conveyance path 32. Roller pair 23 and third transport roller pair 23 A second reading unit 12 that reads a document image on the same side as the one side S1 (the lower surface in FIG. 1) of the sent document S that is read by the first reading unit 11, and the second reading unit 12 reads the document image. A fourth conveying roller pair 24 for sending the original, a paper discharge conveying path 36 for guiding the original to be discharged, a paper discharge roller 25 for sending the original, and a document discharged from the paper discharge roller 25. And a paper discharge tray 30 to be placed.
[0040]
In addition, the image reading apparatus sends the first reversal conveyance path through which a document sent from the second conveyance roller pair 22 is sent and guided for reversing the front and back of the document through a part of the small size conveyance path 32. 33, a first reverse conveyance roller pair 27 and a third reverse conveyance roller pair 29 that can be rotated forward and backward so as to convey an original in both the right direction and the left direction in the drawing, and a first reverse conveyance roller pair. 27, the first circulation conveyance path 34 for guiding the document to be circulated to the first reading unit 11, and the second reading unit 12 to read the document and the fourth conveyance roller pair 24. A second circulation conveyance path 35 for guiding the original to the third reverse conveyance roller pair 29 and an inversion for reversing the front and back of the original sent from the fourth conveyance roller pair 24 and discharging them to the paper discharge tray 30. The paper discharge path 37 and the second reverse conveying roller pair 2 that can rotate forward and backward It is equipped with a door.
[0041]
Further, the image reading apparatus includes a second reading unit 12 and a scanning reading unit 13. The second reading unit 12 includes a first platen glass 14, an optical system 16 that is stationary and fixed at a position directly below the first platen glass 14, reads an original image, an imaging optical system 55, and a CCD image pickup device. An element 56 is included. Many members of the second reading unit 12 also serve as a scanning reading unit. The scanning reading unit 13 receives a second platen glass 15 and a document image of a document placed on the second platen glass. The optical system 16 ′ that scans and reads, the imaging optical system 55, and the CCD image sensor 56 are configured.
[0042]
When the second reading unit 12 reads the document S, light is emitted from the light source 51 to the document image surface of the document S being conveyed on the platen glass 14, and the reflected light is guided by the mirrors 52, 53, and 54. Then, the reflected light is taken into the CCD image pickup device 56 via the imaging optical system 55, whereby an original image is formed on the light receiving surface of the CCD image pickup device 56 and read.
[0043]
Further, the reading of the document S by the scanning reading unit 13 is performed by scanning the optical system 16 ′ along the platen glass 15 and scanning the optical system 16 ′ along the platen glass 15. By irradiating light from 51 ', the original image is read by the CCD image pickup device 56 in the same manner as the second reading section.
[0044]
In the reading by the first reading unit 11, a compact image sensor (CIS) in which a light emitting diode and a light receiving element are combined is used, and the second reading unit 12 and the scanning reading unit 13 are composed of halogen lamps. Although the light source 51 and the CCD image sensor 56 are used in combination, a compact image sensor (CIS) in which the light source 51 and the CCD image sensor 56 are combined with a light emitting diode and a light receiving element similar to those of the first reading unit 11. ) May be used.
[0045]
Each of the transport roller pairs 21 to 25 constitutes a transport mechanism together with the motor 65 (FIG. 7), and changes the speed at which the document is transported by switching the rotational speed of each of the transport roller pairs 21 to 25 that are rotationally driven by the motor 65. In addition, it is possible to control the document conveyance speed, that is, the reading speed, in the first reading unit 11 and the second reading unit 12. In order to perform such switching of the conveyance speed, at least the roller pair 21 and 22 and the roller pair 23 and 24 are configured to be driven independently.
[0046]
The image reading apparatus shown in FIG. 1 is provided with a conveyance direction switching mechanism so as to change the conveyance direction of the document in each of the conveyance paths 31 to 37 in order to perform each operation as shown in FIGS. However, as a representative example, the conveyance direction switching member 40 disposed on the downstream side of the second conveyance roller pair 22 will be described with reference to FIG. The conveyance direction switching member 40 in FIG. 6 includes a switching guide 41 and a rotation shaft 42. The switching guide 41 rotates in the rotation directions r and r ′ in FIG. Are guided to the large-size conveyance path 31 or the small-size conveyance path 32. When the switching guide 41 is rotated in the direction r ′, the document S is guided to the small-size conveyance path 32 as shown in FIG. 6A, and when the switching guide 41 is rotated in the direction r, as shown in FIG. It is guided to the large size conveyance path 31. The switching operation of the switching guide 41 is performed by operating the rotating shaft 42 at an appropriate timing by a solenoid, a motor (not shown) or the like. Similarly, a conveyance direction switching member 43 for switching between the conveyance path 35 and the conveyance path 36 and a conveyance direction switching member 44 for switching between the conveyance path 36 and the reverse discharge path 37 are provided.
[0047]
FIG. 7 is a block diagram of the flow of image data and control signals read by the image reading apparatus and the image forming apparatus according to the present embodiment, and a control unit. Here, the solid line indicates the flow of the image data, and the broken line indicates the flow of the control signal. The original image data read by the first reading unit 11, the second reading unit 12, or the scanning reading unit 13 is subjected to data conversion processing by the first image processing unit 57 or the second image processing unit 58. After image processing such as correction processing, compression processing, and color image processing is performed, it is stored in the memory. Here, in the first image processing unit 57 and the second image processing unit 58, when the first reading unit reads by the CIS and the second reading unit reads by the CCD image pickup device, different image processing is performed. Is preferably converted into the same kind of image data and stored in the memory 59. When the same type of CIS is used, the first image processing unit 57 and the second image processing unit 58 may perform the same image processing.
