Fingerprint authentication device

Abstract

To provide a fingerprint authentication device that can suppress increase in overall size of the device.SOLUTION: A fingerprint authentication device includes: a fingerprint sensor unit having a detection surface for detecting a fingerprint of a finger of an operator; a substrate on which the fingerprint sensor unit is mounted; a metal frame provided to cover the substrate; and a holding member that holds the substrate. The fingerprint authentication device then includes a conductive elastic body provided in a vicinity of the fingerprint sensor between the metal frame and the substrate to connect the metal frame to a ground potential of the substrate.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a fingerprint authentication device. [Background technology]

[0002] The following Patent Document 1 discloses a technology in which, in a fingerprint reading device installed in a terminal device, a conductive plate that is connected to a ground potential on a substrate is installed in the fingerprint reading unit, and when a user's finger is placed on the fingerprint reading unit, static electricity charged on the user's finger is removed via the plate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-5951 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology of Patent Document 1 mentioned above employs a configuration in which the plate is fixed to the fingerprint reading device using screws, springs, etc., and therefore a fixing portion for fixing the plate needs to be provided on the plate, which increases the size of the plate and, as a result, may increase the size of the entire device. [Means for solving the problem]

[0005] A fingerprint authentication device according to one embodiment comprises a fingerprint sensor unit having a detection surface for detecting the fingerprint of an operator's finger, a substrate on which the fingerprint sensor unit is mounted, a metal frame placed over the substrate, and a holding member for holding the substrate, and further comprises a conductive elastic body placed between the metal frame and the substrate near the fingerprint sensor unit and connecting the metal frame to the ground potential of the substrate. [Effects of the Invention]

[0006] According to the fingerprint authentication device of the embodiment, it is possible to prevent the size of the entire device from increasing. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is an external perspective view of a fingerprint authentication device according to an embodiment; [Figure 2] FIG. 1 is an exploded perspective view of a fingerprint authentication device according to an embodiment; [Figure 3] 2 is a cross-sectional view of the fingerprint authentication device according to the embodiment taken along the line AA in FIG. 1. [Figure 4] FIG. 1 is a perspective view of the appearance of a fingerprint authentication device according to an embodiment, seen from below; [Figure 5] FIG. 1 is a diagram illustrating an assembly procedure for a fingerprint authentication device according to an embodiment. [Figure 6] FIG. 1 is a diagram illustrating an assembly procedure for a fingerprint authentication device according to an embodiment. [Figure 7] FIG. 1 is a diagram illustrating an assembly procedure for a fingerprint authentication device according to an embodiment. [Figure 8] FIG. 1 is a diagram illustrating an assembly procedure for a fingerprint authentication device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment will be described with reference to the drawings.

[0009] (Configuration of fingerprint authentication device 100) Fig. 1 is an external perspective view of a fingerprint authentication device 100 according to an embodiment. Fig. 2 is an exploded perspective view of the fingerprint authentication device 100 according to an embodiment. Fig. 3 is a cross-sectional view of the fingerprint authentication device 100 according to an embodiment taken along the AA cross-sectional line in Fig. 1. Fig. 4 is an external perspective view of the fingerprint authentication device 100 according to an embodiment as viewed from the bottom (negative side of the Z axis).

[0010] In the following description, for convenience, the X-axis direction will be referred to as the left-right direction, the Y-axis direction as the front-rear direction, and the Z-axis direction as the up-down direction. However, the positive X-axis direction will be referred to as the rightward direction, the positive Y-axis direction as the forward direction, and the positive Z-axis direction as the upward direction. These directions indicate relative positional relationships within the device and do not limit the installation direction or operation direction of the device. Any devices that have the same relative positional relationships within the device, even if they have different installation directions or operation directions, are all within the scope of the present invention.

[0011] A fingerprint authentication device 100 shown in FIG. 1 is provided on an operation panel mounted in the interior of a vehicle such as an automobile, for example, and is a device that detects the fingerprint of an operator's finger.

[0012] As shown in FIGS. 1 to 4, the fingerprint authentication device 100 includes a metal frame 110, a fingerprint sensor unit 120, a flexible substrate 130, a holding member 140, and a conductive elastic body 150.

