JP2005352722A - Fingerprint recognition device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a static elimination countermeasure which is friendly to a human body by an easy method while taking costs into consideration. <P>SOLUTION: A fingerprint recognition sensor part 1 is covered with a resistor sheet type member 2 which has an opening part 3 whose narrow part is ≤10 mm wide and also has ≥10<SP>4</SP>Ω/square. Detection by such a fingerprint sensor is carried out through a series of operations for gradually discharging electric charges accumulated in a human body by touching a resistor sheet member, lightly pressing the surface of the fingerprint recognition sensor with a finger for fingerprint detection, and recognizing its pattern, so no abrupt discharge is caused to be friendly to a person and the fingerprint recognition sensor can be protected against dielectric breakdown. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fingerprint recognition device, and in particular, to protect a fingerprint detection sensor for identifying a fingerprint from static electricity accumulated in a human body and at the same time to control rapid discharge of static electricity to control rapid discharge. The present invention relates to a fingerprint recognition device characterized by

  There are a number of methods for security measures to eliminate operations other than the person in an information processing device such as a personal computer. Among them, a capacitive fingerprint recognition device is a small and simple method and is inexpensive. Therefore, it has become widespread widely (see, for example, Patent Document 1).

See FIG.
FIG. 6 is an explanatory view of a conventional electrostatic capacitance type fingerprint recognition device, and a barrier metal layer 52 such as Ti is formed on a silicon substrate 51 on which a semiconductor element such as a transistor (not shown) is formed. Charge storage electrodes 53 made of Al or the like and electrically connected to semiconductor elements formed on the silicon substrate 51 are arranged in a two-dimensional matrix, and the entire surface is covered with a protective insulating film 54.

  When a finger touches the fingerprint recognition device, the distance between the finger surface via the protective insulating film 54 and each charge storage electrode 53 varies according to the unevenness 55 of the fingerprint. Therefore, it is possible to detect a fingerprint pattern by plotting the capacitance value of each charge storage electrode 53 two-dimensionally.

  As described above, since the sensor unit of the fingerprint recognition device is composed of a semiconductor chip made into an LSI, when the static electricity accumulated in the human body touches the sensor unit, it discharges and destroys the semiconductor element. There are drawbacks.

  For this reason, it is common practice to protect the fingerprint recognition device from electrostatic breakdown by discharging static electricity accumulated in the human body by touching a grounded electrode or the like before the finger touches the sensor unit.

  For example, the surface of the semiconductor fingerprint sensor element is a metal plate that is grounded on the surface side, and a lid provided with an insulating plate on the back side that opposes the surface side of the semiconductor fingerprint sensor element is covered, and contacts the surface of the lid Thus, it has been proposed to discharge static electricity of the human body through an operation of opening the lid (see, for example, Patent Document 2).

  Alternatively, it has also been proposed to reliably discharge charges accumulated in the human body by placing a grounded metal finger guide on the fingerprint recognition sensor (see, for example, Patent Document 3).

  Alternatively, the main body cover to which the fingerprint recognition sensor is attached has a rotation-free sensor cover arranged to protect the fingerprint recognition sensor and an iron ground arranged so that the finger to be recognized touches the fingerprint recognition sensor before touching it. It has also been proposed to attach a plate (see, for example, Patent Document 4).

  Alternatively, it has also been proposed to provide a lid portion that protects the fingerprint sensor portion with respect to the fingerprint sensor portion, and a grounded contact portion that is provided at a position where the operator's finger can contact when the lid portion is operated. (For example, see Patent Document 5).

  As a countermeasure against static electricity in the fingerprint detection LSI itself, it has been proposed that the LSI frame is grounded and the mounting package is bonded to the frame as a conductive material, for example, conductive plastic, using a conductive adhesive. (For example, refer to Patent Document 6).

