CN102865928A - Infrared image micro-scanning system based on electric-control birefringence effect - Google Patents

Abstract

The invention provides an infrared image micro-scanning system based on electric-control birefringence effect. The infrared image micro-scanning system based on the electric-control birefringence effect is mainly composed of an optical medium, a filtering portion, a power supply portion and a signal control portion. The optical medium with electrooptical effect is used, an appropriate external electric field is exerted on the medium so as to enable optical properties of the medium to be changed, electric induction birefringence effect is generated, a light beam of an infrared image generates small deflection after passing through the optical medium, and then an optical filter is used for filtrating the light which is not deflected. By controlling size and change cycle of the external electric field and thickness of the optical medium, 2*2 periodic micro-displacement of the infrared image is generated on an infrared detector array, and four undersampled low-resolution images are acquired so as to achieve micro-scanning of the infrared imaged. The infrared image micro-scanning system based on the electric-control birefringence effect can avoid difficulties of finish machining of a traditional mechanical micro-scanning device, and promotes development of the infrared imaging technology.

Description

Infrared image micro-scanning system based on electronically controlled birefringence effect

technical field

The invention belongs to the field of infrared thermal imaging technology, and specifically relates to an infrared image micro-scanning system based on electronically controlled birefringence effect, which is mainly used for biomedical microscopic thermal imaging, large-scale integrated circuit fault detection, and collection of military and meteorological remote sensing images.

Background technique

The existing micro-scanning methods mainly realize the movement of the image on the array by mechanical translation method, swing mirror method, plate rotation method and so on. The mechanical translation method includes a lens translation method and a detector translation method. It mainly uses a mechanical method to form a controllable displacement between the optical system and the detector to realize micro-scanning.

The known micro-scanning system includes the two-dimensional micro-scanner disclosed in Chinese patent 200580032739.x, which consists of two mirrors that can rotate around a fixed axis. The first mirror can scan the light beam in the first direction, and the second The result is a very miniaturized 2D scanner in which two individual mirrors are independent of each other, but can still be very close to each other, eliminating or at least reducing the image distortion. Chinese patent 200810130717.2 discloses a face element conversion micro-scanning display technology and the LED display module manufactured, which uses the combination of face element shape transformation and local micro-scanning to achieve high-resolution display with larger-scale pixel light-emitting devices. The resolution display technology can greatly break through the size limitation of the original pixel device, and obtain a high-resolution display device that is much higher than the constraints of the original pixel scale, and can be widely used in indoor and outdoor high-resolution display needs.

As another example, Chinese patent 200310111008.7 discloses a microscopic scanning platform, which consists of a base, an x-axis slider and its two-way moving traction mechanism, a Y-axis slider and its two-way moving traction mechanism, and an x-axis slider and its two-way moving traction mechanism. The traction mechanism is arranged on the Y-axis slider and moves integrally with the Y-axis slider. The Y-axis slider and its bidirectional movement traction mechanism are arranged on the base, and the Y-axis slider moves bidirectionally under the traction of its bidirectional movement traction mechanism. The mechanism of the Z-axis movement is further designed, which is composed of a Z-axis lifting assembly and a traction assembly, which are located between the base of the entire platform and the Y-axis slider. The device of the invention is independent of the microscope and is used for installation on the existing microscope, which can realize precise movement in three-dimensional space in the directions of X, Y and even Z axes, has high repeatability and low manufacturing cost. Chinese patent 200710100165.6 discloses a microscopic thermal imaging method based on an uncooled focal plane detector assembly, including: 1) imaging the radiation image of an object on an uncooled focal plane detector assembly through an infrared microscope objective lens; 2) uncooled focal plane detector assembly; The cooling focal plane detector assembly converts the radiation image into an electronic image, and outputs it as a standard video; 3) The image acquisition card converts the standard video thermal image into a digital image for storage; 4) Uses the scene-based adaptive non-uniformity correction method to digitally The image is non-uniformly corrected to reduce the fixed pattern noise of the image caused by the deviation of the detector sensitivity; 5) The microthermal image display, analysis, storage and other processing are performed on the corrected image. Because the uncooled focal plane detector assembly has the characteristics of high cost performance, no cooling, low power consumption, small size, and light weight, the cost of the thermal microscopic imaging system is greatly reduced, which can promote its application in various fields.

