TWI236636B - Sweep-type fingerprint sensor module and a sensing method therefor - Google Patents

Abstract

A sweep-type fingerprint sensor module includes a microprocessor and a sweep-type fingerprint sensor, which includes a substrate, and a sensing members array, a speed-detecting unit, and a processing circuit on the substrate. The sensing members array is composed of a plurality of fingerprint sensing members. When the finger sweeps across the sweep-type fingerprint sensor, the sensing members array sequentially acquires plural fingerprint fragment images from the finger with a sampling time interval. The speed-detecting unit is composed of first and second plate electrodes. The processing circuit processes and then outputs signals form the sensing members array and the speed-detecting unit. The microprocessor electrically connected to the processing circuit derives a sweeping speed of the finger by the time difference between different time points when the plate electrodes contact the finger, determines the sampling time interval and then stitches the fingerprint fragment images into a complete fingerprint image.

Description

1236636 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to a sliding fingerprint sensor module and a sensing method thereof, and more particularly to a sliding fingerprint sensing II module having a speed sensing unit. Group and its sensing method. > Day, ~ [Previously learned on the paper, the more and more, the more electrified band-type surgery. It is said that its chip-type disadvantages. It is measured by the area, and the package is tested for 10 yuan.

With the known fingerprint reading method, an ink-dipped finger is pressed, and then the paper is scanned with an optical scanner to charge the fingerprint and then compared with the fingerprint pattern in the database. However, the above-mentioned method is unfortunately unable to achieve the purpose of real-time processing. Therefore, the helmet method meets the needs of immediate certification. The bee stings the security system and so on. = 体 ::: r-type fingerprint sensor The fingerprint sensor is born to overcome the kyouxue type sensor of the body

Due to the size limitation of the finger, the conventional chip-type fingerprint is at least greater than 9inm * 9mffl. In addition, due to the silicon integrated circuit * ° sense-only 5 can be produced in a 6-leaf wafer. Up to 70 effective: The cost of test limit will make the price of the fingerprint sensor small, plus the above, this will limit its application to various consumer electronics, such as US computers and mobile phones. , Personal digital assistant, computer week =, such as a personal identification card with a fingerprint sensor. Birth deduction

1236636 V. Description of the invention (2) Therefore, one-dimensional area of the conventional two-dimensional wafer-type fingerprint sensor can be reduced 'to increase the number of effective wafers and reduce the unit price of wafers. The principle is to slide the finger across the surface of the chip to complete the scanning of the entire finger, and then concatenate each captured fingerprint image into a complete fingerprint image.

Mai nguet in U.S. Patent No. 6,289,114 discloses a sliding fingerprint sensor formed by pyroelectric (thermal) or piezoelectric material (pressure) and a method for concatenating multiple images, and its main disadvantages Because: It is impossible to judge the speed of the finger sliding, so a considerable number of fragment fingerprint images must be captured and then recombined into a complete fingerprint image. This not only requires a powerful microprocessor, a large amount of memory, but also easily leads to reorganization errors. The conventional sliding fingerprint sensor only knows that the area of the sensor is reduced by reducing the number of sensing elements in the γ-axis direction (defined as the direction in which the finger slides), so that the size in the Y-axis direction is between 〇 · 8 to 1 · βmin, so the number of captured fingerprint images is quite large. FIG. 1 shows a schematic diagram of a finger sliding over a conventional sliding fingerprint sensor. As shown in FIG. 1, ‘finger 丨 2 〇 slides across the sliding fingerprint sensor 11 0 at a speed v along the γ-axis direction, so that the sliding fingerprint sensor 11 0 obtains a plurality of pieces of fingerprint images. &

FIG. 2 is a schematic diagram of the reorganization of a segment fingerprint image captured by the fingerprint sensor of FIG. 1. As shown in FIG. 2, the captured segment fingerprint images 丨 (丨) to I I (N) can be reconstituted into a complete fingerprint image of the finger 丨 20. Since the number of sensing elements of the conventional sliding fingerprint sensor in the γ-axis direction is too small, tens to hundreds of images Π (1) to Π (N) must be stored. Conventional sliding fingerprint sensor

