CN1940960A - Semi-reflective composite fingerprint identification device - Google Patents

Abstract

The invention relates to a semi-reflection composite fingerprint identification device, which comprises a composite double lens, a sensor and at least one light source; the sensor is arranged below the combined double-lens, and the combined double-lens is provided with a first curved surface, a second curved surface and a third curved surface; the second curved surface and the third curved surface are metal films or dielectric material films with the semi-penetrating and semi-reflecting characteristics, so that light rays generated by the light source are imaged on the sensor through the composite double lenses. In addition, the invention utilizes the design of the composite double-lens to ensure that the angle of light entering the lens is smaller, thereby achieving the focusing imaging effect under the condition of wide angle.

Description

Semi-reflective composite fingerprint identification device

technical field

The invention relates to a fingerprint identification device, in particular to a semi-reflection composite fingerprint identification device.

Background technique

In addition to genes, fingerprints are the earliest and most stable biological characteristics of human beings. No two people's fingerprints are the same. According to biologists, the fingerprints of human beings are already formed in the embryonic stage of three months old. In the following life, the fingerprint characteristics will almost never change, which can be said to be the most stable biological characteristics.

With the rapid development of science and technology, the traditional method of identifying the authenticity of ID cards with naked eyes and confirming people's identities has become difficult to prevent intelligent crimes by malicious people. In order to protect their own rights and avoid loss of rights and interests caused by fraudulent use of ID cards, most of them are gradually using fingerprint recognition devices to confirm their identities.

Currently, most of the fingerprint identification devices used are mainly of the traditional optical refraction type, and do not use reflective fingerprint identification devices. However, when using a total reflection fingerprint identification device, since the light reflected from the fingerprint surface of the finger enters the lens at a large angle, the focus imaging effect is blurred. Therefore, the purpose of the present invention is to propose a device to solve this problem.

Contents of the invention

The main purpose of the present invention is to provide a semi-reflective composite fingerprint identification device to achieve a good focusing effect.

Another object of the present invention is to form a light path that reflects and penetrates between the lenses at the same time through the design of the compound double lens, thereby achieving a light, thin, and short design of the fingerprint recognition device.

According to the present invention, a semi-reflective compound fingerprint identification device includes a compound double lens, a sensor and at least one light source, the sensor is arranged under the compound double lens, and the compound double lens includes a first curved surface, a second The two curved surfaces and the third curved surface, the first curved surface is for a finger to be placed on it, the light generated by the light source can be irradiated to the fingerprint surface of the finger on the first curved surface, and the light reflected by the fingerprint surface of the finger passes through the composite double lens, so It has both reflective and penetrating functions, so that reflected light can be imaged on the sensor.

In the following, a detailed description will be made through specific embodiments and accompanying drawings, so that it will be easier to understand the purpose, technical content, characteristics and effects of the present invention.

Description of drawings

Figure 1 is a schematic diagram of the present invention.

Fig. 2 is the first embodiment of the present invention.

Fig. 3 is a second embodiment of the present invention.

Fig. 4 is a third embodiment of the present invention.

[Description of main component symbols]

2--compound double lens 21, 21’, 21”--the first curved surface

23--Second curved surface 24--Third curved surface

3--Light source 4--Sensor

Detailed ways

The invention relates to a semi-reflective composite fingerprint identification device, which utilizes the design of composite double lenses to achieve the effect of focusing and imaging under wide-angle conditions.

As shown in FIG. 1 , which is a schematic view of the present invention, a semi-reflective composite fingerprint recognition device includes a composite double lens 2 , at least one light source 3 and a sensor 4 . Wherein, the at least one light source 3 is located at the bottom of the double lens 2 .

When in use, a finger is placed on the compound double lens 2, and the sensor 4 is arranged under the compound double lens 2. Through the structure of the compound double lens 2, the image of the fingerprint surface of the finger can be transmitted to the sensor 4, so that The sensor 4 senses the accurate fingerprint image, and then achieves the identification of the user.

As shown in Figure 2, it is the first embodiment of the present invention, and the composite double lens 2 of the present invention has a first curved surface 21, a second curved surface 23 and a third curved surface 24, and the first curved surface 21 is for a finger Placed on it, it is a transparent material made of glass or plastic or a mixture of glass and plastic, and the first curved surface 21 is a convex surface, and the light generated by at least one light source 3 is directly irradiated on the first curved surface 21. Fingerprint surface, and the first curved surface 21 can be a spherical or aspherical convex surface, and due to the concave-convex texture of the fingerprint surface, different light and dark reflected light rays are generated, and the reflected light rays pass through the composite double lens 2 to achieve reflection and penetration. Efficacy is because the mirror surface of the composite double lens 2 has a metal film or a dielectric material film with semi-penetrating and semi-reflective properties, so the light reflected by the finger print can penetrate the second curved surface 23 and the third curved surface 24. semi-transparent metal film or dielectric material film, and is reflected by semi-reflective metal film or dielectric material film at the same time.

