JP2005222472A - Fingerprint sensor, fingerprint collation apparatus and fingerprint reading method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fingerprint sensor, a fingerprint collation apparatus and a fingerprint reading method, which can reduce wasteful electric power consumption in a period until a finger is placed on a reading surface. <P>SOLUTION: The fingerprint collation apparatus has a first reading surface, on which a plurality of sensor cells are arranged like an array; a fingerprint data acquisition sensor 22, which acquires fingerprint data of a finger placed on the first reading surface; a second reading surface, on which at least one sensor cell is provided on an area different from the first reading surface, i.e., on its neighborhood; a finger existence detection sensor 23, which acquires data to detect the existence of a finger on the second reading surface; and a detection part 24, which is inputted with data acquired by the finger existence detection sensor to detect the existence of a finger on the second reading surface and outputs a start signal for fingerprint data acquisition when detecting that the finger is placed on the second reading surface. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fingerprint sensor, a fingerprint collation apparatus, and a fingerprint reading method, and more particularly to a fingerprint sensor, a fingerprint collation apparatus, and a fingerprint reading method corresponding to a sweep type or an area type.

  Fingerprint sensors are attracting attention as identity verification tools in security systems on computer networks and mobile terminals. As a fingerprint detection method used for the fingerprint sensor, an optical detection method, a capacitance detection method disclosed in Patent Document 1, for example, and the like are known.

The capacitance type detection method as described above is a method of detecting a capacitance value (hereinafter also simply referred to as a capacitance value) between an electrode of a fingerprint sensor and a finger.
For example, Patent Document 2 discloses a fingerprint sensor in which the influence of variations in parasitic capacitance due to manufacturing variations is reduced by providing dummy blocks made of dummy cells in a capacitance fingerprint sensor.

  Since the electrostatic capacitance type fingerprint sensor and the fingerprint collation device including the same are easily reduced in size, it is an advantageous method for mounting on a portable terminal. Development of fingerprint verification device is underway.

However, when mounted on a mobile terminal, reduction of power consumption is an indispensable item in order to increase the use time of the mobile terminal.
However, the conventional fingerprint sensor operates regardless of whether the finger is on the reading surface of the fingerprint sensor when the fingerprint acquisition is activated, and wastes power in the time until the finger is placed on the reading surface. I was doing it.

In particular, a so-called sweep type fingerprint sensor that moves a finger while touching a reading surface smaller than the fingerprint region and divides and reads the fingerprint region of the finger acquires and outputs a large amount of data in a short time. So the above problem has become serious.
In addition, reduction in power consumption is also desired in a so-called area-type fingerprint sensor that reads a fingerprint area of a finger at a time with a reading surface larger than the fingerprint area.
JP-A-4-231803 JP 2003-28606 A

  The problem to be solved is that, in the fingerprint sensor and the fingerprint collation device, useless power is consumed until the finger is placed on the reading surface, and the power consumption is large.

  The fingerprint sensor of the present invention includes a first reading surface on which a plurality of sensor cells are arranged in an array, the fingerprint data acquiring sensor for acquiring fingerprint data of a finger placed on the first reading surface, and the first A finger placement detection sensor that includes a second reading surface provided with at least one sensor cell in a region different from the reading surface, and that acquires data for detecting the presence or absence of a finger on the second reading surface; and the finger placement When data obtained from the detection sensor is input to detect the presence or absence of a finger on the second reading surface, a fingerprint data acquisition start signal is detected when it is detected that the finger is placed on the second reading surface. And a detector for outputting.

The fingerprint sensor according to the present invention includes a fingerprint data acquisition sensor having a first reading surface in which a plurality of sensor cells are arranged in an array, and at least one sensor cell in a region different from the first reading surface. A finger placement detection sensor having a second reading surface and a detection unit are provided.
In the finger placement detection sensor, data for detecting the presence or absence of a finger on the second reading surface is acquired and input to the detection unit.
When the detection unit detects the presence or absence of a finger on the second reading surface from the data for detecting the presence or absence of the finger on the second reading surface and detects that the finger is placed on the second reading surface. A fingerprint data acquisition start signal is output to the fingerprint data acquisition sensor.
When a fingerprint data acquisition start signal is input to the fingerprint data acquisition sensor, fingerprint data of a finger placed on the first reading surface is acquired.

