JP5857427B2 - Image reading device - Google Patents

Description

  The present invention relates to an image reading apparatus.

  In Patent Document 1 below, it is determined for each page whether or not the read data of the document is blank, and the image of the page determined to be blank after displaying all pages of the document is displayed to allow the user to select an image to be deleted. Technology is disclosed.

JP 2004-289476 A

However, since the above-described device stores all read data of the original including blank data in the memory, there is a possibility that the memory usage exceeds the limit amount and a memory error occurs during the reading of the original.
The present invention has been completed based on the above-described circumstances, and an object thereof is to suppress a decrease in throughput of reading processing by suppressing occurrence of a memory error.

  An image reading device disclosed in this specification includes a reading unit that reads an image of a document, a storage unit that stores read data read by the reading unit, and blank data from the read data stored in the storage unit. A blank page determination unit that executes blank page determination processing; a deletion unit that deletes blank page data determined by the blank page determination unit from the storage unit when the usage amount of the storage unit exceeds a limit amount; A control unit that controls the reading unit so as to continue reading the image after the blank page data is deleted. According to this configuration, even when the usage amount of the storage unit temporarily exceeds the limit amount during image reading, the usage amount can be lowered to the limit amount or less by deleting the blank data. Therefore, it is possible to continue the reading process, and it is possible to suppress a decrease in the throughput of the reading process.

  The image reading apparatus may further include a conveyance unit that conveys the document, and the reading unit may read an image of the document conveyed by the conveyance unit.

  In the image reading apparatus, the control unit includes a first function unit that controls the reading unit, and a second function unit that functions as a blank page determination unit that determines the blank page data, and the amount of use of the storage unit When the value exceeds the limit amount, a process for determining the blank data may be executed.

  In the image reading apparatus, the control unit and the blank page determination unit are different devices that operate independently of each other, and the blank page determination unit is scanned each time an image of one page of the document is read by the reading unit. The blank page determination process is performed, and the storage unit stores blank page determination process information, which is a result of the blank page determination process, in association with the blank page data to be determined, and the deletion unit stores the blank page determination process information in the blank page determination process information. Based on this, the blank page data may be deleted.

  Further, in the image reading apparatus, a determination unit that determines a deletion priority based on whether or not blank data is closer to a blank page, and the deletion unit has a usage amount of the storage unit exceeding a limit amount. In this case, among the blank data, the blank data having a high priority may be deleted with priority.

  In the image reading apparatus, the determination unit may lower the deletion priority of blank data in which a standard image is formed on a document edge portion of blank data.

  Further, in the image reading apparatus, the blank page determination unit determines that read data having a pixel number equal to or higher than a predetermined density is equal to or less than a first threshold value as blank page data, and the determination unit includes a predetermined density or more of the blank page data. If the number of pixels is less than a second threshold value that is less than or equal to the first threshold value, the priority of deletion may be increased.

  In the image reading apparatus, when the read data stored in the storage unit is non-blank paper and the read data of the previous page is non-blank data, a flag is set for the read data of the non-blank paper to be stored. You may make it provide the flag provision part to provide.

  According to the present invention, it is possible to suppress a decrease in the throughput of the reading process by suppressing the occurrence of a memory error.

1 is a perspective view of a multifunction machine in Embodiment 1. FIG. Cross section of image reading unit Block diagram showing the electrical configuration of the MFP Memory error avoidance sequence flowchart FIG. 3 is a block diagram showing an electrical configuration of a multifunction machine in the second embodiment. Memory error avoidance sequence flowchart Diagram showing sub flow of memory error avoidance sequence The figure which shows the data structure of RAM Diagram showing sub flow of memory error avoidance sequence The figure which shows blank page information in the figure 4 which shows the subflow of a memory error avoidance sequence in Embodiment 3. Explanatory drawing of a fixed form image in Embodiment 4. Diagram showing sub flow of memory error avoidance sequence Explanatory drawing of blank page information in Embodiment 5. Diagram showing sub flow of memory error avoidance sequence Diagram showing sub flow of memory error avoidance sequence

<Embodiment 1>
A first embodiment will be described with reference to FIGS.

1. FIG. 1 is a perspective view showing an appearance of a multifunction machine 1 as an example of an image forming apparatus and an image reading apparatus according to the present invention. FIG. 2 is a cross-sectional view of an image reading unit 5.

  As shown in FIG. 1, the multifunction machine 1 has an image reading unit 5 disposed above a box-type main body 2. The image reading unit 5 reads a document, and includes a CIS (an example of a “reading unit” of the present invention) 30, an ADF 40, and a document placement unit 50 as shown in FIG. The document placing unit 50 includes a frame 51, a first platen glass 52 made of a transparent glass plate, a second platen glass 53, and an intermediate frame 54 disposed between these glasses 52 and 53. The document cover 48 can be rotated between a closed posture that covers the document placement portion 50 and an open posture that opens the document placement portion 50, and is connected to the rear side of the main body portion 2 of the multifunction device 1. An ADF 40 is provided on the document cover 48.

