Image reading device, image forming apparatus, and image processing method

Abstract

To improve processing speed to avoid a reduction in productivity.SOLUTION: An image reading device comprises: a first image processing unit that performs first image processing on read images of both front and back sides from a reading unit; an image storage unit that is provided to store the read images of both front and back sides on which the first image processing is performed, and stores the read images of both front and back sides to be alternately replaced with each other over a plurality of pages; a second image processing unit that performs second image processing on the read image of the front side or the back side taken out from the image storage unit; and a control unit that can perform in parallel processing of writing out the read images on which the first image processing is performed to the image storage unit, and processing of reading out the read images stored in the image storage unit to perform the second image processing.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an image reading apparatus, an image forming apparatus, and an image processing method. [Background technology]

[0002] Conventionally, in image processing of a multifunction peripheral (MFP: Multifunction Peripheral / Printer / Product), a technology is known in which the image processing unit performs image processing on both sides of the image (mainly removing the characteristics of the reading unit), stores the images of one page each on the front and back (two pages in total on both sides) in a buffer memory that can accumulate them, and processes the images according to the output target as image data of one page on each side, alternating between the front and back.

[0003] Furthermore, Patent Document 1 discloses a technology in which, in a configuration for detecting electronic inclination to accurately determine the inclination of a document, the read image data of the front and back sides is stored in a buffer memory, and image data of one page for the front and back sides is passed alternately to an image processing unit. Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional technology, when performing image processing in which parameters are detected from the entire image before writing to the buffer memory and the detection results are reflected in the image processing after writing to the buffer memory, this can only be achieved by alternating between processing before writing to the buffer memory and processing after writing to the buffer memory, resulting in a significant decrease in productivity.

[0005] The present invention has been made in view of the above, and has an object to prevent a decrease in productivity by improving processing speed. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the present invention is characterized by comprising a first image processing unit which performs a first image processing on both the front and back read images from a reading unit; an image storage unit which is provided for storing the read images of both the front and back sides which have been subjected to the first image processing, and which stores each of the read images of both the front and back sides over multiple pages in an alternating manner; a second image processing unit which performs a second image processing on the read image of the front or back side taken out from the image storage unit; and a control unit which enables parallel processing of writing the read image which has been subjected to the first image processing to the image storage unit and reading out the read image stored in the image storage unit for performing the second image processing. Effect of the Invention

[0007] According to the present invention, an effect is achieved in that a decrease in productivity can be avoided by improving the processing speed. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of an image reading unit of an image forming apparatus according to a first embodiment, as viewed from the front. [Diagram 2] FIG. 2 is an enlarged view showing a schematic configuration of the SDF unit as viewed from the front. [Diagram 3] FIG. 3 is a block diagram showing a hardware configuration of the image forming apparatus. [Figure 4] FIG. 4 is a diagram showing an example of an outline of an operation performed by a conventional image reading device during reading. [Diagram 5] FIG. 5 is a diagram showing another example of the outline of the operation of a conventional image reading device during reading. [Figure 6] FIG. 6 is a timing chart showing the operation of a conventional image reading device during reading. [Figure 7] FIG. 7 is a diagram showing an example of an outline of an operation during reading. [Figure 8] FIG. 8 is a diagram showing another example of the outline of the operation during reading. [Figure 9] FIG. 9 is a timing chart showing the operation during reading. [Figure 10] FIG. 10 is a diagram illustrating an example of an outline of an operation at the time of reading according to the second embodiment. [Figure 11] FIG. 11 is a diagram showing another example of the outline of the operation during reading. [Figure 12] FIG. 12 is a timing chart showing the operation during reading. [Figure 13] FIG. 13 is a diagram showing an example of an outline of the operation of a conventional image reading device when reading from the front side. [Figure 14] FIG. 14 is a diagram showing another example of the outline of the operation of a conventional image reading device when reading the back side. [Figure 15] FIG. 15 is a timing chart showing the operation of a conventional image reading device during reading. [Figure 16] FIG. 16 is a diagram illustrating an example of an outline of an operation at the time of reading according to the third embodiment. [Figure 17] FIG. 17 is a timing chart showing the operation during reading. [Figure 18] FIG. 18 is a diagram illustrating an example of an outline of an operation at the time of reading according to the fourth embodiment. [Figure 19] FIG. 19 is a timing chart showing the operation during reading. [Figure 20] FIG. 20 is a timing chart of the operation of a configuration in which the toggle buffer is a single buffer like in a conventional image reading device. [Figure 21] FIG. 21 is a diagram illustrating an example of an outline of an operation at the time of reading according to the fifth embodiment. [Figure 22] FIG. 22 is a timing chart showing the operation during reading. [Diagram 23] FIG. 23 is a timing chart of the operation of a configuration in which the toggle buffer is a single buffer like in a conventional image reading device. [Figure 24] FIG. 24 is a diagram illustrating an example of an outline of an operation at the time of reading according to the sixth embodiment. [Diagram 25] FIG. 25 is a diagram illustrating an example of an outline of an operation at the time of reading according to the seventh embodiment. [Figure 26] FIG. 26 is a diagram illustrating an example of an outline of an operation at the time of reading according to the eighth embodiment. [Figure 27] FIG. 27 is a timing chart showing the operation during reading. [Figure 28] FIG. 28 is a timing chart of the operation of a configuration in which the toggle buffer is a single buffer like in a conventional image reading device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of an image reading device, an image forming device, and an image processing method will be described in detail with reference to the accompanying drawings. In this embodiment, an image forming device generally called a multifunction peripheral / printer / product (MFP) having at least two functions of a copy function, a printer function, a scanner function, and a facsimile function is shown as an example.

