JP2003324586A - Original-imaging device, method, computer program and computer-readable storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve an original imaging device using a simple configuration capable of reading a high-definition image by preventing a set-off and by performing stable shading corrections. <P>SOLUTION: A switching means 20 for switching between a white reference face 17a to be an absolute color reference of an original reading means 2 and a colored face 19 which is different from the face 17a are provided at a position facing the backside of an original 3 to be read by the means 2a, and the face 19 is arranged so as to face the means 2a in reading an original whose both sides are printed, thereby preventing the set-off. Further, since the image can be read, without allowing the original 3 whose both sides are printed to contact the face 17a to be the absolute color reference, the image can be read without staining the face 17a, and the stable shading correction can be performed. In this way, the original-imaging device capable of stably reading a high-definition image can be achieved. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document imaging apparatus, a method, a computer program, and a computer-readable storage medium, and particularly to a projector, which reads a document image and generates a video signal from the read image. It is suitable for use in a device for outputting to an external device such as a CRT or a liquid crystal display.

[0002]

2. Description of the Related Art Conventionally, a document-conveying-type document reading device which conveys a sheet-like document and is provided with a document reading sensor for reading a document image during a document conveying process, and a document-reading-type document reading device or glass. 2. Description of the Related Art A document fixing type document reading device is known in which a document is fixed between a plate and a guide, and a document reading sensor is moved to read the document.

This type of document reading apparatus photoelectrically converts the reflected light image of the document illuminated by the illumination means to read it as an electrical signal. However, if the document is simply read by the reading unit, the unevenness of the light amount of the illumination unit and the unevenness of reading due to the unevenness of the sensitivity of the reading unit will occur. Therefore, in order to correct the reading unevenness, a reference reflecting surface such as a white sheet serving as a reference is provided, and the unevenness of the reflected light from the reference reflecting surface is detected to correct the image data of the read original image (hereinafter referred to as the shading). Ding correction).

[0004]

However, in the above-mentioned prior art, the shading correction is usually performed before reading the original, and the white reference plane for the shading correction is placed at the reading position of the original. Therefore, the following problems have occurred.

When an original image for double-sided printing is to be read, not only the light of the illumination means for illuminating the original is reflected on the front surface of the original, but also transmitted through the original and reflected by the white reference surface, and the reflected light reflects on the rear surface of the original. Since the light is emitted, there is a problem that the image on the back side of the document is displayed as a show-through in the image read by the document reading sensor.

Further, since the white reference surface comes into contact with the recording surface of the original document, it is easy to get dirty, and when the white reference surface gets dirty, the white reference level fluctuates, and proper shading correction can be performed. There was a problem that the density of the read image changed because it could not be done.

The present invention has been made in view of the above-mentioned problems, and realizes an original image pickup apparatus capable of reading a high-quality image by preventing show-through of an original with a simple structure and performing stable shading correction. The purpose is to do.

[0008]

An original image pickup device of the present invention is located opposite an original reading means for reading image information of an original and a rear surface of the original read by the original reading means, and is an absolute position of the original reading means. A white reference surface serving as a color reference, at least one or more colored surfaces different from the white reference surface, and switching means for switching the position of the colored surface.

Another feature of the original image pickup device of the present invention is that the switching means sets the position of the colored surface to the position of the white reference surface or retracts it from the position of the white reference surface. It is a feature.

Another feature of the original image pickup device of the present invention is that the at least one colored surface has a black surface.

Another feature of the document image pickup apparatus of the present invention is that the relative position between the document reading unit and the document is changed at a predetermined speed in a direction orthogonal to the main scanning direction of the document reading unit. It is characterized by having sub-scanning means.

Another feature of the document image pickup apparatus of the present invention is that the sub-scanning unit drives the document in a direction orthogonal to the main scanning direction of the document reading unit. Is.