Most of the known micro-scanning imaging methods are still mechanical, and the micro-scanning of infrared images requires that the displacement of the infrared image in the infrared detection array is very small, so the mechanical micro-scanning method is theoretically feasible, but in practice It is very difficult to process. The use of the electric induction birefringence effect of the optical medium provides a non-mechanical micro-scanning method, and the production cost is greatly reduced, which can promote the application of infrared microscopic imaging in many fields.

Contents of the invention

The object of the present invention is to overcome the shortcomings of the above-mentioned existing scanning methods, and provide an infrared image micro-scanning system based on electronically controlled birefringence effect.

The infrared image micro-scanning system based on the electronically controlled birefringence effect provided by the present invention includes an optical medium part, a filter part, electrodes, a power supply part, a signal control part and an infrared detector array;

The electrodes include vertical electrodes installed on the upper and lower ends of the optical medium part and horizontal electrodes installed on the left and right ends of the optical medium part; the power supply part applies an external electric field of 4kv-5kv to the vertical electrodes and horizontal electrodes around the optical medium part , causing the optical medium part to produce an electro-induced birefringence effect, causing the infrared imaging beam to be deflected with a deflection distance of the order of microns after passing through the optical medium part, and then use the filter part to filter out the light that has not been deflected; The signal control part is connected with the power supply part. By controlling the size and change period of the external electric field, the infrared image will generate 2×2 periodic micro-displacement on the infrared detector array, and four under-sampled low-resolution images will be collected to realize the infrared Microscanning of images.

The scanning method of the present invention is a non-mechanical scanning, which uses the electric mass-induced birefringence effect of the optical medium to realize the micro-displacement of the infrared image on the infrared detector array, and micro-scans the infrared image.

The optical medium part can be liquid crystal or semiconductor material. The liquid crystal material used can be mixed with a liquid crystal material with a positive birefringence index of Δn>0 and a liquid crystal material with a negative birefringence index of Δn<0, and the liquid crystal material with a positive birefringence index and the liquid crystal material with a negative refractive index are mixed according to a certain ratio. mixed to prepare a liquid crystal material in which Δn does not vary with the wavelength of the incident light. The formulation formula is: Δn=χ ₁ Δn ₁ +χ ₂ Δn ₂ , where χ ₁ and χ ₂ are molar ratios.

The filter part is an infrared filter, and its function is to filter out the infrared light that passes through the optical medium part without light deflection. The infrared filter rotates to filter light according to the change in the direction of the micro-displacement of the infrared light on the infrared detector array, that is, when the infrared light is slightly displaced in the vertical direction, the infrared filter rotates in the vertical direction. In the direction, the light in the vertical direction is filtered. When the infrared light is slightly displaced in the horizontal direction, the infrared filter rotates in the horizontal direction to filter the light in the horizontal direction.

The power supply part varies according to the optical material of the optical medium part. When the optical medium part is liquid crystal, the power supply part provides a high-frequency AC voltage of 150Hz-200Hz; when the optical medium part is a semiconductor material, then The power supply part provides 1800V-2500V high-voltage direct current.

The signal control part controls the power supply part to provide vertically upward, vertically downward, horizontally leftward, horizontally rightward voltages to the vertical electrodes and horizontal electrodes respectively, so that the infrared image is generated on the infrared detector array with a 2×2 Periodic micro-displacement. In the case of a certain infrared detector array, according to the wavelength of the transmitted infrared light, the magnitude of the applied voltage and the distance between the optical medium and the detector are adjusted to realize the micro-movement of the infrared image on the infrared detector array. Yuan half of the micro-distance.

