JP2000244691A - Data transfer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data transfer technique for reducing a influence due to bit errors increasing according to the acceleration of a data transfer speed. SOLUTION: This data transfer device is provided with a digital imaging part 12 such as a scanner having a data segmentation circuit 42 for segmenting data into data strips and an error control encoding circuit 44 for calculating an error control code for each data strip, an image formatter 14 for receiving the data strip and the related error control code transferred from the digital imaging part 12, and an image forming part 16 such as a printer. The image formatter 14 compares the data strip with the related error control code by a comparator circuit 46, and identifies error data in each data strip. Moreover, the image formatter 14 compares adjacent data by an interpolating circuit 48, and interpolates a substitute value for the error data by pixel units based on the interpolation of the adjacent data for correcting the identified error data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transfer technique between components of a computer system. Related to transfer technology.

[0002]

2. Description of the Related Art Computer systems have a host in a plurality of devices connected together to provide functionality for users utilizing the computer system with increasing speed. In recent years, with the advance of technology, a multiple function peripheral device (M) having several devices in a single housing (housing) has been developed.
FP) has been devised. For example, some multiple function peripherals (MFPs) include an inkjet printer, scanner, facsimile, and copier in a single housing. Such multiple function peripherals are suitable for use in small offices and homes. And, regardless of whether such a plurality of devices are included in the housing of the multiple function peripheral device or connected together by a cable, the operation speed between these devices is improved, and the data between the devices is improved. It is desirable to minimize the effects of bit errors that occur during transfer.

[0003]

A bit error occurs, for example, when transmitting data from a scanner to a printer. Generally, since the data transfer rate between the scanner and the printer is relatively low, the bit error rate is, for example, 1 /
Very low, less than 100,000. On the other hand, the data transfer rate between the scanner and the printer formatter can be increased, but if the bit error rate must be maintained at an acceptable low level, the balance between the data transfer rate and the bit error rate will be lost. . Therefore, if accuracy must be maintained when transferring data, it is necessary to limit the data transfer rate. Therefore, a trade-off between data rate and accuracy must be made. However, low data rates can affect the print speed achievable by the printer formatter, and often require the use of complex and expensive techniques to ensure "accurate" data transfer. There was a problem.

An object of the present invention is to provide a data transfer technique capable of increasing the data transfer speed between a scanner and a printer, while reducing the influence of bit errors that increase due to the increase in the data transfer speed.

[0005] The present invention also provides an aggressive method.
It is an object of the present invention to provide a data transfer technology that enables high-speed printing by a printer by realizing a data transfer speed and reducing the influence caused by transferring erroneous data to an image formatter.

[0006]

A faster data transfer between a scanner and a printer is achieved by implementing an interpolation algorithm within the firmware / hardware of the image formatter of the printer and replacing the detected error data with replacement data using said interpolation. Is realized by reducing the influence of the bit error rate due to the replacement of.

According to one aspect of the present invention, a data transfer device includes a digital imaging unit for detecting an image. By connecting the data segmentation circuit of the device to the digital imaging section, data can be segmented into data strips. Also, by associating the error control coding circuit with the data segmentation circuit, an error control code can be calculated for each data strip. The image formatter is also configured to receive individual data strips and associated error control codes transferred from the digital imaging unit. Also, the comparator circuit is operable to identify the error data present in each transferred data strip by comparing the data strip transferred to the image formatter with an associated error control code by associating the data strip with the associated error control code. Further, the identified error data can be corrected by associating an interpolation circuit with the image formatter, comparing adjacent data, and interpolating a replacement value for the error data in pixel units based on the interpolation of the adjacent data.

According to another aspect of the present invention, a scanner / printer combination device includes a scanner having a data segmentation circuit and an error control code circuit. The scanner can detect the image, the data segmentation circuit can segment the data into data strips, and the error control code circuit can calculate an error control code for each data strip. Also, the scanner / printer combination device has a printer. The printer has an image formatter configured to receive individual data strips and associated error control codes transferred from the digital imaging section. The printer also has a comparator associated with the image formatter to compare the transferred data strip with an associated error control code,
Error data present in each transfer data strip can be identified. In addition, the printer has an interpolator associated with the image formatter and compares the adjacent data and identifies the pixel by interpolating a replacement value for error data on a pixel-by-pixel basis based on the interpolation of the adjacent data. Erroneous data can be corrected.