Another feature of the original image pickup apparatus of the present invention is that it comprises original selection means for manually selecting the type of the original, and controls the switching means based on the selection of the original selection means. It is characterized by doing.

Another feature of the original image pickup apparatus of the present invention is that it is provided with original discriminating means for automatically discriminating the type of the original, and the switching means is controlled based on the discrimination by the original discriminating means. It is characterized by doing.

According to the document image pickup method of the present invention, a document reading unit for reading image information of a document and a white reference which is located opposite to a back surface of the document read by the document reading unit and serves as an absolute color reference of the document reading unit. A document image capturing method using a document image capturing device having a surface and at least one colored surface other than the white reference surface, the method having a step of switching the position of the colored surface. It is a thing.

The computer program of the present invention is a document reading means for reading image information of a document, and a white reference surface which is located opposite to the back surface of the document read by the document reading means and serves as an absolute color reference of the document reading means. And a computer program for controlling an original image pickup device having at least one or more colored surfaces other than the white reference surface, which executes processing for switching the position of the colored surface. It is what

A computer-readable storage medium according to the present invention is characterized by storing the computer program described above.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of a document imaging apparatus, method, computer program and computer-readable storage medium of the present invention will be described with reference to the accompanying drawings.

(First Embodiment) A document image pickup apparatus according to a first embodiment of the present invention will be described with reference to FIGS. 1 is a cross-sectional view showing a schematic configuration of a document imaging apparatus according to the present embodiment, FIG. 2 is a cross-sectional view showing a schematic configuration of the document reading unit A shown in FIG. 1, and FIG. 3 is a document reading unit A at the time of shading correction. FIG. 4 is a flowchart showing a processing procedure, and FIG. 4 is a flowchart showing a processing procedure of the document reading unit A at the time of reading a document.

In the document imaging apparatus 1 shown in FIG. 1, a document reading section A is arranged in a frame (not shown). Place the document stack 4 on the document tray 5 with the image side facing up,
A reading operation is started by operating an operation method designating switch (not shown). Hereinafter, the configuration of each unit will be described in detail.

As the document conveying means, among the document bundles 4 set on the document tray 5, several document bundles 4 from the top are the primary separation pad 13, the paper feed roller 8, and the secondary separation pad 1.
4. The separating roller 7 separates and conveys the uppermost original 3 one by one. The separated original 3 is conveyed to the original reading position by the main roller 9 and the main auxiliary roller 15.

Here, the above-mentioned document reading position means the lower side in the optical axis direction of the sensor portion 2a of the linear image sensor 2.

As the document reading means, the image of the document 3 conveyed to the document reading position includes a light source lamp 2b, a short focus image forming lens (a lens may not be provided), a sensor section 2a, a transparent cover section 2c and the like. The linear image sensor 2 reads the image information, and the image information is converted into an electric signal.

Here, the linear image sensor 2 is a CC
This is a so-called line-type reading sensor including D, contact sensor, etc.
A large number of photoelectric conversion elements are linearly arranged along a direction (main scanning direction) orthogonal to the.

A paper discharge roller 10 and a paper discharge auxiliary roller 16 which are adjacent to the linear image sensor 2 are provided on the downstream side of the linear image sensor 2 in the document conveying direction, and the document 3 after image reading is discharged. .

Here, the detailed configuration and operation contents of the above-mentioned document reading section A will be described with reference to FIG. As shown in FIG. 2, the document reading section A is configured to extend from the main roller 9 and the main auxiliary roller 15 to the paper ejection roller 10 and the paper ejection auxiliary roller 16 on the downstream side in the document conveyance direction, and engage with the linear image sensor 2. Base 6, auxiliary roller base 12 that locks the main auxiliary roller 15, the paper ejection auxiliary roller 16, and the like, the linear image sensor 2 (sensor unit 2
a, a light source lamp 2b, a transparent cover portion 2c), and an auxiliary roller spring 11 having a function of bringing the main auxiliary roller 15 and the paper ejection auxiliary roller 16 into close contact with the main roller 9 and the paper ejection roller 10. .