[0048]
In image formation, the image data in the memory 59 is sent to the image writing unit 60 of the image forming unit via the first image processing unit 57 or the second image processing unit 58. The image writing unit 60 writes an electrostatic latent image on the photosensitive member, develops the electrostatic latent image, and transfers and fixes the image on a recording sheet to form an image.
[0049]
FIG. 7 is a block diagram for controlling the document conveyance speed, the reading speed (the conveyance speed at the time of reading may be referred to as the reading speed), the conveyance direction switching, various modes, and the like in the image reading apparatus. Yes. The image data read by the first reading unit 11 is subjected to image processing by the first image processing unit 57, and based on the output level, the document image is a monochrome image or a color image, or the document image is Based on the determination result, a determination unit 61 that determines the size of the image, and the conveyance speed at the time of reading by the second reading unit based on the determination result, in the case of a monochrome image, at a high first conveyance speed, In the case of a color image, a control unit 64 composed of a CPU or the like that controls to convey a document at a low second conveyance speed, and a motor for rotationally driving the conveyance roller pairs 19 to 29 controlled in various modes. 65, an operation display unit 66 having a mode selection unit 67 for selecting a mode such as single-sided / double-sided mode, monochrome-color mode, and mixed loading mode, which can be operated from the outside of the apparatus, Leading and trailing document detection sensor K1, K2 for taking, and a transport direction switching member 40,43,44 for switching the conveying direction.
[0050]
In the control unit in FIG. 7, the document transport speed is controlled. In order to increase the productivity in reading a document, it is preferable to transport the document at a higher speed than at the time of reading other than at the time of reading.
[0051]
As an embodiment having the above-described effects, the conveyance speed from the document table to the reading unit and the conveyance speed in the conveyance path from the reading unit to the discharge tray or the next reading unit after reading are controlled to be high. . That is, a high-speed first conveyance speed from the document table to the reading unit, a medium-speed second conveyance speed at the time of reading, and a high-speed third conveyance speed to the discharge tray after reading or the next reading unit. Then, the control unit 64 controls to convey the original. The first transport speed and the third transport speed, which are the high transport speeds, are preferably the same high transport speed from the viewpoint of simplification of control.
[0052]
The above-described medium second conveyance speed at the time of reading indicates the conveyance speed in the case of a monochrome document, and the same second conveyance speed may be applied in the case of a color document. In a color original, it is necessary to read sufficient image data even if more detailed color separation is performed, and therefore it is preferable to set the fourth conveyance speed at a low speed.
[0053]
Further, the reading speed for determining whether the image is a monochrome document or a color document may be the fourth conveyance speed in the case of reading the color document, but it is sufficient if the image data for color determination can be read. It is preferable that the fifth transport speed is a medium speed that is higher than the fourth transport speed. In this case, if the second conveyance speed for the monochrome document is applied, or if image processing for color discrimination is possible, the higher first and third conveyance speeds are applied to simplify the control. Preferably it is done.
[0054]
Furthermore, since it is sufficient for the reading speed in the mixed original mode to obtain the image data of the outline portion for determining the original size, it is preferable to set the reading speed to the high sixth conveyance speed. In this case, if the second conveyance speed for the monochrome original is applied, or if image discrimination for size detection is possible, the higher first conveyance speed and the third conveyance speed are applied to simplify the control. It is preferable to carry out.
[0055]
The first to sixth transport speeds are, for example, a first transport speed of 800 mm / second, a second transport speed of 400 mm / second, a third transport speed of 800 mm / second, and a fourth transport speed of 300 mm / second. Second, the fifth transport speed may be 400 mm / second, and the sixth transport speed may be 400 mm / second.
[0056]
In FIG. 7, in the mode selection unit 67 of the operation display unit 66 such as a liquid crystal touch panel, a duplex mode for reading a document image of a duplex document, a color mode for reading a color document image of a color document, and each document of a mixed document. The mode can be set by selecting the mixed loading mode for detecting the document size and reading the document image every time. In addition to the modes described above, each mode may be provided in the mode selection unit 66 so that a single-sided mode, a monochrome mode, and the same document size mode can be selected. However, the duplex mode is not selected by default setting. In this case, it is preferable that the single-side mode is selected, the monochrome mode is selected when the color mode is not selected, and the same document size mode is selected and set when the mixed mode is not selected.
[0057]
When the duplex mode is selected and set by the mode selection unit 67, the control unit 64 controls the motor 65 for driving each conveyance roller so as to convey the document corresponding to the duplex document. When the duplex mode is not selected by default setting, the motor 65 for driving each conveyance roller is controlled so as to convey the original corresponding to the single-sided original.
[0058]
When the mode selection unit 67 selects the color mode, the control unit 64 causes the motor 65 and the motor 65 to drive each conveyance roller at the fourth conveyance speed at the time of reading so that the conveyance speed corresponding to the color original is obtained. Each part is controlled and image discrimination is performed to determine whether the original is a color original or a monochrome original for performing image processing suitable for a color image after reading. Note that when the color mode is not selected by default setting, a motor 65 for driving each conveyance roller so as to have a second conveyance speed corresponding to a monochrome document so as to achieve a reading speed corresponding to the monochrome document, and Control each part.
[0059]
In the image determination, when it is determined that the document is a color document, control is performed so that the second reading unit transports the document at the fourth transport speed so as to perform reading corresponding to the color document.
