CN102854737B - Three-dimensional image-taking device - Google Patents

Abstract

The invention relates to a three-dimensional imaging device, which includes two imaging units and a processing unit, each imaging unit includes a lens module and a sensor, the lens module includes a liquid crystal lens and a driving unit, and the liquid crystal lens includes a first light-transmitting substrate, a second Two light-transmitting substrates, a first electrode layer, a second electrode layer, and a liquid crystal layer, the first electrode layer and the second electrode layer are respectively arranged on the first light-transmitting substrate and the second light-transmitting substrate, and the first electrode layer includes a plurality of The ring electrode, the liquid crystal layer includes a plurality of ring regions respectively located between the plurality of ring electrodes and the second electrode layer, and the drive unit respectively applies a voltage between the ring electrodes and the second electrode layer to change the radial direction of the liquid crystal lens. Its refractive index, the sensor forms an image, and the processing unit receives two images formed by the two sensors and synthesizes a stereoscopic image and controls the drive unit to apply voltage.

Description

Stereo imaging device

technical field

The invention relates to a stereo imaging device.

Background technique

A stereo imaging device generally includes a lens module for guiding incident light. The lens module realizes the change of the focal length of the lens module by changing the relative positions of the lenses in the lens module, so that the scene in the image can be enlarged or reduced.

However, the movement of each lens needs to be driven by an additional driving device, such as a motor and related structures, which makes the structure of the lens module more complicated, which is not conducive to the miniaturization and portability of the stereo imaging device.

Contents of the invention

In view of this, it is necessary to provide a stereo imaging device with a variable focus lens module and a simple structure, so as to facilitate the miniaturization and portability of the stereo imaging device.

A stereoscopic imaging device, which includes two mutually spaced imaging units and an image processing unit electrically connected to the two imaging units, each imaging unit includes a lens module and an image located on the image side of the lens module sensor, the lens module includes a lens barrel, a liquid crystal lens arranged in the lens barrel and a drive unit electrically connected to the liquid crystal lens, the liquid crystal lens includes a first light-transmitting substrate, a second light-transmitting substrate, a first electrode layer, The second electrode layer and the liquid crystal layer arranged between the first light-transmitting substrate and the second light-transmitting substrate, the first electrode layer is arranged on the first light-transmitting substrate, the second electrode layer is arranged on the first light-transmitting substrate On two light-transmitting substrates, the driving unit is electrically connected to the first electrode layer, the second electrode layer and the image processing unit, the first electrode layer includes a plurality of mutually insulated concentric annular electrodes, and the liquid crystal layer includes respectively distribution density of liquid crystal molecules in the middle liquid crystal region and the plurality of ring liquid crystal regions located between the plurality of ring electrodes and the second electrode layer and the plurality of ring liquid crystal regions gradually away from the middle liquid crystal region gradually increasing from the middle liquid crystal region to a direction away from the middle liquid crystal region, and the drive unit is used to respectively apply voltages between the plurality of annular electrodes and the second electrode layer to change the liquid crystal lens along the radial direction of the liquid crystal lens Refractive index, the image sensor is used to receive light passing through the liquid crystal lens to form an image, the image processing unit is used to receive two images formed by the two image sensors and synthesize a stereoscopic image and to control the drive voltage applied to the unit.

Compared with the prior art, the stereo imaging device provided by the present invention can make the liquid crystal layer between the first electrode layer and the second electrode layer The refractive index can be distributed in a gradient, so that lenses with different refractive index gradients can be formed to realize the zooming of the liquid crystal lens, which reduces the driving device used to drive the lens to move in the prior art, and makes the structure of the lens module and the stereoscopic imaging device It is simple, and thus beneficial to the miniaturization and portability of the stereo imaging device.

Description of drawings

FIG. 1 is a schematic structural diagram of a stereoscopic imaging device including a liquid crystal lens provided in a first embodiment of the present invention.

FIG. 2 is a schematic structural diagram of a liquid crystal lens in FIG. 1 .

FIG. 3 is a top view along the liquid crystal lens of FIG. 2 .

FIG. 4 is a schematic structural diagram of another liquid crystal lens in FIG. 1 .

FIG. 5 is a top view along the liquid crystal lens of FIG. 4 .