[0013] The metal frame 110 is a metal member that is provided over the upper side of the base portion 131 of the flexible substrate 130. In a plan view from above, the metal frame 110 has a rectangular frame shape that surrounds the fingerprint sensor unit 120 mounted on the base portion 131 of the flexible substrate 130. The metal frame 110 is conductive and is connected to the ground potential of the flexible substrate 130 via the conductive elastic body 150.

[0014] When an operator places his / her finger on detection surface 120A of fingerprint sensor unit 120, metal frame 110 dissipates static electricity charged on the operator due to contact with the operator's finger to the ground potential of flexible substrate 130, thereby preventing damage to fingerprint sensor unit 120 due to static electricity. Metal frame 110 sandwiches base 131 of flexible substrate 130 and conductive elastic body 150 between itself and holding member 140 (see FIG. 3).

[0015] The metal frame 110 has a flat portion 111, a raised portion 112, and four claw portions 113. The flat portion 111 is a portion parallel to the detection surface 120A of the fingerprint sensor unit 120. An opening 111A that is rectangular in plan view from above is formed in the center of the flat portion 111. The opening 111A is formed to expose at least a portion of the detection surface 120A of the fingerprint sensor unit 120.

[0016] The raised portions 112 are portions that are raised upward from the flat portion 111 by drawing, and are formed in a rectangular shape along the edge of the opening 111A and surrounding the opening 111A. The four claw portions 113 are an example of "fixed portions," and are thin plate-like portions that are provided so as to extend downward from the vicinity of each of the four corners of the flat portion 111.

[0017] Specifically, the two claws 113 extend downward from a front end (end on the positive side of the Y-axis) and a rear end (end on the negative side of the Y-axis) on the right edge (edge ​​on the positive side of the X-axis) of the flat portion 111. The other two claws 113 extend downward from a front end (end on the positive side of the Y-axis) and a rear end (end on the negative side of the Y-axis) on the left edge (edge ​​on the negative side of the X-axis) of the flat portion 111.

[0018] Each of the claws 113 has a slit 113A formed at its tip. Each of the claws 113 is bent at a substantially right angle along the side surface 140C and the bottom surface 140B of the holding member 140, and with the protrusions 141 of the holding member 140 inserted into the slits 113A, the protrusions 141 of the holding member 140 are crimped to fix the metal frame 110 to the protrusions 141 of the holding member 140. With each of the four claws 113 fixed to each of the four protrusions 141, the metal frame 110 is fixed to the holding member 140 with the conductive elastic body 150 compressed. Details of the assembly procedure will be described later.

[0019] The fingerprint sensor unit 120 is a thin plate-like member mounted on the upper surface of the base 131 of the flexible substrate 130. The fingerprint sensor unit 120 has a rectangular shape when viewed from above. The fingerprint sensor unit 120 has a detection surface 120A on its upper surface, and detects the fingerprint of an operator's finger on the detection surface 120A. For example, the fingerprint sensor unit 120 can optically detect the fingerprint of a finger placed on the detection surface 120A and output a fingerprint detection signal indicating the pattern of the detected fingerprint. However, the detection method of the fingerprint sensor unit 120 is not limited to an optical method, and other detection methods such as an electrostatic method may also be used.

[0020] The flexible substrate 130 is an example of a "substrate." The flexible substrate 130 is a substrate in which a conductive circuit is covered with a bendable, insulating resin sheet-like member. The flexible substrate 130 can transmit a fingerprint detection signal detected by the fingerprint sensor unit 120 to the outside.

[0021] 1 to 3, flexible substrate 130 has base portion 131, folded portion 132, flat portion 133, lead-out portion 134, and connection portion 135. Base portion 131 has a rectangular shape in a plan view from above, and is a portion on which fingerprint sensor unit 120 is mounted. Base portion 131 is supported by holding member 140 by being provided on top of holding member 140.