Page 7 1236636 Five Λ invention description (3) When designing the mobile device, the designer only knows the number of sensor elements in the green direction, so sensor = element = sensor / device area (minus the outer axis from 0.8 to 1.6) In addition, the two-inch ¥ axis of the pass / pass, the sliding speed of some fingers, and the safety sensor ^ j sensor, which does not detect the overlapping area of AA (1) to AA (Nl). Placement, resulting in the number of images and difficulty required for image reconstruction between each image. The product is too large, and the aforementioned disadvantages of image synthesis are further increased. The green image is used as a feature = fingerprint sensor module. It is difficult, therefore, there are already ^ ^ extractions, and even subsequent recognition. Direct conversion of gray-scale images ^ is the use of frequency spectrum to capture a large number of image-taking actions into frequency distribution. The advantages of this move No need for stains on the surface of the chip, the spectrum identification method is susceptible to wet and dry fingers, and therefore, the block error rate is high. How to provide a pattern sensor module, fb reduction, reorganized image slide number Means, “the problem to be solved in this case. [Summary of the Invention] Therefore, this issue The purpose of a sliding finger is to provide a device that can reduce the number of reorganized images of the present invention. The mobile fingerprint sensor module spoon provides a kind of slide that can distinguish the authenticity of the fingers in order to achieve the above. The objective module includes a back sound. The present invention provides a sliding fingerprint sensor. The sensor includes a substrate controller and a sliding fingerprint sensor. The fingerprint includes a speed sensing unit and a fingerprint sensor. One sensor element array and processing circuit on the substrate. The sensor element array is composed of a plurality of fingers. Page 1236636 V. Description of the invention (4) The pattern sensor element is used to sense the fingerprint of a finger and take a sample. The fingerprint images of the multiple fragments of the finger are continuously taken at time intervals. The speed sensing unit is composed of a first and a second electrode plate. The processing circuit processes and outputs signals from the sensing element array and the speed sensing unit. The microprocessor is electrically connected to the processing circuit, used to find the sliding speed of the finger based on the time difference between the contact between the electrode plate and the finger, and then determines the sampling time interval, and re-prints the fingerprint images of the fragments. Make up a complete fingerprint image.

To achieve the above object, the present invention also provides a method for sensing a sliding fingerprint sensor module, including the following steps: detecting a sliding speed of a finger; determining a sampling time interval according to the sliding speed; and using the sampling time A plurality of fragment fingerprint images of the finger are successively captured at intervals to output a plurality of fragment fingerprint signals corresponding to the fragment fingerprint images; that is, the plurality of fragment fingerprint signals are processed and recombined to form a complete fingerprint image. By detecting the sliding speed of the finger, the number of fingerprint images of the ^ capture = segment can be effectively reduced, thereby simplifying the reorganization process and reducing costs. [Embodiment] FIG. 3 shows a finger sliding over a sliding fingerprint of the present invention

Illustration. FIG. 4 is a schematic diagram of the images, σσ ′, and sigma captured by the fingerprint sensor of FIG. 3. As shown in Figures 3 and 4, when the finger 9 uses the heavy fingerprint sensor 10 of the speed image, the sliding fingerprint senses the monthly motion through the sliding speed V, and the complex number is retrieved according to the speed V. " Finger 9 is rigid, where n is a positive integer. Two adjacent films; image 1 (1 \ to domain A (1) to A (N -1), in order to facilitate the use of feature points ~ the image of the Fengfeng District ", and compare these methods

