TWI526944B - Fingerprint Sensing Device and Method of Detecting Finger Touch Thereof - Google Patents
Fingerprint Sensing Device and Method of Detecting Finger Touch Thereof Download PDFInfo
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
- G06V40/00—Recognition of biometric, human-related or animal-related patterns in image or video data
- G06V40/10—Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
- G06V40/12—Fingerprints or palmprints
- G06V40/13—Sensors therefor
- G06V40/1306—Sensors therefor non-optical, e.g. ultrasonic or capacitive sensing
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Description
本發明係關於一種指紋感測裝置，尤指一種可在待機模式下偵測有無手指觸碰的指紋感測裝置。 The invention relates to a fingerprint sensing device, in particular to a fingerprint sensing device capable of detecting the presence or absence of a finger touch in a standby mode.
目前電容式指紋檢測器廣泛應用於電子裝置，如手機、筆記型電腦等，以確認使用者身份用。一般電容式指紋檢測器概分為陣列型及線型，當該陣列型或線型指紋檢測器係與一感測電路一併成形於晶片上，易受靜電影響而損壞，且製作成本較高；因此，當陣列型或線型指紋檢測器係獨立成形於軟性電路板等類似的基板上，再與外部感測電路電連接，靜電防護效果佳，其中以線性指紋檢測器的尺寸較矩陣型指紋檢測器小，可供小型化電子裝置使用。 At present, capacitive fingerprint detectors are widely used in electronic devices, such as mobile phones, notebook computers, etc., to confirm the identity of users. Generally, a capacitive fingerprint detector is roughly classified into an array type and a line type. When the array type or line type fingerprint detector is formed on a wafer together with a sensing circuit, it is easily damaged by static electricity and has a high manufacturing cost; When the array type or line type fingerprint detector is independently formed on a flexible circuit board or the like and then electrically connected with an external sensing circuit, the electrostatic protection effect is good, wherein the size of the linear fingerprint detector is larger than the matrix type fingerprint detector. Small, available for miniaturized electronic devices.
不論矩陣型或線型指紋檢測器的感測電路均藉由其感測電路進行掃描，以擷取手指指紋影像，並與儲存的使用者指紋影像進行比對識別。然而，就使用者使用電子裝置時間，該指紋檢測器實際上被喚醒的運作時間佔電子裝置整體使用時間的比例偏低，若電子裝置不論在待機或工作模式下均讓指紋檢測器以不間斷掃描的方式持續擷取其影像且同時判斷是否有手指碰觸時，此方式將相當耗電。因此，目前已針對線型指紋檢測器提出一種省電的掃描方法，如圖7所示，習用指紋檢測器係於一基板50上形成有複數並排驅動線51、 二條與該等複數驅動線51耦接的接收線52、52a及二條驅動線53、54，該二條驅動線53、54係與其中一條接收線52a並排；該等線均與一感測電路(圖中未示)連接。其中該感測電路係包含有一工作模式、一待機模式及一休眠模式。 The sensing circuit of the matrix type or line type fingerprint detector is scanned by its sensing circuit to capture the finger fingerprint image and compare and recognize it with the stored user fingerprint image. However, in the case of the user using the electronic device, the operation time of the fingerprint detector being actually woken up is a low proportion of the total use time of the electronic device, and if the electronic device is in the standby or working mode, the fingerprint detector is kept uninterrupted. This method consumes a lot of power when the scanning method continues to capture its image and at the same time determine if there is a finger touch. Therefore, a power-saving scanning method has been proposed for the line fingerprint detector. As shown in FIG. 7, the conventional fingerprint detector is formed with a plurality of side-by-side driving lines 51 on a substrate 50. Two receiving lines 52, 52a and two driving lines 53, 54 coupled to the plurality of driving lines 51, the two driving lines 53, 54 are arranged side by side with one of the receiving lines 52a; and the lines are connected to a sensing circuit ( Connections are not shown in the figure. The sensing circuit includes an operating mode, a standby mode, and a sleep mode.
於工作模式下，該感測電路係驅動該複數驅動線51並自該接收線52、52a接收感應訊號，以擷取手指的指紋影像；其中該二接收線52、52a係同時接收感應訊號，以消除感應訊號的雜訊。如該感測電路於一段時間未檢測到有手指碰觸，則會自工作模式進入待機模式。在待機模式下，該感測電路驅動該二條驅動線53、54並利用該二接收線52、52a檢測是否有手指觸碰，當有手指60觸碰時感應訊號的振幅大小會變化，可檢測是否有手指60觸碰。若檢測有手指60觸碰，則喚醒該感測電路自待機模式返回工作模式，以擷取手指指紋影像。 In the working mode, the sensing circuit drives the complex driving line 51 and receives an inductive signal from the receiving lines 52, 52a to capture a fingerprint image of the finger; wherein the two receiving lines 52, 52a receive the sensing signal simultaneously. To eliminate the noise of the inductive signal. If the sensing circuit does not detect a finger touch for a certain period of time, it will enter the standby mode from the working mode. In the standby mode, the sensing circuit drives the two driving lines 53, 54 and detects whether there is a finger touch by using the two receiving lines 52, 52a. When the finger 60 touches, the amplitude of the sensing signal changes, which can be detected. Is there a finger 60 touch? If it is detected that the finger 60 touches, the sensing circuit is awakened to return to the working mode from the standby mode to capture the finger fingerprint image.
