KR20040088465A - System and method for biometric image capturing - Google Patents

Abstract

The present invention relates to a system and method for enhancing the task of capturing an image of a biometric object. These systems and methods prevent undesired blocking of total internal reflection of the prism that results in inadequate biometric imaging. In an embodiment of the invention, a thermal assembly consisting of a plurality of thermal elements is disposed adjacent to the image capture device. When a current is supplied, the thermal element can heat or cool the image capture device or platen of the image capture device. If cooling of the biometric object receiving surface is required, the thermal element is controlled to reduce the temperature of the region on which the biometric object is placed or the region adjacent to the region on which the biometric object is placed. When heating of the biometric object receiving surface is required, the thermal element is controlled to remove moisture and prevent accumulation of moisture by increasing the temperature of the region on which the biometric object is placed or the region adjacent to the region on which the biometric object is placed.

Description

SYSTEM AND METHOD FOR BIOMETRIC IMAGE CAPTURING}

Biometrics refers to a technique for analyzing the characteristics of a living body. Biometric imaging techniques capture human measurable characteristics (eg, fingerprints) to identify a particular individual. For example, Gary Roethenbaugh's article "Speaking of Biometrics" (Biometrics Explained), published on pages 1-34 of the 1998 International Computer Security Association, Inc., issue, 1998. ) Reference. The paper is incorporated herein by reference in its entirety.

Traditionally, techniques for capturing biological images include, for example, applying ink at the tip of a person's finger and rolling or simply pressing the tip of the individual's finger at the appropriate location on the recording card. This technique can be messy because the ink must be applied, and the obtained fingerprint is often difficult to read.

Today, biometric capture techniques include electro-optical devices for obtaining biometric data from biometric objects, such as fingers and palms. In some cases, the electro-optical device may be a fingerprint scanner, a palm scanner, or another type of biometric scanner. These scanners are also referred to as bioprint scanners. When using a biometric scanner, there is no need to apply ink to a person's finger or palm. Instead, the biometric scanner may include a prism disposed in the optical path. The platen is used as the surface for receiving the biometric object. For example, when using an optical fingerprint scanner, a finger is placed on the platen and the camera detects an image of the fingerprint. The platen may be the surface of the prism or may be another surface provided on the prism and in optical contact with the prism. The fingerprint image detected by the camera is composed of relatively bright and dark areas. These areas correspond to the valleys and ridges of the fingerprint.

Biometric pattern scanners use the optical principle of total internal reflection (TIR). The light rays from the light sources built into these optical scanners reach the platen at an angle of incidence that can reflect all the rays back. This phenomenon occurs when the angle of incidence is equal to or greater than the critical angle, which is at least partially defined by the ratio of the two refractive indices of the medium at or above the surface of the platen.

In the case of a biometric fingerprint scanner, one or more fingers are placed on the platen to acquire a fingerprint image. The ridges of the finger change the refractive index in the platen, thereby blocking total internal reflection of the prism. By this blocking of total internal reflection, optical images of the ridges and valleys of the fingerprint propagate through the receiving surface and are captured by the camera embedded in the device.

There is an increasing demand for biometric fingerprint scanners that can operate in a variety of ambient conditions. The above conditions depend on temperature and humidity. Different conditions can affect the quality of the image detected. In addition, certain characteristics of an individual's finger may affect the quality of the image detected (eg, whether the finger is dry or oily).

For example, in some cases the presence of moisture and / or fluid in the finger improves the image quality of the fingerprint detected. However, it is undesirable to have excessive moisture and / or fluid present in the finger. Excessive moisture and / or fluid may alter the refractive index at the receiving surface and block total internal reflection of the prism at undesirable locations on the receiving surface. This may reduce the quality of the image. Excessive heat or cold at or near the surface of the platen may also degrade the image.

Accordingly, there is a need for a biometric fingerprint scanner capable of operating in various ambient conditions and capable of capturing high quality fingerprint images.

The present invention relates to the field of biological imaging capture.

The following accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate the present invention, illustrate the principles of the invention in addition to the description of the invention, and enable those skilled in the art to practice the invention. And as a guide in their use.

1A is a diagram illustrating a biological image capture assembly according to one embodiment of the invention.

FIG. 1B is a diagram differently illustrating the assembly shown in FIG. 1A.

1C is an illustration of the selector shown in FIG. 1A that may be used to select an operating mode of the present invention.

FIG. 2 is a diagram illustrating one embodiment of a thermal element attached to a surface of a prism according to one embodiment of the present invention shown in FIG. 1A.

3 is a flow chart illustrating the operation of the assembly of the present invention.

4 is a diagram illustrating a transparent electric heater assembly according to one embodiment of the invention.

5 is a diagram illustrating a transparent electric heater assembly placed on a prism according to one embodiment of the present invention.

6 is a diagram illustrating a transparent electric heater assembly attached to an adjacent surface of a prism according to one embodiment of the present invention.

7 is a diagram illustrating a transparent heater assembly lying between a removable finger receiving surface overlying a prism according to one embodiment of the invention.

8 is a diagram illustrating an opaque heating apparatus according to an embodiment of the present invention.

9 is a diagram illustrating heat dissipation of the heating apparatus of FIG. 8 in accordance with one embodiment of the present invention.

10 is a preferred circuit diagram of the heating device of FIG. 8 in accordance with one embodiment of the present invention.

FIG. 11 is a table showing a relationship between a power state of the thermostat controller of FIG. 8 and a temperature of a heater assembly according to an embodiment of the present invention.

The features, objects and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which like reference numerals are assigned to corresponding elements. In the drawings, like reference numerals refer to the same, functionally similar, and / or structurally similar elements. The first element to appear is indicated by the leftmost digit in the corresponding reference number.

The present invention relates to a thermal assembly capable of increasing or decreasing the temperature of a biometric object receiving surface or platen of a biological image capture device. The thermal element is thermally coupled to the image capture prism to lower the temperature of the platen. The thermal element is controlled to reduce the temperature of the platen. If it is necessary to increase the temperature of the platen, a thermal element is used to heat the platen.

In a hot, dry atmosphere, the moisture may be too low to detect high-quality patterned images. One advantage of the present invention is that the platen is cooled under such conditions, so that a high quality pattern image can be detected.

On the other hand, heating the platen reduces or eliminates moisture and / or fluid around the platen area on which the biometric object is placed. As such, when the excess moisture around the biometric object on the platen is reduced or removed, the halo effect may be prevented from appearing in the pattern image to be detected.

In an embodiment of the invention, the controller controls each thermal element to cool or heat the platen. In one embodiment, the controller supplies current to the thermal assembly to increase or decrease the temperature of the thermal element. The temperature sensor attached to the controller detects the temperature of the platen. If the temperature of the platen exceeds a certain threshold, the temperature sensor signals the controller to supply current to the thermal assembly to increase the temperature of the platen. Increasing the temperature of the platen reduces or eliminates moisture and the halo effect disappears. If the platen's temperature is below a certain threshold, the temperature sensor signals the controller to supply current to the thermal assembly to reduce the platen's temperature.

