JP2004310574A - Concavo-convex pattern detecting device, manufacturing method thereof and portable device - Google Patents

Abstract

A main object of the present invention is to provide an improved concavo-convex pattern detection device capable of stably obtaining a high-quality image.
An uneven pattern detecting device includes an optical plate. A finger 8 having a fingerprint as an uneven pattern is brought into contact with one surface 7 of the optical plate 6. On the other surface 9 of the optical plate 6, a light source 10 and an image sensor 11 are provided. Of the one surface 7 of the optical plate 6, the finger contact portion 12 to which the finger 8 contacts is higher than the portion 13 to which the finger does not contact so that the finger contact portion 12 becomes a convex portion. .
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention generally relates to an uneven pattern detecting device, and more particularly to an uneven pattern detecting device that detects a minute uneven pattern formed on the surface of a soft object such as a fingerprint or a rubber stamp. The present invention also relates to a method for manufacturing such an uneven pattern detecting device. The present invention further relates to a portable device on which such an uneven pattern detecting device is mounted.
[0002]
[Prior art]
When mounting an uneven pattern detection device that detects minute uneven patterns such as fingerprints on mobile devices, if the surface of the uneven pattern detection device is flat, the contact surface of the finger will be lower than the housing surface of the mobile device. I was For this reason, there is a problem that it is difficult for the finger to make contact with the finger, and a step formed between the portable device and the finger contact surface changes the contact shape and pressure of the finger, thereby deteriorating the detection image.
[0003]
As a conventional method for solving this problem, with reference to FIGS. 20 and 21, there is disclosed a technique of providing a finger rest portion 3 on which a finger 2 as a subject is placed on an upper surface portion of an apparatus main body 1 (for example, FIG. 20). And Patent Document 1). For example, the index finger 2 placed on the finger placing portion 3 is higher than the thumb and the middle finger located on both sides thereof. By doing so, the finger 2 can be placed on the finger contact portion of the finger placing portion 3 in a natural hand posture.
[0004]
[Patent Document 1]
JP-A-5-89229
[0005]
[Problems to be solved by the invention]
However, in the devices as shown in FIGS. 20 and 21, the finger contact surface of the uneven pattern detection device needs to be significantly higher than other portions, which is disadvantageous for downsizing the entire device. was there.
[0006]
Further, it is necessary to increase the entire surface to which the finger comes in contact, and this is disadvantageous in downsizing the entire device.
[0007]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to provide an improved concavo-convex pattern detection device capable of reducing the size of the entire device.
[0008]
It is another object of the present invention to provide an improved concavo-convex pattern detection device that can stably obtain a high-quality image.
[0009]
Another object of the present invention is to provide an improved concavo-convex pattern detection device that can stably obtain a high-quality image, particularly in a swipe type.
[0010]
Another object of the present invention is to provide a method for manufacturing such an uneven pattern detecting device.
[0011]
Still another object of the present invention is to provide a portable device provided with such an uneven pattern detecting device.
[0012]
[Means for Solving the Problems]
An uneven pattern detection device according to a first aspect of the present invention includes an optical plate having one surface on which a subject having an uneven pattern is brought into contact, and another surface opposed to the one surface. A light source and an image sensor are provided on the other surface of the optical plate. Of the one surface of the optical plate, an object contact portion where the object comes into contact is higher than a portion where the object does not come into contact so that the object abutment portion becomes a convex portion. ing.
[0013]
According to the present invention, of the one surface of the optical plate, the object contact portion where the object comes into contact with the object comes into contact with the object such that the object contact portion becomes a convex portion. Not higher than the part. Therefore, it is possible to prevent the subject abutting portion from becoming extremely concave when mounted on a portable device. As a result, a high-quality image can be stably obtained.
[0014]
The width of the projection is smaller than the length from the first joint to the tip of the finger as the subject. Therefore, the effect is remarkable in the swipe type in which the measurement is performed by sliding the subject.
[0015]
According to a preferred embodiment of the present invention, R is provided on an upper portion of at least one of the side walls extending in the longitudinal direction of the projection.
[0016]
By providing the R on the upper part of the side wall, it is possible to improve the touch feeling when a finger is brought into contact without deteriorating basic performance. In addition, injury can be eliminated by rounding the edge.
[0017]
Further, when the R is provided on only one of the side walls, an effect that the direction in which the finger slides intuitively can be easily recognized is produced.
[0018]
According to a further preferred embodiment of the present invention, both side walls of the convex portion extending in the longitudinal direction are slopes inclined outward.
[0019]
By inclining the wall surface of the convex portion, when the total reflection light is used as the incident light and the outgoing light, the entire finger contact surface can be uniformly irradiated. When scattered light is used as incident light, it is not always necessary to provide a slope on the incident side. In the case where scattered light is used as the output light, if a slope is provided on the output side, light from the entire finger contact surface can be guided to the image sensor.
[0020]
According to a further preferred embodiment of the present invention, the angle of inclination of the inclined surface in the outward direction is the same as the irradiation angle of light emitted from the light source toward the surface of the convex portion where the finger contacts. , Or more.
[0021]
According to the present invention, since the light emitted from the light source toward the surface on which the finger of the convex portion comes into contact is not blocked by the side wall surface of the convex portion, it is possible to uniformly irradiate the entire finger contact surface. Can be.
[0022]
According to a further preferred embodiment of the present invention, a fiber array in which fibers are bundled is provided at a thickness portion of the optical plate, one end of which is directed to the convex portion, and the other end is directed to the image sensor. As shown, it is embedded diagonally. The protrusion covers the one end of the fiber array.
[0023]
By providing a fiber array on the outgoing light side, the light reflected on the finger contact surface can be efficiently guided to the image sensor, and at the same time, the incidence of extra light can be restricted, so that the contrast can be improved and the characteristics can be improved. Can be improved.
