WO2008083538A1

WO2008083538A1 - Fingerprint acquisition method and highly definition type fingerprint acquisition apparatus

Info

Publication number: WO2008083538A1
Application number: PCT/CN2007/002415
Authority: WO
Inventors: Quanhong Che
Original assignee: Quanhong Che
Priority date: 2007-01-12
Filing date: 2007-08-13
Publication date: 2008-07-17
Also published as: CN101034437A

Abstract

A fingerprint acquisition method and a highly definition thin type of fingerprint acquisition apparatus are provided. In order to solve the problem of the small acquisition surface and worse definition, the method is that a light source irradiates the bottom base of a prism through the prism, the fingerprint on the bottom base of the prism is reflected to the reflecting mirror plate of the hypotenuse side of the prism and the black lacquer layer of the upper base of the prism, the fingerprint image on the reflecting mirror plate and the black lacquer layer is projected on a photoelectric detector through the right angle side of the prism anda lens. The fingerprint acquisition apparatus is composed of a light source, a right trapezoid prism on whose profile section the length of the base is greater than the height, a lens and a photoelectric detector, the lens and the photoelectric detector are positioned on the right angle side of the prism, the hypotenuse side of the prism has a reflecting mirror plate, a inclined reflecting mirror is mounted on the outside of the lens, the photoelectric detector is above the reflecting mirror, the upper base of the prism is coated with a black lacquer layer, the black lacquer layer and the reflecting mirror plate are used as reflecting surface.

Description

TECHNICAL FIELD The present invention relates to a fingerprint image acquisition technology, and in particular to a fingerprint collection method and a high-definition thin fingerprint collector. BACKGROUND OF THE INVENTION Fingerprint collectors currently in use have the drawbacks of being bulky and inconvenient to be used with other devices. For example, existing large-volume, heavy-weight fingerprint collectors are not suitable for use with devices with limited installation space such as mice, keyboards, door locks, automobiles, USB flash drives, and mobile phones. In addition, the existing fingerprint collection method has the defects of small fingerprint collection area and low definition. SUMMARY OF THE INVENTION An object of the present invention is to overcome the above-mentioned deficiencies of the prior art and to provide a fingerprint collecting method having a large reflecting surface and high definition. The invention also relates to a high definition thin fingerprint collector for carrying out the method.

In order to achieve the above object, the fingerprint collection method of the present invention uses a fingerprint collector composed of a light source, a right-angled prism having a longitudinal section with a bottom edge larger than a height, a lens and a photodetector, and the light source is irradiated through the prism to the lower surface of the prism, and the lower surface of the prism. The fingerprint is reflected on the mirror surface of the prismatic lumbar surface and the black lacquer layer on the bottom surface of the prism. The fingerprint image on the mirror surface and the black lacquer layer is then projected through the straight waist surface of the prism and the lens onto the photodetector. The principle of the optical path is as follows: The fingerprint image on the bottom surface of the prism is pressed in the longitudinal direction, and the fingerprint collecting surface on the lower surface of the prism is also distributed in the longitudinal direction, and the transverse direction is substantially not compressed and stretched, and the longitudinal direction is obviously compressed and stretched. When there is no black lacquer layer on the upper bottom surface of the prism, the fingerprint is only reflected by the mirror surface. Due to the limitation of the height of the mirror surface, the fingerprint length will be excessively compressed, and even some fingerprints cannot be reflected. When the over-compressed fingerprint image is finally restored by software, the distortion is too large. After adopting the method of the invention, the prism reflecting surface and the black lacquer layer on the upper surface of the prism form a reflecting surface of the fingerprint image, and the total length of the black lacquer layer of the mirror surface and the upper bottom surface is about ten times that of the mirror surface, that is, when reflecting The compression amount of the longitudinal length of the fingerprint is small, and the overall image of the fingerprint can be totally reflected. When the image is restored by software stretching, the image distortion is small, and the sharpness of the fingerprint image is not reduced; in addition, since the length of the reflection surface is not limited to the mirror surface length So rib The mirror can become very thin. Because of its advantages, it has a large collecting surface, a large reflecting surface, a good overall image of the fingerprint, and high definition.