然而，上述指紋檢測器的感測電路為了節省耗電量而設置一待機模式，且必須配合改變該指紋檢測器的結構，以增加二條驅動線，反而加大了該線型指紋檢測器的尺寸，對於要求尺寸的電子裝置來說，絕非為最佳的選擇。 However, the sensing circuit of the fingerprint detector has a standby mode in order to save power consumption, and must change the structure of the fingerprint detector to increase two driving lines, thereby increasing the size of the line type fingerprint detector. It is by no means the best choice for electronic devices of the required size.
有鑑於上述技術缺陷，本發明主要目的係提供一指紋感測裝置及其手指觸碰偵測方法，可在不更改原指紋檢測器的感應結構下，達到省電的功效。 In view of the above technical defects, the main object of the present invention is to provide a fingerprint sensing device and a finger touch detecting method thereof, which can achieve the power saving effect without changing the sensing structure of the original fingerprint detector.
欲達上述目的所使用的主要技術手段係令該指紋感測裝置包含有：一指紋檢測器，係於一基板上形成有複數驅動線、一第一跡線及一第二跡線，該第一跡線設置於該複數驅動線及該第二跡線之間；及 一控制器，係分別電性連接該複數驅動線、該第一跡線及該第二跡線，其中該控制器包含有一工作模式及一待機模式；其中，於該工作模式下該控制器係提供一驅動訊號予該複數驅動線，並且接收該第一跡線及第二跡線對應該各驅動線之間的的電容感應訊號，而於該待機模式下該控制器係令該第一跡線及該第二跡線之間產生電容感應訊號，並依據該電容感應訊號變化判斷手指觸碰與否。 The main technical means for achieving the above purpose is that the fingerprint sensing device comprises: a fingerprint detector, wherein a plurality of driving lines, a first trace and a second trace are formed on a substrate, the first a trace disposed between the plurality of drive lines and the second trace; and a controller electrically connected to the plurality of driving lines, the first trace and the second trace, wherein the controller comprises an operating mode and a standby mode; wherein the controller is in the working mode Providing a driving signal to the plurality of driving lines, and receiving the capacitive sensing signals between the first and second traces corresponding to the driving lines, and in the standby mode, the controller causes the first trace A capacitive sensing signal is generated between the line and the second trace, and the finger touch is determined according to the change of the capacitive sensing signal.
欲達上述目的所使用的主要技術手段係令一指紋檢測器的手指觸碰偵測方法，該指紋檢測器包含有複數驅動線、一第一跡線及一第二跡線；其中該手指觸碰偵測方法包括：將該指紋檢測器設定於一工作模式及一待機模式的其中之一下運作；其中：於該工作模式下，提供一驅動訊號至該複數驅動線，並且接收該第一跡線及該第二跡線對應該各驅動線之間的電容感應訊號，並自該二電容感應訊號中擷取並識別該指紋影像；及於該待機模式下，係令該第一跡線及該第二跡線之間產生一電容感應訊號，並依據該電容感應訊號變化判斷手指有無觸碰。 The main technical means for achieving the above purpose is a finger touch detection method of a fingerprint detector, the fingerprint detector comprising a plurality of driving lines, a first trace and a second trace; wherein the finger touch The touch detection method includes: setting the fingerprint detector to operate in one of a working mode and a standby mode; wherein: in the working mode, providing a driving signal to the plurality of driving lines, and receiving the first trace The line and the second trace correspond to a capacitive sensing signal between the driving lines, and the fingerprint image is captured and recognized from the two capacitive sensing signals; and in the standby mode, the first trace is A capacitive sensing signal is generated between the second traces, and the finger is touched according to the change of the capacitive sensing signal.
上述本發明的第一跡線及第二跡線於工作模式下作為接收跡線使用，可消除第一跡線之電容感應訊號所包含環境雜訊，而於待機模式下不再驅動該複數驅動線，而使該第一及第二跡線之間產生電容感應訊號，當手指觸碰時，該電容感應訊號產生變化，故該控制器可依據該電容感應訊號的變化判斷手指有無觸碰；因此，本發明於待機模式下檢測手指觸碰時，藉由在工作模式下作為接收跡線用的第一及二跡線，而不必另外增加跡線配合省電的待機模式進行手指觸碰的檢測，故本發明的指紋檢測器尺寸不會增加。 The first trace and the second trace of the present invention are used as receiving traces in the working mode, which can eliminate the environmental noise included in the capacitive sensing signal of the first trace, and no longer drive the complex driving in the standby mode. a line, and a capacitive sensing signal is generated between the first and second traces. When the finger touches, the capacitive sensing signal changes, so the controller can determine whether the finger touches according to the change of the capacitive sensing signal; Therefore, when detecting the finger touch in the standby mode, the present invention uses the first and second traces for receiving the trace in the operation mode, and does not need to additionally increase the standby mode of the trace with the power saving for the finger touch. Detection, the size of the fingerprint detector of the present invention does not increase.