[0024]
Further, since the protrusion covers one end of the fiber array, the surface of the fiber is prevented from being damaged. Further, since the incident surface, which is the finger contact surface, becomes flat, irregular reflection on the surface can be prevented, and image quality degradation can be prevented.
[0025]
The position of the light source is selected such that the light emitted from the light source is totally reflected on one surface of the optical plate and where the subject abuts, and the inclination angle of the fiber array is set to the light source. When the light is emitted from the optical plate and totally reflected on the surface of the convex portion of the optical plate, and again passes through the convex portion and travels toward the fiber array, the light is selected to propagate through the fiber array. Of the uneven pattern detecting device.
[0026]
Further, the position of the light source is selected such that light emitted from the light source is one surface of the optical plate and is not totally reflected at a portion where the subject abuts, and the inclination angle of the fiber array is selected. The light emitted from the light source and transmitted from the surface of the convex portion of the optical plate to the subject side, re-incident from the surface of the convex portion via an air layer, and the light is re-incident at the re-incident surface. If the light bent so as to approach the line is selected so as not to propagate through the fiber array, a scattering-type uneven pattern detection device described later can be provided.
[0027]
In a modified example of the present invention, a fiber array in which fibers are bundled in a thickness portion of the optical plate is slanted such that one end thereof faces the convex portion and the other end faces the image pickup device. Embedded. The one end of the fiber array reaches a surface of the convex portion where a finger contacts.
[0028]
With this configuration, light hitting a finger as a subject can be effectively guided to the fiber array.
[0029]
In the present invention, the position of the light source is selected such that light emitted from the light source is totally reflected at a portion of the optical plate on one surface where the subject abuts, and the inclination angle of the fiber array is selected. Is selected so that the light radiated from the light source and totally reflected on the surface of the convex portion of the optical plate propagates through the fiber array, a total reflection type uneven pattern detecting device can be obtained.
[0030]
Further, the position of the light source is selected such that light emitted from the light source is one surface of the optical plate and is not totally reflected at a portion where the subject abuts, and the inclination angle of the fiber array is selected. Light emitted from the light source and transmitted from the surface of the convex portion of the optical plate to the subject side, and re-entered from the surface of the convex portion of the optical plate via an air layer propagates through the fiber array. If not selected, a scattering type uneven pattern detection device can be obtained.
[0031]
According to a further preferred embodiment of the present invention, the refractive index of the material forming the convex portion is the same as the refractive index of the core of the fiber.
[0032]
With this configuration, it is not necessary to consider extra refraction and the like.
[0033]
The refractive index of the material forming the convex portion may be smaller than the refractive index of the core of the fiber.
[0034]
With this configuration, by increasing the distance between the light source and the image sensor, it is possible to prevent the deterioration of the imaging characteristics caused by the light emitted from the light source directly entering the image sensor.
[0035]
According to a further preferred embodiment of the present invention, the height of the convex portion is selected so that light emitted from the light source does not cross the fiber array.
[0036]
Since light does not pass through the fiber array, a decrease in luminance can be prevented, and thus a deterioration in luminance distribution on the finger contact surface can be prevented.
[0037]
In a further modification of the present invention, the thickness of the optical plate is obliquely embedded such that one end thereof faces the projection and the other end faces the light source, and is introduced from the other end. A radiated light introducing fiber array for projecting radiated light from the light source from the one end toward the subject is provided.
[0038]
With this configuration, it is possible to reduce restrictions on the irradiation direction of the irradiation light.
[0039]
In a further preferred embodiment of the present invention, except for the optical path through which the radiated light passes, all of the optical plates are made of a light absorbing material.
[0040]
Since the absorber absorbs light that enters from the outside, only light that travels along the optical path propagates to the emission surface. As a result, a high-quality image can be stably obtained.
[0041]
According to a further preferred embodiment of the present invention, a light-shielding film is provided on one surface of the optical plate other than the surface on which the subject abuts, and the other surface of the optical plate is provided. In addition, a light-shielding film is also provided on a portion where the linear light source and the image sensor are not mounted.
[0042]
According to the present invention, by providing the light-shielding film, external light can be completely blocked.
[0043]
In the method of manufacturing the uneven pattern detecting device according to the second aspect of the present invention, first, one surface on which the subject having the uneven pattern is arranged and the other surface facing the one surface and on which the light source is mounted. An optical plate having a surface is prepared. On one surface of the optical plate, and a portion that abuts the subject, an optically transparent material so that a portion that abuts the subject is higher than a portion that does not abut the subject. The formed convex part is formed. An image sensor and a light source are mounted on the other surface of the optical plate while being separated from each other.
[0044]
As the optical plate, a fiber array having an incident surface and an exit surface in which fibers are bundled is inclined and embedded in a thickness portion thereof, and the incident surface of the fiber array is exposed to the one surface, and a fiber array is formed. The projection may be formed so as to cover the incidence surface of the fiber array using a substrate having the emission surface exposed to the other surface.
[0045]
Further, as the optical plate, the thickness thereof is embedded at an inclination angle opposite to that of the fiber array, and the emitted light from the light source introduced from the incident surface is directed from the emission surface toward the subject. The projection may be formed using a substrate further provided with a radiation light introducing fiber array for projecting light so as to cover the emission surface of the radiation light introducing fiber array.
[0046]
The invention according to a third aspect of the present invention relates to a portable device having an uneven pattern detection sensor. The portable device includes a housing having an opening for exposing a finger contact surface of the uneven pattern detection sensor, and an uneven pattern detection sensor mounted in the housing. The uneven pattern detection sensor includes an optical plate having one surface including the finger contact surface and the other surface facing the one surface. The finger contact surface of the one surface of the optical plate is higher than a portion where the finger does not contact so that the finger contact surface becomes a convex portion. The projection is fitted into the opening of the housing.
