CN102043947A - A small fingerprint collector - Google Patents

Abstract

The utility model provides a small-size fingerprint collection ware, including the prism, the formation of image objective, image acquisition unit and light source, the prism is six trapezoidal prisms, light path between prism and formation of image objective is equipped with the plane mirror, the light that the light source sent gets into the prism through the little terminal surface of prism, be pressed the partly of the finger reflection light on the big terminal surface of prism, on penetrating out the plane mirror by the downside of prism, get into the formation of image objective through the plane mirror total reflection, form an image on image acquisition unit's image receiving face, image acquisition unit converts the image of receiving into the signal of telecommunication output. The planar reflector is adopted, the light source and the image acquisition unit share one main board, and the imaging objective base is clamped and fixed by the shell and the positioning holes in the main board of the image acquisition unit, so that the space utilization efficiency can be improved, the cost is saved, and the miniaturization of the fingerprint collector is effectively realized. In addition, the imaging lens group is positioned by the imaging objective lens, so that fingerprint images are collected without focusing, the production efficiency can be improved, and the cost can be further saved.

Description

Translated fromChinese

一种小型指纹采集器A small fingerprint collector

技术领域technical field

本发明涉及应用电子电路进行指纹识别的装置，特别是涉及一种小型指纹采集器。The invention relates to a device for fingerprint identification using an electronic circuit, in particular to a small fingerprint collector.

背景技术Background technique

现有以生理特征的识别技术中，指纹识别技术是目前最成熟的一种。然而，现有指纹采集器的光路设计不甚合理，指纹光学成像质量较差，有效用户指纹难以被安全识别，给用户正常使用带来不便，而且，其结构比较复杂，体积也比较大，生产成本比较高，在小型化的指纹识别系统中难以大量推广使用。Among the existing identification technologies based on physiological characteristics, fingerprint identification technology is currently the most mature one. However, the optical path design of the existing fingerprint collector is unreasonable, the quality of fingerprint optical imaging is relatively poor, and the effective user fingerprint is difficult to be safely identified, which brings inconvenience to the normal use of the user. Moreover, its structure is relatively complicated and the volume is relatively large. The cost is relatively high, and it is difficult to popularize and use it in a miniaturized fingerprint identification system.

发明内容Contents of the invention

本发明所要解决的技术问题是弥补上述现有技术的缺陷，提供一种小型指纹采集器。The technical problem to be solved by the present invention is to provide a small fingerprint collector to make up for the above-mentioned defects of the prior art.

本发明技术问题通过以下技术方案予以解决。The technical problem of the present invention is solved by the following technical solutions.

这种小型指纹采集器，包括壳体和设置在所述壳体内的光学指纹成像模块，所述光学指纹成像模块包括顺应光路设置的棱镜、成像物镜、图像采集单元和光源，所述棱镜是纵截面底边大于高的均匀对称的六面梯形棱镜，包括有相互平行正对的大端面、小端面、下侧面和其余三个侧面，所述大端面是图像采集面，所述小端面是光源射入面，所述下侧面是与成像物镜相对的成像面。This small fingerprint collector includes a housing and an optical fingerprint imaging module arranged in the housing. The optical fingerprint imaging module includes a prism arranged along the optical path, an imaging objective lens, an image acquisition unit and a light source. The prism is a longitudinal A uniform and symmetrical six-sided trapezoidal prism with a cross-sectional base greater than the height, including a large end face, a small end face, a lower side and the remaining three sides parallel to each other, the large end face is the image collection surface, and the small end face is the light source As for the incident surface, the lower side is the imaging surface opposite to the imaging objective lens.

