CN202771445U - Novel capacitive type fingerprint image acquisition system - Google Patents

Novel capacitive type fingerprint image acquisition system Download PDF

Info

Publication number
CN202771445U
CN202771445U CN 201220476953 CN201220476953U CN202771445U CN 202771445 U CN202771445 U CN 202771445U CN 201220476953 CN201220476953 CN 201220476953 CN 201220476953 U CN201220476953 U CN 201220476953U CN 202771445 U CN202771445 U CN 202771445U
Authority
CN
China
Prior art keywords
sensing
sensing element
capacitance
array
reference
Prior art date
Application number
CN 201220476953
Other languages
Chinese (zh)
Inventor
徐启波
Original Assignee
成都方程式电子有限公司
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 成都方程式电子有限公司 filed Critical 成都方程式电子有限公司
Priority to CN 201220476953 priority Critical patent/CN202771445U/en
Application granted granted Critical
Publication of CN202771445U publication Critical patent/CN202771445U/en

Links

Abstract

The utility model provides a novel capacitive type fingerprint image acquisition system. The fingerprint image acquisition comprises a sensing element array with a plurality of sensing elements; a sensing element array driving circuit used for inputting a voltage signal to the sensing element array; an insulating surface covering the sensing element array and used as a contact surface of a finger; a comparator array arranged besides the sensing element array and inputting the output of the sensing element array; a programmable reference voltage source as an input reference voltage of the comparator array; and an adaptive algorithm logic circuit used for adaptively adjusting the programmable reference voltage source. The sensitivity of the capacitance sensor is increased, the clear fingerprint image of the dry, wet, oil or normal finger can be acquired, and the fingerprint image acquisition system is more suitable for acquiring the fingerprint of some special finger.

Description

一种新型电容式指纹图像采集系统技术领域 A novel capacitive fingerprint image acquisition system Field

[0001] 本实用新型涉及集成电路设计领域,尤其涉及一种适用于特殊手指采集的新型电容式指纹图像采集系统。 [0001] The present invention relates to integrated circuit design, and more particularly relates to a special one for the acquisition of the new finger capacitive fingerprint image acquisition system.

背景技术 Background technique

[0002] 随着电子自动化设计的高速发展,活体生物特征认证和身份识别越来越多的运用到人们的生活中,指纹认证作为在生物特征认证中具有最高可靠性和性价比,已经成为了当前生物认证的主流。 [0002] With the rapid development of electronic design automation, live biometric authentication and identification applied to more and more people's lives, as a fingerprint authentication with the highest reliability and value for money in biometric authentication, has become the current mainstream biometric authentication. 与此同时,指纹采集技术也高速发展,一个更低成本,更小体积的传感器将会占领巨大的市场,因此具有上述优点的传感器成为当前研究的重点。 At the same time, the rapid development of fingerprint technology, a lower cost, smaller size sensor will be occupying a huge market, so the sensor with the advantages become the focus of current research. 其中电容式传感器成为当前主流产品之一。 In which the capacitive sensor become one of the mainstream products.

[0003] 随着指纹技术的逐渐成熟,以及成本的越来越低,相信指纹识别技术会广泛的应用到我们日常生活中来。 [0003] With the maturity of fingerprint technology, as well as the cost of getting lower and lower, we believe fingerprint recognition technology will be widely applied to our daily lives. 与此同时,对传感器的要求也越来越高。 At the same time, the requirements of the sensor are also increasing. 一个好的指纹识别系统,不仅是从算法上解决指纹识别系统中存在的不足,更应该从根本上解决传感器采集到的图像质量问题,使得某些特殊手指都能够采集到清晰的指纹图像。 A good fingerprint recognition system, not only solve the problem of fingerprint identification system present on the algorithm, the sensor should solve the acquired image quality problem fundamentally, making some special fingers are able to capture a clear image of the fingerprint. 现有的电容式传感器是通过利用电荷分享原理来实现的,比起过去利用电容充放电原理来感测微小电容值的结构有很大的改进,如中国专利编号ZL02105960. 8,提供了一种电容式指纹读取芯片,包含以二维方式排列的电容感测元阵列以及一类动态随机存取存储器DRAM周边电路,此类感测元阵列利用DRAM的电荷分享原理检测指纹的纹峰和纹谷。 Conventional capacitive sensor principle is by utilizing the charge-sharing achieved than in the past by using the principle of capacitor charge and discharge the capacitance value sensed minute structure greatly improved, Chinese Patent No. ZL02105960. 8, there is provided a capacitive fingerprint reader chip, capacitive sensing element comprises an array of two-dimensionally arrayed, and a class of dynamic random access memory DRAM peripheral circuit, such sensing DRAM cell array using charge sharing principle of detecting fingerprint patterns of peaks and groove Valley. 该现有的电容式传感器的感测元结构不能消除背景电容(感测电极到其电极的寄生电容,包括感测电极到参考电极,感测电极到衬底等的寄生电容,而且每个感测元的寄生电容可能存在不一致性),其感测元输出信号通过一比较器或A/D转换器得到的二进制或者灰度级的影像信息,只通过改变感测元的参考电容值或者改变屏蔽电容大小及所接的电位来粗调指纹图像的质量,该方法对于太湿或者太油的手指存在采集到的图像模糊不清,对于干燥及断裂的手指,采集到的图像纹路太浅或者根本分辨不出指纹纹路,导致特殊手指应用受到限制,同时如果采集到不清晰的指纹图像,给后续指纹处理及识别造成一定的影响 The sensing element structure of a conventional capacitance type sensor can not eliminate background capacitance (parasitic sensing electrodes to the capacitor electrode comprising a sensing electrode to the parasitic capacitance of the reference electrode, a sensing electrode to the substrate or the like, and each sense parasitic capacitance can be measured membered inconsistencies), the sensing element output signal which is obtained by a comparator or a / D converter is a binary or gray level image information, simply by changing the reference capacitance value or change the sensing element shield capacitance and size of the contact potentials mass of the coarse fingerprint image, the present method for the captured image is too wet or too blurred oil finger, finger breakage and for drying, the collected image lines or too light not distinguish fingerprint lines, resulting in a special finger application is limited, but if you do not clear fingerprint image capture to, and to the subsequent processing of fingerprint identification have been affected

