JP4618139B2 - Image reading apparatus and method for adjusting color position of color counter in image reading apparatus - Google Patents

Description

  The present invention relates to an image reading apparatus having a sensor substrate on which an image sensor is mounted and a main substrate for performing image processing, and more particularly to color position adjustment of color counters on the sensor substrate side and the main substrate side.

  An image reading apparatus typified by a scanner device has a flat table-like document table on the top, and a flat bed that reads data by operating the reading mechanism with the document placed on the document table. The method is common and widely used.

  The flat-bed type image reading apparatus includes a one-dimensional (main scanning direction) imaging device (image sensor) as a reading mechanism, and moves the sensor substrate on which the imaging device is mounted in the sub-scanning direction with respect to the document. Two-dimensional image information is acquired by reading the reflected light from.

  In addition, the image reading apparatus includes a main board that controls reading processing, image processing, and the like. The sensor board and the main board are connected by a flat cable, and transmit and receive a clock, read data, and the like.

  FIG. 7 is a block diagram showing a configuration of a conventional image reading apparatus. As shown in the figure, the image reading apparatus includes a main board 120, a sensor board 130, and a drive mechanism 160 that drives the sensor board 130 in the sub-scanning direction.

  The main board 120 has a drive control circuit 121 that controls the drive mechanism 160, M: a timing adjustment circuit 122 that outputs an image reading start signal for each line, a period for each color (RGB) of the read image data. For the ADCK shown, M: a color counter 123 for aligning the RGB colors, a sampling circuit 124 for sampling the read image data, an image processing circuit 125 for performing image processing, and a CPU 126 for controlling various processes in the image reading apparatus. Is provided.

  The sensor substrate 130 includes an image sensor 131 configured by a CCD or the like, an A / D conversion circuit 132, and a TG (Timing Generator) unit 133.

  The TG unit 133 includes a clock generation circuit 134 that generates a clock for operating the image sensor 131 and the like, a sensor control circuit 135 that controls reading processing of the image sensor 131, and a TGCK sent from the main board 120, on the sensor board side TG: adjusting the color position of the color counter 137: a timing adjusting circuit 136, and a sensor substrate side color counter TG: color counter 137.

  The main board 120 and the sensor board 130 are connected by a flat cable, and the above-described TGCK signal, ADCK signal, data signal, and control signal are exchanged via the flat cable.

  FIG. 8 is a timing chart showing the relationship between the ADCK signal, the TGCK signal, and the color counter in the main board 120 and the TG unit 133 of the sensor board 130.

  In the initial state, the TG unit 133 of the sensor substrate 130 outputs ADCK, which is a clock indicating a color cycle, to the main substrate side, and repeatedly counts RGB with a TG: color counter 137 synchronized with ADCK. Since one pixel is composed of “R”, “G”, and “B”, one pixel is represented by three clocks of ADCK. That is, a pixel counter (not shown) is incremented by 1 with 3 clocks of ADCK.

  In addition, in the main board 120, RGB is repeatedly counted by the M: color counter 123 in synchronization with the ADCK received from the sensor board 130.

  Since both color counters count independently, in the initial state, the RGB position is shifted.

  In order to accurately read the image data acquired on the sensor substrate 130 side on the main substrate side, it is necessary to synchronize the start portion of each pixel. For this reason, the positions of “R”, “G”, and “B” of each color counter must be present.

  In order to correct this color counter displacement, conventionally, the color position of the TG: color counter 137 on the sensor substrate side is adjusted using TGCK which is an image reading start signal output from the main substrate 120. Yes.

  That is, in the example of this figure, the M: timing adjustment circuit 122 of the main board 120 outputs the TGCK signal to the TG: timing adjustment circuit 136 at a timing when the M: color counter 123 indicates “R”.

  Upon receiving the TGCK signal, the TG: timing adjustment circuit 136 on the sensor board side adjusts the TG: color counter 137 to “G” that is the next count of “R” in the next ADCK. As a result, the color positions of the color counter 123 on the main board side and the color counter 137 on the sensor board side are synchronized. Then, the line reading process is started in a state where the color positions of both color counters are present.

  In order to match the color position of the TG: color counter 137 on the sensor side to the color position of the M: color counter 123 on the main board side by the TGCK signal, the edge of the TGCK is transferred to the sensor board 130 during one ADCK cycle. Have to communicate. This is because the M: color counter 123 advances the count for each ADCK.

  However, when the edge of TGCK is blunted to reduce unnecessary radiation noise, or when the cycle of ADCK is increased to improve the image data transfer speed, the edge of TGCK is transmitted in one cycle of ADCK. There is a problem that is difficult.

