JP2002533848A - Person identification device - Google Patents

Abstract

SUMMARY OF THE INVENTION The present invention provides at least one light source for illuminating and / or transilluminating the front region of a finger using light pulses, and at least one fiber optic finger for capturing an optical image of a fingerprint. At least one of the following: a mounting surface, the optical image being transferable to the at least one sensor unit through the finger mounting surface, wherein the optical image is convertible to an electrical signal within the sensor unit. The invention relates to a device for identifying a person using two fingerprints, wherein at least one light source is arranged side by side on the finger placement surface, and in which case the light from the light source is A light path which is radiable in the direction of the mounting surface opposite to the sensor unit and on the side provided for mounting the front region of the finger, and in which case it is radiated from at least one light source; The length and / or intensity of the scan can be controlled according to ambient light conditions.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a device for identifying a person using at least one fingerprint, at least one light source for illuminating and / or transilluminating the front region of the finger with light pulses. And-at least one fiber optic finger placement surface for acquiring an optical image of the fingerprint, through which the optical image can be transferred to the at least one sensor unit. The optical image can be converted into an electrical signal in the sensor unit, in which case at least one light source is arranged side by side on the finger rest surface, and The light from the light source can be emitted in the direction of the finger placement surface, opposite to the sensor unit, on the side provided for placing the front region of the finger. This type of device is used to record and process fingerprints and can be used in any area where personal identification is required.

For example, in this context, mention may be made of the areas of computer technology, admission systems, forensic sciences, medical care, general and protection systems in the banking and financial areas. In the field of devices for identifying a person using at least one fingerprint, a system is known (WO 98/27509), which has a light source which is arranged above a finger to be transilluminated. Since the finger is placed on the finger placement surface, the finger is located between the light source and the finger placement surface. The light emitted from the light source passes through the front region of the finger, after recording information about the fingerprint, reaches the sensor unit disposed below the finger placement surface through the fiber of the finger placement surface, After that, it is analyzed by an evaluation unit arranged downstream of the sensor unit.

However, in connection with the direct optical method described above, a person to be identified using the fingerprint inserts a certain finger into a hollow space or an opening between the light source and the finger placement surface. What has to be done has proven to be a significant problem. This is very psychologically uncomfortable and, according to experience, makes the barrier to using devices based on this field very high. The person to be identified needs to be inserted, so to speak, into a hollow space where the exposed body part in the form of the front area of the finger cannot be visually perceived, and therefore the fear is increased. Not uncommon.

[0004] The above-mentioned problem of psychological overcoming is a problem in devices based on this field for inputting irregular patterns (see DE 44 04 918 A1).
Not given. The device has a bundle of light guides, with input and output surfaces formed at each end. The illuminating device outputs the illuminating light such that a light pattern is formed according to the convex portion of the target that contacts the input surface and according to the concave portion of the target that does not contact the input surface. An incident surface that does not come into contact with the concave portion of the object when the incident angle of the irradiation light is adjusted, which is larger than the critical angle at the interface between the core portion of each light guide fiber of the bundle of light guides and air, and is adjusted. It is possible to obtain a total reflection at, and not at the entrance surface in contact with the convex part of the object, which results in reflected light having a light pattern corresponding to an irregular pattern . The obtained light pattern is input to a photoelectric converter via an output surface, and is converted into electrical information by the photoelectric converter.

[0005] However, the device known from DE 44 04 918 A1 has proven to be unfavorable, as long as it operates with light of constant intensity and is based on the principle of disturbed total reflection. As a result, the type of illumination and the light guide are fixed and not flexible. The reason is that if the illumination intensity of the ambient light is greater than about 3,000 lux, a very rapid saturation of the photoelectric converter will result, so that conventional devices can no longer provide reliable results. is there.

[0006] Based on the above-mentioned drawbacks and unfamiliarity, it is an object of the present invention to provide a person identification device based on this field, which is capable of illuminating the front area of the finger with sufficient and reliable results, In that case, the device for further identifying the person can be completely peeped,
Be developed so that the person to be identified can follow the process of person identification, be transparent, and always have a certain good and reliable result regardless of the ambient lighting conditions It is.

This object is achieved by a device according to the preamble of the main claim, in which the length and / or intensity of the light pulse emitted from at least one light source is controllable according to the ambient light situation, according to the teachings of the present invention. It is solved by being. Thus, in a manner not foreseen by a person skilled in the art, adaptive light control (= ALR or ALC = “adaptive light control”), ie a kind of “intelligent light control”, is provided, whereby, for example, changing rooms The disadvantages of changing ambient light conditions, such as illumination or changing sun incidence, can be compensated for by adapting the device according to the invention or the algorithm controlling the invention to the respective light conditions.

For this purpose, in a device according to the invention, at least one control means for controlling the length and / or intensity of the light pulse is provided in a preferred manner. By means of this control means, a continuous or temporary measuring method can be carried out, whereby a good image quality can be determined permanently, and the contrast and the depth of focus as required by the measuring method. Optimum saturation with a short light pulse can be obtained, tailored to the time, where the short light pulse is precisely adjusted to the amount of light actually required in its length and / or intensity .

According to a preferred development of the invention, the control means comprises: at least one detection module for detecting an ambient light situation, wherein the detection module is a sensor At least one for determining the length and / or intensity of the light pulse in accordance with the ambient light situation detected by the detection module, which can be formed integrally with the unit and / or as part of the sensor unit; An evaluation module, wherein the evaluation module is integrated with at least one evaluation unit and / or
Alternatively, it can be formed as part of an evaluation unit, which evaluation unit is preferably arranged downstream of the sensor unit; and a threshold defined for controlling the length and / or intensity of the light pulse. At least one memory module for storing a value, wherein the memory module can be formed integrally with the at least one memory unit and / or as part of the at least one memory unit, The memory unit is preferably arranged after the sensor unit.

In this case, the working method and the function of the control means are, for example, that the detection module detects the respective ambient light conditions, the ambient light conditions are evaluated and analyzed in the evaluation module, and the memory is stored in the evaluation module. It is configured to be compared with a predetermined threshold value stored in the module.

Then, according to the result of this comparison, the light source, which is connected to the control means and in this case, in particular, to the evaluation module, is driven by the control means, in which case the length and / or the intensity of the light pulse emitted from the light source is determined Adapted to the required ambient light situation.

[0012] Thereby, the light pulse can be of any kind in ambient light, both in length and in intensity.
Provides the required light incidence for eg strong sunshine, weak sunshine, twilight, diffused light, gas light, moonlight, artificial lighting ...) and thus provides rich and sharp fingerprint contrast It can be dynamically and adaptively configured to obtain images.

In particular, with adaptive light control, illumination intensities from zero lux to about 40,000 lux can be realized, in which case the latter illumination intensity values approximately correspond to direct solar incidence. . The result that can be obtained by this adaptive light control is to have a contrast and depth of focus increase of up to about 80% over conventional illumination systems with continuous light, in which case the type of light according to the invention The control varies substantially in all possible light situations because the light control can adjust and provide the amount of light required in the event of changing lighting conditions within a time range of less than 100 ms. There is an advantage that no image quality can be obtained.

An inventive advantage of the device is therefore seen in “intelligent driving”, which adjusts the amount of incident light to some extent automatically and around the object to be illuminated, ie in the front area of the finger. Since the circumference is calculated and provided separately for each region, over- or under-illumination is reliably eliminated with close probability.

In this connection, a lighting unit, such as provided in a conventional device for recognizing a person using at least one fingerprint, for example, also outputs the amount of light produced thereby in relation to the object. Is not done, ie 1
A 0 millimeter thick object has the disadvantage that it is illuminated with the same amount of light as a 5 millimeter thick object, thereby also causing blurring and partial over-illumination.

[0016] In contrast, the present invention provides a method that is independent of the thickness of an object, which is considered to have more or less strong light-guiding ability or more or less strong power of reflection, especially in other respects, and that the object is noisy. Enables uniform illumination of the front area of the object, for example a finger, whether illuminated from the front, from the side and / or from behind. Thus, in the present invention, at what angle and at what point the light is incident on the object to be illuminated plays no role, only the additionally required light duration and / or intensity. Is controlled individually for each region.

The advantage of this adaptive light control is that fingerprints can ultimately be determined without substantial changes in illumination time, while maintaining the full range of contrast and depth of focus. Preferably, the control means for adaptive light control comprises at least one logic element and / or at least one logic circuit, in particular at least one standard logic element, or at least one programmable logic element (F
It is formed as PGA (field programmable gate array). Alternatively or additionally, the control means comprises at least one digital signal processing unit (DSP = digital signal)
It can be formed as a processor and / or as at least one microcontroller.

As already mentioned above, the control means provided for providing adaptive light control are, according to a preferred embodiment, at least one detection module, at least one evaluation module and at least one memory module. have. If the detection module is formed in an effective manner integral with the sensor unit and / or as part of the sensor unit, the light-sensitive surface and / or the light-sensitive layer of the sensor unit may be partially automated by adaptive light control. In particular—and especially for each region thereof—requires itself the required light quantity, especially if the evaluation module of the control means is formed integrally with the evaluation unit and / or as part of the evaluation unit. Works in a preferred manner.