In an embodiment of the invention, a thermal element, such as a Peltier element, is attached to the image capture prism at a location that does not affect image illumination or fingerprint imaging operations. For example, in some embodiments a thermal element is located at the end of the prism platen.

According to another aspect of the present invention, the controller may operate in a manual mode or an automatic mode. In manual mode, the user sets the controller to the "cooling" or "heating" mode. The controller then controls the thermal assembly to cool or heat the platen accordingly. In the automatic mode, it is automatically determined whether the platen should be cooled or heated depending on the detected ambient conditions (eg, depending on the ambient temperature and / or ambient humidity).

Other embodiments, features, advantages, and the like of the present invention are described in detail below with reference to the accompanying drawings, in addition to the configuration and operation of various embodiments of the present invention.

Contents

Introduction

2. Explanation of terms

3. Temperature controlled biometric scanner

4. Temperature based controller

(A) cooling

(B) heating

(C) automatic control

5. Thermal connection

6. How to change the temperature of the platen

7. Conclusion

Introduction

The present invention relates to a system and method for capturing a biological image using a biometric scanner. In particular, the present invention relates to a biometric scanner comprising an optical device coupled to a thermal assembly. The thermal assembly also includes a controller. The controller may manually or automatically control the temperature of the biometric object receiving surface or platen of the biometric scanner. In one embodiment, a controller can be used to adjust the thermal state of the platen based on various ambient conditions.

While the invention has been described in connection with specific embodiments, it will be apparent to those skilled in the art that various modifications, rearrangements, and substitutions of the invention can be made without departing from the spirit of the invention. In addition, while specific examples are described using a fingerprint scanner for clarity, the present invention is not limited to the fingerprint scanner. Other types of biometric scanners may be used without departing from the scope of the present invention. For example, the present invention can be applied to fingerprints, finger prints, or other biometric scanners.

2. Explanation of terms

In order to more clearly show the present invention, the following description will be made of terms before the description of the present invention. These terms have the same meaning throughout the specification.

The term "finger" refers to the fingers of the hand, including the thumb, forefinger, gown finger, weak finger, and little finger. However, it is not limited to this.

The term "bio scan" refers to scanning a fingerprint image, a partial pattern image of the foot and / or a palm pattern image performed by a pattern scanner. A biometric scan may be performed by a slap pattern of four fingers except thumb, rolled finger, flat finger, thumb, thumb print, palm print, foot, toe, heel, or a combination of fingers, such as one or more of the hands placed on the platen. Scans of a finger and / or thumb aggregate or one or more palms, but are not limited thereto.

For example, in a biometric scan, one or more fingers or palms of the left or right hand or both hands may be placed on the platen of the scanner. Different types of fringe images are detected depending on the particular application. For example, a flat pattern consists of a fingerprint image of a finger (four fingers other than thumb or thumb) pressed flat on the platen. The rolled pattern consists of an image of a finger (four fingers other than the thumb or thumb) that is produced as the finger (four fingers other than the thumb or thumb) is rolled from one side of the finger to the other of the finger on the surface of the platen. do. The slab pattern consists of images of four flat four fingers pressed flat on the platen. The palm print consists of images obtained by pressing all or part of the palm onto the platen. The platen may be configured to be mobile or stationary, depending on the type of scanner or the type of fringe captured by the scanner.

The terms “bioimaging system”, “scanner”, “bioscanner”, “bioprint scanner”, “fingerprint scanner” and “pattern scanner” are used interchangeably and in biometric scanning one or more fingers, palms, hands Or any type of scanner capable of acquiring an image of all or part of the foot. The obtained images can be combined in formats including the United States Federal Investigation Bureau (FBI), state or international pattern formats. However, it is not limited to the above format.

The term "platen" refers to a component that includes an imaging surface on which a portion of at least one finger, palm, hand or foot is placed during a biometric scan. The platen may comprise an optical prism, a set of prisms, a surface of a micro prism set, or a surface of a silicon layer or other element disposed in optical contact with the surface of an optical prism, prism set, or micro prism set. However, it is not limited to this.

3. Temperature controlled biometric scanner

1A and 1B illustrate a biometric scanning system according to an embodiment of the present invention. 1A is an exploded perspective view of one embodiment of the present invention, and FIG. 1B is another view of the embodiment shown in FIG. 1A. Referring to FIG. 1A, the biometric scanning assembly 100 includes an image capture prism 106 and a thermal assembly 160. The thermal assembly 160 includes two thermal elements 102a and 102b, a controller 110, a selector 112, a temperature center 108, and an optional humidity sensor 113.

Although two thermal elements 102a and 102b are used, the present invention is not limited to two thermal elements. In another embodiment, only one thermal element may be used. In other embodiments of the invention, three or more thermal elements may be used.

As shown in FIG. 1A, thermal elements 102a and 102b are thermally coupled to an image capture prism 106. The first thermal element 102a is thermally connected to the first side 115a of the image capture prism 106. The second thermal element 102b is thermally connected to the second side 115b of the image capture prism 106.

The first side 115a of the image capture prism 106 is disposed opposite the second side 115b of the image capture prism 106. Therefore, the 1st column element 102a and the 2nd column element 102b are mutually arrange | positioned. However, the thermal elements 102a and 102b may be arranged in other forms. Also, as shown in FIG. 1A, although two thermal elements are connected to the image capture prism 106, different number of thermal elements may be connected to the image capture prism 106. Thermal elements 102a and 102b may be attached directly or indirectly to image capture prism 106 and only need to be thermally connected. Moreover, the image capture prism 106 is not limited to the size and shape shown in FIG. 1A.

Connectors 120a and 120b connect thermal elements 102a and 102b to controller 110. The connector 120a connects the thermal element 102a and the controller 110. Similarly, the connector 120b connects the thermal element 102b and the controller 110. Connectors 120a and 120b may be attached to each thermal element and controller 110 by known means. In one embodiment, the connectors 120a and 120b may be soldered to the appropriate circuit elements of each of the thermal elements 102a and 102b as well as the appropriate circuit elements of the controller 110.

The temperature sensor 108 may be disposed at or near the image capture prism 106. In one embodiment, the temperature sensor 108 is used to detect the temperature of the image capture prism 106. In another embodiment, temperature sensor 108 is used to detect the temperature of a biometric object receiving surface or platen that may be attached to prism 106. When the temperature is detected, the temperature sensor 108 transmits the detected information to the controller 110.

4. Temperature based controller

Depending on various conditions around the biometric scanning assembly 100, it is necessary to change the temperature of the biometric object receiving surface or platen 140 of the image capture prism 106. For this temperature change, the thermal assembly 160 of the present invention includes a controller 110 and a temperature sensor 108 (connected to the controller 110 and the image capture prism 106).