[0060]
In the image determination, when it is determined that the document is a monochrome document, the second reading unit is controlled to perform reading corresponding to the monochrome document. Alternatively, data used for image discrimination by the first reading unit may be stored and held in a memory as image data of a document, and subsequent documents when a monochrome document is read by the first reading unit. The conveyance control may be carried out similarly to the monochrome mode.
[0061]
When the mixed loading mode is selected by the mode selection unit 67, the control unit 64 reads and reads the originals at the sixth conveyance speed by the first reading unit 11 for each original and after reading. The document size is determined from the read image data, and the second reading unit 12 performs reading control corresponding to the document size based on the detected document size information, and at the second conveyance speed at the time of reading. The motor 65 that drives each conveyance roller and each unit are controlled so as to convey the original. When the mixed loading mode is not selected by default setting, the motor 65 for driving each conveyance roller and each unit are controlled so as to convey documents corresponding to the same document size.
[0062]
In the image determination in the color mode, it is preferable to determine the document size together with the color document. In this case, since the user does not have to select the mixed loading mode, the operability is improved.
[0063]
According to the above-described image reading apparatus, even when the original is a single-sided original or double-sided original, a monochrome original or a color original, a mixed original size, and a mixed original of monochrome and color originals, highly productive reading can be performed. it can. Hereinafter, the operation of the image reading apparatus will be described in detail with reference to FIGS. In FIGS. 2 to 5, portions that are not used for operation in the portions shown in FIG. 1 are omitted.
[0064]
1. Operation for single-sided originals in monochrome mode (Figure 2)
[0065]
As shown in FIG. 2, when reading a plurality of monochrome (monochrome) documents S1 and S2, the monochrome mode is selected unless any mode is selected by the mode selection unit 67 of the operation display unit 66 of FIG. The first document S1 is fed from the document tray 20 by the feeding roller 19 and is passed through the first reading unit 11 without being read at the first conveying speed. 22 and the document S1 is a small size such as A4 or B5, for example, as shown in FIG. 2A, it is guided to the transport path 32 by the transport direction switching member 40, or the document S1 is, for example, In the case of a large size such as A3, B4, etc., the transport direction switching member 40 guides the transport path 31 and transports the transport roller 26 to the vicinity of the second reading unit 12. When the leading edge of the document S1 is detected by the sensor K2 provided in the vicinity of the second reading unit 12, the transport speed of the document S1 is switched to a second transport speed that is a transport speed for reading a monochrome document, and a transport roller 23, 24, the second reading unit 12 generates a document image on one side (one side) of the document S1 at the timing of the leading edge position of the document S based on the information that the leading edge of the document S1 is detected by the sensor K2 while being transported by the sensors 23 and 24. read. Note that the conveyance speed may be switched at a predetermined timing after the conveyance of the document is started without providing the sensor K2. As timing in such a case, information on the elapsed time from the start of document conveyance and the number of steps for driving a stepping motor used as a drive source can be applied. The reading timing is a timing at which image data acquisition is started by the CCD image sensor after the exposure by the light source 51 is started.
[0066]
  The original S1 after one side (one side) of the original image is read by the second reading unit 12 is switched from the second conveying speed to the third conveying speed, and the conveying roller 24 and the conveying direction switching member 43 are switched. , 44Paper delivery path 36Are sequentially stacked so that the one surface that is discharged by the discharge roller 25 and read on the discharge tray 30 is the lower surface.
[0067]
The next original S2 is similarly sent out during the conveyance of the original S1, and is conveyed to the vicinity of the first reading unit at the first conveyance speed. When the leading edge of the document S2 is detected by the sensor K1 provided in the vicinity of the first reading unit 11, the transport speed of the document S2 is switched to a second transport speed that is a transport speed for reading a monochrome document, and a transport roller A document image on one side (one side) of the document S2 is detected by the first reading unit 11 in accordance with the timing at which the leading edge of the document S2 is detected based on information detected by the sensor K1 while being conveyed by the sensors 21 and 22. Read.
[0068]
The original S2 after one side (one side) of the original image is read by the first reading unit 11 is switched from the second conveyance speed to the third conveyance speed, and is read by the second reading unit 12. The paper is passed through without being performed, and is discharged so that one surface read on the paper discharge tray 30 is the lower surface in the same manner as the original S1, and sequentially stacked on the original S1.
In reading the plurality of documents S1 and S2, the conveyance of the documents S1 and S2 is controlled so that the reading is executed almost simultaneously. That is, the conveyance is controlled so that the original S2 as the subsequent original reaches the vicinity of the first reading section 11 at the same time when the original S1 as the previous original reaches the vicinity of the second reading section 12. The In order to carry out such conveyance, after the conveyance of the previous document S1 is started, the next document is started after a predetermined time has elapsed since the conveyance of the previous document S1 is started so as to have a predetermined document interval. What is necessary is just to control conveyance so that conveyance of S2 may be started.
[0069]
Further, the next original S3 following the original S2 is sent out after a predetermined time has elapsed since the start of the conveyance of the previous original S2 so that the predetermined original interval is continued during the conveyance of the original S2. It is controlled so that it is transported in the same manner as in FIG.
[0070]
Further, the document S4 subsequent to the document S3 is controlled to be conveyed in the same manner as the document S2. Thereafter, the conveyance of the originals S5, S6,... Is controlled in the same manner as the original S3 or the original S4.
[0071]
When the originals S1 and S2 are large sizes such as A3 and B4, the original images of the originals S1 and S2 pass through the conveyance path 31 as shown in FIG. 2B as in FIG. Read. The document tray 20 is preferably provided with a mechanism for detecting the document size of the placed document when the document is placed. Based on the detected document size information of the document, FIG. Control is performed to switch the switching guide 40 as shown in FIG.