Conventional devices for identifying a person using at least one fingerprint cannot do this. This is because known devices of this kind—as they can—adjust incident light over the entire area of the sensor unit, rather than flexibly. On the other hand, only an adaptive control determines the required amount of light with respect to the duration of the light and / or with respect to the light intensity according to the ambient light conditions for each area of the sensor unit surface and / or layer. Within, it can be calculated for optimal saturation and provided without delay.

According to a particularly preferred development of the invention, it is provided that the amplification of the electrical signal is variable in the sensor unit and / or in the evaluation unit over different regions of the optical image. (= ALR or ALC = "adaptive
light control "), ie, part of" intelligent light control ".

The background of this particularly preferred development is that the intensity distribution of light scattered inside the front region of the finger and consequently the contrast is not uniform or constant over the width of the optical image, but rather the optical image. The fact that in the central region is smaller than in the edge region of the optical image, in particular that at least one light source is arranged side by side with the finger rest surface and the light from the light source is On the finger resting surface,
In connection with the fact that it is possible to radiate in the direction opposite to the sensor unit on the side provided for resting the front region of the finger. By doing so,
On the opposite side of the sensor unit, into the central area covered by the front area of the finger, less light reaches than on the side areas, so that the intensity of the scattered light and-in direct proportion thereto- The contrast is weaker than in the lateral areas.

In order to eliminate this drawback, according to a preferred development of the invention, the amplification of the electrical signal in the central region of the optical image is greater than the amplification in the edge region of the optical image, and its amplification In this case, for example, it can be increased by a factor of approximately 2 to 3. This kind of electronic modulation with a variable amplification factor then
This can be done for each row of the optical image.

It is thereby possible to compensate in an electronically elegant way for the fact that the intensity and contrast of the scattered light is weaker in the central area than in the lateral areas, In some cases, the amplification may be selected over various regions of the optical image, such that the output signal, which is directly proportional to the product of the respective scattered light intensity / contrast and the respective amplification factor, is of substantially constant intensity. it can. By this technical measure, the quality of the results obtainable by the present invention is significantly improved.

According to an inventive development of the device, the device is designed to enter a non-operational state. This is advantageous, for example, in the context of using the device in mobile phones or in automotive parts, for example in steering wheels, in switching knobs or in door closers. In this type of use, the voltage required to drive the device is mostly derived from the battery, possibly supplemented by the use of solar cells, so that the non-operating state of the device The potential savings of having a large number are greatly appreciated.

To this end, it is possible to provide a circuit, preferably at least one capacitive, preferably integrated in the control means, by means of which the device is deactivated after a predetermined period of non-use. State (so-called “sleep mode”),
And the circuit causes the device to "wake up" again when the front region of the finger rests on the finger resting surface, i.e. to a state ready for driving. It is assumed that the “sleep function” and the “wake-up function” can be implemented in the device for identifying a person.

As already mentioned above, in adaptive light control within the framework of the present invention, at least one light source fulfills an important function. It must be taken into account that in many practical cases more than one, for example two or four light sources are provided in order to evenly illuminate the front region of the finger, Can be arranged symmetrically with respect to one another and / or can be arranged in the form of a ring on or around the finger rest surface, in particular substantially evenly distributed.

According to a particularly inventive development of the device, the respective lengths and / or the respective intensities of the light pulses emitted from the respective light sources can be selectively controlled according to the ambient light situation. . This means that, in other words, the respective lengths and / or the respective intensities of the light pulses emitted from the individual light sources can be controlled independently of one another, in which case in particular according to a preset threshold value. That means. Thus, all light sources can be driven independently of one another, in which case their respective lengths and / or their respective intensities are preferably calculated individually for each light source in the evaluation module.

The drive of the light sources and the number of light sources, as well as their arrangement, play an inventive role in the present invention. A light source is arranged side by side on the finger placement surface, and light from the light source is provided for placing a finger front region of the finger placement surface, opposite to the sensor unit, on the finger placement surface. Being able to radiate in the lateral direction allows sufficient and reliable lighting of the front region of the finger.

The incidence of light on the front region of the finger is then largely from the side, in which case at least part of the light enters the interior of the front region of the finger and is scattered there. ,
The scattering then takes place in almost all directions, in particular also in the direction of the fiber-optic finger rest surface. The invention is therefore based in part on the transmitted light technology, ie the optical image of the fingerprint is treated as a transmitted light image.

In the process of identifying a person, a skin ridge or nipple line is placed on the finger resting surface of the front region of the finger, which supports the skin ridge or nipple line, so that the skin ridge or nipple line is localized. In this area of the fiber optic finger resting surface, which is closed by skin ridges or nipple lines, it scatters inside the front region of the finger, as it "closes" the fiber entrance of the finger resting surface. The so-called transmitted light does not reach the finger placement surface or reaches only a small amount.

On the other hand, in the region of the depression between the skin ridges or papillary lines, a lot of scattered light reaches into the fibers of the finger resting surface, and thus preferably passes through at least one photosensitive surface. Since the sensor unit having the surface and / or the at least one photosensitive layer is reached, the person is fingerprinted, in particular using the area of the skin ridge or nipple line and using the area between the skin ridge or nipple line. A very sensitive instrument is provided for identifying the

Therefore, the recorded optical image of the fingerprint is passed through the fiber on the finger placing surface,
A sensor unit arranged downstream of the finger placement surface is reached, which is then analyzed and processed by an evaluation unit effectively arranged downstream of the sensor unit. The data and information obtained during the analysis and during the processing are then collected and stored in at least one memory unit, which is preferably arranged downstream of the sensor unit.

In this connection, it is important that the device according to the invention is completely visible and that the person to be identified can follow the person identification process and is transparent. This is because the person only has to put the front area of the finger on the finger resting surface in a psychologically favorable manner and does not need to insert the finger into the hollow space or opening. .

In addition, optional inventive features of the device include a design for survival recognition (so-called “life support”, ie, between the area of the skin ridge or nipple line and the skin ridge or nipple line). Based on the brightness difference from the region, according to the invention, an observation or investigation is made as to whether the illuminated object, for example the front region of the finger, is alive, ie, for example, is flowing blood and / or has a pulse. In this context, the device according to the invention is designed to determine the oxygen saturation in the blood in the front region of the finger, for example by comparing the results obtained for two different wavelengths. be able to.

Also, according to the present invention, for example, a person is identified as authenticated or authorized only if its actual pulse frequency does not deviate upward or downward from the stored pulse frequency by more than 10 percent. be able to. Therefore, the pulse frequency is another criterion for identifying a person.

This additional biometric data, for example on the pulse, reduces the error probability of the identification process. This is because the data makes it possible to distinguish the living finger of the person to be identified from the previously obtained imprint of this finger. The data present on the change in the transparency of the front part of the finger is obtained by calculating the pulse of the person to be identified, preferably in an evaluation unit, and the transparency curve thus obtained is obtained in the same way as an electrocardiogram (EKG). To use for medical purposes.

[0037] Furthermore, the device according to the invention seeks an optical image whose sharpness is high and in which the sweat glands located in the anterior region of the finger and which are uniquely located in a person are clearly and clearly recognizable. Therefore, there is a possibility that the sweat glands can be used for identifying a person in the frame of driving the present apparatus.

According to a preferred development of the invention, the light source is arranged on the side of the finger placement surface facing the sensor unit. This means that light from the light source can be emitted in the direction of the finger resting surface, opposite to the sensor unit, on the side provided for resting the front area of the finger, i.e. to be identified. This is a sufficient premise for the front area of the person's finger to be illuminated from below the side.

Furthermore, the light source is preferably arranged laterally away from the sensor unit. This structural separation of the light source and the sensor unit is recommended, as long as light should be prevented from reaching the sensor unit directly from the light source in order to obtain an orderly drive of the device. Rather, for a sensor unit, which is preferably semiconductor-based, in particular silicon-based, the light which is scattered beforehand inside the front region of the finger and thereby carries information about the skin ridge or papillary line, i.e. about the fingerprint Should only be reached.

According to an inventive development of the device for identifying a person, the light from the light source is provided for placing the front region of the finger on the finger placement surface, opposite to the sensor unit. Side can be incident on the side of This deployment is particularly advantageous for light sources, where the finger rest surface
The sensor units are considered if they are arranged side by side on the opposite side or already approximately above them. Also, in this deployment, the light source can be placed sideways, so to speak, to emit light “flat” onto the front area of the finger.

As an alternative, the light source can be formed as a pulsed light source, which is designed to emit pulsed light, so that the device according to the invention provides a precisely modulated pulsation For example, the battery can be completely driven by the light. In each case, a significant reduction in the current required for driving the device according to the invention can be achieved. This is because ambient light can be used and the additionally required light can be precisely adjusted by adaptive light control. The pulse length of the light pulse emitted in that case is preferably from approximately zero milliseconds to about 9 milliseconds.
It moves with a size of 0 milliseconds.

In connection therewith, the device according to the invention comprises at least one
It is possible to have one pulse detection unit, wherein the pulse detection unit is preferably arranged between the light source and at least one control element for the sensor unit.

According to a preferred embodiment of the present invention, in order to signal the driving status of the device to each person to be identified, at least one of the various driving statuses of the device is indicated.
One display device is provided. In this case, the display preferably has at least one monochromatic or various color light-emitting display, which signals the various operating states of the device (for example, green light: "device"). Is ready to identify the person "or also" the device has systematically identified the person "; red light:
"The device is not ready to identify the person" or "The device does not recognize the person in an orderly manner.")