  The fingerprint collation device of the present invention includes a first reading surface, and is disposed in a fingerprint data acquisition sensor that acquires fingerprint data of a finger placed on the first reading surface, and in a region different from the first reading surface. Provided with a second reading surface, a finger placement detection sensor for acquiring data for detecting the presence or absence of a finger on the second reading surface, and data obtained from the finger placement detection sensor are input to input the second Detected by the presence or absence of a finger on the reading surface and acquired by the fingerprint data acquisition sensor and a detection unit that outputs a fingerprint data acquisition start signal when detecting that the finger is placed on the second reading surface A storage unit for storing fingerprint data acquired in advance, which is different from fingerprint data, as registration data; a fingerprint unit acquired by the fingerprint data acquisition sensor; and a verification unit for verifying the registration data; A.

The fingerprint collation device of the present invention includes a fingerprint data acquisition sensor having a first reading surface in which a plurality of sensor cells are arranged in an array, and at least one sensor cell in a region different from the first reading surface. And a finger placement detection sensor having a second reading surface, a detection unit, a storage unit, and a verification unit.
In the finger placement detection sensor, data for detecting the presence or absence of a finger on the second reading surface is acquired and input to the detection unit.
When the detection unit detects the presence or absence of a finger on the second reading surface from the data for detecting the presence or absence of the finger on the second reading surface and detects that the finger is placed on the second reading surface. A fingerprint data acquisition start signal is output to the fingerprint data acquisition sensor.
When a fingerprint data acquisition start signal is input to the fingerprint data acquisition sensor, fingerprint data of a finger placed on the first reading surface is acquired.
The collation unit collates the fingerprint data acquired by the fingerprint data acquisition sensor with the registered data stored in advance in the storage unit.

  The fingerprint reading method of the present invention includes a first reading surface in which a plurality of sensor cells are arranged in an array, and a second reading surface in which at least one sensor cell is provided in a region different from the first reading surface. A step of acquiring data for detecting presence / absence of a finger on the second reading surface by a fingerprint sensor, and detecting data on the second reading surface from data for detecting presence / absence of a finger on the second reading surface. Detecting the presence or absence of a finger, and detecting the presence or absence of a finger on the second reading surface, and then detecting that the finger is placed on the second reading surface, and then detecting the fingerprint from the first reading surface. Acquiring data.

The above fingerprint reading method of the present invention uses a fingerprint sensor having a first reading surface in which a plurality of sensor cells are arranged in an array and a second reading surface in which at least one sensor cell is provided in a different area. Data for detecting the presence or absence of a finger on the second reading surface is acquired, and the presence or absence of the finger on the second reading surface is detected from the obtained data.
As a result of detecting the presence or absence of a finger on the second reading surface, fingerprint data is obtained from the first reading surface after detecting that the finger is placed on the second reading surface.

  In the fingerprint sensor of the present invention, since the fingerprint data acquisition sensor is activated after detecting that the finger is placed on the finger placement detection sensor, the time until the finger is placed on the reading surface is mainly the power consumption. A certain fingerprint data acquisition sensor is not operating, so that wasteful power consumption can be prevented and power consumption can be suppressed.

  In the fingerprint collation device of the present invention, since the fingerprint data acquisition sensor is activated after detecting that the finger is placed on the finger placement detection sensor, the time until the finger is placed on the reading surface The fingerprint data acquisition sensor is not operating, so that wasteful power consumption can be prevented and power consumption can be suppressed.

  The fingerprint reading method of the present invention acquires fingerprint data from the first reading surface after detecting that the finger is placed on the second reading surface arranged in a different area from the first reading surface. It is not necessary to perform the fingerprint data acquisition operation from the first reading surface until the time is placed, so that wasteful power consumption can be prevented and power consumption can be suppressed.

  Embodiments of a fingerprint sensor, a fingerprint collation device, and a fingerprint reading method according to the present invention will be described below with reference to the drawings.

First Embodiment The present embodiment is a fingerprint collation apparatus including a so-called sweep type fingerprint sensor that moves a finger while making contact with a reading surface smaller than the fingerprint area and divides and reads the fingerprint area of the finger.
FIG. 1 is a block diagram showing the configuration of the fingerprint collation apparatus according to this embodiment.
A fingerprint collation apparatus 1 according to this embodiment includes a fingerprint sensor 2 and a collation block 3.
The fingerprint sensor 2 has a sensor unit 21. The sensor unit 21 includes a sweep type fingerprint data acquisition sensor 22 having a first reading surface and a finger placement detection sensor 23 having a second reading surface.
The fingerprint sensor 2 further includes a detection unit 24 and a fingerprint data acquisition sensor peripheral unit 25 as peripheral circuits of the sensor unit.
The collation block 3 includes a storage unit 31 and a collation unit 32 including a data reconstruction unit.

