JPH07220054A - Detection part for surface rugged pattern measurer and its utilizing method - Google Patents

Abstract

PURPOSE:To provide the detection part for surface rugged pattern measurer and its utilizing method which facilitate detection of a surface rugged pattern of a fingerprint, an object, or the like to improve the identification precision. CONSTITUTION:With respect to the surface rugged pattern measurer where illuminating light is thrown to the inside of a transparent solid body 1 having a refractive index higher than that of air and the intensity distribution of light reflected to the transparent solid body side by a face 2, to which an object 4 to be measured is pressed, of the transparent solid body is optically detected by a photodetector group 3, the transparent solid body or an adjacent support body of the object 4 are oscillated in such direction that the interval between the face 2 and the object 4 is changed, and volatile liquid and air are sprayed to the face 2 of the transparent solid body or/and the object 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a detecting portion of a surface-dying pattern measuring device for automatically measuring or identifying a surface-dying pattern of a fingerprint or an object and a method of utilizing the same.

[0002]

2. Description of the Related Art For example, in the case of identifying a fingerprint, as a conventional technique, several methods have been proposed in which a finger is pressed against the surface of a glass plate to position the finger and the finger is read from the opposite surface of the glass plate. However, not only is the detection of fingerprints uncertain by either of these methods, and the accuracy of repetition is poor,
The individual difference was extremely large. Possible causes are differences in water and oil content on the glass plate surface and the target finger surface, stains, and it is difficult to obtain a clear image on a single screen, but we have proposed a technology to overcome this problem. Most of the improvements were in the overall equipment and analysis / calculation methods, and the calculations and equipment were complicated.

[0003]

DISCLOSURE OF THE INVENTION The present invention facilitates the detection of surface droopy patterns such as fingerprints and objects, makes the image clear over a wide range, and improves the identification accuracy. The purpose is to provide the utilization method.

[0004]

The present invention is constructed as follows. (1) Illumination light is sent to the inside of a transparent solid having a higher refractive index than air, and the intensity distribution of the light reflected to the transparent solid side by the surface of the transparent solid pressed against the object to be measured is optically detected by the light receiving element group. In the surface dimple pattern measuring device configured as described above, a structure in which the transparent solid or the object support adjacent to it is vibrated in a direction in which the distance between the object pressing surface and the object is changed The detection unit of the surface pattern measuring device is characterized in that the volatile liquid and the air are ejected toward the object-pressing surface of the transparent solid or the object or both of the objects.

For example, the illumination light as shown in FIG. 1 or FIG. 2 is sent to the inside 1 of a transparent solid having a refractive index higher than that of air, and the light reflected by the object pressing surface 2 of this transparent solid toward the transparent solid side. In the surface dimple pattern measuring device configured to optically detect the intensity distribution of the light by the light receiving element group 3, the transparent solid (FIG. 1) or an object support adjacent to the transparent solid and the object to be measured supported by the same. The object (FIG. 2) vibrates in a direction in which the distance between the object pressing surface 2 and the object 4 and the contact area change. In order to vibrate the object pressing surface of the transparent solid or the object support adjacent to the object pressing surface, known mechanical means such as electromagnetic means or cam rotation can be used. As the volatile liquid, a solvent such as ethanol or methanol which is harmless to the object to be measured, has a strong detergency, is quick-drying and is inexpensive, and other additives and water can be mixed therein. It is desirable to dehumidify or raise the temperature of the jetted air in order to accelerate the volatilization and drying of the volatile liquid. Although the volatile liquid and air pipes are partially branched, it is desirable that the jet nozzle unit 5 joins and use the air for jetting the volatile liquid. In addition, it is desirable that the measurement environment be adjusted to a predetermined temperature and humidity.

According to the present invention, a transparent solid or an object support adjacent to the transparent solid vibrates in a direction in which the distance between the object pressing surface 2 and the object 4 is changed so that, for example, a finger is moved. It is possible to repeatedly press the object pressing surface a plurality of times in an extremely short time, and it is possible to produce the effect that a person repeatedly presses a finger. It has the excellent effect of minimizing it. The volatile liquid is sprayed on the surface of the transparent solid to be pressed against the object to be measured 2 or the surface of the object to be measured 4 or both of them to remove disturbances due to dirt and adjust measurement conditions. Further, the wetted area of the contact surfaces of the two is intentionally changed in a wide range from a large state to a small so-called dry state. At this time, the amount of information that changes the measurement conditions over a wide range can be shortened by reducing the wetted area between the two in a short time due to the change in the distance between the two and the change in the contact state due to the blowing of air and the vibration of the transparent solid. Can be captured. In this way, when the image is recorded by changing the contact surfaces of the two from the wet state to the dry state, it is possible to record the change in the contact state of the two during this time with high accuracy. In other words, selecting the optimum image from among these and detecting subtle image changes that appear near the boundary between the wet part and the dry part with high accuracy, synthesizing the high-precision image of this moving boundary part and displaying it. It is possible to improve the accuracy of the whole. In the present invention, in order to make the image of the wet portion clear, total reflection occurs when the illumination light incident angle A of the transparent object pressure surface 2 is not wet by the volatile liquid as shown in FIG. It is desirable that the angle is equal to or larger than the angle, and that the light can enter the side of the volatile liquid when it is wet by the volatile liquid. By doing this, the incident light is totally reflected on the part that is not wet by the volatile liquid, and the wet part is partially reflected.
The two can be clearly distinguished by the intensity of the reflected light, and the light and dark binarization of the image can be easily performed in a short time.