[0022] Folded portion 132 is a portion that extends downward (in the negative direction of the Z axis) from the right end portion (end portion on the positive side of the X axis) of base portion 131, and is a portion that folds the extension direction of flexible substrate 130 from the right direction (positive direction of the X axis) to the left direction (negative direction of the X axis) and connects to flat portion 133. Flat portion 133 is a portion that extends leftward (negative direction of the X axis) from the lower end portion (end portion on the negative side of the Z axis) of folded portion 132, and is a portion that is sandwiched between a mating component (not shown) and lower surface 140B via elastic block 136 in a state where it is positioned by positioning protrusion 142 on lower surface 140B of holding member 140.

[0023] The lead-out portion 134 is a portion that extends downward (in the negative direction of the Z axis) from the left end (the end on the negative side of the X axis) of the flat portion 133. The connection portion 135 is provided at the end of the lead-out portion 134 and is a portion that is connected to a connector (not shown) that leads to the outside.

[0024] Holding member 140 is a flat resin member that is provided so as to overlap the underside of base 131 of flexible substrate 130. Holding member 140 has a substantially rectangular shape when viewed from above. Holding member 140 supports base 131 of flexible substrate 130 from below by placing base 131 of flexible substrate 130 on support surface 140A, which is its upper surface.

[0025] Four protrusions 141 are provided at each of the four corners on the lower surface 140B of the holding member 140, protruding downward (in the negative direction of the Z axis). Each of the four protrusions 141 is an example of a "fixing portion," and, as described above, fixes the claw portion 113 by being inserted into the slit 113A of the claw portion 113 of the metal frame 110 and crimped.

[0026] In this embodiment, thermal crimping, which applies pressure and heat, is used as the crimping method for the protrusion 141, but this is not limiting and other crimping methods (for example, a crimping method which applies pressure only) may also be used. Note that the protrusion 141 shown in Fig. 4 is compressed in the height direction by crimping and has a substantially cylindrical shape with a radial dimension greater than the height dimension, but the protrusion 141 before compression has a substantially cylindrical shape with a height dimension greater than the radial dimension, as shown in Fig. 5.

[0027] The conductive elastic body 150 is a member having conductivity and elasticity. The conductive elastic body 150 is provided on a ground pattern (not shown) on the upper surface of the base part 131 of the flexible substrate 130 and in the vicinity of the periphery of the fingerprint sensor part 120. Although not shown, the ground pattern formed on the base part 131 is connected to the ground potential of the device in which the fingerprint authentication device 100 is mounted.

[0028] The conductive elastic body 150 is sandwiched between the metal frame 110 and the base 131 by fixing the metal frame 110 to the holding member 140. As a result, the conductive elastic body 150 connects the metal frame 110 to the ground potential of the flexible substrate 130. In this embodiment, the conductive elastic body 150 is adhered to the ground pattern on the upper surface of the base 131 of the flexible substrate 130 by conductive double-sided tape. However, this is not limiting, and for example, the conductive elastic body 150 may be adhered to the lower surface of the flat portion 111 of the metal frame 110 (at a position facing the ground pattern) by conductive double-sided tape.

[0029] In this embodiment, the conductive elastic body 150 is any one of conductive urethane, conductive silicone, conductive polyethylene, and conductive foam. In this embodiment, the fingerprint authentication device 100 includes two conductive elastic bodies 150 provided at two diagonally opposite positions in the vicinity of the periphery of the fingerprint sensor unit 120. However, the number and arrangement positions of the conductive elastic bodies 150 are not limited to this.

[0030] The fingerprint authentication device 100 configured as described above can detect the fingerprint of the operator's finger by the detection surface 120A of the fingerprint sensor unit 120, which is exposed from the opening 111A of the metal frame 110, when the operator places his / her finger on the detection surface 120A of the fingerprint sensor unit 120. The fingerprint authentication device 100 can output a fingerprint detection signal indicating the pattern of the detected fingerprint to the outside through the flexible substrate 130. At this time, when the operator's finger comes into contact with the raised portion 112 of the metal frame 110, the fingerprint authentication device 100 can release the static electricity charged on the operator to the ground potential of the flexible substrate 130 via the metal frame 110 and the conductive elastic body 150, thereby preventing damage to the fingerprint sensor unit 120 due to static electricity.

