CN210572838U - Prism of optical fingerprint acquisition instrument - Google Patents
Prism of optical fingerprint acquisition instrument Download PDFInfo
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- CN210572838U CN210572838U CN201921666083.2U CN201921666083U CN210572838U CN 210572838 U CN210572838 U CN 210572838U CN 201921666083 U CN201921666083 U CN 201921666083U CN 210572838 U CN210572838 U CN 210572838U
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Abstract
The utility model provides an optics fingerprint collection appearance prism belongs to check out test set technical field. The prism solves the problems that the existing prism is not enough in universality in the manufacturing process of an optical fingerprint acquisition instrument switch and the like. The prism of the optical fingerprint acquisition instrument comprises a quadrangular prism-shaped body, wherein the side surface of the body comprises a first side surface, a second side surface, a third side surface and a fourth side surface which are sequentially connected, the included angle between the first side surface and the second side surface is 57-65 degrees, the included angle between the first side surface and the fourth side surface is 42-60 degrees, the first side surface is set to be an acquisition surface which is used for being contacted with fingers, the second side surface is set to be a light-transmitting emergent surface, a light absorption layer can be arranged on any one of the third side surface and the fourth side surface, and the other remaining one of the third side surface and the fourth side surface is set to be a light-transmitting incident. The optical fingerprint acquisition instrument prism improves the universality of the prism in the development and manufacturing process of the acquisition instrument.
Description
Technical Field
The utility model belongs to the technical field of check out test set, a optics fingerprint collection appearance prism is related to.
Background
The fingerprint collecting instrument is a precise electronic instrument for identifying the identity of a person by utilizing the characteristics of different fingerprints, and the working principle comprises four functions of collecting fingerprint images, extracting fingerprint characteristics, storing data and comparing fingerprints. Wherein reading the fingerprint image is the most basic and most important function of the fingerprint acquisition instrument. By imaging with uneven patterns of a finger fingerprint, we generally refer to the raised patterns as "ridges" and the depressed pattern formation as "valleys", and the process of fingerprint acquisition is essentially that of fingerprint imaging. Among them, the optical fingerprint collecting instrument images by the optical principle, and is the most commonly used fingerprint collecting instrument at the earliest time. The optical fingerprint collector comprises a prism, a light source and an imaging device, wherein the light emitting diode provides the light source, and the imaging device comprises a lens and a photosensitive chip. The side of the prism comprises a collecting surface, an incident surface and an emergent surface, the collecting surface is in contact with the finger, a light source is arranged on the outer side of the incident surface, and an imaging device is arranged on the outer side of the emergent surface. Light enters the prism from the incident surface, is reflected on the collecting surface, then exits the prism through the emergent surface and is imaged on the imaging device.
At present, optical imaging of an optical fingerprint acquisition instrument has bright background imaging and dark background imaging. When imaging with bright background, if the finger does not contact the collecting surface, the light is totally reflected on the collecting surface, and the image collected by the imaging device is a bright background called bright background; when the finger contacts the collecting surface, ridge lines in the fingerprint are tightly attached to the collecting surface, a part of light in the light is absorbed by the finger at the ridge lines, and a dark line is formed on a bright background after reflection imaging. When imaging a dark background, if the finger does not contact the acquisition surface, the light is refracted on the acquisition surface and is emitted from the acquisition surface, and the image acquired by the imaging device is a dark background called the dark background; when a finger contacts the collecting surface, ridge lines in the fingerprint are tightly attached to the collecting surface, light is reflected at the ridge lines, and bright lines are formed on a dark background after reflection imaging. The two imaging principles have respective advantages and disadvantages and are suitable for different occasions. In practical application, some customers select bright background imaging and some customers select dark background imaging according to the difference of different occasions or integrated development capabilities.
Chinese patent literature document discloses a prism of an optical fingerprint sensor [ application No.: CN 200820086319.0; the notice number is: CN201191320Y ], wherein the prism for imaging the bright background is a triangular prism, the prism for imaging the dark background is a trapezoidal prism, and the shape of the prisms is different, which results in a change in the structure of the acquisition instrument, and the optical path of the imaging is also different, for example, when a customer needs to replace another acquisition instrument with another imaging principle, there are more places to be adjusted, which increases the cost of the change and increases the development time.
