JPH08279035A - Fingerprint input device - Google Patents

Abstract

PURPOSE: To constitute a fingerprint input device irrelevantly to the size of a finger and obtain the fingerprint input device which is extremely small by outputting fingerprint information for fingerprint recognition on the basis of plural fingerprint part images which are inputted divisionally from plural input parts. CONSTITUTION: A fingerprint input part 110 is divided into three, and the light beam from a light source 102 is scattered by a scattering body 103 and made incident on one reverse flank under prism 101 to generate illumination light 104 which lights up a fingerprint uniformly. The light beam of this illumination light 104 is totally reflected by the glass-air border surface of the prism 101 that the finger 107 comes into contact with. The illumination light 104 is reflected directly on an image pickup device 106 to form a fingerprint image, which is picked up and inputted to a control means 108 including an image processing means, and the image is properly processed and outputted as the fingerprint information for fingerprint recognition. Consequently, the fingerprint input part 110 is constituted without reference to the size of the finger and even by the extremely small input part can be constituted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fingerprint input device used for personal identification.

[0002]

2. Description of the Related Art A conventional fingerprint input device, for example, reference "Japanese Patent Laid-Open No. 62-212892 (Mitsubishi Electric, Ikebata et al.)"
In the described "Fingerprint pattern input device", a part corresponding to one input window is installed in the part for inputting the fingerprint pattern, and the fingerprint pattern for one finger is imaged through the window. Was there. Moreover, the size of the window needs to be as large as the size of the finger in order to capture the entire fingerprint image. Furthermore, a relatively large optical component such as a triangular prism is used in the portion corresponding to the window, and its thickness is about the same as the size of a finger. In addition, a camera having a relatively large size has been used as an image pickup device for the fingerprint image.

[0003]

As described above, in the conventional fingerprint input device, the size of the window for inputting the fingerprint needs to be at least one finger in order to capture the entire fingerprint image. However, it was difficult to make a large size by ignoring the size of the finger. Furthermore, the presence of a relatively large-scale fingerprint image pickup device has made it difficult to flatten it.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a fingerprint input device which is significantly miniaturized and flattened as compared with the prior art.

[0005]

The outline of typical means for achieving the above object in the present invention will be described below.

<Means 1> In a fingerprint input device including at least a light source, an image pickup device, and an input unit for touching a finger and inputting a fingerprint image of the finger, the input unit for inputting the fingerprint image has a plurality of small input units. It is characterized by being divided into. Further, the present invention is characterized in that fingerprint recognition can be executed based on a plurality of divided partial fingerprint images input from the fingerprint input unit.

<< Means 2 >> The construction of the means 1 is characterized in that a contact type image sensor is used for the image pickup device in the fingerprint input section divided into the plurality of input sections.

<Means 3> In the configuration of the means 1, each of the plurality of input sections of the fingerprint input section is provided with a transparent waveguide having a refractive index larger than that of air, an illuminating light source thereof, and an image pickup device. It is characterized by that.

<Means 4> The configuration of the means 1 is characterized by further comprising control means for integrally processing the respective fingerprint image signals output from the image pickup device of the fingerprint input part divided into the plurality of input parts. To do.

<Means 5> In the structure of means 3, the transparent waveguide of the fingerprint input portion divided into a plurality of portions is provided with a triangular prism, a rectangular prism, a polygonal prism, or a cylindrical waveguide. The feature is that a trapezoidal prism is used.

[0011]

In the structure of the means 1, the fingerprint input section is divided into a plurality of sections, so that the fingerprint input section can be constructed without being restricted by the size of the finger, and a very small fingerprint input section can be constructed. In other words, the degree of freedom in designing the size of the fingerprint input device is increased, and the optical components such as the light source are made smaller or thinner, so that the fingerprint input device is much smaller than the conventional fingerprint input device or very thin. A fingerprint input device can be realized. In addition, when inputting a fingerprint, instead of inputting the entire fingerprint image, the partial image can be divided and input, so that the amount of input information is greatly reduced, and high-speed input processing and recognition are performed. Ready to process. That is, the identification using the fingerprint can be executed at a higher speed.

