CN210324228U

CN210324228U - Novel fingerprint and palm print acquisition optical system

Info

Publication number: CN210324228U
Application number: CN201921169328.0U
Authority: CN
Inventors: 朱健吾
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-07-24
Filing date: 2019-07-24
Publication date: 2020-04-14
Anticipated expiration: 2029-07-24

Abstract

The utility model discloses a novel fingerprint and palm print collecting optical system, which comprises a prism, wherein an inclined reflector is arranged below the prism, an imaging objective lens is arranged on the right side of the reflector, and an image sensor is arranged on the right side of the imaging objective lens; the right side of the prism is provided with a light source, the prism is also provided with a collecting surface, a first reflecting surface, a second reflecting surface and a light source incidence surface, and the second reflecting surface is provided with an internal reflecting film; the light source is positioned outside the light source incidence surface and is parallel to the light source incidence surface; the fingerprint or palm print pattern on the collecting surface sequentially passes through the first reflecting surface, the second reflecting surface and the reflecting mirror, passes through the imaging objective lens and finally reaches the image sensor. The utility model provides a novel optical system is gathered to fingerprint, palm print adopts the mode of hi-lite collection background, has effectively reduced the influence of external parasitic light to fingerprint, palm print image acquisition effect, effectively dwindles system size and equipment volume simultaneously, reduces and makes the degree of difficulty and manufacturing cost.

Description

Novel fingerprint and palm print acquisition optical system

Technical Field

The utility model relates to the field of optical technology, especially, relate to a novel optical system is gathered to fingerprint, palm print.

Background

The prior fingerprint or palm print acquisition equipment has the defects of easy interference of acquisition effect by external stray light, larger equipment volume, high production difficulty, high manufacturing cost and the like. The present invention is intended to provide a solution in these respects.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects of the prior art, the utility model provides a novel fingerprint and palm print collecting optical system.

The utility model discloses technical scheme as follows: a novel fingerprint and palm print collecting optical system comprises a prism, wherein an inclined reflector is arranged below the prism, an imaging objective lens is arranged on the right side of the reflector, and an image sensor is arranged on the right side of the imaging objective lens;

the right side of the prism is provided with a light source, the prism is also provided with a collecting surface, a first reflecting surface, a second reflecting surface and a light source incidence surface, the collecting surface is positioned above the first reflecting surface and is parallel to the first reflecting surface, the collecting surface and the second reflecting surface form an obtuse angle and form an acute angle with the light source incidence surface, and the second reflecting surface is provided with an internal reflecting film;

the light source is positioned outside the light source incidence surface and is parallel to the light source incidence surface;

the fingerprint or palm print patterns on the collecting surface sequentially pass through the first reflecting surface, the second reflecting surface and the reflector, pass through the imaging objective lens and finally reach the image sensor.

Preferably, the imaging objective is a non-telecentric objective or a telecentric objective.

Preferably, the light source is an LED backlight plate.

According to the above scheme the utility model discloses, its beneficial effect lies in, uses the highlight to gather the background, and the external parasitic light of greatly reduced has formed the cubic turn to fingerprint or palm print image acquisition effect's influence in gathering the imaging process for the volume of system reduces greatly, and weight reduction, manufacturing cost reduce.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a schematic structural view of the present invention with the reflector removed.

In the figure, 10, a prism; 11. collecting noodles; 12. a first reflective surface; 13. a second reflective surface; 14. a light source incident surface; 20. a mirror; 30. an imaging objective lens; 40. an image sensor.

Detailed Description

The invention is further described with reference to the following figures and embodiments:

the technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and obviously, the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

As shown in fig. 1-2, a novel optical system for collecting fingerprints and palmprints comprises a prism 10, an inclined reflector is arranged below the prism 10, an imaging objective lens 30 is arranged on the right side of the reflector, and an image sensor 40 is arranged on the right side of the imaging objective lens 30;

a light source (not shown) is arranged on the right side of the prism 10, the prism 10 is further provided with a collecting surface 11, a first reflecting surface 12, a second reflecting surface 13 and a light source incidence surface 14, the collecting surface 11 is positioned above the first reflecting surface 12 and is parallel to the first reflecting surface 12, the collecting surface 11 and the second reflecting surface 13 form an obtuse angle and form an acute angle with the light source incidence surface 14, and the second reflecting surface 13 is provided with an internal reflecting film;

the light source (not shown) is located outside the light source incidence surface 14 and is parallel to the light source incidence surface 14;

the fingerprint or palm print pattern on the collecting surface 11 passes through the first reflecting surface 12, the second reflecting surface 13 and the reflector 20 in sequence, passes through the imaging objective lens 30 and finally reaches the image sensor 40.

