200825942 九、發明說明： 【發明所屬之技術領域】 本發明係有關一種微小型指紋辨識光學結構，尤指一種 於辨識前供指紋影像聚焦成像之微小型光學結構。 【先前技術】 如第6圖所示，為習用之稜鏡3 〇，其上有一辨識區3 1，並另設有一光源3 2、一供聚光之透鏡3 3與—供聚 焦成像之影像感測器3 4。 本習知技術係利用全内反射式（Frustrated Total Internal Renacti〇n，簡稱FTIR)，而當光照射到辨識區 3 1時，對應到手指指紋谷線3 5 1的光會產生反射，對 應到手指指紋脊線3 5 2的光會產生散射與折射，其中大 部分為折射光，少部分為散射光，並藉稜鏡3 〇 一端之透 鏡3 3將上述之反射光與散射光聚焦成像於影像感測器3 4上，其中影像感測器3 4上較亮的部分為對應谷線3 5 1之反射光，較暗的部分為對應脊線3 5 2之散射光。 但以全内反射式進行指紋辨識時，因對應於指紋之谷 線3 5 1與脊線3 5 2分別有光線之反射與散射產生，而 於最終成像時，將會產生明暗對比不夠以及存在過多灰色 地帶之問題，如此電腦於進行辨識時易產生誤判，而造成 辨識效率之降低。 緣是，如何解決上述指紋辨識不佳之問題實為重要。 5 200825942 【發明内容】 本發明之主要目的，在於解決上述的問題而提供一種 微小型指紋辨減學結構，係利用表面增強不㈣反射並 搭配本發明之衫結構1提高缺_的品質與效率。 本發明之次-目的，藉由本發明之光束導引機制，可 供含有指紋影像之光束-較佳之光導引路徑，可避免混雜200825942 IX. Description of the Invention: [Technical Field] The present invention relates to a micro-miniature fingerprint identification optical structure, and more particularly to a micro-miniature optical structure for focusing imaging of a fingerprint image before recognition. [Prior Art] As shown in Fig. 6, it is a conventional 稜鏡3 〇, which has a recognition area 3 1, and is provided with a light source 3 2, a lens for collecting light 3 3 and an image for focusing imaging. Sensor 34. The prior art utilizes Frustrated Total Internal Renacti〇n (FTIR), and when light is incident on the recognition zone 31, light corresponding to the finger fingerprint valley 353 will produce reflection, corresponding to The light of the finger fingerprint ridge 3 5 2 will produce scattering and refraction, most of which is refracted light, a small part is scattered light, and the reflected light and scattered light are focused by the lens 3 3 at the end of the 3 〇 On the image sensor 34, wherein the brighter portion of the image sensor 34 is the reflected light corresponding to the valley line 35, and the darker portion is the scattered light corresponding to the ridge line 325. However, when fingerprint recognition is performed by total internal reflection, light rays are reflected and scattered by the valley line 3 5 1 and the ridge line 3 5 2 corresponding to the fingerprint, respectively, and the final contrast will result in insufficient contrast and presence of light and dark. The problem of too much gray area, so that the computer is easy to produce misjudgment when identifying, which leads to the reduction of identification efficiency. The reason is how to solve the above problem of poor fingerprint recognition is really important. 5 200825942 SUMMARY OF THE INVENTION The main object of the present invention is to solve the above problems and provide a micro-small fingerprint subtraction structure, which utilizes surface enhancement not (four) reflection and is combined with the shirt structure of the present invention to improve the quality and efficiency of the lack of _ . The second-purpose object of the present invention is that the beam guiding mechanism of the present invention can provide a beam containing a fingerprint image - a preferred light guiding path to avoid mixing
