JP2001283205A - Image reader, its method and device applying the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader capable of reading both of fingerprints and a reading object such as characters with gradation by using a linear photoelectric conversion element with high accuracy. SOLUTION: A finger 1 is placed on an input surface 2 of an input member 3. A light source 4 for illumination exists on the opposite side of the reading object and the input surface 2 and the entire image is composited from partial images by moving the finger. In this case, a refraction angle 7 in the input member of diffused light to be received by the photoelectric conversion element is equal to or larger than the critical angle 8 between the input surface and the air, and on the other hand, an incident angle 6 of light from the light source 4 is smaller than the critical angle 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear photoelectric conversion element, which has an uneven pattern such as a fingerprint by synthesizing an entire image from a linear partial image by a relative movement of an object and an image reading apparatus. The present invention relates to an image reading apparatus capable of reading both a reading target and a reading target having a light and shade pattern such as a character or a picture and an application device thereof.

[0002]

2. Description of the Related Art An image reading apparatus which has a linear photoelectric conversion element and combines a whole image from a linear partial image by relative movement of a reading object and an image reading apparatus to read a fingerprint and an original is disclosed in Japanese Patent Application Laid-Open No. HEI 9-163702. 10-240906 discloses an example in which illumination light is vertically incident on an input surface and vertical reflected light is detected.

[0003]

According to the method using the normal incidence and reflection, the reading of the original is easy, but the difference in the reflected light between the peaks and valleys of the finger is significantly inferior to that of the total reflection, so that the fingerprint reading accuracy is low. Not good.

SUMMARY OF THE INVENTION An object of the present invention is to provide a simple and accurate image reading apparatus capable of reading both an object having unevenness such as a fingerprint and an object having shading such as an original.

[0005]

According to the present invention, incident light for illuminating an input surface to be read, that is, an impression surface of a finger, is incident at an incident angle smaller than a critical angle at which total reflection is caused, and the light is input to the input member. The scattered light from the object to be read incident on the input member at a refraction angle larger than the critical angle is detected.

As a result, both fingerprint detection and document reading can be performed. In particular, when fingerprint detection is performed, only scattered light from the mountain is received, so that fingerprint reading can be performed with high accuracy.

Further, the input member has a shape having a second surface parallel to the input surface, and scattered light to be detected is detected by detecting scattered light from the object to be read which is totally reflected between the input surface and the second surface. This ensures that light and other scattered light can be easily separated.

The structure can be simplified by using a prism as the input member.

Furthermore, by providing a mirror between the light source and the input surface or between the input surface and the linear photoelectric conversion element and changing the optical path, miniaturization and thinning can be achieved.

Further, by providing an imaging optical system between the input surface and the linear photoelectric conversion element, the size of the photoelectric conversion element can be reduced.

Alternatively, an optical fiber bundle in which a number of optical fibers are bundled is provided between the input member and the photoelectric conversion device.
As a result, the degree of freedom of the optical path is increased and the size of the apparatus can be reduced.

By using a synthetic resin for the input member, complicated and accurate processing such as a prism can be easily performed at low cost.

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 has an incident angle component smaller than a critical angle; An image input device in which the linear photoelectric conversion element receives scattered light from the object to be read having a refraction angle within the input member larger than the critical angle; And the whole image is synthesized from the linear partial images by relative movement of the image input device.

Thus, it is possible to realize an image reading apparatus having a simple structure capable of accurately reading both an object to be read having unevenness such as a fingerprint and an object having light and shade such as a manuscript by the linear photoelectric conversion element.

Further, by integrating a portable wireless communication device such as a mobile phone and a PHS, a portable information device such as an electronic organizer and the above-described image reading device, fingerprint authentication and characters such as characters and figures can be performed with a simple structure. Can input information.

[0016]

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

FIG. 1 is a view showing an image reading apparatus according to the present invention.

One surface of an input member 3 for inputting an object to be read such as a fingerprint or a character is an input surface 2. For example, in the case of a fingerprint, the finger 1 is stamped.

A light source 4 for illumination is located on the opposite side of the input surface 2 from the object to be read.

