JPH10255050A - Fingerprint detecting method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the cuticle of a finger from distorting when the finger is moved, to make this device compact and inexpensive and to accurately detect a fingerprint pattern in a fingerprint detecting device in which a one-dimensional image sensor is fixed and a finger is moved. SOLUTION: An optical finger base 13 to which a finger 15 is closely attached is fixed to a slider 14 that can linearly move along a guide 12. The cuticle of a finger is prevented from distorting when the finger moves by parallelly moving the finger in the direction of an arrow with the finger attached closely on the base 13. Equal interval patterns are formed on the base 13, they are read by an one-dimensional image sensor that detects a fingerprint pattern and the image sensor for fingerprint pattern detection is also shared as a sensor for moved distance detection of a finger. Therefore, the number of parts is reduced, the device is made simple and small, and low costs are realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method and an apparatus for detecting a fingerprint pattern, and more particularly to a method for detecting a pattern caused by unevenness of a fingerprint by optical means and an apparatus used for the method.

[0002]

2. Description of the Related Art With the advance of computerization, demands for electronic processing of personal identification and security are increasing in fields such as financial relations and secret management. The use of fingerprint patterns converted into electronic information is considered to be an effective means for meeting the above demand, but has not yet been widely used. The biggest reason is that a fingerprint detection device for converting a fingerprint pattern into electronic information is large and expensive.

A method that has been widely used in the past for clearly detecting a fingerprint pattern is to place a finger on a diagonal surface of a right-angle prism and to apply a light from a light source from one of two orthogonal surfaces, as shown in FIG. Is irradiated, and the light emitted from the other is read by an optical image sensor. Although the incident light from the light source is totally reflected on the diagonal surface, when the finger is put on the portion where the peak of the fingerprint is in close contact, most of the incident light is absorbed and the total reflection component is reduced. On the other hand, the valley of the fingerprint
Since the state in which most of the incident light is totally reflected remains unchanged, the fingerprint pattern read by the optical image sensor is obtained as an image in which the peaks are black and the valleys are white. In this method, the size of the prism cannot be reduced, and since the object is viewed obliquely, it is necessary to increase the depth of focus, which increases the optical distance, and also requires image correction after reading by the image sensor. There is a problem, especially for miniaturization.

As an example of a conventional technique for reducing the size of a prism, a technique using a microprism plate is disclosed in Japanese Patent Application Laid-Open No. 4-182879.
It is shown in the figure. FIGS. 10A and 10B are respectively
FIG. 3 is a view showing FIG. 1 and FIG. 2; However, the reference numerals in the drawings are omitted or changed from those of the original drawings for convenience of explanation (note that the reference numerals in the drawings are changed or omitted in some of the prior arts described later). The same applies to the description relating to Referring to FIG. 10, a film 51 formed by arranging many fine prisms 51 can be used in the same manner as a conventional right-angle prism. In this conventional example, although the prism can be made thinner in the form of a film, the problem is that the optical distance cannot be shortened and the image must be corrected after being read by the image sensor because the object remains obliquely viewed. Remains, and it is difficult to reduce the size of the entire apparatus.

[0005] The above publication also discloses a technique in which a one-dimensional image can be captured using a line image sensor, and a two-dimensional image is synthesized from the one-dimensional image obtained by moving the imaging device. I have. By using the line image sensor in this way, it is considered that the problem of distortion caused by obliquely viewing the target can be solved. However, in this case, a driving device such as a motor is required to precisely move the line image sensor. Therefore, when viewed as a whole fingerprint detecting device, there is a limit to downsizing and cost reduction.

The use of a line image sensor to avoid the occurrence of distortion in a fingerprint image and to detect a uniform fingerprint pattern without density unevenness is also disclosed in, for example,
These are widely known in Japanese Patent Application Laid-Open Nos. 1206771, 63-221485 and 63-205777.

