JP2001250112A - Device and method for reading image and application device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader which uses a linear photoelectric converting element and can precisely read both features of a read object having light and shade like a fingerprint and a character. SOLUTION: One surface of an input member 3 is an input surface 2; when a fingerprint is inputted, the finger 1 is impressed and a light source for lighting is on the opposite side from the read object across the input surface. The incident light from the light source includes incident light 4 having a large angle of incidence on the input surface 2 and incident light 5 having a small angle of incidence.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object to be read having irregularities such as fingerprints, which has a linear photoelectric conversion element and combines an entire image from a partial image by a relative movement of the object to be read and an image reading device; The present invention relates to an image reading apparatus, an image reading method, and an application apparatus capable of reading both reading objects having shading such as an original.

[0002]

2. Description of the Related Art Conventionally, fingerprint reading utilizes the difference in reflected light due to the difference in the state of skin contact between valleys and mountains when a finger is imprinted on an optical member having a transparent input surface such as glass. .

That is, as shown in FIG. 16, when a finger 1 is impressed on an input surface 2 to be read by a triangular prism as an input member 3 made of glass, synthetic resin, or the like, the mountain portion comes into contact with the right-angle prism and the skin. However, since the valley portion comes into contact with air, if the incident angle exceeds the critical angle at the interface between the right-angle prism and air, total reflection occurs at the valley portion, and a large reflectance difference occurs between the valley and the valley, and the fingerprint The peaks and valleys are read in a shade pattern.

However, in the method utilizing the total reflection at an incident angle exceeding the critical angle as described above, the reading of an object such as paper, for which optically incomplete contact cannot be obtained, for example, the reading of an original can be performed because of the total reflection. Absent.

[0005] Japanese Patent Application Laid-Open No. H10-240906 discloses an image reading apparatus which has a linear photoelectric conversion element and combines a partial image and an entire image by a relative movement of a reading object and an image reading apparatus to read a fingerprint and an original. Discloses an example in which illumination light is vertically incident on an input surface and vertical reflected light is detected.

[0006]

According to the method using the normal incidence / reflection, the reading of the original is easy, but the difference in the reflected light between the peaks and valleys of the finger is extremely inferior to the total reflection, so that the fingerprint reading is easy. is not.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a simple image reading apparatus which can read both an object having irregularities such as a fingerprint and an object having shading such as an original.

[0008]

According to the present invention, light incident on a linear region of an input surface from a light source has a plurality of different incident angle components.

This makes it possible to read both a fingerprint and a shaded pattern such as a character or a picture written on paper or the like.

In particular, the incident light has an angle component smaller than the critical angle and an angle component larger than the critical angle.

The photoelectric conversion element is located at a position for receiving a reflected light defined by Snell's law with respect to the input surface with respect to a component having a large incident angle out of light incident on the input member from the light source.

In particular, the photoelectric conversion element is placed at a position where the reflected light becomes total reflected light.

Thus, the fingerprint can be read by total reflection light, and a light and shade pattern from paper or the like can be read by diffused light by incident light having an incident angle smaller than the critical angle.

Alternatively, a photoelectric conversion element is placed at a position where scattered light having an angle smaller than the critical angle is received.

Thus, the fingerprint can be read by the scattered light from the valley.

Further, the light source is a planar light source having a curved surface.

A half mirror between the light source and the input surface,
An optical fiber bundle is provided.

Alternatively, two or more light sources are provided.

Thus, the light incident on the linear area on the input surface can have a plurality of different incident angle components.

The incident angle component of the incident light is switched according to the object to be read.

Thus, unnecessary reflected light or diffused light can be avoided.

Alternatively, the input member has a semi-cylindrical shape.

Thus, any incident light can be perpendicularly incident on the input member, thereby simplifying the design.

By providing an imaging optical system between the input member and the photoelectric conversion device, the size of the photoelectric conversion element can be reduced.

Also, there is provided a light source, an input member having an input surface to be read, and a linear photoelectric conversion element, and light incident on the linear region of the input surface from the light source has a plurality of different incident angle components. In the image reading device, the whole image is synthesized from the partial image by the relative movement of the reading object and the image reading device.

With this structure, the linear photoelectric conversion element has a simple structure capable of accurately reading both an object to be read having irregularities such as a fingerprint and an object having shading such as paper and other objects having characters and pictures. An image reading device can be realized.

