JP2011114529A - Apparatus, method and program for reading double-sided image and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double-sided image reader which diverts the existing single-sided image reader, a double-sided image reading method, a double-sided image reading program and a recording medium. <P>SOLUTION: In the double-sided image reader 1, two scanner units 2a and 2b simultaneously read the front surface and rear surface of an original, compressing parts 4a and 4b respectively perform compression for each page by a predetermined compression method, the compressing part 4a stores front surface compressed image data obtained by compressing front surface image data of one page of the original and a data size thereof in a storage area 5a for front surface of a memory 5, and the compressing part 4b stores rear surface compressed image data obtained by compressing the rear surface image data of one page of the original and a data size thereof in a storage area 5b for rear surface of the memory 5, respectively, and when the total data amount of the front surface compressed image data and the rear surface compressed image data of the memory 5 becomes a data amount that is not higher than the data amount for one page of uncompressed original image data, the front surface compressed image data and the rear surface compressed image data are sequentially transferred to a controller board 6 of a post stage in order of a page. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a double-sided image reading device, a double-sided image reading method, a double-sided image reading program, and a recording medium, and more specifically, a double-sided image reading device that simultaneously reads both sides of a document by using an existing single-sided image reading device. The present invention relates to an image reading method, a double-sided image reading program, and a recording medium.

  Conventionally, there is an image reading device that reads images on both sides of a document at the same time. However, when configuring an image reading device that reads both sides of a document at the same time, in order to reduce development costs, an existing one-side reading device is used. In the above configuration, the image reading unit of the document and the necessary image processing are performed on the read image, and two mechanism portions that are output to the subsequent stage are used.

  For example, when such a single-sided image reading device is used to configure a double-sided image reading device that simultaneously reads both sides of a document, a scanner unit 101, an engine board 102, a controller board 103, and the like as shown in FIG. 8 are provided. Two scanner units 101 and two engine boards 102 of the single-sided image reading apparatus 100 are applied. In FIG. 8, a scanner unit 101 irradiates one side of a document with reading light from a light source, photoelectrically converts reflected light reflected by the document by a photoelectric conversion element, and outputs analog image data. Is equipped with a scanner image processing LSI (Large Scale Integrated circuit) 104, and the scanner image processing LSI digitally converts analog image data from the scanner unit 101 and also performs unique image processing related to image reading. And output to the controller board 103. The controller board 103 includes a controller image processing LSI 105, an MPU (Micro Processing Unit) 106, a memory 107, and the like. The MPU 106 controls each unit of the image reading apparatus 100 based on a program in the memory 107, and an engine board. The image data sent from 102 is subjected to image processing such as image compression by the controller image processing LSI 105 and stored in the memory 107.

  Then, when a double-sided image reading device is constructed using two main parts of such a single-sided image reading device 100, as shown in FIG. 9, the double-sided image reading device 120 includes a scanner unit for the front side and the back side. Image processing LSIs 104 and 105 for the front surface and the back surface are mounted on the engine boards 121a and 101b and the engine board 121, and are connected to the controller board 122. The controller board 122 includes the controller image processing LSI 105, the MPU 106, and the memory 107 that are the same as those of the single-sided image reading apparatus 100, and the image data sent from the two scanner units 101a and 101b in the subsequent controller in order. An image adjusting unit 123 and a memory 124 are mounted for delivery to the image processing LSI 105.

  As shown in FIG. 10, the double-sided image reading apparatus 120 having such a configuration has page memory areas P1 to P4 for four pages of originals as shown in FIG. 10, and the scanner unit 101a and the scanner unit 101b read simultaneously. When the front surface image data and the back surface image data are input to the image adjustment unit 123 of the controller board 122 through the scanner image processing LSIs 104a and 104b, as shown in FIG. Is output as it is to the controller image processing LSI 105 in the subsequent stage, and the back surface image data is stored in the page memory area P1 of the memory 124. Next, when the double-sided image reading device 120 performs double-sided reading of the second original with the scanner units 101a and 101b, as shown in FIG. 11B, the first image is read from the page memory area P1 of the memory 124. Since the back side image data of the document is being transferred to the controller image processing LSI 105 at the subsequent stage, the front side image data cannot be transferred as it is, and the front side image data and the back side image data are stored in the page memory areas P 2 and P 3 of the memory 124. To store. Further, when double-side reading of the third page of the document is subsequently performed by the scanner units 101a and 101b, the back side image data of the second document is stored in the page memory area P2 of the memory 124 as shown in FIG. Therefore, the front image data and the back image data are stored in the page memory areas P1 and P4 of the memory 124.

