JPH10269340A - Fingerprint detector - Google Patents
Fingerprint detectorInfo
- Publication number
- JPH10269340A JPH10269340A JP9075356A JP7535697A JPH10269340A JP H10269340 A JPH10269340 A JP H10269340A JP 9075356 A JP9075356 A JP 9075356A JP 7535697 A JP7535697 A JP 7535697A JP H10269340 A JPH10269340 A JP H10269340A
- Authority
- JP
- Japan
- Prior art keywords
- fingerprint
- layer
- elastic layer
- light
- transparent substrate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000001050 lubricating effect Effects 0.000 claims abstract description 46
- 229920001296 polysiloxane Polymers 0.000 claims abstract description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 7
- 239000006087 Silane Coupling Agent Substances 0.000 claims abstract description 5
- 239000000758 substrate Substances 0.000 claims description 40
- 238000001514 detection method Methods 0.000 claims description 20
- 239000010409 thin film Substances 0.000 claims description 9
- 239000011347 resin Substances 0.000 claims description 6
- 229920005989 resin Polymers 0.000 claims description 6
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 claims description 5
- 239000003795 chemical substances by application Substances 0.000 claims description 5
- 229910052731 fluorine Inorganic materials 0.000 claims description 5
- 239000011737 fluorine Substances 0.000 claims description 5
- 230000001678 irradiating effect Effects 0.000 claims description 2
- 239000006082 mold release agent Substances 0.000 abstract 1
- 239000010408 film Substances 0.000 description 8
- 238000010586 diagram Methods 0.000 description 6
- 230000003287 optical effect Effects 0.000 description 6
- 239000005304 optical glass Substances 0.000 description 6
- 230000000694 effects Effects 0.000 description 4
- 229920002379 silicone rubber Polymers 0.000 description 4
- 239000000428 dust Substances 0.000 description 3
- 239000000499 gel Substances 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 238000005461 lubrication Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 239000004945 silicone rubber Substances 0.000 description 3
- 229920000742 Cotton Polymers 0.000 description 2
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 2
- 239000007822 coupling agent Substances 0.000 description 2
- 230000005489 elastic deformation Effects 0.000 description 2
- 239000013013 elastic material Substances 0.000 description 2
- 239000004744 fabric Substances 0.000 description 2
- 239000011344 liquid material Substances 0.000 description 2
- 229910000077 silane Inorganic materials 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000004528 spin coating Methods 0.000 description 2
- 238000002834 transmittance Methods 0.000 description 2
- NCGICGYLBXGBGN-UHFFFAOYSA-N 3-morpholin-4-yl-1-oxa-3-azonia-2-azanidacyclopent-3-en-5-imine;hydrochloride Chemical compound Cl.[N-]1OC(=N)C=[N+]1N1CCOCC1 NCGICGYLBXGBGN-UHFFFAOYSA-N 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000014509 gene expression Effects 0.000 description 1
- 239000004519 grease Substances 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000010137 moulding (plastic) Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 239000005871 repellent Substances 0.000 description 1
- 238000007761 roller coating Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 210000004243 sweat Anatomy 0.000 description 1
Landscapes
- Image Input (AREA)
- Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、指紋検知装置に関
し、特に透明基体を介して指の指紋に光を照射し、その
反射光から指紋パターンを検出する指紋検知装置に関す
るものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fingerprint detection device, and more particularly, to a fingerprint detection device that irradiates a fingerprint of a finger with light through a transparent substrate and detects a fingerprint pattern from the reflected light.
【０００２】[0002]
【従来の技術】一般に、透明基体に押し当てられた指の
指紋に対して光を照射し、その反射光から指紋パターン
を検出する場合、図５に示すような、光学的性質が利用
されている。図５は、境界面における光の振る舞いを示
す説明図であり、１は光学ガラスなどの透明基体、１Ｓ
は透明基体１の表面、８は空気である。例えば、透明基
体１の下部ｇから、透明基体表面１Ｓの垂直軸ｊｋと入
射角θｂを持って、透明基体表面１Ｓの点ｂに入射され
た光は、透明基体表面１Ｓの垂直軸ｊｋと屈折角θａを
なして空気８中のｃに向けて出射される。2. Description of the Related Art Generally, when light is applied to a fingerprint of a finger pressed against a transparent substrate and a fingerprint pattern is detected from the reflected light, the optical properties shown in FIG. 5 are used. I have. FIG. 5 is an explanatory view showing the behavior of light at the boundary surface, where 1 is a transparent substrate such as optical glass, and 1S.
Is the surface of the transparent substrate 1, and 8 is air. For example, from the lower part g of the transparent substrate 1, light having a vertical axis jk of the transparent substrate surface 1S and an incident angle θb and incident on the point b of the transparent substrate surface 1S is refracted by the vertical axis jk of the transparent substrate surface 1S. The light is emitted toward c in the air 8 at an angle θa.
【０００３】このとき、透明基体１および空気８の屈折
率をそれぞれｎｂ，ｎａとすると、入射角θｂと屈折角
θａとの関係は、スネルの法則により、 ｎａ sinθａ＝ｎｂ sinθｂ となる。なお、通常、空気８の屈折率ｎａは例えば光学
ガラスなどの透明基体１の屈折率ｎｂより小さい（ｎａ
＜ｎｂ）ことから、屈折角θａは入射角θｂより大きく
（θａ＞θｂ）なる。At this time, assuming that the refractive indices of the transparent substrate 1 and the air 8 are nb and na, respectively, the relationship between the incident angle θb and the refraction angle θa is given by Snel's law as na sin θa = nb sin θb. Normally, the refractive index na of the air 8 is smaller than the refractive index nb of the transparent substrate 1 such as optical glass (na).
