KR20160105571A - Fingerprint Input Apparatus Using Mobile Terminal Equipped with Camera, and External-Optical Device thereof - Google Patents

Abstract

Disclosed are an apparatus for fingerprint input using a mobile terminal equipped with a camera, and an external optical device for fingerprint input. According to the present invention, a fingerprint image can be generated by using the external optical device via an optical fingerprint input method even when an existing mobile terminal does not include a configuration for optical fingerprint input therein. For this purpose, the external optical device is configured in the form of an external device which can be attached to an existing mobile terminal including a camera and which can generate a fingerprint image of a user as needed by using the optical fingerprint input method without interfering with primary usage of the camera and LED of the existing mobile terminal. The external optical device comprises a light refractor, a mirror, first and second lenses, and a housing. In particular, according to the present invention, proposed is the external optical device which maintains a relatively short light path extending from the light refractor to the camera of the mobile terminal and which has a structure enabling a close-up image to be photographed, and thus the external optical device can be manufactured to have a simple structure and a small size.

Description

Technical Field [0001] The present invention relates to a fingerprint input device using a portable terminal equipped with a camera and an external optical device for fingerprint input,

The present invention relates to a fingerprint input device capable of inputting a user fingerprint image using a portable terminal equipped with a camera, such as a smart phone, and an external optical device for the fingerprint input device.

The use of biometric information of users who have excellent immutability and uniqueness in personal authentication using information devices has already been generalized. Among them, fingerprint recognition has become the most noted and generalized authentication means compared to other means because of its superior performance compared with a simple structure. As a method of acquiring fingerprint information, a generalized method is an optical method using a photorefractor such as a prism.

1, a conventional optical fingerprint input device includes a light source 1 for irradiating fingerprint identification light, a prism 3 for contacting a finger, and a fingerprint image outputting device for imaging the fingerprint image emitted from the prism 3 And an image sensor 5 for converting a fingerprint image formed on the lens 4 into an electrical signal. The optical fingerprint input device has a scattering device and an absorption device according to the arrangement structure of the prism 3 and the light source 1.

The light emitted from the light source 1 is incident on the prism 3 to form a fingerprint image while being reflected, absorbed or scattered by the ridges and ridges of the fingerprints contacted with the fingerprint contact surface 3a of the prism 3, 3 via the exit surface 3b. The fingerprint image emitted from the prism 3 is imaged on the image sensor 5 through the lens 4 to acquire a digital fingerprint image.

Since the prism 3 has a triangular cross section and changes the optical path to more than a certain angle, the fingerprint input apparatus using the prism 3 has a larger volume than that of a semiconductor type or the like in any way. Therefore, it is difficult to apply the optical fingerprint input device to a relatively thin panel-shaped mobile device.

In this alternative, the applicant invented an external optical device (Korean Patent Registration No. 1479609) mounted on the outer surface of a portable terminal having an LED and a camera portion.

2 and 3, a conventional external optical apparatus 230 includes a plate-shaped optical refractor 231, a first mirror 235 provided above the portable terminal camera unit 211, A light blocking portion 241, and a light incidence portion 243, which are provided in the outer space portions on both sides and rear surface of the optical refractor 231, respectively.

At this time, the light refractor 231 has a fingerprint contact surface 231a with which the fingerprint is contacted at an upper portion thereof, and a light incident surface 231c at a lower portion thereof. The exit surface 231b is provided at the front end of the light refractor 231. [ The light refractor 231 may be disposed apart from the upper portion of the LED 213 of the portable terminal 210 so that the second mirror 237 may transmit light emitted from the LED 213 of the portable terminal 210, And reflects it to the refractor 231.

The light intercepting portion 241 is disposed between the second mirror 237 and the light refractor 231 so that the light reflected by the second mirror 237 is not directly incident on the light refractor 231 do. Instead, the light incident portion 243 is disposed below the light incident surface 231c, and part of the light reflected by the second mirror 237 is incident on the light incident surface 231c.