Advantages and beneficial effects of the present invention:

The infrared image micro-scanning system based on the electronically controlled birefringence effect was proposed after investigating the known micro-scanning methods and the design ideas of the micro-scanning system. The traditional micro-scanning methods are all mechanical, although they are theoretically feasible. Yes, however, since the micro-displacement of the infrared image on the arrayed infrared detector array is generally on the order of microns, the machining of mechanical parts must be fine machining, which is relatively difficult to process, and in the process of taking pictures It is not easy to control, so it is not good to use mechanical micro-scanning. The infrared image micro-scanning system based on the electronically controlled birefringence effect uses the electro-optic effect of some optical media to apply an appropriate external electric field to the optical media to cause the media to produce an electro-induced birefringence effect, so that the infrared beam of the object passes through the optical media. Afterwards, a small deflection is generated, so that the infrared image produces a 2×2 periodic micro-displacement on the infrared detector array, and the micro-scanning of the infrared image can be realized, which can avoid the difficulty of finishing the traditional mechanical micro-scanning device, and is easy to implement with a program For the control of the shooting process, the structure is simple, the weight is light, the volume is small, and the production cost is relatively low.

Description of drawings

Figure 1 is a schematic diagram of an infrared image micro-scanning system based on the electronically controlled birefringence effect;

Fig. 2 is a voltage change diagram of an infrared image micro-scanning system based on the electronically controlled birefringence effect;

Fig. 3 is a scanning process diagram of the infrared image micro-scanning system based on the electronically controlled birefringence effect.

In the figure, 1 is an optical medium part, 2 is a power supply part, 3 is a signal control part, 4 is a filter part, 5 is an electrode, and 6 is an infrared detector array.

Detailed ways

Combining with the principle diagram and scanning process diagram of the infrared image micro-scanning system based on the electronically controlled birefringence effect, the characteristics and effects of the infrared image micro-scanning system based on the electronically controlled birefringence effect will be introduced in detail for the embodiment proposed according to the present invention. .

As shown in Figure 1, the infrared image micro-scanning system based on electronically controlled birefringence effect is composed of six parts: optical medium 1, power supply part 2, signal control part 3, filter part 4, electrode 5 and infrared detector array 6.

The system is realized by using the electro-optical effect of some optical media 1, the signal control part 3 controls the power supply part 2 to apply an external electric field of 4kv-5kv to the optical medium, so that the optical properties of the medium change, and the electro-induced birefringence effect is generated. Make the beam of the infrared image pass through the optical medium to produce micron-scale deflection, and then the filter part 4 filters out the undeflected light. According to different needs, it can control the size and change period of the external electric field and adjust the optical medium. Thickness, so that the infrared image generates 2×2 periodic micro-displacement on the infrared detector array 6, and collects 4 under-sampled low-resolution images in each period, and then performs image fusion on these four images to realize the micro-displacement of the infrared image. scanning.

The specific process is as follows:

As shown in Figure 2, the signal control part 3 controls the power supply part 2 to alternately supply power to the vertical direction and the horizontal direction, and the voltages of the two pairs of electrodes 5 in the vertical and horizontal directions change 4 times in one cycle, and in the first T/ Within 4 cycles, the upper electrode in the vertical direction is at low voltage, the lower electrode in the vertical direction is at low voltage, the left electrode in the horizontal direction is at low voltage, and the right electrode in the horizontal direction is at low voltage. At this time, the optical medium is not in the electric field, and the filter part 4 At this time, the infrared light passing through the optical medium is not filtered, and the infrared image on the infrared detector array is not slightly displaced at this time.

In the second T/4 period, the electrode in the vertical direction is at high voltage, the electrode at the bottom is at low voltage in the vertical direction, the left electrode is at low voltage in the horizontal direction, and the right electrode in the horizontal direction is at low voltage. At this time, the optical medium is at the vertical In the electric field in the vertical direction, the filter part 4 filters the undeflected infrared light passing through the optical medium at this time, and at this time, the infrared image on the infrared detector array is slightly displaced downward in the vertical direction.

In the third T/4 cycle, the vertical electrode is at high voltage, the vertical electrode is at low voltage, the horizontal left electrode is at low voltage, and the horizontal right electrode is at high voltage. At this time, the optical medium is at the same time In the electric fields in the vertical and horizontal directions, the filter part 4 filters the infrared light that has not been deflected through the optical medium at this time, and at this time, the infrared image on the infrared detector array moves horizontally to the left on the basis of the above Make micro shifts.