  The ADF 40 includes an ADF cover 41, a document tray 42, a transport path 43, various rollers such as a paper feed roller 44 </ b> A, a pair of transport rollers 44 </ b> B, a pair of paper discharge rollers 44 </ b> C, an ADF motor 66 that drives these various rollers, and a paper discharge tray 46. And a pressing member 47. The ADF 40 conveys the originals placed on the original tray 42 one by one by the paper feed roller 44 </ b> A, passes the second platen glass 53, and discharges the originals to the paper output tray 46. The pressing member 47 presses the document against the second platen glass 53 so that the document passing over the second platen glass 53 does not float from the second platen glass 53. Further, the ADF 40 is provided with a document sensor 49 such as a photo sensor for detecting a document set on the document tray 42. Of the ADF 40, the conveyance path 43, the paper feed roller 44 </ b> A, the conveyance roller 44 </ b> B, the paper discharge roller 44 </ b> C, and the ADF motor 66 are examples of the “conveyance unit” of the present invention.

  The CIS 30 is provided below the document placement unit 50. The CIS 30 includes a linear image sensor 33 in which a plurality of light receiving elements are linearly arranged in a direction perpendicular to the paper surface of FIG. 2, a light source 31 composed of RGB three-color light emitting diodes, etc., and a reflection from the light source 31 reflected from the document. It includes a rod lens array 32 that focuses light on each light receiving element of the linear image sensor 33, a carriage 34 on which these are mounted, and a transport mechanism (not shown) that transports the carriage 34. The linear image sensor 33 detects the brightness and chromaticity of the reflected light imaged on the light receiving element, and generates data based on the image of the document.

  When reading an original set on the first platen glass 52, the image reading unit 5 conveys the CIS 30 in the sub-scanning direction (A direction in FIG. 2) parallel to the first platen glass 52 by an FB motor (not shown). While reading the original line by line. On the other hand, when reading a document conveyed by the ADF 40, the image reading unit 5 moves the CIS 30 directly below the second platen glass 53 by the FB motor, and reads the document passing the reading position P on the second platen glass. The image sensor 33 reads each line.

  Further, on the front side of the multifunction device 1, an operation unit 11 that includes various buttons and receives an operation command from a user, and a display unit 12 that includes a liquid crystal display that displays the state of the multifunction device 1 are provided.

2. Electrical Configuration FIG. 3 is a block diagram showing an electrical configuration of the multifunction machine 1. The multi-function device 1 includes a CPU (an example of “blank sheet determination unit”, “deletion unit”, and “control unit” in the present invention) 60A, a ROM 61, a RAM (an example of “storage unit” in the present invention) 63, an A A / D converter 65, a motor control circuit 67, an output device 71, a display unit 12, buttons and sensor switches are provided. The A / D converter 65 is a circuit that converts an analog output signal output from the CIS 30 into a digital output signal. The motor control circuit 67 is a driver for the ADF motor 66.

The CPU 60A has the following four functions.
(1) reader control Function (2) image processing, blank page determination function (3) Output processing function (4) Memory error avoidance function

  The reading unit control function is a function of controlling the ADF 40 and the CIS 30 of the image reading unit 5 to automatically read a document conveyed by the ADF 40 with the CIS 30.

  The image processing function is a function of reading image data (corresponding to “read data” of the present invention) from the A / D converter 65 and performing image processing such as gamma correction and shading correction. Then, the CPU 60A also performs a memory operation for storing the image processed image data in the RAM 63.

  The blank page determination function is a function for determining whether the image data stored in the RAM 63 is blank page data. In the blank data determination, first, the number of pixels exceeding the reference density for each page is obtained for the image data. Then, the calculated number of pixels is compared with the first threshold set as the blank determination threshold. If the calculated number of pixels is less than the first threshold, the image data is read as a blank document. It is determined as generated blank paper data.

  The output processing function is a function for outputting image data read by the image reading unit 5. The multi-function device 1 includes a communication device and a recording device (printing device) as the output device 71, and the CPU 60A controls the communication device and the recording device so that the image data read by the image reading unit 5 is a communication device. Is used for fax transmission, and the read image data is recorded (printed) on a recording medium.

  The memory error avoidance function is a function for automatically avoiding the usage amount of the RAM 63 exceeding the limit amount. This memory error avoidance function will be described in detail in the memory error avoidance sequence described below.

  The ROM 61 stores various programs executed by the CPU 60A (programs for executing a memory error avoidance sequence), data used for executing the programs, and the like. The RAM 63 is used as a main storage device for the CPU 60A to execute each process, and also serves to store image data read by the image reading unit 5.

3. Memory error avoidance sequence The MFP 1 of this embodiment has a function of suppressing the occurrence of a memory error by deleting the blank data stored in the RAM 63 when the usage amount of the RAM 63 exceeds the limit amount. ing. Here, the memory error means that when the usage amount of the RAM 63 exceeds the limit amount, the image reading process, the communication, and the printing process are controlled to be stopped.

  Hereinafter, the contents of the memory error avoidance sequence process will be described separately with reference to FIG. 4 when the usage amount of the RAM 63 does not exceed the limit amount and when it exceeds the limit amount.

<When the usage amount of the RAM 63 does not exceed the limit amount>
Here, a case will be described as an example in which the user transmits two originals to the memory using the multifunction device 1. When two documents are set on the document tray 42 and the start key of the operation unit 11 is pressed by the user, first, a process of reading the document is started. Specifically, by driving the ADF 40, the first page of the document set on the document tray 42 is sent to the transport path 43 with the front side facing up (S10).

  Thereafter, when the leading end of the sent document (here, the first page document) reaches the reading position P, the document is read by the CIS 30. Specifically, the image sensor 33 reads one line of the document passing the reading position P on the second platen glass 53. The image data read by the image sensor 33 is then converted into a digital signal by the A / D converter 65. Then, the CPU 60A reads the image data from the A / D converter 65, and performs gamma correction and shading correction (S20, S30).