Referring to FIG. 1A, the selector 112 is connected to the controller 110 via a bus 111. Selector 112 may be used to switch the mode of operation of thermal assembly 16. In one embodiment, selector 112 may switch thermal assembly 160 to manual heating mode, manual cooling mode, automatic heating / cooling mode. Of course, those skilled in the art will understand that the thermal assembly 160 may have other modes of operation.

1C illustrates one embodiment of the selector 112 in greater detail. Selector 112 includes a selector switch 171 that changes the mode of operation of thermal assembly 160. The selector 112 has a passive cooling mode 175 and a manual heating mode 177. The selector 112 also has an automatic heating / cooling mode 173. Finally, selector 112 has an off mode 179.

In the passive cooling mode 175 and the heating mode 177, the user can change the thermal state of the platen 140. To manually heat the platen 140, the user moves the selector switch 171 toward the heating mode 177. To manually cool the platen 140, the user moves the selector switch 171 toward the cooling mode 175.

In the automatic heating / cooling mode, thermal assembly 160 controls its thermal state in accordance with the current ambient conditions. To automatically adjust the temperature of the platen 140, the user moves the selector switch 171 toward the automatic heating / cooling mode 173. The thermal assembly 160 then automatically controls the temperature of the platen 140.

Finally, it may be desirable to operate the assembly 100 without cooling or heating the platen 140. In this case, the user only needs to move the selector switch 171 toward the "off" mode 179. The thermal state of the platen 140 is determined by the ambient conditions.

Hereinafter, manual cooling and heating modes and automatic heating / cooling modes will be described in more detail. Those skilled in the art will understand that the present invention is not limited to the modes described below.

(A) cooling

If the conditions around the biometric scanning assembly 100 are hot and dry, it is necessary to cool the biometric object receiving surface or platen 140 of the image capture prism 106. Even under these conditions, images of fingerprints can sometimes be obtained, but excessive high temperature drying is undesirable and affects the image quality. Therefore, it is necessary to cool the platen.

Referring to FIGS. 1A and 1C, the selector 112 is switched to the cooling mode to cause the thermal assembly 160 to reduce the temperature of the platen 140. This is accomplished by moving the selector switch 171 towards the passive cooling mode 175. In this mode, the user can manually lower the temperature of the platen 140.

In one embodiment, the user may lower the temperature by placing the selector switch 171 in the passive cooling mode 175. In this case, current flows to the thermal elements 102a and 102b by the controller 110 in a specific direction. The controller 110 may allow a current to flow continuously or intermittently based on the detected temperature as needed. By allowing a current to flow through the thermal elements 102a and 102b in this manner, the temperature of the platen 140 is lowered. When current is flowing in the thermal elements 102a and 102b in a particular manner, the sides of each thermal element 102a and 102b adjacent the platen 140 are cooled (as described in more detail below). By cooling the sides of the thermal elements 102a and 102b adjacent to the platen 140, the temperature of the platen 140 is reduced.

In another embodiment, to manually reduce the temperature of the platen 140, the user moves the selector switch 171 toward the passive cooling mode 175, when the temperature of the platen 140 becomes unsuitable for the user. Each time, a current may be manually supplied from the controller 110 to the thermal elements 102a and 102b. The user may use the temperature data supplied by the temperature sensor 108 to control the current supplied to the thermal elements 102a and 102b. In one embodiment, thermal assembly 160 may optionally include a monitor (not shown) that displays the temperature of platen 140.

As the user sees the temperature of the platen 140 rise, the user manually supplies current from the controller 110 to the thermal elements 102a and 102b for cooling. As discussed above, when current is supplied to the thermal elements 102a and 102b in a particular direction, the temperature of the platen 140 decreases to the desired temperature.

Those skilled in the art will appreciate that other methods of cooling the platen 140 are also possible. Hereinafter, thermal elements 102a and 102b that can be used by thermal assembly 160 to lower the temperature of platen 140 will be described.

2 shows a first column element 102a. The structure and operation of the second column element 102b are similar to the structure and operation of the first column element 102a. The first thermal element 102a has a first portion 202 and a second portion 204. The first portion 202 is connected to the second portion 204. The first side 116a of the first thermal element 102a is outside of the first portion 202 and the second side 117a of the first thermal element 102a is outside of the second portion 204.

Thermal element 102a is configured in such a way that first portion 202 begins to remove heat when current flows in the thermal element in one direction. At the same time, the second portion 204 absorbs the amount of energy needed to lower the temperature of the first portion 202. By absorbing energy in this manner, the temperature of the second portion 204 of the thermal element 102a is raised.

However, when current flows in the thermal element in the opposite direction, the first portion starts to generate heat. In this case, the second portion 204 of the thermal element 102a begins to remove heat. At the same time, the first portion 202 absorbs energy from the second portion 204. As a result, the temperature of the first portion 202 is increased.

As mentioned above, the structure and operation of the second thermal element 102b are similar to the structure and operation of the first thermal element 102a.

In one embodiment, the thermal elements 102a and 102b may be Peltier elements. The Peltier element is a bidirectional heating and cooling device. When current is applied in one direction, the Peltier element acts as a cooling element (also called a heat sink) to dissipate heat out. When current is applied in the opposite direction, the Peltier element generates heat.

(B) heating

At certain ambient conditions, the air extremely close to the fingerprint has a very high relative humidity. When water contacts the surface of the prism, total internal reflection of the prism is stopped. This interruption of total internal reflection causes an optical image of water on the platen (eg, a halo known in the art to be halo effect) propagates through the platen and is captured by a camera embedded in the device. As a result of this interruption of total internal reflection, there is an undesirable visible image of water in the image of the biometric object.

Therefore, it may be desirable to raise the temperature of the platen to eliminate the effects of moisture, fluid and / or water placed on the surface of the prism. By raising the temperature of the platen 140, the moisture accumulated on the platen can be evaporated, thereby increasing the quality of the image and preventing the "halo" effect.

To increase the temperature of the platen 140, the user may follow steps similar to the cooling process described above. As shown in FIGS. 1A and 1C, the selector 112 is switched to a heating mode to cause the thermal assembly 160 to raise the temperature of the platen 140. This is accomplished by moving the selector switch 171 towards manual heating mode 177. In this mode, the user can manually increase the temperature of the platen 140.

In one embodiment, the user may increase the temperature by placing the selector switch 171 in the manual heating mode 177. In this case, current flows to the thermal elements 102a and 102b by the controller 110 in a direction opposite to the current direction in the cooling mode. The controller 110 may allow a current to flow continuously or intermittently based on the detected temperature as needed. By causing a current to flow in the thermal elements 102a and 102b in the opposite direction, the temperature of the platen 140 increases. The thermal elements 102a and 102b become heating elements. The temperature of the side of each of the thermal elements 102a and 102b adjacent to the platen 140 is raised. This is in contrast to the cooling mode where these sides cool the platen 140. By heating the sides of the thermal elements 102a and 102b adjacent to the platen 140, the temperature of the platen 140 increases.

