JP5549137B2 - Image reading device - Google Patents

Description

  The present invention relates to an image reading apparatus that reads an image of a document.

In an image reading apparatus that reads an image of an original, the image of the original is enlarged and read or reduced.
As a prior art described in the publication, there is a technique for reducing the speed at which the reading position of the original is moved when reading an enlarged image of the original compared to reading the original image at an equal magnification without enlargement. (See Patent Document 1).

JP 2003-259092 A

  The present invention suppresses an increase in the capacity of a memory used for correcting a shift in a reading position between image pickup device rows when an image of a document is enlarged and read using a plurality of image pickup device rows arranged side by side. The purpose is to do.

According to the first aspect of the present invention, a plurality of image pickup element arrays each including a plurality of image pickup elements arranged in the main scanning direction are arranged, and the plurality of image pickup element arrays are arranged in the sub-scanning direction so that the document can be read from the reading position. A plurality of image sensor rows, a light receiving portion that receives the reflected light of the document, a moving portion that moves the reading position of the document by the light receiving portion in the sub-scanning direction, and a plurality of the image sensor rows. In addition, a positional deviation correction unit that corrects a positional deviation caused by a difference in the reading position in the sub-scanning direction for each column in each imaging data, and a magnification of the document in the sub-scanning direction Based on the specified sub-scanning specified magnification, the reading magnification in the sub-scanning direction of the document using the light receiving unit and the moving unit is set to 100% or less. 100% is set for the magnification of 1, and 200% is set for the second magnification where the sub-scanning specified magnification exceeds 100% and 200% or less, and the sub-scanning specified magnification exceeds 200%. In the third magnification that is 400% or less, the setting means for setting 400%, and when the second magnification is set by the setting means, the movement is more than when the first magnification is set. The moving speed of the reading position by the scanning unit is reduced to ½, and the number of columns of each imaging data captured by the plurality of imaging element columns is halved compared to the case where the first magnification is set. When the third magnification is set by the setting means, the number of columns is adjusted so as to be reduced to be supplied to the misregistration correction unit, and the movement is performed more than when the first magnification is set. By department The moving speed of the sampling position is reduced to ¼, and the number of columns of each imaging data captured by the plurality of imaging element columns is reduced to ¼ than when the first magnification is set. And adjusting means for adjusting the number of columns so as to be supplied to the misalignment correction unit, and the misalignment corrected imaging data output from the misalignment correction unit so as to have the specified sub-scanning magnification. An image reading apparatus including a reduction correction unit that performs reduction magnification correction in the sub-scanning direction.

According to the first aspect of the present invention, when an image of a document is enlarged and read using a plurality of image pickup element rows arranged side by side as compared with the case where the present configuration is not provided, reading between the image pickup element rows is performed. It is possible to suppress an increase in the capacity of a memory used for correcting a positional shift, to easily correct a positional shift between a plurality of image sensors, and to support a sub-scanning specified magnification other than an integer. It becomes possible .

It is a figure which shows an example of the whole structure of the reading apparatus with which this Embodiment is applied. It is a figure which shows the structure of a light-receiving part. It is a figure which shows the relationship between each image pick-up element row | line | column which comprises a light-receiving part, and the position of the subscanning direction on the original document read by these each image pick-up element row | line | column. It is a figure which shows the circuit structure of a light-receiving part. It is a timing chart for demonstrating basic operation | movement of a light-receiving part. 3 is a block diagram illustrating a main configuration of a control / image processing unit according to Embodiment 1. FIG. 6 is a diagram illustrating a relationship between a sub-scanning designated magnification and a reading condition in Embodiment 1. FIG. 6 is a timing chart for explaining the output of the light receiving unit and the output of the gap correction unit when the sub-scanning specified magnification is 100% in the first embodiment. 5 is a timing chart for explaining the output of the light receiving unit and the output of the gap correction unit when the sub-scanning specified magnification is 200% in the first embodiment. 6 is a timing chart for explaining the output of the light receiving unit and the output of the gap correction unit when the sub-scanning specified magnification is 400% in the first embodiment. 6 is a diagram for explaining a reading row on a document M when sub-scanning specified magnifications are 100%, 200%, and 400% in Embodiment 1. FIG. FIG. 10 is a block diagram illustrating a main configuration of a control / image processing unit according to a second embodiment. FIG. 10 is a diagram illustrating a relationship between a sub-scanning specified magnification and a reading condition in the second embodiment. 12 is a timing chart for explaining the output of the light receiving unit, the output of the sub-scanning averaging unit, and the output of the gap correction unit when the sub-scanning specified magnification is 200% in the second embodiment. 10 is a timing chart for explaining the output of the light receiving unit, the output of the sub-scanning averaging unit, and the output of the gap correction unit when the designated sub-scanning magnification is 400% in the second embodiment. FIG. 10 is a diagram for explaining a reading row on a document M when sub-scanning specified magnifications are 100%, 200%, and 400% in the second embodiment.

<Embodiment 1>
FIG. 1 is a diagram showing an example of the overall configuration of a reading apparatus to which the present embodiment is applied.
The reading apparatus includes a document feeding device 10 that sequentially conveys documents from a stack of stacked documents, and a scanner device 40 that reads an image of a document by scanning.

  The document feeder 10 includes a document storage unit 11 on which a bundle of documents composed of a plurality of documents M is stacked, and a paper discharge storage unit 12 that is provided below the document storage unit 11 and stacks the document M that has been read. . In addition, the document feeder 10 includes a take-out roll 13 that takes out and transports the document M in the document storage unit 11. Further, on the downstream side of the take-out roll 13 in the document conveyance direction, a mechanism 14 for separating the documents M one by one is provided. A pre-registration roll 16, a registration roll 17, a platen roll 18, an out roll 19, and a discharge roll 20 are provided in order from the upstream side in the document conveyance direction in the conveyance path 15 where the document M is conveyed. The pre-registration roll 16 conveys the original M, which is rolled up one by one, toward the downstream roll, and forms a loop of the original M. The registration roll 17 rotates and temporarily stops, then restarts at the same timing, and supplies the document M while performing registration adjustment on the document reading unit. The platen roll 18 assists the conveyance of the document M being read by the scanner device 40. Further, the platen roll 18 is used as a white reference for shading correction in the scanner device 40. The out roll 19 conveys the document M read by the scanner device 40 further downstream. The discharge roll 20 further conveys the read original M and discharges it to the paper discharge storage unit 12.

  On the other hand, the scanner device 40 supports the document feeding device 10 described above so that it can be opened and closed, supports the document feeding device 10 with a device frame 41, and reads an image of the document M conveyed by the document feeding device 10. . The scanner device 40 is provided below a device frame 41 that forms a casing, a first platen glass 42A on which a document M to be read is placed stationary, and a platen roll 18, and is transported by the document feeder 10. 2nd platen glass 42B which comprises the opening part of the light for reading the original M to be read is provided.

  Further, the scanner device 40 is stationary under the second platen glass 42B, or scans the entire first platen glass 42A to read an image, and the light obtained from the full rate carriage 43 is input to the imaging unit. A half-rate carriage 45 is provided. Here, the full-rate carriage 43 receives the reflected light obtained from the original M and the light source device 44A that irradiates the original M with light, the light source mirror 44B that reflects the light from the light source device 44A toward the original M, and the like. 1 mirror 46A. Further, the half-rate carriage 45 includes a second mirror 46B and a third mirror 46C that provide the light obtained from the first mirror 46A to the imaging unit.

  Furthermore, the scanner device 40 includes an imaging lens 47 and a light receiving unit 48. Among these, the imaging lens 47 optically reduces the optical image obtained from the third mirror 46C. The light receiving unit 48 photoelectrically converts the optical image formed by the imaging lens 47. That is, in the scanner device 40, an image is formed on the light receiving unit 48 using a so-called reduction optical system. Further, in the present embodiment, as will be described later, as the light receiving unit 48, the red, green, and blue image pickup element arrays provided along the main scanning direction are arranged side by side in the sub scanning direction. Is used. As a result, the image formed on the original M is read as a full-color image using the light receiving unit 48.

  The scanner device 40 further includes a control / image processing unit 49. The control / image processing unit 49 performs various types of image processing on the image data of the document M input from the light receiving unit 48. The control / image processing unit 49 controls the operation of each unit in the reading operation of the reading device.

  For example, in the fixed reading mode in which the image of the document M placed on the first platen glass 42A is read, the full rate carriage 43 and the half rate carriage 45 move in the arrow direction at a ratio of 2: 1. At this time, light from the light source device 44 </ b> A provided in the full rate carriage 43 is irradiated on the read surface of the document M. Then, the reflected light from the document M is reflected in the order of the first mirror 46 A, the second mirror 46 B, and the third mirror 46 C and guided to the imaging lens 47. The light guided to the imaging lens 47 is imaged on the light receiving surface of the light receiving unit 48. The image pickup element arrays for each color constituting the light receiving unit 48 are each constituted by a one-dimensional sensor and process one line at the same time. The full-rate carriage 43 and the half-rate carriage 45 are moved in the direction (sub-scanning direction of reading) intersecting the line direction (reading main-scanning direction), and the next line of the document M is read. By executing this over the entire document M, reading of one page of the document is completed.

  On the other hand, in the transport reading mode in which the image of the document M transported by the document feeder 10 is read, the document M transported in the sub-scanning direction passes over the second platen glass 42B. At this time, the full rate carriage 43 and the half rate carriage 45 are stopped at the position indicated by the solid line in FIG. Then, the reflected light of the first line of the conveyed document M is imaged by the imaging lens 47 through the first mirror 46A, the second mirror 46B, and the third mirror 46C, and is imaged by the light receiving unit 48. Is read. That is, after one line in the main scanning direction is simultaneously processed by the light receiving unit 48, one line in the next main scanning direction of the document M conveyed by the document feeder 10 is read. Then, after the leading edge of the document M reaches the reading position of the second platen glass 42B, the trailing edge of the document M passes the reading position on the second platen glass 42B, so that the document M is moved by one line in the main scanning direction. By sequentially reading each page, reading of one page of the document is completed in the sub-scanning direction.

  Here, in the fixed reading mode, the full rate carriage 43 and the half rate carriage 45 function as moving parts. On the other hand, in the conveyance reading mode, the document feeder 10 functions as a moving unit.

FIG. 2 is a diagram for explaining the configuration of the light receiving unit 48 used in the reading device described above.
The light receiving unit 48 includes a substrate 48a having a rectangular shape, and three image sensor rows 50, 60, and 70 mounted side by side on one surface of the substrate 48a. Here, a filter that selectively transmits red light is attached to the image sensor array 50 located on the most upstream side in the sub-scanning direction SS, and the image sensor array 50 functions as an image sensor for detecting red light. doing. In addition, a filter that selectively transmits green light is attached to the image sensor array 60 that is located downstream of the image sensor array 50 in the sub-scanning direction SS, and the image sensor array 60 is for detecting green light. It functions as an image sensor. Further, a filter that selectively transmits blue light is attached to the imaging element array 70 that is located downstream and downstream of the imaging element array 60 in the sub-scanning direction SS. It functions as an image sensor for detection.