  After performing various corrections in S30, the CPU 60A accesses the RAM 63 and determines whether the usage amount of the RAM 63 is equal to or greater than the limit amount (S40). The usage amount of the RAM 63 is determined based on the count value of the memory counter 63A provided in the RAM 63. The memory counter 63A counts down the count value as the free capacity of the RAM 63 decreases. When there is no free capacity, the count value becomes “zero”. In this embodiment, when the threshold value of the count value is set to “CX” larger than zero and the count value of the memory counter 63A is “CX” or less, the usage amount of the RAM 63 is equal to or greater than the limit amount. If it is determined that the amount is “CX” or more, it is determined that the amount used is not greater than the limit amount. Here, the description will be continued assuming that the amount is not over the limit amount.

  When the usage amount of the RAM 63 is not equal to or greater than the limit amount (in the case of NO), the CPU 60A stores the image data corrected in S30 in the RAM 63 (S50). As a result, the image data of the first line of the document is stored in the RAM 63.

  Thereafter, until the reading of all lines is completed, NO is determined in the determination process of S60, and the processes from S10 to S50 are sequentially executed. For this reason, reading of a document by the CIS 30, data conversion by the A / D converter 65, and image data correction processing by the CPU 60 </ b> A are executed in units of lines, and then the image data of each line is stored in the RAM 63.

  When the reading of all lines is completed, a YES determination is made in S60, and the process proceeds to S70. On the other hand, the original of the first page after completion of reading is discharged onto the discharge tray 46 by the ADF 40.

  In S <b> 70, it is determined based on the output of the document sensor 49 whether there is a next page, that is, whether there is a document on the document tray 42. Here, only the first of the two originals to be transmitted to the memory has been read, and the original remains on the original tray 42. Therefore, the output of the document sensor 49 is turned on, and the CPU 60A determines YES.

  If YES is determined in S <b> 70, the second page of the document set on the document tray 42 is sent to the transport path 43 with the front side facing up by driving the ADF 40 (S <b> 10). Thereafter, the second page of the document is read in line units by the CIS 30 in the same procedure as the first page of the document, and the read image data is subjected to data conversion and correction processing and then stored in the RAM 63.

  Thereafter, when the reading of all the lines for the second page of the document is completed, the second page of the document is discharged onto the discharge tray 46. Thereafter, in S70 again, it is determined whether or not there is a next page, that is, whether or not there is a document on the document tray 42. At this stage, since reading of all the two pages of the document to be transmitted to the memory has been completed and there is no document left on the document tray 42, NO is determined in S70, and the process proceeds to S80.

  In S80, a process for determining whether the image data stored in the RAM 63 is blank paper data is executed by the CPU 60A. Specifically, the CPU 60A obtains the number of pixels exceeding the reference density for each page of the image data, and compares the obtained number of pixels with a first threshold set as a blank page determination threshold. Then, when the obtained number of pixels is less than the first threshold value, it is determined that the page is blank.

  If it is determined that the data is blank paper data, the CPU 60A removes the image data from the RAM 63 (S90). On the other hand, if it is not blank page data, it is determined whether blank page determination has been performed for all pages without deleting the image data from the RAM 63 (S100). When blank page determination is performed for all pages and the process of deleting blank page data is completed, a YES determination is made in S100, and the process proceeds to S110.

  In S110, the CPU 60A executes output processing such as printing and FAX transmission. Here, a process of transmitting the image data of two pages stored in the RAM 63 to the memory is executed. Thus, a series of processing ends.

<When the amount of RAM 63 used exceeds the limit>
Here, it is assumed that five originals are transmitted in memory. Then, reading up to the fourth page of the five sheets is completed without the usage amount of the RAM 63 exceeding the limit amount, and the usage amount of the RAM 63 exceeds the limit amount in the middle of reading the fifth page. To do.

  When the usage amount of the RAM 63 becomes equal to or larger than the limit amount, YES is determined in the determination process of S40, and the process proceeds to S120. In S120, the CPU 60A executes a process of determining whether the read image data (image data for one page) stored in the RAM 63 includes blank page data. The determination in S120 is performed by obtaining the number of pixels exceeding the reference density and comparing it with the first threshold value set as the blank paper determination threshold, as in the determination in S80. The function of the “blank sheet determination unit” of the present invention is realized by the processing of S120 executed by the CPU 60A.

  Further, the determination of the blank data is performed in the order of storage in the RAM 63 (new order), for example. Accordingly, first, it is determined whether the image data of the fourth page is blank page data. When the image data of the fourth page is not blank data, a process for determining whether or not the next page, that is, the page, is blank data is performed. If the third page is not blank page data, a process for determining whether the next page, that is, the second page is blank page data, is performed. As described above, in S120, the determination process is repeatedly performed until blank data is detected, and YES is determined when blank data is detected. Here, it is assumed that the image data of the third page is determined to be blank paper data.

  If YES is determined in S120, the process proceeds to S130. In S <b> 130, the CPU 60 </ b> A executes processing for deleting the image data determined as blank paper data in S <b> 120 from the RAM 63. Accordingly, the image data for the third page is deleted from the RAM 63 here. Then, the amount of use of the RAM 63 decreases due to the deletion of the image data, and returns to a state below the limit amount. Note that the function of the “deleting unit” of the present invention is realized by the processing of S130 executed by the CPU 60A.