FIG. 6 is a schematic structural diagram of a stereoscopic imaging device including a liquid crystal lens provided in a second embodiment of the present invention.

FIG. 7 is a schematic structural diagram of the liquid crystal lens in FIG. 6 .

FIG. 8 is a schematic structural diagram of a stereo imaging device provided by a third embodiment of the present invention.

Explanation of main component symbols

Stereo imaging device 100, 600, 700 Image acquisition unit 11, 12 image processing unit 13 circuit board 14 lens module 110, 510, 810 image sensor 112,512 lens barrel 210,710 mirror mount 211 first spacer 212,712

second spacer 213 lens group 214 Infrared cut filter 215,715 Drive unit 244,544 LCD lens 141,741 optical lens 142 Clear hole 216 first light-transmitting substrate 240,640 Second transparent substrate 241,641 first electrode layer 242,642 second electrode layer 243,643 liquid crystal layer 245 The outer surface 401, 411 The inner surface 402, 412, 602, 612 middle electrode 420, 520 ring electrode 421, 422, 423, 424, 521, 522, 523, 524 middle liquid crystal area 450 Circular Liquid Crystal Region 451, 452, 453, 454

The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings.

detailed description

The embodiments provided by the present invention will be further described in detail below in conjunction with the accompanying drawings.

Please refer to Fig. 1 to Fig. 5 together, the stereo imaging device 100 provided by the first embodiment of the present invention includes two mutually spaced imaging units 11, 12 (hereinafter referred to as the first imaging unit 11 and the second imaging unit 12) Electrically connect to the image processing unit 13 and the circuit board 14 of the two image capturing units 11 and 12 .

The first image capturing unit 11 includes a lens module 110 and an image sensor 112 located on the image side of the lens module 110 . The lens module 110 includes a lens barrel 210 , a lens base 211 , a first spacer 212 , a second spacer 213 , a lens group 214 , an infrared cut filter 215 and a driving unit 244 . The lens group 214 includes a liquid crystal lens 141 and an optical lens 142 , and the driving unit 244 is electrically connected to the liquid crystal lens 141 . The optical lens 142 is made of plastic or glass. The lens barrel 210 and the lens base 211 are screwed and fixed to each other. A light hole 216 is defined at the top of the lens barrel 210 .

The liquid crystal lens 141, the first spacer 212, the optical lens 142, the second spacer 213 and the infrared cut filter 215 are all housed in the lens barrel 210 and arranged in sequence along the direction from the object side to the image side of the lens module 110 .

The liquid crystal lens 141 includes a first transparent substrate 240 , a second transparent substrate 241 , a first electrode layer 242 , a second electrode layer 243 and a liquid crystal layer 245 .

The liquid crystal layer 245 is disposed between the first transparent substrate 240 and the second transparent substrate 241 . The first transparent substrate 240 is substantially parallel to the second transparent substrate 241 . Materials of the first light-transmitting substrate 240 and the second light-transmitting substrate 241 can be selected from glass or light-transmitting plastic.

The first transparent substrate 240 includes an outer surface 401 and an inner surface 402 located on opposite sides of the first transparent substrate 240 , and the first electrode layer 242 is disposed on the outer surface 401 . The first electrode layer 242 includes an intermediate electrode 420 located in the middle of the liquid crystal lens 141 and four ring-shaped electrodes 421, 422, 423, 424 concentric with the intermediate electrode 420 (hereinafter referred to as the first ring-shaped electrode 421, the second ring electrode 420). shape electrode 422, the third ring electrode 423 and the fourth ring electrode 424). The middle electrode 420 is located in the innermost ring electrode 421 of the first electrode layer 242 , that is, the first ring electrode 421 . In this embodiment, the middle electrode 420 is circular, and the four ring electrodes 421 , 422 , 423 , 424 are all circular.