For example, when the fingerprint collation apparatus 1 is turned on, an activation signal ST1 is sent from the collation block 3 to the fingerprint sensor 2.
Upon receiving the activation signal ST1, the fingerprint sensor 2 acquires the fingerprint data FD from the fingerprint data acquisition sensor 22 and outputs it to the verification block 3. The detailed configuration and operation of the fingerprint sensor 2 will be described later.
The verification block 3 combines the fingerprint data FD input from the fingerprint sensor 2 into the fingerprint data of the entire fingerprint area in the reconstruction unit included in the verification unit 32, and on the other hand, separately from the fingerprint data FD input above. The acquired fingerprint data that is stored in the storage unit 31 is read out to the collation unit 32, and the collation unit 32 collates both data.
As a result of the collation, that is, whether the inputted fingerprint data FD and registered data match or do not match are externally output or displayed on a display unit (not shown).

Hereinafter, the configuration of the fingerprint sensor 2 will be described.
The fingerprint sensor 2 of the fingerprint collation apparatus according to the present embodiment is a capacitive fingerprint sensor, and the fingerprint data acquisition sensor 22 has a configuration in which a plurality of sensor cells are arranged in an array.
FIG. 2 is a schematic cross-sectional view of the fingerprint data acquisition sensor 22. Metal electrodes 103 constituting each sensor cell are arranged in an array on a silicon substrate 101 via an interlayer insulating film 102 such as silicon oxide, and a protective layer 104 such as silicon oxide covers the metal electrode 103 on the upper layer. Is formed. The surface of the protective layer 104 becomes the first reading surface.
When the finger F is placed on the first reading surface, a capacitor is formed between the finger surface and the metal electrode 103. Here, since the finger F has unevenness due to the fingerprint, the capacitance value of each capacitor formed in each sensor cell varies depending on the distance between the finger surface and the metal electrode 103.
Thus, fingerprint data can be obtained by reading the capacitance value of each capacitor, converting the obtained capacitance value (charge) into a voltage, and digitizing it into an 8-bit display, for example.

The finger placement detection sensor 23 basically has the same cross section as the fingerprint data acquisition sensor 22. That is, a metal electrode is provided on a silicon substrate via an interlayer insulating film and is covered with a protective layer. The surface of the protective layer becomes the second reading surface.
Unlike the fingerprint data acquisition sensor 22, the finger placement detection sensor 23 only needs to be provided with at least one sensor cell, and may be provided by integrating a plurality of sensors or discretely arranging them. However, the second reading surface is an area different from the first reading surface, and is preferably disposed in the vicinity of the first reading surface, for example, adjacent to the first reading surface.

FIG. 3 is a plan view showing a specific example of the layout of the fingerprint sensor 2.
The fingerprint data acquisition sensor 22 has a rectangular area. For example, 128 × 16 sensors are arranged in an array. Relative to the slide direction DR _S of the finger is the operation when the fingerprint data acquisition, the short sides of the rectangular area are parallel, long sides are perpendicular.
The finger placement detection sensor 23 is adjacent to the two long sides of the area of the fingerprint data acquisition sensor 22 and has a configuration in which, for example, a total of 16 sensor cells, 8 in total, are discretely arranged.
By arranging the finger placement detection sensor 23 in the vicinity, particularly adjacent to the fingerprint data acquisition sensor 22 in this way, a finger is always placed on the finger placement detection sensor 23 whenever the finger is placed on the fingerprint data acquisition sensor 22. It is possible to be in a state of being.
The detection unit 24 and the fingerprint data acquisition sensor peripheral unit 25 that are peripheral circuits of the sensor unit are arranged in areas around the finger placement detection sensor 23 and the fingerprint data acquisition sensor 22 (26a, 26b, 26c, and 26d).

FIG. 4 is a circuit diagram showing a specific configuration of the finger placement detection sensor 23 and the detection unit 24.
In each sensor cell of the finger placement detection sensor 23, an electrode constituting a capacitor is connected to the surface of the finger via the switch SW1, and is connected to one sense line SL via the switch SW2. .
Also, it has the same configuration as the finger placement detection sensor 23, and the electrode of each sensor cell is grounded via the switch SW3, while being connected to the sense line SL via the switch SW4. A comparison sensor 23r is provided. The comparison sensor 23r is arranged in a region where a normal finger is not placed in the layout of FIG. 3, for example, the area 26c.