10、10a‧‧‧指紋檢測器 10, 10a‧‧‧ fingerprint detector
101‧‧‧基板 101‧‧‧Substrate
11‧‧‧驅動線 11‧‧‧Drive line
111‧‧‧第一端 111‧‧‧ first end
112‧‧‧第二端 112‧‧‧ second end
12、12’‧‧‧第一跡線 12, 12’‧‧‧ first trace
121‧‧‧延伸部 121‧‧‧Extension
13、13’‧‧‧第二跡線 13, 13’‧‧‧ second trace
131‧‧‧延伸部 131‧‧‧Extension
20、20a‧‧‧控制器 20, 20a‧‧‧ controller
21‧‧‧驅動單元 21‧‧‧ drive unit
211‧‧‧第一切換單元 211‧‧‧ first switching unit
212‧‧‧一對多多工器 212‧‧‧One-to-many multi-tool
22‧‧‧處理單元 22‧‧‧Processing unit
221‧‧‧差動放大器 221‧‧‧Differential Amplifier
222‧‧‧混波器 222‧‧‧Mixer
223‧‧‧低通濾波器 223‧‧‧low pass filter
224‧‧‧類比數位轉換器 224‧‧‧ Analog Digital Converter
23‧‧‧觸碰感應單元 23‧‧‧Touch sensing unit
231‧‧‧第二切換單元 231‧‧‧Second switching unit
232、232a‧‧‧電荷轉移單元 232, 232a‧‧‧ Charge Transfer Unit
233‧‧‧比較器 233‧‧‧ comparator
30‧‧‧手指 30‧‧‧ fingers
50‧‧‧基板 50‧‧‧Substrate
51‧‧‧驅動線 51‧‧‧ drive line
52‧‧‧接收線 52‧‧‧ receiving line
52a‧‧‧接收線 52a‧‧‧ Receiving line
53‧‧‧驅動線 53‧‧‧ drive line
54‧‧‧驅動線 54‧‧‧ drive line
60‧‧‧手指 60‧‧‧ fingers
圖1A：係本發明指紋感測裝置之一第一較佳實施例於工作模式下的電路動作圖。 1A is a circuit operation diagram of a first preferred embodiment of the fingerprint sensing device of the present invention in an operating mode.
圖1B：係本發明指紋感測裝置之一第一較佳實施例於待機模式下的電路動作圖。 FIG. 1B is a circuit operation diagram of a first preferred embodiment of the fingerprint sensing device of the present invention in a standby mode.
圖2A：係本發明指紋感測裝置之一第二較佳實施例於工作模式下的電路動作圖。 2A is a circuit operation diagram of a second preferred embodiment of the fingerprint sensing device of the present invention in an operating mode.
圖2B：係本發明指紋感測裝置之一第二較佳實施例於待機模式下的電路動作圖。 2B is a circuit operation diagram of a second preferred embodiment of the fingerprint sensing device of the present invention in a standby mode.
圖3：係本發明指紋感測裝置之另一指紋檢測器。 Figure 3 is another fingerprint detector of the fingerprint sensing device of the present invention.
圖4：係本發明指紋感測裝置之處理單元的功能方塊圖。 Figure 4 is a functional block diagram of a processing unit of the fingerprint sensing device of the present invention.
圖5：係本發明指紋感測裝置之觸碰感應單元的功能方塊圖。 Figure 5 is a functional block diagram of a touch sensing unit of the fingerprint sensing device of the present invention.
圖6A：係本發明觸碰感應單元之電荷移轉單元的一電路圖。 Fig. 6A is a circuit diagram of a charge transfer unit of the touch sensing unit of the present invention.
圖6B：係本發明觸碰感應單元之電荷移轉單元的另一電路圖。 Fig. 6B is another circuit diagram of the charge transfer unit of the touch sensing unit of the present invention.
圖7：係既有一手指檢測器的結構示意圖。 Figure 7 is a schematic view showing the structure of a finger detector.
本發明主要針對電容式指紋感測裝置進行改良，可省電且不改變既有結構的電容式指紋感測裝置。以下配合圖式及本發明之較佳實施例，進一步闡述本發明為達成預定目的所採取的技術手段。 The invention mainly aims at improving the capacitive fingerprint sensing device, and can save power without changing the capacitive fingerprint sensing device of the existing structure. The technical means adopted by the present invention for achieving the intended purpose are further explained below in conjunction with the drawings and preferred embodiments of the present invention.
首先請參閱圖1A所示，係為本發明電容式指紋感測裝置的第一較佳實施例，其包含有一指紋檢測器10及一控制器20，其中該控制器20係與該指紋檢測器10電連接。 Referring to FIG. 1A, a first preferred embodiment of the capacitive fingerprint sensing device of the present invention includes a fingerprint detector 10 and a controller 20, wherein the controller 20 is coupled to the fingerprint detector. 10 electrical connections.
上述指紋檢測器10係於一基板101上形成有複數驅動線11、一第一跡線12及一第二跡線13。於本實施例中，該複數驅動線11係與一第一方向x(即手指掃滑方向S1)平行且相互等距排列，且各該驅動線11包含有一第一端111及一第二端112，各該驅動線11的第二端112係分別對應與該控制器20的複數接點Tx1~Txn電連接。該第一跡線12與垂直第一方向x的一第二方向y平行，且該第一跡線12對應設置於各該驅動線11的第一端111之一側，且與各該第一端111保持相同間距。該第二跡線13係與該第一跡線12相互平行設置，使該第一跡線12位於該複數驅動線11及第二跡線13之間；因此，該第一跡線12係分別與各該驅動線11及該第二跡線13耦接，且該第一跡線12與該第二跡線13之間的電容C_finger耦接面積(如圖1B所示)係大於該第一跡線12與各該驅動線11之間的電容C_img耦接面積的總合(如圖1A所示)。又，該第一跡線12的形狀係對應第二跡線13的形狀，較佳地該第一跡線12與第二跡線13的形狀及尺寸(長度、寬度)均相同。在本實施例該第一及第二跡線12、13均為長條形，再如圖3所示，係為指紋檢測器10a的另一實施例，即圖1A的第一及第二跡線12、13係分別自其一端形成一延伸部121、131，使該第一及第二跡線12’、13’呈L形，由於該第一及第二跡線12、13各自形成該延伸部121、131，藉此增加其二者之間的耦接面積，使其二者之間的電容耦合量能數倍於該第一跡線12與各該驅動線11之間的電容耦合量。 