JP2001245133A - Image readout device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems that some limits exist on the reading velocity and the high speed reading is difficult because of the scan reading by the one- dimensional image device, and thus to realize and provide an image readout device, which is able to readout at a high speed and moreover possesses the sufficient resolving power, and the image forming device to be built in the proper image readout device. SOLUTION: These devices use multiple two-dimensional readout devices and generates the image data of one image plane through means of compositing of the image data from the proper multiple two-dimensional readout devices by using the image compositing means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention converts an optical image information into an electric image data and generates an image data, and forms an image based on the image data generated by the image reading device. The present invention relates to an image forming apparatus, and more particularly, to an image reading apparatus and an image forming apparatus in which reading time is greatly reduced.

[0002]

2. Description of the Related Art An image reading apparatus widely used in a digital copying machine or the like scans and reads a document image using a one-dimensional image sensor, that is, an image sensor constituted by a line CCD, and converts image data. Generate. In such an image reading apparatus, when reading one screen of a document, the one-dimensional image sensor is moved from one end of the document to the other end, thereby performing scanning reading or moving the document. Scanning reading is performed by a stationary one-dimensional image sensor.

[0003]

In order to be able to read a large number of documents and accumulate image data or to reproduce the images, it is desired to read the images of the documents at a high speed. There is a need for a high-speed copying apparatus capable of copying a large number of documents in a short time.

Although high-speed image forming means for forming an image on the basis of image data has been achieved to some extent, an image reading apparatus for reading an original document has been delayed, so that a high-speed digital copying machine has been realized. What is not up is the current situation.

Accordingly, it is an object of the present invention to provide an image reading apparatus capable of reading an image at high speed and an image forming apparatus having such an image reading apparatus.

[0006]

The object of the present invention is achieved by the following invention.

[0007] 1. A plurality of two-dimensional reading means having an imaging range for each of a plurality of regions of the divided document image, and an image for generating image data of one screen by combining image data from the plurality of two-dimensional reading means An image reading device comprising a combining unit.

[0008] 2. 2. The image reading apparatus according to claim 1, wherein the plurality of two-dimensional reading units perform reading while shifting an imaging time.

3. 3. The image reading apparatus according to claim 1, wherein the plurality of two-dimensional reading units include a distortion correction unit configured to correct image distortion.

[0010] 4. The image reading device according to any one of claims 1 to 3, wherein the plurality of two-dimensional reading units include a rotation shift correction unit that corrects a rotation shift of an image.

5. The plurality of two-dimensional reading units include a brightness correction unit that performs brightness correction between image data obtained by reading the plurality of regions.
The image reading device according to any one of claims 1 to 4.

6. The image forming apparatus according to any one of claims 1 to 5, wherein the image synthesizing unit performs image synthesis by performing image position alignment between the divided areas.

7. The image reading apparatus according to any one of claims 1 to 6, wherein each of the plurality of two-dimensional reading units has an overlapping imaging range.

8. A document table on which a document is placed, the document table having fiducial marks provided corresponding to each of the imaging ranges of the plurality of two-dimensional reading means; 8. The image reading apparatus according to any one of claims 1 to 7, wherein positioning between a plurality of areas is performed based on image data obtained by reading the mark.

9. The platen has a reference density pattern provided in each of the imaging ranges of the respective image sensors of the plurality of two-dimensional reading means, and the luminance correction means outputs image data obtained by reading the reference density pattern. 9. The image reading apparatus according to the item 8, wherein the luminance of each area is corrected based on the area.

10. 10. An image forming apparatus, comprising: the image reading apparatus according to any one of 1 to 9; and an image forming unit that forms an image based on image data from the image reading apparatus.

[0017]

FIG. 1 is a perspective view of an image reading apparatus according to an embodiment of the present invention. A document table T on which a document is placed is formed on an upper surface of the image reading apparatus. At one end, a document cover F is provided so as to be openable and closable. FIG. 2 is a cross-sectional view of the image reading apparatus according to the embodiment of the present invention, in which a two-dimensional reading unit S described in FIG.
A plurality of imaging units U1 to U constituting K1 to SK10
10 are provided. Each of the imaging units U1 to U10 has a two-dimensional image sensor constituted by a two-dimensional CCD, a lens for projecting an image of a document onto the two-dimensional image sensor, and flash lamps R1 to R10. FIG. 2 shows only the flash lamps R6 to R10. 2D CC
As D, for example, a pixel having about 2 million pixels or more is used. For example, when an original of A3 size is divided into 10 parts, image pickup units U1 to U10 are provided corresponding to the respective divided areas, and when a reading operation is performed with a button, each of the flash lamps R1 to R10 emits light at the same time and each divided area is divided. Is read, and the read image data of 10 divisions are respectively stored. And these 1
The image data of the A3 size is read instantaneously by synthesizing the image data of 0 division (plural), and the image data of one screen of the original is obtained.