In the configuration of the means 2, the contact image sensor is used in the fingerprint image pickup device to simplify the configuration of the image pickup device and further reduce the thickness of the device itself. That is, it is possible to easily realize a flat fingerprint input device.

According to the structure of the means 3, it is possible to pick up a fingerprint image having a high contrast ratio and a good image quality by using a transparent waveguide instead of directly picking up an image of minute unevenness of a fingerprint.

In the structure of the means 4, by providing the control means, the fingerprint images obtained by dividing the image into a plurality of images are integrated. By this means, it is possible to handle the fingerprint information that is divided and input independently as one piece of integrated information without treating it as independent information, increase the resistance to erroneous input, and input more accurate fingerprint information. .

In the structure of the means 5, a triangular prism, a rectangular parallelepiped prism, a polygonal prism, or a transparent prism of the fingerprint input section divided into a plurality of sections is used.
By using a cylindrical waveguide or a trapezoidal prism, the degree of freedom of the fingerprint input device configuration is increased, and a smaller fingerprint imaging device can be realized.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings.

<< Embodiment 1 >> FIG. 1A shows a first embodiment of the present invention.
An example of is shown. In this embodiment, the rectangular fingerprint input unit 1
10 is divided into three and arranged in the housing 109.
The structure of one of the fingerprint input units 110 is shown in the figure as a perspective view. Here, three input units 11
Although the example in which 0 is arranged is shown, it can be easily inferred that any number of the input units 110 can be realized.

FIG. 1B shows the fingerprint input unit 1 for one
The structure (side view) of 10 and the figure explaining the operation | movement are shown. The image pickup operation of the fingerprint in this configuration is as follows.
The light beam from the light source 102 is scattered by the scatterer 103 and is incident on one side surface below the triangular prism 101 to generate illumination light 104 that uniformly illuminates the fingerprint. This illumination light 1
The ray 04 is designed to cause total internal reflection at the glass-air interface where the finger 107 of the triangular prism is in contact, and when the finger 107 is not in contact with the interface, the interface behaves like a plane mirror. In this case, the illumination light 104 is directly reflected by the imaging device 106 to be imaged. This phenomenon similarly occurs in the concave portion of the fingerprint in which the finger does not directly contact the glass interface, and the reflected light 105-1 from the concave portion of the fingerprint is reflected without being substantially attenuated and is displayed on the image pickup device 106 as a bright image. It is imaged. On the other hand, for the convex portion of the fingerprint in which the finger touches the glass interface, the total reflection condition is broken because the finger directly touches the glass-air interface, and the illumination light 10
4 is converted into scattered light 105-2 from the convex part of the fingerprint,
The light will be imaged. The reflected light 105-1 from the concave portion of the fingerprint and the scattered light 105-from the convex portion of the fingerprint
The intensity ratio of 2 is captured by the image capturing device 106.
With such a configuration, fine unevenness of a fingerprint can be converted into an image with a high contrast ratio, and thus a good fingerprint image can be captured.

The fingerprint image picked up by the image pickup device 106 is inputted to the control means 108 including the image processing means, appropriately subjected to image processing and outputted to the stage for executing fingerprint recognition. Although the device itself is normally in an operable state at all times, since the fingerprint input unit 110 is divided into a plurality of parts, the light source 102 is connected to the control means 108 and each light source 102 is sequentially time-divided. Fingerprint input unit 110 such as lighting
Each can be controlled to operate in a time division manner. This makes it possible to reduce the power consumption of the device.

2 (a), (b), (c) and FIG.
(A), (b), and (c) show examples of the divided configuration of the fingerprint input unit 110, respectively.

FIG. 2A shows an example in which a plurality of rectangular input units 201 are arranged in a housing 202 so as to cross the fingerprint of the finger 203. This has the same configuration as that shown in the embodiment of FIG.

FIG. 2B shows an example in which a plurality of input units 201 are radially arranged on the housing 202 from the center of the fingerprint of the finger 203.