In this connection, if the device is to be formed particularly elegantly and / or compactly, the display device is integrated in the light source and / or the display device and the light source are formed integrally. It is recommended. According to a preferred alternative or complementary embodiment, for example, in order to allow a person who does not recognize the color to know the respective driving states of the device, the display device displays the various driving states of the device by at least one flashing. It can also be signaled by a pulsating optical signal.

According to a particularly inventive development of the invention, at least one optical system is arranged downstream of the light source. This type of optical system provides, in part, a certain protection function,
That is, the optical system prevents a person to be identified using the fingerprint from contacting a delicate and easily damaged light source when placing the front region of the finger.

However, particularly preferably, the optical system redirects the light emitted from the light source to the side of the finger placement surface opposite to the sensor unit and / or converts the light emitted from the light source to the finger. It is designed to distribute evenly and / or diffusely on the opposite side of the mounting surface from the sensor unit. This assures uniform illumination of the front area of the finger, thereby ensuring that
A useful optical image is created based on the front region of the finger. This is important for a satisfactory function of the device according to the invention.

Preferably, the optical system comprises at least one filter, at least one lens, at least one prism, at least one light guide, at least one light guide element, and / or at least one mirror In which case the use of the optical element described above, alone or
Alternatively, the combination also relates, for example, to the space provided or the required illumination.

In order to fulfill the above-mentioned protection function, it is proposed to select plastic as an optical material also in light distribution. Plastics are inexpensive and significant materials that have excellent optical properties, especially in transparent specifications.

In order to fulfill the above-mentioned protection function, furthermore, at least the side of the optical system opposite to the light source is provided by at least one material that transmits the light of the light source, in particular a material that transmits infrared light and / or visible light. , It appears to be effective when coated. This protects the optics, which are not often delicate, from damage, for example from scratches due to rough handling and / or from dirt, in which case the coating of the light-transmitting material also facilitates cleaning of the optics. Become.

According to a particularly inventive development of the device, the finger placement surface, opposite to the sensor unit,
At least one, preferably ergonomically shaped finger guide is provided on the side provided for resting the front region of the finger. This type of finger guide, for example formed in the form of a "shoes", makes handling of the device not only psychological, but also practically easier for the female or male user of the device, for example the person to be identified. become. This is because the person to be identified instinctively depends on the placement of the finger guide, at which position on the opposite side of the finger placement surface from the sensor unit, and at which location the front region of the finger should be placed. Because you understand.

If the device according to the invention is to be deployed particularly skillfully, it is recommended that the optical system be finger-guided. In this way, the advantage of the finger guide, i.e. the optimal positioning of the front region of the finger, especially for detecting fingerprints, is in an effective way the advantage of the optical system, i.e. especially for the light generated. The function as a turning element and the clean and uniform illumination of the front area of the finger to be illuminated are combined.

In this connection, it must be mentioned that adaptive light control provides a smooth and uniform transition for the various regions of the overall image that can be combined in a particularly favorable manner. It is. Thus, the cooperation of the adaptive light control and the finger guide, which is optionally implemented in the optical system, ensures a uniform light distribution on the object to be illuminated, with as high a contrast as possible.

The measures described above for coating the optical system with a light-transmitting material also apply to the preferred embodiment of the invention, in which the finger rest surface at least on the side opposite the center unit is a light source. , In particular, a material that transmits infrared light and / or visible light.
Such a coating of the finger resting surface in this case requires a clean finger resting surface that is undamaged, i.e. not particularly scratched, for the orderly function of the device to identify a person. Is of inventive importance. The material that transmits the light of the light source, both in the case of the optical system and in the case of the finger resting surface, is, according to a preferred embodiment, a lacquer.

In the context of the present invention, it is advantageous if the light source is a light-emitting diode (LED), in which case the advantages of such a light-emitting diode are particularly small, and therefore in the course of miniaturization. It can be seen that it is also used in a device according to the invention, where only a small amount of space is provided. Other advantages include the light weight of the light-emitting diode, tight specifications, low drive voltage and long life.

According to a preferred development of the invention, the light source emits infrared light, wherein the infrared light has a wavelength of, for example, about 900 nanometers. In a preferred embodiment, the light source, which can also emit infrared light of two different wavelengths, has an output of, for example, from about 0.1 milliwatt to about 5 watts, in particular, to avoid extremely high heating of the device. It should have an output of about 2 milliwatts to about 100 milliwatts.

In order to provide a certain stability to the device for identifying a person, the sensor unit is preferably arranged on at least one support unit. This support unit can also be arranged on at least one conductor plate unit.

To ensure that light supporting the optical image of the fingerprint, based on the front area of the finger, is transported through the finger rest surface to the sensor unit, the fibers in the finger rest surface are According to a typical development, the orientation is substantially perpendicular to the entrance and / or exit plane of the finger placement plane.

For the same purpose, according to a preferred embodiment of the present invention, the fibers in the finger rest surface are arranged substantially parallel to one another. Instead, according to an inventive development, the fibers in the finger resting surface have roughly two directions, which are arranged at an angle with respect to each other. In a preferred embodiment then, the fibers in the finger resting surface are arranged in layers, wherein the fibers inside the layers are arranged substantially parallel to one another and are adjacent to one another. Are arranged at an angle with respect to each other.

In the preferred embodiment described above, the fibers of the finger placement surface, which are arranged at an angle in one direction with respect to the other direction, direct the light in the opposite direction to the sensor unit of the finger placement surface. The fibers arranged in the other direction of the finger rest surface are preferably provided for transferring the optical image of the fingerprint to the sensor unit.

In this connection, it should be noted that the preferred embodiment described above with two preferred directions for the fibers allows the finger resting surface to be oriented in one direction relative to the other. The arrangement of the optics can be obsolete as long as the fibers arranged at an angle ensure uniform illumination of the front region of the finger.

According to a particularly inventive development of the device for identifying a person, at least some of the fibers in the finger resting surface are at least regionally coated with the shape and / or coating.
Or it is surrounded by a (light absorbing) material in the form of a jacket. As a result, if light incident from the outside through the side of the fiber and / or light incident from an adjacent fiber is absorbed, the light is absorbed into the finger placement surface in a predetermined region through each fiber. Only the incoming light is guided through the finger rest surface to its exit surface. In this way, a change in the light pattern obtained at the entrance of the finger placement surface is reliably prevented.

According to a similarly particularly inventive development of the device for identifying a person, alternatively or in addition thereto, at least a part of the fibers in the finger rest surface is at least partially at least part of the coating. Surrounded by a (light) -reflecting material in the form and / or in the form of a jacket, the coating and / or jacket reflecting light from the walls of the respective fiber back into the interior of the fiber within the respective fiber. return. Thereby, the transfer of the optical image to the sensor unit through the finger placement surface, as long as each fiber transfers only the light that has entered the finger placement surface in a given area through the light placement surface to its exit surface. Supported.
In this way, a change in the light pattern obtained on the entrance surface of the finger placement surface is reliably prevented.

Regardless of the point of view omitting the optics, the light source is covered and protected from manual intervention because the finger resting surface provides an extension that extends to the area above the light source. Of course, the sensor unit should carry information about the optical image of the fingerprint, i.e. only the light scattered by the front region of the finger should reach, so that light is transmitted inside the finger rest surface It is recommended to provide at least one barrier layer. This is because the light-impermeable blocking layer prevents light emitted from the light source from reaching the sensor unit directly, ie without scattering in the front region of the finger. In that case, this barrier layer can be realized, for example, in the form of a closed fiber.

Used for the same purpose as the shielding layer inside the finger placement surface is at least one light-impermeable shielding layer that can be provided between the light source and the sensor unit.
In this connection, the material of the blocking layer that does not transmit the light of the light source can be, for example, a lacquer.

When the present device for identifying a person is to be developed by an inventive method,
At least one filter, preferably formed as a linear filter, is provided to absorb the obstructive ambient light and the excess ambient light, thereby ensuring that oversaturation of the sensor unit is eliminated.

This means, in other words, that the adaptive light control does not mean that the sensor unit goes into a “saturated” state to some extent eg by normal daylight, in which case this kind of supersaturation is just a filter. If the placement can effectively prevent this,
It means deploying its optimal action. This is because this filter allows the device for identifying a person to work even when the ambient light intensity is higher than about 3,000 lux, in which case the actual light intensity This is because the upper limit can be set to about 40,000 lux. To that end, the filter preferably has an absorption of about 99 percent, ie a filter that absorbs light acts like a “dark room” in the result (for example, as disclosed in DE 44 04 918 A1 for supersaturation, (Unlike filters with "windows", which do not provide effective protection and cannot perform the function of a "dark room").

The arrangement of the filter inside the apparatus for identifying a person depends on the structure of the apparatus,
Determined by size and intended use. However, it may be effective to:-place the filter between the finger rest and the sensor unit; and / or-place the filter on the finger rest and the sensor unit. And / or-the filter is arranged on the side of the finger-bearing surface facing the sensor unit; and / or the filter is provided inside the finger-bearing surface.

According to a particularly preferred development of the invention, configuring the absorbance of the filter to be variable over different regions of the optical image is achieved by adaptive light control (ALR or ALC).
"adaptive light control").