Light incident on the input surface 2 from the light source 4 forms an incident angle 6, and scattered light from the object to be read is received by the photoelectric conversion element 5.

The photoelectric conversion element is linear, rectangular or one-dimensional, and may be called a line sensor or a linear sensor.

The whole image is synthesized from the partial images by moving the finger.

At this time, the refraction angle 7 of the scattered light received by the photoelectric conversion element at the input member is greater than the critical angle 8 with the air on the input surface, while the incident angle 6 is smaller than the critical angle 8. That is, the photoelectric conversion element is placed at a position for receiving scattered light having a relation of incident angle <critical angle <refraction angle.

In this case, in order to receive scattered light having a refraction angle larger than the critical angle, a surface 13 intersecting with the input surface 2 of the input member 3
Scattered light is received by the photoelectric conversion element 5.

The surface 13 needs to have an angle at which the scattered light is not totally reflected.

Here, the scattered light refers to the skin of the finger or paper or an object with characters or pictures, or the interface between air and skin, or the interface of paper or an object with characters or pictures and air with the input member of the incident light from the light source. Reflected at the interface of the input member and returned to the input member side.

FIG. 2 shows that the light source 4 and the photoelectric conversion element 5 are connected to the input surface 2.
Are on the same side with respect to the normal direction.

Either configuration is possible, but as shown in FIG. 2, the intensity of scattered light from the mountain to the light receiving element is increased by moving the light source closer to the critical angle than normal incidence and positioning the light receiving element on the same side as the light source. it can.

Therefore, in order to improve the accuracy of fingerprint detection, it is preferable to arrange the light source closer to the critical angle than normal incidence and to position the light receiving element on the same side as the light source.

FIGS. 3A and 3B show the scattered light from the valleys and peaks of the finger at the time of fingerprint detection. FIG. 3A shows the scattered light from the valleys, and FIG. 3B shows the scattered light from the peaks. Therefore, the scattered light from the valley forms a wide angle with respect to the scattered light from the valley. Therefore, as shown in FIGS. 1 and 2, when the detection angle of the photoelectric conversion element is set to an angle larger than the critical angle, Since only the scattered light from the mountain is received and the reflected light from the input surface 2 is not received, fingerprint detection can be performed with high accuracy, and, of course, light and shade patterns can be detected.

FIG. 4 also shows an image reading apparatus according to the present invention, in which the scattered light larger than the critical angle is totally reflected by a surface 14 parallel to the input surface 2 of the input member 3 to guide the scattered light to the light receiving position. , Two photoelectric conversion elements 8 are drawn, but the photoelectric conversion elements 5 are provided on either the side opposite to the light source 4 or on the same side.
Are shown, and there are no two photoelectric conversion elements 8 in particular.

Also in this case, in order to improve the accuracy of fingerprint detection, it is preferable to arrange the light source closer to the critical angle than normal incidence and to arrange the light receiving element on the same side as the light source.

FIG. 5 shows a case where the input member 3 is a triangular prism.

6, 7, 9, 12, 13, and 1
Reference numeral 4 denotes a case in which a mirror 9 is placed between the light source 4 or the photoelectric conversion element 5 and the input member 3 to change the optical path, thereby making it possible to reduce the thickness and size.

FIGS. 8, 10 and 11 show the surface 9 of the input member 2.
Is used for a mirror.

In this case, the surface 9 forms an angle for totally reflecting scattered light.

FIG. 15 shows a case where the image forming optical system 11 is placed between the input member 3 and the photoelectric conversion element 5, and the size of the photoelectric conversion element 5 can be reduced.

FIG. 16 shows a case where the optical fiber bundle 11 is placed between the input member 3 and the photoelectric conversion element 5, and has a high degree of freedom in the optical path.

FIG. 17 shows a portable telephone according to the present invention, in which the image reading device 12 is integrated.

As described above, by integrating a portable wireless communication device such as a portable telephone and a PHS, and a portable information device such as an electronic organizer with the above-described image reading device, the fingerprint authentication and the characters and figures can be performed with a simple structure. It is possible to input information in light and shade patterns.