FIG. 2C shows an example in which a plurality of input units 201 are arranged in a housing 202 so as to vertically cut a fingerprint of a finger 203.

FIG. 3A shows an example in which a plurality of input units 201 are arranged in the housing 202 so as to cross the fingerprint of the finger 203 diagonally.

FIG. 3B shows an example in which a plurality of input units 201 are arranged in a housing 202 in a cross pattern with respect to the center of the fingerprint of the finger 203.

FIG. 3C shows an example in which a plurality of minute input units 201 are arranged in a housing 202 in a grid pattern in the range of the fingerprint of the finger 203.

It can be easily inferred that, as another example of the divided configuration other than this, a configuration in which the above arrangement examples are combined can be similarly realized.

By thus dividing the fingerprint input section into a plurality of sections, each input area can be made smaller,
It is possible to reduce the amount of fingerprint input information. Therefore, if an input device having the same processing capability is used, fingerprint input can be executed at higher speed. Further, the fingerprint input unit can be made smaller than the conventional device, which is advantageous for downsizing.

<< Embodiment 2 >> FIG. 4 shows the configuration of a second embodiment of the present invention. In this embodiment, a one-dimensional contact image sensor 303 is used as the image pickup device. By using the contact image sensor 303, the distance between the finger 301 and the sensor 303 can be minimized, and the thickness of the entire device can be reduced.

Reference numeral 302 denotes a light source, which is a finger 3 to be imaged.
Illuminate 01. Reference numeral 304 represents the illumination light beam.
Reflected light 30 from finger 301 illuminated by light source 302
5 is detected by the contact image sensor 303 and converted into an electric signal. Here, the contact type image sensor 3
In 03, a plurality of independent photosensors are integrated, and further, their size and arrangement pitch are arranged finer than the fingerprint pitch. Therefore, this sensor 303
By closely contacting with the finger 301, the intensity pattern of the reflected light 305 from the finger 301 can be detected as it is. This signal has fingerprint information (pattern information) of the finger, and the signal is processed / recognized by the control means 308 as in the first embodiment and output to the stage for executing fingerprint recognition. Here, 306 is a housing, and 307 corresponds to a window for imaging.

In this embodiment, it is premised that a one-dimensional contact image sensor which has been often used for reading an original document is used, but the same fingerprint can be picked up by using a two-dimensional contact image sensor. Can be easily analogized.

<< Embodiment 3 >> FIG. 5 shows the configuration of a third embodiment of the present invention. The feature of this embodiment is that a transparent waveguide is used for the fingerprint detection portion.

FIG. 5A shows an embodiment in which a glass rectangular prism 404 is used as a transparent waveguide. The operation of this embodiment is as follows. The illumination light beam 402 emitted from the light source 401 is first scattered by the scattering plate 403 arranged on one end surface of the rectangular prism glass prism 404, and illuminates the entire inside of the rectangular prism 404. Since the refractive index of glass is about 1.5, which is higher than that of air,
A portion of the illuminating beam 402 is a glass-air interface 420.
Causes total internal reflection at. However, in the part where the finger 405 is in contact with the prism 404, the total reflection condition is broken,
Scattered light from finger 404 will be produced. The reflection pattern of the totally reflected light 406 and the scattered light 407 is converted to the prism 404.
The image is picked up by the image pickup device 408 arranged on the other end face of the. The portion that produces the totally reflected light 406 corresponds to the concave portion of the fingerprint,
Since the portion where the scattered light 407 is generated corresponds to the convex portion of the fingerprint, the reflected light intensity ratio matches the uneven pattern of the fingerprint. As a result, it is possible to capture a fingerprint image.

Here, an example in which a quadrangular prism is used for the transparent waveguide has been shown, but it can be easily inferred that a fingerprint image pickup device can be similarly realized with a polygonal prism other than this.