  In addition, the imaging element rows 50, 60, and 70 are provided along the main scanning direction FS, respectively. Here, each of the imaging element arrays 50, 60, and 70 is configured by arranging, for example, a plurality of (in this example, k) square imaging elements (photodiodes) PD in the main scanning direction FS. Further, the imaging element rows 50, 60, and 70 are arranged in this order in the sub-scanning direction SS as described above. At this time, the image sensor array 50 and the image sensor array 60 adjacent thereto are arranged at a distance G in the sub-scanning direction SS, and the image sensor array 60 and the image sensor array 70 adjacent thereto are sub-scanned. A distance G is arranged in the direction SS. Therefore, the imaging element array 50 and the imaging element array 70 are separated by a distance 2G in the sub-scanning direction SS.

FIG. 3 shows the relationship between the image sensor rows 50, 60, 70 constituting the light receiving unit 48 and the position in the sub-scanning direction SS on the document M read by the image sensor rows 50, 60, 70. FIG.
In the present embodiment, the image sensor arrays 50, 60, and 70 are arranged at a distance G in the sub-scanning direction SS, so that the image sensor arrays 50, 60, and 70 are placed on the document M at the same timing. A different position is read in the sub-scanning direction SS. Here, in the present embodiment, a red light imaging element array 50, a green light imaging element array 60, and a blue light imaging element array 70 are arranged in order from the preceding side of the document M in the sub-scanning direction SS. Has been. For this reason, for example, when reading at a sub-scan magnification of equal magnification (100%), at the same timing, when the image sensor row 50 is reading an image of the nth row Ln in the sub-scanning direction SS of the document M. The image sensor row 60 reads the image of the n−4th row Ln−4 of the same document M in the sub-scanning direction SS, and the image sensor row 70 scans the n−th row of the same document M in the sub-scanning direction SS. The image in the eighth column Ln-8 is read. From the opposite viewpoint, for example, images in the same column (for example, nth) in the sub-scanning direction SS of the document M are first read by the image sensor row 50, then read by the image sensor row 60, and finally. The image is read by the imaging element array 70. That is, the distance G in the present embodiment corresponds to four columns in the sub-scanning direction SS when reading at the same magnification in the sub-scanning direction SS.

FIG. 4 is a diagram for explaining a circuit configuration of the light receiving unit 48 shown in FIG.
The light receiving unit 48 controls the readout in the vertical direction in the figure of the image sensor rows 50, 60, 70 corresponding to the respective colors and the charges accumulated in the image sensor PDs constituting the image sensor rows 50, 60, 70. Horizontal transfer registers 52, 62, 72 for transferring charges in the horizontal direction in the figure, and charges accumulated in the image pickup devices PD constituting the image pickup device rows 50, 60, 70 in the horizontal transfer registers Shutter drains 53, 63, 73 for selectively ejecting the image sensor PD as a unit before transferring to 52, 62, 72 are provided.

  The light-receiving unit 48 generates a shift pulse SH for controlling the shift gates 51, 61, 71 and a vertical transfer pulse for generating a control signal DS corresponding to the image pickup device PD that is a charge discharge target in the shutter drains 53, 63, 73. A circuit 81 is included. Further, the light receiving unit 48 includes a horizontal transfer pulse generation circuit 82 that generates transfer pulses φ1 and φ2 that drive the horizontal transfer registers 52, 62, and 72, and charge-voltage converters 54 and 64 that convert the transferred charges into voltages. 74, and analog amplifiers 55, 65, and 75 that amplify the outputs from the charge-voltage converters 54, 64, and 74, respectively.

  Among these, the shift gates 51, 61, 71 are controlled by the shift pulse SH supplied from the vertical transfer pulse generation circuit 81, and the charges of the imaging element arrays 50, 60, 70 are transferred horizontally based on the supply of the shift pulse SH. The data is read out to the registers 52, 62, 72.

  The horizontal transfer registers 52, 62, and 72 each supply the charge of the pixel unit (image pickup device PD unit) read out through the shift gates 51, 61, and 71 to the phase supplied from the horizontal transfer pulse generation circuit 82. Are sequentially transferred in the horizontal direction in the figure by the different transfer pulses φ1 and φ2, and charges are output to the charge voltage converters 54, 64 and 74.

  Further, the shutter drains 53, 63, 73 are controlled by the control signal DS supplied from the vertical transfer pulse generation circuit 81, and are generated in the image pickup devices PD of the image pickup device arrays 50, 60, 70 based on the supply of the control signal DS. The discharged electric charges are controlled in units of the image sensor PD. In this example, when the control signal DS becomes high level, the charge generated in the corresponding image sensor PD is discharged, and when the control signal DS becomes low level, the charge generated in the corresponding image sensor PD. Is not discharged.

  FIG. 5 is a timing chart for explaining the basic operation of the light receiving unit 48 shown in FIG. In the following description, a period from when the shift pulse SH rises to the next rise of the shift pulse SH is referred to as an imaging cycle T. Here, for convenience of explanation, the three consecutive imaging periods T in FIG. 5 are referred to as a first imaging period T1, a second imaging period T2, and a third imaging period T3, respectively. Further, here, a case where charge is not discharged due to the control signal DS being maintained at a low level is taken as an example.

  When the shift pulse SH supplied from the vertical transfer pulse generating circuit 81 rises, the shift gates 51, 61, 71 start to operate accordingly, and a plurality of imaging devices that constitute the imaging element arrays 50, 60, 70, respectively. The charges accumulated in the element PD are read out to the horizontal transfer registers 52, 62, 72. Then, the charges read out to the horizontal transfer registers 52, 62, 72 are converted into voltages by the charge-voltage converters 54, 64, 74, respectively, and then amplified by the analog amplifiers 55, 65, 75, and the analog signals The color component signal (RGB) is output to the control / image processing unit 49.

  In the first imaging cycle T1 to the third imaging cycle T3, in the imaging device rows 50, 60, and 70, respectively, following the charge P1 from the first imaging device PD provided on one end side in the main scanning direction FS. Thus, the charges are sequentially output in the order of the numbers of the image pickup devices PD, and finally the charge Pk from the k-th image pickup device PD provided on the other end side in the main scanning direction FS is output. Note that the last charge Pk is output until each imaging cycle T ends. Therefore, data for one line is output within each imaging period T.

  At this time, if the original M is read at the same magnification, for example, in the first imaging cycle T1, the nth column in the sub-scanning direction SS from the imaging element column 50 (indicated by R in the drawing). The light reception results (charges P1 to Pk) from Ln are output, and the light reception results (charges) from the n-4th column Ln-4 in the sub-scanning direction SS from the imaging element column 60 (indicated by G in the figure). P1 to Pk) is output, and the light receiving results (charges P1 to Pk) from the n-8th column Ln-8 in the sub-scanning direction SS are output from the imaging element column 70 (indicated by B in the drawing). Will be. For example, in the second imaging cycle T2, the light receiving results (charges P1 to Pk) from the (n + 1) th row Ln + 1 in the sub scanning direction SS are output from the imaging device row 50, and the sub scanning direction is output from the imaging device row 60. The light reception results (charges P1 to Pk) from the n-3th row Ln-3 of SS are output, and the light reception results from the n-7th row Ln-7 in the sub-scanning direction SS (from the imaging element row 70) Charges P1 to Pk) are output. Further, for example, in the third imaging cycle T3, the light receiving results (charges P1 to Pk) from the (n + 2) th column Ln + 2 in the sub-scanning direction SS are output from the image sensor column 50, and the sub-scanning direction is output from the image sensor column 60. The light reception results (charges P1 to Pk) from the (n-2) th column Ln-2 of SS are output, and the light reception results (from the n-6th column Ln-6 in the sub-scanning direction SS) are output from the image sensor column 70 ( Charges P1 to Pk) are output.

FIG. 6 is a block diagram showing a main configuration of the control / image processing unit 49 in the present embodiment.
The control / image processing unit 49 includes an A / D conversion unit 91, a light amount distribution correction unit 92, a gap correction unit 93, a color conversion processing unit 94, a sub-scanning enlargement / reduction unit 95, and a user interface control unit 96. A motor drive control unit 97, an image sensor driving unit 98, and a CPU (Central Processing Unit) 99.

  Among these, the A / D conversion unit 91 converts the RGB color component signals (analog signals) input from the light receiving unit 48 into digital signals. Here, the A / D conversion unit 91 includes three A / D conversion circuits 91a corresponding to RGB colors. The A / D conversion unit 91 may be provided outside the control / image processing unit 49.

  Further, the light amount distribution correction unit 92 uses, for example, shading correction data obtained by reading the white reference such as the platen roll 18 (see FIG. 1) by the light receiving unit 48, and converts the digital signal corresponding to each RGB color component. It has a function of correcting the light amount distribution. Here, the light amount distribution correction unit 92 includes three light amount distribution correction circuits 92a corresponding to the respective RGB colors.

   Further, the gap correction unit 93 is caused by the difference in the mounting positions of the three image sensor rows 50, 60, and 70 included in the light receiving unit 48 based on digital signals corresponding to the RGB color components after the light amount distribution correction. The distance (gap) is corrected. Here, the gap correction unit 93 includes a first-in first-out (FIFO) memory 93a for executing line delay processing for each color component signal of RGB. The FIFO memory 93a has a capacity to store data for 12 lines of data (k pixels per line) for the FS1 line in the main scanning direction in the present embodiment. The FIFO memory 93a stores R color component signals for 8 lines and G color component signals for 4 lines.

  Furthermore, the color conversion processing unit 94 has a function of converting each color component signal of RGB after the gap is corrected by the gap correction unit 93 into a signal in a color space different from RGB. Here, examples of signals in different color spaces include Lab signals, Luv signals, XYZ signals, and s-RGB signals. In order to perform such color space conversion, the color conversion processing unit 94 detects color originals that detect whether the image on the original M is color or black and white by a look-up table (LUT), matrix calculation, or the like. A detection determination unit 94a that realizes a function and a background detection function for detecting the background color of the document M, a lightness conversion unit 94b that converts the lightness for each RGB color component according to the detection determination result in the detection determination unit 94a, A color conversion unit 94c that converts each color component signal after brightness conversion into a target color space signal.

