九、發明說明： 【發明所屬之技術領域】 本發明係關於一種電容式指紋感應器及其面板，特別是 關於一種使用複數個電晶體之電容式指紋感應器及其面 板。 【先前技術】 指紋感應器為一種用於辨認手指紋樣式及提供可靠度之 個人身份識別的感應器。該指紋感應器也廣泛地使用於可 攜式產品，例如手機、筆記型電腦，用以確保個人保密資 料的安全性0 圖1A和1B顯示指紋感應器之等效電路。大體而言，指紋 感應器可以被實現於一晶片内，在圖1A的編號13代表一保 護層’其作為電容之介電層。若該指紋感應器被嵌入於 —影像面板，在圖1A的編號11代表一 ITO層，且編號13代 表玻璃和薄膜，例如彩色濾光片、偏光板等。以下之敘述 以嵌入於影像面板之指紋感應器為例。在圖1A，一玻璃 U、一上金屬層11及一基板12以串聯方式結合，且該玻璃 13是使用者手指可以碰觸的地方。通常一電容&存在於玻 璃13内’且一電容Q存在於上金屬層11和基板12之間。在 圖1B’使用者手指的表面可分為凸部14和凹部15。該凹部 15和該玻璃13有一個距離d2，而該玻璃13之厚度為^。基 於該結構，一額外電容C2存在於該使用者手指的凹部及該 玻璃13之表面。該凸部電容值(^,係與C1相關，該凹部電容 值吓係與C1//C2相關，而C1和C1//C2可用以下方式表示： 124406.doc 1334994 ^ ，且 <v/c2=_ d' n £\A ε2Α 通常該凸部電容值遠大於該凹部電容值 為了感應使用者手指，一讀出電路應 1刀辨該凸部電容 值及凹部電容值。然而，其並 丨电今 m ^ 易传到所需之準確度， 因為一些環境上的因素，例如雜訊或 【發明内容】 串θ都會減知該結果。IX. INSTRUCTIONS: TECHNICAL FIELD The present invention relates to a capacitive fingerprint sensor and a panel thereof, and more particularly to a capacitive fingerprint sensor using a plurality of transistors and a panel thereof. [Prior Art] A fingerprint sensor is a sensor for recognizing a hand fingerprint pattern and providing personal identification for reliability. The fingerprint sensor is also widely used in portable products such as mobile phones and notebook computers to ensure the security of personal confidential information. Figures 1A and 1B show the equivalent circuit of the fingerprint sensor. In general, the fingerprint sensor can be implemented in a wafer, reference numeral 13 in Figure 1A, which represents a protective layer' as a dielectric layer for the capacitor. If the fingerprint sensor is embedded in an image panel, numeral 11 in Fig. 1A represents an ITO layer, and numeral 13 represents a glass and a film, such as a color filter, a polarizing plate, and the like. The following description takes the fingerprint sensor embedded in the image panel as an example. In Fig. 1A, a glass U, an upper metal layer 11 and a substrate 12 are joined in series, and the glass 13 is a place where a user's fingers can touch. Usually a capacitor & is present in the glass 13' and a capacitor Q is present between the upper metal layer 11 and the substrate 12. The surface of the user's finger in Fig. 1B' can be divided into a convex portion 14 and a concave portion 15. The recess 15 and the glass 13 have a distance d2, and the thickness of the glass 13 is ^. Based on this configuration, an additional capacitor C2 is present on the recess of the user's finger and the surface of the glass 13. The convex capacitance value (^ is related to C1, the concave capacitance value is related to C1//C2, and C1 and C1//C2 can be expressed in the following manner: 124406.doc 1334994 ^ , and <v/c2 =_ d' n £\A ε2Α Usually, the capacitance value of the convex portion is much larger than the capacitance value of the concave portion to sense the finger of the user. A readout circuit should recognize the capacitance value of the convex portion and the capacitance value of the concave portion. However, The current m ^ is easy to pass to the required accuracy, because some environmental factors, such as noise or [invention] string θ will reduce the result.
