JP4552154B2 - Image reading device - Google Patents

Description

  The present invention relates to an image reading apparatus.

2. Description of the Related Art Conventionally, as an image reading device, a document is read line by line by a reading sensor such as a CCD, and the obtained data is transmitted to a control unit via a transmission line such as a harness, where various image processing is performed. It has been. In such an image reading apparatus, part of the data may be damaged due to the influence of noise or the like during data communication, and the quality of the image may be reduced, or image processing may not be performed normally. On the other hand, for example, in Patent Document 1, the received data is checked at the time of facsimile transmission, and if it is determined that the data is defective, the data for the previous line that has been normally received is received. Techniques for replacing data are described. By using such a technique for an image reading apparatus, it is possible to reduce a decrease in image quality.
JP-A-6-245048

  However, in order to check the suitability of the received data as described above, conventionally, information for checking (parity information or the like) is added to the data on the transmission side and transmitted, and the reception side based on the information. It was judged whether there was a reception failure. For this reason, there is a problem that the amount of data to be communicated increases, and as a result, the communication speed decreases, and consequently the reading execution speed decreases.

  The present invention has been completed based on the circumstances as described above, and provides an image reading apparatus capable of avoiding an increase in the amount of communication data and suppressing the influence due to poor reception of data. Objective.

As means for achieving the above object, the invention of claim 1 is an image reading apparatus comprising a reading unit and a control unit connected to the reading unit via a transmission path , wherein the reading unit is a document. a reading means for obtaining a read pixel data, transmission of the transmitted to the pixel data read data added with the attribute data to take shows regularly values the attributes of the pixel data acquired by the reading unit to the control unit and means, wherein the control unit is configured with a reference generating means for generating a value equal to the reference value of the attribute data attached to the read data in the transmitting unit, the received read attribute data the reference value data determine the comparison, determines that fit the read data when the attribute data is equal to the reference value, is determined as irrelevant to fit the read data when not equal to And when the received read data is determined to be suitable by the determining means, the read data is output. When the read data is determined to be incompatible by the determining means, the read data is adapted and output. An adaptation unit, and an image processing unit that performs image processing on the read data output by the adaptation unit .

  According to a second aspect of the present invention, in the image reading apparatus according to the first aspect, when the received read data is determined to be non-conforming by the determining means, the adapting means outputs attribute data included in the read data. Replace with the reference value generated by the reference generation means.

  According to a third aspect of the present invention, in the image reading apparatus according to the first or second aspect, the image reading apparatus further comprises storage means for storing pixel data of the received read data, and the adapting means is the read received by the determining means. When the data is determined to be compatible, the pixel data of the read data is stored in the storage unit, and when the data is determined to be incompatible, the pixel data of the received read data is stored in the storage unit and Replace with pixel data determined to be compatible by the determination means.

  According to a fourth aspect of the present invention, in the image reading apparatus according to any one of the first to third aspects, the reading unit reads a document line by line, and the reading unit reads the original. Second determination means for determining whether the read data of each line is compatible or non-compliant based on the number of data determined to be non-conforming, and the pixel data of the read data output from the adapting means for each line Storage means for changing and storing the writing area, and the storage means does not change the writing area corresponding to the line when the second determination means determines that the line is incompatible.

  According to a fifth aspect of the present invention, in the image reading apparatus according to the fourth aspect of the present invention, a moving unit that relatively moves the reading unit and the document in the sub-scanning direction, and a movement control unit that controls the operation of the moving unit. The movement control means moves the reading unit and the document relative to a position corresponding to the non-conforming line when the second determination means determines that the line is non-conforming.

  According to a sixth aspect of the present invention, in the image reading apparatus according to any one of the first to fifth aspects, the attribute data includes information indicating whether or not the pixel data is the head of a line.

  According to a seventh aspect of the present invention, in the image reading apparatus according to any one of the first to sixth aspects, the attribute data includes color information of pixel data.