[0010] (First embodiment) Here, FIG. 1 is a diagram showing a schematic configuration of an image reading section 10 of an image forming apparatus 1 according to the first embodiment as viewed from the front, and FIG. 2 is an enlarged diagram showing a schematic configuration of an SDF unit 15 as viewed from the front.

[0011] As shown in Fig. 1, the image forming apparatus 1 includes an image reading unit (image reading device) 10. The image reading unit 10 includes an original reading table (original table) 12 on the upper part of a housing 11. A contact glass is usually provided on the original reading table 12. An openable and closable original pressing plate 13 is provided on the upper part of the original reading table 12. The original pressing plate 13 presses an original G set on the original reading table 12 so as to be in close contact with the contact glass of the original reading table 12.

[0012] 1, an original transport section 14 is disposed on the upper right side of the housing 11. The original transport section 14 includes an SDF (sheet-through document feeder) unit 15 and an original tray 16. An original transport stepping motor 17 is provided within the SDF unit 15. A plurality of originals G are placed on the original tray 16 in a stack with the reading surface facing up.

[0013] 2, the document transport section 14 rotates a separation roller 18 and a transport roller 19 disposed in the SDF unit 15 using a document transport stepping motor 17. The SDF unit 15 separates the documents G on the document tray 16 one by one using the rotationally driven separation roller 18. The SDF unit 15 also passes the separated documents G one by one through a document transport path in the SDF unit 15 using the rotationally driven transport roller 19, sends the documents G onto the document reading table 12, and further transports them onto a paper output tray (not shown).

[0014] The SDF unit 15 includes a CIS (Contact Image Sensor) 15a, a pair of photosensors 15b, a white board 15c, and the like arranged along the document transport path.

[0015] The CIS 15a is a reading unit that reads an image on the back side of the document G transported on the document transport path.

[0016] Incidentally, the image reading unit 10 has a book mode and an SDF mode as document reading modes. Here, the SDF mode for simultaneous double-sided reading will be mentioned.

[0017] As shown in FIG. 2, when a plurality of originals G are set on the original tray 16, the image reading unit 10 first turns on the light source 21a, reads the white reference plate 20, and then drives the original transport stepping motor 17. The image reading unit 10 moves the first traveling body 21 to the reading position of the SDF window 15d and stops it. Next, the image reading unit 10 drives the original transport stepping motor 17 to separate the originals G set on the original tray 16 one by one with the separation roller 18. Next, the image reading unit 10 transports the originals G separated one by one at a constant speed (uniform speed) by the transport roller 19, and reads the back image of the originals G by the CIS 15a. The image reading unit 10 transports the originals G, the back of which has been read, at a constant speed (uniform speed) to the position of the SDF window 15d, which is the predetermined reading position of the first traveling body 21.

[0018] The image reading unit 10 conveys the document G at a constant speed (uniform speed), and while the first traveling body 21 and the second traveling body 22 are stopped at the reading position, the light source 21a on the first traveling body 21 irradiates the conveyed document G with light through the SDF window 15d. The image reading unit 10 reflects the light reflected by the document G again through the SDF window 15d, by the mirror 21b and the mirrors 22a and 22b on the second traveling body 22, and makes the light enter the CCD 24 through the lens 23, and the CCD 24 performs photoelectric conversion to read an image of the surface of the document G. In other words, the CCD 24 is a reading unit that reads an image of the surface of the document G conveyed on the document conveying path.

[0019] Next, the hardware configuration of the image forming apparatus 1 will be described.

[0020] 3 is a block diagram showing a hardware configuration of the image forming apparatus 1. As shown in this figure, the image forming apparatus 1 has a configuration in which a controller 110 and an engine unit (Engine) 160 are connected by a PCI (Peripheral Component Interface) bus. The controller 110 is a controller that controls the entire image forming apparatus 1 and controls drawing, communication, and input from an operation unit (not shown). The engine unit 160 is a printer engine that can be connected to the PCI bus, and is, for example, a black-and-white plotter, a one-drum color plotter, a four-drum color plotter, a scanner, or a fax unit. Note that the engine unit 160 includes an image processing unit such as error diffusion and gamma conversion in addition to a so-called engine unit such as a plotter.

[0021] The controller 110 includes a controller SoC (System on a chip) 111, a controller memory (MEM-P) 112, and a controller ASIC (Application Specific Integrated Circuit) 116, with the controller SoC 111 and the controller ASIC 116 connected via a bus.

[0022] The controller SoC 111 performs overall control of the image forming apparatus 1, includes a CPU (Central Processing Unit), and is connected to other devices.

[0023] The MEM-P 112 is a controller memory used as a memory for storing programs and data, a memory for expanding programs and data, a memory for printer drawing, etc., and is composed of a ROM (Read Only Memory) 112a and a RAM (Random Access Memory) 112b. The ROM 112a is a read-only memory used as a memory for storing programs and data, and the RAM 112b is a writable and readable memory used as a memory for expanding programs and data, a memory for printer drawing, etc.