[0031] (Assembly procedure for fingerprint authentication device 100) 5 to 8 are diagrams for explaining the assembly procedure of the fingerprint authentication device 100 according to one embodiment. Note that, in explaining the assembly procedure below, it is assumed that the fingerprint sensor unit 120 is mounted in advance on the base part 131 of the flexible substrate 130 by solder bumps or the like.

[0032] 5, holding member 140 is placed between base portion 131 and flat portion 133 of flexible substrate 130, thereby holding flexible substrate 130 by holding member 140. At this time, base portion 131 of flexible substrate 130 is held by support surface 140A of holding member 140.

[0033] 5, conductive elastic bodies 150 are placed at two diagonally opposite positions on the upper surface of base portion 131 of flexible substrate 130 (both on the ground pattern).

[0034] 6, the metal frame 110 is placed over the base portion 131 of the flexible substrate 130. At this time, the conductive elastic body 150 is crushed between the flat portion 111 of the metal frame 110 and the base portion 131 of the flexible substrate 130.

[0035] 7, each of the four claws 113 of the metal frame 110 is bent inward at a substantially right angle so as to fit along the lower surface 140B of the holding member 140. As a result, the protrusions 141 of the holding member 140 are inserted into the slits 113A of each of the four claws 113.

[0036] 8, each of the four protrusions 141 of the holding member 140 is compressed in the height direction and crimped, thereby fixing each of the four claws 113 of the metal frame 110 to the holding member 140. As a result, the metal frame 110 is fixed to the holding member 140 in a state where it is connected to the ground potential of the flexible substrate 130 via the conductive elastic body 150, and is in the state shown in FIG.

[0037] At this time, the conductive elastic body 150 is crushed between the flat portion 111 of the metal frame 110 and the base portion 131 of the flexible substrate 130, and therefore its restoring force causes it to come into strong contact with both the metal frame 110 and the flexible substrate 130, and the state in which the metal frame 110 is connected to the ground potential is stably maintained via the conductive elastic body 150. The conductive elastic body 150 also functions as a buffer material, absorbing variations in the bending positions of the claw portions 113 of the metal frame 110 and dimensional variations in related parts, and the metal frame 110 is maintained in a fixed state without any rattle.

[0038] (effect) As described above, the fingerprint authentication device 100 according to one embodiment is a fingerprint authentication device 100 including a fingerprint sensor unit 120 having a detection surface 120A for detecting the fingerprint of an operator's finger, a flexible substrate 130 on which the fingerprint sensor unit 120 is mounted, a metal frame 110 that is provided over the flexible substrate 130 and can be contacted by a finger placed on the detection surface 120A, and a holding member 140 that holds the flexible substrate 130, and includes a conductive elastic body 150 that is provided between the metal frame 110 and the flexible substrate 130 near the fingerprint sensor unit 120 and connects the metal frame 110 to the ground potential of the flexible substrate 130.

[0039] As a result, the fingerprint authentication device 100 of one embodiment does not require screw fastening parts or the like required to connect the metal frame 110 to ground potential, so the area of ​​the metal frame 110 can be reduced, and since there is no risk of it spreading unintentionally like a conductive adhesive, the clearance between the conductive elastic body 150 and the fingerprint sensor unit 120 can be reduced, thereby preventing the overall size of the device from becoming larger.

[0040] In one embodiment of the fingerprint authentication device 100, the holding member 140 has a protrusion 141, and the metal frame 110 has a claw portion 113, and the claw portion 113 is fixed to the protrusion 141 of the holding member 140, thereby fixing the conductive elastic body 150 to the holding member 140 in a compressed state.

[0041] As a result, the fingerprint authentication device 100 of one embodiment can stably maintain the compressed state of the conductive elastic body 150, so that even if the dimensions of the components vary, the metal frame 110 does not rattle, and the fixed state of the metal frame 110 and the state of connection to the ground potential can be stably maintained.