The light incident portion 243 may also be a mirror. The mirror 243 at this time forms a slit s between itself and the optical refractor 231 so that a part of the light reflected by the second mirror 237 is allowed to flow and reflects or scatters the introduced light, Incident on the light incident surface 231c of the light guide plate 231. Further, the light incidence portion may be a diffusion plate.

The fingerprint image emitted from the exit surface of the optical refractor 231 is reflected by the first mirror 235 and is incident on the camera unit 211 of the portable terminal 210 to become a fingerprint image.

Such a structure may be advantageous for focusing the fingerprint image by lengthening the optical path, but may not be suitable for miniaturization. Therefore, the applicant intends to propose a new type of external optical apparatus by providing another method of inputting LED light into a light refractor and a structure capable of taking a close-up image by a relatively short optical path.

In this process, there is a problem caused by the characteristics of the camera unit 211 of the portable terminal which is a ready-made product. The image sensor 211b of the portable terminal 210 such as a recent smart phone provides a high resolution of Full HD (1920x1080 pixels) class. On the other hand, a fingerprint image for fingerprint authentication basically suffices to have a resolution of approximately 500 dpi, and when considering one fingerprint (for example, approximately 12 x 12 mm), approximately 236 pixels in the vertical direction is sufficient. Therefore, the fingerprint image for fingerprint authentication does not need to be a full height image using the entire image sensor 211b.

In order to achieve the object of miniaturization of the external optical apparatus with the recent tendency that the camera unit 211 and the LED 213 of the portable terminal 210 are disposed very close to each other, the image sensor 211b The image of the fingerprint imaged on the image sensor 211b must be a large image of 500 dpi or more and the minimum photographable distance (approximately 7 cm or more) of the camera unit 211 is required, As shown in FIG.

On the other hand, with respect to focusing, it is also problematic that the camera unit 211 of the portable terminal 210 basically operates in the automatic focus adjustment mode. In the case of the automatic focus adjustment mode, it takes a time corresponding to the focus adjustment operation in the fingerprint input process. Such a time is likely to exceed the tolerable range of the general user in the fingerprint input process.

[Related Technical Literature]

1. A fingerprint input device using a portable terminal equipped with a camera and an external optical device for fingerprint input (Korean Patent No. 1479609)

An object of the present invention is to provide an external optical apparatus capable of inputting a user fingerprint into a portable terminal by using an optical fingerprint input method using the portable terminal equipped with a camera like a smart phone as it is and generating the user fingerprint image.

It is another object of the present invention to provide an external optical apparatus that is simple in structure and can be further downsized by providing a structure capable of taking a close-up image while maintaining a relatively short optical path leading from a light refractor to a camera unit of a portable terminal.

It is another object of the present invention to provide a portable terminal which is operated in a fixed focus mode instead of an automatic focus mode by reducing the time required for inputting fingerprints, And a fingerprint input device.

It is another object of the present invention to provide an external optical apparatus which can be universally applied to a plurality of portable terminals having different distances between a camera unit and an LED.

In order to achieve the above object, the present invention provides an external optical device capable of receiving and inputting a user fingerprint image using the camera unit and the LED, having a structure that can be attached to and detached from a portable terminal having a camera unit and LEDs on the same outer surface, present.

The external optical apparatus includes a light refractor, a mirror, a first lens and a second lens, and a housing. The photorefractor includes a light incidence surface on which light for acquiring a fingerprint is incident, a fingerprint contact surface formed on an upper surface parallel to the outer surface and contacting the fingerprint, and a fingerprint contact surface formed on the inclined front surface at a predetermined acute angle with the fingerprint contact surface, Emitting surface to which the light is emitted. The mirror is provided on the upper side of the camera unit, and reflects the fingerprint image emitted from the exit surface to the camera unit to cause the camera unit to generate a fingerprint image.

