JP2009271808A - Apparatus and method for acquiring biological information, and electronic apparatus including biological information acquiring apparatus - Google Patents

Abstract

A biometric information acquisition apparatus capable of capturing an effective image for authentication inexpensively and quickly and efficiently.
An irradiation unit 100 that irradiates a subject with light, an imaging unit 200 having one or more pixel columns, and a drive unit 300 that can reciprocate the imaging unit 200 in a direction intersecting the pixel columns. It is a biological information acquisition device. The biometric information acquisition apparatus 1 further evaluates an image captured by the imaging unit 200 according to preset conditions, and the next time the subject is imaged based on the evaluation result of the evaluation unit 402. A control unit 403 for controlling the light irradiation condition on the subject or the imaging condition of the subject by the imaging unit.
[Selection] Figure 3

Description

  The present invention relates to a biological information acquisition device, a biological information acquisition method, and an electronic apparatus including the biological information acquisition device.

  In recent years, the development of technology related to biometric authentication has been remarkable. As is well known, biometric authentication is a technique for identifying an individual from other individuals based on a determination whether biometric information acquired from an individual to be examined is equal to biometric information registered in advance. . For example, there are a method for identifying an individual based on the iris of a human pupil, a method for identifying an individual based on a vein pattern such as a human finger, and a method for identifying an individual based on a fingerprint pattern of a finger.

  However, biometric information that is effective for authentication cannot be acquired from the captured image due to disturbances such as the environment (for example, sunlight, fluorescent lamps, etc.) or individual differences (for example, light transmittance) when acquiring biometric information. There is a case.

  Therefore, the biometric information acquisition apparatus of Patent Document 1 analyzes an image captured by the imaging unit, obtains a luminance distribution of the image, and controls the irradiation unit so that the luminance distribution is uniform. In addition, the biological information acquisition apparatus controls camera control parameters (for example, gain and shutter speed) from the analysis result of the image.

  The biometric information acquisition apparatus of Patent Document 2 determines the gain of a signal of an image captured by the imaging unit, and controls the gain of the image signal according to the determination result.

By the way, the biometric information acquisition apparatus of patent document 3 moves the imaging part which has one or more pixel columns to the direction which cross | intersects the said pixel column by a drive part, and images the partial image of a subject one by one. This biological information acquisition apparatus is configured to control the light amount of the irradiation unit in advance according to the position of the imaging unit.
JP 2007-102421 A JP-A-10-240913 JP 2007-257307 A

  The biometric information acquisition apparatuses of Patent Documents 1 and 2 are not biometric information acquisition apparatuses configured to capture an image by reciprocating an imaging unit having one or more pixel columns in a direction intersecting the pixel columns. Therefore, it is necessary to arrange pixels over the entire area corresponding to the image to be captured, which increases costs.

  On the other hand, the biometric information acquisition apparatus of Patent Document 3 is configured to capture an image by moving an imaging unit having one or more pixel columns in a direction intersecting the pixel columns. However, this biological information acquisition apparatus is not configured to evaluate the image captured last time by reciprocating the imaging unit and reflect the evaluation result to capture an image effective for the next authentication. . Therefore, an image effective for authentication cannot be captured quickly and efficiently.

  An object of the present invention is to provide a biological information acquisition device and a biological information acquisition method capable of capturing an image effective for authentication inexpensively and quickly and efficiently, and an electronic apparatus including the biological information acquisition device. To do.

The biological information acquisition apparatus according to the present invention is
An irradiation unit for irradiating the subject with light;
An imaging unit having one or more pixel columns;
A drive unit capable of reciprocating the imaging unit in a direction intersecting the pixel row;
A biological information acquisition device comprising:
An evaluation unit that evaluates an image captured by the imaging unit according to a preset condition;
Based on the evaluation result of the evaluation unit, a control unit that controls the irradiation condition of light to the subject when imaging the subject next time or the imaging condition of the subject by the imaging unit;
It has. As a result, it is possible to capture an image effective for authentication inexpensively and quickly and efficiently.

  It is preferable that the above-described control unit controls the irradiation condition or the imaging condition in the return path of the imaging unit based on the evaluation result of the image captured by the imaging unit in the outward path.

  It is preferable that the control unit described above controls the amount of light emitted from the irradiation unit to the subject as the irradiation condition.

  It is preferable that the control unit described above controls an amplification factor of a signal from a pixel in the pixel column as the imaging condition.

  It is preferable that the control unit described above controls an image capturing period of the image capturing unit as the image capturing condition.

A light control unit is provided on the imaging unit described above,
It is preferable that the control unit electrically controls a light transmission amount of the light control unit as the imaging condition.

  An electronic apparatus according to the present invention includes the biological information acquisition apparatus according to any one of claims 1 to 6. As a result, it is possible to capture an image effective for authentication inexpensively and quickly and efficiently.

The biological information acquisition method according to the present invention includes:
A method of acquiring biological information of the subject by irradiating the subject with light,
An image pickup unit having one or more pixel columns is moved in a direction intersecting the pixel columns by a drive unit, and an image is captured.
The evaluation unit evaluates the image captured by the imaging unit,
The control unit, based on the evaluation result of the evaluation unit, controls the irradiation condition of light to the subject when imaging the subject next time or the imaging condition of the subject by the imaging unit,
The imaging unit is moved by the driving unit in a direction crossing the pixel column, and an image is captured under the controlled irradiation condition or imaging condition. As a result, it is possible to capture an image effective for authentication inexpensively and quickly and efficiently.

  It is preferable that the above-described control unit controls the irradiation condition or the imaging condition in the return path of the imaging unit based on the evaluation result of the image captured by the imaging unit in the outward path.

  The control unit described above preferably controls the amount of light emitted to the subject as the irradiation condition.

  It is preferable that the control unit described above controls an amplification factor of a signal from a pixel in the pixel column as the imaging condition.

  It is preferable that the control unit described above controls an image capturing period of the image capturing unit as the image capturing condition.

  It is preferable that the control unit described above electrically controls the light transmission amount of the light control unit as the imaging unit.