Further, there is provided an input member having a light source and an input surface to be read, and a linear photoelectric conversion element, and light incident on the linear region of the input surface from the light source has a plurality of different incident angle components. With an image reading device, a reading object having unevenness such as a fingerprint and a reading object having light and shade such as paper and other objects having characters and pictures are converted from a partial image to an entire image by relative movement of the reading object and the image reading device. By integrating the image reading device to be combined with a portable wireless communication device such as a mobile phone or a PHS, or a portable information device such as an electronic organizer, personal authentication and input of characters and pictures can be performed.

[0028]

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

FIG. 1 is a diagram showing the incidence of illumination light from a light source on an input surface of an image reading apparatus according to the present invention.

One surface of the input member 3 serves as the input surface 2. For example, in the case of fingerprint input, the finger 1 is stamped.

The light source for illumination is on the opposite side of the input surface from the object to be read.

The incident light has an incident light 4 having a large incident angle and an incident light 5 having a small incident angle with respect to the input surface. Alternatively, the illuminance may be at least a certain value or more for each incident angle.

FIG. 2 is a diagram showing another example of the incidence of light from the light source on the input surface of the image reading apparatus of the present invention.

The incident light 4 having a large incident angle has an incident angle larger than the critical angle 6, and the incident light 5 having a small incident angle has a critical angle 6
It has a smaller angle of incidence. Alternatively, the illuminance has at least a certain fixed value or more.

FIG. 3 is a graph showing an incident angle-reflectance characteristic when glass or a synthetic resin is used as an input member.

This is the case where the input member has a refractive index of 1.5 and comes into contact with air.

The reflectivity is small and hardly changed until the incident angle is 30 degrees. However, when the incident angle exceeds 30 degrees, the reflectivity sharply increases, and at a critical angle of about 41.8 degrees, the reflectivity becomes 1 and total reflection occurs.

Therefore, for incident light having an incident angle equal to or greater than the critical angle or more, fingerprint detection can be performed accurately using reflected light. However, detection of a character or a gray-scale pattern such as a picture on paper is performed by reflection on the input surface. If it cannot be performed well or exceeds the critical angle, it becomes impossible due to total reflection.

However, in the present invention, since there is incident light at a low angle smaller than the critical angle, it is also possible to detect light and shade patterns such as characters or pictures.

FIG. 4 is a diagram showing a light receiving position of the photoelectric conversion device of the image reading apparatus according to the present invention.

There is an input member 3 having an input surface 2 and a surface 9 parallel to the input surface 2. A finger 1 is imprinted on the input surface, for example, in fingerprint reading. In the case of reading an original, it is of course paper.

A linear photoelectric conversion element 5 for receiving reflected light
There is.

By moving the finger 1 in the direction of the arrow,
The whole image is synthesized from the partial images.

Since the photoelectric conversion element is linear, incident light may have an illuminance equal to or greater than a value corresponding to the linear area of the input surface.

The linear photoelectric conversion element 5 is located at a position for receiving the reflected light from the incident light having a large incident angle among the reflected lights defined by Snell's law from the input surface.

When the light having a large incident angle exceeds the critical angle, the reflected light becomes total reflection, and if a photoelectric conversion element is placed so as to be received at this position, the accuracy of fingerprint detection is extremely improved. A light source for illumination is on the side opposite to the object to be read with respect to the input surface, and the incident light from the light source is reflected light according to Snell's law at the input surface interface of the input member. Light transmitted through the input member and reflected on the skin of the finger or paper or an object with characters or pictures, or at the interface between air and skin, or at the interface between paper or an object with characters or pictures and air, and returned to the input member side. .

Since this scattered light is subjected to multiple reflections, it spreads over a wide angle, and if the illuminating light is at an incident angle smaller than the critical angle, there is no total reflection from the input surface side to the input member. But it can be detected.

In other words, when a fingerprint is detected, reflected light is used, and when a document is read, diffused light is used to read both a fingerprint and a document.

In the present invention, the peak direction of the radiated light of the light source and the direction of the incident light are slightly deviated, and the peak direction of the reflected light is slightly deviated from the normal direction of the detection surface of the linear photoelectric conversion element. This is not a problem.

