KR20000013995A - Fingerprint image detection device and apparatus thereof - Google Patents

Abstract

PURPOSE: An apparatus for detecting a fingerprint image device is provided to minimize power consumption and achieve miniaturization by erasing a space for forming an illumination light path and an optical device. CONSTITUTION: The apparatus comprises a fingerprint image detecting device illuminating light corresponding to a contacted fingerprint shape in own itself and receiving the illuminated light to perform photoelectric conversion, an image signal processor for processing an image signal of the photoelectric-converted electric signal, and a fingerprint recognizer for recognizing the contacted fingerprint shape from the image signal.

Description

Fingerprint image detecting element and its device

The present invention relates to a fingerprint image detecting device and a device thereof, and more particularly, to enable the fingerprint image detecting device to be manufactured in a single semiconductor or an ultra-small configuration without separate lighting means and optical means, thereby forming an optical path. The present invention relates to a microscopic and highly sensitive fingerprint image detecting device for eliminating power consumption due to the use of noise components and lighting means.

BACKGROUND With the development of the electronic industry, electronic security devices have been rapidly manufactured, spread, and used, and therefore, devices and methods for preventing the use of third parties or controlling access are proposed and used. As a representative example, a device and a method for controlling usage and controlling access by a unique number and a password are used, which causes a problem of losing its effectiveness when accidental number matching occurs due to leakage or repeated input. It became.

Therefore, in recent years, a device and method for detecting a unique fingerprint shape which only an individual has and performing a third party's usage restriction and access control function have been widely used. A representative embodiment of the device for detecting the fingerprint shape is described below with reference to FIG. 1.

1 is a block diagram of a conventional fingerprint image detection device. First of all, its configuration includes an LED 2 for illuminating light of constant brightness; A prism (4) for selectively retransmitting the reflected light transmitted through the illuminated illumination light and reflected again; A focus lens (FL) for condensing the retransmitted reflected light at a focal position at a predetermined distance; A solid state image pickup device 3 for photoelectrically converting the focused light; An image signal processor 6 which processes the photoelectrically converted electrical signal into a fingerprint pattern image; A pattern recorder (7) which compares the fingerprint pattern image with a preset reference pattern image and determines whether the fingerprint pattern image is matched; And a display unit 8 for displaying the determination result.

The operation of the conventional fingerprint image detection device configured as described above, first, when the power supply to the LED (2) generates an illumination light of a constant brightness, in order to prevent the shadow is formed on the brighter illumination light and the reflector is usually symmetrical Use it in place. The illumination light must maintain a certain length of light path in order to form a spot of a certain size as a diffused light, in particular, in order to form a spot of a fingerprint size, the illumination light passes through a 45 degree prism 4 in cross section. The reflected light Bb reflected by the part of the user's fingerprint that is in contact with the prism is again transmitted through the prism, while the reflected light Ba and Bc by the non-contacted part are different by the inclination (45 degrees) of the prism. Reflected in the direction, the prism will not be retransmitted.

However, some of the non-contact reflected reflected light Ba, Bc is changed to scattered light by foreign matter on the surface of the prism, and eventually passes through the prism. The scattered light Ba, Bc is applied to the reflected light Bb. It acts as a noise light component.

Meanwhile, the reflected light Bb and the scattered light Ba and Bc, which are retransmitted to the prism, are focused at a focal position separated by a distance from the focus lens FL, and the reflected reflected light Bb and the scattered light Ba and Bc are collected. A solid state image pickup device (CCD: Charge Coupled Device, hereinafter referred to as CCD) converting into an electrical signal is converted into an electrical signal and output. Thereafter, the converted electric signal is processed into a fingerprint pattern image by the image signal processor 6 and input to the fingerprint recognition unit 7. The fingerprint pattern image is again a preset reference pattern. The user's permission or access permission is controlled according to the comparison result, i.e., whether or not it matches. In addition, the display unit 8 displays a use / access restriction warning or a use / access permission confirmation message according to whether the user agrees with the match, so that the user can recognize the current situation.

FIG. 2 illustrates a fingerprint pattern image detected by a conventional fingerprint image detecting apparatus, and corresponds to a noise component among the focused reflected light Bb and scattered light Ba and Bc, that is, scattered light Ba, The fingerprint pattern image in the state where noise is introduced by Bc) shows that it is a low resolution image.

On the other hand, the conventional fingerprint image detection device as described above has two LEDs to output the illumination light, so power consumption is greatly generated, and furthermore, the size of the device is increased due to the space required for the formation of the optical path of the illumination light. In addition, there is a problem in that the resolution decreases due to the use of a prism, that is, scattered light (Ba, Bc) scattered by the prism, that is, noise light component inflow.

Accordingly, the present invention has been created to solve the above problems, without the use of a separate illumination means and optical means, by using a prism to detect the fingerprint image detection element in a single chip (chip) or micro configuration, using a prism and It is an object of the present invention to provide a microscopic, high-sensitivity fingerprint image detection device and apparatus for removing noise components according to optical path formation, as well as removing power consumption due to use of lighting means in advance.