  The invention according to claim 8 is the image reading apparatus according to claim 7, wherein the transmission unit receives read data including pixel data of a plurality of colors and attribute data including color information of each pixel data for one pixel. The reference generation means sequentially generates a reference value of attribute data corresponding to each of the plurality of colors based on the synchronization signal.

<Invention of Claim 1>
The attribute data included in the received read data is compared with a reference value, and if the read data is determined to be incompatible, the read data is adapted and output. Since the reception failure check is performed based on the attribute data, it is not necessary to add new check data to the read data. Therefore, it is possible to avoid an increase in the amount of communication data and to suppress the influence due to poor data reception.

<Invention of Claim 2>
If the received read data is determined to be incompatible, the attribute data is replaced with a reference value. Thereby, it is possible to prevent an error from occurring in a process (image processing or the like) performed using the output read data.

<Invention of Claim 3>
When the received read data is determined to be compatible, the pixel data is stored in the storage unit. When the received read data is determined to be incompatible, the pixel data is replaced with pixel data stored in the storage unit and determined to be compatible. As a result, a decrease in image quality can be reduced.

<Invention of Claim 4>
If it is determined that the line is incompatible, the writing area of the storage means is not changed, so that the pixel data of that line is overwritten with the data of the next output line. Therefore, it is possible to prevent the image quality from being deteriorated due to the pixel data of the nonconforming line.

<Invention of Claim 5>
When a non-conforming line is generated, the reading unit or the document is moved to a position corresponding to the non-conforming line. Thereby, the non-conforming line is read again, so that it is possible to prevent the image quality from being deteriorated.

<Invention of Claims 6 and 7>
The attribute data includes information indicating that the pixel data is the head of the line and color information of the pixel data (information indicating whether the pixel data is monochrome pixel data or RGB). In this way, since reception failure is checked based on the attribute data added to the pixel data, it is not necessary to add new check data to the read data.

<Invention of Claim 8>
When color read data is transmitted / received, a reference value of attribute data corresponding to each color is periodically generated based on the synchronization signal. Therefore, based on the color information of the attribute data, it can be accurately determined whether the read data is compatible or non-compatible.

  Next, an embodiment of the present invention will be described with reference to FIGS.

(Schematic configuration of MFP)
In the present embodiment, an example in which the present invention is applied to a multifunction device 1 (an example of an image reading apparatus) having a scanner function, a printer function, a copy function, a facsimile function, and the like will be described. FIG. 1 is an external perspective view of the multifunction device 1, and FIG. 2 is an external perspective view showing a state in which the document cover 6 is raised.

  The multi-function device 1 includes a main body unit 2 that houses a printing unit (not shown) that prints an image on a sheet, and a document reading unit 3 for reading a document above the main unit 2. The document reading unit 3 includes a document placing unit 4 made of a transparent glass plate, and a reading unit 10 including a reading sensor 16 described below is provided below the document placing unit 4. The upper surface of the document placing portion 4 is covered with a document cover 6 provided with an ADF (automatic document feeder) 5 so as to be opened and closed. The ADF 5 includes a document tray 7 on which a plurality of documents can be stacked, and conveys the documents placed on the document tray 7 to the reading position one by one.

  There are cases where the original is read by placing the original on the original placing portion 4 and using the ADF 5. In the former case, the reading unit 10 is moved in the sub-scanning direction (see arrow B) by the power of the motor 13 (see FIG. 3), and at that time, the reading sensor 16 moves one line in the main scanning direction (see arrow A). The originals on the original placement unit 4 are read one by one. In the latter case, when the reading unit 10 is fixed at the left end position of the document placing portion 4 and the document is conveyed to a position where the reading sensor 16 can read by driving the ADF 5, the document is read. One line is performed in the main scanning direction.

(Image reading system)
FIG. 3 is a block diagram showing the configuration of the image reading system in the multifunction machine 1. The image reading system includes a reading unit 10, a control board 12 (an example of a control unit) connected to the reading unit 10 via a harness 11 (an example of a transmission path), and a motor for moving the reading unit 10. 13 (an example of moving means).