The sense line SL is connected to the detection unit 24. The detection unit 24 includes, for example, a sense amplifier SA1, a comparator CP1, a latch circuit LC1, and the like, and an output OUT1 is obtained.
The sense amplifier SA1 and the comparator CP1 are provided with an input terminal for the activation signal ST1.

FIG. 5A is an equivalent circuit diagram of the sense amplifier SA1.
The sense amplifier SA1 is composed of, for example, two MOS transistors, and one source / drain of each transistor is connected to the power supply voltage _Vdd via the load resistance element RS, and the other source / drain is connected via the switch SW7. Connected to current source. The two inputs (IN1, IN2) are connected to the gates of the two MOS transistors, and an output OUT2 is obtained between the source / drain of one of the transistors and the load resistance element RS.
Referring also to FIG. 4, the capacity of each sensor cell of the finger placement detection sensor 23 or the comparison sensor 23r is determined by turning on / off the switches (SW1 to SW4) provided in the finger placement detection sensor 23 and the comparison sensor 23r. When the accumulated charge is input to the sense amplifier SA1, the difference between the two inputs (IN1, IN2) is amplified and further subjected to charge / voltage conversion according to the configuration of the load resistance element RS, and an output OUT2 is obtained. This is output to the comparator CP1.
Here, the switch SW7 is turned on / off in response to the above-described activation signal ST1, that is, the sense amplifier SA1 is activated by inputting the activation signal ST1.

FIG. 5B is an equivalent circuit diagram of the comparator CP1.
The comparator CP1 has a configuration in which an input IN3 and an output OUT3 of an inverter configured by connecting an NMOS transistor and a PMOS transistor in series are connected by a switch SW6.
Referring also to FIG. 4, by alternately inputting the finger placement detection sensor 23 and the comparison sensor 23r to the sense amplifier SA1, the voltage output from the sense amplifier SA1 is alternately input to the comparator CP1. The increase in the capacitance value due to is detected and is output to the latch circuit LC1 as “0” or “1” data depending on the presence or absence of a finger.
Here, the ground GND is connected to the input terminal via the switch SW8, and the switch SW8 is turned on / off according to the above-described activation signal ST1, that is, the comparator CP1 is activated by inputting the activation signal ST1.

  The output OUT1 of the latch circuit LC1 is input to the fingerprint data acquisition sensor peripheral section 25 as the fingerprint data acquisition start signal ST2.

FIG. 6 is a timing chart of the switch operation of the finger placement detection sensor 23, the comparison sensor 23r, and the detection unit 24.
First, at time T1, the switch SW1, the switch SW3, and the switch SW5 are turned on, and the finger placement detection sensor 23, the comparison sensor 23r, and the sense amplifier SA1 are initialized.
Next, at time T2, the switches SW2 and SW6 are turned ON, and the output of the finger placement detection sensor 23 is input to the sense amplifier SA1.
Next, at time T3, the switch SW1, the switch SW3, and the switch SW5 are turned on to initialize the finger placement detection sensor 23, the comparison sensor 23r, and the sense amplifier SA1, and at time T4, the switch SW4 is turned on to compare the sensor 23r. Are input to the sense amplifier SA1. After T1, T1 to T4 are alternately repeated.
In this way, by alternately inputting the outputs of the finger placement detection sensor 23 and the comparison sensor 23r to the sense amplifier SA1, the voltage output from the sense amplifier SA1 is alternately input to the comparator CP1, and as described above, An increase in capacitance value is detected.

FIG. 7 is an example of a circuit for preventing erroneous detection, and is a circuit of a portion connected after the comparator CP1 constituting the detection unit 24.
That is, the output of the comparator CP1 is taken into the shift register SR with the clock CLK of the detection operation cycle, and the number of stages of the shift register SR is four times. In FIG. Only, the detection confirmation signal OUT4 is output.
Accordingly, it is possible to prevent erroneous detection when a detection signal is output from the comparator even though the finger is not placed due to sudden disturbance.

FIG. 8 is a circuit diagram showing a specific configuration of the fingerprint data acquisition sensor 22 and the peripheral part 25 of the fingerprint data acquisition sensor.
The fingerprint data acquisition sensor 22 has a configuration in which sensor cells are integrated in an array, and a part of the drawing is shown in the drawing. In each sensor cell of the fingerprint data acquisition sensor 22, an electrode constituting a capacitor is grounded via a switch SW 9 while a plurality of sense lines (SL 1, SL 2 .SL 3 are connected via a switch SW 10. ···)It is connected to the.
Similarly to the finger placement detection sensor 23 described above, a comparison dummy sensor DS is provided for the fingerprint data acquisition sensor 22. This dummy sensor DS is also arranged in an area where a normal finger is not placed in the layout of FIG.

