KR100626936B1 - An identification apparatus for providing an information signal distinctive of the iris of an individual's eye, and an optical apparatus - Google Patents

Abstract

An optical device is disclosed for recording light B reflected from one or more user facial features, while other images viewed by the user or visible light A from display 170 are captured by the user while the image is captured. Passing 110 and if a conventional device of this type is arranged, the specific portion of the light reflected from the user's face does not enter the image capturing device in the device, and the above-described embodiment is the movable iris pattern capturing device 12. In which the near infrared ray B is directed towards the user's eye 110 from the point of reflection back into the device, and visible light A from the LCD display installed at the rear of the device travels from the device to the user's eye 110 In the device, the hot mirror 145 is a device in which the near infrared rays B reflected from the user's eyes are directed toward the camera unit 135 and radiate from the display 170. That it does not particularly weaken the light (A) it is an optical device according to claim.

Description

FIELD OF THE INVENTION IDENTIFICATION APPARATUS FOR PROVIDING AN INFORMATION SIGNAL DISTINCTIVE OF THE IRIS OF AN INDIVIDUAL'S EYE, AND AN OPTICAL APPARATUS}

The present invention relates to a method and apparatus for personal identification. This is particularly useful for devices that need to capture an image of the front of the eye and present the image of the eye at the same time. The device is used in an authentication device for capturing an image of a user's iris.

Background of the Invention Devices are known for providing a display by looking into a human eye to simultaneously capture an image of the human eye. For example, it is a System 2000 EAC (trade name) authentication apparatus of IriScan Inc. Another example is a porosimetry device known from WO 92/05736.

The former device is composed of an iris type capturing unit and an identification code generating unit. The iris form capture unit has a housing having two holes. The infrared illumination source is arranged for irradiating infrared light and visible light through the first hole for infrared light to illuminate the human eye. The camera installed in the device is arranged such that the range of view is as if through the second hole. When using the device, the person sees through the second hole in the display which reproduces the image shown by the camera. At the same time, light from the illumination source is reflected from the human eye through the second hole and towards the camera. The display places a person in the middle of the camera's field of view and in focus.

Indeed, in order to successfully capture an image of the user's eye, the user may know that the eye should be positioned at a narrow range from the device.

Retinal centers and fovea-centered eye fundus are known from European Patent Application No. 0 126 549. The device is complex and bulky because it uses scanning optics to examine the base of the eye (retina and choroid).

1 illustrates a personal computer arranged for remote access to a separate computer.

2 is a schematic diagram illustrating an iris imaging device.

3 is a schematic diagram illustrating a possible hardware structure for an imaging device.

4 is a flowchart of an image capturing and encoding process;

5A and 5B are diagrams illustrating a display provided to a user with eyes positioned accurately and incorrectly, respectively.

They have two problems raised by the present invention, which provide an apparatus for providing the information signal characteristic of the eye,

A housing having an inlet window;

An illumination source mounted to the housing and operable to illuminate the eye of the pupil outer region;

An image capture device disposed within the housing and in optical communication with the inlet window, the image capture device operative to provide an image signal indicative of one or more characteristics of the front face of the eye upon light incidence of the illumination source reflected from the eye; And

Consists of optical devices,

Visible light then travels through the optical device along the first optical path to the eye to provide a visible image seen by the eye, and light from the illumination source reflected from the eye is directed to the optical device along the second optical path. Proceed to the image capture device via;

The optical device is arranged to interact with at least one of the visible light and the illumination light such that all illumination light of a given type further travels towards the image capture device along the second optical path, with the principal portion of the visible light being the first. 1 Follow the light path toward your eyes.

As used herein, the terms "optical" and "light" relate to the electromagnetic radiation of infrared, visible and ultraviolet radiation in the electromagnetic spectrum with wavelengths ranging from 10 nm to 1 mm.

Since certain types of illumination light mostly reach the image capture device, the present invention has a number of advantages.

First, because more light reaches the image capture device, the aperture of the optical arrangement in this regard can be reduced. This results in an increase in the focal length of the image capturing device. Therefore, the force of the position where the eye should be placed in the device has been loosened in order to provide a sufficiently focused image.

