KR20030094634A - System of multiple focus using of slit in iris recognition - Google Patents

Abstract

PURPOSE: A multi-focus device using a slit of an iris recognition system is provided to fit a focus from some positions by equipping with the slit having a different thickness to the iris recognition system using a single focus lens, and inserting and removing it. CONSTITUTION: A CCD(Charge Coupled Device, 303) detects that a user approaches within a focal distance by using the straight LEDs(Light Emitting Diode, 301,302). Lights(304,305) are turned on if the CCD recognizes the user within the focal distance. An optical tube(307) keeps the focal distance and includes the lens(306) for picturing an iris image. The transparent slit(308) changes the focal distance by being inserted or removed between the CCD and the optical tube. A motor(309) inserts or removes the transparent slit by joining to the transparent slit in a hinge form.

Description

Multi-Focus Device Using Slit of Iris Recognition System {SYSTEM OF MULTIPLE FOCUS USING OF SLIT IN IRIS RECOGNITION}

The present invention relates to a multifocal device using slits of an iris recognition system. In particular, in an iris recognition system using a single focus lens, a slit having a different thickness can be provided to allow insertion or removal of a slit having a different thickness to focus at various positions. The present invention relates to a multifocal device using slits of an iris recognition system.

As is known, it is a system for security, crime prevention, and identity authentication. It goes beyond the existing contact or contactless card system to recognize human fingerprints, or to authenticate identity through iris recognition and access to specific places or access to specific information. Systems to allow or deny such have been prevalent.

Among them, the iris recognition system has a high recognition rate and more accurate recognition than the fingerprint recognition. The iris recognition system is a system that authenticates an individual by comparing a characteristic pattern of an iris with an image processing technology in an iris image captured by a video camera and comparing it with previously registered iris data.

In the conventional iris recognition system, an iris image extraction method includes a method of focusing by directly moving a user by looking at a screen and locating a face and eyes using multiple cameras, and taking an iris image. In addition, a method of measuring a distance from a user using a distance sensor and automatically focusing a camera and obtaining an iris image has been proposed.

1 is a view showing the configuration of a general iris recognition system, the operation of the iris recognition system with reference to the bar shown in FIG.

When the user approaches the iris recognition system, the distance measuring sensor 109 measures the distance to the user, and the controller 105 receives the distance measurement value obtained through the driver 107 to operate the distance measurement value. Determine if you are in range.

If the user is within the operating range, a control signal is sent to the driver 107 to prepare to extract the iris image. The driver 107 sends an active signal to the external indicator 108 to inform the user that the system is operating. Accordingly, when the user places the eye on the optical axis of the camera 103 through the optical window 101, the cold mirror ( 102 blocks visible light and passes infrared light. In addition, by displaying the part where the iris should be positioned, the user can check whether the eye is located on the optical axis of the camera 103.

The controller 105 receives the distance measurement value from the distance measurement sensor 109 to the user, and calculates the zoom and focus values of the camera 103 using the distance measurement value to perform zoom in / zoom out and focusing control. Perform. Thereafter, the controller 105 allows the driver 107 to capture the iris image according to the distance measurement value, and the photographed iris image is signal-processed in the frame grabber 104 for iris image analysis, and the processed iris is processed. The image information is stored in the DB 110 (database), and with the stored information, the control device 105 performs iris recognition to determine whether the user is authenticated.

In addition, when using a single light source may cause reflection problems caused by glasses, in order to solve this problem by using a plurality of LED lights, such as the left and right, the position of the lights to avoid secondary reflection by the glasses. The image was acquired by changing.

Here, the photographing lens of the iris recognition system of FIG. 1 uses a zoom / focus lens to automatically recognize a distance from a user and capture an iris image. However, in the case of using the zoom / focus lens, since the complexity and the precision of the mechanism and the lens are required, the price is expensive and the bulky disadvantage occurs, which causes a problem of commercialization.

On the other hand, Figure 2 is a view schematically showing the configuration of a single focus lens unit of the conventional iris recognition system. As shown therein, when approaching the iris recognition system, the left and right straight LEDs 201 and 202 are arranged to measure whether the iris recognition system is approached within a recognizable distance; A charge coupled device (CCD) 205 for detecting an approach within a recognition distance of the user; Lights 203 and 204 that light up to capture an image; A barrel 206 for maintaining a focal length for taking an iris image; It is composed of a lens 207 for converging the light to pass through the light maintained the focal length to form a focus.

Here, the iris recognition system having the short focus lens of FIG. 2 is mechanically simpler than the iris recognition system using the autofocus lens of FIG. It can be widely used.

However, since the iris recognition system having the single focal length lens unit configured as shown in FIG. 2 is determined to have a single focused distance, it is difficult for the user to be accurately focused within the distance, so that the user can accurately enter the focal length. This problem occurs.

The present invention has been made to solve the above problems, and in particular, in an iris recognition system using a single focal lens, the slits having different thicknesses can be inserted or removed so that they can be focused at various positions. An object of the present invention is to provide a multifocal device using slits of an iris recognition system.

