JPH11134496A - Image collating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save power and allow a power source of limited capacity to be used by selectively supplying an operation power source to a circuit block requiring image fetching or image collating, etc. SOLUTION: When a fingerprint registration mode is selected which is obtained from a fingerprint reading part 4, power is supplied to a living body detecting part 2 by a control part 3 to which a power source is normally supplied together with an input/output part 6 in a fingerprint collating device 1. When the placement of a finger is detected, power is fed to an illuminating part 8 and an image pickup 9, power is no longer supplied to the living body detecting part. Then, the finger on the placement position is illuminated by the illuminating part 8 and image pickup data is generated by an image pickup part 9. The power source of the image collating part 5 is continuously built up and the power source of the illuminating part 8 and the image pickup part 9 is made to fall. Thus, data generated by the image pickup part 9 is registered in a database in the image collating part 5. Thus, the power source is successively supplied only to a required circuit block so that power consumption is saved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image collating apparatus, for example, applied to a fingerprint collating apparatus. To reduce.

[0002]

2. Description of the Related Art Conventionally, in a fingerprint collating apparatus comprising this kind of image collating apparatus, a fingerprint image is read through an image pickup means, and a characteristic portion such as a branch, a dot, a cut, etc. of the fingerprint is read from the fingerprint image. Is extracted to perform fingerprint collation based on this characteristic portion.

[0003]

By the way, in this type of fingerprint collating apparatus, imaging means comprising image reading means,
If the arithmetic processing means for executing the fingerprint collation processing and the like are integrated, miniaturized and unitized, it can be considered to be applicable to room entrance / exit management, for example.

However, if such a unit is formed, it may be used in a place where the power supply capacity is limited, and it is required to reduce power consumption.

The present invention has been made in view of the above points, and it is an object of the present invention to propose an image matching apparatus capable of reducing power consumption.

[0006]

According to the present invention, an operation power supply is selectively supplied to an image capturing unit and an image collating unit under the control of a control unit.

By selectively supplying power for operation to the image capturing means and the image collating means under the control of the control means,
Operation power is supplied only when necessary, and power consumption can be reduced accordingly.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(1) Overall Configuration FIG. 2 is a block diagram showing a fingerprint matching device according to an embodiment of the present invention. This fingerprint matching device 1 is configured by a unit in which a living body detecting unit 2, a control unit 3, a fingerprint reading unit 4, an image matching unit 5, and an input / output unit 6 are integrated in a small size. The fingerprint collation device 1 includes an external device 7 such as a personal computer while the unit is arranged at a predetermined position.
And is applied to, for example, room entry / exit management.

In this fingerprint collation apparatus 1, when a finger is placed at a predetermined finger placement position, the living body detection unit 2 controls the control unit 3
Notify.

The fingerprint reading section 4 captures an image of the finger placed at this finger placement position under the control of the control section 3 and outputs a video signal SV.

The image collating unit 5 switches the operation mode under the control of the control unit 3 and binarizes the video signal SV to generate image data. In the fingerprint registration mode, the image collating unit 5 receives the fingerprint data D 1 or the input / output unit 6.
Register the fingerprint data input through the built-in database. Thus, in this fingerprint registration mode, the image matching unit 5 registers a reference image serving as a reference for fingerprint matching.

In the fingerprint matching mode, the reference image registered in the built-in database is compared with a fingerprint image based on predetermined fingerprint data, and a matching result is output. Here, in the fingerprint matching device 1, the fingerprint matching mode matches the reference image held in the image matching unit 5 with the fingerprint image obtained through the fingerprint reading unit 4 by using the detection result of the living body detection unit 2 as a trigger. A first self-verification mode, a second self-verification mode for collating a reference image held in the image collating unit 5 with a fingerprint image obtained from the fingerprint reading unit 4 in response to an instruction from the external device 7, An external matching mode for matching a reference image held in the image matching unit 5 with an instruction from the device 7 and a fingerprint image input from the external device 7 is provided.

The image matching section 5 converts a fingerprint image obtained through the fingerprint reading section 4 and a fingerprint image input from the external device 7 through the input / output section 6 in correspondence with these three fingerprint matching modes. A fingerprint collation process is executed between a reference image set as a collation target and a reference image held in a database.

The input / output unit 6 notifies the control unit 3 of a control command input from the external device 7 and outputs image data input from the external device to the image matching unit 5 under the control of the control unit 3. Further, the matching result by the image matching unit 5 is output to the external device 7.