<Nb), the refraction angle θa is larger than the incident angle θb (θa> θb).
【０００４】ここで、 sinθｂ＞ｎａ／ｎｂとなるよう
なもっと大きな入射角θｂを選択した場合、スネルの法
則を満たす屈折角θａが存在しなくなり、入射された光
は透明基体表面１Ｓにて全反射するものとなる。この全
反射が起こる入射角すなわち臨界角θｃは、 θｃ＝sin-1（ｎａ／ｎｂ） で求められる。Here, when a larger incident angle θb is selected such that sin θb> na / nb, there is no refraction angle θa satisfying Snell's law, and the incident light is totally reflected on the transparent substrate surface 1S. It will reflect. The incident angle at which this total reflection occurs, that is, the critical angle θc is obtained by θc = sin −1 (na / nb).
【０００５】図５において、∠ｇｂｋ＝θｃ（＝∠ｈｂ
ｋ）とすると、ｇｂｆ（ｈｂｉ）で示される角度領域か
ら入射された光は、光路ｄｂｅ（ｅｂｄ）により透明基
体１側へ全反射される。また、角度領域ｇｂｈから入射
された光は、 sinθａ＞ｎａ／ｎｂが成立しないことか
ら、光路ａｂｃにより空気８に出射される。なお、空気
８側から入射される光も同様であり、透明基体１側に出
射される光は、角度領域ｇｂｈにしか出射されない。In FIG. 5, ∠gbk = θc (= ∠hb
If k), the light incident from the angle region indicated by gbf (hbi) is totally reflected toward the transparent substrate 1 by the optical path dbe (ebd). Light incident from the angle region gbh is emitted to the air 8 through the optical path abc because sinθa> na / nb is not satisfied. The same applies to the light incident from the air 8 side, and the light emitted to the transparent base 1 side is emitted only to the angle region gbh.
【０００６】このような、光学的特性において、透明基
体１側から全反射が発生するような所定入射角にて光を
指紋に照射するようにしたものが、図６に示す従来の指
紋検知装置である。図６において、１は透明基体、３は
指紋３Ａを有する指、４は光源、５は画像検出部であ
り、光源４からの光が透明基体１を介して指紋３Ａに照
射され、その反射光が画像検出部５により検出される。[0006] In such optical characteristics, a fingerprint is irradiated with light at a predetermined incident angle such that total reflection is generated from the transparent substrate 1 side. It is. 6, reference numeral 1 denotes a transparent substrate, 3 denotes a finger having a fingerprint 3A, 4 denotes a light source, and 5 denotes an image detecting unit. Light from the light source 4 is applied to the fingerprint 3A via the transparent substrate 1 and reflected light thereof. Is detected by the image detection unit 5.
【０００７】通常、指紋の稜線部（凸部）の屈折率は、
空気の屈折率ｎａより大きく、光学ガラスなどの透明基
体の屈折率ｎｂに近いことから、指紋のうち空気が存在
する谷間部（凹部）に接する透明基体表面でのみ全反射
が発生し、透明基体の屈折率ｎｂに近い屈折率を有する
指紋３Ａの稜線部では全反射が発生せず、通過した光は
指に吸収され、あるいは乱反射する。[0007] Usually, the refractive index of the ridge portion (convex portion) of the fingerprint is
Since the refractive index is larger than the refractive index na of air and close to the refractive index nb of a transparent substrate such as optical glass, total reflection occurs only on the surface of the transparent substrate in contact with the valley (concave portion) where air exists in the fingerprint, and the transparent substrate Does not occur at the ridge of the fingerprint 3A having a refractive index close to the refractive index nb, and the passed light is absorbed by the finger or irregularly reflected.
【０００８】したがって、画像検出部５では、指紋３Ａ
の谷間部が明るく、稜線部が暗い指紋パターンが得られ
る。ここで、従来の指紋検知装置では、図６に示すよう
に、透明基体１の表面に弾性層２を設けて、指紋３Ａの
稜線部の密着性を改善している（例えば、特開平１−１
４５７８５号公報など）。Therefore, in the image detecting section 5, the fingerprint 3A
A fingerprint pattern with bright valleys and dark ridges can be obtained. Here, in the conventional fingerprint detecting device, as shown in FIG. 6, an elastic layer 2 is provided on the surface of a transparent base 1 to improve the adhesion of the ridge of the fingerprint 3A (for example, see Japanese Patent Application Laid-Open No. 1
No. 45785).
【０００９】稜線部には、図７に示すように、微細な凹
凸３５が存在しており、この凹凸３５に空気が存在する
と稜線部３１において谷間部３２と同様に全反射が発生
し、稜線部と谷間部との区別が付きにくくなる。したが
って、弾性層２を設けて稜線部の密着性を改善すること
により、稜線部３１では全反射が発生せず、通過した光
は指に吸収され、あるいは乱反射するものとなり、鮮明
な画像が得られるものとなる。[0009] As shown in FIG. 7, fine ridges and valleys 35 are present in the ridges. When air is present in the ridges and valleys 35, total reflection occurs in the ridges 31 as in the valleys 32. It becomes difficult to distinguish between the part and the valley. Therefore, by providing the elastic layer 2 to improve the adhesiveness of the ridgeline portion, total reflection does not occur at the ridgeline portion 31, and the passed light is absorbed by the finger or diffusely reflected, and a clear image is obtained. It will be something that can be done.