1 is a view showing the configuration of a general iris recognition system.

2 is a view schematically showing the configuration of a single focus lens unit of the conventional iris recognition system.

3 is a view schematically showing the configuration of an embodiment of a multifocal device using the slit of the iris recognition system according to the present invention.

<Description of the symbols for the main parts of the drawings>

205, 303 --- CCD 206, 307 --- Tube

207, 306 --- Lens 308 --- Transparent Slit

309 --- motor

In order to achieve the above object, the multifocal device using the slit of the iris recognition system according to the present invention,

A CCD for detecting an approach within a focal length of the user using a straight LED;

A barrel for maintaining a focal length by arranging a lens for photographing an iris image with a predetermined length;

A transparent slit for changing a focal length while being inserted or removed between the CCD and the barrel;

It is characterized in that it comprises a motor that is hingedly coupled to the transparent slit and drives the transparent slit to be inserted or removed.

In particular, the transparent slit is characterized by selectively inserting or removing the slit according to the focal length by providing two transparent slits having different thicknesses.

According to the present invention, in particular, in an iris recognition system using a single focal lens, the slits having different thicknesses can be provided so that they can be inserted or removed so that they can be focused at various positions.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a diagram schematically illustrating a configuration of an embodiment of a multifocal device using slits of an iris recognition system according to the present invention. As shown therein, the CCD 303 detects an approach within a focal length of the user by using the straight LEDs 301 and 302; Illuminations 304 and 305 which are turned on when the CCD 303 is recognized within the focal length; A barrel 307 including a lens 306 for capturing an iris image and maintaining a predetermined focal length; A transparent slit (308) for changing a focal length while being inserted or removed between the CCD (303) and the barrel (307); And a motor 309 coupled to the transparent slit 308 in a hinged manner to drive the transparent slit to be inserted or removed.

The distance between the camera and the user is measured by using the straight LEDs 301 and 302, and the CCD 303 detects whether the user approaches the recognition distance based on the measured distance value.

When detected within the recognition distance by the CCD 303, the lights 304 and 305 are turned on to capture the iris image, and are turned on while changing the illumination depending on whether the image is reflected to focus the image.

The barrel 307 is provided with the lens 306 by maintaining a predetermined length, which is to maintain the focal length at a certain distance, and the actual focal length at a predetermined magnification with the object based on the focal length. Get to know.

Therefore, the constant magnification value of the length between the barrel 307 and the lens 306 becomes the focal length with the real object, and the actual focal length also changes as the length thereof changes. Here, the focal length is simply changed because it is structurally complicated and difficult to implement the focal length differently while varying the length of the barrel and the lens.

Therefore, when the focal length with the user does not match, the transparent slit 308 is inserted between the CCD 303 and the barrel 307 to change the focal length. If the focal length between the lens and the object is 40 cm, when the transparent slit 308 is inserted, the focal length increases to 45 cm.

In other words, the principle that the focal length is far away when the transparent slit is inserted is conceived according to the change of the refractive index. Here, the material used as the transparent slit 308 may be made of plastic or glass, but the refractive index should be higher than that of air.

The transparent slit 308 has thin slits and thick slits, respectively, when the thin slits are inserted, when the thick slits are inserted, when the two thin slits and the thick slits are inserted, and the slits are both When removed, the focal length will vary.

If the original focal length between the barrel 307 and the lens 306 is 60 mm, the focal length when the thin transparent slit is inserted is 61 mm and the focal length when the thick slit is inserted. 62 mm, and the focal length is 63 mm when both the thin slit and the thick slit are inserted. Here, of course, the constant magnification value of the focal length becomes the focal length with the real object.

On the other hand, inserting the transparent slit 308 suitable for the corresponding focal length with the user allows the CCD 303 to detect the focal length and selectively insert the corresponding transparent slit 308. Here, the driving of the transparent slit 308 is inserted or removed by driving of the motor 309 hingedly coupled to the transparent slit 308.

Therefore, when the user approaches the recognition distance and the focus distance is too close to focus, the transparent slit considering the focus distance at the position is inserted to focus by lengthening the focus distance.

On the other hand, in the above embodiment has been described as using two transparent slits, the slit may be further provided to vary the focal length.

As a result, according to the present invention, since the range of the focal length becomes longer, the user can focus without accurately approaching the focal length.

Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

As described above, the multifocal device using the slit of the iris recognition system according to the present invention has a slit having a different thickness, in particular in an iris recognition system using a single focal lens, so that it can be inserted or removed at various positions. You can focus.

Claims (2)

A CCD for detecting an approach within a focal length of the user using a straight LED; A barrel for maintaining a focal length by arranging a lens for photographing an iris image with a predetermined length; A transparent slit for changing a focal length while being inserted or removed between the CCD and the barrel; And a motor coupled to the transparent slit and hinged to drive the transparent slit so that the transparent slit can be inserted into or removed from the slit of the iris recognition system. The method of claim 1, The transparent slit is provided with two transparent slits having different thicknesses, thereby focusing by selectively inserting or removing slits according to a focal length.