  An ASIC (Application Specific IC) 14 is provided on the control board 12. The ASIC 14 transmits a unit drive signal including a clock signal and a line synchronization signal to the reading unit 10 to control its operation. The ASIC 14 also transmits a motor drive signal to the motor 13 to control its operation.

  The reading unit 10 includes a reading sensor 16 (an example of reading means) and an AFE (Analog Front End) 17. The AFE 17 generates a reading timing signal for driving the reading sensor 16 and outputs the reading timing signal to the reading sensor 16. The reading sensor 16 is, for example, a CCD (Charge Coupled Device), and includes photodiodes arranged in a line, and the individual photodiodes receive reflected light when light is applied to the document from the light source. The light intensity (brightness) of the reflected light is converted into an electrical signal (analog image signal) for each pixel.

  The AFE 17 quantizes the image signal output from the reading sensor 16 by the A / D converter 18 and delivers the obtained pixel data to the data transmission unit 19 (the A / D converter 18 and the data transmission unit 19 transmit). Example of means). As will be described later, the data transmission unit 19 generates read data obtained by adding attribute data to the pixel data, and transmits the read data together with the data synchronization signal to the control board 12 side. The control board 12 receives the read data at the data receiving unit 20 and delivers the data to the image processing unit 21. The image processing unit 21 performs various types of image processing on the obtained data.

(Read data)
FIG. 4 is a diagram for explaining the contents of monochrome read data, and FIG. 5 is a diagram for explaining the contents of color (RGB) read data.

  The read data and the data synchronization signal are transmitted from the reading unit 10 to the control board 12 via the harness 10 by the LVDS (Low Voltage Differential Signaling) method. The data transmission unit 19 outputs a data synchronization signal as a one-channel LVDS signal (RXCLK) using a pair of pair lines, and reads data as a three-channel LVDS signal (RX0, RX1) using three pairs of pair lines. , RX2). As read data, 7 bits for each channel and 21 bits in total are transmitted for one cycle of the data synchronization signal. As shown in FIG. 4, monochrome read data includes 16-bit pixel data (gradation data, D [0] to D [15]) and 5-bit attribute data (C [0] to C [ 4]), and pixel data for one pixel and its attribute data are transmitted for each period of the data synchronization signal. In addition, as shown in FIG. 5, the color read data is composed of 16-bit pixel data and 5-bit attribute data for each RGB element in one pixel. The pixel data of the element and its attribute data are transmitted. Further, the color read data includes, for example, the R element, the G element, and the B element of the pixel “n”, followed by the R element, the G element, and the like of the pixel “n + 1” in a predetermined order. It is transmitted continuously.

  6 and 7 are diagrams for explaining the contents of the attribute data. The attribute data is added to the pixel data to indicate the attribute. As shown in FIG. 6, 1 bit (C [4]) of the 5-bit attribute data indicates that the pixel data is the head of one line. ("1") or not ("0"). Further, as shown in FIG. 7, the other 4 bits (C [3: 0]) of the attribute data indicate whether the pixel data is invalid pixel data at both ends of the line (“0000”), or RGB Is it valid pixel data for each color (“0001”, “0010”, “0011”), whether it is black reference data for each color of RGB (“0110”, “0111”, “1000”), or the reading start position Indicates whether it is data (“1111”). Further, attribute data (C [4: 0]) indicating that the pixel data is monochrome effective pixel data has a constant value such as “00010”, for example.

(Configuration of data receiving unit and image processing unit)
FIG. 8 is a block diagram showing the configuration of the data receiving unit 20 and the image processing unit 21 provided on the ASIC 14.