这种小型指纹采集器的特点是：The characteristics of this small fingerprint collector are:

在所述棱镜和所述成像物镜之间的光路设有平面反射镜，所述光源发出的光经所述棱镜的小端面进入棱镜，被按压在所述棱镜的大端面上的指头反射光线的一部分，由所述棱镜的下侧面射出到所述平面反射镜上，经所述平面反射镜全反射进入所述成像物镜，并经成像物镜消畸变、色差，成像于所述图像采集单元的图像接收面上，所述图像采集单元将接收到的图像转换成电信号输出。采用平面反射镜进行全反射，光路呈折线，相比直线光路可以明显缩短指纹采集器的纵向尺寸，实现小型化。The optical path between the prism and the imaging objective lens is provided with a plane reflector, the light emitted by the light source enters the prism through the small end face of the prism, and is pressed against the large end face of the prism to reflect the light A part is emitted from the lower side of the prism onto the plane reflector, is totally reflected by the plane reflector and enters the imaging objective lens, and is imaged on the image of the image acquisition unit through the imaging objective lens to eliminate distortion and chromatic aberration. On the receiving surface, the image acquisition unit converts the received image into an electrical signal for output. The flat mirror is used for total reflection, and the optical path is a broken line. Compared with the linear optical path, the longitudinal dimension of the fingerprint collector can be significantly shortened to achieve miniaturization.

本发明技术问题通过以下进一步的技术方案予以解决。The technical problem of the present invention is solved by the following further technical solutions.

所述平面反射镜是只有一个反射镜面的长方体状薄平面镜，平面反射镜与主光轴倾角为137.25°，其反射的光线直接进入成像物镜。The plane reflector is a rectangular parallelepiped thin plane mirror with only one mirror surface. The inclination angle between the plane reflector and the main optical axis is 137.25°, and the reflected light directly enters the imaging objective lens.

所述光源是至少1个可见光或红外光的发光二极管(light emitting diode，缩略词为LED)光源，焊接在图像采集单元主板上，位于所述棱镜的小端面上方，所述光源与所述图像采集单元共用一个主板和电源，可以进一步实现指纹采集器小型化。可见光或红外光的LED光源可作为持续的光源，提供小型指纹采集器长时间使用。The light source is at least one light emitting diode (light emitting diode, abbreviated as LED) light source of visible light or infrared light, which is welded on the main board of the image acquisition unit and located above the small end face of the prism. The image acquisition unit shares a main board and power supply, which can further realize the miniaturization of the fingerprint collector. The LED light source of visible light or infrared light can be used as a continuous light source, providing the small fingerprint collector with long-term use.

所述光源和成像物镜的透镜组在同一水平面上，所述成像物镜对成像透镜组成像定位，免对焦采集指纹图像，可以提高生产效率和进一步节约成本。The light source and the lens group of the imaging objective lens are on the same horizontal plane, and the imaging objective lens positions the image of the imaging lens group to collect fingerprint images without focusing, which can improve production efficiency and further save costs.

本发明技术问题通过以下再进一步的技术方案予以解决。The technical problem of the present invention is solved by the following further technical solutions.

所述棱镜的小端面贴附有扩散片，具有分散光线、均匀柔和光线的作用。所述光源的光线通过所述扩散片分散而均匀地照射在所述棱镜的大端面，给按压在其上的指头照明，既不刺眼，又可避免指纹图像信息不能被图像采集单元充分识别转换，从而提高小型指纹采集的精确度和清晰度，显著提高采集质量和识别效率。The small end surface of the prism is attached with a diffusion sheet, which has the function of dispersing light and making the light uniform and soft. The light from the light source is dispersed by the diffuser and evenly irradiated on the large end surface of the prism to illuminate the finger pressed on it, which is not dazzling, and can prevent the fingerprint image information from being fully recognized and converted by the image acquisition unit , so as to improve the accuracy and clarity of small fingerprint collection, and significantly improve the collection quality and identification efficiency.

所述扩散片是聚乙烯(Polyethylene，缩略词为PE)薄膜，采用型号为MB-433P底部扩散膜。The diffusion sheet is a polyethylene (Polyethylene, abbreviated as PE) film, and the model is MB-433P bottom diffusion film.

所述棱镜的图像采集面与主光轴的夹角为45°。The included angle between the image collection surface of the prism and the main optical axis is 45°.

所述棱镜的等效空气面与主光轴的夹角为57.69°。The included angle between the equivalent air surface of the prism and the main optical axis is 57.69°.