  Further, the sub-scanning enlargement / reduction unit 95 as an example of the reduction correction unit converts the image by the color conversion processing unit 94 in order to correspond to the scanning speed that increases or decreases according to the reading magnification in the sub-scanning direction SS of the image on the document M. The obtained color space signal has a function of performing enlargement processing or reduction processing in the sub-scanning direction SS as necessary, and outputting the processed signal to a subsequent image processing unit (not shown). For this purpose, the sub-scanning enlargement / reduction unit 95 includes three enlargement / reduction circuits 95a corresponding to the respective colors in the converted color space. Here, in each enlargement / reduction circuit 95a, the input color signal of each color is subjected to enlargement processing or reduction processing by calculation using a known sub-scanning two-point interpolation method, and is output. In the subsequent image processing unit, for example, enlargement processing or reduction processing in the main scanning direction FS corresponding to the reading magnification in the main scanning direction FS is performed.

Further, the user interface control unit 96 is configured to control a user interface such as an operation panel (not shown) and to accept an instruction such as an instruction (for example, reading magnification) from the user.
Furthermore, the motor drive control unit 97 controls the drive of the motors connected to the full-rate carriage 43 and the half-rate carriage 45 shown in FIG. 1 and various rolls provided in the document feeder 10 shown in FIG. It has become.

The image sensor driving unit 98 drives the light receiving unit 48 and controls it.
The CPU 99 as an example of a setting unit performs operation control of each unit described above, that is, the entire reading apparatus shown in FIG. 1, by executing a program read from a memory (not shown) or the like.

  In the reading apparatus of the present embodiment, when reading an image of the original M, not only reading at the same size as the original original M, that is, equal magnification, for example, reading reduced in the sub-scanning direction SS or sub-scanning is performed. Reading expanded in the direction SS is also possible. However, in the present embodiment, the range of reduction and enlargement allowed in the sub-scanning direction SS is 25% or more and 400% or less.

  FIG. 7 is a diagram illustrating the relationship between the reading magnification in the sub-scanning direction SS (referred to as sub-scanning designated magnification Y) and each reading condition in the present embodiment. Here, the sub-scanning designated magnification Y is set based on an instruction received via the user interface control unit 96 at the time of reading. In the present embodiment, according to the sub-scanning specified magnification Y, the reading conditions include the scanning speed V in the sub-scanning direction SS in reading, the imaging period T of the light receiving unit 48 in reading, and the imaging element rows 50, 60, and 70. The presence / absence of execution of charge discharge using the shutter drains 53, 63, and 73 and the setting in the execution and the sub-scanning reduction ratio R used in the enlargement / reduction processing in the sub-scanning enlargement / reduction unit 95 are changed. These setting conditions are stored in a memory (not shown) or the like provided in the control / image processing unit 49. Then, the CPU 99 reads out these reading conditions in accordance with the sub-scanning designated magnification Y set through the user interface control unit 96, and sets the scanning speed V through the motor drive control unit 97 and the image sensor driving unit 98. The imaging period T and the imaging element array charge discharge are controlled through the sub scanning enlargement / reduction unit 95, and the sub scanning reduction ratio R is controlled through the sub scanning enlargement / reduction unit 95, respectively.

  Further, in FIG. 7, as a reference, the amount of use of the FIFO memory 93a used for gap correction in the gap correction unit 93 corresponding to the sub-scanning designated magnification Y (denoted as gap correction used memory amount in the drawing). ).

  In this description, the scanning speed V when the sub-scanning specified magnification Y is 100%, that is, the same magnification is referred to as a reference scanning speed Vs. The imaging cycle T when the sub-scanning specified magnification Y is 100% is referred to as a reference imaging cycle Ts.

When the sub-scanning designated magnification Y is 100% (equal magnification), the scanning speed V is set to the reference scanning speed Vs, and the imaging period T is set to the reference imaging period Ts. Further, when the sub-scanning designated magnification Y is 100%, the imaging element column charge discharge is set to “none”, and the sub-scanning reduction ratio R is set to 1.
When the sub-scanning designated magnification Y is 25% (reduction), the scanning speed V is set to the reference scanning speed Vs, and the imaging cycle T is set to the reference imaging cycle Ts. Further, when the sub-scanning designated magnification Y is 25%, the image pickup device column charge discharge is set to “none”, and the sub-scanning reduction ratio R is set to ¼.
When the sub-scanning designated magnification Y is 50% (reduction), the scanning speed V is set to the reference scanning speed Vs, and the imaging period T is set to the reference imaging period Ts. Further, when the sub-scanning designated magnification Y is 50%, the image pickup device column charge discharge is set to “none”, and the sub-scanning reduction ratio R is set to ½.

When the sub-scanning designated magnification Y is 200% (enlargement), the scanning speed V is set to half the reference scanning speed Vs (Vs / 2), and the imaging period T is set to the reference imaging period Ts. . Further, when the sub-scanning designated magnification Y is 200%, the image pickup device column charge discharge is set to “Yes (1/2)”, and the sub-scanning reduction ratio R is set to 1. Note that the meaning of “½” in the imaging element array charge discharge will be described later.
When the sub-scanning designated magnification Y is 400% (enlargement), the scanning speed V is set to 1/4 (Vs / 4) of the reference scanning speed Vs, and the imaging period T is set to the reference imaging period Ts. The Further, when the sub-scanning designated magnification Y is 400%, the image pickup device column charge discharge is set to “present (3/4)” and the sub-scanning reduction ratio R is set to 1. Note that the meaning of “3/4” in the image pickup device array charge discharge will be described later.

On the other hand, when the designated sub-scanning magnification Y exceeds 25% and is less than 50% (reduction), the scanning speed V is set to the reference scanning speed Vs, and the imaging period T is set to the reference imaging period Ts. The Further, when the sub-scanning designated magnification Y exceeds 25% and is less than 50%, the imaging element array charge discharge is “none”, and the sub-scanning reduction ratio R is more than ¼ and less than ½. Set to each selected value.
When the sub-scanning designated magnification Y exceeds 50% and is less than 100% (reduction), the scanning speed V is set to the reference scanning speed Vs, and the imaging period T is set to the reference imaging period Ts. Further, when the sub-scanning specified magnification Y exceeds 50% and does not reach 100%, the image pickup device column charge discharge is selected as “None”, and the sub-scanning reduction ratio R is selected from a range exceeding 1/2 and less than 1. Is set to each value.

When the sub-scanning designated magnification Y exceeds 100% and is less than 200% (enlargement), the scanning speed V is half of the reference scanning speed Vs (Vs / 2), and the imaging period T is the reference imaging period Ts. Respectively. Further, when the sub-scanning designated magnification Y exceeds 100% and is not less than 200%, the image pickup device column charge discharge is “Yes (1/2)”, and the sub-scanning reduction ratio R is more than 1/2 and is 1 Each value is set to a value selected from a non-existing range.
When the sub-scanning specified magnification Y exceeds 200% and is less than 400% (enlargement), the scanning speed V is ¼ (Vs / 4) of the reference scanning speed Vs, and the imaging cycle T is the reference imaging cycle. Each is set to Ts. Further, when the sub-scanning designated magnification Y exceeds 200% and does not reach 400%, the image pickup device column charge discharge is “Yes (3/4)”, and the sub-scanning reduction ratio R exceeds 1/2 and is 1 Each value is set to a value selected from a non-existing range.

Thus, in the present embodiment, when the sub-scanning designated magnification Y is less than 100%, reading is performed at the same scanning speed V and imaging cycle T as when the sub-scanning designated magnification Y is 100%. As a result, after acquiring the image data in a state of being larger than the target sub-scanning specified magnification Y, the target sub-scanning reduction ratio R used in the sub-scanning enlargement / reduction unit 95 is changed to thereby achieve the target sub-scanning. The image is reduced to a specified magnification Y.
For example, when the sub-scanning specified magnification Y is 75%, the original M is read at the same scanning speed V and imaging cycle T as when the sub-scanning specified magnification Y is 100%, and the obtained image data is read. In the sub-scanning enlargement / reduction unit 95, digital reduction processing is performed in a state where the sub-scanning reduction ratio R is set to 3/4 (0.75), and as a result, image data (according to the sub-scanning designated magnification Y) ( 100% × 0.75 = 75%) is output.

In the present embodiment, when the sub-scanning specified magnification Y exceeds 100% but is not less than 200%, the same scanning speed V and imaging cycle T (imaging element) as when the sub-scanning specified magnification Y is 200%. (Including the presence / absence and setting of column charge discharge). As a result, after acquiring image data in an enlarged state than the target sub-scanning specified magnification Y, the sub-scanning reduction ratio R used in the sub-scanning enlargement / reduction unit 95 is changed to thereby change the target sub-scanning reduction ratio R. The image is reduced to the scanning designated magnification Y.
For example, when the sub-scanning designated magnification Y is 150%, the document M is read at the same scanning speed V and imaging cycle T as when the sub-scanning designated magnification Y is 200%, and the obtained image data is read. In the sub-scanning enlargement / reduction unit 95, digital reduction processing is performed in a state where the sub-scanning reduction ratio R is set to 3/4 (0.75), and as a result, image data (according to the sub-scanning designated magnification Y) ( 200% × 0.75 = 150%) is output.

Further, in the present embodiment, when the sub-scanning specified magnification Y exceeds 200% but is less than 400%, the same scanning speed V and imaging cycle T (imaging element) as when the sub-scanning specified magnification Y is 400%. (Including the presence / absence and setting of column charge discharge). As a result, after acquiring image data in an enlarged state than the target sub-scanning specified magnification Y, the sub-scanning reduction ratio R used in the sub-scanning enlargement / reduction unit 95 is changed to thereby change the target sub-scanning reduction ratio R. The image is reduced to the scanning designated magnification Y.
For example, when the sub-scanning designated magnification Y is 300%, the original M is read at the same scanning speed V and imaging period T as when the sub-scanning designated magnification Y is 400%, and the obtained image data is read. In the sub-scanning enlargement / reduction unit 95, digital reduction processing is performed in a state where the sub-scanning reduction ratio R is set to 3/4 (0.75), and as a result, image data (according to the sub-scanning designated magnification Y) ( 400% × 0.75 = 300%) is output.

  Now, explanation will be given with specific examples. The contents of the processing described below are common to the above-described fixed reading mode and conveyance reading mode.

  FIG. 8 is a timing chart for explaining the output (RGB) of the light receiving unit 48 and the output (RGB) of the gap correction unit 93 provided in the control / image processing unit 49 when the sub-scanning designated magnification Y is 100%. It is. When the sub-scanning specified magnification Y is 100%, as described above, the scanning speed V is the reference scanning speed Vs, the imaging period T is the reference imaging period Ts, and the imaging element array charge discharge is “none”. The sub-scanning reduction ratio R is set to 1, respectively.

