CN108629253B - Fingerprint Identification Device - Google Patents

Abstract

The invention discloses a fingerprint identification device, which comprises a cover plate, an image sensing chip, a light guide part, at least one light emitting part, a collimating part and a light folding part. The image sensing chip is positioned on one side of the cover plate; the light guide piece covers the image sensing chip and comprises a light inlet surface and a light outlet surface, and the light outlet surface is provided with a microstructure; the light emitting element is arranged adjacent to the light incident surface. The collimating component is positioned between the light-emitting surface and the image sensing chip, and the refraction component is positioned between the collimating component and the image sensing chip and comprises a plurality of refraction structures; the outer diameter of the refraction structure is gradually reduced to form sharp angles with the distance from the collimation piece, and the angles of the sharp angles are gradually increased with the distance from the central line of the refraction piece.

Description

Fingerprint Identification Device

technical field

The present invention relates to a device for reading or identifying patterns, and more particularly, to a fingerprint identification device.

Background technique

Fingerprint identification technology is widely used in various electronic devices because of its good anti-theft and personal privacy protection functions to prevent electronic devices from being stolen.

In the past, the size of the image sensor chip in the fingerprint recognition device was mainly determined by the size of the sensing area. More specifically, the smaller the sensing area is, the smaller the size of the image sensing chip is; conversely, the larger the sensing area is, the larger the size of the image sensing chip is, and the size of the image sensing chip is also larger. It will be the same as the size of the sensing area, so as to improve the resolution capability of the image sensor chip. However, large-sized image sensor chips have disadvantages such as high cost and large volume.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a fingerprint identification device, which can reduce the size of the image sensor chip to reduce the cost.

A fingerprint identification device provided by the present invention has a finger sensing area and includes a cover plate, an image sensing chip, a light guide member, at least one light-emitting member, a collimating member and a light-refracting member. The image sensing chip is located on one side of the cover plate; the light guide element covers the image sensing chip and includes a light incident surface and a light emitting surface, the light emitting surface is provided with a microstructure; the light emitting element is arranged adjacent to the light incident surface. The collimating member is located between the light-emitting surface and the image sensing chip, and the refractive member is located between the collimating member and the image sensing chip, and includes a plurality of refractive structures; the outer diameter of the refractive structures is formed by tapering as it moves away from the collimating member. A sharp corner, and the angle of the sharp corner of the refractive structure gradually increases as it moves away from the center line of the refractive element.

In one embodiment of the present invention, the image sensing chip includes a plurality of sensing pixels. When the length of the cross section of the image sensing chip formed by the optical axis of the sensing pixels is a, the finger sensing area is at When the length of the cross section is b, the following conditions are met: b ≥ 2a.

In an embodiment of the present invention, the number of the sensing pixels is the same as the number of the refractive structures

In an embodiment of the present invention, the number of the sensing pixels is smaller than the number of the refractive structures.

In one embodiment of the present invention, the fingerprint identification device further includes a plurality of microlenses, and the microlenses are respectively disposed on the sensing pixels.

In an embodiment of the present invention, the collimator includes a plurality of light-shielding parts and a plurality of light-transmitting parts, the light-shielding parts and the light-transmitting parts are arranged in a staggered manner, and the light-transmitting parts correspond to the light-transmitting parts. The refraction structure described above is set.

In an embodiment of the present invention, the refractive element further includes a base, the refractive structure is disposed on the base, and the outer diameter of the refractive structure tapers away from the base to form a sharp corner.

In an embodiment of the present invention, the outer surface of the refractive structure is a plane or a curved surface.

In an embodiment of the present invention, the fingerprint identification device further includes a light shaping member disposed between the light emitting surface and the collimating member.

In one embodiment of the present invention, the fingerprint identification device further includes a first adhesive member and a second adhesive member, the first adhesive member is disposed between the cover plate and the light-emitting surface, and the second adhesive member is disposed on the light-emitting surface and the collimator between pieces.

In the present invention, the angle of the reflected light beam generated in the finger sensing area is refracted by the refracting structure of the refracting element, so that the size of the image sensing chip can be reduced, and the effect of cost reduction is achieved.