所述棱镜其余三个侧面的表面均涂覆有用于遮光的黑漆层。The surfaces of the remaining three sides of the prism are all coated with a black paint layer for light shielding.

在所述壳体的下方与所述图像采集单元主板之间设有成像物镜底座，由壳体和图像采集单元主板上的定位孔夹住固定，不需要采用螺丝或胶粘方式固定，以提高空间利用效率，节约成本，再进一步实现指纹采集器小型化。An imaging objective lens base is arranged between the bottom of the housing and the main board of the image acquisition unit, which is clamped and fixed by the positioning holes on the housing and the main board of the image acquisition unit, and does not need to be fixed by screws or glue, so as to improve the Space utilization efficiency, cost saving, and further miniaturization of the fingerprint collector.

所述图像采集单元是彩色互补金属氧化物半导体(Complementary Metal-Oxide-Semiconductor，缩略词为CMOS)光电转换器，所述图像采集单元主板包括彩色CMOS芯片、分别与所述彩色CMOS芯片连接的存储单元芯片、晶体振荡器、低压差线性稳压器(low dropout regulator，缩略词为LDO)、复位电路和数据通讯接口，所述LDO还分别与存储单元芯片、数据通讯接口和光源连接。The image acquisition unit is a color complementary metal-oxide-semiconductor (Complementary Metal-Oxide-Semiconductor, abbreviated as CMOS) photoelectric converter, and the main board of the image acquisition unit includes a color CMOS chip, connected with the color CMOS chip respectively. Storage unit chip, crystal oscillator, low dropout regulator (low dropout regulator, abbreviated as LDO), reset circuit and data communication interface. The LDO is also connected to the storage unit chip, data communication interface and light source respectively.

所述彩色CMOS芯片的感光面到所述成像物镜的透镜组的后焦距为2.7～3.0mm，呈现在彩色CMOS芯片感光阵列上的光线中的物像即采集的指纹图像被转换成电信号。The back focus distance from the photosensitive surface of the color CMOS chip to the lens group of the imaging objective lens is 2.7-3.0mm, and the object image presented in the light on the photosensitive array of the color CMOS chip, that is, the collected fingerprint image is converted into an electrical signal.

所述存储单元芯片主要用于存储指纹采集器的设计参数、采集指纹图像的大小，曝光度等参数。The storage unit chip is mainly used to store the design parameters of the fingerprint collector, the size of the collected fingerprint image, the exposure and other parameters.

所述彩色CMOS芯片是分辨率为30万像素的彩色CMOS芯片。The color CMOS chip is a color CMOS chip with a resolution of 300,000 pixels.

所述壳体包括主壳体，以及固定平面反射镜的盖板。The housing includes a main housing and a cover plate for fixing the plane reflector.

本发明与现有技术对比的有益效果是：The beneficial effect that the present invention compares with prior art is:

本发明采用平面反射镜，光源与图像采集单元共用一个主板，以及由壳体和主板夹住固定成像物镜底座，可以提高空间利用效率，节约成本，有效实现指纹采集器小型化。此外，成像物镜对成像透镜组成像定位，免对焦采集指纹图像，可以提高生产效率和进一步节约成本。The invention adopts a plane reflector, the light source and the image acquisition unit share a main board, and the base of the imaging objective lens is clamped and fixed by the housing and the main board, which can improve space utilization efficiency, save cost, and effectively realize the miniaturization of the fingerprint collector. In addition, the imaging objective lens positions the image of the imaging lens group, and collects fingerprint images without focusing, which can improve production efficiency and further save costs.

附图说明Description of drawings

图1是本发明具体实施方式的解体结构图；Fig. 1 is a disassembled structure diagram of a specific embodiment of the present invention;

图2是图1的梯形棱镜立体结构图；Fig. 2 is the three-dimensional structural diagram of the trapezoidal prism of Fig. 1;

图3是图1的光路图；Fig. 3 is the optical path diagram of Fig. 1;

图4是图3的图像采集单元主板电路方框图。FIG. 4 is a circuit block diagram of the main board of the image acquisition unit in FIG. 3 .