[0072]
2A and 2B described above, image data for two pages read by the second reading unit 12 and the first reading unit 11 from one side (one side) of the originals S1 and S2. Is sent to the second image processing unit 58 or the first image processing unit 57 in FIG. 7 and subjected to image processing such as compression processing and data conversion at the same time, and then stored in the memory 59.
[0073]
When there are many originals for reading in FIG. 2, as shown in the table of FIG. 2 (c), the odd numbered pages 1, 3, 5,. The even numbered pages 2, 4, 6,... Are sequentially read by the first reading unit 11 and sent to the first image processing unit 57 or the second image processing unit 58. The image processing for each of the two pages is stored in the memory 59, and the subsequent pages 3 and 4 are similarly stored in the memory 59 after the image processing for three and four pages is performed at approximately the same time. A plurality of document images are sequentially read page by page at approximately the same time, subjected to image processing, and thereafter stored in the memory 59.
[0074]
As described above, a plurality of documents are sequentially conveyed, and a plurality of document images are read by a plurality of reading units, for example, the two reading units 11 and 12, almost at the same time. Since the image processing unit 57 and the second image processing unit 58 perform a plurality of image processes almost simultaneously, a plurality of single-sided originals can be read efficiently, and image formation (copying) productivity is achieved. Will be improved. Furthermore, by setting the document conveyance speed other than during reading higher than that during reading, a plurality of single-sided originals can be read more efficiently, and productivity can be further improved.
[0075]
2. Operation when monochrome mode is duplex (Figure 3)
[0076]
As shown in FIG. 3A, both surfaces of a plurality of monochrome (monochrome) documents S1 and S2, that is, the front surface (S1-1) and the back surface (S1-2) of the document S1, and the front surface of the document S2 ( When reading the original images on S2-1) and the back side (S2-2), the duplex mode is selected by the mode selection unit 67 of the operation display unit 66 of FIG. When the duplex mode is selected, the operation is performed in the duplex mode, and the first document S1 is fed from the document tray 20 by the feeding roller 19 to the vicinity of the first reading unit at the first transport speed. Be transported. When the leading edge of the document S1 is detected by the sensor K1 provided in the vicinity of the first reading unit 11, the transport speed of the document S1 is switched to a second transport speed that is a transport speed for reading a monochrome document, and a transport roller The document image on the surface S1-1 of the document S1 is read by the first reading unit 11 in accordance with the information that the leading edge of the document S1 is detected by the sensor K1 while being transported by the sensors 21 and 22. Read.
[0077]
  After the original image on the front surface S <b> 1-1 is read by the first reading unit 11, the original S <b> 1 is switched from the second conveyance speed to the first conveyance speed and conveyed to the conveyance path 33. The document S1 conveyed to the conveyance path 33 has a trailing edge.FirstReverse rollerversusWhen the vicinity of 27 is reached, the rear end is detected by the sensor K3, and based on the detection information of the rear endFirstReverse rollerversus27 in a state of being sandwiched betweenFirstReverse rollerversusThe rotation direction of 27 is switched, and the paper is reversely conveyed and conveyed to the second reading unit 12. When the leading edge of the document S1 is detected by the sensor K2 provided in the vicinity of the second reading unit 12 and the sensor K2 provided in the vicinity of the second reading unit 12, the conveyance speed of the document S1 is controlled for monochrome document reading. The second reading unit 12 is switched to the second conveyance speed, which is the speed, and is synchronized with the leading edge position of the document S based on the information that the sensor K2 detects the leading edge of the document S1 while being conveyed by the conveyance rollers 23 and 24. The original image on the back surface S1-2 of the original S1 is read. The document S1 after the document image on the back surface S1-2 is read by the second reading unit 12 is switched from the second transport speed to the third transport speed, so that the transport roller 24 and the transport direction switching member 43 are switched. , 44 to convey path 37And the trailing edge of the document S1 isSecondReverse rollerversusWhen it reaches the vicinity of 28, the rear end is detected by the sensor K4, and based on the detection information of the rear endSecondReverse rollerversusIn a state of being sandwiched between 28SecondReverse rollerversusThe rotation direction of 28 is switched, and the sheet is reversely conveyed and guided toward the upper discharge roller 25 by the transfer direction switching member 44, and the discharge roller25Are sequentially stacked on the paper discharge tray 30 so that the front surface S1-1 becomes the lower surface.
[0078]
The next original S2 is similarly sent out during the conveyance of the original S1, and is conveyed to the vicinity of the first reading unit at the first conveyance speed. When the leading edge of the document S2 is detected by the sensor K1 provided in the vicinity of the first reading unit 11, the transport speed of the document S2 is switched to a second transport speed that is a transport speed for reading a monochrome document, and a transport roller A document image on the surface S2-1 of the document S2 is read by the first reading unit 11 in accordance with the timing at which the leading edge of the document S2 is detected based on the information detected by the sensor K1 while being conveyed by the sensors 21 and 22. Read.
[0079]
The original S2 after the original image on the front surface S2-1 is read by the first reading unit 11 is transported in the same manner as the original S1, and the original image on the back surface S2-2 in the second reading unit. Are read out and discharged onto the paper discharge tray 30.
In the above-described reading of the back surface S1-2 of the plurality of documents S1 by the second reading unit and the reading of the front surface S2-1 of the document S2 by the first reading unit, the documents are so read as to be executed almost simultaneously. The conveyance of S1 and S2 is controlled. That is, the conveyance is controlled so that the original S2 as the subsequent original reaches the vicinity of the first reading section 11 at the same time when the original S1 as the previous original reaches the vicinity of the second reading section 12. The
[0080]
Further, the original S3 following the original S2 is conveyed and read on both sides in the same manner as the original S2 (FIG. 3B).
