Patent Publication Number: US-9418306-B2

Title: Iris recognition device and mobile device having the same

Description:
CROSS-REFERENCE TO THE RELATED APPLICATION 
     This application claims priority from Korean Patent Application No. 10-2014-0034196 filed on Mar. 24, 2014, the entire contents of which are incorporated herein by reference in their entirety. 
     BACKGROUND 
     1. Field 
     Apparatuses and methods consistent with exemplary embodiments of the inventive concept relate to an iris recognition device, and more particularly, to an iris recognition device that removes noise in an iris image signal, such as a ghost generated by an ambient light, using sampling signals having different phases with one another and a mobile device having the same. 
     2. Description of the Related Art 
     Iris recognition is one of the most promising approaches for biometric authentication. The iris is the only internal organ that is easily captured by a camera from the outside of a body. Moreover, because iris patterns between the pupil and the sclera have rich textures with unique and stable features, biometric authentication with iris recognition has a higher recognition accuracy than other biometric signatures. 
     With this availability and accuracy, iris recognition has been used in many security applications. Especially, there have been attempts to apply iris recognition technology to the security of mobile phones. The security issue of mobile phone applications becomes critical for banking or shopping services. They require a reliable and easy method to protect against unauthorized access. In the case of bank transaction service by using a mobile phone, iris recognition is used for a high level of security. 
     SUMMARY 
     Various exemplary embodiments of the inventive concept provide an iris recognition device and a method of biometric authentication using the same which may remove noise in an image of the iris such as a ghost generated by ambient light. 
     The exemplary embodiments of the inventive concept also provide a mobile device having the iris recognition device. 
     The technical objectives of the inventive concept are not limited to the above disclosure, and other objectives may become apparent to those of ordinary skill in the art based on the following descriptions. 
     In accordance with an aspect of an exemplary embodiment, there is provided an iris recognition device which may include: a light source unit configured to transmit a light signal to an iris; and a light source receiver configured to receive a reflected light signal of an image of the iris from the iris, and remove an offset of the reflected light signal, corresponding to noise (e.g., a ghost) in the iris image, using a plurality of reference signals having different phases. 
     The light source receiver may be configured to generate a plurality of sampling signals by synchronizing the reflected light signal with the plurality of reference signals having different phases, and the lights source receiver may be configured to obtain information about the iris using the plurality of sampling signals to remove the offset. 
     The light source receiver may calculate an amplitude of the reflected light signal using the plurality of sampling signals. 
     The light source receiver may remove the offset using the amplitude of the reflected light signal. 
     The light source receiver may calculate the offset using the plurality of sampling signals. 
     The frequency of each of the plurality of sampling signals may be equal to that of the light signal. 
     The light source receiver may calculate a distance from the iris using the plurality of sampling signals. 
     The light signal transmitted by the light source unit may include a near infrared ray (NIR). 
     The offset may be generated by an ambient light. 
     In accordance with an aspect of another exemplary embodiment, there is provided a mobile device which may include the above iris recognition device and an application processor configured to control the iris recognition device. 
     In accordance with an aspect of still another exemplary embodiment, there is provided a method of biometric authentication using an iris recognition device. The method may include: transmitting a light signal to an iris and receiving a light signal reflected from the iris; generating a plurality of sampling signals by synchronizing the reflected light signal with a plurality of reference signals having different phases; removing an offset in the reflected light signal, corresponding to noise included in an iris image, by analyzing the sampling signals, thereby generating iris image data; and comparing the iris image data with pre-stored iris image data. 
     The reference signals may include photo-gate signals. 
     The removing the offset may be performed by calculating an amplitude of the reflected light signal using the plurality of sampling signals. 
     The above method may further include calculating a distance between the light source receiver and the iris using the plurality of sampling signals. 
     A frequency of each of the plurality of sampling signals may be equal to a frequency of the light signal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other features and advantages of the inventive concepts will be apparent from the more particular description of exemplary embodiments, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the inventive concepts. In the drawings: 
         FIG. 1  is a block diagram illustrating an iris recognition device, according to an exemplary embodiment; 
