CN102053384B - Speckle elimination device based on field emission deformation polymer - Google Patents

Abstract

The invention relates to the field of display technology using coherent light as a light source, in particular to a speckle elimination device based on field-induced deformation polymers, which solves the problems of poor speckle elimination effect and complicated structure in existing speckle elimination methods. , easily damaged, and high cost, the speckle elimination device based on field-induced deformation polymers includes a light pipe whose inner wall is a reflective mirror, field-induced deformation polymers arranged in the light pipe, and used to generate polymerization in the drive tube The actuating device for the external field required for object deformation; there is a gap between the field deformation polymer and the inner wall of the light pipe; the actuating device includes at least two external field application components arranged inside or outside the light pipe. The invention has the advantages of reasonable and compact structure, good speckle elimination effect, easy realization, low manufacturing cost, high laser utilization rate, stable performance, safety and reliability, and light uniformity function.

Description

Speckle Elimination Device Based on Field Deformable Polymer

technical field

The present invention relates to the field of display technology using coherent light as a light source, specifically a speckle elimination device based on field-induced deformation polymers, mainly aimed at the optical speckle phenomenon existing in laser display technology and optical instruments.

Background technique

When the laser is used as the light source to irradiate the screen, due to the coherence of the laser and the roughness of the screen, the human eye sees an image covered by speckle, which seriously affects the image display quality and prevents the observer from extracting useful information from the image. Therefore, how to eliminate speckle has always been a research and development hotspot in the field of optical instruments and display technology with laser as the light source. As far as the current research results are concerned, the methods used to eliminate speckle can be roughly divided into two categories: 1. Reduce speckle by controlling the temporal coherence of the laser light source. The principle is to adjust the laser wavelength (or frequency) and multi-wavelength light sources produce boiling speckle. At present, the technical solution to successfully eliminate the light spot by controlling the laser time coherence to meet the practical requirements is basically based on the superposition of multiple light sources; the current technical solution to successfully eliminate the light spot by controlling the laser time coherence to meet the practical requirements Basically, the superposition of multiple light sources is the main method; second, eliminating speckle by controlling the spatial coherence of the laser beam is the main method for eliminating speckle at present. Spatial distribution, multiple speckle images are superimposed within the integration time of the human eye to obtain an image with uniform light energy distribution, thereby achieving the purpose of eliminating speckles. Specific methods include: using rotating scatterers, vibrating screens, vibrating scatterers with Hadamard graphics, high-frequency vibration fibers, etc. The above methods require mechanical vibration, or even high-frequency or large-scale vibration, or integrate multiple light sources, resulting in complex structure, easy damage, high cost, and more importantly, poor speckle elimination effect. the

There are also technical solutions that do not rely on mechanical vibration. For example, the Chinese patent No. 200820122639.7 discloses "a decoherent shimming device based on scattering", which requires the use of particles containing particles whose diameter must be smaller than one-tenth of the wavelength of the incident light. Scattering media to achieve Rayleigh scattering of incident laser light. In the patent, inorganic salt or organic alcohol aqueous solution (such as NaCl, KCl, KNO ₃ or ZnSO ₄ aqueous solution) is used as the scattering medium, based on the existence form of inorganic salt or organic alcohol aqueous solution is hydrated ion or macromolecule, which is much smaller than the laser wavelength. Rayleigh scattering will be formed on the incident laser light, so as to realize the beam splitting of the incident laser light, and conduct it in the light pipe, in order to reduce the coherence of the incident laser light to eliminate speckle Homogenize to shim decoherence. However, according to the technical method described in the application, at room temperature, using a light guide with a length of only 50 mm and filled with a saturated NaCl aqueous solution to eliminate speckles, the results are shown in Figure 1. The speckle contrast is 70%, and there is almost no effect. to reduce speckle.

Contents of the invention

The present invention provides a speckle elimination device based on a field-induced deformation polymer in order to solve the problems of poor speckle elimination effect, complex structure, easy damage, and high cost existing in existing speckle elimination methods.