1 is a block diagram of a conventional fingerprint image detection device,

2 illustrates a fingerprint pattern image detected by a conventional fingerprint image detecting apparatus.

Figure 3 shows an embodiment of the light emitting means applied to the present invention,

4 illustrates a fingerprint image detecting device and an apparatus thereof according to an embodiment of the present invention.

5 is a flowchart illustrating an operation of a fingerprint image detection apparatus according to an embodiment of the present invention.

6 illustrates a fingerprint image detection device and its device according to another embodiment of the present invention,

7 illustrates a fingerprint image detection device and a fingerprint pattern image detected by the apparatus according to the present invention.

※ Explanation of code for main part of drawing

22: fingerprint image detection device 23: protective film 1

24: ELD (Electro Luminescent Device) 25: Protective Film 2

26,35: CCD (Charge Coupled Device) or CMOS image sensor

27,36: image signal processing unit 28,37: fingerprint recognition unit

According to an aspect of the present invention, there is provided a fingerprint image detecting device and a device comprising: light emitting means for self-emitting light corresponding to a contacted fingerprint shape; And a photoelectric conversion means for photoelectrically converting the emitted light, and further, itself emits light corresponding to the contacted fingerprint shape, and directly receives the emitted light. A fingerprint image detection device for photoelectric conversion; Image signal processing means for processing the photoelectrically converted electrical signal into an image signal; And fingerprint recognition means for recognizing the contacted fingerprint shape from the video signal.

The fingerprint image detecting element and the apparatus according to the present invention made as described above use light emitting means for self-emitting a corresponding light by a fingerprint shape contacted without a separate lighting means and optical means, and in particular, the emitted light By directly receiving and photoelectric conversion, it is possible to provide a high-sensitivity, ultra-small fingerprint image detection device and device free of noise components.

Hereinafter, a preferred embodiment of a fingerprint image detection device and apparatus according to the present invention will be described with reference to the accompanying drawings.

3 illustrates an embodiment of a light emitting means applied to the present invention. An electroluminescent device (ELD) is exemplarily described below. First, the structure of the ELD is composed of a back electrode 11, dielectrics 1, 2, 3 (12, 13, 14), a transparent electrode 15, and a substrate 16. The ELD will be briefly described. ELD is called "individual identification sensor", and the manufacturing method of the said individual identification sensor uses the "liquid method" which uses a high-purity, ultra-fine dielectric powder. As such, the rear electrode 11, which is one of the components of the ELD manufactured by the liquid phase method, enhances the stability of the phase detected by the individual identification sensor, and generates a constant light even in a material having a different resistance. Al or Cu is used as a general material. However, in FIG. 3, a capacitor ground switch operated when a finger is touched is attached. The dielectric 1 (12), by using a polymer having a dielectric constant value (Polymer) to enhance the dielectric constant, and serves to protect the device by directly blocking the device from the outside, the dielectric 2 (13) is identified individually As a layer that is very close to the performance of the device, the high purity, ultra-fine dielectrics made by the liquid phase method are powder-synthesized to form a shape with a high-pressure press, and the deposition process by magnetron sputtering A thin film is formed by this. In addition, the dielectric 3 14 is used by doping an activator to a II-IV compound semiconductor (eg, ZnS, ZnO, CdZnS) that generates light when directly receiving electrical energy. Depending on the type of light can generate different colors of light. Then, the transparent electrode 15 serves to transmit the generated light.

On the other hand, the substrate 16 is a substrate having a large transmittance (Transmittance) value, and a low surface roughness, for example, it may be used a borosilicate glass or a polymer substrate having excellent transparency.

Hereinafter, a detailed configuration and operation of the fingerprint image detection device and its device will be described in detail with reference to FIGS. 4 to 7.

4 illustrates a fingerprint image detection device and a device according to an embodiment of the present invention, wherein a protective film 1 (23) directly contacting a human finger, in particular, a thumb, which is easy to detect a unique fingerprint shape, An ELD 24 positioned under the passivation layer to self-emit light having a shape corresponding to a fingerprint shape, a CCD 26 for directly receiving and photoelectrically converting the emitted light, and the CCD to protect the CCD. A protective film 2 (25) located above, an image circuit (27) which is an image signal processing means for processing the photoelectrically converted electrical signal, and a recognition circuit (28) for recognizing a fingerprint image from the image signal. In particular, as shown, the components 23 to 26 are fingerprint image detection devices 22 made of one semiconductor chip, and the operation of the configuration is as follows.

When the user's finger contacts the ELD 24 through the protective film 1 23, the light corresponding to the contact portion, that is, the shape of the contacted fingerprint is emitted by itself, and the emitted light is again protected by the protective film 2. It passes through 25, is received by the CCD 26, and converted into an electrical signal. The converted electric signal is processed into a fingerprint pattern image through a series of signal processing, and thus fingerprint recognition is possible.