FIG. 3 is a diagram showing reading of a divided area of a document image. Although only the imaging unit U10 is shown in the figure and other imaging elements are omitted, the imaging unit U1 corresponds to each of the divided areas d1 to d10 of the document.
To U10. By operating a reading start button (not shown), the flash units R1 to R10 of the imaging units U1 to U10 emit light to perform imaging.

At the time of imaging, the flash lamps R1 to R1 are used.
For example, it is preferable that the R10 emits light with a time interval of several msec shifted, and performs imaging with a time offset. This is to eliminate the influence of the exposure light on the adjacent area, which occurs when the light is emitted simultaneously and the simultaneous imaging is performed.

For example, the points J1 and J in the figure are A3 size.
It is assumed that the area indicated by the solid line surrounded by 5, J7, and J12 is the mounting position of the A3-size original on the original platen. The solid line A3 size area is divided into, for example, an area d1 surrounded by J1, J2, J14, and J13 and an area d2 surrounded by J2, J3, J15, and J14, and similarly, ten areas including areas d1 to d10. For example, although not shown in the figure, one imaging unit is provided for each divided area so that the imaging unit U10 corresponds to the area d10, and a total of ten imaging units are provided. It is configured to read at U1 to U10. Each imaging unit has, for example, flash light sources R1 to R10, and is configured to illuminate a document when reading. Further, as another example, for example, as shown in FIG. 4, two imaging units U1 and U2 corresponding to the region d6 and the region d1 are provided, and the two imaging units U1 and U2 are respectively
Two-dimensional CCD, lens and flash lamp R1, R2
And moves integrally to the right in the figure to simultaneously read the area d1 and the area d6, and sequentially read the areas d2 and d5 and the area d.
It is also possible to adopt a configuration in which 3 and d4 are read. Also in this case, it is preferable to perform reading control so that the imaging units U1 and U2 perform imaging with a time lag.

FIG. 6 shows the image pickup units U1 to U1 shown in FIG.
The range read by U10 is indicated by a broken line. FIG. 6 is a plan view of FIG. 5 shown in a perspective view. For example, H1, H3, H3 slightly larger than the d1 region for the d1 region.
9. The range of the dashed line surrounded by H23 is the imaging unit CCD.
Read by 1. This range is defined as a region h1.
Similarly, the range surrounded by H2, H5, H37, and H40 is the area h2, and similarly, the areas h1 to h10 are read by the imaging units U1 to U10. As shown in FIG. 5, a range surrounded by H24, H11, H12, and H23, a range surrounded by H2, H3, H20, and H21, H
4, H5, H18, H19, H6, H
7, H16, H17, and H8, H9,
The range surrounded by H14 and H15 is read by the adjacent imaging units U1 to U10 so as to overlap each other. In addition, the number of pixels of a CCD which is a component of an imaging unit to be used is, for example, 2000 × 1000 = 2,000,000 (2,000,000 pixels).

As shown in FIG. 6, reference marks Z1 to Z14 of crosses (+) are formed as registration marks in the image area of the document, for example, at a main point (for example, the overlapping portion) outside the A3 size area. Have been. White reference plates (hereinafter, referred to as white plates) W1 to W14 as standard density patterns are provided adjacent to the reference marks. Then, the reference mark and the white plate are read together with the image of the document, and image data for distortion correction, rotational displacement correction, magnification correction, etc. of the image formed on the CCD of each image sensor using the reference mark are read. The reference mark is also used for registering when synthesizing the image data of each area described later. The white plate is used for correcting a luminance (density) difference between the respective image pickup units described later.

FIG. 7 is a block diagram of an image data processing system of the image reading apparatus according to the embodiment of the present invention. The two-dimensional reading means SK1 including a CCD which is an image pickup device of the image pickup units U1 to U10 of FIG. ~ SK10, two-dimensional reading means S
1 shows an image reading apparatus including an image synthesizing unit CG for generating image data of one screen of a document by synthesizing image data from K1 to SK10 and a control unit CPU for controlling the whole.
FIG. 8 is a block diagram showing the configuration of the two-dimensional reading means in FIG. 7 using the two-dimensional reading means SK1 as an example.
The dimension reading means SK2 to SK10 have the same configuration.