发明内容 SUMMARY

[0004] 本实用新型为了解决上述问题,提供一种改进型的电容式指纹图像采集系统,在现有技术的基础上通过改善感测元电路和对感测元输出信号所通过的比较器的参考电压进行自适应调整。 [0004] The present invention to solve the above problems and to provide a capacitive fingerprint image acquisition system is improved, on the basis of the prior art by improving the circuitry and the sensing element of the sensing element by the output signal of the comparator adaptively adjust the reference voltage.

[0005] 本实用新型提供一种新型电容式指纹图像采集系统,包括一感测元阵列,包含多个感测元;一感测元阵列驱动电路,用于向感测元阵列输入电压信号;一绝缘表面,覆盖于该感测元阵列之上,作为一手指的接触面;一比较器阵列,配置于该感测元阵列旁,感测元阵列的输出作为其输入;一可编程的参考电压源,作为比较器阵列的一输入参考电压;一自适应过程算法逻辑电路,用于自适应调节可编程的参考电压源;其特征在于,感测元阵列接被输入一第一电压信号,使该每一个感测兀内的一参考电容两端或感测电容两端产生一电压差;之后输入一第二电压信号,使参考电容两端与屏蔽电容两端无电压差,或者感测电容两端和屏蔽电容两端无电压差;然后输入一第三电压信号,使屏蔽电极链接到一电压,使该感测电容,该屏蔽电容与该参考电容进 [0005] The present invention provides a novel capacitive fingerprint image acquisition system, comprising a sensing element array including a plurality of the sensing element; a sensing cell array driving circuit for an input voltage signal to the sensing element array; an insulating surface, overlying the sensing cell array, as a finger contacting surface; a comparator array, disposed beside the sensing cell array, the output of the sensing cell array as an input; a programmable reference voltage source, as a reference input voltage comparator array; a process of adaptive arithmetic logic circuit for adaptively adjusting the programmable reference voltage source; wherein the sensing element array is connected to a first input voltage signal, the sense of each of the two ends of a reference capacitance or capacitance in the sensing ends of the sensing Wu sensing a voltage difference is generated; a second voltage after the input signal, so that no voltage difference across the reference capacitor and the shield across the capacitor, sensing or and blocking both ends of the capacitor across the capacitor no voltage difference; and a third input voltage signal, so that a link to the shield electrode voltage so that the sensing capacitor, with the capacitance of the shield into the reference capacitor 行电荷分享之后再断开该参考电容与该感测电容和该屏蔽电容的链接;顺序的重复输入第二,第三电压信号,直到比较器发生翻转再将每一个比较器的翻转信号输出,作为采集到的灰度级影像信息。 After the charge sharing line disconnect the link to the reference capacitor and the sensing capacitor and the capacitance of the shield; repeating sequence of a second input, a third voltage signal, until the comparator again inverted for each occurrence of the comparator output signal inversion, as acquired grayscale image information.

[0006] 每一个感测元还包含:一传感器结构,包括:一感测电极,与手指、绝缘表面形成感测电容; [0006] Each of the sensing element further comprises: a sensor structure, comprising: a sensing electrode, and the finger sensing capacitor is formed, an insulating surface;

[0007] 两个参考电极;及一绝缘层,配置于两个参考电极间,且在两个参考电极及绝缘层之间会形成参考电容;一屏蔽电极及配置于屏蔽电极与感测电极间的一绝缘层,在屏蔽电极、绝缘层及感测电极之间形成屏蔽电容;及多个开关电路。 [0007] The two reference electrodes; and an insulating layer disposed between the two reference electrodes, and between the two reference electrodes and the insulating layer will form a reference capacitance; a shield electrode and a shield electrode disposed between the sensing electrode an insulating layer, forming a shield electrode capacitance between the shield, the insulating layer and sense electrodes; and a plurality of switching circuits.

[0008]自适应过程算法逻辑电路实时分析比较器阵列输入其中的灰度级指纹影像信息,之后输出一反馈信号用于调节比较器阵列的参考电压值。 [0008] Adaptive real-time analysis algorithm process logic comparator array input gray level information wherein the fingerprint image, and then outputs a feedback signal for adjusting the reference voltage of the comparator array.