  In the conventional double-sided reading device 120, the image data is stored in all the page memory areas P1 to P4 of the memory 124 when the fourth original is read by the scanner units 101a and 101b. It is necessary to wait for the reading of the original by the scanner units 101a and 101b until two pages are free in P1 to P4.

  When reading a document using the double-sided image reading device 120, it is not always 3 or less. Therefore, in order to continuously read 4 or more documents, the reading of the scanner units 101a and 101b is required. The speed is transferred from the image adjustment unit 123 to the controller image processing LSI 105 in the subsequent stage, and after the image data is temporarily stored in the memory 124 and the transfer of the previous image data is completed, the subsequent image data is transferred from the memory 124 in the subsequent stage. Considering the transfer processing speed of the transfer to the controller image processing LSI 105, it is necessary to set the reading speed of the scanners 101a and 101b so that the image data read by the scanner units 101a and 101b does not overflow in the memory 124. Alternatively, a mechanism for temporarily stopping the operation of the scanner units 101a and 101b when the memory 124 is full is necessary. In this case, the front surface image data and the back surface image data read by the front surface and back surface scanner units 101a and 101b may be compressed by the compression unit, stored in the memory 124, and transferred to the subsequent stage. (See Patent Document 1).

  However, even in the prior art described in the above publication, since the front and back image data are simply transferred to the subsequent stage after the front image data and the back image data are simply compressed, the reading speed of the front and back scanner unit Depending on the capacity of the memory and the transfer speed of the image data in the memory to the subsequent stage, the memory will become full, and it will be necessary to slow down the document reading speed or pause the document. In order to improve the usability while improving the quality, there was a need for improvement.

  Therefore, the present invention uses two existing single-sided reading mechanisms to reduce the memory capacity and improve the reading speed while improving the usability at a low cost, the image reading method, and the image reading The object is to provide a program and a recording medium.

  In order to achieve the above object, the present invention reads the front and back surfaces of a document at the same time by a front image reading unit and a back image reading unit, and compresses them by a predetermined compression method for each page by the front image compression unit and the back image compression unit, respectively. Then, the surface image compression means compresses the surface image data of one original and its data size, and the back face image compression means compresses the back face image data of one original and its back surface compressed image data. When the data size is stored in the storage area for the front surface and the storage area for the back surface of the image storage means, respectively, and the total data amount of the compressed surface data and the compressed back image data of the image storage means reaches a predetermined data amount, The compressed image data and the back surface compressed image data are sequentially transferred to the subsequent image processing means in the page order.

  In the present invention, the amount of data equal to or less than the amount of data for one page of the uncompressed document image data is used as the predetermined data amount, and the front side compressed image data and the back side compressed image data are sequentially supplied to the subsequent image processing means in page order. In addition to the transfer, if the total transfer data amount of the front side compressed image data and the back side compressed image data is less than one page of the uncompressed original image data, the data is adjusted to the data amount of one page of the uncompressed original image data. Adjustment data may be added.

  Further, according to the present invention, for the first original, the surface compressed image data compressed by the surface image compressing unit is directly transferred to the subsequent image processing unit with the data size added, and the back side. The back side compressed image data compressed by the image compression unit is stored in the back side storage area of the image storage unit, and for the second and subsequent originals, the front side compressed image data compressed by the front side image compression unit and the The back side compressed image data compressed by the back side image compressing means is added to the front side storage area and the back side storage area with the data size added, respectively. When the transfer to the subsequent image processing means is completed, the back surface compressed image data stored in the back surface storage area of the image storage means is converted into the back image. The second and subsequent originals are transferred to the processing means, and for the second and subsequent originals, the front side compressed image data stored in the front side storage area and the back side compressed image stored in the back side storage area The data may be sequentially transferred to the subsequent image processing means in page order.

  Further, the present invention may be characterized in that the data size is written in a register that can be read by an image processing means at a subsequent stage, instead of being added to the front surface compressed image data and the back surface compressed image data.

  According to the present invention, two existing single-side reading mechanisms can be used to reduce the memory capacity and improve the reading speed while improving the usability at a low cost.

1 is a block diagram of a double-sided image reading apparatus to which an embodiment of the present invention is applied. Explanatory drawing of the data size addition process to compressed image data. The figure which shows an example of the data storage state of memory. 7 is a flowchart showing compressed image data transfer processing. Explanatory drawing of the data transfer accompanying a page adjustment. Explanatory drawing of data transfer of the first document when data is transferred every time one document is read. Explanatory drawing of data transfer of the second original when data is transferred every time one original is read. The block block diagram of a single-sided image reading apparatus. The block block diagram of the conventional double-sided image reading apparatus. The figure which shows an example of the memory structure of the conventional double-sided image reading apparatus. Explanatory drawing of the data transfer by the conventional double-sided image reading apparatus.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, since the Example described below is a suitable Example of this invention, various technically preferable restrictions are attached | subjected, However, The range of this invention is unduly limited by the following description. However, not all the configurations described in the present embodiment are essential constituent elements of the present invention.