過多非指紋影像之散射光’故可提供較佳且清晰之指紋影 像，以便後續之指紋辨識工作。 為達前述之目的，本發明係包括： 數光源； 一棱鏡，係包含一可進行表面增強不規則反射並位於 稜鏡頂面之辨識區以及一第一鏡面與一第二鏡面，其中該 第一鏡面位於該辨識區一侧並相連接，並與該辨識區形成 一夾角0，且經該第一鏡面反射之光束係與該辨識區之平 面成一夾角α，又該稜鏡於該第一鏡面之相對遠離侧具有 該第二鏡面，另，各該光源係位於該稜鏡外並對應該第一 鏡面而可供光束射入； 一反射鏡，係於該第二鏡面之一侧傾斜設置，並可將 經該第二鏡面射出之光束反射； 一聚光透鏡，其一面係與該反射鏡相對應，並可將經 該反射鏡反射之光束聚焦； 一影像感測器，係與該聚焦透鏡之另一面相對應，並 6 200825942 紋影像的光束成像於其 可供經該聚光透鏡聚焦後之帶有指 上0 —本發明之上述及其他目的與優點，不難從下述所選用 貫施例之詳細說明與關中，獲得深入了解。 當然，本發明在某些另件上，或另件之安排上容許有 所不同，但所制之實施例’料本制 說明，並於附圖中展示其構造。 平、、、田 【實施方式】 請參閱第1圖至第5圖，圖中所示者為本發明所選用 之實施例結構，此僅供說明之用，在專射請上並不受此 種結構之限制。 ^凊參閱第1圖至第3圖，係本發明微小型指紋辨識光 學結構之一實施例，其係包括··數光源1 〇，於本實施例 中係為四個L E D光源；一梯形結構之稜鏡i i，係包含 一位於稜鏡1 1頂面可進行表面增強不規則反射（SurfaceExcessive non-fingerprint image scattered light' provides a better and clearer fingerprint image for subsequent fingerprinting. For the purpose of the foregoing, the present invention includes: a plurality of light sources; a prism comprising: an identification region capable of surface-enhanced irregular reflection and located on the dome surface; and a first mirror surface and a second mirror surface, wherein the a mirror surface is located on one side of the identification area and connected to each other, and forms an angle 0 with the identification area, and the beam path reflected by the first specular surface forms an angle α with the plane of the identification area, and the first The second mirror surface is disposed on a relatively distant side of the mirror surface, and each of the light sources is located outside the ridge and corresponds to the first mirror surface for the light beam to enter; a mirror is disposed on one side of the second mirror surface And reflecting the light beam emitted through the second mirror surface; a collecting lens having a side corresponding to the mirror and focusing the light beam reflected by the mirror; an image sensor and the The other side of the focusing lens corresponds to, and the light beam of the 200825942 image is imaged on the finger with the focus of the lens. The above and other objects and advantages of the present invention are not difficult to obtain from Selection For a detailed explanation of the example and Guanzhong, get a deeper understanding. Of course, the invention may be varied on certain components, or in the arrangement of the components, but the embodiments are described in the context of the present invention and the construction thereof is shown in the drawings. [Embodiment] Please refer to Fig. 1 to Fig. 5, which shows the structure of the embodiment selected for the present invention. This is for illustrative purposes only. The limitations of the structure. 1 to 3, which is an embodiment of the micro-miniature fingerprint recognition optical structure of the present invention, which includes a digital light source 1 〇, which in this embodiment is a four LED light source; a ladder structure稜鏡ii, contains a surface-enhanced irregular reflection on the top surface of 稜鏡1 1 (Surface)