  When reading of the document M is started, the image sensor driving unit 98 provided in the control / image processing unit 49 sends the reference image capturing period Ts and the image sensor column charge discharge to the vertical transfer pulse generating circuit 81 of the light receiving unit 48. A signal corresponding to “None” is supplied. Then, in the light receiving unit 48, the vertical transfer pulse generation circuit 81 generates a shift pulse SH based on this signal and supplies it to the shift gates 51, 61, 71. The vertical transfer pulse generation circuit 81 generates a control signal DS that is always maintained at a low level and supplies the control signal DS to the shutter drains 53, 63, and 73.

Further, in each of the image pickup devices PD constituting the image pickup device arrays 50, 60, and 70, charges are accumulated by receiving reflected light from the document M.
In the light receiving unit 48, the shift pulse SH is supplied to the shift gates 51, 61, and 71 at the same timing, so that the imaging elements 50, 60, and 70 are synchronized with the shift pulse SH in the imaging cycle T (in this case). For each reference imaging cycle Ts), the charges for the FS1 line in the main scanning direction are sequentially output to the horizontal transfer registers 52, 62, 72. Then, the charges for the main scanning direction FS1 line transferred to the horizontal transfer registers 52, 62, 72 pass through the charge / voltage converters 54, 64, 74 and the analog amplifiers 55, 65, 75, and then the control / image processing unit 49. Are output sequentially.

  However, in the light receiving unit 48, the image sensor rows 50, 60, and 70 are arranged at a distance G in the sub-scanning direction SS as shown in FIG. 3, and the sub-scanning designated magnification Y is 100%. Reads positions on the document M that are separated by four columns in the sub-scanning direction SS. For this reason, the capture of green (G) data (charge) from the image sensor array 60 is started four delays after the start of the capture of red (R) data (charge) from the image sensor array 50. . Further, the capture of the green (G) data (charge) from the image sensor array 60 is started, and the capture of the blue (B) data (charge) from the image sensor array 70 is started after a delay of 4 columns. That is, in this example, when the image sensor row 50 starts reading the first row L1, the image sensor row 60 starts reading the first row L1 when reading the fifth row L5. . Further, in this example, when the image sensor column 50 reads the ninth column L9 and when the image sensor column 60 reads the fifth column L5, the image sensor column 70 starts reading the first column L1. Will do.

  Here, when the sub-scanning designated magnification Y is set to 100%, the charge drain operation by the shutter drains 53, 63, 73 is not performed by maintaining the control signal DS at a low level. For this reason, the read data of each column output from the imaging element columns 50, 60, and 70 are sequentially output in the order of the column numbers.

In the gap correction unit 93 provided in the control / image processing unit 49, the FIFO memory 93 a receives the red (R) color component signal input from the imaging element array 50 in the first column L 1 and the second column. Eight columns are sequentially stored in the order of the eyes L2,... And after the eighth column L8 is stored, the data are sequentially output in the order of the first column L1, the second column L2,. Further, the FIFO memory 93a stores the green (G) color component signals input from the image sensor column 60 for four columns in order of the first column L1, the second column L2,. After storing up to the eye L4, the data are sequentially output in the order of the first row L1, the second row L2,. On the other hand, the FIFO memory 93a does not particularly store the blue (B) color component signal input from the image sensor column 70, and synchronizes with the output of the blue (B) first column L1 color component signal. Thus, the red (R) first color component signal and the green (G) first color component signal are output.
Therefore, the n-th color component signal of red (R), green (G), and blue (B) obtained by reading the same column from the gap correction unit 93 in the sub-scanning direction SS of the document M is In the synchronized state, the data are sequentially output in numerical order.

  FIG. 9 illustrates the output (RGB) of the light receiving unit 48 and the output (RGB) of the gap correction unit 93 provided in the control / image processing unit 49 when the sub-scanning designated magnification Y is 200%. It is a timing chart. When the sub-scanning designated magnification Y is 200%, as described above, the scanning speed V is half the reference scanning speed Vs (Vs / 2), the imaging period T is the reference imaging period Ts, and the imaging element array charge. The discharge is set to “present (1/2)”, and the sub-scanning reduction ratio R is set to 1.

  When reading of the document M is started, the image sensor driving unit 98 provided in the control / image processing unit 49 sends the reference image capturing period Ts and the image sensor column charge discharge to the vertical transfer pulse generating circuit 81 of the light receiving unit 48. A signal corresponding to “Yes (1/2)” is supplied. Then, in the light receiving unit 48, the vertical transfer pulse generation circuit 81 generates a shift pulse SH based on this signal and supplies it to the shift gates 51, 61, 71. The vertical transfer pulse generation circuit 81 generates a control signal DS that becomes low level in the odd-numbered imaging cycle T and high level in the even-numbered imaging cycle T, and supplies the control signal DS to the shutter drains 53, 63, 73. Accordingly, “existence (1/2)” of the image pickup device array charge discharge refers to a case where the control signal DS that becomes a high level at a rate of ½ is output.

Further, in each of the image pickup devices PD constituting the image pickup device arrays 50, 60, and 70, charges are accumulated by receiving reflected light from the document M.
In the light receiving unit 48, the shift pulse SH is supplied to the shift gates 51, 61, and 71 at the same timing, so that the imaging elements 50, 60, and 70 are synchronized with the shift pulse SH in the imaging cycle T (in this case). For each reference imaging cycle Ts), the charges for the FS1 line in the main scanning direction are sequentially output to the horizontal transfer registers 52, 62, 72. Then, the charges for the main scanning direction FS1 line transferred to the horizontal transfer registers 52, 62, 72 pass through the charge / voltage converters 54, 64, 74 and the analog amplifiers 55, 65, 75, and then the control / image processing unit 49. Are output sequentially.

  However, in the light receiving unit 48, the imaging element rows 50, 60, and 70 are arranged at a distance G in the sub-scanning direction SS as shown in FIG. 3, and the sub-scanning designated magnification Y is 200%. Since the scanning speed V is ½ compared to the case where the sub-scanning designated magnification Y is 100%, the positions on the original M that are separated by 8 columns in the sub-scanning direction SS are read. For this reason, after the start of taking in the red (R) data (charge) from the image pickup device array 50, the start of taking in the green (G) data (charge) from the image pickup device array 60 after eight columns. . In addition, the capture of green (G) data (charge) from the image sensor array 60 is started, and the capture of blue (B) data (charge) from the image sensor array 70 is started after a delay of 8 columns. That is, in this example, when the image sensor column 50 starts reading the first row L1, the image sensor column 60 starts reading the first row L1 when reading the ninth row L9. . Further, in this example, when the image sensor column 50 reads the 17th column L17 and when the image sensor column 60 reads the ninth column L9, the image sensor column 70 starts reading the first column L1. Will do.

  Here, when the sub-scanning designated magnification Y is set to 200%, the control signal DS repeats the low level and the high level in the odd-numbered imaging cycle T and the even-numbered imaging cycle T, thereby releasing the shutter drain. The charge discharging operation by 53, 63 and 73 is performed in the even-numbered imaging period T. Therefore, among the charges accumulated in the image sensor rows 50, 60, and 70, those acquired in the odd-numbered rows (L1, L3, L5,...) On the document M are used for the horizontal transfer registers 52, 62, 72. Are output to the outside via a line (shown by a solid line in the figure), but those obtained in the even-numbered columns (L2, L4, L6,...) On the original M are first shutter drains 53, 63. 73, the output is not output to the outside via the horizontal transfer registers 52, 62, 72 (indicated by broken lines in the figure). For this reason, the read data of each column output from the imaging element columns 50, 60, and 70 is sequentially output in ascending order of column numbers in odd-numbered columns (L1, L3, L5,...). Become. That is, when the sub-scanning designated magnification Y is set to 200%, the light receiving unit 48 determines the number of pixels of read data for the FS1 line in the main scanning direction acquired in each of the imaging element rows 50, 60, and 70. The number of pixels of read data for one line in the main scanning direction FS output to the control / image processing unit 49 is ½.

In the gap correction unit 93 provided in the control / image processing unit 49, the FIFO memory 93a receives the red (R) color component signal input from the imaging element array 50 in the first column L1, the third column. Eight columns are sequentially stored in the order of the eyes L3,... And after the 15th column L15 is stored, the data are sequentially output in the order of the first column L1, the third column L3,. At this time, from the FIFO memory 93a, the color component signal of the red (R) first column L1 is used as a new color component signal of the first column L1 ′, and the red (R) third column L3. Are output as new color component signals of the second column L2 ′. The FIFO memory 93a stores the green (G) color component signals input from the image sensor column 60 in order of the first column L1, the third column L3,... After storing up to the column L7, the data are sequentially output in the order of the first column L1, the third column L3,. At this time, from the FIFO memory 93a, the color component signal of the first row L1 of green (G) is used as the new color component signal of the first row L1 ′, and the third row L3 of green (G). Are output as new color component signals of the second column L2 ′. On the other hand, the FIFO memory 93a does not particularly store the blue (B) color component signal input from the image sensor column 70, and synchronizes with the output of the blue (B) color component signal of the first column L1. Thus, the red (R) first color component signal L1 and the green (G) first color component signal are output. However, from the FIFO memory 93a, the color component signal of the blue (B) first column L1 is used as the new color component signal of the first column L1 ′, and the blue (B) third column L3 of the blue column (B). The color component signals are respectively output as new color component signals of the second column L2 ′.
Therefore, from the gap correction unit 93, the nth row of red (R), green (G), and blue (B) obtained by reading the same row in the sub-scanning direction SS of the document M (in this case, n is n). Odd) color component signals are sequentially output in numerical order in a synchronized state.

  FIG. 10 is a diagram for explaining the output (RGB) of the light receiving unit 48 and the output (RGB) of the gap correction unit 93 provided in the control / image processing unit 49 when the sub-scanning designated magnification Y is 400%. It is a timing chart. When the sub-scanning specified magnification Y is 400%, as described above, the scanning speed V is set to ¼ (Vs / 4) of the reference scanning speed Vs, and the imaging period T is set to the reference imaging period Ts. The element array charge discharge is set to “present (3/4)”, and the sub-scanning reduction ratio R is set to 1.

  When reading of the document M is started, the image sensor driving unit 98 provided in the control / image processing unit 49 sends the reference image capturing period Ts and the image sensor column charge discharge to the vertical transfer pulse generating circuit 81 of the light receiving unit 48. A signal corresponding to “present (3/4)” is supplied. Then, in the light receiving unit 48, the vertical transfer pulse generation circuit 81 generates a shift pulse SH based on this signal and supplies it to the shift gates 51, 61, 71. Also, the vertical transfer pulse generation circuit 81 generates a control signal DS that becomes low level in the first imaging cycle T and becomes high level in the other second to fourth imaging cycles T among four consecutive imaging cycles T. And supplied to the shutter drains 53, 63, 73. Therefore, “existence (3/4)” of the image pickup device array charge discharge refers to a case where the control signal DS that becomes a high level at a rate of 3/4 is output. Thus, in the present embodiment, the shutter drains 53, 63, 73 function as the adjusting means.