In the two-dimensional reading means SK1 of FIG. 8, an image pickup device CC constituted by a two-dimensional CCD by a lens L1.
An image of the area h1 of the document is formed on D1, converted into an electric signal, and converted into a digital signal (image data) by the A / D converter AD1.
And stored in the buffer memory BM1. Then, the coordinates of the principal points such as the reference marks of the read image are stored in the coordinate memory CM1.

In this embodiment, the image synthesizing means C
When one screen of image data is created by G, various errors and deviations between images included in the image data from the two-dimensional reading units SK1 to SK10 are corrected prior to the synthesis.

The first error is correction of optical distortion due to aberration of the lens L1 and the like. Image sensor CC by lens L1
The image formed on D1 causes optical distortion due to the lens L1, and the image signal of the image sensor CCD1 becomes a barrel-shaped or pincushion-shaped image signal containing this distortion. FIG. 9 is a diagram for explaining various types of distortion and its correction. For example, an image that should be a rectangle 201 as shown in FIG. 9A is stored in a buffer memory BM1, and an image like a barrel 202 is stored in the buffer memory BM1. The coordinates associated with the image are taken (stored) in the coordinate memory CM1.

The second error is due to the document surface and the light receiving surface of the image sensor not being parallel. If the original surface and the light receiving surface of the image sensor are not parallel and inclined with respect to the optical axis, an image like a trapezoid 203 shown in FIG. 9B is obtained. A method for correcting such an image is disclosed in, for example, Japanese Patent Application Laid-Open No. 11-9634.
Nos. 6 and 8-256295. Various other methods have been proposed. Therefore, the buffer memory B shown in FIG.
The image data read from M1 is corrected by various correction means as described below.

First, the theoretical value of the distance between the reference mark coordinates is stored in, for example, a ROM for distortion correction processing by the distortion correction means E1a.
(Not shown, provided in the distortion correction means E1a)
The corrected reference mark coordinates are stored (corrected) in the coordinate memory CM1 while performing the correction described later.

Next, a correction is made by the rotation deviation correcting means E1b, the corrected coordinates of the correct reference mark are stored in the coordinate memory CM1, and then a magnification correction is made by the magnification correcting means E1c. The coordinates of the correct reference mark are stored in the coordinate memory CM1.

In order to correct the distorted image indicated by 202 in FIG. 9A, the image data read and acquired is temporarily stored in the buffer memory BM1, and when the image data is read, the P1 point of the correct image 201 is read. The uncorrected image data stored as the point p1 is read at the timing at which is to be read, and the points P2 and P3 are similarly corrected by reading the points p2 and p3 at the read timing to obtain the rectangular image 201. . FIG. 9 (c)
As shown in (1), the characteristics related to the relative distance (%) from the optical axis center of the correct image and the relative distance (%) from the same optical axis center of the distorted image are examined, and the results are corrected by the readout timing. Is also possible.

In order to correct the image of the trapezoid 203 shown in FIG. 9B in which the original surface and the light receiving surface of the image sensor are inclined with respect to each other, a short horizontal direction reduced by distortion is used. With reference to the length of the side u_v and the length of the long side U_V, a correction parameter for horizontal enlargement that makes the short side the same length as the long side is calculated and corrected. This parameter Q1 changes according to the distance B from the long side U_V. For example, if the distance from U_V to u_v is B0, the parameter Q1 is
Q1 = (B / BO) × [(U_V) / (u_v)]. Then, similar parameters are calculated and corrected also in the vertical direction.

For example, as shown in FIG. 9D, the coordinates of the reference marks Z1 and Z2 associated with the image data read by the image sensor CCD1 are set to Z1 (100,
50), Z2 (200, 51) and the coordinate memory CM1
Is stored in If it is assumed that Z2 is rotated by one dot (that is, 51-50) in the clockwise direction with Z1 as a fulcrum, the distance between the reference marks Z1 and Z2 is α, the rotation deviation angle is θ, and the correction coordinate is γ. α = [(200-100) ² + (51-50) ² ] ^1/2 =
100.005, and γ = (100 + α, 50), that is, the coordinate is γ
(200.005,50), and COSθ = 1 / α
The coordinate is corrected (corrected) from (200-100) to θ = 0.75, and is stored again in the coordinate memory CM1.