  SUMMARY OF THE INVENTION An object of the present invention is to ensure that the color positions of a color counter on a sensor board and a color counter on a main board can be aligned.

In order to solve the above problems, an image reading apparatus according to a first aspect of the present invention includes:
An image reading apparatus including a sensor substrate including a line sensor that reads pixels composed of a plurality of color signals in units of lines, and a main substrate that performs image processing on the read pixel group,
The sensor substrate is
Color signal clock generation means for generating a clock in units of color signals;
Sensor color counting means for counting the color position of the color signal clock;
Image pattern output means for outputting a predetermined image pattern signal,
The main board is
Main color counting means for counting the color position of the input color signal clock;
And a color position adjusting unit configured to input the image pattern signal and adjust a color position of the main color counting unit based on a color position specified by the image pattern.

  According to the present invention, since the color alignment is performed based on the image pattern without using the TGCK signal for color alignment, the color counter on the sensor substrate side and the color counter on the main substrate side regardless of the shape of the TGCK signal. It is possible to reliably perform the color alignment.

  Here, the color position adjusting means may adjust the color position prior to the start of image reading by the line sensor, or may adjust the color position every time the line sensor reads an image. May be performed.

  In the latter case, the image pattern output means further increases the degree of freedom of the line reading start signal (TGCK) by outputting the predetermined image pattern signal in response to a line reading start instruction signal sent from the sensor substrate. be able to.

The predetermined image pattern signal is
Only a specific color signal can be an image pattern signal having a value.

In order to solve the above problem, a color position adjustment method in the image reading apparatus according to the second aspect of the present invention is as follows:
A line sensor that reads pixels composed of a plurality of color signals in units of lines, a color signal clock generation unit that generates a clock in units of color signals, and a sensor color count unit that counts the color positions of the color signal clocks A sensor substrate;
A color position adjustment method in an image reading apparatus having a main substrate provided with a main color counting means for counting the color position of an input color signal clock,
Outputting a predetermined image pattern signal from the sensor substrate;
The main board includes the step of inputting the image pattern signal and adjusting the color position of the main color counting means based on the color position specified by the image pattern.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing the configuration of the image reading apparatus according to the first embodiment of the present invention.

  As shown in the figure, the image reading apparatus includes a main board 20, a sensor board 30, and a drive mechanism 60 that drives the sensor board 30 in the sub-scanning direction.

  The main board 20 has a drive control circuit 21 for controlling the drive mechanism 60, M: a timing adjustment circuit 22 for outputting TGCK as an image reading start signal for each line, and a cycle for each color (RGB) of the read image data. For the ADCK shown, M: a color counter 23 for aligning RGB colors, a sampling circuit 24 for sampling the read image data, an image processing circuit 25 for performing image processing, and a CPU 26 for controlling various processes in the image reading apparatus. , M: a color counter position adjustment circuit 27 for adjusting the color position of the color counter 23 and a mode register 28 are provided.

  In the mode register 28, the CPU 26 records information indicating whether or not the mode is the color position adjustment mode of the M: color counter 23.

  The sensor substrate 30 includes an image sensor 31 configured by a CCD or the like, an A / D conversion circuit 32, and a TG (Timing Generator) unit 33.

  In the present embodiment, since one pixel is constituted by “R”, “G”, and “B”, one pixel is represented by three clocks of ADCK. However, the present invention is not limited to an image processing apparatus that expresses one pixel with three colors of RGB, and can be applied to an image reading apparatus that expresses one pixel with a plurality of signals.

  The TG unit 33 includes a clock generation circuit 34 that generates a clock for operating the image sensor 31, a sensor control circuit 35 that controls a reading process of the image sensor 31, and an image reading start timing based on TGCK sent from the main board 20. TG: timing adjustment circuit 36, sensor substrate side color counter TG: color counter 37, mode register 38, image pattern output circuit 39 for outputting a predetermined image pattern, and switching circuit 41 are provided.

  An ADCK signal indicating a period for each color is generated by the TG unit 33 and sent to the main board 20.

  Similarly to the mode register 28, the CPU 26 records information on whether or not the mode is the color position adjustment mode of the M: color counter 23.

  When the mode register 38 indicates that the adjustment mode is in the adjustment mode, the switching circuit 41 outputs the predetermined image pattern output from the image pattern output circuit 39 to the main board side, and the mode register 38 is in the adjustment mode. If not, the image data read by the image sensor 31 is output to the main board side.

  Here, the predetermined image pattern output from the image pattern output circuit 39 is image data that can identify the position of a specific color in the read image data. As such image data, for example, an image having a value for only one specific color for each pixel and having no value for the other two colors can be used. That is, the image data is any one of “R”, “G”, and “B”.