The first lens and the second lens are disposed between the exit surface of the light refractor and the mirror to support close-up photography of the camera unit despite the focal distance set in the camera unit operating in the fixed focus mode.

The housing accommodates the light refractor, the mirror, the first lens, and the second lens, and a diaphragm is formed so as to focus the fingerprint image by blocking the light emitted from the mirror and incident on the camera unit.

According to an embodiment of the present invention, the first lens has a plane in which the incident surface is flat and the opposite surface has a positive magnification, and an upper portion of the first lens is tilted toward the exit surface of the light refractor, .

According to another embodiment, the diaphragm is formed in the housing in the form of a pin hole, and a transparent dust-protective film is attached to the outer surface of the diaphragm.

According to another embodiment, when the light refractor is mounted apart from the upper part of the LED, the exterior optical device may have a light guide accommodated in the housing. The light guide has a first surface opened to the outside so as to face the LED of the portable terminal and a second surface arranged to face the light incident surface, and the light emitted from the LED and incident through the first surface And exits through the second surface to the light incidence surface.

The present invention also relates to a fingerprint input device including the external optical device and the portable terminal. In this case, the portable terminal may be provided with a fingerprint acquisition control unit for controlling the fingerprint application process. The fingerprint acquisition control unit controls the LED unit to light up and then controls the camera unit to generate the fingerprint image so that the camera unit operating in the auto focus adjustment mode operates in the fixed focus mode, It is desirable to reduce the time required.

According to the present invention, a fingerprint image can be generated by an optical fingerprint input method using an external optical device of the present invention, even if the existing portable terminal does not have a built-in configuration for optical fingerprint input.

The external optical device is provided in an external form mounted on an existing portable terminal equipped with a camera and can generate a fingerprint image of the user as an optical fingerprint input method as needed without interfering with the main use of the camera and the LED of the existing portable terminal will be.

Accordingly, many wireless terminals that do not have a built-in fingerprint input device can use the authentication method using the user fingerprint, thereby enhancing the security of the device.

In addition, the external optical apparatus of the present invention can further reduce the size by providing a simple structure for keeping the optical path leading from the optical refractor in which the fingerprint image is initially output to the camera section of the portable terminal as short as possible. As the optical path becomes shorter in this process, a so-called close-up photograph of the fingerprint existing within the minimum photographable range of the ready-made portable terminal is possible, but the structure for minimizing the distortion of the fingerprint image as a whole is proposed.

In addition, the fingerprint input device using the external optical device of the present invention allows the camera portion of the portable terminal, which is a ready-made product, to operate in the fixed focus mode instead of the automatic focus adjustment mode, which is a normal operation mode, And the fingerprint input time was shortened. Furthermore, the external optical apparatus of the present invention solves the problem that the camera unit of the portable terminal operates out of the fixed focus mode and is out of focus.

Further, the external optical apparatus of the present invention includes a light guide that allows light emitted from the LED to enter the light refractor, so that the light refractor must be disposed apart from the LED as the distance between the camera and the LED is short Solve the problem. Furthermore, the optical guide provides an optimal simple optical path in the external optical device, thereby making it possible to manufacture the external optical device in a small size.

Meanwhile, since the light guide is universally applied to various portable terminals having various distances between the camera unit and the LED and has a structure capable of transmitting light, the external optical apparatus of the present invention has a structure in which the distance between the camera unit and the LED is different And can be commonly applied to various portable terminals.

1 is a view showing a conventional optical fingerprint input device,
FIG. 2 is a cross-sectional view of a conventional external optical apparatus mounted on a portable terminal,
FIG. 3 is a conceptual diagram showing a coupling relationship between the external optical apparatus and the portable terminal of FIG. 2,
4 is a cross-sectional view of an external optical apparatus according to an embodiment of the present invention,
Fig. 5 is a view provided for explaining the optical path of the fingerprint image passing through the lens unit of the external optical apparatus of Fig. 4,
6 is an enlarged cross-sectional view of a light guide portion of the external optical apparatus of Fig. 4, and Fig.
7 is a view provided to explain a light path on a first surface of a light guide according to an embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to the drawings.