FIG. 11 shows the view shown in FIG. 1 of the above-mentioned Japanese Patent Laid-Open Publication No. Hei 4-120671. Referring to FIG.
The invention described in this publication has a structure in which the illumination device 61 and the one-dimensional image sensor 62 are integrated and rotate around a finger fixed to the finger guide 63. The fingerprint detection device according to the prior art requires a driving device 64 for generating a rotational motion, an angle sensor 65 for detecting a rotational position, and the like.
It was difficult to reduce the price.

[0008] Both the inventions described in JP-A-63-221485 and JP-A-63-205777 use a hologram to extract light incident on an image sensor, thereby reducing the size of an optical system. The light source unit and the image pickup device have a structure that can move in parallel with the contact surface of the finger. Therefore, these conventional fingerprint detecting devices require a space and a driving device for moving the light source unit and the imaging device, and have a problem that it is difficult to reduce the size and the cost.

In contrast to the above-mentioned prior art, a device which is made smaller by moving a finger instead of moving a light source or an image sensor is disclosed in JP-A-63-273.
975 and JP-A-63-273976. In any of the fingerprint detection devices described in these publications, a finger is slid on a finger base and moved, and the movement distance at that time is detected by a movement distance detection sensor pressed by the tip of the finger to be slid. Is used as a parameter to synthesize a one-dimensional image read by a line sensor to obtain a two-dimensional fingerprint pattern. The most serious disadvantage of these conventional fingerprint detection devices is that when the finger is slid on the finger base, the skin on the finger surface is distorted due to the friction between the finger and the finger base, and this distortion may cause the finger to slip. Is not constant.
For this reason, it is difficult to always obtain a stable fingerprint pattern, and there has been a problem that the identification rate in personal identification is low. Furthermore, these conventional fingerprint detection devices use a moving distance detection sensor in addition to a line sensor for reading a fingerprint pattern, and have disadvantageous factors in reducing the size and cost of the device. Had.

As another conventional example of a fingerprint detecting device in which a finger is moved, a device disclosed in Japanese Patent Application Laid-Open No. 4-190470 is known. FIG. 12 is a diagram showing FIG. 1 of the above publication. Referring to FIG. 12, in this fingerprint detection device, a finger is put on a fingerprint input table 72 provided with a slit 71, and a roller 73 provided in the slit is rotated when the finger is slid. Then, the rotation amount at that time is detected by the rotary encoder 74,
The one-dimensional image read by the line image sensor 75 is synthesized using the detection signal as a parameter to obtain a two-dimensional fingerprint pattern. This fingerprint detection device is characterized by being unaffected by dirt on the fingerprint input table because it reads the fingerprint exposed on the slit, but on the other hand, it depends on the magnitude of the force pressing the finger against the fingerprint input table. Has the disadvantage that the surface of the finger exposed to the slit swells greatly inside the slit, resulting in increased resistance to finger movement and the skin on the finger surface being pulled and distorted, making it difficult to obtain an accurate fingerprint pattern. Have. Further, the use of a roller and a rotary encoder to detect the moving distance of a finger complicates the configuration of the apparatus, and has been a major obstacle in reducing the size and cost.

[0011]

As described in the above prior art, the size and cost of the fingerprint detection device are reduced, the fingerprint image is detected without uneven density, and the fingerprint image is not affected by the stain on the finger rest. One-dimensional image sensors have been used for detection. However, those requiring a device configuration for moving a light source for illumination or a one-dimensional image sensor and detecting the moving distance have limitations in miniaturization and cost reduction.
Practical demands in the field of personal identification and security have not been fully met.

On the other hand, even in a fingerprint detection device which attempts to simplify the device configuration by fixing the light source or the one-dimensional image sensor and moving the finger, the mechanism for detecting the moving distance of the finger is separately provided. However, it was not possible to sufficiently meet the demands for downsizing and price reduction. Also, when the finger is slid on the surface of the finger base or pressed against the rotating roller when the finger is moved, the surface of the finger is distorted and it is difficult to detect an accurate fingerprint pattern. .