The present invention is described in detail below with reference to the accompanying drawings and specific embodiments, but is not intended to limit the present invention.

Description of drawings

1 is a top view of a digital electronic device according to a first embodiment of the present invention;

2 is a cross-sectional view of a fingerprint identification device according to a first embodiment of the present invention;

3 is a cross-sectional view of the collimating member and the refracting member according to the first embodiment of the present invention;

4 is a cross-sectional view of a fingerprint identification device according to a second embodiment of the present invention; and

FIG. 5 is a cross-sectional view of a collimating member and a refracting member according to a second embodiment of the present invention.

reference number

1 Digital Electronics

10 Housing

11 screens

12 Fingerprint identification device

123 Finger sensing area

124 substrates

1240 top surface

126 Cover

1260 inner surface

1262 External surface

128 Image Sensor Chip

1280 sensing pixels

1282 Electrodes

130 Lights

132 Light guide

1320 light entrance

1321 light incident surface

1322 Light guide

1323 light-emitting surface

1324 Microstructure

1326 Groove

133 accommodating space

134 Collimator

1340 Shading part

1342 Translucent part

136 Refractors

1360 base

1362 refractive structure

137 wires

138 Light Shaping Parts

139 Adhesives

140 first adhesive

142 Second adhesive

144 Micro lenses

C Centerline

I Optical axis

Detailed ways

Please refer to FIG. 1 , which shows a top view of a digital electronic device according to a first embodiment of the present invention. The digital electronic device 1 can be a smart phone, a tablet computer, a personal computer, a personal digital assistant, a media player and other stationary and portable electronic devices; the digital electronic device 1 includes a casing 10, a screen 11 and a The fingerprint identification device 12; the screen 11 and the fingerprint identification device 12 are respectively exposed outside the casing 10. The screen 11 is used to display information for the user to watch and operate by touch; the fingerprint identification device 12 is used to display information to the user. The identity of the device performs fingerprint authentication, thereby increasing the security of the digital electronic device 1 .

Please refer to FIG. 2 , which is a cross-sectional view of the fingerprint identification device according to the first embodiment of the present invention, the cross-sectional position of which is along the line segment 2 shown in FIG. 1 . The fingerprint recognition device 12 has a finger sensing area 123 , and the size of the finger sensing area 123 can be set to capture the fingerprint of a finger of a single hand. In FIG. 2 , the fingerprint identification device 12 includes a cover plate 126 , an image sensing chip 128 , at least one light-emitting element 130 , a light-guiding element 132 , a collimating element 134 and a light-refracting element 136 , which are used in conjunction with pickup. The fingerprint information of the user is verified and the fingerprint information is authenticated.

The cover plate 126 has an inner surface 1260 and an outer surface 1262, the inner surface 1260 is opposite to the outer surface 1262, and the outer surface 1262 is the touch operation surface of the fingerprint identification device 12; in other words, the user touches the cover plate 126 with his finger the outer surface 1262 for fingerprint pickup and authentication. The cover plate 126 can be a substrate with high mechanical strength and high transmittance (for example, a glass substrate). The transmittance can avoid blocking the light beam from the light-emitting element 130 .

The image sensor chip 128 is located on one side of the cover plate 126 and is adapted to receive fingerprint information generated by the light beam reflected by the finger in the finger sensing area 123 and authenticate the fingerprint information. The image sensor chip 128 can be mounted on the upper surface 1240 of the substrate 124 and is connected to the circuit on the substrate 124 by connecting the electrodes 1282 of the image sensor chip 128 (as shown in FIG. 3 ) and the wires 137 on the upper surface 1240 (not shown in the figure) electrical connection is formed; the authentication result of the fingerprint information can be transmitted to the screen 11 through the circuit wiring formed on the substrate 124 for display. The image sensor chip 128 may include a Charge-Coupled Device (CCD for short) or a Complementary Metal Oxide Semiconductor (CMOS for short) device.

As shown in FIG. 1 , the image sensing chip 128 may be rectangular, and may include a plurality of sensing pixels 1280 (as shown in FIG. 3 ) spaced apart and arranged in an array thereon; wherein, the sensing pixels 1280 are suitable for It is used to receive the light beam reflected by the finger and generate fingerprint information.

