Self-heating temperature control system for palm/finger print instrument

Abstract

The invention relates to a self-heating temperature control system for a palm / finger print instrument. The self-heating temperature control system mainly comprises a temperature control optical component, a temperature control electronic component, an imaging optical component group and an image receiver; the temperature control optical component comprises a base layer, a conductive film layer anda protective layer; the conductive film layer is directly optically coated on the base layer and has high light transmittance and conductivity under an extremely thin thickness condition, that is, the conductive film layer can meet a self-heating requirement without effecting the overall optical path of the system; when the system works, light passes through the temperature control optical component, then passes through the imaging optical component group, and is ultimately imaged on the image receiver; the temperature control electronic component controls the conductive film layer so that the temperature of the temperature control optical component is within a suitable range, thus, the influence of environment temperature change on image resolution can be effectively eliminated, and fogon the surface of a collection surface under non-ideal ambient temperature can be effectively eliminated, and the stability of the palm / finger print instrument can be improved.

Description

technical field [0001] The invention belongs to the technical field of precision optical instruments, and relates to a self-heating temperature control system, in particular to a self-heating temperature control system for a palm fingerprint instrument. Background technique [0002] With the maturity of precision optical instruments and equipment, optical palm fingerprint devices are more and more widely used in people's daily life, but the impact of environmental temperature changes on imaging quality is increasingly restricting its application range and market development. The traditional palm fingerprint device is directly composed of an optical component group and an image receiver. The best image acquisition effect can only be achieved at room temperature. As the temperature changes, the imaging quality will continue to deteriorate, and even the surface of the acquisition surface is too foggy to Use; For example, due to the lower ambient temperature in winter in the nor...

AI Technical Summary

Problems solved by technology

[0002] With the maturity of precision optical instruments and equipment, optical palm fingerprint devices are more and more widely used in people's daily life, but the impact of environmental temperature changes on imaging quality is increasingly restricting its application range and market development.

The traditional palm fingerprint device is directly composed of an optical component group and an image receiver. The best image acquisition effect can only be achieved at room temperature. As the temperature changes, the imaging quality will continue to deteriorate, and even the surface of the acquisition surface is too foggy to Use; for example, due to the lower ambient temperature in winter in the north, the temperature of the prism of the fingerprint sensor drops, and the fog is generated after the human hand presses the collection surface, which reduces the image collection effect and even makes it impossible to recognize the palm fingerprint.

As the problem becomes more and more obvious, some methods to solve the influence of ambient temperature have appeared one after another: some palmprint collection systems attach heating modules on the surface of the collection prism which is not transparent to light, such as "Palmprint Defog System" (Application No. 201020662394.4) , although this kind of system can effectively eliminate the fog, it needs to add a fixing mechanism of the heating module, which is fixed outside the prism, which increases the volume of the system, and there is a hidden danger of high internal working temperature in the closed precision optical equipment

Some optical glasses with defogging function do not need to increase the volume of the system, but they cannot be used in the application field of palm fingerprint devices: such as "A Method for Making Conductive and Heating Defogging Glass" (application number 99113595.4), the conductive film layer of this kind of glass requires Attached to the plastic film, the refractive index inside the glass is not uniform. Since the optical palm fingerprint device has high requirements on the accuracy of the collection prism angle, the defogging glass made by this method cannot guarantee the image collection quality of the palm fingerprint device; another example is " A preparation method of defogging glass using electric heating wire to generate heat" (application number 99113594.6), this kind of glass needs to add metal heat conducting wire in the middle of the glass, even if the metal heat conducting wire can be made transparent as described, it will cause refraction inside the glass The rate is different, the optical path cannot be precisely controlled, and the image acquisition quality of the palm fingerprint sensor cannot be guaranteed

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