As an optimization, the right-angled trapezoidal prism has triangular notches on both sides of the bottom surface, and the light sources are arranged at the triangular notches on both sides, and the light source is transmitted through the oblique wall at the notch to the lower surface of the prism. So designed, the light source is efficient and uniform.

As an optimization, the side of the upper surface of the prism near the oblique waist surface is coated with a black lacquer layer, and the fingerprint on the bottom surface of the prism is reflected on the mirror surface of the prism oblique waist surface and the black paint layer on the upper side of the prism near the inclined waist surface. The side of the prism with the bottom surface close to the straight waist surface has no black paint layer for setting the light source or the anti-counterfeit mark for automatic identification. This is because the upper surface of the prism near the side of the inclined waist can be used to reflect the fingerprint image. Therefore, the side of the upper surface of the prism near the straight waist surface can be used to set other functional components without applying a black lacquer layer.

The high-definition thin fingerprint collector of the invention comprises a light source, a right-angled trapezoidal prism with a longitudinal section with a bottom edge larger than a height, a lens, a mirror and a photodetector, and the lens and the photodetector are arranged on one side of the straight waist surface of the prism, and the oblique waist of the prism The mirror surface is arranged on the surface, and the mirror is arranged on the outer side of the lens, and the photoelectric detector is arranged on the upper side of the mirror. The special feature is that the bottom surface of the prism is coated with a black paint layer, and the black paint layer and the mirror surface are used as the reflection surface. So designed, the inventors have found that: the upper surface of the prism coated with black paint and the inclined waist surface made of prism with mirror can simultaneously serve as the reflecting surface, so that the length of the collected fingerprint is no longer limited by the length of the inclined waist surface of the mirror. . Since the length of the fingerprint is no longer limited by the length of the inclined waist surface of the mirror, that is, it is no longer limited by the thickness of the prism, the thickness of the prism can be further thinned on the basis of the prior art, and the prism collecting surface can be arbitrarily enlarged. Since the fingerprint length of the collection is not limited by the thickness of the prism, it can be arbitrarily increased as needed, the area of the fingerprint can be increased, the imaging area of the fingerprint is increased, and the amount of information of the fingerprint image is also increased, so the sharpness of the fingerprint image can be further improved. Clear. The utility model has the advantages of thin prism, small thickness of the collector, small volume, light weight, large collecting surface and reflecting surface, and high definition.

As an optimization, the side of the upper surface of the prism near the straight waist surface is coated with an anti-counterfeit mark. This design increases the anti-counterfeiting function.

As an optimization, the side of the upper surface of the prism near the inclined waist surface is coated with a black lacquer layer. So designed, because only the side of the prism with the bottom surface close to the inclined waist surface has the function of reflecting fingerprint image, the upper surface of the prism only applies the black lacquer layer on the side close to the oblique waist surface, and does not affect the integrity of the fingerprint image. At the same time, other functional components such as illumination sources, micro switches, etc. can be placed on the part of the prism whose bottom surface is not painted with black paint. As an optimization, the length of the portion coated with the black lacquer layer is 2/3 of the length of the upper surface of the prism. Designed to meet the needs of fingerprint capture length.

As an optimization, the prism thickness is 5-9 mm; the light source, prism, lens and photodetector are all mounted in a black box. More specifically: the light source, prism, lens and photodetector are all mounted in an optical black box. In this way, the former, when the prism thickness is 5-9 mm, the length of the fingerprint collected can still be increased from the existing 18 mm to 24 mm. The overall collector thickness can be as small as 7-12 mm. The latter is beneficial to improve the sharpness of the fingerprint image.

As an optimization, a right-angled trapezoidal prism has triangular notches on both sides of the bottom surface, and light sources are arranged at the triangular notches on both sides. In this way, the former is beneficial to increase the light intensity, while the latter is beneficial to make the light distribution more uniform.

As an optimization, three triangular light sources are sequentially arranged at the triangular notches on both sides. This design helps to increase the illuminance and make the light source distribution more uniform.