【００１０】[0010]
【発明が解決しようとする課題】しかしながら、このよ
うな従来の指紋検知装置では、透明基体１の表面に設け
た弾性層２をシリコーンゴムなどの弾性材などから形成
していたことから、埃や指の汚れなどが付着しやすく、
弾性層２の表面を常にクリーニングする必要があり、実
用性に欠けるという問題点があった。これは、弾性層２
としては、細かな指紋の稜線部との密着性を高めるた
め、弾性係数の大きな膜を透明基体１の表面に形成する
必要があり、弾性層２として適切と思われる弾性係数の
大きな膜は、埃や指の汚れなどが付着しやすいという性
質を合わせ持っているからである。However, in such a conventional fingerprint detecting device, since the elastic layer 2 provided on the surface of the transparent substrate 1 is formed from an elastic material such as silicone rubber or the like, dust and dirt are not present. It is easy for dirt on the finger to adhere,
It is necessary to always clean the surface of the elastic layer 2, and there is a problem that it is not practical. This is the elastic layer 2
It is necessary to form a film having a large elastic coefficient on the surface of the transparent substrate 1 in order to enhance the adhesion of the fine fingerprint to the ridge line portion. This is because it has a property that dust and dirt on the finger easily adhere.
【００１１】したがって、乾燥した指については皮膚な
どのカスや埃が、指紋パターンに沿って弾性層２の表面
に付着し、また湿った指については、脂分や汗が弾性層
２の表面に付着し、その表面をこすっても容易に除去す
ることができなくなる。特に、シリコーンゴムやシリコ
ーンゲルは、表面に物を密着させる性質が顕著であり、
当初においては明瞭な指紋パターンが得られるものの、
短時間でその表面に視認可能な汚れが付着し、不明瞭な
指紋パターンしか得られなくなるという問題点があっ
た。本発明はこのような課題を解決するためのものであ
り、明瞭な指紋パターンを長期的に得ることができると
ともに、汚れを容易にクリーニングできる指紋検知装置
を提供することを目的としている。Therefore, for a dry finger, scum and dust such as skin adhere to the surface of the elastic layer 2 along the fingerprint pattern, and for a wet finger, grease and sweat accumulate on the surface of the elastic layer 2. It adheres and cannot be easily removed even if its surface is rubbed. In particular, silicone rubber and silicone gel have a remarkable property of adhering things to the surface,
Although a clear fingerprint pattern is obtained at first,
There is a problem that visible dirt adheres to the surface in a short time, and only an unclear fingerprint pattern can be obtained. An object of the present invention is to solve such a problem, and an object of the present invention is to provide a fingerprint detecting device that can obtain a clear fingerprint pattern for a long period of time and can easily clean dirt.
【００１２】[0012]
【課題を解決するための手段】このような目的を達成す
るために、本発明による指紋検知装置は、請求項１とし
て、透明基体上に形成された光透過性を有する薄膜から
なり指紋稜線部の押圧によりわずかに弾性変形する弾性
層と、この弾性層上に形成された光透過性を有する薄膜
からなり撥水性を有し指紋稜線部の押圧により変形する
潤滑層とを備えるものである。したがって、指紋稜線部
が押圧された場合には、その稜線部の微細な凹凸が潤滑
層を介して弾性層で吸収されるとともに、弾性層に対す
る汚れの付着が潤滑層により抑止される。In order to achieve the above object, a fingerprint detecting device according to the present invention is characterized in that the fingerprint detecting device comprises a light-transmitting thin film formed on a transparent substrate. And a lubricating layer made of a light-transmitting thin film formed on the elastic layer and having water repellency and deforming by pressing the fingerprint ridge. Therefore, when the fingerprint ridge is pressed, fine irregularities on the ridge are absorbed by the elastic layer via the lubricating layer, and the adhesion of dirt to the elastic layer is suppressed by the lubricating layer.
【００１３】また、請求項２として、請求項１記載の指
紋検知装置において、潤滑層を、フッ素系樹脂またはシ
リコーン系離型剤から形成したものである。したがっ
て、光透過性と撥水性とが得られる。また、請求項３と
して、請求項２記載の指紋検知装置において、潤滑層
を、弾性層表面に予めシラン系のカップリング剤を塗布
した後に形成するようにしたものである。したがって、
シラン系のカップリング剤により、弾性層と潤滑層とが
密着される。According to a second aspect of the present invention, in the fingerprint detecting device according to the first aspect, the lubricating layer is formed of a fluorine-based resin or a silicone-based release agent. Therefore, light transmittance and water repellency can be obtained. According to a third aspect of the present invention, in the fingerprint detecting device according to the second aspect, the lubricating layer is formed after a silane-based coupling agent is applied to the surface of the elastic layer in advance. Therefore,
The elastic layer and the lubricating layer are adhered to each other by the silane coupling agent.
【００１４】また、請求項４として、請求項１記載の指
紋検知装置において、潤滑層を、５μｍ以下であって、
好ましくは０．５〜３μｍの膜厚で形成したものであ
る。したがって、指紋稜線部の微細な凹凸が潤滑層を介
して弾性層に伝達される。また、請求項５として、請求
項１記載の指紋検知装置において、弾性層を、５０μｍ
以下であって、好ましくは１０〜２０μｍの膜厚で形成
したものである。したがって、潤滑層を介して伝達され
た指紋稜線部の微細な凹凸が吸収される。According to a fourth aspect, in the fingerprint detecting device according to the first aspect, the lubricating layer has a thickness of 5 μm or less,
Preferably, it is formed with a thickness of 0.5 to 3 μm. Therefore, the fine unevenness of the fingerprint ridge portion is transmitted to the elastic layer via the lubricating layer. According to a fifth aspect of the present invention, in the fingerprint detection device according to the first aspect, the elastic layer has a thickness of 50 μm.
The following, preferably formed with a film thickness of 10 to 20 μm. Therefore, the fine unevenness of the fingerprint ridge transmitted through the lubricating layer is absorbed.