Further, according to another aspect of the present invention, there is disclosed a data transfer technique for increasing the data transfer speed between a scanner and a printer formatter and reducing the effects of increased bit errors. The technique involves parsing a scanned bitmap array into a plurality of data strips.
Each data strip has a plurality of data pixels. The technology also includes calculating an error control code for each data strip. Further, the technique includes transferring each data strip and associated calculated error control code from the scanner to a printer formatter. In addition, the present technology may be used to determine whether a transferred data strip is erroneous.
Comparing each transmitted data strip with an associated error control code. The technique also includes interpolating, on a pixel-by-pixel basis, replacement values for data pixels in the identified erroneous data strip based on interpolation of data values proximate to each data pixel. Further, the technique includes replacing the data pixels in the erroneous data strip with a replacement value if the value of the erroneous data pixel exceeds a threshold.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing a multiple function peripheral device (MFP) 10 according to an embodiment of the present invention. The multiple function peripheral (MFP) 10 is shown as a scanner / printer combination unit having a digital imaging unit 12, an image formatter 14, and an image forming unit 16. According to one embodiment, as shown in FIG. 2, the digital imaging unit 12 includes a digital scanner (hereinafter, simply referred to as a scanner), and the image forming unit 16 includes a printer.

As shown in FIG. 2, the digital imaging section 12 has a scanner. Further, the digital imaging unit 12 is realized by two general types of scanners,
That is, it can be formed by one of a contact image sensor (CIS) and a charge-coupled device (CCD). Such scanners can be contact image sensors (CIS) or charge coupled devices (CCD)
Regardless of which method is used, an image is generated using a linear array in which sensor elements are arranged two-dimensionally. Further, the digital imaging unit 12 can generate an image using an area array in which sensor elements are arranged three-dimensionally. For example, some handy-type video cameras and digital cameras use an area array to generate an image. The digital imaging unit 12
Regardless of whether the image is generated by a linear array or an area array, the image can be formed by any of the devices described above.

Further, a multiple function peripheral device (MFP) 10 provides a data transfer device according to the present invention, which can facilitate high-speed data transfer between a digital imaging unit 12 and an image formatter 14. However, while data transfer can be achieved at higher speeds, the bit error rate generally increases. The increase in bit error rate is reduced by providing an algorithm to the image formatter 14 firmware / hardware that allows interpolation for the recognized "error bits" and replaces the erroneous data bits with replacement data bits. You. Thus, high-speed transfer of scan data tends to cause bit errors, which are corrected by performing the interpolation described below with reference to FIG.

The digital imaging section 12 has a control circuit 18 and a motor control section 20. Control circuit 18
Are implemented as dedicated microprocessors.
Alternatively, the control circuit 18 can be realized by an electronic circuit. Further, the motor control unit 20 includes a control circuit 18
The digital imaging unit 12 is configured to control the operation of a drive motor (not shown) provided to enable scanning of documents / paper.

The image formatter 14 includes a control circuit 2
2 In one embodiment, control circuit 22 includes In
It is implemented as a microprocessor such as the Tel 1960 or Motorola 68000. In another embodiment, the control circuit 22 can be realized by an electronic circuit. The image formatter 14 includes a printer formatter that can be used with a laser electrophotographic unit or a printing unit.

The image forming section 16 has a print engine 24 and a print controller 26. If the image forming unit 16 includes a document printer such as a laser printer, the print engine 24 actually affixes the image to the print medium, ie, fixes or fuses one or more toner components to the print medium. Thus, an apparatus for generating an image is formed. Similarly, print controller 26 supports electronic controls for the print engine and provides an interface to the print engine. If the image forming unit 16 is a laser printer, the print controller 26 adjusts the laser for photoconductor exposure, relative bias voltage and fuser temperature (fuser temperature).
temperatures).