(2) Illumination light is sent to the inside of a transparent solid having a refractive index higher than that of air, and the intensity distribution of the light reflected to the transparent solid side by the object pressing surface of the transparent solid is optically analyzed by a light receiving element group. In the surface irregular pattern measuring device configured to detect automatically, the transparent solid or the object support adjacent thereto vibrates in the direction in which the distance between the object pressing surface and the object 4 changes. A structure, and a structure in which a volatile liquid and air are jetted toward the object pressing surface of the transparent solid or the object to be measured, or both of them, using the detection part of the surface dagger pattern measuring device. Utilization of surface diaper pattern measuring instrument characterized by creating a series of images showing the effect of time variation of surface diaper pattern at the same position in Is the way.

In the present invention, a series of images showing the influence of the temporal change of the surface irregular pattern at the same position of the object 4 to be measured are created by using the detecting portion of the surface irregular pattern measuring device described above.
Necessary information can be extracted by comparing, analyzing, and synthesizing these images. In the present invention, in order to measure the surface irregular pattern of the DUT 4 with high accuracy, the volatile liquid and air are sprayed on the transparent pressing surface 2 of the DUT and the measuring surface of the DUT 4 as a disturbance to cause disturbance. Then, the surface conditions of the both are adjusted to a predetermined condition suitable for the inspection. Then, both the liquid adhesion amount and the pressing force, which are the conditions for wetting the contact surfaces of the two, are changed over a wide range in a short time. That is, the transparent solid or the object support adjacent to it vibrates in the direction in which the distance between the object pressing surface 2 and the object 4 changes, and as shown in FIG. The pressing force is periodically changed, and the contact area between the two is also changed. Then, as described above, the pressing surface 2 or the measured object 4 which is a transparent solid is measured.
Or by injecting volatile liquid and air towards both,
As shown in FIG. 4, the wetted area between the two is changed with time. By utilizing these effects, a series of images showing the influence of the time-dependent change of the surface drooping pattern at the same position of the DUT 4 is created, and these images are compared, analyzed and synthesized with a clear and high-precision characteristic. You will be able to extract images. By changing the contact surfaces of the two from the wet state to the dry state in this way, it is possible to accurately and accurately record the change in the contact state between the two. The optimum image can be selected from many images, and its features can be extracted from the changes between consecutive still images, and the vicinity of the boundary between wet and dry parts and the contact part can be extracted. The precise images and subtle image changes that appear in the ring-shaped region near the boundary between the non-contact part and the non-contact part are detected with high accuracy to clarify and extract their characteristics, and a high-precision image of the boundary part that moves between these still images is displayed. It is also possible to combine them to expand the high-precision image area over the entire screen, and to clarify and extract the features over a wide range. In the present invention, since such comparative analysis / synthesis of images can be performed during one finger insertion, the positional displacement is remarkably smaller than that in the case of manually inserting and measuring a plurality of fingers, and thus image synthesis is easy. The advantages are that the image accuracy is high and the finger insertion inspection time and the determination time are extremely short. According to the method of the present invention, for example, in fingerprint identification, a printed matter having the same pattern as a fingerprint registered in advance or a counterfeit product such as a fingerprint made by an artificial finger is discriminated by a change state of wetness or a change state of a boundary portion between a wet portion and a dry portion. Can be eliminated. Further, it is possible to detect a dynamic shape change or surface condition change of the object to be measured, which can also be used for improving the identification accuracy.

(3) Illumination light is sent to the inside of a transparent solid having a refractive index higher than that of air, and the intensity distribution of the light reflected to the transparent solid side by the object pressing surface of this transparent solid is optically analyzed by a light receiving element group. In a surface dimple pattern measuring device configured to detect automatically, a structure in which a transparent solid or an object support adjacent to the transparent object vibrates in a direction in which the distance between the object pressing surface and the object changes And the surface of the transparent solid pattern measuring device having a structure in which a volatile liquid and air are jetted toward the object-pressing surface of the transparent solid or the object-to-be-measured or both, and the object-to-be-measured is measured. Create a series of images showing the effect of time-dependent changes in the surface of the same pattern, and extract the necessary information by comparing, analyzing, and synthesizing these images, and the volatile liquid sprayed on the measured object or its Fluid containing gas And min analysis, a method utilizing a surface uneven pattern measuring device, characterized in that to determine the contrast consistent with previously registered information.