  According to the present invention, an image effective for authentication can be captured at low cost and quickly and efficiently.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each embodiment is simplified for convenience of explanation. Since the drawings are simple, the technical scope of the present invention should not be interpreted narrowly based on the drawings. The drawings are only for explaining the technical matters, and do not reflect the exact sizes or the like of the elements shown in the drawings. The same elements are denoted by the same reference numerals, and redundant description is omitted. Words indicating directions such as up, down, left, and right are used on the assumption that the drawing is viewed from the front.

<Embodiment 1>
Embodiment 1 of a biological information acquisition apparatus and biological information acquisition method according to the present invention and an electronic apparatus including the biological information acquisition apparatus will be described with reference to FIGS.

  As shown in FIG. 1, the biological information acquisition apparatus 1 of the present embodiment compares a biological information acquisition image acquired by irradiating light on a finger 2 as a subject with a template of biological information registered in advance. Authenticate. The biological information acquisition apparatus 1 is mounted on a mobile phone 3 that is a kind of electronic equipment. Incidentally, as shown in FIG. 2, the mobile phone 3 is a typical folding mobile phone, and includes an upper body 4, a lower body 5, and a hinge 6. The upper body 4 includes a display unit 7 on the inner surface thereof, and includes the biological information acquisition device 1 on the outer surface under the surface region 4a. The lower main body 5 includes a numeric keypad 8 and the like on its inner surface. However, the biometric information acquisition apparatus 1 is not limited to the mobile phone 3 and can be suitably used for personal computers, bank ATMs (Automated Teller Machines), and the like.

  As shown in FIG. 3, the biological information acquisition apparatus 1 includes an irradiation unit 100, an imaging unit 200, a driving unit 300, a processing unit 400, an authentication unit 500, and a storage unit 600.

  The irradiation unit 100 is, for example, a semiconductor light emitting element (LED (Light Emitting Diode)) or a semiconductor laser element (LD (Laser Diode)) that emits near infrared light (hereinafter sometimes referred to as inspection light). By passing a current through the irradiation unit 100, the irradiation unit 100 irradiates the finger 2 with near infrared light (wavelength: 580 nm to 1000 nm, more preferably wavelength: 780 nm to 960 nm). The irradiation unit 100 is provided in the driving unit 300 so as to emit inspection light upward. However, the irradiation unit 100 of the present embodiment is configured to emit near-infrared light so as to acquire a finger vein pattern as biometric information, but emits visible light when acquiring a fingerprint pattern. It is supposed to be configured. Moreover, although the irradiation part 100 of this embodiment is provided in the drive part 300, you may provide so that a test | inspection light may be radiate | emitted from the side in the upper side main body 4 of the mobile telephone 3. FIG. That is, the arrangement of the irradiation unit 100 may be any arrangement that can irradiate the finger 2 with inspection light.

  As shown in FIG. 4, the imaging unit 200 is an optical component in which an optical function unit 202 is stacked on a line sensor 201. The imaging unit 200 is provided in the driving unit 300 so that inspection light is incident from above.

  As shown in FIG. 5, the line sensor 201 includes a pixel PX, a vertical scanning circuit 203, a horizontal scanning circuit 204, an amplifier 205, and the like. However, although the CMOS (Complementary Metal Oxide Semiconductor) image sensor is used as the line sensor 201 of this embodiment, a solid-state image sensor using a semiconductor such as a CCD (Charge Coupled Device) image sensor is used. Can do.

  The pixel PX is a photoelectric conversion element such as a photodiode. A plurality of the pixels PX are arranged in a line at a predetermined interval. The vertical scanning circuit 203 and the horizontal scanning circuit 204 access the pixel PX at a predetermined readout timing, and output an image signal captured from the pixel PX. The amplifier 205 amplifies the input signal with a predetermined amplification factor and outputs the amplified signal to the processing unit 400. It should be noted that correlated double sampling is preferably performed in order to reduce noise as a stage before the signal is amplified by the amplifier 205.

  In the optical function unit 202, an optical channel separation layer 206, a microlens array 207, and a bandpass filter 208 are arranged in this order from the bottom to the top.

  The bandpass filter (filter member) 208 is a plate-like optical member that selectively allows near-infrared light from the irradiation unit 100 to pass through.

  The microlens array 207 includes a transparent substrate 209 and a lens (condensing lens) 210. A spacer layer 211 that supports the bandpass filter 208 is disposed on the upper surface of the transparent substrate 209.

  The plurality of lenses 210 are arranged in a line corresponding to each pixel PX of the line sensor 201 as shown in FIG. A pixel PX is disposed on the optical axis of the lens 210. The top view shape of the lens 210 is a quadrangle.

  The transparent substrate 209 and the lens 210 are made of a material that is substantially transparent to the inspection light. The transparent substrate 209 is a quartz substrate. The lens 210 is an optical component manufactured on the transparent substrate 209 by photolithography, UV curing molding, injection molding, hot embossing, or the like. In addition, by providing the microlens array 207 above the pixel PX, it is possible to preferably image a finger vein pattern located at a predetermined depth from the epidermis of the finger 2.

  The optical channel separation layer 206 includes a light shielding film 212, a first transparent layer 213, a second transparent layer 214, and a light absorption layer 215.

  The light shielding film 212 is a layer in which a metal material is formed in a lattice shape on the lower surface of the microlens array 207 based on a normal semiconductor process technology (sputtering, vapor deposition, or the like). The light shielding film 212 has a plurality of openings OP <b> 1 formed corresponding to the respective lenses 210 of the microlens array 207. Note that the plurality of openings OP1 means openings in an optical sense. Here, the opening OP <b> 1 is filled with the first transparent layer 213.

  The first transparent layer 213 is a layer made of a resist (resin material) and is substantially transparent to inspection light. The first transparent layer 213 is formed on the lower surface of the microlens array 207 after the light shielding film 212 is formed by a normal coating method (spin coating method or the like). By the heat treatment after coating, the viscosity of the first transparent layer 213 is lost.

  The second transparent layer 214 is a resist layer made of the same material as the first transparent layer 213. Therefore, the second transparent layer 214 is also substantially transparent to the inspection light. The second transparent layer 214 has a plurality of lands 214a that are separated from each other. In the land 214 a, a second transparent layer 214 is formed on the lower surface of the first transparent layer 213 by a normal coating method (spin coating method or the like), and then a lattice-shaped groove is formed in the second transparent layer 214. Is formed. That is, a plurality of lands 214a separated from each other are formed by forming the lattice-like grooves. The separated land 214a is two-dimensionally arranged corresponding to each pixel PX of the line sensor 201. In addition, a land means the island-shaped part prescribed | regulated by a groove | channel. Each land need not be completely separated from each other.