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a fingerprint detection method and apparatus capable of detecting a fingerprint pattern without distortion and realizing sufficient miniaturization and low cost.

[0014]

According to the present invention, a finger is brought into close contact with a surface of an optical finger base which is configured to be movable in one predetermined direction so that a finger touches the surface, and the above-mentioned close contact state is maintained. The optical finger base is moved by moving the finger in the movement direction in parallel with the finger being held, and the optical finger base is provided along the movement direction while the optical finger base is moving. The interval pattern is read by an one-dimensional image sensor arranged orthogonal to the moving direction through an optical imaging means arranged on the back side of the optical finger base to generate a timing signal, and the timing signal is triggered. A fingerprint pattern that is visible from the back side of the optical finger base is read by the image sensor and a fingerprint image signal is output.

Further, according to the present invention, there is provided an optical finger base for bringing a finger into close contact with a surface, and a slider for fixing and holding the optical finger base at a peripheral portion thereof. A slider for moving the finger in parallel while maintaining the close contact state, whereby the optical finger base and the finger can be moved in parallel integrally, and a back side of the optical finger base. Optical imaging means for imaging a fingerprint pattern visible from the back surface of the optical finger stand to which a finger is in close contact, and an optical image formed on an imaging surface of the optical imaging means A one-dimensional image sensor arranged orthogonal to the moving direction of the optical finger base to read an image, reading the fingerprint pattern through the optical imaging means and outputting a fingerprint image signal; Along the surface A timing signal is generated from an evenly-spaced pattern signal obtained by reading an equally-spaced pattern provided by the one-dimensional image sensor, and the fingerprint image signal is output from the one-dimensional image sensor based on the timing signal. And a driving means.

According to the present invention, there is provided an optical finger base for bringing a finger into close contact with a front surface, the optical finger base including a microprism plate having a large number of microprisms formed on a rear surface, and a guide for a guide. A slider that is configured to be able to move linearly along the optical finger base and that can move the optical finger base in parallel by moving the finger in parallel while maintaining the close contact state between the finger and the optical finger base. A slider that fixes and holds the optical finger base at a peripheral portion thereof such that a ridge line formed by the apex of the microprism is orthogonal to the moving direction; Optical imaging means for imaging a fingerprint pattern visible from the back surface of the optical finger rest to which the optical imaging means is adhered, and an optical image formed on an imaging surface of the optical imaging means to be read. The optical A one-dimensional image sensor arranged orthogonal to the moving direction of the finger base and reading the fingerprint pattern through the optical imaging means and outputting a fingerprint image signal; a light emitting means having an elongated light emitting surface; and a cylindrical lens. The light source means is arranged on the back side of the optical finger base, and the light emitting means and the cylindrical lens move along the elongated light emitting surface through a ridge line formed by the apex of the microprism through the cylindrical lens. Light source means arranged to form a linear light source image parallel to the ridge line of the microprism, and when the linear light source image overlaps the ridge line of the microprism. According to the darkening of the optical image formed by the optical image forming means,
And a driving unit for generating a timing signal from an equally-spaced pattern signal obtained by reading with the one-dimensional image sensor and outputting the fingerprint image signal from the one-dimensional image sensor based on the timing signal. Is obtained.

The optical finger base according to the present invention is held by a slider that can move linearly along the guide, and can be moved with a small force. On the other hand, when the finger is in close contact with the optical finger base, the frictional force between the optical finger base and the finger in close contact is sufficiently larger than the frictional force generated when the slider moves. Therefore, by touching the finger to the optical finger base and moving the finger in the direction of the guide while keeping the finger in close contact, the optical finger base can also be moved without shifting from the finger. That is, since the finger can be moved without substantially changing the state of close contact between the finger and the finger base, a stable fingerprint pattern that is almost the same as the fingerprint pattern obtained by pressing the finger against the conventional prism can be obtained.