1236636 V. Description of the invention (5) Fragment fingerprint image is reconstructed. The main sensor described above can be implanted in any application. It is placed on the platform and slides in the direction of the arrow. When a segment fingerprint image is obtained in a row, the sensor 10 can adjust the fingerprint image by direct movement. Because the hand #, # action two θ break processing to recombine one piece or to move at a fixed speed within a fixed distance, and suppress V, it will be very helpful for image extraction. 2: Understanding the number of sliding images to reorganize. This can be done without using the minimum processor and Ogoya's PM. Instead, it is necessary to take advantage of this powerful micro-processing, which can greatly reduce the application level of the machine that identifies errors. The sensing is effectively promoted particularly. FIG. 5 shows a sliding fingerprint according to the first embodiment of the present invention. Fig. 6 shows a sectional view taken along the line L6_L6 of Fig. 5 and showing a sliding fingerprint sensor according to the first embodiment of the present invention in a side view in operation. It is worth noting that the sizes of the fingers and sensors in Figure 7 are not drawn according to the actual scale. As shown in FIGS. 5 to 7, the sliding fingerprint sensor module of the present invention includes a microprocessor 11 and 1 sliding fingerprint sensor 10 electrically connected to the microprocessor. The sliding fingerprint sensor includes a substrate i, a sensor element array 2, a speed sensing unit 3, a processing circuit 4, an impedance sensor 5, and a plurality of solder pads 6. The pads 6 are electrically connected to the micro-location ^ '11. The sensor element array 2 is located on the substrate 1 and is composed of a plurality of fingerprint sensor elements 2 1 (for simplicity, only one sensor element is drawn) in a two-dimensional array. The fingerprint sensing element 21 may be a capacitive, pressure or temperature difference sensing element, as disclosed by the applicant of the present application in the following patent application. Page 10 1236636

1. The Republic of China invention patent application number 9 1 1 0 68 06, application, date 2 00 2/4/3, the invention name is: capacitive fingerprint reading chip; Ming 2. The Republic of China invention patent application number 9 1 1 1 0 4 4 3, application date 2002/5/17, the name of the invention is ... pressure pressure fingerprint reading chip and its manufacturer 3. Republic of China invention patent application number 90 1 1 3755, application date 20 0 1/7/6, the invention name is: temperature difference induction fingerprint recognition crystal < and manufacturing. < 纟 Ya Ye In order to match the size of at least 2.5 to 3.5mm, the measurement signal is transparent to the outside world. The gain amplifier and the "capacitive fingering method" are specifically designed to sense and use a sampled image to trace the signal.

The size of the finger 9 is aligned with the Z-axis direction of the sensor element array 2 (transverse to 8mm, and the optimized γ-axis direction (longitudinal) dimension is ^ 2, which is explained later. The complex number from the sensor element array 2 A. The processing circuit 4 is processed and passed through the input / output pad 6 while the 1 processing circuit 4 basically includes a logic control circuit and an analog digital converter, and its related architecture is also described in the above-mentioned pattern read chip. ”And“ Pressure-type fingerprint reading in the Jingli application. ”&Amp; The meta array 2 senses the sliding through the fingerprint time interval of the finger 9 (Fig. 3) on it to continuously capture a plurality of fragments of the finger. The fingerprint output corresponds to To understand the shortcomings of the fingerprint images of these fragments, in order to understand the disadvantages of the known technology, the present invention integrates the speed sensing unit 3 into a sliding fingerprint sensor. The speed sensing unit W is also located on the substrate 1. And is composed of a first electrode plate 31 and a second electrode plate 32. First