As an optimization, the bottom surface of the right-angled trapezoidal prism is coated with a transparent elastic resin film; the angle between the prism reflecting surface and the lower bottom surface is 70-75 degrees; the angle of the mirror is 45 degrees. In this way, the former, the introduction of the transparent elastic resin film can overcome the defect that the dry finger can not be normally imaged, and is beneficial to improve the sharpness of the fingerprint image. The latter helps to ensure the clarity and integrity of the image. Helps improve image quality.

As an optimization. The part of the prism whose bottom surface is close to the straight waist side and is not covered with a black lacquer layer is provided with an illumination light source or a micro switch. In this way, the former can increase the light intensity, and the latter can realize the function of opening when the fingerprint is pressed and closing when the finger is released with the simplest structure.

After adopting the above technical solution, the fingerprint collection method of the invention has the advantages of large fingerprint reflection surface, large collection area and sharpness.

After adopting the above technical solution, the high-definition thin fingerprint collector of the invention has the advantages of small thickness, small volume, light weight, large fingerprint image acquisition and reflection area, high definition, and high precision, and the collector and the prism can be realized compared with the existing fingerprint collector. Ultra-thin, convenient for use with devices with limited installation space such as mouse, keyboard, door lock, car, USB flash drive, and mobile phone. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic structural view of a high-definition thin fingerprint collector according to the present invention;

Figure 2 is a left side view of the prism portion of Figure 1; Figure 3 is a bottom plan view of the prism portion of Figure 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following further describes the present invention with reference to the accompanying drawings and specific examples:

The fingerprint collection method of the invention uses a fingerprint collector composed of a light source, a right-angled prism with a longitudinal section greater than a height, a lens and a photodetector, and the light source is irradiated to the lower surface of the prism through the prism, and the fingerprint on the lower surface of the prism is reflected to the prism. On the black lacquer layer on the mirror surface of the inclined waist and the bottom surface of the prism, the fingerprint image on the mirror surface and the black lacquer layer is then projected onto the photodetector through the straight waist surface of the prism and the lens. Right-angled trapezoidal prisms have triangular notches on both sides of the bottom surface, and light sources are arranged at the triangular notches on both sides, and the light source is transmitted through the oblique wall at the notch to the lower surface of the prism. The side of the upper surface of the prism near the inclined waist surface is coated with a black lacquer layer, and the fingerprint on the bottom surface of the prism is reflected on the mirror surface of the prism oblique waist surface and the black paint layer on the upper side of the prism near the inclined waist surface. The side of the prism with the bottom surface close to the straight waist surface has no black paint layer. It can be used to set the anti-counterfeiting mark for automatic identification or to set the light source for enhancing the illumination intensity and improving the definition.

As shown in the figure, the high-definition thin fingerprint collector of the present invention is composed of a light source 1, a right-angled trapezoidal prism with a longitudinal section whose bottom edge is larger than a high angle, a lens 3, a mirror 5 and a photodetector 4, and the lens 3 and the photodetector 4 are arranged. On the side of the straight waist surface of the prism 2, the inclined surface of the prism 2 is provided with a mirror surface 8, and the outer side of the lens 3 is provided with a mirror 5 disposed obliquely. Above the mirror 5 is a photodetector 4, and the bottom surface of the prism 2 is close to the slope. One side of the waist is coated with a black lacquer layer 7, a black lacquer layer 7 and a mirror surface 8 as reflecting surfaces. The ratio of the length of the 7-part black lacquer to the length of the upper surface of the prism 2 is 2/3. Right-angled trapezoidal prism 2 has a triangular notch on both sides of the upper bottom surface. 6 Both sides of the triangular notch are equipped with a light source 1. There are three high-brightness LED light sources 1 arranged in sequence in each of the six triangular notches on both sides. The lower corner of the rectangular trapezoidal prism 2 is coated with a transparent elastic resin film 9. The angle between the reflective surface of the prism and the lower surface is 70-75 degrees. The angle of inclination of the mirror 5 is 45 degrees. The light source 1, the prism 2, the lens 3, the mirror 5 and the photodetector 4 are all mounted in a black box.