The fingerprint detector 10 is formed on a substrate 101 with a plurality of driving lines 11, a first trace 12 and a second trace 13. In this embodiment, the plurality of driving lines 11 are parallel to a first direction x (ie, the finger sweeping direction S1) and are equidistant from each other, and each of the driving lines 11 includes a first end 111 and a second end. 112. The second ends 112 of the driving lines 11 are respectively electrically connected to the plurality of contacts Tx1 TTxn of the controller 20. The first trace 12 is parallel to a second direction y of the vertical first direction x, and the first trace 12 is correspondingly disposed on one side of the first end 111 of each of the driving lines 11, and each of the first Ends 111 maintain the same spacing. The second trace 13 is disposed parallel to the first trace 12 such that the first trace 12 is located between the plurality of drive lines 11 and the second trace 13; therefore, the first trace 12 is respectively The driving line 11 and the second trace 13 are coupled to each other, and a capacitance C_finger coupling area (shown in FIG. 1B ) between the first trace 12 and the second trace 13 is greater than the first The sum of the coupling areas of the capacitance C_img between the trace 12 and each of the driving lines 11 (as shown in FIG. 1A). Moreover, the shape of the first trace 12 corresponds to the shape of the second trace 13. Preferably, the shape and size (length, width) of the first trace 12 and the second trace 13 are the same. In the present embodiment, the first and second traces 12, 13 are all elongated, and as shown in FIG. 3, it is another embodiment of the fingerprint detector 10a, that is, the first and second traces of FIG. 1A. The wires 12 and 13 respectively form an extending portion 121, 131 from one end thereof, so that the first and second traces 12', 13' are L-shaped, since the first and second traces 12, 13 respectively form the Extending portions 121, 131, thereby increasing the coupling area between the two, so that the capacitive coupling between the two can be several times the capacitive coupling between the first trace 12 and each of the driving lines 11. the amount.
上述控制器20係包含有一驅動單元21、一第一切換單元211及一處理單元22，並具有一工作模式及一待機模式。該驅動單元21係電連接至該指紋檢測器10的複數驅動線11的第二端112，以依序輸出一驅動訊號至各該驅動線11，又該驅動單元21透過該第一切換單元211電連接至該指紋檢測器10的第一及第二跡線12、13的其中一條；在本實施例中，該驅動單元21係透過一個一 對多多工器212連接至該複數驅動線11的第二端112，且透過該第一切換單元211連接該第二跡線13，以輸出一刺激訊號至該第二跡線13。 The controller 20 includes a driving unit 21, a first switching unit 211 and a processing unit 22, and has an operating mode and a standby mode. The driving unit 21 is electrically connected to the second end 112 of the plurality of driving lines 11 of the fingerprint detector 10 to sequentially output a driving signal to each of the driving lines 11, and the driving unit 21 transmits the first switching unit 211. Electrically connected to one of the first and second traces 12, 13 of the fingerprint detector 10; in this embodiment, the drive unit 21 is transmitted through one The multi-multiplexer 212 is connected to the second end 112 of the complex driving line 11 and is connected to the second trace 13 through the first switching unit 211 to output a stimulation signal to the second trace 13.
該處理單元22係具有一第一差動輸入端D1及一第二差動輸入端D2。該第一差動輸入端D1係電連接至該第一跡線12的一端Rx，而該第二差輸入端D2則透過該第一切換單元211電連接至該第二跡線13的一端Rx_dummy。 The processing unit 22 has a first differential input terminal D1 and a second differential input terminal D2. The first differential input terminal D1 is electrically connected to one end Rx of the first trace 12, and the second differential input terminal D2 is electrically connected to one end of the second trace 13 through the first switching unit 211. Rx_dummy .
如圖1A所示，當該控制器20於一工作模式下，該驅動單元21輸出一驅動訊號，並透過該一對多多工器212依序輸出至各該驅動線11，同時由該處理單元22接收該第一跡線12的電容感應訊號及第二跡線13的電容感應訊號，並對該二電容感應訊號進行差分運算。由於該第一及第二跡線12、13可能受到環境雜訊的影響，藉由差分運算後即可消除該第一跡線接12接收的電容感應訊號所包含的雜訊成份。由於環境雜訊通常為低頻訊號，故該驅動單元21的驅動訊號較佳地可使用一高頻交變電壓訊號；其中該交變電壓訊號可為脈衝電壓訊號或弦波電壓訊號等。由該處理單元22擷取該第一跡線12與各該驅動線11耦合的電容感應訊號，再依據數次差分計算後的電容感應訊號，計算並組合出一手指30的指紋影像。 As shown in FIG. 1A, when the controller 20 is in an operating mode, the driving unit 21 outputs a driving signal, and sequentially outputs the driving signals to each of the driving lines 11 through the one-to-multiple multiplexer 212, and simultaneously by the processing unit. The receiving of the capacitive sensing signal of the first trace 12 and the capacitive sensing signal of the second trace 13 and performing a differential operation on the two capacitive sensing signals. Since the first and second traces 12 and 13 may be affected by environmental noise, the noise component included in the capacitive sensing signal received by the first trace 12 can be eliminated by differential operation. Since the ambient noise is usually a low frequency signal, the driving signal of the driving unit 21 can preferably use a high frequency alternating voltage signal; wherein the alternating voltage signal can be a pulse voltage signal or a sine wave voltage signal. The processing unit 22 captures the capacitive sensing signal coupled to the driving line 11 by the first trace 12, and calculates and combines the fingerprint image of the finger 30 according to the differential sensing capacitive sensing signal.