Disclosure of Invention
The utility model aims at the above-mentioned problem that prior art exists, provide an optics fingerprint collection appearance prism, the technical problem of solution is how to improve the commonality of prism in gathering appearance development manufacturing process.
The purpose of the utility model can be realized by the following technical proposal:
the prism of the optical fingerprint collector comprises a quadrangular prism-shaped body, wherein the side surface of the body comprises a first side surface, a second side surface, a third side surface and a fourth side surface which are sequentially connected, the prism is characterized in that the included angle between the first side surface and the second side surface is 57-65 degrees, the included angle between the first side surface and the fourth side surface is 42-60 degrees, the first side surface is set to be a collecting surface which is used for being contacted with fingers, the second side surface is set to be a light-transmitting emergent surface, a light-absorbing layer can be arranged on any one of the third side surface and the fourth side surface, and the other of the third side surface and the fourth side surface is a light-transmitting incident surface.
The imaging device is arranged on the outer side of the second side surface. When the light absorbing layer is arranged on the third side, the fourth side is an incident surface, light emitted by the light source is incident into the prism from the fourth side, the included angle between the first side and the fourth side is 42-60 degrees, the included angle between the second side and the first side is 57-65 degrees, the light is totally reflected when passing through the first side which is the collecting surface, the light is emitted from the second side after being reflected, a bright background is formed on the imaging device, when a finger presses on the first side, the ridge line absorbs part of the light, and the light forms a dark line on the bright background after being reflected at the ridge line to image the bright background. When the light absorbing layer is arranged on the fourth side face, the third side face is set as an incident face, light emitted by the light source is incident into the prism from the third side face, the third side face is opposite to the first side face set as the collecting face, the included angle between the first side face and the fourth side face is 42-60 degrees, the included angle between the first side face and the second side face is 57-65 degrees, the light is refracted when passing through the collecting face, the light is emitted out of the prism from the collecting face after being refracted, a dark background is formed on the imaging device, when a finger presses the first side face, the light is reflected at the ridge line, and the reflected light is emitted from the second side face, so that a bright line is formed on the dark background, and imaging is performed on the dark background. Therefore, when imaging with a bright background is required, the light absorption layer is arranged on the third side face, and the fourth side face is arranged as an incident face; when imaging of a dark background is required, the light absorption layer is arranged on the fourth side face, and the third side face is arranged as an incident face, so that the geometric structure of the prism is not required to be modified.
The imaging on the bright background and the dark background is reflected light at the ridge line, the imaging light path of the dark background and the bright background, namely the reflection light path at the ridge line, is almost unchanged, when a customer requires to change the imaging background, only the position of a light absorption layer of the prism needs to be adjusted, the geometric structure of the whole prism does not need to be changed, and on an adapted acquisition instrument, only the position of a light source needs to be adjusted, and the integral structure of the imaging device and the acquisition instrument does not need to be adjusted. The optical fingerprint acquisition instrument prism design improves the universality of the prism in the development and manufacturing process of the acquisition instrument, reduces the change cost and shortens the development time.
In the prism of the optical fingerprint acquirer, an included angle between the third side surface and the fourth side surface is an obtuse angle, and an included angle between the third side surface and the fourth side surface is smaller than an included angle between the third side surface and the second side surface. Therefore, the integrity of fingerprint collection during bright background imaging is improved, the imaging quality is improved, and the universality of the prism is ensured.
In the optical fingerprint sensor prism, an area of the third side surface is smaller than an area of the fourth side surface. Therefore, the integrity of fingerprint collection during bright background imaging is improved, the imaging quality is improved, and the universality of the prism is ensured.
In the optical fingerprint acquirer prism described above, the light absorbing layer completely covers the third side surface when the light absorbing layer is provided on the third side surface, and the light absorbing layer completely covers the fourth side surface when the light absorbing layer is provided on the fourth side surface. This arrangement can improve the image quality.
In the prism of the optical fingerprint acquisition instrument, the light absorption layer is made of black light absorption materials and is arranged on the body through a silk-screen printing process. The light absorption layer arranged in this way has good light absorption and uniform coating, and is favorable for improving the imaging quality.