5B, 5C and 5D, a triangular prism 404-2 and a cylindrical prism 404-2 are respectively shown.
3 shows an example of a transparent waveguide using the trapezoidal prism 404-4. A similar fingerprint imaging device can be realized by replacing the transparent waveguide 404 shown in FIG. 5A with the prism.

Here, the triangular prism 40 of FIG.
4-2 and the trapezoidal prism 404-4 of FIG.
In the case of using, the illuminating light beam can be arranged in two types, that is, the illuminating light beam 410-1 having the end face arrangement and the illuminating light beam 410-2 having the side face arrangement. Of course, the illumination light beam 410-
It goes without saying that the image pickup device 408 is arranged at each of the end points of No. 1 and 410-2.

<Embodiment 4> FIG. 6 shows the configuration of a fourth embodiment of the present invention. This embodiment is similar to FIG. 1 of the first embodiment.
It is a control block diagram of the fingerprint input device shown in (a). The feature of the present embodiment is that a control unit 501 for integrally processing information from a plurality of independent fingerprint input units 502-1 to 502-4 is provided.

In a fingerprint input device having a plurality of independent fingerprint input sections as shown in FIG. 1A, basically only a partial image of a fingerprint can be input, and information on the entire fingerprint image can be obtained only from the partial image. It is difficult to grasp. In such a case, when the partial fingerprint image is displaced due to the displacement of the finger at the time of inputting the fingerprint (finger 503-1, 503-2 in FIG. 6), it is not possible to grasp how it is displaced. , It becomes a big problem in matching and recognizing with the original fingerprint image. in this way,
The problem caused by the positional deviation at the time of fingerprint input cannot be corrected by simply arranging a plurality of fingerprint input sections.

In order to solve such a problem, in this embodiment, the control means 501 for integrating and processing the signals from the plurality of fingerprint input sections 502-1 to 502-4 is installed. The specific control method is as follows. When the fingerprint is applied to the input area of each fingerprint input unit 502-1 to 502-4, the reflected light from the fingerprint changes from the normal state. Therefore, if the level of the reflected light when the fingerprint is applied is set in advance, the presence or absence of the fingerprint can be confirmed. Further, in the input areas of the respective fingerprint input sections 502-1 to 502-4, the area (size) of the area where the fingerprint is input and the area where the fingerprint is not hit are measured by the above method. Further, from the area ratio of the both, an estimation process of the position where the fingerprint is applied is performed. This is based on the reason that the size and shape of the entire fingerprint are constant to some extent. Through this series of processing, the position of the entire fingerprint image can be grasped and corrected. This correction can improve the fingerprint recognition rate.

The control means 501 is more specifically composed of an interface means 501-2 for signals from the fingerprint input sections 502-1 to 502-4 and a processing means 501-1 for signals received from the interface means 501-2. The interface unit 501-2 can be configured by a peripheral circuit LSI that receives or drives signals from the fingerprint input units 502-1 to 502-4, and the processing unit 501-1 is a microprocessor LSI or a semiconductor memory LSI. It can be composed of the electronic circuit used.

[0041]

As described above, according to the fingerprint input device of the present invention, it is possible to realize a much smaller size and a flat surface as compared with the conventional fingerprint input device.

More specifically, according to the means 1 of the present invention, since the fingerprint input section can be divided into a plurality of parts, a very small input section can be constructed regardless of the size of the finger. That is, the degree of freedom in designing the size of the fingerprint input device is increased, and the optical components such as the light source are made smaller and thinner. Can be realized. In addition, when inputting a fingerprint, the partial image is divided and input instead of inputting the entire fingerprint image, so the amount of input information can be greatly reduced, and the input processing and recognition processing can be performed at high speed. it can. That is, the identity verification using the fingerprint can be executed at higher speed.

According to the means 2 of the present invention, since the contact image sensor is used in the fingerprint image pickup device, the structure of the fingerprint image pickup device can be simplified and the thickness of the device itself can be reduced. That is, a flat fingerprint input device can be easily realized.

