JP2001256487A - Fingerprint collating unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of light sources and to attain miniaturization. SOLUTION: A light transmission plate 43 is arranged in the lower part of a fingerprint reading window member 7 with which a fingertip is brought into contact. A light emitting element 42 as a light source is disposed at the one end surface side of the plate 43. The plate 43 is arranged by inclination to be adjacent to the window member 7. Detection light beams from the element 42 are sufficiently diffused while passing through the plate 43 and emitted by surface toward the window member 7 from the plate 43. A reflection light from the member 7 is reflected against mirrors 33 and 34 without being disturbed by the plate 43 and a light source device L and, then, inputted to an imaging element 36 through a lens 35. The light transmission plate 43 is composed of a main body plate part 43A and a front surface plate part 43B. Multiple grooves 46 extending in a direction in nearly parallel with the input direction of the detection light beams from the element 42 are formed on the front surface of the main body plate part 43A over the input direction. The diffusing action of the detection light beams is enhanced by the grooves 46 and, then, the light beams are corrected to be the uniform beams by the front surface plate part 43B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fingerprint collator.

[0002]

2. Description of the Related Art Instead of using a password for identity verification, it is common to confirm whether or not the user is an identity by fingerprint collation. For this purpose, a fingerprint collation machine is used. In an optical fingerprint collation device, the unevenness of a fingerprint is converted into light intensity, and this is converted into an electric signal (an image signal corresponding to the fingerprint) by an image sensor. By comparing with the stored personal electric signal, it is confirmed whether or not the person is the person. Such an optical fingerprint collation device has a fingerprint reading window through which a fingertip is brought into contact, and a detection light beam from a light source provided inside the fingerprint reading window is applied to the fingerprint reading window. The light reflected from the window is finally input to the image sensor. Japanese Patent Application Laid-Open No. Hei 10-2 discloses an optical fingerprint collator.
No. 89304.

Incidentally, the detection light beam applied to the fingerprint reading window member needs to emit surface light in order to irradiate the entire fingertip. Conventionally, in order to obtain such surface light emission, a structure in which a large number of light emitting elements are dispersedly arranged on a substrate arranged opposite to a window member has been adopted.

[0004]

However, in a structure in which a large number of light-emitting elements are dispersedly arranged on a substrate as in the above-described conventional technique, it is necessary to use a large number of expensive light-emitting elements, and as a whole it is very expensive. At the same time, the power consumption becomes extremely large. In addition to this, it is necessary to sufficiently diffuse the detection light beam from the light emitting element, and it is necessary to ensure a considerably large space between the substrate and the window member. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fingerprint collation device which can be reduced in size while reducing the number of light sources.

[0006]

In order to achieve the above object, the present invention adopts the following solution. That is, in an optical fingerprint collation device configured to irradiate a detection light beam from a light source to a window member for fingerprint reading, a light guide plate disposed such that a plate surface faces the window member, By inputting a detection light beam from a light source from one end surface side of the light guide plate, the detection light beam emits surface light emitted from the entire surface of the light guide plate. According to such a solution, the detection light beam from the light source is sufficiently diffused before passing through the light guide plate, and is emitted from the entire surface of the light guide plate. Due to the diffusion of the detection light beam by the light guide plate, the number of light sources to be used can be reduced, which is advantageous in terms of cost and power consumption can be reduced. In addition, the distance between the light guide plate and the fingerprint reading window member can be made close to each other, so that the fingerprint collation device can be reduced in size, in particular, reduced in thickness.

It is preferable that the light guide plate is arranged to be inclined with respect to the fingerprint reading window member. In this case, a detection light path for guiding the reflected light from the window member to the image sensor is secured with a sufficient margin. be able to.

[0008] The light guide plate may be composed of a main body plate portion and a surface plate portion provided on the surface side (the surface facing the window member) of the main body plate portion. On the surface of
By forming a large number of grooves extending in a direction substantially parallel to the input direction of the detection light beam from the light source over the input direction of the detection light beam, the diffusion effect of the light guide plate is enhanced, and the surface light is emitted by the surface plate portion. The detected detection light can be corrected to a uniform light.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One example of a fingerprint collating apparatus to which the present invention is applied will be described below with reference to the drawings. First, the outline of the present invention will be described with reference to FIGS. The case K constituting the outer shell of the fingerprint collation device is composed of a lower case 1 and an upper case 2 each formed of a synthetic resin. The lower case 1 and the upper case 2 are fixed and integrated with each other by screws 3 (see FIG. 4) attached and removed from below the lower case 1.
In such a case K, a space in which various components described later are provided is defined.