Compared with the prior art, the utility model has the advantages of it is following:
the included angle between the first side surface and the second side surface of the prism and the included angle between the first side surface and the fourth side surface of the prism are set to be included angles within a specific angle range, then the first side surface is limited to be a collecting surface, the second side surface is limited to be an emergent surface, the third side surface is set to be an incident surface, when a light absorption layer is arranged on the fourth side surface, imaging of a dark background can be achieved, the light absorption layer is arranged on the third side surface, when the fourth side surface is set to be the incident surface, imaging of a bright background can be achieved, the universality of the prism in the development and manufacturing process of the collecting instrument is improved, when a customer requires to change an imaging principle, the geometric structure of the prism and the structure of the collecting instrument do not need to be changed. The light absorption layer completely covers the third side face or the fourth side face, and the light absorption layer is made of black light absorption materials and arranged on the prism through a silk-screen printing process, so that the imaging quality is improved.
Drawings
FIG. 1 is a schematic diagram of the optical path of the prism used for imaging a bright background;
fig. 2 is a schematic diagram of the optical path of the prism when used for imaging a dark background.
In the figure, 1, a body; 1a, a first side; 1b, a second side; 1c, a third side; 1d, a fourth side; 2. a light absorbing layer; 3. an imaging device; 4. a light source.
Detailed Description
The following are specific embodiments of the present invention and the accompanying drawings are used to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.
Example one
As shown in fig. 1 and 2, an optical fingerprint sensor prism includes a quadrangular prism-shaped body 1, wherein a bottom surface and a top surface of the body 1 are arranged in parallel, and a side surface of the body 1 is perpendicular to the bottom surface of the body 1. The side surface of the body 1 includes a first side surface 1a, a second side surface 1b, a third side surface 1c and a fourth side surface 1d which are connected in sequence. The included angle between the first side surface 1a and the second side surface 1b is 57 degrees to 65 degrees, and generally 57 degrees, 58 degrees, 59 degrees, 60 degrees, 61 degrees, 62 degrees, 63 degrees, 64 degrees, 65 degrees or the like is selected. The angle between the first side 1a and the fourth side 1d is 42-60 °, typically 46 °, 50 °, 54 ° or 58 °. The included angle between the third side 1c and the fourth side 1d is an obtuse angle, and the included angle between the third side 1c and the fourth side 1d is smaller than the included angle between the third side 1c and the second side 1 b. The area of the third side 1c is smaller than that of the fourth side 1d, that is, the side length of the side of the bottom surface of the body 1 connected to the third side 1c is smaller than the side length of the side of the bottom surface of the body 1 connected to the fourth side 1 d.
The first side surface 1a is provided as a collecting surface for contact with a finger, the second side surface 1b is provided as a light-transmitting exit surface, the light absorbing layer 2 may be provided on any one of the third side surface 1c and the fourth side surface 1d, and the remaining other one of the third side surface 1c and the fourth side surface 1d is provided as a light-transmitting entrance surface. The light absorption layer 2 is made of black light absorption materials and arranged on the prism body 1 through a silk-screen printing process. The imaging device 3 is disposed outside the second side surface 1b, and the imaging device 3 includes a lens and an imaging chip. When the light absorbing layer 2 is disposed on the third side surface 1c, the fourth side surface 1d is an incident surface, the light source 4 is disposed outside the fourth side surface 1d, and the light absorbing layer 2 completely covers the third side surface 1 c. When the light absorbing layer 2 is disposed on the fourth side surface 1d, the third side surface 1c is an incident surface, the light source 4 is disposed outside the third side surface 1c, and the light absorbing layer 2 completely covers the fourth side surface 1 d.
When a customer requires the optical fingerprint acquisition instrument to image with a bright background, as shown in fig. 1, a light absorbing layer 2 is arranged on a third side 1c of a prism body 1, a light source 4 is arranged outside a fourth side 1d, light emitted by the light source 4 is incident into the prism from the fourth side 1d, because the fourth side 1d and the second side 1b are both adjacent to a first side 1a which is an acquisition surface, and an included angle between the first side 1a and the fourth side 1d is one of 42 degrees to 60 degrees, and an included angle between the first side 1a and the second side 1b is one of 57 degrees to 65 degrees, the light is totally reflected when passing through the first side 1a which is the acquisition surface, and the light is emitted from the second side 1b after being reflected, so as to form a bright background on an imaging device 3, when a finger is pressed on the first side 1a, a ridge line absorbs part of the light, and the light forms a dark line on the bright background after being reflected at the ridge line, imaging a bright background.