Each sensing pixel 1280 has an optical axis I, and the optical axes I of all the sensing pixels 1280 are arranged in a cross section (for example, a cross section along the line segment 2 shown in FIG. 1 ); when the image sensor chip 128 is in the aforementioned When the length of the cross section is a, and the length of the finger sensing region 123 on the aforementioned cross section is b, the following conditions are satisfied:

b≥2a.

The light-emitting element 130 is disposed on the upper surface 1240 of the substrate 124 and beside the image sensor chip 128 . FIG. 2 schematically shows two light-emitting elements 130, and the two light-emitting elements 130 are respectively disposed on the left and right sides of the image sensor chip 128; in actual implementation, the number of light-emitting elements 130 and the number of the light-emitting elements 130 are related to the image sensor chip. The relative disposition relationship of the 128 is not limited to that shown in FIG. 2 , and the fingerprint identification device 1 includes a plurality of light-emitting elements 130 , and the light-emitting elements 130 may be disposed beside the image sensor chip 128 equiangularly, for example. The light emitting element 130 is adapted to emit light beams toward a light incident surface 1321 of the light guide element 132 . The light emitting element 130 can be, for example, a light emitting diode, and is used to generate a non-visible light beam (eg, an infrared light beam).

The light guide 132 can transmit light, is disposed between the substrate 124 and the cover plate 126 and covers the image sensing chip 128 ; the light guide 132 can guide the light beam generated by the light emitting element 130 to the finger sensing area 123 except for , the light beam reflected by the finger (hereinafter referred to as the reflected light beam) can also be guided, so that the reflected light beam can be transmitted to the image sensor chip 128 through the collimating member 134 and the refracting member 136 .

In FIG. 2 , the light guide member 132 is made of a material with high transmittance, and includes a light incident portion 1320 , a light guide portion 1322 and a plurality of microstructures 1324 . The light incident portion 1320 can be in a ring shape, one end of which is connected to the light guide portion 1322 and the other end is disposed on the upper surface 1240 of the substrate 124 . As shown in FIG. 2 , the light incident surface 1321 of the light incident portion 1320 may be formed with a plurality of grooves 1326 recessed toward the direction of the light guide portion 1322 for accommodating the light emitting element 130 therein, thereby increasing the amount of light emitted by the light emitting element 130 . The probability of the light beam entering the light incident part 1320 . The number of the grooves 1326 is the same as the number of the light-emitting elements 130 . The light incident portion 1320 is disposed on the substrate 124 for supporting the light guide portion 1322 on the substrate 124 with a certain distance. The image sensor chip 128 , the collimating member 134 and the refracting member 136 are respectively located on the substrate 124 and the light incident portion. 1320 and the light guide portion 1322 fit into a defined accommodating space 133 .

Further, the outer diameter of the light incident portion 1320 is gradually reduced in the direction from the base plate 124 to the cover plate 126 , so that the side cross-sectional view of the light guide member 132 is roughly trapezoidal; thereby, the light beam emitted by the light emitting member 130 can be It is transmitted to the finger sensing area 123 . In the present invention, the light incident portion 1320 and the light guide portion 1322 can be integrally formed; the top surface of the light guide portion 1322 can be attached to the inner surface 1260 of the cover plate 126 through a first adhesive member 140 . The first adhesive member 140 is transparent, and its refractive index can be, for example, the same as that of the cover plate 126 .

The light guide member 132 further includes a light exit surface 1323 , which is the surface of the light guide portion 1322 away from the cover plate 126 ; in this embodiment, the normal direction of the light exit surface 1323 is parallel to the normal direction of the light incident surface 1321 . The microstructure 1324 is disposed on the light exit surface 1323, and the microstructure 1324 and the light guide portion 1322 can be integrally formed. As shown in FIG. 2 , the microstructure 1324 may be a sawtooth structure in which the light exit surface 1323 is recessed into the light guide portion 1322 ; in actual implementation, the microstructure 1324 may also be a sawtooth structure protruding from the light exit surface 1323 , Columnar structure or prismatic structure.

