WO2019062810A1 - 一种电荷型传感器和具有其的传感器阵列及积分电路失配调整参数的获取方法 - Google Patents

一种电荷型传感器和具有其的传感器阵列及积分电路失配调整参数的获取方法 Download PDF

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Publication number
WO2019062810A1
WO2019062810A1 PCT/CN2018/107951 CN2018107951W WO2019062810A1 WO 2019062810 A1 WO2019062810 A1 WO 2019062810A1 CN 2018107951 W CN2018107951 W CN 2018107951W WO 2019062810 A1 WO2019062810 A1 WO 2019062810A1
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Prior art keywords
circuit
charge
adjustment
integrating
integration
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PCT/CN2018/107951
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English (en)
French (fr)
Inventor
李扬渊
许科峰
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苏州迈瑞微电子有限公司
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Publication of WO2019062810A1 publication Critical patent/WO2019062810A1/zh

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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

Definitions

  • the invention belongs to the field of sensors, and in particular relates to a charge type sensor with an integral circuit.
  • the non-signal quantity will cause the integration speed of the integrator to be too fast, which further causes the integrator to process the signal integrator to be easily saturated, resulting in insufficient amplification of the signal.
  • signal processing Circuits can create mismatches.
  • the ability of the fingerprint sensor to penetrate the surface medium is one of the main indicators for measuring the performance of the fingerprint sensor.
  • the requirement for the fingerprint sensor on the front screen of the smart phone is to penetrate the chemically strengthened glass of 1mm-2mm to ensure the structural strength of the screen.
  • the fingerprint sensor needs to achieve a capacitance resolution of 10 ⁇ -19f.
  • the fingerprint sensor needs to deal with the compensation of the DC component (non-signal quantity) of the fingerprint.
  • the ratio of the DC component to the AC component is above 1000, and the fingerprint image is extracted.
  • the only thing that matters is the AC component of the fingerprint.
  • the DC component during the integration process causes the integration rate of the integrator to be too fast, and the saturation of the integrator affects the image quality.
  • the setting adjustment circuit of the present invention is respectively connected with the charge generation circuit and the integration circuit, and the adjustment circuit is connected between the charge generation circuit and the integration circuit to adjust the charge accumulation amount of the integration circuit, so that the dynamic range of the circuit only needs to be covered. AC component and a small amount of DC component.
  • a charge generating circuit includes a non-electrical signal sampling circuit and a charge transfer switch.
  • the sampling circuit is used to convert the non-electrical signal quantity into a charge signal quantity, and the charge signal quantity generated by the charge generating circuit is related to the non-electrical signal quantity.
  • the amount of non-electrical signals may be a physical signal quantity or a chemical signal quantity. For example, in a fingerprint sensor, the amount of distance between the finger ridge line and the valley line pattern is an amount of charge that can be converted by the charge generation circuit to be related to the distance.
  • the integration circuit is connected to the charge generation circuit, the adjustment circuit is connected to the integration circuit and the charge generation circuit, and a positive or negative charge is injected into the integration circuit during the integration process of the integration circuit to adjust the integration speed to prevent the integration circuit from being too fast and saturated.
  • the sampling circuit in the charge generating circuit includes a capacitor, and the amount of charge generated by the charge generating circuit is related to the size of the capacitor.
  • the charge generating circuit has a sensing electrode and a driving electrode, and the sensing electrode is used for sensing and to be sensed.
  • the target surface forms a sampling capacitor.
  • the driving electrode is configured to form a driving capacitor with the sensing electrode, the sensing electrode is connected to the reference voltage through a reset switch, and the driving electrode and the target to be detected are respectively connected to the first level driver and the second level driver, and the driving electrode is used for sampling
  • the amount of charge associated with the fingerprint texture surface distance d is formed in the capacitor; in the capacitive fingerprint sensor, the distance between the ridge line of the fingerprint and the sensing electrode of the capacitance sampling circuit is small, and the distance between the valley line and the sensing electrode of the capacitance sampling circuit is large, and thus the valley
  • the amount of charge formed by the line portion capacitance sampling is large, and the amount of charge formed by the ridge line portion capacitance sampling is small.
  • the integrating circuit is such that the amount of charge corresponding to the ridge line and the valley line of the capacitance sampling circuit forms a measurable voltage signal.
  • the output end of the capacitance sampling circuit is connected to the input end of the integrating circuit through a charge transfer switch, and the integration circuit is configured to accumulate the charge amount and output a voltage signal corresponding to the distance of the fingerprint distance; that is, repeat the integral capacitance in the integrator multiple times Charge it.
  • the integrator Before repeating the integration, in order to ensure the consistency of the measurement, the integrator needs to be reset before the integration.
  • the reset process causes the integral capacitor to have an initial charge. For example, the reference voltages Vref1, Vref2, and the integrated capacitor Cr are assumed across the integral capacitor.
  • the adjusting circuit is connected to the integrating circuit and the capacitor sampling circuit through an adjustment switch, and a positive or negative charge is injected into the integrating circuit to adjust the integration rate.
  • the adjustment circuit includes an adjustment capacitor, a level driver, and a reset switch.
  • the adjustment capacitor is connected to the level driver, and the adjustment capacitor is connected to the reference voltage through the second reset switch.
  • the adjustment circuit has two operating states, and the adjustment state causes the adjustment capacitor to be turned on to the integration circuit, so that the stored charge in the adjustment capacitor is injected into the integration circuit.
  • the second reset state causes the adjustment capacitor to conduct the reference voltage such that the adjustment capacitor has an initial charge amount.
  • the initial charge of the trim circuit is determined by the trim capacitor value, the drive voltage of the level driver, and the reference voltage; the level driver can also be replaced with a fixed reference voltage as long as the amount of charge is compensated to meet the design requirements.
  • the process of repeating charging of the integrating circuit is:
  • S2 disconnects the charge transfer switch and turns off the adjustment switch
  • the S4 charge generation circuit level driver control signal is high, and the adjustment circuit level driver control signal is high;
  • S5 disconnects the charge generation circuit reset switch, and turns off the adjustment circuit reset switch
  • the S7 charge generation circuit level driver control signal is low, and the adjustment circuit level driver control signal is low;
  • the capacitance of the sampling capacitor is Cf
  • the capacitance of the driving capacitor is Cd
  • the capacitance of the parasitic capacitor is Cb.
  • the value of the bus parasitic capacitance connecting the capacitance sampling circuit and the integrating circuit is Cp
  • the adjustment capacitance is Cc.
  • the value of the reference voltage for resetting the drive electrode is Vint
  • the value of the comparison circuit reference voltage is VREF3.
  • the adjustment circuit reference voltage is VREF5
  • the first level driver of the charge generation circuit is high level V12 low level is V11
  • the second level driver of the charge generation circuit is high level V22 low level is V21
  • the adjustment circuit is flat drive high
  • the adjustment circuit causes the charge transfer amount to generate a compensation charge amount ( ⁇ V3 + VREF1 - VREF5) * Cc.
  • the Cf contains a large DC component, which affects the extraction of the fingerprint AC component
  • the amount of charge caused by the DC component in the Cf can be neutralized by properly arranging the values of ⁇ V3, VREF5, and Cc. Since the DC component in Cf is a variable amount, the fingerprint sensor may encounter different Cfs each time it is acquired, and of course there will be different DC components, so the compensation charge amount needs to be adjusted in real time, that is, the third level.
  • the driver is an adjustable level driver, such that the ⁇ V3 is adjustable or the compensation capacitor Cc is a tunable capacitor, and the integrated capacitor is injected with different charge amounts for different sampling capacitors; the charge adjustment of the adjustment circuit can be seen from the process of integration
  • the quantity is also repeatedly injected into the integration circuit in multiple steps, that is, the compensation of the integration circuit is discontinuous in time.
  • the output of the integrating circuit is coupled to the input of the comparator circuit.
  • the output of the integrator undergoes a one-way change.
  • the output end of the integrator is connected to the comparison circuit.
  • the voltage signal output by the comparison circuit is inverted, and the time T of the inversion is the output of the fingerprint sensor.
  • the value of the comparison reference voltage be VREF3
  • Qr.end is The value according to the formula ⁇ Q is only a linear function of Cf, and is output as a result for the simple T rounding in engineering practice.
  • the charge generating circuit can generate an electric charge using the optical sensing element, the amount of electric charge generated by the electric charge generating circuit is related to the amount of light received by the optical sensing element, and the electric charge generating circuit has an optical sensing element for receiving
  • the target finger reflects the light and produces an induced charge containing the fingerprint information component. Since the ridges and valleys of the target finger are different in distance from the contact surface, the intensity of the reflected light is also different, resulting in a corresponding change in the charge generated by the optical sensing element as the light changes.
  • a piezoelectric element can be used to generate electrical charge, and the piezoelectric element is used to detect ultrasonic pressure.
  • the amount of charge generated by the charge generating circuit is proportional to the pressure experienced by the piezoelectric element.
  • the piezoelectric element receives the ultrasonic wave reflected from the finger, the piezoelectric element outputs the charge with the fingerprint information, and the piezoelectric element portion corresponding to the ridge line generates a larger amount of charge than the piezoelectric element corresponding to the valley line.
  • the output of the piezoelectric or optical charge generating circuit is coupled to the input coupled to the integrating circuit via a charge transfer switch for accumulating the amount of charge and outputting a voltage signal associated with the amount of charge.
  • the integrator needs to be reset before the integration.
  • the adjustment circuit is connected to the integration circuit and the charge generation circuit through an adjustment switch, and the adjustment circuit adjusts the integration of the integration circuit power.
  • the adjustment circuit includes a current source and an adjustment switch that provides a positive or negative charge for injecting the integration circuit.
  • the adjusting circuit has two operating states, one of which adjusts the state, so that the current source is turned on to the integrating circuit, so that a positive or negative charge in the current source is injected into the integrating circuit; and in the second reset state, the adjusting switch is turned off.
  • the current source is used to adjust the amount of charge accumulated by the integrating circuit, the process of charge injection into the integrator is continuous without interruption.
  • the output end of the charge generating circuit is connected to the input end of the integrating circuit through a charge transfer switch, and the output end of the integrating circuit is connected to the input end of the comparison circuit, and when the value of the reference voltage changes to the value of the reference voltage in the comparison circuit, the comparison is made.
  • (Qr.end-Qr.rst) is a fixed value
  • (I L -I n ) is only a linear function of Cf, in the engineering practice, for the convenience of T rounding as the result output, T as the output .
  • the invention also provides an acquisition method for acquiring a mismatch adjustment parameter of a charge integration circuit based on the adjustment circuit, comprising the steps of:
  • the default input means that the charge generation circuit does not have any external input or only includes background input.
  • the fingerprint sensor is the default input when no finger is set on the sensor, but the signal input by the default includes the background signal of the fingerprint sensor itself;
  • the target point (T0, V0) is set to verify the sensor configuration parameters.
  • the sensor configuration parameter is considered to be able to reach the design goal.
  • the step of configuring the parameter Ki for any adjustment circuit in the step S3 includes the following steps:
  • the integration circuit output characteristic curve is a plurality of straight lines passing through the same initial point when different configuration parameters are used.
  • An advantage of the present invention over the prior art is that a positive or negative charge is injected into the integration circuit to adjust the integration rate of the integration circuit.
  • a positive or negative charge is injected into the integration circuit to adjust the integration rate of the integration circuit.