Alternatively, it has also been proposed to provide a grounded pattern on the surface of the insulating protective film of the cell array portion of the fingerprint sensor in a region not facing the detection cell (see, for example, Patent Documents 7 and 8).
Japanese Patent Laid-Open No. 04-231803 JP 2000-353235 A JP 2002-175523 A JP 2001-357390 A JP 2002-123821 A JP 2002-213911 A Japanese translation of PCT publication No. 2003-510588 Special table 2003-510618 gazette

  In the proposals listed above, measures for preventing the influence of static electricity accumulated on the human body on the fingerprint recognition sensor have been disclosed. Although the fingerprint recognition sensor will certainly be immune from destruction, There is no consideration, and there is a problem that humans may be painful due to the sudden discharge of accumulated charges.

  In addition, when countermeasures against static electricity such as providing a ground electrode on the LSI itself are taken, there are problems that the manufacturing process becomes complicated and the number of steps increases, resulting in high costs.

  Accordingly, an object of the present invention is to provide a countermeasure against static electricity that is simple and friendly to the human body while considering cost.

FIG. 1 is a block diagram showing the principle of the present invention, and means for solving the problems in the present invention will be described with reference to FIG.
Refer to FIG. 1 In order to solve the above-mentioned problem, the present invention is a fingerprint recognition device having a fingerprint recognition sensor unit 1 for detecting a fingerprint. The fingerprint recognition sensor unit 1 has an opening 3 with a narrow portion having a width of 10 mm or less. And it is covered with the resistor sheet-like member 2 which has a surface resistivity of 10 ⁴ Ω / □ or more.

Thus, by using the resistor sheet-like member 2 having a surface resistivity of 10 ⁴ Ω / □ or more, the static electricity accumulated in the human body is gradually discharged, so that the fingerprint can be felt without feeling the pain associated with the discharge. Verification work becomes possible.
The width of the narrow portion of the opening 3 provided in the resistor sheet-like member 2 needs to be 10 mm or less, which is narrower than the width of a normal finger including a child.

In addition, the surface resistivity of the resistor sheet-like member 2 is desirably 10 ⁹ Ω / □ or less in order to reliably protect the fingerprint recognition sensor unit 1 from electrostatic breakdown due to discharge.

  In addition, the gap between the resistor sheet-like member 2 and the surface of the fingerprint recognition sensor unit 1 may be set to 0.5 to 2 mm through the spacer 4 or the like without pressing the finger against the fingerprint recognition sensor unit 1. Desirably, when it is less than 0.5 mm, it is highly possible that the discharge by the resistor sheet-like member 2 is not sufficient because the time until the finger contacts the fingerprint recognition sensor unit 1 is short. There is a possibility that electrostatic breakdown may occur due to the above. On the other hand, when the thickness exceeds 2 mm, it is often felt uncomfortable with the act of bringing a finger into contact with the surface of the fingerprint recognition sensor unit 1.

  In this case, the finger is brought into contact with the surface of the fingerprint recognition sensor unit 1 without a sense of incongruity, and the distance between the resistor sheet-like member 2 and the surface of the fingerprint recognition sensor unit 1 in a state where the finger is not pressed against the fingerprint recognition sensor unit 1. In order to surely return to 0.5 mm or more, it is desirable that the resistor sheet-like member 2 has elasticity to contact the fingerprint recognition sensor unit 1 in a state where the finger is pressed against the fingerprint recognition sensor unit 1.

  Further, it is desirable that the resistor sheet-like member 2 is detachably fixed to the apparatus main body 5 by the attachment mechanism 6, so that the resistivity of the resistor sheet-like member 2 deteriorates over time or breaks. Or when it becomes dirty, it is possible to easily replace it, and it is always possible to discharge static electricity accumulated in the human body under preset discharge conditions.

  By installing the above-described fingerprint recognition device, an information processing device such as a personal computer excellent in security measures can be realized without increasing costs.

  In the detection by the fingerprint sensor of the present invention, first, the resistor sheet member is touched to gradually discharge the electric charge accumulated in the human body, and then the finger is lightly pressed on the surface of the fingerprint recognition sensor to perform fingerprint detection, Since it is based on a series of operations for recognizing the pattern, it is gentle to humans without generating a rapid discharge, and the fingerprint recognition sensor can be protected from electrostatic breakdown.