[0009] 多个感测元的版图结构如下: [0009] The plurality of sensing elements layout structure as follows:

[0010] 最后一层金属作为感测电极,到数第二层金属作为屏蔽电极,用于隔绝其他电路从而消除背景电容,这两层金属之间的绝缘层与该两层金属之间形成屏蔽电容;每个感测元的屏蔽电极被顺序划分为多块,其中边缘两块连接恒定电压,使得各感测元之间的边缘寄生电容相同,其余的块连接在可变的电压源上,由感测元驱动电路驱动。 [0010] Finally, a metal layer as the sensing electrodes, a second layer of metal to the number of the shield electrode, isolated from other circuitry for eliminating background capacitance, the insulating layer is formed between the two metal layers between the metal shield capacitance; shield electrode of each sensing element sensing the order is divided into multiple blocks, wherein two edges connecting a constant voltage, such that between the edge of the same parasitic capacitance sensing element, the remaining blocks are connected to the variable voltage source, a drive circuit for driving the sensing element.

[0011] 本实用新型根据电荷分享原理,通过自适应调整感测元输出信号所通过的比较器的参考电压,改善现有的感测元阵列进行电容值的检测,该系统能够增加电容传感器的灵敏性,可使得干,湿,油,以及正常手指都能够采集到清晰的指纹图像,更加适用于某些特殊的手指的采集。 [0011] The present invention according to the charge sharing principle, by adaptively adjusting the reference voltage of the sensing element output signal by the comparator, the improvement of existing sensing cell array to detect a capacitance value, the system can increase the capacitance of the sensor sensitivity, can cause dry, wet, oil, and a normal finger are able to collect a clear fingerprint image, more suitable for acquiring special finger. 自适应过程算法由数字逻辑电路实现。 Process by the digital adaptive algorithm logic circuit.

[0012] 本实用新型另提供一种感测元的版图结构,使得数百上千个感测元的电荷分享一致性(各个感测元寄生电容的一致性),进一步提高指纹输出图像的品质。 [0012] The present invention further provides a layout structure of the sensing element, so that hundreds of thousands of the charge sensing element share the consistency (consistency for each of the parasitic capacitance sensing element), to further improve the quality of the fingerprint image output .

附图说明 BRIEF DESCRIPTION

[0013] 图I是本实用新型电容式指纹采集系统示意图; [0013] FIG. I is a schematic diagram of the present invention, capacitive fingerprint collection system;

[0014]图2是本实用新型实施例的电容式指纹采集系统的感测元结构示意图; [0014] FIG. 2 is a schematic view of the sensing element for a capacitive fingerprint collection system according to an embodiment of the invention;

[0015]图3是本实用新型实施例的电容式指纹采集系统的感测元版图结构示意图; [0015] FIG. 3 is a schematic layout structure of a sensing element for a capacitive fingerprint collection system according to an embodiment of the invention;

[0016] 图4是本实用新型电容式指纹采集系统采集到的干手指指纹图像,其中图4a是未调整比较器参考电压值采集到的图像;图4b是调整比较器参考电压值采集到的图像。 [0016] FIG. 4 is present disclosure capacitive fingerprint acquisition system to dry finger fingerprint image, wherein FIG. 4a is unadjusted comparator reference voltage value acquired image; FIG. 4b is adjusted comparator reference voltage values ​​collected image.

[0017] 图5是本实用新型电容式指纹采集系统采集到的湿手指指纹图像,其中图5a是未调整比较器参考电压值采集到的图像;图5b是调整比较器参考电压值采集到的图像。 [0017] FIG. 5 is a present invention capacitive fingerprint acquisition system to wet finger fingerprint image, wherein FIG. 5a is not to adjust the comparator reference voltage value acquired image; FIG. 5b is adjusted comparator reference voltage values ​​collected image.

[0018] 图中符号说明: [0018] REFERENCE SIGNS:

[0019] I指纹采集系统 [0019] I Fingerprint Acquisition System

[0020] 10感测元阵列 [0020] 10 sensing element array

[0021 ] 11感测元阵列驱动电路 [0021] 11 sensing element array driver circuit

[0022] 12输入参考电压可编程的比较器阵列 [0022] 12 of programmable input reference voltage comparator array

[0023] 121输入参考电压可编程的比较器 [0023] The programmable voltage reference input 121 of comparator

[0024] 13自适应过程算法逻辑电路[0025] 14可编程参考电压源 [0024] The logic circuit 13 adaptive algorithm process [0025] The programmable reference voltage source 14

[0026] 2 手指 [0026] 2 fingers

[0027] 20感测电极 [0027] 20 sensing electrodes

[0028] 201感测电容 [0028] The sensing capacitor 201

[0029] 202参考电容 [0029] The reference capacitance 202

[0030] 203a>203b>203c>203d>203e>203e 屏蔽电容[0031] 301 302 303 304a 304b 305a 305b 306a 306b 开关 [0030] 203a> 203b> 203c> 203d> 203e> 203e shield capacitor [0031] 301 302 303 304a 304b 305a 305b 306a 306b switch

[0032] 401 402 403 404a 404b 405a 405b 406a 406b 电压源 [0032] 401 402 403 404a 404b 405a 405b 406a 406b voltage source