The radius of the middle electrode 420 is smaller than the inner diameter of the first annular electrode 421 . The intermediate electrode 420 and the ring electrodes 421 , 422 , 423 , 424 are insulated from each other. The radius of the intermediate electrode 420 and the width of the annular electrodes 421, 422, 423, 424 along the radial direction of the liquid crystal lens 141 gradually decrease from the center to the edge of the liquid crystal lens 141, that is, R>L1>L2>L3>L4, wherein , R represents the radius of the middle electrode 420, L1, L2, L3 and L4 respectively represent the first ring electrode 421, the second ring electrode 422, the third ring electrode 423 and the fourth ring electrode 424 along the radius of the liquid crystal lens 141 direction width. In this embodiment, two adjacent electrodes are closely arranged but insulated from each other, for example, separated from each other by insulating glue. It can be understood that in practical applications, there may be a small gap between two adjacent electrodes, as long as the overall optical performance of the liquid crystal lens 141 is not affected.

The second transparent substrate 241 includes an outer surface 411 and an inner surface 412 located on opposite sides of the second transparent substrate 241 . The second electrode layer 243 is disposed on the outer surface 411 . The second electrode layer 243 is a flat electrode layer. Materials of the first electrode layer 242 and the second electrode layer 243 can be selected from indium tin oxide (ITO) or carbon nanotube film. The carbon nanotube film includes single-walled carbon nanotubes (Single-walledCarbonNanotube, SWNT), multi-walled carbon nanotubes (Multi-walledCarbonNanotube, MWNT), single-walled carbon nanotube bundles (SWNTBundles), multi-walled carbon nanotubes Tube bundles (MWNTBundles) or super-aligned MWNTYarns, etc.

The liquid crystal layer 245 includes a middle liquid crystal region 450 and four ring-shaped liquid crystal regions 451, 452, 453 and 454 (hereinafter referred to as the first ring-shaped liquid crystal region 451, the second ring-shaped liquid crystal region 452, the third ring-shaped liquid crystal region 453 and the Tetracyclic liquid crystal region 454). The middle liquid crystal region 450 corresponds to the liquid crystal region between the middle electrode 420 and the second electrode layer 243, the first annular liquid crystal region 451 corresponds to the liquid crystal region between the first annular electrode 421 and the second electrode layer 243, and the first annular liquid crystal region 451 corresponds to the liquid crystal region between the first annular electrode 421 and the second electrode layer 243. The second ring-shaped liquid crystal region 452 corresponds to the liquid crystal region between the second ring-shaped electrode 422 and the second electrode layer 243, and the third ring-shaped liquid crystal region 453 corresponds to the liquid crystal region between the third ring-shaped electrode 423 and the second electrode layer 243. The liquid crystal region, the fourth ring-shaped liquid crystal region 454 corresponds to the liquid crystal region between the fourth ring-shaped electrode 424 and the second electrode layer 243 . In this embodiment, the distribution density of liquid crystal molecules in the liquid crystal layer 245 is from the middle liquid crystal region 450 to the first ring liquid crystal region 451, the second ring liquid crystal region 452, the third ring liquid crystal region 453, and the fourth ring liquid crystal region. 454 gradually increases.

The driving unit 244 is electrically connected to the first electrode layer 242 , the second electrode layer 243 and the image processing unit 13 . Specifically, the driving unit 244 is electrically connected to the middle electrode 420 and the four ring electrodes 421 , 422 , 423 and 424 respectively. The drive unit 244 is used between the intermediate electrode 420 and the second electrode layer 243, between the first ring electrode 421 and the second electrode layer 243, between the second ring electrode 422 and the second electrode layer 243, and between the third ring electrode Voltages are applied between 423 and the second electrode layer 243 and between the fourth ring electrode 424 and the second electrode layer 243 to change the refractive index of the liquid crystal lens 141 along the radial direction of the liquid crystal lens 141 .

When in use, the drive unit 244 drives between the middle electrode 420 and the second electrode layer 243, between the first ring-shaped electrode 421 and the second electrode layer 243, between the second ring-shaped electrode 422 and the second electrode layer 243, and between the third ring-shaped electrode 420 and the second electrode layer 243. Voltages are respectively applied between the electrode 423 and the second electrode layer 243 and between the fourth annular electrode 424 and the second electrode layer 243, and each applied voltage is greater than that of the liquid crystal layer 245 corresponding to each electrode 420, 421, 422, 423, 424 and Threshold voltages of the liquid crystal regions 450 , 451 , 452 , 453 , 454 between the second electrode layer 422 . The middle liquid crystal region 450 , the first annular liquid crystal region 451 , the second annular liquid crystal region 452 , the third annular liquid crystal region 453 and the fourth annular liquid crystal region 454 are respectively located in the electric field generated by the corresponding voltage. Because each of the above-mentioned voltages is greater than the threshold voltage of each liquid crystal region corresponding to the liquid crystal layer 245, that is, greater than the deflection voltage of the liquid crystal molecules in the liquid crystal layer 245, the liquid crystal molecules will deflect. Properly controlling the distribution of the voltage can make the deflection angle of the liquid crystal molecules The liquid crystal lens 141 has a gradient distribution from the center to the edge.