再如圖1B所示，當該控制器20自該工作模式進入一待機模式，例如經過一預設時間內未檢測到有對應手指碰觸的指紋，即自該工作模式進入該待機模式；此時該驅動單元21不再輸出驅動訊號至該複數驅動線11，而控制該第一切換單元211，將原連接至第二差動輸入端D2的第二跡線13之一端Rx_dummy切換連接至該驅動單元21，因此該驅動單元21在該待機模式下僅對該第二跡線13輸入一刺激訊號。由於該第一跡線12耦接該第二跡線13，此時該處理單元22可自該第一跡線12一端Rx接收到電容感應訊號，因此該刺激訊號可為直流固定電壓訊號或交變電壓訊號。由於該處理單元22可預設一手指觸碰臨界值，故該電容感應訊號經轉換為對應的電容感應值，可與該手指觸碰臨界值 相比，若大於該手指觸碰臨界值，則判斷有手指30觸碰至該手指檢測器10；反之則未有手指觸碰。當該處理單元22判斷已有手指30觸碰，則令該控制器20返回該工作模式，進行指紋影像的擷取。是以，在裝設有本發明指紋感應裝置的電子裝置，於使用電子裝置期間中有長時間未觸碰該手指檢測器10，該控制器20會保持在該待機模式，進而有效地節省電量。 As shown in FIG. 1B, when the controller 20 enters a standby mode from the working mode, for example, a fingerprint that has a corresponding finger touch is not detected within a preset time, that is, the standby mode is entered from the working mode; When the driving unit 21 no longer outputs the driving signal to the complex driving line 11, the first switching unit 211 is controlled to switch the first end Rx_dummy of the second trace 13 originally connected to the second differential input terminal D2 to the The driving unit 21, therefore, the driving unit 21 inputs only a stimulation signal to the second trace 13 in the standby mode. Since the first trace 12 is coupled to the second trace 13, the processing unit 22 can receive the capacitive sensing signal from the end Rx of the first trace 12, so the stimulus signal can be a DC fixed voltage signal or Variable voltage signal. Since the processing unit 22 can preset a finger touch threshold, the capacitive sensing signal is converted into a corresponding capacitive sensing value, and the finger can be touched with the threshold. In contrast, if the finger touches the threshold value, it is determined that the finger 30 touches the finger detector 10; otherwise, no finger touches. When the processing unit 22 determines that the finger 30 has been touched, the controller 20 returns the working mode to capture the fingerprint image. Therefore, in the electronic device equipped with the fingerprint sensing device of the present invention, the finger detector 10 is not touched for a long time during use of the electronic device, and the controller 20 is maintained in the standby mode, thereby effectively saving power. .
請參閱圖2A所示，係為本發明指紋感測裝置的第二較佳實施例，其與第一較佳實施例大致相同，惟該控制器20a進一步包含有一觸碰感應單元23及一第二切換單元231。該第一跡線12之一端Rx係連接該第二切換單元231，且藉由該第二切換單元231的控制，可使該第一跡線12的一端Rx切換至連接該處理單元22的第一差動輸入端D1或該觸碰感應單元23。在圖2A中，該控制器20a係於該工作模式下，該驅動單元21同樣透過該一對多多工器212將一驅動訊號依序輸出至各該驅動線11，同時該處理單元22獲得該第一及第二跡線12、13的電容感應訊號，並進行差分運算。 The second preferred embodiment of the fingerprint sensing device of the present invention is substantially the same as the first preferred embodiment. The controller 20a further includes a touch sensing unit 23 and a first Second switching unit 231. One end Rx of the first trace 12 is connected to the second switching unit 231, and one end Rx of the first trace 12 can be switched to be connected to the processing unit 22 by the control of the second switching unit 231. A differential input terminal D1 or the touch sensing unit 23. In FIG. 2A, the controller 20a is in the working mode, and the driving unit 21 also sequentially outputs a driving signal to each of the driving lines 11 through the one-to-many multiplexer 212, and the processing unit 22 obtains the driving signal. The capacitive sensing signals of the first and second traces 12, 13 are subjected to differential operations.
請配合圖4所示，該處理單元22係包含有一差動放大器221、一混波器222、一低通濾波器223及一類比數位轉換器224。該差動放大器221具有二輸入端及一輸出端，其中該二輸入端係分別連接至該第一及第二差動輸入端D1、D2。該混波器222具有一輸入端及一輸出端，該輸入端係連接至該差動放大器211的輸出端，且該混波器222的振盪頻率係與該驅動單元21的驅動訊號的頻率相同，以擷取出正確的電容感應訊號。該低通濾波器223係連接至該混波器222的輸出端，以過濾電容感應訊號的雜訊並輸出至該類比數位轉換器224，轉換為一電容感應數值，於一驅動週期結束後，即進行計算並組合出手指的指紋影像。 As shown in FIG. 4, the processing unit 22 includes a differential amplifier 221, a mixer 222, a low pass filter 223, and an analog-to-digital converter 224. The differential amplifier 221 has two input ends and an output end, wherein the two input ends are respectively connected to the first and second differential input terminals D1, D2. The mixer 222 has an input terminal and an output terminal. The input terminal is connected to the output end of the differential amplifier 211, and the oscillation frequency of the mixer 222 is the same as the frequency of the driving signal of the driving unit 21. To extract the correct capacitive sensing signal. The low pass filter 223 is coupled to the output of the mixer 222 to filter the noise of the capacitive sensing signal and output the analog signal to the analog converter 224 for conversion to a capacitive sensing value. That is, the fingerprint image of the finger is calculated and combined.
