JPH04271477A - Device for inputting fingerprint picture - Google Patents

Abstract

PURPOSE:To provide a pressure sensor in a transparent optical component having the taking part surface of a fingerprint picture and to execute the attitude-controlling of the transparent optical component based on the output of the pressure sensor in a fingerprint picture input device which inputs the fingerprint picture. CONSTITUTION:The device is provided with the transparent optical component 1 having the taking part surface of the fingerprint picture, a detecting means 2 which is attached to the optical component 1 and detects what kind of pressure distribution the taking surface is pressed with, a control means which executes the attitude controlling of the optical component 1 in accordance with the detection output of the means 2, a holding component 4 which holds the optical component 1 by the instruction of the control means and has the attitude controlling mechanism of the optical component 1, an illuminating means 5 which illuminates the taking surface through the optical component 1 and a photoelectric conversion means 6 which collects light reflected in the taking surface from the illuminating means 5 through the optical component 1 so as to execute photoelectric conversion.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fingerprint image input device for inputting a fingerprint image.

The present invention provides a fingerprint image input device for inputting a fingerprint image, in which a pressure sensor is provided on a transparent optical member provided with a fingerprint image collection surface, and the attitude of the transparent optical member is determined based on the output of the pressure sensor. It is something that controls.

[0003] By controlling the posture by pressure,
By eliminating the problem of distortion due to pressure applied to the finger surface and the problem that individual identification ability is affected by the way the finger is placed, it is now possible to input fingerprint images that can be highly accurately identified with a simple device. It is something.

0004

2. Description of the Related Art Various devices are known that perform highly accurate individual identification based on information specific to the human body. Among these, fingerprints are highly trusted and widely used as personal identification information because the information contained within a narrow range cannot be forged or transferred. In such devices for inputting fingerprint images, distortion of the fingerprint image often poses a problem.

[0005] Since the human finger is not a rigid body, the pressure applied when placing the finger on the finger distorts the fingerprint.

Conventionally, the following devices are known. That is, the conventional fingerprint image input device is disclosed in Japanese Patent Application Laid-Open No. 64-6889.
4, and as shown in FIG. It consists of an illumination means 11 for capturing a fingerprint image, an image sensor 12, and a control device 13, and the finger 14 is attached to a transparent body 15.
In the fingerprint image input device that obtains a fingerprint image by pressing the finger onto the transparent body 15, the mechanism unit 16 that moves the transparent body 15 and the finger 14 pressed onto the transparent body 15 are strained by a certain amount in a certain direction.
A spring 17 that applies a force in the opposite direction to the direction of movement of the transparent body 15 detects the amount of movement when the transparent body 15 reaches a predetermined movement amount and controls the input/output switch of the control device 13. This is a fingerprint image input device having a detector 18. In addition, in the figure, 19 is a communication device.

[0007]

[Problems to be Solved by the Invention] According to this fingerprint image input device, since fingerprints are collected when a certain pressure is applied to the finger, the fingerprint image is collected under a certain degree of distortion regardless of individual differences. Collection can be carried out. However, a problem arises when the fingerprint image is always distorted, for example when the finger is placed poorly due to individual habits or when pressure is applied in the lateral direction. Also,
Basically, fingers are distorted, so it is a burden to process and judge fingerprint images.

[0008]

[Means for Solving the Problems] The gist of the present invention is to provide a transparent optical member 1 provided with a fingerprint image collection surface 9.
and a detection means 2 attached to the optical member 1 and capable of determining with what kind of pressure distribution the sampling surface 9 is being pressed;
It has a control means 3 for controlling the attitude of the optical member 1 according to the detection output of the detection means 2, and a mechanism for holding the optical member 1 and controlling the attitude of the optical member 1 according to commands from the control means 3. A holding member 4, an illumination means 5 for illuminating the sampling surface 9 through the optical member 1, and a photoelectronic system that collects light from the illumination means 5 reflected on the sampling surface through the optical member 1. This is a fingerprint input device equipped with a photoelectric conversion means 6 for converting the fingerprint.

[0009]

[Production] The explanation will be made according to the examples shown in FIGS. 1 to 4.

By moving the optical member 1 having the fingerprint collecting surface so that the pressure on the finger surface is appropriate, an input fingerprint image is obtained with less distortion.