The series of processes will be described in detail with reference to FIG. First, FIG. 5 is a flowchart illustrating an operation of a fingerprint image detecting apparatus according to an embodiment of the present invention. When the user's finger contacts the fingerprint image detecting device 22, that is, the ELD is provided under the protective film 1 23. When contacting (S10) (24), the ELD (24) itself emits light corresponding to the fingerprint shape of the user in contact, the emitted light is a CCD (26) provided under the protective film 2 (25) Photoelectric conversion into an electrical signal. Thereafter, the amount (level) of the photoelectrically converted electric signal is detected (S20), and it is determined whether the detected amount (= light quantity) of the electric signal is a predetermined amount or more (S30). In order to extract the current still image, the CCD is shutter-on (S40), thereby extracting the current fingerprint image corresponding to one screen. In this way, the extracted fingerprint image is removed by the filtering (S50) operation of removing the high frequency component (noise) and output as a fingerprint pattern image (S60), and detects the characteristics of the fingerprint shape from the fingerprint pattern image (S70). To perform the operation. Thereafter, the characteristics of the fingerprint shape detected by the operation, that is, the characteristics of the fingerprint pattern, are compared with the characteristics of the pre-stored reference pattern (S80), and the use / access permission and confirmation message (S90) are respectively displayed according to the comparison result. Or use / access restrictions and warning messages.

Such a fingerprint image detecting device and its device according to an embodiment of the present invention are used for optical path formation and prism because the light emitted by the ELD 24 is directly received by the CCD 26 without a separate optical lens. The influx of noise components can be prevented in advance, so that a fingerprint image of high resolution can be detected, and since a separate lighting means and an optical means are unnecessary, it is possible to manufacture a microminiature.

6 illustrates a fingerprint image detecting device and a device according to another embodiment of the present invention, wherein a protective film 1 (33) in which a human finger, in particular, a thumb that easily detects a unique fingerprint shape is in contact with each other is shown. And an ELD 34 positioned below the passivation layer to emit light having a shape corresponding to a fingerprint, a focus lens FL for condensing the emitted light at a focal point away from the predetermined distance, and the focused light. And a CCD 35 for receiving and photoelectrically converting the light, a CCD circuit 36 for processing an image signal of the photoelectrically converted electrical signal, and a recognition circuit 37 for recognizing a fingerprint image from the video signal. Therefore, the use of the focus lens 35, which is different from the above-described configuration of FIG. 4, will be described.

In general, if the human thumb size is 2cm x 2cm, the size of the CCD corresponding to the size should have the same size. In general, the size of a universal CCD is 1/3 inch or 1/2 inch CCD. I use it a lot. Therefore, in order to use the 1 / 3-inch or 1 / 2-inch CCD, the use of the focus lens FL for condensing is inevitably necessary. In FIG. 6, a preferred configuration thereof is shown in FIG. 6. The CCD may be replaced with a CMOS image sensor.

The fingerprint image detection device and the device, in particular, the detection device according to another embodiment of the present invention can be miniaturized because it prevents the influx of noise components in advance and uses a small amount of optical means without a separate lighting means. In addition, it is possible to secure economic feasibility of using a generalized small size CCD.

Fingerprint image detection device and the device according to the present invention made as described above can minimize the power consumption because it does not use a separate lighting means, and also eliminates the necessary space in the device for forming the optical path of the illumination light and In addition, by minimizing the use of optical means (prism, focus lens, etc.) it is possible to miniaturize the device accordingly.

On the other hand, by eliminating the use of the prism, it is possible to prevent the degradation of the resolution due to the inflow of scattered light, that is, the noise light, thereby detecting a high resolution fingerprint image. Therefore, the ultra-small and high-resolution fingerprint image detection device and the device according to the present invention are very suitable for all devices requiring restriction of use or access control, especially notebook computers, cellular phones, vehicle door controllers, etc., which require miniaturization, and of course, low cost. In addition, it is a very useful invention that can be mass-produced and can greatly improve the price economic power of the applied product.

Claims (8)

Light emitting means for emitting light by itself corresponding to the contacted fingerprint shape; And And a photoelectric conversion means for photoelectrically converting the emitted light. According to claim 1, And the light emitting means is an electro luminescent device (ELD). According to claim 1, The photoelectric conversion means is a fingerprint image detection device, characterized in that the charge coupled device (CCD). According to claim 1, The photoelectric conversion means is a fingerprint image detection device, characterized in that the CMOS (Complementary-MOS) imaging device. According to claim 1, And a protective film for preventing damage due to external force, respectively, on the upper layer of the light emitting means and the photoelectric conversion means. A fingerprint image detecting device which emits light corresponding to the contacted fingerprint shape by itself and photoelectrically converts the emitted light; Image signal processing means for processing the photoelectrically converted electrical signal into an image signal; And fingerprint recognition means for recognizing the contacted fingerprint shape from the video signal. The method of claim 6, The fingerprint image detecting device comprises a single semiconductor chip. The method of claim 6, The fingerprint image detecting device may include: light emitting means for emitting light by itself corresponding to the contact shape of the fingerprint; Condensing means for condensing the emitted light to a predetermined focal position; And And a photoelectric conversion means for photoelectric conversion of the focused light.