JP2004233256A - Fingerprint reading sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fingerprint reading sensor for preventing influence to a display by the press of fingers. <P>SOLUTION: The fingerprint reading sensor comprises an image display section 40 for displaying characters or images; first and second transparent substrates 61, 62 for transmitting light having a specific wavelength; fingerprint detection circuits 71, 72 that are circuits formed between the second surface of the first transparent substrate 61 and the first surface of the second transparent substrate 62 and read fingerprints when fingers come into contact with the second surface of the second transparent substrate 62; and a spacer 63 for retaining the image display section 40 and the first transparent substrate 61 in a specific interval so that the display screen of the image display section 40 opposes the first screen of the first transparent substrate 61. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fingerprint reading sensor for reading a fingerprint.
[0002]
[Prior art]
Conventionally, a fingerprint reading sensor or a fingerprint reading device for reading a fingerprint has been used. In recent years, in such a fingerprint reading sensor or a fingerprint reading device, space saving has been required.
As a device that meets the demand for space saving as described above, a device in which a liquid crystal panel and a fingerprint reading sensor or a fingerprint reading device are integrated is known (for example, see Patent Documents 1 and 2).
[0003]
Patent Document 1 includes a capacitance type fingerprint reading sensor provided on a liquid crystal panel and a driving circuit thereof, wherein the fingerprint reading sensor includes a detection electrode disposed at a predetermined position, A fingerprint reader having an active element connected to each of the electrodes and a protective film provided on the surface is described. However, the fingerprint reader disclosed in Patent Literature 1 does not dispose a fingerprint reading sensor on a display area of a liquid crystal panel.
[0004]
Patent Document 2 discloses an active matrix liquid crystal cell, an illuminating unit for irradiating light from the back side of the active matrix liquid crystal cell, and a light source provided on the front side of the active matrix liquid crystal cell and transmitting light from the back side. Is a light guide plate that emits light from the front side to one end face, light receiving means that is on one end side of the light guide plate and receives light emitted from the one end face, and a fingerprint that contacts the light guide plate. And a drive circuit for positioning and irradiating light from the illuminating means via the active matrix liquid crystal cell and positioning and receiving reflected light from the fingerprint by the light receiving means to obtain an image of the fingerprint. Readers are listed. However, in the fingerprint reader disclosed in Patent Document 2, when reading a fingerprint, there is a possibility that a pressing force of a finger may be applied to the liquid crystal panel via the fingerprint reader. When the finger pressing force is applied to the liquid crystal panel, a temporary abnormality may occur in the liquid crystal panel or the liquid crystal panel may be broken.
[0005]
[Patent Document 1]
JP 2001-52148 A (page 1, FIG. 2)
[Patent Document 2]
JP 2001-52151 A (page 1, FIG. 1)
[0006]
[Problems to be solved by the invention]
In view of the above, an object of the present invention is to provide a fingerprint reading sensor capable of preventing the influence of a finger pressing force on a display while saving space.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, a fingerprint reading sensor according to the present invention is a sensor for reading a fingerprint, and maintains a predetermined interval between a display panel for displaying characters or images and the display panel. And first and second substrates having first and second surfaces, respectively, and transmitting light of a predetermined wavelength, a second surface of the first substrate, and a second substrate of the second substrate. A plurality of circuits formed in a matrix between the first surface and the first surface, wherein each of the circuits is generated between the second surface of the second substrate and the finger when the finger contacts the second surface of the second substrate. A plurality of circuits for detecting capacitance.
[0008]
Here, the display device may further include holding means for holding the display panel and the first substrate at a predetermined interval so that the display surface of the display panel and the first surface of the first substrate face each other.
[0009]
ADVANTAGE OF THE INVENTION According to this invention comprised as mentioned above, the influence of the pressing force of a finger on a display can be prevented, saving space.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the same components are denoted by the same reference numerals, and description thereof will be omitted.