[0024] The controller ASIC 116 is an IC (Integrated Circuit) for image processing purposes having hardware elements for image processing, and serves as a bridge connecting various buses and an HDD (Hard Disk Drive) 118. This controller ASIC 116 is made up of a PCI target and an AGP master, an arbiter (ARB) which is the core of the controller ASIC 116, a memory controller which controls the HDD 118, a plurality of DMACs (Direct Memory Access Controllers) which rotate image data using hardware logic, and a PCI unit which transfers data between the engine unit 160 and the controller ASIC 116 via the PCI bus.

[0025] The HDD 118 is a storage for storing image data, programs, font data, and forms.

[0026] To the controller SoC111, a FCU (Facsimile Control Unit) 130, a USB (Universal Serial Bus) 140, and an IEEE1394 (the Institute of Electrical and Electronics Engineers 1394) interface 150 are connected via a PCI bus. The operation display unit 120 is directly connected to the controller SoC111.

[0027] The engine unit 160 includes an engine SoC 161, an image processing ASIC 162, a memory 163 for the image processing ASIC, an image forming unit 164, an image reading unit 10, and the like.

[0028] The engine SoC 161 controls the image forming unit 164 , the image reading unit 10 , and the image processing ASIC 162 .

[0029] The engine SoC 161 and the controller SoC 111 communicate with each other via the controller ASIC 116 and the image processing ASIC 162 and operate in cooperation with each other to realize the operation of the entire image forming apparatus 1, such as the desired operation set by the user on the operation display unit 120, etc.

[0030] The image processing ASIC 162 includes a first image processing unit 162-1 and a second image processing unit 162-2 (see FIG. 4). The first image processing unit 162-1 performs a first image processing on the read image from the image reading unit 10. The second image processing unit 162-2 performs a second image processing on the read image.

[0031] More specifically, the first image processing unit 162-1 is a feature extraction unit that extracts feature amounts from the entire image based on the image stored in the image processing ASIC memory 163 or the image input from the reading unit and before being written to the image processing ASIC memory 163. The second image processing unit 162-2 is a feature amount reflection processing unit that reflects the feature amounts extracted by the first image processing unit 162-1.

[0032] The image processing ASIC memory 163 is used for processing in the image processing ASIC 162. More specifically, the image processing ASIC memory 163 is a toggle buffer having a front toggle buffer TB1 and a back toggle buffer TB2. The image processing ASIC memory 163 is an image storage unit that stores the scanned image subjected to the first image processing in the first image processing unit 162-1 over multiple pages so as to alternately switch between the front toggle buffer TB1 and the back toggle buffer TB2.

[0033] The image processing ASIC 162 also functions as a control unit that enables parallel processing of writing the scanned image that has been subjected to the first image processing by the first image processing unit 162-1 to the memory 163 for the image processing ASIC, and reading out the scanned image stored in the memory 163 for the image processing ASIC for performing the second image processing by the second image processing unit 162-2.

[0034] With this configuration, the image read by the image reading unit 10 is input to the image processing ASIC 162 .

[0035] As described above, when reading, the image reading unit 10 reads an image from the original G while transporting the original G at a constant speed (uniform speed).

[0036] In addition, when reading during continuous transport, the document transport speed is determined by factors such as the paper transport performance of the image reading unit 10 mechanism, the performance of the sensors such as the CIS 15a and CCD 24 that are the reading unit, the light source 21a, the reading resolution, etc. Therefore, in order to improve reading productivity by increasing the reading transport speed, it is necessary to improve the performance of the image reading unit 10 mechanism, a higher performance sensor, a brighter light source, etc., which will increase manufacturing costs.

[0037] Here, FIG. 4 is a diagram showing an example of an outline of operation of a conventional image reading device when reading, FIG. 5 is a diagram showing another example of an outline of operation of a conventional image reading device when reading, and FIG. 6 is a timing chart showing operation of a conventional image reading device when reading.

[0038] 4 shows the timing (1) of the timing chart shown in FIG. 6 for the reading operation in a one-pass configuration for both sides in the conventional image reading device 500. Image data for both sides is input from the reading unit 501 to the image processing ASIC 502, and after image processing A' is performed on the front side and image processing A'' on the back side, the data is written to a front side normal buffer 503-1 and a back side normal buffer 503-2, which are secured for one page on each side in the image processing ASIC memory 503. In the conventional image reading device 500, a reading operation is also performed at the same time as the writing operation. Thereafter, in the conventional image reading device 500, the image data stored in the front side normal buffer 503-1 is read, and after image processing B is performed, the data is written to the controller memory 506 via the controller ASIC 504 and SoC 505.

[0039] 5 shows the reading operation of a conventional image reading device 500 in a double-sided one-pass configuration, with respect to timing (2) in the timing chart shown in FIG. 6. In the conventional image reading device 500, the reading unit 501 is between the sheets at this timing, and no image is input. Meanwhile, in the conventional image reading device 500, the image of the second page has already been written in its entirety to the back-side normal buffer 503-2, and the accumulated image data is read and, after image processing B, written to the controller memory 506 via the controller ASIC 504 and SoC 505.