  1 to 7 are diagrams showing an embodiment of a double-sided image reading device, a double-sided image reading method, a double-sided image reading program, and a recording medium according to the present invention. FIG. 1 is a block configuration diagram of a double-sided image reading apparatus 1 to which an embodiment of an image reading method, a double-sided image reading program and a recording medium are applied.

  In FIG. 1, a double-sided image reading device 1 includes a front surface scanner unit 2a, a back surface scanner unit 2b, an engine board 3, an image adjustment unit 4, a memory 5, a controller board 6, and the like. It is applied to an image reading unit such as a composite apparatus or a facsimile apparatus.

  As the front scanner unit 2a and the back scanner unit 2b, a scanner unit used in an existing single-sided image reading apparatus that reads one side of a document is used, and a document to be stopped or a document to be conveyed is read from a light source. By irradiating the light and photoelectrically converting the reflected light by a photoelectric conversion element such as a CCD (Charge Coupled Device), the document is scanned to read an image of the document.

  The surface scanner unit (surface image reading means) 2 a scans the surface of the document, reads the image of the surface, and outputs the surface image data to the engine board 3.

  The back side scanner unit (back side image reading means) 2b scans the back side of the document simultaneously with the front side scanner unit 2a, reads the back side image, and outputs the back side image data to the engine board 3.

  The double-sided image reading apparatus 1 generally separates a plurality of documents placed on a document table one by one and sequentially conveys them to a document reading position by the front scanner unit 2a and the back scanner unit 2b. An ADF (Auto Document Feeder) is provided, and when the front scanner unit 2a and the back scanner unit 2b continuously read a document, images on both sides of the document sequentially conveyed one by one by the ADF. Read simultaneously.

  The engine board 3 includes a scanner image processing LSI 3a for the front side and a scanner image processing LSI 3b for the back side. The scanner image processing LSI used in the above is used. The scanner image processing LSI 3a and the scanner image processing LSI 3b respectively convert the analog image data of the original read by the corresponding scanner unit 2a and scanner unit 2b, and perform image processing specific to image reading to the image adjustment unit 4 Output.

  The image adjusting unit (image data storage unit, transfer unit) 4 includes a front surface compression unit (front surface image compression unit) 4a, a back surface compression unit (back surface image compression unit) 4b, and the like. The compressed image data is compressed by the compression unit 4 b and stored in the memory 5, and the compressed front surface image data and back surface image data in the memory 5 are adjusted and output to the controller board 6.

  In the compression unit 4a and the compression unit 4b, conventionally, the compression units included in the input processing unit of the controller image processing LSI are respectively provided for the front side and the back side. The compression unit 4a and the compression unit 4b receive image data processed by the scanner image processing LSI 3a and the scanner image processing LSI 3b, respectively. The image data input from the scanner image processing LSI 3a and the scanner image processing LSI 3b is unit by page. Then, the image data is compressed by a predetermined compression method (for example, a variable length compression method such as JPEG (Joint Photographic Experts Group)), and is sequentially stored in the memory 5 as the front surface compressed image data and the back surface compressed image data. Data sizes (data amounts) of the compressed front surface compressed image data and back surface compressed image data are added to the front surface compressed image data and back surface compressed image data.

  The memory (image storage means) 5 includes a front-side memory area (front-side storage area) 5a and a back-side memory area (back-side storage area) 5b, and each of the front-side memory area 5a and the back-side memory area 5b is not yet provided. A memory capacity of one page or more of compressed image data is provided. In the surface memory area 5a of the memory 5, the surface compressed image data obtained by compressing the surface image data for one page by the compression unit 4a is sequentially stored for each page with the data size information added thereto. In the back side memory area 5b, the back side compressed image data obtained by compressing the back side image data for one page by the compression unit 4a is sequentially stored for each page with the data size information added thereto.

  The image adjustment unit 4 is configured such that the total data amount of the front side compressed image data stored in the front side memory region 5a and the back side compressed image data stored in the rear side memory region 5b is a predetermined image data amount, For example, if the image data for one page of the next original is compressed and stored, the compressed image data after storage is close to one page of uncompressed image data and less than one page. When the data amount exceeds one page of uncompressed image data (hereinafter referred to as transfer start data amount), the front side compressed image data in the front side memory region 5a and the back side compressed image data in the back side memory region 5b When the data is sequentially read from the memory 5 and transferred to the controller board 6 and the amount of compressed image data transferred is less than one page of uncompressed image data, Performing padding processing for adjusting the image data of less than a page to the data amount of the uncompressed image data of one page.