When the lengthwise orientation of the liquid crystal molecules has the above-mentioned deflection angle with respect to the propagation direction of light, the deflection angle is different, and the refractive index is also different. When the length direction of the liquid crystal molecules changes from parallel to the direction of light propagation to perpendicular to the direction of light propagation, the refractive index of the liquid crystal layer gradually increases; when the length direction of the liquid crystal molecules is parallel to the direction of light propagation, the refractive index of the liquid crystal layer Minimum, when the length direction of liquid crystal molecules is perpendicular to the direction of light propagation, the refractive index of the liquid crystal layer is maximum. Therefore, between the intermediate electrode 420 and the second electrode layer 243, between the first ring-shaped electrode 421 and the second electrode layer 243, between the second ring-shaped electrode 422 and the second electrode layer 243, between the third ring-shaped electrode 423 and the first electrode layer Appropriate voltages are respectively applied between the two electrode layers 243 and between the fourth annular electrode 424 and the second electrode layer 243 to make the middle liquid crystal region 450, the first annular liquid crystal region 451, the second annular liquid crystal region 452, and the third annular liquid crystal region The included angle (that is, the deflection angle) formed by the length direction of the liquid crystal molecules in the ring-shaped liquid crystal region 453 and the fourth ring-shaped liquid crystal region 454 and the light propagation direction changes correspondingly, and then the refractive index of the middle liquid crystal region 450, the second The refractive index of the first annular liquid crystal region 451 , the refractive index of the second annular liquid crystal region 452 , the refractive index of the third annular liquid crystal region 453 and the refractive index of the fourth annular liquid crystal region 454 present a corresponding distribution.

If it is necessary to form a liquid crystal lens 141 (GRINLens) with a gradient refractive index along the center to the edge, the driving unit 244 is located between the middle electrode 420 and the second electrode layer 243, between the first ring-shaped electrode 421 and the second electrode layer 243, and between the second electrode layer 243. Corresponding voltages are applied between the ring electrode 422 and the second electrode layer 243, between the third ring electrode 423 and the second electrode layer 243, and between the fourth ring electrode 424 and the second electrode layer 243, so that the middle liquid crystal region 450 The refractive index of the first annular liquid crystal region 451, the refractive index of the second annular liquid crystal region 452, the refractive index of the third annular liquid crystal region 453 and the refractive index of the fourth annular liquid crystal region 454 are in a gradient distribution . Therefore, the refractive index of the liquid crystal lens 141 may gradually increase from the center to the edge of the liquid crystal lens 141 , or gradually decrease from the center to the edge of the liquid crystal lens 141 .

It can be seen from the above that the focal length of the liquid crystal lens 141 can be applied between the intermediate electrode 420 and the second electrode layer 243, between the first ring electrode 421 and the second electrode layer 243, and between the second ring electrode 422 and the second electrode layer 243. between the third ring-shaped electrode 423 and the second electrode layer 243 and between the fourth ring-shaped electrode 424 and the second electrode layer 243 to control.

Both the mirror base 211 and the image sensor 112 are disposed on the circuit board 14 , and the mirror base 211 and the circuit board 14 package the image sensor 112 . The image sensor 112 is electrically connected to the circuit board 14 . The image sensor 112 is used for receiving the light passing through the aperture 216 and the lens group 214 to form an image. The image sensor 112 can be selected from a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor device (CMOS) with 5 million, 8 million, 12 million, 16 million, 20 million or 100 million pixels ( Megapixel), and the pixel size (Pixelsize) can be 1.75, 1.4, 1.1, 0.9, 0.8 or 0.6 microns. In addition, the complementary metal oxide semiconductor device (CMOS) type image sensor 112 has power saving characteristics.