  • Figures 1a and 1b are schematic diagrams of a charge sensor circuit.
  • FIGS. 2a and 2b are schematic diagrams of a charge sensor circuit in which a charge generation circuit includes a sampling capacitor and a driving capacitor.
  • 3a to 3c are schematic diagrams of a charge sensor circuit in which the charge generation circuit includes an optical sensor element.
  • FIGS. 4a to 4c are schematic diagrams of a charge sensor circuit in which a charge generating circuit includes a piezoelectric element.
  • 5a to 5c are schematic views of an adjustment circuit.
  • 6a to 6c are schematic diagrams of an integrating circuit.
  • FIG. 7a and 7b are schematic diagrams of a charge generation circuit including a sampling capacitor integral adjustment circuit.
  • 8a and 8b are schematic diagrams of a charge generation circuit including an optical sensor element integration adjustment circuit.
  • 9a and 9b are schematic diagrams of a charge generation circuit including a piezoelectric element integration adjustment circuit.
  • FIG. 10 is a schematic diagram showing the process output characteristic curve of the method for adjusting the mismatch parameter adjustment of the integration circuit.
  • the present invention provides a charge integration adjustment circuit and a fingerprint sensor and a fingerprint detection method therewith.
  • the present invention uses a fingerprint sensor as an example to explain the working principle of the integral adjustment circuit, but The scope of the present invention is not limited, and the scope of the present invention should be determined by the scope of the claims.
  • the circuit of FIG. 1 includes a charge generating circuit 10, an integrating circuit 20, and an adjusting circuit 40.
  • X to Q in the charge generating circuit 10 X represents a non-electrical signal amount, such as a physical signal amount, a chemical signal amount, etc., but such a signal usually includes an uneffective signal amount that does not wish to enter the circuit, such as a noise signal, etc.;
  • Q represents a charge
  • the charge generating circuit 10 internally includes a non-electrical signal measuring circuit, such as a capacitive sampling circuit, a light sensing circuit/pressure sensing circuit, which functions to convert a non-electrical signal amount into a charge amount associated therewith.
  • the output of the adjustment circuit 40 is connected to the output of the charge generating circuit 10 and the input of the integrating circuit 20, respectively.
  • the adjusting circuit 40 is for adjusting the charge accumulation amount of the integrating circuit 20, and adjusting the non-effective signal amount in the circuit 40.
  • the adjusting circuit 40 prevents the integrating circuit 20 from being saturated by adjusting the integration rate, increases the signal amplification rate, and compensates the integration circuit 20 for mismatch.
  • the comparator 30 can be connected to the output terminal of the integration circuit 20 to facilitate calculation of the integration time of the integration circuit 20.
  • the amount of distance for the fingerprint surface texture is converted into a charge amount.
  • the amount of charge generated by the charge generating circuit 10 is inversely proportional to the fingerprint surface distance.
  • the amount of distance between the finger ridge line and the valley line pattern can be converted into a charge signal amount by the charge generating circuit 10.
  • the integrating circuit 20 and the charge generating circuit 10 are connected by a charge transfer switch 11.
  • the adjustment circuit 40 is connected to the integration circuit 20 and the charge generation circuit 10 through the adjustment switch 41, and injects electric charge into the integration circuit 20 during the integration of the integration circuit 20 to adjust the integration speed, preventing the integration circuit 20 from being excessively fast and saturated.
  • the charge generating circuit 10 includes a sampling capacitor 13, and the amount of charge generated by the charge generating circuit 10 is proportional to the capacitance.
  • the charge generating circuit 10 has a sensing electrode and a driving electrode.
  • the target to be detected for example, the surface of the finger forms a target electrode, the sensing electrode and the target electrode form a sampling capacitor 13, and the driving electrode and the sensing electrode form a driving capacitor 12.
  • the sensing capacitor is electrically connected to the first level driver vd1
  • the sampling capacitor 13 is electrically connected to the second level driver Vd2; in FIG. 2a to FIG. 2b, the sensing electrode, the driving electrode and the finger are equivalently regarded as a series connection.
  • the sampling capacitor 12 and the driving capacitor are connected, and the sensing electrode is connected to the reference voltage Vint through the reset switch 11.
  • the sensing electrode forms a sampling capacitance with the ridge line of the fingerprint surface, the sampling capacitance formed by the smaller distance d is larger than 13; when the sensing electrode forms a sampling capacitance with the valley line of the fingerprint surface, the sampling capacitance formed by the larger distance d 13 small.
  • the driving electrode is configured to form a charge amount corresponding to the distance d of the fingerprint texture surface in the sampling capacitor 13; in the capacitive fingerprint sensor, the distance between the ridge line of the fingerprint and the sensing electrode of the capacitance sampling circuit is small, and the valley line and the capacitance sampling circuit are The distance between the sensing electrodes is large, so that the amount of charge Q formed by the capacitance sampling of the valley portion is large, and the amount of charge Q formed by the capacitance sampling of the ridge portion is small.
  • An equivalent parallel parasitic capacitance cb is also included in the fingerprint sensor.
  • the sampling capacitor 13 and the driving capacitor 12 are respectively connected to the charge transfer switch 14, and the outlet end of the charge transfer switch 14 serves as an output terminal out of the charge generating circuit 10, and simultaneously charges.
  • the output terminal out of the generating circuit 10 is connected to the input terminal of the integrating circuit 20.
  • a plurality of the charge generating circuits 10 may form a charge generating array, and each of the charge generating circuits 10 may be connected to a bus through a charge transfer switch 14, and the bus serves as an output terminal of the plurality of charge transfer switches 14 simultaneously.
  • the input of the integrating circuit 20 is connected.
  • the charge generating circuit 10 generates an electrical charge using the optical sensing element 16, the amount of charge generated by the optical sensing element 16 being associated with the luminous flux.
  • Optical sensing element 16 is preferably a photodiode, photoresistor or the like that is well known in the art.
  • the optical sensing element 16 is for receiving light reflected from a surface of a finger (not shown) and outputting an induced charge that reflects the component of the fingerprint information associated with the flux of the reflected light.
  • the optical sensing elements 16 are respectively connected to the load circuit 15 and the first port of the charge transfer switch 17, and the second port of the charge transfer switch 17 is connected to the output terminal out of the charge generating circuit 10.
  • the output terminal out is connected to the input terminal of the integrating circuit 20, and the optical sensing element 16 is connected to the reset reference voltage Verf through the reset switch 18.
  • a plurality of the charge generating circuits 10 may form a charge generating array.
  • the plurality of charge generating circuits 10 may multiplex the reset switch 18 and the reset reference voltage 18. Similarly, the plurality of charge generating circuits 10 may multiplex the charge transfer switch 17, and the charge transfer switch 17 functions as a primary switch, and the charge generating circuit 10 is internally disposed. Secondary switch 171. As shown in FIG. 3c, a plurality of charge generating circuits 10 are connected to the bus, and the bus serves as an output terminal of the plurality of charge generating circuits 10 while being connected to the input terminal of the integrating circuit 20.
  • the charge generating circuit 10 generates a charge using the piezoelectric element 19, and the amount of charge generated by the piezoelectric element 19 is related to the mechanical shock energy received by the piezoelectric element 19.
  • the piezoelectric element 19 is preferably an ultrasonic transducer, and the transducer is preferably an absorbable ultrasonic vibration mechanical energy formed by piezoelectric ceramics.
  • the piezoelectric element 19 is used in conjunction with an ultrasonic pulse emitting element (not shown) that emits an ultrasonic beam to a finger.
  • the peaks of the fingerprint and the ultrasonic waves reflected by the valleys contain different energies, resulting in a corresponding change in the charge generated by the piezoelectric element 19 as the texture of the fingerprint surface changes.
  • the piezoelectric element 19 is connected to the reference level Vu and the first port of the charge transfer switch 191, respectively, and the other end of the charge transfer switch 191 is connected to the output terminal out of the charge generating circuit 10.
  • a plurality of charge generating circuits 10 form a charge generating array.
  • the plurality of charge generating circuits 10 can multiplex the charge transfer switch 191 and the reference voltage Vrst.
  • the plurality of charge generating circuits 10 can multiplex the charge transfer switch 191.
  • the charge transfer switch 191 functions as a primary switch, and a secondary switch 190 is provided inside the charge generating circuit 10.
  • the piezoelectric element 19 is connected to the first port of the secondary switch, the second port of the secondary switch is connected to the first port of the charge transfer switch 191, and the second port of the charge transfer switch 191 is connected to the output terminal out.
  • a plurality of charge generating circuits 10 are connected to the bus, and the bus serves as an output terminal of the plurality of charge generating circuits 10, and serves as an input terminal of the integrating circuit 20.
  • the adjustment circuit 40 shown in FIG. 5a each includes an adjustment capacitor Cc.
  • the first pole of the adjustment capacitor Cc is connected to the adjustment switch 41 while the first pole is connected to the reference voltage Vt through the reset switch 42.
  • the second pole of the adjustment capacitor Cc is connected to the reference voltage Vf or the drive level Vd3.
  • the adjustment circuit 40 shown in Fig. 5b is different from Fig. 5a in that the second pole of the adjustment capacitor is connected to the third level driver Vd3, and the voltage of the third level driver Vd3 is variable.
  • the 5b has two operating states, one of which is a reset state, the reset switch 42 is closed, and the adjustment switch 41 is turned off to turn on the adjustment capacitor Cc to the reference voltage Vt.
  • the adjustment capacitor has an initial charge amount. The initial charge amount is determined by the adjustment capacitance value Cc, the drive voltage difference of the third level driver Vd3, and the reference voltage Vt, wherein the third flat driver can also be replaced with a fixed reference voltage Vf.
  • the adjustment switch 41 is closed, and the reset switch 42 is turned off to turn on the adjustment capacitor Cc to the integration circuit 20, so that the stored charge in the adjustment capacitor is injected into the integration circuit 20 to adjust the integration speed of the integration circuit 20.
  • the amount of charge accumulated by the integrating circuit 20 is adjusted using the adjusting circuit 40 including the capacitor, it can be seen from the process of integration that the charge adjusting amount of the adjusting circuit 40 is also repeatedly injected into the integrating circuit 20, that is, the integrating circuit 20 The compensation is non-continuous in time.
  • the adjustment circuit 40 includes a current source 43 which is connected to the charge generation circuit 10 and the integration circuit 20 via an adjustment switch 41.
  • the adjustment switch 41 When the adjustment switch 41 is closed, the electric charge of the current source 43 is injected into the integrating circuit 20, and the integral speed of the integrating circuit 20 is adjusted.
  • the two operating states of the adjustment circuit 40 are the adjustment state and the reset state, and the charge injection integration circuit 20 of the current source is adjusted in the adjustment state when the adjustment switch is closed.
  • the adjustment switch 41 When the adjustment switch 41 is turned off, it is in a reset state, and when the adjustment circuit 40 having the current source 43 adjusts the amount of charge accumulated by the integration circuit 20, the integrator can be adjusted to be in time according to the process of the integrator. Continuous or discontinuous.
  • the integration circuit 20 includes an amplifier Amp, an integration capacitor Cr and a reset switch 21 as shown in FIG. 6a; the first input terminal 22 of the amplifier Amp serves as an input terminal of the integrator 20 in The second input of the amplifier is connected to the reference voltage Verf1, and the output of the amplifier Amp is used as the output out of the integrator.
  • the two ends of the integrating capacitor Cr are respectively connected to the first input terminal of the amplifier Amp and the output terminal out of the amplifier.
  • the integral capacitor Cr is connected to the reset switch 21 at both ends. When the reset switch 21 is closed, the level of the integral capacitor is the same, and the charge in the integral capacitor Cr is reset and cleared.
  • the integrating circuit 20 shown in FIG. 6b is different from FIG. 6a in that the reset switch includes two 21/24, and the first pole of the integrating capacitor is connected to the first reference voltage Verf1 through the first reset switch 21, and the first reference voltage Verf1 and the amplifier The reference voltage of the second input terminal 23 is multiplexed.
  • the second pole of the integrating capacitor cr is connected to the second reference voltage Vef2 through the second reset switch 24, while the second pole of the integrating capacitor Cr is connected to the output of the amplifier Amp via the follow switch 25.