4, the fingerprint input device of the present invention includes a portable terminal 210 having a camera unit 211 and an LED 213, and an external optical device (400). The exterior-optical device 400 acquires the fingerprint image from the user fingerprint and the portable terminal 210 acquires the fingerprint image using the fingerprint image. The fingerprint input method of the present invention utilizes the camera unit 211 of the portable terminal 210 as an image sensor for inputting an optical fingerprint and uses the LED 213 as a light source for inputting an optical fingerprint, The external-optical apparatus 400 provides the optical path between the camera units 211. [

The portable terminal 210 includes a camera unit 211 for capturing an image of an external subject and generating an image and is capable of performing image processing on an image generated by the camera unit 211 And may have other main functions irrespective of the fingerprint input of the present invention, such as a mobile communication terminal or a personal digital terminal. For example, in recent smart phones and tablet PCs, a camera unit 211 and an LED 213 are arranged side by side on the front and / or rear side.

 The portable terminal 210 includes a camera unit 211, an LED 213, and a control unit 215. As described above, the portable terminal 210 may naturally include a configuration related to its main function, but such a configuration or function is not essential to the present invention and does not contribute to the description of the present invention, And the description thereof is omitted.

The camera unit 211 includes a basic lens 211a and an image sensor 211b to generate an image of an external subject. In addition to the original function of generating an image of an external subject, And provides the fingerprint image to the control unit 215.

As described above, the image sensor 211b of the portable terminal 210 such as a recent smart phone provides a high resolution of Full HD (1920x1080 pixels) class. However, the fingerprint image for fingerprint authentication does not need to be a full-resolution image using the entire image sensor 211b.

The camera unit 211 operates in an auto focus (AF) mode and a fixed focus mode. When the fingerprint input process is not performed, the camera unit 211 operates in an auto focus (AF) mode to focus on a subject at a set minimum photographable distance to generate an image. However, it takes a certain time to adjust the focus of the automatic focus adjustment function, and this time is inconvenient in the fingerprint image creation process. Therefore, in the present invention, it is controlled to operate in the " fixed focus mode " .

In addition to the original function given in the portable terminal 210, the LED 213 serves to irradiate light for generating an optical fingerprint image to the external-optical device 400 in the present invention. The LEDs 213 are arranged on the outer surface 210a of the portable terminal 210 in parallel with the camera 211 as shown in FIG.

The control unit 215 includes a fingerprint acquisition control unit 217 for controlling the entire optical fingerprint input process using the LED 213 and the camera unit 211. The control unit 215 may be configured to be installed specifically for the present invention, but it may be configured to perform the main function of the portable terminal 210 described above.

In the case where the control unit 215 is installed to perform the main function of the portable terminal 210, the control unit 215 includes a processor chip, which is basically hardware of the portable terminal, It may be a functional indication of a configuration implemented in an application that is software. Here, an application is software written in a programming language that can be interpreted by a computer and process a specified set of instructions.

The fingerprint acquisition control unit 217 may be a program or a plurality of program aggregates installed for the implementation of the present invention and executed by the processor chip as one of the applications.

Specifically, the fingerprint acquisition control unit 217 controls the LED 213 to emit light for fingerprint input, and then controls the camera unit 211 to generate a fingerprint image. In this process, the fingerprint acquisition control unit 217 controls the camera unit 211 to operate in the fixed focus mode instead of the automatic focus adjustment mode, thereby eliminating the time required for the automatic focus adjustment, . The focus adjustment is processed in the exterior-optical device 400 as described below.

If necessary, the fingerprint acquisition control unit 217 may extract the feature points from the fingerprint image generated by the image sensor 211b of the camera unit 211 to directly perform the fingerprint authentication process, or may perform the fingerprint authentication process using another external device A fingerprint image or minutia data may be provided.