The present invention is achieved by adopting the following technical scheme: a speckle elimination device based on field-induced deformation polymers, including a light guide whose inner wall is a mirror surface, and a field-induced deformation polymer (this type of polymer) arranged in the light guide Driven by the corresponding external field, deformation will occur, the external field generally refers to electric field and magnetic field), an actuating device for generating the external field required to drive the deformation of the polymer in the tube; there is a gap between the field-induced deformation polymer and the inner wall of the light guide tube Gap; the actuating device includes at least two external field applying components arranged inside or outside the light pipe.

The field-deformable polymer is an electro-deformable polymer, and the corresponding actuating device is an electric field generator, and the external field application component of the electric field generator-paired electrode plates are arranged inside or outside the light guide tube;

The electrode plate placed in the light guide adopts a "mirror" electrode plate (that is, the surface of the electrode plate has high reflectivity characteristics and can "totally reflect" the laser beam incident in the light guide), and is fixed along the inner wall of the light guide;

The field-induced deformation type polymer is a magneto-induced deformation type polymer, and the corresponding actuating device is a magnetic field generating device, and the external field application component of the magnetic field generator-the electromagnet is arranged outside the light guide;

In application, as shown in Figures 2 and 3, the laser beam is expanded by an optical lens, and incident into the tube from one end of the light guide tube, partly transmitted through the polymer, reflected on the inner wall of the light guide tube, and then incident on the polymer; The internal reflection on the surface splits the beam into multiple beams with different intensities, and after multiple reflections and transmissions, it emerges from the other end of the light guide; during the transmission of the laser beam in the light guide, the corresponding external field is generated by the actuator , and control the order and intensity of the external field generated by its external field application components, and drive the field-induced deformation polymer in the light pipe to undergo a variety of continuous deformations, thereby changing the propagation direction and path of the incident laser beam in the light pipe after splitting, The phase distribution and the distribution of the exit angle of the outgoing light are changed randomly. After projection, the outgoing light with different phase distributions and exit angle distributions will generate a speckle image respectively; within the integration time of the human eye (50ms), multiple speckle images are superimposed to obtain a uniform light energy distribution. image, thereby achieving the purpose of eliminating speckle phenomenon.

Compared with the prior art, the present invention transmits laser light with a built-in light pipe of field-induced deformation polymer, and the laser beam is split during the transmission process due to the deformation of the polymer and the existence of the gap between the polymer and the inner wall of the light pipe , and generate an external field that drives the deformation of the field-induced deformation-like polymer through the corresponding actuator device, so that the field-induced deformation-like polymer is continuously deformed, causing the surface shape of the field-induced deformation-like polymer and the size of the gap between the inner wall of the light pipe Change, and then randomly change the propagation direction and path of the beam-splitting laser in the light guide, so that the laser incident into the light guide exits with different phase distributions and scattering angle distributions at different times; thus changing the speckle after projection Spatial distribution, so that multiple speckle images are superimposed within the integration time of the human eye to obtain an image with uniform light energy distribution, thereby effectively eliminating speckle. And after testing, after using the device of the present invention, the speckle contrast of the image can be lower than 4%, as shown in Figure 4, the speckle contrast of the image has been as low as 3.16%, and the speckle elimination effect is excellent; and can By controlling the actuating device, the deformation amount and deformation frequency of the field-induced deformation polymer can be increased to improve the effect of speckle elimination; in addition, because the inner wall of the light guide is a mirror surface with high reflectivity, the incident laser The overall light energy loss is very small, which ensures the high utilization rate of the laser, and achieves the purpose of uniform light during the transmission of the laser; each component of the device in the present invention is solid, and there is no liquid leakage or suspension settlement And other issues, stable performance, safe and reliable. In addition, the structure of the light pipe used in the present invention is very common, the field-induced deformation polymer is also very easy to obtain, and the corresponding actuating device is also very easy to manufacture, so it has the advantage of low manufacturing cost.