[0047]
When the uneven pattern detection sensor is mounted on the mobile device, the height of the finger contact surface is reduced by the thickness of the housing of the mobile device, but the height of the finger contact surface of the uneven detection sensor is increased. This allows the finger contact surface to be higher or slightly lower than the surface of the housing. In either case, it is possible to intuitively recognize that the user has touched the surface of the unevenness detection sensor, and it is possible to improve reading accuracy.
[0048]
According to a preferred embodiment of the present invention, the amount of protrusion of the convex portion from the opening portion is equal to or less than the amount of protrusion of other parts most protruding.
[0049]
With this configuration, in the case of a folding type device, damage to the surface of the projection is prevented.
[0050]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0051]
(Embodiment 1)
FIG. 1 is a perspective view for explaining the uneven pattern detection device according to the first embodiment. FIG. 2 is a sectional view taken along the line II-II in FIG.
[0052]
With reference to these figures, the uneven pattern detecting device 5 includes an optical plate 6. The optical plate 6 is formed of, for example, glass, resin, or the like. A finger 8 having a fingerprint as an uneven pattern is brought into contact with one surface 7 of the optical plate 6. On the other surface 9 of the optical plate 6, a light source 10 and an image sensor 11 are provided. Of the one surface 7 of the optical plate 6, the finger contact portion 12 to which the finger 8 contacts is higher than the portion 13 to which the finger does not contact so that the finger contact portion 12 becomes a convex portion. . The length of the protrusion (the length in the direction orthogonal to the length direction of the finger) that is the finger contact portion 12 is larger than the width of the finger 8. The width of the protrusion, which is the finger contact portion 12, is smaller than the length of the finger 8 from the first joint to the tip. In the drawings, the case where the length of the protrusion is longer than the width of the finger 8 is illustrated, but the length of the protrusion may be equal to or slightly smaller than the width of the finger 8.
[0053]
As the light source, a light emitting diode or an organic EL is preferably used.
[0054]
The finger is brought into contact with the finger contact portion 12 and slid in the direction of arrow P to detect a fingerprint. The convex portion is formed, for example, by bonding a glass substrate of the same type on a flat glass using an ultraviolet curable resin.
[0055]
According to the present embodiment, it is possible to prevent the finger contact portion 12 from becoming extremely concave when mounted on a portable device. As a result, a high-quality image can be stably obtained. The width of the projection is smaller than the length from the first joint to the tip of the finger 8 as the subject. Therefore, the effect is remarkable in the swipe type in which the finger 8 is slid to measure.
[0056]
(Embodiment 2)
FIG. 3 is a cross-sectional view of the uneven pattern detection device according to the second embodiment.
[0057]
Referring to FIG. 3, R is provided on upper portions of both side walls 15 extending in the longitudinal direction of protrusion 14. By providing R on both side walls 15 of the convex portion 14, it is possible to improve a touch feeling when a finger is brought into contact without deteriorating basic performance. In addition, by rounding the edge, injuries and the like can be eliminated.
[0058]
In addition, as shown in FIG. 4, when R is provided only on one side wall, an effect is obtained that the directions 16a and 16b in which the finger slides can be easily recognized. That is, when R is provided on only one side as shown in the figure, the resistance applied to the finger decreases in the forward direction 16a, and increases in the reverse direction 16b. Due to this difference in resistance, the directions 16a and 16b in which the finger slides can be easily understood.
[0059]
(Embodiment 3)
FIG. 5 is a sectional view of the uneven pattern detection device according to the third embodiment. Both side walls 15 extending in the longitudinal direction of the convex portion 14 are formed as slopes inclined outward. By inclining both side walls 15 of the convex portion 14, when the total reflection light is used as the incident light and the output light, the entire finger contact surface can be uniformly irradiated. When scattered light is used as incident light, it is not always necessary to provide a slope on the incident side. In the case where scattered light is used as the output light, if a slope is provided on the output side, light from the entire finger contact surface can be guided to the image sensor.
[0060]
Here, the total reflection type uneven pattern detecting device and the scattering type uneven pattern detecting device referred to in this specification will be described.
[0061]
FIG. 6 is a diagram for explaining the concept of the total reflection type uneven pattern detection device. In the total reflection type, light 17 incident on the finger contact surface at an angle equal to or larger than the critical angle is totally reflected at the concave portion 18 of the fingerprint pattern, and refracted by the medium at the surface in contact with the convex portion 19 of the fingerprint pattern. Non-total reflection depends on the rate. Thereby, the reflected light of the concave portion 18 becomes stronger than the reflected light of the portion where the convex portion 19 is in contact, so that a light pattern having a high contrast according to the concave and convex pattern is formed.
[0062]
FIG. 7 is a conceptual diagram for explaining a scattering type uneven pattern detection device. The light 17 arriving at the incident surface 20 facing the concave portion 18 (where air exists) of the fingerprint pattern enters the air and is scattered by the concave portion 18, and the scattered light 17 c enters the incident surface 20 again. . The light 17 arriving at the incident surface 20 with which the convex portion 19 of the fingerprint pattern is in contact does not pass through the convex portion 19 but directly enters the incident surface 20 and is scattered. The scattered light amount and the scattered angle range are different between the incident surface where the convex portion 19 of the fingerprint pattern contacts and the incident surface where the concave portion 18 of the fingerprint pattern faces. Therefore, a light pattern having a high contrast according to the unevenness can be obtained.
[0063]
The present invention can be applied to either the total reflection type or the scattering type.
[0064]
Referring to FIG. 8, when the uneven pattern detection device according to the present embodiment is used for a total reflection type, inclination angle θ that inclines outward of the inclined surface ₂ And the inclination angle θ ₂ Is the irradiation angle θ of the light emitted from the light source 10 toward the surface of the projection 14 on which the finger contacts. ₁ It is preferable that the irradiation angle is equal to or larger than the irradiation angle. With such a configuration, the light emitted toward the convex portion 14 does not hit the slope, and is entirely applied to the finger contact surface of the convex portion 14.