c, =- 1 本發明之電容式指紋感應器之—實施例包含—第—電曰 體、-指紋電容、一參考電容及一第二電晶體。該第； 晶體包含-閉極端、一輸入端及_輸出端，其中該閑極端 由一第一讀出選擇線所控制，且該輸入端連接至一偏壓 VA。該指紋電容連接至該第一電晶體之輸出端，其中該指 紋電容的電容值為一凹部電容值Q或一凸部電容值Q。該 參考電容之一端連接至該第一電晶體之輸出端，另一端連 接至一第二讀出選擇線，其中該第二讀出選擇線緊鄰於該 第一讀出選擇線，該參考電容具有一電容值Cs，且 該第二電晶體包含一閘極端、一輸入端及一輸 出端，其中該閘極端由一掃描線所控制，該輸入端連接至 該參考電容’且該輸出端連接至一讀出線。 本發明之電谷式指紋感應器之另一實施例包含一指紋電 容心、一參考電容、一第一電晶體及一第二電晶體。該指 紋電容之電谷值為一凹部電容值或一凸部電容值 CfR。該參考電谷具有一電容值Cs，且< C„J。該第一電 I24406.doc • 6· 晶體用於在一預充電階段時預充電該參考電容及指紋電 容。該第二電晶體用於在一估算階段時輸出該指紋電容之 電壓至一讀出線。該預充電階段由一第一讀出選擇線所控 制，該估算階段由一第二讀出選擇線所控制，該第二讀出 選擇線緊鄰於該第一讀出選擇線，且存取該讀出線之有效 時間位於該第二讀出選擇線之啓動期間内。 本發明之包含電容式指紋感應器之面板系統之一實施例 包含一具有電容式指紋感應器之主動式矩陣區域、一資料 驅動器、一掃描驅動器、一讀出電路及一影像處理電路。 该資料驅動器用於驅動影像晝素之資料線。該掃描驅動器 用於控制連接至該電容式指紋感應器之掃描線。該讀出電 路用於接收該電容式指紋感應器之讀出線且辨認該指紋電 谷之種類。該影像處理電路連接至該讀出電路。 【實施方式】 圖2顯示本發明之面板之一具體實施例。該面板系統包含 一主動式矩陣區域25、一資料驅動器2卜一掃描驅動器22、 一％出電路23及一影像處理電路24。該主動式矩陣區域25 包含複數個電容式指紋感應器31，而每一個電容式指紋感 應器3 1都可以選擇性地和一影像畫素共存於一畫素單元。 該資料驅動器21用於驅動資料。該掃描驅動器22用於控制 連接至該電容式指紋感應器31之掃描線。大體而言，當該 電容式指紋感應器31被操作時，連接至該電容式指紋感應 器31之掃描線在整個操作過程被啓動。該讀出電路23用於 接收該電容式指紋感應器3 1之讀出線的類比訊號，且辨認 124406.doc 1334994 該指紋電容3 1之型式’例如凹部電容值或凸部電容值 。該影像處理電路24連接至該讀出電路23。圖2之結構 係以影像面板之嵌入式結構為例，但熟悉該項技術者均可 知悉圖2之結構可以被輕易轉換及應用於一晶片内。 圖3顯示本發明之指紋感應器之一具體實施例。該電容式 才曰紋感應器31包含一第一電晶體33、一第二電晶體34、一 指紋電容Q及一參考電容CSe圖3係顯示連接至同一掃描線 之同一行之兩組相鄰的指紋感應器31。大體而言，當一電 容式指紋感應器31在一預充電階段，其前級相鄰之電容式 指紋感應器32則在一估算階段。當該電容式指紋感應器3 i 在估鼻陡段，其後級相鄰之電容式指紋感應器則在一預 充電階段。該第一電晶體33包含一閘極端、一輸入端及一 輸出端，其中該閘極端由一第一讀出選擇線Cm所控制，且 该輸入端連接至一偏壓VA〇該第二電晶體34包含一閘極 端、一輸入端及一輸出端，其中該閘極端由一掃描線心所 控制，該輸入端連接至該參考電容，且該輸出端連接至一 讀出線。該指紋電容連接至該第二電晶體％之輸入端， 其中該指紋電容的電容值為一凹部電容值Cf[/或一凸部電 合值仰。該參考電容連接至該第一電晶體33之輸出端，其 令該參考電容具有一電容值Cs，且C/v<Q<Cra。 圖4顯示圖3電路之時序圖。大體而言，在同一列之指紋 電容共用同一個掃描線心，其在該列所有指紋電容之整個 操作過輊被啓動。連接至每一指紋感應器之該讀出選擇線 ^至匕被循序啓動且彼此未重疊。該讀出選擇線至&被 I24406.doc • 8· 1334994 使用於啓動每一指紋感應器之預充電階段及估算階段，以 循序地由對應於該掃描線之同一列指紋感應器讀取資料。 每一讀出選擇線的脈波寬度被表示為VD。該讀出電路23 在對應的讀出選擇線被取銷前讀取該讀出線。例如，讀取 该讀出線[Cm+1]的時間開始於讀出選擇線[cm+i]被啓 動’而結束於讀出選擇線[Cm+1 ]被取銷。c, =- 1 - The embodiment of the capacitive fingerprint sensor of the present invention comprises - a first body, a fingerprint capacitor, a reference capacitor and a second transistor. The crystal includes a closed-end, an input, and an output, wherein the idle terminal is controlled by a first sense select line, and the input is coupled to a bias voltage VA. The fingerprint capacitor is connected to the output end of the first transistor, wherein the capacitance of the fingerprint capacitor is a recess capacitance value Q or a convex portion capacitance value Q. One end of the reference capacitor is connected to the output end of the first transistor, and the other end is connected to a second read select line, wherein the second read select line is adjacent to the first read select line, the reference capacitor has a capacitor value Cs, and the second transistor includes a gate terminal, an input terminal and an output terminal, wherein the gate terminal is controlled by a scan line connected to the reference capacitor 'and the output terminal is connected to A readout line. Another embodiment of the electric valley fingerprint sensor of the present invention