  Since the process returns to S50 after the process of S130, the CPU 60A performs a process of storing image data being read, that is, image data of 5 pages in the RAM 63.

  Subsequent processing is similar to the case described in the case where two originals are transmitted to the memory, and if the reading of one page is not completed, the processing of S10 to S60 is repeated, and the control of the CPU 60A is performed. Then, reading of the image by the CIS 30 is continued. When reading of all five sheets is completed, a NO determination is made in S70, and the process proceeds to S80 to S100. After the blank page data is deleted in S130, the process of S10 to S60 is executed by the CPU 60A after returning to S50, thereby realizing the function of the control unit of the present invention.

  In S80 to S100, the CPU 60A executes a process for determining whether the image data stored in the RAM 63 is blank sheet data, and the image data determined to be blank sheet data is deleted. Here, among the five originals, the image data of the third and fourth pages have already been determined as blank pages in S120, so the remaining originals, that is, the images of the first, second, and fifth pages. A process for determining whether the data is blank paper data is performed, and the image data determined to be blank paper data is deleted. Here, it is assumed that there is no determined image data that is blank paper data.

  Thereafter, the process proceeds to S110 and the output process is executed. In this example, the remaining four originals, that is, the image data of the first page, the second page, the fourth page, and the fifth page, except the deleted third page of the original, are transmitted to the memory. The Thus, a series of processing ends.

  Next, the case where NO is determined in S120, that is, the case where the blank image data is not included in the image data stored in the RAM 63 will be described.

  If NO is determined in S120, then the process proceeds to S140. In S140, it is determined whether or not the CPU 60A executes the memory full process. The memory full process is a process of discarding the image data being read so that no more data is stored in the RAM 63 while the image data already stored in the RAM 63 is output.

  Whether or not the memory full process can be executed can be set by the user. If the memory full process is not executed, a NO determination is made in S140, and the process ends there. In this case, the read image data for four pages is not transmitted to the memory, and the process ends.

  On the other hand, if the user is set to execute the memory full process, YES is determined in S140, and the process proceeds to S150. In S150, a memory full process is executed. That is, the five-page document is fed through the transport path 43 without being read by the CIS 30 and discharged onto the discharge tray 46.

  Thereafter, after S110, the process of transmitting the image data of the first page to the fourth page, excluding the fifth page of the document whose reading is stopped, is executed.

  As described above, even when the amount of use of the RAM 63 temporarily exceeds the limit amount during image reading, the amount of use can be lowered to the limit amount or less by deleting blank paper data. Therefore, it is possible to continue the document reading process by the CIS 30, and it is possible to suppress a decrease in the throughput of the reading process.

  In particular, in the ADF that reads a plurality of documents in one reading process, the usage amount of the RAM 63 tends to exceed the limit amount. In this regard, application of the present technology can suppress the usage amount from exceeding the limit amount, so that a decrease in throughput of the reading process can be suppressed.

  In this configuration, since the CPU 60A combines the reading unit control function and the blank page determination function, both processes cannot be performed in parallel. Therefore, when the usage amount of the RAM 63 exceeds the limit amount, the blank data determination process (the process of S120) is executed, so that the blank data determination process is executed each time an image is read. It can suppress that the throughput of a reading process falls.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIGS. In the first embodiment, the CPU 60A is burdened with four functions: (1) reading unit control function, (2) image processing, blank page determination function, (3) output processing function, and (4) memory error avoidance function. Explained.

  In the second embodiment, among the above four functions, (2) the image processing and blank page determination function are executed by the image processing circuit 83. As shown in FIG. An image processing circuit 83 and a direct memory controller 81 are added.

  The direct memory controller 81 has a function of writing the image data that has been subjected to gamma correction and shading correction by the image processing circuit 83 to the RAM 63. The CPU 60B and the image processing circuit 83 correspond to different devices of the present invention. That is, the CPU 60B is a device corresponding to the “control unit, deletion unit” of the present invention, and the image processing circuit 83 is a device corresponding to the “blank sheet determination unit” of the present invention.

  In the second embodiment, since the image processing circuit 83 performs blank page determination of the read image data simultaneously with the reading of the original by the CIS 30, the process of S65 is performed for the memory error avoidance sequence of the first embodiment. Is added, and the blank sheet determination result determined by the image processing circuit 83 is written in the RAM 63 every time one page of the document is read.

  Hereinafter, the processing content of the memory error avoidance sequence (see FIG. 6) according to the second embodiment will be described separately when the usage amount of the RAM 63 does not exceed the limit amount and when it exceeds the limit amount.

<When the usage amount of the RAM 63 does not exceed the limit amount>
Here, a case will be described as an example in which the user transmits two originals to the memory using the multifunction device 1. When two documents are set on the document tray 42 and the start key of the operation unit 11 is pressed by the user, first, a process of reading the document is started. Specifically, by driving the ADF 40, the first document set on the document tray 42 is sent to the transport path 43 with the front side facing up (S10).

  Thereafter, when the leading end of the sent document (here, the first page document) reaches the reading position P, the document is read by the CIS 30. Specifically, the image sensor 33 reads one line of the document passing the reading position P on the second platen glass 53. The image data read by the image sensor 33 is then converted into a digital signal by the A / D converter 65. The image processing circuit 83 reads the image data from the A / D converter 65 and performs gamma correction and shading correction (S20, S30).