  The controller board (second-stage image processing means) 6 uses a controller board of an existing single-sided image reading apparatus, and includes a controller image processing LSI 11, an MPU 12, a memory 13, and the like. The controller image processing LSI 11 includes an input processing unit 21, a bus 22, a bus I / F 23, and the like. The controller image processing LSI 11 performs necessary image processing on the input image data and passes it to the MPU 12. Although the input processing unit 21 includes a compression unit (not shown), conventionally, the read image data is compressed by the compression unit. However, in the double-sided image reading apparatus 1 of the present embodiment, the image adjustment unit 4 compresses the image data. Since the units 4a and 4b are installed and already compressed by the compression units 4a and 4b, the image data sent from the image adjustment units 4a and 4b is directly used as the bus 22 as shown by broken lines in FIG. Send to. The bus I / F 23 is an interface for accessing the memory 13 from the controller image processing LSI 11 via the MPU 12, and PCI (Peripheral Component Interconnect) -E (Express) or the like is used. The bus I / F 23 is not limited to the PCI-E, and may be an interface that directly accesses the memory 13 by a DRAM controller, for example.

  The memory 13 is used as a program memory for storing a program, a work memory for the MPU 12, a temporary storage memory for parameters and image data necessary for processing, and is particularly read by the double-sided image reading program and the scanner units 2a and 2b of the present invention. The front side compressed image data and the back side compressed image data compressed by the compression units 4a and 4b are stored.

  The double-sided image reading apparatus 1 performs further necessary image processing on the image data stored in the memory 13 in response to a request from an application, and then transfers the image data to a printer unit (not shown) for printing processing or a network port. The image data is transferred to an external device (personal computer or the like) via the network or stored in a hard disk provided in the double-sided image reading device 1.

  The double-sided image reading apparatus 1 of this embodiment includes a ROM, an EEPROM (Electrically Erasable and Programmable Read Only Memory), an EPROM, a flash memory, a flexible disk, a CD-ROM (Compact Disc Read Only Memory), and a CD-RW (Compact). Double-sided image for executing the image reading method of the present invention recorded on a computer-readable recording medium such as Disc Rewritable), DVD (Digital Versatile Disk), SD (Secure Digital) card, MO (Magneto-Optical Disc), etc. By reading the reading program and introducing it into the memory 13 of the controller board 6 or the memory (not shown) of the image adjustment unit 4, two main parts of an existing single-sided image reading apparatus to be described later are used to simultaneously read both sides of the document. Constructed as a double-sided image reading device 1 for executing a double-sided image reading method Yes. This double-sided image reading program is a computer-executable program written in a legacy programming language such as assembler, C, C ++, C #, Java (registered trademark), an object-oriented programming language, or the like, and is stored in the recording medium. And can be distributed.

  Next, the operation of this embodiment will be described. The double-sided image reading device 1 of this embodiment uses two existing single-sided image reading devices, and reduces the capacity of the memory 5 by the image adjustment unit 4 and the memory 5 while reducing the image data on the front and back sides of the document. Is efficiently transferred to the subsequent controller board 6 at high speed.

  That is, when the original is set in the ADF and the start of reading is instructed by the operation display unit, the double-sided image reading apparatus 1 conveys the original one by one to the reading position by the ADF, and the front surface scanner unit 2a and the rear surface The scanner unit 2b simultaneously reads images on the front and back sides of the document and outputs them to the scanner image processing LSI 3a and the scanner image processing LSI 3b of the engine board 3, respectively. The scanner image processing LSI 3a and the scanner image processing LSI 3b respectively perform necessary image processing, and output the front surface image data and the back surface image data to the compression unit 4a and the compression unit 4b of the image adjustment unit 4, and the compression unit 4a and the compression unit 4b compresses the input front surface image data and back surface image data by a variable length compression method such as JPEG. As shown in FIG. 2, the image adjustment unit 4 acquires the data size (data length, data amount) of the surface compressed image data obtained by compressing the surface image data of one page by the compression unit 4a, and the surface compressed image data The compression unit 4b obtains the data size of the back side compressed image data obtained by compressing the back side image data of one page, and the predetermined position (eg, the back side compressed image data) Header). Then, as shown in FIG. 3, the image adjustment unit 4 stores the surface compressed image data compressed by the compression unit 4a in the surface memory area 5a of the memory 5 with the data size information added thereto, and the compression unit 4b The compressed back side compressed image data is stored in the back side memory area 5b with the data size information added. In the following description, the data size of uncompressed image data for one document page is referred to as one document page size.