1236636 V. Description of the invention (7) _ and the second electrode plates 31 and 32 are substantially flat with each other D1. The electrode plates are located at the sensing element array 7 and are separated by a predetermined distance and have approximately two sides (upper and lower sides) of the X-axis square of the sensing element array 2 (upper and lower sides). Outputs a length of + ° when touched. When the first electrode plate 32 is in contact with the finger 9, an = signal is output. In detail, when the finger g is along the γ-axis square wind, the signal is above the first electrode plate 31 and contacts it. For the formation principle, please refer to the above-mentioned "Capacitive fingerprint reading and electric dagger related circuits and a trigger pulse. This trigger pulse can be transferred from the second to the second), and the shape (this can reduce the sensor when not in use: said second sense: the power of f will slide across the surface of the sensing element array 2 to the second power consumption). Then, the finger 9 # 1 ^ ^ ^ ίΐχ 〇 0 ^ M ^ if ^ 32, and the distance between these two trigger pulses is calculated: = the sliding speed v of the finger 9 is obtained. In this example, the processor U can find the sliding speed V. After the micro-microprocessor 11 finds the sliding speed of the finger 9, it can judge that the mother-sheet fragment fingerprint is received. The sampling time interval of the image, and then the fragment fingerprint image can be received and processed. In this way, there is no need to store too many clips or images, and a powerful microprocessor is not needed, which will help reduce costs. First, the inventor of the present case weighed the characteristics and cost of the fingerprint sensor and considered the optimization size of the Y-axis direction of the sensing element array 2 between 2.5 and 3.5 mm. In this embodiment, the dimension w in the χ-axis direction is 疋 10 mm, and the dimension L in the Y-axis direction is 3.2 mm (converted to 50 0 DPI specifications as

Page 12 1236636 V. Description of the invention (8) ----— 2 0 0 * 64 day element). This is because when the two fingerprint images are connected, there must be a Y-axis square, about 40 to 80. The overlapping length of micrometers is used as the basis for determining the accuracy of the drawing. The heavy area is shown as A (l) to A (N-1) area shown in FIG. 4. If the length of the sensing element array like the conventional technology in the γ-axis direction is only 0.8 to 16111111, there will be 'most of the area is wasted in the overlapping area of the image' and therefore a large number of pictures are needed to piece together a complete image. The present invention cooperates with the detection of the finger sliding speed to define the optimized γ-axis size of the sensor element array 2 between 2.5 and 35 mm, as shown in FIG. 4. Except for the overlapping area, the length of the image in the non-overlapping area in the γ-axis direction remains from L 5 to 2.5 mm. Therefore, as little as 3 to 5 pictures and as many as 7 to 9 pictures can be pieced together to form a complete image. In this way, not only can the number of required segment fingerprint images be greatly reduced, but also the recombination can be performed by using a general and stable feature point comparison method. The processing circuit 4 is electrically-connected to the sensing element array 2 and the speed sensing unit 3, and is used to receive and process the fingerprint signals of the plurality of fragments, the first time signal, and the second time signal, and borrow The processed signals are output from the pads 6 to the microprocessor 11. The microprocessor 11 obtains a sliding speed V of the finger 9 based on the first time signal, the second time signal, and the predetermined distance D1, and determines the sampling time interval according to the sliding speed V. The fingerprint signals of a plurality of fragments are processed and reconstituted into a complete fingerprint image. -The impedance sensor 5 is located on the substrate 1 to sense an electrical resistance value of the finger 9 to help identify the authenticity of the finger 9. The impedance sensor 5 includes a pair of bare metal strip electrodes 51 and 52. When the finger 9 is placed above the two electrodes 51 and 52, the resistance value R of the skin of the finger 9 can be detected and recorded in the microprocessing

Page 13 1236636 V. Description of the invention

In the state, ‘Hand !:’ and the resistance value of the chopped finger are different, so the processing of the microprocessor 11 can be used to identify the authenticity of the finger. Fig. 8 shows a top view of a sliding fingerprint sensor according to a second embodiment of the present invention. As shown in FIG. 8, the second embodiment is similar to the first embodiment, except that the second electrode plate 32 of the second embodiment is located in the sensor element array 1 and the first electrode plate 31 is located in the sensor One longitudinal side (upper side) of the cell array 2. At this time, the second electrode plate 32 can be integrated with the metal mesh of the sensing element array so that