As described above, the linear image sensor 2
Is a so-called line-type reading sensor that reads an image directly or in close proximity to the original surface of the original 3, and a white reference which is an absolute color reference necessary for shading correction is provided on the lower side in the optical axis direction. White member 1 having surface 17a on the upper side
7 is provided.

The white member 17 is pressed from the back surface side (lower side in FIG. 2) by a pressing spring 18 which is a pressing member,
It is pressed at the reading position of the linear image sensor 2.
Further, in order to define the position of the white member 17 in the transport direction (the left-right direction in FIG. 2) and further limit the height direction (the vertical direction in FIG. 2), the lower ends of the white member 17 are attached to the auxiliary roller base 12. It is locked by the locking portion 12p.

The pressing spring 18 is provided on the auxiliary roller base 1 disposed below the original reading position in the optical axis direction (the lower side in FIG. 2).
It is fixed to 2, and is configured to press the reading position of the linear image sensor 2 from the back surface of the white member 17. Here, a resin material is used for the white member 17, and the white reference surface 17a may be a white sheet attached.

Since the original 3 is conveyed between the white reference surface 17a of the white member 17 and the transparent cover portion 2c disposed below the linear image sensor 2 in the optical axis direction, the white reference surface 1
The pressing spring 18 is used so that a gap between the transparent cover portion 2c and the transparent cover portion 2c can be easily formed, so that the cardboard original 3 can be smoothly conveyed.

Regarding the cross-sectional shape of the white reference surface 17a located on the upper side of the white member 17, the vicinity of the original reading position of the linear image sensor 2 is flat, and the flat surface is upstream and downstream of the original conveying direction. Has a substantially circular shape.

By forming the white reference surface 17a into the above-described shape, the white reference surface 17a can be brought into close contact with or close to the reading position of the linear image sensor 2 in a plane, and evenly with respect to the pressing force of the pressing spring 18. The document 3 can be pressed against the document reading position of the linear image sensor 2 with a sufficient width. As a result, it is possible to perform shading correction and reading of the original 3 at low cost without having to increase the component accuracy. Furthermore, by making the upstream side of the flat surface of the white reference surface 17a in the document transport direction substantially circular, the document 3 can be transported smoothly without causing resistance during document transportation.

Here, the white member 17 is slightly larger than the reading width of the linear image sensor 2 (2 to 3 m on each side) in order to prevent outside light from entering the linear image sensor 2.
Wider than m). Further, a sheet guide 22 that restricts the feeding direction and the approach angle of the original 3 is provided on the upstream side of the white member 17 in the original feeding direction.

The sheet guide 22 is fixed to the auxiliary roller base 12 on the upstream side in the document transport direction, and has a free end on the downstream side in the document transport direction. Here, an elastic member such as a polyester sheet is used as the sheet guide 22, and the sheet is slightly wider (2 to 3 mm or more per side) than the reading width of the linear image sensor 2. Further, one end of the sheet guide 22 is adhered to the auxiliary roller base 12 with an adhesive tape or the like, and the adhering surface is formed to be inclined at a certain angle with respect to the original conveying surface. As described above, the leading end of the sheet guide 22 on the downstream side in the document conveying direction is not fixed and is free, so that even if the document 3 is a thick sheet, the sheet guide 2
Since 2 is inclined downward in the optical axis direction (downward in FIG. 2), the original 3 can be conveyed without jamming.

Further, a black sheet 19 colored in black is held between the white member 17 and the sheet guide 22, and a switching claw 20 of switching means which rotates in synchronization with the rotary shaft 21 is provided. ing. One end of the switching claw 20 is fixed by a rotary shaft 21 provided on the upstream side in the document transport direction, and the other end fixes a black sheet 19. Also,
One end of the rotary shaft 21 is pivotally supported by the auxiliary roller base 12, and the other end is connected to a control means (not shown). Further, one end of the black sheet 19 is fixed by the switching claw 20, and the other end is free.