  The read data and the data synchronization signal transmitted from the data transmission unit 19 are input to the LVDS receiver 23 of the data reception unit 20. The LVDS receiver 23 includes a PLL (phase synchronization circuit) 24 and a serial-parallel converter 25. The PLL 24 converts a clock signal obtained by multiplying the frequency of the input data synchronization signal by 7 to read data (RX0, RX1, RX2) It is given to the serial-parallel converter 25 as a clock signal for capturing. Further, the PLL 24 generates a clock signal (CLKOUT) having the same frequency as that of the data synchronization signal from the data receiving unit 20 such as a latch / separation circuit 26, a reference sequence generation circuit 27, a compatible data storage circuit 29, a data selector 30, and the like described below. Each part is given as a reference clock. Further, the PLL 24 has a lock detection function. When the lock (synchronization) with respect to the data synchronization signal is released, the PLL 24 notifies the CPU 42 to that effect.

  The serial-parallel converter 25 converts the 7-bit read data for each of the 3 channels into 21-bit parallel data at the timing based on the clock signal from the PLL, and outputs it to the latch / separation circuit 26.

  The latch / separation circuit 26 temporarily holds the input read data and separates the read data into 16-bit pixel data and 5-bit attribute data and outputs the separated data. The pixel data is output to the compatible data storage circuit 29 and the data selector 30, and the attribute data is output to the reference sequence generation circuit 27, the comparison circuit 28, and the data selector 30.

  When the attribute data indicating the head data of the line is output from the latch / separation circuit 26, the reference sequence generation circuit 27 (reference generation means) is synchronized with the clock signal (CLKOUT) output from the PLL 24. To generate a reference sequence. This reference sequence is a reference value of attribute data. When the read data is monochrome, the reference sequence is a constant attribute data value (“00010”) indicating a monochrome effective pixel. If the read data is color, the attribute data value (“00001”) indicating that the pixel data is an R effective pixel, and the attribute data value (“00010”) indicating that the pixel data is a G effective pixel. )) And the attribute data value (“00011”) indicating that it is a valid pixel of B are repeatedly generated in order.

  The reference sequence generated by the reference sequence generation circuit 27 is output to the comparison circuit 28 and the data selector 30. The comparison circuit 28 (an example of a determination unit) compares the attribute data output from the latch / separation circuit 26 with the value of the reference sequence. Then, a determination signal indicating a determination result of whether or not the two are equal is output to the compatible data storage circuit 29, the data selector 30, and the non-conforming counter 31.

  The adaptive data storage circuit 29 (an example of a storage unit) can temporarily store pixel data (16 bits) for each element of RGB when the read data is in color, and in the case of monochrome. Pixel data for one pixel can be temporarily stored. When the matching data storage circuit 29 receives the determination signal (H) indicating that the attribute data is equal to the reference sequence from the comparison circuit 28, that is, it is determined that the read data is normally received matching data. In this case, the pixel data output from the latch / separation circuit 26 is stored in a predetermined storage area. When the determination signal (L) indicating that the attribute data and the reference sequence are different from the comparison circuit 28 is received, that is, when it is determined that the read data is non-conforming data that has not been normally received, The pixel data output from the latch / separation circuit 26 is not saved.

  FIG. 9 is a timing chart illustrating the contents of processing when the data receiving unit 20 receives color read data. As shown in the figure, for example, when the attribute data (“VG (n−2)”) of the received read data is equal to the value of the reference sequence (“VG”), the comparison circuit 28 sets H A determination signal is output. Based on the determination signal, the matching data storage circuit 29 stores pixel data (“DG (n-2)”) corresponding to the attribute data (“VG (n-2)”) in the storage area corresponding to the G element. Save to. This pixel data ("DG (n-2)") is the newly received G element pixel data (usually after 3 clocks) (usually after 3 clocks). Is replaced with "DG (n-1)").

  For example, when the attribute data (“VB (n−1)”) of the received read data is not equal to the value of the reference sequence (“VB”), an L determination signal is output from the comparison circuit 28. Is done. In this case, the matching data storage circuit 29 does not store the pixel data ("DB (n-1)") corresponding to the attribute data ("VB (n-1)"). The pixel data ("DB (n-2)") stored as the matching data is left as it is.