To correct the magnification between the CCDs, the distance between the reference marks, for example, the distance between Z1 and Z2 is calculated after the distortion correction, and the corresponding theoretical value (distance) previously stored in a memory such as a ROM. Are compared with each other, and a correction is made based on the shift amount.
At this time, as shown in FIG. 6, the imaging device CCD1 for reading the region h1, the imaging device CCD5 for reading the region h5, the imaging device CCD6 for reading the region h6, and the imaging device CCD10 for reading the region 10 can read three reference marks. Therefore, the vertical magnification and the horizontal magnification can be corrected independently, but the image sensor that reads the other area can read only two fiducial marks and can basically correct only the horizontal magnification. The correction is made as the same shift amount.

The correction coordinates shown here are different from the coordinates on the processing memory S and the main memory M in the case of combining, which will be described later.

As described above, the correction is performed in the order of distortion correction, inclination correction, rotation deviation correction, and magnification correction, and the corrected coordinates are stored in the coordinate memory CM1 again.

After the above-described various corrections have been performed, the image data of one screen of the original in which the image data from the two-dimensional reading means SK1 to SK10 are synthesized by the image synthesizing means CG shown in FIG. You. Two-dimensional reading means SK
The image data from 1 to SK10 is stored in the processing memory S. The processing memory S stores the respective image data in the areas h1 to h10 in which the various errors have been corrected in the storage areas s1 to s10.
And memorize them independently. Then, each coordinate on the processing memory S is determined.

Next, a method of synthesizing these corrected image data and creating image data of a document size screen, for example, an A3 size screen will be described. First, the coordinate and luminance difference correction will be described.

Since the method of synthesizing each image data read by the two-dimensional reading means SK1 to SK10 is the same,
The coordinate display of the image data of the areas h1 and h2 read by the two-dimensional reading means SK1 and SK2 and stored in the processing memory S of FIG. 10 will be described with reference to FIGS.

FIGS. 11 and 12 show the coordinates in the processing memory S of the image data of the read areas h1 and h2. The short side (horizontal axis) of the region is shown as the X axis, and the long side (vertical axis) is shown as the Y axis. The coordinates of the area h1 on the processing memory S are represented by s1 (x, y),
The coordinates of No. 2 are indicated by s2 (x, y). For example, it is assumed that the X coordinate value of each of the coordinates s1 and s2 ranges from 0 to 999 and the Y coordinate value ranges from 0 to 1999, and that all the pixels of one imaging device CCD are composed of 2 million pixels.

Each pixel has, for example, an 8-bit pixel value (corresponding to luminance or density) and expresses a gradation. However, since each of the imaging devices CCD1 to CCD10 has a different reading sensitivity, uneven brightness (density) occurs. Further, the image data from the two-dimensional reading means SK1 to SK10 includes, in addition to the brightness unevenness due to individual differences between the image pickup devices CCD1 to CCD10, the lens L in each two-dimensional reading means.
Since there is uneven brightness according to the COS ⁴ rule of 1 to L10, it is desirable to correct the uneven brightness.
That is, it is desirable to perform shading for converting image data dependent on the angle of view as shown in FIG. 9E into image data independent of the angle of view as shown in FIG. 9F. This shading correction is performed by the two-dimensional reading means SK1 to SK1.
The correction coefficient can be determined by previously examining the characteristics of the lens, which is a component of 0, to perform the correction. Although not shown, the two-dimensional reading means SK1 to SK10 are provided with photographing elements CCD1 to CCD10 and lenses L1 to L10.

Next, prior to synthesizing the respective image data, the luminance difference between the respective CCDs is corrected from the read information of the white plates W1 to W14.

Hereinafter, the luminance correction will be described by taking as an example a case where the image is read by the image pickup devices CCD1 and CCD2 in the same manner as described above. The same applies to other image sensors, and a description thereof will be omitted.

The information read by the image pickup device CCD1 is subjected to various corrections (excluding luminance correction) as described above and stored in the processing memory S. Therefore, information on the white plate W1 is also stored. Similarly, information on the white plate W2 read by the image sensor CCD2 is also stored in the processing memory S. Since the white plates W1 and W2 are located at positions adjacent to the respective reference marks Z1 and Z2, the coordinates of each white plate are fixed, and information on the white plates can be immediately read. Each white plate W1, W2,.
[00 dots] × [100 dots]. Therefore, the information h1 read by the image sensor CCD1
Is the average w of the pixel values of the white plates W1, W2, and W14.
1, w2, w14, and the average of these, ie,
[W1 + w2 + w14] ÷ 3 = Wa1 is calculated and set as the average luminance.