  In the present embodiment, it is assumed that image data indicating red in which R (red) is 255 and G (green) and B (blue) are 0 is used as an image pattern. Of course, an image in which values other than R are given values may be used as the image pattern. In addition, since it is sufficient if the position of a specific color can be identified, the image may not necessarily be one of “R”, “G”, and “B”.

  The main board 120 and the sensor board 130 are connected by a flat cable, and the above-described TGCK signal, ADCK signal, data signal, and control signal are exchanged via the flat cable.

  FIG. 2 is a timing chart showing the relationship between the ADCK signal, the TGCK signal, the image data, and the color counter in the main board 20 and the TG unit 33 of the sensor board 30.

  In the initial state, the TG unit 33 of the sensor substrate 30 outputs ADCK, which is a clock indicating a color cycle, to the main substrate side, and repeatedly counts RGB with a TG: color counter 37 synchronized with ADCK. At this time, the image data from the image sensor 31 is output from the switching circuit 41. However, since it is before the reading process, it may not be output.

  In the main board 20, RGB is repeatedly counted by the M: color counter 23 in synchronization with the ADCK received from the sensor board 30.

  Since both color counters count independently, in the initial state, the RGB position is shifted.

  In order to correct this shift, in this embodiment, a color position adjustment mode is provided. In the color position adjustment mode, in order to adjust the color position of the M: color counter 23 on the main board side, the switching circuit 41 of the sensor board 30 outputs a predetermined image pattern as a data signal to the main board 20.

  This image pattern is an image pattern having a value only for R as described above. For this reason, as shown in this figure, when the TG: color counter 37 of the sensor substrate 30 indicates “R”, it is output in synchronization with ADCK.

  The color counter position adjustment circuit 27 of the main board 20 adjusts the color position of the M: color counter 23 so that ADCK corresponding to the color data having the value of the received image data becomes “R”. As a result, the color positions of the TG: color counter 37 on the sensor substrate 30 and the M: color counter 23 on the main substrate 20 are matched.

  This color position adjustment process is performed before the start of the reading process, for example. Then, a line reading process is started by outputting a TGCK signal from the main board 20 in a state where there is a color position.

  As described above, since the TGCK signal is not used for color alignment, it is sufficient to transmit the TGCK to the main substrate side not at the color cycle but at the pixel cycle (color cycle 3 clocks). Therefore, the edge of TGCK can be blunted to reduce unnecessary radiation noise, and the frequency of ADCK can be increased to improve the data transfer speed.

  FIG. 3 is a flowchart for explaining the flow of the color position adjustment process. In this drawing, for the sake of simplicity, preprocessing such as white reference reading processing performed at the time of image reading, transfer processing of read image data, and the like are omitted.

  The color position adjustment process is performed prior to the image reading process, for example, every time an image reading start instruction is received from the user (S101).

  In the color position adjustment process, the CPU 26 writes information indicating the adjustment mode in the mode register 28 and the mode register 38, thereby shifting to the adjustment mode (S102).

  When shifting to the adjustment mode, the switching circuit 41 of the sensor substrate 30 outputs predetermined image data output from the pattern output circuit 39 to the main substrate 20 (S103).

  The color counter position adjustment circuit 27 compares the sent image data with the M: color counter 23 and determines whether the color position of the M: color counter 23 matches the color position of the TG: color counter 37 on the sensor side. Is determined (S104).

  Since the transmitted image data has only R value, it can be easily determined whether the color position of the M: color counter 23 matches the color position of the TG: color counter 37.

  As a result, if the color position is shifted, M: adjusts the color position of the color counter 23 (S105). As a result, the color position of the M: color counter 23 matches the color position of the TG: color counter 37 on the sensor side.

  After the color position is adjusted, or after a predetermined time has elapsed, the CPU 26 writes information indicating that the adjustment mode has ended in the mode register 28 and the mode register 38, thereby terminating the output of the image pattern (S106). The mode is released (S107).

  Next, the main board 20 outputs TGCK which is an image reading start signal (S108), and image reading processing is started (S109).

  Next, a second embodiment of the present invention will be described.

  FIG. 4 is a block diagram showing the configuration of the image reading apparatus according to the second embodiment of the present invention. In addition, the same code | symbol is attached | subjected about the same structure as 1st Embodiment.

  As shown in the figure, the image reading apparatus includes a main board 20, a sensor board 30, and a drive mechanism 60 that drives the sensor board 30 in the sub-scanning direction.