  • the integrating circuit 20 has two operating states, one of which is an integral state and the other of which is a reset state. In the integrated state, the charge transfer switch and the follow switch 25 are closed, and the first reset switch 21 and the second reset switch 24 are turned off. The second is the reset state, in which the follow switch 25 is turned off, and the two reset switches 21/25 are closed.
  • the integrating circuit 20 shown in Fig. 6c differs from Figs. 6a, 6b in that the integrating circuit 20 includes only the integrating capacitor Cr, and the first pole of the integrating capacitor is connected to the input terminal in of the integrating circuit 20 while being connected to the output terminal out of the integrating circuit 20.
  • the second pole of the integrating capacitor is grounded, and the second pole of the integrating capacitor Cr known to those skilled in the art can also be connected to the reference voltage.
  • the first pole of the integrating circuit 20 is connected to the reset switch 21, and the reset switch 21 is connected to the first reference voltage Verf1.
  • the integrating circuit 20 has two operating states, one of which is the integral state reset switch 21 is open, and the other is the reset state integral reset switch. 21 closed.
  • the charge generation circuit 10 includes a sampling capacitor 13, and an output terminal of the charge generation circuit 10 is connected to an input terminal of the integration circuit 20 through a charge transfer switch 14.
  • the common set of steps of the charge integral adjustment circuit includes:
  • S5 turns off the charge generation circuit reset switch 42, and turns off the adjustment circuit reset switch 11.
  • the reset integration circuit 20 in step S1 in order to ensure the consistency of the measurement, it is necessary to reset the integration capacitance Cr in advance before integration.
  • the reset process causes the integral capacitor Cr to have an initial power.
  • the integration circuit 20 repeats the integration process a plurality of times, that is, the process in which the charge generated by the charge generation circuit 10 is repeatedly charged to the integration capacitor Cr. Each time the integration capacitor Cr is charged, the adjustment circuit 40 is connected to the integration circuit 20 and the charge generation circuit 10 via the adjustment switch 41, and charges are injected into the integration circuit 20.
  • step S2 the electrical connection between the charge generating circuit 10 and the adjusting circuit 40 is turned off, and the functions of steps S3 and S4 are respectively formed in the sampling capacitor 13 of the charge generating circuit 10 and the adjusting capacitor Cc of the driving capacitor 12, respectively.
  • the initial amount of charge The amount of charge of the sampling capacitor 13 depends on the distance of the finger surface. If the sensing electrode is above the ridge line of the finger, the amount of charge is large, and if the sensing electrode is above the valley line of the finger, the amount of charge is small.
  • the reset switch 11 is turned off in step S5 in preparation for charge transfer.
  • the charge transfer switch 14 is closed in step S6, and the charge generating circuit 10 is electrically connected to the integrating circuit 20; the adjusting circuit 40 injects electric charge into the integrating circuit 20, and adjusts the integrated charge integrated amount of the integrating circuit 20.
  • the capacitance value of the sampling capacitor 13 is Cf
  • the capacitance value of the driving capacitor 12 is Cd
  • the capacitance value of the parasitic capacitance is Cb
  • the value of the bus parasitic capacitance of the charge generating circuit 10 and the integrating circuit 20 is Cp
  • the reference voltage of the charge generating circuit 10 The value of the reference circuit is VREF
  • the reference voltage of the comparison circuit 30 is VREF3
  • the reference voltage of the adjustment circuit 40 is VREF5
  • the high level of the first level driver is V12 low level is V11
  • the second level driver high level is V22 low.
  • the level is V21, and the third level driver is high level V32 and low level is V31.
  • V1 V12-V11
  • ⁇ V2 V22-V21
  • ⁇ V3 V32-V31
  • ⁇ VREF VREF1-Vint.
  • the adjustment circuit 40 causes the charge transfer amount to generate a charge amount ( ⁇ V3 + VREF1 - VREF5) * Cc.
  • Cf contains a large DC component, which affects the extraction of fingerprint AC components
  • the amount of charge caused by the DC component in Cf can be neutralized by reasonable configuration of the values of ⁇ V3, VREF5 and Cc;
  • the DC component is a variation.
  • the fingerprint sensor may encounter different Cfs for each acquisition, and of course there will be different DC components. Therefore, the amount of compensation charge needs to be adjusted in real time, that is, the third level driver is an adjustable level driver such that ⁇ V3 is adjustable or the compensation capacitor Cc is a tunable capacitor to form different compensation charges for different sampling capacitors. .
  • the charge generating circuit 10 can be arranged in an array to perform image acquisition on the surface above the dot matrix, and 90*90 pixels are used in the fingerprint sensor. 500ppi capacitor array.
  • the integration capacitor Cr needs to be repeatedly charged when the image is acquired, and the process of repeatedly charging the integrating capacitor is:
  • S2 breaks the charge transfer switch 14, turns off the adjustment switch 41;
  • S4 charge generation circuit 10 driver Vd1/Vd2 control signal is high, adjustment circuit 40 driver Vd3 control signal is high;
  • S4 disconnects the charge generating circuit 10 reset switch 11, and turns off the adjustment circuit 40 reset switch 42;
  • Steps S2 to S4 are steps of resetting the charge generating circuit 10 and resetting the adjusting circuit 40, and the purpose thereof is to make the sampling capacitor 13 inside the charge generating circuit 10 and the adjusting capacitor Cc of the adjusting circuit 40 have a certain initial charge amount.
  • Closing the charge transfer switch 14 in step S5 is closed so that the charge generating circuit 10 is electrically connected to the integrating circuit 20.
  • the level driver Vd1/Vd2 of the charge generating circuit 10 and the level driver reset Vd3 of the adjusting circuit 40 in step S6 prepare for the next charge transfer process.
  • step S7 to repeat steps S2 to S6.
  • the output terminal of the integrating circuit 20 is connected to the first input terminal of the comparison circuit 30.
  • the charge transfer amount corresponding to the process of completing the charge transfer is the above ⁇ Q.
  • the charge in the integrating capacitor Cr is continuously accumulated so that the output of the integrating circuit 20 generates a one-way change.
  • the output of the integrating circuit 20 reaches the reference voltage Verf3 of the comparing circuit 30, the voltage signal outputted by the comparing circuit 30 is inverted, and the time T of the inversion is performed.
  • (Qr.end - Qr. rst) is a fixed value, and according to the formula ⁇ Q is only the sampling capacitor 13 Linear function. In the actual project, for the sake of simplicity, T is taken as the result output.
  • the optical charge generation circuit 10 is used to form a measurable voltage signal in order to make the amount of charge corresponding to the ridge line and the valley line of the optical charge generation circuit 10.
  • the output of the charge generating circuit 10 is connected to the input terminal of the integrated circuit 20 through the charge transfer switch 17, and the co-grouping steps of the charge integral adjusting circuit include:
  • S3 closes the charge transfer switch 17 and the multiplexing switch 171, closing the adjustment switch 41;
  • the method of resetting the integrator in step S1 is the same as the reset method of the integrating circuit 20 shown in Figs. 7a and 7b.
  • step S2 the charge generation circuit 10 is reset by the reset switch 18, and the adjustment circuit 40 turns off the adjustment switch 41 to perform reset.
  • the charge transfer switch 17 and the multiplexing switch 171 are closed at step S3, and the charge generating circuit 10 is electrically connected to the integrating circuit 20.
  • the adjustment circuit 40 injects electric charge into the integration circuit 20, and adjusts the integrated charge accumulation amount of the integration circuit 20.
  • the output of the charge generating circuit 10 is connected to the input of the integrating circuit 20 via a charge transfer switch 17, and the output of the integrating circuit 20 is connected to the input of the comparison circuit 30.
  • the output of the comparison circuit 30 serves as the output of the sensor, and the time T at which the comparison circuit 30 outputs the inverted voltage signal reflects the magnitude of the amount of charge generated by the charge generating circuit 10.
  • the comparison circuit 30 Inverts the output signal.
  • Qr.end-Qr.rst is a fixed value
  • (I L -I n ) is only a one-time function of the sampling capacitor 13, which is output as a result for simple T-rounding in engineering practice.
  • the piezoelectric charge generation circuit 10 is used to form a measurable voltage in order to make the charge amount corresponding to the ridge line and the valley line of the piezoelectric charge generation circuit 10. signal.
  • the output of the piezoelectric charge generating circuit 10 is connected to the input terminal of the integrating circuit 20 through the charge transfer switch 191.
  • the common steps of the charge integral adjusting circuit include:
  • S3 closes the charge transfer switch 191 and the multiplexing switch 190, closing the adjustment switch 41;
  • the method of resetting the integrating circuit 20 in step S1 is the same as the resetting method of the integrating circuit 20 shown in Figs. 7a and 7b.
  • step S2 including step S21, the charge generating circuit 10 closes the reset switch 192 for resetting; further includes S22, and the adjusting circuit 40 closes the reset switch 42 by turning off the adjusting switch 41 to perform resetting.
  • the charge transfer switch 191 is closed in step S3, the charge generation circuit 10 is electrically connected to the integration circuit 20, and the adjustment circuit 40 injects electric charge into the integration circuit 20 to adjust the integrated charge accumulation amount of the integration circuit 20.
  • the output of the charge generating circuit 10 is connected to the input of the integrating circuit 20 via a charge transfer switch 191, and the output of the integrating circuit 20 is connected to the input of the comparison circuit 30.
  • the output of the comparison circuit 30 serves as the output of the sensor, and the time T at which the comparison circuit 30 outputs the inverted voltage signal reflects the magnitude of the amount of charge generated by the charge generating circuit 10.
  • the comparison circuit 30 Inverts the output signal.
  • the process of integrating the integrating capacitance Cr in step S3 is similar to the integration process with respect to the integrating circuit 20 shown in Figs. 7a and 7b.
  • (Qr.end - Qr. rst) is a fixed value, and according to the formula ⁇ Q and the compensation capacitor Cc
  • the initial charge amount is related. In the actual project, it is output as a result for the convenience of T rounding.
  • the invention also provides an acquisition method for acquiring a mismatch adjustment parameter of a charge integration circuit based on the adjustment circuit, comprising the steps of:
  • the default input means that the charge generation circuit does not have any external input or only includes background input.
  • the fingerprint sensor is the default input when no finger is set on the sensor, but the signal input by the default includes the background signal of the fingerprint sensor itself;
  • the target point (T0, V0) is set for verifying the sensor configuration parameter, and the sensor configuration parameter is considered when the output characteristic curve of the sensor can pass through or is very close to the target point (T0, V0). Able to achieve design goals.
  • the circuit configuration parameters include, but are not limited to, a reference voltage Verf1, a reference voltage Vrst, a reference voltage Verf3, and a Vint.
  • the steps include:
  • S33 continuously running the charge integration circuit; operating the integration circuit is a process of obtaining an output value when the charge generation circuit inputs a default value.
  • the integration circuit output characteristic curve is a plurality of straight lines passing through the same initial point when the different configuration parameters are; the coordinate value of the same initial point is (0, V), where V represents the initial voltage value of the integration circuit.
  • FIG. 10 output voltage characteristic curves of different configuration parameter integration circuits, where the abscissa represents the voltage unit and the ordinate represents the time unit.
  • the four diagonal lines correspond to the output voltage characteristic curves of the charge generating circuit integrator under different configuration parameters, which are respectively represented as L1, L2, L3, and L4.
  • the target point P coordinate is (T0, V0). It can be seen from the figure that as the charge is continuously accumulated in the integral capacitor, the output voltage characteristic curve (L1, L2, L3, L4) continuously decreases, but in different configuration parameters. The lowering speed of the output voltage is different. Wherein, the output voltage L2 passes through the target point P, that is, when the output voltage characteristic curve of the sensor is L2, the configuration parameters of the integration circuit can reach the design goal.
  • the same target point P can be set, and the configuration parameters are adjusted in the same manner, so that the output characteristics of different charge generating circuits are the same, thereby improving the mismatch condition of the integrating circuit.
  • An advantage of the present invention over the prior art is that the charge adjustment circuit injects a positive or negative charge into the integration circuit to adjust the integration rate of the integration circuit. By setting the polarity and rate of charge injected into the charge adjustment circuit, it is possible to adjust the charge integration rate and compensate for the integration circuit mismatch.