Similarly, as for the luminance of the information h2 read by the image pickup device CCD2, the average of w2 and w3 is calculated, and the average [w2 + w3] ÷ 2 = Wa2 is obtained as the average luminance. Then, for example, the average pixel value Wa corresponding to the region h1
Assuming that the average pixel value Wa2 corresponding to the area h2 is 0.95 when 1 is 1, 1 ÷ 0.95
Area h2 read by the image sensor CCD2 from 1.05
Are corrected by multiplying all pixel values by 1.05. By performing similar luminance correction using the white plates W1 to W14 for all the regions h1 to h10 in this manner, the image data read by each imaging element stores the image values of the corrected luminance (density) in the processing memory S. Is done. As described above, for the regions h1, h5, h6, and h10, the average luminance is obtained from the three white plates, and in the other regions, the average luminance is obtained from the two white plates, and the correction is performed.

Next, a method of synthesizing each area will be described.
11 and 12 show the coordinates of each main point in the processing memory S. Since the synthesizing method is the same for each area, the area h1 and the area h2 will be described as representative examples.

FIG. 11 is a diagram showing the XY coordinates on the processing memory S of the area h1 read by the image sensor CCD1,
FIG. 12 is a diagram showing the XY coordinates on the processing memory S of the area h2 read by the image sensor CCD2. In FIG. 11, the coordinates of H1 on the processing memory S are s1 (0, 199).
9), the coordinates of H3 are s1 (999, 1999),
The coordinates of H23 on the processing memory S are s1 (0,0), H
The coordinates of 39 are s1 (999,0). Also, the area h
12, the coordinates of H2 on the processing memory S in FIG. 12 are s2 (0, 1999), and the coordinates of H5 are s2 (9
99, 1999), the coordinates of H40 on the processing memory S are s2 (0, 0), and the coordinates of H37 are s2 (999, 1999).
0).

The coordinates of the reference mark Z1 of the area h1 (read by the image sensor CCD1) on the processing memory S are s1 (102, 1905), and the coordinates of Z2 are s1 (90).
2,1905), and the coordinates of Z2 on the processing memory S in the area h2 (read by the image sensor CCD2) are s2.
(103, 1901), the coordinate of Z3 is s2 (903, 1
901). Then, the pixel values stored in the respective coordinates of the processing memory S are moved to the respective coordinates of the main memory M, and are stored (transferred) to synthesize the entire image. The main memory M is provided in the control means CPU and stores a large number of combined image data and control data.

FIG. 13 shows each coordinate in the main memory M to be moved from each coordinate in the processing memory S, and FIG. 14 shows an enlarged portion corresponding to the areas h1 and h2. When the XY coordinates on the main memory are represented by G (x, y), for example, the coordinates of Z1 on the main memory are G (0, 36).
00), and the coordinate of Z2 is G (800, 3600).
The coordinates of Z6 are G (4000, 3600). That is, the number of dots (coordinate difference) in the X direction between each Z is 800 dots.

Therefore, first, Z1, that is, the pixel value of the coordinate s1 (102, 1905) in the processing memory S is transferred (stored) to the coordinate G (0, 3600) in the main memory M.

Next, as shown in FIG. 11, the pixel value of the adjacent coordinate s1 (103, 1905) in the X direction on the processing memory S is converted to the corresponding coordinate G (1, 360) on the main memory M.
Transfer to 0). That is, the pixel value of s1 (102, 1905) is transferred to G (0, 3600), and s1 (103, 19).
05) is transferred to G (1,3600).
The coordinates 104, 105... And the pixel values are sequentially stored in the main memory M.
Then, the pixel value of s1 (951, 1905) is transferred to G (849, 3600), and at this point, the transfer of one line in the X direction of the area h1 has been completed.

Here, s1 (951, y) is the X coordinate of Z2 as shown in FIG.
This is the number of dots obtained by adding the dots, and the coordinates s1 (951,
The pixel values of 49 dots from y) to H3, ie, s1 (1000, y), are not used for the processing of the overlapping area described later (the hatched portion in FIG. 14). Also, coordinates G (84
9, y) is the number of dots obtained by adding 49 dots to 800.

The same applies to s1 for the second line.
The pixel value of (102, 1904) is transferred to G (0, 3600), and the pixel value of s1 (103, 1904) is transferred to G (1, 3).
600), and similarly 104 (X coordinate), 105 (X
) And the pixel values of s1 (951, 1904) are sequentially transferred to G (849,
3599), at which point the transfer of two lines in the X direction has been completed.