The light emitting element 130 and the light guide element 132 cooperate to generate a light beam transmitted to the finger sensing area 132; the light beam generated by the light emitting element 130 mainly enters the light incident portion 1320 through the light incident surface 1321, and then is transmitted to the light guide portion 1322; There are two light propagation paths of the light guide portion 1322: one is directly refracted by the light guide portion 1322 and then transmitted to the user's finger located in the finger sensing area 123 through the cover plate 126, and the other is transmitted to the guide portion by total internal reflection. The light portion 1322 is transmitted back and forth until the propagation angle of the light beam is smaller than the critical angle of total internal reflection by the microstructure 1324 , and the light beam can be transmitted to the user's finger located in the finger sensing area 123 through the cover plate 126 . In other words, the microstructure 1324 is used to restrain the light beam from being continuously transmitted in the light guide portion 1322 by total internal reflection. The light beam reflected by the finger (ie, the reflected light beam) is emitted from the light emitting surface 123 and transmitted to the image sensor chip 128 through the collimating member 134 and the refracting member 136 in sequence.

The collimating member 134 is located between the light-emitting surface 1323 of the light guide member 132 and the image sensing chip 128 , and can be attached to the light guide member 132 through a second adhesive member 142 . The length of the finger sensing region 123 may be approximately the same as the length of the collimator 134 . The collimating member 134 can just touch the bottom end of the microstructure 1324 to prevent the reflected light beam from being directly transmitted to the substrate 124 after passing through the light guide portion 1322 (that is, it is transmitted to the substrate 124 without passing through the collimating member 134 and the refracting member 136 ). ), resulting in problems of poor contrast and image quality of the image sensor chip 128 . In addition, when the second adhesive member 142 is attached to the microstructure 1324, in addition to preventing the microstructure 1324 from inhibiting the light beam from being transmitted in the light guide portion 1322 by total internal reflection, it can also allow part of the light beam that has not been reflected by the finger to be refracted downward. and transmitted to the image sensor chip 128, so that the image sensor chip 128 generates wrong fingerprint information. Therefore, during assembly, the second adhesive member 142 for fixing the collimator 134 on the light guide member 132 should be avoided from being attached to the microstructure 1324; in FIG. A position adjacent to the light-emitting surface 1323 . The second adhesive member 142 can be, for example, a photocurable adhesive (eg, UV curable adhesive).

The collimating member 134 is used to limit the reflected light beam emitted from the light exit surface 1323 to transmit to the light incident area of the refracting member 136 . Referring to FIG. 3 , the collimator 134 includes a plurality of light-shielding parts 1340 and a plurality of light-transmitting parts 1342 , and the light-transmitting parts 1342 are arranged between two adjacent light-shielding parts 1340 ; in other words, the light-shielding parts 1340 and the light-transmitting parts 1342 are staggered arrangement.

Among the reflected light beams, those incident at a large angle will be blocked by the light shielding portions 1340 arranged on both sides of the light-transmitting portion 1342 and cannot be transmitted to the refractive element 136 , while those incident at a small angle can be directly transmitted to the refractive element through the light-transmitting portion 1342 136. Here, the light beam passing through the collimator 134 is defined as a collimated light beam. In addition, the number of the light-transmitting parts 1342 is designed to be the same as the number of the sensing pixels 1280, that is, the collimated light beam passing through the single light-transmitting part 1342 is used for the single sensing pixel 1280 to generate fingerprint information; furthermore, the collimation is adjusted. The length L of the member 134 and the aperture ψ of the light-transmitting portion 1342 can adjust the light incident area of the collimated beam transmitted to the refracting member 136 .

The refracting member 136 is disposed between the collimating member 134 and the image sensing chip 128 , and is located above the image sensing chip 128 with an interval. The refracting member 136 receives the collimated light beam, and is used for condensing the collimated light beam passing through the light-transmitting portion 1342 to the sensing pixels 1280 of the image sensing chip 128 . The thickness T of the refractive element 136 may be 50˜200 μm.