In order to read a one-dimensional image sequentially with a one-dimensional image sensor while moving a finger and to synthesize the two-dimensional fingerprint pattern to obtain a two-dimensional fingerprint pattern, the moving distance of the finger is detected, and the moving distance is read. It is necessary to clarify the correspondence with the two-dimensional image. In the present invention, an evenly-spaced pattern is formed on the optical finger base, and the one-dimensional image sensor reads the equally-spaced pattern together with the fingerprint image. Since the equally-spaced pattern is formed so as to be parallel to the one-dimensional image sensor, the output of the image sensor when reading this pattern always shows a constant value, which is different from the output of a fingerprint image having a change in density. Therefore, it can be easily identified. Therefore, the fingerprint image read at a certain timing after identifying this pattern signal is
It shows fingerprint patterns arranged at equal intervals on the surface of the finger,
By combining these one-dimensional images, a two-dimensional fingerprint pattern without distortion can be formed. Since there is no need to separately provide a sensor for detecting the moving distance, the configuration of the apparatus is simplified, which is extremely effective for miniaturization and cost reduction.

[0019]

Next, an embodiment of the present invention will be described in detail with reference to the drawings. Referring to FIG.
A preferred embodiment of the present invention includes a light source unit, an optical imaging unit, and a top surface of a housing 11 having a one-dimensional image sensor disposed therein for reading a fingerprint image.
A slider 14 is provided so as to be able to move linearly along the guide 12 and holds an optical finger base 13 for bringing a finger into close contact. As shown in the figure, when the finger is moved in parallel in the direction indicated by the arrow along the guide 12 while the finger 15 is kept in close contact with the optical finger base,
3 also moves with the slider 14 without shifting from the finger. During this movement, the fingerprint pattern is read by a one-dimensional image sensor provided inside the housing. Guide 12
The slider 14 is always translated and held smoothly by a well-known method.

As shown in FIG. 2, the light source means 17, the optical imaging means 18 and 1
A dimensional image sensor 19 is provided. The optical finger base 13 is configured such that its periphery 20 is held by the slider 14.

The optical finger base 13 has a large number of micro prisms 21 as schematically shown in an enlarged cross section in FIG.
Is constituted by a microprism plate 22 formed on the back surface. Illumination light from the illumination light source means 17 is incident on the entrance surface 23 of the microprism 21. From the emission surface 24 of the microprism 21, the illumination light from the light source means 17 totally reflected by the surface 25 is emitted. The light emitted from the exit surface 24 is formed on the image forming surface 26 through the optical image forming means 18. The photoelectric conversion element 27 of the one-dimensional image sensor 19 is disposed on the image forming surface 26, and the formed light is converted into an electric signal according to the intensity of the light. Thus, from the one-dimensional image sensor 19,
A one-dimensional image signal corresponding to the optical pattern on the surface 25 is output.

When a finger is placed on the surface 25, since an air layer is formed between the fingerprint valley and the surface 25, total reflection of light inside the micro prism plate 22 is not hindered at all. On the other hand, since the ridge of the fingerprint adheres to the surface 25 due to moisture or grease on the finger surface, most of the light passes through the surface 25 to reach the ridge of the fingerprint, where most is absorbed and some is absorbed. Scattered. Therefore, inside the microprism plate 22 corresponding to the peak of the fingerprint,
Totally reflected light is greatly attenuated. As a result, a high-contrast one-dimensional image in which the peaks of the fingerprint are black and the valleys are white is formed on the imaging surface 26.

When the finger pressed against the surface 25 of the optical finger base 13 is moved, the optical finger base 1 held by the slider 14 is moved.
3 moves with it. This is because the frictional resistance between the slider 14 and the guide 12 can be easily made sufficiently smaller than that between the surface 25 of the optical finger base 13 and the finger 15 by well-known mechanical design and processing technology. Because. Since the pressed finger 15 can be moved while sensing the contact state with the surface 25, the finger 15 can be easily prevented from being displaced with respect to the surface 25 during the movement. As a result, a high-quality image without distortion can be easily formed stably.