The background of this particularly preferred development is that the intensity distribution of the light scattered inside the front region of the finger and consequently the contrast is not uniform or constant over the entire width of the optical image; Is smaller in the central region of the optical image than in the edge region of the optical image, in particular that at least one light source is arranged side by side with the finger rest surface, and It is associated with the fact that light can be emitted in the direction of the finger rest surface, opposite to the sensor unit, on the side provided for resting the front region of the finger. Thereby, on the opposite side of the finger placement surface from the sensor unit, less light reaches the central region covered by the front region of the finger than the lateral region, so that the scattered light Strength and-
In direct proportion-the contrast is weaker than in the lateral regions.

To eliminate this drawback, according to a preferred development of the invention, the absorbance of the filter in the edge region of the optical image is greater than that of the filter in the central region of the optical image, And in that case, for example, roughly a factor of 2
From about 3 and / or from about 6 to about 10 decibels.

This is thus an inventive alternative, in which the density of the optical filter is configured to be variable over different areas of the optical image, and the density in the edge area of the filter is: Greater than the density of the filter in the central region of the optical image, and then, for example, roughly by a factor of only 2 to 3 and / or
Or about 6 to 10 dB greater.

Thereby, in an elegant way provided by optical modulation, it is possible to compensate for the fact that the intensity and contrast of the scattered light is weaker in the central region than in the lateral regions, The absorbance is then selectively over various regions of the optical image, such that the output signal, which is directly proportional to the respective scattered light intensity / contrast and the quotient based on the respective absorbance, is of substantially constant intensity. You can choose. This technical measure improves the quality of the results obtainable by the device.

In this connection, it should not be overlooked that the above-mentioned alternative technical means of optical modulation are compared with the above-mentioned alternative means of electronic modulation by amplification factor. Another advantage is that in the case of optical modulation, especially in the central region of the optical image, amplification due to the influence of noise, such as, for example, electronic noise, is eliminated. Rather, the effects of this type of unwanted noise can be further reduced by optical modulation.

In a preferred embodiment, the sensor unit is directly adjacent to the finger rest surface, and / or to enable the optical signal to be detected directly by the sensor unit without being distorted by the influence of noise. The sensor unit is mounted on the exit surface of the finger placement surface.

The sensor unit can preferably have at least one component based on CMOS technology or at least one circuit based on CMOS technology.
CMOS == complementary MOS). Alternatively or additionally, at least one charge-coupled device or at least one charge-coupled circuit (CCD = charge cup)
led device) can be provided. In that case it is in particular at least one area-CCD, which functions as a photosensitive unit and does not have a separate light-protected area.

In this context, those skilled in the art will appreciate that the need for a semiconductor surface in the CCD-sensor unit which is merely half the previously required surface should be evaluated as favorable. There will be. Because, in the CCD-sensor unit,
The resulting image can be read out directly in the dark mode, as in the case of conventional sensor units, where the sensor surface occupies much of 50% and eventually is read out of the light-insensitive area. This is because there is no need to transfer to

In this case, the image construction and the charge read-out take place in an integrated manner in the photosensitive unit, in which case the image construction process and the charge read-out process are separated from one another in time. However, unlike the two-region CCD, they are not spatially separated from each other. In this case, the one-region CCD is particularly characterized in that it can be formed much simpler and cheaper than the two-region CCD. That is, 1 area-C
In a CD, if the dimensions of the photosensitive units are approximately equal, the number of elements is two.
Area-only half the size of the CCD.

Of course, in this connection, it has to be taken into account that the one-region CCD cannot be used for continuously or constantly illuminating the object to be illuminated. This is because if the image construction process and the readout process are performed simultaneously, undesirable mixing of the generated images will occur.

For this reason, as already mentioned above, the light source can be designed as a pulsed light source, which is designed to emit pulsed light. In this connection, the device according to the invention has at least one pulse detection unit for controlling the light source, wherein the pulse detection unit preferably has a light source and at least one pulse for the sensor unit. And two control elements.

In this context, those skilled in the art will recognize that illuminating the front region of the finger with a light pulse may result in instability both in the resulting fingerprint image and in the resulting electrical signal. It will be appreciated that providing a significant reduction in heterogeneity should be evaluated as particularly preferred. This effect is a direct result of a short temporal light pulse, preferably about 1 millisecond in length, in which the blood flow in the front region of the finger to be transilluminated is reduced by the resulting fingerprint. The effect on the quality of the optical image is negligible.

Furthermore, by reducing the image construction time, the influence of the ambient light conditions on the optical image of the skin relief is also decisively reduced. Thus, by using the apparatus for identifying a person according to the present invention, instead of the blurred optical image that occurs when using constant exposure and the exposure time associated with the image pre-processing time, the fingerprint can be used. This provides the possibility of obtaining a clear and sharp optical image, which contains global information about the interior and / or surface of the front region of the finger at a given point in time.

This improvement in the quality of the resulting image makes it possible to significantly reduce the frequency and probability of errors during person identification. Also, the image sequence processing enhances the information content of the image for fingerprint inspection by acquiring additional biometric data of the person to be identified, for example, the uniqueness of the pulse, thus further improving the certainty of the person identification. It is possible to do.

The use of a pulsed light source not only provides the fundamental improvement in image quality described above, but also allows at least one camera with one area-CCD to be used as a photosensitive unit. The use of one-area-CCD makes it possible to obtain a high-quality image of a larger area. This increase in area, together with improved stability of the optical image, further reduces the probability of error in identifying a person.

In this case, the formation of a single-area CCD having a diagonal photosensitive area of, for example, about 16 to about 24 mm and a fiber-optic input is a technically less complicated task. , Thereby relatively simple and cheap,
A device for identifying a person can be formed. Furthermore, less information distortion occurs in devices according to the invention with a one-area CCD than in devices with other types of charge transfer.

It is not possible to use a one-area CCD in a base that operates with continuous or constant illumination. This is because continuous or constant light can impinge on the CCD not only during the image construction mode, but also during the read-out mode, thus causing charge mixing, which can occur at the front of the finger. This makes it impossible to obtain a clear optical image of the skin relief in the area.

Other embodiments, features and advantages of the present invention will now be described with reference to the drawings in FIGS.
C will be described, and those figures will clarify three embodiments of the person identification device according to the present invention as examples. In that case, FIG. 1 shows a first embodiment of the person identification device based on the present invention, FIG. 2 shows a second embodiment of the person identification device based on the present invention, and FIG. FIG. 3B shows a part of the finger placement surface of the person identification device shown in FIG. 3A, and FIG. 3C shows a part of the finger placement surface shown in FIG. 3B. FIG. 4A is a diagram schematically illustrating the contrast of light scattered inside the front region of the finger over the width of the optical image, and FIG. The amplification of the electric signal selected in the person identification device shown in FIG.
FIG. 4C shows a diagram schematically drawn over the width of the optical image, and FIG. 4C shows a diagram schematically drawn over the width of the optical image the selected absorption in the person identification device shown in FIG. Equivalent or similar components or features of the present invention have the same reference numerals in FIGS. 1 to 4C.

Three embodiments of the apparatus for identifying a person using a fingerprint, as shown in FIGS.
It is used to record and process fingerprints and can be used in any area where personal identification is required. For example, in this context, mention may be made of computer technology, admission systems, criminal sciences, medical care, general and protection systems in the banking and financial areas.

In that case, the three embodiments of the device for identifying a person using a fingerprint, shown in FIGS. 1 to 3A, are, on the one hand, the illumination of the front region of the finger, which shows a sufficient and reliable result. While possible, on the other hand the device itself for identifying a person is characterized in that it is completely transparent and can follow the person identification process for the person to be characterized and is transparent.

This is because the three embodiments of the device for identifying a person using a fingerprint, shown in FIGS. 1-3A, respectively, are symmetrical with respect to the sensor unit 40 for illuminating the front region of the finger. Four light sources 10 arranged (only two of each of these four light sources are shown for reasons of clarity in FIGS. 1 to 3A) and for capturing an optical image of the finger One fiber optic finger placement surface 30
Has been realized.

The fingerprint optical image is transferred to the sensor unit 40 through the finger placement surface 30, and the fingerprint optical image is converted into an electric signal in the sensor unit.
The sensor unit 40 is arranged on a support unit 50, which support unit is also arranged on the conductor plate unit 60.

What is decisive is that the light source 10 is arranged side by side with the finger placement surface 30, and the light from the light source 10 is opposite to the sensor unit 40 on the finger placement surface 30. Radiating in the direction of the side provided for placing the front region of the finger. In that case, the light incident on the front region of the finger is largely from the side, in which case at least part of the light enters inside the front region of the finger and is scattered there, in which case Scattering takes place in almost all directions, and thus also in particular in the direction of the fiber optic finger resting surface 30; thus, the present invention, as revealed with reference to FIGS. That is, the optical image of the fingerprint is treated as a transmitted light image.

During the person identification process, the skin ridge or nipple line is placed on the finger resting surface 30 by the surface of the front region of the finger that supports the skin ridge or nipple line. Regionally, the entrance of the fiber 310 (see FIGS. 3B and 3C) of the finger rest surface 30 is "closed" so that the fiber optic finger rest surface 30 is closed by the skin ridge or nipple line. In this region, so-called transmitted light scattered inside the front region of the finger does not reach the finger placement surface 30 or reaches only a small amount.