  The light absorption layer 215 is filled so as to cover the land 214a. The light absorption layer 215 is a resist layer containing a material that absorbs inspection light (such as phthalocyanine). The light absorbing layer 215 is formed by applying a resist material so as to cover the land 214a (so as to fill a groove formed in the second transparent layer 214) based on a spin coating method or the like. Then, based on lithography, an opening OP <b> 2 corresponding to the condensing portion of each lens 210 of the microlens array 207 is formed in the light absorption layer 215. The opening OP2 also corresponds to the arrangement position of each pixel PX of the line sensor 201. The opening OP2 is arranged in a line corresponding to each pixel PX of the line sensor 201.

  In such an imaging unit 200, the inspection light reflected inside the finger 2 is condensed on the pixel PX of the line sensor 201 via the lens 210 of the microlens array 207.

  Specifically, the near infrared light emitted from the irradiation unit 100 is irradiated on the human finger 2. Near infrared light is reflected inside the finger 2.

  The inspection light reflected from the finger 2 enters the imaging unit 200. First, the inspection light passes through the band pass filter 208. The disturbance light other than the inspection light is blocked by the band pass filter 208. Since the noise component can be blocked by the band-pass filter 208, a higher quality image can be taken.

  The inspection light that has passed through the bandpass filter 208 enters the microlens array 207. In the microlens array 207, the light is condensed on each pixel PX of the line sensor 201 by each lens 210 disposed on the upper surface of the transparent substrate 209.

  The light condensed by the lens 210 of the microlens array 207 enters the optical channel separation layer 206. As described above, the optical channel separation layer 206 includes the opening OP1 and the opening OP2 arranged in a line corresponding to each pixel of the line sensor 201. The optical channel separation layer 206 includes lands 214a arranged in a line corresponding to each pixel of the line sensor 201. A light absorption layer 215 is filled between adjacent lands 214a. A light absorption layer 215 is also formed on the lower surface of the land 214a. The light absorption layer 215 contains a pigment that absorbs near infrared rays. Therefore, the inspection light incident on the light absorption layer 215 is effectively absorbed by the pigment contained in the light absorption layer 215.

  With such a configuration, the optical channel separation layer 206 separates optical paths (optical channels) from the lenses 210 of the microlens array 207 to the pixels PX of the line sensor 201. Then, crosstalk (interference) that can occur between optical channels is suppressed. Since the inspection light is collected as it proceeds from the lens 210 to the pixel PX, the opening width of the opening OP2 is set to be narrower than the opening width of the opening OP1.

  The light condensed on each pixel of the line sensor 201 is photoelectrically converted at each pixel as described above. Then, for example, after being read and amplified as a signal voltage, the processing unit 400 performs analog / digital conversion.

  The drive unit 300 includes a sliding member 301 that reciprocates left and right on the surface region 4 a of the upper body 4 of the mobile phone 3, and two rail members 302 that guide the sliding member 301. As shown in FIG. 1, the sliding member 301 includes a plurality of irradiation units 100 arranged in a line in a direction intersecting the moving direction of the sliding member 301. Furthermore, the imaging member 200 is arranged on the sliding member 301 in parallel with the irradiation unit 100 arranged in a line. That is, the irradiation unit 100 and the imaging unit 200 reciprocate in the direction intersecting the pixel column of the line sensor 201 (the arrow direction in FIG. 1) by the driving unit 300, as shown in FIG. At this time, the image capturing unit 200 sequentially captures images over a moving period of the image capturing unit 200, and images are captured within a range corresponding to the moving range of the image capturing unit 200. In this way, since the biological information acquisition device 1 sequentially captures images by moving the pixel row, it is not necessary to arrange pixels throughout the region corresponding to the image to be captured, and the image can be captured at low cost. .

  Incidentally, the sliding member 301 is reciprocated by a driving device such as a motor (not shown). For example, a thread portion is formed on the outer periphery of the rail member 302. A motor is provided on the sliding member 301, and a pinion gear is provided on the rotating shaft of the motor. The threaded portion of the rail member 302 and the pinion gear of the motor are engaged with each other, and the sliding member 301 moves along the rail member 302 by the driving force of the motor. However, the configuration of the drive unit 300 is not limited to this, and any configuration that can move at least the imaging unit 200 in the direction intersecting the pixel column of the line sensor 201 is sufficient.

  The processing unit 400 includes an image forming unit 401, an evaluation unit 402, a control unit 403, and the like. The image forming unit 401 performs image processing such as analog / digital processing, binarization processing, correction, and a plurality of captured images as a single composite image of the image signal from each pixel, and biometric information Form an acquired image.

  The evaluation unit 402 evaluates the image captured by the imaging unit 200 according to a preset condition. Specifically, the evaluation unit 402 evaluates whether or not the biometric information acquisition image formed by the image forming unit 401 is valid for authentication from the captured image. At this time, since the imaging unit 200 is configured to reciprocate in a direction intersecting the pixel column of the line sensor 201, it is determined whether or not the evaluation unit 402 uses the image captured in the forward path as an image effective for authentication. Can be evaluated. For example, the evaluation unit 402 partitions the biological information acquisition image in parallel with the arrangement direction of the pixel row, extracts at least one partition region, and the distribution of brightness variations in the partition region is substantially concentrated on an appropriate value. In addition, it is evaluated whether or not the variation satisfies a condition that is not more than an arbitrary multiple of the standard deviation. As an arbitrary multiple, it is set to 3 times, for example.

  The evaluation unit 402 outputs the biometric information acquisition image directly to the authentication unit 500 because it is highly likely that the biometric information acquisition image is already effective for authentication if the above conditions are satisfied.

  On the other hand, if the above condition is not satisfied, the evaluation unit 402 is highly likely to be a biometric information acquisition image that is not valid for authentication. Therefore, the control unit 403 instructs the control unit 403 to move the imaging unit 200 again to capture an image. Output to.