The present invention has reasonable and compact structure, good speckle elimination effect, easy realization, low cost, high laser utilization rate, stable performance, safety and reliability, and has light uniformity function.

Description of drawings

Fig. 1 is a concrete structural representation of the present invention;

Fig. 2 is a schematic diagram of the transmission state of the light beam in the device of the present invention when the field-induced deformation polymer is not deformed;

Fig. 3 is a schematic diagram of the transmission state of the light beam in the device of the present invention when the field-induced deformation polymer is deformed;

Fig. 4 is a diagram of test results obtained by using the device of the present invention to eliminate speckles;

Fig. 5 is a test result diagram obtained by using a prior art to eliminate speckles;

6 is a schematic diagram of the application of the device of the present invention in a point scanning display system;

FIG. 7 is a schematic diagram of the application of the device of the present invention in a full-frame display system;

In the figure: 101-incident laser;

200-external field application component;

300-speckle elimination device; 301-light pipe; 302-gap; 303-diffusion lens; 304, 305, 306-speckle elimination device;

400-field-induced deformation polymer;

501, 502, 503-lasers; 504, 505, 506-mirrors;

601, 602, 603-signal source;

700-lens; 701-relay lens; 702-light modulator DLP; 703-TIR prism; 704-relay lens; 705-TIR prism; 706-light modulator DLP; 707-relay lens; 708-plane mirror; 709-TIR prism; 710-light modulator DLP; 711-prism; 712-micro scanning mirror; 713, 714, 715-diffusion lens;

800-screen.

Detailed ways

As shown in Figure 1, the speckle elimination device based on field-induced deformation polymers includes a light pipe 301 whose inner wall is a mirror surface, and a field-induced deformation type polymer 400 (this type of polymer Under the driving of the corresponding external field, deformation will occur, and the external field generally refers to electric field and magnetic field), an actuating device for generating the external field required to drive the deformation of the polymer in the tube; between the field-induced deformation polymer 400 and the inner wall of the light pipe 301 A gap 302 is left; the actuating device includes at least two external field applying components 200 arranged inside or outside the light pipe 301 .

The field-deformable polymer 400 is an electro-deformable polymer, and the corresponding actuating device is an electric field generating device. The external field applying component 200 of the electric field generating device-paired electrode plates are arranged in the light guide tube 301 or the tube Outside; the electrode plate uses ITO electrodes, or metal electrodes, or grid-type actuation electrodes processed by MEMS technology.

The electrode plate placed in the light guide 301 adopts a "mirror" electrode plate (that is, the surface of the electrode plate has high reflectivity characteristics and can "totally reflect" the laser beam incident in the light guide), and is fixed along the inner wall of the light guide. the

The field-deformable polymer 400 is a magneto-deformable polymer, and the corresponding actuating device is a magnetic field generating device, and the external field applying component 200-electromagnet of the magnetic field generator is arranged outside the light pipe.

During specific implementation, the field-deformable polymer 400 should be selected from a high molecular polymer that does not absorb the incident laser wavelength band, such as PDMS (polydimethylsiloxane) gel. In order to effectively reduce the laser speckle contrast and improve the laser speckle elimination effect, the field-induced deformation polymer can be doped with particles that enhance its deformability, for example: PDMS gel doped with titanium dioxide particles—used as an electric Deformation polymer, PDMS gel doped with silica magnetic microspheres, or polystyrene magnetic microspheres, or ferroferric oxide magnetic microspheres, or ferroferric oxide magnetic microspheres—used as magnetotropic Deformable polymers; in addition, another benefit of doped particles: For example, the linearity of doped particles can cause Mie scattering of incident laser light to perform scattering beam splitting, and the scattered beam is also affected by the external field on field-induced deformation polymers , and randomly change its propagation direction and path in the light pipe, so that the phase distribution and exit angle distribution of the scattered light are randomly changed when it exits, which is more conducive to eliminating the speckle phenomenon.