[0040] 6 is a timing chart of a double-sided 1-pass configuration in a conventional image reading device 500. As described above, timings (1) and (2) show the operation timings in FIG. 4 and FIG. 5, respectively. In the conventional image reading device 500, the reading operation by the reading unit 501 is started, and the image data of the front and back sides are written to the front normal buffer 503-1 and the back normal buffer 503-2, respectively, and then reading of the front normal buffer 503-1 is started, and the above-mentioned image processing B is performed, and then the front processed image is written to the controller memory 506. In the conventional image reading device 500, when reading of the front normal buffer 503-1 is finished and image processing B for the front side is completed, reading of the back normal buffer 503-2 is started, image processing B is performed, and the processed image is written to the controller memory 506.

[0041] In the conventional image reading device 500, after the front and back images have been written, the images written to the controller memory 506 are input to the JPEG compression module of the controller ASIC 504 in Fig. 4 and Fig. 5, respectively, to generate JPEG code data, which is then written to the storage 507 via the storage I / F. In the conventional image reading device 500, this process is repeated alternately for the front and back sides.

[0042] 6, the read time for one page of the front normal buffer 503-1 is longer than the read time for one page of the back normal buffer 503-2. This is because the read operation of the front normal buffer 503-1 starts before the read operation of the front side is completed, so the throughput of image processing B is faster than the read processing of the reading unit 501, but the read operation of the front normal buffer is slower because it is limited by the read processing of the reading unit 501. On the other hand, the read operation of the back side reading unit 501 ends in the middle of the read operation of the back normal buffer, so that the operation is not limited by the linear speed of the reading unit 501, and therefore the processing time is shorter than the read operation of the front normal buffer 503-1.

[0043] As described above, in the conventional image reading device 500, the linear speed of the reading unit 501 determines the rate of processing after buffer reading, resulting in reduced productivity.

[0044] According to the conventional image reading device 500, there is a period (paper interval) during which the document is not read and data is not written to the front normal buffer 503-1 and the back normal buffer 503-2. According to the conventional image reading device 500, the paper interval can be considered as the time obtained by subtracting the front image reading time from the processing time of the front image processing B, the processing time of the back image processing B, communication, and the time required for setting in the image processing ASIC 502. In other words, if the processing time of the front image processing B or the processing time of the back image processing B can be shortened, the paper interval can be shortened and productivity can be improved. Also, compared to the case of increasing the conveying speed of the reading speed, the effect is limited by the reading linear speed, but it can be realized while suppressing the increase in cost. This point will be described in detail below.

[0045] Here, FIG. 7 is a diagram showing an example of an outline of the operation during reading, FIG. 8 is a diagram showing another example of the outline of the operation during reading, and FIG. 9 is a timing chart showing the operation during reading.

[0046] 7, 8, and 9 respectively show an example of an outline of the operation during reading, another example of an outline of the operation during reading, and a timing chart for one-pass double-sided image reading by the image reading unit 10 when a toggle buffer is used to reduce the space between sheets as a means of solving the productivity problem in the conventional configuration. Timing (3) and timing (4) in the timing chart shown in Fig. 9 show the timings shown in Fig. 7 and Fig. 8, respectively.

[0047] 7 illustrates the reading operation of the image reading unit 10 in a double-sided, single-pass configuration, with respect to timing (3) in the timing chart shown in FIG. 9. In a conventional image reading device 500, the front image is subjected to image processing A', and the back image is subjected to image processing A'', after which the images are stored in the front normal buffer 503-1 and the back normal buffer 503-2, respectively. In contrast, the image processing ASIC 162 of this embodiment performs image processing A' on the front image, performs image processing A'' on the back image, and then stores the images in buffer B3 of the front toggle buffer TB1 and buffer B4 of the back toggle buffer TB2, which have buffer capacities for two pages per side.

[0048] Meanwhile, simultaneously with this operation, the image processing ASIC 162 reads from the buffer B1 the image data of the front side of the document read just before the document being read, which has already been accumulated in the buffer B1 of the front side toggle buffer TB1, and performs image processing B. Thereafter, the image processing ASIC 162 writes the data to the controller memory 112 via the controller ASIC 116 and the controller SoC 111.

[0049] The image reading unit 10 of this embodiment has such a toggle buffer configuration, so that the buffer into which the image from the image reading unit 10 is written is separate from the buffer into which the accumulated images are read.

[0050] 8 illustrates the reading operation of the image reading unit 10 in a double-sided, single-pass configuration, with respect to timing (4) in the timing chart shown in FIG. 9. In a conventional image reading device 500, the front image is subjected to image processing A', and the back image is subjected to image processing A'', after which the images are stored in the front normal buffer 503-1 and the back normal buffer 503-2, respectively. In contrast, the image processing ASIC 162 of this embodiment performs image processing A' on the front image, performs image processing A'' on the back image, and then stores the images in buffer B3 of the front toggle buffer TB1 and buffer B4 of the back toggle buffer TB2, which have buffer capacities for two pages each on one side.

[0051] Meanwhile, simultaneously with this operation, the image processing ASIC 162 reads from the buffer B2 the image data of the back side of the document that was read just before the document being read and that has already been accumulated in the buffer B2 of the back side toggle buffer TB2, and performs image processing B. Thereafter, the image processing ASIC 162 writes the data to the controller memory 112 via the controller ASIC 116 and the controller SoC 111.

[0052] The image reading unit 10 of this embodiment has such a toggle buffer configuration, so that the buffer into which the image from the image reading unit 10 is written is separate from the buffer into which the accumulated images are read.