FIG. 1 is a diagram showing an outline of a mobile phone device using a fingerprint reading sensor according to a first embodiment of the present invention. As shown in FIG. 1, the mobile phone device 1 includes a housing 2, an antenna 3, a receiving unit 4, a transmitting unit 5, a baseband processing unit 6, an audio processing unit 7, a speaker 8, and a microphone. 9, a fingerprint reading and image display device 10 as one embodiment of the present invention, a fingerprint reading signal processing unit 11, an LCD driver 12, and switches 21 to 32.
[0011]
The receiving unit 4 receives radio waves in the mobile phone frequency band via the antenna 3 and converts them into signals. The signal output from the receiving unit 4 is input to the baseband processing unit 6.
The baseband processing unit 6 performs baseband processing on the received signal, outputs audio data to the audio processing unit 7, and outputs image data, character data, control data, and the like to the CPU 11. Further, the baseband processing unit 6 receives voice data from the voice processing unit 7, character data, control data, and the like from the CPU 11, converts the voice data into a signal in a mobile phone frequency band, and outputs the signal to the transmitting unit 5.
[0012]
The transmitting unit 5 converts a signal received from the baseband processing unit 6 and transmits a radio wave of a mobile phone frequency band via the antenna 3.
The audio processing unit 7 converts the audio data received from the baseband processing unit 6 into an audio signal, drives the speaker 8, and the speaker 8 outputs audio. The audio processing unit 7 converts the audio signal received from the microphone 9 into audio data and outputs the audio data to the baseband processing unit 6.
[0013]
The LCD driver 12 causes the fingerprint reading and image display device 10 to display an image based on the image signal received from the CPU.
The fingerprint reading and image display device 10 displays an image based on the signal received from the LCD driver 12, and outputs a signal obtained by reading the fingerprint of the user. This signal is input to the fingerprint reading signal processing unit 11 and subjected to predetermined signal processing, and then input to the CPU 13.
[0014]
The CPU 13 controls the baseband processing unit 6 and the audio processing unit 7 according to an instruction signal and the like received from the switches 21 to 32. Further, the CPU 13 receives image data, character data, and the like from the baseband processing unit 6, outputs the data to the LCD driver 12, and causes the fingerprint reading and image display device 10 to display images, characters, and the like. Further, the CPU 13 performs a process of recognizing the fingerprint of the user based on a signal obtained by reading the fingerprint of the user.
[0015]
FIG. 2 is a diagram illustrating an appearance of the mobile phone device 1. As shown in FIG. 2, an antenna 3 is attached to an upper side surface of the housing 2 in the figure. A speaker 8 is disposed above the housing 2 in the figure, and a fingerprint reading and image display device 10 is disposed below the speaker 8 in the figure. Further, switches 21 to 32 are arranged below the fingerprint reading and image display device 10 in the figure, and a microphone 9 is arranged below the figure. "1" to "0" are printed on the surfaces of the switches 21 to 30, respectively, "*" is printed on the surface of the switch 31, and "#" is printed on the surface of the switch 32. .
[0016]
FIG. 3 is a cross-sectional view of the fingerprint reading and image display device 10 taken along line II-II ′ in FIG. As shown in FIG. 3, the fingerprint reading and image display device 10 includes an image display unit 40, a first transparent substrate 61, a second transparent substrate 62, and a spacer 63.
The image display unit 40 is a transmissive liquid crystal display, and includes a light emitting unit 41, a first polarizing plate 42, a third transparent substrate 43, a first alignment film 44, a fourth transparent substrate 45, It includes a spacer 46, a common transparent electrode 47, a second alignment film 48, and a second polarizing plate 49.
[0017]
On the upper surface of the first polarizing plate 42 in FIG. 3, a third transparent substrate 43 is formed. One end of a spacer 46 is fixed above the third transparent substrate 43 in FIG. 3, and a fourth transparent substrate 45 is fixed to the other end of the spacer 46. A plurality of transistors 51 and transparent electrodes 52 are formed in a matrix on the upper surface in FIG. 3 of the third transparent substrate 43 inside the spacer 46. On the third transparent substrate 43 and the plurality of transistors 51 and the transparent electrodes 52, a first alignment film 44 is formed.