FIG. 9 shows a top view of a sliding fingerprint sensor according to a third embodiment of the present invention. As shown in FIG. 9, the third embodiment is similar to the first embodiment, except that both the first and second electrode plates 31 and 32 of the third embodiment are located in the same longitudinal direction of the remote sensing element array 2. Side (upper side). Similarly, both the first and second electrode plates 31 and 32 may be in the το array 2. FIG. 10 shows the sensing method of the sliding fingerprint sensor of the present invention. The present invention also provides a sliding fingerprint sensing method, which includes the following steps: Step S1 0: Detect the sliding speed of the finger 9 v · · First, go to the whale

When the first electrode plate 31 is contacted, the first time signal is output; then, "~" means that the finger 9 outputs a second time signal when it contacts the second electric plate u that is separated from the first electrode plate 31 by a predetermined distance D1. ; Then divide the predetermined distance D 丨 by the difference between the one and the second time signal to obtain the sliding speed V; step S2 0 ·· determine a sampling time interval according to the sliding speed v; first, use the fingerprint image of each segment The long image along the direction of finger sliding ($ 感 1236636 five --- ^ -----—_____________, invention description () 0) degrees (then the effective length divided by the sliding speed to obtain the interval ; The sampling time interval continuously captures the plurality of segments of the finger 9 to refer to the shadow gold, in order to output the length of the Y-axis of the anti-fingerprint shadow shadow cell array) minus the overlap length L of the adjacent two segment fingerprint images ( (Determined by the image processing software of the fingerprint) to obtain the effective length; then: the effective length is divided by the sliding speed to obtain the sampling time step S 3 0: continuously capture the plural number of the finger 9 at the sampling time interval Fragment fingerprint image to output pairs To the fragmented fingerprint signals of the fingerprint images of these fragments; to process and recombine the fragmented fingerprint signals of several fragments; + step S40 ······························································· the multiple-segment fingerprint signals-70 whole fingerprint images; Detect the impedance of the finger to identify the true fingerprint of the finger "J ::: Measure the sliding speed of the finger" * Determine the number of fragments and simplify the image The specific examples in the technical content of the invention are only used for: the examples, without exceeding the invention of the present invention; the restrictions on the implementation of all changes made by the brother, all belong to this example. Schematic diagram of sliding through a traditional sliding fingerprint sensor. Figure 2 shows the reorganized schematic diagram of a fragmented fingerprint image captured by the fingerprint sensor of Fig. 1. Figure 3 shows a finger sliding over the sliding fingerprint sensor of the present invention. Schematic diagram. Fig. 4 shows the unintended reorganization of the fragmented fingerprint image captured by the fingerprint sensor of Fig. 3. Fig. 5 shows a top view of the sliding fingerprint sensor module according to the first embodiment of the present invention. Fig. 6 shows a cross-sectional view along the line L6-L6 of Fig. 5. Fig. 7 shows a side view of the sliding fingerprint sensor according to the first embodiment of the present invention during operation. Fig. 8 shows a second embodiment of the present invention. Top view of a sliding fingerprint sensor. FIG. 9 shows a top view of a sliding fingerprint sensor according to a third embodiment of the present invention. FIG. 10 shows a flowchart of a sensing method of the sliding fingerprint sensor of the present invention. [Explanation of Symbols of Components] 2 ~ sensor element array 4 ~ processing circuit 6 ~ solder 8 ~ capacitive sensor element array 1 ~ substrate 3 ~ speed sensing unit 5 ~ impedance sensor 7 ~ pressure sensor element Array Page 16 1236636 Schematic description 9 ~ finger 1 1 ~ microprocessor 3 1 ~ first electrode plate 5 1 ~ metal strip electrode 7 1 ~ pressure sensor 1 0 ~ slide fingerprint sensor 2 1 ~ fingerprint sensor 3 2 ~ second electrode plate 5 2 ~ metal strip electrode 8 1 ~ capacitive sensor