[0042] In one embodiment of a fingerprint authentication device 100, a metal frame 110 has a flat portion 111 parallel to a detection surface 120A, an opening 111A formed in the center of the flat portion 111 and exposing at least a portion of the detection surface 120A, a raised portion 112 raised to surround the opening 111A, and a plurality of claw portions 113 extending downward from the edge of the flat portion 111, each of which is bent along a side surface 140C and a bottom surface 140B of the holding member 140.

[0043] As a result, the fingerprint authentication device 100 according to one embodiment can easily manufacture the parts because the metal frame 110 can be integrally formed from a single metal plate through a series of press processes including drawing and bending processes.

[0044] In one embodiment of the fingerprint authentication device 100, the holding member 140 has a plurality of protrusions 141 on the lower surface 140B, and each of the plurality of claw portions 113 has a slit 113A at the tip, and the protrusion 141 is inserted into the slit 113A and crimped to be fixed to the protrusion 141.

[0045] As a result, the fingerprint authentication device 100 according to one embodiment can fix the metal frame 110 to the holding member 140 with a relatively simple operation and without using any additional parts. Also, the fixed state of the metal frame 110 can be stably maintained.

[0046] In the fingerprint authentication device 100 according to one embodiment, the conductive elastic body 150 is made of any one of conductive urethane, conductive silicone, conductive polyethylene, and conductive foam.

[0047] This allows the fingerprint authentication device 100 according to one embodiment to have suitable conductivity and elasticity for fixing and grounding the metal frame 110.

[0048] Furthermore, the fingerprint authentication device 100 according to one embodiment includes two conductive elastic bodies 150 provided at two diagonal positions around the periphery of the fingerprint sensor unit 120.

[0049] As a result, the fingerprint authentication device 100 according to one embodiment can stably support the metal frame 110 in a well-balanced manner, and can reduce costs compared to a configuration including four conductive elastic bodies 150.

[0050] Although one embodiment of the present invention has been described in detail above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0051] 100 Fingerprint authentication device 110 Metal Frame 111 Plane section 111A opening 112 Ridge 113 Claw part (fixed part) 113A Slit 120 Fingerprint sensor unit 120A detection surface 130 Flexible PCB (PCB) 131 Base 132 Folded section 133 Plane section 134 Drawer section 135 Connection 136 Elastic Block 140 Retaining member 140A support surface 140B Bottom 140C side 141 Protrusion (fixed part) 142 Positioning protrusion 150 Conductive elastic body

Claims

1. a fingerprint sensor unit having a detection surface for detecting the fingerprint of an operator's finger; a substrate on which the fingerprint sensor unit is mounted; a metal frame provided to cover the substrate; a holding member for holding the substrate; A fingerprint authentication device comprising: a conductive elastic body provided between the metal frame and the substrate near the fingerprint sensor unit, the conductive elastic body connecting the metal frame to the ground potential of the substrate; A fingerprint authentication device characterized by:

2. The holding member has a fixing portion, The metal frame has a fixed portion, and the fixed portion is fixed to the fixing portion of the holding member, whereby the conductive elastic body is fixed to the holding member in a compressed state.

2. The fingerprint authentication device according to claim 1.

3. The metal frame is a flat surface parallel to the detection surface; an opening formed in a center portion of the planar portion and exposing at least a portion of the detection surface; a raised portion that is raised so as to surround the opening; a plurality of fixed portions extending downward from an edge portion of the flat portion; and Each of the plurality of fixed portions is bent along the side and bottom surfaces of the holding member 3. The fingerprint authentication device according to claim 2.

4. The holding member is The fixing portion has a plurality of fixing portions on the lower surface, Each of the plurality of fixed portions is The tip has a slit, and the fixing part is inserted into the slit and crimped to be fixed to the fixing part.

4. The fingerprint authentication device according to claim 3.

5. The conductive elastic body is any one of conductive urethane, conductive silicone, conductive polyethylene, and conductive foam.

5. The fingerprint authentication device according to claim 1, wherein the fingerprint authentication device is a fingerprint authentication device.

6. The fingerprint sensor includes two conductive elastic bodies provided at two diagonal positions around the fingerprint sensor.

6. The fingerprint authentication device according to claim 1, wherein the fingerprint authentication device is a fingerprint authentication device.

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