         FIGS. 2A and 2B  are images that capture an iris by the iris recognition device  100  shown in  FIG. 1 , according to an exemplary embodiment; 
         FIG. 3  is a timing diagram illustrating the modulated light signal shown in  FIG. 1  and photo gate signals, according to an exemplary embodiment; 
         FIG. 4  is a timing diagram illustrating the modulated light signal ML shown in  FIG. 1 , and first to fourth sampling signals, according to an exemplary embodiment; 
         FIG. 5A  is an example image capturing the iris by the iris recognition device in the presence of ambient light; 
         FIG. 5B  is an example image by cutting and spreading an iris shown in  FIG. 5A ; 
         FIG. 6A  is an example image in which a ghost G generated by an ambient light is removed; 
         FIG. 6B  is an example image by cutting and spreading an iris shown in  FIG. 6A ; 
         FIG. 7  is a block diagram illustrating the iris recognition device shown in  FIG. 1 , according to an exemplary embodiment; 
         FIG. 8  is a flowchart explaining a method of biometric authentication using an iris recognition device, according to an exemplary embodiment. 
         FIG. 9  is a block diagram illustrating a mobile device including the iris recognition device shown in  FIG. 1  in accordance with an exemplary embodiment; 
         FIG. 10  is a block diagram illustrating a mobile device including the iris recognition device shown in  FIG. 1  in accordance with another exemplary embodiment; 
         FIG. 11  is a block diagram illustrating a mobile device including the iris recognition device shown in  FIG. 1  in accordance with still another exemplary embodiment; and 
         FIG. 12  is a view illustrating a display device including the iris recognition device shown in  FIG. 1  in accordance with an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     Exemplary embodiments of the present inventive concept are described below in sufficient detail to enable those of ordinary skill in the art to embody and practice the inventive concept. It is important to understand that the inventive concept may be embodied in many alternate forms and should not be construed as limited to the exemplary embodiments set forth herein. 
     Various exemplary embodiments will now be described more fully with reference to the accompanying drawings. The inventive concept may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure is thorough and complete and fully conveys the inventive concept to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. 
     It will be understood that, although the terms “first,” “second,” “A,” “B,” etc. may be used herein in reference to elements of the embodiments, such elements should not be construed as limited by these terms. For example, a first element could be termed a second element, and a second element could be termed a first element, without departing from the scope of the inventive concept. Herein, the term “and/or” includes any and all combinations of one or more referents. 
     It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements. Other words used to describe relationships between elements should be interpreted in a like fashion (i.e., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). 
     The terminology used herein to describe the embodiments is not intended to limit the scope of the inventive concept. The articles “a,” “an,” and “the” are singular in that they have a single referent, however the use of the singular form in the present document should not preclude the presence of more than one referent. In other words, elements of the embodiments referred to as singular may number one or more, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including,” when used herein, specify the presence of stated features, items, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, items, steps, operations, elements, components, and/or groups thereof. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be interpreted as is customary in the art to which these embodiments belong. It will be further understood that terms in common usage should also be interpreted as is customary in the relevant art and not in an idealized or overly formal sense unless expressly so defined herein. 
     Meanwhile, when it is possible to implement any embodiment in any other way, a function or an operation specified in a specific block may be performed differently from a flow specified in a flowchart. For example, two consecutive blocks may actually perform the function or the operation simultaneously, and the two blocks may perform the function or the operation conversely according to a related operation or function. 
     The embodiments of the inventive concept will be described below with reference to attached drawings. 
       FIG. 1  is a block diagram illustrating an iris recognition device, according to an exemplary embodiment. 
     Referring to  FIG. 1 , an iris recognition device  100  according to an exemplary embodiment may transmit a modulated light signal ML to an iris  110 , and receive a reflected light signal RL which is generated as the modulated light signal ML is reflected from an iris. According to an exemplary embodiment, the iris recognition device  100  may capture an image of an iris  110  illuminated by a near infrared ray (NIR) using a time-of-flight (ToF) sensor. The ToF sensor may correlate four sampling signals generated using the reflected light signal RL to obtain depth information (i.e., distance information from an object). Noise such as a ghost G may occur in an image of the iris  110  since an ambient light  120  is reflected off a cornea. 