[0081]
As described above, for example, the image data for two pages read by the second reading unit 12 and the first reading unit 11 from the back surface S1-2 of the document S1 and the front surface S2-1 of the document S2 are as follows. 7 and sent to the second image processing unit 58 or the first image processing unit 57 in FIG. 7 and subjected to image processing such as compression processing and data conversion at the same time, and then stored in the memory 59.
[0082]
If there are a large number of originals to be read in FIG. 3, the first reading unit 11 reads the surface of each original as shown in FIG. Each page is read in order, and the second reading unit 12 sequentially reads each page on the back side of each document like 2, 4, 6,..., And the first image processing unit 57 or the second image processing unit. 58, and is subjected to image processing of the page on the back side of the previous document and the page on the front side of the subsequent document at approximately the same time, and then stored in the memory 59.
[0083]
In this case, as shown in FIG. 3C, the first reading unit 11 or the second reading unit 12 respectively reads the front surface S1-1 of the first document S1 and the back surface of the last document. Is read independently, and reading is not performed at the same time.
[0084]
As described above, a plurality of originals are sequentially conveyed, and each original image on both sides of the plurality of originals is read at the same time by a plurality of reading units, for example, two reading units 11 and 12. The image processing units, for example, the first image processing unit 57 and the second image processing unit 58, perform a plurality of image processing almost at the same time, so that a plurality of double-sided originals can be read efficiently. Thus, productivity of image formation (copying) is improved. Furthermore, by setting the document conveyance speed other than during reading higher than that during reading, a plurality of single-sided originals can be read more efficiently, and productivity can be further improved.
[0085]
3. In case of a single-sided color document (Fig. 4)
[0086]
As shown in FIG. 4A, when a plurality of color originals S1 and S2 are read, if the color mode is selected by the mode selection part 67 of the operation display part 66 in FIG. Then, the first document S1 is fed from the document tray 20 by the feeding roller 19 and conveyed to the vicinity of the first reading unit 11. When the leading edge of the document S1 is detected by the sensor K1 provided in the vicinity of the first reading unit 11, the transport speed of the document S1 is switched to a fifth transport speed that is a transport speed for reading image discrimination. A document image on one side (one side) of the original S1 is read by the first reading unit 11 in accordance with the timing at which the front end of the original S1 is detected based on information detected by the sensor K1 while being conveyed by the rollers 21 and 22. Read.
[0087]
The image data of the document S1 read by the first reading unit 11 is sent to the first image processing unit 47, and the discrimination unit 61 performs image discrimination processing. As the image discrimination, it is discriminated whether it is a color original or a monochrome original, and the control unit 64 controls the driving of the motor 65 based on the determination result to change the rotation speed of the transport rollers 23 and 24, thereby changing the first. The conveyance speed for reading by the second reading unit 12 is controlled to a low fourth conveyance speed for a color original, and to a medium second conveyance speed for a monochrome original.
[0088]
The original S1 after one side (one side) of the original image for image discrimination is read by the first reading unit 11 is switched from the fifth conveyance speed to the third conveyance speed, and the second reading is performed. When the leading edge of the document S1 is detected by the sensor K2 provided near the second reading unit 12 and provided near the second reading unit 12, the conveyance speed of the document S1 is set as follows when the document S1 is a color document. Switching to a fourth transport speed, which is a transport speed for reading a color document, or when the document S1 is a monochrome document, switching to a second transport speed, which is a transport speed for reading a monochrome document, is performed. 24, the second reading unit 12 matches the leading edge position of the document S1 based on the information that the leading edge of the document S1 is detected by the sensor K2 while being transported by the sensor K2. (B) of the original image is read.
[0089]
  The document S1 after the document image is read by the second reading unit 12 is switched from the fourth transport speed or the second transport speed to the third transport speed, and the transport roller 24, the transport direction switching member. 43, 44Reverse paper dischargePath 37And the trailing edge of the document S1 isSecondReverse rollerversusWhen it reaches the vicinity of 28, the rear end is detected by the sensor K4, and based on the detection information of the rear endSecondReverse rollerversusIn a state of being sandwiched between 28SecondReverse rollerversus28 is switched, reversed and conveyed, guided by the conveyance direction switching member 44 toward the upper sheet discharge roller 25, discharged by the sheet discharge roller, and read on the sheet discharge tray 30 by the document S1. It is sequentially loaded so that the surface becomes the lower surface.
[0090]
The next original S2 is similarly sent out during the conveyance of the original S1, and is conveyed to the vicinity of the first reading unit at the first conveyance speed. When the leading edge of the document S2 is detected by the sensor K1 provided in the vicinity of the first reading unit 11, the transport speed of the document S2 is switched to a fifth transport speed that is a transport speed for reading image discrimination. A document on one side (one side) of the original S2 is read by the first reading unit 11 in accordance with the timing at which the leading edge of the original S1 is detected based on information detected by the sensor K1 while being conveyed by the rollers 21 and 22. Read the image.
[0091]
The original S2 after the original image of the original S2 is read by the first reading unit 11 is transported thereafter, the original image is read by the second reading unit, and the paper discharge tray in the same manner as the original S1. 30 is discharged.
In the above-described reading by the second reading unit for reading the original images of the plurality of originals S1 and the reading by the first reading unit for image discrimination of the originals S2, the readings are performed almost simultaneously. In this way, the conveyance of the documents S1 and S2 is controlled. That is, the conveyance is controlled so that the original S2 as the subsequent original reaches the vicinity of the first reading section 11 at the same time when the original S1 as the previous original reaches the vicinity of the second reading section 12. The
[0092]
Further, the original S3 following the original S2 is conveyed and image-determinated in the same manner as the original S2, and the original image is read according to the image discrimination result.