Similarly, transfer is performed with lines 3, 4,...
The pixel value of s1 (102,56) is transferred to G (0,1751), and the pixel value of s1 (103,56) is transferred to G (1,175).
1), and similarly, sequentially transfer pixel values to the main memory M in the order of 104 (X coordinate), 105 (X coordinate),.
The pixel value of s1 (951, 56) is represented by G (849, 175).
Transferring to 1), at which point the transfer of the h1 area by the image sensor CCD1 has been completed.

Next, the transfer of the pixel value of the h2 area read by the image pickup device CCD2 will be described. The coordinates G (75) on the main memory M to which the pixel values of the h1 area are transferred.
1,3600) and the coordinates s2 on the processing memory S
The pixel values of (54, 1901) are combined at a ratio of 99: 1, and stored at coordinates G (751, 3600).

Here, the X coordinate s2 (54, y) is used for combining 49 dots on the X axis right and left from the center of the Z2 coordinate of the overlapping area, and the remaining overlapping portion, that is, the hatched area in FIG. Are not used for the synthesis. Similarly, the coordinates G (7
52, 3600) and coordinates s2 (55, 190).
The pixel values of 1) are synthesized at a ratio of 98: 2, and the coordinates G (75
2, 3600).

Similarly, when the X coordinate on the processing memory S is 75
3, 754... (Increase), the processing is continued by changing the combination ratio of the pixel values, and the coordinates G (800, 360
0) and the pixel value of the coordinates s2 (103, 1901) at a ratio of 50 to 50, and the coordinates G (800, 360).
0). G (800, y) is the X coordinate of Z2 and the center of the overlapping area.

Further, similarly, X coordinates 801, 802,.
The process is continued, and the pixel value of the coordinate G (849, 3600) and the pixel value of the coordinate s2 (152, 1901) are combined at a ratio of 1:99, and stored in the coordinate G (849, 3600). Here, 152 is the number of dots obtained by adding 49 to 103.

The pixel value at the coordinates s2 (153, 1901) is transferred to the coordinates G (850, 3600).

The pixel value of the coordinates s2 (154, 1901) is transferred to the coordinates G (851, 3600). Similarly, transfer is performed with 155, 156... Of the X coordinate, and the coordinate s2 (95
The pixel value of (2,1901) is represented by coordinates G (1649,360).
Transfer to 0). Here, 952 of the X coordinate is 49 in 903.
Is the number of dots obtained by adding. At this point, one line of the h2 area has been combined with the h1 area.

In the same manner, the transfer with the 2, 3,... Line is continued, and the pixel value of the coordinate G (751, 1751) and the coordinate s
2 (54, 52) are combined at a ratio of 99: 1,
The coordinates are stored at coordinates G (751, 1751).

The pixel value of the coordinate G (752, 1751) and the pixel value of the coordinate s2 (55, 52) are synthesized at a ratio of 98: 2, and stored in the coordinate G (752, 1751). Similarly, the transfer is continued to the X coordinates 753, 754,.
The pixel value of the coordinate G (800,1751) and the coordinate s2 (10
The pixel values of (3, 52) are combined at a ratio of 50 to 50, and stored at the coordinate G (800, 1751). .. Are transferred to the X-coordinates 801, 802... Of the main memory, and the pixel value of the coordinate G (849, 1751) and the coordinate s2 (152
52) are combined at a ratio of 1:99, and the coordinates G (8
49, 1751). Thus, an effective overlapping area can be synthesized.

The pixel value of the coordinates s2 (153, 52) is transferred to the coordinates G (850, 1751). Coordinates s2 (15
4, 52) are transferred to the coordinates G (851, 1751).

Similarly, 155, 15 of the X coordinate of the processing memory
, And the pixel value at the coordinates s2 (952, 52) is transferred to the coordinates G (1649, 1751).

At this point, the area h1 and the area h2 have been combined by processing the overlapping area. In this manner, the two-dimensional reading means SK1 to SK1 are similarly applied to other areas.
The image data read at 0 is synthesized. In the above example, in the overlapping area, the pixel values are synthesized at a ratio of 50 to 50 at the midpoint of the area from the ratio of 99: 1 to obtain a smooth image, but instead of synthesizing at such a linear ratio. To
In some cases, a method of synthesizing using a weighting curve such as an S-shaped curve is also effective.