[0065]
(Embodiment 4)
FIG. 9 is a cross-sectional view of the uneven pattern detection device according to the fourth embodiment.
[0066]
Referring to FIG. 9, a fiber array 21 formed by bundling fibers is obliquely embedded in a thickness portion of optical plate 6. The fibers constituting the fiber array 21 are formed of a core and a clad. Note that a fiber array provided with an absorber around the cladding may be used. One end of the fiber array 21 faces the projection 14, and the other end faces the image sensor 11. The protrusion 14 covers one end of the fiber array 21. The space between the imaging element 11 and the other end of the fiber array 21 is filled with a resin having a refractive index equal to or higher than the refractive index of the core of the fiber. The light source 10 is provided at a position where the incident angle of light on the finger contact surface of the projection 14 of the optical plate 6 is larger than the critical angle at the interface between the finger contact surface of the projection 14 of the optical plate and air. Have been. This is a so-called total reflection type uneven pattern detecting device.
[0067]
According to the present embodiment, since the optical fiber is used for the propagation of the light pattern, it is possible to reduce the restriction on the irradiation direction of the irradiation light from the finger contact surface of the projection 14 toward the image sensor 11.
[0068]
In addition, since the one end of the fiber array 21 is covered with the protrusion 14, the surface of the one end of the fiber array 21 can be prevented from being damaged.
[0069]
Furthermore, since the surface on the emission light side (the surface of the convex portion 14) becomes flat, irregular reflection on the surface can be prevented, and deterioration of image quality can be prevented.
[0070]
In this case, by using a material similar to the refractive index of the core of the fiber constituting the fiber array 21 as the material constituting the convex portion 14, it is not necessary to consider extra refraction or the like.
[0071]
On the other hand, when the refractive index of the material forming the convex portion 14 is smaller than the refractive index of the core of the fiber, the light is made to approach the normal at the interface between the convex portion 14 and the incident surface of the fiber array 21. Can be bent.
[0072]
FIG. 10 is intended for a so-called scattering type uneven pattern detection device, and the position where the light source 10 is provided is such that the irradiation direction of the irradiation light emitted from the light source 10 is directly reflected by the regular reflection light on the finger contact surface. It is chosen so that it does not enter the fiber and propagate. In the drawing, the light source 10 is provided immediately below the protrusion 14. The present invention can be applied to such a scattering type. In the case where scattered light is used as incident light, it is not always necessary to provide a slope on the side wall on the incident side of the projection 14 as shown in the figure. In the case where scattered light is used as the emitted light, if an inclined surface is provided on the emission side wall of the protrusion 14 as shown in the figure, light from the entire finger contact surface can be guided to the image sensor 11.
[0073]
Next, the position where the light source 10 is provided and the inclination angle of the fiber array 21 will be described in more detail. Here, for the sake of simplicity, it is assumed that the refractive index of the projection 14 of the optical plate is equal to the refractive index of the core of the optical fiber.
[0074]
First, a case of using a total reflection type will be described.
[0075]
Referring again to FIGS. 6 and 9, light 17 is emitted from light source 10. The incident angle θ of light on the finger contact surface of the projection 14 of the optical plate 6 is made larger than the critical angle at the interface between the finger contact surface of the projection 14 of the optical plate and air. In this case, the reflected light 17a is totally reflected on the surface 20 facing the concave portion 18 of the finger 8, and is not totally reflected on the incident surface 20 in contact with the convex portion 19 of the finger 8 due to the refractive index of the medium. . As a result, the reflected light of the portion of the finger 8 facing the concave portion 18 becomes stronger than the reflected light of the portion of the finger 8 where the convex portion 19 is in contact. A light pattern having a correspondingly strong contrast is formed.
[0076]
Here, by making the inclination angle of the fiber array 21 substantially coincide with the total reflection angle θ, the reflected light 17a, which is the totally reflected light, propagates through the optical fibers in the fiber array 21. At this time, non-total reflection occurs at a portion where the projection 19 of the concavo-convex pattern of the finger 8 is in contact with the incident surface 20, so that the totally reflected light does not propagate through the optical fibers in the fiber array. For this reason, there is a large difference in light intensity propagating in the fiber array between the concave portion and the convex portion. As a result, a light pattern corresponding to the uneven pattern of the finger 8 forms an image on the image sensor 11.
[0077]
The imaging element 11 has photodiodes arranged in a rectangular area. 256 × 16 elements are arranged at a pitch of about 50 μm, and the resolution is 500 dpi. The output of each element can be sequentially read out based on an instruction such as a control signal from the outside. The output of each element of the image sensor is converted into an 8-bit digital value by an A / D converter.
[0078]
As shown in FIG. 1, the subject places the finger on the finger rest surface and slides the finger in the finger length direction P. The output from the image sensor is repeatedly read at regular time intervals, and the output value read when the finger is slid is reconstructed into a two-dimensional image by an arithmetic device such as a CPU. In the case of a fingerprint image, the reconstructed image is compared with an image previously stored in a memory or the like, and is used for personal authentication.
[0079]
Note that the image sensor may have an A / D conversion function. Further, when the unevenness pattern detection device according to the present invention is used in a mobile device, the finger placement surface of the unevenness pattern detection device is exposed on the surface of the mobile device, and data is transferred to an internal CPU.
[0080]
Next, a case of using a scattering type will be described.
[0081]
Referring to FIGS. 7 and 10 again, irradiation light 17 emitted from light source 10 reaches incident surface 20 (the surface of convex portion 14 of the optical plate). In this case, the irradiation direction of the irradiation light 17 emitted from the light source 10 is arbitrarily set within a range in which the regular reflection light of the irradiation light on the incident surface 20 does not directly enter the optical fiber and propagate. In the figure, the light source 10 is formed directly below the finger 8.