[0093]
As described above, for example, reading of the document image by the second reading unit 12 of the document S1 and each read image data read for image determination by the first reading unit 11 of the document S2 and for image determination. Are respectively sent to the second image processing unit 58 or the first image processing unit 57 in FIG. 7 and subjected to image processing such as compression processing, data conversion, or image discrimination processing at the same time, and 59, and the conveyance of the document is controlled by the control unit based on the determination result.
[0094]
If there are a large number of originals to be read in FIG. 4, each page of each original as shown by 1, 2, 3,... Are sequentially read and image discrimination is performed. Then, based on the discrimination result, the second reading unit 12 sequentially reads each page of each document like 1, 2, 3,... Alternatively, the image data is sent to the second image processing unit 58, and the image processing of the previous document and the image determination processing of the subsequent document are performed at the same time almost at the same time.
[0095]
In this case, as shown in FIG. 4B, in the reading for image discrimination of the first document S1 and the reading of the document image of the last document, the first reading unit 11 or the second reading respectively. The unit 12 performs independent reading and does not perform reading at the same time.
[0096]
As described above, a plurality of color originals are sequentially conveyed, and a plurality of reading units, for example, two reading units 11 and 12 read each original image of a plurality of originals at about the same time. The image processing unit, for example, the determination unit 61 attached to the first image processing unit 57 performs image determination, and the second image processing unit 58 performs image processing of the image data read almost at the same time. Therefore, a plurality of color originals can be read efficiently, and productivity of image formation (copying) is improved. Furthermore, by making the document conveyance speed other than the reading speed faster than that at the time of reading, a plurality of color originals can be read more efficiently, and the productivity is further improved.
[0097]
Further, even when a monochrome document and a color document are mixed, the determination unit 61 determines whether the document is a monochrome document or a color document, so that a reading conveyance speed suitable for each of the monochrome document and the color document can be applied. As a result, the productivity of image formation (copying) of a color original can be further improved.
[0098]
4). In the case of a color double-sided document (Fig. 5)
[0099]
As shown in FIG. 5A, when reading a plurality of color double-sided originals S1 and S2 original images, color mode and double-sided mode are selected by the mode selection part 67 of the operation display part 66 of FIG. It will operate in the duplex mode. In this case, the conveyance of the original to the second image reading unit 12 on the front surface S1-1 of the first original S1, and the image discrimination in the first reading unit 11 on the front surface S2-1 of the next original S2. The conveyance of the originals S1 and S2 until the reading for printing is controlled in the same manner as in the case of the above-described color single-sided original.
[0100]
  The document S1 after the document image is read by the second reading unit 12 is switched from the fourth transport speed or the second transport speed to the third transport speed, and the transport roller 24, the transport direction switching member. It is guided to the conveyance path 35 by 43, and is conveyed to the subsequent conveyance path 34 (FIG.5 (b)). The trailing edge of the document S1 is provided on the transport path 33.ThirdReverse rollerversus29, the rear end is detected by the sensor K5, and based on the detection information of the rear endThirdReverse rollerversus29.ThirdReverse rollerversusThe rotation direction of 29 is switched, reversely conveyed, guided upward by the conveyance direction switching member 45, and circulated and conveyed to the first reading unit 11. The back surface S1-2 of the document S1 circulated and conveyed to the first reading unit 11 is the same as the front surface S1-1 until the subsequent reading by the second reading unit 12.
[0101]
At the time of reading for image discrimination of the back surface S1-2 by the first reading unit 11 of the back surface S1-2 of the document S1, the document by the second reading unit 12 of the front surface S2-1 of the next document S2 Control is performed so that the documents S1 and S2 are conveyed so that the image is read.
[0102]
Further, at the same time as reading the document image on the back surface S1-2 by the second reading unit 12 on the back surface S1-2 of the document S1, the first reading unit 11 on the back surface S2-2 of the next document S2 The originals S1 and S2 are respectively conveyed or circulated so that reading for image discrimination is performed.
[0103]
  The document S1 after the two-sided document image is read by the second reading unit 12 is switched from the fourth transport speed or the second transport speed to the third transport speed, and the transport roller 24, transport direction The transfer path 3 is switched by the switching members 43 and 44.7The trailing edge of the document S1 isSecondReverse rollerversusWhen it reaches the vicinity of 28, the rear end is detected by the sensor K4, and based on the detection information of the rear endSecondReverse rollerversusIn a state of being sandwiched between 28SecondReverse rollerversusThe rotation direction of 28 is switched, and the sheet is reversely conveyed and guided toward the upper discharge roller 25 by the transfer direction switching member 44, and the discharge roller25Are sequentially stacked on the paper discharge tray 30 so that the surface of the document S1 is the lower surface (FIG. 5C).
[0104]
The next original S2 and the subsequent original S3 convey the original S2 from the first reading unit 11 to the second reading unit 12 and convey the next original S3 to the original tray while the original S1 is being conveyed to the paper discharge tray. 20 and is transported to the vicinity of the first reading unit at the first transport speed.
[0105]
At the same time as the reading of the back surface S2-2 of the document S2 by the second reading unit, the first reading unit 11 performs reading for image discrimination of the front surface S3-1 of the document S3.
[0106]
The original S2 after the original images on both sides of the original S2 are read by the second reading unit 12 is discharged onto the discharge tray 30 in the same manner as the original S1.