In the area of the depression between the skin ridges or papillary lines, on the other hand, a lot of scattered light enters the fibers 310 of the finger rest surface 30 and consequently through the finger rest surface 30 Since reaching 40, a very sensitive instrument is provided for identifying a person using fingerprints, especially using the area of the skin ridge or nipple line, and using the area between the skin ridge or nipple line. Is done.

The fibers 310 in the finger rest surface 30 are surrounded by a (light) reflecting material in the form of a coating, the coating of which is the respective fiber 31.
Within 0, light is reflected back from the walls of the fiber 310 back into the interior of the fiber 310. Thus, transferring the optical image to the sensor unit 40 through the finger placement surface 30 means that each fiber 310 only transmits light that enters the finger placement surface in a predetermined area through the finger placement surface 30 to its exit surface. It is effective as far as guidance is given. In this way, a change in the light pattern obtained on the entry surface of the finger placement surface 30 is prevented.

Accordingly, the optical image of the fingerprint recorded in this manner reaches the sensor unit 40 disposed downstream of the finger placement surface 30 through the fiber 310 of the finger placement surface 30, and thereafter, It is analyzed and processed by an evaluation unit arranged downstream of the unit 40.

In this case, according to the present invention shown in FIGS. 1 to 4C, the illumination is performed based on the luminance difference between the area of the skin ridge or nipple line and the area between the skin ridge or nipple line. It is also possible to observe or investigate whether the subject, for example the front region of the finger, is alive and / or has a pulse (so-called "life support").

That is, according to the invention as revealed in FIGS. 1 to 4C, a person is determined to have his / her actual pulse frequency not deviating upward or downward from the stored pulse frequency by more than 10%. Only can be identified as authenticated or authorized. Thus, the pulse frequency is another criterion for identifying a person.

This additional, for example, biometric data on the pulse, reduces the error probability of the identification process. Because the data makes it possible to distinguish the living finger of the person to be identified from the previously obtained fingerprint of that person. The existing data on the change in the permeability of the front region of the finger is obtained by calculating the pulse of the person to be identified by computer and using the permeability curve thus obtained in the same manner as an electrocardiogram (EKG). Allow to use for purpose.

In addition, with the device shown in FIGS. 1 to 3A, the sweat glands arranged differently in the front region of the finger are distinctly and clearly distinguished as follows, namely because of their high definition: Because it is recognizable, an optical image can also be determined within the framework of the operation of the device shown in FIGS.

In this case, the device according to the invention, illustrated in FIGS. 1 to 3A, is completely peepable, can follow the process of person identification for the person to be identified and is transparent and transparent. is there. This is because the person only has to place the front area of the finger on the finger resting surface 30 in a psychologically favorable manner, without having to insert the finger into the hollow space or opening. Because.

The invention described using the three embodiments shown in FIGS. 1 to 3A is characterized in that the length and intensity of the light pulse emitted from the light source 10 can be controlled according to the ambient light conditions. Or adaptive light control (= ALR or ALC = “ada”
ptive light control "), and thus some kind of" intelligent light control "is provided, which has the disadvantage of changing ambient light conditions, such as, for example, changing room lighting or changing sunlight incidence.
The three embodiments of the device shown in FIGS. 1 to 3A or the algorithms for controlling the device can be compensated for by adapting to the respective lighting situation.

For this purpose, in the apparatus for identifying a person illustrated in FIGS. 1 to 3A, control means 40 and 70 are provided for controlling the length and intensity of the light pulse, respectively.
Digital signal processing unit with a microcontroller (DSP = digital)
By means of these control means 40, 70, which are formed as tal signal processors, a continuous or temporary measuring method can be carried out, whereby a good image quality can be determined permanently, and If necessary, a short light pulse can be used to obtain an optimum saturation adapted for contrast and depth of focus, where a short light pulse is actually needed in its length and its intensity It is precisely adjusted to the amount of light.

The control means 40, 70 have a detection module 40 for detecting ambient light conditions, in which case the detection module 40 is a sensor unit 40 in the three embodiments of FIGS. And are formed integrally with it. After the detection module 40, the length and intensity of the light pulse
Evaluation module 70 for adapting to the ambient light situation detected by zero
a is connected, in which case the evaluation module 70a
The evaluation unit is disposed after the sensor unit 40, which will be described later in detail.

Similarly, a memory module 70b for storing a predetermined threshold value for controlling the length and intensity of the light pulse is connected to the subsequent stage of the detection module 40. The module 70b is formed integrally with at least one memory unit 70b, and the memory unit is disposed after the sensor unit 40, which will be described later in detail.

If the detection module 40 detects each ambient light situation, this ambient light situation is evaluated and analyzed in the evaluation module 70a, in which case it is stored in the memory module 70b in the evaluation module 70a. A comparison with a preset threshold is performed.

According to the result of this comparison, the light source 10, which is connected to the control means 40, 7 and in that case, in particular, the evaluation module 70 a, is driven by the control means 40, 70, in which case the light pulse emitted from the light source 10 Length and intensity are adapted to the required ambient light conditions.

The light pulse can thereby be configured dynamically and adaptively both in its length and in its intensity, so that for each type of ambient light (eg strong sunlight incidence, weak sunlight incidence, Twilight, diffused light, gas light, moonlight, artificial lighting ...) provides the required light incidence, thus providing a rich and clear image with rich fingerprint contrast.

In particular, an illumination intensity of from zero lux to about 40,000 lux can be achieved by adaptive light control, in which case the latter illumination intensity value approximately corresponds to, for example, direct sunlight incidence. The result obtained by this adaptive light control is:
Light control of the type illustrated with FIGS. 1 to 3A has increased contrast and depth of focus up to about 80 percent compared to conventional lighting systems with continuous light, where the lighting conditions have changed The amount of light required in each case can be adjusted and provided within a time range of less than 100 milliseconds, so that it has the advantage that almost the same image quality can be obtained in all possible light situations. .

Thus, a decisive advantage of the device illustrated with the three embodiments in FIGS. 1 to 3A is found in “intelligent driving”, which intelligent driving requires the amount of incident light. It adjusts automatically to some extent and provides the amount of light around the object to be illuminated, ie around the front area of the finger, separately calculated and provided for each area. Overexposure and underexposure are eliminated with near certainty.

The invention shown in FIGS. 1 to 4C also provides for uniform illumination of the object, for example the front region of the finger, in particular having an otherwise more or less strong light guiding ability or a more or less strong reflecting ability. Irrespective of the thickness of the object, and whether this object is illuminated by noise light from the front, from the side and / or from behind.

Therefore, the angle at which the light is incident on the object to be illuminated and from which point do not play any role. However, the additionally required light length and intensity are individually controlled for each region. The advantage of this adaptive light control ultimately allows the finger image to be determined without substantial changes in illumination time, while maintaining full contrast and depth of focus.

As already suggested, the control means 40, 70 provided to provide adaptive light control in FIGS.
0a and a memory module 70b. If the detection module 40 is formed integrally with the sensor unit 40 (see FIGS. 1 to 3A), the light-sensitive surface of the sensor unit 40 can be controlled to some extent automatically by adaptive light control—and in particular in each region. For each-you can ask yourself the required amount of light, which works in an effective way. This is because the evaluation module 70a of the control means 40, 70
Is formed integrally with the evaluation unit 70a.

Thus, the adaptive light control calculates, for each area of the surface of the sensor unit 40, the amount of light required according to the ambient light conditions in terms of length and intensity in the evaluation module 70a for optimal saturation. , Can be supplied without delay. With respect to the operation of adaptive light control, the three embodiments of the present invention, shown in FIGS. 1-3A, absorb obstructive ambient light and extra ambient light, thereby reducing oversaturation of the sensor unit 40. It is very important that filters 90, each formed as a linear filter, be provided in order to ensure elimination.

In other words, adaptive light control means that the sensor unit 40 does not "spontaneously" transition to a supersaturated state to some extent by, for example, normal daylight, but this type of supersaturated state It means deploying its optimal effect in FIGS. 1-3A, just as it would be prevented by the placement of the filter 90. This is because the filter 90 allows the person identification device illustrated in FIGS. 1 to 3A to operate even when the ambient light intensity is greater than about 3,000 lux,
A practical upper limit can then be an ambient light intensity of about 40,000 lux. To that end, the filter 90 has about 99 percent absorbance,
That is, the filter 90 that absorbs light acts as a “dark room” as a result.

The arrangement of the filter 90 inside each device for identifying a person is determined by the structure, dimensions and intended use of the device. In the first embodiment (see FIG. 1), the filter 90 is arranged between the finger placement surface 30 and the sensor unit 40; in the second embodiment (see FIG. 2). Reference), the filter 90 of the finger placement surface 30,
Located on the side facing the sensor unit 40 and, in that case, inside the finger rest surface 30; and in a third embodiment (see FIG. 3), the filter 90 comprises a finger rest surface. 30 is arranged on the side opposite to the sensor unit 40.

As already mentioned above, within the framework of the present invention, the light source 10 (
FIGS. 1-3A) fulfill an important function. In this case, it is important to consider that in the three embodiments described with reference to FIGS. 1 to 3A, more than one light source (3 to FIG. 1 to FIG. In one embodiment, four light sources are provided, which are arranged symmetrically with respect to one another and are ring-shaped around the finger rest surface 30, in this case in particular approximately They are evenly distributed.