The control section 3 is constituted by a microcomputer for controlling the operation of the entire fingerprint collation apparatus 1, and sets an operation mode under the control of the external device 7.

(1-1) Fingerprint Reading Unit FIG. 3 is a block diagram showing the fingerprint reading unit 4. The fingerprint reading unit 4 includes an illuminating unit 8 for illuminating the fingerprint and an imaging unit 9 for imaging the illuminated fingerprint.

In the illumination section 8, the digital-to-analog conversion circuit 11 latches the control data output from the control section 3, converts the control data into a digital-to-analog signal, and outputs the data. The transistor 12 is constituted by a common emitter circuit receiving the output signal of the digital-to-analog conversion circuit 11 at the base, and drives the light emitting diode 13 by a collector output. Thereby, the lighting unit 8
Changes the amount of illumination light by the light emitting diode 13 under the control of the control unit 3 and further stops emission of the illumination light.

The light emitting diode 13 emits the illuminating light L to the right-angle prism 14 arranged in the image pickup section 9, thereby illuminating the fingerprint placed on the finger placement position of the right-angle prism 14.

That is, in the image pickup unit 9, the right-angle prism 14 has the inclined surface set at the finger placement position, and the light emitted from the light emitting diode 13 enters from one surface forming a right angle. Accordingly, when the right-angle prism 14 is not placed at any finger placement position, the illumination light of the light-emitting diode 13 is totally reflected by the inclined surface and emitted from another surface forming a right angle. On the other hand, when a finger is placed on the fingerprint, the light is irregularly reflected by contacting the slope at the peak of the fingerprint. , The incident light is emitted from the other surface forming a right angle so that the brightness changes according to the shape of the fingerprint.

The CCD 15 receives the light emitted from the other surface of the right-angle prism 14 via the lens 16 and thereby captures a fingerprint image formed on the slope of the right-angle prism 14.

Drive pulse generation circuit, output signal processing circuit 1
Reference numeral 7 generates various driving pulses necessary for driving the CCD 15, drives the CCD 15, and processes an output signal of the CCD 15 to output a video signal SV.

(1-2) Living Body Detecting Unit FIG. 4 is a block diagram showing the living body detecting unit 2. The living body detection unit 2 detects whether or not a finger has been placed at the finger placement position based on a change in the oscillation frequency of the pulse oscillation circuit 18. That is, the pulse oscillation circuit 18 connects the inverters 18A and 18B having a Schmitt trigger configuration in series, and
And a series circuit of R2 are arranged in the first-stage inverter 18A as a feedback circuit.

Further, the pulse oscillating circuit 18 separates the transparent electrode 1 from the inclined surface of the right-angle prism 14 at the position where the finger is placed.
When 4A and 14B are arranged and no finger is placed,
The capacitance between the transparent electrodes 14A and 14B is several [p
F], and when a finger is placed, the transparent electrode 1
It is formed so that the capacitance between 4A and 14B increases.

The pulse oscillating circuit 18 includes resistors R1 and R2
Is connected to one transparent electrode 14B, and the output terminal of the other inverter 18B is connected to the other transparent electrode 14A via a resistor R. The resistance values of these resistors R1, R2, R are each 10 [k
Ω], 100 [kΩ], and 2 [kΩ].

Thus, the pulse oscillation circuit 18 changes the frequency of the oscillation output signal S1 according to the capacitance between the transparent electrodes 14A and 14B which changes when a finger is placed. Further, by connecting the transparent electrode 14A and the output terminal of the inverter 18B via the resistor R,
The charge / discharge current between the transparent electrodes 14A and 14B is reduced, and as shown in FIG. 5, the signal waveform applied to the electrode 14B is blunted. As a result, the pulse oscillation circuit 18 reduces unnecessary radiation at a frequency of 30 to 300 [MHz] by up to 20 times as compared with a case where no resistor R is inserted.
[DB].

The edge detection circuit 20 shapes the waveform of the oscillation output signal S1 of the pulse oscillation circuit 18 and outputs it. The counter 21 operates at predetermined time intervals.
Of the oscillation output signal S1.
And outputs a count value whose value changes according to the frequency of.
The latch circuit 22 latches and holds the count value, and the comparison circuit 23 places a finger on the finger placement position based on a comparison result between the latch output of the latch circuit 22 and a predetermined threshold value. Is notified to the control unit 3. Thus, the living body detection unit 2 detects the placement of the finger on the finger placement position and notifies the control unit 3 of the detection.