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Abstract

一种电荷型传感器，包括：电荷产生电路(10)，用于输出与传感器目标物理量的大小相关的电荷量；积分电路(20)，输入端与电荷产生电路的输出端连接，用于累积所述电荷量，并输出电压信号；电荷调整电路(40)，向积分电路注入正电荷或负电荷。通过设置电荷调整电路注入电荷的极性和速率，可以起到调整积分电路电荷累积速率，补偿积分电路失配的作用。

Description

一种电荷型传感器和具有其的传感器阵列及积分电路失配调整参数的获取方法
本申请要求了申请日为2017年09月30日，申请号为CN201710923788.7，发明名称为“一种电荷型传感器和具有其的传感器阵列及积分电路失配调整参数的获取方法”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本发明属于传感器领域，特别涉及一种具有积分电路的电荷型传感器。
背景技术
在积分电路处理信号过程中，非信号量会导致积分器积分速度过快，进一步导致积分器处理信号积分器容易发生饱和，导致信号的放大率不够；同时由于积分器本身的差异性，信号处理电路可能会产生失配现象。
以电容指纹传感器为例，指纹传感器对表面介质的穿透能力，是衡量指纹传感器性能的主要指标之一。特别是，随着指纹传感器在智能手机领域被广泛应用，为配合智能手机的工业设计，对指纹传感器的穿透能力提出了更高的要求。目前智能手机对正面屏幕下置指纹传感器的要求是能穿透1mm-2mm的化学强化玻璃，以保证屏幕的结构强度，折算下来，指纹传感器需要达到10^-19f的电容分辨率。而指纹传感器要达到1mm化学强化玻璃的穿透力，需要处理好指纹的直流分量(非信号量)的补偿，在这个尺度下直流分量和交流分量的比值在1000以上，而对指纹图像提取有意义的只是指纹的交流分量。在积分过程中直流分量使得积分器的积分速率过快，积分器饱和影响图像质量。
调整直流分量对积分电路电荷累计量的影响，使读出电路的动态范围只要覆盖交流分量的范围，可以简化读出电路的设计，提高读出电路的性能。
因此需要提出一种新的电路和方法调整积分电路的积分速率，减少直流分量对指纹图像的影响。
发明内容
为了解决上述技术问题，本发明设置调整电路分别与电荷产生电路和积分电路连接，调整电路在电荷产生电路与积分电路之间连接，调整积分电路的电荷累计量，使电路的动态范围只需要覆盖交流分量和少量直流分量。
电荷产生电路，包括非电信号采样电路和电荷转移开关。采样电路用于将非电信号量转换成 电荷信号量，电荷产生电路产生的电荷信号量与非电信号量相关。该非电信号量可以是物理信号量，也可以是化学信号量。例如在指纹传感器中，手指脊线和谷线纹路的距离量为可被电荷产生电路转换为与距离相关的电荷量。积分电路与电荷产生电路连接，调整电路与积分电路和电荷产生电路连接，并在积分电路积分过程中向积分电路注入正电荷或负电荷以调整积分速度，防止积分电路积分速率过快而饱和。
在本发明一种实施例中电荷产生电路中采样电路中包括电容，电荷产生电路产生的电荷量与电容大小相关，电荷产生电路具有感测电极和驱动电极，感测电极用于和待感测目标表面形成采样电容。在指纹传感器中采样电容的大小与指纹表面的纹理呈函数关系，根据电容公式C＝εS/4πkd，其中，d为手指表面纹理与感测电极之间的距离，当感测电极与指纹表面的脊线形成采样电容时，距离d较小形成的采样电容较大，当感测电极与指纹表面的谷线形成采样电容时，距离d较大形成的采样电容小。驱动电极用于和感测电极形成驱动电容，感测电极通过复位开关与参考电压连接，驱动电极和待检测目标分别与第一电平驱动器和第二电平驱动器连接，驱动电极用于使得采样电容内形成与指纹纹理表面距离d相关的电荷量；在电容指纹传感器中指纹的脊线与电容采样电路的感测电极距离小，而谷线与电容采样电路的感测电极距离大，从而谷线部分电容采样形成的电荷量多，脊线部分电容采样形成的电荷量少。积分电路，使得所述电容采样电路脊线和谷线对应的电荷量形成可测量的电压信号。所述电容采样电路的输出端通过电荷转移开关连接积分电路的输入端，积分电路用于累积所述电荷量并输出与指纹距离量相应的电压信号；即多次重复对积分器中的积分电容进行充电。在重复积分前，为了保证测量的一致性在积分前需要预先对积分器复位，复位的过程即使得积分电容具有一个初始的电量，例如假设在积分电容两端的参考电压Vref1、Vref2、积分电容Cr的复位后点电量为Qrst＝(Vref2-Vref1)*Cr,为了简化复位电路的结构可用复位开关直接连接积分电容的两端，即复位后积分电容Cr的电量Qrst＝0。而每次对积分电容充电时，调整电路通过调整开关与所述积分电路和电容采样电路连接，向所述积分电路注入正电荷或负电荷以调整积分速率。
在本发明一些实施例中，调整电路包括调整电容、电平驱动器和复位开关，调整电容与电平驱动器连接，调整电容通过第二复位开关与参考电压连接。调整电路具有两种工作状态，调整状态使所述调整电容对所述积分电路导通，使得调整电容中的存储电荷注入积分电路。其二复位状态，使所述调整电容导对所述参考电压导通，使得调整电容具有初始的电荷量。调整电路的初始电量由调整电容值、电平驱动器的驱动电压和参考电压决定；电平驱动器也可以用固定的参考电压替换，只要补偿电荷量可以满足设计要求。
积分电路重复充电的过程为：
S1复位积分电路；
S2断开电荷转移开关，断开调整开关；
S3闭合电荷产生电路复位开关，闭合调整电路复位开关；
S4电荷产生电路电平驱动器控制信号为高，调整电路电平驱动器控制信号为高；
S5断开电荷产生电路复位开关，断开调整电路复位开关；
S6闭合电荷转移开关，闭合调整开关；
S7电荷产生电路电平驱动器控制信号为低，调整电路电平驱动器控制信号为低；
S8回到步骤S2
对上述积分过程分析：令采样电容的电容值为Cf，驱动电容的电容值为Cd，寄生电容的电容值为Cb。连接电容采样电路和积分电路的总线寄生电容的值为Cp，调整电容为Cc。用于复位驱动电极的参考电压的值为Vint，比较电路参考电压的值为VREF3。调整电路参考电压为VREF5，电荷产生电路第一电平驱动器高电平为V12低电平为V11，电荷产生电路第二电平驱动器高电平为V22低电平为V21，调整电路平驱动器高电平为V32低电平为V31。定义ΔV1＝V12-V11，ΔV2＝V22-V21，ΔV3＝V32-V31，ΔVREF＝VREF1-Vint。
根据电荷平衡原理和积分器工作原理，可以得到积分电容每次充电的电荷量ΔQ：ΔQ＝(ΔVREF-ΔV1)*Cf+(ΔVREF-ΔV2)*Cd+ΔVREF*Cb+(ΔV3+VREF1-VREF5)*Cc。
从以上等式中可以看出，调整电路使电荷转移量产生了一个补偿电荷量(ΔV3+VREF1-VREF5)*Cc。当Cf中包含了较大的直流分量，影响了指纹交流分量提取的时候，可以通过合理的配置ΔV3、VREF5以及Cc的值，中和掉Cf中直流分量带来的电荷量。由于Cf中的直流分量是个变化量，指纹传感器每次采集都可能碰到不同的Cf，当然也会有不同的直流分量，所以补偿电荷量就需要做成可实时调节的，即第三电平驱动器为可调电平驱动器，使得ΔV3可调或者补偿电容Cc为可调电容，以针对不同的采样电容形成不同的电荷量注入所述积分电容；从积分的过程可以看出调整电路的电荷调整量也是分多次重复注入积分电路中，即对积分电路的补偿在时间上是非连续的。
在本发明中的一些实施方式中，积分电路的输出端连接比较电路的输入端。
在采样电容向积分电容重复充电的过程中，积分器的输出会产生单向变化。积分器的输出端接到比较电路，当积分器的输出电压与比较电路的参考电压交叉时，比较电路输出的电压信号会发生翻转，翻转的时间T就是指纹传感器的输出。令比较参考电压的值为VREF3，那么比较电路输出翻转的时刻积分电容的电荷量Qr.end＝(VREF3-VREF1)*Cr。
比较电路的翻转时间为T＝(Qr.end-Qr.rst)/ΔQ，在一些实施方式中，积分电路初始化积分电容Qr.rst＝0，对于给定的指纹传感器设计，Qr.end是定值而根据式ΔQ只是Cf的一次函数，在工程实际中为了简便T取整作为结果输出。
在本发明一种实施例中，电荷产生电路可以使用光学传感元件产生电荷，电荷产生电路产生的电荷量与光学传感元件受光量的大小相关，电荷产生电路具有光学传感元件用于接收目标手指 反射光，并产生含有指纹信息成分的感应电荷。由于目标手指的脊和谷与接触表面的距离不同，其反射光的强度也不同，导致光学传感元件产生的电荷随着光的变化而相应变化。