The respective lengths and respective intensities of the light pulses emitted from the respective light sources 10 can be selectively controlled according to the ambient light conditions in the three embodiments of FIGS. 1 to 3A. This means that, in other words, the respective lengths and the respective intensities of the light pulses emitted from the individual light sources 10 are independent of one another and can in particular be controlled according to a predetermined threshold value. That means. Thus, all the light sources 10 can be driven independently of one another, in which case the respective length and the respective intensity are calculated individually for each light source 10 in the evaluation module 70a.

The evaluation unit 70a and the memory unit 70b have already been described. These are, in the first embodiment (see FIG. 1), structurally integrated as control means 70, the control means comprising the light source 10 and the support unit 50 and the conductor plate unit 60 In the second embodiment (see FIG. 2), it is provided as a control means 70 in a structurally separate manner, the control means comprising a conductor plate unit 60 Light source 1 through
0 and the sensor unit 40 via the support unit 50 and the conductor plate unit 60; and in a third embodiment (see FIG. 3), And functionally integrated.

Accordingly, as is clear from FIGS. 1 to 3A, the evaluation unit 70a is disposed downstream of the sensor unit 40 and is disposed downstream of the finger placement surface 30 through the fiber 310 of the finger placement surface 30. It has a function of analyzing and processing the recorded optical image of the fingerprint that reaches the inside of the sensor unit 40. Data and information obtained in the analysis and processing in that case are similarly collected and stored in a memory unit 70b disposed downstream of the sensor unit 40.

The memory unit 70b further stores data and information of the person to be identified, in particular fingerprints and fingerprint information, in which case the evaluation unit uses the actual optical image of the fingerprint during the identification process. The data and information calculated in 70a can be correlated with the data and information stored in memory unit 70b and compared therewith.

If a match is obtained during this comparison, the person using the device is identified, authenticated, or deemed to be authorized, so that entry is allowed, for example. If there is no match, the person using the device is not identified, is not authenticated, or is deemed not authorized, so that entry is denied, for example.

In the two first embodiments of the present invention shown in FIGS. 1 and 2, an optical system 20 made of plastic, which is formed as a lens, is disposed downstream of the light source 10. This optical system 20 provides, on the one hand, a certain protective function, i.e. the optical 20 allows a person to be identified by their fingerprint to contact the delicate and fragile light source 10 when placing the front area of the finger. Is prevented.

However, in particular, the optical system 20 guides the light radiated from the light source 10 to the side opposite to the sensor unit 40 of the finger placement surface 30 and guides the light radiated from the light source 10 to the finger placement surface. 30 is designed to diffuse and distribute to the side opposite to the sensor unit 40. This assures uniform illumination of the front region of the finger, thereby producing a useful optical image of the fingerprint based on the front region of the finger. This is important for a satisfactory function of the device according to the invention.

The two first embodiments of the invention shown in FIGS. 1 and 2 are, in this connection, in particular,
It is characterized by being formed as an ergonomically shaped finger guide.
Therefore, a finger guide is provided on the side of the finger placement surface 30 opposite to the sensor unit 40 and provided for placing the front region of the finger, and the finger guide is formed in the shape of the finger receiving portion. And the finger guide makes it easier for the female or male user of the device, for example the person to be identified, to handle the device not only from a psychological point of view, but also from a practical point of view. That is to say, the person to be identified instinctively depends on the arrangement of the finger guide, and the front area of the finger for detecting the fingerprint, and at what position and at which position the finger placement surface 30 and the sensor unit 40 This is because it is possible to understand whether it should be placed on the opposite side (see FIGS. 1 and 2).

Thus, in two first embodiments of the invention, shown in FIGS. 1 and 2,
The advantage of the finger guide, i.e. the optimal positioning of the front area of the finger, especially for detecting fingerprints, is the advantage of the optical system 20, i.e. the function as a redirecting element, especially for the generated light and the illumination of the finger. Combined with guaranteeing a clean and even illumination of the front area to be.

In this connection, it should be particularly noted that adaptive light control allows
A flexible and uniform transition is obtained for various regions of the overall image that can be combined. Thus, with the cooperation of the adaptive light control and the finger guide (see FIGS. 1 and 2) mounted in the optical system 20, a uniform light distribution on the object to be illuminated with as high a contrast as possible is obtained. Guaranteed.

In the first embodiment of the present invention shown in FIG. 1, the side of the optical system 20 opposite to the light source 10 is made of a material that transmits light of the light source 10, that is, a material 80 that transmits infrared light. Coated by. This protects the optical system 20, which is not often delicate, from damage, for example from scratching and / or dirt due to rough handling, in which case the coating of the light-permeable material 80 also cleans the optical system 20. It will be easier.

Similarly, in the first embodiment of the present invention shown in FIG. 1, the side of the finger placement surface 30 opposite to the sensor unit 40 is made of a material that transmits light from the light source 10, that is, It is coated with a material 10 that transmits external light. In this case, such a coating of the finger resting surface 30 requires an intact, ie, especially scratch-free, clean finger resting surface 30 for the orderly functioning of the person identification device shown in FIG. To some extent, it is extremely important. In both the optical system 20 and the finger placement surface 30, the material 80 that transmits the light from the light source 10 is a lacquer.

With respect to the first embodiment of the invention shown in FIG. 1, it is further worth mentioning that the amplification of the electrical signal in the sensor unit 40 or in the evaluation unit 70a can be performed by using an optical image. Configurable over various regions x (see FIGS. 4A and 4B) of adaptive light control (= ALR or ALC = “a
adaptive light control "), ie, part of" intelligent light control ".

The background is that the intensity distribution of the light scattered inside the front region of the finger and consequently the contrast is not uniform or constant over the entire width x of the optical image, but rather the central region of the optical image. Is smaller than in the edge region of the optical image (see the diagram of FIG. 4A, in which the contrast of the light scattered inside the front region of the finger is lower than that of the optical image). Schematically described over the width x). In particular, the light source 10 is arranged side by side on the finger placement surface 30, and light from the light source 10 is applied to the front of the finger on the finger placement surface 30, which is opposite to the sensor unit 40. Associated with being able to radiate in the direction of the side provided for mounting the area. Thereby, on the opposite side of the finger placement surface 30 from the sensor unit 40, the central area covered by the front area of the finger receives less light than the lateral area and is scattered. The light intensity and, in direct proportion thereto, the contrast are weaker in the central region than in the lateral regions.

To eliminate this drawback, in a first embodiment of the invention described with reference to FIG. 1, the amplification of the electrical signal in the central region of the optical image is controlled by the edge of the optical image. A factor of about 2 to 3 greater than the amplification of the electrical signal in the edge region (
4B, wherein the amplification of the electrical signal selected in the person identification device shown in FIG. 1 is schematically described over the width x of the optical image).

In this case, such an electronic modulation with a variable amplification factor takes place in each row of the optical image. Thereby, in an electronically provided manner, the intensity and contrast of the scattered light is weaker in the central region than in the lateral regions (see FIG. 4A),
The amplification can then be selectively performed over different regions x of the optical image, with respective scattered light intensities / contrasts (see FIG. 4A) and respective amplification factors (see FIG. 4B). ) Can be selected such that the output signal, which is directly proportional to the product of By this technical measure, the quality of the results obtainable by the embodiment shown in FIG. 1 is significantly improved.

The second embodiment shown in FIG. 2 is different from the first embodiment shown in FIG. 1 in that a material that transmits light from the light source 10 is applied to both the optical system 20 and the finger placement surface 30. Not only that, but also in particular, that the light source 10 is arranged on the sensor unit 40 side of the finger placement surface 30, i.e. below the finger placement surface 30 in FIG. I have.

In that case, the light from the light source 10 is applied to the sensor unit 40 on the finger placement surface 30.
In the opposite direction, the radiation is emitted in the direction of the side provided for placing the front region of the finger, that is, the front region of the finger of the person to be identified is illuminated from below the side. ,
It is a sufficient premise.

With respect to the second embodiment of the present invention shown in FIG. 2, it should be further noted that the absorbance of the filter 90 can be varied over various regions x of the optical image (see FIGS. 4A and 4C). The variable configuration is based on adaptive light control (= ALR or A
LC = “adaptive light control”), ie, part of “intelligent light control”.

The background is that the intensity distribution of the light scattered inside the front region of the finger and thus the contrast is not uniform or constant over the entire region x of the optical image, but in the central region of the optical image. (See the diagram of FIG. 4A, in which the contrast of the light scattered inside the front region of the finger is less than in the region of the optical image). x)); in particular, that the light source 10 is arranged side by side with the finger rest surface 30 and that the light from the light source 10 is transmitted to the sensor unit 40 of the finger rest surface 30.
The opposite is true of being able to radiate in the direction of the side provided for resting the front region of the finger. This causes less light to reach the central area of the finger placement surface 30 opposite the sensor unit 40, which is covered by the front area of the finger, than the lateral areas, so that scattered light And-in direct proportion to it-
The contrast is weaker in the central area than in the lateral areas.