The structure of the second image capturing unit 12 is the same as that of the first image capturing unit 11 , and will not be repeated here. Please refer to Figures 4-5, the following lists only the components and labels of the second imaging unit 12 used in the subsequent description: lens module 510, image sensor 512, drive unit 544, second electrode layer 543, intermediate electrode 520 , a first ring electrode 521 , a second ring electrode 522 , a third ring electrode 523 , and a fourth ring electrode 524 .

The distance H between the optical axes O1 and O2 of the two lens modules 110 and 510 ranges from 25 to 40 millimeters (mm). In this embodiment, the distance H is 32.5 mm.

The image processing unit 13 and the driving unit 244 are disposed on the circuit board 14 and electrically connected to the circuit board 14 . The image processing unit 13 is also electrically connected to the two image sensors 112, 512 and is used to receive two images formed by the two image sensors 112, 512 to synthesize a stereoscopic image and to control the drive unit 244, 544 in the middle Between the electrodes 420, 520 and the second electrode layers 243, 543, between the first annular electrodes 421, 521 and the second electrode layers 243, 543, between the second annular electrodes 422, 522 and the second electrode layers 243, 543, Voltages are applied between the third ring electrodes 423 , 523 and the second electrode layers 243 , 543 and between the fourth ring electrodes 424 , 524 and the second electrode layers 243 , 543 . Wherein, the second image capturing unit 12 includes a driving unit 544, an intermediate electrode 520, a second electrode layer 543, a first ring electrode 521, a second ring electrode 522, a third ring electrode 523 and a fourth ring electrode 524 .

The stereoscopic image synthesis of the image processing unit 13 can adopt a known stereoscopic image synthesis method, and the stereoscopic image output format of the image processing unit 13 can be a side-by-side format or other formats.

The stereo imaging device 100 provided by the present invention can control the voltage applied between the plurality of annular electrodes and the second electrode layer, so that the refractive index of the liquid crystal layer between the first electrode layer and the second electrode layer can be Gradient distribution, so that lenses with different refractive index gradients can be formed to realize the zooming of the liquid crystal lens, reducing the driving device and structure used to drive the lens to move in the prior art, such as motors, so that the lens module and the stereoscopic imaging device 100 The structure is simple, which is beneficial to the miniaturization and portability of the stereo imaging device 100 . In addition, compared to the power consumption of the existing driving device, the power consumption of the liquid crystal lens is much smaller, and the stereo imaging device 100 can use more power for other aspects, such as more power to allow stereo imaging The shooting frame rate of the device 100 when shooting stereoscopic video has a large dynamic range, such as up to 10-90 fps, preferably 20-40 fps.

Please refer to FIG. 6 and FIG. 7 in conjunction with FIG. 1 , a stereo imaging device 600 provided in the second embodiment of the present invention is different from the stereo imaging device 100 in the first embodiment in that the first electrode layer 642 is disposed on On the inner surface 602 of the first transparent substrate 640 , the second electrode layer 643 is disposed on the inner surface 612 of the second transparent substrate 641 .

Please refer to FIG. 8 , a stereo imaging device 700 provided in the third embodiment of the present invention is different from the stereo imaging device 100 in the first embodiment in that the lens barrel 710 is provided with only one liquid crystal lens 741 and no other optical lens 741 is provided. lens. In this case, the second spacer can be omitted, and the liquid crystal lens 741 , the first spacer 712 and the infrared cut filter 715 are sequentially arranged along the direction from the object side to the image side of the lens module 810 .

It can be understood that, in other embodiments, the first electrode layer can be disposed on the inner surface of the first transparent substrate, and the second electrode layer can be disposed on the outer surface of the second transparent substrate; the first electrode layer can be disposed on the The outer surface of the first transparent substrate, and the second electrode layer is disposed on the inner surface of the second transparent substrate. The number of ring-shaped electrodes can also be 2, 3, 5 or more, and the ring-shaped electrodes can be in the shape of a square ring or other shapes; the middle electrode can be omitted so that the inner surface and the outer surface of the middle position of the first transparent substrate are not provided The electrodes make the liquid crystal lens and the liquid crystal region corresponding to the intermediate position have a constant refractive index. The distribution density of liquid crystal molecules in the liquid crystal layer can gradually decrease from the middle liquid crystal region to the first ring liquid crystal region, the second ring liquid crystal region, the third ring liquid crystal region and the fourth ring liquid crystal region. The number of circuit boards may be 2, and each circuit board is correspondingly provided with an image sensor. The image processing unit and the image sensor can be separately arranged on different circuit boards, as long as the image transmission between the image processing unit and the image sensor can be ensured. The drive unit can also be placed in a place other than the circuit board, such as on the lens barrel or lens base, as long as the drive unit can be electrically connected to the liquid crystal lens, image processing unit and other components. .