By the operation of the control means, the switching claw 20 performs clockwise and counterclockwise rotational movements about the rotary shaft 21, and the black sheet 19 fixed to the switching claw 20 is placed on the upper surface of the white member 17. It is configured to move along the white reference surface 17a so as to cover or not cover the original reading position of the linear image sensor 2. Here, the black sheet 19 is made of a thin elastic member such as a polyester sheet, and is slightly larger than the reading width of the linear image sensor 2 (2 to 3 mm or more per side).
It is a wide sheet.

One end of the switching claw 20, which is a switching means, is fixed to the rotary shaft 21 via a torque limiter (not shown), and the amount of rotation thereof is restricted by the white member 17 and the auxiliary roller base 12. (Θ = 80 °). Further, the black sheet 19 is fixed to one end of the switching claw 20, and the switching claw 20 operates in conjunction with the rotational movement of the switching claw 20.

The black sheet 19 is a member having a thin plate thickness and elasticity, and the other end not fixed to the switching claw 20 is arranged on the white reference surface 17a of the white member 17 in a free state. Therefore, even when the black sheet 19 covers the white reference surface 17 a on the upper surface of the white member 17, the black sheet 19 is pressed by the original 3 and deforms along the white reference surface 17 a to convey the original 3. be able to. further,
Since the pressing spring 18 is pushed down by the document 3 to the lower side in the optical axis direction (lower side in FIG. 2), the white member 17 is lowered in the lower side in the optical axis direction (lower side in FIG. 2), and a linear image is obtained. A gap can be formed between the transparent cover portion 2c of the sensor 2 and the black surface 19a of the black sheet 19 so that the original 3 can be smoothly conveyed, and the original 3 can be conveyed without affecting the conveyance. .

Here, the document reading operation of the above-mentioned document reading section A will be described. In the document reading section A, unevenness occurs in the output voltage from the linear image sensor 2 due to variations due to the light source lamp 2b incorporated in the linear image sensor 2, the short-focus imaging lens, and the photoelectric conversion system of the sensor section 2a. I have something to do.

Therefore, first, in order to remove this unevenness,
Performs shading correction. In order to perform this shading correction, with the light source lamp 2b turned on, the switching claw 20 is rotated by the control means to move the black sheet 19 to a position where the white reference surface 17a is not covered, and the optical axis direction of the sensor portion 2a. The white reference surface 17a of the white member 17 provided on the lower side (lower side in FIG. 2) is made to face the transparent cover portion 2c, and the reflected light from the light source lamp 2b is directed to the sensor portion 2a. In this state, the reflected light of the white reference surface 17a is read by the sensor unit 2a, and the shading unevenness data is obtained. Based on this data, the output voltage of the photoelectric conversion element when the image of the original 3 is read is corrected.

After performing the above-mentioned shading correction,
Using the document reading unit A, the information recorded on the document 3 is read as follows.

First, reading in the case of a single-sided original having information recorded on only one side or a transparent original such as OHP paper will be described.

The white reference surface 17a of the white member 17 provided on the lower side in the optical axis direction of the sensor portion 2a (lower side in FIG. 2) is opposed to the transparent cover portion 2c as in the case of performing the above-described shading correction. . In this state, the original 3 conveyed from the paper feed roller 8 is sandwiched between the main roller 9 and the main auxiliary roller 15, and the main roller 9 is rotated in the clockwise direction so that the original 3 is read by the linear image sensor 2. The sheet is conveyed to the lower side in the optical axis direction (lower side in FIG. 2).