As shown in FIG.
1 are formed at equal intervals. Therefore, if the distance is read by the one-dimensional image sensor 19, the moving distance when the finger pressed against the optical finger base 13 is moved can be detected, and a two-dimensional fingerprint image without distortion is synthesized from the one-dimensional fingerprint image. It is possible to do. However, the optical imaging means 18
Is focused on the surface 25 of the microprism plate 22, even if the boundary between the microprisms 21 is within the viewing angle of the optical imaging means 18, this is clearly imaged on the imaging surface 26. Can not. As a result, the one-dimensional image sensor cannot clearly read the interval.

In order to solve this problem, in one embodiment (embodiment 1), the light source means 17 is composed of a light emitting means 28 and a cylindrical lens 29. It is desirable that the light emitting means 28 be one in which light emitted from various types of lamps or LED light emitting elements is made to have a uniform light intensity in a long and narrow plane using a diffusion plate or the like. A surface light emitter such as an EL light emitting element is also suitable as the light emitting means 28. The cylindrical lens 29 is
The elongate surface of the light emitting means 28 which emits light is focused on the focal point 3
It is used to reduce the projection to 0 and convert it to a linear light-emitting image 31. The light source means 17 is provided at the focal position 30 described above.
Is on a plane 33 on which a ridge line 32 formed of the vertices of the microprism 21 moves, and the linear light emission image 31 is in line with the ridge line 32.
And are arranged in parallel. When the micro-prism plate 22 is moved in such an arrangement, when the linear light-emitting image 31 overlaps the incident surface 23, light enters the inside of the micro-prism.
When it overlaps with 2, most of the incident light passing through the light emission image 31, in particular, many components perpendicular to the incident surface 23 are scattered and cannot enter the inside of the microprism 21. This is because it is difficult to form the angle exactly at the ridgeline 32 that forms the vertex of the microprism, and the tip is necessarily rounded. At this time, the surface 2 inside the microprism
Since the intensity of the light totally reflected at 5 is greatly reduced, the one-dimensional image sensor outputs a one-dimensional image signal of a uniform level corresponding to the dark level. This image signal is clearly different from a one-dimensional fingerprint pattern signal having various light and dark levels, and can be easily identified.

FIG. 4 shows a circuit configuration when a CCD sensor is used as a one-dimensional image sensor in this embodiment. The driver circuit 35 is operated based on the synchronization signal generated by the synchronization signal generation circuit 34 according to a well-known driving method of the CCD sensor. With this, CCD
The operation of accumulating the photoelectric conversion charge, transferring the accumulated charge, and transferring the transferred charge in the sensor is performed. The one-dimensional image signal is output from the CCD sensor as a voltage signal corresponding to the amount of charge transferred inside the CCD sensor. The output image signal is sent to the signal processing circuit 36, where the black level, the white level, and the dynamic range are adjusted.
Further, a one-dimensional image signal that is temporally continuous is obtained by the sample hold. Whether the continuous one-dimensional image signal is obtained by detecting a fingerprint pattern or by detecting the interval between microprisms is determined by the timing signal extraction circuit 37 based on the amplitude change in the continuous one-dimensional image signal. Do to see the degree. While the amplitude of the image signal corresponding to the fingerprint pattern changes according to the shading,
In an image signal corresponding to the interval between the microprisms, the amplitude value and the change are small. The timing signal extracting circuit 37 outputs a timing signal when it is determined from the difference in the amplitude that the image signal corresponds to the interval between the microprisms. In response to the timing signal, the A / D conversion circuit 38 fetches the one-dimensional image signal output from the signal processing circuit 36 for one line and converts it into a digital signal. To be stored. One-dimensional image signals are sequentially stored in the memory circuit 39, and finally a two-dimensional image signal corresponding to a fingerprint pattern is formed.