再請參閱圖2B所示，當控制器20a自該工作模式進入該待機模式，此時該驅動單元21不再輸出驅動訊號至該複數驅動線11，而控制該第一切 換單元211，將原連接至該第二差動輸入端D2的第二跡線13之一端Rx_dummy切換連接至該驅動單元21，且該控制器20a亦控制該第二切換單元231，將原連接至該第一差動輸入端D1的第一跡線12之一端Rx切換連接至該觸碰感應單元23，因此該驅動單元21在該待機模式下僅對該第二跡線13輸入該刺激訊號，同時改由該觸碰感應單元23接收該第一跡線12的電容感應訊號，並依據該電容感應訊號判斷是否有手指觸碰該指紋檢測器10。 Referring to FIG. 2B again, when the controller 20a enters the standby mode from the working mode, the driving unit 21 no longer outputs a driving signal to the complex driving line 11, but controls the first cutting. The switching unit 211 switches the one end Rx_dummy of the second trace 13 originally connected to the second differential input terminal D2 to the driving unit 21, and the controller 20a also controls the second switching unit 231 to connect the original One end Rx of the first trace 12 to the first differential input terminal D1 is switched and connected to the touch sensing unit 23, so the driving unit 21 inputs only the stimulation signal to the second trace 13 in the standby mode. At the same time, the touch sensing unit 23 receives the capacitive sensing signal of the first trace 12, and determines whether a finger touches the fingerprint detector 10 according to the capacitive sensing signal.
請配合參閱圖5所示，該觸碰感應單元23係包含有一電荷移轉單元232及一比較器233。該電荷轉移單元232係透過該第二切換單元231連接至該第一跡線12之一端Rx。該比較器233具有一第一輸入端及一第二輸入端，該第一輸入端係連接至一參考電壓Vref，該第二輸入端係連接至該電荷移轉單元232。由於第一及第二跡線12、13之間的耦接面積為該第一跡線12與各該驅動線11之間電容耦合量之總合的數倍，較佳者為十倍以上，故可透過具有較大電容耦合量的優勢直接比較從該第一跡線12所接收之該電容感應訊號移轉後的電壓與該參考電壓Vref，並產生一比較結果，其中，該比較結果被用來判斷有無手指觸碰；因此，本發明在待機模式下不需要喚醒該處理器22來將電容感應訊號轉換為電容感應數值，再與該預設手指觸碰臨界值比較，使得本發明相較習用技術更為省電。 Referring to FIG. 5 , the touch sensing unit 23 includes a charge transfer unit 232 and a comparator 233 . The charge transfer unit 232 is connected to one end Rx of the first trace 12 through the second switching unit 231. The comparator 233 has a first input terminal and a second input terminal. The first input terminal is connected to a reference voltage Vref, and the second input terminal is connected to the charge transfer unit 232. The coupling area between the first and second traces 12 and 13 is a multiple of the total amount of capacitive coupling between the first trace 12 and each of the drive lines 11, preferably 10 times or more. Therefore, the voltage after the transfer of the capacitive sensing signal received from the first trace 12 and the reference voltage Vref can be directly compared by the advantage of having a large capacitive coupling amount, and a comparison result is generated, wherein the comparison result is It is used to determine whether there is a finger touch; therefore, the present invention does not need to wake up the processor 22 in the standby mode to convert the capacitive sensing signal into a capacitive sensing value, and then compares with the preset finger touch threshold, so that the present invention It is more energy efficient than the conventional technology.
再如圖2B及圖6A所示，係為該電荷移轉單元232的一個較佳電路圖，其包含有一開關SW及一接地電容C1；其中該開關SW連接至該第一跡線12之一端RX與一接地端之間，而該接地電容C1未接地的一端係連接至該開關SW與該比較器233的第二輸入端。當該控制器20a進入該待機模式時，該第一切換單元211及第二切換單元231分別切換至該驅動單元21及該觸碰感應單元23的該電荷移轉單元232，且亦控制該開關SW導通開啟，使該接地電容C1放電至0電位後，再斷開該開關SW；之後，由該驅動單元21輸出一交變電壓訊號作為 刺激訊號至該第二跡線13，此時，該第一及第二跡線12、13之間的耦合電容C_finger與該接地電容C1開始充電，直到刺激訊號消失。此時，該耦合電容C_finger與該接地電容C1的電位並不相同，加上該耦合電容C_finger的電容量會受到手指觸碰而改變；因此，當該比較器的第二輸入端獲得該接地電容C1的電位，並與該參考電壓Vref相比較後，若該接地電容C1電位高於該參考電壓Vref，代表目前有手指觸碰，令該控制器20a自該待機模式返回該工作模式。其中該交變電壓訊號可為脈衝電壓訊號或弦波電壓訊號等。 2B and FIG. 6A, a preferred circuit diagram of the charge transfer unit 232 includes a switch SW and a ground capacitor C1; wherein the switch SW is connected to one end of the first trace 12 RX An end of the grounding capacitor C1 that is not grounded is connected to the switch SW and the second input of the comparator 233. When the controller 20a enters the standby mode, the first switching unit 211 and the second switching unit 231 are respectively switched to the driving unit 21 and the charge transfer unit 232 of the touch sensing unit 23, and the switch is also controlled. After the SW is turned on, the grounding capacitor C1 is discharged to a potential of 0, and then the switch SW is turned off; after that, the driving unit 21 outputs an alternating voltage signal as The stimulation signal is sent to the second trace 13. At this time, the coupling capacitance C_finger between the first and second traces 12 and 13 and the grounding capacitor C1 start to be charged until the stimulation signal disappears. At this time, the coupling capacitor C_finger is not the same as the potential of the grounding capacitor C1, and the capacitance of the coupling capacitor C_finger is changed by the finger touch; therefore, when the second input of the comparator obtains the grounding capacitor After the potential of C1 is compared with the reference voltage Vref, if the potential of the grounding capacitor C1 is higher than the reference voltage Vref, it means that there is a finger touch at present, so that the controller 20a returns to the working mode from the standby mode. The alternating voltage signal can be a pulse voltage signal or a sine wave voltage signal.