1 1 0 ~ Slide fingerprint sensor 1 2 0 ~ Finger 11 (1)-II (N) ~ Fragment fingerprint image I (1)-I (N) ~ Fragment fingerprint image AA (1) -AA (N- 1) ~ overlapping area A (1) -A (N-1) ~ overlapping area

Page 17

Claims (1)

1236636 6. Scope of patent application 1. A sliding fingerprint sensor module including a microprocessor; and a monthly fingerprint sensor which is electrically connected to the microprocessor and includes: a substrate ; An array of sensing elements is located on the substrate, and is composed of a plurality of fingerprint sensors arranged in a one-dimensional array. The array of sensing elements senses the fingerprints of one of the fingers sliding on the array to A plurality of fragment fingerprint images of the finger are continuously captured at a sampling time interval, so as to output a plurality of fragment fingerprint signals corresponding to the fingerprint images of the fragments; a speed sensing unit is located on the substrate and consists of a first electrode plate And a second electrode plate, the first and second electrode plates are substantially parallel to each other and separated by a predetermined distance, and the first electrode plate outputs a first time signal when in contact with the finger, and the second electrode The board outputs a second time signal when in contact with the finger; and A processing circuit is electrically connected to the sensing element array and the obscuration sensing unit to receive, process, and output the plurality of fragment fingerprint signals, the first time signal, and the second time signal, which causes the The microprocessor obtains a sliding speed of one of the fingers according to the first time signal, the second time signal, and the predetermined distance, determines the sampling time interval according to the sliding speed, and further assigns the plurality of fragment fingerprint signals. Process and reassemble a complete fingerprint image. 2. The sliding fingerprint sensor module according to item 1 of the patent application scope, wherein the size of the sensing array in the direction along which the finger slides is actually 1236636 VI. Patent application group, where the method of the column is ranked 11. If group, the method of the column is ranked 12. If group, the method of the column is ranked 13. The following steps: Detect one based on which to take the image , By means of a grain signal; and the multi-grain image. 14. Such as module sensing includes: When the hand sensor element array is composed of a plurality of capacitive sensor elements in a two-dimensional array. The sliding fingerprint sensor module described in item 1 of the scope of the patent application consists of a plurality of temperature difference type sensing elements in a two-dimensional array. The sliding-type fingerprint sensor module described in the first item of the patent application includes a plurality of pressure-type sensing elements in a two-dimensional array. A sensing method of a sliding fingerprint sensor module includes sliding speed with one finger; the sliding speed determines a sampling time interval; the sample time interval continuously captures a plurality of fragment fingerprints of the finger and the output corresponds to the fragment fingerprints A plurality of image segments, an index pen segment, and a fingerprint signal are processed and reconstituted into a sliding fingerprint sensor method as described in item 13 of the patent application scope, wherein the step of detecting the sliding speed of the finger refers to touching a When the first electrode plate, output a first time signal -The distance is set to 1 in advance and separated; the board number pole telecommunications room on page 20 1236636 6. The scope of the patent application is based on the predetermined sliding speed of 15 The slice minus the adjacent effective length, and the effective interval. 16 · The sensing side of Rushen module is between 5mm. 17. The sensor of the Rushen module is between 800 micrometers (18. The sensor of the Rushen module detects the difference between the signals between the hands to obtain the distance divided by the first and the first patent scope. The sliding fingerprint sensor method according to item 3, wherein the sampling time is determined according to the sliding speed and includes: an image of a segment of the fingerprint image along the direction of the finger slide is one of two overlapping segments of the fingerprint image to obtain a The length is divided by the sliding speed to obtain the sampling time. The sliding fingerprint sensor method described in item 15 of the patent range, wherein the range of the image length is substantially 2.5 to 3. Please patent range The sliding fingerprint sensor method according to item 15, wherein the range of the overlapping length is substantially from 40 to the sliding fingerprint sensor method described in item 13 of the patent scope, and further includes the following steps: An impedance of a finger to identify the authenticity of the finger. Page 21