In another embodiment, to manually increase the temperature of the platen 140, the user moves the selector switch 171 toward the manual heating mode 175, when the temperature of the platen 140 is undesirably lowered. Each time, a current may be supplied from the controller 110 to the thermal elements 102a and 102b. The user may use the temperature data supplied to the user by the temperature sensor 108 to control the current supplied to the thermal elements 102a and 102b. In one embodiment, thermal assembly 160 may optionally include a monitor (not shown) that displays the temperature of platen 140.

When the temperature of the platen 140 is low enough for the user to see, the user manually supplies current from the controller 110 to the thermal element 102. As discussed above, when the current is supplied to the thermal element 102 in a direction opposite to the direction of the current in the cooling mode, the temperature of the platen 140 increases to the desired temperature.

When a lot of moisture is present on the biometric object to be scanned, increasing the temperature of the platen 140 removes excess moisture from the object and the platen 140. By removing excess moisture from the platen 140, the image quality of the object is increased, and the "halo" effect is eliminated.

Referring again to FIG. 1A, an optional humidity sensor 113 is shown. The humidity sensor 113 is connected to the controller 110 via a bus 115. The humidity sensor 113 detects a humidity coefficient and transmits the detected data to the controller 110. The purpose of installing the humidity sensor 113 is to provide separate information to the controller 110. Increasing the humidity, the controller 110 increases the current supplied to the thermal elements 102a and 102b to further remove moisture from the platen 140. When the humidity is reduced, the controller 110 reduces the current supplied to the thermal elements 102a and 102b.

Those skilled in the art will appreciate that other methods of heating the platen 140 are also possible. The thermal elements 102a and 102b may be thermal elements used to cool the platen 140. However, a separate thermal element may be thermally connected to the platen 140 to heat the platen.

In another embodiment, the biometric scanning system 100 may be modified to only heat the platen 140. 4 to 11 show a heater assembly according to an embodiment capable of heating only of the present invention.

4 illustrates one embodiment of a heater assembly of the present invention. The heater assembly may be attached to the top of the prism in the electro-optical fingerprint scanner. As discussed above, the heater assembly eliminates the effects of moisture surrounding the biometric object resulting from excess moisture and / or fluid on an individual's finger that changes the relative humidity around the platen area where the finger is placed for image acquisition. It works. The heater assembly 100 includes a transparent conductive film 410, two electrically conductive rods 420A and 420B, a connector 445A and 445B, a power source 440, and a temperature sensor 108. The electrically conducting rods 420A and 420B are similar to the thermal elements 102a and 102b shown in FIG. 1A.

The electrically conductive rod 420A is attached to the first edge of the transparent conductive film 410. The electrically conductive rod 420B is attached to the second edge of the transparent conductive film 410. Electrically conductive rods 420A and 420B are arranged such that current can be distributed throughout the transparent conductive film 410. In other words, the purpose is to provide a uniform density across the transparent conductive film 410. Otherwise, conductive rods 420A and 420B may also be placed at the top and bottom edges of the film to achieve uniform density within the film.

Connectors 445A and 445B electrically connect electrically conductive rods 420A and 420B to power source 440. One end of the connector 445A is connected to the electrically conductive rod 420A, and the other end of the connector 445A is connected to the power source 440. Similarly, one end of the connector 445B is connected to the electrically conductive rod 420B, and the other end of the connector 445B is connected to the power source 440. The connectors 445A and 445B may be attached to the power source and the electrically conductive rods 420A and 420B by means known to those skilled in the art. For example, in one embodiment, the ends of the connectors 445A and 445B may be soldered to the conducting rods 420A and 420B and the power source 440.

The temperature sensor 108 may be connected on or near the transparent conductive film 410. In one embodiment, temperature sensor 108 is used with a control system to maintain the temperature in conductive film 410 at a desired temperature. In this embodiment, the temperature sensor 108 is connected to a control system (not shown in FIG. 4). The control system is connected to a power source 440. In another embodiment, temperature sensor 108 may be embedded in power source 440.

The transparent conductive film 410 generates heat on the biometric object receiving surface, such as the platen (as shown in FIG. 1A). The transparent conductive film 410 may be made of plastic or an electrically conductive material known in the art. For example, in one embodiment, the transparent conductive film 410 consists of a transparent polyester substrate. In one embodiment, the transparent conductive film 410 has a transparency of 80% and can operate at 20 ohms per square. The transparent conductive film 410 may take any shape. For example, the transparent conductive film 410 may be rectangular or circular. In an embodiment in which the transparent conductive film 410 is circular, the contours of the conductive rods 420A and 420B are modified to fit the outer edge of the transparent conductive film 410.

Electrically conducting rods 420A and 420B act as contacts of connectors 445A and 445B. The electrically conductive rods 420A and 420B may be made of metal, copper, silver, or other conductive material. Furthermore, the electrically conductive rods 420A and 420B may be formed in a pattern that can be attached to the transparent conductive film 410.

The connectors 445A and 445B transfer energy from the power source 440 to the transparent conductive film 410 through the conductive rods 420A and 420B. Connectors 445A and 445B may be electrical wires or other channels capable of transferring energy.

By power dissipated from the power source 440 into the transparent conductive film 410, the temperature of the transparent conductive film 410 rises above room temperature to remove excess moisture on the platen surrounding the fingertips and the halo appears in the image of the fingerprint. Prevent effect. The power source 440 may supply alternating current or direct current.

The temperature sensor 108 observes the temperature of the transparent conductive film 410. When the heat dissipated in the transparent conductive film 410 causes the transparent conductive film 410 to obtain a temperature high enough to prevent the formation of excess moisture on the platen or to evaporate the excess moisture, the signal from the temperature sensor 108. The control system received above causes the power source 440 to automatically adjust the generation of that power. If the temperature in the transparent conductive film 410 is detected to fall below a certain temperature, the temperature sensor 108 informs the control system to cause the power supply 440 to generate sufficient power to increase the temperature.

5 shows the transparent heater assembly 100 attached to one side of the prism 106. The heater assembly 100 may be attached to the surface of the prism 106 by means known to those skilled in the art. The heater assembly 100 heats the surface of the prism 106 to prevent and / or remove excess moisture from forming excess moisture on the platen surrounding the biometric object from which the image will be captured. This removes the halo effect that may be generated in the captured image of the biometric object.

Prism 106 is an optical device made of a lightweight propagating material made of plastic, glass, or a combination of these materials. The characteristics of the lightweight propagating material are determined by the refractive index. Prism 106 is designed to utilize the optical principle of total internal reflection. The operation of the prism in a fingerprint scanner is described in US Patent No. 5,467,403, filed by Fishbine et al., Issued November 14, 1995 to Digital Biometrics, Inc. Name: portable fingerprint scanning device for identification verification). The patent is hereby incorporated by reference in its entirety. Prism 106 is also described above with respect to FIGS. 1A-1C.