     The ghost G may be removed through a correlation process. In this matter, the iris recognition device  100  includes a light source unit  10  and a light source receiver  20 . 
     The light source unit  10  may modulate a light source to generate the modulated light signal ML. The light source unit  10  may transmit the modulated light source ML to the iris  110 . According to an exemplary embodiment, the light source unit  10  may modulate an NIR and transmit the modulated NIR to the iris  110 . 
     The light source receiver  20  may receive the reflected light signal RL or the ghost G generated by the ambient light  120 . 
     The light source receiver  20  may receive the reflected light signal RL from the iris  110  in synchronization with four reference signals having different phases to be explained later. The light source receiver  20  calculates size information of the reflected light signal RL, and removes the ghost G generated by the ambient light  120  using the size information. According to an exemplary embodiment, the light source receiver  20  may include a ToF sensor or an electrical optical shutter. An operation of the iris recognition device  100  will be described with  FIGS. 3 and 4  in detail. 
       FIGS. 2A and 2B  are images that capture an iris by the iris recognition device  100  shown in  FIG. 1 , according to exemplary embodiments. 
     Referring to  FIGS. 1 and 2A , the light source unit  10  may use an NIR in order to ensure the quality of an image of the iris  110  in low illumination and minimize an effect of the ambient light  120 . When the light source receiver  20  includes an NIR pass filter, the light source receiver  20  may nearly remove noise (i.e., the ghost G) generated by reflection from visible light in an indoor environment. 
     When the light source unit  10  transmits the modulated light signal ML to the iris  110 , a specular reflection is the only reflection in the iris  110  if there is no ambient light  120 . That is, only a reflection (i.e., a specular reflection) by the modulated light signal ML is output from the iris  110 . 
     Referring to  FIGS. 1 and 2B , there is a lot of light in an outdoor environment. Therefore, the size of the iris  110  may become smaller. Moreover, a light having various wavelengths may generate the ghost G reflected in an image of the iris  110 . 
     The cornea is an optical outer layer capable of protecting the eye by covering the iris  110 . The cornea has minor-like reflection characteristics. When the light source unit  10  transmits the modulated light signal ML to the iris  110  in an outdoor environment in which the ambient light  120  is abundant, the ghost G may occur in the iris  110  due to the specular reflection and the ambient light  120 . 
       FIG. 3  is a timing diagram illustrating the modulated light signal shown in  FIG. 1  and photo gate signals, according to an exemplary embodiment. 
     Referring to  FIGS. 1 and 3 , the light source unit  10  transmits the modulated light signal ML having a sinusoidal wave to the iris  110 . The light source unit  10  may generate the modulated light signal ML to have a constant frequency. According to an exemplary embodiment, the light source unit  10  may set a frequency of the modulated light signal ML as 20 MHz. 
     The light source receiver  20  may generate the first to fourth photo gate signals PG 1  to PG 4  which are used as reference signals to measure a distance from the iris  110  or remove the ghost G generated by the ambient light  120 . The first to fourth photo gate signals PG 1  to PG 4  are reception synchronization signals of the light source receiver  20 . 
     The light source receiver  20  may receive the reflected light signal RL in synchronization with each of the first to fourth gate signals PG 1  to PG 4 . That is, while each of the first to fourth photo gate signals PG 1  to PG 4  is activated, the light source receiver  20  may receive the reflected light signal RL. 
     The first photo gate signal PG 1  has the same phase as the modulated light signal ML. The second photo gate signal PG 2  has a phase difference of 90-degrees with the modulated light signal ML. The third photo gate signal PG 3  has a phase difference of 180-degrees with the modulated light signal ML. And, the fourth photo gate signal PG 4  has a phase difference of 270-degrees with the modulated light signal ML. 
     While the modulated light signal ML is reflected, a phase of the modulated light signal ML may be changed. For example, a phase difference occurs according to the distance from the iris  110 . That is, the phase difference may be measured through comparing the modulated light signal ML with the reflected light signal RL. The light source receiver  20  may obtain amplitude information about the reflected light signal RL using the phase difference information. The light source receiver  20  may remove the ghost G using the amplitude information of the reflected light signal RL. A method of removing the ghost G using the amplitude information of the reflected light signal GL will be described with  FIG. 4 . 
       FIG. 4  is a timing diagram illustrating the modulated light signal ML shown in  FIG. 1 , and first to fourth sampling signals, according to an exemplary embodiment. 
     Referring to  FIGS. 1, 3 and 4 , the light source unit  10  may transmit the modulated light source ML to the iris  110 . The modulated light signal ML may be represented in the form of a sinusoidal wave changing according to time. That is, when the modulated light signal ML is s(t), the modulated light signal ML may be represented by Equation 1.
 