In the present invention, a resistor sheet having an opening with a width of a narrow portion of 10 mm or less and a surface resistivity of 10 ⁴ Ω / □ to 10 ⁹ Ω / □ is spaced from a fingerprint recognition sensor portion via a spacer. The cover member is fixed to the apparatus main body so as to cover the fingerprint recognition sensor portion with an attachment member so that the thickness is 0.5 to 2 mm, and a lid member having an opening for exposing the resistor sheet and the fingerprint recognition sensor portion is provided. Is.

Here, with reference to FIG. 2 thru | or FIG. 4, the fingerprint recognition apparatus of Example 1 of this invention is demonstrated.
See FIG. 2 and FIG.
2 is an explanatory diagram of the fingerprint recognition apparatus according to the first embodiment of the present invention, the left figure is a plan view, the right figure is a side view, and FIG. 3 is a cross-sectional view of the fingerprint recognition apparatus according to the first embodiment. FIG.

  This fingerprint recognition device 10 includes a plastic lower cover 11 having a recess 12 for accommodating a fingerprint recognition sensor 30, a fingerprint recognition sensor 30, and a resistor sheet 14 having an opening 15 through a gap of 0.5 to 2 mm. The plastic spacer 13 facing the fingerprint recognition sensor 30, the fixing member 17 made of screws for fixing the resistor sheet 14 to the lower cover 11 via the holding frame member 16, and the finger are brought into contact with the surface of the fingerprint recognition sensor 30. A plastic upper cover 18 having an opening 19 and a connection portion 20 for transmitting information detected by the fingerprint recognition sensor 30 to the information processing apparatus main body side. The lower cover 11 and the upper cover 18 are screws. The members 21 to 24 are fixed to each other.

In this case, the resistor sheet 14 is a sheet-like member having a surface resistivity of 10 ⁴ Ω / □ to 10 ⁹ Ω / □, for example, cropoly sheet (trade name, manufactured by Achilles), cropoly mat (commercial product, manufactured by Achilles). Name) or CMPS601 (trade name, manufactured by Ohira Chemical Co., Ltd.), and this resistor sheet 14 is electrically connected to the grounding portion (not shown) of the lower cover 11 via the pressing frame member 16 and the fixing member 17. It is connected to the.
In any case, since the resistor sheet 14 is not a perfect conductor but requires a certain surface resistance, the lower limit value of the surface resistivity is particularly important, and care must be taken when selecting.

In addition, an opening 15 is provided at the center of the resistor sheet 14 so that the finger does not penetrate, and the resistor sheet 14 can be surely contacted with the finger before contacting the surface of the fingerprint recognition sensor 30. The width of the opening 15 in the minor axis direction is 10 mm or less, for example, 8 mm, which is narrower than the width of a normal human finger including a child.
By providing such an opening 15, the finger can be reliably grounded through the resistor sheet 14 in a state where the finger is in contact with the surface of the fingerprint recognition sensor 30, so that it can act as a counter electrode.

  The fingerprint recognition sensor 30 is formed with a semiconductor element such as a transistor (not shown) as in the conventional electrostatic capacitance type fingerprint recognition device, as shown in the enlarged view of the main part in the lower diagram of FIG. On the silicon substrate 31, the charge storage electrodes 33 made of Al and the like and electrically connected to the semiconductor elements are arranged in a two-dimensional matrix form through a barrier metal layer 32 such as Ti, and the entire surface is protected and insulated. The film 34 is covered.

See Figure 4
FIG. 4 is a cross-sectional view of the fingerprint recognition device according to the first embodiment of the present invention in a state where a finger is pressed. The width of the opening 15 provided in the resistor sheet 14 in the short axis direction is larger than the width of a normal finger. Since it is narrow, the finger 25 comes into contact with the surface of the fingerprint recognition sensor 30 after first contacting the resistor sheet 14.

  In this case, since the finger 25 is pressed against the surface of the fingerprint recognition sensor 30 in contact with the resistor sheet 14 due to the elasticity of the resistor sheet 14, the finger 25 surely functions as a ground electrode and has high accuracy. Can be detected stably.