A part of the upper case 2 is constituted by a lid member 4. The lid member 4 is formed separately from the upper case 2 by a synthetic resin, and forms a considerably large area portion and a part of a side surface of the upper surface of the upper case 2. The lid member 4 is detachable from the upper case 2 without using a separate fixture, and an opening 5 having a shape corresponding to the shape of the lid member 4 is formed in the upper case 2. Of course, the opening 5 is covered with the lid member 4, and in the mounted state in which the opening 5 is covered with the lid member 4, the surface of the outer peripheral edge of the lid member 4 is the same as the inner peripheral edge of the opening 5. It is flush with the surface.

An opening 6 is formed in a portion of the lid member 4 that constitutes the upper surface of the upper case 2, and the opening 6 is covered with a window member 7. The window member 7 is provided on the inner side of the lid member 4 (space side in the case K), and is held by the lid member 4 with the opening 6 covered as described later. Of course, the fingertip contacts the upper surface of the window member 7.

The lid member 4 is detachably attached to the upper case 2 (case K) from the outside without using a fixing tool such as a screw, as described later. FIGS. 1 to 3 show a state where the lid member 4 is attached to the upper case 2, and FIG. 4 shows a state where the lid member 4 is removed from the upper case 2. Since the window member 7 is held by the lid member 4,
By removing the lid member 4 from the upper case 2, the window member 7 is removed.
Is removed from the upper case 2 together with the lid member 4. Similarly,
By attaching the lid member 4 to the upper case 2, the lid member 7
Is attached to the upper case 2.

The set of the cover member 4 and the window member 7 can be provided (sold) separately and separately from other members for replacement when the window member 7 is soiled. That is, when the window member 7 is soiled, the set body of the old soiled window member 7 and the cover member 4 is removed from the upper case 2, and
A new set of the window member 7 and the cover member 4 may be newly attached to the upper case 2. Of course, since only the set body of the window member 7 and the lid member 4 is replaced, the replacement can be performed at extremely low cost in view of the cost of the entire fingerprint collation device. Of course, the replacement of the set body can be easily performed by the user himself.

As described later, various elements for obtaining a signal corresponding to the fingerprint of the fingertip touching the window member 7 are built in the case K, and the obtained signal is finally converted into an electric signal. Output to the outside via the connection cable 8. The type of the connection cable 8, that is, the connection terminal 8a is
Although the USB type is used in the embodiment, other types may be adopted.

Next, an embodiment of the present invention will be described in detail. First, the details of the cover member 4 and the window member 7 will be described with reference to FIGS. The periphery of the opening 6 formed in the thin-walled lid member 4 is inclined so as to gradually increase as the distance from the opening 6 increases (this inclined surface is indicated by reference numeral 4a). Is set to be easily introduced into the opening 6 (that is, the window member 7). A plurality (four in the embodiment) of holding legs (constituting a holding portion) 11 protrude from the inner surface of the lid member 4 at a position immediately adjacent to the opening 6. The holding legs 11 are elongated and can be sufficiently elastically deformed, and are integrally formed with the lid member 4. The four holding legs 11 are positioned so as to be located at four corners of the rectangle. Note that an engaging portion is formed on the cover member 4 for detachable attachment to the case K, which will be described later.

The window member 7 is formed in a thin plate shape by a light-transmitting (light transmitting) member.
As shown in FIG. 18, the four corners of the rectangle are cut off diagonally. Projections 7a slightly projecting from the left and right (up and down directions in FIG. 18) end surfaces of the window member 7
Are formed. The pair of left and right protrusions 7a extend relatively long along the side surface of the window member 7, but have ends that do not reach the front-rear direction (the left-right direction in FIG. 18) of the window member 7. . The protrusion 7a is formed integrally with the window member 7.