The original image is read and the combined image data is sequentially stored in the main memory M. Then, an image can be formed in accordance with the image data read from the main memory M. For example, it is possible to configure an image forming apparatus as a general copying apparatus in which the electrophotographic image forming unit PR and the reading device are integrated.

Next, for example, the configuration of an image forming section PR using an electrophotographic method as an image forming means will be described with reference to FIG. FIG. 15 is a diagram illustrating an image forming unit of the image forming apparatus according to the embodiment of the present invention.

The image data read from the main memory M is input to an image writing unit 33 shown in the figure, and a laser beam modulated in accordance with the image data from a laser light emitting device (not shown) is rotated by a polygon mirror. The photosensitive drum 31 is subjected to main scanning exposure. Then, the main scanning exposure in the axial direction of the photosensitive drum 31 and the photosensitive drum 31 are performed on the photosensitive drum 31 to which the charging potential has been previously given by the charger 32.
The sub-scanning is performed by the rotation of the image forming apparatus to form an electrostatic latent image based on image data on the photosensitive layer. The electrostatic latent image is reversal-developed by a developer in a developing device 40 as a developing unit to form a toner image. This developer is, for example, a two-component developer in which a magnetic material having a particle size of about 20 μm is used as a carrier and a resin toner having a particle size of several μm is mixed. A layer of about several mm is formed and developed. At the same time, the recording paper is fed from the manual paper feed unit 19 as the recording paper supply means or the paper feed tray 7 containing the recording paper. The paper feed tray 7 has, for example, three stages of 7A, 7B, and 7C, and each of the paper feed rollers 51.
A, 51B, or 51C is operated, and the recording paper is carried out and fed to the conveyance rollers 55 and 56 and the timing roller 39, and is sent to the photosensitive drum 31 in synchronization with the toner image on the photosensitive drum 31. Paper is fed. The toner image on the photosensitive drum 31 is transferred to a recording paper side by applying a voltage of an opposite polarity by a transfer unit 35 and transferred to the recording paper side, and the recording paper on which the toner image has been transferred is neutralized by a static eliminator 36 to be removed.
The sheet is further separated and conveyed to a fixing device 38 as a fixing unit via a conveying belt, and is fixed by welding and fixing the toner by press-fitting and heating of a heat roller pair. The sheet is discharged from a fixing discharge roller 61 of a discharge section 6 and discharged. The image is discharged to the tray 64 and an image based on the image data is formed.

On the other hand, the photosensitive drum 31 from which the recording paper is separated
After the residual potential is removed, the image forming apparatus is configured so that the residual toner is removed and cleaned by the cleaning device 37 and the cleaning operation is performed for the next image forming process, and the control CPUb performs overall control of the image forming apparatus. Therefore,
The reading device is controlled by the CPUa, and the image forming unit PR
Is controlled by the CPUa. As described above, the reading apparatus and the image forming unit are combined and integrated to form an image forming apparatus that reads a document and forms an image.

As described above, a document image is transferred to a plurality of CCs.
D, and by combining the image data read by each CCD to form the original image data, there is almost no driving portion, the reading speed is dramatically high, and there is sufficient resolution, and there is no luminance unevenness. A reading device and an image forming device can be provided.

[0070]

According to the first aspect of the present invention, it is impossible to realize a sufficient resolution with a single two-dimensional image pickup device, and therefore, it is possible to realize a high speed reading which has been extremely difficult in the past.
An image reading apparatus that can read an image at a high speed and generates image data that can form an image having a sufficient resolution is realized.

According to the second aspect of the present invention, even when a document is divided and photographed using a large number of light-emitting light sources, the image is photographed under uniform illuminance without illumination unevenness, and an image with less density unevenness in each divided area. Data is obtained.

According to the third aspect of the present invention, it is possible to prevent the image from being deteriorated due to the distortion of the image generated by each of the two-dimensional reading means when the image of the document is read by the plurality of two-dimensional reading means, and to provide an image faithful to the document. Image data that can be reproduced is obtained.

According to the fourth aspect of the invention, it is possible to prevent the occurrence of a shift between the divided images caused by a shift in the angle between the two-dimensional reading means and the document table, and to reproduce a high quality image. Image data is obtained.

According to the fifth or ninth aspect of the present invention, each of the two
The difference in luminance (density) between the divided areas due to the difference in sensitivity between the dimension reading means is corrected, and image data capable of reproducing a high-quality image is obtained.

According to the seventh aspect of the present invention, it is possible to form an image having very little change in image quality at the boundary between the divided areas.