  The main board 20 has a drive control circuit 21 for controlling the drive mechanism 60, M: a timing adjustment circuit 22 for outputting TGCK as an image reading start signal for each line, and a cycle for each color (RGB) of the read image data. For the ADCK shown, M: a color counter 23 for aligning RGB colors, a sampling circuit 24 for sampling the read image data, an image processing circuit 25 for performing image processing, and a CPU 26 for controlling various processes in the image reading apparatus. , M: a color counter position adjustment circuit 27 for adjusting the alignment of the color counter 23 and a switching control circuit 29 are provided.

  The switching control circuit 29 instructs the color counter position adjustment circuit 27 to adjust the color position of the M: color counter 23 before line reading.

  The sensor substrate 30 includes an image sensor 31 configured by a CCD or the like, an A / D conversion circuit 32, and a TG (Timing Generator) unit 33.

  The TG unit 33 generates a clock generation circuit 34 that generates a clock for operating the image sensor 31, a sensor control circuit 35 that controls a reading process of the image sensor 31, and an image reading start timing based on TGCK sent from the main board 20. A TG to be adjusted: timing adjustment circuit 36, a TG: color counter 37 which is a color counter on the sensor substrate side, an image pattern output circuit 39 for outputting a predetermined image pattern, a switching circuit 41, and a switching control circuit 42 are provided.

  An ADCK signal indicating a period for each color is generated by the TG unit 33 and sent to the main board 20.

  The switching control circuit 42 controls the switching circuit 41 so as to output a predetermined image pattern output from the image pattern output circuit 39 to the main board side before the line reading. It controls to output the image data read by 31 to the main board side.

  Here, the predetermined image pattern output from the image pattern output circuit 39 can be the same as in the first embodiment.

  FIG. 5 is a timing chart showing the relationship between the ADCK signal, the TGCK signal, the image data, and the color counter in the main board 20 and the TG section 33 of the sensor board 30.

  In the initial state, the TG unit 33 of the sensor substrate 30 outputs ADCK, which is a clock indicating a color cycle, to the main substrate side, and repeatedly counts RGB with a TG: color counter 37 synchronized with ADCK. At this time, the image data from the image sensor 31 is output from the switching circuit 41. However, since it is before the reading process, it may not be output.

  In the main board 20, RGB is repeatedly counted by the M: color counter 23 in synchronization with the ADCK received from the sensor board 30.

  Since both color counters count independently, in the initial state, the RGB position is shifted.

  In order to correct this deviation, in this embodiment, the color position of the M: color counter 23 on the main board side is adjusted before reading each line. In the adjustment of the color position, when the line reading start signal TGCK is received from the main board side, the switching control circuit 42 of the sensor board 30 sends the predetermined image pattern to the switching circuit 41 as a data signal before the line reading. To output.

  As described above, this image pattern is an image pattern in which only R has a value. For this reason, as shown in this figure, when the TG: color counter 37 of the sensor substrate 30 indicates “R”, it is output in synchronization with ADCK.

  When the timing adjustment circuit 22 transmits the TGCK signal to the sensor substrate, the switching control circuit 29 of the main substrate 20 corresponds to the color data having the value of the received image data to the color counter position adjustment circuit 27. M: The color position of the color counter 23 is adjusted so that ADCK becomes “R”. As a result, the color positions of the TG: color counter 37 on the sensor substrate 30 and the M: color counter 23 on the main substrate 20 are matched.

  Since this color position adjustment process is performed before each line reading is started, the line reading process is started in a state where the color position is present.

  As described above, since the TGCK signal is not used for color alignment, it is sufficient to transmit the TGCK to the main substrate side not at the color cycle but at the pixel cycle (color cycle 3 clocks). Therefore, the edge of TGCK can be blunted to reduce unnecessary radiation noise, and the frequency of ADCK can be increased to improve the data transfer speed.

  Further, since the color position is adjusted by the TGCK signal for each line, the degree of freedom of TGCK is increased. Specifically, TGCK need not be an integer multiple of the clock for each pixel.

  FIG. 6 is a flowchart for explaining the flow of color position adjustment processing in the second embodiment. In this figure, processes other than the color position adjustment process are omitted.

  The color position adjustment process is performed prior to the line reading process by TGCK (S201) which is an image reading start signal. For example, the time for transferring the read data of the previous line can be used.

  With TGCK, the switching control circuit 42 of the sensor substrate 30 causes the switching circuit 41 to output a predetermined image pattern as a data signal to the main substrate 20 (S202).

  In addition, the switching control circuit 29 of the main board 20 causes the color counter position adjustment circuit 27 to perform the color adjustment of the M: color counter 23.

