The utility model content
In view of this, the utility model has proposed a kind of novel laser projection screen in order to solve above-mentioned traditional eliminating coherence device shortcoming, the demonstration interference fringe that described laser projection screen can be eliminated laser coherence preferably and brought.Its concrete technical scheme is as following description:
A kind of laser projection screen, comprise optical scattering screen or cylindrical mirror screen, also comprise the eliminating coherence screen that is used for eliminate laser speckle, described eliminating coherence screen comprises transparency carrier and a plurality of transparent bubble, between described transparent bubble and transparency carrier, be provided with transparency electrode, described transparency electrode is connected in outside electrode modulating device, can impel the transparent bubble that is arranged on the transparency electrode to expand or stretch.
Further, preferred construction is, also comprises the Fresnel screen, and described eliminating coherence screen is arranged between Fresnel screen and optical scattering screen or the cylindrical mirror screen.
Further, preferred construction is that described eliminating coherence screen is arranged on the close beholder's of optical scattering screen or cylindrical mirror screen a side.
Further, preferred construction is that the diameter of described transparent bubble is less than 20mm.
Further, preferred construction is that the summation of all transparent bubble areas is more than or equal to 50% of the transparency carrier area.
Further, preferred construction is, the shape of described transparent bubble be circle, rectangle, triangle, parallelogram, pentagon or hexagon any one.
Further, preferred construction is, described electrode modulating device and transparency electrode can control transparent bubble make at one time in the partially transparent bubble in running order, the transparent bubble of another part is in idle state.
Further, preferred construction is that described transparent bubble is arranged to individual layer or multilayer on described transparency carrier.
Further, preferred construction is that described transparent bubble is transparent bubble or vacuole.
Further, preferred construction is that described transparent bubble or vacuole are evenly distributed on above the described transparency carrier.
Adopted after the above-mentioned design, because laser is in the process that sees through above-mentioned eliminating coherence screen, the surface topography of eliminating coherence screen changes constantly, cause also fluctuating on the speckle plane of the image of eliminating coherence screen surfaces thereupon, be in several instantaneous speckle pattern in human eye integral time through stack, in human eye, form the image that does not have speckle on the impression, reached and weakened or the effect of eliminate laser speckle phenomenon.
Embodiment
Below in conjunction with accompanying drawing the utility model is described in further detail.
In general, the laser investigation of projection display system mainly comprises laser projection device and laser projection screen.Laser projection device is made up of LASER Light Source, light engine, light engine comprises optical shaping parts, three primary colors light valve, projection lens and modulation circuit, in work, modulation circuit makes the little picture that generates red, green, blue three look correspondences on the light valve respectively, introduce three look laser lightings then respectively and project on the laser projection screen, thereby produce panchromatic display image.
We also know simultaneously, the interference pattern that highly relevant laser produces is commonly called as speckle, and laser speckle is because the intrinsic coherence of laser produces, in above-mentioned optical projection system, if not to laser in addition eliminating coherence handle, the phenomenon of laser speckle just can appear on screen inevitably.The utility model makes improvements the laser projection screen, the eliminating coherence screen of arranging a large amount of transparent bubbles on the layer of transparent substrate is set between the Fresnel of rear projection screen screen and diffuser screen, perhaps between the diffuser screen of front projection screen and spectators, be close to diffuser screen the eliminating coherence screen of arranging a large amount of transparent bubbles on the layer of transparent substrate is set, transparent bubble is expansion contraction work under the effect of transparency electrode, its objective is that the image speckle that makes projection screen finally present is weakened or eliminates.
Embodiment 1:
Fig. 1 is the structural representation of an embodiment of laser projection screen described in the utility model.As shown in the figure, this laser projection screen is applicable to that mainly in the laser back-projection system, therefore, we design the inside that the eliminating coherence device is arranged on the laser projection screen, thereby it has assembling effect and display effect preferably.Promptly this projection screen comprises Fresnel screen 1, eliminating coherence screen 5 and diffuser screen 4, from the light of projection arrangement by Fresnel screen 1, eliminating coherence screen 5 and diffuser screen 4 after, enter into human eye 6 again.Because in this device, described Fresnel screen 1 can pool parallel rays with the laser of going into to shine, and increases the brightness of screen in certain angular field of view.And, because mostly the laser beam that sends from laser projection device is relatively to disperse, after becoming directional light or restrain light after it shielding 1 by Fresnel, also need to handle by eliminating coherence screen 5, watch with beam divergence and by human eye by diffuser screen 4 again.
Principle of the present utility model is to disturb laser optical path and reach the effect of eliminating laser coherence by means of the eliminating coherence screen, Fig. 2 is the structural representation of the eliminating coherence screen 5 of the utility model laser projection screen, as shown in the figure, described eliminating coherence screen 5 comprises transparency carrier 2 and transparent bubble 3, and, below transparent bubble 3, be provided with transparency electrode (prior art, not shown), as shown in the figure, transparent bubble 3 be evenly distributed on transparency carrier 2 above.