  The next time the control unit 403 moves the image capturing unit 200 to capture an image, the control unit 403 calculates the amount of light that matches the arrangement position of each irradiation unit 100 so that the captured image satisfies the above conditions. As a calculation method, the control unit 403 calculates the amount of light emitted from each irradiation unit 100 to the finger 2 so that the image signal from each pixel is substantially uniformized to an appropriate value. For example, the relationship between the signal voltage from the pixel and the light amount of the irradiation unit 100 and the appropriate value of the signal voltage from the pixel are calculated in advance by simulation or the like, and based on the difference between the signal voltage from each pixel and the appropriate value. Thus, the light quantity of each irradiation unit 100 is calculated. The signal of the image from each pixel does not need to be strictly uniformed to an appropriate value as long as it is uniform within a range where biometric information effective for authentication can be acquired.

  The control unit 403 controls each irradiation unit 100 to the calculated light amount. That is, the biological information acquisition apparatus 1 of the present embodiment reflects the evaluation result of the image captured by the movement of the imaging unit 200, controls the light amount of each irradiation unit 100, and moves the imaging unit 200 next time to perform an image. When an image is captured, an image effective for authentication can be captured. In particular, since the imaging unit 200 reciprocates, it is possible to reflect the evaluation result of the image captured on the outward path, control each irradiation unit 100 on the return path, and capture an image effective for authentication. Therefore, an image effective for authentication can be quickly and efficiently captured at low cost. In addition, even if it is affected by disturbances such as the environment (for example, sunlight, fluorescent lamps, etc.) and individual differences (for example, light transmittance, etc.) when acquiring biological information, An image effective for authentication can be taken.

  The authentication unit 500 performs authentication by comparing the biometric information template stored in the storage unit 600 with the formed biometric information acquisition image. A specific authentication method by the authentication unit 500 is arbitrary. Biometric authentication methods depend on various methods for determining pattern similarity.

  The storage unit 600 stores information such as a program for realizing biometric authentication, a program for realizing image formation, a template of biometric information, and an authentication history.

Using the biological information acquisition apparatus 1 having such a configuration, the biological information acquisition method of the present embodiment is implemented as follows.
First, as shown in FIG. 7, the sliding member 301 is set in a preset initial state or a current finger 2 when imaging the finger 2 with the light irradiation condition on the finger 2 and the imaging condition of the finger 2 by the imaging unit 200. It is moved in the direction crossing the pixel column. Then, the imaging unit 200 captures an image and outputs the image to the image forming unit 401 of the processing unit 400 (S1). Here, the irradiation condition is the amount of light emitted from the LED forming the irradiation unit 100 to the finger 2. The imaging conditions are the light emission timing of the irradiation unit 100 (switching between ON and OFF), the amplification factor of the image signal from each pixel, and the imaging period of the image by the imaging unit.

  The image forming unit 401 processes the input image to form a biometric information acquisition image, and outputs the biometric information acquisition image to the evaluation unit 402 (S2).

  The evaluation unit 402 divides the input biometric information acquisition image in parallel with the arrangement direction of the pixel rows, and calculates the brightness variation in at least one of the divided areas. Incidentally, in the partitioned area, for example, a biometric information acquisition image as shown in FIG. Here, Fig.8 (a) has shown the arrangement | positioning relationship of LED and a pixel. FIG. 8B shows a portion corresponding to a partitioned area of the biometric information acquisition image formed by the arrangement of the LED and the pixel. FIG. 9 is a diagram showing the relationship between the pixel position and the brightness in the partitioned area of the biometric information acquisition image together with the relationship with the LED irradiation area.

  Next, the evaluation unit 402 determines whether or not the variation in brightness in the partitioned area of the biometric information acquisition image is substantially concentrated on an appropriate value, and the variation satisfies a condition that is an arbitrary multiple (for example, three times) or less of the standard deviation. Whether or not is evaluated (S3). For example, when an 8-bit grayscale biometric information acquisition image is formed, the appropriate brightness variation value is set to 128 colors, which is half of full scale (256 colors). Incidentally, FIG. 10A shows variations in brightness of samples A, B, and C. In FIG. 10A, the vertical axis represents the number of pixels, and the horizontal axis represents the number of colors. FIG. 10B shows biological information acquisition images formed under the conditions of samples A, B, and C. Here, it can be seen that the condition of sample B is a biometric information acquisition image effective for authentication.

  The evaluation unit 402 outputs the biometric information acquisition image directly to the authentication unit 500 because it is highly likely that the biometric information acquisition image is already effective for authentication if the above conditions are satisfied.

  On the other hand, if the above condition is not satisfied, the evaluation unit 402 is highly likely to be a biometric information acquisition image that is not valid for authentication. Therefore, the control unit 403 instructs the control unit 403 to move the imaging unit 200 again to capture an image. Output to.

  When the image capturing unit 200 is moved next time to capture an image, the control unit 403 calculates an amount of light that matches the arrangement position of each irradiation unit 100 so that the captured image satisfies the above-described conditions. As a calculation method, as described above, the control unit 403 calculates the light amount of each irradiation unit 100 so that the image signal from each pixel is substantially uniformized to an appropriate value (S4).

  And the control part 403 controls each irradiation part 100 to the calculated light quantity. Under the irradiation conditions controlled in this way, the processing unit 400 moves the sliding member 301 in a direction intersecting the pixel row, sequentially captures images again by the imaging unit 200, and the image forming unit 401 of the processing unit 400 captures images. An image is output (S5).

  Thereafter, the above-described steps S2 and subsequent steps are repeated until the formed biometric information acquisition image satisfies the above conditions. When the formed biometric information acquisition image satisfies the above conditions and the biometric information acquisition image is input to the authentication unit 500, the authentication unit 500 calls the biometric information template from the storage unit 600, and the biometric information input as the template The acquired image is compared and authenticated (S6).

  As described above, the biological information acquisition method of the present embodiment reflects the evaluation result of the image captured by the movement of the imaging unit 200, controls the light amount of each irradiation unit 100, and moves the imaging unit 200 next time. When capturing an image, an image effective for authentication can be captured. In particular, since the imaging unit 200 reciprocates, it is possible to reflect the evaluation result of the image captured on the outward path, control each irradiation unit 100 on the return path, and capture an image effective for authentication. Therefore, an image effective for authentication can be quickly and efficiently captured at low cost. Moreover, even if it is influenced by disturbances such as the environment when acquiring biometric information and individual differences, an image effective for authentication can be taken in a state in which this influence is reflected.