[0033] 5 节点 [0033] 5 Node

具体实施方式 Detailed ways

[0034] 本实用新型提供了一种电容式指纹图像采集系统,包含:一感测元阵列,包含多个感测元;一感测元阵列驱动电路;一绝缘表面,覆盖于该感测元阵列之上,作为一手指的接触面;一比较器阵列,配置于该电容感测元阵列旁,感测元阵列的输出作为其输入;一可编程的参考电压源,作为比较器阵列的一输入参考电压;一自适应过程算法逻辑电路,用于自适应调节可编程的参考电压源。 [0034] The present invention provides a capacitive fingerprint image acquisition system, comprising: a sensing element array including a plurality of the sensing element; a driving circuit of the sensing element array; an insulating surface, covering the sensing element on the array, as the contact surface of a finger; a comparator array, disposed beside the capacitive sensing element array, the output of the sensing cell array as an input; a programmable reference voltage source as a comparator array the input reference voltage; a process of adaptive arithmetic logic circuit for adaptively adjusting the programmable reference voltage source. 该感测元阵列被输入一第一电压信号,使该每一个感测元内的一参考电容两端产生一电压差;之后输入一第二电压信号,使感测电容两端和屏蔽电容两端无电压差;然后输入一第三电压信号,使屏蔽电极链接到某一电压,使该感测电容、该屏蔽电容与该参考电容进行电荷分享之后再断开该参考电容与该感测电容和该屏蔽电容的链接;顺序的重复输入第二,第三电压信号,直到比较器发生翻转再将每一个比较器的翻转信号输出作为采集到的灰度级影像信息。 The sensing element array is input to a first voltage signal to generate a difference between a reference voltage across the capacitor in each of the sensing element; a second voltage after the input signal to the sensing and the shielding across the capacitor capacitance two no voltage difference; and a third input voltage signal, so that after a link to the shield electrode voltage so that the sensing capacitor, the shield capacitor and the reference capacitor charge sharing disconnect the reference capacitor and the sensing capacitor and the shield link capacitor; a second input sequence is repeated, the third voltage signal, until the inversion signal inverted output of each comparator then comparator occur as the collected gray level image information.

[0035] 该输出信号输入到自适应过程算法逻辑电路处理后反馈回一信号用于调节可编程参考电压源,反复循环该过程,直到输出一副清晰的指纹图像。 [0035] The output signal is input to the arithmetic logic circuit for processing the adaptation process a signal fed back for adjusting a programmable reference voltage source, the process cycle is repeated until the output of a clear fingerprint image.

[0036] 根据本实用新型的一实施例,此电容式指纹图像采集系统,包含:一感测元阵列、一感测元阵列驱动电路、一绝缘表面、一比较器阵列、一可编程的参考电压源和一自适应过程算法逻辑电路;其中感测元阵列包含多个感测元,每一个感测元:还包含一传感器结构,包括一感测电极、两参考电极及配置于参考电极间的一绝缘层、一屏蔽电极及配置于屏蔽电极与感测电极间的一绝缘层、多个开关电路。 [0036] According to an embodiment of the present invention embodiment, the capacitive fingerprint image acquisition system, comprising: a sensing cell array, a sensing cell array driving circuit, an insulating surface, a comparator array, a programmable reference voltage source and an adaptive arithmetic logic process; wherein the sensing element array including a plurality of sensing element, each sensing element: further comprises a sensor structure comprising a sensing electrode, reference electrode and disposed between the two reference electrodes an insulating layer, a shielding electrode and an insulating layer disposed between the shield electrode and the sensing electrodes, a plurality of switching circuits.

[0037] 其中,绝缘表面覆盖于感测元阵列之上,作为一手指接触面;手指、绝缘表面及感测电极会形成感测电容,在两参考电极及绝缘层之间会形成参考电容,在屏蔽电极、绝缘层及感测电极之间会形成屏蔽电容;多个开关在感测元阵列驱动电路的作用下完成电容感测兀的电荷分享;其中感测兀阵列驱动电路输入一第一电压信号,使该每一个感测兀内的一参考电容两端产生一电压差(或感测电容两端产生电压差);之后输入一第二电压信号,使感测电容两端(或参考电容两端)和屏蔽电容两端无电压差;然后输入一第三电压信号,使屏蔽电极链接到某一电压,使该感测电容,该屏蔽电容与该参考电容进行电荷分享之后再断开该参考电容与该感测电容和该屏蔽电容的链接;顺序的重复输入第二,第三电压信号,直到比较器发生翻转再将每一个比较器的翻 [0037] wherein the insulating surface overlies the sensing cell array, as a finger contact surface; a finger, an insulating surface and a sensing electrode of the sensing capacitor formed, between both the reference electrode and the insulating layer will form a reference capacitance, between the shielding electrode, an insulating layer and a sensing electrode capacitance formed shield; a plurality of switching complete charge-sharing capacitor Wu sensed by the action of the sensing element array driver circuitry; Wu wherein the sensing circuit input to a first array driver voltage signal, so that a sense of each of the reference measured across the capacitor Wu generating (or both ends of a voltage difference sensing capacitance) a voltage difference; after the input of a second voltage signal, so that across the capacitive sensing (or reference across the capacitor) and the shield no voltage difference across the capacitor; and a third input voltage signal, the shield electrode is linked to a certain voltage, so that the sensing capacitor, the charge-sharing capacitor shield and the reference capacitance after disconnect the link with the reference capacitor and the capacitance of the sensing capacitor shield; repeating sequence of a second input, a third voltage signal, until the comparator then flip the turn of each of the comparators 信号输出作为采集到的灰度级影像信息。 Signal is output as a grayscale captured image information.