comprises a fingerprint capacitor core, a reference capacitor, a first transistor, and a second transistor. The electric valley value of the fingerprint capacitor is a concave capacitance value or a convex capacitance value CfR. The reference valley has a capacitance value Cs, and < C „ J. The first electric I24406.doc • 6· crystal is used to precharge the reference capacitor and the fingerprint capacitor during a precharge phase. The second transistor For outputting the voltage of the fingerprint capacitor to a readout line during an estimation phase. The precharge phase is controlled by a first read select line, the estimation phase being controlled by a second read select line, the The second read select line is adjacent to the first read select line, and the effective time for accessing the read line is within the start period of the second read select line. The panel system of the present invention comprising a capacitive fingerprint sensor An embodiment includes an active matrix area having a capacitive fingerprint sensor, a data driver, a scan driver, a readout circuit, and an image processing circuit. The data driver is used to drive an image line of the image element. The scan driver is configured to control a scan line connected to the capacitive fingerprint sensor. The readout circuit is configured to receive a readout line of the capacitive fingerprint sensor and identify the type of the fingerprint valley. The circuit is connected to the readout circuit. [Embodiment] Figure 2 shows a specific embodiment of the panel of the present invention. The panel system comprises an active matrix area 25, a data driver 2, a scan driver 22, and a % out The circuit 23 and an image processing circuit 24. The active matrix region 25 includes a plurality of capacitive fingerprint sensors 31, and each of the capacitive fingerprint sensors 31 can selectively coexist with an image pixel in a pixel. The data driver 21 is used to drive data. The scan driver 22 is used to control a scan line connected to the capacitive fingerprint sensor 31. Generally, when the capacitive fingerprint sensor 31 is operated, it is connected to the The scan line of the capacitive fingerprint sensor 31 is activated during the entire operation. The readout circuit 23 is configured to receive the analog signal of the readout line of the capacitive fingerprint sensor 31, and identify 124406.doc 1334994 the fingerprint capacitor 3 A type of 'such as a recess capacitance value or a convex portion capacitance value. The image processing circuit 24 is connected to the readout circuit 23. The structure of Fig. 2 is an embedded structure of the image panel. For example, those skilled in the art will appreciate that the structure of Figure 2 can be easily converted and applied to a wafer. Figure 3 shows a specific embodiment of the fingerprint sensor of the present invention. A first transistor 33, a second transistor 34, a fingerprint capacitor Q and a reference capacitor CSe are shown in FIG. 3 to show two sets of adjacent fingerprint