Second, the exposure time may be reduced, thereby reducing the need for a person to stay to capture the image.

Third, the present invention also allows a satisfactory image to be captured in a situation where the light captured by the image capture device is at least possible. This is advantageous because it considers safety and limits the light traveling towards the eyes. It is also useful to reduce the power required for the device, which is particularly advantageous for mobile devices powered by batteries.

Those skilled in the art can realize the above advantages individually or in combination. In general, providing more light to the image capture device improves the quality of the resulting image.

The increase in the user light of a certain type incident on the image capture device (compared to the conventional device) leads to any improvement in performance. However, it is desirable that at least 75% of the user light of a given type travel towards the image capture device along the light path.

In addition, increasing the brightness of the display by allowing visible light to be weakly directed towards the user. This means that the amount of power consumed by the device is reduced; It is a particularly useful property for mobile devices. More than 75% of the visible light is further directed towards the user along the light path.

The characteristics of the front of the eye may be the iris, cornea, sclera, or eyelids or a combination of two or more thereof.

The device may be applied to his eyes presented by the user or to the eyes of another person or animal. Alternatively, the device can be fixed in a suitable place and needs to center its head in order to illuminate the eye.

In some cases, the visible image seen by the eye can simply be seen through the device. In other cases, the display means overlay some display that has already appeared to provide a visible image or to provide a visible image. This has the advantage that information is provided to the eye when using the device. In another aspect, the user image capture unit may be activated while eye information is shown on the display.

One example of using a display relates to a display device that represents an image received by the image capture device. This has the advantage that a person moves his head to improve the quality of the captured image.

In a preferred embodiment, the visible light is directed towards the eye and the light is directed towards the image capture device having a different spectrum. This does not mean that the light is directed towards an image capture device that needs to be present outside the visible region of the electromagnetic spectrum. For example, a display can be made using red, blue and green LEDs that emit light in a narrow spectral band, and the image capture device accepts visible light outside these bands, but is located within the visible portion of the electromagnetic spectrum. .

In an advantage of this embodiment the optical device comprises a wavelength selective reflector for allowing different paths and for effectively reflecting the light or the visible light of different spectra. The reflector is economical and its use allows the parts of the device to be conveniently located. For example, the selectivity can be obtained using dielectric coatings or metal coatings.

Since illumination light is incident on the eye, the device will be more convenient in use if any type of light consists of invisible light.

Preferably any light of a given type consists of near infrared light (having a wavelength between 700 nm and 3 μm). This can generally result in distortion of the image because only hot objects emit large amounts of light in the electromagnetic spectral region.

Another advantage is obtained when the optics are configured as "hot mirrors". Hot mirrors are devices that operate to reflect all infrared light while allowing a path of visible light. This is feasible to those skilled in the art who readily use “cold mirrors” (allowing infrared paths and reflecting all visible light).

An advantage of using an illumination source is that the direction of light used to form the spectrum and the image can be adjusted.

A particularly useful embodiment is when the device is designed to capture an image of the iris. Light that affects the eye can be invisible and make the device convenient to use. Moreover, by increasing the amount of light incident on the image capturing device, the density of illumination light can be reduced. In other words, this makes the device more convenient to use.

In some embodiments, the device further comprises a transmitting device arranged to be moved by the user to an operating position and operative to transmit the information signal derived from the image signal to a remote device. The transmission device may be a wireless transmission device that provides RF, ultrasonic waves, and infrared rays in communication with the remote device. In this case, the use of an optical device is particularly advantageous in reducing the required power of the device.

Specific embodiments of the invention will be described in detail by way of example only with reference to the accompanying drawings.

1 shows that a user's personal computer (PC) 10 is added to a regular input / output device and associated with an interface, including an infrared receiver 22, a transmitter 23 and an infrared signal interface card (not shown). . The additional element enables data communication between the user PC 10 and the image capture device 12.

The user PC 10 is connected to the intermediate routing computer 18 via the modem 14 and the telecommunications line 16, which routes signals from the user PC 10 to the server 20. The server 20 has storage means, for example, belonging to a company and containing a file which is a specific value of the company. However, when the user of the PC 10 is an employee of the company, the communication link device between the PC 10 and the server 20 has the advantage of allowing the employee to work at home.