  The color counter position adjustment circuit 27 compares the sent image data with the M: color counter 23 and determines whether the color position of the M: color counter 23 matches the color position of the TG: color counter 37 on the sensor side. Is determined (S203).

  Since the transmitted image data has only R, it can be easily determined whether or not it matches the color position of the TG: color counter 37.

  As a result, if the color position is shifted, M: adjusts the color position of the color counter 23 (S204). As a result, the color position of the M: color counter 23 matches the color position of the TG: color counter 37 on the sensor side.

  After a predetermined time elapses due to the timer control, the switching circuit 41 ends the output of the image pattern (S205).

  Then, line reading processing is performed (S206). The above processing is repeated until all lines are read (S207).

  As described above, in the present invention, since the TGCK signal is not used for color position alignment, the color position of the color counter on the sensor board side and the color counter on the main board side regardless of the shape of the TGCK signal. Matching can be performed reliably.

1 is a block diagram illustrating a configuration of an image reading apparatus according to a first embodiment. The timing diagram which shows the relationship between the signal between a main board | substrate and a sensor board | substrate, and a color counter. The flowchart explaining the process in 1st Embodiment. FIG. 5 is a block diagram illustrating a configuration of an image reading apparatus according to a second embodiment. The timing diagram which shows the relationship between the signal between a main board | substrate and a sensor board | substrate, and a color counter. The flowchart explaining the process in 2nd Embodiment. FIG. 10 is a block diagram illustrating a configuration of a conventional image reading apparatus. The timing diagram which shows the relationship between the signal between a main board | substrate and a sensor board | substrate, and a color counter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 ... Main board | substrate, 21 ... Drive control circuit, 22 ... M: Timing adjustment circuit, 23 ... M: Color counter, 24 ... Sampling circuit, 25 ... Image processing circuit, 26 ... CPU, 27 ... Color counter position adjustment circuit, 28 Mode register, 29 ... Switching control circuit, 30 ... Sensor substrate, 31 ... Image sensor, 32 ... Conversion circuit, 33 ... TG section, 34 ... Clock generation circuit, 35 ... Sensor control circuit, 36 ... TG: Timing adjustment circuit, 37 ... TG: Color counter, 38 ... Mode register, 39 ... Image pattern output circuit, 41 ... Switching circuit, 42 ... Switching control circuit, 60 ... Drive mechanism, 120 ... Main board, 121 ... Drive control circuit, 122 ... M: Timing adjustment circuit, 123... M: color counter, 124... Sampling circuit, 125... Image processing circuit, 130. An image sensor, 132 ... converter, 133 ... TG section, 134 ... clock generating circuit, 135 ... sensor control circuit, 136 ... TG: timing adjustment circuit, 137 ... color counter, 160 ... drive mechanism

Claims (6)

An image reading apparatus including a sensor substrate including a line sensor that reads pixels composed of a plurality of color signals in units of lines, and a main substrate that performs image processing on the read pixel group,
The sensor substrate is
Color signal clock generation means for generating a clock in units of color signals;
Sensor color counting means for counting the color position of the color signal clock;
Image pattern output means for outputting an image pattern signal indicating a specific color position of the color signal clock ,
The main board is
Main color counting means for counting the color position of the input color signal clock;
Image inputting the image pattern signal, based on the color locus of the color signal clock specified by the image pattern, characterized in that it comprises a color position adjusting means for adjusting to match the color location of the main color counting means Reader. The image reading apparatus according to claim 1,
The color position adjusting means adjusts the color position prior to the start of image reading by the line sensor. The image reading apparatus according to claim 1,
The image reading apparatus according to claim 1, wherein the color position adjusting unit adjusts the color position every time the line sensor reads the image in units of lines. The image reading apparatus according to claim 3,
The image pattern output unit, an image reading apparatus and outputting a pre-outs image pattern signals by a line reading start instruction signal sent from the sensor board. The image reading apparatus according to any one of claims 1 to 4,
Before Kiga image pattern signal,
An image reading apparatus characterized by being an image pattern signal having a value only for a specific color signal. A line sensor that reads pixels composed of a plurality of color signals in units of lines, a color signal clock generation unit that generates a clock in units of color signals, and a sensor color count unit that counts the color positions of the color signal clocks A sensor substrate;
A color position adjustment method in an image reading apparatus having a main substrate provided with a main color counting means for counting the color position of an input color signal clock,
Outputting an image pattern signal indicating a specific color position of the color signal clock from the sensor substrate;
The main board, the type the image pattern signal, and characterized in that based on the color position of the color signal clock specified by the image pattern, and a step of adjusting to match the color location of the main color counting means Color position adjustment method.

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