JPH10290328A - Scanning method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scanning method capable of obtaining an image with fidelity to an original even when the surface of the original has ruggedness. SOLUTION: In order to allow a scanner to scan an original 2 without causing a shade or distortion even when the surface of an original 2 like a filling margin of a thick book has ruggedness, a CCD sensor is scanned in a scanning direction of the original to catch the reflected light of a light emitted on the original from a light source. Furthermore, a sensor rod 4 in contact with the surface of the original and a position sensor 6 to detect the height of the sensor rod 3 are used to detect unevenness of the original, and the strength of the lighting light of the light source and the direction of the light of the light source are changed in response to a distance from the light source to the original so as to prevent production of undesired shade and distortion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning method using a scanner.

[0002]

2. Description of the Related Art Conventionally, when a manuscript having a rough surface or a rough paper such as a thick book is scanned by a flat bed type or a handy type scanner, the uneven portion is shaded or distorted. A copy image appeared, and the original could not be copied faithfully. For example, when taking a book as an example, as is often experienced when copying a book, a “binding” that binds right and left pages is usually used.
It is very difficult to place the entire book surface in close contact with the flat platen of the flatbed type scanner device, or to have the handy type scanner device trace the entire book surface properly. Difficult. For this reason, in an image obtained by photographing the book surface with the scanner device, a shadow or a distortion appears at a portion centered on the “binding”.

[0003]

However, in the conventional scanning method, the intensity of the illuminating light applied to the surface of the document is constant irrespective of the distance from the light source to the document, and
Since the direction of the light emitted from the light source is constant regardless of the irregularities on the original surface, when copying a book with a "binding" at the center, such as a book, the copied image will be shaded due to insufficient light source. Or the direction of the light source is not perpendicular to the surface of the scanner, causing distortion in the copied image.

Accordingly, an object of the present invention is to provide a scanning method capable of obtaining an image faithful to a document even if the document surface has irregularities.

[0005]

According to the present invention, a CCD sensor is scanned with respect to a document in a scanning direction to capture reflected light of illumination light radiated from the light source to the document, and detect irregularities of the document. Is changed according to the distance from the light source to the document. In addition, the present invention scans a document in a scanning direction with a CCD sensor to capture reflected light of illumination light applied to the document from a light source, detects irregularities of the document, and changes the direction of illumination light of the light source. Let it. With this configuration, it is possible to obtain a highly readable copy image without damaging the document, even if the document has irregularities on the surface, without causing shadows and distortions in the copy image.

[0006]

According to the first aspect of the present invention, a CCD sensor is scanned with respect to a document in a scanning direction to capture reflected light of illumination light applied to the document from a light source and detect irregularities of the document. The intensity of the illumination light of the light source is changed according to the distance from the light source to the document. According to a second aspect of the present invention, a CCD sensor is scanned with respect to a document in a scanning direction to capture reflected light of illumination light emitted from the light source to the document, detect irregularities on the document, and detect the direction of illumination light of the light source. To change. According to this configuration, a good image without shading or distortion can be obtained even for a document having an uneven surface.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Here, FIG. 1 is a perspective view of a scanner device using a scanning method according to an embodiment of the present invention, FIG. 2 is a process explanatory view of the scanning method according to an embodiment of the present invention, and FIG. FIG. 4 is a structural diagram of a hand-held scanner device using a scanning method according to an embodiment of the present invention.

In a flat-bed type scanner, when a document 2 (a book or the like) having an uneven surface is scanned, as shown in FIG. 1, the document 2 may be lifted up from the scanner surface 4 of the document table. Occurs. Therefore,
As shown in FIG. 1, the shape of the surface of the document 2 is grasped by the sensor rod 3 protruding from the scanner surface 4. Then, at the same time that the document 2 placed on the scanner surface 4 is scanned, the sensor rod 3 also moves in the scanning direction. here,
As shown in FIG. 1, the sensor rod 3 is supported by a spring 5 so as to be freely protruded and retracted, and the extension and contraction of the spring 5 is detected by a position detection sensor 6, and the distance between the scanner surface 4 and the document 2 is detected. . In this way, the shape of the surface of the document 2 is grasped, and the intensity and direction of the illumination light of the light source are changed accordingly.