 s ( t )=cos(2 πft )  (1),
 
where f denotes a modulated frequency.
 
     Further, the reflected light signal RL reflected from the iris  110  may be represented in the form of a sinusoidal wave changing according to time. That is, when the reflected light signal RL is r(t), the reflected light signal RL may be represented according to Equation 2.
 
 r ( t )= k+A  cos(2 πft −Φ)  (2),
 
where A denotes an amplitude of the light signal according to the integration time. A may be determined by the reflectivity of an object and sensitivity of an image sensor. Due to scattering of light, A may decrease according to a distance. Φ denotes a phase shift according to the distance from the iris  110 .
 
     The light source unit  10  transmits s(t) to the iris  110 . The light source receiver  20  receives the reflected r(t) from the iris  110 . The light source receiver  20  receives r(t) in synchronization with each of the first to fourth photo gate signals PG 1  to PG 4 . 
     The light source receiver  20  receives r(t) and synchronizes the received r(t) with the first to fourth photo gate signals PG 1  to PG 4  to generate the first to fourth sampling signal I 0 , I 1 , I 2  and I 3 . 
     That is, the first sampling signal I 0  is generated by sampling r(t) in synchronization with the first photo gate signal PG 1  having the same phase as s(t). The second sampling signal I 1  is generated by sampling r(t) in synchronization with the second photo gate signal PG 2  having a phase difference of 90-degrees with s(t). The third sampling signal I 2  is generated by sampling r(t) in synchronization with the third photo gate signal PG 3  having a phase difference of 180-degrees with s(t). Further, the fourth sampling signal I 3  is generated by sampling r(t) in synchronization with the fourth photo gate signal PG 4  having a phase difference of 270-degrees with s(t). 
     The first to fourth sampling signals I 0  to I 3  may be represented in Equations 3(a) to 3(d).
 
 I   0   =A  cos Φ+ B   3(a),
 
 I   1   =A  sin φ+ B   3(b),
 
 I   2   =−A  cos Φ+ B   3(c),
 
 I   3   =−A  sin Φ+ B   3(d),
 
where B denotes an offset or offset coefficient generated by the ambient light  120 .
 
     Equation 4 denotes a formula to calculate Φ. That is, Φ may be computed using the first to fourth sampling signals I 0  to I 3  disclosed in Equations 3(a) to 3(d). 
     
       
         
           
             
               
                 
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     Equation 5 denotes a formula that calculates the distance d from the object using the frequency of the modulated light signal ML and the shifted phase Φ. The distance d from the object may be computed using the speed c (i.e., c=3×10 8  m/s) of the modulated light signal ML. 
     
       
         
           
             
               
                 
                   d 
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     Equation 6 is a formula to calculate A. 
     
       
         
           
             
               
                 
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     Equation 7 is a formula to calculate B. 
     
       
         
           
             
               
                 