In FIG. 3 , the refractive element 136 includes a base portion 1360 and a plurality of refractive structures 1362 ; the base portion 1360 is a light-transmitting sheet, which can be attached to the collimating member 134 by an adhesive 139 , and can be made of polyethylene terephthalate for example. It is made of polymer materials such as ethylene formate (polyethyleneterephthalate; PET for short). The refractive structure 1362 is disposed on the substrate 1360, and its outer diameter tapers away from the base 1360 to form a sharp corner; the refractive structure 1362 can be made of, for example, a photocurable adhesive. The outer surface of the refractive structure 1362 is flat.

The number of the refractive structures 1362 is the same as the number of the sensing pixels 1280 , and the angle of the sharp corners of the refractive structures 136 gradually increases with the distance from the center line C of the refractive element 136 , so as to allow the collimated light beams far from the center line C of the refractive element 136 The collimated light beam close to the centerline C of the refractive element 136 converges on the corresponding sensing pixel 1280 after being turned by a large angle and then converges to the corresponding sensing pixel 1280 .

To sum up the above, in the fingerprint identification device of the present invention, the light beam generated by the light emitting element 130 enters the light guide element 132 from the light incident surface 1321 and is transmitted to the finger sensing area 123; The light-emitting surface 1323 , the collimating member 134 and the refracting member 136 are sequentially focused on the sensing pixels 1280 of the image sensing chip 128 . Wherein, through the refractive structure 1362 on the refractive element 136 of the present invention, the angle at which the collimated light beam passing through the collimating element 134 is incident on the sensing pixel 1280 can be changed to achieve the effect of reducing the length of the image sensing chip 128 .

Please refer to FIG. 4 , which is a cross-sectional view of a fingerprint identification device according to a second embodiment of the present invention. The fingerprint identification device 12 shown in FIG. 4 is applied to the digital electronic device 1 shown in FIG. 1 to perform a fingerprint authentication function on the user's identity, thereby increasing the security of the digital electronic device 1 .

The fingerprint identification device 12 is disposed on an upper surface 1240 of a substrate 124 and is used for picking up fingerprint information and authenticating the fingerprint information. The fingerprint identification device 12 includes a cover plate 126 , an image sensor chip 128 , a plurality of light emitting elements 130 , a light guide element 132 , a collimation element 134 and a light refraction element 136 .

An outer surface 1262 of the cover plate 126 is the touch operation surface of the fingerprint identification device 12 ; the user touches the outer surface 1262 with his fingers to perform fingerprint pickup and authentication.

The image sensor chip 128 is located on one side of the cover plate 126 and is adapted to receive a light beam (hereinafter referred to as a reflected light beam) reflected by a finger in a finger sensing area 123 to generate fingerprint information and perform authentication. The image sensor chip 128 is mounted on an upper surface 1240 of the substrate 124 .

The image sensor chip 128 is rectangular (as shown in FIG. 1 ), and can include a plurality of sensing pixels 1280 spaced apart from each other and arranged in an array, as shown in FIG. 5 ; the sensing pixels 1280 are suitable for receiving The fingerprint reflects the light beam and generates the fingerprint information. Each sensing pixel 1280 has an optical axis I, and the optical axes I of all the sensing pixels 1280 are arranged in a cross section (for example, a cross section along the line segment 2 shown in FIG. 1 ); when the image sensor chip 128 is in the aforementioned The length of the cross section is a, and the finger sensing area 123 satisfies the following conditions when the length of the aforementioned cross section is b:

b≥2a.

The light emitting element 130 is disposed on the substrate 124 and located beside the image sensor chip 128 , and is suitable for emitting invisible light beams toward a light incident surface 1321 of the light guide element 132 .