In operation, the digital imaging unit 12
Capture an image as a scan bitmap array. Such a scan bitmap array is divided into data segments, and before being transferred to the image formatter 14, a Cyclic Redundancy Code (C).
RC) or the like. (This is described in more detail below with reference to FIG. 2.) Next, the image formatter 14 compares the transferred data segment with an associated cyclic redundancy code (CRC), It is determined whether (CRC) matches the transferred data strip. If a mismatch is determined here, the data strip is determined to be incorrect or corrupted. If defined, the data contained in the erroneous data strip is modified by interpolating the data in the data strip with adjacent related data. For example, data immediately above and below one particular piece of data is replaced by performing linear interpolation on a bit-by-bit basis, filling in data values for data between them that is erroneous or corrupted.

FIG. 2 is a block diagram showing the configuration and operation of the data transfer device embodied as the multiple function peripheral device 10 of FIG. 1 in more detail. First, the digital imaging unit 12 includes a control circuit 1 operable to implement the functionality and features of a standard scanner.
8 is shown in the form of a scanner. The control circuit 18 is realized as a scanner circuit on a scanner print wiring (PC) board (not shown) for converting an analog signal into a digital signal. Further, the control circuit 18
It includes a data segmentation circuit 42 and an error control coding circuit 44 shown as a cyclic redundancy coding circuit 45.

The data segmentation circuit 42
Before transferring the continuous data stream generated by the scanner 12 to the image formatter 14,
It is used to subdivide into appropriately sized blocks called data strips 56 (see FIG. 3). For example, one suitable data strip may contain one of the sequential data
Includes 1 inch strips of pixel width. It should be noted that other lengths and widths are possible for the data strip 56.

Data transfer from the scanner 12 to the image formatter 14 in a 1 inch × 1 pixel data strip is performed at 300 pixels / inch and 8 bits / pixel. Such a data transfer represents 300 bytes, or 2,400 bits. The 16-bit Cyclic Redundancy Code (CRC) is accumulated in the data strip data and transferred with the associated data strip.

The cyclic redundancy coding circuit 45 is used to calculate a cyclic redundancy code (CRC) for each data strip. Each data strip and the associated cyclic redundancy code (CRC) is then forwarded to the image formatter 14. Thus, the associated Cyclic Redundancy Code (CRC) is compared with the individual bits of the data contained in the data strip to determine if the transferred data is incorrect. For example, if the cyclic redundancy code (CRC) transferred with the data strip does not match the transferred data (within the data strip),
The data strip is marked as erroneous. FIG. 3 shows an example of a data strip.
Will be described later.

As shown in FIG. 2, the error control encoding circuit 4
4 includes a cyclic redundancy coding circuit 45. Error control coding circuit 44 includes an error control code (CRC) implemented by electronic circuits such as a memory, a processor, and / or a controller. One suitable error control coding circuit 44 comprises a cyclic redundancy coding circuit 45. However, any of a number of data protection devices and / or algorithms, such as data protection circuits and / or error control coding circuits, can be utilized in accordance with the present invention. For example, a linear block code, a Hamming code, a convolutional code, a Reed-Solomon code (such as a BCH code), and a cyclic code can be used to implement an error control coding circuit according to the present invention.

In one embodiment, the cyclic redundancy coding circuit 45 is a linear block code having an algebraic structure capable of realizing coding by a linear feedback shift register and realizing decoding without a look-up table. It is. Such families of redundant codes can detect data errors very efficiently and are often used with data recording and data transfer systems.

Further, the data strip is transferred and compared with an associated cyclic redundancy code (CRC) to determine if the transferred data is erroneous. The counter 66 is connected to the control circuit (microprocessor) 22 and counts the number of erroneous strips detected in a particular scan bitmap array (representing the document pages to be printed). This number is stored in the memory of the microprocessor 22. If the number of detected error data strips per document page exceeds a predetermined value, a warning is issued from the output unit 68. According to one embodiment, output 68 forwards the alert message to a printer operating system (not shown) for image forming unit 16. For example, the image forming unit 16 includes a printer having a light that visually notifies a user when a defective print job exceeds a predetermined value.