A circuit for outputting a timing signal by examining the degree of change in the amplitude of the image signal can be constructed using ordinary circuit technology. One embodiment is shown in FIG.
The one-dimensional image signal output from the signal processing circuit 36 is converted into a signal indicating a change by a differentiating circuit 40, then converted into an absolute value by an absolute value amplifier 41, and further integrated by an integrating circuit 42.
, All the changes in the one-dimensional image signal are integrated, and the total change is compared with a reference value in a comparator 43.
3 is turned on, the image signal is determined to correspond to the interval between the microprisms, and the timing signal generating circuit 44 generates one or a plurality of timing signals in response to the on state of the comparator 43. . As the one-dimensional image sensor in the above embodiments, for example, a sensor widely known as a MOS type, an image sensor made of an amorphous silicon semiconductor material, and the like can be used in addition to the CCD sensor.

Next, in another embodiment (Embodiment 2) showing a structure for detecting a moving distance when a finger pressed against the optical finger base 13 is moved, as shown in FIG. An evenly-spaced pattern 45 on the surface 25 for applying the finger of the finger base 13
To form The equally-spaced pattern 45 is constituted by, for example, a line or a stripe pattern orthogonal to the moving direction of the slider 14. The moving distance is detected by reading the equally-spaced pattern 45 with an image sensor.

In this embodiment, as in the first embodiment, the optical finger base 13 is provided with a micro prism plate 22.
The light source unit 17, the optical imaging unit 18, and the one-dimensional image sensor 19 similar to those in the first embodiment are arranged on the back side as shown in the enlarged sectional view of FIG. . However, in this embodiment, the light source means 17 is composed of only the light emitting means 28. The cylindrical lens 29 required for the first embodiment is unnecessary. The equally-spaced pattern 45 is printed on the surface 25 using an ink in which a black pigment or dye is dispersed in a binder having a refractive index smaller than that of the optical finger base 13. Alternatively, the surface 25 of the optical finger base 13 is formed by engraving a pattern at equal intervals by using a photo-etching technique known as a processing technique for an inorganic material such as glass. When the equally-spaced pattern is formed by printing using ink, light entering the inside of the microprism 22 from the light source means 17 is absorbed by the ink in the pattern forming portion. Therefore, the amount of light totally reflected by the surface 25 and input to the one-dimensional image sensor 19 is greatly reduced. On the other hand, when the equally-spaced pattern is inscribed on the surface 25, the light incident on the inside of the microprism is scattered in the inscribed portion at the pattern-marked portion. Therefore, also in this case, the light input to the one-dimensional image sensor 19 is greatly reduced. In any case, as in the first embodiment, the one-dimensional image sensor outputs a one-dimensional image signal having a certain dark level uniformly corresponding to the equally-spaced pattern. Can easily be distinguished from a one-dimensional fingerprint pattern signal having

Referring to FIG. 8, another preferred embodiment of the present invention uses an optical finger base 13 having a flat plate shape. The periphery 20 of the optical finger base is held by the slider 14, and the surface 25 is formed with an equally-spaced pattern 45 by the same method as in the second embodiment described above.
In the present embodiment, the light source means 17 is connected to the optical finger base 1.
The light from the light source means 17 is obliquely incident on the inside of the finger base 13 from the end 46 of the finger base.
The incident light propagates inside the finger base while being totally reflected by the front surface 25 and the rear surface 47 of the optical finger base. When the finger 15 is pressed against the finger platform surface 25 in this state, the light propagating inside the optical finger platform 13 is partially absorbed and partially absorbed at the peak of the fingerprint that is in close contact with the surface 25 without being totally reflected. Scattered. On the other hand, in the valley of the fingerprint, there is an air layer between the surface 25 and the finger, so that the state of total reflection of light inside the optical finger rest 13 does not change. The light scattered by the peaks of the fingerprint is imaged on the image plane 26 through the optical imaging means 18 arranged on the back side of the optical finger base 13. The formed one-dimensional fingerprint pattern is obtained by inverting the light / dark relationship from that in the first embodiment. That is, the peaks of the fingerprint are bright and the valleys are dark. The photoelectric conversion element of the one-dimensional image sensor 19 is arranged on the image forming surface 26, and converts the formed light into an electric signal according to the intensity of the light. As the driving circuit and the image processing circuit of the one-dimensional image sensor, those shown in FIGS. 4 and 5 of the first embodiment can be used. When it is necessary to make the relationship between the lightness and darkness of the image the same as in the first embodiment, a well-known signal inversion function may be added to the signal processing circuit 36 having the circuit configuration shown in FIG.