再如圖2B及圖6B所示，係為該電荷移轉單元232a的另一個較佳電路圖，其包含一第一開關SW1、第二開關SW2、第三開關SW3及一接地電容C1。該第一開關SW1係透過第二切換開關231連接至該第一跡線12之一端Rx與一接地之間。該第二開關SW2的一第一端連接至該第一開關SW1，而一第二端則連接至該接地電容C1，其中該接地電容C1係與該比較器233的第二輸入端連接。該第三開關SW3的一端連接至一直流固定電壓源V1，而另一端則連接至該第二開關SW2的第二端。於待機模式下，該第一切換單元211及第二切換單元231分別切換至該驅動單元21及該觸碰感應單元23的該電荷移轉單元232，且該第一及第三開關SW1、SW3導通開啟，此時，由於該第二跡線13連接至該驅動單元21，且該驅動單元21提供一直流電壓準位V2，可使該耦合電容C_finger具有一基準電位；較佳地，該驅動單元21可提供一類比接地(AGND)與SW1導通後連接的電位相同，令該耦合電容C_finger的基準電位為0，同時該電荷移轉單元232a的一直流固定電壓源V1透過該第三開關SW3對該接地電容C1充電，該接地電容C1具有一電位；之後，關閉該第一及第三開關SW1、SW3，然後開啟該第二開關SW2，由於該接地電容C1電位較該耦合電容C_finger高，故會向該耦合電容C_finger放電，當電荷平衡後，由該比較器233的第二輸入端獲得該接地電容C1的電位，以與該參考電壓Vref比較。由於該耦合電容C_finger的電容量 會受到手指觸碰而改變，相對改變電荷平衝後該接地電容C1的電位，故當該接地電容C1電壓大於該參考電壓Vref，即代表目前已有手指觸碰。同理，若於待機模式下，該驅動單元21提供一非0電壓的直流電壓準位V2，而該耦合電容C_finger的基準電位非為0，當關閉該第一及第三開關SW1、SW3，而該第二開關SW2導通開啟時，該耦合電容C_finger與該接地電容C1之間仍因電位不同而同樣進行電荷平衡，故該比較器同樣可藉由獲得該接地電容C1的電位，以與該參考電壓Vref比較，惟該參考電壓須依驅動單元21提供直流電壓準位而調整。 2B and FIG. 6B, another preferred circuit diagram of the charge transfer unit 232a includes a first switch SW1, a second switch SW2, a third switch SW3, and a grounding capacitor C1. The first switch SW1 is connected to one end Rx of the first trace 12 and a ground through the second switch 231. A first end of the second switch SW2 is connected to the first switch SW1, and a second end is connected to the grounding capacitor C1, wherein the grounding capacitor C1 is connected to the second input end of the comparator 233. One end of the third switch SW3 is connected to the constant current fixed voltage source V1, and the other end is connected to the second end of the second switch SW2. In the standby mode, the first switching unit 211 and the second switching unit 231 are respectively switched to the driving unit 21 and the charge transfer unit 232 of the touch sensing unit 23, and the first and third switches SW1 and SW3 are respectively switched. Turning on, at this time, since the second trace 13 is connected to the driving unit 21, and the driving unit 21 provides the DC voltage level V2, the coupling capacitor C_finger can have a reference potential; preferably, the driving The unit 21 can provide a type of potential equal to ground (AGND) and the connection of the SW1 after the conduction, the reference potential of the coupling capacitor C_finger is 0, and the constant current fixed voltage source V1 of the charge transfer unit 232a passes through the third switch SW3. Charging the grounding capacitor C1, the grounding capacitor C1 has a potential; thereafter, turning off the first and third switches SW1 and SW3, and then turning on the second switch SW2, since the grounding capacitor C1 has a higher potential than the coupling capacitor C_finger, Therefore, the coupling capacitor C_finger is discharged. When the charge is balanced, the potential of the grounding capacitor C1 is obtained by the second input terminal of the comparator 233 to be compared with the reference voltage Vref. Due to the capacitance of the coupling capacitor C_finger It will be changed by the touch of the finger, and the potential of the grounding capacitor C1 after the charge is flushed is relatively changed. Therefore, when the voltage of the grounding capacitor C1 is greater than the reference voltage Vref, it means that the finger has been touched. Similarly, if in the standby mode, the driving unit 21 provides a non-zero voltage DC voltage level V2, and the reference potential of the coupling capacitor C_finger is not 0, when the first and third switches SW1, SW3 are turned off, When the second switch SW2 is turned on, the coupling capacitor C_finger and the grounding capacitor C1 are also charge-balanced due to different potentials, so the comparator can also obtain the potential of the grounding capacitor C1. The reference voltage Vref is compared, but the reference voltage must be adjusted according to the DC voltage level provided by the driving unit 21.