[0082]
In the incident surface 20, specular reflection light and transmitted light into the air are generated on the incident surface 20 facing the concave portion 18 of the finger uneven pattern, and scattered on the incident surface 20 in contact with the convex portion 19 of the finger uneven pattern. Light 17b is generated.
[0083]
Here, the regular reflection light from the incident surface 20 facing the concave portion 18 of the finger uneven pattern is set so as not to propagate through the optical fiber. Is propagated in the fiber array 21. Therefore, it is possible to obtain a light pattern corresponding to the convex portion of the concave / convex pattern of the finger 8.
[0084]
On the other hand, the light 17c that has passed through the incident surface 20 facing the concave portion 18 of the finger concave and convex pattern and entered the air, and the light 17c scattered on the inner wall surface of the concave portion 18 once passes through the air and enters Re-enter surface 20. At this time, the light 17c is refracted at the interface between the air and the incident surface 20 so as to approach the normal 100 and becomes the light 17d traveling toward the fiber array 21 due to the relationship between the refractive index of the air and the optical plate. Therefore, in order to obtain a light pattern with a higher contrast, it is important to prevent the light 17d from propagating in the optical fiber.
[0085]
That is, when the inclination angle of the fiber array 21 is selected so that the light 17d does not propagate through the fiber array 21 and the scattered light 17b can propagate through the fiber array 21, the convex portions 19 of the concave and convex pattern of the finger come into contact with each other. Only the scattered light 17b on the incident surface 20 can be propagated to the image sensor 11 through the optical fiber.
[0086]
(Embodiment 5)
The present embodiment relates to a method of manufacturing the uneven pattern detecting device in which the fiber array according to the present invention is embedded.
[0087]
Referring to FIG. 11A, a fiber array 21 in which fibers are bundled and a glass 22 are prepared. Referring to FIG. 11B, the fiber array 21 is bonded by sandwiching it between glasses 22. At this time, the optical axis of the fiber is set to be parallel to the surface of the glass 22. Examples of the joining method include heat fusion, adhesion, and direct joining.
[0088]
Referring to FIG. 11C, the joined body of the fiber array 21 and the glass 22 is cut into a flat plate at an angle with respect to the joining surface. The cutting interval was 1.1 mm.
[0089]
11 (c) and 11 (d), the cut-out flat plate was cut into a rectangular shape with its ends dropped. The main surface of the flat plate was optically polished to form an optical plate 6 containing fibers. The thickness after polishing was 1.0 mm, and the planar shape was a rectangle of 20 mm × 10 mm.
[0090]
Referring to FIG. 11 (e), the optical surface of one surface 7 of optical plate 6, which is in contact with a finger, is positioned higher than the portion not in contact with the finger. The protrusions 14 formed of a transparent material are formed. The projections 14 are formed, for example, by bonding glass of the same type as the glass constituting the optical plate 6 using an ultraviolet curable resin.
[0091]
Referring to FIG. 11F, a metal film 24 is formed on the other surface of the optical plate 6 by depositing chromium and gold.
[0092]
Referring to FIGS. 11F and 11G, the metal film 24 is patterned to form an electrode 25.
[0093]
Referring to FIG. 11H, a linear light source including a light emitting diode (LED) 26 and a light guide plate 27 is formed on the other surface of the optical plate 6. The light emitting diode (LED) 26 is connected to the electrode 25. Further, the image sensor 11 is formed so as to be connected to the electrode 25. Thereby, the uneven pattern detection device is completed.
[0094]
FIG. 12 is a cross-sectional view taken along the line XII-XII in FIG. 11H and is a view for explaining the function of the light guide plate 27. The irradiation light 17 emitted from the LED 26 is reflected by an uneven pattern provided on the light guide plate 27, and becomes parallel light. Referring to FIG. 11H again, the parallel light travels to the convex portion 14 that is the subject contact surface.
[0095]
In the above-described embodiment, a linear light source including one light emitting diode (LED) 26 and a light guide plate 27 is exemplified as the light source. However, the present invention is not limited to this, and the light guide plate 27 is used. Alternatively, a plurality of light emitting diodes may be arranged to face the image sensor 11.
[0096]
(Embodiment 6)
FIG. 13 is a cross-sectional view of the uneven pattern detecting device according to the sixth embodiment.
[0097]
Referring to FIG. 13, a different point from the uneven pattern detection device according to the fourth embodiment is that one end of fiber array 21 is extended to a surface of projection 14 on which a finger abuts. . With this configuration, the uneven pattern of the finger can be brought into close contact with the incident surface.
[0098]
When the light source 10 is used in the total reflection type, the position of the light source 10 is selected such that the light emitted from the light source 10 is totally reflected on the surface of the convex portion 14 where the subject comes into contact. The inclination angle of the fiber array 21 is selected such that the light emitted from the light source 10 and totally reflected on the surface of the projection 14 propagates through the fiber array 21.
[0099]
When the light source 10 is used in a scattering type, the position of the light source 10 is selected so that the light emitted from the light source 10 is not totally reflected on the surface of the convex portion 14 where the subject comes into contact. The inclination angle of the fiber array 21 is the light emitted from the light source 10 and transmitted from the surface of the convex portion 14 to the subject side, re-incident from the surface of the convex portion 14 through the air layer, and re-incident. Light that is bent so as to approach the normal on the surface is selected so as not to propagate through the fiber array 21.
[0100]
(Embodiment 7)
FIG. 14 is a cross-sectional view of the uneven pattern detection device according to the seventh embodiment.
[0101]
Referring to FIG. 14, the height of protrusion 14 is selected so that light emitted from light source 10 does not cross fiber array 21. With this configuration, the light incident on the finger contact surface reaches the finger contact surface of the convex portion 14 without passing through the fiber array 21. When the incident light from the light source 10 passes through the fiber array 21, the luminance decreases, that is, the luminance distribution on the finger contact surface deteriorates. However, in the present embodiment, since the incident light does not pass through the fiber array 21, Such a problem does not occur.