具体实施方式Detailed ways

下面结合具体实施方式并对照附图对本发明进行说明。The present invention will be described below in combination with specific embodiments and with reference to the accompanying drawings.

一种如图所示的1～4所示的小型指纹采集器，包括壳体和设置在壳体内的光学指纹成像模块，光学指纹成像模块包括顺应光路设置的棱镜1、成像物镜6、图像采集单元5和光源3，棱镜1是纵截面底边大于高的均匀对称的六面梯形棱镜，包括有相互平行正对的大端面10、小端面8、下侧面9和其余三个侧面，大端面10是图像采集面，小端面是光源射入面8，下侧面9是与成像物镜6相对的成像面。A small fingerprint collector as shown in 1 to 4 as shown in the figure, including a housing and an optical fingerprint imaging module arranged in the housing, the optical fingerprint imaging module includes aprism 1 arranged along the optical path, an imagingobjective lens 6, an image acquisition Theunit 5 and the light source 3, theprism 1 is a uniform and symmetrical six-sided trapezoidal prism whose bottom side is greater than the height in the longitudinal section, and includes a large end face 10, asmall end face 8, a lower side 9 and the remaining three sides parallel to each other, the large end face 10 is the image acquisition surface, the small end surface is the lightsource incident surface 8 , and the lower side 9 is the imaging surface opposite to the imagingobjective lens 6 .

在棱镜1和成像物镜6之间的光路设有平面反射镜2，光源3发出的光经棱镜1的小端面8进入棱镜1，被按压在棱镜1的大端面10上的指头反射光线的一部分，由棱镜1的下侧面9射出到平面反射镜2上，经平面反射镜2全反射进入成像物镜6，并经成像物镜6消畸变、色差，成像于图像采集单元5的图像接收面上，图像采集单元6将接收到的图像转换成电信号输出。采用平面反射镜2进行全反射，光路呈折线，相比直线光路可以明显缩短指纹采集器的纵向尺寸，实现小型化。The light path between theprism 1 and the imagingobjective lens 6 is provided with aflat reflector 2, the light that the light source 3 sends enters theprism 1 through thesmall end face 8 of theprism 1, and is pressed on a part of the finger reflected light on the large end face 10 of theprism 1 , is emitted from the lower side 9 of theprism 1 onto theplane reflector 2, is totally reflected by theplane reflector 2 and enters the imagingobjective lens 6, and is imaged on the image receiving surface of theimage acquisition unit 5 through the imagingobjective lens 6 to eliminate distortion and chromatic aberration. Theimage acquisition unit 6 converts the received images into electrical signals for output. Theplane reflector 2 is used for total reflection, and the optical path is a broken line. Compared with the linear optical path, the longitudinal dimension of the fingerprint collector can be significantly shortened to achieve miniaturization.

平面反射镜2是只有一个反射镜面的长方体状薄平面镜，平面反射镜与主光轴倾角为137.25°，其反射的光线直接进入成像物镜6。Theplane reflector 2 is a cuboid thin plane mirror with only one mirror surface. The inclination angle between the plane reflector and the main optical axis is 137.25°, and the light reflected by it directly enters the imagingobjective lens 6 .

光源3是四个可见光LED光源，安装在图像采集单元6主板上，位于棱镜1的小端面8上方。光源3与图像采集单元6共用一个主板和电源，可以进一步实现指纹采集器小型化。可见光LED光源可作为持续的光源，提供小型指纹采集器长时间使用。The light source 3 is four visible light LED light sources, which are installed on the main board of theimage acquisition unit 6 and located above thesmall end face 8 of theprism 1 . The light source 3 and theimage acquisition unit 6 share the same main board and power supply, which can further realize the miniaturization of the fingerprint collector. The visible light LED light source can be used as a continuous light source to provide a small fingerprint collector for long-term use.