When a customer requires the optical fingerprint acquisition instrument to image with a dark background, as shown in fig. 2, a light absorbing layer 2 is arranged on a fourth side 1d of a prism body 1, a light source 4 is arranged outside the third side 1c, light emitted by the light source 4 is incident into the prism from the third side 1c, because the third side 1c is opposite to a first side 1a arranged as an acquisition surface, a second side 1b is adjacent to the first side 1a, an included angle between the first side 1a and the fourth side 1d is one of 42 degrees to 60 degrees, an included angle between the first side 1a and the second side 1b is one of 57 degrees to 65 degrees, the light is refracted when passing through the acquisition surface, the light is emitted out of the prism from the acquisition surface after being refracted, so that the dark background is formed on an imaging device 3, and when a finger is pressed on the first side 1a, the light is reflected at a ridge line, the reflected light is emitted from the second side surface 1b, thereby forming a bright line on a dark background, which is imaged.
The imaging on bright background and dark background is the reflection light of ridge department, and the imaging light path of dark background and bright background is ridge department reflection light path and has hardly changed, and when the customer required to change the imaging background, only need adjust the position of prism light absorption layer 2, need not change the geometric structure of whole prism body 1, and on the adapted collection appearance, only need adjust the position of light source 4, imaging device 3 and the holistic structure of collection appearance do not need the adjustment. The optical fingerprint acquisition instrument prism design improves the universality of the prism in the development and manufacturing process of the acquisition instrument, reduces the replacement cost and shortens the development time.
The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made or substituted in a similar manner to the specific embodiments described herein by those skilled in the art without departing from the spirit of the invention or exceeding the scope of the invention as defined in the appended claims.
Claims (5)
1. An optical fingerprint acquisition instrument prism comprises a quadrangular prism-shaped body (1), wherein the side surface of the body (1) comprises a first side surface (1a), a second side surface (1b), a third side surface (1c) and a fourth side surface (1d) which are sequentially connected, characterized in that the angle between the first side surface (1a) and the second side surface (1b) is 57-65 degrees, the included angle between the first side surface (1a) and the fourth side surface (1d) is 42-60 degrees, the first side surface (1a) is arranged as a collecting surface for contacting with fingers, the second side surface (1b) is arranged as a light-transmitting emergent surface, a light absorbing layer (2) may be provided on either one of the third side face (1c) and the fourth side face (1d), the other of the third side surface (1c) and the fourth side surface (1d) is a light-transmitting incident surface.
2. The optical fingerprint scanner prism according to claim 1, characterized in that the third side (1c) and the fourth side (1d) are at an obtuse angle and the third side (1c) and the fourth side (1d) are at a smaller angle than the third side (1c) and the second side (1 b).
3. Optical fingerprinter prism as claimed in claim 2, characterized in that the area of the third side (1c) is smaller than the area of the fourth side (1 d).
4. Optical fingerprinter prism according to any of claims 1-3, characterized in that the light-absorbing layer (2) completely covers the third side (1c) when the light-absorbing layer (2) is provided on the third side (1c), and that the light-absorbing layer (2) completely covers the fourth side (1d) when the light-absorbing layer (2) is provided on the fourth side (1 d).
5. The optical fingerprint scanner prism as claimed in any one of claims 1 to 3, wherein said light absorbing layer (2) is provided on the body (1) by a silk-screen process from a black light absorbing material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921666083.2U CN210572838U (en) | 2019-09-30 | 2019-09-30 | Prism of optical fingerprint acquisition instrument |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921666083.2U CN210572838U (en) | 2019-09-30 | 2019-09-30 | Prism of optical fingerprint acquisition instrument |
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| Publication Number | Publication Date |
|---|---|
| CN210572838U true CN210572838U (en) | 2020-05-19 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921666083.2U Active CN210572838U (en) | 2019-09-30 | 2019-09-30 | Prism of optical fingerprint acquisition instrument |
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| CN (1) | CN210572838U (en) |
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- 2019-09-30 CN CN201921666083.2U patent/CN210572838U/en active Active
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