[0053] In this embodiment, as described above, the front side image storage is configured with buffers B1 and B3, and the back side image storage is configured with buffers B2 and B4, which are toggle buffers. In the case of the front side, when writing out buffer B1, buffer B3 is read, and when writing out buffer B3, buffer B1 is read (similar for the back side). In addition, buffer writing is performed for each read original in a buffer different from the previous original.

[0054] By adopting such a configuration, the problem in the single buffer configuration of the conventional image reading device 500 that the read speed of the toggle buffer is limited by the productivity of the image reading unit 10, resulting in a drop in productivity, is resolved, and it is possible to speed up processing to the point where the read processing of the toggle buffer for one document (front and back) is completed during the read time of the image reading unit 10 for one document (approximately equivalent to the write time to the toggle buffer).

[0055] Thus, according to this embodiment, when storing the results of image processing on double-sided input from the reading unit in the buffer, two pages of buffer are toggled for each side. In other words, by using different pages for the buffer to write image data input from the reading unit and the buffer to read the stored image, it is possible to eliminate the linear speed limitation of the image reading unit when reading the stored image, and therefore it is possible to improve the processing speed and avoid a decrease in productivity.

[0056] (Second embodiment) Next, a second embodiment will be described.

[0057] In the description of the second embodiment, the description of the same parts as in the first embodiment will be omitted, and only the parts different from the first embodiment will be described.

[0058] Here, FIG. 10 is a diagram showing an example of an outline of an operation during reading according to the second embodiment, FIG. 11 is a diagram showing another example of an outline of an operation during reading, and FIG. 12 is a timing chart showing the operation during reading.

[0059] 10, 11, and 12 show an outline of the operation when reading the front side, an outline of the operation when reading the back side, and a timing chart, respectively, for one-pass double-sided operation of image reading by the image reading unit 10, which is characterized in that, as a means for solving the productivity problem in the conventional configuration, the first image processing unit 162-1 uses a toggle buffer to determine the top-bottom discrimination, and the image is rotated by the image rotation circuit 202 of the second image processing unit 162-2 based on the result of the top-bottom discrimination determination. Timing (5) and timing (6) in the timing chart shown in Fig. 12 show the timings described as Fig. 10 and Fig. 11, respectively.

[0060] In the first embodiment, it has been described that productivity is improved by changing the image path of the one-pass double-sided image reading unit 10 from the single buffer of the conventional image reading device 500 to a toggle buffer. The following describes secondary effects that can be obtained by using a toggle buffer in the image path of the one-pass double-sided image reading unit 10.

[0061] Here, FIG. 13 is a diagram showing an example of an outline of operation of conventional image reading device 500 when reading the front side, FIG. 14 is a diagram showing another example of an outline of operation of conventional image reading device 500 when reading the back side, and FIG. 15 is a timing chart showing the operation of conventional image reading device 500 when reading.

[0062] In a conventional image reading device, as shown in Fig. 13 and Fig. 14, images are read from a reading unit 501 by inputting images of both sides or one side to an image processing ASIC 502 connected to the reading unit 501, and each input image is subjected to image processing by a first image processing unit 502-1. In the image processing A500, the image processing ASIC 502 reads images stored in a memory 503 for the image processing ASIC, performs image processing by a second image processing unit 502-2, and passes the images to a controller ASIC 504. At this time, the processing by the second image processing unit 502-2 is performed one side at a time. Note that timing (1) and timing (2) in the timing chart shown in Fig. 15 indicate the timings shown in Figs. 13 and 14, respectively.

[0063] In the conventional image reading device 500, a "buffer" is reserved for one input image per side. In double-sided one-pass processing, data written sequentially from the top of the buffer from the reading unit 501 on the front side (and sometimes on the back side) is read from the top of the buffer to the controller ASIC 504 side before one side's worth of data is completely written in the buffer. For this reason, when front side buffer reading starts, the feature amount derived from the entire image is not yet determined, and it cannot be reflected in the image processing parameters of the second image processing unit 502-2. If the buffer were read after the feature amount was determined, it would be necessary to alternate between writing one side's worth of image data from the reading unit 501 to the buffer and then reading one side's worth of data, which would significantly reduce productivity.

[0064] In addition, a program executed by the CPU in the SoC 505, which performs controller processing, transfers images placed in the controller memory 506 to the JPEG compressor in the controller ASIC 504, converts them into JPEG images, and then stores them in the storage 507 from the controller ASIC 504 via the storage I / F.

[0065] Meanwhile, the upside-down identification program P1 on the CPU in the SoC 505 that processes the controller performs upside-down identification based on the image, reflects the result in the PDF, and transmits it. After a series of processes, such as reading by the reading unit 501, writing the image to the controller memory 506, compressing it, and storing it in the storage, the program reads the image stored in the storage 507 via the storage I / F, expands it with a JPEG expander, expands the image in the controller memory 506, and performs upside-down identification based on the image expanded by the upside-down identification program P1. In the conventional image reading device 500, the judgment result is incorporated into the PDF element, and the PDF is generated by packing it together with the original JPEG image, and transmitted according to the purpose.

[0066] Furthermore, if you reconfigure this program to output images with orientation information added in Exif format rather than PDF format, the image itself will not be rotated, so depending on the viewer, it may ignore the orientation information saved in Exif format and display the image, in which case the image will not be displayed in the correct orientation.