綜上所述，本發明對指紋檢測器可提出一手指觸碰偵測方法，係先將該指紋檢測器設定於該工作模式及該待機模式的其中之一下運作；若於該工作模式下，依序輸出一驅動訊號至各該驅動線11，並同時接收該第一跡線12及該第二跡線13對應各該驅動線11之間的電容感應訊號，由此二電容感應訊號中擷取並識別該指紋影像。再於該待機模式下，係提供該刺激訊號至該第一跡線12及該第二跡線13的其中一條，使該第一跡線12及該第二跡線13之間產生該電容感應訊號，並自未接收該刺激訊號的另一條跡線判斷該第一跡線12及該第二跡線13之間電容感應訊號的變化，依據該電容感應訊號變化判斷目前該指紋檢測器上是否有手指觸碰。 In summary, the present invention can provide a fingerprint detection method for a fingerprint detector, which firstly operates the fingerprint detector in one of the working mode and the standby mode; if in the working mode, And outputting a driving signal to each of the driving lines 11 in sequence, and simultaneously receiving the capacitive sensing signals between the first traces 12 and the second traces 13 corresponding to the driving lines 11, thereby generating a two-capacitance sensing signal Take and identify the fingerprint image. And in the standby mode, the stimulation signal is provided to one of the first trace 12 and the second trace 13 to generate the capacitive sensing between the first trace 12 and the second trace 13 And determining, by the other trace that does not receive the stimulation signal, a change in the capacitance sensing signal between the first trace 12 and the second trace 13 according to the change of the capacitive sensing signal to determine whether the current fingerprint detector is Have a finger touch.
本發明的第一跡線及第二跡線於該工作模式下係同時作為接收跡線使用，可消除環境雜訊對該第一跡線12所耦合之電容感應訊號的影響，提高指紋識別的正確性。本發明於該待機模式下不驅動該複數驅動線11，僅對該第一跡線12及第二跡線13的其中一條提供該刺激訊號，另一條則作為接收其間產生的電容感應訊號用，以較大電容進行檢測是否有手指觸碰於該指紋檢測器上；因此，由於刺激訊號僅提供予該第一跡線12及第二條跡線13的其中一條，故可有效節省電能。由於本發明於該待機模式下檢測手指觸碰時，是藉由在該工作模式下作為接收跡線用的該第一跡線12及第二跡線13進行檢測，故不必另 外增加其它跡線，故本發明可在不改變指紋檢測器結構及尺寸的基礎上，達到省電功效。 The first trace and the second trace of the present invention are simultaneously used as receiving traces in the working mode, which can eliminate the influence of environmental noise on the capacitive sensing signal coupled to the first trace 12, and improve fingerprint recognition. Correctness. The present invention does not drive the complex driving line 11 in the standby mode, and only provides the stimulation signal to one of the first trace 12 and the second trace 13, and the other is used as a capacitive sensing signal generated during reception. The larger capacitance is used to detect whether a finger touches the fingerprint detector; therefore, since the stimulation signal is only supplied to one of the first trace 12 and the second trace 13, energy can be effectively saved. Since the present invention detects the finger touch in the standby mode, the first trace 12 and the second trace 13 for receiving the trace are detected in the operation mode, so that it is not necessary to use another The other traces are added, so the invention can achieve power saving effect without changing the structure and size of the fingerprint detector.
10‧‧‧指紋檢測器 10‧‧‧Fingerprint detector
101‧‧‧基板 101‧‧‧Substrate
11‧‧‧驅動線 11‧‧‧Drive line
111‧‧‧第一端 111‧‧‧ first end
112‧‧‧第二端 112‧‧‧ second end
12‧‧‧第一跡線 12‧‧‧First Trace
13‧‧‧第二跡線 13‧‧‧Second Trace
20‧‧‧控制器 20‧‧‧ Controller
21‧‧‧驅動單元 21‧‧‧ drive unit
211‧‧‧第一切換單元 211‧‧‧ first switching unit
212‧‧‧一對多多工器 212‧‧‧One-to-many multi-tool
22‧‧‧處理單元 22‧‧‧Processing unit
30‧‧‧手指 30‧‧‧ fingers
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| TW103136749A TWI526944B (en) | 2014-10-24 | 2014-10-24 | Fingerprint Sensing Device and Method of Detecting Finger Touch Thereof |
| CN201410682340.7A CN105700757A (en) | 2014-10-24 | 2014-11-24 | fingerprint sensing device and finger touch detection method thereof |
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| TW103136749A TWI526944B (en) | 2014-10-24 | 2014-10-24 | Fingerprint Sensing Device and Method of Detecting Finger Touch Thereof |
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| CN107526993A (en) * | 2016-06-20 | 2017-12-29 | 康达生命科学有限公司 | Capacitive fingerprint sensing device |
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| KR102625444B1 (en) * | 2016-08-03 | 2024-01-15 | 삼성전자주식회사 | Semiconductor device |
| TWI626596B (en) | 2017-02-14 | 2018-06-11 | 宏碁股份有限公司 | Fingerprint sensing device, electronic device and calibration method for fingerprint sensor |
| TW201901392A (en) * | 2017-05-09 | 2019-01-01 | 新益先創科技股份有限公司 | Biometric sensing device |
| KR102410015B1 (en) * | 2017-12-27 | 2022-06-16 | 삼성전자주식회사 | Touch screen controller, Touch screen system having the same and Operating method of touch screen controller |
| TWI688899B (en) * | 2018-11-05 | 2020-03-21 | 友達光電股份有限公司 | Fingerprint identification module and fingerprint identification touch display using the same |
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| CN1212588C (en) * | 2002-04-10 | 2005-07-27 | 祥群科技股份有限公司 | Capacitance type fingerprint access chip |
| TWI315852B (en) * | 2005-08-05 | 2009-10-11 | Nat Chi Nan Cuniversity | A fingerprint acquisition apparatus and method therefor |
| CN103745194B (en) * | 2013-12-20 | 2017-11-28 | 深圳市汇顶科技股份有限公司 | Finger print detection device and mobile terminal |
| CN104036265B (en) * | 2014-07-02 | 2018-12-21 | 南昌欧菲生物识别技术有限公司 | Fingerprint Identification sensor and electronic device |
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