[0031]

As described above, in the present invention, the optical finger base is placed on the slider, and the finger pressed against the finger base and the slider are moved in an integrated state. Therefore,
The finger is moved while sensing the state of contact with the optical finger base 13. Thus, according to the present invention, it is possible to hold the fingerprint pattern formed on the finger platform surface 25 with little change during movement, and to stably capture a high-quality fingerprint pattern. .

Further, in the present invention, an equal spacing pattern is formed on the optical finger base, and the pattern is read by a one-dimensional image sensor for detecting the fingerprint pattern, so that the moving distance of the finger can be reduced. Also serves as a sensor to detect.

Thus, according to the present invention, not only the number of parts can be reduced to simplify the device configuration and the device can be downsized, but also the components widely available on the market can be used. As a result, the cost of the apparatus was significantly reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing Example 1 of one embodiment of the present invention.

FIG. 2 is a cross-sectional view when FIG. 1 is cut along line AA.

FIG. 3 is an enlarged view centering on an optical finger base in FIG. 2;

FIG. 4 is a circuit configuration diagram for driving a one-dimensional CCD sensor and outputting an image signal.

FIG. 5 is a circuit configuration diagram for generating a timing signal for capturing a one-dimensional image.

FIG. 6 is a perspective view showing Example 2 of one embodiment of the present invention.

FIG. 7 is an enlarged view centering on the optical finger base in FIG. 6;

FIG. 8 is a cross-sectional view showing another embodiment of the present invention.

FIG. 9 is a cross-sectional view for explaining a conventional fingerprint detection operation.

FIG. 10 is a cross-sectional view of an example of a conventional fingerprint detection device.

FIG. 11 is a cross-sectional view of another example of a conventional fingerprint detection device.

FIG. 12 is a sectional view of still another example of the conventional fingerprint detection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Housing 12 Guide 13 Optical finger stand 14 Slider 15 Finger 16 Arrow 17 Light source means 18 Optical imaging means 19 Image sensor 20 Around optical finger stand 21 Microprism 22 Microprism plate 23 Entrance surface 24 Emission surface 25 Surface 26 Image Forming Surface 27 Photoelectric Conversion Element 28 Light Emitting Means 29 Cylindrical Lens 30 Focus Position 31 Linear Emitted Image 32 Edge Line 33 Edge Movement Plane 34 Synchronization Signal Generation Circuit 35 Driver Circuit 36 Signal Processing Circuit 37 Timing Signal Extraction Circuit 38 A / D conversion circuit 39 Memory circuit 40 Differentiating circuit 41 Absolute value amplifier 42 Integrating circuit 43 Comparator 44 Timing signal generating circuit 45 Equidistant pattern 46 End of finger base 47 Back of finger base

Claims (8)