A common transparent electrode 47 is formed inside the spacer 46 and on the lower surface of the third transparent substrate 45 in FIG. 3, and a second alignment film is formed on the lower surface of the common transparent electrode 47 in FIG. 48 are formed.
[0018]
A liquid crystal 50 is sealed in a space formed by the spacer 46, the first alignment film 44, and the second alignment film 48.
The light emitting unit 41 emits light of a predetermined wavelength upward in FIG. 3, and the light emitted from the light emitting unit 41 becomes polarized by transmitting through the first polarizing plate 42, and becomes a third transparent substrate 43. And the first alignment film 44.
[0019]
When the transistor 51 is turned on, a potential difference is generated between the transparent electrode 52 connected to the transistor 51 and the common transparent electrode 47, so that the liquid crystal molecules located between the transparent electrode 52 and the common transparent electrode 47 are shown in FIG. The polarized light transmitted through the first alignment film 44 passes through the liquid crystal 50 and reaches the second alignment film 48. On the other hand, when the transistor 51 is off, a potential difference does not occur between the transparent electrode 52 connected to the transistor 51 and the common transparent electrode 47, so that the liquid crystal molecules located between the transparent electrode 52 and the common transparent electrode 47 Not aligned. Therefore, the polarized light transmitted through the transparent substrate 43 does not pass through the liquid crystal 50 and does not reach the second alignment film 48.
[0020]
The polarized light transmitted through the liquid crystal 50 is transmitted through the second alignment film 48, the common transparent electrode 47, the fourth transparent substrate 45, and the second polarizing plate 49.
Therefore, only a predetermined transistor among the plurality of transistors 51 is turned on, and only the portion of the transparent electrode 52 connected to the turned-on transistor transmits polarized light, whereby a character or an image can be displayed.
[0021]
FIG. 4 is an enlarged view of a region 65 in the first and second transparent substrates 61 and 62 of FIG. A plurality of fingerprint detection circuits are formed between the first transparent substrate 61 and the second transparent substrate 62 in a matrix. FIG. 4 shows two fingerprint detection circuits 71 and 72 among a plurality of fingerprint detection circuits formed in a matrix.
[0022]
FIG. 5 is a diagram showing the fingerprint detection circuit 71 of FIG. As shown in FIG. 5, the fingerprint detection circuit 71 includes a transistor Q1, wirings 81 and 83, an electrode 82, and a light-shielding film 67.
A gate 91 is formed on the upper surface of the first transparent substrate 61 in FIG. 5, and a first insulating film 92 is formed on the upper surface of the first transparent substrate 61 and the gate 91 in FIG. ing. The portion of the first insulating film 92 corresponding to the portion above the gate 91 is convex in the upward direction in FIG. An amorphous layer 93 is formed so as to cover a protruding portion in the first insulating film 92.
An electrode 82 is formed on the upper surface of the first insulating film 92 in FIG. 5 and to the right of the protruding portion in the first insulating film 92. The electrode 82 can be made of ITO (Indium Tin Oxide) or the like.
[0023]
A second insulating film (etching protection film) 94 is formed at the center of the upper surface of the amorphous layer 93 in FIG.
A source 95 is formed on the upper surface of the left end of the second insulating film 94 in FIG. 5 to the upper surface of the left end of the amorphous layer 93, and the upper surface of the right end of the second insulating film 94 in FIG. A drain 96 is formed on the upper surface of the right end of the amorphous layer 93.
The gate 91, the first insulating film 92, the amorphous layer 93, the second insulating film 94, the source 95, and the drain 96 constitute the transistor Q1.