In addition to the above-mentioned method, the present invention is a method of utilizing a surface dent pattern measuring device characterized by performing a component analysis of a fluid containing a volatile liquid or its gas sprayed onto the object to be measured 4. As the analytical instrument, known rapid analytical instruments can be used. Since many volatile liquids have high solubility of organic substances such as oil and fat, they have a great cleaning effect on the DUT 4 such as a finger. By analyzing the components of this solution, characteristic components are registered in advance by individuals. It is possible to improve the identification accuracy as compared with the component having Further, by determining the presence or absence of a component peculiar to a living body, it can be regarded as a living body determination, and a counterfeit product can be excluded. In the present invention, preferably, the temperature change of the DUT 4 is measured by the optical temperature measuring device 7 shown in FIG. 1 and compared with the temperature change registered in advance to improve the identification accuracy thereof. By comparing with the temperature change peculiar to the living body, it can be determined whether or not it is the living body. The absolute value of the temperature of the DUT is greatly affected by environmental conditions such as climate and room temperature at that time, and it is difficult to obtain important information for identification, but the process of changing from wet to dry by spraying volatile liquid and air is physically If it is evaluated as a temperature change in an environment accompanied by vibration, it is possible to obtain important information for identifying the object to be measured from the form of the temperature change. For example, when the temperature, speed, and flow rate of the air to be jetted, and the temperature of the transparent solid contacting the object to be measured are constant, the heat removal effect due to the heat of vaporization of the volatile liquid and the heat generation effect due to physical vibration are contradictory. The effect occurs in the surface layer of the object to be measured, and the characteristic of the object to be measured appears in the temperature change.

(4) Illumination light is sent to the inside of a transparent solid having a refractive index higher than that of air, and the intensity distribution of the light reflected to the transparent solid side by the object pressing surface of the transparent solid is optically analyzed by the light receiving element group. In a surface dimple pattern measuring device configured to detect automatically, a structure in which a transparent solid or an object support adjacent to the transparent object vibrates in a direction in which the distance between the object pressing surface and the object changes And the surface of the transparent solid pattern measuring device having a structure in which a volatile liquid and air are jetted toward the object-pressing surface of the transparent solid or the object-to-be-measured or both, and the object-to-be-measured is measured. Create and register as a master image an image obtained by dividing the image of the surface pattern into two values, light and dark, and a positional relationship diagram composed of a plurality of feature points extracted from this image, and then from the measured object. Under the same conditions as above Create a positional relationship diagram composed of the image divided into light and dark binary values and a plurality of feature points extracted from this image, and include that position including the position where the positional relationship of the feature points of both images best matches. One is oscillated in a direction displaced from the other to obtain the maximum or minimum value of the transmitted light amount or the difference between the two, and the case where one or more of the transmitted light amount values reaches a predetermined value is regarded as coincident. This is how to use the pattern measuring device.

For example, following the above-mentioned technique, an image obtained by dividing the image of the surface pattern of the object to be measured into two values, light and dark, and a positional relationship diagram composed of a plurality of characteristic points extracted from this image are master images. Create and register as. In the case of a fingerprint, for example, in the case of a fingerprint, different points such as intersections, end points or break points of ridges, centers of swirl patterns, wrinkles and scratches are selected. Then, for example, a simple figure such as a triangle is drawn between three adjacent feature points and drawn on the master image and stored. Similar to the master image, create an image of the measured object to be identified after that, which is divided into light and dark binary under the same conditions as above, and a positional relationship diagram composed of multiple feature points extracted from this image. To do. Then, select a congruent simple figure of both images from a simple figure, for example, a triangle connecting the characteristic points, and superimpose it, and the position where the positional relationship of the characteristic points is closest is included in the vibration range And the maximum value L or the minimum value S of the transmitted light amount as shown in FIG. 5 or the difference (L−
S) is calculated. The case where one or more of the transmitted light amount values reaches a predetermined value is regarded as coincidence. Here, a calculated value can be used as the transmitted light amount. By doing so, not only the positional relationship of the feature points, but also the degree of coincidence between the fine dough of the cloth and the physical properties can be accurately evaluated in a short time.