In the fingerprint identification device of the present invention, the fingerprint identification process is that the light source 3 emits light and the light is diffused and uniformed, and guided to the first curved surface 21 . When the light irradiates the finger on the first curved surface 21, the reflected light b1 with different brightness and darkness will be generated due to the unevenness of the fingerprint surface of the finger. The reflected light b1 generated by the finger on the first curved surface 21 passes through the second curved surface 23 The penetrating light b2 is generated to pass to the third curved surface 24, and the reflected light b3 is formed on the third curved surface 24, and the reflected light b3 is reflected from the third curved surface 24 to the second curved surface 23, and the reflected light b4 generated by the second curved surface 23 The light is reflected to the third curved surface 24 and penetrates the third curved surface 24 to form the light b5, and finally the light b5 is focused on the sensor 4 to form an image. Therefore, the light path is light b1 → light b2 → light b3 → light b4 → light b5 → imaging.

As shown in Figure 3, it is the second embodiment of the present invention. The difference between the second embodiment and the first embodiment is that the first curved surface 21' of the compound double lens 2 is a plane, and its structure is the same.

As shown in FIG. 4 , it is the third embodiment of the present invention. The difference between the third embodiment and the first embodiment is that the first curved surface 21 ″ of the compound double lens 2 is concave, and other structures are the same.

To sum up, the present invention provides a semi-reflective fingerprint recognition device. The difference between it and the conventional one is that the reflected light from the fingerprint surface of the conventional finger enters the lens at a large angle, resulting in blurred focusing and imaging effects, and the volume is too large. Therefore, the present invention utilizes the design of the composite lens, and its maximum thickness cannot exceed 15 millimeters, forming a penetrating and reflecting effect between the composite lenses and thereby prolonging the optical path, so that the angle at which the light finally focuses on the sensor is small, so as to achieve About 1/5 of the traditional optical refraction lens has a short total optical path length, and can achieve wide-angle focusing imaging effect, and the volume is only 1/4 of the traditional optical refraction lens.

The above description refers to the preferred embodiments of the present invention, and specifically represents and explains, but those skilled in the art should understand that various changes in form and details cannot deviate from the spirit and spirit of the present invention. Apply for a patent scope.

Claims (10)

1. A semi-reflective fingerprint recognition device, characterized in that it comprises: A composite double lens, which includes a first curved surface, a second curved surface, and a third curved surface; at least one light source, the light generated by it can irradiate the fingerprint on the first curved surface, so that the light reflected by the fingerprint is transmitted to the compound double lens; and A sensor, which is arranged under the compound double lens, is used to receive the light transmitted by the compound double lens, so that the sensor senses the image of the finger print. 2. The semi-reflective fingerprint identification device according to claim 1, wherein the first curved surface is a transparent transparent surface made of glass, plastic or glass-plastic mixture. material. 3. The semi-reflective fingerprint identification device according to claim 2, wherein the first curved surface can be one of a convex surface, a flat surface or a concave surface. 4. The semi-reflective fingerprint recognition device according to claim 3, wherein the first curved surface can be a spherical surface. 5. The semi-reflective fingerprint recognition device according to claim 1, wherein the maximum thickness of the composite double lens cannot exceed 15 mm. 6 . The semi-reflective fingerprint identification device according to claim 4 , wherein the second curved surface and the third curved surface have metal thin films with semi-transmissive and semi-reflective properties. 7. The semi-reflective fingerprint identification device according to claim 1 or 6, wherein the second curved surface and the third curved surface further include a semi-transmissive and semi-reflective dielectric material film. 8. The semi-reflective fingerprint identification device according to claim 1 or 5, wherein the light reflected by the fingerprint is a semi-penetrating metal that can penetrate the second curved surface and the third curved surface. film and is reflected by a semi-reflective metal film. 9. The semi-reflective fingerprint recognition device according to claim 1, wherein the lens is to focus the light reflected from the fingerprint surface of the finger onto the sensor. 10. The semi-reflective fingerprint identification device according to claim 1, wherein the light generated by the at least one light source is diffused to form a uniform light, and then irradiated onto the first curved surface finger prints on.

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