【００１５】[0015]
【発明の実施の形態】次に、本発明について図面を参照
して説明する。図１は本発明の一実施の形態である指紋
検知装置を示す説明図であり、同図において、前述の説
明（図６参照）と同じまたは同等部分には同一符号を付
してあり、１は光学ガラスなどの三角プリズムからなる
透明基体、２は指３の指紋３Ａを密着させるための弾性
層、５は光源４から透明基体１を介して得られた指紋パ
ターンを画像として検出する画像検出部である。Next, the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view showing a fingerprint detecting apparatus according to an embodiment of the present invention. In FIG. 1, the same or equivalent parts as those described above (see FIG. 6) are denoted by the same reference numerals. Is a transparent substrate made of a triangular prism such as optical glass, 2 is an elastic layer for adhering the fingerprint 3A of the finger 3, and 5 is an image detection for detecting a fingerprint pattern obtained from the light source 4 via the transparent substrate 1 as an image. Department.
【００１６】特に、本発明では、前述の説明（図６参
照）と比較して、弾性層２の表面に撥水性を有する潤滑
層１１を設けたものである。まず、弾性層２には、透明
性のある弾性材としてシリコーンゴムやシリコーンゲル
が適している。これらシリコーンゴムやシリコーンゲル
の原料形態としては、一液型や二液型で加熱効果型のも
のが良く知られており、硬化前は液状で粘度が小さいも
のが適している。Particularly, in the present invention, a lubricating layer 11 having water repellency is provided on the surface of the elastic layer 2 as compared with the above description (see FIG. 6). First, silicone rubber or silicone gel is suitable for the elastic layer 2 as a transparent elastic material. As a raw material form of these silicone rubbers and silicone gels, a one-part type or a two-part type and a heating effect type are well known, and those which are liquid and have low viscosity before curing are suitable.
【００１７】弾性層２を形成する場合、まず液状の原料
を透明基体表面に適量垂らし、ローラーコートや回転塗
布などにより、透明基体１の表面に薄く塗布した後、常
温から１５０゜Ｃくらいまでの温度範囲にある所定温度
により加熱硬化させる。弾性層２の膜厚は５０μｍ以下
とすることにより良好な密着性が得られ、特に１０〜２
０μｍが最適である。なお、指紋３Ａの稜線部３１の高
さ（谷間部３２の深さ）は約５０〜１００μｍ、また稜
線部３１のピッチは約１００μｍであり、弾性層２の膜
厚が薄過ぎると弾性変形が小さくなって指紋との密着性
が得られなくなるとともに、膜厚が厚過ぎると弾性変形
が大きくなって指紋に歪みが生じる。When the elastic layer 2 is formed, first, an appropriate amount of a liquid material is dripped on the surface of the transparent substrate, and the liquid material is thinly applied to the surface of the transparent substrate 1 by a roller coating or a spin coating. The resin is cured by heating at a predetermined temperature within a temperature range. By setting the thickness of the elastic layer 2 to 50 μm or less, good adhesion can be obtained.
0 μm is optimal. The height of the ridge 31 of the fingerprint 3A (depth of the valley 32) is about 50 to 100 μm, and the pitch of the ridge 31 is about 100 μm. If the elastic layer 2 is too thin, elastic deformation may occur. When the thickness becomes too small, the adhesion to the fingerprint cannot be obtained, and when the film thickness is too large, the elastic deformation increases and the fingerprint is distorted.
【００１８】一方、潤滑層１１には、フッ素系樹脂やシ
リコーン系の離型剤が適しており、特に、薄膜成形に適
したフッ素系の樹脂として、ハーフルオロ溶媒に溶解さ
せたものが知られている。潤滑層１１の膜厚は５μｍ以
下とすることにより、指紋稜線部の微細な凹凸が潤滑層
を介して弾性層に伝達され、指紋稜線部と弾性層とが確
実に密着される。特に、非晶質特性を有するフッ素樹脂
は、溶解しやすく、また透明性も優れており、回転塗
布、浸漬引き上げ、またはスプレーなどの方法により、
膜厚が約５μｍ以下の薄膜を形成することができるが、
膜厚０．５μｍ未満ではピンホールなどが発生しやす
く、膜厚５μｍを越えるとその表面の凹凸により潤滑層
１１として不適当となる。On the other hand, a fluorine-based resin or a silicone-based release agent is suitable for the lubricating layer 11. In particular, as a fluorine-based resin suitable for forming a thin film, one dissolved in a herfluoro solvent is known. I have. By setting the thickness of the lubricating layer 11 to 5 μm or less, fine irregularities on the fingerprint ridge are transmitted to the elastic layer via the lubricating layer, and the fingerprint ridge and the elastic layer are securely adhered to each other. In particular, a fluororesin having an amorphous property is easily dissolved and has excellent transparency, and is applied by a method such as spin coating, dipping and pulling, or spraying.
Although a thin film having a thickness of about 5 μm or less can be formed,
When the film thickness is less than 0.5 μm, pinholes and the like are liable to occur, and when the film thickness exceeds 5 μm, the lubricating layer 11 becomes unsuitable due to unevenness on the surface.
【００１９】なお、潤滑層１１を形成する場合、弾性層
２表面に、予めシラン系のカップリング剤を塗布してお
くことにより、潤滑層１１と弾性層２との密着性を高め
ることができ、塗布後、１８０゜Ｃくらいまでの温度範
囲で加熱し、溶媒を乾燥させることにより、潤滑層１１
が形成される。シリコーン系の離型剤としては、溶液型
やエマルジョン型が知られており、前述した塗布方法に
より薄膜を形成でき、１５０〜２００゜Ｃの加熱により
潤滑層１１が形成される。この場合にも、シラン系のカ
ップリング剤を利用することにより、弾性層２との密着
性を高めることができる。When the lubricating layer 11 is formed, the adhesion between the lubricating layer 11 and the elastic layer 2 can be improved by applying a silane coupling agent on the surface of the elastic layer 2 in advance. After the application, the lubricating layer 11 is heated in a temperature range up to about 180 ° C. and the solvent is dried.