In order to eliminate this drawback, in a second embodiment of the invention, described with reference to FIG. 2, the density of the optical filter 90 in the edge region of the optical image and the corresponding absorption The degree is greater than the absorbance of the filter 90 in the central region of the optical image by about a factor of two to three, or by about six to about ten decibels (see the diagram of FIG. 4C, wherein FIG. The absorption of the selected filter 90 in the person identification device shown in FIG. 2 is schematically described over the width x of the optical image).

The intensity and contrast of the scattered light is thereby weaker in the central area than in the lateral areas, in a way brought about by means of optical modulation (FIG. 4A).
), In which case the absorption can be selectively adjusted over the various regions x of the optical image by the respective scattered light intensity / contrast (
The output signal, which is directly proportional to the quotient consisting of the respective absorbances (see FIG. 4A) and the respective absorbances (see FIG. 4C), can be selected to be of substantially constant intensity; The quality of the result obtained by the second embodiment shown is significantly improved.

Further, in the three embodiments of the present invention shown in FIGS. 1 to 3A, the light source 10 is arranged laterally away from the sensor unit 40. Light source 10 and sensor unit 4
This structural separation of the light from the light source 10
This is effective as long as it is prevented from reaching the inside of the sensor unit 40 directly. Rather, only light that is scattered within the front region of the finger in advance, and thus carries information about the skin ridge or nipple line, ie, about the fingerprint, should reach into the sensor unit 40.

The first two embodiments shown in FIGS. 1 and 2 differ from the third embodiment shown in FIG. 3 in that the light supporting the optical image of the fingerprint is based on the front area of the finger. The difference lies in the fact that the fibers 310 are arranged substantially parallel to one another in the finger rest surface 30 in order to ensure a neat transport through the finger rest surface 30 to the sensor unit 40.

Instead, the fibers 310, 320 in the finger resting surface 30 of the third embodiment (see FIGS. 3A, 3B and 3C) have roughly two directions, Are arranged at an angle of about 45 degrees with respect to each other. In that case,
The fibers 310, 320 in the finger rest surface 30 are arranged in layers, i.e., the fibers 310, 320 inside the layers are arranged substantially parallel to each other, and the fibers 310, 320 in adjacent layers are , At an angle of about 45 degrees with respect to each other.

In that case, in the third embodiment (see FIG. 3A, FIG. 3B and FIG. 3C)
The fiber 320, which is arranged at an angle of about 45 degrees in one direction with respect to the other direction on the finger placement surface 30, causes the light of the light source 10 to emit light from the finger placement surface 30 to the side opposite to the sensor unit. The fiber 310 is provided for transferring the optical image of the fingerprint to the sensor unit 40. The fiber 310 is provided for transferring the fingerprint image to the sensor unit 40.

In this context, it should be noted that, according to the embodiment shown in FIGS. 3A, 3B and 3C, which has two preferred directions for the fibers 310, 320, FIGS. The arrangement of the optical system 20 shown in FIG. 2 is such that the fibers 32 arranged on the finger placement surface 30 at an angle of about 45 degrees in one direction with respect to the other direction.
Zero means that it can be out of date, as long as uniform illumination of the front region of the finger is guaranteed. Irrespective of the viewpoint in which the optical system 20 is omitted in that case, the finger resting surface 30 is provided with an extension extending to the area above the light source 10 so that the light source is covered and protected from manual intervention. (See FIGS. 2 and 3).

Of course, the sensor unit 40 should carry information about the optical image of the fingerprint, ie only the light scattered by the front region of the finger should reach, so that the invention shown in FIG. In the second embodiment, two blocking layers 130 that do not transmit light from the light source 10 are provided inside the finger placement surface 30. This blocking layer 130 prevents light emitted from the light source 10 from reaching the sensor unit 40 directly, ie without scattering in the front region of the finger.

The two blocking layers 140 are also used for the same purpose as the blocking layer 130 inside the finger resting surface 30 (see FIG. 2), and the blocking layers are the three layers of the present invention shown in FIGS. 1 to 3A. In one embodiment, each light source is provided between the light source 10 and the sensor unit 40, and similarly does not transmit light from the light source 10.

Also, in the third embodiment of the present invention shown in FIG. 3A (similar to the first embodiment of the present invention shown in FIG. 1), the finger placement surface 30 is opposite to the light source 10. It must also be mentioned that the side is coated by a light-transmitting material of the light source 10, ie by a material 80 transmitting infrared light, for example by a commercially available clear lacquer. This protects the finger resting surface 30, which is not often delicate, from damage, for example from scratching and / or dirt due to rough handling, in which case the finger resting surface 30 is coated with a light-permeable material. Is also easy to clean.

Furthermore, the third embodiment of the present invention shown in FIG. 3A has a display device 65 for displaying various driving states of the device. The display device 65 is provided with a light-emitting indicator for signaling the respective driving states of the device to the person to be identified, and the light-emitting indicator can be used to flash light appropriately even for a person who does not identify the color. The signals enable the recognition of the respective operating states of the device.

Finally, the device according to the third embodiment of FIG. 3A is also designed to go into a non-active state (= so-called “sleep mode”), which is a potential saving on the current consumption of the device. To form To this end, an integrated capacitive circuit 75 is provided in the control means 40, 70, by means of which the device shown in FIG. 3A goes into "sleep mode" after a non-use for a preset period. 3A, and the circuit shown in FIG. 3A re-displays “Finger” when the front region of the finger is placed on the finger placement surface 30.
"Awake", that is, a transition is made again to a state ready for driving. It is assumed that the device for identifying a person has both a “sleep function” and a “wake-up function”.

────────────────────────────────────────────────── ─── Continuation of the front page (31) Priority claim number 199 58 378.1 (32) Priority date December 3, 1999 (1999.12.3) (33) Priority claim country Germany (DE) ( 81) Designated countries EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SL, SZ, TZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, C , CR, CU, CZ, DE, DK, DM, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG , SI, SK, SL, TJ, TM, TR, TT, TZ, UA, UG, US, UZ, VN, YU, ZA, ZW

Claims (83)