[0038] 根据本实用新型的另一实施例,此感测元的版图结构如下: [0038] Another embodiment of the present invention, a sensing element layout structure as follows:

[0039] 最后一层金属作为感测电极,到数第二层金属作为屏蔽电极,用于隔绝其他电路从而消除背景电容,这两层金属及该两层金属之间的绝缘层形成屏蔽电容。 [0039] Finally, a metal layer as the sensing electrodes, a second layer of metal to the number of the shield electrode, isolated from other circuitry for eliminating background capacitance, the insulating layer between the metal layers and the two layers of metal form a shield capacitor. 每个感测元的屏蔽电极被顺序划分为多块,其中边缘两块连接恒定电压,使得各感测元之间的边缘寄生电容相同,其余的块连接在可变的电压源上,由感测元驱动电路驱动。 Each sensing element of the shield electrode is divided into a plurality of order, where edges of two connecting a constant voltage, such that between the edge of the same parasitic capacitance sensing element, the remaining blocks are connected to the variable voltage source, the sense sensing element drive circuit drives.

[0040] 在本是实施例中,每个感测元屏蔽电极被划分为5小块A、B、C、D、E,其中A、E连接恒定电压,使得各感测元之间的边缘寄生电容大致相同,B、C、D连接在可变的电压源上,由感测元驱动电路驱动。 [0040] In the embodiment according to the present embodiment is, each sensing element shield electrode is divided into five small blocks A, B, C, D, E, wherein A, E are connected a constant voltage, such that the edge between the sensing element substantially the same parasitic capacitance, B, C, D connected to the variable voltage source, a drive circuit for driving the sensing element. 通过调节B、C、D所链接的可变电压源可以得到一种最佳灵敏性的感测元。 By adjusting the B, C, D linked variable voltage source can be obtained an optimal sensitivity of the sensing element. 参考电容及开关电路置于该两层金属之下。 Reference capacitance and a switch circuit placed under the two metal layers. 该版图结构使得数百上千个感测元的电荷分享一致性(各个感测元寄生电容的一致性),进一步提高指纹输出图像的品质。 The layout structure so that charge hundreds of thousands of sensing elements share the consistency (consistency for each of the parasitic capacitance sensing element), to further improve the quality of the fingerprint image output.

[0041] 不同于其他电容式指纹图像采集系统,本实用新型通过改善感测元的电路结构及其版图结构来提高采集图像品质,同时通过一个自适应算法过程来调节一个输入参考电压可编程的比较器来实现对特殊手指的采集。 [0041] Unlike other capacitive fingerprint image acquisition system, the present invention by improving the circuit configuration of the sensing element and the layout structure to improve the quality of the captured image, while the reference voltage is adjusted a programmable input by an adaptive algorithmic process comparator to implement the acquisition of special finger. 无论是采集正常的指纹或是采集特殊指纹,通过实时自适应的调整输入参考电压可编程的比较器,从而调整比较器的输出指纹影像品质,都能够采集到比较清晰的指纹图像。 Whether normal fingerprint collection or special fingerprint acquisition, real-time adaptive adjustment of the reference voltage input of the programmable comparator, the output of the comparator to adjust the image quality of the fingerprint, can be collected relatively clear fingerprint image. · ·

[0042] 参见图1,其是本实用新型电容式指纹采集系统示意图。 [0042] Referring to Figure 1, a schematic view of the present invention which is a novel capacitive fingerprint collection system. 该指纹采集系统I包含:一感测元阵列10,包含多个感测元101,用于检测手指表面与感测电极所形成的感测电容;感测元阵列驱动电路11,用于向感测元阵列输入电压信号;一输入参考电压可编程的比较器阵列12,包含多个比较器121,将感测元的输出转换为二进制灰度级指纹影像信息;一自适应过程算法逻辑电路13,用于实时分析输入其中的二进制灰度级指纹影像信息,之后输出一反馈信号用于调节比较器阵列12的参考电压值;一可编程参考电压源14,作为比较器阵列12的输入。 The fingerprint acquisition system I comprises: a sensing cell array 10, comprising a plurality of the sensing element 101 for sensing the capacitance detection of the finger surface and the sensing electrode is formed; the sensing element array driver circuit 11 for the sensing sensing cell array input voltage signal; a programmable reference voltage input of the comparator array 12, comprising a plurality of comparator 121, the output of the sensing element is converted into a binary gray scale fingerprint image information; a process of adaptive arithmetic logic circuit 13 for real-time binary information analyzing grayscale fingerprint image input thereto, and then outputs a feedback signal for adjusting the reference voltage of the comparator array 12; 14, enter a programmable reference voltage source as a comparator array 12.