  Thereafter, the memory controller 81 accesses the RAM 63 and determines whether the usage amount of the RAM 63 is equal to or larger than the limit amount (S40). Note that the determination in S40 is performed by comparing the count value of the memory counter 63A with the threshold “CX”, as in the first embodiment.

  If the usage amount of the RAM 63 is not equal to or greater than the limit amount, the memory controller 81 reads the image data corrected in S30 from the image processing circuit 83 and stores it in the RAM 63 (S50). As a result, the image data of the first line is stored in the RAM 63.

  Thereafter, until the reading of all lines is completed, NO is determined in the determination process of S60, and the processes from S10 to S50 are sequentially executed. Therefore, the reading of the original by the CIS 30, the data conversion by the A / D converter 65, and the image data correction processing by the CPU 60 </ b> B are executed for each line, and then the image data of each line is stored in the RAM 63.

  The image processing circuit 83 detects the density of the image data read from the CIS 30 while the processes of S10 to S50 are repeated, and detects the number of pixels exceeding the reference density. Then, the image processing circuit 83 determines whether the image data is blank paper data or page units when reading of all lines is completed. That is, the number of pixels exceeding the reference density is compared with the first threshold value, and it is determined whether the page is blank data based on the magnitude relationship.

  On the other hand, in the memory error avoidance sequence, when all the lines have been read, a YES determination is made in S60, and the process proceeds to S65. In S <b> 65, the CPU 60 </ b> B executes a process of reading the blank sheet determination result from the image processing circuit 83 and writing it to the RAM 63.

  Specifically, the process of S65 includes S151 to S153 and the process shown in FIG. 7, and a process of reading a blank page determination result from the image processing circuit 83 is first executed, and then, according to the read blank page determination result. Thus, blank page information is written in the meta information portion.

Describing in detail with reference to FIG. 8, the RAM 63 is provided with an area for storing image data and a meta information part for writing meta information. The meta information is summary information of the image data, and includes page number, start address, size, blank page information, meta information address of the previous page, and meta information address of the next page for each image data.

In this example, when the blank page determination result is “not blank” from the image processing circuit 83, “00” is written as “blank page information”. On the other hand, when the read blank page determination result is “blank page data”, “01” is written as “blank page information”. The blank page information corresponds to “blank page determination processing information” of the present invention. In addition, RAM63 is, it stores a blank page information as meta information.

  Returning to FIG. 6 and continuing the description, in S70 following S65, the CPU 60B determines whether there is a next page, as in the first embodiment. Here, only the first page of the two originals to be transmitted to the memory has been read, and the original for the second page remains on the original tray 42. Therefore, in S70, the CPU 60B determines YES.

  If YES is determined in S <b> 70, the second page of the document set on the document tray 42 is sent to the conveyance path 43 with the front side facing up by driving the ADF 40.

  Thereafter, until the reading of all lines for the second page of the document is completed, the processes from S10 to S50 are executed in order as in the first page, the document is read by the CIS 30, and the data is converted by the A / D converter 65. Then, correction processing by the image processing circuit 83 and storage of the image data in the RAM 63 by the memory controller 81 are executed in line units.

  Then, the image processing circuit 83 detects the density of the image data read from the CIS 30 while the processes of S10 to S50 are repeated, and detects the number of pixels exceeding the reference density. Then, the image processing circuit 83 determines whether the image data of the second page is blank page data when reading of all lines is completed for the second page.

  On the other hand, in the memory error avoidance sequence, when all the lines have been read, a YES determination is made in S60, and the process proceeds to S65. In S65, the CPU 60B executes a process of writing the blank sheet determination result to the RAM 63.

  That is, the blank page determination result is first read from the image processing circuit 83, and when the read blank page determination result is “not blank”, information “00” is written in the meta information portion of the RAM 63 as blank page information. On the other hand, when the read blank page determination result is “blank page data”, “01” is written as “blank page information”.

  When the processing of S65 ends, it is next determined in S70 whether there is a next page. At this stage, since reading of all the two originals to be transmitted to the memory has been completed and there is no original left on the original tray 42, a NO determination is made in S70, and the process proceeds to S90.

  In S90, the CPU 60B performs a process of deleting blank data. Specifically, the blank page information is read for each image data from the meta information portion of the RAM 63, and the image data in which “01” information is registered as the blank page information is deleted.

  Thereafter, the process proceeds to S110 and the output process is executed. As a result, the process of transmitting the image data stored in the RAM 63 (however, excluding the image data deleted in S90) to the memory is executed. Thus, a series of processing ends.

<When the amount of RAM 63 used exceeds the limit>
Here, it is assumed that five originals are transmitted in memory. For the fourth page of the five sheets, the reading of the original and the writing of the meta information to the RAM 63 are completed without the amount of use of the RAM 63 exceeding the limit amount, and the use of the RAM 63 is being performed while the original of the fifth page is being read. It is assumed that the amount exceeds the limit amount and YES is determined in S40.

  If YES is determined in S40, the CPU 60B executes the processes of S171 to S183 shown in FIG. 9, and the process of determining blank page information while sequentially updating the page of interest from the first page. That is, first in S171, the page of interest in the meta information section is set to the first page. In step S173, it is determined whether the blank page information of the first page that is the page of interest is “01”.