Each sense line (SL1, SL2, SL3...) Is connected to the peripheral part 25 of the fingerprint data acquisition sensor. The fingerprint data acquisition sensor peripheral section 25 has a configuration similar to that of the detection section 24 described above. For example, the charge accumulated in each sensor cell input from each sense line (SL1, SL2.SL3...) The sense amplifier SA2 performs charge / voltage conversion and amplification, and outputs it as fingerprint data FD via the comparator CP2 and the latch circuit LC2. The comparator CP2 is provided with a switch so that the reference voltage V _ref from the dummy sensor DS is also input, and the AD conversion is performed by comparing the data from the fingerprint data acquisition sensor 22 with the reference voltage V _ref. Yes.

The sense amplifier SA2 and the comparator CP2 are provided with an input terminal for a fingerprint data acquisition start signal ST2 output from the detection unit 24.
The configuration of the sense amplifier SA2 and the comparator CP2 is substantially the same as the configuration shown in FIGS. 5A and 5B. That is, the sense amplifier SA2 and the comparator CP2 acquire fingerprint data from the detection unit 24. When the start signal ST2 is input, the sense amplifier SA2 and the comparator CP2 are activated. Therefore, until the detection unit 24 outputs the fingerprint data acquisition start signal ST2, the sense amplifier SA2 and the comparator CP2 are not activated, that is, the fingerprint data acquisition sensor peripheral portion 25 is not activated.

Here, the fingerprint sensor according to the present embodiment is a sweep type, that is, when the first reading surface of the fingerprint data acquisition sensor 22 is smaller than the fingerprint region and moved while the finger is in contact with the first reading surface. In this method, the fingerprint area of the finger is divided and read, and the fingerprint data FD obtained by dividing the fingerprint area is individually output to the collation block 3.
The collation unit 32 of the collation block 3 includes a reconstruction unit that reconstructs the obtained fingerprint data, and the reconstruction unit synthesizes the fingerprint data obtained by dividing as described above into one.
The collation unit 32 collates the fingerprint data of the combined fingerprint area with the registration data read from the storage unit 31.

Next, the operation of the fingerprint collation apparatus provided with the fingerprint sensor according to the present embodiment will be described.
FIG. 9 is a flowchart for explaining the operation of the fingerprint collation device according to the present embodiment.
When the fingerprint collation operation starts, the fingerprint collation apparatus is brought into an initial state (STEP 1). In the initial state, the fingerprint sensor 2 is not operating and the power consumption is almost zero.

  Next, an activation signal ST1 is input from the verification block 3 to the fingerprint sensor 2 (STEP 2).

  When the activation signal ST1 is input to the detection unit 24 of the fingerprint sensor 2, finger placement detection data is acquired (STEP 3). That is, in response to the activation signal ST1, the sense amplifier SA1 and the comparator CP1 in the detection unit 24 are activated, and charges are input to the electrodes of the sensor cells of the finger placement detection sensor 23 to the sense amplifier SA1.

  Further, the activation of the sense amplifier SA1 and the comparator CP1 in the detection unit 24 detects the presence or absence of a finger on the second reading surface of the finger placement detection sensor 23 (STEP 4).

  Until the above steps, the fingerprint data acquisition sensor 22 and the fingerprint data acquisition sensor peripheral portion 25 are not operating. Since the circuit scale of the finger placement detection sensor 23 and the detection unit 24 is sufficiently smaller than the fingerprint data acquisition sensor 22 and the peripheral unit 25, the fingerprint data acquisition sensor 22 and the peripheral unit 25 operate at the power consumption up to the above steps. The power consumption can be greatly suppressed because the power consumption is sufficiently smaller than when the power is on.

When detecting the presence / absence of a finger on the second reading surface (STEP 4), as shown in the schematic diagram of FIG. 10, the second reading surface of the finger placement detection sensor 23 provided in the sensor unit 21 becomes a reading target. When the finger F is in contact, it is detected that the finger is placed on the second reading surface (Yes), and the fingerprint data acquisition start signal ST2 is input from the detection unit 24 to the fingerprint data acquisition sensor peripheral unit 25, The sense amplifier SA2 and the comparator CP2 in the peripheral part 25 of the fingerprint data acquisition sensor are activated, and the fingerprint data acquisition sensor 22 starts acquiring the fingerprint data FD (STEP 5). When it is not detected that the finger is placed on the second reading surface (No), acquisition of finger placement detection data (STEP 3) and detection of the presence or absence of the finger on the second reading surface (STEP 4) are repeated.
Since the second reading surface of the finger placement detection sensor 23 is provided in the vicinity of the first reading surface of the fingerprint data acquisition sensor 22, the fact that the finger is placed on the second reading surface is also present on the first reading surface. This indicates that the finger F is in contact or that the finger F is at least in the vicinity of the first reading surface, and wasteful power is consumed even when the fingerprint data acquisition sensor 22 and its peripheral portion 25 start operating. Never happen.