[0043] 参见图2,其是本实用新型实施例电容式指纹采集系统其中一个感测元的结构示意图。 [0043] Referring to Figure 2, which is an embodiment of the present invention, capacitive fingerprint collection system in which a schematic view of the sensing element. 该感测元包含:一感测电容201,由手指2、感测电极20及绝缘表面21所形成的电容;一参考电容202 ;多个屏蔽电容203a、203b、203c、203d、203e ;多个开关301、302、303、304a、304b、305a、305b、306a、306b ;多个电压源401、402、403、404a、404b、405a、405b、406a、406b ;当手指2接触感测元表面21时,感测元阵列驱动电路11会输入一第一电压,使得开关303关闭,参考电容202充电到某一电压值,如VDD,后断开开关303。 The sensing element comprising: a sensing capacitor 201 by 2, the sensing electrode 20 and the capacitor insulating surface 21 formed finger; a reference capacitor 202; a plurality of shielding capacitors 203a, 203b, 203c, 203d, 203e; a plurality of switch 301,302,303,304a, 304b, 305a, 305b, 306a, 306b; plurality of voltage sources 401,402,403,404a, 404b, 405a, 405b, 406a, 406b; the sensing element when the second contact surface of the finger 21 when the sensing element array driver circuit 11 will be a first input voltage, so that the switch 303 is closed, the capacitor 202 is charged to a reference voltage, such as the VDD, the switch 303 is disconnected. 之后感测元阵列驱动电路11输入一第二电压,使得开关301,304a,305a, 306a关闭,开关304b,305b, 306b断开,使感测电极上的电荷为零(如感测电容和屏蔽电容的两端电压为零)后断开关301,304a,305a,306a。 After the sensing element array driver circuit 11 inputs a second voltage such that the switch 301,304a, 305a, 306a is closed, the switch 304b, 305b, 306b are turned off, the charge on the sense electrode to zero (e.g., sensing capacitor and shielding after the voltage across the capacitor is zero) off switch 301,304a, 305a, 306a. 然后输入一第三电压,使得开关302、304b、305b、306b关闭,电容203b、203c、203d链接到某一电压上,如VDD,感测电容、参考电容和屏蔽电容发生电荷分享后断开开关302、304b、305b、306b。 And a third input voltage, so that the switch 302,304b, 305b, 306b closed, capacitor 203b, 203c, 203d linked to a certain voltage, such as the VDD, the sensing capacitor, reference capacitor, and the capacitance of the charge sharing shield off switch 302,304b, 305b, 306b. 重复输入第二、第三电压数次后,直到参考电容202的电压下降到比较器的参考电压值,使比较器发生反转。 Was repeated a second input, the third voltage several times, the reference capacitor 202 until the voltage decreases to the reference voltage value of the comparator, the comparator reversed. 最后将比较器的输出传入实时的自适应过程算法逻辑电路13,自适应过程算法逻辑电路13反馈回一数字信号用于调节可编程参考电压源14。 Finally, the output of the comparator incoming real-time adaptive algorithm logic circuit 13 processes, the process of adaptive arithmetic logic circuit 13 is fed back to a digital signal for adjusting a programmable reference voltage source 14. 无论是正常手指或是特殊手指,通过该指纹采集系统后,可以输出一幅清晰的指纹图像。 Whether the finger is normal or special finger, the fingerprint acquisition by the system may output a clear fingerprint image.

[0044] 此外,重复输入第二、第三电压一定的次数后,可以使屏蔽电容203a、203b、203c、203d、203e贡献到节点5的净电荷为零,从而消除背景电容的影响。 [0044] In addition, a second input is repeated after a certain number of the third voltage, capacitance can shield 203a, 203b, 203c, 203d, 203e contribution to the net charge is zero node 5, thereby eliminating the influence of the background capacitance.

[0045] 参见图3,其是本实用新型实施例电容式指纹采集系统的感测元的版图,由两层金属构成,最后一层金属(102)作为感测电极,到数第二层金属(101)作为屏蔽电极,用于隔绝其他电路从而消除背景电容,101,102及这两层金属之间的绝缘层形成屏蔽电容。 [0045] Referring to Figure 3, which is sensing element of the embodiment of the present invention, capacitive fingerprint acquisition system layout, formed of two layers of metal, the final metal layer (102) as the sensing electrode, a second layer of metal to the number of (101) as a shield electrode for insulating other circuits so as to eliminate background capacitance between the insulating layer, metal layers 101 and 102 and which form a shield capacitor. 每个感测元屏蔽电极被划分为5块(101a,101b,101c,101d,101e),其中101a,IOle连接恒定电压,使得各感测元间的边缘寄生电容大致相同,101b,101c,IOld连接在可变的电压上,由感测元驱动电路驱动。 Each sensing element shield electrode is divided into five (101a, 101b, 101c, 101d, 101e), wherein 101a, IOle connected to a constant voltage, such that the edge between each sensing element is substantially the same parasitic capacitance, 101b, 101c, IOld connected to the variable voltage, a drive circuit for driving the sensing element. 通过调节101b,101c,IOld所链接的可变电压可以得到一种最佳灵敏性的感测元。 By adjusting 101b, 101c, IOld linked variable voltage can be obtained an optimal sensitivity of the sensing element. 参考电容及开关电路置于该两层金属之下。 Reference capacitance and a switch circuit placed under the two metal layers. 该版图结构使得数百上千个感测元的电荷分享一致性(各个感测元寄生电容的一致性),进一步提高指纹输出图像的品质。 The layout structure so that charge hundreds of thousands of sensing elements share the consistency (consistency for each of the parasitic capacitance sensing element), to further improve the quality of the fingerprint image output.

[0046] 参见图4和图5,其中图4a图是传统电容式采集系统采集到干手指所得到的指纹图像,看上去指纹纹路太浅很难识别,图4b是本实用新型电容式指纹采集系统通过实时的自适应过程算法电路来调节输入参考电压可编程的比较器阵列得到的指纹图像,看上去清晰可见。 [0046] Referring to FIGS. 4 and 5, wherein FIG. 4a is a typical capacitive fingerprint image acquisition system to a dry finger obtained fingerprint is looked shallow difficult to identify, according to the present invention, FIG. 4b is a capacitive fingerprint collection the system adjusts the reference voltage input fingerprint image programmable comparator array obtained by the process of real-time adaptive algorithm circuit, it looks clearly visible. 图5a图是传统电容式采集系统采集到湿手指所得到的指纹图像,看上去指纹纹路模糊不清很难识别,图5b图是本实用新型电容式指纹采集系统通过实时的自适应过程算法电路来调节输入参考电压可编程的比较器阵列得到的指纹图像,看上去清晰可见。 FIG. 5a is a typical capacitive fingerprint image acquisition system to obtained wet fingers, looks blurred fingerprint is difficult to identify, FIG. 5b show the present invention, capacitive fingerprint acquisition system with real-time adaptive algorithm circuit process adjusting the reference voltage input fingerprint image programmable comparator array obtained appear clearly visible.