在本发明一种实施例中可以使用压电元件产生电荷，压电元件用于检测超声波压力。电荷产生电路产生的电荷量与压电元件受到的压力成正比。通常压电元件接收手指反射回来的超声波，压电元件输出系带指纹信息的电荷，脊线对应的压电元件部分产生的电荷量大于谷线对应的压电元件产生的电荷量。
同样地，压电或光学电荷产生电路的输出端通过电荷转移开关与连接积分电路的输入端连接，用于累积所述电荷量并输出与电荷量相关的电压信号。为了保证测量的一致性，在积分前需要预先对积分器复位，复位的过程即使得积分电容具有一个初始的电量。例如假设在积分电容两端的参考电压Vref2、Vref1、积分电容Cr的复位后电量为Qrst＝(Vref2-Vref1)*Cr,为了简化复位电路的结构可用复位开关直接连接积分电容的两端，即复位后积分电容Cr的电量Qrst＝0。
在本发明的一种实施例中，调整电路通过调整开关与所述积分电路和电荷产生电路连接，调整电路调整积分电路电量累计。调整电路包括电流源和调整开关,所述电流源提供用于注入积分电路的正电荷或负电荷。调整电路具有两种工作状态，其一调整状态，使所述电流源对所述积分电路导通，使得电流源中正电荷或负电荷注入积分电路；其二复位状态，断开调整开关。在使用电流源对积分电路累积的电荷量进行调整时，电荷注入积分器的过程是连续的没有间断的。电荷产生电路的输出端通过电荷转移开关连接至积分电路的输入端，积分电路的输出端连接至比较电路的输入端，当该参考电压的值变化到比较电路中的参考电压的值时，比较电路将输出信号翻转，该信号翻转的时间T＝(Qr.end-Qr.rst)/(I L-I n)，I L视为一定时间段内通过的平均电荷，I n视为在一定时间内通过调整电路对积分电容补偿的平均电荷量。对于给定的指纹传感器设计，(Qr.end-Qr.rst)是定值，(I L-I n)只是Cf的一次函数,在工程实际中为了简便T取整作为结果输出,T作为输出。
本发明还提供一种基于所述调整电路获取电荷积分电路失配调整参数的获取方法，包括步骤：
S1：设置电荷产生电路为默认输入；
所述默认输入是指电荷产生电路没有任何外部输入或仅包括背景输入。例如在指纹传感器中，传感器上不设置手指时指纹传感器为默认输入，但在此默认输入的信号中包含指纹传感器本身的背景信号；
S2：在时间-电压坐标平面上设置目标点(T0,V0)；
该目标点(T0,V0)是为了验证传感器配置参数而设置的，当传感器的输出特性曲线能够穿过或很接近目标点(T0,V0)，则认为传感器配置参数能够达到设计目标。
S3：对调整电路设置的不同的配置参数，获取每一个配置参数对应的电荷积分电路在时间- 电压坐标平面上的输出特性曲线；
S4：选取与所述目标点(T0,V0)最接近的输出特性曲线；
S5：获取与所述目标点最接近的输出特性曲线对应的调整电路配置参数。
优选的，所述步骤S3中对于任意调整电路配置参数Ki包括步骤：
S31：初始化积分电路；
S32：将所述调整电路配置参数设置为Ki；
S33：持续运行所述电荷积分电路；
S34：描绘所述电荷积分电路在时间-电压坐标平面上的输出特性曲线。
优选的，不同的配置参数时积分电路输出特性曲线，为通过同一初始点的多条直线。
本发明相对现有技术的优势在于，向积分电路注入正电荷或负电荷，以调整积分电路的积分速率。通过设置电荷调整电路注入电荷的极性和速率，可以起到调整电荷积分速率，补偿积分电路失配。
附图说明
图1a和图1b是电荷性传感器电路示意图。
图2a和图2b是电荷性传感器电路示意图，其中，电荷产生电路包括采样电容和驱动电容。
图3a至图3c是电荷性传感器电路示意图，其中，电荷产生电路包括光学传感元件。
图4a至图4c是电荷性传感器电路示意图，其中，电荷产生电路包括压电元件。
图5a至图5c是调整电路示意图。
图6a至图6c是积分电路示意图。
图7a和图7b是电荷产生电路包含采样电容积分调整电路示意图。
图8a和图8b是电荷产生电路包含光学传感元件积分调整电路示意图。
图9a和图9b是电荷产生电路包含压电元件积分调整电路示意图。
图10是获取积分电路失配参数调整配置方法过程输出特性曲线示意图。
具体实施方式
以下结合附图对本发明技术方案和技术原理进行解释，本发明提供一种电荷积分调整电路及具有其的指纹传感器和指纹检测方法，本发明以指纹传感器为例解释积分调整电路的工作原理，但不限制本发明保护范围，本发明保护范围应以权利要求书的记载内容为准。
请参照图1a，图1中的电路包括电荷产生电路10、积分电路20和调整电路40。电荷产生电路10中X to Q,X代表非电信号量，例如物理信号量、化学信号量等，但这种信号通常包含不希望进入电路的非有效信号量，例如噪声信号等；Q代表电荷信号量，电荷产生电路10内部包 括非电信号测量电路，例如电容采样电路、光感电路/压感电路，其作用是将非电信号量转成与之相关的电荷量。
调整电路40的输出端分别与电荷产生电路10的输出端和积分电路20的输入端连接。调整电路40用于调整积分电路20的电荷累积量，调整电路40中和非有效信号量；调整电路40通过调整积分速率防止积分电路20饱和，提高信号放大率，补偿积分电路20失配。
请参照图1b在上述电荷产生电路10、调整电路40、积分电路20的基础上可在积分电路20的输出端连接比较器30、以便于计算积分电路20的积分时间。
例如在照图2a和2b中所示的电荷产生电路10中，用于将指纹表面纹理的距离量转换成电荷量。电荷产生电路10产生的电荷量与指纹表面距离呈反比。手指脊线和谷线纹路的距离量为可被电荷产生电路10转换为电荷信号量。积分电路20与电荷产生电路10通过电荷转移开关11连接。调整电路40通过调整开关41与积分电路20和电荷产生电路10连接，并在积分电路20积分过程中向积分电路20注入电荷以调整积分速度，防止积分电路20积分速度过快而饱和。
在图2a和2b中电荷产生电路10包括采样电容13，电荷产生电路10产生的电荷量与电容成正比关系。电荷产生电路10具有感测电极和驱动电极，待检测目标例如手指表面形成目标电极,感测电极与目标电极形成采样电容13，驱动电极与感测电极形成驱动电容12。感测电容与第一电平驱动器vd1电性连接，采样电容13与第二电平驱动器Vd2电性连接；在图2a至图2b中感测电极、驱动电极和手指被等效视为串联的采样电容12和驱动电容，感测电极通过复位开关11与参考电压Vint连接。在手指(图中未示出)按压在指纹传感器表面上时，在指纹传感器中的采样电容13的大小与指纹表面的纹理的距离d相关；根据电容公式C＝εS/4πkd，其中，d为手指表面纹理与感测电极之间的距离。当感测电极与指纹表面的脊线形成采样电容时，距离d较小形成的采样电容较13大；当感测电极与指纹表面的谷线形成采样电容时，距离d较大形成的采样电容13小。驱动电极用于使得采样电容13内形成与指纹纹理表面距离d相应的电荷量；在电容指纹传感器中，指纹的脊线与电容采样电路的感测电极距离小，而谷线与电容采样电路的感测电极距离大，从而谷线部分电容采样形成的电荷量Q多，脊线部分电容采样形成的电荷量Q少。在指纹传感器中还包括等效并联的寄生电容cb，所述采样电容13和驱动电容12分别与电荷转移开关14连接，电荷转移开关14的出口端作为电荷产生电路10的输出端out，同时电荷产生电路10的输出端out连接积分电路20的输入端。如图2b所示，多个所述电荷产生电路10可以形成一个电荷产生阵列，每个电荷产生电路10可通过电荷转移开关14与总线连接，总线作为多个电荷转移开关14的输出端out同时连接积分电路20的输入端。
请参照图3a至图3c，电荷产生电路10使用光学传感元件16产生电荷，光学传感元件16产生的电荷量与光通量相关联。光学传感元件16优选的为光电二极管、光敏电阻等本技术领域公知元件。光学传感元件16用于接收手指表面(图中未示出)反射的光线，并输出与反射光线 光通量相关的反映指纹信息成分的感应电荷。由于目标手指的脊和谷与接触表面的距离不同，其反射光在一定时间内的光通量也不同，导致光学传感元件16产生的电荷随着光的变化而相应变化。光学传感元件16分别与负载电路15和电荷转移开关17的第一端口连接，电荷转移开关17的第二端口连接电荷产生电路10的输出端out。该输出端out连接积分电路20的输入端，同时光学传感元件16通过复位开关18与复位参考电压Verf连。如图3b所示，多个所述电荷产生电路10可形成一个电荷产生阵列。多个电荷产生电路10可复用复位开关18和复位参考电压18，类似的，多个电荷产生电路10可复用电荷转移开关17，电荷转移开关17作为一级开关，电荷产生电路10内部设置二级开关171。如图3c所示，多个电荷产生电路10与总线连接，总线作为多个电荷产生电路10的输出端，同时连接积分电路20的输入端。