<Embodiment 2>
In the first embodiment, the light amount of the irradiation unit 100 that is the irradiation condition is controlled to capture an image effective for authentication, but this is not restrictive.

  That is, the control unit 403 calculates the amplification factor of the image signal from each pixel PX of the amplifier 205 so as to satisfy the above condition. As a calculation method, the control unit 403 calculates the amplification factor of the image signal from the pixel PX so that the image signal from each pixel PX is substantially uniformized to an appropriate value. For example, an appropriate value of the signal voltage from the pixel is calculated in advance by simulation or the like, and the amplification factor is calculated so that the signal voltage from each pixel becomes an appropriate value.

  Then, the control unit 403 controls the amplifier 205 with the calculated amplification factor. A method of controlling the amplification factor of the amplifier 205 is arbitrary. For example, it can be controlled by providing a resistor in front of the amplifier 205 and in the section and changing the resistance value.

  In such an embodiment, the evaluation result of the image captured by the movement of the imaging unit 200 is reflected to control the amplification factor of the amplifier 205, and the next time the imaging unit 200 is moved to capture an image, An image effective for authentication can be taken. In particular, since the imaging unit 200 reciprocates, the evaluation result of the image captured in the forward path is reflected, and the amplification factor of the amplifier 205 is controlled in the backward path, so that an image effective for authentication can be captured. Therefore, an image effective for authentication can be quickly and efficiently captured at low cost.

<Embodiment 3>
Further, the imaging period of the image of each pixel PX by the imaging unit 200 may be controlled. Specifically, the charge accumulation amount in the pixel PX of the imaging unit 200 is controlled.

  That is, the control unit 403 calculates the imaging period of the image of each pixel PX by the imaging unit 200 so as to satisfy the above conditions, and further reads the image signal from each pixel PX to realize this imaging period. Is calculated. As a calculation method, the control unit 403 calculates the timing for reading the image signal from the pixel PX so that the image signal from each pixel PX is substantially uniformized to an appropriate value. For example, the relationship between the signal voltage from the pixel PX and the imaging period of the image of the pixel PX and the appropriate value of the signal voltage from the pixel are calculated in advance by simulation or the like, and the signal voltage from each pixel and the appropriate value are calculated. Based on the difference, the timing for reading the image signal from each pixel PX is calculated.

  The control unit 403 controls the vertical scanning circuit 203 and the horizontal scanning circuit 204 at the calculated readout timing.

  In such an embodiment, the evaluation result of the image captured by the movement of the imaging unit 200 is reflected, the imaging period of the image of each pixel PX by the imaging unit 200 is controlled, and the imaging unit 200 is moved the next time to move the image. When an image is captured, an image effective for authentication can be captured. In particular, since the imaging unit 200 reciprocates, it is possible to capture an image effective for authentication by reflecting the evaluation result of the image captured on the forward path and controlling the imaging period of the image of each pixel PX on the return path. Therefore, an image effective for authentication can be quickly and efficiently captured at low cost.

  In the present embodiment, the image capturing period of each pixel PX is controlled by the vertical scanning circuit 203 and the horizontal scanning circuit 204, but the electronic shutter of the pixel PX may be controlled.

<Embodiment 4>
Furthermore, as shown in FIG. 11, when a dot matrix type liquid crystal filter 700 is provided as a dimmer on the imaging unit 200, the light transmission amount of the liquid crystal filter 700 may be controlled. Incidentally, the liquid crystal filter 700 is provided on the sliding member 301 so as to cover the imaging unit 200, and follows the movement of the sliding member 301. However, the liquid crystal filter 700 of the present embodiment is configured to cover only the imaging unit 200, but may be configured to cover the entire surface region 4a.

  The liquid crystal filter 700 includes a voltage control circuit 704 that individually controls voltages of a liquid crystal panel 701 in which liquid crystals are arranged according to a predetermined rule, upper and lower electrodes 702 and 703, and an upper electrode 702. The liquid crystal filter 700 is configured such that the liquid crystal of each dot is opened and closed by a voltage applied from the upper and lower electrodes 702 and 703.

  Therefore, the control unit 403 calculates the light transmission amount of the liquid crystal of each dot so as to satisfy the above condition, and calculates the voltage applied to the liquid crystal of each dot in order to realize the light transmission amount of the liquid crystal. As a calculation method, the control unit 403 calculates the voltage to be applied to the liquid crystal of each dot so that the image signal from each pixel PX is substantially uniformized to an appropriate value. For example, the relationship between the signal voltage from the pixel PX and the voltage applied to the liquid crystal of each dot and the appropriate value of the signal voltage from the pixel are calculated in advance by simulation or the like, and the signal voltage and the appropriate value from each pixel are calculated. Based on the difference, a voltage to be applied to the liquid crystal of each dot is calculated.

  Then, the control unit 403 controls the electrodes 702 and 703 to a voltage calculated via the voltage control circuit 704, and controls the light transmission amount of the liquid crystal of each dot.

In such an embodiment, the evaluation result of the image captured by moving the imaging unit 200 is reflected to control the light transmission amount of the liquid crystal filter 700, and the next time the imaging unit 200 is moved to capture an image. Can capture an image effective for authentication. Particularly, since the imaging unit 200 reciprocates, the evaluation result of the image captured in the forward path is reflected, and the light transmission amount of the liquid crystal of the liquid crystal filter 700 is controlled in the backward path, so that an image effective for authentication can be captured. . Therefore, an image effective for authentication can be quickly and efficiently captured at low cost.
The dimmer is not limited to a liquid crystal filter.

<Embodiment 5>
In the first to fourth embodiments, a biological information acquisition image is formed once from a captured image, and this biological information acquisition image is evaluated. As shown in FIG. 12, a signal of an image read from each pixel is obtained. The evaluation unit 402 may evaluate directly.