According to the sixth or eighth aspect of the present invention, image data for forming a composite image having no positional displacement between divided images is created, and image data capable of reproducing a high quality image is generated. can get.

According to the tenth aspect of the present invention, an image forming apparatus capable of reading an image and forming an image at a high speed and having a sufficient resolution is realized.

[Brief description of the drawings]

FIG. 1 is a perspective view of an image reading apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view of the image reading apparatus according to the embodiment of the present invention.

FIG. 3 is a diagram illustrating reading of a divided area of a document image.

FIG. 4 is a diagram showing another example of reading a divided area of a document image.

FIG. 5 is a perspective view showing a divided area of a document image.

FIG. 6 is a plan view of a divided area of a document image.

FIG. 7 is a block diagram of an image data processing system of the image reading apparatus according to the embodiment of the present invention.

FIG. 8 is a block diagram of a two-dimensional reading unit of the image reading device according to the embodiment of the present invention.

FIG. 9 is a diagram for explaining correction of various errors.

FIG. 10 is a block diagram of an image synthesizing unit of the image reading device according to the embodiment of the present invention.

FIG. 11 is a diagram showing coordinates on a processing memory of a divided area of a document image.

FIG. 12 is a diagram showing coordinates on a processing memory of a divided area of a document image;

FIG. 13 is a diagram illustrating coordinates of a document image on a main memory.

FIG. 14 is an enlarged view showing coordinates of a document image on a main memory.

FIG. 15 is a diagram illustrating an image forming unit of the image forming apparatus according to the embodiment of the present invention.

[Explanation of symbols]

 F Document cover T Document table U1 to U10 Imaging unit CCD1 to CCD10 Imaging element BM1 Buffer memory CM1 Coordinate memory L1 Lens SK1 to SK10 Two-dimensional reading means S Processing memory M Main memory E1a Distortion correction means E1b Rotational deviation correction means E1c Magnification correction means W1 to W14 White plate Z1 to Z14 Reference mark

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 2H027 DB01 DB10 DE02 EC06 EC11 FB15 FD01 5B057 AA11 BA11 CA08 CA12 CB08 CB12 CC02 CD02 CD03 CD12 CE08 CE11 DA08 DB02 DB09 5C072 AA01 AA05 BA03 BA10 BA17 EA05 EA08 FA05 FB01 LA02 LA20 RA07 RA15 RA20 UA01 UA11 UA20 WA07 XA01 5C076 AA19 AA23 AA24 AA36 BA01 BA06 CA05 9A001 GG01 HH28 HH34

Claims (10)

[Claims] A plurality of two-dimensional reading means having an imaging range for each of a plurality of regions of a divided document image; and combining image data from the plurality of two-dimensional reading means to obtain one
An image reading apparatus comprising an image synthesizing unit for generating image data of a screen. 2. The image reading apparatus according to claim 1, wherein the plurality of two-dimensional reading units perform reading while shifting an imaging time. 3. The image reading apparatus according to claim 1, wherein the plurality of two-dimensional reading units include a distortion correcting unit that corrects an image distortion. 4. The image reading apparatus according to claim 1, wherein the plurality of two-dimensional reading units include a rotation shift correction unit that corrects a rotation shift of an image. 5. The image processing apparatus according to claim 1, wherein the plurality of two-dimensional reading units include a luminance correcting unit that performs luminance correction between image data obtained by reading the plurality of areas.
The image reading device according to any one of claims 1 to 4. 6. The image forming apparatus according to claim 1, wherein said image synthesizing unit performs image synthesizing by performing image position alignment between the divided areas. apparatus. 7. The image reading apparatus according to claim 1, wherein each of the plurality of two-dimensional reading units has an imaging range overlapping each other. 8. A document table on which a document is placed, said document table having reference marks provided corresponding to each of the imaging ranges of said plurality of two-dimensional reading means, and said image combining means. The image reading apparatus according to claim 1, wherein the means performs position alignment between a plurality of areas based on image data obtained by reading the reference mark. 9. The document table has a reference density pattern provided in each of an image pickup range of each image pickup device of the plurality of two-dimensional reading means, and the luminance correction means obtains by reading the reference density pattern. 9. The image reading device according to claim 8, wherein correction of luminance between the respective regions is performed based on the obtained image data. 10. An image forming apparatus, comprising: the image reading apparatus according to claim 1; and an image forming unit that forms an image based on image data from the image reading apparatus. apparatus.