Is formed. As a silicone release agent, a solution type or an emulsion type is known, and a thin film can be formed by the above-mentioned coating method, and the lubricating layer 11 is formed by heating at 150 to 200 ° C. Also in this case, the adhesion to the elastic layer 2 can be improved by using the silane coupling agent.
【００２０】このように、弾性層２上に撥水性のある潤
滑層１１を設けたので、従来のように数回の指紋検知と
いう短時間に汚れが発生するものと比較して、数１０回
の指紋検知を行った場合でも表面の汚れは目立つほどで
はなく、明瞭な指紋パターンが得られた。また、さらに
指紋検知を実施して視認可能な汚れが付着した場合で
も、柔らかい綿布やティッシュペーパーなどで潤滑層表
面１１Ｓの汚れをふき取ることができ、容易にクリーニ
ングできる。As described above, since the water-repellent lubricating layer 11 is provided on the elastic layer 2, it is several tens of times as compared with the conventional method in which a fingerprint is detected several times and a stain is generated in a short time. Even when the fingerprint detection was performed, the surface dirt was not so noticeable that a clear fingerprint pattern was obtained. In addition, even when fingerprint detection is performed and visible dirt adheres, the dirt on the lubricating layer surface 11S can be wiped off with a soft cotton cloth or tissue paper, and can be easily cleaned.
【００２１】次に、図２を参照して、本発明の動作とし
て、光源４から透明基体１に入射された光の振る舞いに
ついて説明する。光源４から透明基体１に入射された光
は、弾性層２を通過して潤滑層１１の表面１１Ｓに所定
入射角θｄで照射される。この場合、この入射角θｄ
は、潤滑層表面１１Ｓに空気８が接している場合に全反
射が発生する臨界角θｃより大きな角度を有している。Next, with reference to FIG. 2, the behavior of light incident on the transparent substrate 1 from the light source 4 will be described as the operation of the present invention. Light incident on the transparent substrate 1 from the light source 4 passes through the elastic layer 2 and irradiates the surface 11S of the lubricating layer 11 at a predetermined incident angle θd. In this case, the incident angle θd
Has an angle larger than the critical angle θc at which total reflection occurs when the air 8 is in contact with the lubricant layer surface 11S.
【００２２】潤滑層表面１１Ｓ上には指３の指紋が押し
当てられており、前述と同様に、指紋３Ａの稜線部（凸
部）３１と谷間部（凹部）３２とでは、その光の振る舞
いが異なる。まず、谷間部３２の部分では、空気８が潤
滑層表面１１Ｓに接していることから、全反射が発生す
る。一方、稜線部３１では、微細な凹凸３５が潤滑層１
１を介して弾性層２に吸収されており、潤滑層表面１１
Ｓと密着している。The fingerprint of the finger 3 is pressed against the surface 11S of the lubricating layer, and the light behavior at the ridges (convex portions) 31 and the valleys (concave portions) 32 of the fingerprint 3A is the same as described above. Are different. First, since the air 8 is in contact with the lubricating layer surface 11S in the valley portion 32, total reflection occurs. On the other hand, in the ridge 31, fine irregularities 35 are formed on the lubrication layer 1.
1 is absorbed by the elastic layer 2 through the lubricating layer surface 11
Close contact with S.
【００２３】これにより、稜線部３１では、指紋の稜線
部（凸部）の屈折率ｎｒが、空気８の屈折率ｎａより大
きく、光学ガラスなどの透明基体の屈折率ｎｂに近いこ
とから、全反射が発生せず、その部分に照射された光
は、指３に吸収され、あるいは乱反射する。したがっ
て、画像検出部５では、稜線部３１が暗く谷間部３２が
明るい指紋パターンが得られる。Thus, in the ridgeline portion 31, since the refractive index nr of the ridgeline portion (convex portion) of the fingerprint is larger than the refractive index na of the air 8 and close to the refractive index nb of the transparent base such as optical glass, Reflection does not occur, and the light applied to that portion is absorbed by the finger 3 or is irregularly reflected. Therefore, in the image detecting unit 5, a fingerprint pattern in which the ridge portions 31 are dark and the valley portions 32 are bright can be obtained.
【００２４】弾性層２および潤滑層１１の屈折率ｎａ，
ｎｊは、透明基体１の屈折率ｎｂとほぼ等しいものが用
いられる。なお、潤滑層１１の膜厚は、弾性層２と比較
して５μｍ以下と薄く、その中を通過する光の光路長も
極端に短いことから、潤滑層１１における屈折は無視で
きる程度となるため、その屈折率についてはあまり限定
されるものではない。The refractive indices na,
As nj, a refractive index substantially equal to the refractive index nb of the transparent substrate 1 is used. The thickness of the lubricating layer 11 is as thin as 5 μm or less as compared with the elastic layer 2 and the optical path length of light passing therethrough is extremely short, so that the refraction in the lubricating layer 11 is negligible. The refractive index is not so limited.