sensors 31 connected to the same row of the same scan line. When a capacitive fingerprint sensor 31 is in a pre-charging stage, its pre-adjacent capacitive fingerprint sensor 32 is in an estimation stage. When the capacitive fingerprint sensor 3 i is in the estimated steep section, thereafter The adjacent adjacent capacitive fingerprint sensor is in a pre-charging stage. The first transistor 33 includes a gate terminal, an input terminal and an output terminal, wherein the gate terminal is controlled by a first readout selection line Cm. And the input terminal is connected to a bias voltage VA, the second transistor 34 includes a gate terminal, an input terminal and an output terminal, wherein the gate terminal is controlled by a scanning core, and the input terminal is connected to the reference Capacitor, and the output is connected to a Qualify. The fingerprint capacitor is connected to the input end of the second transistor %, wherein the capacitance value of the fingerprint capacitor is a recess capacitance value Cf [/or a convex portion value). The reference capacitor is coupled to the output of the first transistor 33 such that the reference capacitor has a capacitance value Cs and C/v < Q < Cra. Figure 4 shows a timing diagram of the circuit of Figure 3. In general, the fingerprint capacitors in the same column share the same scan line center, which is activated after the entire operation of all fingerprint capacitors in the column. The read select lines ^ to 连接 connected to each fingerprint sensor are sequentially activated and do not overlap each other. The read select line to & is used by I24406.doc • 8· 1334994 to initiate a precharge phase and an estimation phase of each fingerprint sensor to sequentially read data from the same column of fingerprint sensors corresponding to the scan line . The pulse width of each read selection line is represented as VD. The readout circuit 23 reads the readout line before the corresponding readout selection line is taken out. For example, the time at which the read line [Cm+1] is read starts when the read select line [cm+i] is activated and ends at the read select line [Cm+1].
圖5 A顯示在預充電階段，該指紋感應器3丨之等效電路。 在預充電階段，該讀出選擇線Cm被啓動，該第一電晶體3 3 被致能，且該偏壓VA分別預充電該參考電容和該指紋電 容。 圖5B顯示在估算階段，該指紋感應器31之等效電路。在 估算階段，該讀出選擇線Cm+1被啓動如VD，且儲存於該參 考電容和指紋電容之電荷被重新分佈。此時，掃描線仍然 被啓動，該第二電晶體34被致能，該讀出線依據使用者手Figure 5A shows the equivalent circuit of the fingerprint sensor 3丨 during the pre-charge phase. In the precharge phase, the read select line Cm is enabled, the first transistor 3 3 is enabled, and the bias VA precharges the reference capacitor and the fingerprint capacitor, respectively. Figure 5B shows the equivalent circuit of the fingerprint sensor 31 during the estimation phase. In the estimation phase, the read select line Cm+1 is activated as VD, and the charge stored in the reference capacitor and the fingerprint capacitor is redistributed. At this time, the scan line is still activated, the second transistor 34 is enabled, and the read line is based on the user's hand.