Further, in each of the image pickup devices PD constituting the image pickup device arrays 50, 60, and 70, charges are accumulated by receiving reflected light from the document M.
In the light receiving unit 48, the shift pulse SH is supplied to the shift gates 51, 61, and 71 at the same timing, so that the imaging elements 50, 60, and 70 are synchronized with the shift pulse SH in the imaging cycle T (in this case). For each reference imaging cycle Ts), the charges for the FS1 line in the main scanning direction are sequentially output to the horizontal transfer registers 52, 62, 72. Then, the charges for the main scanning direction FS1 line transferred to the horizontal transfer registers 52, 62, 72 pass through the charge / voltage converters 54, 64, 74 and the analog amplifiers 55, 65, 75, and then the control / image processing unit 49. Are output sequentially.

  However, in the light receiving unit 48, the imaging element rows 50, 60, and 70 are arranged at a distance G in the sub-scanning direction SS as shown in FIG. 3, and the sub-scanning designated magnification Y is 400%. Since the scanning speed V is 1/4 compared to the case where the sub-scanning designated magnification Y is 100%, the positions on the original M that are separated by 16 columns in the sub-scanning direction SS are read. For this reason, taking in the green (G) data (charge) from the image sensor array 60 is started 16 delays after the start of taking in the red (R) data (charge) from the image sensor array 50. . Further, the capture of green (G) data (charge) from the image sensor array 60 is started, and the capture of blue (B) data (charge) from the image sensor array 70 is started with a delay of 16 columns. That is, in this example, when the image sensor row 50 starts reading the first row L1, and then reads the 17th row L17, the image sensor row 60 starts reading the first row L1. . Further, in this example, when the image sensor column 50 reads the 33rd column L33 and when the image sensor column 60 reads the 17th column L17, the image sensor column 70 starts reading the first column L1. Will do.

  Here, when the sub-scanning designated magnification Y is set to 400%, in the four imaging periods T in which the control signal DS is continuous, the first imaging period T becomes a low level and the other 2 to 4th imaging periods T are set. Then, by repeating the high level state, the charge discharging operation by the shutter drains 53, 63, 73 is performed in the second to fourth imaging periods T among the four consecutive imaging periods T. Therefore, among the charges accumulated in the image sensor rows 50, 60, and 70, those obtained in the row (L1, L5, L9...) Whose remainder becomes 1 when divided by 4 on the document M. Although output is made to the outside via the horizontal transfer registers 52, 62, 72 (shown by solid lines in the figure), the other columns on the document M (L2-L4, L6-L8, L10-L12,...). ) Is previously discharged by the shutter drains 53, 63, 73, and therefore is not output to the outside via the horizontal transfer registers 52, 62, 72 (indicated by broken lines in the figure). It is like that. For this reason, the read data of each column output from the image sensor column 50, 60, 70 is the column number of the first column (L1, L5, L9,...) Whose remainder is 1 when divided by 4. Are output sequentially in ascending order. That is, when the sub-scanning designated magnification Y is set to 400%, the light receiving unit 48 determines the number of read data pixels for the FS1 line in the main scanning direction acquired in each of the imaging element rows 50, 60, and 70. The number of pixels of read data for one line in the main scanning direction FS output to the control / image processing unit 49 is ¼.

Further, in the gap correction unit 93 provided in the control / image processing unit 49, the FIFO memory 93a receives the red (R) color component signal input from the image sensor column 50 in the first column L1 and the fifth column. Eight columns are sequentially stored in the order of the eyes L5,... And the 29th column L29 is stored, and then sequentially output in the order of the first column L1, the fifth column L5,. At this time, from the FIFO memory 93a, the color component signal of the red (R) first column L1 is used as a new color component signal of the first column L1 ′, and the red (R) fifth column L5. Are output as new color component signals of the second column L2 ′. The FIFO memory 93a stores the green (G) color component signals input from the image sensor array 60 in order of the first column L1, the fifth column L5,... After storing up to the column L13, the data are sequentially output in the order of the first column L1, the fifth column L5,. At this time, from the FIFO memory 93a, the color component signal of the first row L1 of green (G) is used as a new color component signal of the first row L1 ′, and the fifth row L5 of green (G). Are output as new color component signals of the second column L2 ′. On the other hand, the FIFO memory 93a does not particularly store the blue (B) color component signal input from the image sensor column 70, and synchronizes with the output of the blue (B) color component signal of the first column L1. Thus, the red (R) first color component signal L1 and the green (G) first color component signal are output. However, from the FIFO memory 93a, the color component signal of the first column L1 of blue (B) is the new color component signal of the first column L1 ′, and the color component signal of the fifth column L3 of blue (B) The color component signals are respectively output as new color component signals of the second column L2 ′.
Therefore, from the gap correction unit 93, the nth row of red (R), green (G), and blue (B) obtained by reading the same row in the sub-scanning direction SS of the document M (in this case, n is n). The number of color component signals that have a remainder of 1 when divided by 4 is sequentially output in numerical order in a synchronized state.

  FIG. 11 illustrates a reading row on the document M when the sub-scanning designated magnification Y is 100% (see FIG. 8), 200% (see FIG. 9), and 400% (see FIG. 10) in the first embodiment. FIG. Here, FIG. 11A shows the case where the sub-scanning designated magnification Y is 100%, FIG. 11B shows the case where the sub-scanning designated magnification Y is 200%, and FIG. 11C shows the sub-scanning designated magnification Y. , 400%, respectively.

  In the present embodiment, when the sub-scanning designated magnification Y is 100%, the imaging period T is set to the reference imaging period Ts, and the scanning speed V is set to the reference scanning speed Vs. Here, as shown in FIG. 11A, in the read data input to the gap correction unit 93 of the control / image processing unit 49 when the sub-scanning designated magnification Y is set to 100%, the sub-scan direction An interval between two reading columns (for example, the first column L1 and the second column L2) adjacent to the SS is referred to as a 100% inter-column distance D100.

  Further, in the present embodiment, when the sub-scanning specified magnification Y is 200%, the imaging period T is set to the reference imaging period Ts, while the scanning speed V is changed to ½ of the reference scanning speed Vs. . That is, when the sub-scanning specified magnification Y is 200%, the scanning period V is reduced to ½ although the imaging cycle T is the same as when the sub-scanning specified magnification Y is 100%. Then, as shown in FIG. 11B, the image sensor rows 50, 60, and 70 of the light receiving unit 48 perform reading at the same 100% inter-column distance D100 as when the sub-scanning designated magnification Y is 100%. Become. However, in the present embodiment, the light receiving unit 48 uses the shutter drains 53, 63, 73 to thin out even-numbered read data. For this reason, only the read data in the odd-numbered column is output to the control / image processing unit 49. As a result, in the reading data input to the gap correction unit 93 of the control / image processing unit 49 when the sub-scanning specified magnification Y is set to 200%, two reading rows (for example, the first scanning row adjacent to the sub-scanning direction SS) The distance between the first row L1 and the third row L3) is a 200% inter-row distance D200 that is twice the 100% inter-row distance D100.

  Further, in the present embodiment, when the sub-scanning specified magnification Y is 400%, the imaging period T is set to the reference imaging period Ts, while the scanning speed V is changed to ¼ of the reference scanning speed V. . That is, when the sub-scanning specified magnification Y is 400%, the scanning speed V is reduced to ¼ although the imaging cycle T is the same as when the sub-scanning specified magnification Y is 100%. Then, as shown in FIG. 11C, the image sensor rows 50, 60, and 70 of the light receiving unit 48 perform reading at the same 100% inter-column distance D100 as when the sub-scanning designated magnification Y is 100%. Become. However, in the present embodiment, the light receiving unit 48 performs thinning of the read data of the second column that does not have a remainder of 1 when divided by 4 out of 4 consecutive columns using the shutter drains 53, 63, 73. ing. For this reason, only the read data of the second column whose remainder is 1 when divided by 4 out of the four consecutive columns is output to the control / image processing unit 49. As a result, in the read data input to the gap correction unit 93 of the control / image processing unit 49 when the sub-scanning designated magnification Y is set to 400%, two read columns (for example, the first scan rows adjacent to the sub-scan direction SS) The interval between the first row L1 and the fifth row L5) is a 400% inter-column distance D400 that is four times the 100% inter-column distance D100.

  In the present embodiment, when the sub-scanning designated magnification Y exceeds 100%, that is, when enlargement of the magnification in the sub-scanning direction SS is designated, the read data of each RGB color is reduced in units of columns in advance on the light receiving unit 48 side. I tried to keep it. This suppresses an increase in the capacity of the FIFO memory 93a required when synchronizing the read data of each RGB color by performing the delay process in the gap correction unit 93. In particular, in the present embodiment, the capacity of the FIFO memory 93a necessary for gap correction is necessary when the sub-scanning specified magnification Y is 100% in the range where the sub-scanning specified magnification Y exceeds 100% and is 400% or less. The capacity of the FIFO memory 93a is sufficient.

  In the present embodiment, when the sub-scanning designated magnification Y is set to 100% <Y <200%, the read data is acquired under the condition that the sub-scanning designated magnification Y is set to 200%. If the sub-scanning designated magnification Y is set to 200% <Y <400% by performing a reduction process by calculation later to obtain data of the desired sub-scanning designated magnification Y, the sub-scanning designated magnification Y is After obtaining the read data under the condition of setting it to 400%, the reduction processing by the calculation is performed to obtain the data of the desired sub-scanning designated magnification Y. When such a process is not employed, it is necessary to perform gap correction below the decimal point using a known sub-scanning two-point interpolation or the like in the gap correction unit 93. By adopting such a process, the gap is corrected. The increase in the capacity of the FIFO memory 93a necessary for correction and the complicated processing in the gap correction unit 93 are suppressed.

  In this embodiment, when the sub-scanning specified magnification Y is 200%, the read data of the odd-numbered columns is left while the read data of the even-numbered columns is discarded. However, the present invention is limited to this. Instead, the reverse relationship is also possible. Further, in the present embodiment, when the sub-scanning designated magnification Y is 400%, the read data of the column whose remainder becomes 1 when it is divided by 4 out of the 4 consecutive columns is left, while the remaining columns Although the read data is discarded, the present invention is not limited to this, and any one of the remaining columns may be selectively left.