(1-3) Control of Power Supply FIG. 1 is a block diagram showing the relationship between each circuit block and a power supply circuit. The fingerprint matching device 1 includes a selection circuit 30A
Power is selectively supplied to each circuit block through 30D. That is, the fingerprint collation device 1 has two power supply circuits 31 and 32,
And 32, a power supply required for driving the fingerprint collation apparatus 1 is generated from an external input power supply or a battery. Among them, the power supply circuit 31 generates a power supply required for driving the imaging unit 9, and the power supply circuit 32 supplies a power supply required for driving other logic circuits.

Under the control of the control unit 3, the selection circuits 30A to 30D selectively supply power to the corresponding circuit blocks during a period required for the operation of the fingerprint collation apparatus 1. On the other hand, the input / output unit 6 and the control unit 3 are always supplied with power.

FIG. 6 is a table showing the power supply in the fingerprint registration mode and the first self-verification mode.
The control unit 3 is set to the operation mode by a control command input through the input / output unit 6 or by setting a predetermined operation element in a state where power is constantly supplied together with the input / output unit 6. In this state, the control unit 3 operates the selection circuit 30C.
Is set to the ON state, power is supplied to the living body detecting unit 2 and the living body detecting unit 2 is maintained in the operating state. Thus, the control unit 3 stops supplying unnecessary power to the illumination unit 8, the imaging unit 9, and the image matching unit 5, and waits for a finger to be placed.

In this state, when the placement of the finger is notified from the living body detecting section 2, the control section 3 stops supplying power to the living body detecting section 2, thereby reducing wasteful power consumption. The control unit 3 sets the selection circuits 30A and 30B to the ON state, and starts the operations of the illumination unit 8 and the imaging unit 9. Thereby, the control unit 3 illuminates the finger placed at the finger placement position, and captures the fingerprint image by the imaging unit 9.

Subsequently, the control section 3 turns on the power supply of the image collating section 5, registers the fingerprint image captured by the imaging section 9 in the database, or collates the fingerprint image with the reference image registered in the fingerprint database. At this time, the control unit 3 stops supplying power to the illumination unit 8 and the imaging unit 9 that have been supplying power up to that time, thereby reducing power consumption.

Subsequently, in the case of fingerprint collation, the control unit 3 outputs the collation result via the input / output unit 6, and switches the entire operation to the original standby state.

FIG. 7 is a chart showing the power supply in the second self-verification mode. The control unit 3 is set to the operation mode by a control command input through the input / output unit 6 or by setting a predetermined operation element in a state where power is constantly supplied together with the input / output unit 6. In this state, the control unit 3 stops supplying unnecessary power to the living body detection unit 2, the illumination unit 8, the imaging unit 9, and the image comparison unit 5, and waits for a subsequent operation.

When a predetermined operator is operated in this state,
The control unit 3 sets the selection circuits 30A and 30B to the ON state, and starts the operations of the illumination unit 8 and the imaging unit 9. Thereby, the control unit 3 illuminates the finger placed at the finger placement position, and captures the fingerprint image by the imaging unit 9.

Subsequently, the control unit 3 turns on the power supply of the image matching unit 5 and matches the fingerprint image captured by the imaging unit 9 with the reference image registered in the fingerprint database. At this time, the control unit 3 stops supplying power to the illumination unit 8 and the imaging unit 9 that have been supplying power up to that time, thereby reducing power consumption.

Subsequently, the control section 3 outputs the collation result via the input / output section 6, and switches the entire operation to the original standby state.

FIG. 8 is a table showing the power supply in the case of registering the fingerprint image transferred from the external device and in the external verification mode. The control unit 3 is set to the operation mode by a control command input through the input / output unit 6 or by setting a predetermined operation element in a state where power is constantly supplied together with the input / output unit 6. In this state, the control unit 3 suspends useless power supply to the living body detection unit 2, the illumination unit 8, the imaging unit 9, and the image comparison unit 5 and stands by.

In this state, when a fingerprint collation control command is input from an external device and subsequently the image data of the fingerprint image is transferred, the control unit 3 turns on the power supply of the image collation unit 5 and transmits the image data. The image is taken into the image collating unit 5 and subsequently registered in the fingerprint database or collated with the reference image registered in the fingerprint database. Subsequently, the control unit 3 outputs the collation result via the input / output unit 6, and switches the entire operation to the original standby state.