[Claims] 1. A finger is brought into close contact with a surface of an optical finger base that is configured to be movable in one predetermined direction so that a fingerprint touches the surface, and the finger is kept parallel to the moving direction while maintaining the close contact state. Moving the optical finger platform by moving, while the optical finger platform is moving, an evenly-spaced pattern provided along the moving direction on the optical finger platform, A one-dimensional image sensor arranged perpendicular to the moving direction reads through an optical imaging means arranged on the back side to generate a timing signal, and the timing signal is used as a trigger to be seen from the back of the optical finger base. A fingerprint detection method comprising reading a fingerprint pattern with the image sensor and outputting a fingerprint image signal. 2. A fingerprint comprising: an optical finger base made of a transparent plate material for bringing a finger into close contact with the front surface; and a one-dimensional image sensor for reading a fingerprint pattern visible from the back surface of the optical finger base to which the finger is brought into one-dimensional contact. Pattern reading means,
In a fingerprint detection device configured to generate a two-dimensional image of a fingerprint pattern by relatively horizontally moving a finger and the fingerprint pattern reading unit, a state in which a finger is in close contact with the optical finger base is maintained. ,
A fingerprint detection device, wherein the finger and the optical finger base are integrally movable horizontally. 3. The apparatus according to claim 2, wherein said fingerprint pattern reading means is also used as a movement distance detection sensor when said finger and said optical finger base are moved in an integrated manner. Fingerprint detection device. 4. An optical finger base for bringing a finger into close contact with a surface, and a slider for fixing and holding the optical finger base at a peripheral portion thereof, the slider being configured to be linearly movable along a guide. By moving the finger in parallel while maintaining the close contact state, a slider that allows the optical finger base and the finger to be able to move in parallel integrally, and a slider that is disposed on the back side of the optical finger base, Optical imaging means for imaging a fingerprint pattern visible from the back surface of the optical finger base in close contact with the optical finger base, and an optical image formed on an imaging surface of the optical imaging means for reading the optical image. A one-dimensional image sensor arranged orthogonal to the moving direction of the optical finger base and reading the fingerprint pattern through the optical imaging means and outputting a fingerprint image signal; Equally spaced along Driving means for generating a timing signal from an evenly-spaced pattern signal obtained by reading a turn with the one-dimensional image sensor, and outputting the fingerprint image signal from the one-dimensional image sensor based on the timing signal. A fingerprint detection device, comprising: 5. An optical finger base comprising a microprism plate having a plurality of microprisms formed on a back surface thereof in a direction orthogonal to a moving direction, wherein the optical finger base has a finger in close contact with a front surface thereof. It has light source means arranged to illuminate a fingerprint pattern seen from the back side, and an equidistant pattern for absorbing or scattering light from the light source means is formed on the surface of the optical finger base. The fingerprint detection device according to claim 4, wherein: 6. An optical finger base comprising a flat member made of a transparent member, light source means is disposed on an end face of the flat member to guide light into the flat member, and a finger of the flat member is provided. 5. The fingerprint detecting device according to claim 4, wherein an equidistant pattern that scatters the light guided into the inside is formed on a surface on which the light is adhered. 6. 7. An optical finger platform for bringing a finger into close contact with a front surface, the optical finger platform comprising a microprism plate having a large number of microprisms formed on a rear surface, and linearly moving along a guide. Configured as possible,
A slider that allows the optical finger base to move in parallel by moving the finger in parallel while maintaining the contact state between the finger and the optical finger base, wherein a ridge line formed by the apex of the microprism is moved. A slider that fixes and holds the optical finger base at its peripheral portion so as to be orthogonal to the direction, and is arranged on the back side of the optical finger base and is visible from the back side of the optical finger base to which a finger is closely attached Optical imaging means for imaging a fingerprint pattern, and arranged perpendicular to the moving direction of the optical finger base so as to read an optical image formed on an imaging surface of the optical imaging means. A one-dimensional image sensor that reads the fingerprint pattern through the optical imaging unit and outputs a fingerprint image signal; a light source unit that includes a light emitting unit having an elongated light emitting surface and a cylindrical lens. Thus, the light emitting means and the cylindrical lens are arranged on the back side of the optical finger stand, and the light emitting means and the cylindrical lens form an image of the elongated light emitting surface on a plane on which a ridge line composed of vertices of the micro prism moves through the cylindrical lens. And light source means arranged so as to form a linear light source image parallel to the ridge line of the microprism, and the optical imaging means when the linear light source image overlaps the ridge line of the microprism In response to the darkening of the optical image formed by the above, a timing signal is generated from the equally-spaced pattern signal obtained by reading with the one-dimensional image sensor.
And a driving unit for outputting the fingerprint image signal from the three-dimensional image sensor. 8. An optical device comprising:
The fingerprint detecting device according to claim 4 or 7, wherein the fingerprint detecting device is integrated in a line.