The original S3 after the image reading of the surface S3-1 of the original S3 is performed by the first reading unit 11 is the surface of the subsequent second reading unit 12 in the same manner as the original S1. Reading of the original image in S3-1, circulation conveyance, reading for image discrimination of the back surface S3-2 in the first reading unit 11, reading of the original image of the back surface S3-2 in the second reading unit 12, and discharge Paper is discharged onto the paper tray 30.
[0107]
Further, the document S4 subsequent to the document S3 is conveyed in the same manner as the document S2, and the image determination of the front and back surfaces and the reading of the document image according to the image determination result are performed. Thereafter, both sides are read in the same manner as a set of a plurality of two-sheet originals in the same manner as the originals S1 and S2.
[0108]
As described above, for example, a document image is read by the second reading unit 12 on the surface S1-1 of the document S1 and is read for image discrimination by the first reading unit 11 on the surface S2-1 of the document S2. Each read image data and image data for image discrimination are respectively sent to the second image processing unit 58 or the first image processing unit 57 in FIG. Processing or image discrimination processing is performed and stored in the memory 59, and the conveyance of the document is controlled by the control unit based on the discrimination result.
[0109]
When there are a large number of originals for reading in FIG. 5, as shown in the table of FIG. 5D, each double-sided original such as 1, 3, 2, 4,... Are sequentially read and image discrimination is performed. Then, based on the discrimination result, the second reading unit 12 sequentially reads each page of each double-sided document as 1, 3, 2, 4,. The image data is sent to the first image processing unit 57 or the second image processing unit 58, and the image processing of the previous document and the image determination processing of the subsequent document are performed at the same time almost at the same time.
[0110]
In this case, as shown in FIG. 5D, the front side S1-1 of the first document S1 is also read in the first reading in the reading for image discrimination and the reading of the document image on the back side of the last document. The unit 11 or the second reading unit 12 performs independent reading, and does not perform reading at the same time.
[0111]
As described above, a plurality of color double-sided originals are sequentially conveyed, and each original image of a plurality of double-sided originals is read at the same time by a plurality of reading units, for example, two reading units 11 and 12 at the same time. Image determination is performed by a plurality of image processing units, for example, a determination unit 61 attached to the first image processing unit 57, and image processing of image data read by the second image processing unit 58 almost at the same time Therefore, a plurality of color double-sided originals can be efficiently read, and the productivity of image formation (copying) is improved. Furthermore, by making the document conveyance speed other than the time of reading higher than that at the time of reading, a plurality of color double-sided originals can be read more efficiently, and the productivity is further improved.
[0112]
In addition, even when a monochrome document and a color document are mixed, the determination unit 61 determines whether the document is a monochrome document or a color document, thereby applying a reading conveyance speed suitable for each of the monochrome document and the color document. As a result, the productivity of image formation (copying) of a color original can be further improved.
[0113]
As described above, according to the image reading apparatus shown in FIG. 1, FIG. 6, and FIG. 7, when the document image is fixed to the monochrome mode (or color mode), the original image is shown in FIG. As described above, the original images can be efficiently read by the two reading units 11 and 12, and the image processing can be simultaneously performed by the two image processing units 57 and 58, so that a more efficient reading operation can be performed. , Productivity can be improved. In the mixed mode of color and monochrome, whether the original image is single-sided or double-sided, as shown in FIG. 4 and FIG. Therefore, more efficient reading operation is possible, productivity can be improved, and discrimination processing by discrimination scanning is performed by the discrimination unit 61, and at the same time, image processing of image information by main scanning is performed. This can be performed by the image processing unit, and efficient image processing is possible. In this way, by fully utilizing the two reading units in all modes, we provide an image reading device (scanner) that can always achieve the highest productivity regardless of the type of document (monochrome / color and double-sided / single-sided). can do.
[0114]
Image processing signals are sent from the image processing units 57 and 58 of the image reading apparatus described above to, for example, an ink jet or electrophotographic printer, and an image is formed by the printer based on the image processing signals. When the image reading apparatus described above is built in the image forming apparatus, an image processing signal is sent to the image writing apparatus 60 as shown in FIG. 7, and the image information writing apparatus 60, for example, based on the image processing signal. The image information is written by irradiating the photosensitive drum with the modulated laser beam, the image information written on the photosensitive drum is developed, and the image information is formed by transferring the image information onto a recording sheet. An example of such an image forming apparatus will be described with reference to FIG.
[0115]
FIG. 8 is a side view illustrating a schematic configuration of the image forming apparatus. An image forming apparatus 70 shown in FIG. 8 includes the image reading apparatus shown in FIG. 1 at the upper part thereof, and the image writing unit 60 shown in FIG. 7 to which the image signal from the CCD image pickup device 56 shown in FIG. Prepare for. In addition, the image forming apparatus 70 includes a photosensitive drum 71 that is exposed to laser light modulated based on an image processing signal by the image writing unit 60 to form a latent image, and a charger that is disposed around the photosensitive drum 71. 72, a developing unit 73, transfer units 74 and 75, and a cleaning unit 76.
[0116]
In the image forming apparatus 70 of FIG. 8, an image is formed on the recording paper 30 as follows. The laser beam from the image writing unit 60 is exposed to the rotating photosensitive drum 71 to form a latent image, and this latent image is developed with toner by the developing unit 73. The recording paper 30 fed upward from the drawing cassette OA or OB in the lower part of FIG. 8 by the conveying roller pair is synchronized with the rotation of the photosensitive drum 71 by the conveying roller pair 61 in a timely manner. , 75, and the developed image is transferred onto the recording paper. Next, the recording paper is conveyed by the conveying belt 77 in the direction of the arrow in the figure, and the toner image is fixed by the fixing device 78 to form an image on the recording paper.