It is an object of the present invention that incident light having a certain value or more is incident at a predetermined incident angle, and reflected or scattered light having a certain value or more is detected.

FIG. 15 shows a case where scattered light is used for fingerprint reading.

The photoelectric conversion element 7 is located at a position where the scattered light 16 having an angle smaller than the critical angle 6 is received.

At the time of reading a fingerprint, the incident light 4 having an angle larger than the critical angle is totally reflected on the peak of the finger and is not received, but only the scattered light from the valley is received.

In this case, it is more preferable to make the incident light having a small incident angle as close to the critical angle as possible, or to block or turn off the light.

FIG. 5 is a view showing an image reading apparatus according to the present invention. The light source 8 is a curved planar light source, so that illumination light enters the linear area of the input surface at different incident angles. .

FIG. 6 is a diagram showing another image reading apparatus according to the present invention, in which light from a light source 8 is split into two by a half mirror 10 and is incident on an input surface.

FIG. 7 is a view showing another image reading apparatus according to another embodiment of the present invention. There are two light sources, and light for illumination enters the linear area of the input surface at different incident angles.

FIG. 8 is a view showing still another image reading apparatus according to the present invention, in which light from a light source is divided into two by a bundle of optical fibers, so that a linear area on the input surface is formed at different incident angles. Light for illumination enters.

By the way, for example, when light having an angle larger than the critical angle and light having a smaller angle are incident at the same time during fingerprint detection, scattered light from the incident light having a smaller angle is also received, which adversely affects the detection accuracy.

Therefore, in FIG. 9, the incident light is switched by the shutter in accordance with the object to be detected.

Of course, when there are two light sources, it is possible to switch electrically.

By thus blocking or extinguishing one of the incident lights, the reading accuracy of the fingerprint and the light and shade pattern can be improved.

FIG. 10 shows a case where the input member 2 has a semi-cylindrical shape.

As shown in FIG. 11, in the semi-cylindrical input member, incident light from any direction is perpendicularly incident, and the design is simpler than in the case of a plate or prism.

FIG. 12 shows a semi-cylindrical input member whose cross section is shaped like a regular polyhedron cut in half. Similarly, a plurality of incident lights are perpendicularly incident to simplify the design.

Even if the input members having various shapes are made of synthetic resin, they can be easily manufactured at low cost by injection molding, press molding, etc., which is very convenient.

FIG. 13 shows a case where an imaging optical system 14 is provided between the input member 3 and the linear photoelectric conversion device 7, and the size of the photoelectric conversion element can be reduced.

In this case, the input member is not limited to the triangular prism.

In the case of fingerprint reading, it is easy to fix the reading device and move a finger, and to read a document or the like, it is easy to operate the reading device by moving the reading device.

Although the term linear photoelectric conversion element has been mainly used in the above description, the present invention refers to a linear photoelectric conversion element as a one-dimensional or rectangular photoelectric conversion element or a line sensor or a linear sensor. It includes all those that combine the entire image from the one-dimensional, linear, or rectangular partial image.

FIG. 14 shows an example of an application apparatus according to the present invention. The image reading apparatus 15 according to the present invention is integrated into a portable telephone, whereby personal authentication can be performed by using a fingerprint and characters from paper or the like can be obtained. And data of figures and illustrations can be read.

In addition to the portable telephone, PHS (registered trademark), other portable radio communication devices, and portable information devices such as electronic organizers can similarly perform personal authentication by fingerprints by integrating and incorporating the image reading device of the present invention. With the confidentiality, it becomes possible to read the data of characters and pictures from paper or the like.

[0073]

As described above, according to the method of the present invention, a light source, an input member having an input surface to be read, and a linear photoelectric conversion element are provided. An image reading device in which light has a plurality of different incident angle components. By combining the whole image from the partial image by the relative movement of the reading object and the image reading device, the reading object has an uneven reading object such as a fingerprint and a character. Thus, both reading objects having shading such as a picture can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing incidence of illumination light from a light source on an input surface according to the present invention.

FIG. 2 is a diagram showing incidence of illumination light from a light source on an input surface according to the present invention.

FIG. 3 is a diagram showing an incident angle-reflectance characteristic of the present invention.

FIG. 4 is a diagram showing a light receiving position of a photoelectric conversion device of the image reading device of the present invention.