In the embodiment shown in FIG. 5, the heater assembly 100 is disposed directly on the top surface of the prism 106. The transparent conductive film 410 is the only exposed element of the heater assembly 100. The transparent conductive film 410 serves as a platen, and the biometric object is placed directly on the transparent conductive film 410 of the heater assembly 100. The heated transparent conductive film 410 functions to remove the effect of excess moisture close to the biometric object placed on its surface, thereby eliminating the halo effect. Moreover, the transparent conductive film 410 may be made disposable and eventually discarded, and may be replaced with a new transparent conductive film as mechanical wear increases.

In another embodiment, the heater assembly 100 is directly attached to the top surface of the prism 106. A biometric object receiving surface (eg, glass or plastic platen) is placed on top of the heater assembly 100. The fingerprint on which the image is to be captured is then placed on the image capture platen. The heater assembly 100 heats the platen. When a finger rests on the platen for image capture, heat prevents excess moisture from forming on the platen or removes excess moisture, thereby removing the halo effect that may appear within the captured image area.

6 shows the heater assembly 100 attached to the proximal surface 630 of the prism 106. The biometric object is placed on the biometric object receiving surface 602 (eg, on top of the prism 106). In this embodiment, the heater assembly 100 is attached to the adjacent surface 630 of the prism 106, so that the transparent conductive film 410 is disposed on the top surface of the prism 106, thereby preventing the tearing eventually caused. In other words, if the transparent conductive film 410 is placed over the adjacent surface 630 of the prism 106, the finger will not be in direct contact with the transparent conductive film 410. As a result, the lifetime of the transparent conductive film 410 increases. In the embodiment shown in FIG. 6, the biometric object receiving surface 602 is the top surface of the prism 106. In another embodiment, the biometric object receiving surface 602 is a silicone rubber sheet with good optical quality. This is described in detail in U.S. Provisional Patent Application No. 60 / 286,373 filed on April 26, 2001, by Arnold et al., Entitled "Silicone Rubber Surface for Internal Fingerprint Prism Inside Biological Fingerprint." It is incorporated herein by reference. The biometric object receiving surface 602 may place a finger on which the image is to be captured.

Instead of heating the top surface of the prism 106, the heater assembly 100 heats the adjacent surface 630 of the prism 106. The heater assembly 100 increases the temperature of the top surface of the prism 106 by heating the adjacent surface 630 of the prism 106. The heat from the top surface of the prism 106 increases the temperature of the biometric object receiving surface 602. When a certain temperature is reached, excess moisture is prevented from forming on the biometric object receiving surface 602 or excess moisture is removed to remove halo effects that may appear in the captured image of the finger.

7 shows the heater assembly 100 inserted between two silicon pads 720A and 720B. The silicon pad 720B is attached to the upper surface of the prism 106. Heater assembly 100 lies on silicon pad 720B. Silicon pad 720A lies on heater assembly 100. A biometric object (eg, a finger) for capturing an image is placed on the top surface of the silicon pad 720A. In other words, the silicon pad 720A serves as a platen. The heater assembly 100 heats the silicon pad 720A to a specific temperature that prevents the formation of excess moisture resulting from a finger placed on the silicon pad 720A, as described above.

Referring to FIG. 8, one embodiment of a heating device 800 of the present invention is illustrated. The heating device 800 can provide thermal energy to the prism 106 and the biometric object receiving surface 602. In one embodiment, the heating device 800 includes heater assemblies 805A and 805B, a thermostat controller 810, a transistor and a switchboard 811. The heater assembly 805A includes a conductor 806A and a resistance heating element 807A. Similarly, heater assembly 805B includes conductor 806B and resistive heating element 807B (not shown in FIG. 8),

The thermostat controller 810 is connected to the resistance heating element 807A, the transistor, and the switchboard 811. The transistor and switchboard 811 are also connected to each of the resistance heating elements 807A and 807B, as shown in FIG. 8, and are connected to a power supply (not shown).

The resistive heating elements 807A and 807B generate heat in accordance with the amount of power provided by the transistors and the switchboard 811. The resistive heating elements 807A and 807B are respectively thermally connected to the conductors 806A and 806B so that heat from the resistive heating elements 807A and 807B is transferred through the conductors 806A and 806B to the prism 106. And to a biometric object receiving surface 602.

Each of the heater assemblies 805A, 805B may be placed in direct contact with or in thermal contact with each end 801A, 801B of the prism 106 in the pattern scanner. For example, the conductor 806A of the heater assembly 805A may be connected at the same height to the first end 801A of the prism 106. Likewise, the heater assembly 805B may be connected at the same height to the second end 801B of the prism 106. In one embodiment of the invention, each conductor 806A, 806B consists of a thermally conductive element such as copper, aluminum, or nickel. The pattern scanner may be any type of optical pattern scanner such as a fingerprint scanner and / or a palm pattern scanner.

As mentioned above, the heater assemblies 805A and 805B operate to raise the surface temperature of the biometric object receiving surface 602 portion. This prevents water from condensing on the biometric object receiving surface 602. As a result, the halo effect mentioned above is prevented.

9 is a diagram showing heat dissipation in a prism according to one embodiment of the present invention. 9, heater assemblies 805A and 805B and prisms 106 are shown. Heater assembly 805A generates a first set of energy waves 905A. Likewise, heater assembly 805B generates a second set of energy waves 905B. The energy waves 905A and 905B are distributed throughout the prism 106, thereby increasing the temperature of the prism 106 and the biometric object receiving surface 602. In this way, the biometric object receiving surface 602 is heated to a temperature sufficient to prevent excessive moisture from forming on the platen in the vicinity of the biometric object. As a result, the quality of the image detected by the pattern scanner is improved, and the halo effect as described above is prevented.

According to another feature of the invention, the thermostat controller 810 adjusts the heating operation according to three states consisting of full power, half power, no power (off). The thermostat regulator 810 serves as a transducer and senses the temperature of the heater assembly 805A. Thermostat regulator 810 controls the amount of power supplied to each resistive heating element 807A and 807B by transistor and switchboard 811. Operation of the thermostat regulator 810 is described below in connection with the preferred embodiment (see FIGS. 10 and 11).

10 shows a preferred electrical circuit 1000 that may be provided on transistors and switchboards 811 to connect thermostat controller 810 and resistive heating elements 807A and 807B.

As shown in FIG. 10, the electric circuit 1000 includes a bias voltage (+ 12V), an in-circuit protection fuse 1010, and a transistor Q1. Transistor Q1 is connected in series between the resistance heating elements 807A and 807B. The bias provided to transistor Q1 is controlled by two switches and thermostat controller 810. These two switches SW1 and SW2 are connected to the base of the transistor Q1, respectively. Zener diode 1005 functions to keep the bias voltage source of thermostat controller 810 constant. In-circuit protection fuses 1010 are added to protect against excessive current caused by resistive heating elements 807A and 807B in overheating conditions or in circuit failure.