[0047] 本领域的技术人员在不脱离权利要求书确定的本实用新型的精神和范围的条件下,还可以对以上内容进行各种各样的修改。 [0047] Those skilled in the art without departing from the claims of the present invention from the spirit and scope determined, various modifications may also be about the above. 因此本实用新型的范围并不仅限于以上的说明,而是由权利要求书的范围来确定的。 Thus the scope of the present invention is not limited to the above description, but rather determined by the scope of the claimed requirements.

Claims (4)

1. 一种新型电容式指纹图像采集系统,包括一感测元阵列,包含多个感测元; 一感测元阵列驱动电路,用于向感测元阵列输入电压信号; 一绝缘表面,覆盖于该感测元阵列之上,作为一手指的接触面; 一比较器阵列,配置于该感测元阵列旁,感测元阵列的输出作为其输入; 一可编程的参考电压源,作为比较器阵列的一输入参考电压; 一自适应过程算法逻辑电路,用于自适应调节可编程的参考电压源; 其特征在于,感测兀阵列接被输入一第一电压信号,使该每一个感测兀内的一参考电容两端或感测电容两端产生一电压差;之后输入一第二电压信号,使参考电容两端与屏蔽电容两端无电压差,或者感测电容两端和屏蔽电容两端无电压差;然后输入一第三电压信号,使屏蔽电极链接到一电压,使该感测电容,该屏蔽电容与该参考电容进行电荷分享之 1. A novel capacitive fingerprint image acquisition system, comprising a sensing element array including a plurality of the sensing element; a sensing cell array driving circuit for an array of input voltage signal to the sensing element; an insulating surface, covering on top of the sensing cell array, a finger as a contact surface; a comparator array, disposed beside the sensing cell array, the output of the sensing cell array as an input; a programmable reference voltage source, as a comparative a reference voltage input array; a process of adaptive arithmetic logic circuit for adaptively adjusting the programmable reference voltage source; wherein the sensing array Wu connected to a first input voltage signal to each of the sense a reference capacitance sensing ends or both ends of the capacitance measurement generating a measured voltage difference Wu; a second voltage after the input signal, both ends of the reference capacitance across the capacitor and the shield no voltage difference, or both ends of the sensing capacitance sensing and shielding no voltage difference across the capacitor; and a third input voltage signal, so that a link to the shield electrode voltage so that the sensing capacitor, with the charge shield capacitance of the reference capacitor to share 再断开该参考电容与该感测电容和该屏蔽电容的链接;顺序的重复输入第二,第三电压信号,直到比较器发生翻转再将每一个比较器的翻转信号输出,作为采集到的灰度级影像信肩、O And then disconnects the link with the reference capacitor and the capacitance of the sensing capacitor shield; repeating sequence of a second input, a third voltage signal, until the inversion signal inverted output of each comparator then comparator occurs, as collected grayscale image channel shoulder, O
2.根据权利要求I所述的一种新型电容式指纹图像采集系统,其特征在于,每一个感测元还包含: 一传感器结构,包括: 一感测电极,与手指、绝缘表面形成感测电容; 两个参考电极;及一绝缘层,配置于两个参考电极间,且在两个参考电极及绝缘层之间会形成参考电容; 一屏蔽电极及配置于屏蔽电极与感测电极间的一绝缘层,在屏蔽电极、绝缘层及感测电极之间形成屏蔽电容;及多个开关电路。 2. A novel capacitive fingerprint image acquisition system according to claim I, wherein each sensing element further comprises: a sensor structure, comprising: a sensing electrode, the sensing finger is formed, the insulating surface capacitance; two reference electrodes; and an insulating layer disposed between the two reference electrodes, and between the two reference electrodes and the insulating layer will form a reference capacitance; and a shield electrode arranged between the shield electrode and the sensing electrode an insulating layer, forming a shield electrode capacitance between the shield, the insulating layer and sense electrodes; and a plurality of switching circuits.
3.根据权利要求I所述的一种新型电容式指纹图像采集系统,其特征在于,自适应过程算法逻辑电路实时分析比较器阵列输入其中的灰度级指纹影像信息,之后输出一反馈信号用于调节比较器阵列的参考电压值。 3. A novel capacitive fingerprint image acquisition system according to claim I, wherein the real-time analysis algorithm adaptation process comparator array logic circuit input gray level information wherein the fingerprint image, and then outputs a feedback signal to adjust the reference voltage of the comparator array.
4.根据权利要求2所述的一种新型电容式指纹图像采集系统,其特征在于,多个感测元的版图结构如下: 最后一层金属作为感测电极,倒数第二层金属作为屏蔽电极,用于隔绝其他电路从而消除背景电容,这两层金属之间的绝缘层与该两层金属之间形成屏蔽电容;每个感测元的屏蔽电极被顺序划分为多块,其中边缘两块连接恒定电压,使得各感测元之间的边缘寄生电容相同,其余的块连接在可变的电压源上,由感测元驱动电路驱动。 4. A novel capacitive fingerprint image acquisition system according to claim 2, wherein the plurality of sensing elements layout structure as follows: As a last layer of metal sensing electrodes, a metal layer as the penultimate shield electrode , isolated from other circuitry for eliminating background capacitance, a capacitance is formed between the shield and the insulating layer between the two metal layers a metal; each sensing element to the shielding electrode is divided into a plurality of sequentially, wherein two edges connecting a constant voltage, such that the edge between the same parasitic capacitance sensing element, the remaining blocks connected to the variable voltage source, a drive circuit for driving the sensing element.
CN 201220476953 2012-09-19 2012-09-19 Novel capacitive type fingerprint image acquisition system CN202771445U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN 201220476953 CN202771445U (en) 2012-09-19 2012-09-19 Novel capacitive type fingerprint image acquisition system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN 201220476953 CN202771445U (en) 2012-09-19 2012-09-19 Novel capacitive type fingerprint image acquisition system