[0117]
When the image formation on one side is completed, the recording sheet is discharged to the discharge unit 80 by the conveyance roller pair 85 by the operation of the conveyance direction switching member 81. When an image is formed on the opposite side of the recording paper, the conveyance direction switching member 81 is actuated so that the recording paper is sent to the lower reversing unit 83 by the reversing roller pair 82 and then sent upward. After passing through the transport section 84 and transported in a state of being inverted below the photosensitive drum 71, an image is formed on the opposite surface in the same manner, and then ejected to the eject section 80.
[0118]
As described above, the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made within the scope of the technical idea of the present invention. For example, the first reading unit 11 may be configured from a CCD image sensor, and the second reading unit 12 may be configured from a compact image sensor (CIS). Further, the reading speed for reading a color image may be set in a plurality of stages.
[0119]
【The invention's effect】
  According to the present invention, a scanned original is a single-sided original.In the articleIn some cases, a color document, a mixed color document and a monochrome document, and a mixed-size document can be read efficiently and an image reading device with extremely high productivity.PlaceAnd an image forming apparatus.
[Brief description of the drawings]
FIG. 1 is a side view showing a schematic configuration of an image reading apparatus according to an embodiment of the present invention.
2 is a side view (a), (b) and table (c) for sequentially explaining operations when a single-sided original is read in a monochrome mode by the image reading apparatus of FIG. 1;
FIGS. 3A and 3B are side views (a) and (b) and a table (c) for sequentially explaining operations when a double-sided original is read in a monochrome mode by the image reading apparatus of FIG. 1;
4 is a side view (a) and a table (b) for sequentially explaining operations when a single-sided original is read in a mixed mode of color and monochrome by the image reading apparatus of FIG. 1;
FIGS. 5A and 5B are side views (a), (b), (c) and a table (d) for sequentially explaining operations when a double-sided original is read in a mixed mode of color and monochrome by the image reading apparatus of FIG. 1; is there.
6A and 6B are diagrams illustrating an example of a document transport direction switching member provided in the image reading apparatus of FIG.
FIG. 7 is a block diagram of the flow of image data and control signals read by the image reading apparatus and the image forming apparatus according to the present embodiment, and a control unit.
FIG. 8 is a side view illustrating a schematic configuration of the image forming apparatus according to the present exemplary embodiment.
[Explanation of symbols]
11 First reading unit
12 Second reading unit
21-25 Conveyance roller pair (conveyance mechanism)
31 Transport path for large size
32 Transport path for small size
33 Front-reverse transport path
34 1st circulation front and back reverse conveyance path
35 Second circulation front / reverse reverse path
37 Reverse paper delivery path
57 First image processing unit
58 Second image processing unit
59 memory
60 Image writer
61 Discriminator
64 Control unit
65 motor
66 Operation display
67 Mode selector
70 Image forming apparatus
S, S1-S4 manuscript
S1-1 Surface of document S1
S1-2 Back side of document S1
S2-1 Surface of document S2
S2-2 Back side of document S2

Claims (12)

An image reading apparatus comprising: a document table on which a document is placed; a plurality of reading units that read a document image while conveying the document; and a paper discharge tray on which a document to be discharged is stacked. The reading unit includes a first reading unit and a second reading unit arranged on the downstream side of the first reading unit, and is arranged on one side of a conveyance path through which the document is conveyed. Between the reading units, at least one of the plurality of conveyance paths having a length longer than the maximum size of the readable document, switching means for switching the plurality of conveyance paths, and the conveyance path are switched according to the paper type. An image reading apparatus comprising: control means for controlling conveyance of the document. The control unit sequentially conveys a plurality of documents at a first conveyance speed to a first reading unit and a second reading unit disposed downstream of the first reading unit, respectively. While the document is being transported at the second transport speed, the document images on the same side of the plurality of documents are respectively read, and the transport speed is controlled so that the respective documents after being read at the third transport speed are discharged. The image reading apparatus according to claim 1, wherein: A plurality of documents are conveyed, and the images on the same side of the plurality of documents are simultaneously read by the first reading unit and the second reading unit, respectively, while the plurality of documents are being conveyed. The image reading apparatus according to claim 1 or 2. The image reading apparatus according to claim 1, further comprising a plurality of image processing units corresponding to the plurality of reading units. The control means performs control so that the first reading unit performs reading for acquiring document information, and the second reading unit performs reading of a document image based on the document information. The image reading apparatus according to claim 1, wherein: The image reading apparatus according to claim 5, wherein the control unit includes a determination unit configured to determine whether the document is a monochrome document or a color document based on document information acquired by the first reading unit. 7. The control unit according to claim 6, wherein the control unit performs control so as to change a conveyance speed for reading a document image of a document by the second reading unit based on a determination result by the determination unit. Image reading apparatus. 8. The control unit according to claim 7, wherein the control unit performs control so that a conveyance speed for reading a document image of a monochrome document is higher than a conveyance speed for reading a document image of a color document. Image reading device. The image reading apparatus according to any one of claims 5 to 8, comprising a monochrome mode for reading a document image of a monochrome document and a color mode for reading a document image of a color document. . The image reading apparatus according to claim 9, further comprising a selection unit that selects the monochrome mode and the color mode. 11. The image reading apparatus according to claim 1, wherein the second reading unit also serves as a reading unit for fixed document scanning. 12. An image comprising: the image reading apparatus according to claim 1; and an image forming apparatus main body that forms an image based on image data read by the image reading apparatus. Forming equipment.

Images