【００２５】また、弾性層２の屈折率ｎｄについては、
透明基体１の屈折率ｎａとの差により、図３に示すよう
に、透明基体１に入射された光は、透明基体１と弾性層
２との間の境界面１Ｓにて屈折する。この場合、潤滑層
表面１１Ｓへの入射角θｄが得られれば良いことから、
ｎｂ sinθｂ＝ｎｄ sinθｄを満足する入射角θｂに
て、光源４から光を入射すれば良いことがわかる。The refractive index nd of the elastic layer 2 is as follows:
Due to the difference from the refractive index na of the transparent substrate 1, the light incident on the transparent substrate 1 is refracted at the interface 1S between the transparent substrate 1 and the elastic layer 2, as shown in FIG. In this case, since the incident angle θd to the lubricating layer surface 11S only needs to be obtained,
It can be seen that light should be incident from the light source 4 at an incident angle θb satisfying nb sin θb = nd sin θd.
【００２６】この場合、上述した式が満足されることが
前提であり、光源４から入射された光が境界面１Ｓにて
全反射しないような入射角θｂ、屈折率ｎｂ，ｎｄを選
択する必要がある。なお、以上の説明において、透明基
体１として光学ガラスなどからなる三角プリズムを用い
た場合を例に説明したが、これに限定されるものではな
く、例えば、図５に示すように、マイクロプリズムプレ
ートを用いても良い。In this case, it is premised that the above-mentioned expressions are satisfied, and it is necessary to select an incident angle θb and refractive indexes nb and nd such that the light incident from the light source 4 is not totally reflected at the boundary surface 1S. There is. In the above description, the case where a triangular prism made of optical glass or the like is used as the transparent substrate 1 has been described as an example. However, the present invention is not limited to this. For example, as shown in FIG. May be used.
【００２７】図５において、１Ａはマイクロプリズムプ
レートからなる透明基体である。この透明基体１Ａは、
弾性層２が形成される面とは反対側の面に、多数のマイ
クロプリズムが、射出成形などのプラスチック成形技術
により形成されたものであり、厚さが薄いにもかかわら
ず三角プリズムと同等の光学特性を有している。したが
って、前述と同様の作用効果が得られるとともに、装置
の小型化を実現できる。In FIG. 5, reference numeral 1A denotes a transparent base made of a microprism plate. This transparent substrate 1A
On the surface opposite to the surface on which the elastic layer 2 is formed, a large number of microprisms are formed by plastic molding technology such as injection molding, and have the same thickness as a triangular prism despite their small thickness. Has optical properties. Therefore, the same operation and effect as described above can be obtained, and the size of the apparatus can be reduced.
【００２８】なお、以上の説明において、図２に示すよ
うに、例えば指紋３Ａの谷間部３２に存在する空気８と
接する部分でのみ全反射が生じるように光を照射する方
式を例に説明したが、これに限定されるものではなく、
他の方式の指紋検知装置にも本発明を適用することがで
きる。例えば、前述した図５に示すように、全反射を発
生させない入射角、すなわち角度領域ｇｂｈ内から光を
照射し、角度領域ｈｂｉに反射した光を映像として検出
しても良い。In the above description, as shown in FIG. 2, for example, a method of irradiating light so that total reflection occurs only in a portion in contact with air 8 existing in valley 32 of fingerprint 3A has been described. However, it is not limited to this,
The present invention can be applied to other types of fingerprint detection devices. For example, as shown in FIG. 5 described above, light may be emitted from an incident angle that does not cause total reflection, that is, light may be emitted from the angle region gbh, and the light reflected on the angle region hbi may be detected as an image.
【００２９】この場合、谷間部３２と接する部分では、
光が潤滑層表面１１Ｓを透過して谷間部３２に吸収さ
れ、あるいは角度領域ｇｂｈに反射され、稜線部３１と
接する部分において乱反射した光のみが角度領域ｈｂｉ
で検出される。また、角度領域ｈｂｉ内から光を照射
し、同じく角度領域ｈｂｉに反射した光を映像として検
出しても良く、この場合、谷間部３２と接する部分で
は、角度領域ｄｂｆへ全反射し、稜線部３１と接する部
分において乱反射した光のみが角度領域ｈｂｉで検出さ
れる。このように、いずれの方式であっても、弾性層２
上に潤滑層１１を設けることができ、前述と同様の作用
効果を奏することができる。In this case, at the portion in contact with the valley 32,
Light is transmitted through the lubricating layer surface 11S and is absorbed by the valley portion 32 or is reflected by the angle region gbh, and only the light irregularly reflected at the portion in contact with the ridgeline portion 31 is the angle region hbi.
Is detected by Further, light may be emitted from within the angle region hbi, and light reflected on the angle region hbi may be detected as an image. In this case, in the portion in contact with the valley portion 32, the light is totally reflected on the angle region dbf, and the ridge portion Only the light diffusely reflected at the portion in contact with 31 is detected in the angle region hbi. Thus, in either case, the elastic layer 2
The lubricating layer 11 can be provided thereon, and the same operation and effect as described above can be obtained.
【００３０】[0030]
【発明の効果】以上説明したように、本発明は、請求項
１として、透明基体上に弾性を有する薄膜からなる弾性
層を形成するとともに、この弾性層上に撥水性を有する
薄膜からなる潤滑層を設けて、指紋稜線部の押圧時に
は、その稜線部の微細な凹凸を潤滑層を介して弾性層で
吸収するとともに、弾性層に対する汚れの付着を潤滑層
により抑止するようにしたので、従来のように数回の指
紋検知という短時間に汚れが発生するものと比較して、
数１０回の指紋検知を行った場合でも表面の汚れは目立
つほどではなく、明瞭な指紋パターンを得ることができ
るまた、さらに指紋検知を実施して視認可能な汚れが付
着した場合でも、柔らかい綿布やティッシュペーパーな
どで潤滑層表面の汚れをふき取ることができ、容易にク
リーニングできる。As described above, the present invention provides, as a first aspect, a method of forming an elastic layer of a thin film having elasticity on a transparent substrate, and forming a lubricating film of a thin film having water repellency on the elastic layer. By providing a layer, when the fingerprint ridge is pressed, fine irregularities on the ridge are absorbed by the elastic layer via the lubricating layer, and the adhesion of dirt to the elastic layer is suppressed by the lubricating layer. Compared to the case where dirt occurs in a short time of several fingerprint detections like
Even when fingerprint detection is performed several tens of times, the surface dirt is not so noticeable that a clear fingerprint pattern can be obtained. Even when fingerprint detection is performed and visible dirt adheres, a soft cotton cloth is used. The surface of the lubricating layer can be wiped off with a paper or tissue paper, and can be easily cleaned.