The holding leg 11 formed on the lid member 4
Are located at the longitudinal ends of the pair of left and right projections 7a of the window member 7 so as to elastically hold the window member 7 from its peripheral edge. The holding function of the window member 7 can be further enhanced by forming a claw at the tip of the holding leg 11 and setting the claw to be located on the lower surface of the window member 7. The window member 7 is a holding leg 11
Is held by the window member 7 in the holding state.
Opening 6 is covered from the inside. In this cover state, the surface of the window member 7 which is to be the upper surface is provided with a coating layer 12 (such as a silicon film) for improving the detection accuracy of the unevenness of the fingerprint (making the intensity of the light more clear) as shown in FIG. 17)) is formed. In addition,
In FIG. 17, the coating layer 12 is exaggeratedly thicker than it is in order to clearly show its existence.

In order to make the cover member 4 detachable from the upper case 2 without using a separate fixing tool, as shown in FIG. Part 22
Are formed. The first locking portion 21 is formed as a pair of left and right openings near the one end of the opening 5 on the upper surface of the upper case 2. Also, the second
The locking portion 22 is located near the other end of the opening 5.
The lower case 1 is formed on the inner surface of the upper side wall as a single concave form. A first engaging portion 23 is integrally formed with the lid member 4 corresponding to the first locking portion 11, and a second engaging portion 24 is integrally formed with the second locking portion 22. The first engagement portion 23 is formed as a pair of left and right tongue-like shapes protruding from one end of the lid member 4. Also, the second
In the vicinity of the other end of the lid member 4, the engaging portion 24 has a claw-shaped tip at the tip.

When the cover member 4 holding the window member 7 is attached to the case K, the cover member 4 is slightly inclined with respect to the upper surface of the upper case 2 as shown in FIG. The part 23 is inserted into the first locking part 21. Next, the lid member 4 is swung downward around the vicinity of the locking portion 11,
When the second engaging portion 24 is engaged with the second locking portion 12, the mounting is completed. Removal of the lid member 4 from the case K may be performed in a procedure reverse to the above. That is, a slight pressing force is applied to the position corresponding to the second engaging portion 24 from the outside of the lid member 4 so that the second engaging portion 24 is disengaged from the second locking portion 22. 4 is swung upward, and then
What is necessary is just to pull out the 1st engaging part 23 from the 1st locking part 21.
As described above, in the embodiment, the lid member 4 is attached to and detached from the case K by a predetermined motion of two motions. For example, the lid member 4 is attached to and detached from the case K by sliding the lid member 4 with respect to the case K. The predetermined movement of the lid member 4 required for attachment / detachment (that is, the selection of the structure of the engaging portion and the engaging portion), for example, can be appropriately changed.

Next, details of the case K will be described with reference to FIGS. First, a holder H made of a synthetic resin is provided in the case K. This holder H
Is a claw-shaped engaging portion 31 formed on the upper side surface thereof.
Is fixed to a predetermined position in the case K by projecting from the inner surface of the upper case 2 and engaging the front end with the locking portion 32 having a claw shape. The holder H includes a light source device L
, The first and second two reflection mirrors 33 and 34, the lens 35, and the image sensor 36 are held. The light source device L includes a light emitting element 42 (a LED in the embodiment) as a light source.
But is not limited to this), and a light guide plate 43 for widely diffusing light rays from the light emitting element 42 in a planar manner. Irradiate in a shape. The reflected light from the window member 7 is transmitted to the first mirror 3
3 is input to the lens 35 via the second mirror 34, and the reflected light beam passing through the lens 35 is input to the image sensor 36. The image sensor 36 converts the intensity of the input reflected light into an electric signal.

The upper surface of the left and right side walls of the holder H is formed as a bearing surface 37 for supporting the window member 7. That is, even when the pair of left and right protrusions 7a of the window member 7 in the mounted state are placed on the support surface 37 and the window member 7 is pressed by a fingertip, the window member 7 is not displaced downward. The window member 7 is firmly supported from below.
When the window member 7 is mounted, the window member 7 is sandwiched between the bearing surface 37 and the lid member 4 (the inner peripheral edge of the opening 6), and the window member 7 is displaced vertically (in the thickness direction). Not to be. In addition, the left and right wall portions 3 extending upward slightly higher than the bearing surface 37 around the window member 7 in the attached state (supported by the bearing surface 37) are attached to the holder H.
8 and a front wall portion 39 are formed. Further, a rear wall portion 41a extending slightly higher and higher than the bearing surface 37 is formed in a holder 41, which will be described later, of the light source device L.
9 and 41a prevent the window member 7 in the attached state from being largely displaced in the front-rear and left-right directions.