In the present embodiment, described transparent bubble 3 is taked transparent vacuole or bubble, since transparency electrode can external outside the electrode modulating device, the electrode modulating device can inspire transparency electrode, and then make superincumbent vacuole or air bubble expansion or flexible are set, adopted after the above-mentioned design, because laser is in the process that sees through above-mentioned eliminating coherence screen, the surface topography of eliminating coherence screen changes constantly, cause also fluctuating on the speckle plane of the image of eliminating coherence screen surfaces thereupon, be in human eye several instantaneous speckle pattern in integral time through stack, in human eye, form the image that does not have speckle on the impression, reached and weakened or the effect of eliminate laser speckle phenomenon.
In addition, the distribution of described transparent bubble 3 can be uniformly, also can be uneven.And we can control synchronization and only allow 3 work of partially transparent bubble, and next allows other transparent bubbles 3 carry out work constantly, by this, eliminate aspect the speckle adjusting more at random, and, the better effects if of eliminate laser speckle.
In principle, the distribution of transparent bubble 3 on transparency carrier 2 is good evenly to be distributed as, but can not be equally distributed also.Consider that spectators' sighting distance is generally 2~10 meters, the human eye angular resolution limit is 1 minute (a 500nm green-yellow light), therefore require the diameter of each transparent bubble 3 must be less than 20mm, putting before this, the shape of transparent bubble 3 can be various geometric configuratioies such as circle, rectangle, triangle, parallelogram, pentagon or hexagon, the shape of each transparent bubble 3, area greatly can be little different, only need satisfy all transparent bubble 3 area summations and get final product more than or equal to 50% of the area of transparency carrier 2.
The position of eliminating coherence screen 5 between Fresnel screen 1 and diffuser screen 4 can image on the transparent bubble 3 with image is advisable, and eliminating coherence effect herein is best.
Those of ordinary skills will be understood that, the Fresnel screen is not essential in rear projection screen, do not emphasize wide viewing angle at some and pursue the occasion of high-gain, for example in the screen of back projection TV, operated by rotary motion has the Fresnel screen, and requiring in the occasion of wide viewing angle such as square large screen back projection shadow demonstration etc., the Fresnel screen is then optional.
It should be noted that above-mentioned diffuser screen 4 also can change cylindrical mirror screen into, can reach identical elimination or weaken the result of laser coherence phenomenon.In addition, described transparent bubble 3 can be the design of one deck, also can be the design of multilayer, can reach identical technique effect.
Embodiment 2:
Fig. 3 is the structural representation of another embodiment of the utility model laser projection screen, and as shown in the figure, this laser projection screen is mainly used in orthographic projection system.As shown in the figure, described laser projection screen comprises eliminating coherence screen 5 and diffuser screen 4, and is different with the disclosed structure of Fig. 1, and eliminating coherence screen 5 is arranged on the outside of diffuser screen 4, promptly is arranged on the side of projection screen near human eye 6.
The principle of work of rear projection screen is similar among front projection screen and the embodiment 1, be that the electrode modulating device can inspire transparency electrode, and then make and be provided with that superincumbent transparent bubble expands or flexible, because above-mentioned transparent bubble expands or is flexible, cause by the laser of transparent bubble and upset, thereby reach the eliminating coherence effect.
In addition, described transparent bubble 3 is transparent vacuole or transparent bubble, and the distribution of described transparent bubble 3 can be uniformly, also can be uneven.And we can control synchronization and only allow 3 work of partially transparent bubble, and next allows other transparent bubbles 3 carry out work constantly, by this, eliminate aspect the speckle adjusting more at random, and, the better effects if of eliminate laser speckle.
In principle, the distribution of transparent bubble 3 on transparency carrier 2 is good evenly to be distributed as, but can not be equally distributed also.Consider that spectators' sighting distance is generally 2~10 meters, the human eye angular resolution limit is 1 minute (a 500nm green-yellow light), therefore require the diameter of each transparent bubble 3 must be less than 20mm, the shape of transparent bubble 3 can be various geometric configuratioies such as circle, rectangle, triangle, parallelogram, pentagon or hexagon, the shape of each transparent bubble, area greatly can be little different, only need satisfy all transparent bubble area summations and get final product more than or equal to 50% of transparency carrier area.
The position of eliminating coherence screen 5 between Fresnel screen 1 and diffuser screen 4 can image on the transparent bubble 3 with image is advisable, and eliminating coherence effect herein is best.
Similarly, among this kind front projection screen structure, described transparent bubble 3 can be the design of one deck, also can be the design of multilayer, can reach identical technique effect.
Below, we carry out simple a description at the bubble layer of this laser projection screen or the production method of vacuole layer, in general, this bubble layer (perhaps vacuole layer) can directly take the processing mode of mould method to process, thereby, on lens substrate, produce satisfactory bubble (or vacuole).
Then, transparency carrier and above-mentioned diffuser screen (or cylindrical mirror screen) that we will be covered with vacuole (bubble) assemble, and have just constituted our described laser projection screen.
Above-mentioned specific embodiment is exemplary, and under above-mentioned instruction of the present utility model, those skilled in the art can carry out various improvement and distortion on the basis of the foregoing description, and these improvement or distortion drop in the protection domain of the present utility model.It will be understood by those skilled in the art that top specific descriptions just in order to explain the purpose of this utility model, are not to be used to limit the utility model.Protection domain of the present utility model is limited by claim and equivalent thereof.