Enhanced Irregular Ref lection，簡稱 S E I R )之辨識 區111以及一第一鏡面112與一第二鏡面ii3，其 中該第一鏡面112位於該辨識區111下方一側並相連 接，且與该辨識區1 1 1之間形成一夾角0，又該稜鏡1 1於該第一鏡面1 1 2之相對遠離侧具有該第二鏡面1工 3;各該光源1〇之光束穿過該第一鏡面112並投射至 該辨識區1 1 1時，將於手指2 〇指紋與該辨識區1 1工 間產生一不規則反射之反射光束2 1，即為散射式之反 7 200825942 射，又該辨識區1 1 1之指紋影像係藉反射光束2 i反射 導引至該第一鏡面1 1 2，並經第一鏡面i丄2反射後由 卓一鏡面1 1 3射出’其中經該第一鏡面1 1 2反射之反 射光束2 1其路徑係與辨識區之平面方向成一夾角α，且 上述之夾角θ = 42度以及夾角α = 6度時，為最佳之光 束路徑；另外，各該光源係位於該稜鏡外並對應該第一鏡 面而可供光束經此射入稜鏡内； 一反射鏡1 2，係於該第二鏡面1 1 3之外侧傾斜設 置’且該反射鏡1 2之反射面係與該第二鏡面1 1 3傾斜 相對應，並可將經該第二鏡面113射出之光束21進行 向下反射； 一聚光透鏡1 3，其一面係與該反射鏡1 2相對應， 並可將經該反射鏡12反射之光束21聚焦；一影像感測 器1 4 ’係與該聚光透鏡1 3之另一面相對應，並可供經 該聚光透鏡1 3聚焦後之含有指紋影像的光束2 1成像於 該影像感測器1 4上，且該影像感測器1 4係一感光躺合 元件（Charge Coupled Device，簡稱 C C D )或一互補式 金屬氧化物半導體元件（Complementary Metal Oxide Semiconductor ，簡稱 C Μ 0 S )。 請參閱第3圖，各該光源1 〇發光時，光向周圍發散 ’其中經該第一鏡面1 1 2折射進入該稜鏡1 1内且照射 於該辨識區1 1 1上之光束，係於手指2 〇指紋與該辨識 區1 1 1間形成一SE I R式之反射光束2 1，且反射光 束21另受該第一鏡面112反射後經該第二鏡面113 8 200825942 牙透而出’並經該反射鏡1 2反射到該聚光透鏡1 3上， 再經聚光透鏡1 3聚焦後成像於該影像感測器1 4上。 承上述，因本發明採用S E I R式對指紋影像進行散 射式之成像’其中當光照射到指紋谷線時係直接穿透並折 射進入皮膚内，當光照射到指紋脊線時會產生散射與折射 ’其中折射光於折射後被皮膚吸收而僅存散射光，且於影 像感測器上成像時，會出現對應到脊線上較暗的散射光以 及對應到吞線上完全沒有光打到之部分，而藉此成像時光 之有無，可提鬲指紋影像其明暗之對比程度。 綜上所述’於成像時，因影像感測器上幾無打到谷線 的光’所以其明暗對比將會很明顯，因此電腦於辨別時將 不易產生誤判，故可提高指紋辨識之效率。 此外’藉由上述之光束導引機制，可供含有指紋影像 之光束一較佳之光導引路徑，可避免混雜過多非指紋影像 之散射光，故可提供較佳指紋影像之成像品質，以便後續 訊號處理之指紋辨識工作。 當然’本發明仍存在許多例子，其間僅細節上之變化 。請參閱第4圖’其係本發明之第二實施例，其中於該棱 鏡1 1之第二鏡面1 1 3上形成有一可供經該第一鏡面1 1 2反射之光束2 1聚焦之單面凸透鏡1 1 4。 藉此單面凸透鏡1 1 4之設置，可提供經該第一鏡面 1 1 2反射之光束2 1預先聚焦之功能，並搭配後面之聚 光透鏡1 3以形成兩段式之光束聚焦，藉以提高指紋影像 9 200825942 其成像於影像感測器14上之品質與清晰度。 請參閱第5圖，係本發明之第三實施例，其中於該稜 鏡1 1外並對應該第一鏡面1 1 2處設有一可將光源1 〇 於發光後其偏離之光束2 2重新反射回稜鏡1 1内之反射 播板1 5。 藉此反射擔板1 5之設置，可將光源1 〇於發光後其 無射入至稜鏡1 1之部分光束2 2，藉該反射擋板1 5之 反射重新導引入該稜鏡1 1内，並照射於該辨識區1 1 1 上’藉以提高辨識區1 1 1之光的均勻度與亮度，進而提 高指紋影像其最終成像的品質。 以上所述實施例之揭示係用以說明本發明，並非用以 限制本發明，故舉凡數值之變更或等效元件之置換仍應隸 屬本發明之範疇。 由以上詳細說明，可使熟知本項技藝者明瞭本發明的 痛可達成前述目的，實已符合專利法之規定，爰提出專利 申請。 【圖式簡單說明】 第1圖係本發明之光學結構的立體示意圖。 第2圖係第一鏡面與辨識區之夾角0以及經第一鏡面反射 之光束與辨識區平面方向的夹角α示意圖。 第3圖係光束於辨識區反射後之光束路徑示意圖。 第4圖係於第二鏡面上增設—單面凸透鏡之示意圖。 第5圖係增設-可將光源於發光後其偏離之光束反射回稜鏡内 200825942 之反射擔板的示意圖。 第6圖係習用稜鏡以全内反射式進行指紋辨識前之聚焦成 像示意圖。 【主要元件符號說明】 (習用部分） 棱鏡3 0 辨識區3 1The identification area 111 of the Enhanced Irregular Ref lection (SEIR) and a first mirror 112 and a second mirror ii3, wherein the first mirror 112 is located on the lower side of the identification area 111 and connected to the identification area 1 1 An angle 0 is formed between the two, and the second surface of the first mirror 1 1 2 has the second mirror 1; each of the light beams of the light source passes through the first mirror 112. When projecting to the identification area 1 1 1 , an irregularly reflected reflected beam 2 1 is generated between the finger 2 〇 fingerprint and the identification area 1 1 , which is a scattering type inverse 7 200825942, and the identification area 1 The fingerprint image of 1 1 is guided by the reflected beam 2 i to the first mirror 1 1 2, and is reflected by the first mirror i 丄 2 and then emitted by the mirror 1 1 3 'through the first mirror 1 1 2 The reflected reflected beam 2 1 has an angle α with the plane direction of the identification region, and the angle between the above-mentioned angle θ = 42 degrees and the angle α = 6 degrees is the best beam path; in addition, each