Since the fingerprint sensor of the fingerprint collation apparatus according to the present embodiment is a sweep type, when the fingerprint data acquisition sensor 22 acquires the fingerprint data FD, as shown in FIG. 10, the finger F is in contact with the first reading surface while sliding. sliding the DR _S. At this time, at the time of fingerprint data acquisition (STEP 5), the fingerprint area of the finger F is divided into a plurality of areas and read according to the movement of the finger F.

Next, the fingerprint data FD obtained by dividing as described above is output to the collation block 3 shown in FIG. 1 as described above (STEP 6).
When the output of the fingerprint data is finished, the operation of all the circuits of the fingerprint sensor 2 can be finished.

Thereafter, the processing is performed in the collation block 3. That is, the reconstruction unit included in the collation unit 32 of the collation block 3 combines the fingerprint data obtained by the above division into one (STEP 7).
For example, as schematically shown in FIG. 11, t ₁ ~t joining the fingerprint data obtained by dividing into six ₆ as the joint of the fingerprint pattern matches, one corresponding to the entire fingerprint area Composite to fingerprint data.

Next, the collation unit 32 collates the combined fingerprint data FD of the entire fingerprint region with the fingerprint data previously acquired separately from the fingerprint data and stored in the storage unit 31 (STEP 8). .
The collation result, that is, whether the input fingerprint data FD and the registered data match or not is displayed on an external output or a display unit (not shown).
This completes the operation of the fingerprint collation device.

  The fingerprint sensor and fingerprint collation device of this embodiment can be applied to, for example, the fingerprint sensor or fingerprint collation device described in Patent Document 2.

According to the fingerprint sensor, the fingerprint collation device including the fingerprint sensor, and the fingerprint reading method according to the present embodiment described above, a small finger placement detection sensor and its peripheral circuit detection unit are operated and a finger is placed. Since the entire circuit can be operated to acquire fingerprint data when it is detected, power consumed when a finger is not placed can be reduced.
Further, by detecting periodically the presence or absence of a finger and outputting a detection signal when the detection state continues a plurality of times, erroneous detection due to sudden disturbance is suppressed.

Second Embodiment This embodiment is a fingerprint collation apparatus provided with a so-called area-type fingerprint sensor that touches a reading surface larger than the fingerprint area and reads the fingerprint area at a time.
FIG. 12 is a block diagram showing the configuration of the fingerprint collation apparatus according to the present embodiment.
The fingerprint collation apparatus 1a according to the present embodiment has substantially the same configuration as the fingerprint sensor of the first embodiment and the fingerprint collation apparatus including the fingerprint sensor shown in FIG. Includes an area-type fingerprint data acquisition sensor 22a having a first reading surface larger than the fingerprint area, and a finger placement detection sensor 23 similar to that of the first embodiment, and the fingerprint data acquisition sensor The peripheral portion 25a has a configuration corresponding to the area-type fingerprint data acquisition sensor 22a, and includes a reconfiguration unit for the collation unit 32a of the collation block 3 to synthesize fingerprint data input from the fingerprint sensor 2. It is not different.
Since it is an area type, the fingerprint data acquisition sensor 22a reads the fingerprint data of the entire fingerprint area at once, and the obtained fingerprint data is output from the fingerprint sensor 2 to the collation block 3.
The configuration other than the above can be the same as in the first embodiment.

FIG. 13 is a plan view showing a specific example of the layout of the fingerprint sensor 2.
The fingerprint data acquisition sensor 22a has an area larger than the fingerprint area, and is configured by, for example, 128 × 128 sensors arranged in an array.
The finger placement detection sensor 23 is adjacent to the area of the fingerprint data acquisition sensor 22a, and has a configuration in which, for example, a total of 16 sensor cells are discretely arranged.
The detection unit 24 and the fingerprint data acquisition sensor peripheral unit 25a, which are peripheral circuits of the sensor unit, are arranged in areas around the finger placement detection sensor 23 and the fingerprint data acquisition sensor 22a (26a, 26b, 26c, 26d) and the like.