The light guide 132 can transmit light, is disposed between the substrate 124 and the cover plate 126 and covers the image sensing chip 128 ; the light guide 132 includes a light incident portion 1320 , a light guide portion 1322 and a plurality of microstructures 1324 . The light incident portion 1320 is in the shape of a ring, and its outer diameter gradually decreases in the direction from the substrate 124 to the cover plate 126 , so that the light beam emitted by the light emitting element 130 can be transmitted to the finger sensing area 123 . One end of the light incident portion 1320 is connected to the light guide portion 1322 , and the other end is disposed on the upper surface 1240 of the substrate 124 and includes a light incident surface 1321 ; a plurality of grooves 1326 can be formed on the light incident surface 1321 for the light emitting element 130 to be accommodated in the light incident surface 1321 . The light beam generated by the light emitting element 130 can be transmitted to the light guide portion 1322 thereby. The substrate 124 , the light incident portion 1320 and the light guide portion 1322 cooperate to define an accommodating space 133 for accommodating the image sensor chip 128 , the collimating member 134 and the refracting member 136 therein. The top surface of the light guide portion 1322 can be attached to an inner surface 1260 of the cover plate 126 through a first adhesive member 140 .

The microstructure 1324 is formed on the light exit surface 1323 and is used to prevent the light beam transmitted from the light incident portion 1320 to the light guide portion 1322 from being continuously transmitted in the light guide portion 1322 by total internal reflection; the microstructure 1324 can be a concave light exit surface 1323 jagged structure.

The light-emitting element 130 and the light-guiding element 132 cooperate to generate a light beam transmitted to the finger sensing area 132; the light beam generated by the light-emitting element 130 enters the light-guiding portion 1322 from the light-incident surface 1321, and there are two propagation paths for the light entering the light-guiding portion 1322: One of them is directly refracted by the light guide portion 1322 and then transmitted to the user's finger through the cover plate 126 , and the other is transmitted back and forth in the light guide portion 1322 by total internal reflection until the microstructure 1324 makes the propagation angle of the light beam less than full. The critical angle of internal reflection allows the light beam to pass through the cover plate 126 to the user's finger. The light beam reflected by the finger (ie, the reflected light beam) is emitted from the light emitting surface 123 and transmitted to the image sensor chip 128 through the collimating member 134 and the refracting member 136 in sequence.

It should be noted here that the angle of the microstructure 1324 shown in FIG. 5 is smaller than the angle of the microstructure 1324 shown in FIG.

The collimating member 134 is located between the light-emitting surface 1323 of the light guide member 132 and the image sensing chip 128, and can be attached to the light guide member 132 through a second adhesive member 142; wherein, the second adhesive member 142 is disposed on the collimation member 132. Between the straight member 134 and the microstructure 1324 of the light guide member 132, the second adhesive member 142 may be, for example, a photocurable glue.

The collimating member 134 is used to limit the incident area of the reflected light beam transmitted to the refracting member 136 , and may include a plurality of light-shielding portions 1340 and a plurality of light-transmitting portions 1342 arranged in a staggered manner (as shown in FIG. 5 ). The light-shielding portion 1340 is used to prevent the reflected light beam incident at a large angle from being transmitted to the refracting member 136 , and the light-transmitting portion 1342 allows the reflected light beam incident therein with a small angle to pass to the refractive member 136 . Here, the light beam passing through the collimator 134 is defined as a collimated light beam.

The refracting member 136 is located between the collimating member 134 and the image sensing chip 128 , and is located above the image sensing chip 128 with an interval; Each sensing pixel 1280.

The refracting member 136 includes a base portion 1360 and a plurality of refracting structures 1362 ; the base portion 1360 is a light-transmitting sheet, which can be attached to the bottom of the collimating member 134 through the adhesive 139 . The refractive structure 1362 is disposed on the substrate 1360 , and its outer diameter tapers away from the base 1360 to form a sharp corner. In FIG. 5 , the outer surface of the refractive structure 1362 is a curved surface; wherein, the curved surface design can further expand its turning angle toward the collimated beam.