2 shows the image capture device in more detail. The device has a T-shaped housing 125 with an extended horizontal barrel section 130 and a handle section that depends from below the barrel 130 from an intermediate position of the end. The handle section is empty in the middle and the bottom end is closed. The charge coupled device (CCD) camera 135 is located at the inner base of the handle section. The camera is a monochrome camera having the same sensitivity to near infrared light and visible light. A connection (not shown) is provided to contact the rear of the liquid crystal display (LCD) 170 located inside the front end of the barrel 130 from the output of the CCD camera. The handle portion also includes a suitable electronic circuit 180 included in the housing (shown in greater detail in FIG. 2).

The window 120 is formed at the rear end of the barrel 130. The eye cup 115 is in contact with the periphery of the window 120 and the rear end of the barrel. The eye cup 115 acts as a means for aligning the user's eyes with the window 120 and as a means for minimizing the amount of ambient light entering the device.

'Hot Mirror' 145 (eg, sold under catalog number 35-6681 by Ealing Optics of Greylaine Rd, Watford, U. K.) is positioned to face CCD camera 135. The mirror 145 is tilted 45 ° forward and downward with respect to the longitudinal axis of the barrel 130. The mirror is formed from a glass slide having a coating layer of dielectric material on the underside. The other side of the glass slide is coated with an antireflective coating layer 147. Dielectric material coating layer 146 effectively reflects about 80% of infrared light and allows passage of about 90% of visible light.

The near infrared light emitting diode (LED) 150 is positioned inside the barrel 130 between the mirror 145 and the eye cup 115 and is operated to illuminate the user's eyes. The source is located on the back contact surface of the screen 155 to prevent light propagating directly from the source 150 to the camera 135 via the mirror. The barrel 130 also includes an internally mounted optical indicator 185 that includes red and green LEDs positioned to be within the user's viewing area.

The infrared (IR) transmitter 160 and receiver 162 are located in front of the housing 125, aligned with the longitudinal axis of the barrel 130, and the trigger button 165 transmits and / or transmits the image to the user PC 10. Or on the handle portion which is controllable by the user when captured.

The overall size of the device depends primarily on the openness and comfort of the eye 120 and the ease of use required by the device user. The hardware of the device is designed as a single ASIC chip, and the size of the chip is not a limiting factor on the size of the device. Known CCD cameras also have millimeter ratings (or tens of millimeters if the printed circuit board installation size is considered) and are not a limiting factor in device size.

3 shows a possible hardware structure arrangement of the device. As already mentioned, the processing hardware is preferably enhanced with a single application specific integrated circuit (ASIC). The device is controlled by the processor 200 which drives the software of the ROM 205. Processor 200 is coupled to ROM 205 via bus 210, to a block of RAM 215, and to input / output (I / O) controller 220. The RAM is large enough to hold at least one captured eye image. The I / O controller 220 is connected to an IR transmitter 160 and receiver 162, CCD camera 135, trigger 165, near infrared LED 150 and light indicator by suitable circuitry and drivers (not shown). 185. The entire device is powered by a suitable battery (not shown).

The processor 200 is sensitive to signals received by the trigger 165, the IR receiver 162 and the CCD camera 135. The processor also controls the IR transmitter 160, the near infrared LED 150, the CCD camera operation and the light indicator 185.

The flow diagram of FIG. 4 shows one possible procedure for image capture, processing and transmission characteristics of a user effective system. The procedure includes an encoding process for improving the safety level. The encoding system uses a private key (known as the receiver of the decrypted data) for decrypting the data and the "public key" as the encoded data.

In step 300, the imaging device 12 is in a state where the trigger's malfunction is waiting to start the processor. The user generates a signal received by the processor to press the trigger and take the imaging device 12 into the eye. The processor then controls the IR transmitter 160 to send a signal to the user PC 10 for initial communication at step 305. Accordingly, the user PC 10 sends a return message to the image device 12.

If the return message is not received by the imaging device 12 in step 315, for example as a result of the user PC 10 not receiving the first signal, the red LED of the light indicator light in step 320 indicates a failure and Pressing the trigger 165 again informs the user of the restart of the processor.