Next, the sheet guide 2 in which the original 3 conveyed below the linear image sensor 2 in the optical axis direction (the lower side in FIG. 2) is inclined at a constant angle with respect to the original conveying surface.
The original 3 is conveyed along the inclination of the white image 2 and is conveyed to the transparent cover portion 2c of the linear image sensor 2 and is abutted against the white reference surface 17a of the white member 17 having a substantially circular cross section. . Then, when the document 3 is conveyed between the white reference surface 17a and the transparent cover portion 2c, the image is read by the sensor portion 2a of the linear image sensor 2. As described above, the images of the single-sided original and the transparent original in which the information is recorded on only one side are read.

Next, reading in the case of a double-sided original having information recorded on both sides will be described.

By rotating the switching claw 20 by the control means,
The black sheet 19 is moved to a position covering the white reference surface 17a, and the black sheet 19 and the transparent cover portion 2c of the linear image sensor 2 are opposed to each other. In this state, a single-sided document in which information is recorded on only one side as described above, or an OHP
As in the case of a transparent original such as paper, the original 3 conveyed from the paper feed roller 8 is sandwiched between the main roller 9 and the main auxiliary roller 15, and the main roller 9 is rotated clockwise. Then, the original 3 is conveyed to the lower side of the linear image sensor 2 in the optical axis direction (lower side of FIG. 2).

Then, the sheet guide 2 in which the original 3 conveyed to the lower side of the linear image sensor 2 in the optical axis direction (lower side in FIG. 2) is arranged at a certain angle with respect to the original conveying surface.
The original 3 is conveyed along the inclination of the white image 2 and is conveyed to the transparent cover portion 2c of the linear image sensor 2 and is arranged along the white reference surface 17a of the white member 17 in a state of being substantially in close contact with the transparent cover portion 2c. It hits against the black sheet 19 on which it is attached.
Then, when the document 3 is conveyed between the black surface 19a of the black sheet 19 and the transparent cover portion 2c, the image is read by the sensor portion 2a of the linear image sensor 2. As described above, the double-sided document with information recorded on both sides is read.

Next, the procedure of the shading correction of the original 3 and its reading will be described. Figure 3
4 and FIG. 4 are flowcharts showing the processing procedure of the document reading unit of this embodiment. The shading correction procedure will be described with reference to FIG. 3, and the document image reading procedure will be described with reference to FIG.

First, the procedure of shading correction will be described. In FIG. 3, first, a power source (not shown) of the document imaging apparatus 1 is turned on, an initial setting operation is performed, and shading is started.

In step S101, the transparent cover portion 2c
It is determined whether or not it is the white reference surface 17a that faces the sensor portion 2a of the linear image sensor 2 via. If the result of this determination is that it is the white reference surface 17a, the routine proceeds to step S103. On the other hand, step S101
As a result of the determination, if the white reference surface 17a is covered with the black sheet 19, the process proceeds to step S102.

Succeedingly, in a step S102, the switching claw 2
0 is driven so that the black sheet 19 does not cover the white reference surface 17a, the white reference surface 17a is set at a position facing the sensor portion 2a, and the process proceeds to step S103.

Subsequently, in step S103, the light source lamp 2b is turned on, the reflected light of the white reference surface 17a is read by the sensor portion 2a of the linear image sensor 2, and the output of the read light amount (R, G, B) is checked. To balance the output of each color. Here, the light from the light source lamp 2b travels toward the sensor unit 2a of the linear image sensor 2 after being reflected by the white reference surface 17a. Further, the reflected light of the white reference surface 17a is read by the sensor unit 2a of the linear image sensor 2 in a state where the outputs of the respective colors are balanced, shading unevenness data is obtained, and the image of the original 3 is read based on this data. When the correction value of the output voltage from the sensor unit 2a at this time is obtained and stored in the RAM, the process proceeds to the next step.

Next, the procedure for reading the original image will be described. In FIG. 4, the document 3 is set on the document tray 5, and an operation method designation switch (not shown) is operated to
Start the scanning operation (original scan).