  A data selector 30 (an example of an adaptation unit) illustrated in FIG. 8 also serves as an interface to the image processing unit 21. The data selector 30 outputs one of the pixel data output from the latch / separation circuit 26 and the pixel data output from the matching data storage circuit 29 to the image processing unit 21 and outputs from the latch / separation circuit 26. One of the attribute data and the reference sequence value output from the reference sequence generation circuit 27 can be output to the image processing unit 21. The data selector 30 outputs the attribute data and pixel data output from the latch / separation circuit 26 to the image processing unit 21 when receiving a determination signal indicating that the read data is matching data from the comparison circuit 28. When the determination signal indicating that the read data is nonconforming data is received, the attribute data output from the reference sequence generation circuit 27 and the pixel data output from the conformance data storage circuit 29 are displayed in the image processing unit 21. Output to.

  In the above example, if the attribute data (“VG (n-2)”) of the received read data is equal to the reference sequence value (“VG”), the attribute data (“VG (n -2) ") and pixel data (" DG (n-2) ") corresponding to the attribute data (" VG (n-2) ") are output. If the attribute data (“VB (n−1)”) of the received read data is not equal to the reference sequence value (“VB”), the reference sequence value and the matching data storage circuit 29 are stored. The B element pixel data ("DB (n-2)"), that is, the adapted attribute data and pixel data are output.

  The nonconforming counter 31 counts the number of read data determined to be nonconforming data in each line based on the determination signal from the comparison circuit 28, and the second counter circuit 32 (an example of second determining means) ). The second comparison circuit 32 determines whether the count number is equal to or greater than a predetermined set value. Here, in the second comparison circuit 32, when the number of read data determined to be nonconforming data in one line is less than the set value, it is determined that the read data of that line is compatible, and the same read If the number of data is greater than or equal to the set value, it is determined that the read data for that line is incompatible. When it is determined that the read data of the line is incompatible, a nonconforming signal is output to a buffer counter 38, a write pointer 37 and a CPU 42 which will be described later.

  Note that the setting value used in the second comparison circuit 32 can be, for example, a value that is half the number of pixels in one line. In addition, when non-conforming read data is continuously generated in one line, it is more noticeable than when non-conforming read data is intermittently generated. The set value may be set to a value larger than that generated intermittently. As will be described later, since the read data of the line determined to be incompatible is discarded, the quality of the finally obtained image data can be ensured.

  FIG. 10 is a diagram showing the structure of the line buffer 34 of the image processing unit 21, and FIG. 11 is a timing chart showing the operation of the image processing unit 21.

  The image processing unit 21 includes a line buffer 34 (an example of a storage unit) for performing image processing, and a buffer control circuit 35 that controls reading and writing of data with respect to the line buffer 34. For example, as shown in FIG. 10, the line buffer 34 can store pixel data of 0x1000 pixels per line and 0x100 lines per color.

  The buffer control circuit 35 writes the pixel data output from the data selector 30 to the line (write area) indicated by the write pointer 37. The write pointer 37 is provided for each color of RGB, and when the read data is color, each time one pixel data is written, the writing position is moved to the line indicated by the corresponding light pointer 37 in the order of RGB. . After the writing of pixel data for one line is completed, when a line synchronization signal is received from a line synchronization generation circuit (not shown) provided in the ASIC 14, the counter that controls the write pointer 37 is counted up. Thus, the write pointer 37 indicates the start address of the next line (write area), and the next line can be prepared for writing.

  When the writing of pixel data for one line is completed, the buffer counter 38 indicating the number of lines that can be processed by two-dimensional image processing, which will be described later, is simultaneously incremented. When the buffer control circuit 35 determines that pixel data of the number of lines that can be processed is written to the line buffer 34 based on the value of the buffer counter 38, the buffer control circuit 35 reads the data of the line indicated by the read pointer 39 from the line buffer 34, The data is output to the two-dimensional image processing circuit 40. When the reading of data for one line is completed, the counter that controls the read pointer 39 is incremented, so that the read pointer 39 indicates the start address of the next line (reading area), and the next line can be read. . Along with this, the buffer counter 38 is decremented.