<Embodiment 2>
The basic configuration of the present embodiment is the same as that of the first embodiment. In the first embodiment, the number of columns in the read data is reduced on the light receiving unit 48 side, whereas in the present embodiment, control is performed. The number of columns in the read data is reduced on the image processing unit 49 side. In this embodiment, the method for reducing the number of columns of read data is different from that in the first embodiment. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 12 is a block diagram showing the main configuration of the control / image processing unit 49 in the present embodiment. The difference from the control / image processing unit 49 (FIG. 6) in the first embodiment is that a sub-scanning averaging unit 90 is further provided.
The sub-scanning averaging unit 90 is connected to the output side of the light quantity distribution correction unit 92 and is connected to the input side of the gap correction unit 93. Therefore, in the present embodiment, the gap correction unit 93 performs gap correction based on the output from the sub-scanning averaging unit 90.

  The sub-scanning averaging unit 90 outputs, based on digital signals corresponding to the RGB color components after light amount correction, output values acquired by the same color and the same image sensor PD in a plurality of reading rows continuous in the sub-scanning direction SS. Then, after adding up the number of target read columns, it is divided by the number of target read columns, thereby calculating the average output value for each pixel. Here, with reference to FIG. 5, when averaging is performed for two consecutive columns in the sub-scanning direction SS, for example, the red (R) n-th column Ln is positioned at one end in the main scanning direction FS. The output value of the first image sensor PD provided (corresponding to the charge P1) and the output value of the first image sensor PD in the red (R) n + 1-th column Ln + 1 (corresponding to the charge P1) are added. After that, the calculation is performed by dividing by 2 which is the number of columns. Then, this calculation is sequentially performed in the order of the number of the image sensor PD, and finally the kth image sensor PD is calculated to average a plurality of columns (two columns in this example) continuous in the sub-scanning direction SS. To obtain a digital signal in one row. Here, the sub-scanning averaging unit 90 includes three averaging circuits 90a corresponding to RGB colors.

  FIG. 13 is a diagram showing a relationship between the sub-scanning designated magnification Y and each reading condition in the present embodiment. In the present embodiment, according to the sub-scanning specified magnification Y, the reading conditions include the scanning speed V in the sub-scanning direction SS in reading, the imaging period T of the light receiving unit 48 in reading, and the sub-scanning in the sub-scanning averaging unit 90. The sub-scanning reduction ratio R used in the enlargement / reduction processing in the sub-scanning enlargement / reduction unit 95 is changed as well as whether or not the averaging is executed. These setting conditions are stored in a memory (not shown) or the like provided in the control / image processing unit 49. Then, the CPU 99 reads out these reading conditions in accordance with the sub-scanning designated magnification Y set through the user interface control unit 96, and sets the scanning speed V through the motor drive control unit 97 and the image sensor driving unit 98. The sub-scanning averaging unit 90 controls the sub-scanning averaging, and the sub-scanning enlargement / reduction unit 95 further controls the sub-scanning reduction ratio R.

  Further, in FIG. 13, as a reference, the usage amount of the FIFO memory 93a used for gap correction in the gap correction unit 93 corresponding to the sub-scanning designated magnification Y (denoted as gap correction usage memory amount in the figure). ).

When the sub-scanning designated magnification Y is 100% (equal magnification), the scanning speed V is set to the reference scanning speed Vs, and the imaging period T is set to the reference imaging period Ts. Further, when the sub-scanning designated magnification Y is 100%, the sub-scan averaging is set to “none”, and the sub-scan reduction ratio R is set to 1.
When the sub-scanning designated magnification Y is 25% (reduction), the scanning speed V is set to the reference scanning speed Vs, and the imaging cycle T is set to the reference imaging cycle Ts. Further, when the sub-scanning designated magnification Y is 25%, the sub-scan averaging is set to “none”, and the sub-scan reduction ratio R is set to ¼.
When the sub-scanning designated magnification Y is 50% (reduction), the scanning speed V is set to the reference scanning speed Vs, and the imaging period T is set to the reference imaging period Ts. Further, when the sub-scanning designated magnification Y is 50%, the sub-scan averaging is set to “none”, and the sub-scan reduction ratio R is set to 1/2.

When the sub-scanning designated magnification Y is 200% (enlargement), the scanning speed V is set to half the reference scanning speed Vs (Vs / 2), and the imaging period T is set to the reference imaging period Ts. . Further, when the sub-scanning designated magnification Y is 200%, the sub-scan averaging is set to “Yes (2 columns)”, and the sub-scanning reduction ratio R is set to 1. The meaning of “two columns” in sub-scanning averaging will be described later.
When the sub-scanning designated magnification Y is 400% (enlargement), the scanning speed V is set to 1/4 (Vs / 4) of the reference scanning speed Vs, and the imaging period T is set to the reference imaging period Ts. The Further, when the sub-scanning designated magnification Y is 400%, the sub-scan averaging is set to “Yes (4 columns)”, and the sub-scan reduction ratio R is set to 1. The meaning of “four columns” in the sub-scanning averaging will be described later.

On the other hand, when the designated sub-scanning magnification Y exceeds 25% and is less than 50% (reduction), the scanning speed V is set to the reference scanning speed Vs, and the imaging period T is set to the reference imaging period Ts. The Further, when the sub-scanning specified magnification Y exceeds 25% and is less than 50%, the sub-scan averaging is selected as “None”, and the sub-scan reduction ratio R is selected from a range that exceeds 1/4 and does not reach 1/2. Is set to the value to be set.
When the sub-scanning designated magnification Y exceeds 50% and is less than 100% (reduction), the scanning speed V is set to the reference scanning speed Vs, and the imaging period T is set to the reference imaging period Ts. Further, when the sub-scanning designated magnification Y exceeds 50% and is less than 100%, the sub-scan averaging is selected as “None” and the sub-scanning reduction ratio R is selected from the range exceeding 1/2 and less than 1. Each value is set.

When the sub-scanning designated magnification Y exceeds 100% and is less than 200% (enlargement), the scanning speed V is half of the reference scanning speed Vs (Vs / 2), and the imaging period T is the reference imaging period Ts. Respectively. Further, when the sub-scanning specified magnification Y exceeds 100% and is not less than 200%, the sub-scan averaging is “Yes (2 columns)”, and the sub-scanning reduction ratio R is more than 1/2 and less than 1. Each value is set to a more selected value.
When the sub-scanning specified magnification Y exceeds 200% and is less than 400% (enlargement), the scanning speed V is ¼ (Vs / 4) of the reference scanning speed Vs, and the imaging cycle T is the reference imaging cycle. Each is set to Ts. Further, when the sub-scanning specified magnification Y is over 200% and less than 400%, the sub-scan averaging is “Yes (4 columns)”, and the sub-scanning reduction ratio R is over 1/2 and less than 1. Each value is set to a more selected value.

Thus, in the present embodiment, when the sub-scanning designated magnification Y is less than 100%, reading is performed at the same scanning speed V and imaging cycle T as when the sub-scanning designated magnification Y is 100%. As a result, after acquiring the image data in a state of being larger than the target sub-scanning specified magnification Y, the target sub-scanning reduction ratio R used in the sub-scanning enlargement / reduction unit 95 is changed to thereby achieve the target sub-scanning. The image is reduced to a specified magnification Y.
For example, when the sub-scanning specified magnification Y is 75%, the original M is read at the same scanning speed V and imaging cycle T as when the sub-scanning specified magnification Y is 100%, and the obtained image data is read. In the sub-scanning enlargement / reduction unit 95, digital reduction processing is performed in a state where the sub-scanning reduction ratio R is set to 3/4 (0.75), and as a result, image data (according to the sub-scanning designated magnification Y) ( 100% × 0.75 = 75%) is output.

In the present embodiment, when the sub-scanning specified magnification Y exceeds 100% but is not less than 200%, the same scanning speed V and imaging cycle T (imaging element) as when the sub-scanning specified magnification Y is 200%. (Including the presence / absence and setting of column charge discharge). As a result, after acquiring image data in an enlarged state than the target sub-scanning specified magnification Y, the sub-scanning reduction ratio R used in the sub-scanning enlargement / reduction unit 95 is changed to thereby change the target sub-scanning reduction ratio R. The image is reduced to the scanning designated magnification Y.
For example, when the sub-scanning designated magnification Y is 150%, the document M is read at the same scanning speed V and imaging cycle T as when the sub-scanning designated magnification Y is 200%, and the obtained image data is read. In the sub-scanning enlargement / reduction unit 95, digital reduction processing is performed in a state where the sub-scanning reduction ratio R is set to 3/4 (0.75), and as a result, image data (according to the sub-scanning designated magnification Y) ( 200% × 0.75 = 150%) is output.

Further, in the present embodiment, when the sub-scanning specified magnification Y exceeds 200% but is less than 400%, the same scanning speed V and imaging cycle T (imaging element) as when the sub-scanning specified magnification Y is 400%. (Including the presence / absence and setting of column charge discharge). As a result, after acquiring image data in an enlarged state than the target sub-scanning specified magnification Y, the sub-scanning reduction ratio R used in the sub-scanning enlargement / reduction unit 95 is changed to thereby change the target sub-scanning reduction ratio R. The image is reduced to the scanning designated magnification Y.
For example, when the sub-scanning designated magnification Y is 300%, the original M is read at the same scanning speed V and imaging period T as when the sub-scanning designated magnification Y is 400%, and the obtained image data is read. In the sub-scanning enlargement / reduction unit 95, digital reduction processing is performed in a state where the sub-scanning reduction ratio R is set to 3/4 (0.75), and as a result, image data (according to the sub-scanning designated magnification Y) ( 400% × 0.75 = 300%) is output.

  Now, explanation will be given with specific examples. However, in the present embodiment, when the sub-scanning specified magnification Y is 100%, the sub-scan averaging is set to “none”, and as a result, the same processing as in the first embodiment is performed. Detailed description thereof will be omitted.

  FIG. 14 shows the output (RGB) of the light receiving unit 48 when the designated sub-scanning magnification Y is 200%, the output (RGB) of the sub-scanning averaging unit 90 provided in the control / image processing unit 49, and the gap correction unit 93. It is a timing chart for demonstrating the output (RGB) of this. When the sub-scanning designated magnification Y is 200%, as described above, the scanning speed V is 1/2 (Vs / 2) of the reference scanning speed Vs, the imaging cycle T is the reference imaging cycle Ts, and the sub-scanning is performed. The averaging is set to “present (2 columns)”, and the sub-scanning reduction ratio R is set to 1.

  When reading of the document M is started, the image sensor driving unit 98 provided in the control / image processing unit 49 supplies a signal corresponding to the reference imaging cycle Ts to the vertical transfer pulse generating circuit 81 of the light receiving unit 48. . Then, in the light receiving unit 48, the vertical transfer pulse generation circuit 81 generates a shift pulse SH based on this signal and supplies it to the shift gates 51, 61, 71. In the present embodiment, the vertical transfer pulse generation circuit 81 generates a control signal DS that is always maintained at a low level and supplies it to the shutter drains 53, 63, 73.