In the fourth T/4 period, the electrode in the vertical direction is at low voltage, the electrode in the vertical direction is at low voltage, the left electrode in the horizontal direction is at low voltage, and the right electrode in the horizontal direction is at high voltage. At this time, the optical medium is at the level In the electric field in the direction, the filter part 4 filters the infrared light that has not been deflected through the optical medium at this time. At this time, the infrared image on the infrared detector array is slightly displaced vertically upward on the basis of the above. (The specific movement process of the image is shown in Figure 3); in this way, the signal control part 3 controls the power supply part 2 to apply a periodically changing external electric field to the optical medium 1, so that the infrared image is displayed on the infrared detector 6 array in the vertical and horizontal directions Generate 2×2 periodic micro-displacement, collect 4 under-sampled low-resolution images, and then fuse these four images, thus realizing micro-scanning of infrared images.

The present invention has different requirements for the resolution of infrared images for different application fields. By setting the signal control part, 9 or even 16 infrared images can be captured in one cycle, and then the infrared images captured in one cycle can be fused to obtain Higher-resolution infrared images meet the requirements for image resolution in different fields.

After the implementation is described in detail, those familiar with this technology can clearly understand that various changes and modifications can be made without departing from the scope of the above-mentioned patent application, and the present invention is not limited to the examples listed in the description. implementation.

Claims (8)

1. the infrared image micro scanning system based on electro-optic birefringent effect is characterized in that this system comprises optical medium part, optical filtering part, electrode, power pack, signal controlling part and infrared detector array;

Described electrode comprise be installed in optical medium part up and down two ends vertical electrode and be installed in the horizontal electrode at two ends, the optical medium part left and right sides; The external electric field that power pack applies a 4kv-5kv to the vertical electrode around the optical medium part and horizontal electrode, make optical medium partly produce electricity and cause the induced birefringence effect, the light beam that makes infrared imaging produces the deviation distance after through this optical medium part and be the deviation of micron number magnitude, and the light that then with optical filtering deviation will not occur partly filters; The signal controlling part is connected with power pack, size and period of change by the control external electric field, make infrared image produce 2 * 2 periodic micrometric displacements at infrared detector array, gather 4 width of cloth and owe the low-resolution image of sampling, realize the micro scanning to infrared image.

2. system according to claim 1 is characterized in that described optical medium partly is liquid crystal or semiconductor material.

3. system according to claim 1 is characterized in that described optical filtering part is infrared fileter, and effect is that the Infrared that will deflection of light not occur by the optical medium part filters.

4. system according to claim 2, it is characterized in that: described power pack changes according to the difference of optical medium part optical material, and when optical medium partly was liquid crystal, then power pack provided the high-frequency ac voltage of 150Hz-200Hz; When optical medium partly was semiconductor material, then power pack provided the periodic high voltage direct current of 1800V-2500V.

5. system according to claim 4, it is characterized in that: in the situation that infrared detector array is certain, according to saturating infrared light wavelength, according to the relation between the image, adjust the distance between optical medium and the detector, realize the micrometric displacement that infrared image requires at infrared detector array, distance is half of detector array elemental size.

6. system according to claim 1, it is characterized in that described signal controlling partly control power pack respectively to vertical electrode and horizontal electrode provide straight up, straight down, level left, level voltage to the right, make infrared image produce 2 * 2 periodic micrometric displacements at infrared detector array.

7. system according to claim 2, it is characterized in that: used liquid crystal material uses Δ n〉0 the liquid crystal material with positive birefringence is mixed mutually with the liquid crystal material with negative birefringence rate of Δ n＜0, modulate in proportion the liquid crystal material that Δ n does not change with lambda1-wavelength, allotment formula: Δ n=χ ₁Δ n ₁+ χ ₂Δ n ₂, χ wherein ₁, χ ₂Be mol ratio.

8. system according to claim 3, it is characterized in that variation that described infrared fileter at infrared detector array the direction of micrometric displacement occurs according to Infrared is rotated filters, namely when infrared light during at vertical direction generation micrometric displacement, infrared fileter rotates in the vertical direction, light on the vertical direction is filtered, when infrared light in the horizontal direction micrometric displacement occured, infrared fileter rotated in the horizontal direction, and the light on the horizontal direction is filtered.

Images