光源3和成像物镜6的透镜组在同一水平面上，成像物镜6对成像透镜组成像定位，免对焦采集指纹图像，可以提高生产效率和进一步节约成本。The lens groups of the light source 3 and the imagingobjective lens 6 are on the same horizontal plane, and the imagingobjective lens 6 positions the imaging lens group to collect fingerprint images without focusing, which can improve production efficiency and further save costs.

在壳体的下方与图像采集单元6主板之间设有成像物镜底座，由壳体和图像采集单元6主板上的定位孔夹住固定，以提高空间利用效率，节约成本，再进一步实现指纹采集器小型化。An imaging objective lens base is provided between the bottom of the housing and the main board of theimage acquisition unit 6, which is clamped and fixed by the housing and the positioning holes on the main board of theimage acquisition unit 6, so as to improve space utilization efficiency, save costs, and further realize fingerprint collection device miniaturization.

棱镜1的小端面8贴附有型号为MB-433P底部扩散膜片，具有分散光线、均匀柔和光线的作用。光源3的光线通过扩散膜片分散而均匀地照射在棱镜1的大端面10，给按压在其上的指头照明，既不刺眼，又可避免指纹图像信息不能被图像采集单元充分识别转换，从而提高小型指纹采集的精确度和清晰度，显著提高采集质量和识别效率。Thesmall end face 8 of theprism 1 is attached with a diffuser film at the bottom of the model MB-433P, which has the effect of dispersing light and making it even and soft. The light from the light source 3 is dispersed by the diffusion film and uniformly irradiated on the large end surface 10 of theprism 1, illuminating the finger pressed on it, which is not dazzling, and can prevent the fingerprint image information from being fully recognized and converted by the image acquisition unit, thereby Improve the accuracy and clarity of small fingerprint collection, significantly improve the quality of collection and identification efficiency.

棱镜1的图像采集面与主光轴的夹角为45°。The included angle between the image collection surface of theprism 1 and the main optical axis is 45°.

棱镜1的等效空气面与主光轴的夹角为57.69°。The included angle between the equivalent air surface ofprism 1 and the main optical axis is 57.69°.

棱镜1的其余三个侧面的表面均涂覆有用于遮光的黑漆层。The surfaces of the remaining three sides of theprism 1 are all coated with a black paint layer for light shielding.

图像采集单元6是彩色CMOS光电转换器，图像采集单元6主板包括彩色CMOS芯片、分别与彩色CMOS芯片连接的存储单元芯片、晶体振荡器、LDO、复位电路和数据通讯接口，LDO还分别与存储单元芯片、数据通讯接口和光源连接，彩色CMOS芯片的感光面到成像物镜6的透镜组的后焦距为2.8mm，呈现在彩色CMOS芯片感光阵列上的光线中的物像即采集的指纹图像被转换成电信号；存储单元芯片主要用于存储指纹采集器的设计参数、采集指纹图像的大小，曝光度等参数。Theimage acquisition unit 6 is a color CMOS photoelectric converter, and theimage acquisition unit 6 mainboards include a color CMOS chip, a storage unit chip connected to the color CMOS chip, a crystal oscillator, an LDO, a reset circuit and a data communication interface, and the LDO is also connected to the storage unit respectively. The unit chip, the data communication interface and the light source are connected, and the back focus distance from the photosensitive surface of the color CMOS chip to the lens group of theimaging objective lens 6 is 2.8mm, and the object image in the light that is presented on the photosensitive array of the color CMOS chip is the fingerprint image collected. Converted into electrical signals; the storage unit chip is mainly used to store the design parameters of the fingerprint collector, the size of the collected fingerprint image, the exposure and other parameters.

彩色CMOS芯片是格科微电子(上海)有限公司出品的分辨率为30万像素的彩色传感器芯片GC0307。The color CMOS chip is a color sensor chip GC0307 with a resolution of 300,000 pixels produced by Geke Microelectronics (Shanghai) Co., Ltd.

壳体包括主壳体7，以及固定平面反射镜2的盖板12。The housing includes amain housing 7 and acover plate 12 for fixing theplane reflector 2 .