11 shows the relationship between the relative and various other elements of the heating device 800. Referring to FIG. 11, the thermostat controller 810 senses the temperature of the heater assembly 805A. The switches SW1 and SW2 are switched on and off depending on whether the sensed temperatures have reached the first and second thresholds, respectively. The switch SW1 has a first threshold corresponding to a temperature greater than or equal to 115.5 ° F. The switch SW2 is switched on or off depending on whether the second threshold is greater than or equal to 121 ° F. As shown in FIG. 11, the switch SW1 (SW2) is in the OFF state in the initial state where the temperature of the heater assembly 805A is less than 115.5 ° F. In this state, transistor Q1 is fully saturated and full power is supplied over resistive heating elements 807A and 807B. In one example, the resistance of the resistive heating element 807A has a resistance value R1 equal to about 20 ohms. Similarly, the resistance value of the second resistive heating element 807B is represented by a value R2 equal to about 20 ohms. Since the resistive heating elements 807A and 807B are arranged in series, each resistive heating element emits the same heating power. According to one example of the invention, the combined power of the heating elements in the full power state is about 3.7 watts.

When the temperature of the heater assembly 805A rises to a first threshold greater than or equal to 115.5 ° F., the thermostat controller switch SW1 is turned on but the switch SW2 remains off. This changes the bias provided to transistor Q1, halving the overall power across resistive heating elements 807A and 807B. When the temperature of the heater assembly 805A rises to a second threshold that is greater than or equal to 121 ° F, both switches SW1 and SW2 are turned on. In this state, transistor Q1 is turned off and zero power is provided across resistive heating elements 807A and 807B.

The invention is not limited to two thresholds. If more precise heating control is required as a function of heater assembly 805A temperature, a separate threshold may be used. In another embodiment, the thermostat controller 810 can be completely excluded so that constant heating power can be provided regardless of temperature changes. In addition, when simpler heating power control is required, the thermostat controller 810 can be operated using only one switch and one threshold. Finally, the thresholds 115.5 ° F. and 121 ° F. are merely values used as examples in one embodiment of the present invention. Those skilled in the relevant art will clearly understand from the description of the present invention that other temperature values may be used.

(C) automatic control

1A-1C, the thermal assembly 160 of the present invention may operate in an automatic heating / cooling mode 173. In this mode, thermal assembly 160 may automatically control heating or cooling of platen 140. When moisture is present, thermal assembly 160 will heat platen 140. When the ambient conditions are hot drying, the thermal assembly 160 cools the platen 140.

In order to perform automatic heating / cooling, the thermal assembly 160 needs to be switched to the automatic heating / cooling mode 173 as shown in FIG. 1C. The selector switch 171 is moved towards the automatic heating / cooling mode 173.

In one embodiment, when the temperature of the platen 140 falls below or below the first threshold, the thermal assembly 160 heats the platen 140. Likewise, when the temperature of the platen 140 rises above the high or second threshold, the thermal assembly 160 cools the platen 140. Those skilled in the art will appreciate that upon heating and cooling, the threshold range of temperatures may be preset to values below or above the threshold at which the thermal assembly 160 responds appropriately. In another embodiment, the user may set a number of temperature thresholds, where the thermal assembly 160 adjusts the temperature of the platen 140 appropriately as each threshold is reached.

In the automatic mode, the temperature sensor 108 connected to the controller 110 via the bus 116 detects the temperature of the platen 140. When the ambient conditions surrounding the biopsy scanning assembly 100 are hot and dry, the temperature of the platen rises. The temperature sensor 108 detects a new temperature of the platen 140 and transmits the detected data to the controller 110.

Depending on the ambient conditions and the temperature of the platen 140, the controller 110 increases or decreases the temperature of the platen 140. When the temperature of the platen 140 reaches a high threshold, the controller 110 passes through the connectors 120a and 120b to the thermal elements 102a and 102b, respectively, in a direction opposite to the current direction in the heating mode. Send the current. The thermal elements 102a and 102b act as platen coolers and, as described above, lower the temperature of the platen 140.

When the temperature of the platen 140 reaches a low threshold, the controller 110 currents each of the thermal elements 102a and 102b through the connectors 120a and 120b in a direction opposite to the current direction in the cooling mode. Send it. The thermal elements 102a and 102b serve as platen heaters to raise the temperature of the platen 140 as described above.

Temperature sensor 108 detects the temperature of platen 140 and thermal elements 102a and 102b through respective buses 116 and 118. When the image capture prism 106 has a temperature low enough to prevent overheating of the prism 106 due to cold air dissipated in the platen 140, the controller 110 supplies the thermal elements 102a and 102b. Control the generation of current When it is sensed that the temperature of the platen 140 has exceeded a certain temperature, the controller 110 generates enough power to reduce the temperature.

On the other hand, when there is a lot of moisture on the biometric object to be scanned, it is necessary to increase the temperature of the platen 140 to remove excess moisture from the object and the platen 140. Thus, in order to increase the temperature of the platen 140, the first side portions 116a and 116b of the first and second thermal elements 102a and 102b are respectively heated. This is achieved when the controller 110 causes current to flow through the connectors 120a and 120b in a direction opposite to that when the controller 110 cools the image capture prism. By causing the thermal elements 102a and 102b to apply heat to the image capture prism 106, the temperature of the platen 140 increases.

Those skilled in the art will understand that the automatic control of the heating / cooling operation of the present invention is not limited to the embodiment described above. The above embodiment operates with two thermal elements 102a and 102b connected to the platen 140 of the image capture prism 106. However, it is to be understood that at least one thermal element is required to heat or cool the platen 140.

Hereinafter, a method of connecting the thermal elements 102a and 102b to the platen 140 in a specific embodiment will be described.

5. Thermal connection

The present invention uses two thermal elements 102a and 102b to uniformly increase or decrease the temperature of the platen 140. In order to achieve a uniform temperature change, thermal elements 102a and 102b are thermally connected to the platen. However, only one thermal element is needed to increase or decrease the temperature of the platen.

1A and 1B, the first column element 102a includes a first side portion 116a and a second side portion 117a. The first side 116a of the thermal element 102a is inward with respect to the image capture prism 106 (or platen 140). The first side 116a is connected to the first side 115a of the image capture prism 106 (or platen 140). The second side 117a of the thermal element 102a is outward with respect to the image capture prism 106 (or platen 140). The connector 120a connects the controller 110 and the second side portion 117a. The first side 116a of the thermal element 102a is attached to the first side 115a of the image capture prism 106 (or platen 140) by conventionally known means. In one example, the means may be an epoxy or other adhesive element.