(2) Operation of the Embodiment In the above configuration, the fingerprint collation device 1 operates in the fingerprint registration mode of the fingerprint image obtained from the fingerprint reading unit 4 under the control of an external device or by operating a predetermined operation element. (FIGS. 1, 2, and 6), the supply of power to the living body detection unit 2 is started under the control of the control unit 3 which is constantly supplied with power together with the input / output unit 6. When a finger is placed at the finger placement position in this state (FIG. 4), the capacitance between the transparent electrodes 14A and 14B arranged at the finger placement position changes, and the pulse formed by the Schmitt trigger circuit is changed. In the oscillation circuit 18, the oscillation frequency changes in response to the change in the capacitance. The oscillation output signal S1 of the pulse oscillation circuit 18 is counted by the counter 21, and the count value is compared by the comparison circuit 23, thereby detecting a change in the oscillation frequency, thereby detecting the placement of the finger. .

In this series of finger detection processing, in the fingerprint collation device 1, the high frequency component is suppressed in the signal waveform applied to the electrode 14B by the interposition of the resistor R on the transparent electrode 14A side (see FIG. 5) and electrodes 14A and 1
The charge / discharge current between 4B is reduced, thereby reducing unnecessary radiation.

When the finger is placed in this manner, the supply of power to the illumination unit 8 and the imaging unit 9 is started under the control of the control unit 3, and the supply of power to the living body detection unit 2 is stopped. .
As a result, the light emitting diode 13 is turned on in the illumination unit 8 (FIG. 3), the finger placed at the finger placement position is illuminated by the illumination of the light emitting diode 13, and the fingerprint is imaged by the imaging unit 9. A video signal SV is generated.

Subsequently, under the control of the control unit 3, the power of the image collating unit 5 is turned on, and the power of the illumination unit 8 and the imaging unit 9 is turned off. Thereby, after the video signal SV obtained from the imaging unit 9 is binarized in the image matching unit 5,
Registered in the database. After that, the power supply of the image collating unit 5 is turned off, and waits for input of a subsequent control command.

On the other hand, when a fingerprint image input from an external device is registered (FIG. 8), the power of the image collating unit 5 is controlled by the control unit 3 while the power of the other circuit blocks is turned off. Is started, and image data input from an external device is input to the image matching unit 5 and registered in the database. After that, the power supply of the image matching unit 5 is turned off,
Wait for the next control command.

In the fingerprint collation mode, in the first self collation mode (FIG. 6), the power supply of the living body detection unit 2 is turned on, the placement of the finger is detected, and then the illumination unit 8,
The power of the imaging unit 9 is turned on, and the power of the living body detection unit 2 is turned off. Thus, a fingerprint image is obtained from the finger placed at the finger placement position. Subsequently, the power supply of the image matching unit 5 is turned on, and the power supplies of the illumination unit 8 and the imaging unit 9 are turned off, whereby the fingerprint image is sequentially compared with the reference image held in the image matching unit 5. You. Subsequently, the power of the image collating unit 5 is turned off, and the collation result is output to the external device via the input / output unit 6.

In the second self-verification mode (FIG. 7), when a predetermined operator is operated in a state where the power of the other circuit blocks is turned off, the power of the illumination unit 8 and the imaging unit 9 is turned off. The fingerprint image is obtained from the finger that has been set up and placed at the finger placement position. Subsequently, the power supply of the image matching unit 5 is turned on, and the power supplies of the illumination unit 8 and the imaging unit 9 are turned off, whereby the fingerprint image is sequentially compared with the reference image held in the image matching unit 5. You. Subsequently, the power of the image collating unit 5 is turned off, and the collation result is output to the external device via the input / output unit 6.

Further, when the external collation mode is selected (FIG. 8), the power of the image collating unit 5 is turned on under the control of the control unit 3 while the power of the other circuit blocks is turned off. The input image data is input to the image matching unit 5. Thus, the fingerprint image input from the external device is sequentially collated with the reference image held in the image collating unit 5. Subsequently, the power of the image collating unit 5 is turned off, and the collation result is output to the external device via the input / output unit 6.

(3) Effects of the Embodiment According to the above configuration, power can be selectively supplied to each circuit block, so that necessary circuit blocks are sequentially supplied with power and always operated. It is possible to keep it in a possible state and reduce the overall power consumption. As a result, the rise in internal temperature can be reduced, and the operating conditions can be expanded. In addition, deterioration of used parts and the like can be reduced, and reliability can be improved accordingly.