When it is detected that the finger is placed on the finger placement detection sensor 23, the finger placement detection sensor is configured so that the finger is substantially placed on the first reading surface of the fingerprint data acquisition sensor 22a. The second reading surface 23 is arranged in an area different from, for example, the vicinity of the first reading surface of the fingerprint data acquisition sensor 22a. However, since the fingerprint data acquisition sensor 22a is an area type, it is relatively wide with respect to the fingerprint area. In some cases, it is not sufficient to provide the finger placement detection sensor 23 in the vicinity of the fingerprint data acquisition sensor 22a.
In such a case, the finger placement detection sensor 23 is provided adjacent to the fingerprint data acquisition sensor 22a, or a layout is provided in the area of the fingerprint data acquisition sensor 22a that does not interfere with fingerprint data acquisition. It is preferable to do.

  In the present embodiment as well, a small finger placement detection sensor and its peripheral circuit detection unit are operated, and the entire circuit is operated for fingerprint data acquisition when it is detected that a finger is placed. Therefore, it is possible to reduce the power consumed when the finger is not placed, and periodically detect the presence or absence of the finger and issue a detection signal when the detection state continues multiple times. By doing so, erroneous detection due to sudden disturbance is suppressed.

The present invention is not limited to the above description.
For example, the placement position of the finger placement detection sensor may be a place where the finger hits when the finger is placed on the reading surface of the fingerprint sensor, and does not necessarily have to be around the fingerprint data acquisition sensor.
Further, the circuit configuration of the detection unit is not limited to that shown in the embodiment, and various circuit configurations can be adopted.
In addition, various modifications can be made without departing from the scope of the present invention.

The fingerprint sensor of the present invention can be applied to a fingerprint sensor used for a security system on a computer network, an identity verification tool in a portable terminal, and the like.
The fingerprint collation apparatus of the present invention can be applied to a fingerprint collation apparatus used for a security system on a computer network, an identity verification tool in a portable terminal, and the like.
The fingerprint reading method of the present invention can be applied to a method of reading a fingerprint in order to perform fingerprint collation.

FIG. 1 is a block diagram showing the configuration of the fingerprint collation apparatus according to the first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of a fingerprint data acquisition sensor of the fingerprint collation apparatus according to the first embodiment of the present invention. FIG. 3 is a plan view showing a specific example of the layout of the fingerprint sensor of the fingerprint collation apparatus according to the first embodiment of the present invention. FIG. 4 is a circuit diagram showing a specific configuration of the finger placement detection sensor and detection unit of the fingerprint collation apparatus according to the first embodiment of the present invention. FIGS. 5A and 5B are equivalent circuit diagrams of the sense amplifier and the comparator of the detection unit of the fingerprint collation device according to the first embodiment of the present invention, respectively. FIG. 6 is a timing chart of the switch operation of the finger placement detection sensor, the comparison sensor, and the detection unit of the fingerprint collation apparatus according to the first embodiment of the present invention. FIG. 7 is a circuit example for preventing erroneous detection of the fingerprint collation apparatus according to the first embodiment of the present invention. FIG. 8 is a circuit diagram showing a specific configuration of the fingerprint data acquisition sensor and the peripheral portion of the fingerprint data acquisition sensor of the fingerprint collation apparatus according to the first embodiment of the present invention. FIG. 9 is a flowchart for explaining the operation of the fingerprint collation apparatus according to the first embodiment of the present invention. FIG. 10 is a schematic diagram for explaining how a finger is placed on the second reading surface and slid in the fingerprint collation apparatus according to the first embodiment of the present invention. FIG. 11 is a schematic diagram showing fingerprint data synthesized in the fingerprint collation apparatus according to the first embodiment of the present invention. FIG. 12 is a block diagram showing a configuration of a fingerprint collation apparatus according to the second embodiment of the present invention. FIG. 13 is a plan view showing a specific example of the layout of the fingerprint sensor of the fingerprint collation apparatus according to the second embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fingerprint collation apparatus, 2 ... Fingerprint sensor, 3 ... Collation block, 21 ... Sensor part, 22, 22a ... Fingerprint data acquisition sensor, 23 ... Finger placement detection sensor, 23r ... Comparison sensor, 24 ... Detection part, 25, 25a ... peripheral part of fingerprint data acquisition sensor, 26a, 26b, 26c, 26d ... peripheral area, 31 ... storage part, 32, 32a ... collation part, 101 ... silicon substrate, 102 ... interlayer insulating film, 103 ... metal electrode, 104 ... Protective layer, CLK ... Clock, CP1, CP2 ... Comparator, DS ... Dummy sensor, DR _S ... Slide direction, F ... Finger, FD ... Fingerprint data, GND ... Ground, IN1-3 ... Input, LC1, LC2 ... Latch circuit , OUT1-4 ... output, RS ... load resistance element, SA1, SA2 ... sense amplifier, SL, SL1-3 ... sense line, SR ... shift Register, ST1 ... activation signal, ST2 ... fingerprint data acquisition start signal, STEP1~8 ... step, SW1 to SW8 ... switch, V _dd ... supply voltage.