Similarly, thermal element 102b has a first side 116b and a second side 117b. The first side 116b of the thermal element 102b is inward with respect to the image capture prism 106 (or platen 140). The first side 116b is attached to the second side 115b of the image capture prism 106 (or platen 140). The second side 117b of the thermal element 102b is external to the image capture prism 106 (or platen 140). The connector 120b connects the controller 110 and the second side portion 117b. The first side 116b of the thermal element 102b is attached to the second side 115b of the image capture prism 106 (or platen 140) by conventionally known means. In one example, the means may be an epoxy or other adhesive element.

By connecting the thermal elements 102a and 102b to both sides of the platen 140 or the image capture prism 106, the thermal element uniformly increases or evens the temperature of the image capture prism 106 or the platen 140. Can be reduced.

In one embodiment, the image capture prism 106 is an optical device made of a lightweight propagating material made of plastic, glass, or a combination of these materials. The characteristics of the lightweight propagating material are determined by the refractive index. Prism 106 is designed to utilize the optical principle of total internal reflection. The operation of the prism in a fingerprint scanner is described in US Patent No. 5,467,403, filed by Fishbine et al., Issued November 14, 1995 to Digital Biometrics, Inc. Name: portable fingerprint scanning device for identification verification). The patent is hereby incorporated by reference in its entirety.

6. How to change the temperature of the platen

3 illustrates a method 300 of changing the temperature of the platen 140. In step 302, a biometric object to be scanned is provided (eg, a finger). The biometric object is placed on the platen 140 of the image capture prism 106. In one embodiment, the biometric object is placed on platen 140. The platen 140 may be an upper surface of the image capture prism 106. However, in another embodiment, the platen 140 may be a protective cover disposed in optical contact with the surface of the image capture prism 106.

In step 306, the temperature of the platen 140 is detected using the temperature sensor 108. The temperature sensor 108 transmits temperature data to the controller 110. When it is necessary to cool the image capture prism 106 and / or platen 140, the controller 110 causes the current to flow in one direction. When the platen 140 needs to be heated, the controller 110 causes current to flow in the opposite direction.

In step 308, when the conditions around the platen 140 are hot dry, it is necessary to reduce the temperature of the platen 140. By reducing the temperature of the platen 140, the image capture prism 106 is not overheated.

As a result of the detection of the temperature sensor 108, when the temperature of the platen 140 exceeds a certain threshold, the controller 110 generates a current to reduce the temperature of the platen 140. Current is delivered to thermal elements 102a and 102b through connectors 120a and 120b, respectively. Here, the current is delivered in a specific direction. This is because the thermal elements 102a and 102b need to reduce the temperature of the platen 140 by removing heat.

In step 310, when excess moisture is present on the biometric object and / or platen 140, it is necessary to increase the temperature of the platen 140. By increasing the temperature of the platen 140, excess moisture is evaporated. By removing excess moisture, the halo effect is reduced.

If the temperature of the platen 140 is less than a certain threshold as a result of the detection of the temperature sensor 108, the controller 110 generates a current to increase the temperature of the platen 140. Current is delivered to thermal elements 102a and 102b through connectors 120a and 120b, respectively. The current is delivered in a direction opposite to that of the current when the image capture prism 106 or platen 140 is to be cooled. This is because the thermal elements 102a and 102b need to increase the temperature of the platen 140 by generating heat.

7. Conclusion

The present invention is not limited to the operation mode described above. Those skilled in the art will appreciate that other modes of operation are possible.

When heating and / or cooling platen 140, the present invention is not limited to a single temperature threshold. Separate thresholds may be used where more precise control of the heating and / or cooling behavior is required. In another embodiment, the temperature sensor 108 may be completely excluded to allow constant heating and / or cooling of the biometric object receiving surface regardless of temperature change. Finally, the thresholds of temperature values for heating and cooling can be set as needed, as will be apparent to those skilled in the art from the description of the present invention.

Moreover, it will be understood by those skilled in the art that the controller 110 may be equipped with a current source and a switching circuit. The switching circuit may control the direction of the current supplied to the thermal elements 102a and 102b through the connectors 120a and 120b. If necessary, the controller 110 may be configured differently.

While various embodiments of the invention have been described above, these embodiments are merely examples for illustrating the invention. Those skilled in the art will understand that various changes can be made in the overall configuration and details without departing from the spirit and scope of the invention. Therefore, it is to be understood that the present invention is not limited by the above preferred embodiment, but only by the claims set forth below.

Claims (53)