  For example, if the blank page information of the first page, which is the page of interest, is “00”, that is, it is not blank, a NO determination is made in S173, and the process proceeds to S175. If there is a next page in S175, a NO determination is made. Therefore, the process proceeds to S177, and a process of setting the page of interest as the next page is executed. As described above, when the blank page information of the page of interest is not “01”, the page of interest is updated in order from the first page.

  When the page of interest is updated, the process thereafter returns to S173, and it is determined whether the blank page information of the updated page of interest is “01”. If the updated blank page information is “01”, a YES determination is made in S173, and the process proceeds to S181. Here, it is assumed that the blank page information on the second page is “01”.

In S181, the CPU 60B executes a process of releasing, that is, deleting, image data whose blank page information is “01”. Accordingly, in S181, the image data of the second page is released. Specifically, the image data is released by deleting all the meta information of the second page. In step S183, page linkage processing is executed. Incidentally, S171 is executed by CPU60B, S173, S175, S177, the processing of S181, namely to delete the image data of the page to find the page blank page information is "01".

  As described above, by releasing and deleting the image data in S181, the usage amount of the RAM 63 decreases and returns to a state below the limit amount. Thereafter, the process returns to S50 in FIG. 6, so that the process of storing the image data being read, that is, the image data of the fifth page in the RAM 63 is performed.

  Subsequent processing proceeds in the same manner as described in the case where two originals are transmitted in memory. That is, when reading of all five pages is completed, NO is determined in S70, and the process proceeds to S90.

  In S90, the CPU 60B performs a process of deleting blank data. Specifically, blank page information is read for each image data from the meta information portion of the RAM 63, and image data in which “01” information is registered as blank page information is released and deleted.

  Thereafter, the process proceeds to S110 and the output process is executed. In S110, a process of transmitting image data that has not been deleted among all the five pieces of image data to the memory is executed. Therefore, if there is no deleted data other than the second page, the remaining 4 originals out of all 5 pages, that is, the first page, the third page, the fourth page, and the fifth page are transmitted to the memory. Will be. Thus, a series of processing ends.

  If no blank page data is included in all four pages read until the usage amount of the RAM 63 reaches the limit amount, the blank page information for the fourth page is determined in S173, and then in S175 There is no page, and the “next page is currently being read” state is entered, so a YES determination is made. If YES is determined in S175, the process ends there. Therefore, in this case, the read image data, that is, the image data from the first page to the fourth page is not transmitted to the memory. In this case, the multifunction device 1 executes error handling such as deleting the read image data or notifying the user.

  As described above, even if the amount of use of the RAM 63 temporarily exceeds the limit amount during image reading, the amount of use can be lowered to the limit amount or less by deleting blank paper data. Therefore, it is possible to continue the document reading process by the CIS 30, and it is possible to suppress a decrease in the throughput of the reading process.

  In this configuration, blank page determination processing is performed for each page, and blank page information is stored in the meta information portion of the RAM 63. Therefore, it is possible to specify a blank page by accessing the RAM 63 and checking blank page information, and it is not necessary to perform blank page determination for each image data stored in the RAM 63 when reducing the amount of use of the RAM 63. . Therefore, it is possible to perform the process of reducing the usage amount of the RAM 63 in a short time, and it is possible to suppress a decrease in the throughput of the reading process.

<Embodiment 3>
Next, Embodiment 3 of the present invention will be described with reference to FIG. In the second embodiment, when the usage amount of the RAM 63 exceeds the limit amount, the usage amount of the RAM 63 is reduced by executing the processing of S171 to S183 to release and delete the blank paper data.

  The third embodiment is common in that when the usage amount of the RAM 63 exceeds the limit amount, the usage amount of the RAM 63 is reduced by releasing and deleting the blank paper data. The difference is that the second embodiment deletes only one page of blank paper data, whereas the third embodiment deletes all blank data stored in the RAM 63.

  Note that the specific difference between the processes is that the process shifts to S175 after the process of S183 as shown in FIG. 10 and the process of S185 is newly provided in accordance with the above change. .

  As described above, in the third embodiment, when the usage amount of the RAM 63 exceeds the limit amount, all the blank paper data stored in the RAM 63 is deleted. There is room for the limit amount of usage. Therefore, since the possibility that the usage amount of the RAM 63 exceeds the limit amount during the subsequent reading is reduced, it is possible to suppress a reduction in the throughput of the reading process.

<Embodiment 4>
Next, a fourth embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the blank page information is composed of two patterns of information “00” that is not blank and blank data “01”.

  The fourth embodiment is different from the second embodiment in that the pattern of blank page information is expanded from two patterns to three patterns. In the fourth embodiment, the blank page information is “00” which is not a blank page, and a standard image. The blank page data “01” does not include the blank page data and the blank page data “02” includes the standard image.

  Here, the standard image means an image that is used in a fixed manner such as a date and a file name on the upper and lower portions (indicated by a dotted frame in FIG. 11) corresponding to the document edge. The blank page data including the standard image means image data including only the standard image and not including other images. Blank paper data that does not include a standard image means image data that does not include any image including a standard image.

  In order to classify the image data read by the CIS 30 into these three patterns, first, the number of pixels exceeding the reference density is obtained for the central area (area shown by hatching in FIG. 11) except the top and bottom of the document. Then, it is compared with a first threshold value set as a blank page determination threshold value. Thereby, it can be determined whether the image data to be determined is blank paper data or non-blank paper.