  That is, as shown in FIG. 13, the sliding member 301 is moved in a direction intersecting the pixel row under a preset initial state or a current irradiation condition and imaging condition. Then, an image is picked up by the image pickup unit 200, and an image signal picked up from each pixel is input to the evaluation unit 402 of the processing unit 400 (S10).

  Next, the evaluation unit 402 evaluates whether or not the image signal from each pixel is substantially uniformized to an appropriate value (S20).

  The evaluation unit 402 inputs a signal to the image forming unit 401 because there is a high possibility that the image signal from each pixel is an image that is effective for authentication when the signal of the image from each pixel is substantially uniform.

  On the other hand, if the image signal from each pixel is far away from the appropriate value or has a large variation with respect to the appropriate value, the evaluation unit 402 is likely not an image effective for authentication. A command for moving the imaging unit 200 to capture an image is output to the control unit 403.

  When the image capturing unit 200 is moved next time to capture an image, the control unit 403 calculates the irradiation condition or the image capturing condition in the same manner as in the first to fourth embodiments so that the captured image satisfies the above conditions. (S30). In the state where the irradiation condition or the imaging condition is controlled in this way, the processing unit 400 moves the sliding member 301 in the direction intersecting the pixel row, and the imaging unit 200 captures an image again, and the processing unit 400 is evaluated. An image signal is input from each pixel to the unit 402 (S40).

  Thereafter, the above-described steps S20 and subsequent steps are repeated until the image signal from each pixel is substantially uniformized to an appropriate value, and the image signal from each pixel is input from the evaluation unit 402 to the image forming unit 401. Then, the image forming unit 401 processes an image signal from each pixel to form a biometric information acquisition image (S50).

  The image forming unit 401 outputs the biometric information acquisition image to the authentication unit 500, and the authentication unit 500 calls the biometric information template from the storage unit 600 and compares the template with the input biometric information acquisition image for authentication ( S60).

  Even in such an embodiment, the evaluation result of the image captured by the movement of the imaging unit 200 is reflected to control the irradiation condition or the imaging condition, and the next time the imaging unit 200 is moved to capture an image, An image effective for authentication can be taken. In particular, since the imaging unit 200 reciprocates, it is possible to capture an image effective for authentication by reflecting the evaluation result of the image captured in the forward path and controlling the irradiation condition or the imaging condition in the backward path. Therefore, an image effective for authentication can be quickly and efficiently captured at low cost.

<Embodiment 6>
In the first to fifth embodiments, the sliding member 301 of the driving unit 300 is reciprocated by a driving device such as a motor.

  That is, the biological information acquisition apparatus 1000 of this embodiment includes a base plate (base member) 3001 (3001a to 3001c), a carrier member 3005 (3005a to 3005k), and a storage member 3007, as shown in FIG. Note that the base plate 3001, the carrier member 3005, and the storage member 3007 are all made of a resin material. The biological information acquisition apparatus 1000 includes a rail member (guide member) 3003 (3003a, 3003c), a buffer member 3004 (3004a to 3004d), a linear actuator 3006 (3006a to 3006d), an irradiation unit 100, and an imaging unit 200. ing. Note that the imaging unit 200 includes the line sensor 201 and the optical function unit 202 as described above. The biological information acquisition apparatus 1000 includes a cover plate on the upper surface of the storage member 3007, although not shown.

  First, a description will be given with reference to FIG. As shown in FIG. 16, the base plate 3001 is a plate-like member having a substantially U-shape when viewed from above, and includes a connecting portion 3001a, a left flat plate portion 3001b, and a right flat plate portion 3001c. The base plate 3001 is fixed to the substrate in the casing of the mobile phone 3 by fixing means such as screws or adhesive.

  The left flat plate portion 3001b and the right flat plate portion 3001c extend in parallel to each other along the x axis (the left-right direction in FIG. 1). The connecting portion 3001a extends along the y axis (vertical direction in FIG. 1) orthogonal to the x axis. The upper ends of the left flat plate portion 3001b and the right flat plate portion 3001c are connected by a connecting portion 3001a. An opening is formed between the left flat plate portion 3001b and the right flat plate portion 3001c.

  The base plate 3001 includes four support portions 3002 (3002a to 3002d) at four corners. The support part 3002a is formed at the upper end of the left flat plate part 3001b. The support part 3002b is formed at the lower end of the left flat plate part 3001b. The support portion 3002c is formed at the upper end of the right flat plate portion 3001c. The support portion 3002d is formed at the lower end of the right flat plate portion 3001c. The support portions 3002a to 3002d are integrally formed with the base plate 3001. Note that the support portions 3002a to 3002d may be separate members from the base plate 3001, and the support portions 3002a to 3002d may be fixed to the base plate 3001.

  The support part 3002a includes a wide part 3002a1 and a narrow part 3002a2. The wide portion 3002a1 is formed on the inner side of the narrow portion 3002a2, and the width along the x-axis is wider than that of the narrow portion 3002a2. Note that the description of the support portion 3002a is also applicable to the other support portions 3002b to 3002d, and thus a duplicate description is omitted.

  The rail member 3003 is mechanically held between the support portions 3002 facing each other. The rail member 3003 is made of a rod-shaped metal and guides the movement of the carrier member 3005. Lubricating oil may be attached to the rail member 3003 in order to move the carrier member 3005 smoothly.

  The rail member 3003a is bridged between the support part 3002a and the support part 3002b facing each other. The rail member 3003a has an upper end fixed to the support portion 3002a and a lower end fixed to the support portion 3002b. The rail member 3003c is bridged between the support part 3002c and the support part 3002d facing each other. The rail member 3003c has an upper end fixed to the support portion 3002c and a lower end fixed to the support portion 3002d.

  The buffer member 3004a is disposed on the inner surface of the narrow portion 3002a2 of the support portion 3002a. The buffer member 3004a is made of an elastic material such as rubber or sponge. By making the inner surface of the buffer member 3004a contactable with the side surface of the carrier member 3005, the impact of the moving carrier member 3005 on the wide portion 3002a1 can be reduced. Thus, by causing the buffer member 3004a to function as an impact absorbing member, the movement of the carrier member 3005 can be stopped more stably mechanically or structurally. This description also applies to the other buffer members 3004b to 3004d and the wide portions 3002b to 3002d.