The present invention can be used for identifying art objects, industrial products, etc. in addition to fingerprints, and the accuracy of identification can be improved by combining with magnetic cards, photographs and computer data in which information is registered in advance. When the object to be measured is repeatedly identified over a long period of time, it is possible to learn by using, for example, measurement data, and to provide judgment reference information according to the actual condition of the object to be measured, which follows changes with time. In addition, it becomes possible to leave a highly accurate history and predict future characteristic changes,
As a result, it is possible to perform highly accurate identification that immediately corresponds to the actual condition of the measured object that changes with time.

[0014]

According to the present invention, it is possible to provide a detection unit of a surface-dwelling-pattern measuring device and a method of utilizing the same, which facilitates detection of a surface-dwelling pattern of a fingerprint, an object, etc., makes an image clear over a wide range, and improves identification accuracy. It will be possible to provide.

[Brief description of drawings]

FIG. 1 is an explanatory view of a configuration concept of the present invention, in which a transparent solid is vibrated.

FIG. 2 is an explanatory diagram of a configuration concept of the present invention, which is a case where a measured object is vibrated.

FIG. 3 is an explanatory diagram of changes in pressing force according to the present invention.

FIG. 4 is an explanatory diagram of changes in wetted area in the present invention.

FIG. 5 is an explanatory diagram of changes in the amount of transmitted light in the present invention.

[Explanation of symbols]

 1 Transparent Solid Inside 2 Transparent Solid Pressing Surface of Object to be Measured 3 Light-Receiving Element Group 4 Object to be Measured 5 Jet Nozzle Unit 6 Vibration Device 7 Optical Temperature Measuring Device 8 Light Source A Incident and Reflection Angle of Irradiated Light L Maximum Transmitted Light Amount Value S Minimum amount of transmitted light

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G06T 7/00 // G01B 11/24 C

Claims (4)

[Claims] 1. An intensity distribution of light reflected by the illumination light is sent to the inside of a transparent solid having a higher refractive index than that of the air by the object pressing surface of the transparent solid by the light receiving element group. In the surface dimple pattern measuring device configured to detect, the transparent solid or the object support adjacent to this is a structure that vibrates in a direction in which the distance between the object pressing surface and the object is changed. And a structure for injecting a volatile liquid and air toward the object pressing surface of the transparent solid or the object to be measured, or both of them. 2. The intensity distribution of the light reflected by the illumination light is sent to the inside of the transparent solid having a higher refractive index than that of the air by the surface of the transparent solid to be pressed by the light receiving element group. In the surface dimple pattern measuring device configured to detect, the transparent solid or the object support adjacent to this is a structure that vibrates in the direction in which the distance between the object pressing surface and the object is changed. , And the surface of the transparent solid having a structure for injecting a volatile liquid and air toward the pressing surface of the measured object or the measured object or both, and Create a series of images showing the effect of the time-dependent change of the surface surface pattern
A method for utilizing a surface dent pattern measuring device, which is characterized by comparing, analyzing, and synthesizing these images to extract necessary information. 3. The intensity distribution of the light reflected by the illumination light is sent to the inside of the transparent solid having a higher refractive index than that of the air by the object pressing surface of the transparent solid by the light receiving element group. In the surface dimple pattern measuring device configured to detect, the transparent solid or the object support adjacent to this is a structure that vibrates in the direction in which the distance between the object pressing surface and the object is changed. , And the surface of the transparent solid having a structure for injecting a volatile liquid and air toward the pressing surface of the measured object or the measured object or both, and Create a series of images showing the effect of the time-dependent change of the surface surface pattern
These images are compared, analyzed and synthesized to extract the necessary information, and the fluid containing the volatile liquid or its gas sprayed on the object to be measured is subjected to component analysis and compared with the information registered in advance to determine a match. A method of utilizing the surface diaper pattern measuring device characterized in that 4. An illumination light is sent to the inside of a transparent solid having a refractive index higher than that of air, and the intensity distribution of the light reflected to the side of the transparent solid by the object pressing surface of the transparent solid is optically detected by a light receiving element group. In the surface dimple pattern measuring device configured to detect, the transparent solid or the object support adjacent to this is a structure that vibrates in the direction in which the distance between the object pressing surface and the object is changed. , And the surface of the transparent solid having a structure for injecting a volatile liquid and air toward the measurement object pressing surface or the measurement object or both, and the surface of the measurement object An image in which a pattern image is divided into two values, bright and dark, and a positional relationship diagram formed between a plurality of feature points extracted from this image are created and registered as a master image, and thereafter, the above-mentioned image is measured from an object to be measured. Under the same conditions as One of the images is created by including an image divided into two values of darkness and a positional relationship diagram composed of a plurality of feature points extracted from this image, including the position where the positional relationship of the feature points of both images is closest. Is oscillated in a direction displaced from the other to obtain the maximum or minimum value of the transmitted light amount or the difference between the two, and if one or more of the transmitted light amount values reaches a predetermined value, it is regarded as a coincidence. How to use the vessel.