[0067] Therefore, in this embodiment, the single buffer of the one-pass double-sided configuration in the conventional image reading device 500 is replaced with a toggle buffer, and an upside-down identification circuit 201, which is an upside-down identification unit, is added to the first image processing unit 162-1, and an image rotation circuit 202, which is an image rotation unit, is added to the second image processing unit 162-2. The toggle buffer is the same as that described in the first embodiment.

[0068] The top / bottom discrimination circuit 201 discriminates the orientation of the image based on the input image of one side of each side. The image rotation circuit 202 writes the input image to the controller memory 112 while rotating it.

[0069] In this embodiment, by using a toggle buffer as the buffer, the entire image of a certain page is processed by the first image processing unit 162-1, and then processed by the second image processing unit 162-2, and the image is sent to the controller ASIC 116. Therefore, it is possible to transmit the result of extracting a feature amount determined from the entire image by the first image processing unit 162-1 to the second image processing unit 162-2 as a parameter and reflect the result of the second image processing unit 162-2 without reducing the productivity of the image reading unit 10.

[0070] In this embodiment, after the first image processing unit 162-1 has completed image input, the image processing ASIC 162 reflects the upside-down discrimination result in the rotation direction parameter to be sent to the image rotation circuit 202 of the second image processing unit 162-2.

[0071] By performing processing as in this embodiment, the JPEG image itself is rotated and stored with the image orientation adjusted, so there is no need to specify the image orientation in the Exif format Orientation when outputting the JPEG, and the image can be displayed in the correct orientation in any viewer.

[0072] In addition, according to the image reading unit 10 of this embodiment, in the case of PDF output by the upside-down identification program P1 in the conventional image reading device 500, the “storage reading / expanding / upside-down identification process” that was necessary for the CPU in the SoC 505 to perform the upside-down identification process is no longer necessary, thereby enabling faster processing.

[0073] Thus, according to this embodiment, productivity can be improved compared to conventional image reading devices that do not use a toggle buffer. Also, according to this embodiment, compared to when the top and bottom are detected after output to the controller memory and embedded in the image as tag information, the image itself is rotated, so the image is displayed in the correct orientation regardless of the viewer software implementation, and productivity is also improved.

[0074] (Third embodiment) Next, a third embodiment will be described.

[0075] The third embodiment differs from the second embodiment in that it is replaced with an upside-down identification program P2 executed by an internal CPU built into the image processing ASIC 162. In the following explanation of the third embodiment, explanations of the same parts as in the first and second embodiments will be omitted, and only differences from the first and second embodiments will be explained.

[0076] FIG. 16 is a diagram showing an example of an outline of an operation during reading according to the third embodiment, and FIG. 17 is a timing chart showing the operation during reading.

[0077] 16 and 17 show a third embodiment in which the upside-down identification circuit 201 described in the second embodiment is replaced with an upside-down identification program P2 executed by an internal CPU 162-3 built into an image processing ASIC 162.

[0078] 17, after writing one page to buffer B1 of front toggle buffer TB1 of image processing ASIC 162, image processing ASIC 162 executes top / bottom identification program P2 to obtain the top / bottom identification result. Image processing ASIC 162 reads the top / bottom identification result obtained here from buffer B1 of the same front toggle buffer TB1, and reflects it in the processing as a rotation direction parameter when operating image rotation circuit 202 in second image processing unit 116a-2.

[0079] By performing processing as in this embodiment, as in the second embodiment, the JPEG image itself is rotated and stored with the image orientation adjusted, so there is no need to specify the image orientation in the Exif format Orientation when outputting the JPEG, and the image can be displayed in the correct orientation in any viewer.

[0080] In addition, according to the image reading unit 10 of this embodiment, in the case of PDF output using the upside-down identification program P1 in a conventional image reading device, the “storage reading / expanding / upside-down identification process” that was necessary for the CPU in the SoC 505 to perform the upside-down identification process is no longer necessary, thereby enabling faster processing.

[0081] (Fourth embodiment) Next, a fourth embodiment will be described.

[0082] The fourth embodiment differs from the second embodiment in that it is a single-sided reading embodiment. In the following description of the fourth embodiment, the description of the same parts as the first and second embodiments will be omitted, and only the differences from the first and second embodiments will be described.

[0083] Here, Fig. 18 is a diagram showing an example of an outline of the operation during reading according to the fourth embodiment, Fig. 19 is a timing chart showing the operation during reading, and Fig. 20 is a timing chart showing the operation in a configuration in which the toggle buffer is a single buffer like the conventional image reading device 500.

[0084] 18 and 19 show the configuration described in the second embodiment, but for single-sided reading. Meanwhile, FIG. 20 is a timing chart of the operation in a configuration in which the toggle buffer in the configuration according to the fourth embodiment is used as a single buffer. As shown in FIG. 20, in the configuration in which the toggle buffer is used as a single buffer, writing of the front side is completed and the top-bottom identification circuit 201 outputs the top-bottom identification result, and finally the buffer can be read and the top-bottom identification result can be reflected in the image rotation circuit 202 of the second image processing unit 162-2 for processing. That is, as shown in the timing chart in FIG. 20, writing of the buffer and reading of the buffer can only be performed alternately.