The image formatter 14 is a microprocessor 2 programmed by firmware 30 such as a dynamic random access memory (DRAM) 34 and a read only memory (ROM) 36.
2 The strip output buffer 38 is a DRAM
34, and stores the transmitted data strip and the associated cyclic redundancy code (CRC). The instruction code 40 is used as an interpolation circuit 48 in the formatter board 28.
As in the interpolation algorithm (48) implemented above, R
Stored in the OM 36. In this manner, control codes or programming instructions are stored and instruct the microprocessor 22 to receive and store the transferred data strip and to interpolate replacement data values for erroneous data bits.

The control circuit 22 of the image formatter 14 has a comparison circuit 46. The comparison circuit 46 is used to compare the transferred data strip and the associated cyclic redundancy code (CRC) to determine whether the data strip is corrupt or contains erroneous data. Essentially, a data strip contains a message polynomial and a cyclic redundancy code (CRC) contains a codeword polynomial. In a systematic form, the message and codeword polynomials have forms in which multiplication and division can be easily implemented via shift registers. As a result, decoding is performed on the word (the
word) is a multiple of the generator polynomial. By simply obtaining the remainder by division using the generator polynomial, it is possible to determine whether or not an error pattern has occurred. Details of cyclic redundancy codes (or checks) are well known in the art and are described in “The Mobile Communications Handbook” (Gibso
n, Jerry D., CRC Press 1996 (pp. 139-141)), which is incorporated by reference.

FIG. 3 shows, in a simplified representation, a document page 50 constituted by a scan bitmap array 52 of data having a data scan line 54 containing the correct cyclic redundancy code (CRC) that has been checked. In addition, an erroneous, that is, defective cyclic redundancy code (C
A data strip 56 with (RC) is also shown in FIG. The data scan line located after the mismatched cyclic redundancy code (CRC) detected in data strip 56 is also identified by reference numeral 58. Also, the data pixels 64 selected to be corrected located within the corrupted data strip 56 are circled in FIG. Further, adjacent data pixels are:
The “upper pixel” 60 and the “lower pixel” 62 are circled.

In this specification, "data pixel" represents a pixel. In image processing, a pixel refers to the smallest element of a digital image that can be assigned a gray level. Also, in computer graphics, a pixel refers to the smallest element of the display surface to which independent features can be assigned. If a data pixel is used to represent grayscale, the data pixel can take on values ranging from 0 to 256. Here, 8 bits are used to represent each pixel. If a pixel is simply represented as having only binary values, one data pixel includes one data bit. Thus, a pixel consists of the smallest elements that can be resolved by the image formatter and image former. Further, when data is transmitted, there is a possibility that the bits constituting the data pixel are transmitted erroneously. Therefore, to determine the error transfer of a data pixel, it is necessary to evaluate the error transfer of the associated data bit.

Good data is transferred to the data scan line 58.
Data strip 5 if it appears to have been transferred
An attempt is made to correct the bad data located at 6. In one embodiment, data pixels 6 of data strip 56
If upper, lower, and / or horizontal data bits 4 are the same or within a threshold, data pixel 64 may be set to the average of surrounding data pixels. In yet another embodiment, data pixel 64 may be set to an interpolated value based on a value calculated for a detected neighboring data pixel. Any of a number of interpolation or averaging techniques can be used to correct bad values for data pixels 64 based on the data values of neighboring data pixels. Further, it is possible to look for patterns that occur in the scan bitmap array 52 through the data pixels 64. For example, pattern recognition techniques can be used to identify whether a narrow line passes through the data pixels 64 and explains the identified bad data present therein.

According to the apparatus shown in FIG. 2 and the document page 50 of FIG. 3, in one embodiment, by examining the values of the data pixels 60 and 62 that are vertically above and below the damaged data pixel 64, respectively. , The wrong data strip 56 can be corrected. A linear interpolation is performed between the data pixels 60 and 62 to determine a predicted value for the corrupted data pixel 64. Such calculations are performed on a pixel-by-pixel basis within each corrupted data strip 56 in array 52.