请参照图4a至图4c，电荷产生电路10使用压电元件19产生电荷，压电元件19产生的电荷量与压电元件19接收的机械震动能量相关。压电元件19优选的为超声波换能器，换能器优选的为压电陶瓷制作形成的可吸收超声波震动机械能。压电元件19与超声波脉冲发射元件(图中未示出)配合使用，超声波发射元件向手指发射超声波束。指纹的波峰和波谷反射的超声波包含的能量不同，导致压电元件19产生的电荷随着指纹表面的纹理变化而产生相应的变化。压电元件19分别与参考电平Vu和电荷转移开关191的第一端口连接，电荷转移开关191的另一端连接电荷产生电路10的输出端out。
如图4b所示，多个电荷产生电路10形成一个电荷产生阵列。多个电荷产生电路10可复用电荷转移开关191和参考电压Vrst。类似的，多个电荷产生电路10可复用电荷转移开关191。电荷转移开关191作为一级开关，电荷产生电路10内部设置二级开关190。压电元件19连接二级开关的第一端口，二级开关的第二端口连接电荷转移开关191的第一端口，电荷转移开关191的第二端口连接输出端out。
如图4c所示，多个电荷产生电路10与总线连接，总线作为多个电荷产生电路10的输出端，同时作为积分电路20的输入端。
请参照图5a至图5b所示的调整电路40示意图，图5a中展示的调整电路40均包括调整电容Cc。调整电容Cc的第一极连接调整开关41，同时第一极通过复位开关42连接参考电压Vt。调整电容Cc的第二极连接参考电压Vf或驱动电平Vd3。图5b中所示的调整电路40与图5a不同之处在于调整电容的第二极连接第三电平驱动器Vd3，第三电平驱动器Vd3的电压为可变的。图5a和图5b中所示的调整电容Cc具有两种工作状态，其一为复位状态，闭合复位开关42、断开调整开关41使所述调整电容Cc对所述参考电压Vt导通，使调整电容具备初始电荷量。该初始电荷量由调整电容值Cc、第三电平驱动器Vd3的驱动电压差值以及参考电压Vt决定，其中，第三平驱动器也可以用固定的参考电压Vf替换。其二调整状态，闭合调整开关41、断开复位开关42使所述调整电容Cc对所述积分电路20导通，使得调整电容中的存储电荷注入积分电路20， 以调整积分电路20的积分速度。在使用包含电容的调整电路40对积分电路20累积的电荷量进行调整时，从积分的过程可以看出调整电路40的电荷调整量也是分多次重复注入积分电路20中，即对积分电路20的补偿在时间上是非连续的。
参照图5c所示的调整电路40，调整电路40包括电流源43，电流源43通过调整开关41与电荷产生电路10和积分电路20连接。调整开关41闭合时电流源43的电荷注入积分电路20，调整积分电路20的积分速度。与图5a和图5b所示的调整电路40有所区别，调整电路40的两种工作状态为调整状态和复位状态，调整开关闭合时电流源的电荷注入积分电路20为调整状态。调整开关41断开时为复位状态，积分电路20在使用具有电流源43的调整电路40对积分电路20累积的电荷量进行调整时，可根据积分器的过程将积分器调整为在时间上是连续的或不连续的。
请参照图6a至图6c所示的积分电路示意图，如图6a所示积分电路20包括放大器Amp、积分电容Cr和复位开关21；放大器Amp的第一输入端22作为积分器20的输入端in，放大器的第二输入端连接参考电压Verf1，放大器Amp的输出端作为积分器的输出端out。积分电容Cr两端分别连接放大器Amp的第一输入端in和放大器的输出端out。积分电容Cr两端连接复位开关21，复位开关21闭合时积分电容两端电平相同，积分电容Cr内的电荷被复位清空。
如图6b所示的积分电路20与图6a不同在于复位开关包括两个21/24，积分电容的第一极通过第一复位开关21与第一参考电压Verf1连接，第一参考电压Verf1与放大器的第二输入端23的参考电压复用。积分电容cr的第二极通过第二复位开关24连接第二参考电压Vef2，同时积分电容Cr的第二极通过跟随开关25连接放大器Amp的输出端。积分电路20具有两种工作状态，其一为积分状态、其二为复位状态。在积分状态时电荷转移开关和跟随开关25开关闭合，第一复位开关21和第二复位开关24断开。其二为复位状态，在复位状态时跟随开关25断开，两复位开关21/25闭合。
如图6c所示的积分电路20与图6a、6b不同在于积分电路20仅包括积分电容Cr，积分电容的第一极连接积分电路20的输入端in，同时连接积分电路20的输出端out。积分电容的第二极接地，被技术领域人员公知的积分电容Cr的第二极也可以连接参考电压。积分电路20的第一极连接复位开关21，复位开关21连接第一参考电压Verf1，积分电路20具有两种工作状态，其一为积分状态复位开关21断开，其二为复位状态积分复位开关21闭合。
以下进一步对电荷积分调整电路的工作过程和工作原理进行叙述。
请参照图7a和图7b所示的电荷积分调整电路，电荷产生电路10包括采样电容13，电荷产生电路10的输出端通过电荷转移开关14与积分电路20的输入端连接。
电荷积分调整电路的共组步骤包括：
S1复位积分电容20；
S2断开电荷转移开关14、调整开关41；
S3闭合电荷产生电路复位开关42，闭合调整电路复位开关11；
S4电荷产生电路驱动器Vd2,Vd1控制信号为高，调整电路驱动器Vd3控制信号为高；
S5断开电荷产生电路复位开关42，断开调整电路复位开关11。
S6闭合电荷转移开关14，闭合调整开关41；
S7电荷产生电路电平驱动器Vd1、Vd2控制信号为低，调整电路电平驱动器Vd3控制信号为低；
S8返回步骤S2。
在步骤S1复位积分电路20中，为了保证测量的一致性，在积分前需要预先对积分电容Cr复位。复位的过程即使得积分电容Cr具有一个初始的电量，例如假设在积分电容两端的参考电压Vref1、Vref2、积分电容Cr的复位后点电量为Qrst＝(Vref1-Vref2)*Cr。为了简化复位电路的结构可用复位开关21直接连接积分电容Cr的两端(如图7a所示)，即复位后积分电容Cr的电量Qrst＝0。积分电路20多次重复积分的过程即电荷产生电路10产生的电荷多次重复向积分电容Cr充电的过程。而每次对积分电容Cr充电时，调整电路40通过调整开关41与所述积分电路20和电荷产生电路10连接，向所述积分电路20注入电荷。
在步骤S2中即断开电荷产生电路10和调整电路40之间的电连接，步骤S3和S4的作用是分别在电荷产生电路10的采样电容13和驱动电容12的调整电容Cc中形成一定的初始电荷量。其中,采样电容13的电荷量依赖于手指表面距离，若感测电极上方为手指的脊线则电荷量大，若感测电极上方为手指的谷线则电荷量小。在步骤S5中断开复位开关11为电荷转移做准备。
在步骤S6闭合电荷转移开关14，电荷产生电路10与积分电路20电连接；调整电路40向积分电路20注入电荷，对积分电路20的积分电荷累计量进行调整。令采样电容13的电容值为Cf，驱动电容12的电容值为Cd，寄生电容的电容值为Cb，电荷产生电路10和积分电路20的总线寄生电容的值为Cp，电荷产生电路10参考电压的值为Vint，比较电路30参考电压的值为VREF3，调整电路40参考电压为VREF5，第一电平驱动器高电平为V12低电平为V11，第二电平驱动器高电平为V22低电平为V21，第三电平驱动器高电平为V32低电平为V31。定义ΔV1＝V12-V11，ΔV2＝V22-V21，ΔV3＝V32-V31，ΔVREF＝VREF1-Vint。
根据电荷平衡原理和积分器工作原理，可以得到积分电容Cr每次充电的电荷量ΔQ：ΔQ＝(ΔVREF-ΔV1)*Cf+(ΔVREF-ΔV2)*Cd+ΔVREF*Cb+(ΔV3+VREF1-VREF5)*Cc。
从以上等式中可以看出，调整电路40使电荷转移量产生了一个电荷量(ΔV3+VREF1-VREF5)*Cc。当Cf中包含了较大的直流分量，影响了指纹交流分量提取的时候，可以通过合理的配置ΔV3，VREF5以及Cc的值，中和掉Cf中直流分量带来的电荷量；由于Cf中的直流分量是个变化量，指纹传感器每次采集都可能碰到不同的Cf，当然也会有不同的直流分量。所以补偿电荷量 就需要做成可实时调节的，即第三电平驱动器为可调电平驱动器使得ΔV3可调或者补偿电容Cc为可调电容，以针对不同的采样电容形成不同的补偿电荷量。