  As shown in FIG. 11, when the buffer counter 38 and the write pointer 37 receive a non-conformance signal indicating that the line is non-conforming from the second comparison circuit 32, the write timing of the line (line synchronization) At the timing synchronized with the signal), the buffer counter 38 is not incremented or the counter for controlling the write pointer 37 is not counted up. For this reason, image processing is not performed on the pixel data of the line determined to be incompatible, and the start address of the line (write area) indicated by the write pointer 37 is not updated. Subsequently, it is overwritten by the pixel data of the line input from the data receiving unit 20 side. Here, the data to be overwritten on the pixel data of the non-conforming line is pixel data obtained by re-reading the portion corresponding to the non-conforming line on the document by the reading sensor 16 as will be described later. As a result, image data without missing lines can be obtained.

  In addition, when a non-conforming line is generated, it may be configured not to re-read a portion corresponding to the non-conforming line. In that case, since the head address of the line indicated by the write pointer 37 is not updated as described above, the pixel data of the nonconforming line in the line buffer 34 is overwritten by the pixel data of the next line. For this reason, the obtained pixel data is lost in one line and compressed in the sub-scanning direction. However, in practice, non-conforming lines are not frequently generated, and two-dimensional image processing described later is used. Since the compressed line becomes inconspicuous, there is no practical problem.

  As described above, the two-dimensional image processing circuit 40 receives the pixel data of the line buffer 34 indicated by the read pointer 39 via the buffer control circuit 35, and uses the data as a two-dimensional image such as various correction processes and filter processes. Processing is performed, and the obtained image data is sequentially stored in a RAM (not shown) provided on the control board 12.

(Motor control)
On the ASIC 14, a CPU 42 (an example of movement control means, see FIG. 8) is provided, and the CPU 42 controls the motor 13 for moving the reading unit 10 relative to the document. FIG. 12 is a flowchart showing the contents of the interrupt process by the CPU 42, and FIG. 13 is a flowchart showing the contents of the motor control process by the CPU 42.

  The second comparison circuit 32 described above outputs a nonconforming signal as an interrupt signal to the CPU 42 when it is determined that the line is nonconforming. The PLL 24 described above outputs a nonconforming signal as an interrupt signal to the CPU 42 when the lock is released. The CPU 42 starts the interrupt processing shown in FIG. 12 when receiving the interrupt signal. If the interrupt signal is a nonconforming signal (S101: Yes), the value of the line invalid flag is set to “1”. (S102). This line invalid flag is provided on the RAM and is normally set to a value of “0”. If the interrupt signal is not a nonconforming signal (S101: No), processing corresponding to the interrupt signal is executed (S103).

  The CPU 42 starts the motor control process shown in FIG. 13 when instructed to read the document placed on the document placement unit 4. The CPU 42 first sets the value of the counter indicating the reading position (position of the reading sensor 16 relative to the document) provided on the RAM to 0 (corresponding to the reading start position), and starts driving the motor 13 (S201). As the motor 13 is driven, the reading sensor 16 moves from the home position (initial position) in the sub-scanning direction with respect to the document. The CPU 42 determines whether the reading sensor 16 has reached the reading start position (S202). When the reading sensor 16 has reached the reading start position (S202: Yes), the CPU 42 instructs the start of the data fetching operation (S203). Thus, the read data obtained by the reading unit 10 is sequentially transmitted to the control board 12 side, and the above-described image processing and the like are performed.