【００３１】また、請求項２として、請求項１記載の指
紋検知装置において、潤滑層を、フッ素系樹脂またはシ
リコーン系離型剤から形成したので、良好な光透過性と
撥水性とが得られるものとなり、さらに低い反応性とあ
る程度高い沸点を有していることから、長期間にわたり
安定した効果が得られる。また、請求項３として、請求
項２記載の指紋検知装置において、潤滑層を、弾性層表
面に予めシラン系のカップリング剤を塗布した後に形成
するようにしたので、潤滑層として比較的反応性の低い
材料を用いた場合でも、弾性層と潤滑層との間で良好な
密着が得られる。According to a second aspect of the present invention, in the fingerprint detecting device according to the first aspect, since the lubricating layer is formed of a fluorine-based resin or a silicone-based release agent, good light transmittance and water repellency can be obtained. And has a lower reactivity and a somewhat higher boiling point, so that a stable effect can be obtained over a long period of time. According to a third aspect of the present invention, in the fingerprint detecting device according to the second aspect, the lubricating layer is formed after a silane-based coupling agent is applied to the surface of the elastic layer in advance, so that the lubricating layer is relatively reactive. Good adhesion can be obtained between the elastic layer and the lubricating layer even when a material having a low viscosity is used.
【００３２】また、請求項４として、請求項１記載の指
紋検知装置において、潤滑層を、５μｍ以下であって、
好ましくは０．５〜３μｍの膜厚で形成したので、指紋
稜線部の微細な凹凸が潤滑層を介して弾性層に伝達さ
れ、指紋稜線部と弾性層とが確実に密着される。また、
請求項５として、請求項１記載の指紋検知装置におい
て、弾性層を、５０μｍ以下であって、好ましくは１０
〜２０μｍの膜厚で形成したので、指紋パターンに歪み
を生じることなく、潤滑層を介して伝達された指紋稜線
部の微細な凹凸を弾性層により確実に吸収できる。According to a fourth aspect, in the fingerprint detecting device according to the first aspect, the lubricating layer has a thickness of 5 μm or less,
Since the film is preferably formed with a thickness of 0.5 to 3 μm, fine irregularities on the fingerprint ridge are transmitted to the elastic layer via the lubricating layer, and the fingerprint ridge and the elastic layer are securely adhered to each other. Also,
According to a fifth aspect of the present invention, in the fingerprint detection device according to the first aspect, the elastic layer has a thickness of 50 μm or less, preferably 10 μm or less.
Since the film is formed to have a thickness of about 20 μm, fine elasticity of the fingerprint ridge transmitted through the lubricating layer can be reliably absorbed by the elastic layer without causing distortion in the fingerprint pattern.
【図面の簡単な説明】[Brief description of the drawings]
【図１】 本発明の一実施の形態による指紋検知装置を
示す説明図である。FIG. 1 is an explanatory diagram showing a fingerprint detection device according to an embodiment of the present invention.
【図２】 潤滑層表面における光の振る舞いを示す説明
図である。FIG. 2 is an explanatory diagram showing the behavior of light on the surface of a lubrication layer.
【図３】 透明基体と弾性層との境界面における光の振
る舞いを示す説明図である。FIG. 3 is an explanatory diagram showing a behavior of light at a boundary surface between a transparent substrate and an elastic layer.
【図４】 本発明の他の実施の形態による指紋検知装置
を示す説明図である。FIG. 4 is an explanatory diagram showing a fingerprint detection device according to another embodiment of the present invention.
【図５】 透明基体と空気との境界面における光の振る
舞いを示す説明図である。FIG. 5 is an explanatory diagram showing the behavior of light on a boundary surface between a transparent substrate and air.
【図６】 従来の指紋検知装置を示す説明図である。FIG. 6 is an explanatory diagram showing a conventional fingerprint detection device.
【図７】 従来の弾性層表面を示す説明図である。FIG. 7 is an explanatory view showing a conventional elastic layer surface.
１，１Ａ…透明基体、１Ｓ…透明基体表面、２…弾性
層、３…指、３Ａ…指紋、３１…稜線部（凸部）、３２
…谷間部（凹部）、３５…稜線部の微細な凹凸、４…光
源、５…画像検出部、８…空気、１１…潤滑層、１１Ｓ
…潤滑層表面。1, 1A: Transparent substrate, 1S: Transparent substrate surface, 2: Elastic layer, 3: Finger, 3A: Fingerprint, 31: Ridge (convex), 32
.. Valleys (recesses), 35... Fine ridges and ridges, 4. Light source, 5... Image detector, 8. Air, 11.
... the surface of the lubrication layer.
Claims (5)
し、その反射光から指紋パターンを検出する指紋検知装
置において、 透明基体上に形成された光透過性を有する薄膜からなり
指紋稜線部の押圧によりわずかに弾性変形する弾性層
と、 この弾性層上に形成された光透過性を有する薄膜からな
り撥水性を有し指紋稜線部の押圧により変形する潤滑層
とを備えることを特徴とする指紋検知装置。1. A fingerprint detecting device for irradiating a finger print of a finger with light through a transparent substrate and detecting a fingerprint pattern from the reflected light, comprising a light transmitting thin film formed on the transparent substrate and a fingerprint ridge line. An elastic layer that is slightly elastically deformed by pressing the part, and a lubricating layer that is formed of a light-transmitting thin film formed on the elastic layer, has water repellency, and is deformed by pressing the fingerprint ridge. Fingerprint detection device.