指被偵測到的部位，即指紋凸部或凹部，而輸出電壓 VA + —^—~xVD VA + —^—xVD S FR 或 Cs+CFy 。很明顯地，若指紋凹部被偵 測到’則其讀出線之電壓大於若指紋凸部被偵測到之電壓。 圖6顯示本發明之一具體實施例之讀出電路。該讀出電路 23包含一多工器62和一比較器61。該多工器62之輸入端連 接至該讀出線’該多工器62之輸出端連接至該比較器61， 且該比較器61輸出一個位元至該影像處理電路24。為了分 辨凸部電容和凹部電容，該比較器6 1使用一閥值電壓^^， 广 且 VA + c'+r xVD>V^>VA+ Cs xVD。據此’若該比較器 61Refers to the detected part, ie the convex or concave part of the fingerprint, and the output voltage VA + —^—~xVD VA + —^—xVD S FR or Cs+CFy . Obviously, if the fingerprint recess is detected, then the voltage of the read line is greater than the voltage at which the fingerprint is detected. Figure 6 shows a readout circuit in accordance with one embodiment of the present invention. The readout circuit 23 includes a multiplexer 62 and a comparator 61. An input of the multiplexer 62 is coupled to the sense line. The output of the multiplexer 62 is coupled to the comparator 61, and the comparator 61 outputs a bit to the image processing circuit 24. In order to distinguish the convex portion capacitance and the concave portion capacitance, the comparator 61 uses a threshold voltage ^^, and VA + c' + r xVD > V^ > VA + Cs x VD. According to this, if the comparator 61
十 cs+cFR 124406.doc -9- 1334994 輸出邏輯高位準，Μ由指紋感應器接收到❸資料為凹部 電容。反之，則為凸部電容。 本發明之技術内容及技術特點已揭示如上， …、叩热悉本 項技術之人士仍可能基於本發明之教示及揭示而作種種不 背離本發明精神之替換及修飾。因此，本發明之保護範= 應不限於實施例所揭示者，而應包括各種不背離本發明之 替換及修飾，並為以下之申請專利範圍所涵蓋。 【圖式簡單說明】 圖1A和1B顯示指紋感應器之等效電路； 圖2顯示本發明之面板之一具體實施例； 圖3顯示本發明之指紋感應器之一具體實施例； 圖4顯示圖3電路之時序圖； 圖5A和5B顯示圖3電路之預充電階段及估算階段；及 圖6顯示本發明之一具體實施例之讀出電路。 【主要元件符號說明】Ten cs+cFR 124406.doc -9- 1334994 The output logic is high level, and the data received by the fingerprint sensor is the concave capacitance. On the contrary, it is a convex capacitor. The technical and technical features of the present invention have been disclosed above, and those skilled in the art can still make various substitutions and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is not limited by the scope of the invention, and should be construed as being included in the following claims. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A and 1B show an equivalent circuit of a fingerprint sensor; FIG. 2 shows a specific embodiment of a panel of the present invention; FIG. 3 shows a specific embodiment of a fingerprint sensor of the present invention; FIG. 5A and FIG. 5B show the precharge phase and the estimation phase of the circuit of FIG. 3; and FIG. 6 shows the readout circuit of one embodiment of the present invention. [Main component symbol description]
11 上金屬板 12 基板 13 保護層 14 指紋凸部 15 指紋凹部 21 資料驅動器 22 掃描驅動器 23 讀出電路 24 影像處理電路 25 面板 31 電容式指紋感應器 32 電容式指紋感應器 124406.doc -ία 1334994 33 第一電晶體 34 第二電晶體 CF 指紋電容 Cs 參考電容 61 比較器 62 多工器 124406.doc -\b11 Upper metal plate 12 Substrate 13 Protective layer 14 Fingerprint convex portion 15 Fingerprint concave portion 21 Data driver 22 Scan driver 23 Readout circuit 24 Image processing circuit 25 Panel 31 Capacitive fingerprint sensor 32 Capacitive fingerprint sensor 124406.doc -ία 1334994 33 First transistor 34 Second transistor CF Fingerprint capacitor Cs Reference capacitor 61 Comparator 62 Multiplexer 124406.doc -\b