If a return message is received at step 315, the signal from user PC 10 includes the selection of an iris code that formats the public encoding key and the image device 12 that should be used for successful transmission. Multiple public encoding keys and multiple iris code algorithms from the selection are stored in RAM (or ROM) of the image device 12. User PC 10 also transmits time stamps and data to imaging device 12.

The information of the return signal sent by the user PC 10 is stored in the RAM of the image device 12 for the next access.

Next, in step 325 the processing means means a signal to a camera that captures one or more images. Image data captured by the CCD camera 135 is sent via the connection described above to the display 170 as a display reflecting the image currently received by the CCD camera 135. Light from the display travels along the path A to the user's eye 110 through the hot mirror 145. The light is only slightly weakened by the mirror (about 90% of the transmitted visible light). If the user's eyes are correctly fitted to the window 120, he or she may see a display similar to that shown in FIG. 5A. However, if the user's eyes are not correctly aligned he or she may see a display similar to that shown in FIG. 5B. The user can change his eye's position relative to the window.

The near infrared LED 150 illuminates the user's eye 110 and the light from the LED travels along path B, ie, from the infrared LED 150 to the user's iris when reflected towards the hot mirror 145. Upon reaching the hot mirror, 80% of the near infrared light is reflected towards the CCD camera 135 by the surface coating layer 146.

The captured image is stored in RAM 135. In step 330 the processing means determines whether the stored image or image is suitable for encoding. If no suitable image is found, the processor signal is sent to the camera to recapture the image.

The image capturing step includes a control step of the near infrared LED 150. The near infrared LED 150 is connected to a control loop so that the processor 200, for example, the user's iris color: light blue iris reflects more light and needs less illumination than the dark brown iris. Accordingly, the light density of the source 150 can be changed. Multiple successive captured images, similar to video sequences, are needed for software and processors to determine the optimal illumination for the eye before a suitable image is obtained.

Image capture needs to be synchronized with a pulse of light to ensure proper illumination, but it is more desirable to pulse the near infrared LED 150 than to use a continuous source. Pulsed light has the advantage of exposing the user's eyes with less optical radiation. Pulsed sources also use less energy.

Multiple image capture can overcome problems such as user flicker at one point when an image is captured. Known digital signal processing techniques can be used to reject inappropriate images and to produce the best image.

When a suitable image is obtained, the image data is derived from the RAM 215 and proceeds to form the iris code in step 335 using the iris code generation algorithm selected by the user PC 10 in step 315. Examples of algorithms are disclosed in US Pat. No. 5,291,560. Iris code results are stored in RAM.

The processor 200 encodes the iris code in step 340 using the public key selected according to the time stamp and data provided by the user PC 10 in step 315. The data result is stored in RAM 215. The coded and encoded data is transmitted by the IR transmitter 160 to the user PC 10 in step 345.

The image capture, processing, and encoding steps are completed without the interference step of storing data in RAM, i.e. processing proceeds significantly to speed up the operation of the device. However, the processing is more expensive and requires more complex electronics.

As a result, if the data is successfully received by the user PC 10, the user PC 10 sends a 'success' signal to the imaging device 12 in step 350. The processing means thus causes the user to turn on the green LED of the light indicator 185 at step 360. After repeated failed data transfers, for example after five attempts, the red LED of the light indicator 185 turns on at step 355, requiring the user to restart the entire procedure.

A simpler process than the one described above relates to an image device 12 defined for using a plurality of common encoding keys. The selection can be made using a pseudo random number generator in the imaging device 12. If each public key has an index reference, each reference can be included in the unsigned form to represent the encoded data on the user PC 10 in which the public key was used, and the private key can be used for decryption. . The extension of the device is that a new set of public keys is downloaded from the user PC 10 to the image device 12 and is successful at each time. Other encoding possibilities are possible to those skilled in the art.

In practice, near-infrared LED 150 is controlled by processor 200 (not shown but via suitable electronic circuitry). The processor 200 controls according to its control software or according to a signal received from the user PC 10 when the infrared LED 150 is turned on to illuminate the eye. The processor also determines when the image capture process occurs under illuminated conditions.