FIG. 5 is a diagram showing an image reading device of the present invention.

FIG. 6 is a diagram showing an image reading device of the present invention.

FIG. 7 is a diagram showing an image reading device of the present invention.

FIG. 8 is a diagram showing an image reading apparatus of the present invention.

FIG. 9 is a diagram showing an image reading device of the present invention.

FIG. 10 is a diagram showing an image reading apparatus of the present invention.

FIG. 11 is a view showing an image reading apparatus of the present invention.

FIG. 12 is a diagram showing an image reading device of the present invention.

FIG. 13 is a diagram showing an image reading device of the present invention.

FIG. 14 is a diagram showing an application device of the present invention.

FIG. 15 is a diagram showing a light receiving position of the photoelectric conversion device of the image reading device of the present invention.

FIG. 16 is a diagram illustrating an image reading device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Finger 2 ... Input surface 3 ... Input member 4, 5 ... Incident light 6 ... Critical angle 7 ... Photoelectric conversion element 8 ... Light source 9 ... Surface 10 ..Half mirror 11 Mirror 12 Optical fiber bundle 13 Shutter 14 Imaging optical system 15 Scattered light

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Satoshi Machida 1-8-1, Nakase, Mihama-ku, Chiba-shi, Chiba F-term (reference) in Seiko Instruments Inc.

Claims (16)

[Claims] 1. An image reading apparatus comprising a light source, an input member having an input surface to be read, and a linear photoelectric conversion element, wherein a plurality of different incident lights from the light source enter a linear region of the input surface. An image reading apparatus having an angular component, wherein an entire image is synthesized from a linear image by a relative movement of the reading object and the image reading apparatus. 2. The image reading apparatus according to claim 1, wherein the incident light has an angle component smaller than the critical angle and an angle component larger than the critical angle. 3. The photoelectric conversion device according to claim 1, wherein the photoelectric conversion element is located at a position for receiving a reflected light defined by Snell's law from an input surface of the input member with respect to a component having a large incident angle of the incident light. The image reading device according to claim 1. 4. An image reading apparatus according to claim 3, wherein said reflected light is total reflected light. 5. The image reading apparatus according to claim 2, wherein said photoelectric conversion element is located at a position for receiving scattered light smaller than a critical angle. 6. The image reading apparatus according to claim 1, wherein the plurality of different incident angle components are formed by a planar light source. 7. The image reading apparatus according to claim 1, wherein the plurality of different incident angle components are formed by a half mirror. 8. The image reading apparatus according to claim 1, wherein the plurality of different incident angle components are formed by a plurality of different light sources. 9. An image reading apparatus according to claim 1, wherein said plurality of different incident angle components are formed by an optical fiber bundle. 10. The image reading apparatus according to claim 1, wherein the plurality of different incident angle components are switched according to a reading target. 11. The image reading apparatus according to claim 1, wherein said input member has a semi-cylindrical shape. 12. An image reading apparatus according to claim 1, further comprising an image forming optical system between said input member and said photoelectric conversion element. 13. An input member having a light source and an input surface to be read, and a linear photoelectric conversion element, wherein light incident on the linear region of the input surface from the light source forms a plurality of different incident angle components. An image reading method comprising: synthesizing a whole image from a partial image by a relative movement of the reading object and the image reading device. 14. The image reading method according to claim 13, wherein the reading target is a reading target having irregularities such as a fingerprint and a reading target having a shade such as a character or a picture. 15. An input member having a light source and an input surface to be read, and a linear photoelectric conversion element, wherein light incident on the linear region of the input surface from the light source forms a plurality of different incident angle components. The read target is a read target having irregularities such as a fingerprint, and a read target having shades such as characters and pictures, and the whole image is converted from a linear image by the relative movement of the read target and the image reading device. A portable wireless communication device comprising an image reading device for synthesizing the image data. 16. An input member having a light source, an input surface to be read, and a linear photoelectric conversion element, wherein light incident on the linear region of the input surface from the light source forms a plurality of different incident angle components. The read target is a read target having irregularities such as a fingerprint, and a read target having shades such as characters and pictures, and the whole image is converted from a linear image by the relative movement of the read target and the image reading device. A portable information device having an image reading device for synthesizing an image.