[0024]
A wiring 81 for supplying a charge to the source 95 is formed on the upper surface of the source 95 in FIG. 5 to the upper surface of the first insulating film 92, and the upper surface of the drain 96 in FIG. The wiring 83 is formed on the upper surface of the portion.
A fifth transparent substrate 66 is formed on upper surfaces of the first insulating film 92, the wiring 81, the second insulating film 94, the wiring 83, and the electrode 82 in FIG. A light-shielding film 67 is formed on the upper surface of the fifth transparent substrate 66 in FIG. 5 and above the transistor Q1. The light-shielding film 67 can be made of chromium or the like.
[0025]
A sixth transparent substrate 68 is formed on the upper surface of the fifth transparent substrate 66 and the light shielding film 67 in FIG. The fifth transparent substrate 66 and the sixth transparent substrate 68 constitute the second transparent substrate 62. Note that the fifth transparent substrate 66 and the sixth transparent substrate 68 can each be constituted by DLC (Diamond Like Carbon).
The electrode 82 forms a capacitor with the finger when the finger contacts the upper surface of the second transparent electrode 62 in FIG. 5 (see FIGS. 3 and 4).
The circuit configuration of the fingerprint detection circuit 72 is the same as the circuit configuration of the fingerprint detection circuit 71 shown in FIG.
[0026]
Referring again to FIG. 4, a valley of a finger 64 is located at a portion corresponding to an upper part of the fingerprint detection circuit 71 on the upper surface of the second transparent substrate 62 in FIG. The crest of the finger 64 is located in a portion corresponding to the upper part of the fingerprint detection circuit 72 in the upper surface of the substrate 62 in FIG. Therefore, the distance between the electrode 82 in the fingerprint detection circuit 71 and the finger 64 is longer than the distance between the electrode 82 and the finger 64 in the fingerprint detection circuit 72. Therefore, the capacitance of the capacitor formed by the electrode 82 and the finger 64 in the fingerprint detection circuit 72 is different from the capacitance of the capacitor formed by the electrode 82 and the finger 64 in the fingerprint detection circuit 72.
[0027]
Referring to FIG. 1 again, the fingerprint reading signal processing unit 11 supplies a constant current to a plurality of fingerprint detection circuits in the fingerprint reading and image display device 10. The potential of the electrode 82 in each fingerprint detection circuit is determined by the capacitance of a capacitor formed by each fingerprint detection circuit and the finger 64. The fingerprint reading signal processing unit 11 can read the unevenness of the finger 64, that is, the fingerprint, by detecting the potential of the electrode 82 in each fingerprint detection circuit.
[0028]
Referring again to FIG. 3, when the user presses the finger 64 against the upper surface of the second transparent substrate 62 in FIG. 3, the pressing force of the finger 64 causes the first transparent substrate 61 and the second transparent substrate It may occur that the flexure 62 is bent downward in FIG. However, even when the first transparent substrate 61 and the second transparent substrate 62 are bent downward in FIG. 3, the first transparent substrate 61 does not contact the image display unit 40.
As described above, according to the fingerprint reading and image display device 10, it is possible to prevent the pressing force of the finger 64 from affecting the image display unit 40.
[0029]
Next, a fingerprint reading sensor according to a second embodiment of the present invention will be described. FIG. 6 is a diagram illustrating a fingerprint reading and image display device 110 according to a second embodiment of the present invention. As shown in FIG. 6, the fingerprint reading and image display device 110 includes an image display unit 140, a seventh transparent substrate 161, an eighth transparent substrate 162, and a spacer 163. A plurality of fingerprint detection circuits are formed in a matrix between the seventh transparent substrate 161 and the eighth transparent substrate 162.