The posture of the optical member 1 provided with the fingerprint collection surface 9 is controlled by the output from the detection means 2 attached thereto.

[0012] This allows the finger to be properly pressed against the fingerprint collection surface 9.

[0013]

Embodiment An embodiment of the fingerprint image input device of the present invention is shown in FIGS. 1 to 4.

FIG. 1 shows an optical member 1 made of acrylic material, for example, having a fingerprint collecting surface 9, and a pressure sensor 2 provided on the optical member 1 and serving as a detection means 2 for sensing the pressure exerted by a finger 14 on the fingerprint collecting surface 9. , for example, LE for generating illumination light L0 for illuminating the fingerprint collection surface 9 of the optical member 1.
An illumination means 5 such as D, a condenser lens 7 for condensing the light L1 totally reflected by the fingerprint collection surface 9, and a condenser lens 7.
The photoelectric conversion means 6, such as a CCD image sensor, inputs the light L1 collected by the photoelectric conversion means 6. The irradiation light L0 generated by the illumination means 5 enters the optical member 1 having the fingerprint collecting surface 9 and is attached at an angle such that it is directed toward the collecting surface 9.

The irradiated light L0 reaching the fingerprint collecting surface 9 is
Irradiates the surface of the finger. As shown in the detailed diagram in FIG. 4, the irradiated light L0 is divided into two parts: light that is scattered due to the difference in reflection conditions on the surface of the finger 14, and light L1 that is directed toward the condensing lens.
It can be divided into

At point P in the ridge portion of the fingerprint, the irradiated light L0 is scattered and only a small amount of light is directed toward the condenser lens.

At the valley line part of the fingerprint, the irradiation light L0 is
It is totally reflected and becomes reflected light L1. The reflected light L1 passes through the optical member 1 and heads toward the condenser lens 7. Condensing lens 7
The light L1 focused by is inputted as a fingerprint image by the photoelectric conversion means 6. Since the amount of light L1 totally reflected at the valley line portion of the fingerprint is greater, the valley line portion is input as a bright portion.

FIG. 2 shows an optical member 1 and a pressure sensor 4 serving as a detection means 2 provided on the optical member 1. As shown in FIG. In the diagram,
One pressure sensor 2 is attached to each of the four sides of the light-collecting surface of the optical member 1, and the pressure of a finger on the fingerprint collecting surface 9 of the optical member 1 can be divided into four parts and detected. The attitude of the optical member 1 is controlled based on this detection result.

FIG. 3 is a signal flow diagram. Regarding the optical part, a side view and a full view are shown above as seen from the finger.

[0020] Pressure sensor 2 is attached to transparent optical member 1.
is installed. The pressure sensor 2 is electrically coupled so that a signal is input to the control means 3. The control means 3 controls the attitude of the optical member 1 based on the detection result of the pressure sensor 2.

[0021]

[Effects of the Invention] According to the fingerprint image input device according to the present invention,
Since the pressure on the fingerprint collection surface of the optical member is measured and the posture of the optical member is controlled based on this, the fingerprint image can be input with the appropriate pressure, allowing for highly accurate fingerprint matching and judgment. It can be used as an input means for devices that perform

[0022] Since the distortion of the fingerprint is small and the difference in the placement of the finger due to individual differences is controlled, it is possible to always obtain a high-quality fingerprint image.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention.

FIG. 2 is a perspective view of the main parts of the same as above.

FIG. 3 is a configuration diagram of the main parts of the same as above.

FIG. 4 is an enlarged view of the main part of FIG. 1.

FIG. 5 is a schematic diagram showing a conventional example.

[Explanation of symbols]

1 Optical components 2 Detection means 3 Control means 4 Holding member 5. Illumination means 6 Photoelectric conversion means 7 Condensing lens 9 Lighting surface 14 Finger

Claims (1)

[Claims] 1. A transparent optical member 1 provided with a fingerprint image collection surface 9, a detection means 2 attached to the optical member 1, and detecting means 2 for detecting with what kind of pressure distribution the collection surface 9 is pressed. , a control means 3 for controlling the attitude of the optical member 1 according to the detection output of the detection means 2; a holding member 4 having a holding member 4; an illumination means 5 for illuminating the collection surface 9 through the optical member 1; and a light reflected from the illumination means 5 on the collection surface through the optical member 1; A fingerprint input device comprising a photoelectric conversion means 6 for photoelectric conversion.