Claims (13)

A fingerprint data acquisition sensor comprising a first reading surface in which a plurality of sensor cells are arranged in an array, and acquiring fingerprint data of a finger placed on the first reading surface;
A finger placement detection sensor comprising a second reading surface provided with at least one sensor cell in a region different from the first reading surface, and acquiring data for detecting the presence or absence of a finger on the second reading surface;
When the data obtained from the finger placement detection sensor is input to detect the presence or absence of a finger on the second reading surface, fingerprint data acquisition is performed when the finger is placed on the second reading surface. A fingerprint sensor having a detection unit that outputs a start signal. The fingerprint sensor according to claim 1, wherein a second reading surface of the finger placement detection sensor is disposed in the vicinity of the first reading surface. Acquisition of data for detecting presence / absence of a finger on the second reading surface by the finger placement detection sensor, and detection of a finger on the second reading surface from data obtained from the finger placement detection sensor by the detection unit The fingerprint sensor according to claim 1, wherein presence / absence detection is periodically performed. When the detection unit detects that a finger is placed on the second reading surface in a plurality of times continuously from data periodically obtained from the finger placement detection sensor, the fingerprint data acquisition starts. The fingerprint sensor according to claim 3, which outputs a signal. The first reading surface is smaller than the fingerprint area, and when the finger is moved while contacting the first reading surface, the fingerprint area of the finger is divided and read,
The fingerprint sensor according to claim 1, further comprising a reconstruction unit that combines the fingerprint data obtained by the division into one. The fingerprint sensor according to claim 1, wherein the first reading surface is larger than a fingerprint region, and the fingerprint region of a finger is read at a time with the first reading surface. A fingerprint data acquisition sensor that includes a first reading surface and acquires fingerprint data of a finger placed on the first reading surface;
A finger placement detection sensor comprising a second reading surface arranged in a region different from the first reading surface, and acquiring data for detecting the presence or absence of a finger on the second reading surface;
When the data obtained from the finger placement detection sensor is input to detect the presence or absence of a finger on the second reading surface, fingerprint data acquisition is performed when the finger is placed on the second reading surface. A detection unit that outputs a start signal; a storage unit that stores, as registration data, fingerprint data acquired in advance different from the fingerprint data acquired by the fingerprint data acquisition sensor;
A fingerprint collation apparatus comprising: fingerprint data acquired by the fingerprint data acquisition sensor; and a collation unit that collates the registered data. A fingerprint sensor having a first reading surface in which a plurality of sensor cells are arranged in an array and a second reading surface in which at least one sensor cell is provided in a region different from the first reading surface, the second reading surface Acquiring data for detecting the presence or absence of the upper finger;
Detecting the presence or absence of a finger on the second reading surface from data for detecting the presence or absence of the finger on the second reading surface;
Obtaining fingerprint data from the first reading surface after detecting that a finger is placed on the second reading surface as a result of detecting the presence or absence of the finger on the second reading surface. . The fingerprint reading method according to claim 8, wherein the second reading surface uses a fingerprint sensor provided in the vicinity of the first reading surface. Acquisition of data for detecting the presence / absence of a finger on the second reading surface and the presence / absence of a finger on the second reading surface using data for detecting the presence / absence of a finger on the second reading surface The fingerprint reading method according to claim 8, wherein the detection is periodically performed. After detecting periodically that the finger is placed on the second reading surface from the data for detecting the presence or absence of the finger on the second reading surface obtained periodically, the first The fingerprint reading method according to claim 10, wherein fingerprint data is acquired from a reading surface. The first reading surface is smaller than the fingerprint area, and when the finger is moved while contacting the first reading surface, the fingerprint area of the finger is divided and read,
The fingerprint reading method according to claim 8, further comprising a step of synthesizing the fingerprint data obtained by the division into one. The fingerprint reading method according to claim 8, wherein the first reading surface is larger than a fingerprint region, and the fingerprint region of a finger is read at a time with the first reading surface.

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