  That is, in the conventional single-sided image reading apparatus, the image data compressed by the controller image processing LSI of the controller board is stored in the memory via the MPU. The apparatus 1 is provided with an image adjustment unit 4 including a compression unit 4a and a compression unit 4b on both the front and back sides in front of the controller board 6, and a conventional single-sided image reading apparatus using the compression units 4a and 4b. The compression processing that has been performed by the controller image processing LSI is performed. Then, the double-sided image reading apparatus 1 of the present embodiment transfers the front side compressed image data and the back side compressed image data compressed by the compression unit 4 a and the compression unit 4 b of the image adjustment unit 4 to the subsequent controller board 6 via the memory 5. To do. When the image data is compressed by the variable length compression method as described above, conventionally, the controller image processing LSI itself at the subsequent stage performs the compression process, so the data size of the image data after compression is reduced. The controller image processing LSI can grasp this. However, since the double-sided image reading apparatus 1 of the present embodiment compresses image data by the compression unit 4a and the compression unit 4b of the previous image adjustment unit 4 of the controller image processing LSI 21, the controller image processing LSI 21 performs surface compression. The data size of the image data and the back side compressed image data is unknown. Therefore, in the double-sided image reading apparatus 1 of this embodiment, in order to appropriately perform the subsequent processing, as described above, the image adjustment unit 4 adds data size information to the front surface compressed image data and the back surface compressed image data, respectively. Thus, the controller image processing LSI 21 at the subsequent stage can grasp the data size.

  The image adjustment unit 4 does not add the data size information of the compressed image data to the compressed surface data and the compressed back image data obtained by compressing the front image data and the back image data of one page, respectively. The image data may be stored in a register built in the image adjustment unit 4 that can be read by the controller image processing LSI 11 in the subsequent stage. The image adjustment unit 4 not only records the data size to specify the data size of the compressed image data but also records the data start address and data end address of the memory 5 storing the compressed image data in a register. May be.

  At this time, since the data compression method of the compression units 4a and 4b is the variable length compression method, the images on the front and back surfaces (2 pages) obtained by simultaneously reading the front and back surfaces of the document by the scanner units 2a and 2b are compressed by the compression units 4a and 4b. Since the end of the compressed image data for one page (one page) on the front or back side is not known until the compression process is completed, it is packed in the memory 5 and compressed into the surface. It is difficult to store image data and back side compressed image data. However, since the double-sided image reading apparatus 1 of this embodiment has the memory 5 divided into the front-side memory area 5a and the back-side memory area 5b, the front-side compressed image data is sequentially packed and stored in the front-side memory area 5a. Thus, the back side compressed image data can be sequentially packed and stored in the back side memory area 5b, and the use efficiency of the memory 5 can be improved.

  In the double-sided image reading apparatus 1, the image adjustment unit 4 performs a transfer process of the compressed image data in the memory 5 as shown in FIG. 4. That is, when the image adjustment unit 4 sequentially stores (accumulates) the front side compressed image data and the back side compressed image data compressed by the compression units 4a and 4b in the front side memory region 5a and the back side memory region 5b of the memory 5, 5 pages of uncompressed images (hereinafter simply referred to as images) in which the total data amount of the front surface compressed image data and the back surface compressed image data stored in the front surface memory region 5a and the back surface memory region 5b is a predetermined data amount. It is checked whether the data amount of one page has been exceeded or whether all the originals have been read (steps S101 and S102), and the data amount has not exceeded one page of the uncompressed image. When the reading of the original is not completed, the surface image data of the next original read by the scanner units 2a and 2b, for example, at predetermined timings Each time the plane image data is compressed by the compression units 4a and 4b and stored in the memory 5 or every predetermined time, the total data amount of the front surface compressed image data and the back surface compressed image data in the memory 5 is uncompressed as described above. It is checked whether the amount of data for one page of the image has been exceeded or whether all the originals have been read (steps S101 and S102).

  In step S101 or step S102, when the total data amount of the front surface compressed image data and the back surface compressed image data in the memory 5 exceeds one page of the uncompressed image, or when all the originals have been read, the image adjustment unit 4 Then, the transfer of the front side compressed image data and the back side compressed image data is started from the front side compressed image data for each original document (step S103), and when the next front and back side of the compressed image data for one page is transferred, the total data of the transferred data It is checked whether the amount (the total data amount of the front side compressed image data and the back side compressed image data to be transferred) exceeds one page size of the document (step S104).

  If the total amount of transfer data does not exceed one page size in step S104, the image adjustment unit 4 returns to step S103, and sequentially stores the front side compressed image data and the back side compressed image data of the next document from the memory 5. The same process as described above is performed from the transfer process (steps S103 and S104).