4 and 5 includes a light refractor 401, a mirror 403, a lens portion 405, a light guide 407, a diffuser plate 409, and a housing 411 And is provided externally so as to be positioned at a predetermined posture with respect to the portable terminal 210 (hereinafter simply referred to as 'mounting'). Hereinafter, even if the expression 'mounting' is used, it does not mean that the external-optical device 400 requires direct and mechanical coupling with the portable terminal 210.

The optical refractor 401 includes a fingerprint contact surface 401a on which the finger F is contacted, a light incident surface 401b on which light emitted from the LED 213 is incident, and an exit surface 401c on which the fingerprint image is finally emitted Any type or kind of optical refractor or prism may be included. However, in consideration of the fact that the optical refractor 401 is provided as a separate external device, a thin flat plate is preferable.

The size of the fingerprint contact surface 401a can be variously designed according to the number of fingers to be used for fingerprint authentication. For example, in the case of generating a fingerprint image of one finger, a size of about 12 x 12 mm is usually sufficient.

4 includes a fingerprint contact surface 401a on the upper surface parallel to the outer surface 210a of the portable terminal 210 and a light incident surface 401b on the lower surface parallel to the fingerprint contact surface 401a And the exit surface 401c disposed at the front end portion are formed, and the exit surface 401c is inclined at an acute angle to the fingerprint contact surface 401a again. The fingerprint contact surface 401a and the light incident surface 401b are arranged to be parallel to the outer surface 210a of the portable terminal 210. [

When the exterior-optical device 400 is mounted on the portable terminal 210, the position of the mirror 403 is the upper side of the camera unit 211. The path of the light emitted through the exit surface 401c of the optical refractor 401 (i.e., the fingerprint image) is arranged substantially parallel to the outer surface 210a of the portable terminal 210. [

Specifically, of the spaces defined by two parallel virtual planes extending from the fingerprint contact surface 401a and the light incident surface 401b, the space between the exit surface 401c and the mirror 403 is defined by the exit surface 401c (Fingerprint image) emitted from the light source (fingerprint image), and the lens unit 405 is disposed on the path. The optical path from the exit surface of the optical refractor 401 to the mirror 403 can be sealed with a material having no reflecting ability so as to form one optical path. Therefore, only the light refracted toward the closed optical path out of the light emitted from the exit surface 401c of the optical refractor 401 becomes a valid fingerprint image.

The fingerprint image refracted by the exit surface 401c is reflected by the mirror 403 through the lens unit 405 and is incident on the camera unit 211. [ The fingerprint image input to the camera unit 211 is imaged on the image sensor 211b to become a fingerprint image.

In the present invention, the lens unit 405 plays the following role as an important configuration enabling the fingerprint input device of the external-optical device 400 type. First, the lens unit 405 controls the focal distance so that the photographing is possible regardless of the focal distance set in the camera unit 211 to be operated in the fixed focus mode, so that the fingerprint image has a size of about 500 dpi . Secondly, the lens unit 405 reduces various kinds of distortion of the fingerprint image formed on the image sensor 211b.

First, the lens portion 405 optically reduces the combined focal length with the camera portion 211, thereby enabling close-up photography of the optical refractor 401 positioned very closely. The focal distance controllable by the camera unit 211 in the automatic focus adjustment mode is not short. However, when the camera unit 211 is operated in the fixed focus mode, fingerprinting on the fingerprint contact surface 401a becomes more difficult. The lens unit 405 reduces the size of the fingerprint image emitted from the exit surface 401c of the light refractor 401 while reducing the focal distance so that the fingerprint image can be taken, do. For example, assuming that the size of the fingerprint contact surface 401a is 12 mm in the vertical direction, 500 dpi is satisfied if the resolution is about 236 pixels in the vertical direction. However, since the subject, that is, the fingerprint contact surface 401a of the light refractor 401 is too close to the image sensor 211b, the fingerprint image is not superimposed on the image having a very large resolution of 500 dpi or more . A fingerprint image generated by the fingerprint contact surface 401a having a size of 12 mm in the vertical direction and outputted through the exit surface 401c of the light refractor 401 is captured by the image sensor 211b of full HD (1920 x 1080 pixels) , The lens unit 405 adjusts the magnification of the image so that the image is formed at a size of 236 pixels in the vertical direction. In summary, the magnification should be adjusted to have a resolution of about 500 dpi while the fingerprint image is in focus in the fixed focus mode.