Next, the structure of the flatbed type scanner will be described more specifically. As shown in FIG. 2, the scanner device includes a platen having a flat scanner surface 4, a light source 8, a mirror 9, a lens 10, a CCD
A sensor 11 is provided. CCD sensor 11,
The mirror 9, the lens 10, and the light source 8 are arranged parallel to each other (at right angles to the scanning direction). Here, an orthogonal coordinate system as shown in FIG. 2 is introduced. Here, the y-axis is CCD
In parallel with the moving direction (scanning direction) of the sensor 11, x
The axis is parallel to the CCD sensor 11, the z axis is orthogonal to the scanner surface 4, and the x and y axes are both included in the scanner surface 4. The mirror 9 is used to guide light reflected from the surface of the document 2 to the CCD sensor 11. An intersection line between the xy plane and the vertical plane V is defined as a scanning line S.
The light source 8 and the mirror 9 are composed of a lens 10 and a CCD sensor 1.
The surface of the original 2 on the scanner surface 4 is scanned while moving at a lower portion of the xy plane while keeping a certain distance from the original 1.

As shown in FIG. 2, the light source 8 has an elongated cylindrical shape. A film 7 that blocks light is provided around the light source 8, and light is emitted from a slit A where the film 7 is not provided. Here, it is considered that the width of the slit portion A is sufficiently small, and the light source 8 is approximated by a linear light source. Then, in the yv coordinate system shown in FIG. 3, the position of the line light source is represented by (-d1, -d2). This position corresponds to the center of the slit.

As is apparent from FIG. 3, the light source direction Ψ when viewed from the surface of the original 2 depends on the distance d between the scanner surface 4 and the surface of the original 2 Ψ = arctan (d1 / d2).
+ D). Therefore, the direction of the light source can be determined by the distance d according to this equation. That is, the direction of the irradiation light of the light source 8 can be changed by moving the film 7 covering the light source 8. Scanner surface 4
Of the illumination light Is at the surface of the document 2 at a distance d from
(D) takes into account that the intensity of the illumination light from the linear light source is inversely proportional to the distance between the light source 8 and the surface of the document 2 and that an ambient light component Ie generated by irregular reflection inside the scanner device can be included. α is a parameter representing the intensity of the light source, and Is (d) = α / β; β = ((d1) 2+ (d + d)
2) The square root of 2 + Ie). Therefore, the distance d
Thereby, the intensity of the illumination light of the light source 8 can be guided. By deriving the distance between the light source 8 and the document 2 by the above two equations, the intensity of the illumination light of the light source 8 and the direction of the light source 8 are changed from the distance from the light source 8 to correspond to the unevenness of the document 2.

Next, an example in which the scanning method is applied to a handy type scanner will be described. In FIG. 4, first, a transparent and flat scan plate 14 is placed on a document 15 having an uneven surface, and a hand-held scanner device 12 is placed thereon. The scanner device 12 includes:
A sensor rod 13 is attached. The transparent scan plate 14 has a groove 16 through which the sensor rod 13 passes.
The sensor rod 13 penetrates the groove 16, and the tip of the sensor rod 13 contacts the surface of the document 15, thereby detecting irregularities on the surface of the document 15 and performing the same process as described above. The intensity of the illumination light from the light source 8 and the direction of the illumination light from the light source 8 are changed.

[0013]

According to the present invention, the intensity of the illuminating light of the light source and the direction of the light source are changed in accordance with the irregularities on the surface of the original. A copy image is obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a scanner device using a scanning method according to an embodiment of the present invention.

FIG. 2 is a process explanatory diagram of a scanning method according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating a relationship between a position and a direction of a light source according to an embodiment of the present invention.

FIG. 4 is a structural diagram of a handy type scanner device using a scanning method according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Scanner apparatus 2 Document 3 Sensor rod 4 Scanner surface 6 Position detection sensor 8 Light source 11 CCD sensor

Claims (4)

[Claims] A CCD sensor scans a document in a scanning direction to capture reflected light of illumination light applied to the document from a light source, detect irregularities of the document, and reduce the intensity of the illumination light of the light source. A scanning method, wherein the scanning method is changed according to a distance from a light source to a document. 2. A method according to claim 1, wherein the CCD sensor scans the original in a scanning direction to capture reflected light of illumination light emitted from the light source to the original, detects irregularities of the original, and changes the direction of the illumination light of the light source. A scanning method characterized by: 3. The scanning method according to claim 1, wherein the document is placed on a document table of a flatbed type scanner. 4. The scanning method according to claim 1, wherein the original is traced by a hand-held scanner.