  Also in this case, as shown in the enlarged view in the lower part of FIG. 4, when the finger 25 touches the surface of the fingerprint recognition sensor 30, the surface between the surface of the finger 25 through the protective insulating film 34 and each charge storage electrode 33 is interposed. The distance varies according to the unevenness 26 of the fingerprint, and this variation is detected as a variation in the capacitance between each charge storage electrode 33 and the finger 25 functioning as the ground electrode. A fingerprint pattern can be detected by two-dimensionally plotting the capacitance values.

As described above, in Example 1 of the present invention, the resistor sheet 14 having a surface resistivity of 10 ⁴ Ω / □ or more is provided via a gap of 0.5 mm or more, so that the static electricity accumulated in the human body is discharged. Is gradually performed using the surface resistance of the resistor sheet 14, and is performed without a human being perceived to discharge, and after the electric charge accumulated in the human body is reliably discharged, the surface of the fingerprint recognition sensor 30 is contacted. Therefore, the fingerprint recognition sensor 30 is sufficiently protected from electrostatic breakdown.

  Further, since the resistor sheet 14 is detachably fixed to the lower cover 11 by the fixing member 17 via the presser frame member 16, if the resistor sheet 14 deteriorates or is damaged due to repeated use, the resistor sheet 14 is screwed. It is possible to easily replace the resistor sheet 14 by removing the members 21 to 24 and the upper cover 18 and then removing the fixing member 17.

Next, the fingerprint recognition apparatus according to the second embodiment of the present invention will be described with reference to FIG. 5. However, since the structure other than the upper cover mounting structure is exactly the same as the first embodiment, only the upper cover mounting structure is described. Will be explained.
See Figure 5
FIG. 5 is a cross-sectional view of the fingerprint recognition apparatus according to the second embodiment of the present invention. The upper cover 42 is attached to the lower cover 41 via a hinge mechanism 43 and various types provided on the opposite side of the hinge mechanism 43. The upper cover 42 can be freely opened and closed by a lock mechanism 44 utilizing the fitting of the structure.

  Thus, in Example 2 of the present invention, since the upper cover 42 can be freely opened and closed, the resistor sheet 14 can be replaced more easily.

As mentioned above, although each Example of this invention was described, this invention is not restricted to the structure and conditions described in each Example, A various change is possible.
For example, in each of the above embodiments, the shape of the opening provided in the resistor sheet is an ellipse, but it may be a circle or a square.

  Further, in each of the above embodiments, a screw is used as a fixing member for fixing the resistor sheet. However, the screw is not limited to the screw, and is locked using a fitting mechanism by pressing toward the lower cover side. Accordingly, a one-touch fixing member that sandwiches the resistor sheet with the lower cover may be used, and the resistor sheet can be replaced more easily.

  In addition, the fingerprint recognition sensor shown in each of the above embodiments is merely an example, and it goes without saying that various known electrostatic capacitance type fingerprint recognition sensors may be used.

  In each of the above embodiments, the connection unit 20 is configured to be connected to the information processing apparatus main body side. However, the connection unit is configured to communicate with the information processing apparatus main body side wirelessly. It is good as a less type.

  In the second embodiment, the upper cover is locked using the fitting mechanism, but a magnet may be used.

  In each of the above-described embodiments, a mouse-type fingerprint recognition device connected to the information processing apparatus main body side through the connection unit 19 is described. It may be mounted so as to be incorporated in the portable information processing device itself.

  Further, in each of the above embodiments, the security mechanism for logging on various information processing apparatuses is described. However, the security mechanism is not limited to the information processing apparatus. It can also be used as a security mechanism when opening and closing an entrance door provided at the entrance of a built house or various restricted access areas.

  Furthermore, taking advantage of its small and portable characteristics, it can also be used as a fingerprint recognition device that is always used in police stations and patrol cars. The detected fingerprint is transmitted to the public prosecutor's office or the like by communication means and collated with the stored fingerprint data, so that the identity of the unknown person can be quickly confirmed.