  Next, a description will be given with reference to FIG. As shown in FIG. 17A, the carrier member 3005 is a U-shaped member in a top view, and includes a left portion 3005i, a central portion 3005j, and a right portion 3005k. Both the left portion 3005i and the right portion 3005k extend substantially parallel along the x-axis. The central portion 3005j extends along the y axis and connects the upper end portions of the left portion 3005i and the right portion 3005k.

  The carrier member 3005 includes thick plate portions 3005a to 3005g and a thin plate portion 3005h. A storage member 3007 is stored in a space surrounded by the thick plate portions 3005a to 3005g. The lower surface of the storage member 3007 is bonded to the upper surface of the thin plate portion 3005h with an adhesive. In this way, the storage member 3007 is fixed inside the carrier member 3005.

FIG. 17B shows a cross-sectional configuration of the carrier member 3005 between Y1 and Y1 in FIG.
As shown in FIG. 17B, the carrier member 3005 has a hole through which the rail member 3003a is inserted into the thick plate portion 3005b, and the rail member 3003a is inserted into this hole. In addition, when the rail member 3003a is inserted into the hole of the thick plate portion 3005b, it is assumed that a play space that allows the carrier member 3005 to move along the rail member 3003a is maintained. In addition, a hole for partially accommodating the linear actuator 3006 is provided on the outer surface of the thick plate portion 3005b of the carrier member 3005.

FIG. 17C shows a cross-sectional configuration of the carrier member between Y2 and Y2 in FIG.
As shown in FIG. 17C, the carrier member 3005 has a hole through which the rail member 3003c is inserted into the thick plate portion 3005e, and the rail member 3003c is inserted into this hole. Similar to the description of FIG. 17C, a play space is maintained in this case as well. Further, a hole for partially accommodating the linear actuator 3006 is provided on the outer surface of the thick plate portion 3005e of the carrier member 3005.

  Note that the inner ends of the linear actuators 3006 are attached to the thick plate portions 3005b and 3005e. Accordingly, the thick plate portions 3005b and 3005e protrude outward from the thick plate portions 3005a, 3005c, 3005d, and 3005f. Similarly, each of the thick plate portions 3005a, 3005c, 3005d, and 3005f includes a hole through which the rail member 3003 is inserted.

Returning to FIG.
As shown in FIG. 14, the outer end (upper end) of the linear actuator 3006a is fixed to the support portion 3002a, and the inner end (lower end) is fixed to the thick plate portion 3005b of the carrier member 3005. The outer end (lower end) of the linear actuator 3006b is fixed to the support portion 3002b, and the inner end (upper end) thereof is fixed to the thick plate portion 3005b of the carrier member 3005. The outer end (upper end) of the linear actuator 3006c is fixed to the support portion 3002c, and the inner end (lower end) thereof is fixed to the thick plate portion 3005e of the carrier member 3005. The outer end (lower end) of the linear actuator 3006d is fixed to the support portion 3002d, and the inner end (upper end) thereof is fixed to the thick plate portion 3005e of the carrier member 3005. In addition, the attachment method of a coil is arbitrary. For example, a structure in which the tip of the coil is hooked and hooked on a thick plate portion or a support portion may be employed.

  In this embodiment, the linear actuators 3006a and 3006c are coil members in which a Ti—Ni-based or Ti—Ni—Cu-based linear alloy (shape memory alloy) is wound in a coil shape. In this embodiment, a pulse-modulated current is applied to the linear actuators 3006a and 3006c. The linear actuators 3006a and 3006c function as resistors and generate heat according to the amount of current flowing. When the linear actuators 3006a and 3006c reach a predetermined temperature or higher, the linear actuators 3006a and 3006c contract.

  Thereby, as shown in FIGS. 14 and 15, the carrier member 3005 can be moved from the bottom to the top. The imaging unit 200 is mounted on the carrier member 3005 via the storage member 3007. The imaging unit 200 moves as the carrier member 3005 moves. By sequentially capturing images with the imaging unit 200 over the movement period of the carrier member 3005, it is possible to capture an image within a range corresponding to the movement range of the imaging unit 200. In this way, an image effective for authentication can be captured by the imaging unit 200 having a small number of pixels.

  The linear actuators 3006b and 3006d are ordinary helical springs formed by winding a metal wire. Therefore, when no pulse current is applied to the linear actuators 3006a and 3006c, the carrier member 3005 is in the position shown in FIG. 14 according to the pulling force of the helical springs 3006b and 3006d. In other words, the carrier member 3005 is normally located closer to the support portions 3002b and 3002d to which the helical springs 3006b and 3006d are fixed. At the time of biometric information acquisition, the carrier member 3005 moves from the support portions 3002b and 3002d toward the support portions 3002a and 3002c with the application of the pulse current to the linear actuators 3006a and 3006c.

  Note that the pulling force of the linear actuators 3006a and 3006c accompanying the pulse current application is sufficiently larger than the pulling force of the helical springs 3006a and 3006c. Accordingly, the carrier member 3005 can be moved to the state shown in FIGS. 14 to 15 in a relatively short time. Here, the tensile force is increased by winding a shape memory alloy gold wire in a coil shape.

  As described above, since the carrier member 3005 can be moved only by applying a pulse current to the linear actuators 3006a and 3006c, compared to other driving mechanisms (for example, a driving mechanism using a driving device such as a motor). There are advantages such as no noise, no vibration, and low current consumption. In addition, since the space for arranging a driving device such as a motor can be omitted, the biological information acquisition device can be miniaturized.

  Note that the current flowing through the linear actuators 3006a and 3006c may be a direct current or a simple alternating current. However, the amount of flowing current can be adjusted with relatively high accuracy by flowing pulse-modulated current through the linear actuators 3006a and 3006c.

  When returning to the state of FIG. 15 from FIG. 14, the supply of the pulse current to the linear actuators 3006a and 3006c may be stopped. The carrier member 3005 naturally moves from the position shown in FIG. 15 to the position shown in FIG. 14 according to the pulling force of the helical springs 3006b and 3006d. The linear actuators 3006a and 3006c do not exhibit an effective spring action unless heated.