  Subsequently, the CPU 42 determines whether or not the end of one line has been reached (S204), and when it reaches the end (S204: Yes), it checks the value of the line invalid flag (S205). When the value of the line invalid flag is “0”, that is, when the reading data for one line received by the control board 12 is suitable, 1 is added to the value of the counter indicating the reading position ( S206). Subsequently, it is checked whether the reading sensor 16 has reached the reading end position (S207). If the reading sensor 16 has not reached the reading end position (S207: No), the process returns to S204. If the reading end position has been reached (S207: Yes), the motor 13 is instructed to return the reading sensor 16 to the home position (S208), and the motor control process ends.

  In S205, if the value of the line invalid flag is “1”, that is, if the read data for one line received by the control board 12 is incompatible, first, the value of the line invalid flag is set to “0”. ”(S209) to instruct the motor 13 to stop. Next, the motor 13 is instructed to return the reading sensor 16 to the re-reading position, that is, the position corresponding to the non-conforming line (the previous line) (S211), and then the reading sensor 16 is again read in the reading direction. The motor 13 is instructed to move to (S212), and the process returns to S204. As a result, the non-conforming line is read again.

(Effect of this embodiment)
As described above, according to the present embodiment, the attribute data included in the received read data is compared with the reference value, and when the read data is determined to be incompatible, the read data is adapted and output. Since the reception failure check is performed based on the attribute data, it is not necessary to add new check data to the read data. Therefore, it is possible to avoid an increase in the amount of communication data and to suppress the influence due to poor data reception.

  If the received read data is determined to be incompatible, the attribute data is replaced with a reference value. Thereby, it is possible to prevent an error from occurring in a process (image processing or the like) performed using the output read data.

  If the received read data is determined to be compatible, the pixel data is stored in the compatible data storage circuit 29. If the received read data is determined to be incompatible, the pixel data is stored in the compatible data storage circuit 29 and is determined to be compatible. Replace with the determined pixel data. As a result, a decrease in image quality can be reduced.

  If it is determined that the line is incompatible, the writing area of the line buffer 34 is not changed, so that the pixel data of the line is overwritten with the data of the next output line. Therefore, it is possible to prevent the image quality from being deteriorated due to the pixel data of the nonconforming line.

  If a non-conforming line is generated, the reading unit 10 or the original is moved to a position corresponding to the non-conforming line. Thereby, the non-conforming line is read again, so that it is possible to prevent the image quality from being deteriorated.

  The attribute data includes information indicating that the pixel data is the head of the line and color information of the pixel data (information indicating whether the pixel data is monochrome pixel data or RGB color). Yes. In this way, since reception failure is checked based on the attribute data added to the pixel data, it is not necessary to add new check data to the read data.

  Further, when color read data is transmitted and received, a reference value (reference sequence) of attribute data corresponding to each color is periodically generated based on the synchronization signal. Therefore, based on the color information of the attribute data, it can be accurately determined whether the read data is compatible or non-compatible.

<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 above-described embodiment, when a non-conforming line occurs when reading a document placed on the document placement portion, the reading unit 10 is moved to a reread position with respect to the document and is read again. However, according to the present invention, even when an incompatible line occurs when the document side is moved with respect to the reading sensor by ADF or the like, the document side is similarly moved to the re-reading position and again. It can be set as the structure which reads.

(2) In the above embodiment, when the read data is determined to be incompatible, the attribute data and the pixel data are both adapted. However, according to the present invention, only the attribute data is adapted. It is also possible to configure so that the data is output. Also by this, it is possible to prevent a problem in image processing or the like from occurring due to non-conforming read data.

(3) In the above embodiment, only the pixel data determined to be compatible is stored in the compatible data storage circuit. However, according to the present invention, for example, the storage unit includes non-conforming data for several lines. A configuration may be adopted in which data is stored, and only conforming data is selected and output at the time of output.
(4) In the above-described embodiment, an example in which the present invention is applied to a multifunction peripheral has been described. However, the present invention is not limited to an image reading apparatus provided with a printer function, a copy function, a facsimile function, or the like as long as it has a reading function. It can also be applied to.