The speckle elimination device of the present invention can be applied to laser projection display technology, for example, it can be applied to a point-scanning projection (Raster-Scanned Displays) system, as shown in FIG. 6 . The signal sources 601, 602, 603 respectively modulate the output power of the three primary color lasers 501, 502, 503 according to the information of each pixel on the two-dimensional image. The three-primary-color laser beams are simultaneously coupled into the speckle elimination device 300 of the present invention through the mirrors 504, 505, 506 and the diffusion lens 303. After being modulated, they are exported on the projection exit surface and projected through the lens 700 and the micro scanning mirror (Scan Mirror) 712. to screen 800. Driven by electrical signals, the micro scanning mirror 712 scans the two-dimensional image onto the screen 800 pixel by pixel. This application example is suitable for point-scanning laser projectors and laser TV displays.

As shown in Figure 7, it can be applied to a full-frame display projection (Full-Frame Displays) system. The three primary color lasers 501, 502, and 503 output constant power laser beams, which are coupled into the present invention through diffusion lenses 714, 713, and 715 respectively. Speckle reduction means 305 , 306 , 304 . After modulation, the relay lenses 701, 704, 707, plane mirrors 708 and TIR prisms 703, 705, 709 converge to light modulators DLP 702, 706, 710. DLP 702, 706, 710 modulates and generates a monochrome image according to the 2D image information of each frame. The three primary color images are blended by the prism 711 and projected onto the screen 800 by the lens 700 . This application example is suitable for laser projectors and laser TV displays based on light modulation devices such as DMD and LCOS.

Claims (8)

1. one kind causes the speckle cancellation element of deformation base polymer based on the field, it is characterized in that: comprise inwall be mirror surface light pipe (301), be arranged at causing deformation base polymer (400), be used to produce the actuating device in the required outfield of driving tube interpolymer deformation in the light pipe (301); The field causes between deformation base polymer (400) and light pipe (301) inwall leaves space (302); Said actuating device comprises at least two and is arranged in the light pipe (301) or the outer outfield of pipe applies assembly (200); Said field causes the high molecular polymer of deformation base polymer (400) for the incident laser wave band not being had absorb.

2. the speckle cancellation element that causes the deformation base polymer based on the field according to claim 1; It is characterized in that: said causes deformation base polymer (400) is the electroluminescent deformation base polymer; Corresponding actuating device is an electric field generation device, and the battery lead plate that the outfield of electric field generation device applies assembly (200)-be provided with in pairs is arranged in the light pipe or outside the pipe.

3. according to claim 2ly cause the speckle cancellation element of deformation base polymer based on the field, it is characterized in that: said battery lead plate adopts ITO electrode or metal electrode, or the grating type activation electrodes that obtains with the processing of MEMS technology.

4. according to claim 2ly cause the speckle cancellation element of deformation base polymer, it is characterized in that: place the battery lead plate in the light pipe (301) to adopt " minute surface " battery lead plate, fixedly install along the light pipe inwall based on the field.

5. the speckle cancellation element that causes the deformation base polymer based on the field according to claim 1; It is characterized in that: said causes deformation base polymer (400) is the magnetostriction base polymer; Corresponding actuating device is a field generator for magnetic, and the outfield of magnetic field generator applies assembly-electromagnet and is arranged at outside the light pipe.

6. according to claim 1ly cause the speckle cancellation element of deformation base polymer based on the field, it is characterized in that: said field causes deformation base polymer (400) and is doped with the particle that strengthens its deformability.

7. according to claim 5ly cause the speckle cancellation element of deformation base polymer based on the field, it is characterized in that: said magnetostriction base polymer adopts the PDMS gel that is doped with silicone dioxide magnetic microsphere or polystyrene magnetic microsphere or Fe 3 O 4 magnetic microballoon or di-iron trioxide magnetic microsphere.

8. according to claim 2ly cause the speckle cancellation element of deformation base polymer based on the field, it is characterized in that: said electroluminescent deformation base polymer adopts the PDMS gel that is doped with TiO 2 particles.

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