[0085] On the other hand, according to the image reading unit 10 of this embodiment, as shown in Fig. 19, when the data of the 2n+1th page is written to the buffer B1 of the front toggle buffer TB1 of the image processing ASIC 162, the top / bottom identification result of the 2nth page has already been determined, and reading from the buffer B1 of the front toggle buffer TB1 of the image processing ASIC 162 and writing from the buffer B3 of the front toggle buffer TB1 of the image processing ASIC 162 can be performed simultaneously. Therefore, productivity can be improved compared to the configuration of the conventional image reading device 500 shown in Fig. 20, which can only alternately write and read data to and from the buffer.

[0086] (Fifth embodiment) Next, a fifth embodiment will be described.

[0087] The fifth embodiment differs from the third embodiment in that it is a single-sided reading embodiment. In the following description of the fifth embodiment, the description of the same parts as the first to third embodiments will be omitted, and only the differences from the first to third embodiments will be described.

[0088] Here, Fig. 21 is a diagram showing an example of an outline of the operation during reading according to the fifth embodiment, Fig. 22 is a timing chart showing the operation during reading, and Fig. 23 is a timing chart showing the operation in a configuration in which the toggle buffer is a single buffer.

[0089] 21 and 22 show the configuration described in the third embodiment, adapted for single-sided reading.

[0090] On the other hand, FIG. 23 is a timing chart of the operation in a configuration in which the toggle buffer according to the fifth embodiment is replaced by a single buffer like in a conventional image reading device.

[0091] According to this embodiment, it is possible to improve productivity compared to the case where the toggle buffer shown in FIG. 23 is made into a single buffer.

[0092] (Sixth embodiment) Next, a sixth embodiment will be described.

[0093] In the description of the sixth embodiment, the description of the same parts as those in the first to third embodiments will be omitted, and only the parts different from the first to third embodiments will be described.

[0094] Here, Fig. 24 is a diagram showing an example of an outline of an operation during reading according to the sixth embodiment. Fig. 24 shows an example of a configuration in which the upside-down identification program P2 of the third embodiment is replaced with the upside-down identification program P4 and machine learning inference is used as the sixth embodiment.

[0095] The upside-down identification program P4 generates an image by normalizing the image stored in the toggle buffer of the image processing ASIC memory 163 with respect to an inference model for upside-down identification, and writes the image to the image processing ASIC memory 163. Then, the upside-down identification program P4 performs inference based on this normalized image using a model trained for upside-down identification (included in the upside-down identification program P4) to derive an upside-down identification result.

[0096] The image processing ASIC 162 outputs an image in the correct orientation by reflecting the upside-down identification result derived by the upside-down identification program P4 in the image rotation circuit 202 of the second image processing unit 162-2.

[0097] Incidentally, FIG. 24 shows a configuration in which a MAC (Multiply and ACumulate unit) 162-4 is used by the built-in CPU 162-3 of the image processing ASIC 162 in order to reduce the processing load on the built-in CPU 162-3 built into the image processing ASIC 162 during calculations during inference.

[0098] The MAC 162-4 may be implemented as a circuit specialized for multiply-and-accumulate operations, or may be configured to perform multiply-and-accumulate operations using a general-purpose circuit such as a GPU.

[0099] Also, if the processing time is tolerable, the multiply-and-accumulate processing may be performed by the built-in CPU 162-3 without using the MAC 162-4. In this case, the cost required for implementing the MAC 162-4 in hardware can be reduced.

[0100] (Seventh embodiment) Next, a seventh embodiment will be described.

[0101] In the description of the seventh embodiment, the description of the same parts as those in the first to sixth embodiments will be omitted, and only the parts different from the first to sixth embodiments will be described.

[0102] Here, Fig. 25 is a diagram showing an example of an outline of an operation during reading according to the seventh embodiment. Fig. 25 shows an example of a configuration of the seventh embodiment in which the upside-down identification program P4 of the sixth embodiment is replaced with the upside-down identification program P5, and an image normalization circuit 203 is added to the first image processing unit 162-1.

[0103] In the sixth embodiment, normalized image generation was performed by the upside-down identification program P4, but in the upside-down identification program P5 of this embodiment, the generation is performed by the image normalization circuit 203 of the first image processing unit 162-1, in order to reduce the load on the built-in CPU of the image processing ASIC 162 and increase its speed.

[0104] The image processing ASIC 162 writes the normalized image generated by the image normalization circuit 203 to the image processing ASIC memory 163. The upside-down identification program P5 uses the normalized image generated by the image normalization circuit 203, performs inference using a model learned for upside-down identification, and derives an upside-down identification result.

[0105] (Eighth embodiment) Next, an eighth embodiment will be described.

[0106] In the description of the eighth embodiment, the description of the same parts as those in the first to seventh embodiments will be omitted, and only the parts different from the first to seventh embodiments will be described.

[0107] FIG. 26 is a diagram showing an example of an outline of the operation during reading according to the eighth embodiment, and FIG. 27 is a timing chart showing the operation during reading.

[0108] In the first to seventh embodiments, the toggle buffer is used in one-pass double-sided (or single-sided) operation to improve the productivity of reading by the image reading unit 10. In particular, in the second to seventh embodiments, the toggle buffer is used to improve the productivity in the latter stage of processing using features that can be derived from the entire image, compared to a single buffer.

[0109] On the other hand, the eighth embodiment has an advantage over the conventional image reading device 500 in that an image that matches an intention can be generated.