[0102]
(Embodiment 8)
FIG. 15 is a cross-sectional view of the uneven pattern detection device according to the eighth embodiment.
[0103]
Referring to FIG. 15, radiation light for projecting irradiation light from light source 10 toward projection 14 from one end thereof in addition to fiber array 21 for emission on the thickness portion of optical plate 6. An introduction fiber array 28 is embedded.
[0104]
According to the present embodiment, since the optical fiber is used for propagating the light for projection, the restriction on the irradiation direction of the irradiation light can be reduced.
[0105]
In addition, a light-shielding film 29 is provided on one surface of the optical plate 6 other than the portion where the subject contacts. In the drawings, the case where the light shielding film 29 is not provided on the slope of the convex portion 14 is illustrated, but the light shielding film 29 may be formed to extend to the slope. The light-shielding film 29 is also provided on the other surface of the optical plate 6 where the light source and the imaging element 11 are not mounted. By providing the light shielding film 29, there is an effect that external light does not enter the sensor.
[0106]
(Embodiment 9)
FIG. 16 is a sectional view of the uneven pattern detection device according to the ninth embodiment.
[0107]
Referring to FIG. 16, in the uneven pattern detection device according to the present embodiment, the refractive index of the material forming convex portion 14 is smaller than the refractive index of the material forming optical plate 6. Irradiation light emitted from the light source can be refracted away from the normal line at the interface between the convex portion 14 and the optical plate 6 as shown in the figure. With this configuration, the distance between the light source and the image sensor can be widened, and deterioration of the imaging characteristics caused by the light emitted from the light source directly entering the image sensor can be prevented. Further, by forming the light shielding film 29, light from the outside is blocked.
[0108]
(Embodiment 10)
FIG. 17 is a cross-sectional view of the uneven pattern detection device according to the tenth embodiment. In the uneven pattern detection device according to the present embodiment, all of the optical plate 6 is made of a material that absorbs light, except for the optical path through which the radiated light 17 passes. Since the absorber absorbs light that enters from the outside, only light that travels along the optical path propagates to the emission surface. As a result, a high-quality image can be stably obtained.
[0109]
These are formed by sandwiching a columnar absorber having a cross-sectional shape as shown in the figure and joining the fiber and the glass. As the absorber, not only a glass material but also a metal such as alumite-treated aluminum, ceramic, carbon, or the like can be used.
[0110]
(Embodiment 11)
The present embodiment relates to a mobile device having an uneven pattern detection sensor.
[0111]
With reference to FIG. 18, the mobile device has an opening 31 for exposing the finger contact surface 30 of the uneven pattern detection device 5. The uneven pattern detection device 5 includes an optical plate 6 having one surface including a finger contact surface 30 and the other surface 9 opposed to the one surface. The finger contact surface 30 of the one surface 7 of the optical plate 6 is higher than the portion where the finger does not contact so that the finger contact surface 30 becomes the convex portion 14. The protrusion 14 is fitted into the opening 31 of the housing 32.
[0112]
When the uneven pattern detection device is mounted on the mobile device, the height of the finger contact surface 30 is reduced by the thickness of the housing 32 of the mobile device. However, the provision of the protrusion 14 allows the finger contact surface 30 to be higher than the surface of the housing 32. In this case, the finger contact surface 30 can be slightly lower than the surface of the housing 32 by selecting a value of the height of the convex portion 14. In either case, the user can intuitively recognize that the user has touched the surface of the uneven pattern detection device, which leads to improvement in reading accuracy. As a result, a high-quality image can be stably obtained.
[0113]
In addition, when the mounting of the mobile device is considered, since the convex portion 14 is provided, the mounting can be accurately performed in the housing of the mobile device.
[0114]
The case of mounting on a portable device will be described in more detail.
[0115]
FIG. 19A is a front view of a portable device. FIG. 19B is a cross-sectional view along the line BB in FIG.
[0116]
With reference to these figures, the protrusion 14 of the uneven pattern detection device 5 is fitted into the opening 31 of the housing 32. One surface 7 of the optical plate 6, other than the protrusion 14, is bonded to the inner surface of the housing 32. A flexible cable 33 is used for extracting an electrode from the uneven pattern detection device 5. The uneven pattern detection device 5 is connected to the substrate 34 provided in the portable device by the cable 33. In the case of a folding portable device, the amount of protrusion of the protrusion 14 from the surface of the housing 32 is preferably equal to or less than the amount of protrusion of the most protruding component. For example, it is preferable that the protrusion amount is equal to or less than the protruding amount of the numeric keypad. For example, the amount of protrusion of the convex portion 14 may be set to 1 mm or less.
[0117]
By mounting a fingerprint authentication sensor on a mobile device, it is now possible to easily release key locks and call up a secret address book, which were previously performed by entering a password such as numbers. Become. In addition, payment of money (small payment) can be performed more accurately and reliably by giving a personal device, such as a portable device, a function to perform fingerprint authentication. It is possible to easily construct a mechanism that can replace (coupon) and the like.
[0118]
The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[0119]
【The invention's effect】
According to the concavo-convex pattern detecting device according to the present invention, of the one surface of the optical plate, an object contact portion where the object comes into contact is such that the object contact portion becomes a convex portion. Since the height is set higher than the portion where the subject does not abut, it is possible to prevent the subject abutting portion from being extremely concave when mounted on a portable device. As a result, a high-quality image can be stably obtained. In particular, the effect is remarkable in the swipe type in which the measurement is performed by sliding the subject.