of the light sources is located The outer surface of the cymbal and the first mirror surface are available for the beam to be injected into the raft; The mirror 1 2 is disposed obliquely on the outer side of the second mirror 1 1 3 and the reflecting surface of the mirror 12 corresponds to the second mirror 1 1 3 and may pass through the second mirror 113 The emitted light beam 21 is reflected downward; a collecting lens 13 has a side corresponding to the mirror 12 and can focus the light beam 21 reflected by the mirror 12; an image sensor 1 4 ' Corresponding to the other side of the concentrating lens 13 , and the light beam 2 1 containing the fingerprint image after being focused by the condensing lens 13 is imaged on the image sensor 14 , and the image sensing is performed. The device 1 is a Charge Coupled Device (CCD) or a Complementary Metal Oxide Semiconductor (C Μ 0 S ). Referring to FIG. 3, when each of the light sources 1 〇 emits light, the light diverges to the periphery. The light beam that is refracted into the 稜鏡1 1 through the first mirror surface 112 and illuminates the identification area 1 1 1 is An SE IR-type reflected beam 2 1 is formed between the fingerprint 2 〇 fingerprint and the identification area 1 1 1 , and the reflected beam 21 is further reflected by the first mirror 112 and then penetrates through the second mirror 113 8 200825942 And being reflected by the mirror 12 to the collecting lens 13 and then being focused by the collecting lens 13 and imaged on the image sensor 14. According to the above invention, the SEIR type is used for the scattering imaging of fingerprint images, wherein when the light is irradiated onto the fingerprint valley line, it directly penetrates and refracts into the skin, and when the light illuminates the fingerprint ridge line, scattering and refraction are generated. 'Where the refracted light is absorbed by the skin after refraction and only scattered light is stored, and when imaged on the image sensor, there will be scattered light corresponding to the dark line on the ridge line and corresponding to the portion of the swallowing line that has no light at all. By taking advantage of the time of imaging, the degree of contrast between the brightness and the brightness of the fingerprint image can be improved. In summary, when the image is imaged, there is no light on the image sensor, so the contrast between light and dark will be obvious. Therefore, the computer will not be easy to misjudge when distinguishing, so the efficiency of fingerprint recognition can be improved. . In addition, by the above-mentioned beam guiding mechanism, a better light guiding path for the beam containing the fingerprint image can be avoided, and the scattered light of the non-fingerprint image can be avoided, so that the image quality of the better fingerprint image can be provided for subsequent Fingerprint identification for signal processing. Of course, there are still many examples of the present invention, only the details of which vary. Referring