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     The iris recognition device  100  according to the embodiment may calculate the amplitude A of the reflected light signal RL using the first to fourth sampling signals having different phases. The iris recognition device  100  may remove the offset B generated by the ambient light  120  using the amplitude A of the reflected light signal RL. 
     That is, the iris recognition device  100  may remove the offset B using the difference between two sampling signals. For example, the iris recognition device  100  may remove the offset B using the difference between the first and third sampling signals or the difference between the second and fourth sampling signals. Further, the iris recognition device  100  may remove the offset B using the difference between the first and third sampling signals and the difference between the second and fourth sampling signals. 
     Therefore, the iris recognition device  100  may remove the ghost G from the reflected light signal RL by removing the offset B generated by the ambient light  120 . 
       FIG. 5A  is an example image capturing the iris by the iris recognition device in the presence of ambient light. 
     Referring to the  FIGS. 1 and 5A , the iris recognition device  100  transmits the modulated light signal ML to the iris  110 , and receives the reflected light signal RL. When there is the ambient light  120 , the ghost G occurs in an image of the iris  110 . Accordingly, the ghost G may occur in the iris  110  due to a specular reflection by the modulated light signal ML and the ambient light  120 . 
       FIG. 5B  is an example image by cutting and spreading an iris shown in  FIG. 5A . 
     Referring to  FIGS. 1, 5A and 5B , the iris recognition device  100  cuts the image of the iris  110  in a ρ direction. The iris recognition device  100  spreads the cut image in a Φ direction. The iris recognition device  100  converts the spread image to digital data. 
     The iris recognition device  100  may perform a biometric authorization through a correlation between the converted digital data and digital data for self-certification which may be pre-stored in the iris recognition device. When there is the ghost G in an image of the iris  110 , the iris recognition device  100  may have difficulty in digitizing the region of the ghost G. 
       FIG. 6A  is an example image in which a ghost G generated by an ambient light is removed. 
     Referring to the  FIGS. 1 and 6A , the iris recognition device  100  transmits the modulated light signal ML to the iris  110 , and receives the reflected light signal RL. When there is no the ambient light  120 , only the specular reflection generated by the modulated light signal ML occurs in an image of the iris  110 . 
       FIG. 6B  is an example image by cutting and spreading an iris shown in  FIG. 6A . 
     Referring to  FIGS. 1, 6A and 6B , the iris recognition device  100  cuts the image of the iris  110  in the ρ direction. The iris recognition device  100  spreads the cut image in the Φ direction. The iris recognition device  100  converts the spread image to digital data. 
     There is no the ghost G in the image of the iris  110 . Accordingly, when comparing  FIG. 5B  with  FIG. 6B , the iris recognition device  100  may digitize a larger region in the iris  110 . 
     The iris recognition device  100  may perform a biometric authorization through the correlation between the converted digital data and digital data for self-certification. For example, when the digital data for self-certification is similar to the converted digital data, the correlation may be high. Accordingly, the iris recognition device  100  may perform a self-certification process using the correlation. 
       FIG. 7  is a block diagram illustrating the iris recognition device shown in  FIG. 1 , according to an exemplary embodiment. 
     Referring to  FIGS. 1 and 7 , the iris recognition device  100  includes the light source unit  10  and the light source receiver  20 . The light source receiver  20  includes a ToF sensor  21 , a coordinate conversion unit  22 , an eye region detection unit  23 , an NIR processing unit  24 , a region of interest (ROI) unit  25 , a segmentation unit  26 , an iris normalization unit  27 , a feature extraction unit  28 , and a matching unit  29 . 
     The ToF sensor  21  may receive the reflected light signal RL from the iris  110 . The ToF sensor  21  extracts depth data and NIR data from the reflected light signal RL. The ToF sensor  21  transfers the depth data, which is depth information from the iris  110 , to the coordinate conversion unit  22 . Further, the ToF sensor  21  transfers the NIR data, which is image information about the iris  110 , to the NIR processing unit  24 . 
     The coordinate conversion unit  22  converts coordinates of the depth information to generate three-dimension (3D) data. The eye region detection unit  23  detects an eye region using the 3D data. The NIR processing unit  24  may remove the ghost G generated by the ambient light  120  using the NIR data. 
     The ROI unit  25  aligns 3D data with a pre-defined reference model. The segmentation unit  26  may extract an ROI from the NIR data. 
     The iris normalization unit  27  normalizes the extracted ROI. The feature extraction unit  28  extracts features for a biometric authentication from the normalized ROI. 
     The matching unit  29  performs a biometric authentication using the extracted features. According to an exemplary embodiment, the matching unit  29  may perform a correlation process for biometric authentication. 
       FIG. 8  is a flowchart explaining a method of biometric authentication using an iris recognition device, according to an exemplary embodiment. 
     According to the biometric authentication method of  FIG. 8 , the iris recognition device transmits a light signal (e.g., a modulated signal ML) to an iris and receives a light signal RL reflected from the iris (S 100 ). The iris recognition device generates four sampling signals by synchronizing the reflected light signal RL with four reference signals having different phases (S 200 ). Since the reflected light signal RL may include an offset represented by noise such as a ghost occurring due to an ambient light, the iris recognition device removes the offset by analyzing the four sampling signals (S 300 ). After removing the offset, the iris recognition device converts image of the iris included in the reflected light signal RL to digital data, and compares the converted data with digital data of the iris for self-certification (S 400 ). 