  Next, for blank paper data, this time, by determining whether or not a standard image is printed at the top or bottom from the optical character recognition (OCR) technology and pixel density, the data is converted into a standard image. It can be reclassified whether it contains blank paper data or blank paper data that does not contain a standard image.

  Note that the determination (classification) of these blank page data information is executed by the image processing circuit 83 as in the second embodiment, and the CPU 60B writes the result as blank page information in the meta information portion of the RAM 63 (see FIG. 7 S151 and S153).

  The fourth embodiment differs from the memory error avoidance sequence (FIG. 6, FIG. 7, FIG. 9) of the second embodiment in the processing after YES is determined in S40, and the usage amount of the RAM 63 is the limit amount. In such a case, blank data that does not include the standard image is preferentially deleted from the blank data, and if there is no blank data that does not include the standard image, the blank data that includes the standard image is deleted.

  More specifically, in the fourth embodiment, if YES is determined in S40 of FIG. 6, the process proceeds to S201 illustrated in FIG. 12, and “target” is set to “01” by the CPU 60B. In step S203, the CPU 60B sets the page of interest to “first page”. In step S205, it is determined whether the blank page information is “target” for the page of interest. Here, since the page of interest is one page and “target” is “01”, the CPU 60B determines whether the blank page data information of the first page is “01”, that is, blank page data not including a standard image. Will be.

  Here, when the blank page data information of the first page is not “01”, after the determination process of S207, the CPU 60B executes a process of moving to S210 and updating the page of interest to the next page. Thereafter, the process returns to S205, and it is determined whether the blank page information is “target”, that is, “01” for the updated page of interest. By repeating such processing, it is determined whether the blank page information of the page is “target”, that is, “01” while updating the page of interest.

  Then, if a page of interest whose blank paper data information is “01” appears, a YES determination is made in S205. Thereafter, the process proceeds to S213, and the CPU 60B executes a process of releasing the image data, and in the subsequent S215, The page linkage process is executed by the CPU 60B. When the page joining process is completed, the process returns to S50 of FIG. The processes in S213 and S215 are the same as S181 and S183 in FIG.

  On the other hand, if there is no page of interest whose blank page data information is “01”, the determination processing of S205 is performed for the last page, and then YES is determined in S207 and S209. “Target” is set to “02”.

  Thereafter, the process returns to S203, and it is determined whether the blank page information of the page is “02”, that is, image data including a standard image, while updating the page of interest. If a target page whose blank page data information is “02” appears, a YES determination is made in S205. Thereafter, the process proceeds to S213 to execute a process of releasing the image data. The splicing process is executed. When the page joining process is completed, the process returns to S50 of FIG.

  On the other hand, if there is no page of interest whose blank page data information is “02”, the determination process of S205 is performed for the last page, and then a YES determination is made in S207 and a NO determination is made in S209. finish.

  As described above, in the fourth embodiment, when the usage amount of the RAM 63 is equal to or larger than the limit amount, blank data that does not include the standard image is preferentially deleted from the blank data. Therefore, it is possible to leave the blank data including the standard image as much as possible while keeping the throughput of the reading process from decreasing. In the fourth embodiment, the processing of S201 to 211 executed by the CPU 60B, that is, the blank page information of the image data to be deleted is first set to “01”. If there is no corresponding page, “02” is set. The function of the “determination unit” of the present invention is realized by the resetting process.

<Embodiment 5>
Next, a fifth embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the blank page information is composed of two patterns of information “00” that is not blank and blank data “01”.

  The fifth embodiment is different from the second embodiment in that the pattern of the blank page information is expanded from two patterns to three patterns. In the fifth embodiment, the blank page information is “00” which is not a blank page, and blank page data. “01” is not a blank sheet, and there are three patterns “03” with no blank sheet on the previous page.

  Here, as a specific example, for example, as shown in FIG. 13, when all five pages of originals are read, only the fourth page is blank, and all other pages are not blank. The pages up to the page are “no blank pages and no blank pages before this page”, and the blank page information is “03”. Since the fourth page is blank page data, the blank page information is “01”. Also, since the fifth page is not blank, blank page information is “00”.

  In this way, if information of “no blank page and no blank page is added to the previous page” is added as blank page information, there is a merit that the trouble of searching blank data from the RAM 63 can be saved somewhat. There is.

  This is because if the update order of the page of interest is determined in ascending order of storage in the RAM 63, in the example of FIG. 13, it is only necessary to search for the presence or absence of blank page data from blank page information of 5 to 3 pages. This is because the first page and the second page can be excluded from the search target.

  The fifth embodiment is different from the memory error avoidance sequence (FIGS. 6, 7, and 9) of the second embodiment in that the processing in S65 is different from the processing after YES is determined in S40. A description will be given of places where the processing differs from that of the second embodiment.

  FIG. 14 illustrates the details of S65 in FIG. 6, and the CPU 60B executes the processing from S251 to S265, so that “00”, “01”, “ Three patterns of information “03” can be written in the meta information portion of the RAM 63.

  More specifically, in S251, the blank page determination result of the image processing circuit 83 is read, and if it is blank page data, the process proceeds to S255. In S255, the blank page information in the meta information section is set to “01” for the page.

  On the other hand, if it is not blank, the process proceeds to S253. In S253, the blank page information in the meta information part of the image data is set to “00”. Thereafter, the process proceeds to S261. In S261, it is determined whether the page is the first page. If it is the first page, a YES determination is made in S261, and then the process proceeds to S265. In S265, the blank page information in the meta information section is set to “03” for the page. That is, the blank page information of the page is reset from “00” set in S253 to “03”.