The image display unit 140 is a transmissive liquid crystal display, and includes a light emitting unit 41, a first polarizing plate 42, a ninth transparent substrate 143, a first alignment film 44, a fourth transparent substrate 45, It includes a spacer 46, a common transparent electrode 47, a second alignment film 48, and a second polarizing plate 49. A plurality of transistors 51 and transparent electrodes 52 are formed in a matrix on the upper surface of the ninth transparent substrate 143 in FIG. 6 inside the spacer 46. A liquid crystal 50 is sealed in a space formed by the spacer 46, the first alignment film 44, and the second alignment film 48.
[0030]
In the fingerprint reading and image display device 110, the horizontal length of the seventh transparent substrate 161 in FIG. The horizontal length in FIG. 6, the horizontal length of the ninth transparent substrate 143 in FIG. 6, and the vertical length of the spacer 163 in FIG. The horizontal length in FIG. 3, the horizontal length of the second transparent substrate 62 in FIG. 3, the horizontal length of the third transparent substrate 43 in FIG. 3, and the spacer 63 3 is longer than the length in the vertical direction.
One end of a spacer 163 is fixed to the upper end of the ninth transparent substrate 143, and the seventh transparent substrate 161 is fixed to the other end of the spacer 163.
[0031]
As shown in FIG. 6, when the user presses the finger 64 against the upper surface of the eighth transparent substrate 162 in FIG. 6, the pressing force of the finger 64 causes the seventh transparent substrate 161 and the eighth transparent substrate 161 to move. 162 may flex downward in FIG. However, even when the seventh transparent substrate 161 and the eighth transparent substrate 162 are bent downward in FIG. 6, the seventh transparent substrate 161 does not come into contact with the image display unit 140.
As described above, according to the fingerprint reading and image display device 110, it is possible to prevent the pressing force of the finger 64 from affecting the image display unit 140.
[0032]
In the first and second embodiments, a transmissive liquid crystal display is used as the image display units 40 and 140. However, a reflective liquid crystal display, an organic EL (electroluminescence) display, a plasma display, or the like is used. It is good.
[Brief description of the drawings]
FIG. 1 is a diagram of a mobile phone device using a fingerprint reading sensor according to a first embodiment.
FIG. 2 is a diagram showing an appearance of the mobile phone device of FIG.
FIG. 3 is a sectional view taken along line II-II ′ in FIG. 2;
FIG. 4 is an enlarged view of a region 65 in FIG. 3;
FIG. 5 is a diagram showing a fingerprint detection circuit 71 of FIG. 4;
FIG. 6 is a diagram showing a fingerprint reading sensor according to a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cellular phone apparatus, 2 housings, 3 antennas, 4 receiving units, 5 transmitting units, 6 baseband processing units, 7 audio processing units, 8 speakers, 9 microphones, 10 and 110 fingerprint reading and image display devices, 11 fingerprint reading Signal processing unit, 12 LCD driver, 13 CPU, 21 to 32 switch, 40, 140 Image display unit, 41 light emitting unit, 42, 49 Polarizing plate, 43, 45, 61, 62, 66, 68, 143, 161, 162 Transparent substrate, 44, 48 alignment film, 46, 63, 163 spacer, 47 common transparent electrode, 50 liquid crystal, 64 fingers, 67 light shielding film, 71, 72 fingerprint detection circuit, 81, 83 wiring, 82 electrode, 91 gate, 92 , 94 insulating film, 93 amorphous layer, 95 source, 96 drain, Q1 transistor

Claims (2)

A sensor for reading a fingerprint,
A display panel for displaying characters or images,
First and second substrates disposed so as to keep a predetermined interval between the display panel and the display panel and having first and second surfaces, respectively, and transmitting light of a predetermined wavelength;
A plurality of circuits formed in a matrix between a second surface of the first substrate and a first surface of the second substrate, wherein a finger is provided on a second surface of the second substrate. A plurality of circuits, each circuit detecting a capacitance generated between the circuit and the finger when the circuit comes into contact with the finger. 2. A holding device for holding the display panel and the first substrate at a predetermined interval so that a display surface of the display panel and a first surface of the first substrate face each other. Fingerprint reading sensor.

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