Publications (1)

Publication Number Publication Date
CN202771445U true CN202771445U (en) 2013-03-06

Family

ID=47778006

Family Applications (1)

Application Number Title Priority Date Filing Date
CN 201220476953 CN202771445U (en) 2012-09-19 2012-09-19 Novel capacitive type fingerprint image acquisition system

Country Status (1)

Country Link
CN (1) CN202771445U (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103778420A (en) * 2014-02-28 2014-05-07 成都费恩格尔微电子技术有限公司 Fingerprint detection system having automatic gain control function and automatic gain control method thereof
CN103810479A (en) * 2014-02-28 2014-05-21 成都费恩格尔微电子技术有限公司 Fingerprint collection system and fingerprint information collection method
WO2015106391A1 (en) * 2014-01-14 2015-07-23 敦泰科技有限公司 Electric field-type fingerprint identification apparatus and state control method and prosthesis identification method thereof
CN105378755A (en) * 2013-07-09 2016-03-02 指纹卡有限公司 Fingerprint sensing system and method
WO2017008495A1 (en) * 2015-07-15 2017-01-19 京东方科技集团股份有限公司 Touch screen, control method thereof and display apparatus

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105378755A (en) * 2013-07-09 2016-03-02 指纹卡有限公司 Fingerprint sensing system and method
CN105378755B (en) * 2013-07-09 2017-04-05 指纹卡有限公司 Fingerprint sensing system and method
US9747489B2 (en) 2014-01-14 2017-08-29 Focaltech Electronics, Ltd. Electric field-type fingerprint identification apparatus and state control method and prosthesis identification method thereof
WO2015106391A1 (en) * 2014-01-14 2015-07-23 敦泰科技有限公司 Electric field-type fingerprint identification apparatus and state control method and prosthesis identification method thereof
CN103810479A (en) * 2014-02-28 2014-05-21 成都费恩格尔微电子技术有限公司 Fingerprint collection system and fingerprint information collection method
CN103778420A (en) * 2014-02-28 2014-05-07 成都费恩格尔微电子技术有限公司 Fingerprint detection system having automatic gain control function and automatic gain control method thereof
CN103810479B (en) * 2014-02-28 2019-04-05 成都费恩格尔微电子技术有限公司 Fingerprint acquisition system and finger print information acquisition method
WO2017008495A1 (en) * 2015-07-15 2017-01-19 京东方科技集团股份有限公司 Touch screen, control method thereof and display apparatus
US10229305B2 (en) 2015-07-15 2019-03-12 Boe Technology Group Co., Ltd. Touch screen, control method thereof and display device

Similar Documents

Publication Publication Date Title
KR101459982B1 (en) Finger sensing device including differential measurement circuitry and related methods
JP4048246B2 (en) Fingerprint reading system with an integrated heating resistor
US8669843B2 (en) Fingerprint detection device and method and associated touch control device with fingerprint detection
US20050110103A1 (en) Finger biometric sensor with sensor electronics distributed over thin film and monocrystalline substrates and related methods
EP0981801B1 (en) Electric field fingerprint sensor having enhanced features and related methods
JP4198239B2 (en) Electrostatic charge protection of the capacitive fingerprint sensing array
CN104155785B (en) An array substrate and a driving method, a display device
US6333989B1 (en) Contact imaging device
US20030091220A1 (en) Capacitive sensor device
DE102012025255A1 (en) Method and device for capacitive image acquisition
Tartagni et al. A fingerprint sensor based on the feedback capacitive sensing scheme
CN1263291C (en) Image reading apparatus and its driving method
US6259804B1 (en) Fingerprint sensor with gain control features and associated methods
US7298875B2 (en) Capacitance-type fingerprint sensor
US8659557B2 (en) Touch finding method and apparatus
Hong et al. Combining LBP difference and feature correlation for texture description
US7366332B2 (en) Surface shape recognition sensor
DE10314682B4 (en) Capacitive fingerprint sensor
DE69921712T2 (en) Capacitive proximity sensor
US7548636B2 (en) Organism recognition system
US6191593B1 (en) Method for the non-invasive sensing of physical matter on the detection surface of a capacitive sensor
CN105593878B (en) Capacitive fingerprint sensor having improved sensing element
US10203826B2 (en) Apparatus and method for TFT fingerprint sensor
JPH1091769A (en) Fingerprint reading system
CN1720001A (en) Live finger detection by four-point measurement of complex impedance

Legal Events

Date Code Title Description
C14 Grant of patent or utility model
TR01