The number of the refractive structures 1362 is the same as the number of the transparent portions 1342 , and the refractive structures 1362 are disposed corresponding to the transparent portions 1342 to receive the collimated light beams passing through the transparent portions 1342 . The angle of the sharp corner of the refractive structure 136 gradually increases as it moves away from the center line C of the refractive element 136 , so that the collimated light beam that is far away from the center line C of the refractive element 136 is deflected by a large angle and then converges on the sensing pixel 1280 , and close to the refraction element 136 . The collimated light beam of the center line C of the component 136 is turned by a small angle and then converges on the sensing pixel 1280 , so as to achieve the effect of reducing the length of the image sensing chip 128 . In this embodiment, the number of sensing pixels 1280 is smaller than the number of refractive structures 1362 ; in other words, a single sensing pixel 1280 can receive light beams from multiple refractive structures 1362 . For example, in FIG. 5, each sensing pixel 1280 accepts light beams from three refractive structures 1362 and generates fingerprint information for authentication.

In addition, the fingerprint identification device 12 may further include a photo-shaping member 138 and a plurality of microlenses 144 ; the photo-shaping member 138 is disposed between the second adhesive member 142 and the collimating member 134 for entering the collimating member 134 For example, the reflected light beam entering the light shaping member 138 at a large angle is shaped to exit the collimating member 134 at a small angle. The microlens 144 is disposed on each sensing pixel 1280 to further focus the light beam passing through the refracting member 136 to the sensing pixel 1280 to improve the sensing effect.

To sum up the above, in the fingerprint identification device of the present invention, the light beam generated by the light emitting element 130 enters the light guide element 132 from the light incident surface 1321 and is transmitted to the finger sensing area 123; The light emitting surface 1323 , the light shaping member 138 , the collimating member 134 and the refracting member 136 are sequentially focused on the sensing pixels 1280 of the image sensing chip 128 . The refractive structure 1362 on the refractive element 136 of the present invention can change the angle at which the collimated light beam passing through the collimating element 134 enters the sensing pixel 1280 , thereby reducing the length of the image sensing chip 128 .

Of course, the present invention can also have other various embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding Changes and deformations should belong to the protection scope of the appended claims of the present invention.

Claims (9)

1. A fingerprint identification device having a finger sensing area, the fingerprint identification device comprising:

a cover plate;

an image sensing chip located on one side of the cover plate;

a light guide member covering the image sensing chip, the light guide member including a light incident surface and a light emergent surface, the light emergent surface having a microstructure;

at least one light emitting element arranged adjacent to the light incident surface;

a collimating element between the light emergent surface and the image sensing chip; and

a refraction piece arranged between the collimation piece and the image sensing chip and comprising a plurality of refraction structures, wherein the outer diameters of the refraction structures are gradually reduced along the direction far away from the collimation piece and close to the image sensing chip to form a sharp angle, and the angles of the sharp angles of the refraction structures are gradually increased along the direction far away from the central line of the refraction piece;

wherein the image sensing chip and the at least one light-emitting element are mounted on the upper surface of a substrate;

the image sensing chip comprises a plurality of sensing pixels, and when the length of the image sensing chip on a cross section formed by optical axes of the sensing pixels is a, and the length of the finger sensing area on the cross section is b, the following conditions are satisfied:

b≥2a。

2. The apparatus of claim 1, wherein the number of the sensing pixels is the same as the number of the refraction structures.

3. The apparatus of claim 1, wherein the number of the sensing pixels is less than the number of the refraction structures.

4. The apparatus of claim 1, further comprising a plurality of microlenses respectively disposed on the plurality of sensing pixels.

5. The fingerprint identification device according to claim 1 wherein said collimating member comprises a plurality of light-shielding portions and a plurality of light-transmitting portions, said plurality of light-shielding portions and said plurality of light-transmitting portions being staggered, and said plurality of light-transmitting portions being disposed in correspondence to said plurality of light-refracting structures.

6. The apparatus of claim 1, wherein the light-deflecting member further comprises a base portion, the plurality of light-deflecting structures are disposed on the base portion, and an outer diameter of each light-deflecting structure tapers away from the base portion to form the sharp angle.

7. The apparatus of claim 1, wherein the outer surface of the refractive structures is a plane or a curved surface.

8. The fingerprint identification device of claim 1, further comprising a light shaping element disposed between the light exit surface and the collimating element.

9. The apparatus of claim 1, further comprising:

the first adhesion piece is arranged between the cover plate and the light outlet surface; and

the second adhesion piece is arranged between the light-emitting surface and the collimation piece.

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