[0041]

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. The incident light from the light source has an incident angle component smaller than the critical angle, and the linear photoelectric conversion element has a refraction angle within the input member larger than the critical angle. In the position for receiving the scattered light, and by combining the whole image from the linear partial image by the relative movement of the reading object and the image reading device, both the reading of the fingerprint and the shading pattern such as a character or a picture can be performed. A simple and compact image reading apparatus that can be realized can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram showing an image reading apparatus of the present invention.

FIG. 2 is a diagram showing an image reading device of the present invention.

FIG. 3 is a diagram showing scattered light from a finger.

FIG. 4 is a diagram showing an 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 illustrating an image reading apparatus according to the present invention.

FIG. 15 is a diagram showing an image reading device of the present invention.

FIG. 16 is a diagram showing an image reading apparatus of the present invention.

FIG. 17 is a view showing a mobile phone of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Finger 2 ... Input surface 3 ... Input member 4 ... Light source 5 ... Photoelectric conversion element 6 ... Incident angle 7 ... Refraction angle 8 ... Critical angle 9 ... Mirror 10 imaging optical system 11 optical fiber bundle 12 image reading device 13, 14 surface

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Satoshi Machida 1-8-1 Nakase, Mihama-ku, Chiba-shi, Chiba F-term in Seiko Instruments Inc. 5C072 AA01 BA20 CA02 DA02 DA04 DA07 DA10 DA21 NA04 VA10

Claims (12)

[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 light incident on a linear region of the input surface from the light source is smaller than a critical angle. An incident angle component, and the linear photoelectric conversion element is located at a position to receive scattered light from the object to be read having a refraction angle in the input member having an angle larger than the critical angle; and An image reading apparatus, wherein a whole image is synthesized from a linear partial image by a relative movement between a reading object and the image reading apparatus. 2. The image reading apparatus according to claim 1, wherein the object to be read is an uneven pattern such as a fingerprint and a light and shade pattern such as a character or a picture. A second input member parallel to the input surface;
2. The image reading apparatus according to claim 1, wherein the image reading device has a surface and receives scattered light totally reflected between the input surface and the second surface. 4. An image reading apparatus according to claim 1, wherein said input member is a prism. 5. The image reading device according to claim 1, wherein a mirror is provided between the light source and the input surface. 6. The image reading apparatus according to claim 1, wherein a mirror is provided between the input surface and the linear photoelectric conversion element. 7. An image reading apparatus according to claim 1, further comprising an image forming optical system between said input member and said photoelectric conversion element. 8. An image reading apparatus according to claim 1, further comprising an optical fiber bundle between said input member and said photoelectric conversion element. 9. An image reading apparatus according to claim 1, wherein said input member is made of a synthetic resin. 10. An input member having a light source, an input surface to be read, and a linear photoelectric conversion element, wherein incident light from the light source to a linear region of the input surface is smaller than a critical angle. An image input device having a linear photoelectric conversion element at a position for receiving scattered light from the object to be read having a refraction angle within the input member having an angle larger than the critical angle. The object to be read is an object to be read having unevenness such as a fingerprint, and an object to be read having shading such as a document. The whole image is synthesized from a linear partial image by relative movement between the object to be read and the image input device. An image reading method comprising: 11. An input member having a light source, an input surface to be read, and a linear photoelectric conversion element, wherein incident light from the light source to a linear region of the input surface is smaller than a critical angle. And the linear photoelectric conversion element is at a position to receive scattered light from the object to be read having a refraction angle in the input member having an angle larger than the critical angle, and the object to be read is a fingerprint. And an image reading device that synthesizes an entire image from a linear partial image by the relative movement of the image reading device and the image reading device. A portable wireless communication device characterized by having 12. An input member having a light source, an input surface to be read, and a linear photoelectric conversion element, wherein an incident light component from the light source to a linear region of the input surface is smaller than a critical angle. And the linear photoelectric conversion element is at a position to receive scattered light from the object to be read having a refraction angle in the input member having an angle larger than the critical angle, and the object to be read is a fingerprint. And an image reading device that synthesizes an entire image from a linear partial image by the relative movement of the image reading device and the image input device. A portable information device having a simplified input device.