  In step S104, when the total amount of transfer data exceeds the size of one page of the document, the image adjustment unit 4 sets the total data amount of the front surface compressed image data and the back surface compressed image data to be transferred to the size of one page of the document. It is checked whether padding processing is necessary (step S105). That is, the image adjustment unit 4 calculates the total data amount of the front surface compressed image data and the back surface compressed image data to be transferred by, for example, summing the data sizes added to the front surface compressed image data and the back surface compressed image data, respectively. Depending on whether or not the calculated total data amount of the data size matches one page size of the original, the padding process is performed to make the total data amount of the front side compressed image data and the back side compressed image data to be transferred equal to the one page size of the original. It is determined whether or not is necessary.

  That is, the controller image processing LSI 11 uses the controller board 6 of the existing single-sided image reading apparatus, and it is assumed that the transfer of image data is one page size of the original, so the compressed image data is converted into the original image. It is necessary to pack it for one page size.

  In step S105, when the padding process is not necessary, the image adjustment unit 4 ends the compressed image data transfer process as it is. When the padding process is necessary, the image adjustment unit 4 determines the total data amount of the front surface compressed image data and the back surface compressed image data to be transferred. Padding data (adjustment data) necessary for the size of one page of the original is transferred to the controller board 6 and the compressed image data transfer process is terminated (step S106).

  That is, as shown in FIG. 5, the image adjusting unit 4 now stores the first surface compressed image data P1a and the second surface compressed image data P2a of the original in the front memory area 5a of the memory 5. When the back side memory area 5b stores the back side compressed image data P1b of the first original and the back side compressed image data P2b of the second original, the front side compressed image data P1a of the first original is stored. ⇒Back side compressed image data P1b of the first document ⇒Front side compressed image data 2a of the second side of the document ⇒Compressed data of the front and back sides of the next one side of the original after transferring the back side compressed image data P2b of the second side of the document Since the page size exceeds one page size of the document, at this stage, it is checked whether padding processing is necessary to make the total data transfer amount the data size corresponding to the one page size of the document. When the image adjustment unit 4 determines that the padding process is necessary, the image adjustment unit 4 calculates the amount of padding data necessary to adjust the total data transfer amount to the original page size for the compressed image data that has already been transferred, The calculated amount of padding data is transferred to the controller board 6.

  Then, when the front side compressed image data and the back side compressed image data are sequentially transferred from the image adjusting unit 4, the controller board 6 compresses the controller board 6 with the controller image processing LSI 11 as in the conventional case. Without passing through the input processing unit 21 and transferred to the MPU 12 through the bus 22 and the bus I / F 23 as shown by a one-dot chain line in FIG. 1, the MPU 12 stores in the memory 13 as shown in FIG. To do.

  Therefore, the processing in the controller image processing LSI 11 at the subsequent stage can be simplified and the compressed image data can be stored in the memory 13, and the processing speed can be improved.

  Further, since the data size information is added to each of the front surface compressed image data and the back surface compressed image data stored in the memory 13, the controller image processing LSI 11 performs the subsequent image processing based on the data size information. Similarly to the case of the single-sided image reading apparatus, image processing can be performed.

  As described above, the double-sided image reading apparatus 1 according to the present embodiment reads the front and back surfaces of the document at the same time with the scanner unit 2a and the scanner unit 2b, and compresses each page by a predetermined compression method by the compression unit 4a and the compression unit 4b. Then, the compression unit 4a compresses the surface image data of the original sheet and the data size thereof, and the compression unit 4b compresses the back surface image data of the original sheet and the data size thereof. 5 is stored in the front surface storage area 5a and the back surface storage area 5b, respectively, and the total data amount of the front surface compressed image data and the back surface compressed image data in the memory 5 is less than the data amount of one page of uncompressed original image data. When the (predetermined data amount) is reached, the front side compressed image data and the back side compressed image data are converted into page controller order (image processing procedure) in page order. ) Are sequentially transferred to the 6.

  Therefore, it is possible to construct the double-sided image reading apparatus 1 that reduces the memory capacity and improves the reading speed by diverting two main structures of the existing single-sided reading image processing, and has excellent usability. The image processing apparatus 1 can be constructed at a low cost.

  That is, since the read image data is compressed and stored in the memory 5, the required capacity of the memory 5 can be reduced. For example, when a compression method in which the compression ratios of the compression units 4a and 4b compress the data amount to an average of 1/5 is used, the front side compressed image data and the back side compressed image data with a memory capacity of one page of uncompressed original image data. Can be stored for at least four pages.