In step S201, it is determined whether or not the original 3 is a double-sided original according to the setting of the key input which is the original selection means provided on the operation panel (not shown). If the result of this determination is a double-sided original, step S20.
Go to 4. On the other hand, if the result of determination in step S201 is that the original is a single-sided original and a transparent original instead of the double-sided original, the process proceeds to step S202.

Succeedingly, in a step S202, the sensor portion 2 of the linear image sensor 2 is inserted through the transparent cover portion 2c.
It is determined whether or not the white reference surface 17a faces a. If the result of this determination is that it is the white reference surface 17a, the routine proceeds to step S206. On the other hand, step S2
As a result of the judgment of No. 02, the black sheet 19 has the white reference surface 17a.
If is covered, the process proceeds to step S203.

Succeedingly, in a step S203, the switching claw 2
0 is driven so that the black sheet 19 does not cover the white reference surface 17a, the white reference surface 17a is set at a position facing the sensor portion 2a, and the process proceeds to step S206.

On the other hand, in step S204, the sensor portion 2a of the linear image sensor 2 is inserted through the transparent cover portion 2c.
It is determined whether or not it is the black surface 19a that faces. As a result of this judgment, the black sheet 19 is used for the white reference surface 17
If a is covered and has a black surface 19a, the process proceeds to step S206. On the other hand, as a result of the determination in step S204, if the white reference surface 17a is not covered with the black sheet 19 and is not the black surface 19a, the process proceeds to step S205.

Succeedingly, in a step S205, the switching claw 2
0 is rotationally driven by the control means, the black sheet 19 is moved along the white reference surface 17a, and the black surface 19a is set at a position facing the sensor portion 2a.
Proceed to 06.

Subsequently, in step S206, the main roller 9 is driven to convey the original 3 between the transparent cover portion 2c of the linear image sensor 2 and the white reference surface 17a, and the image of the original 3 is read ( Scan). After that, the reading operation is terminated and the process proceeds to the next step.

Here, in step S201 of the reading procedure in this embodiment, whether or not the original 3 is a double-sided original is determined according to the setting of the key input which is the original selection means provided on the operation panel (not shown). However, a sensor capable of discriminating the original 3 is provided on the upstream side of the linear image sensor 2 in the original conveying direction, and this sensor (original discriminating means) is provided.
The configuration may be such that the determination is automatically performed by.

Further, in the case of reading a plurality of originals 3, in the present embodiment, since the shading unevenness data of the linear image sensor 2 is read (scanned) by using the correction value obtained at the time of initial setting, the above-mentioned operation is performed. Figure 3
The shading correction procedure is used only when initial setting is performed, and is controlled so as to repeat the flowchart of document reading shown in FIG. However, the present embodiment is not limited to this, and shading may be performed according to the flowchart shown in FIG. 3 every time the document reading operation is performed, and then the document reading may be controlled according to the flowchart shown in FIG.

According to this embodiment, at the position facing the sensor portion 2a of the linear image sensor 2 for reading an image,
Since the switching claw 20 that enables switching between the white reference surface 17a of the white member 17 and the black sheet 19 is provided, the black sheet 19 should be arranged so as to face the sensor portion 2a when reading a document image for double-sided printing. Thus, it is possible to prevent the show-through in which the image recorded on the back surface of the original 3 is read together with the image recorded on the front surface. Further, the white reference surface 17a of the white member 17 which is the absolute color reference and the original 3 for double-sided printing.
Since the reading can be performed without touching and, the white reference surface 17a of the white member 17 can be read without being soiled, and stable shading correction can be performed. With these, it is possible to realize the document imaging apparatus 1 that stably reads a high-quality image.

(Second Embodiment) Next, a document image pickup apparatus according to the second embodiment will be described with reference to FIG. FIG. 5 is a sectional view showing a schematic configuration of the document reading unit A of the present embodiment. Here, components similar to the schematic configuration of the document reading unit A in the first embodiment are denoted by the same reference numerals and the description thereof will be omitted, and only the characteristic portion of the present embodiment will be described below.