On the other hand, the keystone effect of the fingerprint image is increased due to the close-up photographing, so that some of the focuses may not fit, resulting in rectangular distortion or trapezoidal distortion. Basically, the keystone effect occurs when the fingerprint image is tilted to the image sensor 211b to be imaged. Since the exit surface 401c of the optical refractor 401 is disposed in a state inclined with respect to the image sensor 211b, a keystone effect is generated in the fingerprint image formed on the image sensor 211b.

The lens unit 405 can be applied in various forms to solve these problems. 4 and 5, the lens unit 405 includes a first lens 501 and a second lens 503. [

The first lens 501 is designed to have a very large radius of curvature so that the incident surface opposite to the exit surface 401c is planar and the opposite surface has a considerably small positive magnification so that the focal length of the first lens 501 Long design. The second lens 503 is disposed within the focal length of the first lens 501. [

The first lens 501 is disposed such that the upper portion of the first lens 501 is tilted toward the exit surface 401c of the light refractor 401 so that both surfaces of the first lens 501 are arranged on the exit surface 401a of the light refractor 401 401c are inclined in a direction opposite to the tilted direction. 5, the path of the light (first light) arriving at the first upper portion of the first lens 501 is shorter than the path of the light (second light) arriving at the lower most portion. However, in the first lens 501, the first light has a longer path than the second light, thereby contributing to the reduction of the keystone effect.

The second lens 503 is designed to have a very large radius of curvature so that both sides have a positive magnification and a fairly small positive magnification and are not tilted unlike the first lens 501. The second lens 503 images the fingerprint image on the image sensor 211b in a desired size.

The diaphragm 411a controls the focal length of the fingerprint image together with the lens unit 405 so as to solve the focal length problem caused by the camera unit 211 operating in the fixed focus mode. The diaphragm 411a controls the amount of light incident on the image sensor 211b. When the diaphragm 411a is reduced in such a manner that the diaphragm 411a is reduced in the amount of light, the fingerprint image is generally darkened instead of focusing.

Various shapes may be used as the diaphragm 411a, but they are preferably provided in the form of a hole or a pin hole. It is preferable to attach a transparent dust-protective film 505 to the outer surface of the diaphragm 411a because pin holes may be clogged with dust or the like when the pinhole is used as the diaphragm 411a.

<Optical guide>

On the other hand, when the user fingerprint touches the fingerprint input window 401a of the optical refractor 401, the light emitted from the LED 213 enters the light incident surface 401b of the light refractor 401, . (1) First, the distance between the camera unit 211 and the LED 213 is too close to the optical refractor 401 and the mirror 403 to be one imaginary line The optical refractor 401 can not be disposed at a position where it can receive light directly from the LED 213 and (2) the portable The distance between the camera unit 211 and the LED 213 is slightly different for each terminal type.

A structure for transferring the light emitted from the LED 213 to the light incident surface 401b of the light refractor 401 can not be obtained because the light refractor 401 must be mounted while being spaced apart from the LED 213 need. This configuration is the light guide 407. In other words, the light guide 407 provides a light path from the LED 213 of the portable terminal 210 to the light incident surface 401b of the light refractor 401 so that the light emitted from the LED 213 And transmitted to the light incident surface 401b.