以上内容是结合具体的优选实施方式对本发明所作的进一步详细说明，不能认定本发明的具体实施只局限于这些说明。对于本发明所属技术领域的普通技术人员来说，在不脱离本发明构思的前提下做出若干等同替代或明显变型，而且性能或用途相同，都应当视为属于本发明由所提交的权利要求书确定的专利保护范围。The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it cannot be assumed that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, several equivalent substitutions or obvious modifications are made without departing from the concept of the present invention, and the performance or use is the same, all should be regarded as belonging to the present invention by the submitted claims The scope of patent protection determined by the book.

Claims (10)

1. small fingerprint collector, comprise housing and be arranged on the interior optical finger print image-forming module of described housing, described optical finger print image-forming module comprises complies with prism, image-forming objective lens, image acquisition units and the light source that light path is provided with, described prism is that the base, longitudinal section is greater than high six Dove prisms symmetrically, include be parallel to each other over against large end face, small end face, downside and its excess-three side, described large end face is the image acquisition face, described small end face is that light source is injected face, described downside is the imaging surface relative with image-forming objective lens, it is characterized in that:

Light path between described prism and described image-forming objective lens is provided with plane mirror, the light that described light source sends enters prism through the small end face of described prism, be pressed against the part of the finger reflection ray on the large end face of described prism, downside by described prism injects on the described plane mirror, enter described image-forming objective lens through described plane mirror total reflection, and through image-forming objective lens disappear distortion, aberration, image on the image receiving plane of described image acquisition units, described image acquisition units becomes electric signal output with the image transitions that receives.

2. small fingerprint collector as claimed in claim 1 is characterized in that:

Described plane mirror is the rectangular-shaped thin plate mirror that has only a mirror surface, and plane mirror and primary optical axis inclination angle are 137.25 °, and the light of its reflection directly enters image-forming objective lens.

3. small fingerprint collector as claimed in claim 1 or 2 is characterized in that:

Described light source is light emitting diode (the light emitting diode of at least 1 visible or infrared light, initialism is LED) light source, be welded on the image acquisition units mainboard, be positioned at the small end face top of described prism, shared mainboard of described light source and described image acquisition units and power supply.

4. small fingerprint collector as claimed in claim 3 is characterized in that:

The lens combination of described light source and image-forming objective lens is on same surface level, and described image-forming objective lens is exempted from focusing and gathered fingerprint image imaging lens group imaging location.

5. small fingerprint collector as claimed in claim 4 is characterized in that:

The small end face of described prism is pasted with diffusion sheet, and described diffusion sheet is tygon (Polyethylene, initialism are a PE) film.

6. small fingerprint collector as claimed in claim 5 is characterized in that:

The image acquisition face of described prism and the angle of primary optical axis are 45 °;

The equivalent air surface of described prism and the angle of primary optical axis are 57.69 °.

7. small fingerprint collector as claimed in claim 6 is characterized in that:

Be provided with the image-forming objective lens base below the described housing and between the described image acquisition units mainboard, clamping fixing by the pilot hole on housing and the image acquisition units mainboard.

8. small fingerprint collector as claimed in claim 7 is characterized in that:

Described image acquisition units is colored complementary metal oxide semiconductor (CMOS) (Complementary Metal-Oxide-Semiconductor, initialism is CMOS) photoelectric commutator, described image acquisition units mainboard comprises the color cmos chip, the storage unit chip that is connected with described color cmos chip respectively, crystal oscillator, low pressure difference linear voltage regulator (low dropout regulator, initialism is LDO), reset circuit and data communication interface, described LDO also respectively with the storage unit chip, data communication interface is connected with light source, and described color cmos chip is arranged on the lens combination image planes of described image-forming objective lens.

9. small fingerprint collector as claimed in claim 8 is characterized in that:

The light-sensitive surface of described color cmos chip is 2.7～3.0mm to the back focal length of the lens combination of described image-forming objective lens.

10. the described small fingerprint collector any as claim 1～9 is characterized in that:

Described housing comprises main casing, and the cover plate of fixed pan catoptron.

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