[Claims] At least one light source (10) for illuminating and / or transilluminating a front region of a finger with light pulses and at least one fiber optic finger for capturing an optical image of the finger. And a mounting surface (30) through which the optical image passes through the finger mounting surface (30).
0), the optical image can be converted into an electric signal in the sensor unit, and the light source (10) is arranged side by side on the finger placement surface (30). Light from the light source (10) can be emitted in the direction of the finger placement surface (30) opposite to the sensor unit (40) and on the side provided for placing the front region of the finger. An apparatus for identifying a person by at least one fingerprint, characterized in that the length and / or intensity of the light pulse emitted from said light source (10) is controllable according to ambient light conditions. apparatus. 2. The device according to claim 1, wherein at least one evaluation unit is arranged downstream of the sensor unit. 3. The sensor unit (40) and / or the evaluation unit (7).
Device according to claim 1 or 2, characterized in that the amplification of the electrical signal in 0a) is variable over different regions of the optical image. 4. The apparatus according to claim 3, wherein the amplification of the electrical signal in the central region of the optical image is greater than the amplification of the electrical signal in the edge region of the optical image. 5. The amplification of the electrical signal in the central region of the optical image is substantially less than the amplification of the electrical signal in the edge region of the optical image by a factor of two.
The device according to claim 4, characterized in that it is three to three larger. 6. Device according to claim 1, wherein at least one memory unit (70b) is arranged downstream of the sensor unit (40). 7. The device according to claim 1, wherein at least one control means (40, 70) is provided for controlling the length and / or intensity of the light pulse.
An apparatus according to at least one of the preceding claims. 8. The control means (40, 70) includes at least one detection module for detecting an ambient light condition, and a length and / or a light pulse according to the ambient light condition detected by the detection module. At least one evaluation module for determining the intensity and at least one memory module for storing a defined threshold for controlling the length and / or intensity of the light pulse. The apparatus according to claim 7, wherein: 9. The device according to claim 8, wherein the detection module is formed integrally with the sensor unit (40) and / or as part of the sensor unit (40). 10. The evaluation module, integrated with the evaluation unit (70a),
10. The device according to claim 2, 8 or 9, wherein the device is formed as part of an evaluation unit (70a). 11. At least one of claims 6 and 8 to 10, wherein the memory module is formed integrally with the memory unit (70b) and / or as part of the memory unit (70b). An apparatus according to claim 1. 12. The at least one of claims 7 to 11, wherein the control means (40, 70) is formed as at least one logic element and / or as at least one logic circuit. The described device. 13. The control means (40, 70) as at least one standard logic element or programmable logic (FPGA = field program).
13. The device according to claim 12, wherein a mmable gate array is provided. 14. The control means (40, 70) comprises at least one digital signal processing unit (DSP).
14) and / or as at least one microcontroller. 15. The device according to claim 1, wherein the device is designed to transition to a non-operating state. 16. At least one capacitive circuit (75) is provided, by means of which the device goes into an inactive state after a predetermined period of inactivity. An apparatus according to claim 1. 17. The method according to claim 7, wherein the capacitive circuit is integrated in the control means. apparatus. 18. The device according to claim 1, wherein more than one light source (10) is provided. 19. The device according to claim 18, wherein four light sources (10) are provided. 20. Apparatus according to claim 18, wherein the light sources are arranged symmetrically with respect to one another. 21. At least one of claims 18 to 20, characterized in that the light source (10) is arranged in a ring shape on or around the finger placement surface (30). The described device. 22. Apparatus according to claim 18, wherein the light sources (10) are evenly distributed around the finger rest surface (30). 23. The light pulse emitted from each light source (10) may have a respective length and / or a respective intensity selectively controllable according to ambient light conditions. 23. The device according to at least one of 18 to 22. 24. The method according to claim 18, wherein the respective lengths and / or the respective intensities of the light pulses emitted from the individual light sources are controllable independently of one another. An apparatus according to at least one of the preceding claims. 25. The method according to claim 18, wherein the respective lengths and / or the respective intensities of the light pulses emitted from the individual light sources are controllable according to a preset threshold value. 25. The apparatus according to at least one of the preceding claims. 26. A light source (10) comprising a sensor unit (30) on a finger mounting surface (30).
Device according to at least one of claims 1 to 25, characterized in that it is arranged on the side facing (40). 27. Apparatus according to claim 1, wherein the light source (10) is arranged laterally away from the sensor unit (40). 28. Light from a light source (10) is directed to the side of the finger placement surface (30) opposite to the sensor unit (40) and provided for placing the front region of the finger. 28. Apparatus according to at least one of the preceding claims, characterized in that it can be incident laterally. 29. Apparatus according to claim 1, wherein the light source is formed as a pulsed light source. 30. The apparatus according to claim 29, wherein the light source (10) is designed to emit light pulses having a pulse length of approximately zero milliseconds to about 90 milliseconds. 31. Apparatus according to claim 29, wherein at least one pulse detection unit is provided for controlling the light source (10). 32. Apparatus according to claim 1, wherein at least one display device is provided for displaying different operating states of the apparatus. 33. The display device (65) has at least one monochromatic or various color light emitting display, said light emitting display signaling different driving states of the device. 33. The apparatus of claim 32, wherein: 34. The display device (65) is integrated in the light source (10),
Device according to claim 32 or 33, wherein the display device (65) and the light source (10) are formed integrally. 35. At least one of the claims 32 to 34, characterized in that the display device (65) signals the various drive states of the device by at least one blinking and / or pulsating light signal. An apparatus according to claim 1. 36. At least one optical system (20) downstream of the light source (10).
36. The device according to at least one of claims 1 to 35, wherein 37. The optical system (20) guides light emitted from the light source (10) to a side of the finger placement surface (30) opposite to the sensor unit (40), and / or an optical system. The system (20) is characterized in that the light emitted from the light source (10) is uniformly and / or diffusely distributed to a side of the finger placement surface (30) opposite to the sensor unit (40). 37. The device of claim 36, wherein 38. The optical system (20) comprises at least one filter, at least one lens, at least one prism, at least one prism.
38. The method as claimed in claim 36, wherein the at least one light guide is formed as one light guide and / or as at least one mirror.
An apparatus according to claim 1. 39. Apparatus according to at least one of claims 36 to 38, wherein the optical system (20) is made of plastic. 40. The optical system (20), characterized in that at least the side opposite to the light source (10) is coated with a material (80) that transmits infrared and / or visible light. Apparatus according to at least one of 36 to 39. 41. The finger placement surface (30), which is opposite to the sensor unit (40),
41. Device according to at least one of the preceding claims, characterized in that at least one finger guide is provided on the side provided for resting the front region of the finger. 42. The device according to claim 41, wherein the finger guide is ergonomically shaped. 43. Apparatus according to claim 36, wherein the optical system is formed as a finger guide. 44. At least the sensor unit (40) of the finger placement surface (30)
Device according to at least one of claims 1 to 43, characterized in that the side opposite to it is coated with a material (80) that transmits infrared and / or visible light. 45. The material (80) that transmits infrared light and / or visible light,
The device according to claim 40 or 44, which is a lacquer. 46. Apparatus according to claim 1, wherein the light source is a light emitting diode (LED). 47. Device according to at least one of the preceding claims, wherein the light source (10) emits infrared light. 48. The apparatus of claim 47, wherein the infrared light has a wavelength of about 900 nanometers. 49. Apparatus according to at least one of the preceding claims, wherein the light source (10) emits infrared light of two different wavelengths. 50. Apparatus according to at least one of the preceding claims, wherein the light source (10) has an output of about 0.1 milliwatts to about 5 watts. 51. The apparatus according to claim 50, wherein the light source has an output of about 2 milliwatts to about 100 milliwatts. 52. Apparatus according to claim 1, wherein the sensor unit (40) is arranged on at least one support unit (50). 53. Apparatus according to claim 52, wherein the support unit (50) is arranged on at least one conductor plate unit (60). 54. The fiber (310) in the finger resting surface (30) is oriented substantially perpendicular to the inlet and / or outlet face of the finger resting surface (30). 54. An apparatus according to at least one of the preceding claims. 55. Device according to at least one of the preceding claims, wherein the fibers (310) in the finger resting surface (30) are arranged substantially parallel to one another. 56. The fiber (310, 320) in the finger placement surface (30)
55. Apparatus according to at least one of the preceding claims, characterized in that it has approximately two directions, said directions being arranged at an angle (α) with respect to each other. 57. The fibers (310, 320) in the finger placement surface (30)
The fibers (310, 320) are arranged in layers, wherein the fibers (310, 320) are substantially parallel to each other inside the layer and adjacent to each other.
57. Apparatus according to claim 56, wherein 0) are arranged at an angle (α) with respect to each other. 58. A fiber (320) arranged on one side of the finger resting surface (30) at an angle (α) in one direction with respect to the other direction, the sensor unit of the finger resting surface (30). A fiber (310) provided for transport to the side opposite to (40) and arranged in the other direction of the finger resting surface (30) provides an optical image of the fingerprint to the sensor unit (40). 58. Apparatus according to claim 56 or 57, characterized in that it is provided for transport to a). 59. At least a portion of the fibers (310, 320) in the finger rest surface (30) are at least partially surrounded by an absorbing material in the form of a coating and / or a jacket. Claim 1 characterized by the following:
The device of at least one of the preceding items. 60. At least some of the fibers (310, 320) in the finger rest surface (30) are at least partially surrounded by a reflective material in the form of a coating and / or a jacket. Claim 1 characterized by the following:
60. The apparatus according to at least one of the preceding claims. 61. At least one of claims 1 to 60, characterized in that the finger rest surface (30) has a spread extending into the region above the light source (10).
The device according to item. 62. At least one of claims 1 to 61, characterized in that at least one light-impermeable blocking layer (130) is provided inside the finger placement surface (30). Equipment. 63. The device according to claim 62, wherein the barrier layer (130) is realized in the form of a closed fiber (310). 64. At least one of claims 1 to 63, characterized in that at least one light-impermeable blocking layer (140) is provided between the light source (10) and the sensor unit (40). An apparatus according to claim 1. 65. Apparatus according to claim 62, wherein the material of the light blocking layer (130, 140) is a lacquer. 66. Apparatus according to at least one of the preceding claims, wherein at least one filter (90) is provided. 67. Apparatus according to claim 66, wherein the filter (90) is a linear filter. 68. Apparatus according to claim 66, wherein the filter (90) is arranged between the finger rest surface (30) and the sensor unit (40). 69. A filter (90) on the side of the finger placement surface (30) opposite to the sensor unit (40) and / or on the sensor unit (40) of the finger placement surface (30). 69. The device according to at least one of claims 66 to 68, characterized in that it is arranged on the facing side. 70. Device according to at least one of the claims 66 to 69, characterized in that the filter (90) is provided inside the finger rest surface (30). 71. Apparatus according to at least one of claims 66 to 70, wherein the filter (90) has an absorbance of about 99 percent. 72. Apparatus according to at least one of claims 66 to 71, wherein the absorbance of the filter (90) is variable over different regions of the optical image. 73. The filter according to claim 72, wherein the absorbance of the filter in the edge region of the optical image is greater than the absorbance of the filter in the central region of the optical image. apparatus. 74. The absorption of the filter (90) in the edge region of the optical image is generally greater than the absorption of the filter (90) in the central region of the optical image by a factor of two to three and / or about 74. The apparatus of claim 73, wherein the device is between 6 and about 10 decibels. 75. The sensor unit (40) is directly adjacent to the finger rest surface (30) and / or the sensor unit (40) is mounted at the outlet of the finger rest surface (30). 75. Apparatus according to at least one of the preceding claims. 76. Apparatus according to at least one of the preceding claims, wherein the sensor unit (40) has at least one photosensitive surface and / or at least a photosensitive layer. 77. Device according to at least one of the preceding claims, wherein the sensor unit (40) operates on a semiconductor basis. 78. Apparatus according to claim 77, wherein the sensor unit (40) operates on a silicon basis. 79. Sensor unit (40) comprising at least one element based on CMOS technology or at least one circuit based on CMOS technology (CMOS = complementary MOS). The device according to at least one of the preceding items. 80. The sensor unit (40) comprises at least one charge-coupled device or at least one charge-coupled circuit (CCD = charge couple).
80. Apparatus according to at least one of the preceding claims, characterized in that it has a d device). 81. Device according to at least one of the claims 1 to 80, characterized in that the device is designed to be alive and aware (so-called "life support"). 82. The device according to claim 49, wherein the device is designed to determine the oxygen saturation in the blood in the front region of the finger by comparing the results obtained for two different wavelengths. An apparatus according to claim 1. 83. Apparatus according to at least one of the preceding claims, wherein the apparatus is battery operated.