The arrangement of the optical refractor 401, the mirror 403 and the light guide 407 can be basically varied. However, in order to miniaturize the exterior-optical apparatus 400 of the present invention, do. First, a virtual line connecting the camera unit 211 of the portable terminal 210 and the LED 213 (hereafter referred to as a first line) is assumed for convenience of explanation.

6, the exit surface 401c of the light refractor 401 and the mirror 403 are disposed on an imaginary second line parallel to the imaginary first line, and the light refractors 401 and the mirrors 403 403 are sufficiently spaced apart. And a light guide 407 connecting the LED 213 and the light incident surface 401b is disposed along the imaginary third line parallel to the first line and the second line. Thus, the optical refractor 401 can be separated from the camera unit 211 and the LED 213 of the portable terminal 210, and the exterior-optical apparatus 400 can be downsized.

The light guide 407 may have various shapes, but preferably has a flat plate shape. Referring to FIG. 6, the light guide 407 includes a transparent plate-like body 601 and a reflection plate 603 covering the outer surface of the body 601.

A first surface 601a of the plate-like body 601 is exposed at one portion of one surface of the plate 601 toward the LED 213, and a light incidence surface A second surface 601b is formed so as to face the first surface 401b. The reflection plate 603 is provided on the outer surface of the main body 601 so as to cover all surfaces except for the first surface 601a and the second surface 601b so that light in the main body 601 can be transmitted. Accordingly, the light emitted from the LED 213 is incident on the light guide 407 through the first surface 601a, is transmitted to the second surface 601b, and then emitted to the light incident surface 401b.

The first surface 601a may be formed in a basic shape (circular or square) for receiving a main portion of the LED light around the optical axis of the LED 213. The first surface 601a may include LEDs 213 and a camera unit 211, (For example, a rectangle) in which the basic shape extends in the longitudinal direction along the imaginary third line in consideration of the difference in the interval between the first and second imaginary lines, so that the difference according to the model can be overcome. Alternatively, a plurality of first surfaces 601a may be formed on the light guide 407 in consideration of the difference in the arrangement of the LED 213 and the camera unit 211 for each portable terminal device.

&Lt; Embodiment of light guide: Figs. 6 and 7 >

The first surface 601a of the light guide 407 may have a structure for refracting the light incident from the LED 213 and transferring the light toward the second surface 601b. 6, an inclined surface for refracting the light incident from the LEDs 213 toward the second surface 601b is repeatedly formed on the first surface 601a, so that a virtual third line is formed as a whole At least one tooth may be formed.

When the external-optical apparatus 400 is mounted on the portable terminal 210, the mirror 403 is mounted on the upper portion of the camera unit 211. As described above, since the distance between the camera unit 211 and the LED 213 differs for each portable terminal manufacturer, the light guide 407 compensates for the different interval. Therefore, in a case where it is designed so as to be able to receive substantially the light provided from one LED 213 with one or two teeth arranged on the first surface 601a, the light guide 407 The first surface 601a of the first surface 601a is provided with two or more teeth so that light can be input sufficiently even if the position of the LED 213 varies within a predetermined range. At this time, the teeth are arranged along the imaginary third line.

7, the light guide 407 can transmit the light emitted from the LED 213 to the second surface 601b even if the positions of the LEDs 213 are different from each other. The light emitted from the LEDs 213a, 213b and 213c at the first to third positions is refracted in the direction of the second surface 601b from the inclined surface 701 of the tooth, reflected by the reflector 603, Passes through the area of the first surface 601a while being repeatedly reflected from the inner surface, and then is reflected to the second surface 601b while being repeatedly reflected between the reflection plate 603.

On the other hand, in the first surface 601a, no saw tooth is formed at the edge portion farthest from the second surface 601b, and instead, the inner tooth 703 can be formed on the surface facing the edge portion. In FIG. 7, the light emitted from the LED 213d at the fourth position passes through the first surface 601a and is then reflected from the inner tooth 703 toward the second surface. 7, even if an air layer is formed between the outer side of the inner tooth 703 and the reflection plate 603 for the sake of processing, the total inner tooth 703 is totally reflected.