If the value of the erroneous data pixel 64 is determined to be within the "small threshold" of the interpolated value, then when printing the document page 50,
Corrupted values of the data can be used. If it is determined that the value of the erroneous data pixel 64 is outside the “small threshold” of the interpolated value, the value of the interpolated data can be replaced with the erroneous value of the data pixel 64. . Since each data scan line 54 represents only a very small vertical area that can be seen by a human observer, such interpolation will result in incorrect data strip 56
Effectively masks apparent erroneous data transfers at individual data pixels 64 within.

If data errors continue to be detected in the data strip located at the data scan line 58, the firmware 30 indicates that a fatal scan condition exists.
(See FIG. 2). In one embodiment,
Firmware 30 may be reset to rescan the document and start over. In another embodiment, an error message may be sent out via the output unit 68 (see FIG. 2).

According to various possible embodiments according to the embodiment shown in FIG. 2, a finite state machine
error correction coding circuit 44 of the scanner 12 that adjusts the light intensity, corrects the printable light source, illuminates the document, and captures or reuses reflected light.
Can be formed. In one embodiment, the scanner 12
Is implemented as a grayscale digital imaging unit. In another implementation, the scanner 12 is implemented as a color digital imaging unit.

According to various embodiments of the present invention, there is provided an image formatter 14 shown in FIG.
Control circuit 22 that can be realized by a microprocessor
Is operable to receive data, drive an associated printer motor, and notify a user when the printer is out of paper.

According to another embodiment of the present invention, the digital imaging unit (scanner) 12 and the image forming unit (printer) 16 (see FIG. 2) are both connected to a host computer such as a laptop computer. Can be connected separately. Thus, using the hard drive of the host computer, the scan data is transferred to the printer formatter of the printer. Such a device may require an expensive parallel cable connection capable of realizing data transfer eight times faster than a general serial port connection. However, implementing the techniques of the present invention improves data transfer rates and improves quality because a low cost serial cable connector assembly between the printer, scanner and host computer can be utilized. Therefore, data transfer can be performed at higher speed and at lower cost.

Further, an error in data transfer is caused by electromagnetic interference,
Due to noise in cables and connectors, and the occurrence of electrostatic discharge and other related noise derivation phenomena,
It is known to occur during data transmission between components of a computer system. Further, in the related art, data of a continuous strip is transferred or dumped in advance until the entire document page is transferred.
However, in accordance with an embodiment of the present invention, a continuous stream of data is transferred in data strips, and each data strip is checked to ensure that transmission errors do not occur.

Further, the interpolation circuit 48 (see FIG. 2) can be realized by artificial intelligence. In one embodiment, a conventional single layer feedback neural network can be utilized. In other embodiments, fuzzy logic implementations can be utilized. One specific area (one specific are)
In a), the ability to identify relevant topologies or configurations that reveal particular values of erroneous data pixels 64 in data strip 56 (see FIG. 3) is required. Further, one technique for realizing this can be realized in a finite state machine by hard code.

Therefore, with the device according to the above-described embodiment, data can be corrected, and the speed of data transfer between the scanner and the image formatter can be further increased. Therefore, a higher printing speed can be realized by an image forming unit such as a printer. At the same time, this implementation in hardware and software allows the use of inexpensive hardware cables and drivers and receiver circuits, while tending to increase data transmission errors.

The present invention has been described in somewhat specific terms with regard to structural and methodical features. However,
The invention is not limited to the specific features shown and described, since the means described constitute a preferred mode of carrying out the invention. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents.

The embodiments of the present invention will be summarized below. 1. Digital imaging unit (1
2) and a data segmentation circuit (4) connected to said digital imaging section (12) and operable to segment data into data strips (56).
2) and associated with said data segmentation circuit (42), for each data strip (56):
An error control encoding circuit (44) operable to calculate an error control code; and the digital imaging unit (12).
And an image formatter (14) configured to receive the individual data strips (56) and associated error control codes transferred from the image formatter (14) and the transferred data strips (56) associated with the image formatter (14). ) With the associated error control code to identify error data (64) present in each transmitted data strip (56); and a comparison circuit (46) operable to identify the error data (64). The adjacent data (6) associated with (14)
0, 62) and the adjacent data (60, 62).
An interpolation circuit (48) operable to correct the identified error data (64) by interpolating a replacement value for the error data (64) in pixel units based on the interpolation of (62). Data transfer device.