在图7a、图7b和图11中电荷产生电路10可以按照阵列的方式进行排列以采用点阵的方式对在其上方的表面进行图像采集，在指纹传感器中采用90*90像素，分别率为500ppi电容阵列。在指纹传感器中由于指纹表面与感测电极之间形成的采样电容很小，因此采集图像时需要重复对积分电容Cr进行充电，积分电容重复充电的过程为：
S1复位积分电路20；
S2断电荷转移开关14，断开调整开关41；
S3闭合电荷产生电路复位开关11，闭合调整电路复位开关42；
S4电荷产生电路10驱动器Vd1/Vd2控制信号为高，调整电路40驱动器Vd3控制信号为高；
S4断开电荷产生电路10复位开关11，断开调整电路40复位开关42；
S5闭合电荷转移开关11，闭合调整开关41；
S6第一电平驱动器Vd1控制信号为低，第二电平驱动器Vd2控制信号为低，第三电平驱动器Vd3控制信号为低；
S7返回步骤S2。
其中步骤S2至步骤S4为复位电荷产生电路10和复位调整电路40的步骤，其目的是使得电荷产生电路10内部的采样电容13，和调整电路40的调整电容Cc具有一定的初始电荷量。
在步骤S5中闭合电荷转移开关14闭合使得电荷产生电路10与积分电路20电连接。调整电路40向积分电路20注入电荷，对积分电路20的积分电荷累计量进行调整，同样的其满足电荷如图7a中电荷调整电路40的方程即ΔQ＝(ΔVREF-ΔV1)*Cf+(ΔVREF-ΔV2)*Cd+ΔVREF*Cb+(ΔV3+VREF1-VREF5)*Cc。
在步骤S6中电荷产生电路10的电平驱动器Vd1/Vd2与调整电路40的电平驱动器复位Vd3，为下一次电荷转移的过程做准备。
随后进入步骤S7重复步骤S2至步骤S6。
积分电路20的输出端与比较电路30的第一输入端连接，在采样电容13向积分电容Cr重复充电的过程中，每完成一次电荷转移的过程相应的电荷转移量为上述ΔQ。积分电容Cr中电荷不断累计从而积分电路20的输出会产生单向变化，当积分电路20的输出达到比较电路30的参考电压Verf3时，比较电路30输出的电压信号会发生翻转，翻转的时间T作为指纹传感器的输出。令比较参考电压的值为VREF3，那么比较电路30输出翻转的时刻积分电容Cr的电荷量Qr.end＝(VREF3-VREF2)*Cr。
比较电路30的翻转时间为T＝(Qr.end-Qr.rst)/ΔQ对于给定的指纹传感器设计，(Qr.end-Qr.rst)是定值，而根据式ΔQ只是采样电容13的一次函数。在工程实际中为了简便 T取整作为结果输出。
请参照图8a和图8b所示的电荷积分调整电路，使用光学式电荷产生电路10，为了使得所述光学电荷产生电路10的脊线和谷线对应的电荷量形成可测量的电压信号。电荷产生电路10输出端通过电荷转移开关17与连接积分电路20的输入端连接，电荷积分调整电路的共组步骤包括：
S1复位积分电路20；
S2复位电荷产生电路10，复位调整电路40；
S3闭合电荷转移开关17和复用开关171，闭合调整开关41；
S4返回步骤S2。
在步骤S1中积分器复位的方法与图7a和图7b中展示的积分电路20复位方法相同。
在步骤S2中电荷产生电路10通过复位开关18进行复位，调整电路40断开调整开关41进行复位。
在步骤S3闭合电荷转移开关17和复用开关171，电荷产生电路10与积分电路20电连接。调整电路40向积分电路20注入电荷，对积分电路20的积分电荷累计量进行调整。电荷产生电路10的输出端通过电荷转移开关17连接至积分电路20的输入端，积分电路20的输出端连接至比较电路30的输入端。比较电路30的输出端作为传感器的输出，比较电路30输出翻转电压信号的时间T反映电荷产生电路10产电荷量的大小。
当该积分电路20输出电压的值变化到与比较电路30中的参考电压Verf3交叉时，比较电路30将输出信号翻转。该信号翻转的时间T＝(Qr.end-Qr.rst)/(I L-I n)，I L视为一定时间段内通过的平均电荷，I n视为在一定时间内通过调整电路40对积分积分电容20补偿的平均电荷量。对于给定的指纹传感器设计，Qr.end-Qr.rst是定值，(I L-I n)只是采样电容13的一次函数,在工程实际中为了简便T取整作为结果输出。
实施例三，
请参照图9a和图9b所示的电荷积分调整电路，使用压电式电荷产生电路10，为了使得所述压电式电荷生电路10的脊线和谷线对应的电荷量形成可测量的电压信号。压电式电荷产生电路10输出端通过电荷转移开关191连接积分电路20的输入端连接，电荷积分调整电路的共组步骤包括：
S1复位积分电路20；
S2复位电荷产生电路10，复位调整电路40；
S3闭合电荷转移开关191和复用开关190，闭合调整开关41；
S4返回步骤S2。
在步骤S1中积分电路20复位的方法与图7a和图7b中展示的积分电路20复位方法相同。
在步骤S2中包括步骤S21,电荷产生电路10闭合复位开关192进行复位；还包括S22，调整电路40通过断开调整开关41闭合复位开关42进行复位。
在步骤S3闭合电荷转移开关191，电荷产生电路10与积分电路20电连接，调整电路40向积分电路20注入电荷，对积分电路20的积分电荷累计量进行调整。电荷产生电路10的输出端通过电荷转移开关191连接至积分电路20的输入端，积分电路20的输出端连接至比较电路30的输入端。比较电路30的输出端作为传感器的输出，比较电路30输出翻转电压信号的时间T反映电荷产生电路10产电荷量的大小。
当该积分电路20输出电压的值变化与比较电路30中的参考电压值交叉时，比较电路30将输出信号翻转。在步骤S3中对积分电容Cr进行积分的过程与与图7a和图7b中展示的对积分电路20的积分过程类似。比较电路30的翻转时间为T＝(Qr.end-Qr.rst)/ΔQ，对于给定的指纹传感器设计，(Qr.end-Qr.rst)是定值，而根据式ΔQ与补偿电容Cc初始化电荷量相关。在工程实际中为了简便T取整作为结果输出。
实施例四
本发明还提供一种基于所述调整电路获取电荷积分电路失配调整参数的获取方法，包括步骤：
S1：设置电荷产生电路为默认输入；
S2：在时间-电压坐标平面上设置目标点(T0,V0)；
S3：对调整电路设置的不同的配置参数，获取每一个配置参数对应的电荷积分电路在时间-电压坐标平面上的输出特性曲线；
S4：选取与所述目标点(T0,V0)最接近的输出特性曲线；
S5：获取与所述目标点最接近的输出特性曲线对应的调整电路配置参数。
在步骤S1中，所述默认输入是指电荷产生电路没有任何外部输入或仅包括背景输入。例如在指纹传感器中，传感器上不设置手指时指纹传感器为默认输入，但在此默认输入的信号中包含指纹传感器本身的背景信号；
在所述步骤S2中，该目标点(T0,V0)是为了验证传感器配置参数而设置的，当传感器的输出特性曲线能够穿过或很接近目标点(T0,V0)，则认为传感器配置参数能够达到设计目标。
在所述步骤S3中，所述电路配置参数包括但不限于：参考电压Verf1、参考电压Vrst、参考电压Verf3、Vint。对于任意调整电路配置参数Ki包括步骤：
S31：初始化积分电路；该初始化方法与实施例一至实施例三的方法相同。
S32：将所述调整电路配置参数设置为Ki；
S33：持续运行所述电荷积分电路；运行所述积分电路即在电荷产生电路输入为默认值时获取其输出值的过程。
S34：描绘所述电荷积分电路在时间-电压坐标平面上的输出特性曲线；该输出特性曲线为在不同时刻电荷积分电路对应的输出值。
优选的，不同的配置参数时积分电路输出特性曲线，为通过同一初始点的多条直线；该同一初始点的坐标值为(0，V)其中V代表积分电路初始的电压值。
示例性地，请参照图10为不同配置参数积分电路输出电压特性曲线，横坐标表示电压单位，纵坐标表示时间单位。四条斜线分别对应不同配置参数下电荷产生电路积分器输出电压特性曲线,分别表示为L1、L2、L3、L4。其中的目标点P坐标为(T0,V0),从图中可以看出随着电荷不断在积分电容中累计，输出电压特性曲线(L1、L2、L3、L4)不断下降,但在不同配置参数下所述输出电压的下降速度不同。其中,输出电压L2穿过目标点P，即在传感器的输出电压特性曲线为L2时，积分电路的配置参数能够达到设计目标。
对于多个电荷产生电路形成传感器阵列，可设置相同的目标点P,并使用同样的方法调整配置参数，使得不同的电荷产生电路输出特性相同，从而改善积分电路失配的状况。
本发明相对现有技术的优势在于，电荷调整电路，向积分电路注入正电荷或负电荷，以调整积分电路的积分速率。通过设置电荷调整电路注入电荷的极性和速率，可以起到调整电荷积分速率，补偿积分电路失配。