The light source device L will be described with reference to FIGS. The light source device L has a holder 41 formed of a synthetic resin, and the light emitting element 42 and the light guide plate 43 described above.
In addition, a substrate 44 for the light emitting element 42 is held. The holder 41 has a substantially flat support plate portion 41b, and the light guide plate 42 is mounted on the support plate 41b. Holder 41
A thin opening 41c is formed at the rear end (left side in FIG. 9), and the rear end of the light guide plate 43 is fitted into the opening 41c without play. Further, a front end portion of the support plate portion 41b is formed as a stopper wall portion 41d that extends shortly upward, and regulates the forward displacement of the light guide plate 43.

The holder 41 holds a substrate 44 behind the light guide plate 43. As shown in FIG. 10, a locking projection 44 a is formed on the upper end surface of the substrate 44, and the locking projection 44 a is fitted to a locking opening 41 e formed at the base end of the holder 41. It is fitted without sticking. A cutout opening 44b is formed in the lower end surface of the substrate 44, and a locking projection 41f that projects short from the holder 41 to the rear is fitted into the cutout opening 44b.
The substrate 44 thus held by the holder 41 includes:
A plurality (three in the embodiment) of light emitting elements 42 are attached at intervals in the left-right direction (the direction along the rear end face of the light guide plate 43, the vertical direction in FIG. 8). The light-emitting element 42 is located immediately near the rear end face of the light guide plate 43 and emits light toward the rear end face of the light guide plate 43.

As shown in FIG. 11, the light guide plate 43 is
Each is composed of a main body plate portion 43A made of a light transmitting member and a surface plate portion 43B integrated on the upper surface of the main body plate portion 43A. On the upper surface of the main body plate portion 43A, a fine groove portion 46 is formed over almost the entire surface. The groove 46 is for widely dispersing the input light beam from the light emitting element 42 in a planar manner, extends in a direction substantially parallel to the light receiving direction from the light emitting element 42, and has a large number along the light receiving direction. Is formed. By the surface plate portion 43B,
The light beam widely dispersed by the main body plate portion 43A is corrected so as to be a uniform light beam emitted in a predetermined direction.

The holder 41 is placed and held on a holding portion 45 formed on the holding body H from the rear end to the middle part in the front-rear direction (the left-right direction in FIG. 4). Holder 41
A locking hole 41g extending substantially in the vertical direction is formed in the rear of the substrate 44, and the locking hole 41g is formed.
A locking projection 47 formed on the holder H and extending short in the vertical direction is tightly fitted (see FIG. 4). The holder H holds the lens 35 immediately below the holding section 45, and holds the image sensor 36 immediately behind the lens 45. The first reflection mirror 33 is arranged below the window member 7 in the attached state and on an extension of the light guide plate 43. The second reflection mirror 34 is disposed at the lowest position so as to be located below the window member 7 in the mounted state. Since the thickness of the light guide plate 43 is small and the light guide plate 43 can be disposed close to the window member 7, the length of the case K as a whole in the vertical direction can be set small.

The light guide plate 43 is arranged obliquely with respect to the window member 7 in the mounted state, and irradiates light rays from the oblique direction toward the window member 7. Therefore, the first reflection mirror 33 is used for the light guide plate 4.
3 are arranged in the extension direction. That is, the space between the light guide plate 43 and the first reflection mirror 33 is
(Part of) reflected light path from 3 to the second reflecting mirror 34
The reflected light from the second reflecting mirror 34 is made to substantially match the inclination direction of the light guide plate 43, and the reflected light is input to the lens 35 installed below the light guide plate 43. Is set to

In order to confirm whether or not a fingertip is in contact with the window member 7, a light emitting element 51 (LED in the embodiment) is provided on the holder H at the upper portion of the left side wall. , The light emitting element 5
The light receiving element 52 is provided on an extension of the first line.
The height position of each of the elements 51 and 52 is slightly higher than the upper surface of the window member 7 in the mounted state. When the fingertip comes into contact with the window member 7, the light beam from the light emitting element 51 is blocked and is not input to the light receiving element 42,
The presence of the fingertip will be confirmed. A pair of left and right cutout openings 4b are formed on the connection line connecting the light emitting element 51 and the light receiving element 52 in the inner peripheral edge of the opening 6 in the cover member 4 (see FIGS. 4, 12, and 16). ), So that the lid member 4 does not hinder fingertip detection.