1 is an external perspective view of a multifunction machine according to an embodiment of the present invention. External perspective view showing the state in which the document cover of the multifunction machine is raised Block diagram showing the configuration of the image reading system in the multifunction machine Diagram explaining the contents of monochrome read data The figure explaining the content of the reading data of color (RGB) Diagram explaining the contents of attribute data Diagram explaining the contents of attribute data Block diagram showing the configuration of the data receiving unit and the image processing unit Timing chart illustrating the contents of processing when the data receiving unit receives color read data The figure which shows the structure of the line buffer of an image processing part Timing chart showing operation of image processing unit A flowchart showing the contents of interrupt processing by the CPU Flow chart showing contents of motor control processing by CPU

1. Multifunction machine (image reading device)
11. Harness (transmission path)
12 ... Control board (control unit)
13. Motor (moving means)
16. Reading sensor (reading means)
18 ... A / D converter (transmission means)
19. Data transmission part (transmission means)
28. Comparison circuit (determination means)
29. Applicable data storage circuit (storage means)
30 ... Data selector (Adaptation means)
32. Second comparison circuit (second determination means)
34. Line buffer (storage means)
42 ... CPU (movement control means)

Claims (8)

In an image reading apparatus including a reading unit and a control unit connected to the reading unit via a transmission path ,
The reading unit is
Reading means for reading a document and obtaining pixel data;
Transmission means for transmitted to the pixel data read data added with the attribute data to take shows regularly values the attributes of the pixel data acquired by the reading unit to the control unit,
With
The controller is
Reference generation means for generating a reference value equal to the value of the attribute data given to the read data in the transmission means ;
The attribute data of the received read data is compared with the reference value, and when the attribute data is equal to the reference value, the read data is determined to be suitable, and when the attribute data is not equal, the read data is determined to be non-conforming Means,
Adaptation means for outputting the read data when the received read data is determined to be suitable by the determination means, and for adapting and outputting the read data when the read data is determined to be incompatible by the determination means When,
An image processing unit that performs image processing on the read data output by the adaptation unit;
An image reading apparatus comprising: The image reading apparatus according to claim 1,
It said matching means, the image and replaces when received read data is determined as irrelevant by the determining means, the reference value generated by the reference generation unit attribute data included in the read data Reader . The image reading apparatus according to claim 1 or 2,
Comprising storage means for storing pixel data of received read data;
The adaptation unit stores the pixel data of the read data in the storage unit when the read data received by the determination unit is determined to be compatible, and the read data received when the read data is determined to be incompatible. The pixel data is replaced with pixel data stored in the storage unit and determined to be suitable by the determination unit . The image reading apparatus according to any one of claims 1 to 3,
The reading means reads a document in line units,
Second determining means for determining whether the read data of each line is conforming or non-conforming based on the number of the read data determined by the determining means to be incompatible;
Storage means for storing pixel data of read data output from the adapting means by changing a writing area for each line, and
The image reading apparatus according to claim 1, wherein the storage means does not change a writing area corresponding to a line when the second determination means determines that the line is incompatible. The image reading apparatus according to claim 4.
Moving means for relatively moving the reading unit and the document in the sub-scanning direction;
Movement control means for controlling the operation of the movement means,
The image reading apparatus according to claim 1, wherein the movement control unit relatively moves the reading unit and the document to a position corresponding to the non-conforming line when the second determining unit determines that the line is non-conforming. In the image reading device according to any one of claims 1 to 5,
The image reading apparatus according to claim 1, wherein the attribute data includes information indicating whether the pixel data is a head of a line. The image reading apparatus according to any one of claims 1 to 6,
The image reading apparatus , wherein the attribute data includes color information of pixel data. The image reading apparatus according to claim 7.
The transmitting means sequentially transmits read data including pixel data of a plurality of colors and attribute data including color information of each pixel data to one pixel together with a synchronization signal,
The image reading apparatus , wherein the reference generation unit periodically generates a reference value of attribute data corresponding to each of the plurality of colors based on the synchronization signal.

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