<Other Embodiments: FIG. 7>

According to another embodiment, the exterior-optical apparatus 400 of the present invention may further include a diffuser plate 409 between the light incident surface 401b of the light refractor 401 and the light guide 407 have. The diffusion plate 409 diffuses the light emitted through the second surface 601b of the light guide 407 so as to be uniformly incident on the light incident surface 401b.

In addition, other light must not interfere with the optical path from the exit surface 401c of the optical refractor 401 to the mirror 403. [ For example, in the case where the reflection plate 603 is made white, a matte black film or the like is attached to the outer surface of the reflection plate 603 so that light emitted from the emission surface 401c is reflected on the outer surface of the reflection plate 603 So that the phenomenon does not occur.

A diffusion plate 409 may be provided between the light incident surface of the light refractor 401 and the LED 213. The diffusing plate helps the light emitted from the LED 213 to be uniformly directed toward the entire light incident surface.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the invention as defined by the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention.

Claims (5)

An external optical apparatus capable of being attached to and detachable from the outer surface of a portable terminal having an LED and a camera unit on the same outer surface for acquiring a fingerprint image of a user,
A light refractor having a fingerprint contact surface and a light incident surface parallel to the outer surface, and an exit surface formed on a tilted front surface at a predetermined acute angle with the fingerprint contact surface to output a fingerprint image;
A mirror disposed above the camera unit to reflect the fingerprint image emitted from the exit surface to the camera unit to cause the camera unit to generate the fingerprint image;
A first lens and a second lens disposed between the exit surface of the optical refractor and the mirror to support close-up photographing of the camera section in spite of a focal distance set in the camera section operating in a fixed focus mode; And
And a housing accommodating the light refractor, the mirror, the first lens, and the second lens, and a diaphragm formed in the mirror to block light incident on the camera and support the focus of the fingerprint image Exterior optical equipment characterized by.
The method according to claim 1,
Wherein the first lens comprises:
The incident surface is flat and the opposite surface has a positive magnification,
And an upper portion thereof is disposed in an inclined state toward an exit surface of the light refractor, thereby reducing a keystone effect in which the fingerprint image is displayed.
The method according to claim 1,
The diaphragm is formed in the housing in the form of a pin hole,
Wherein a transparent dust-protective film is attached to the outer surface of the diaphragm.
The method according to claim 1,
When the light refractor is mounted apart from the upper portion of the LED,
And a light guide accommodated in the housing,
The light guide
A first surface opened to the outside so as to face the LED of the portable terminal, and a second surface arranged to face the light incident surface, and the light emitted from the LED and incident on the first surface is transmitted And the light is emitted to the light incident surface through the second surface.
A portable terminal having an LED and a camera unit on the same outer surface; and an external optical device mounted on an outer surface of the portable terminal,
The external optical apparatus includes:
A light refractor having a fingerprint contact surface and a light incident surface parallel to the outer surface, and an exit surface formed on a tilted front surface at a predetermined acute angle with the fingerprint contact surface to output a fingerprint image;
A mirror disposed above the camera unit to reflect the fingerprint image emitted from the exit surface to the camera unit to cause the camera unit to generate the fingerprint image;
A first lens and a second lens disposed between the exit surface of the optical refractor and the mirror to support close-up photographing of the camera section in spite of a focal distance set in the camera section operating in a fixed focus mode; And
And a housing accommodating the light refractor, the mirror, the first lens, and the second lens, and having a diaphragm formed therein for blocking the light emitted from the mirror and incident on the camera unit to support the focus of the fingerprint image,
The portable terminal includes:
The control unit controls the camera unit to generate the fingerprint image, and controls the camera unit operating in the auto-focus adjustment mode to operate in the fixed focus mode, thereby controlling the time required for generating the fingerprint image And a fingerprint acquisition control unit for reducing the fingerprint of the fingerprint image.

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