The optical path is: The LED light source 1 is transmitted through the prism 1 to the transparent elastic resin film 9, and the light reflected by the transparent elastic resin film 9 is incident on the inclined waist surface of the prism 2 and the black lacquer layer 7, and the mirror surface 8 of the prism oblique waist surface The light reflected by the black lacquer layer 7 is incident on the lens 3 through the straight waist surface of the prism 2. The light emitted from the lens 3 is reflected by the mirror 5 and then projected to the photodetector 4 above it, thereby completing the collection of the fingerprint image.

Claims

Claim

1. A fingerprint acquisition method, which uses a fingerprint collector composed of a light source, a right-angled prism having a longitudinal section larger than a height, a lens and a photodetector, wherein the light source is irradiated to the lower surface of the prism through the prism, and the lower surface of the prism The upper fingerprint is reflected on the mirror surface of the prismatic lumbar surface and the black lacquer layer on the upper surface of the prism. The fingerprint image on the mirror surface and the black lacquer layer is then projected through the straight waist surface of the prism and the lens onto the photodetector.

2. The fingerprint collection method according to claim 1, wherein the right-angled trapezoidal prism has a triangular notch on both sides of the bottom surface, and the light source is mounted on the triangular notches on both sides, and the light source is transmitted through the oblique wall at the notch. The bottom surface of the prism.

3. The fingerprint collection method according to claim 2, wherein the upper surface of the prism is coated with a black lacquer layer only on a side close to the oblique waist surface, and the fingerprint on the lower surface of the prism is reflected on the mirror surface of the prism oblique waist surface and The bottom surface of the prism is close to the black lacquer layer on the side of the inclined waist surface; the side of the upper surface of the prism near the straight waist surface is not covered with a black lacquer layer, and is used for setting a light source or an anti-counterfeit mark for automatic identification.

4. A high-definition thin fingerprint collector consisting of a light source, a right-angled trapezoidal prism with a longitudinal section greater than a height, a lens, a mirror, and a photodetector. The lens and the photodetector are disposed on one side of the prism straight waist surface, and the prism The inclined waist surface is provided with a mirror surface, and the outer side of the lens is provided with an obliquely arranged mirror. Above the mirror is a photoelectric detector, which is characterized in that the upper surface of the prism is coated with a black lacquer layer, and the black lacquer layer and the mirror surface are used as a reflecting surface.

5. The high-definition thin fingerprint collector according to claim 4, wherein the side of the upper surface of the prism adjacent to the straight waist surface is coated with an anti-counterfeiting mark.

6. The high-definition thin fingerprint collector according to claim 4, wherein a side of the upper surface of the prism adjacent to the inclined waist surface is coated with a black lacquer layer.

7. The 髙 clear thin fingerprint collector according to claim 6, wherein the length of the portion coated with the black lacquer layer is 2/3 of the length of the upper surface of the prism.

8. A high definition thin fingerprint collector according to claim 4 or 5 or 6 or 7, wherein the prism has a thickness of 5 to 9 mm; the light source, the prism, the lens and the photodetector are all mounted in a black casing.

9. The high-definition thin fingerprint collector according to claim 8, wherein the right-angled trapezoidal prism has triangular notches on both sides of the bottom surface, and light sources are arranged at the triangular notches on both sides.

10. The high-definition thin fingerprint collector according to claim 9, wherein each of the three triangular notches is provided with three LED light sources arranged in sequence.

11. The high-definition thin fingerprint collector according to claim 8, wherein the bottom surface of the right-angled trapezoidal prism is coated with a transparent elastic resin film; the angle between the prism reflecting surface and the lower bottom surface is 70-75 degrees; The angle of inclination is 45 degrees.

12. The high-definition thin fingerprint collector according to claim 8, wherein the portion of the upper surface of the prism that is not coated with the black lacquer layer on the side close to the straight waist surface is provided with an illumination source or a micro switch.