The platen on which the biometric object to be scanned is placed, At least one thermal element thermally coupled to the platen to add heat to or remove heat from the platen, and And a controller for controlling the at least one thermal element to add heat to or remove heat from the platen. 2. The biopsy scanner of claim 1, wherein the scanner further comprises a temperature sensor coupled to the at least one thermal element and the controller to detect the temperature of the platen. The biopsy scanner of claim 1, wherein the controller controls the temperature of the platen. The biopsy scanner of claim 1, further comprising a prism in optical contact with the platen and thermally coupled to the at least one thermal element and the platen. The biometric pattern of claim 1, wherein the at least one thermal element comprises a first thermal element and a second thermal element, and the first thermal element and the second thermal element are thermally connected to the platen. scanner. 6. The biopsy scanner of claim 5, wherein the first thermal element and the second thermal element remove heat from the platen. 6. The biopsy scanner of claim 5, wherein the first thermal element and the second thermal element add heat to the platen. The biopsy scanner of claim 1, wherein the platen also includes a surface of the prism. The apparatus of claim 1, wherein the controller controls the at least one thermal element to add or remove heat in response to a manual control input, thereby allowing a user to select whether to cool or heat the platen according to ambient conditions. Biometric scanner. 2. The biopsy scanner of claim 1, wherein the controller automatically controls the at least one thermal element to add or remove heat based on the detected ambient conditions. The apparatus of claim 1, wherein the controller includes a selector switch to enable the controller to control the at least one thermal element so that a user can add heat to or remove heat from the platen. Biometric pattern scanner, characterized in that. The biopsy scanner of claim 1, wherein the scanner further comprises a humidity sensor for detecting humidity in or near the platen region and transmitting a signal indicative of the detected humidity to the controller. (a) detecting an ambient temperature surrounding the biometric scanning surface, and and (b) lowering the temperature of the biometric scanning surface if the detected ambient temperature exceeds the first threshold temperature. 14. The method of claim 13, wherein step (b) further comprises generating a current in a first direction through a thermal element near the biometric scanning surface to lower the temperature of the biometric scanning surface. The method of claim 13, (c) increasing the temperature of the biometric scanning surface if the detected ambient temperature is below the second threshold temperature. 16. The method of claim 15, wherein step (c) further comprises generating a current in a second direction through a thermal element near the biometric scanning surface to increase the temperature of the biometric scanning surface. (a) using a thermal assembly to generate a control signal indicative of a decrease in temperature of the biological scanning surface, and (b) reducing the temperature of the biometric scanning surface in response to the control signal. 2. A method of cooling a biometric scanning surface of a biometric scanning device having a thermal assembly thermally coupled to the biometric scanning surface. The method of claim 17, (c) observing the temperature of the biological scanning surface to maintain the temperature at a predetermined value suitable to prevent overheating of the biological scanning surface. (a) generating a control signal indicative of an increase in temperature of the biological scanning surface, and (b) increasing the temperature of the bioscanning surface in response to the control signal to remove water vapor in the vicinity of the biometric object from which the image placed on the bioscanning surface is to be captured and to prevent the formation of water vapor. A method of heating a biometric scanning surface of a biometric scanning device. The method of claim 19, (c) observing the temperature of the biometric scanning surface to maintain the temperature at a predetermined value suitable for removing excess moisture in the vicinity of the biometric object placed on the biometric scanning surface. (a) detecting the temperature of the biometric object receiving surface, (b) generating a current from a power source in a thermal element assembly connected to the image capture device, (c) reducing the temperature of the biometric object receiving surface to prevent overheating of the image capture device when the temperature of the biometric object receiving surface exceeds the first critical temperature, and and (d) increasing the temperature of the biometric object receiving surface to remove excess moisture from the image capture device when the temperature of the biometric object receiving surface is less than the second threshold temperature. A method for enhancing biological image capture operations using an image capture device having a biometric object receiving surface thereon. The method of claim 21, (e) observing the temperature of the biometric object receiving surface to maintain the temperature at a predetermined value suitable to prevent overheating of the biometric object receiving surface. The method of claim 21, (e) observing the temperature of the biometric object receiving surface to maintain the temperature at a predetermined value suitable for removing excess moisture in the vicinity of the biometric object receiving surface on the biometric object receiving surface. Way. (a) using a thermal assembly to generate at least one control signal indicative of a change in the thermal state of the biometric scanning surface, and (b) altering a thermal state of the biometric scanning surface in response to the at least one control signal. How to change the status. 25. The method of claim 24, wherein step (b) further comprises changing a temperature of the biometric scanning surface in response to the at least one control signal. 25. The method of claim 24, wherein step (a) further comprises generating at least one control signal indicative of a decrease in temperature of the biological scanning surface. 25. The method of claim 24, wherein step (a) further comprises generating at least one control signal indicative of an increase in temperature of the biological scanning surface. A transparent conductive film having a first edge and a second edge opposite the first edge, A first conductor connected to the first edge of the transparent conductive film, A second conductor connected to the second edge of the transparent conductive film, and And a power source connected to the first and second conductors to supply power to the first and second conductors. 29. The heater assembly of claim 28, further comprising a control system coupled to the power source to control the temperature in the transparent conductive film. 30. The heater assembly of claim 29, wherein said control system is embedded in said power source. 29. The heater assembly of claim 28, wherein the heater assembly is an optically transparent electric heater. 29. The heater assembly of claim 28, wherein the heater assembly is coupled to an electro-optical biometric image capture device to directly heat the biometric object receiving surface. 29. The heater assembly of claim 28, wherein the biometric object receiving surface is a platen. 29. The method of claim 28, wherein the heater assembly indirectly heats the biometric object receiving surface coupled to the adjacent surface of the electro-optical bioimaging capture device and coupled to the adjacent surface of the electro-optical bioimage capture device. Heater assembly. 29. The heater assembly of claim 28, wherein said first conductor and said second conductor are made of a conductive material. 36. The heater assembly of claim 35, wherein the conductive material is silver and copper. The method of claim 28, A first translucent pad connected to the first edge of the transparent conductive film, and And a second translucent pad connected to the second edge of the transparent conductive film. The method of claim 29, And a sensor for observing heat dissipated by the transparent conductive film, wherein the sensor is connected to the transparent conductive film and the control system. The method of claim 29, And a sensor for observing heat dissipated by the transparent conductive film, wherein the sensor is disposed near the transparent conductive film and connected to the control system. The method of claim 28, Further comprising a power transistor coupled between the first resistive element and the second resistive element, The first resistor element is connected to the first conductor, and the second resistor element is connected to the second conductor. The method of claim 40, And a zener diode element and a fuse element connected between a power source and said power transistor, The zener diode element serves to keep a bias voltage source of a thermostat controller constant, and the thermostat controller is connected between the first and second resistor elements to control the temperature in the transparent conductive film. A heater assembly. A system for capturing attributes of a biometric object, An electro-optical bioimaging capture device, and A heater assembly connected to the electro-optical bio-image capture device to improve performance of the electro-optical bio-image capture device, And the heater assembly heats the biometric object receiving surface of the electro-optical biometric image capture device to remove excess moisture in the vicinity of the biometric object placed on the biometric object receiving surface. (a) generating heat from a power source within a heater assembly coupled to the electro-optical bioimaging capture device, and (b) a halo effect is applied to the biological image by dispersing heat from the power source throughout the transparent conductive film in order to raise the temperature in the transparent conductive film to a predetermined temperature to remove excess moisture near the biometric object from which the image is captured. Preventing excess water in the vicinity of the biometric object from which the image is to be captured. The method of claim 43, (c) observing heat in said transparent conductive film to maintain a temperature at a predetermined value suitable for removing excess moisture in the vicinity of the biometric object receiving surface on the biometric object receiving surface. . A first heater assembly connected to the first end of the prism, and A second heater assembly connected to the second end of the prism, Each of the first heater assembly and the second heater assembly may include a heating element that raises a temperature in the prism to generate heat in the prism to prevent a halo effect from being formed in the image of the biometric object. Heating the prism of the electronic image capture device to prevent the halo effect from appearing in the image of the biometric object placed on the platen. The method of claim 45, And a thermostat controller for controlling the amount of heat provided by the first heater assembly and the second heater assembly. 47. The heating apparatus of claim 46, wherein the thermostat controller controls the amount of heat provided by each heater assembly as a function of heater assembly temperature. 47. The apparatus of claim 46, wherein the thermostat controller controls the amount of heat provided such that each heater assembly can operate in any one of three states: full power state, half power state, and no power state. Heating device. 49. The apparatus of claim 48, wherein the surface of the prism is a glass platen. 46. The heating device of claim 45, wherein the surface of the prism is a silicon pad. 46. A heating apparatus according to claim 45, wherein said heating element is a resistance heating element. (a) generating heat from a power source in a first heating element connected to the first side of the prism, (b) generating heat from a power source in a second heating element connected to the second side of the prism, and and (c) dispersing heat from the power source throughout the prism such that the biometric object receiving surface of the prism is heated to remove the halo effect from the captured biometric object. And heating the prism to remove water vapor in the vicinity of the biometric object from which the image placed on the biometric object receiving surface of the target is to be captured and to prevent the formation of water vapor. The method of claim 52, wherein And observing said dispersed heat to maintain the temperature at a predetermined value suitable for removing excess moisture in the vicinity of the biometric object receiving surface on the biometric object receiving surface.