Claims (20)

  1. 一种电荷型传感器，其特征在于，包括：
    电荷产生电路，输出大小与被传感量相关的电荷量；
    积分电路，其输入端与电荷产生电路的输出端连接；积分电路用于累积所述电荷量，并输出与已累积的电荷量相关的电信号；
    调整电路，输出端与积分电路的输入端连接；调整电路用于向积分电路注入电荷以调整积分电路累积电荷的速率。
  2. 根据权利要求1所述的一种电荷型传感器，其特征在于，所述电荷产生电路通过电荷转移开关与积分电路连接。
  3. 根据权利要求2所述的一种电荷型传感器，其特征在于，所述电荷产生电路为电容传感电路，产生的电荷量与传感电容的大小相关。
  4. 根据权利要求2所述的一种电荷型传感器，其特征在于，所述电荷产生电路为光电传感电路，产生的电荷量与接收的光能量的大小相关。
  5. 根据权利要求2所述的一种电荷型传感器，其特征在于，所述电荷产生电路为压力传感电路，产生的电荷量与受到的压力的大小相关。
  6. 根据权利要求1所述的一种电荷型传感器，其特征在于：所述积分电路包括第一输入端、第二输入端和输出端，所述第一输入端连接电荷产生电路输出端和调整电路的输出端，所述第二输入端连接参考电压。
  7. 根据权利要求6所述的一种电荷型传感器，其特征在于：所述积分电路包括放大器、积分电容和至少一个复位开关，所述积分电容的第一极和第二极分别连接放大器的第一输入端和输出端；所述复位开关用于复位所述积分电容。
  8. 根据权利要求7所述的一种电荷型传感器，其特征在于：所述积分电容第一极和第二极通过复位开关连接。
  9. 根据权利要求7所述的一种电荷型传感器，其特征在于：所述积分电容的第一极通过复位开关与参考电压连接，积分电容的第二极接地。
  10. 根据权利要求7所述的一种电荷型传感器，其特征在于：所述积分电容的第一极通过第一复位开关与第一参考电压连接，积分电容的第二极通过第二复位开关与第二参考电压连接；第二极通过跟随开关与所述放大器的输出端连接。
  11. 根据权利要求1所述的一种电荷型传感器，其特征在于,所述调整电路向积分电路注入的电荷量的速率和极性是可设置的。
  12. 根据权利要求11所述的一种电荷型传感器，其特征在于，所述调整电路向积分电路注入 的电荷量，在时间上是连续或不连续的。
  13. 根据权利要求12所述的一种电荷型传感器，其特征在于：所述调整电路包括调整电容，调整电容的第一极通过调整开关与所述积分电路的输入端连接；调整电容的第一极通过第二复位开关连接参考电压；调整电容的第二极与电平驱动器连接。
  14. 根据权利要求12所述的一种电荷型传感器，其特征在于：所述调整电路包括电流源，电流源通过调整开关与所述积分电路的输入端连接。
  15. 根据权利要求13和14任一项所述的一种电荷型传感器，其特征在于：调整电路包括两种工作状态：
    调整状态，使得调整电路与积分电路导通，调整电路的电荷注入积分电路；
    复位状态，即对调整电路的参数进行复位设置。
  16. 根据权利要求1所述的一种电荷型传感器，其特征在于，还包括比较电路，比较电路的第一输入端与积分电路的输出端连接，比较电路的第二输入端连接参考电压。
  17. 一种传感器阵列，其特征在于，包括：
    像素阵列，包括行列排布的电荷产生电路，将非电信号量转换为与之相关的电荷量；
    积分电路，其输入端与电荷产生电路的输出端连接；积分电路用于累积所述电荷量并输出与非电信号量相关电信号；
    调整电路，输出端与积分电路的输入端连接；
    并向积分电路注入电荷调整积分电路电荷累计量；
    比较电路，比较电路的第一输入端与积分电路的输出端连接，比较电路的第二输入端连接参考电压，积分电路的输出电压随时间递增或递减与所述参考电压交叉；积分电压与所述参考电压交叉时比较电路输出与时间相关的翻转电压信号。
  18. 一种获取电荷积分电路失配调整参数的获取方法，其特征在于，包括步骤：
    S1：设置电荷产生电路为默认输入；
    S2：在时间-电压坐标平面上设置目标点(T0,V0)；
    S3：对调整电路设置的不同的配置参数，获取每一个配置参数对应的电荷积分电路在时间-电压坐标平面上的输出特性曲线；
    S4：选取与所述目标点(T0,V0)最接近的输出特性曲线；
    S5：获取与所述目标点最接近的输出特性曲线对应的调整电路配置参数。
  19. 根据权利要求18所述的一种获取电荷积分电路失配调整参数的获取方法，其特征在于，所述步骤S3中对于任意调整电路配置参数Ki包括步骤：
    S31：初始化积分电路；
    S32：将所述调整电路配置参数设置为Ki；
    S33：持续运行所述电荷积分电路；
    S34：描绘所述电荷积分电路在时间-电压坐标平面上的输出特性曲线。
  20. 根据权利要求18或19所述的一种获取电荷积分电路失配调整参数的获取方法，其特征在于：不同的配置参数时积分电路输出特性曲线，为通过同一初始点的多条直线。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3812957A1 (en) * 2019-10-24 2021-04-28 Samsung Electronics Co., Ltd. Method of generating fingerprint image and fingerprint sensor

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107688798B (zh) * 2017-09-30 2023-10-17 苏州迈瑞微电子有限公司 一种电荷型传感器和具有其的传感器阵列及积分电路失配调整参数的获取方法
CN108981897A (zh) * 2018-09-26 2018-12-11 李扬渊 超声波信号接收电路和信号检测方法
CN109884711B (zh) * 2018-11-23 2022-09-13 辽宁大学 一种基于感应原理的非接触式煤、岩带电监测传感器
CN110210349B (zh) * 2019-05-22 2021-05-11 上海思立微电子科技有限公司 指纹传感器和移动终端
CN111431532B (zh) * 2020-04-22 2023-11-07 上海微阱电子科技有限公司 一种宽输出范围高精度的积分器

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103487662A (zh) * 2013-07-24 2014-01-01 泰凌微电子（上海）有限公司 电容检测电路
CN103633956A (zh) * 2013-12-18 2014-03-12 浙江天地人科技有限公司 一种电荷放大器
CN105335737A (zh) * 2015-12-02 2016-02-17 苏州迈瑞微电子有限公司 电容指纹传感器
CN107688798A (zh) * 2017-09-30 2018-02-13 苏州迈瑞微电子有限公司 一种电荷型传感器和具有其的传感器阵列及积分电路失配调整参数的获取方法

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6483931B2 (en) * 1997-09-11 2002-11-19 Stmicroelectronics, Inc. Electrostatic discharge protection of a capacitve type fingerprint sensing array
US7777501B2 (en) * 2005-06-03 2010-08-17 Synaptics Incorporated Methods and systems for sigma delta capacitance measuring using shared component
US8599167B2 (en) * 2010-04-22 2013-12-03 Maxim Integrated Products, Inc. Method and apparatus for improving dynamic range of a touchscreen controller
CN102313566B (zh) * 2010-06-29 2013-07-24 汉积科技股份有限公司 具有校正机制的电容式传感器及电容感测方法
CN103714330B (zh) * 2014-01-06 2017-12-19 苏州迈瑞微电子有限公司 电容指纹传感器
CN105046194B (zh) * 2015-06-08 2020-04-10 苏州迈瑞微电子有限公司 一种包含积分器的电容指纹传感器
CN205540784U (zh) * 2016-01-26 2016-08-31 湖南融创微电子有限公司 一种电容式指纹检测电路、传感器及设备
US9806552B2 (en) * 2016-02-15 2017-10-31 Analog Devices Global Analog/digital converter with charge rebalanced integrator
CN106663202B (zh) * 2016-10-27 2019-01-29 深圳市汇顶科技股份有限公司 电容式指纹传感器

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103487662A (zh) * 2013-07-24 2014-01-01 泰凌微电子（上海）有限公司 电容检测电路
CN103633956A (zh) * 2013-12-18 2014-03-12 浙江天地人科技有限公司 一种电荷放大器
CN105335737A (zh) * 2015-12-02 2016-02-17 苏州迈瑞微电子有限公司 电容指纹传感器
CN107688798A (zh) * 2017-09-30 2018-02-13 苏州迈瑞微电子有限公司 一种电荷型传感器和具有其的传感器阵列及积分电路失配调整参数的获取方法

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3812957A1 (en) * 2019-10-24 2021-04-28 Samsung Electronics Co., Ltd. Method of generating fingerprint image and fingerprint sensor
US11227136B2 (en) 2019-10-24 2022-01-18 Samsung Electronics Co., Ltd. Method of generating fingerprint image and fingerprint sensor
US11625942B2 (en) 2019-10-24 2023-04-11 Samsung Electronics Co., Ltd. Method of generating fingerprint image and fingerprint sensor
JP7496733B2 (ja) 2019-10-24 2024-06-07 三星電子株式会社 指紋映像を生成する方法、及び指紋センサ

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