[0110] 26 and 27 show an embodiment in which the top-bottom identification circuit 201 is replaced with a special document detection circuit 301 and the image rotation circuit 202 is replaced with a special document response circuit 302 in the configuration described in the second embodiment. Also, Fig. 28 is a timing chart of the operation of a configuration in which the toggle buffer is replaced with a single buffer like the conventional image reading device 500.

[0111] The special document detection circuit 301 is a special document detection section that searches the entire input image, and when a desired search result is obtained, determines that a special document has been detected.

[0112] The special document handling circuit 302 is a special document handling unit that outputs a special document output result when the special document detection circuit 301 detects a special document.

[0113] As shown in Fig. 28, in the conventional image reading device 500, when a special document is detected by the special document detection circuit of the first image processing unit 502-1, the result is passed to the special document response circuit, and the special document response circuit takes measures such as replacing the image with black regardless of the image read from the buffer. However, when it is determined that a special document is detected at timing (10) in Fig. 28, in the conventional method, since data is written out from the same buffer while reading, the document being read is already partially passed through the special document response circuit, and the document from timing (10) onwards is painted black, and it is not possible to make the entire surface black.

[0114] On the other hand, according to this embodiment, as shown in Figures 26 and 27, the special document detection information is determined at the time of buffer reading and can be reflected in the special document handling circuit 302 of the second image processing unit 162-2 from the beginning of the image, so that the entire front and back can be replaced with black.

[0115] Thus, according to this embodiment, in a configuration that does not use the toggle buffer of the conventional image reading device 500, it was not possible to accommodate special originals (output in black) for part of the leading image in the sub-scanning direction in the front-side output, but it is now possible to accommodate special originals over the entire surface in both front and back outputs.

[0116] In each of the above embodiments, the image forming apparatus of the present invention is described as being applied to a multifunction device having at least two of the functions of a copy function, a printer function, a scanner function, and a facsimile function. However, the image forming apparatus can be applied to any image forming apparatus, such as a copier, printer, scanner device, or facsimile device.

[0117] Although the embodiments of the present invention have been described above, each embodiment is presented as an example and is not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. Each of these embodiments is included in the scope and gist of the invention, and is included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0118] 1. Image forming device 10 Image reading device 15a, 24 Reading section 116 Control Unit 162-1 First image processing unit, feature extraction unit 162-2 Second image processing unit, feature amount reflection processing unit 163 Image storage unit 164 Image forming section 201 Top and Bottom Identification Department 202 Image Rotation Unit 301 Special document detection unit 302 Special manuscript handling section [Prior art documents] [Patent documents]

[0119] [Patent Document 1] JP 2016-086376 A

Claims

1. a first image processing unit that performs a first image processing on the read images of both the front and back sides from the reading unit; an image storage unit that is provided for storing the read images of both sides of the document that have been subjected to the first image processing, and that stores the read images of both sides of the document over a plurality of pages in an alternating manner; a second image processing unit that performs a second image processing on the read image of the front side or the back side retrieved from the image storage unit; a control unit that enables parallel processing of writing the scanned image that has been subjected to the first image processing to the image storage unit and reading the scanned image stored in the image storage unit for performing the second image processing; An image reading device comprising:

2. the first image processing unit executes the first image processing on the read image on either the front or back side; the second image processing unit performs the second image processing on the read image of either the front or back side on which the first image processing has been performed; 2. The image reading apparatus according to claim 1, wherein the image reading apparatus comprises:

3. the first image processing unit includes a special document detection unit that determines that a special document has been detected when a desired search result is obtained by searching an entire input image as the first image processing, the second image processing unit includes a special document handling unit that outputs a special document output result when the special document detection unit detects a special document as the second image processing.

2. The image reading apparatus according to claim 1, wherein the image reading apparatus comprises:

4. the first image processing unit includes a feature extraction unit that extracts a feature from an entire image based on an image stored in the image storage unit or an image input from the reading unit and before being written to the image storage unit, as the first image processing; the second image processing unit includes a feature amount reflection processing unit that reflects the feature amount extracted by the feature amount extraction unit as the second image processing.

2. The image reading apparatus according to claim 1, wherein the image reading apparatus comprises:

5. The feature extraction unit is a top / bottom identification unit that extracts top / bottom identification information that identifies the top / bottom of the image as the feature, The feature amount reflection processing unit is an image rotation unit that rotates an image based on the top-bottom identification information extracted by the top-bottom identification unit.

5. The image reading apparatus according to claim 4,

6. The top-bottom identification unit performs inference using a model trained for top-bottom identification based on an image normalized to an inference model for top-bottom identification of the image stored in the image storage unit, and derives a top-bottom identification result.

6. The image reading apparatus according to claim 5,

7. The top-bottom identification unit generates an image by normalizing the image stored in the image storage unit with respect to an inference model of top-bottom identification.

7. The image reading apparatus according to claim 6,

8. An image reading device according to any one of claims 1 to 7; An image forming unit; An image forming apparatus comprising:

9. a first image processing step of performing a first image processing on the images read from the reading unit on both sides of the document; an image storage step for storing the read images of both the front and back sides of the document, the read images being subjected to the first image processing, in an image storage unit for storing the read images of both the front and back sides of the document over a plurality of pages in an alternating manner; a second image processing step of performing a second image processing on the read image of the front side or the back side taken out from the image storage unit; a control step of enabling parallel processing of writing the scanned image having been subjected to the first image processing to the image storage unit and reading the scanned image stored in the image storage unit for performing the second image processing; 13. An image processing method comprising:

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