  On the other hand, if it is not the first page, a NO determination is made in S261, and then the process proceeds to S263. In S263, it is determined whether the blank page information in the meta information portion of the previous page is “03”. If it is “03”, the process proceeds to S265 and the previous process is performed. If it is not “03”, the process is terminated.

  FIG. 15 is a process executed by the CPU 60B when YES is determined in S40 of FIG. 6, that is, when the usage amount of the RAM 63 exceeds the limit amount. First, in S301, the CPU 60B sets the page of interest to “last page”. In S303, the CPU 60B performs a process of determining blank page information for the page of interest.

  If the blank page information is “01”, then the process proceeds to S313 to execute a process of releasing the image data, and in the subsequent S315, a page joining process is executed. When the page joining process is completed, the process returns to S50 of FIG. These processes of S315 and S315 are the same processes as S181 and S183 of FIG.

  Next, when the blank page data information is “03”, the process ends at that time.

  If the blank page data information is “00”, then a determination process is performed in S305, and then in S307, the page of interest is updated, that is, a process of updating to the previous page of the last page is executed. Thereafter, the process returns to S303. The blank page data information “03” in the fifth embodiment corresponds to the “flag” of the present invention. Further, the function of the “flag assignment unit” of the present invention is realized by the processing of S251, S253, S261, and S265 executed by the CPU 60B.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

  (1) In the first to fifth embodiments, when the usage amount of the RAM 63 is equal to or greater than the limit amount, the blank data is deleted from the RAM 63. However, the limit amount is used with a certain width. It is also possible to delete the blank page data at a stage where the value is included in the limit amount setting range (that is, a near-full state close to the limit level).

  (2) In the fourth embodiment, with respect to the blank page data, two patterns of blank page data that does not include the standard image and blank page data that includes the standard image are provided, and the blank page data that does not include the standard image is preferentially deleted. Indicated. The deletion priority is not limited to the method disclosed in the fourth embodiment, and the deletion priority may be determined based on whether or not the deletion priority is closer.

  For example, in addition to the first threshold value set as the blank page determination threshold value, a second threshold value less than or equal to the first threshold value is set, and among the blank page data, blank page data in which the number of pixels having a predetermined density or more is less than the second threshold value. The CPU 60B may determine that the deletion priority is increased.

1. Multifunction machine (an example of an “image reading apparatus” according to the present invention)
5... Image reading unit 30... CIS (an example of the “reading unit” of the present invention)
40... ADF (an example of the “conveying unit” of the present invention)
43 ... conveying path 60A ... CPU (an example of "control unit", "blank sheet determination unit", "deletion unit" of the present invention)
60B ... CPU (an example of the “control unit”, “deletion unit”, “determination unit”, and “flag assignment unit” of the present invention)
61 ... ROM
63... RAM (an example of the “storage unit” of the present invention)
65 ... A / D converter 71 ... Output device 81 ... Direct memory controller 83 ... Image processing circuit (an example of "blank sheet determination unit" of the present invention)

Claims (3)

A transport section for transporting a document;
A reading unit for reading an image of a document conveyed by the conveyance unit ;
A storage unit for storing read data read by the reading unit;
Each time an image for one page of a document is read by the reading unit, blank data is determined for the read data, and when there is blank data, a blank page determination process for classifying a blank data pattern is performed. A determination unit;
A blank page determination process information storage processing unit that stores the blank page determination process information indicating the pattern in the storage unit in association with the read data to be determined;
A determination unit that determines a deletion priority for the blank data pattern specified by the blank page determination processing information;
When the usage amount of the storage unit is equal to or greater than the limit amount, the read data associated with the blank page determination processing information with high priority is read from the storage unit based on the determination of the deletion priority by the determination unit. A deletion part to be deleted;
A controller that controls the reading unit so as to continue reading an image after the deletion of the read data by the deletion unit ;
The control unit and the blank page determination unit are different devices that operate independently of each other.
The blank page determination unit determines blank data for a central area excluding an upper part and a lower part of a document corresponding to a document edge, and, as the blank data pattern, the center area is blank data, and a fixed pattern is formed on the document edge. It is possible to classify a first pattern that is blank data including an image and a second pattern that is blank data in which the central region is blank data and the document edge does not include a standard image,
The image reading apparatus according to claim 1, wherein the determination unit sets the priority of deletion of the first pattern to be lower than the priority of the second pattern . A flag adding unit that gives a flag to the read data of the non-blank data to be stored when the read data stored in the storage unit is non-blank data and the read data of the previous page is non-blank data. the image reading apparatus according to claim 1 comprising a. A transport section for transporting a document;
A reading unit for reading an image of a document conveyed by the conveyance unit;
A storage unit for storing read data read by the reading unit;
A blank page determination unit that executes blank page determination processing for determining blank page data from the read data stored in the storage unit;
A deletion unit that deletes, from the storage unit, read data that is determined to be blank page data by the blank page determination unit when the usage amount of the storage unit is equal to or greater than a limit amount;
A controller that controls the reading unit to continue reading an image after the deletion unit deletes the read data;
A flag adding unit that gives a flag to the read data of the non-blank data to be stored when the read data stored in the storage unit is non-blank data and the read data of the previous page is non-blank data. An image reading apparatus.

Images