  Further, when the variable length compression method is used as the compression method of the compression units 4a and 4b, read image data is simultaneously input from the scanner unit 2a and the scanner unit 2b to the compression unit 4a and the compression unit 4b. When the compression unit 4b simultaneously compresses the surface compressed image data and the back surface compressed image data, the data size of the surface compressed image data and the back surface compressed image data is not known until the compression is completed. The back side compressed image data cannot be stored continuously. However, since the double-sided image reading apparatus 1 of the present embodiment divides the memory 5 into the front surface storage area 5a and the back surface storage area 5b, the surface compressed image data for each page is stored in the front surface storage area 5a for each page. The back side compressed image data can be sequentially and continuously stored in the back side storage area 5b, and the utilization efficiency of the memory 5 can be improved.

  Further, the double-sided image processing apparatus 1 according to the present embodiment uses a data amount equal to or less than the data amount of one page of uncompressed original image data as a predetermined data amount, and the controller in the subsequent stage for the front side compressed image data and the back side compressed image data in page order If the total transfer data amount of the front side compressed image data and the back side compressed image data is less than one page of the uncompressed original image data, the data amount corresponding to one page of the uncompressed original image data is sequentially transferred to the board 6 Padding data (adjustment data) for data adjustment is added to

  Therefore, even if the controller board of the existing single-sided image reading apparatus is used as the subsequent controller board 6, the compressed image data transferred from the image adjustment unit 4 can be appropriately processed, and both sides can be made more inexpensively. The image reading apparatus 1 can be constructed.

  In the above description, when the total of the front surface compressed image data and the back surface compressed image data in the memory 5 becomes one page size of the document or close to one page size of the document, the compressed image data is transferred to the controller board 6 as the page size of the document. However, the transfer timing of the compressed image data in the memory 5 is not limited to the transfer timing described above. For example, when the number of originals to be read is small, the image adjustment unit 4 reads the scanner unit 2a and the compression unit 4a The compressed surface-compressed image data may be immediately transferred to the subsequent controller board 6 page by page. In this case, the image length west part 4 simultaneously compresses the image data of the front and back surfaces of the first document by the compression unit 4a and the compression unit 4b, and compresses the compression unit 4a as indicated by arrows in FIG. The front surface compressed image data is directly transferred to the controller board 6, and the back surface compressed image data compressed by the compression unit 4 b is stored in the back surface storage area 5 b of the memory 5. Next, when there is a second original, as shown in FIG. 7, the first back side compressed image data stored in the back side storage area 5b of the memory 5 is stored in the back side storage area 5b of the memory 5. And is transferred to the controller image processing LSI 11, and among the image data of the second original, the surface compressed image data compressed by the compression unit 4 a is stored in the surface storage area 5 a of the memory 5, and the compression unit 4 b The compressed back side compressed image data is stored in the back side storage area 5b of the memory. Thereafter, the above processing can be continuously read and compressed for a plurality of originals as long as there is an empty area in the memory 5 and then compressed and stored in the memory 13.

  In this way, when the reading speed of the scanner units 2a and 2b is sufficiently higher than the image processing speed of the compression units 4a and 4b of the image adjustment unit 4, the surface compressed image data of the first document is stored in the memory. Without being accumulated in 5, it can be transferred to the controller board 6 in the subsequent stage to improve the processing speed.

  In the above description, in order to grasp the data sizes of the front surface compressed image data and the back surface compressed image data for each page, the image adjustment unit 4 determines the data sizes of the front surface compressed image data and the back surface compressed image data for each page, Although it is added to the front side compressed image data and the back side compressed image data of each page, it is not limited to the method of adding to the front side compressed image data and the back side compressed image data. For example, an image that can be read by the controller board 6 You may make it store in the register | resistor in the adjustment part 4. FIG.

  In this way, the processing of the front side compressed image data and the back side compressed image data can be performed more easily on the controller board 6 side, and the data capacity can be further reduced.

  The invention made by the present inventor has been specifically described based on the preferred embodiments. However, the present invention is not limited to that described in the above embodiments, and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

  The present invention relates to a double-sided image reading device such as a scanner device, a facsimile device, a copying device, a composite device, etc., a double-sided image reading method, a double-sided image reading program, and two existing single-sided image reading devices. It can be used for recording media.