FIG. 19 shows an example in which the case of the fingerprint collation device is also used as the keyboard case 61 of the notebook personal computer NP. That is, in the notebook personal computer NP, a fingerprint collation device is used instead of a password for identity verification. FIG.
62, a lid side case having a display 63; 64, various keys; 65, a mouse pad;
Is the click key. Key 64, mouse pad 6
5. The keyboard case 61 having the click keys 66 and 67 is used as the case K of the fingerprint collation device described above. Then, the cover member 4 is connected to the keyboard case 61.
Is part of. Of course, various components for the fingerprint collating device as shown in FIG.
It is provided in the keyboard case 61 (however, the connection cable 8 is unnecessary). Of course, the present invention can be applied to a desktop personal computer and other information processing devices other than the notebook personal computer.

[0029]

According to the present invention, it is possible to provide the apparatus at low cost, to consume only a small amount of power, and to reduce the size of the fingerprint collating apparatus as a whole.

[Brief description of the drawings]

FIG. 1 is a plan view of a fingerprint matching device to which the present invention is applied.

FIG. 2 is a right side view of FIG.

FIG. 3 is a left side view of FIG. 2;

FIG. 4 is a sectional view corresponding to line X4-X4 in FIG. 1;

FIG. 5 is a plan view of a holder provided in the case and components attached to the holder.

FIG. 6 is a sectional view taken along line X6-X6 of FIG. 4 in a state excluding a case.

FIG. 7 is an essential part cross-sectional view showing a connected state of the upper case and the holder.

FIG. 8 is a plan view of a light source device.

FIG. 9 is a sectional view corresponding to line X9-X9 in FIG. 8;

FIG. 10 is a diagram of the light source substrate when viewed from the right side of FIG. 9;

FIG. 11 is a sectional side view of a main part of the light guide plate.

FIG. 12 is a perspective view of a lid member.

FIG. 13 is a plan view of a set body of a lid member and a window member.

FIG. 14 is a rear view of a set body of a lid member and a window member.

FIG. 15 is a right side view of FIG.

FIG. 16 is a left side view of FIG.

FIG. 17 is a sectional view taken along line X17-X17 in FIG. 13;

FIG. 18 is a plan view of a window member.

FIG. 19 is an exemplary perspective view showing an example of a notebook computer in which a fingerprint matching device is incorporated.

[Explanation of symbols]

 K: Case H: Holder L: Light source device 1: Lower case 2: Upper case 4: Cover member 5: Opening covered with the cover member 6: Opening formed in the cover member 7: Window member 11: Holding Leg portion (holding portion) 21: first locking portion 22: second locking portion 23: first engaging portion 24: second engaging portion 37: support surface 41: holder 42: light emitting element (light source) 43 : Light guide plate 43A: main body plate portion 43B: surface plate portion 44: substrate 46: groove (main body plate portion)

Claims (3)

[Claims] 1. An optical fingerprint collator for irradiating a fingerprint reading window member with a detection light beam from a light source, wherein a light guide plate disposed so that a plate surface faces the window member is provided. By inputting a detection light beam from the light source from one end surface side of the light guide plate, the detection light beam is configured to emit surface light emitted from the entire plate surface of the light guide plate. Fingerprint collator. 2. The fingerprint matching device according to claim 1, wherein the light guide plate is arranged to be inclined with respect to the window member. 3. The light guide plate according to claim 1, wherein the light guide plate includes a main body plate portion, and a surface plate portion disposed on a surface of the main body plate portion facing the window member. On the surface side of the main body plate portion, a large number of grooves extending in a direction substantially parallel to the input direction of the detection light beam from the light source are formed over the input direction of the detection light beam, Characteristic fingerprint collator.