Instead of the hot mirror used in the above embodiment, a cold mirror may be used. The cold mirror has the same position and orientation as the hot mirror, but with a different coating layer on the backside. The coating allows passage of near infrared light to effectively reflect most of the visible light. Another alternative made in the above alternative embodiment is to exchange the CCD camera and the LCD display.

The above-described embodiment will be described how to provide an optical device wherein more user light is directed towards the camera than the known device. In this embodiment, the near infrared LED 150 has the advantage that it does not need to be as bright as in other methods. This means that the battery lasts longer in the device and less light is directed towards the user's eyes and makes the device safer to use. If the brightness of the near infrared LED 150 is maintained at the same level as the known device, a better image of the user's eye can be obtained. The increased light to the CCD camera has a reduced electronic noise effect compared to known devices.

Although the above embodiment relates to a movable device, the present invention may be applied to a fixed device. For example, the disclosed optical device can be integrated into a known System 2000 EAC (trade name) authentication device. If so, the optical aperture coupled to the camera in the device is blocked, thereby increasing the camera focal length and making the device easy to use.

In addition, unlike the unit source, the problem of reflection from the user's eyes of the light source is reduced. The unit source is positioned to minimize reflections from the cornea of the user to wash away the user image. The human cornea, however, has high reflectivity and strongly reflects light from other sources. Usually the source causes unwanted reflections from the cornea and thereby worsens the performance of the device. By installing the above-described optical system in a System 2000 EAC ™ device, the visible reflection effect can be reliably reduced. Therefore, the combination of the above described optical devices provides an improved implementation in the presence of external light sources with visible light in their output range.

Optical devices similar to those described above may be coupled to an automated teller machine (ATM). The ATM needs to match the form of the depositor's iris with the registered iris before allowing money to be withdrawn from the account. In other words, the present invention is particularly useful because it increases the focal length of the device, making it easier to use ATM.

Claims (9)

An identification device for providing an information signal for identifying an iris of an individual eye, A housing having an entrance window; An illumination source mounted on the housing and illuminating the eye of the pupil outer region; An image capture device mounted in the housing and in optical communication with the inlet window, the image capture device providing an image signal indicative of one or more features of the front face of the eye upon light incidence of the illumination source reflected from the eye; And Includes a wavelength selective reflector, Visible light travels to the eye via the wavelength selective reflector along the first light path to provide a visible image seen by the eye, and light from the illumination source reflected from the eye is directed along the second light path. Proceed to the image capture device via a wavelength selective reflector; The wavelength selective reflector is arranged to reflect one of the visible light and the illumination light such that all illumination light of a predetermined spectrum travels towards the image capture device along the second optical path, and the principal of the visible light of another spectrum The wealth further travels toward the eye along the first light path, At least one feature of the front of the eye comprises an iris pattern of the individual. The method of claim 1, The visible light passes through the eye along the first optical path and proceeds without attenuation. The method according to claim 1 or 2, Further comprising display means for providing at least a portion of the visible image. The method of claim 3, wherein And said display means displays an image captured by said image capture device. The method according to any one of claims 1 to 4, And the predetermined type of light comprises invisible light. The method of claim 5, Iris identification device, characterized in that the type of light is composed of near infrared. The method of claim 6, The optical device comprises a hot mirror. The method according to any one of claims 1 to 4 and 5 to 7, The device is moved to an operating position by a user; And the device further comprises a transmitting device for transmitting the information signal derived from the image signal to a remote device. In an optical system, A user image capture device for capturing a user image of one or more facial features of the user according to incident light reflected from the user; And Including an optical device, Visible light travels to the user's eye via the optical device along a first optical path to provide a visible image viewed by the user, and user light reflected from the user passes through the optical device along a second optical path Proceed to the image capture device; The optical device is arranged to interact with at least one of the visible light and the user light such that all user light of a given type further travels towards the image capture device along the second optical path, with the principal portion of the visible light being the first. Proceed further towards the user along the 1 light path; The predetermined type of light is different in spectrum from the visible light; The optical device includes a wavelength selective reflector effective to reflect the visible light or other spectrum of light and to allow passage of each other; Wherein said one or more facial features comprise an iris pattern of a user.