According to the means 3 of the present invention, the contact state due to the unevenness of the fingerprint is picked up by using the transparent waveguide instead of directly picking up the minute unevenness of the fingerprint, so that a good image quality with a higher contrast ratio is obtained. It is possible to capture the fingerprint image of.

According to the means 4 of the present invention, since the control means is provided, it is possible to integrally process the fingerprint images obtained by being divided into a plurality of images. By this means, the fingerprint information that is divided and input independently is not treated as independent information, but can be treated as one integrated information, the resistance to erroneous input can be increased, and more accurate fingerprint information can be obtained. Can be entered.

According to the means 5 of the present invention, the triangular waveguide, the rectangular prism, the polygonal prism, or the cylindrical waveguide is provided in the transparent waveguide of the fingerprint input portion divided into a plurality of means of the means 3. Alternatively, since a trapezoidal prism is used, the degree of freedom in the configuration of the fingerprint input device increases,
It is possible to realize a smaller fingerprint imaging device.

[Brief description of drawings]

1A and 1B are configuration diagrams showing a first embodiment of the present invention.

FIGS. 2A, 2B, and 2C are diagrams showing an arrangement example (part 1) of a fingerprint input unit divided into a plurality of parts.

FIGS. 3A, 3B, and 3C are diagrams showing an arrangement example (part 2) of a fingerprint input unit divided into a plurality of parts.

FIG. 4 is a configuration diagram showing a second embodiment of the present invention.

5 (a), (b), (c) and (d) are configuration diagrams showing a third embodiment of the present invention.

FIG. 6 is a configuration diagram showing a fourth embodiment of the present invention.

[Explanation of symbols]

 101 ... Trigonal prism 102 ... Light source 103 ... Scatterer 104 ... Illumination light 105 ... Reflected light 105-1 ... Reflected light from finger concave portion 105-2 ... Scattered light from finger convex portion 106 ... Imaging device 107 ... Finger (fingerprint) 108 ... Control means (including image processing means) 109 ... Housing 110 ... Fingerprint input section 201 ... Fingerprint input section 202 ... Housing 203 ... Finger 301 ... Finger 302 ... Light source 303 ... Contact image sensor 304 ... Illumination light beam 305 ... Reflected light 306 ... Casing 307 ... Window (fingerprint input section) 308 ... Control means 401 ... Light source 402 ... Illumination light beam 403 ... Scattering plate 404 ... Transparent waveguide (square prism) 404-2 ... Triangular prism 404-3 ... Cylinder Prism 404-4 ... Trapezoidal prism 405 ... Finger (fingerprint) 406 ... Total reflected light 407 ... Scattered light 408 ... Imaging device 410, 410- 1, 410-2 ... Illumination light beam 420 ... Glass-air interface 501 ... Control means 501-1 ... Processing means 501-2 ... Interface means 502-1 to 502-4 ... Fingerprint input section 503-1 to 503-2 ... Finger

Claims (5)

[Claims] 1. A light source for illumination, an imaging device,
A fingerprint input device comprising a fingerprint input unit for touching a finger and inputting a fingerprint image thereof, wherein the fingerprint input unit is divided into a plurality of input units, and a plurality of fingerprint portions input by dividing from the plurality of input units A fingerprint input device, which outputs fingerprint information for fingerprint recognition based on an image. 2. The fingerprint input device according to claim 1, wherein a contact-type image sensor is used as an image pickup device in the fingerprint input section divided into a plurality of input sections. 3. The fingerprint input device according to claim 1, wherein each of the plurality of fingerprint input units includes a transparent waveguide having a refractive index higher than that of air, an illumination light source, and an imaging device. A fingerprint input device characterized in that 4. The fingerprint input device according to claim 1, further comprising control means for integrally processing each fingerprint image signal output from the imaging device of the fingerprint input unit divided into a plurality of input units. Fingerprint input device. 5. The fingerprint input device according to claim 3, wherein the transparent waveguide of the fingerprint input section is divided into a plurality of input sections,
A fingerprint input device characterized by using a triangular prism, a rectangular prism, a polygonal prism, a cylindrical waveguide, or a trapezoidal prism.