to FIG. 4, which is a second embodiment of the present invention, a second lens 1 1 3 of the prism 11 is formed with a single spot for focusing the light beam 2 1 reflected by the first mirror 112. Convex lens 1 1 4. The arrangement of the single-sided convex lens 1 14 can provide the function of pre-focusing the light beam 2 1 reflected by the first mirror surface 112, and is matched with the rear collecting lens 13 to form a two-stage beam focusing. Enhance the quality and clarity of the fingerprint image 9 200825942 imaged on the image sensor 14. Referring to FIG. 5, a third embodiment of the present invention, wherein the first mirror 1 1 2 is disposed outside the 稜鏡1 1 and a light beam 2 2 which can deflect the light source 1 after being illuminated is re-applied. Reflected back to the reflection board 1 in the 稜鏡1 1 . By means of the arrangement of the reflection plate 15 , the light source 1 can be immersed in the partial light beam 2 2 of the 稜鏡 1 1 after being illuminated, and the 稜鏡 1 is reintroduced by the reflection of the reflection baffle 15 1 and irradiated on the identification area 1 1 1 to improve the uniformity and brightness of the light of the recognition area 1 1 1 , thereby improving the quality of the final image of the fingerprint image. The above description of the embodiments is intended to be illustrative of the invention, and is not intended to limit the scope of the invention. From the above detailed description, it will be apparent to those skilled in the art that the pain of the present invention can achieve the aforementioned objects, and it has been in compliance with the provisions of the Patent Law and has filed a patent application. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing the optical structure of the present invention. Fig. 2 is a schematic diagram showing the angle α between the first mirror surface and the recognition area and the angle α between the beam reflected by the first specular surface and the plane direction of the recognition area. Figure 3 is a schematic diagram of the beam path after the beam is reflected by the recognition zone. Figure 4 is a schematic view of the addition of a single-sided convex lens on the second mirror surface. Figure 5 is an add-on diagram that reflects the deflected light beam of the source after it has been illuminated back into the reflector of the 200825942. Figure 6 is a schematic diagram of the focused imaging before fingerprinting with total internal reflection. [Main component symbol description] (customized part) Prism 3 0 Identification area 3 1
光源3 2 影像感測器3 4 脊線3 5 2 (本發明部分） 光源1 0 辨識區1 1 1 第二鏡面1 1 3 反射鏡1 2 影像感測器1 4 手指2 0 光束2 2 透鏡3 3 谷線3 5 1 稜鏡1 1 第一鏡面1 1 2 單面凸透鏡114 聚光透鏡13 反射擋板15 光束2 1 11Light source 3 2 Image sensor 3 4 Ridge 3 5 2 (part of the invention) Light source 1 0 Identification area 1 1 1 Second mirror 1 1 3 Mirror 1 2 Image sensor 1 4 Finger 2 0 Beam 2 2 Lens 3 3 valley line 3 5 1 稜鏡 1 1 first mirror 1 1 2 single lenticular lens 114 concentrating lens 13 reflecting baffle 15 beam 2 1 11