2. The interpolator (48) compares the replacement value with a small threshold, and when the replacement value is within the small threshold, the identified error data (64) is converted by the image formatter (14) into an image forming unit. (16)
2. The data transfer device according to claim 1, which is used for generating an image via a computer.

3. The error control coding circuit (44)
The data transfer device of claim 1, further comprising a cyclic redundancy coding (CRC) circuit (45) operable to calculate a cyclic redundancy code (CRC) for each data strip (56).

4. The digital imaging unit (12)
Has a scanner, said image formatter (14)
2. The data transfer device according to claim 1, further comprising a printer formatter of the printer.

5. The image formatter (14) has a control circuit (22), and the data transfer device is connected to the control circuit (22) and is operable to detect a number of transferred error data strips (56). 2. The data transfer device according to the above 1, further comprising a counter (66).

6. The data transfer device of claim 5, further comprising an output unit (68) connected to the control circuit (22) and operable to provide a warning before the image forming unit (16) generates an image.

7. Improving data transfer between the scanner (12) and the printer formatter (14),
Parsing the scan bitmap array (52) into a plurality of data strips (56) each having a plurality of data pixels (64), the method comprising: Calculating an error control code for each data strip (56), transferring each data strip (56) and the associated calculated error control code from the scanner (12) to the printer formatter (14); The transferred data strip (5
Comparing each transferred data strip (56) and associated error control code to determine if 6) is in error; and determining whether each data pixel (6) is in error.
4) interpolating, on a pixel-by-pixel basis, replacement values for the data pixels (64) in the identified erroneous data strip (56), based on interpolation of data values proximate to 4); The error data strip (56) if the value of
Replacing the data pixel (64) in the data with the replacement value.

8. The data transfer method according to claim 7, further comprising the step of counting the number of erroneous data strips (56).

9. The number of counted error data strips (56) is compared with a small threshold, and when the number exceeds the small threshold, the error data (6) in the data strip (56) is compared.
8. The data transfer method according to the above 7, further comprising the step of: replacing 4) with the interpolation data.

10. The method of claim 7, wherein the step of interpolating comprises averaging data values for at least two data pixels (60, 62) proximate to data pixels (64) present in the identified erroneous data strip (56). Data transfer method.

[0049]

As described above, according to the present invention,
Since the error data can be corrected, the data transfer speed between the scanner and the image formatter can be increased. Therefore, a higher printing speed can be realized by an image forming unit such as a printer.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a multiple function peripheral device (MFP) according to an embodiment of the present invention.

FIG. 2 is a block diagram showing the configuration and operation of a data transfer device embodied as the multiple function peripheral device of FIG. 1 in more detail;

FIG. 3 is an explanatory diagram schematically showing a document page configured by a scan bitmap array of data having data scan lines.

[Explanation of symbols]

 12 Digital Imaging Unit (Scanner) 14 Image Formatter 16 Image Forming Unit (Printer) 22 Control Circuit (Microprocessor) 42 Data Segmentation Circuit 44 Error Control Coding Circuit 45 Cyclic Redundancy Coding Circuit 46 Comparison Circuit 48 Interpolation Circuit 56 Data Strip 60 , 62, 64 data pixels 66 counter 68 output section

Claims (1)

[Claims] A digital imaging unit (12) for detecting an image; a data segmentation circuit (42) connected to the digital imaging unit (12) and operable to segment data into data strips (56). An error control encoding circuit (4) associated with the data segmentation circuit (42) and operable to calculate an error control code for each data strip (56).
4) an image formatter (14) configured to receive individual data strips (56) and associated error control codes transferred from the digital imaging unit (12); and Operable to identify error data (64) present in each transferred data strip (56) by comparing the associated transferred data strip (56) with the associated error control code. Comparison circuit (46)
And the pixel-by-pixel error data (64) associated with the image formatter (14) and based on comparison of adjacent data (60,62) and interpolation of the adjacent data (60,62). A data transfer device comprising: an interpolation circuit (48) operable to correct the identified error data (64) by interpolation of a replacement value.