In the first embodiment, when no finger or palm is placed on the collecting surface 11, the light emitted from the light source 14 irradiates the collecting surface 11 through the light source incidence surface 14, wherein a portion of the light is totally reflected at the collecting surface 11, then totally reflected for the second time at the first reflection surface 12, reflected for the third time at the second reflection surface 13, reflected for the fourth time at the reflector 20, and then passes through the imaging objective lens 30 to be projected onto the image sensor 40, so as to form a high-brightness collecting background.

When a finger or the like is placed on the collecting surface 11, the convex portion of the fingerprint comes into contact with the collecting surface 11, and the total reflection condition at that place is broken, thereby forming a low-luminance streak pattern on a high-luminance collecting background.

The collection surface 11 and the light source incidence surface 14 form an acute angle, so that a light source (not shown in the figure) can be better collected into the system, the collection surface 11 and the first reflection surface 12 form an obtuse angle, so that fingerprint information can be better reflected into the image sensor 40, and the light source is parallel to the light source incidence surface 14, so that the light source (not shown in the figure) can be better guided into the system. Except for the collecting surface 11, the first reflecting surface 12, the second reflecting surface 13 and the light source incidence surface 14, all the other surfaces of the prism 10 do not participate in imaging, and the other surfaces are coated with black matting paint for eliminating the interference of stray light on imaging.

In the second embodiment, in this system, the mirror 20 is used to divert the optical path, so that the volume of the device is reduced, and in some cases that the volume of the device does not need to be considered, the mirror 20 can be eliminated, and the image acquisition effect is not affected.

The imaging objective 30 is a non-telecentric objective or a telecentric objective. The design of the non-telecentric objective lens is to reduce the manufacturing cost of the product and reduce the volume and weight of the equipment, and the telecentric objective lens can realize the optical correction of image distortion, but the system size is larger and the manufacturing cost is higher.

The light source 14 is an LED backlight. And the LED backlight plate is adopted, so that the illumination is more uniform, and the imaging is easier.

Compared with the prior art, the fingerprint or palm print image acquisition system has the beneficial effects that by adopting the scheme, the influence of external stray light on the fingerprint or palm print image acquisition effect can be greatly reduced.

The second beneficial effect is that the external optical path is greatly shortened by multiple reflections inside the prism 10, thereby reducing the system size and the equipment volume.

The third beneficial effect is that the relative surface of the prism 10 is used as a reflecting surface, so that the external reflecting mirror is reduced, and the precision of the system is easier to ensure.

The prism has the beneficial effects that the related surface of the prism 10 is used as a reflecting surface, so that external reflectors are reduced, the system structure is simpler, and the cost is lower.

It will be understood that modifications and variations can be made by persons skilled in the art in light of the above teachings and all such modifications and variations are considered to be within the scope of the invention as defined by the following claims.

The above exemplary description of the present invention is made in conjunction with the accompanying drawings, and it is obvious that the present invention is not limited by the above manner, and various improvements made by the method concept and technical solution of the present invention or by directly applying the concept and technical solution of the present invention to other occasions without improvement are all within the protection scope of the present invention.

Claims

1. A novel fingerprint and palm print collecting optical system is characterized by comprising a prism, wherein an inclined reflector is arranged below the prism, an imaging objective lens is arranged on the right side of the reflector, and an image sensor is arranged on the right side of the imaging objective lens;

2. The fingerprint and palm print collecting optical system as claimed in claim 1, wherein the imaging objective is a non-telecentric objective or a telecentric objective.

3. The optical system for collecting fingerprint and palm print of claim 1, wherein the light source is a backlight LED panel.