As shown in FIG. 5, in this embodiment, on the lower side in the optical axis direction of the linear image sensor 2 (lower side in FIG. 5),
A white sheet 23 is provided instead of the white member 17. The white sheet 23 is thicker than the black sheet 19 and slightly wider than the width for reading an image (2 to 3 mm per side).
As described above), it is wide and, for example, an elastic member such as a polyester sheet is used.

The white sheet 23 is attached to the auxiliary roller base 12 on the upstream side in the document transport direction by a double-sided tape or the like, while the downstream side in the document transport direction is free. In this case, the back side of the white sheet 23 (the lower side of FIG. 5) may be pressed by a pressing member or the like, but as shown in FIG. 5, the white sheet 23 is tilted at a certain angle with respect to the original conveying surface. By attaching the auxiliary cover to the auxiliary roller base 12 so that the free end on the downstream side in the document conveying direction is brought into contact with the transparent cover portion 2c of the linear image sensor 2, the number of parts is reduced and the efficiency is improved. Is.

In this embodiment, shading correction is performed by the white reference surface 23a of the white sheet 23. By inclining the white sheet 23 from the document transport surface, the image can be read with the document 3 placed along the transparent cover portion 2c of the linear image sensor 2. In addition, when reading the original 3 with information recorded on both sides, the white sheet 2
Since the sheet 3 is inclined with respect to the original conveying surface, the black sheet 19 can be abutted against the white sheet 23, and by moving the black sheet 19 along the white sheet 23, the original 3 becomes a black sheet. The image can be read while being sandwiched between the black surface 19a of 19 and the transparent cover portion 2c of the linear image sensor 2.

According to this embodiment, even if the white sheet 23 is provided instead of the white member 17, the white sheet 23 is provided at a position facing the sensor portion 2a of the linear image sensor 2.
Since it is possible to switch between the white reference surface 23a and the black sheet 19, the black sheet 19 is recorded on the back surface of the original 3 by arranging the black sheet 19 so as to face the sensor portion 2a when reading an original image for double-sided printing. It is possible to prevent the show-through which would occur when the recorded image is read together with the image recorded on the front surface. Further, since the reading can be performed without contacting the double-sided printed original and the white reference surface 23a of the white sheet 23 which is the absolute color reference, the white reference surface 23a of the white sheet 23 can be read without being contaminated. It is possible to perform stable shading correction. As a result, it is possible to realize an original image pickup device that stably reads high-quality images.

(Other Embodiments of the Present Invention) The present invention may be applied to a system including a plurality of devices or an apparatus including a single device.

Further, various devices are operated so as to realize the functions of the above-described embodiments, and a computer in an apparatus or system connected to the various devices is transferred from a storage medium or a transmission medium such as the Internet. The program code of software for realizing the functions of the above-described embodiment is supplied through the computer, and the various devices are operated according to the program stored in the computer (CPU or MPU) of the system or apparatus. Are also included in the scope of the present invention.

Further, in this case, the program code itself of the software realizes the function of the above-described embodiment, and the program code itself and means for supplying the program code to the computer, for example, such program. The storage medium storing the code constitutes the present invention. A storage medium for storing the program code is, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-R.
An OM, a magnetic tape, a non-volatile memory card, a ROM or the like can be used.

Further, the computer executes the supplied program code so that not only the functions described in the above embodiments are realized, but also the OS (operating system) in which the program code is operating in the computer. Alternatively, the program code is also included in the embodiments of the present invention when the functions shown in the above-described embodiments are implemented jointly by other application software or the like.

Further, after the supplied program code is stored in the memory provided in the function expansion board of the computer or the function expansion unit connected to the computer, the function expansion board or function expansion unit is instructed based on the instruction of the program code. The present invention also includes a case where the CPU or the like included in the above performs a part or all of the actual processing and the processing realizes the functions of the above-described embodiments.