Further, in each of the image pickup devices PD constituting the image pickup device arrays 50, 60, and 70, charges are accumulated by receiving reflected light from the document M.
In the light receiving unit 48, the shift pulse SH is supplied to the shift gates 51, 61, and 71 at the same timing, so that the imaging elements 50, 60, and 70 are synchronized with the shift pulse SH in the imaging cycle T (in this case). For each reference imaging cycle Ts), the charges for the FS1 line in the main scanning direction are sequentially output to the horizontal transfer registers 52, 62, 72. Then, the charges for the main scanning direction FS1 line transferred to the horizontal transfer registers 52, 62, 72 pass through the charge / voltage converters 54, 64, 74 and the analog amplifiers 55, 65, 75, and then the control / image processing unit 49. Are output sequentially.

  However, in the light receiving unit 48, the imaging element rows 50, 60, and 70 are arranged at a distance G in the sub-scanning direction SS as shown in FIG. 3, and the sub-scanning designated magnification Y is 200%. Since the scanning speed V is ½ compared to the case where the sub-scanning designated magnification Y is 100%, the positions on the original M that are separated by 8 columns in the sub-scanning direction SS are read. For this reason, after the start of taking in the red (R) data (charge) from the image pickup device array 50, the start of taking in the green (G) data (charge) from the image pickup device array 60 after eight columns. . In addition, the capture of green (G) data (charge) from the image sensor array 60 is started, and the capture of blue (B) data (charge) from the image sensor array 70 is started after a delay of 8 columns. That is, in this example, when the image sensor column 50 starts reading the first row L1, the image sensor column 60 starts reading the first row L1 when reading the ninth row L9. . Further, in this example, when the image sensor column 50 reads the 17th column L17 and when the image sensor column 60 reads the ninth column L9, the image sensor column 70 starts reading the first column L1. Will do.

  In the present embodiment, the charge drain operation by the shutter drains 53, 63, 73 is not performed by maintaining the control signal DS at a low level. For this reason, the read data of each column output from the imaging element columns 50, 60, and 70 are sequentially output in the order of the column numbers.

  In addition, the sub-scanning averaging unit 90 provided in the control / image processing unit 49 receives the RGB color component signals in the order of the numbers in the first column L1, the second column L2,. Input sequentially.

  At this time, the averaging circuit 90a for processing the red (R) color component signal reads the read data of the odd-numbered columns (L1, L3, L5,...) On the document M and the even-numbered columns (L2) adjacent to the subsequent stage. , L4, L6,...) Is averaged pixel by pixel. More specifically, for example, the read data of the first row L1 of red (R) and the read data of the second row L2 of red (R) are averaged, and the first row of red (R) is obtained. The red (R) new first row read data L1 ′ obtained by combining the read data of the eye L1 and the red (R) second row L2 is output. Similarly, a new second red (R) data obtained by combining the read data of the third row L3 of red (R) and the read data of the fourth row L4 of red (R). A new red (R) data obtained by combining the read data L2 ′ of the column, the read data of the fifth column L5 of red (R) and the read data of the sixth column L6 of red (R). Read data L3 ′,... In the third column are sequentially output.

  Further, the averaging circuit 90a that processes the green (G) color component signal also reads the read data of the odd-numbered columns (L1, L3, L5,...) On the original M and the even-numbered columns (L2,. (L4, L6,...) Read data is averaged pixel by pixel. More specifically, for example, the read data of the first row L1 of green (G) and the read data of the second row L2 of green (G) are averaged, and the first row of green (G) The read data L1 ′ of the new first row of green (G) obtained by combining the read data of the eye L1 and the read data of the second row L2 of green (G) is output. Similarly, a new second green (G) obtained by combining the read data of the third row L3 of green (G) and the read data of the fourth row L4 of green (G). The green (G) new data obtained by combining the read data L2 ′ of the row, the read data of the fifth row L5 of green (G) and the read data of the sixth row L6 of green (G). Read data L3 ′,... In the third column are sequentially output.

Further, the averaging circuit 90a for processing the blue (B) color component signal also reads the read data of the odd-numbered columns (L1, L3, L5,...) On the document M and the even-numbered columns (L2,. (L4, L6,...) Read data is averaged pixel by pixel. More specifically, for example, the blue (B) first row L1 read data and the blue (B) second row L2 read data are averaged, and the blue (B) first row is averaged. The new blue (B) first row read data L1 ′ obtained by combining the read data of the eye L1 and the blue (B) second row L2 read data is output. Similarly, the new second data of blue (B) obtained by combining the read data of the third row L3 of blue (B) and the read data of the fourth row L4 of blue (B). The blue (B) new data obtained by combining the read data L2 ′ of the column, the read data of the fifth column L5 of blue (B) and the read data of the sixth column L6 of blue (B) Read data L3 ′,... In the third column are sequentially output.
Therefore, the sub-scan averaging “present (two columns)” refers to a case where two rows of read data continuous in the sub-scanning direction SS are averaged. Thus, in the present embodiment, the sub-scanning averaging unit 90 functions as an adjustment unit.

  Here, the RGB color component signals are input to the sub-scanning averaging unit 90 in a state of being shifted by 8 columns. However, when the sub-scanning designated magnification Y is 200%, the sub-scanning averaging unit 90 performs averaging for every two consecutive columns, so that the RGB color component signals are apparent from the sub-scanning averaging unit 90. It is output in a state shifted by the upper four columns. That is, in this example, after the sub-scanning averaging unit 90 outputs the read data of the new first row L1 ′ of red (R), the read data of the new fifth row L5 ′ of red (R) Is output, the read data of the new first row L1 ′ of green (G) is output. Further, in this example, when the sub-scanning averaging unit 90 outputs the read data of the new ninth row L9 ′ for red (R) and the read data of the new fifth row L5 ′ for green (G). Is output, the read data of the new first row L1 ′ of blue (B) is output.

In the gap correction unit 93 provided in the control / processing unit 49, the FIFO memory 93a converts the red (R) color component signal input from the sub-scanning averaging unit 90 into a new first column L1 ′. , The second second row L2 ′,... Are sequentially stored in the order of eight columns, and after the new eighth column L8 ′ is stored, the new first column L1 ′ previously stored, The data is sequentially output in the order of the second column L2 ′,. Further, the FIFO memory 93a sequentially outputs the green (G) color component signals input from the sub-scanning averaging unit 90 in the order of the new first column L1 ′, the new second column L2 ′,. After the columns are stored and the new fourth column L4 ′ is stored, the new first column L1 ′, the new second column L2 ′,... . On the other hand, the FIFO memory 93a does not particularly store the blue (B) color component signal input from the sub-scanning averaging unit 90, and does not store the blue (B) color component of the first first row L1 ′. The red (R) first color component signal and the green (G) first color component signal are output in synchronization with the signal output.
Therefore, the n-th color component signal of red (R), green (G), and blue (B) obtained by reading the same column from the gap correction unit 93 in the sub-scanning direction SS of the document M is In the synchronized state, the data are sequentially output in numerical order.

  FIG. 15 shows the output (RGB) of the light receiving unit 48 when the designated sub-scanning magnification Y is 400%, the output (RGB) of the sub-scanning averaging unit 90 provided in the control / image processing unit 49, and the gap correction unit 93. It is a timing chart for demonstrating the output (RGB) of this. When the sub-scanning specified magnification Y is 400%, as described above, the scanning speed V is 1/4 (Vs / 4) of the reference scanning speed Vs, the imaging cycle T is set to the reference imaging cycle Ts, and the sub-scanning is performed. The averaging is set to “present (4 columns)”, and the sub-scanning reduction ratio R is set to 1.

  When reading of the document M is started, the image sensor driving unit 98 provided in the control / image processing unit 49 supplies a signal corresponding to the reference imaging cycle Ts to the vertical transfer pulse generating circuit 81 of the light receiving unit 48. . Then, in the light receiving unit 48, the vertical transfer pulse generation circuit 81 generates a shift pulse SH based on this signal and supplies it to the shift gates 51, 61, 71. In the present embodiment, the vertical transfer pulse generation circuit 81 generates a control signal DS that is always maintained at a low level and supplies it to the shutter drains 53, 63, 73.

Further, in each of the image pickup devices PD constituting the image pickup device arrays 50, 60, and 70, charges are accumulated by receiving reflected light from the document M.
In the light receiving unit 48, the shift pulse SH is supplied to the shift gates 51, 61, and 71 at the same timing, so that the imaging elements 50, 60, and 70 are synchronized with the shift pulse SH in the imaging cycle T (in this case). For each reference imaging cycle Ts), the charges for the FS1 line in the main scanning direction are sequentially output to the horizontal transfer registers 52, 62, 72. Then, the charges for the main scanning direction FS1 line transferred to the horizontal transfer registers 52, 62, 72 pass through the charge / voltage converters 54, 64, 74 and the analog amplifiers 55, 65, 75, and then the control / image processing unit 49. Are output sequentially.

  However, in the light receiving unit 48, the imaging element rows 50, 60, and 70 are arranged at a distance G in the sub-scanning direction SS as shown in FIG. 3, and the sub-scanning designated magnification Y is 400%. Since the scanning speed V is 1/4 compared to the case where the sub-scanning designated magnification Y is 100%, the positions on the original M that are separated by 16 columns in the sub-scanning direction SS are read. For this reason, taking in the green (G) data (charge) from the image sensor array 60 is started 16 delays after the start of taking in the red (R) data (charge) from the image sensor array 50. . Further, the capture of green (G) data (charge) from the image sensor array 60 is started, and the capture of blue (B) data (charge) from the image sensor array 70 is started with a delay of 16 columns. That is, in this example, when the image sensor row 50 starts reading the first row L1, and then reads the 17th row L17, the image sensor row 60 starts reading the first row L1. . Further, in this example, when the image sensor column 50 reads the 33rd column L33 and when the image sensor column 60 reads the 17th column L17, the image sensor column 70 starts reading the first column L1. Will do.

  In the present embodiment, the charge drain operation by the shutter drains 53, 63, 73 is not performed by maintaining the control signal DS at a low level. For this reason, the read data of each column output from the imaging element columns 50, 60, and 70 are sequentially output in the order of the column numbers.

  In addition, the sub-scanning averaging unit 90 provided in the control / image processing unit 49 receives the RGB color component signals in the order of the numbers in the first column L1, the second column L2,. Input sequentially.

  At this time, the averaging circuit 90a that processes the red (R) color component signal performs a process of averaging the read data of four consecutive columns (for example, L1 to L4) on the document M in units of pixels. More specifically, for example, read data of the first row L1 of red (R), read data of the second row L2 of red (R), read data of the third row L3 of red (R), and red The read data of the fourth row L4 of (R) is averaged, and the red (R) obtained by combining the read data of the first row L1 to the fourth row L4 of red (R) New read data L1 ′ in the first column is output. Similarly, the red (R) read data L2 ′ of the second second column obtained by combining the read data of the red (R) fifth column L5 to the eighth column L8, red Red (R) new third column read data L3 ′,... Obtained by combining the read data of the ninth column L9 to the twelfth column L12 of (R) are sequentially output.