       FIG. 9  is a block diagram illustrating a mobile device including the iris recognition device shown in  FIG. 1  in accordance with an exemplary embodiment. 
     Referring to  FIG. 9 , a mobile device  210  may be embodied to a smart-phone, a personal digital assistant (PDA), a portable multimedia player (PMP), an MP3 player, or an MP4 player. 
     The mobile device  210  may include a memory device  211 , an application processor (AP)  212  including a memory controller for controlling the memory device  211 , a radio transceiver  213 , an antenna  214 , an input device  215 , and a display device  216 . 
     The radio transceiver  213  may transmit or receive a radio signal through the antenna  214 . For example, the radio transceiver  213  may convert the radio signal received through the antenna  214  into a signal which may be processed in the AP  212 . 
     Accordingly, the AP  212  may process a signal output from the radio transceiver  213 , and transmit the processed signal to the display device  216 . Further, the radio transceiver  213  may convert a signal output from the AP  212  into a radio signal, and output the converted radio signal to an external device through the antenna  214 . 
     As the input device  215  is a device for inputting a control signal for controlling an operation of the AP  212  or data processed by the AP  212 , and may be embodied as a pointing device such as a touchpad and a computer mouse, a keypad, or a keyboard. 
     Further, the mobile device  210  may further include an iris recognition device  217  for biometric authentication. The AP  212  may perform a biometric authentication method through the iris recognition device  217 . For example, when a finance application is performed in the mobile device  210 , the iris recognition device  217  may perform a biometric authentication method. According to the embodiments, the iris recognition device  217  may be implemented with the iris recognition device  100  shown in  FIG. 1 . 
       FIG. 10  is a block diagram illustrating a mobile device including the iris recognition device shown in  FIG. 1  in accordance with another exemplary embodiment. 
     Referring to  FIG. 10 , a mobile device  220  may be a personal computer (PC), a network server, a tablet PC, a netbook, or an e-reader. 
     The mobile device  220  includes a memory device  221 , an AP  222  including a memory controller for controlling a data processing operation of the memory device  221 , an input device  223 , and a display device  224 . 
     The AP  222  may display data stored in the memory device  221  on the display device  224  according to data input through the input device  223 . For example, the input device  223  may be a pointing device such as a touchpad or a computer mouse, a keypad, or a keyboard. The application processor  222  may control overall operations of the mobile device  220 . 
     Further, the mobile device  220  may further include an iris recognition device  225  for biometric authentication. The AP  222  may perform a biometric authentication method through the iris recognition device  225 . According to the embodiments, the iris recognition device  225  may be implemented with the iris recognition device  100  shown in  FIG. 1 . 
       FIG. 11  is a block diagram illustrating a mobile device including the iris recognition device shown in  FIG. 1  in accordance with still another exemplary embodiment. 
     Referring to  FIG. 10 , a mobile device  230  may be an image processing device, for example, a digital camera or a mobile phone having the digital camera, a smartphone, or a tablet PC. 
     The mobile device  230  may include a memory device  231 , an AP  232  including a memory controller for controlling a data processing operation, for example, a write operation or a read operation, of the memory device  231 , an input device  233 , an image sensor  234 , a display device  235 , and an iris recognition device  236 . 
     The image sensor  234  converts an optical image into digital signals, and the converted digital signals are transmitted to the AP  232 . According to the control of the AP  232 , the converted digital signals may be displayed on the display device  235 , or stored in the memory device  231 . 
     The application processor  232  may perform a biometric authentication method through the iris recognition device  236 . In one embodiment, the iris recognition device  236  may be implemented with the iris recognition device  100  shown in  FIG. 1 . 
       FIG. 12  is a view illustrating a display device including the iris recognition device shown in  FIG. 1  in accordance with an exemplary embodiment. 
     Referring to  FIGS. 1 and 11 , a display device  300  may be a display device or the like installed in a smart TV, a monitor, or various mobile devices. 
     The display device  300  may include the iris recognition device  100  shown in  FIG. 1 . According to an exemplary embodiment, the iris recognition device  100  may be a ToF camera device. 
     When the display device  300  is the smart TV, various applications may be installed in the display device  300 . The display device  300  may use the iris recognition device  100  as a self-authorization method. For example, a user may perform a financial application installed in the display device  300 . The iris recognition device  100  photographs an iris of the user for self-authorization. In this matter, the iris recognition device  100  may identify oneself. 
     The iris recognition device according to the above embodiments may remove a ghost generated by an ambient light from an image of an iris. 
     The above embodiments may be applied to an iris recognition device and a mobile device having the same. 
     The foregoing is illustrative of various exemplary embodiments and is not to be construed as limiting thereof. Although a few exemplary embodiments have been described, those skilled in the art will readily appreciate that many modifications are possible without materially departing from the novel teachings and advantages. Accordingly, all such modifications are intended to be included within the scope of this inventive concept as defined in the claims.