なることを特徴とする指紋検知装置。2. The fingerprint detection device according to claim 1, wherein the lubricating layer is made of a fluorine-based resin or a silicone-based release agent.
を塗布した後に形成されることを特徴とする指紋検知装
置。3. The fingerprint detection device according to claim 2, wherein the lubricating layer is formed after applying a silane coupling agent to the surface of the elastic layer in advance.
μｍの膜厚を有することを特徴とする指紋検知装置。4. The fingerprint detecting device according to claim 1, wherein the lubricating layer has a thickness of 5 μm or less, preferably 0.5 to 3 μm.
A fingerprint detection device having a thickness of μm.
弾性層は、５０μｍ以下であって、好ましくは１０〜２
０μｍの膜厚を有する ことを特徴とする指紋検知装置。5. The fingerprint detecting device according to claim 1, wherein
The elastic layer has a thickness of 50 μm or less, preferably 10 to 2 μm.
A fingerprint detection device having a thickness of 0 μm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP09075356A JP3132411B2 (en) | 1997-03-27 | 1997-03-27 | Fingerprint detection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP09075356A JP3132411B2 (en) | 1997-03-27 | 1997-03-27 | Fingerprint detection device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10269340A true JPH10269340A (en) | 1998-10-09 |
| JP3132411B2 JP3132411B2 (en) | 2001-02-05 |
Family
ID=13573879
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP09075356A Expired - Fee Related JP3132411B2 (en) | 1997-03-27 | 1997-03-27 | Fingerprint detection device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3132411B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6844744B2 (en) | 2002-02-08 | 2005-01-18 | Nippon Telegraph And Telephone Corporation | Surface shape recognition sensor and method of manufacturing the same |
| US7660447B2 (en) * | 2005-10-04 | 2010-02-09 | Fujitsu Limited | Detection of fingerprint distortion by deformation of elastic film or displacement of transparent board |
| KR20150108030A (en) * | 2015-03-13 | 2015-09-24 | 주식회사 유니온커뮤니티 | Pattern Image Acquisition Apparatus and Method Comprising Dual Elastic Structure |
| JP5788128B1 (en) * | 2014-04-22 | 2015-09-30 | シャープ株式会社 | Synthetic polymer film having surface with bactericidal action, laminate having synthetic polymer film, sterilization method using surface of synthetic polymer film and method for reactivating surface of synthetic polymer film |
| JP2021111383A (en) * | 2020-01-10 | 2021-08-02 | ベクフン リ | Stamp image acquisition device with excellent clarity and cushioning |
-
1997
- 1997-03-27 JP JP09075356A patent/JP3132411B2/en not_active Expired - Fee Related
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6844744B2 (en) | 2002-02-08 | 2005-01-18 | Nippon Telegraph And Telephone Corporation | Surface shape recognition sensor and method of manufacturing the same |
| US7660447B2 (en) * | 2005-10-04 | 2010-02-09 | Fujitsu Limited | Detection of fingerprint distortion by deformation of elastic film or displacement of transparent board |
| JP5788128B1 (en) * | 2014-04-22 | 2015-09-30 | シャープ株式会社 | Synthetic polymer film having surface with bactericidal action, laminate having synthetic polymer film, sterilization method using surface of synthetic polymer film and method for reactivating surface of synthetic polymer film |
| JP2016120478A (en) * | 2014-04-22 | 2016-07-07 | シャープ株式会社 | Synthetic polymer membrane having surface with bactericidal action, laminate having synthetic polymer membrane, sterilization method by using surface of synthetic polymer membrane, method for reactivating surface of synthetic polymer membrane, mold for producing synthetic polymer membrane, and method for producing mold |
| JP6359787B1 (en) * | 2014-04-22 | 2018-07-18 | シャープ株式会社 | Film having synthetic polymer film, laminate having synthetic polymer film, sterilization method using film surface and method for reactivating film surface |
| JP6420931B1 (en) * | 2014-04-22 | 2018-11-07 | シャープ株式会社 | Surface treatment method of synthetic polymer membrane |
| JP2018183996A (en) * | 2014-04-22 | 2018-11-22 | シャープ株式会社 | Film having synthetic polymer membrane, laminate having synthetic polymer membrane, sterilization method using film surface and film surface reactivation method |
| JP6453517B1 (en) * | 2014-04-22 | 2019-01-16 | シャープ株式会社 | Synthetic polymer film, laminate having synthetic polymer film, sterilization method using surface of synthetic polymer film, and method for reactivating surface of synthetic polymer film |
| JP2019007022A (en) * | 2014-04-22 | 2019-01-17 | シャープ株式会社 | Surface treatment method of synthetic polymer membrane |
| JP2019035081A (en) * | 2014-04-22 | 2019-03-07 | シャープ株式会社 | Synthetic polymer membrane, laminate having synthetic polymer membrane, sterilization method using surface of synthetic polymer membrane, and reactivation method of surface of synthetic polymer membrane |
| KR20150108030A (en) * | 2015-03-13 | 2015-09-24 | 주식회사 유니온커뮤니티 | Pattern Image Acquisition Apparatus and Method Comprising Dual Elastic Structure |
| JP2021111383A (en) * | 2020-01-10 | 2021-08-02 | ベクフン リ | Stamp image acquisition device with excellent clarity and cushioning |
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