Here, the detailed configuration of the present invention will be described again with reference to FIG.
Again see Figure 1
(Additional remark 1) In the fingerprint recognition apparatus which has the fingerprint recognition sensor part 1 which detects a fingerprint, the said fingerprint recognition sensor part 1 has the opening part 3 whose width | variety of a narrow part is 10 mm or less, and a surface more than 10 < ⁴ > ohm / square A fingerprint recognition device characterized by being covered with a resistor sheet-like member 2 having resistivity.
(Additional remark 2) The surface resistivity of the said resistor sheet-like member 2 is 10 < ⁴ > -10 < ⁹ > ohm / square, The fingerprint recognition apparatus of Additional remark 1 characterized by the above-mentioned.
(Supplementary Note 3) A gap between the resistor sheet-like member 2 and the surface of the fingerprint recognition sensor unit 1 is 0.5 to 2 mm without pressing a finger against the fingerprint recognition sensor unit 1. The fingerprint recognition device according to appendix 1 or 2.
(Additional remark 4) The said resistor sheet-like member 2 has the elasticity which contacts the said fingerprint recognition sensor part 1 in the state which pressed the finger against the said fingerprint recognition sensor part 1, The fingerprint recognition of Additional remark 3 characterized by the above-mentioned apparatus.
(Additional remark 5) The said resistor sheet-like member 2 is detachably fixed by the attachment mechanism 6, The fingerprint recognition apparatus of any one of Additional remark 1 thru | or 4 characterized by the above-mentioned.
(Additional remark 6) The information processing apparatus equipped with the fingerprint recognition apparatus in any one of Additional remarks 1 thru | or 5.

  As a practical example of the present invention, a fingerprint recognition device constituting a security mechanism of various information processing devices such as a personal computer is typical, but an entrance of an apartment house, an entrance of a detached house, or Also, it can be applied as a fingerprint recognition device constituting a security mechanism for opening and closing an entrance door provided in various restricted access areas, or a fingerprint recognition device in a police station or the like.

It is explanatory drawing of the fundamental structure of this invention. It is the top view and side view of a fingerprint recognition apparatus of Example 1 of this invention. It is sectional drawing of the fingerprint recognition apparatus of Example 1 of this invention. It is sectional drawing of the fingerprint recognition apparatus of Example 1 of this invention in the state which pressed the finger | toe. It is sectional drawing of the fingerprint recognition apparatus of Example 2 of this invention. It is explanatory drawing of the conventional fingerprint recognition apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fingerprint recognition sensor part 2 Resistor sheet-like member 3 Opening part 4 Spacer 5 Apparatus main body part 6 Attachment mechanism 11 Lower cover 12 Recessed part 13 Spacer 14 Resistor sheet 15 Opening part 16 Holding frame member 17 Fixing member 18 Upper cover 19 Opening part 20 Connecting portion 21 Screw member 22 Screw member 23 Screw member 24 Screw member 25 Finger 26 Fingerprint unevenness 30 Fingerprint recognition sensor 31 Silicon substrate 32 Barrier metal layer 33 Charge storage electrode 34 Protective insulating film 41 Lower cover 42 Upper cover 43 Hinge mechanism 44 Lock mechanism 51 Silicon substrate 52 Barrier metal layer 53 Charge storage electrode 54 Protective insulating film 55 Concavity and convexity of fingerprint

Claims (5)

A fingerprint recognition apparatus having a fingerprint recognition sensor unit for detecting a fingerprint, wherein the fingerprint recognition sensor unit has an opening with a narrow portion having a width of 10 mm or less and a surface resistivity of 10 ⁴ Ω / □ or more. A fingerprint recognition device characterized by covering with a member. 2. The fingerprint recognition apparatus according to claim 1, wherein the resistor sheet-like member has a surface resistivity of 10 < ⁴ > to 10 < ⁹ > [Omega] / □. The gap between the resistor sheet-like member and the surface of the fingerprint recognition sensor unit is 0.5 to 2 mm in a state where a finger is not pressed against the fingerprint recognition sensor unit. Fingerprint recognition device. 4. The fingerprint recognition apparatus according to claim 3, wherein the resistor sheet-like member has elasticity to come into contact with the fingerprint recognition sensor unit in a state where a finger is pressed against the fingerprint recognition sensor unit. 5. The fingerprint recognition apparatus according to claim 1, wherein the resistor sheet-like member is detachably fixed by an attachment mechanism.

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