DESCRIPTION OF SYMBOLS 1 Double-sided image reading apparatus 2a Front scanner unit 2b Back scanner unit 3 Engine board 3a Front scanner image processing LSI
3b Scanner image processing LSI for back side
4 Image adjustment unit 4a Compression unit for front surface 4b Compression unit for back surface 5 Memory 5a Memory region for front surface 5b Memory region for back surface 6 Controller board 11 Controller image processing LSI
12 MPU
13 memory

JP-A-9-205524

Claims (7)

Surface image reading means for reading an image on the surface of the document;
Back side image reading means for reading an image on the back side of the document;
Image storage means having a front-side storage area and a back-side storage area having a predetermined capacity;
Surface image compression means for compressing the surface image data read by the surface image reading means for each page by a predetermined compression method;
Back side image compression means for compressing the back side image data read by the back side image reading means for each page by a predetermined compression method;
The front side image compression means compresses the front side image data of one page of the original document and the data size thereof, and the back side image compression means compresses the back side image data of the original page of one page and its data size. Image data storage means for storing in the front storage area and the back storage area of the image storage means;
When the total data amount of the front surface compressed image data and the back surface compressed image data in the image storage means reaches a predetermined data amount, the front surface compressed image data and the back surface compressed image data are sequentially transferred to the subsequent image processing means in page order. Transfer means to
A double-sided image reading apparatus comprising: The transfer means includes
The front side compressed image data and the back side compressed image data are sequentially transferred to the subsequent image processing means in the page order, with the data amount equal to or less than the data amount of one page of the uncompressed original image data as the predetermined data amount, If the total transfer data amount of the compressed image data and the back side compressed image data is less than one page of the uncompressed document image data, adjustment data for adjusting data to the data amount for one page of the uncompressed document image data is added. The double-sided image reading device according to claim 1. The image data storage means includes
For the first original, the surface compressed image data compressed by the front surface image compressing unit is directly transferred with the data size added to the transfer unit, and the back surface compressed image data compressed by the back surface image compressing unit is transferred. For the second and subsequent originals stored in the back surface storage area of the image storage means, the front surface compressed image data compressed by the front surface image compression means and the back surface compressed image data compressed by the back surface image compression means Are stored in the front-side storage area and the back-side storage area by adding the data size respectively.
The transfer means includes
For the first original, the surface compressed image data delivered from the image data storage means is transferred to the subsequent image processing means, and when the transfer of the surface compressed image data is completed, the back surface of the image storage means The back side compressed image data stored in the storage area is transferred to the subsequent image processing means, and the second and subsequent originals are stored in the front side storage area of the image storage means. 3. The double-sided image reading apparatus according to claim 1, wherein the image data and the back side compressed image data stored in the back side storage area are sequentially transferred to the subsequent image processing means in the page order. The image reading device includes:
The latter image processing means includes a readable register,
The said image data storage means writes the said data size in the said register instead of adding to the said surface compression image data and the said back surface compression image data. Double-sided image reading device. A surface image reading process step for reading an image on the surface of the document;
A reverse image reading process step for reading an image on the reverse side of the document;
A surface image compression processing step of compressing the surface image data read in the surface image reading processing step by a predetermined compression method for each page;
A back side image compression processing step for compressing the back side image data read in the back side image reading processing step by a predetermined compression method for each page;
The surface storage image data compressed by the front surface image compression processing step and the back surface compression image data compressed by the back surface image compression processing step are stored in the image storage means having a front surface storage area and a back surface storage area. The compressed data of the front surface is obtained by acquiring the data size of the compressed image data of the front surface and the compressed image data of the back surface, which is stored in the storage area for the front surface and the storage area for the back surface, and the image data of one page of the document is compressed. And an image data storage processing step to be added to the back surface compressed image data,
When the total data amount of the front surface compressed image data and the back surface compressed image data in the image storage means reaches a predetermined data amount, the front surface compressed image data and the back surface compressed image data are sequentially transferred to the subsequent image processing means in page order. A transfer processing step to
A double-sided image reading method comprising: On the computer,
A surface image reading process for reading an image on the surface of the document;
A back side image reading process for reading a back side image of the document;
Surface image compression processing for compressing the surface image data read in the surface image reading processing for each page by a predetermined compression method;
Backside image compression processing for compressing the backside image data read in the backside image reading processing by a predetermined compression method for each page;
The front side compressed image data compressed by the front side image compression process and the back side compressed image data compressed by the back side image compression process are used for the front side of the image storage means having a front side storage area and a rear side storage area. The data size of the surface compressed image data and the data size of the back surface compressed image data obtained by compressing the image data of one page of the document while being stored in the storage area and the back surface storage area are acquired, and the surface compressed image data and the surface compressed image data Image data storage processing to be added to the back side compressed image data;
When the total data amount of the front surface compressed image data and the back surface compressed image data in the image storage means reaches a predetermined data amount, the front surface compressed image data and the back surface compressed image data are sequentially transferred to the subsequent image processing means in page order. Transfer processing to
A double-sided image reading program characterized in that is executed.   A computer-readable recording medium on which the double-sided image reading program according to claim 6 is recorded.

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