[0073]

According to the present invention, a white reference surface which is an absolute color reference and a coloring surface which is different from the white reference surface are arranged at a position opposed to the back surface of the original read by the original reading means. Therefore, by placing the colored surface so that it faces the original reading unit when reading the original image for double-sided printing, the image recorded on the back side of the original is scanned with the image recorded on the front side. Can be prevented. Further, since the reading can be performed without contacting the double-sided printed original with the white reference surface that is the absolute color reference, the white reference surface can be read without being soiled, and stable shading correction can be performed. As a result, it is possible to realize an original image pickup device that stably reads high-quality images.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a document imaging device according to a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a document reading unit A in the document imaging device according to the first embodiment.

FIG. 3 is a flowchart showing a processing procedure of a document reading unit A in a document imaging device during shading correction.

FIG. 4 is a flowchart illustrating a processing procedure of a document reading unit A in a document imaging device when reading a document.

FIG. 5 is a schematic cross-sectional view showing a document reading unit A in a document imaging device according to a second embodiment.

[Explanation of symbols]

1 Document imaging device 2 Linear image sensor (reading means) 2a Sensor part (built in linear image sensor) 2b Light source lamp (built into the linear image sensor) 2c Transparent cover (built into the linear image sensor) 3 manuscripts 4 manuscript bundle 5 Original tray 6 bases 7 Separation roller 8 paper feed rollers 9 Main roller 10 Paper ejection roller 11 Auxiliary roller spring 12 Auxiliary roller base 12p locking part 13 Primary separation pad 14 Secondary separation pad 15 Main auxiliary roller 16 Paper ejection auxiliary roller 17 White member 17a, 23a White reference plane 18 Pressing spring 19 black sheet 19a black surface 20 Switching claw 21 rotation axis 22 Sheet guide 23 White sheet A Document reading section

Claims (10)

[Claims] 1. An original reading unit for reading image information of an original, a white reference surface which is located opposite to a back surface of the original read by the original reading unit and serves as an absolute color reference of the original reading unit, and the white reference. An original image pickup device comprising: at least one colored surface other than the surface; and a switching unit that switches the position of the colored surface. 2. The original image pickup device according to claim 1, wherein the switching means sets the position of the colored surface to the position of the white reference surface or retracts it from the position of the white reference surface. 3. The document imaging apparatus according to claim 1, wherein the at least one colored surface has a black surface. 4. A sub-scanning unit for changing a relative position between the document reading unit and the document at a predetermined speed in a direction orthogonal to a main scanning direction of the document reading unit. The document imaging apparatus according to any one of items 1 to 5. 5. The document imaging apparatus according to claim 4, wherein the sub-scanning unit drives the document in a direction orthogonal to a main scanning direction of the document reading unit. 6. An original selection unit for manually selecting the type of the original, and the switching unit is controlled based on the selection of the original selection unit. The document imaging device according to the item. 7. An original discriminating unit for automatically discriminating the type of the original, and the switching unit is controlled based on the discrimination of the original discriminating unit. The document imaging device according to the item. 8. An original reading unit for reading image information of an original, a white reference surface which is located opposite to a back surface of the original read by the original reading unit, and which serves as an absolute color reference of the original reading unit, and the white reference. A document imaging method using a document imaging apparatus having at least one colored surface other than the surface, the method having a procedure for switching the position of the colored surface. 9. An original reading unit for reading image information of an original, a white reference surface which is located opposite to a back surface of the original read by the original reading unit, and which serves as an absolute color reference of the original reading unit, and the white reference. A computer program for controlling an original image pickup apparatus having at least one colored surface other than the colored surface, the computer program being characterized by executing processing for switching the position of the colored surface. 10. A computer-readable storage medium on which the computer program according to claim 9 is stored.