[0120]
According to a preferred embodiment of the present invention, since R is provided on an upper portion of at least one of the side walls extending in the longitudinal direction of the projection, without deteriorating basic performance, Touch feeling when a finger is brought into contact can be improved. In addition, by rounding the edge, there is an effect that injuries and the like can be eliminated. Further, when the R is provided on only one of the side walls, an effect that the direction in which the finger slides intuitively can be easily recognized is produced.
[0121]
In addition, by inclining the wall surface of the convex portion, when the totally reflected light is used as the incident light and the outgoing light, the entire finger contact surface can be uniformly irradiated.
[0122]
According to a further preferred embodiment of the present invention, the angle of inclination of the inclined surface in the outward direction is the same as the irradiation angle of light emitted from the light source toward the surface of the convex portion where the finger contacts. , Or more, so that the light emitted from the light source toward the surface on which the finger of the projection abuts is not blocked by the side wall surface of the projection, so that the entire finger contact surface Can be uniformly irradiated.
[0123]
According to a further preferred embodiment of the present invention, a fiber array in which fibers are bundled is provided at a thickness portion of the optical plate, one end of which is directed to the convex portion, and the other end is directed to the image sensor. As shown, it is embedded diagonally. The protrusion covers the one end of the fiber array. According to this embodiment, since the fiber array is provided on the outgoing light side, the restriction on the irradiation direction of the irradiation light can be reduced, and the effect of improving the characteristics can be obtained.
[0124]
Further, since the convex portion covers one end of the fiber array, it is possible to prevent the fiber surface from being damaged. Further, since the incident surface, which is the finger contact surface, becomes flat, it is possible to prevent irregular reflection on the surface and prevent image quality deterioration.
[0125]
According to another embodiment of the present invention, a fiber array in which fibers are bundled in the thickness portion of the optical plate is arranged such that one end thereof faces the projection and the other end faces the image pickup device. Embedded diagonally. The one end of the fiber array reaches a surface of the convex portion where a finger contacts. With such a configuration, it is possible to effectively guide light hitting a finger as a subject to the fiber array.
[0126]
According to a further preferred embodiment of the present invention, since the refractive index of the material forming the convex portion is made the same as the refractive index of the core of the fiber, it is not necessary to consider extra refraction and the like. It works.
[0127]
When the refractive index of the material constituting the convex portion is smaller than the refractive index of the core of the fiber, the distance between the light source and the image sensor can be increased, and the light emitted from the light source directly enters the image sensor. Degradation can be prevented.
[0128]
According to a further preferred embodiment of the present invention, the height of the convex portion is selected so that light emitted from the light source does not cross the fiber array, and does not allow light to pass through the fiber array. Of the brightness distribution on the finger contact surface can be prevented.
[0129]
According to a further preferred embodiment of the present invention, one end of the optical plate is obliquely embedded in the thickness portion so as to face the projection and the other end is directed toward the light source, and is introduced from the other end. A radiation light introducing fiber array for projecting the emitted light from the light source toward the subject from the one end, so that the restriction on the irradiation direction of the irradiation light can be reduced. To play.
[0130]
According to a further preferred embodiment of the present invention, except for the optical path through which the radiated light passes, all of the optical plates are made of a material that absorbs light. , Only light traveling in the optical path is propagated to the exit surface. As a result, there is an effect that a high quality image can be stably obtained.
[0131]
According to a further preferred embodiment of the present invention, on one surface of the optical plate, a light-shielding film is provided on a portion other than the convex portion, and on the other surface of the optical plate, Since a light-shielding film is also provided on a portion where the linear light source and the image sensor are not mounted, external light can be completely blocked.
[0132]
According to the invention portable device according to another aspect of the present invention, the finger contact surface is configured to be a convex portion, and the convex portion is fitted into the opening of the housing, and the finger contact surface is , Or slightly lower than the surface of the housing. In either case, it is possible to intuitively recognize that the user has touched the surface of the unevenness detection sensor, and it is possible to improve the reading accuracy.
[Brief description of the drawings]
FIG. 1 is a perspective view of an uneven pattern detection device according to a first embodiment;
FIG. 2 is a sectional view taken along the line II-II in FIG.
FIG. 3 is a cross-sectional view of the uneven pattern detection device according to the second embodiment;
FIG. 4 is a sectional view of a modified example of the uneven pattern detection device according to the second embodiment;
FIG. 5 is a cross-sectional view of the uneven pattern detecting device according to the third embodiment;
FIG. 6 is a conceptual diagram for explaining the operation of the total reflection type uneven pattern detection sensor;
FIG. 7 is a conceptual diagram for explaining the operation of the scattering type uneven pattern detection sensor.
FIG. 8 is a sectional view of an uneven pattern detecting device according to a modification of the third embodiment;
FIG. 9 is a cross-sectional view of the uneven pattern detection device according to the fourth embodiment;
FIG. 10 is a diagram showing an uneven pattern detection device according to another specific example of the fourth embodiment;
FIG. 11 is a perspective view of each step in the order of the method for manufacturing the fiber-containing uneven pattern detection device according to the fifth embodiment.
FIG. 12 is a sectional view taken along the line XII-XII in FIG.
FIG. 13 is a sectional view of an uneven pattern detection device according to a sixth embodiment;
FIG. 14 is a cross-sectional view of the uneven pattern detection device according to the seventh embodiment.
FIG. 15 is a sectional view of an uneven pattern detection device according to an eighth embodiment;
FIG. 16 is a sectional view of an uneven pattern detection device according to a ninth embodiment;
FIG. 17 is a cross-sectional view of the uneven pattern detection device according to the tenth embodiment.
FIG. 18 is a conceptual diagram of a portable device according to an eleventh embodiment.
19A is a front view of the portable device according to the eleventh embodiment, FIG. 19B is a cross-sectional view taken along line BB in FIG.
FIG. 20 is a diagram of the usage state of the conventional finger image input device viewed from the right.