<Embodiment 7>
In the first to fourth embodiments, the formed biological information acquisition image is partitioned in parallel with the arrangement direction of the pixel rows. However, the entire formed biological information acquisition image may be evaluated. Further, the formed biological information acquisition image may be partitioned in a direction intersecting with the arrangement direction of the pixel rows, and the light emission timing in the moving direction of the irradiation unit 100 may be controlled based on the brightness variation of at least one partition region. good.

  In the first to fourth embodiments, the brightness of the image is an evaluation target, but the amount of change in the signal of the image from an adjacent pixel may be the evaluation target. In short, the irradiation condition or the imaging condition may be controlled so that the image signal from each pixel is substantially uniformized to an appropriate value.

  In the first to fifth embodiments, the control unit 403 calculates the irradiation condition or the imaging condition. That is, it is determined whether the image signal from each pixel is larger or smaller than the appropriate value, and if it is larger, a preset set value is added to the current irradiation condition or imaging condition, and the added irradiation The control unit 403 may control the condition or the imaging condition. On the other hand, when the number is small, a predetermined set value may be subtracted from the current irradiation condition or imaging condition, and the control unit 403 may control the subtracted irradiation condition or imaging condition.

  Although the embodiments of the biological information acquisition apparatus, the biological information acquisition method, and the electronic device including the biological information acquisition apparatus according to the present invention have been described above, various modifications can be made without departing from the gist of the present invention. is there.

It is a schematic diagram which shows the structure of the front surface of the mobile telephone which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the structure of the mobile telephone which concerns on Embodiment 1 of this invention. It is a block diagram of the biometric information acquisition apparatus which concerns on Embodiment 1 of this invention. It is a schematic sectional drawing of an imaging part. It is a schematic circuit diagram of a line sensor. It is a top view which shows the arrangement | positioning relationship between a pixel and a lens. It is a flowchart of the biometric information acquisition method which concerns on Embodiment 1 of this invention. (A) is a top view which shows the arrangement | positioning relationship of LED and a pixel. (B) is an image of a partition area of a biometric information acquisition image formed by the arrangement of LEDs and pixels. It is the figure which showed the relationship between the pixel position and the brightness in the division area of a biometric information acquisition image together with the relationship with the irradiation area of LED. (A) is a distribution diagram showing variations in brightness of samples A, B, and C. FIG. (B) is a biometric information acquisition image acquired under the conditions of samples A, B, and C. It is a general | schematic expanded perspective view of the imaging part and liquid crystal filter in the biometric information acquisition apparatus which concerns on Embodiment 4 of this invention. It is a block diagram of the biometric information acquisition apparatus which concerns on Embodiment 5 of this invention. It is a flowchart of the biometric information acquisition method which concerns on Embodiment 5 of this invention. It is a schematic schematic diagram which shows the upper surface structure of the biometric information acquisition apparatus which concerns on Embodiment 6 of this invention. It is a schematic schematic diagram which shows the upper surface structure of the biometric information acquisition apparatus after the movement which concerns on Embodiment 6 of this invention. It is a schematic schematic diagram which shows the structure of the base part of the biometric information acquisition apparatus which concerns on Embodiment 6 of this invention. (A) is a schematic schematic diagram which shows the structure of the carrier member contained in the biometric information acquisition apparatus which concerns on Embodiment 6 of this invention. (B) is Y1-Y1 sectional drawing of (a). (C) is Y2-Y2 sectional drawing of (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Biometric information acquisition apparatus 3 Cellular phone 100 Irradiation part 200 Imaging part 300 Drive part 402 Evaluation part 403 Control part 500 Authentication part 600 Memory | storage part 700 Liquid crystal filter PX Pixel 1000 Biometric information acquisition apparatus

Claims (13)

An irradiation unit for irradiating the subject with light;
An imaging unit having one or more pixel columns;
A drive unit capable of reciprocating the imaging unit in a direction intersecting the pixel row;
A biological information acquisition device comprising:
An evaluation unit that evaluates an image captured by the imaging unit according to a preset condition;
Based on the evaluation result of the evaluation unit, a control unit that controls the irradiation condition of light to the subject when imaging the subject next time or the imaging condition of the subject by the imaging unit;
A biological information acquisition device comprising:   2. The biological information according to claim 1, wherein the control unit controls the irradiation condition or the imaging condition in a return path of the imaging unit based on an evaluation result of an image captured by the imaging unit in a forward path. Acquisition device.   The biological information acquisition apparatus according to claim 1, wherein the control unit controls the amount of light emitted from the irradiation unit to the subject as the irradiation condition.   The biological information acquisition apparatus according to claim 1, wherein the control unit controls an amplification factor of a signal from a pixel in the pixel column as the imaging condition.   5. The biological information acquisition apparatus according to claim 1, wherein the control unit controls an imaging period of an image by the imaging unit as the imaging condition. A light control unit is provided on the imaging unit,
The biological information acquisition apparatus according to claim 1, wherein the control unit electrically controls a light transmission amount of the light control unit as the imaging condition.   An electronic apparatus comprising the biological information acquisition apparatus according to any one of claims 1 to 6. A method of acquiring biological information of the subject by irradiating the subject with light,
An image pickup unit having one or more pixel columns is moved in a direction intersecting the pixel columns by a drive unit, and an image is captured.
The evaluation unit evaluates the image captured by the imaging unit,
The control unit, based on the evaluation result of the evaluation unit, controls the irradiation condition of light to the subject when imaging the subject next time or the imaging condition of the subject by the imaging unit,
A biological information acquisition method for capturing an image under the controlled irradiation condition or imaging condition by moving the imaging unit in a direction intersecting the pixel row by a driving unit.   The biological information according to claim 8, wherein the control unit controls the irradiation condition or the imaging condition in a return path of the imaging unit based on an evaluation result of an image captured by the imaging unit in an outward path. Acquisition method.   The biological information acquisition method according to claim 8 or 9, wherein the control unit controls the amount of light emitted to the subject as the irradiation condition.   The biological information acquisition method according to claim 8, wherein the control unit controls an amplification factor of a signal from a pixel in the pixel column as the imaging condition.   The biological information acquisition method according to claim 8, wherein the control unit controls an imaging period of an image by the imaging unit as the imaging condition.   The biological information acquisition method according to claim 8, wherein the control unit electrically controls a light transmission amount of a light control unit as the imaging unit.