In addition, those skilled in the art can also make other changes within the spirit of the present invention. Of course, these changes made according to the spirit of the present invention should all be included within the scope of protection claimed by the present invention.

Claims (10)

1. A three-dimensional imaging device, comprising two imaging units spaced apart from each other and an image processing unit electrically connected to the two imaging units, each imaging unit comprising a lens module and being positioned at the image side of the lens module The image sensor of the lens module includes a lens barrel, a liquid crystal lens arranged in the lens barrel, and a drive unit electrically connected to the liquid crystal lens, and the liquid crystal lens includes a first light-transmitting substrate, a second light-transmitting substrate, and a first electrode layer, a second electrode layer, and a liquid crystal layer disposed between the first transparent substrate and the second transparent substrate, the first electrode layer is disposed on the first transparent substrate, and the second electrode layer is disposed on the On the second transparent substrate, the drive unit is electrically connected to the first electrode layer, the second electrode layer and the image processing unit, the first electrode layer includes a plurality of mutually insulated concentric annular electrodes, and the liquid crystal layer It includes an intermediate liquid crystal region located between the plurality of annular electrodes and the second electrode layer and a plurality of annular liquid crystal regions gradually away from the intermediate liquid crystal region, the liquid crystal molecules in the intermediate liquid crystal region and the plurality of annular liquid crystal regions The distribution density gradually increases from the middle liquid crystal region to the direction away from the middle liquid crystal region, and the drive unit is used to apply voltages between the plurality of annular electrodes and the second electrode layer to change the radial direction of the liquid crystal lens. The refractive index of the liquid crystal lens, the image sensor is used to receive light passing through the liquid crystal lens to form an image, and the image processing unit is used to receive two images formed by the two image sensors and synthesize a stereoscopic image and to control The drive unit applies voltage. 2. The stereo imaging device according to claim 1, wherein the first electrode layer further comprises an intermediate electrode located in the innermost annular electrode of the first electrode layer, and the intermediate electrode is connected to the plurality of annular electrodes. The shape electrode is concentric and mutually insulated from the plurality of ring electrodes, and the radius of the middle electrode is smaller than the inner diameter of the innermost ring electrode. 3. The stereoscopic imaging device according to claim 2, wherein the radius of the intermediate electrode and the width of the plurality of concentric ring electrodes along the radial direction of the liquid crystal lens gradually decrease from the center of the liquid crystal lens to the edge . 4. The stereoscopic imaging device according to claim 1, wherein the refractive index of the plurality of liquid crystal regions gradually increases from the center to the edge of the liquid crystal lens. 5. The stereo imaging device according to claim 1, wherein the refractive index of the plurality of liquid crystal regions gradually decreases from the center to the edge of the liquid crystal lens. 6 . The stereo imaging device according to claim 1 , wherein the image sensor is a charge coupled device or a complementary metal oxide semiconductor device. 7. The stereoscopic imaging device according to claim 1, wherein the distance between the optical axes of the two lens modules ranges from 25 to 40 mm. 8. The stereoscopic imaging device according to claim 1, wherein the lens module comprises an infrared cut filter and a spacer located in the lens barrel, and the liquid crystal lens, the spacer and the infrared cut filter The slices are arranged sequentially along the direction from the object side to the image side of the lens module. 9. The stereo imaging device according to claim 1, wherein the first transparent substrate comprises an outer surface and an inner surface on opposite sides of the first transparent substrate, and the first electrode layer is disposed on the first transparent substrate. on the outside. 10. The stereo imaging device according to claim 1, wherein the first transparent substrate comprises an outer surface and an inner surface on two opposite sides of the first transparent substrate, and the first electrode layer is disposed on the first transparent substrate. on the inner surface.