FIG. 21 is a diagram of the usage state of the conventional finger image input device viewed from the left.
[Explanation of symbols]
5 Uneven pattern detector
6 Optical plate
7 One side
8 fingers
9 The other side
10 Light source
11 Image sensor
12 finger contact part

Claims (22)

One surface to which the subject having the concavo-convex pattern is brought into contact, and an optical plate having the other surface opposing the one surface,
A light source and an image sensor provided on the other surface of the optical plate,
Of the one surface of the optical plate, a subject contact portion where the subject contacts is higher than a portion where the subject does not contact so that the subject contact portion becomes a convex portion. , An uneven pattern detection device. The uneven pattern detection device according to claim 1, wherein R is provided on an upper portion of at least one of the side walls extending in the longitudinal direction of the protrusion. The uneven pattern detection device according to claim 1, wherein both side walls extending in a longitudinal direction of the convex portion are formed as slopes inclined outward. The angle of inclination of the slope that is inclined outwardly is equal to or greater than the angle of illumination of light emitted from the light source toward a surface of the projection that contacts a finger of the projection. 3. The uneven pattern detection device according to 3. In the thickness portion of the optical plate, a fiber array formed by bundling fibers is obliquely embedded such that one end thereof faces the projection and the other end thereof faces the image sensor,
The uneven pattern detection device according to any one of claims 1 to 4, wherein the convex portion covers the one end of the fiber array. The position of the light source is selected such that light emitted from the light source is one surface of the optical plate and is totally reflected at a portion where the subject contacts,
The tilt angle of the fiber array is radiated from the light source and totally reflected on the surface of the convex portion of the optical plate, and light traveling toward the fiber array again through the convex portion propagates through the fiber array. The uneven pattern detecting device according to claim 5, wherein the uneven pattern detecting device is selected as follows. The position of the light source is selected so that light emitted from the light source is on one surface of the optical plate and is not totally reflected at a portion where the subject contacts,
The inclination angle of the fiber array is light that is emitted from the light source and transmitted from the surface of the convex portion of the optical plate to the subject side, and is incident again from the surface of the convex portion through the air layer. 6. The uneven pattern detecting apparatus according to claim 5, wherein the light which is bent so as to approach the normal line at the re-incident surface is selected so as not to propagate through the fiber array. In the thickness portion of the optical plate, a fiber array formed by bundling fibers is obliquely embedded such that one end thereof faces the projection and the other end thereof faces the image sensor,
The uneven pattern detection device according to any one of claims 1 to 4, wherein the one end of the fiber array reaches a surface of the convex portion with which a finger contacts. The position of the light source is selected such that light emitted from the light source is one surface of the optical plate and is totally reflected at a portion where the subject contacts,
The uneven pattern according to claim 8, wherein the inclination angle of the fiber array is selected such that light emitted from the light source and totally reflected on the surface of the projection of the optical plate propagates through the fiber array. Detection device. The position of the light source is selected so that light emitted from the light source is on one surface of the optical plate and is not totally reflected at a portion where the subject contacts,
The inclination angle of the fiber array is radiated from the light source and transmitted from the surface of the convex portion of the optical plate to the subject side, and re-incident from the surface of the convex portion of the optical plate via an air layer. The uneven pattern detection device according to claim 8, wherein the light is selected so as not to propagate through the fiber array. The uneven pattern detection device according to any one of claims 5 to 10, wherein a refractive index of a material forming the convex portion is the same as a refractive index of a core of the fiber. The uneven pattern detection device according to any one of claims 5 to 10, wherein a refractive index of a material forming the convex portion is smaller than a refractive index of a core of the fiber. The uneven pattern detecting device according to any one of claims 5 to 12, wherein the height of the convex portion is selected so that light emitted from the light source does not cross the fiber array. In the thickness portion of the optical plate, one end faces the convex portion, and the other end is obliquely embedded so as to face the light source, and radiates the light from the light source introduced from the other end to the one side. The uneven pattern detection device according to any one of claims 1 to 13, further comprising a radiation light introducing fiber array for projecting light from an end toward the subject. The uneven pattern detection device according to any one of claims 1 to 14, wherein all of the optical plates are made of a material that absorbs light, except for an optical path through which the emitted light passes. A light-shielding film is provided on one surface of the optical plate other than the surface with which the subject contacts,
The uneven pattern according to any one of claims 1 to 15, wherein a light-shielding film is provided on a portion of the other surface of the optical plate where the linear light source and the image sensor are not mounted. Detection device. The uneven pattern detection device according to any one of claims 1 to 16, wherein a width of the convex portion is smaller than a length from a first joint to a tip of the finger as the subject. A step of preparing an optical plate having one surface and the other surface on which the subject having the concavo-convex pattern is arranged and the other surface on which the light source is mounted,
On one surface of the optical plate, and a portion that abuts the subject, an optically transparent material so that a portion that abuts the subject is higher than a portion that does not abut the subject. Forming a formed convex portion;
Mounting an image sensor and a light source on the other surface of the optical plate separately from each other. A portable device having an uneven pattern detection sensor,
A housing having an opening for exposing a finger contact surface of the uneven pattern detection sensor,
An uneven pattern detection sensor mounted in the housing,
The uneven pattern detection sensor includes an optical plate having one surface including the finger contact surface and another surface facing the one surface,
Of the one surface of the optical plate, the finger contact surface is higher than a portion where the finger does not contact, so that the finger contact surface becomes a convex portion,
The portable device, wherein the protrusion is fitted into the opening of the housing. 20. The portable device according to claim 19, wherein the protrusion protrudes outward from the opening of the housing. 21. The mobile device according to claim 20, wherein an amount of the protrusion protruding from the opening is equal to or less than a protruding amount of other parts. 20. The mobile device according to claim 19, wherein the protrusion is recessed inward so as not to protrude from an outer surface of the housing.

Images