  The averaging circuit 90a that processes the green (G) color component signal also performs a process of averaging four columns (for example, L1 to L4) of read data on the document M in units of pixels. More specifically, for example, the read data of the first row L1 of green (G), the read data of the second row L2 of green (G), the read data of the third row L3 of green (G) and the green The read data of the fourth row L4 of (G) is averaged, and the green (G) obtained by combining the read data of the first row L1 to the fourth row L4 of green (G) New read data L1 ′ in the first column is output. Similarly, the read data L2 ′ of the new second row of green (G) obtained by combining the read data of the fifth row L5 to the eighth row L8 of green (G), green The green (G) new third column read data L3 ′,... Obtained by combining the read data of the ninth column L9 to the twelfth column L12 in (G) are sequentially output.

Further, the averaging circuit 90a that processes the blue (B) color component signal also performs a process of averaging the read data of four consecutive columns (for example, L1 to L4) on the document M in units of pixels. More specifically, for example, blue (B) first row L1 read data, blue (B) second row L2 read data, blue (B) third row L3 read data, and blue The read data of the fourth row L4 in (B) is averaged, and the blue (B) obtained by combining the read data of the first row L1 to the fourth row L4 of blue (B) New read data L1 ′ in the first column is output. Similarly, the read data L2 ′ of the new second row of blue (B) obtained by combining the read data of the fifth row L5 to the eighth row L8 of blue (B), blue The blue (B) new third column read data L3 ′,... Obtained by synthesizing the read data of the ninth column L9 to the twelfth column L12 in (B) are sequentially output.
Therefore, the sub-scan averaging “present (four columns)” means a case where four columns of read data continuous in the sub-scanning direction SS are averaged.

In the gap correction unit 93 provided in the control / processing unit 49, the FIFO memory 93a converts the red (R) color component signal input from the sub-scanning averaging unit 90 into a new first column L1 ′. , The second second row L2 ′,... Are sequentially stored in the order of eight columns, and after the new eighth column L8 ′ is stored, the new first column L1 ′ previously stored, The data is sequentially output in the order of the second column L2 ′,. Further, the FIFO memory 93a sequentially outputs the green (G) color component signals input from the sub-scanning averaging unit 90 in the order of the new first column L1 ′, the new second column L2 ′,. After the columns are stored and the new fourth column L4 ′ is stored, the new first column L1 ′, the new second column L2 ′,... . On the other hand, the FIFO memory 93a does not particularly store the blue (B) color component signal input from the sub-scanning averaging unit 90, and does not store the blue (B) color component of the first first row L1 ′. The red (R) first color component signal and the green (G) first color component signal are output in synchronization with the signal output.
Therefore, the n-th color component signal of red (R), green (G), and blue (B) obtained by reading the same column from the gap correction unit 93 in the sub-scanning direction SS of the document M is In the synchronized state, the data are sequentially output in numerical order.

  FIG. 16 illustrates a reading row on the document M when the sub-scanning designated magnification Y is 100% (see FIG. 8), 200% (see FIG. 14), and 400% (see FIG. 15) in the second embodiment. FIG. 16A shows the case where the sub-scanning designated magnification Y is 100%, FIG. 16B shows the case where the sub-scanning designated magnification Y is 200%, and FIG. 16C shows the sub-scanning designated magnification Y. , 400%, respectively. Since FIG. 16A is the same as FIG. 11A, description thereof is omitted.

  In the present embodiment, when the sub-scanning designated magnification Y is 200%, the imaging period T is set to the reference imaging period Ts, while the scanning speed V is changed to ½ of the reference scanning speed Vs. That is, when the sub-scanning specified magnification Y is 200%, the scanning period V is reduced to ½ although the imaging cycle T is the same as when the sub-scanning specified magnification Y is 100%. Then, as shown on the left side of FIG. 16B, the image sensor rows 50, 60 and 70 of the light receiving unit 48 read at the same 100% inter-column distance D100 as when the sub-scanning designated magnification Y is 100%. It will be. However, in the present embodiment, the control / image processing unit 49 uses the sub-scanning averaging unit 90 to average two columns in the sub-scanning direction SS to form one column. As a result, in the read data input to the gap correction unit 93 of the control / image processing unit 49 when the sub-scanning designated magnification Y is set to 200%, two read columns adjacent to the sub-scanning direction SS (for example, new As shown on the right side of FIG. 16B, the interval between the first first row L1 ′ and the new second row L2 ′) is a 200% inter-column distance D200 that is twice the 100% inter-column distance D100. It becomes.

  In the present embodiment, when the sub-scanning specified magnification Y is 400%, the imaging period T is set to the reference imaging period Ts, while the scanning speed V is changed to ¼ of the reference scanning speed Vs. . That is, when the sub-scanning specified magnification Y is 400%, the scanning speed V is reduced to ¼ although the imaging cycle T is the same as when the sub-scanning specified magnification Y is 100%. Then, as shown on the left side of FIG. 16C, the imaging element rows 50, 60, and 70 of the light receiving unit 48 perform reading at the same 100% inter-column distance D100 as when the sub-scanning designated magnification Y is 100%. It will be. However, in the present embodiment, the control / image processing unit 49 uses the sub-scanning averaging unit 90 to average four columns that are continuous in the sub-scanning direction SS to form one column. As a result, in the read data input to the gap correction unit 93 of the control / image processing unit 49 when the sub-scanning designated magnification Y is set to 400%, two read columns adjacent to the sub-scanning direction SS (for example, new As shown on the right side of FIG. 16C, the distance between the first first row L1 ′ and the new second row L2 ′) is a 400% inter-column distance D400 that is four times the 100% inter-column distance D100. It becomes.

  In the present embodiment, when the sub-scanning designated magnification Y exceeds 100%, that is, when enlargement of the magnification in the sub-scanning direction SS is designated, the sub-scanning averaging unit 90 preliminarily reads the read data of each RGB color in units of columns. The number of columns was reduced as a result. This suppresses an increase in the capacity of the FIFO memory 93a required when synchronizing the read data of each RGB color by performing the delay process in the gap correction unit 93. In particular, in the present embodiment, the capacity of the FIFO memory 93a necessary for gap correction is necessary when the sub-scanning specified magnification Y is 100% in the range where the sub-scanning specified magnification Y exceeds 100% and is 400% or less. The capacity of the FIFO memory 93a is sufficient.

  In the present embodiment, similarly to the first embodiment, when the sub-scanning designated magnification Y is set to 100% <Y <200%, the sub-scanning designated magnification Y is set to 200%. When the read data is acquired under the above conditions, a reduction process by calculation is performed to obtain data of the target sub-scanning designated magnification Y, and the sub-scanning designated magnification Y is set to 200% <Y <400%. In this case, after the read data is acquired under the condition that the sub-scanning designated magnification Y is set to 400%, the reduction processing by the calculation is performed to obtain the data of the target sub-scanning designated magnification Y. When such a process is not employed, it is necessary to perform gap correction below the decimal point using a known sub-scanning two-point interpolation or the like in the gap correction unit 93. By adopting such a process, the gap is corrected. The increase in the capacity of the FIFO memory 93a necessary for correction and the complicated processing in the gap correction unit 93 are suppressed.

  In the present embodiment, the light receiving unit 48 including the shutter drains 53, 63, 73 is used. However, when the configuration of the present embodiment is adopted, the read data of each column is received on the light receiving unit 48 side. Since it is not necessary to thin out, the light receiving section 48 without the shutter drains 53, 63, 73 may be used.

  In the first and second embodiments, the reading device using a so-called reduction optical system has been described as an example. However, the reading device is not limited to this, and for example, reading using a contact optical system having a rod lens array or the like. It can be applied to the device.

DESCRIPTION OF SYMBOLS 10 ... Document feeder, 40 ... Scanner device, 43 ... Full-rate carriage, 44A ... Light source device, 45 ... Half-rate carriage, 47 ... Imaging lens, 48 ... Light-receiving part, 49 ... Control and image processing unit, 50 ... Imaging Element row 51 ... Shift gate 52 ... Horizontal transfer register 53 ... Shutter drain 60 ... Image sensor row 61 ... Shift gate 62 ... Horizontal transfer register 63 ... Shutter drain 70 ... Image sensor row 71 ... Shift Gate 72, horizontal transfer register 73 73 shutter drain, 90 sub-scanning averaging unit 91 91 A / D conversion unit 92 light intensity distribution correction unit 93 gap correction unit 93a FIFO memory 94 color Conversion processing unit, 95 ... sub-scanning enlargement / reduction unit

Claims (1)

By providing a plurality of imaging element arrays configured by arranging a plurality of imaging elements in the main scanning direction, and arranging the plurality of imaging element arrays in the sub-scanning direction, a plurality of reflected images from the reading position of the document are captured. A light receiving portion for receiving light in each element row;
A moving unit that moves the reading position of the document by the light receiving unit in the sub-scanning direction;
A misregistration correction unit that corrects misregistration due to a difference in the reading position in the sub-scanning direction for each column in each imaging data captured by the plurality of imaging element columns, by a delay process using a memory;
Based on the designated sub-scanning magnification which is the designated value of the magnification in the sub-scanning direction of the document, the reading magnification in the sub-scanning direction of the document using the light receiving unit and the moving unit is set to 100. Is set to 100% for a first magnification that is less than or equal to%, and is set to 200% for a second magnification that is greater than 100% and less than or equal to 200%, and the sub-scan designated magnification is Setting means for setting to 400% in the third magnification exceeding 200% and not more than 400%;
When the second magnification is set by the setting means, the moving speed of the reading position by the moving unit is reduced by half compared to the case where the first magnification is set, and the second magnification is set. Adjusting the number of columns so that the number of columns of each imaging data captured by the plurality of imaging element columns is reduced to ½ and supplied to the misregistration correction unit than when the magnification of 1 is set, When the third magnification is set by the setting means, the moving speed of the reading position by the moving unit is reduced to ¼ compared to the case where the first magnification is set, and the first magnification is set. Adjustment that adjusts the number of columns so that the number of columns of each imaging data captured by a plurality of the imaging element columns is reduced to ¼ and supplied to the misregistration correction unit as compared with the case where a magnification of 1 is set Means,
An image reading apparatus comprising: a reduction correction unit configured to perform reduction magnification correction in the sub-scanning direction so as to obtain the sub-scanning designated magnification with respect to each image data that has been subjected to positional deviation correction and is output from the positional deviation correction unit.

Images