Specifically, during the period of the fingerprint collation in the image collation unit, the power supply to the illumination unit and the imaging unit serving as the fingerprint capturing unit is stopped, so that the finger is again placed at the placement position. Then, by sequentially starting the supply of power to the image capturing unit and the image matching unit, wasteful power consumption can be reduced.

When collating a fingerprint image input via the input / output unit according to the operation mode, the power supply to the fingerprint capturing unit is stopped, and the operation of a predetermined operation element is stopped. In response, by sequentially starting the supply of power to the image capturing unit and the image matching unit, wasteful power consumption can be reduced.

(4) Other Embodiments In the above-described embodiment, not only a fingerprint image input through a fingerprint reading unit but also a fingerprint image input from an external device is described. However, the present invention is not limited to this, and can also be applied to a case where a fingerprint image input simply via a fingerprint reading unit is subjected to fingerprint collation.

In the above embodiment, the case where the fingerprint reading unit is constituted by the illuminating means and the imaging means has been described. However, the present invention is not limited to this. The present invention can be widely applied to a case where a two-dimensional capacitance distribution corresponding to fingerprint irregularities is detected and a fingerprint image is formed.

Further, in the above embodiment, the case where the collation result is output to the external device has been described. However, the present invention is not limited to this, and can be widely applied to the case where the external device is integrated. .

Further, in the above-described embodiment, the case where the present invention is applied to the fingerprint collating apparatus has been described. However, the present invention is not limited to this, and imprints, eye retina patterns, and the like are set in the collation target image. The present invention can be widely applied to various image matching devices described above.

[0055]

As described above, according to the present invention, by selectively supplying power to each circuit block, it is possible to reduce the power consumption by keeping the circuit block always collatable.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a relationship between each circuit block and a power supply of a fingerprint matching device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing the fingerprint matching device of FIG. 1;

FIG. 3 is a block diagram showing a fingerprint reading unit 4;

FIG. 4 is a block diagram showing a living body detection unit 2.

FIG. 5 is a signal waveform diagram showing an oscillation output of the pulse oscillation circuit.

FIG. 6 is a table showing power supply in the fingerprint registration mode and the first self-verification mode.

FIG. 7 is a chart showing the supply of these powers in a second self-verification mode.

FIG. 8 is a table showing a case where a fingerprint image transferred from an external device is registered and how the power is supplied in an external matching mode.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fingerprint collation apparatus, 2 ... Living body detection part, 3 ... Control part, 4 ... Fingerprint reading part, 5 ... Image collation part, 6 ...
Input / output unit 7, external equipment 8, illumination unit 9, imaging unit 14A, 14B transparent electrode 18, pulse oscillation circuit, R to R2 resistance 31, 32 power supply circuit

Claims (6)

[Claims] An image capturing means for capturing an image to be compared, an image matching means for matching the image to be matched with a predetermined reference image by an image matching process, and operations of the image capturing means and the image matching means And a power supply unit for selectively supplying power for operation to the image capturing unit and the image comparison unit under the control of the control unit. 2. The control unit controls the operation of the power supply unit such that the supply of the operation power to the image capturing unit is stopped at least during a period of the image comparison processing by the comparison unit. The image collating apparatus according to claim 1, wherein: 3. The image capturing means captures a fingerprint image of the finger as the collation image from a finger placed at a predetermined location, and the image collating device detects the placement of the finger. When the finger is placed at the placement position based on the detection result of the finger detection unit, the control unit controls the driving of the image capturing unit and the image processing unit. 2. The image matching apparatus according to claim 1, wherein the operation of the power supply unit is controlled so that the supply of power is sequentially started. 4. The control means, in response to a control command input through a predetermined communication means, replaces an image to be verified input through the image capturing means, The image to be collated is supplied to the image collating means, and the image collating means is inputted via the communication means instead of the image to be collated inputted via the image capturing means. The image collation processing is executed for an image to be collated, and the control unit is configured to stop supplying the power for operation to the image capturing unit at least during a period of the image collation processing in the collation unit. The image collating apparatus according to claim 1, wherein the operation of the power supply means is controlled. 5. An image matching apparatus according to claim 4, wherein said power supply means always supplies said driving power to said communication means. 6. The power supply unit according to claim 1, wherein the control unit starts supplying the driving power supply to the image capturing unit and the image comparison unit in response to an operation of a predetermined operation element. The image collating apparatus according to claim 1, wherein the operation is controlled.